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DHM Tables of Contents: 07091113-113-21415-115-2

DHM 2007: 1st International Conference on Digital Human Modeling

Fullname:DHM 2007: 1st International Conference on Digital Human Modeling
Note:Volume 12 of HCI International 2007
Editors:Vincent G. Duffy
Location:Beijing, China
Dates:2007-Jul-22 to 2007-Jul-27
Series:Lecture Notes in Computer Science 4561
Standard No:ISBN: 978-3-540-73318-8 (print), 978-3-540-73321-8 (online); hcibib: DHM07
Links:Online Proceedings | Publisher Book Page
  1. Part I: Shape and Movement Modeling and Anthropometry
  2. Part II: Building and Applying Virtual Humans
  3. Part III: Medical and Rehabilitation Applications
  4. Part IV: Industrial and Ergonomic Applications

Part I: Shape and Movement Modeling and Anthropometry

Simulation of Complex Human Movement Through the Modulation of Observed Motor Tasks BIBAKFull-Text 3-12
  Giuseppe Andreoni; Marco Rabuffetti; Antonio Pedotti
A method for the simulation of human movements driven by real data and correlated with modification of constraints in the external environmental is presented. It was applied to the simulation of the car ingress changing the configuration of the doorway to check early on in the design the man-machine-interface requirements for choosing the best ergonomic solution among different alternative solutions without the physical construction of prototypes. The method for the simulation of the movement is based on the modulation of a real measured performance recorded through an opto-electronic system for motion analysis. The algorithm implements a multifactorial target function to solve the redundancy problem. The reliability of the method was tested through the comparison of simulated and real data showing promising developments in ergonomics.
Keywords: movement; simulation; pattern modulation; ergonomics; virtual prototyping
Simulation of Digital Human Hand Postures of Car Controls Using a Data Based Approach BIBAKFull-Text 13-22
  Georges Beurier; Nicolas Chevalot; Gilles Monnier; Jules Trasbot; Xuguang Wang
This paper introduces a data-based approach to simulate with digital human models hand postures for grasping car control objects, which takes into account hand anthropometry, grasp type and object size. This paper presents more the experimental approach part than the simulation part itself. The simulation part is essentially done by the RPx software. This paper presents mainly a protocol in order to obtain data for the simulation.
Keywords: hand; data based approach; car controls; digital human
Human Articulation Efforts Estimation in the Automobile Vehicle Accessibility Movement -- A Pilot Study BIBAKFull-Text 23-32
  Jean-François Debril; Philippe Pudlo; Mohand Ouidir Ait El Menceur; Philippe Gorce; François Xavier Lepoutre
To build a criterion of discomfort evaluation, based on the kinematics and the dynamics of the performed movement, is an expectation of the car manufacturers. There is no reference concerning the evaluation of the articulation efforts during the automobile vehicle accessibility movement. On this point, we propose to give a first reference. Our method and our computation were verified by a well known movement, the walking. The automobile vehicle accessibility movement of a young and healthy subject is studied. The articulation efforts presented are coherent with the produced movement's analysis.
Keywords: Automobile vehicle accessibility; Inverse dynamics; Articulation efforts
Study on the Appraisal Methods of Hand Fatigue BIBAKFull-Text 33-41
  Li Ding; Feng Yang; Chunxin Yang; Xiugan Yuan; Yang Li
Objective: The evaluation methods of hand fatigue are built and the aim is to provide reference for the numerical human fatigue appraisal.
   Method: 12 females and 14 males in two groups participated in the experiments of changeless force fatigue, which included the grip and pinch and screw, and took part in the nondimensional force fatigue.
   Result: (1) Hand fatigue could be full evaluated basing on grip and pinch and screw. (2) Using stable force could test the fatigue of manual work simply, but it would be largely affected by the characteristic of sex. (3) The nondimensional evaluation can avoid the impact results from the different forces of testees.
   Conclusion: Hand fatigue could be full evaluated basing on grip and pinch and screw. The nondimensional evaluation is a feasible method to research numerical human manual fatigue.
Keywords: Hand performance; Fatigue; Evaluation; Nondimensiona
Experimental Research on Human Body Motion Simulation Based on the Motion Capture Technology BIBAKFull-Text 42-47
  Dayong Dong; Lijing Wang; Xiugan Yuan
Moveable human body model can be built based on human motion data, which is recorded by the VICON optical motion capture system and imported to the MOTION BUILDER software. In this experiment, two simulation projects were designed successfully, and satisfying results were obtained. The first test was an arm swinging test which simulates the pilot's action of manipulating dashboard. The other test involved arm swinging, walking and turning in standing mode, focused on testing the stability of the system in multi-degree-of-freedom complex motion situation.
Keywords: motion capture; VICON; motion simulation; human body model; human factors
Modeling of Human's Pointing Movement on the Effect of Target Position BIBAKFull-Text 48-55
  Junmin Du; Haiwen Shi; Xiugan Yuan
The purpose of this study is to construct a new pointing movement model considering the effect of target position. A pointing movement experiment was designed and carried out, and the pointing movement characteristics when human upper limb touched the targets on front board are studied. The result shows that the starting point position and target position greatly affect the movement time. A new pointing movement model is built, in which the effect of target position is introduced. The new model obtains higher contribution value and could describe the data better than the conventional models.
Keywords: Human upper limb; pointing movement; Mathematic model
A Modified Particle Swarm Optimizer Using an Adaptive Dynamic Weight Scheme BIBAKFull-Text 56-65
  Shu-Kai S. Fan; Ju-Ming Chang
Particle swarm optimization (PSO) is a stochastic, population-based optimization technique that is inspired by the emigrant behavior of a flock of birds searching for food. In this paper, a nonlinear function of decreasing inertia weight that adapts to current performance of PSO search is presented. Meanwhile, a dynamic mechanism to adjust decrease rates is also suggested. Through the experimental study, the new PSO algorithm with adaptive dynamic weight scheme is compared to the exiting models in terms of various benchmark functions. The computational experience shows some great promise.
Keywords: particle swarm optimization (PSO); dynamic inertia weight; population-based optimization technique
Prediction of Discomfort During Arm Movements BIBAFull-Text 66-73
  Florian Fritzsche; Heiner Bubb
On the way to a generalized discomfort model for movements steps are presented that calculate the determining parameters for the model. Discomfort is mainly dependant on posture and relative torque. A multi body system arm model is used to calculate the driving torques of a lifting task using inverse dynamics. A motion analysis of the movement was carried out and the corresponding angles were used to drive the arm model. In order to calculate relative torque a torque velocity relationship according to Hill was implemented in the arm model.
A Motion Compensated De-interlacing Algorithm for Motive Object Capture BIBAKFull-Text 74-81
  Lei Gao; Chao Li; Chengjun Zhu; Zhang Xiong
A motion compensated de-interlacing algorithm is proposed to recover the defects of interlaced video frame for capturing motion object. In this algorithm, two anti-noise background fields are formed by analyzing the temporal correlation of pixels between adjacent same parity fields. To each field, the subtraction with the corresponding background is used to detect motion object. To avoid the inaccurate detection caused by the difference between the spatial scanning positions of odd and even field, the motion objects are detected with same parity field and background field. Then motion estimation technology is used to measures the inter-field motion, find out the motion vector between the odd field and even field. Based on the motion vector, an interpolation filter is designed to shift the pixels of the motion object in the two temporally displaced fields to a common point in time. This de-interlacing algorithm maximizes the vertical resolution of the motion objects. Experimental results show that the proposed algorithm could achieve higher image quality on motion object, and the computational complexity is acceptable for consumer computer applications.
Keywords: de-interlacing; motion compensation; motion estimation; motion detect; motion object
Color 3D Digital Human Modeling and Its Applications to Animation and Anthropometry BIBAFull-Text 82-91
  Bao-zhen Ge; Qing-guo Tian; K. David Young; Yu-chen Sun
With the rapid advancement in laser technology, computer vision, and embedded computing, the application of laser scanning to the digitization of three dimensional physical realities has become increasingly widespread. In this paper, we focus on research results embodied in a 3D human body color digitization system developed at Tianjin University, and in collaboration with the Hong Kong University of Science and Technology. In digital human modeling, the first step involves the acquisition of the 3D human body data. We have over the years developed laser scanning technological know-how from first principles to support our research activities on building the first 3D digital human database for ethnic Chinese. The disadvantage of the conventional laser scanning is that surface color information is not contained in the point cloud data. By adding color imaging sensors to the developed multi-axis laser scanner, both the 3D human body coordinate data and the body surface color mapping are acquired. Our latest development is focused on skeleton extraction which is the key step towards human body animation, and applications to dynamic anthropometry. For dynamic anthropometric measurements, we first use an animation algorithm to adjust the 3D digital human to the required standard posture for measurement, and then fix the feature points and feature planes based on human body geometric characteristics. Utilizing the feature points, feature planes, and the extracted human body skeleton, we have measured 40 key sizes for the stand posture, and the squat posture. These experimental results will be given, and the factors that affect the measurement precision are analyzed through qualitative and quantitative analyses.
Advanced Human Body and Head Shape Representation and Analysis BIBAKFull-Text 92-100
  Afzal Godil
The 3D scans of human bodies contain over hundreds of thousand grid points. To be used effectively for analysis, indexing, searching, clustering and retrieval, these human bodies requires a compact shape representation. We have developed compact representations based on human body shape based on lengths mostly between joints of single large bones and in the second method silhouettes of the human body are created and then encoded as Fourier shape descriptors. We also have developed two such compact representations based on human head shape by applying Principal Component Analysis on the facial surface and in the second method the whole head is transformed to a spherical coordinate system expanded in a basis of Spherical Harmonics.
Keywords: 3D anthropometry; shape searching; PCA; Spherical Harmonics
Hand Grasping Motion Simulation for Astronauts Training BIBAKFull-Text 101-109
  Qiang Guo; Yuqing Liu
The objective of this paper is to find an appropriate method to realize the simulation of hand grasping motion for astronauts training. In this paper, on the basis of analysis and comparison of a variety of methods of hand grasping motion, we come up with an idea combined interpolation and inverse kinematics for hand motion simulation. An example demonstrates the method's effectiveness and practicability.
Keywords: Hand motion simulation; Interpolation methods; Inverse kinematics
Predefined Manikins to Support Consideration of Anthropometric Diversity by Product Designers BIBAKFull-Text 110-119
  Dan Högberg; Keith Case
The paper discusses the complexity involved in considering targeted product users' anthropometric variation in multivariate design problems, such as the design of workplaces or vehicle interiors. The authors argue for the advantages of offering designers a number of predefined digital human models to incorporate in the CAD product models. A study has been carried out in order to illustrate the use of predefined digital human models in vehicle interior design by using the Digital Human Modelling (DHM) tool RAMSIS. The paper takes a designer's view of digital human modelling and illustrates how DHM can be of great value in the design process, but also considers what implications this has on the functionality and usability of DHM tools.
Keywords: Anthropometric Diversity; Digital Human Modelling; Design Process; Product Design; Ergonomics; Human Factors
Comparison of Human and Machine Recognition of Everyday Human Actions BIBAKFull-Text 120-129
  Trevor D. Jones; Shaun W. Lawson; David Benyon; Alistair Armitage
The research presented here makes a contribution to the understanding of the recognition of biological motion by comparing human recognition of a set of everyday gestures and motions with machine interpretation of the same dataset. Our reasoning is that analysis of any differences and/or correlations between the two could reveal insights into how humans themselves perceive motion and hint at the most important cues that artificial classifiers should be using to perform such a task. We captured biological motion data from human participants engaged in a number of everyday activities, such as walking, running and waving, and then built two artificial classifiers (a Finite State Machine and a multi-layer perceptron artificial neural network, ANN) which were capable of discriminating between activities. We then compared the accuracy of these classifiers with the abilities of a group of human observers to interpret the same activities when they were presented as moving light displays (MLDs). Our results suggest that machine recognition with ANNs is not only comparable to human levels of recognition but can exceed it in some instances.
Keywords: Neural network; finite state machine; moving light display; human biological motion
A New Decoding Algorithm in MIMO-ZP-OFDM Systems BIBAKFull-Text 130-135
  Rui Kang; ChaoXiong Xu; Hao Chen; HongBo Xu
In order to adapt for a high-rate transmission and improve the performance of operation, in this paper, a new low complex sphere decoding (SD) algorithm is proposed in the MIMO-ZP-OFDM systems. It is an approximate optimization algorithm and can be used in the space-time coding and uncoded multiple-antenna systems. ML sequence detection compared with SD algorithm the latter can reduce the complex and keep the performance of systems, especial for high-rate transmission operation and the occasion of transmit antenna beyond receive antenna. Simulation results show that the efficiency and superiority of this algorithm.
Keywords: OFDM; MIMO; sphere decoding; ZP
Computer Graphic Modeling and Simulation of Human Musculoskeletal System for Biomechanical Research BIBAKFull-Text 136-143
  Yoon Hyuk Kim
In this paper, the human musculoskeletal model based on the medical images of the Korean standard male and the computer graphics based simulation technology with biomechanical analyses are presented. The virtual human model consists of three components. The model component includes the development of anatomically accurate geometric models with physiologically relevant material data. The analysis component includes various types of mechanical. In the simulation component, task-oriented graphic simulation would be performed for virtual evaluation, test, measurement, design, and planning. Three biomechanical analyses with graphic simulation using the virtual Korean model were performed; the surgical simulation of bone fracture surgery, the biomechanical evaluation of surgical implant in knee, and the graphic visualization and simulation of tennis play. In conclusion, the developed virtual Korean model of the musculoskeletal system would have lots of potentiality for biomechanical research and development in various fields, such as medical industry, automobile, ergonomics, or nuclear industry.
Keywords: Biomechanics; Human model; Musculoskeletal; Virtual Human
The Strength Factor in Digital Human Modeling and Simulation: A Case for a New Framework BIBAKFull-Text 144-146
  Kang Li; Xudong Zhang
It is not well understood whether strength could ever influence performance in which only sub-maximal, moderate exertions are needed although strength may be indicative of the movement performance at or near the maximal level. In this paper, we present some evidence from two studies suggesting the strength effects on performance strategies in volitional physical tasks, and based on the evidence, a new framework was proposed for human movement modeling and simulation that incorporates the strength factor.
Keywords: Strength; Digital human modeling
The Effects of the False Vocal Fold Gaps in a Model of the Larynx on Pressures Distributions and Flows BIBAKFull-Text 147-156
  Sheng Li; Mingxi Wan; Supin Wang
Human phonation does not merely depend upon the vibration of the vocal folds. The false vocal fold (FVF), as an important laryngeal constriction, has also been found by more and more research both in clinically and computer simulations that it plays an important role during phonation and contributes significantly to the aerodynamics and sound generation processes of human voice production. Among many parameters which are used to determine and describe the geometry of the false vocal folds, the false vocal fold gap (GFVF), which means the minimal distance between the two false vocal folds, is regarded as an important and dominant parameter. Therefore, this study explores the effects of the FVF gaps on the intralaryngeal pressure distributions, laryngeal resistance and flows using both three-dimensional Plexiglas model and commercially available computational fluid dynamics code.
   Three glottal angles, divergent 40°, uniform 0°, and convergent -40°were used for this study to explore the effects of FVF gaps, as they represent the basic glottal shapes typically expected in phonation, the angle values also were typically expected for most phonation in modal Register. A wide variety of FVF gaps (GFVF) were parameterized with 12 different values: 0.02, 0.04, 0.06, 0.08, 0.09, 0.1, 0.11, 0.12, 0.16, 0.2, 0.4, 0.6 cm to represent important geometries often appearing within phonatory vibratory cycles. These gaps were used for each glottal angle. The specific design of the FVFs followed prior literature. The minimal glottal diameter (Dg) was constantly at 0.06 cm in this study for each FVF gaps, and the translaryngeal pressure were held constant at 8 cm H2O. A nonvibrating laryngeal airway Plexiglas model, which had linear dimensions 1.732 times of a normal male larynx, was used in this study. In order to measure pressures inside the Plexiglas model, twelve cylindrical ducts were made on the midline of the laryngeal wall of the model. The diameter of each duct was 0.07 cm human size (0.12 cm in the model), so that the connector of an Entran EPE-551 pressure transducer could fit snugly into the holes. The distance between the centers of each hole was 0.14 cm human size. FLUENT (Fluent, Inc., Lebanon, NH), a commercially available computational fluid dynamics code was also used to obtain estimates of the normal wall pressures along the laryngeal surfaces (including the surfaces of vocal folds, ventricles, and false vocal folds) as a function of the FVF gaps and the glottal angles. The code is based on the control-volume technique and was used to solve the Navier-Stokes equations for constant shapes (not for vibrating vocal folds), laminar, incompressible airflow physics occurring inside the symmetric laryngeal geometries. The flow field was assumed to be symmetric across the midline of the glottis in this study, and therefore only the half flow field was modeled.
   The results suggest that (1) the intralaryngeal pressure was lowest and the flow was highest (least flow resistance) when the FVF gap was 1.5-2 times of Dg, the intralaryngeal pressures decreased and flows increased as smaller FVF gaps increased, and the intralaryngeal pressures increased and flows decreased as larger FVF gaps increased, indicating that the least pressure drop for any given flow (that is, the least flow resistance) was found to correspond to the 1.5-2 times of Dg for different glottal angle. Suggesting that the 1.5-2 times of Dg might be the optimal gap for pressure, and efficient phonation may involve laryngeal shaping of this condition. Therefore, the positioning and existing structure of the FVFs can aid in phonation by reducing energy losses and increasing airflow in the larynx when positioned appropriately; (2) both the pressure and flow were unaffected when the FVF gaps larger than 0.4 cm; (3) the divergent glottal angle gave lower pressure and greater flow than the convergent and uniform glottal angle as no FVF conditions; (4) the present of the FVF decreased the effects of the glottal angle on both the intralaryngeal pressure and flow to some extent, and the smaller the FVF gaps, the smaller this effect. Perhaps more important, (5) the present of the FVF also moving the separation points downstream, straitening the glottal jet for a longer distance, decreasing overall laryngeal resistance, and reducing the energy dissipation, suggesting that the FVF would be of importance to efficient voice production; (6) the empirical pressure distributions were supported by computational results. The results suggest that the intralaryngeal pressure distributions and the laryngeal flow resistance are highly affected by the presence of the FVFs, and the FVFs can aid in phonation when by reducing energy losses positioned appropriately. Therefore, the results might be helpful not only in maintaining healthy vocal habits, but also in exploring surgical and rehabilitative intervention of related voice problem. The results also suggest that they may be incorporated in the phonatory models (physical or computational) for better understanding of vocal mechanics.
Keywords: Speech production; false vocal folds; model; pressure distributions
A Robust Algorithm for a System Identification Approach to Digital Human Modeling: An Application to Multi-fingered Hand Movement BIBAKFull-Text 157-160
  Kang Li; Sang-Wook Lee; Xudong Zhang
A recent study [2] proposed a forward bio-dynamic model of multi-fingered hand movement. The model employed a physics-based heuristic algorithm for system identification of the model parameters, and succeeded in replicating measured multi-fingered flexion-extension movement. However, while the model itself is general and readily applicable to other bodily movements, the heuristic algorithm required empirical adjustments to initial setups, and was therefore difficult to generalize. This paper introduces a rigorous and more robust parameter estimation algorithm to enhance the intended general modeling approach for digital human movement simulation. The algorithm is demonstrated by solving the same modeling problem posed in [2].
Keywords: hand movement; system identification; forward dynamics
Mathematical Methods for Shape Analysis and form Comparison in 3D Anthropometry: A Literature Review BIBAKFull-Text 161-170
  Jianwei Niu; Zhizhong Li; Gavriel Salvendy
Form comparison is a fundamental part of many anthropometric, biological, anthropological, archaeological and botanical researches, etc. In traditional anthropometric form comparison methods, geometry characteristics and internal structure of surface points are not adequately considered. Form comparison of 3D anthropometric data can make up the deficiency of traditional methods. In this paper, methods for analyzing 3D other than 2D objects are highlighted. We summarize the advance of form comparison techniques in the last decades. According to whether they are based upon anatomical landmarks, we partition them into two main categories, landmark-based methods and landmark-free methods. The former methods are further sub-divided into deformation methods, superimposition methods, and methods based on linear distances, while the latter methods are sub-divided into shape statistics-based methods, methods based on function analysis, view-based methods, topology-based methods, and hybrid methods. Examples for each method are presented. The discussion about their advantages and disadvantages are also introduced.
Keywords: 3D anthropometry; form comparison
A Case Study of Multi-resolution Representation of Heads BIBAKFull-Text 171-178
  Jianwei Niu; Zhizhong Li; Gavriel Salvendy
A wavelet analysis based multi-resolution representation method is adopted to establish mathematical description of three-dimensional anthropometric head data in this paper. This method provides flexible description of shapes at different resolution levels. Three-dimensional anthropometric data analysis can then be performed with coarse resolutions, which preserve the major shape components but ignore micro shape components. In a case study of 510 3D head scans, quantitative approximation errors, which reflect the approximation of the low-resolution surface to the original one, have been investigated and demonstrated with respect to various decomposition levels.
Keywords: 3D Anthropometry; wavelet analysis; multi-resolution representation
The Application of Kane Equation in the Impact Prediction of Human Motion BIBAKFull-Text 179-188
  Mu Qiao; Chunxin Yang; Xiugan Yuan
This paper presents a computational procedure for deriving and solving the governing dynamical equations of multi-body human systems subjected to impact. The procedure is developed on the basis of the assumption that the duration of the impact is very short, during which the configuration of the system remain the same, although the velocities of the system have undergone significant changes. These assumptions lead to a set of linear algebraic equations for the velocity increments. These equations may then be solved to obtain initial conditions for the analysis of the subsequent motion of the multi-body human system. A calculating task of ejecting seat problem is presented to illustrate and validate the procedure.
Keywords: multi-body; Kane equation; impulse; ejection
A Fast Motion Estimation Algorithm for H.264 BIBAFull-Text 189-196
  Jianbin Song; Bo Li; Qing-lei Meng
Compared with the previous video standard, the performance of H.264 has improved significantly because of multi-block-size motion estimation. However, encoder using above technology is very time-consuming. Making full use of the spatiotemporal correlation of video and similar motion between the different-size block, according to the central-biased characteristic of motion vector, a fast motion estimation algorithm for H.264 is proposed in this paper. By effective prediction of search window center point, adaptive selection of search patterns and termination of the search process, the proposed algorithm speedups 123-186 times than full search algorithm and 4.6-5.9 times than the fast motion estimation algorithm recommended in H.264 while maintains similar rate distortion performance.
Validating Optical Motion Capture Assessments of the Dynamic Aspects of Work BIBAKFull-Text 197-204
  Jackie Sutherland; Vincent G. Duffy
The objective of this study is to validate two three-dimensional motion systems used capture human movement; the Lumbar Motion Monitor (LMM) and optical motion capture. Marras et al. captured the accuracy and reliability of optical motion capture and the LMM in a 1992 validation study, and found several benefits of using the LMM for ergonomic evaluations. However, since 1992, several advances have been made in the field of digital human modeling and optical motion capture, and it is believed that a modern validation of the two systems could serve others in academic and industry alike when choosing a methodology toward capturing ergonomic data. The purpose of this research is to validate the methods of collecting dynamic data and predicting injury risk in humans during lifting procedures.
Keywords: optical motion capture; lumbar motion monitor; dynamic lifting; digital human modeling; ergonomics; validation
Modeling Human Bipedal Navigation in a Dynamic Three Dimensional Virtual Environment BIBAKFull-Text 205-214
  Mark D. Thomas; Daniel W. Carruth; Bryan Robbins; John A. McGinley; Alexander Morais
The current research sought to construct a computational model of human navigation for virtual three dimensional environments. The model was implemented within the ACT-R cognitive architecture [1]. The navigation model incorporates visual search, encoding object features and spatial relationships, motion, obstacle avoidance, and incidental visual memory.
Keywords: walking navigation; ACT-R; digital human model; incidental visual memory; visual search
A Data-Based Modeling Approach of Reach Capacity and Discomfort for Digital Human Models BIBAKFull-Text 215-223
  Xuguang Wang; Elodie Chateauroux; Nicolas Chevalot
In this paper, we have proposed a unified data based approach which aims to predict both reach envelops and reach discomfort for a digital human model. Reach envelops can be obtained by applying the existing reach posture data to a new subject according to simulation scenario. Four reach surfaces are proposed according to the radial distance from the shoulder. The discomfort of a target on each surface needs to be defined at first. Then, the discomfort of an intermediate distance between two reach distances is interpolated. The proposed approach is illustrated by the data of a previous study. In this study, 38 young and elderly subjects were instructed to reach 94 targets for each from a seated position, covering a large reachable space.
Keywords: Reach; discomfort; digital human modeling; reach posture
Motion Retrieval Based on Temporal-Spatial Features by Decision Tree BIBAKFull-Text 224-233
  Jian Xiang; Hongli Zhu
In order to retrieve similar motion data from Mocap database, each human joint's motion clip is regarded as a bag, while each of its segments is regarded as an instance. 3D temporal-spatial features are extracted and data driven decision trees are automatically constructed to reflect the influence of each point during the comparison of motion similarity. At last we use the method of multiple instance retrieval to complete motion retrieval. Experiment results show that our approaches are effective for motion data retrieval.
Keywords: Motion Capture; 3D Temporal-Spatial; Data Driven; Decision Tree; Retrieval
Motion Retrieval Based on an Efficient Index Method for Large-Scale Mocap Database BIBAKFull-Text 234-242
  Jian Xiang; Hongli Zhu
In this paper, a novel approach is presented for motion retrieval based on double-reference inde (DRI) in Motion Capture (Mocap) database. Due to high dimensionality of motion's feature, the Isomap nonlinear dimensionality reduction is used. For handling new motion data, Isomap is generalized based on the estimation of underlying eigenfunctions. Then DRI is build based on selecting a small set of representative motion clips in the database. So we can get candidate set by abandoning most unrelated motion clips to reduce the number of costly similarity measure significantly. Experimental results show that our methods are effective for motion data retrieval in large database.
Keywords: Motion retrieval; reference index; Isomap; Mocap database
Modeling of Layered Fuzzy Facial Expression Generation BIBAKFull-Text 243-252
  Yu-Li Xue; Xia Mao; Zheng Li; Wei-He Diao
This paper proposed a layered fuzzy model of facial expression generation, in which the layers of physiological model at low level, emotional model at middle level and social rules at high level determine the fuzzy facial expression generation. In the layered fuzzy facial expression generation system, facial expressions of 26 emotions can be fuzzily generated, as well as social expressions and instinctive expressions. Experiment results indicated that the model of layered fuzzy facial expression generation works well in displaying lifelike facial expressions.
Keywords: Facial expression generation; fuzzy theory; layered fuzzy model
An Inverse Dynamical Model for Slip Gait BIBAKFull-Text 253-258
  Jiankun Yang; Dewen Jin; Linhong Ji; Jichuan Zhang; Rencheng Wang; Xin Fang; Dawei Zhou
A inverse dynamical model for slip gait developed by using Kane's method of dynamics is described in this paper. The modeling was based on two separate sub-systems: anti-slip and anti-fall. Both sub-systems were modeled as an open kinematic chain and formulated using the same equations, so that the whole slip and fall process could be simulated using the same equations by switching input data. In the simulation, only kinematic data need to be input to obtain the joint moments and horizontal ground reaction force in the whole slip and fall process. The kinematic input data were acquired from one health male subject who was asked to perform the normal and slip gait. The anthropometric data for each body segment in the skeletal model was calculated using the body height, weight and the national standards on inertia parameters regression equations. The kinematic and kinetic results from the simulation are discussed in the paper which are well consistent with the conclusions in previous studies.
Keywords: slip and fall; modeling; human gait; kinetics
Redundant Muscular Force Analysis of Human Lower Limbs During Rising from a Squat BIBAKFull-Text 259-267
  Yiyong Yang; Rencheng Wang; Ming Zhang; Dewen Jin; Fangfang Wu
Muscular coordination analysis of lower limbs during rising from a squat is one of the important categories in rehabilitation engineering and gymnastic science. This paper describes an efficient biomechanical model of the human lower limb with the aim of simulating the real human rising from a squat with lifting. To understand how intermuscular control coordinates limb muscle excitations the optimal control technique is used to solve the muscle forces sharing problem. The validity of the model is assessed comparing the calculated muscle excitations with the registered surface electromyogramm (EMG) of the muscles. The results show that synergistic muscles are build up by the neural control signals using a minimum fatigue criterion during human squat lifting, with distinct phases that include the acceleration during the initial movement and the posture at the final specified position. Synergistic muscular groups can be used to simplify motor control, and are essential to reduce the number of controlled parameters and amount of information needing to be analyzed in the performance of any motor act.
Keywords: Redundant Muscular force; Neural control analysis; Human squat lifting
Optimal Control and Synergic Pattern Analysis of Upper Limb Reaching-Grasping Movements BIBAKFull-Text 268-275
  Yiyong Yang; Rencheng Wang; Ming Zhang; Dewen Jin; Fangfang Wu
A three-dimension, neuromusculoskeletal model of the human upper limb, consisting of 30 muscle-tendon systems, was combined with dynamic optimization theory to simulate reaching-grasping movements. The model was verified using experimental kinematics, muscle forces, and electromyographic (EMG) data from volunteer subjects performing reaching-grasping movements. Despite joint redundancy, the topological invariance was observed in the trajectories of different task performance, and the linear relationships between joints covariation were exhibited. Quantitative comparisons of the model predictions and muscle activations obtained from experiment show that the minimum torque-change criterion is a valid measure of reaching-grasping performance.
Keywords: Synergic Pattern; Optimal Control; Upper limb; Reaching to grasp movements
Low Cost 3D Shape Acquisition System Using Strip Shifting Pattern BIBAKFull-Text 276-285
  Li Yao; Lizhuang Ma; Di Wu
We present a simple and low cost 3D shape acquisition method that can measure the objects with interreflection and high light. The capture system employs a projector to project line shifting shadow on the object, and a digital camera to record videos (image sequence) of the object and the distorted shadow. A novel spacetime edge finding method is introduced to get the shadow edge accurately and overcome the interreflection and high light. The 3D data of the object are got by using the spacetime information. A post-processing 3D filter is proposed to filter the bad data. The 3D filter makes full use of the neighborhoods' geometric constrains and the view point constrain.
Keywords: 3D scanner; shape recovery; surface reconstruction
Automatic Joints Extraction of Scanned Human Body BIBAKFull-Text 286-293
  Yong Yu; Zhaoqi Wang; Shihong Xia; Tianlu Mao
This paper presents an automatic method to extract joints accurately from scanned human body shape. Firstly, model is divided into slices by a group of horizontal parallel planes and primary landmarks are determinated according to the slices. Additionally, we propose a model intersection method based on direction of limbs. Model is separated into five segments including torso and four limbs and approximate direction of each segment can be calculated according to the primary landmarks. Five groups of parallel planes perpendicular to corresponding segments are employed to divide each segment into slices, and contours are calculated by intersection detection between planes and triangles. Finally, we propose a circularity function differentiation technique to extract key contours at joints from segments and the joints can be calculated according to centroids of the key contours. The experimental results demonstrate that the method has more advantages than the conventional ones, especially in algorithm's accuracy and robustness.
Keywords: Joints Extraction; Virtual Human; Scanned Human Body
Wavelet Transform and Singular Value Decomposition of EEG Signal for Pattern Recognition of Complicated Hand Activities BIBAKFull-Text 294-303
  Xiaodong Zhang; Weifeng Diao; Zhiqiang Cheng
Electroencephalogram (EEG) is a useful bioelectrical signal in pattern recognition of hand activities because of its following characteristics: (1) patterns of EEG are different when doing diverse movements and mental tasks; (2) EEG can be real-timely or instantly extracted; (3) the measurement of EEG can reach an enough precision. A new approach for the pattern recognition of four complicated hand activities based on EEG is presented in this paper, in which each piece of raw data sequence for EEG signal is decomposed by wavelet transform (WT) to form a matrix, and the singular value of the matrix is extracted by singular value decomposition (SVD). And then the singular value, as the feature vector, is input to the artificial neural network (ANN) to discriminate the four hand activities including grasping a football, a small bar, a cylinder and a hard paper. Finally the research results show the correct classification rate of 89% was achieved by the approach mentioned above.
Keywords: Electroencephalogram; Pattern recognition; Wavelet transform; Singular value decomposition; Artificial neural network
Capturing 3D Human Motion from Monocular Images Using Orthogonal Locality Preserving Projection BIBAKFull-Text 304-313
  Xu Zhao; Yuncai Liu
In this paper, we present an Orthogonal Locality Preserving Projection based (OLPP) approach to capture three-dimensional human motion from monocular images. From the motion capture data residing in high dimension space of human activities, we extract the motion base space in which human pose can be described essentially and concisely by more controllable way. This is actually a dimensionality reduction process completed in the framework of OLPP. And then, the structure of this space corresponding to special activity such as walking motion is explored with data clustering. Pose recovering is performed in the generative framework. For the single image, Gaussian mixture model is used to generate candidates of the 3D pose. The shape context is the common descriptor of image silhouette feature and synthetical feature of human model. We get the shortlist of 3D poses by measuring the shape contexts matching cost between image features and the synthetical features. In tracking situation, an AR model trained by the example sequence produces almost accurate pose predictions. Experiments demonstrate that the proposed approach works well.
Keywords: OLPP; Human Motion Analysis; Monocular Images
Human Motion Simulation and Action Corpus BIBAKFull-Text 314-322
  Gang Zheng; Wanqing Li; Philip Ogunbona; Liju Dong; Igor Kharitonenko
Acquisition of large scale good quality training samples is becoming a major issue in machine learning based human motion analysis. This paper presents a method to simulate continuous gross human body motion with the intention to establish a human motion corpus for learning and recognition. The simulation is achieved by a temporal-spatialtemporal decomposition of human motion into actions, joint actions and actionlets based on the human kinematic model. The actionlet models the primitive moving phase of a joint and represents the muscle movement governed by kinesiological principles. Joint actions and body actions are constructed from actionlets through constrained concatenation and synchronization. Methods for concatenation and synchronization are proposed in this paper. An action corpus with small number of action vocabularies is created to verify the feasibility of the proposed method.
Keywords: Human Motion; Actions; Simulation; Motion Editing

Part II: Building and Applying Virtual Humans

User Experience Quality: A Conceptual Framework for Goal Setting and Measurement BIBAKFull-Text 325-332
  Russell Beauregard; Philip Corriveau
Although the term 'user experience' has become ubiquitous, variations in its conceptualization can make design objectives unclear. This paper proposes a simple framework for conceptualizing the components of user experience in order to communicate with UX stakeholders and advance goal setting and measurement in applied settings. A deeper understanding of the components of experience provide a greater ability to set strategic direction for the user experience, guide design goals, and assess user experience outcomes. In educating stakeholders on a more complete view of user experience, UCD practitioners have the opportunity to play a key role in planning the level of user experience quality for the product user experience and influencing where user experience studies will have the most impact on products.
Keywords: UX; user experience assessment; experience quality; consumer experience; perceptual quality; customer emotions
Integrating Perception, Cognition and Action for Digital Human Modeling BIBAKFull-Text 333-342
  Daniel W. Carruth; Mark D. Thomas; Bryan Robbins; Alexander Morais
Computational cognitive models are used to validate psychological theories of cognition, to formally describe how complex tasks are performed, and to predict human performance on novel tasks. Most cognitive models have very limited models of how the body interacts with the environment. The present research examines a simple human-machine interaction task and a simple object manipulation task. A cognitive model is integrated with a human avatar within a virtual environment in order to model both tasks.
Keywords: Digital Human Modeling; Cognitive Models; Perception; Cognition; Action
The Usability of Metaphors with Different Degree of Abstract in Interface Design BIBAKFull-Text 343-352
  Ming-Chuen Chuang; Inglen Lo
Recently, more and more devices everywhere are getting "smarter" with a multi-modal hierarchical menu and form interface. One of the main points of the menu or interface design is to provide users with ease-to-use operation environment. This make them not only learn efficiently but also feel fun (interested) in the process of learning. However, there is no one concept of design suit everyone because the needs and purposes of users are much different from individuals. To satisfy them, the varied design concepts have been suggested to fit for their distinct perceptions and experiences. Consequently, new assessment, called usability, is also required to estimate whether the design concepts are good or not. Therefore, this study attempted to investigate into the usability of 3D interface design. For that, 3 types of main menu of the mobile phone's interface metaphor design were developed as stimuli with different degree of abstract in this study. Then, a four-phase experiment was conducted to explore the usability evaluation of 3 types of metaphorical interface design with different degree of abstract, including: (1) to investigate users' opinions on a mobile phone's interface design; (2) to verify whether the simulated graphics and interactions corresponding to the metaphors intended (pilot study); (3) to measure the usability of 3 types of metaphorical interface design simulated in this study; (4) to compare the preference for any one of the 3 types of metaphorical interface design. The experimental procedures and the results of the analysis would be interpreted respectively according to different phases. Additionally, the degree of abstract in the metaphorical interface design was defined by the average ratings in phase 1: metaphor 3 were regarded as abstract interface design and metaphor 1 and metaphor 2 were regarded as concrete interface designs, but the degree of concrete in metaphor 1 was stronger than in metaphor 2.
Keywords: Metaphor; interface design; usability; SUS score; preference
Applications of the Visible Korean Human BIBAKFull-Text 353-362
  Min Suk Chung; Jin Seo Park
Visible Korean Human (VKH) consisting of magnetic resonance, computer tomography, anatomic, and segmented images was created. In the VKH, several techniques were developed and numerous data were acquired. The VKH techniques majorly contributed to the generation of advanced segmented images, Visible Living Human, and Visible Mouse. Also, a software for sectional anatomy, three dimensional images for virtual dissection and virtual endoscopy, was developed based on the VKH data distributed worldwide. The VKH technique and data are expected to promote development of other serially sectioned images and software, which are helpful in medical education and clinical practice.
Keywords: Visible Korean Human; Magnetic resonance images; Anatomic images; Segmented images; Three dimensional images
Role of Humans in Complexity of a System-of-Systems BIBAKFull-Text 363-371
  Daniel DeLaurentis
This paper pursues three primary objectives. First, a brief introduction to system-of-systems is presented in order to establish a foundation for exploration of the role of human system modeling in this context. Second, the sources of complexity related to human participation in a system-of-systems are described and categorized. Finally, special attention is placed upon how this complexity might be better managed by greater involvement of modeling of human behavior and decision-making. The ultimate objective of the research thrust is to better enable success in the various system-of-systems that exist in society.
Keywords: system-of-systems; complexity; human behaviors; connectivity
Digital Human Modeling for Product Lifecycle Management BIBAKFull-Text 372-381
  H. Onan Demirel; Vincent G. Duffy
This paper presents the current and probable future applications of Digital Human Modeling (DHM) in Product Lifecycle Management (PLM) implementations. A Formula 1 race car and a marine vessel were developed by the integration of PLM and DHM software packages. Dassault Systemes' CATIA V5 PLM solution package was used for CAD/CAE design/analysis and UGS Tecnomatix JACK software was utilized for visual/mathematical ergonomics and human analysis. Literature review for future work, [1] and [2], was discussed to investigate the potentials of DHM in PLM for simulation of a blast motion in Navy vessels. The results and observations indicated that integration of DHM and PLM packages have potentials to improve the product development efforts and offer an enhanced approach for simulation of complex systems where there is human-machine integration.
Keywords: Digital Human Modeling; Advance Manufacturing; Product Development; Human Factors and Ergonomics; Product Lifecycle Management; Engineering Design; Motion Capture; Simulation & Modeling
Bridging the Gap: Exploring Interactions Between Digital Human Models and Cognitive Models BIBAKFull-Text 382-391
  Robert Feyen
For years now, most researchers modeling physical and cognitive behavior have focused on one area or the other, dividing human performance into "neck up" and "neck down." But the current state of the art in both areas has advanced to the point that researchers should begin considering how the two areas interact to produce behaviors. In light of this, some common terms are defined so researchers working in different disciplines and application areas can understand each other better. Second, a crude "roadmap" is presented to suggest areas of interaction where researchers developing digital human form and other physical performance models might be able to collaborate with researchers developing cognitive models of human performance in order to advance the "state-of-the-art" in replicating and predicting human performance.
Keywords: Human performance; cognitive models; digital human models
Translating User Experience to Requirements BIBAKFull-Text 392-398
  Ji Gao; Glen J. Anderson; Brian W. Bramlett; Ryan Palmer; Delbert Marsh
In this paper we introduce the Usage-to-Platform Requirements (U2PR) process in the context of a platform product lifecycle at Intel that involves challenges beyond the development of an individual product. We describe the types of research necessary to inform the process, the methods we have evolved in developing use cases and usage requirements, and the practice used to communicate the requirements to the right audiences. The U2PR process provides a practical approach to fill the gap between descriptions of marketing opportunities and actionable, technology capability definitions and experience-quality requirements. It demonstrates how one can apply a general user-centered design process to strategic planning and design.
Keywords: platform; user experience; usage model; use case; requirement
Involving Engineers in User Research and User Experience Design of ICT for China BIBAKFull-Text 399-408
  Chaoyu Huang; Huogao He
Chinese culture and consumer patterns are dramatically different from those in the US and Europe. That greatly impacts the types of products that are relevant to the Chinese market, the product development life cycle and methods by which these products are defined and developed for information and communication technologies (ICT). To address those unique differences, the User Centered Design (UCD) research team at Intel China has developed and refined techniques for involving engineering staff in the early stages of product design, namely user research and experience design. This early involvement has many advantages and improves the overall effectiveness of the product development team. This article describes the role of the engineers in the early phases of the user centered process, and the learnings and challenges that come from this approach. Real-world case studies are used to illustrate the methodologies.
Keywords: ICT; user experience design; user centered design; user centered research; ethnography; brainstorming; field work
Shape Analysis of Human Brain with Cognitive Disorders BIBAFull-Text 409-414
  Tianzi Jiang; Feng Shi; Wanlin Zhu; Shuyu Li; Xiaobo Li
In this paper, we present some of our current studies on how human brain structures are influenced by cognitive disorders occurred from various neurological and psychiatric diseases based on magnetic resonance imaging (MRI). We first give a brief introduction about computational neuroanatomy, which is the basis of these studies. In Section 2, several novel methods on segmentations of brain tissue and anatomical substructures were presented. Section 3 presented some studies on brain image registration, which plays a core role in computational neuroanatomy. Shape analysis of substructures, cerebral cortical thickness and complexity was presented in Section 4. Finally, some prospects and future research directions in this field are also given.
Finding Origin Points for New Coordinate System Suitable for Sign Animation BIBAKFull-Text 415-422
  Tomohiro Kuroda; Kazuya Okamoto; Ryo Kitauchi; Tadamasa Takemura; Naoki Ohboshi; Hiroyuki Yoshihara
This paper proposes new coordinate system suitable for denoting sign language motion. As the proposed coordinate system consists of polar coordinate systems whose origins are certain points of human body, postures shown on the system can be proportional for avatars with any possible shape and fit with existing subjective sign notation systems. This paper extracted coordinate origins from Japanese-Japanese Sign Language Dictionary via morphological analysis. Selected 85 points are successfully mapped on H-ANIM standard humanoid avatar.
Keywords: Japanese Sign Language; Natural Language Processing; Sign Language Dictionary; Sign Animation
User Experience Modeling and Enhancement for Virtual Environments That Employ Wide-Field Displays BIBAKFull-Text 423-433
  James Jeng-Weei Lin; Donald E. Parker
User experience in virtual environments including presence, enjoyment, and Simulator Sickness (SS) was modeled based on the effects of field-of-view (FOV), stereopsis, visual motion frequency, interactivity, and predictability of motion orientation. We developed an instrument to assess the user experience using multivariate statistics and Item Response Theory. Results indicated that (1) presence was increased with a large FOV, stereo display, visual motion in low frequency ranges (.03 Hz), and high levels of interactivity; (2) more SS was reported with increasing FOV, stereo display, .05-.08 Hz visual motion frequency, lack of interactivity and predictability to visual motion; (3) enjoyment was increased with visual motion in low frequency ranges (.03 Hz) and high levels of interactivity. The resulting response surface model visualizes the complex relationships between presence, enjoyment, and SS. Overall, increasing interactivity was found to be the most profound way to enhance user experience in virtual environments.
Keywords: user experience modeling; virtual environment; presence; simulator sickness; enjoyment; interactivity
AIPlayer: A Platform of Intelligent Simulation of Virtual Human in Virtual Environment BIBAFull-Text 434-442
  JianGuo Liu; YanSheng Lu; JiuYun Chen
The research of intelligent simulation of virtual human in virtual environment is an interesting direction in the domain of AI after the research of virtual human's behavior simulation. This paper presents a new research platform named AIPlayer in order to promote this work. Virtual environment is come close to the real world. Some characteristic in virtual environment can realistically represent the real world, at the same time it can provide some advantages to science research. This virtual environment may be MMORPG or virtual reality. The motive of the research is to simulate a virtual human who can autonomous live in the virtual environment. We named this research as intelligent simulation of virtual human in virtual environment. First, this paper argues the significance of this research in theory and application, then analyses the demand of the AIPlayer, the characteristic of its living environment, the aim of AIPlayer and some correlative research domain may be involved, then it describes the architecture of AIPlayer and the core of AIPlayer: BSOAA (based smart object agent architecture), at last a prototype of AIPlayer in virtual environment is introduced.
Understanding RUTH: Creating Believable Behaviors for a Virtual Human Under Uncertainty BIBAKFull-Text 443-452
  Insuk Oh; Matthew Stone
In pursuing the ultimate goal of enabling intelligent conversation with a virtual human, two key challenges are selecting nonverbal behaviors to implement and realizing those behaviors practically and reliably. In this paper, we explore the signals interlocutors use to display uncertainty face to face. Peoples' signals were identified and annotated through systematic coding and then implemented onto our ECA (Embodied Conversational Agent), RUTH. We investigated whether RUTH animations were as effective as videos of talking people in conveying an agent's level of uncertainty to human viewers. Our results show that people could pick up on different levels of uncertainty not only with another conversational partner, but also with the simulations on RUTH. In addition, we used animations containing different subsets of facial signals to understand in more detail how nonverbal behavior conveys uncertainty. The findings illustrate the promise of our methodology for creating specific inventories of fine-grained conversational behaviors from knowledge and observations of spontaneous human conversation.
Keywords: Uncertainty expression; uncertainty recognition; embodied conversational agent; talking head; RUTH
Automatic, Body Measurements Based Generation of Individual Avatars Using Highly Adjustable Linear Transformation BIBAKFull-Text 453-459
  Andreas Volz; Rainer Blum; Sascha Häberling; Karim Khakzar
In this paper part of the work of the research project 'IntExMa' is presented, that aims at the development of an interactive, in-store sales support system focusing on the virtual 'try-on' of clothing. Customers are provided with highly realistic, individualized, three-dimensional virtual counterparts, derived from a small number of body measurements. The paper describes in detail the approach followed for the required automatic generation of avatars. It is based on a sophistication of the well-known concept of parametric deformation. The solution presented here is characterized by a range of means that provide highly flexible, fine-grained adjustments of the linear transformation process leading to precisely controllable results.
Keywords: body measurements; parametric deformation; individualized avatars
A Composite Measure for the Evaluation of Mental Workload BIBAKFull-Text 460-466
  Lee-ming Wang; Vincent G. Duffy; Yingzi Du
Physiological measures have found reliable sensitivity to the variation of mental efforts to tasks of different difficulty levels. The sensitivity needs to be enhanced for further application. This paper proposed a composite measure consisting of three physiological measures, facial skin temperature, eye blinks and pupil dilation. The facial skin temperature will be measured by an infrared camera. One dimensional iris image will be used for the measurement of eye activities. All measurement will be done in real-time and unobtrusively. A preliminary experiment will be conducted for each measure to demonstrate their sensitivity. The combination then will be accomplished by factor analysis and regression analysis. Last, the analysis will focus on the improvement in sensitivity from the combination of individual measures.
Keywords: mental workload; facial skin temperature; pupil dilation; thermography; 1D iris identification
Brain-Computer Interfaces Based on Attention and Complex Mental Tasks BIBAKFull-Text 467-473
  Jue Wang; Nan Yan; Hailong Liu; Mingyu Liu; Changfeng Tai
Brain-Computer Interface (BCI) technology is widely used in rehabilitation field. There are two main applications of BCI systems in assistive technology: regain the movements or communications for people with motor disability and neurofeedback for training the subject to emit a specific brain activity. In this study, we introduce two typical applications of BCI systems in our lab. For the first case, the BCI system based on mental tasks classification for people with motor disability is described. An effective features extraction and classification methods of EEG signals were proposed. For the second case, a neurofeedback (NFB) system was established, which utilized Virtual Reality (VR) to create appropriate feedback information which is more interesting, imaginative and interactive than traditional graphical presentations. Visual & auditory (IVA)-continuous performance test (CPT) results show that it can provide an effective therapy for treating attention deficit hyperactivity disorder (ADHD) children.
Keywords: brain-computer interface; mental tasks; neurofeedback; ADHD rehabilitation
Fractal Modeling of Human Psychomotor Skills Acquisition Process BIBAKFull-Text 474-482
  James Wanliss; Dahai Liu; Vadim Uritsky; Michael Wuergler
Existing research on human skills acquisition studies has shown that learning follows a non-linear pattern, but the exact form remains unknown due to the limitation of traditional experimental methods and lack of systematic modeling of tasks. We applied a non-linear fractal analysis on the time series data produced by human subjects on target-tracking motor learning tasks. Tracking of a non-fractal sinusoid-cosinusoid signal was used as the platform. Our preliminary results suggest that fractal models may prove effective in investigating details of the human learning process.
Keywords: Fractal analysis; human learning; skill acquisition
Effect of Noise-Enhanced on the Balance Control Ability in Older Adults BIBAKFull-Text 483-489
  Fangfang Wu; Rencheng Wang; Dewen Jin; Xiao Hu; Yiyong Yang; Jichuan Zhang; Noboru Youshimura
Somatosensory function declines with age, and such changes have been associated with diminished motor performance. Noise input can enhance sensory and motor function. We tested the effects of the vibrating stimulation applied at the feet on balance control of 6 healthy elderly and 8 young volunteers. Balance performance was characterized using a FASTRAK System. We calculated four traditional measures of postural sway parameters and five stabilogram-diffusion analysis variables. Among the 14 participants, application of noise resulted in a reduction of seven of nine sway parameters in young participants and eight of nine sway variables in elderly participants. The results suggested that the imperceptible noise, when applied to the feet, could enhance the balance performance of healthy older adults. Therefore, using the noise-based devices may be an effective way to improve the balance control of elderly people.
Keywords: Older adults; Balance control; Balance ability; Vibration
Development of the Virtual-Human Santos™ BIBAKFull-Text 490-499
  Karim Abdel-Malek; Jingzhou Yang; Joo H. Kim; Timothy Marler; Steven Beck; Colby Swan; Laura Frey-Law; Anith Mathai; Chris Murphy; Salam Rahmatallah; Jasbir Arora
This paper presents the background and history of the virtual human Santos™ developed by the Virtual Soldier Research (VSR) Program at The University of Iowa. The early virtual human environment was called Mira™. This 15-degree-of-freedom (DOF) upper-body model with posture and motion prediction was funded by John Deere Inc. and US Army TACOM Automotive Research Center. In 2003 US Army TACOM began funding VSR to develop a new generation of virtual humans called Santos (109 DOFs), which was to be another generation of Mira. Later on, Caterpillar Inc., Honda R&D North Americas, Natick Soldier System Center, and USCAR (GM, Ford, and Chrysler) joined the VSR partnership. The objective is to develop anew generation of digital humans comprising realistic human models including anatomy, biomechanics, physiology, and intelligence in real time, and to test digital mockups of products and systems before they are built, thus reducing the significant costs and time associated with making prototypes. The philosophy is based on a novel optimization-based approach for empowering these digital humans to perform, un-aided, in a physics-based world. The research thrusts include the following areas: (1) predictive dynamics, (2) modeling of cloth, (3) hand model, (4) intuitive interface, (5) motion capture, (6) muscle and physiology modeling, (7) posture and motion prediction, (8) spine modeling, and (9) real-time simulation and virtual reality (VR). Currently, the capabilities of Santos include whole-body posture prediction, advanced inverse kinematics, reach envelope analysis, workspace zone differentiation, muscle force and stress analysis, muscle fatigue prediction, simulation of walking and running, dynamic motion prediction, physiologic assessment, a user-friendly interface, a hand model and grasping capability, clothing modeling, thermo discomfort assessment, muscle wrapping and sliding, whole-body vibration analysis, and collision avoidance.
Keywords: Virtual humans; predictive dynamics; muscle wrapping
Validation of Predicted Posture for the Virtual Human Santos™ BIBAKFull-Text 500-510
  Jingzhou Yang; Salam Rahmatallah; Timothy Marler; Karim Abdel-Malek; Chad Harrison
Digital human modeling and simulation plays an important role in product design, prototyping, and manufacturing: it reduces the number of design iterations and increases the safety and design quality of products. Posture prediction is one of the key capabilities. It is especially useful in the design of vehicle interiors for checking the reachability of buttons and determining comfort levels. This paper presents the validation of predicted posture for the virtual human Santos. The predicted posture is a physics-based model and is formulated as a multi-objective optimization (MOO) problem. The hypothesis is that human performance measures (cost functions) govern how humans move. We chose 12 subjects from four different percentiles, all Americans (female 5%, female 50%, male 50%, and male 95%). Four realistic in-vehicle tasks requiring both simple and complex functionality of the human simulations were chosen: reaching a point at the top of the A-pillar, the radio tuner button, the glove box handle, and a point on the driver's B-pillar seatbelt adjuster. The subjects were asked to reach the four target points, and the joint centers for wrist, elbow, and shoulder and the joint angle of elbow were recorded using a motion capture system. We used these data to validate our model. The validation criteria comprise R-square and confidence intervals. The results show that the predicted postures match well with the experiment results, and are realistic postures.
Keywords: Predicted posture; MOO; human performance measures; validation; virtual humans
Modeling of Multi-organization Performance for Emergency Response BIBAKFull-Text 511-520
  Yufei Shu; Kazuo Furuta
To response severe disaster, such as hurricane, tsunami, or terrorists attack, multi-organization, such as government, companies, media, and public are involved. How to make these inter- or intra dependent organizations cooperate timely and accurately when they face uncertainty and stressful situation is the primary concerns. In this paper, we proposed multi-organization performance model, which introduced organizational factors, individual factors and focused on communication and collaboration among different organizations. Based on it we developed multi-agent emergency response system. This IT solution has capability to integrate drills into simulated response activities and reproduce the drills. To demonstrate how the system can be used as a powerful tool for supporting and evaluating the performance of multi-organization in disaster management and response, the test simulation is carried out using a scenario extracted from real-life emergency drills.
Keywords: Multi-organization performance; Multi-agent system; Emergency response; Disaster management
Estimating Mental Fatigue Based on Multichannel Linear Descriptors Analysis BIBAKFull-Text 521-529
  Chong Zhang; Chongxun Zheng; Xiao-mei Pei; Xiaolin Yu
In this paper, two different mental fatigue experiments, sleep deprivation and prolonged time of work, were designed to investigate their effect on mental fatigue respectively. Three parameters of multichannel linear descriptors i.e. Ω, Φ and Σ are used to measure the level of mental fatigue for the first time. When mental fatigue level increases, the brain neurons are restrained, this results in the increase of synchrony degree between the distributed electroencephalogram (EEG). Therefore, spatial complexity Ω, field strength Σ and field changes Φ of regional brain region would reduce. The experimental results also show that the average values of Ω, Φ and Σ of EEG decrease with the prolonging of sleep deprivation and working time, and then also decrease with the increase of mental fatigue level. The average values of Ω, Φ and Σ of EEG strongly correlate with mental fatigue. The multichannel linear descriptors of EEG are expected to serve as the indexes to evaluate mental fatigue level objectively.
Keywords: mental fatigue; Electroencephalogram (EEG); multichannel linear descriptors
Chinese Visible Human Data Sets and Their Applications BIBAKFull-Text 530-535
  Shao-Xiang Zhang; Pheng-Ann Heng; Zheng-Jin Liu; Li-Wen Tan; Ming-Guo Qiu; Qi-Yu Li; Rong-Xia Liao; Kai Li; Gao-Yu Cui; Yan-Li Guo; Yong-Ming Xie
The research on digital visible human is of great significance and application value. The US VHP created the first digital image data set of complete human (male and female) in 1995. To promote worldwide application-oriented VHR, more visible human data sets representative of different populations of the world are in demand. The Chinese Visible Human (CVH) male (created in Oct. 2002) and female (created in Feb. 2003) project achieved greater integrity of images, easier blood vessel identification, and were free of organic lesion. The most noteworthy technical advance of CVH Project was construction of a low temperature laboratory, which contributed to prevention of small structures (including teeth, concha nasalis, and articular cartilage) from falling off of the milling surface. Thus, better integrity of images was ensured. So far, we have achieved acquisition of five CVH data sets and their volume visualization on PC. 3D reconstruction of some organs or structures has been finished. The work of segmentation of a complete data set is also under way. Although there is still a distance to go to make visible human meet the application-oriented needs in various fields, we're taking our first step toward future application by acquiring new data sets, performing segmentation and setting up a platform of computer-assisted medicine.
Keywords: Chinese Visible Human (CVH); dataset; 3-D reconstruction; digital anatomy; computer assisted medicine (CAM)
Visualizing User Experience Through "Perceptual Maps": Concurrent Assessment of Perceived Usability and Subjective Appearance in Car Infotainment Systems BIBAKFull-Text 536-545
  Xianjun Sam Zheng; James Jeng-Weei Lin; Salome Zapf; Claus Knapheide
Users' perceptions of the appearance and the usability of an interactive system are two integral parts that contribute to the users' experience of the system. "Actual usability" represents a system value that is revealed either during usability testing and related methods by experts or during use by the target users. Perceived usability is an assumption about a systems' usability that has been made prior to, or independent of, its use. The appearance of a product can inadvertently affect its perceived usability; however, their relationship has not been systematically explored. We describe an approach that uses "perceptual maps" to visualize the relationship between perceived usability and subjective appearance. A group of professional designers rated representative car infotainment systems for their subjective appearance; a group of usability experts rated the same models for their perceived usability. We applied multidimensional scaling (MDS) to project the ratings into the same Euclidean space. The results show certain overlap between the perceptions of product appearance and usability. The implications of this approach for designing interactive systems are discussed.
Keywords: User experience; usability; perceived usability; appearance; design; interactive systems; multidimensional scaling; visualization

Part III: Medical and Rehabilitation Applications

Digital Human Modelling: A Global Vision and a European Perspective BIBAKFull-Text 549-558
  Gordon Clapworthy; Peter Kohl; Hans Gregerson; S. R. Thomas; Marco Viceconti; D. Rodney Hose; D. Pinney; John Fenner; Keith M. McCormack; Patricia V. Lawford; Serge L. Van Sint Jan; S. Waters; Peter V. Coveney
The Physiome is an umbrella term that refers to human modelling with mathematics and computational methods, accommodating cross-disciplinary science (chemistry, biology, physics) and a breadth of dimensional and temporal scale (sub-cellular to organs, sub-microsecond to tens-of-years). The Virtual Physiological Human is a European initiative that is intended to provide a unifying architecture for the integration and cooperation of multi-scale physiome models, thereby creating a predictive platform for the description of human beings in silico. Unlike the Genome, the challenge of the Physiome may be almost unbounded, as the desire for increased detail imposes a continuing pressure for ever-finer data granularity, and the necessary Information Technology (IT) infrastructure spawns innovations that surpass conventional solutions. It is foreseen that maturing physiome activities will increasingly influence medicine, biomedical research and commercial developments, and the central role of IT highlights the need for a specific and robust IT infrastructure.
   The European Commission has experience of supporting challenging technical endeavours through its Framework Programmes of research, and in the forthcoming 7th Framework Programme, it will invite researchers from within and outside Europe to unite in seeking solutions to key issues of the Physiome. The Virtual Physiological Human (VPH) investment programme will establish the necessary infrastructure and address the grand technical challenges identified by experts. This paper examines the background to the strategy and the ways in which the programme's structure has been determined.
Keywords: Physiome; Virtual Physiological Human; infrastructure; modelling
ICT Methodologies to Model and Simulate Parts of Human Body for Prosthesis Design BIBAKFull-Text 559-568
  Giorgio Colombo; Stefano Filippi; Paolo Rissone; Caterina Rizzi
The work presented in this paper refers to the implementation of a product development process based on the use of virtual model of the human body to design specific custom-fit product, such as a prosthesis socket (interface between the residual limb and the mechanical part of the prosthesis). It considers the integration of advanced ICT tools coming from the reverse engineering, the physics-based modelling and simulation, and the rapid prototyping fields. The paper describes problems related to the implementation of each step within a real socket development process.
Keywords: Product customization; Prosthesis design; Physics-based simulation; Human body modeling
Simulating Cancer Radiotherapy on a Multi-level Basis: Biology, Oncology and Image Processing BIBAKFull-Text 569-575
  Dimitra D. Dionysiou; Georgios S. Stamatakos; Kostas Marias
Tumour growth and response to radiotherapeutic schemes is a markedly multiscale process which by no means can be reduced to only molecular or cellular events. Within this framework a new scientific area, i.e. in silico oncology has been proposed in order to address the previously mentioned hypercomplex process at essentially all levels of biocomplexity. This paper focuses on the case of imageable glioblastoma mulriforme response to radiotherapy and presents the basics of an essentially top-down modelling approach, aiming at an improved understanding of cancer and at a patient-specific optimization of treatment.
Keywords: Radiotherapy; Modelling; Glioblastoma; In silico oncology
Applied User Performance Modeling in Industry -- A Case Study from Medical Imaging BIBAFull-Text 576-585
  Marcela Esteves; Tobias Komischke; Salome Zapf; Antje Weiss
To determine ways of improving a user interface -- so that a person's task produces fewer errors or takes less time -- is a major goal of user interface designers. Usability testing is an established and proven method for revealing these user performance metrics, but is rather time-consuming, resource intensive and requires at least functional prototypes. Therefore, it may not always be the optimal choice during the development of very complex, expensive and context-specific applications like those in medical imaging. A promising alternative is to simulate user performance with computational models based on psychological models. In this paper the Performance Modeling Inventory (PMI), which was developed based on Card, Moran and Newell's (1980) Keystroke Level Model for estimating user performance with medical imaging systems, is introduced for the first time.
Computer Aided Lumbar Support Design and Application BIBAKFull-Text 586-594
  Susanne Frohriep; Jan Petzel
Support properties in the lumbar area have been identified as a major factor for the comfort impression on automotive seats. However, the relationship of human body characteristics to specific properties of seats is not clear. Ongoing research at L&P Automotive Group analyzes seat dimensions and human body characteristics in order to evaluate the man-machine interface of the seated human. Computer tools employed are 3D measuring systems, pressure mapping and subjective comfort assessment. Specific measurement routines have been developed to allow for correlation of human dimensions and seat characteristics. Using computer supported methods for measuring, data collection and data processing in combination with engineering knowledge and knowledge about other soft facts, comfort assessment processes can be developed and effectively used in order to obtain better, meaning more comfortable products.
Keywords: lumbar support; comfort assessment; automotive seating; man-machine interface
Facilitating Pronunciation Skills for Children with Phonological Disorders Using Human Modelling BIBAKFull-Text 595-605
  Jennifer George; Paul Gnanayutham
Children are often forced into mainstream schools while special needs schools are being shut down. Children with phonological disorders in mainstream schools go through fear, shame and frustration of not being understood or misunderstood. The proposed research attempts to address this issue by way of designing and developing a prototype for an assistive device that would help special needs children in mainstream education. This will also help children overcome problems that result from lack of confidence. This work has been very much a pioneering work and has achieved the target it pursued.
Keywords: Phonological disorders; speech disability; pronunciation; interface; sounds and children
FPF-SB: A Scalable Algorithm for Microarray Gene Expression Data Clustering BIBAFull-Text 606-615
  Filippo Geraci; Mauro Leoncini; Manuela Montangero; Marco Pellegrini; M. Elena Renda
Efficient and effective analysis of large datasets from microarray gene expression data is one of the keys to time-critical personalized medicine. The issue we address here is the scalability of the data processing software for clustering gene expression data into groups with homogeneous expression profile. In this paper we propose FPF-SB, a novel clustering algorithm based on a combination of the Furthest-Point-First (FPF) heuristic for solving the k-center problem and a stability-based method for determining the number of clusters k. Our algorithm improves the state of the art: it is scalable to large datasets without sacrificing output quality.
A Finite Element 3D Model of in Vivo Human Knee Joint Based on MRI for the Tibiofemoral Joint Contact Analysis BIBAKFull-Text 616-622
  Zhixiu Hao; Dewen Jin; Yu Zhang; Jichuan Zhang
The contact behaviors of in vivo knee during weight bearing were quantified using MRI-based 3D knee model. The model included the cortical and trabecular bone of the femur and tibia, cartilage of the femoral condyles and tibial plateau, both the medial and lateral menisci with their horn attachments. Explicit dynamic nonlinear finite element techniques were discussed to simulate biomechanical features of tibio-femeral joint under different loads condition, considering the relative slide and friction existing in the knee. The simulating results show that the contact area increased while the loads increased. Both the ratio of the contact area and the ratio of contact force of medial and laterial tibial plateau were almost constant under the different loads along the axis of the tibia during the supporting phase in a gait, and yet the contact points of the compressive force were changed.
Keywords: tibiofemoral joint; contact; finite element
Advances in Visible Human Based Virtual Medicine BIBAKFull-Text 623-632
  Pheng-Ann Heng
In this paper, important virtual medicine research related to visible human data sets would be outlined. In particular, latest visible human related research carried out in the Visualization, Virtual Reality and Imaging Research Centre of the Chinese University of Hong Kong (CUHK) will be discussed in detail, while related applications such as virtual acupuncture, virtual anatomy, and virtual orthopedics training briefly shaped our current and future research and development on visible human-related virtual medicine. Our latest advancement in segmentation, imaging, user-interface design as well as surgical education and training will be discussed.
Keywords: Visible Human data; visualization; surgical simulation; virtual reality
Finite Element Analysis of a Six-Component Force Sensor for the Trans-Femoral Prosthesis BIBAKFull-Text 633-639
  Xiao Hu; Rencheng Wang; Fangfang Wu; Dewen Jin; Xiaohong Jia; Jichuan Zhang; Fuwen Cai; Shuangxi Zheng
It is significant to detect and analyze its mechanical property for the design of the artificial knee joint, especially for the design of an osseointegrated prosthetic limb. Since normal six-component force sensors are unsuitable for detecting the mechanical property of the lower limb prosthesis, a novel sensor is presented in this paper. It can be easily fixed between the artificial knee joint and the stump of the patient to detect the load condition during walking. The mathematic model of the sensor is analyzed, and strength check, stiffness design and the linearity of the sensor were studied with FEA. Finally, the Transmission Matrix is calculated. This kind of sensor can help us to get academic foundations for the designment and the evaluation of the limb prosthesis and its performance.
Keywords: Six-component force sensor; Prosthesis; FEA
The Influence of Shoe-Heel Height on Knee Muscle Activity of Transtibial Amputees During Standing BIBAKFull-Text 640-645
  Xiaohong Jia; Jichuan Zhang; Rencheng Wang; Lidan Fang; Dewen Jin; Ming Zhang
In order to access the effects of shoe-heel height on knee muscle activity for transtibial amputees during standing, five male subjects volunteered for the study. Three pairs of shoes with zero, 20 mm and 40 mm heel height were used during normal standing. Surface EMG of 10 muscles was recorded by the Noraxon surface EMG collection system. EMG-MAV of the medial and lateral gastrocnemius of the sound leg almost change double with increase in heel height from zero to 40 mm, and EMG-MAV of the rectus fomris, vastus lateralis and vastus medialis of prosthetic side became larger to different extent. The finding in this paper suggested that an alignment change was necessary to accommodate the heel height change and the prostheses users should be cautious to choose shoes in daily life.
Keywords: Shoe-heel height; Surface EMG; Prosthesis; Standing
3D Modeling of the Vessels from X-Ray Angiography BIBAKFull-Text 646-654
  Na-Young Lee; Gye-Young Kim; Hyung-Il Choi
Coronary artery diseases are usually revealed using X-ray angiographies. Such images are complex to analyze because they provide a 2D projection of a 3D object. Medical diagnosis suffers from inter- and intra-clinician variability. Therefore, reliable software for the 3D modeling of the coronary tree is strongly desired. This paper focuses on the automatic 3D modeling of the vessels from X-ray angiography. Our approach is based on a 3D model of standard vessels. The model is projected because it is difficult to suitably transform standard into individual vessels on 3D space. The modeling process is carried out in two steps. The first step consists of selecting automatically two sets of corresponding control points between standard and individual vessels. In the second step, 3D model of individual vessels is performed by warping with corresponding control points. Accurate descriptions of 3D model would be useful for quantitative diagnosis of atherosclerosis, for surgical or treatment planning, for monitoring disease progress or remission, and for comparing efficacies of treatments.
Keywords: Coronary Angiography, Control point, Image Transformation, 3D Modeling
Finite Element Modeling to Aid in Refining the Rehabilitation of Amputees Using Osseointegrated Prostheses BIBAKFull-Text 655-658
  Winson Lee; Laurent Frossard; Nicola Cairns; Rickard Branemark; John Evans; Clayton Adam; Mark Pearcy
The direct anchorage of a lower-limb prosthesis to the bone has been shown to be an excellent alternative for amputees experiencing complications in using a conventional prosthetic socket. After surgical implantation, amputees have to go through a weight bearing exercise program to prepare the bone to tolerate forces and promote bone-remodeling. Currently, the load magnitude prescribed by the clinician is measured by a weight scale which reports only the axial force in the limb. Previous study using a load transducer revealed that in addition to the axial force there were other forces and moments. This study develops a FE model and utilizes our load data to investigate the stress distribution at the bone-implant interface. The model shows that the stress distribution could be highly non-uniform during the exercise. Bone-implant interface stress has certain implications in pain adaptation and bone-remodeling, and a good understanding of it can assist in future attempts to refine and shorten the period of rehabilitation exercise.
Keywords: transfemoral amputation; bone anchorage prosthetics; osseointegration; weight bearing exercise; finite element modeling
Actions of an External Electrical Shock on Human Atrial Excitation -- A Computer Model Study BIBAKFull-Text 659-667
  Jihong Liu; Arun V. Holden; Henggui Zhang
Atrial fibrillation (AF) is one of the most common cardiac diseases that cause morbidity and mortality. One of the most frequently used clinical treatments of AF is to use a large and brief external electrical shock to reset atrial tissue from a disordered fibrillation state to a quiescent state, then the pacemaker of the heart resumes its control of atrial excitation rhythm and thus a defibrillation is achieved. Though widely used in practice, the mechanisms underlying the success of an electrical shock in defibrillation is incompletely understood. In this study, we developed a computer model of human atrial tissue to investigate the actions of an external electrical shock on atrial excitations. Using the model, we computed the defibrillation threshold of the human atrium. We found that due to the supernormal excitability of human atrium, the computed successful defibrillation threshold is much less than the excitation threshold of human atrium in resting state. This study provides some new insights to understand the mechanisms underlying AF defibrillation.
Keywords: External electrical stimulation; defibrillation threshold; bi-domain model of cardiac tissue; reentrant excitation
Study and Application of Medical Image Visualization Technology BIBAKFull-Text 668-677
  Jihong Liu; Weina Ma; Fei Liu; Ying Hu; Jinzhu Yang; Xinhe Xu
In medical imaging, many applications require visualization and analysis of three-dimensional (3D) objects. Visualization is the process of exploring, transforming, and view data as images to gain understanding and insight into the data, which requires fast interactive speed and high image quality. In this paper, we describe the key techniques in medical image visualization. In order to improve ray casting rendering speed, a synthetically accelerated algorithm is proposed. Firstly, rendering algorithms are fully studied and compared. Secondly, proximity clouds algorithm has been selected and extended to continuous ray casting. Finally, the accelerated algorithm based on ray coherence has been realized. The experimental results on 3D medical image reconstruction are given, which show the medical image visualization technology has provided a powerful technology base for computer-aided diagnosis, virtual surgery and e-learning in medicine field.
Keywords: Visualization; 3D reconstruction; Proximity Clouds; Volume Rendering
A Method for Gene Identification by Dynamic Feature Choosing BIBAKFull-Text 678-683
  Jiawei Luo; Li Yang; Xizhen Zhang
With growth of sequenced genome, a number of algorithms for gene identification were created. These algorithms use fixed gene features which are chosen based on observation or experience. These features may not be major features of a genome. In this paper, we illustrate several candidate features and propose a dynamic feature choosing algorithm to determine the major features. We describe nucleotide sequence by feature vector and use Discriminant analysis to them to make decision on coding/non-coding. To test the algorithm, we apply the algorithm to the S.cerevisiae genome and achieve accuracy of above 98%.
Keywords: Gene identification; Discriminant analysis; three cross-validation tests
Latest Development of an Interventional Radiology Training Simulation System: NeuroCath BIBAKFull-Text 684-693
  Xin Ma
We describe the latest development of a computer-based virtual reality environment for training interventional neuroradiology procedures. The system, NeuroCath (Neuroradiology Catheterization Simulator), includes extraction and construction of a vascular model from different imaging modalities that represents the anatomy of patient in a computationally efficient manner, and a finite element method (FEM) based physical model that simulates the interaction between the devices and neuro-vasculature. A realistic visual interface with multiple, synchronized windows and plenty of video control functions are developed. The latest version is also equipped with haptic feedback module that gives the sense of touch in real-time, and customizable vascular model so that trainer can understand the importance of vascular variations and practice. According to the validation in several clinical centers, 70%-75% of training features have been realized which makes the system well suitable for training of interventional neuroradiologists.
Keywords: interventional neuroradiology; simulation; augmented reality; modeling
Methodologies to Evaluate Simulations of Cardiac Tissue Abnormalities at a Cellular Level BIBAKFull-Text 694-702
  Nicos Maglaveras; Ioanna Chouvarda
Computer Simulations of cardiac wave propagation may be used as a tool towards understanding the mechanisms of cardiac conduction, the nature of various heart diseases, as well as the effect of drugs in cardiac function. Such simulations depend on the ionuc current model adopted, and various such models have been proposed. The exact propagation wavefront thus depends on the ionic model and the tissue properties, being homogeneous or heterogeneous. The latter case, which corresponds to infracted cardiac tissue, is the focus in this work. The ionic current properties and the sodium kinetics on a two-dimensional grid where wavefront rotations around barriers at bifurcation sites take place, are examined in detail and differences in propagation characteristics elicited by using fast or slow fast inward current kinetics such as can be found in the Beeler-Reuter, Luo-Rudy and Ebihara-Johnson models are elaborated.
Keywords: ionic current models; cardiac propagation; conduction abnormalities
Multi-level Analysis and Information Extraction Considerations for Validating 4D Models of Human Function BIBAKFull-Text 703-709
  Kostas Marias; Dimitra D. Dionysiou; Georgios S. Stamatakos; Fotini Zacharopoulou; Eleni Ch. Georgiadi; Thanasis Margaritis; Thomas G. Maris; Ioannis G. Tollis
Recent research trends focus on how multiscale biomedical information can be modeled and transformed into knowledge, in order to lead to a less interfering but also more individualized diagnosis and therapy. In order to assess the clinical importance of models of human pathology (e.g. cancer), it is necessary to validate them with prior and post treatment clinical data which in turn requires the determination of the tumor size and shape with high resolution, accuracy and precision, as well as structural and physiological information. This paper discusses some of the most important image analysis challenges in order to define an optimal method for extracting more accurate and precise anatomical and functional information related to the underlying pathology, which can be used for initializing and validating models of pathophysiology as well as simulations/predictions of the response to therapeutical regimes.
Keywords: Virtual Physiological Human; biomedical data analysis; modeling
Clinical Patient Safety -- Achieving High Reliability in a Complex System BIBAKFull-Text 710-716
  Kathryn Rapala; Julie Cowan Novak
Since the 2001 Institute of Medicine Report which estimated that 44,000 to 98,000 patients die each year as a result of healthcare error. This report in effect launched a global patient safety movement, with many proposed regulatory, research and administrative solutions. Patient safety areas of focus such as work complexity, teamwork and communication, technology, and evidence based practice provide a basis for understanding healthcare error. Reliability concepts are the goal of healthcare organizations; and applications such as simulation theory provide means to achieve this status. The translation of research into practice is the foundation of organizational patient safety. Understanding and awareness of patient safety issues has increased; however, significant work to improve patient care outcomes remains.
Keywords: patient safety; culture; work complexity; human factors; education; root cause analysis; failure mode event analysis; simulation; high reliability organization
Novel Methods for Human-Computer Interaction in Multimodal and Multidimensional Noninvasive Medical Imaging BIBAKFull-Text 717-726
  Tomasz Soltysinski
The newly developed method for medical noisy data segmentation for the purpose of presentation and supporting the diagnostics is introduced. It also allows for morphometry and visualization of medical multimodal and dynamical data. A general mathematical framework is presented and characterized together with numerous applications. As this tool is designed to support human-computer interaction by means of involving the sense of sight, and suspected to be worthy in the virtual environment sensitive to the sense of touch, the discussion is supported with numerous examples of visualizations and multimodal and multidimensional applications of proposed method.
Keywords: Digital human modeling; Bayesian inference; spectral method; multidimensional imaging; ultrasound; CT; MRI; PET; histopathology
A Hybrid AB-RBF Classifier for Surface Electromyography Classification BIBAKFull-Text 727-735
  Rencheng Wang; Yiyong Yang; Xiao Hu; Fangfang Wu; Dewen Jin; Xiaohong Jia; Fang Li; Jichuan Zhang
In this paper, we aim to classify surface electromyography (sEMG) by using Attribute Bagging-Radial Basis Function (AB-RBF) hybrid classifier. Eight normally-limbed individuals were recruited to participate in the experiments. Each subject was instructed to perform six kinds of finger movements and each movement was repeated 50 times. Features were extracted using wavelet transform and used to train the RBF classifier and the AB-RBF hybrid classifier. The experiment results showed that AB-RBF hybrid classifier achieved higher discrimination accuracy and stability than single RBF classifier. It proves that integrating classifiers using random feature subsets is an effective method to improve the performance of the pattern recognition system.
Keywords: Attribute Bagging Algorithm; RBFN; sEMG; Prosthesis control
An Epileptic Seizure Prediction Algorithm from Scalp EEG Based on Morphological Filter and Kolmogorov Complexity BIBAKFull-Text 736-746
  Guanghua Xu; Jing Wang; Qing Zhang; Junming Zhu
Epilepsy is the most common neurological disorder in the world, second only to stroke. There are nearly 15 million patients suffer from refractory epilepsy, with no available therapy. Although most seizures are not life threatening, they are an unpredictable source of annoyance and embarrassment, which will result in unconfident and fear. Prediction of epileptic seizures has a profound effect in understanding the mechanism of seizure, improving the rehabilitation possibilities and thereby the quality of life for epilepsy patients. A seizure prediction system can help refractory patients rehabilitate psychologically. In this paper, we introduce an epilepsy seizure prediction algorithm from scalp EEG based on morphological filter and Kolmogorov complexity. Firstly, a complex filter is constructed to remove the artifacts in scalp EEG, in which a morphological filter with optimized structure elements is proposed to eliminate the ocular artifact. Then, the improved Kolmogorov complexity is applied to describe the non-linear dynamic transition of brains. Results show that only the Kolmogorov complexity of electrodes near the epileptogenic focus reduces significantly before seizures. Through the analysis of 7 long-term scalp EEG recordings from 5 epilepsy patients, the average prediction time is 8.5 minutes, the mean sensitivity is 74.0% and specificity is 33.6%.
Keywords: Scalp EEG; Epileptic seizure prediction; Kolmogorov complexity; Morphological filter; Artifact removal
A New Virtual Dynamic Dentomaxillofacial System for Analyzing Mandibular Movement, Occlusal Contact, and TMJ Condition BIBAKFull-Text 747-756
  Chi Zhang; Lei Chen; Fengjun Zhang; Hao Zhang; Hailan Feng; Guozhong Dai
This paper describes a new virtual dynamic dentomaxillofacial system. Mechanical articulators have been used to reproduce mandibular movements and analyze occlusal contacts. With the help of VR and visualization technologies, virtual articulator systems can provide dynamic simulation and quantitative information visualization, enhance the functionality, and extend the system to additional application areas. We integrate mandibular movement simulation, occlusal analysis and TMJ analysis into our system, and design new algorithms to improve the results of analysis. This system is helpful to the education, the research, and the clinic in dentistry. An evaluation is conducted to prove the functionality and usability of the system.
Keywords: Visualization; Movement Simulation; Occlusion; Inter-articular Space
Mechanism of Bifurcation-Dependent Coherence Resonance of Excitable Neuron Model BIBAKFull-Text 757-766
  Guang-Jun Zhang; Jue Wang; Jian-Xue Xu; Xiang-Bo Wang; Hong Yao
In contrast to the previous studies that have dealt with phenomenon of coherence resonance induced by external noise in excitable neuron model, in this paper the mechanism of bifurcation-dependent coherence resonance (CR) of excitable neuron model is investigated by researching the random transitions of system motion between attractors in the two sides of bifurcation point. The results of research show: For two excitable neuron model, FHN neuron model and HR neuron model, There exist different attractors in two sides of the two excitable neuron model Hopf bifurcation point, at the presence of internal or external noise the system motion may transit between attractors in two sides of bifurcation point; mechanism of bifurcation-dependent CR of excitable neuron model is related to this kind of random transitions, the frequency of transitions tend towards a certain frequency for a certain optimal noise intensity, and the signal-noise-ratio of system response evaluated at this certain frequency is maximal at the optimal noise intensity, CR occurs.
Keywords: coherence resonance; attractor; transition; bifurcation point
An Integrated Approach for Reconstructing Surface Models of the Proximal Femur from Sparse Input Data for Surgical Navigation BIBAKFull-Text 767-775
  Guoyan Zheng; Miguel Ángel González Ballester
A patient-specific surface model of the proximal femur plays an important role in planning and supporting various computer-assisted surgical procedures including total hip replacement, hip resurfacing, and osteotomy of the proximal femur. The common approach to derive 3D models of the proximal femur is to use imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI). However, the high logistic effort, the extra radiation (CT-imaging), and the large quantity of data to be acquired and processed make them less functional. In this paper, we present an integrated approach using a multi-level point distribution model (ML-PDM) to reconstruct a patient-specific model of the proximal femur from intra-operatively available sparse data. Results of experiments performed on dry cadaveric bones using dozens of 3D points are presented, as well as experiments using a limited number of 2D X-ray images, which demonstrate promising accuracy of the present approach.
Keywords: surface reconstruction; surgical navigation; X-ray; point distribution model; statistical shape analysis

Part IV: Industrial and Ergonomic Applications

Future Applications of DHM in Ergonomic Design BIBAFull-Text 779-793
  Heiner Bubb
Until now DHMs are especially used to design the dimensions of products and production assembly according to anthropometric demands. Recently DHMs are additionally equipped with strengths simulation so that also the dimensioning of reaction forces is possible. First steps are done to describe and evaluate the contact between human body and environment. Some examples will be shown. However in this area further important steps are necessary. Especially the self paced calculation of posture depending on this contact is to be realized. Some proposals exist for the contact of seat and body. Also first basic research is done in order to simulate motion behavior. Especially the detection of "leading body elements" as basic idea for this simulation can be seen as an initial step to generate modeling of cognitive human properties. However, in order to realize it the simulation of the properties of sense organs is necessary. Certain properties of the eyes can be simulated rather simple. Meanwhile some experience exits to understand the glance behavior depending on specific tasks (e.g. car driving). That can serve as basic for input to cognitive models. The output of these can be the track in space of the leading body element. On the other hand sensor organs properties in the field of hearing and climate are possible. In both cases the more difficult problem is to simulate the properties of the environment. General application field of these future development is the computer aided ergonomic design of workplaces in production lines and of products especially vehicles already in the definition and development phase. In this connection is to be considered that in future especially the design of information flow in these areas becomes dominant. An example is the growing development of assistance systems in cars. The application of DHMs will allow achieving the connection between information design and the necessary geometric design of the equipment.
The Design and Exploitation of Visual Feedback System for Rowing BIBAKFull-Text 794-802
  Chunmei Cao; Chuncai Wang; Linhong Ji; Zixi Wang; Xiaoping Chen
Based on Neural Mechanism theory of short-term memory, a predigested model was established. It demonstrated learning, establishment and strengthening process concerning with the motor pattern domination of high-level nerve center system. According to the model three feedback loops and their dialectic correlation were synthetically analyzed during rowing athletes studied the technique in training. The analyzed results provided the technical requests and measuring parameters of the system, then, a visual feedback system for rowing was designed and developed. This system has been primarily used in the national rowing team.
Keywords: visual feedback; Neural Mechanism; rowing
A Method for Garment Pattern Generation by Flattening 3D Body Scan Data BIBAKFull-Text 803-812
  Young Lim Choi; Yunja Nam; Kueng Mi Choi; Ming Hai Cui
The purposes of this study are to manufacture a flat pattern according to silhouettes through the Surface Flattening process of a triangle by the grid method, and to verify the result to present the method for manufacturing patterns according to designs. Based on the data measured by Size Korea, this study modeled a representative figure ranging from 18 year-old to 24 year-old female, modified the modeled body shapes to a semi-fit silhouette and loose-fit silhouette and did the surface flattening development. We manufactured patterns according to silhouettes and analyzed the area differences between 3D-piece and flat patterns and the deviation between a muslin scan data manufactured by a flat pattern and modeled data. The result of the surface flattening development by the method can be utilized for manufacturing garment patterns by converting a 3D scan data into 2D pattern and proved to be excellent at piece re-creating because the result did not show a big difference from a modeled silhouette.
Keywords: 3D scan data; apparel pattern; flattening; grid method; silhouette
Human Body Modeling for Riding Comfort Simulation BIBAKFull-Text 813-823
  Hyung Yun Choi; Kyung Min Kim; Jiwon Han; Sungjin Sah; Seok-Hwan Kim; Su-Hwan Hwang; Kwang No Lee; Jong-Kweon Pyun; Nicole Montmayeur; Christian Marca; Eberhard Haug; Inhyeok Lee
In order to assess the seating and riding comfort design of a vehicle seat in an objective manner, finite element occupant models with anatomically precise features have been developed. The human body models are incorporated into Pam-Comfort, a tool for automotive seat design and analysis, as parts of occupant surrogates that also include HPM I and II. In this paper, the detailed process of FE human body modeling including an effort on the implementation of new anthropometry will be introduced. The validation of some features of human body models in seating and riding comfort simulation against human experiments will be also presented.
Keywords: Seating and riding comfort; Pam-Comfort; Finite element human body model; Anthropometry
Applications of Digital Human Modeling in Industry BIBAKFull-Text 824-832
  H. Onan Demirel; Vincent G. Duffy
This paper represents current and probable applications of Digital Human Modeling (DHM) in different industries. Three real-world challenges, Cummins Inc. (New Product Launches), NASA (Ground Operations), Purdue University (DHM in Curriculum), are investigated for current/probable benefits of DHM. Direct contacts with company representatives and academic faculty were established to understand the current challenges and probable demands of tasks/operations in industry where DHM tools can be utilized. Dassault Systemes' CATIA V5 PLM solution package and UGS Tecnomatix JACK DHM software was utilized to offer a resolution for industrial (Cummins Inc. and NASA) challenges and a software manual (JACK) is developed to enhance the engineering curriculum at Purdue University. The results indicated that DHM tools have potential to improve the product development challenges and provides control of the entire process of designing and analyzing a product before it's ever launched. DHM in engineering curriculum would also increase the integration/adaptation of DHM tools in industry.
Keywords: Digital Human Modeling (DHM); Digital Manufacturing; Computer Aided Design (CAD); Product Development; Human Factors and Ergonomics; Product Lifecycle Management; Engineering Design; Motion Capture
A Computer-Aided Ergonomic Assessment and Product Design System Using Digital Hands BIBAKFull-Text 833-842
  Yui Endo; Satoshi Kanai; Takeshi Kishinami; Natsuki Miyata; Makiko Kouchi; Masaaki Mochimaru
The purpose of this research is to develop a system for computer-aided ergonomic assessment of products without real subjects and physical mockups by integrating a digital hand model with a product model. In previous work, we developed functions of a semi-automatic grasp planning for the digital hand and of quantitatively evaluating the grasp stability of the product based on the force-closure and the grasp quality in our system. We also confirmed the validity of the results of these functions by comparing them with the real grasp postures. In this paper, we propose a new function of evaluating "ease of grasping (EOG)" for the grasp posture based on EOG-map constructed from principal component analysis for finger joint angles in real subjects' grasps.
Keywords: Digital Human; Digital Hand; Computer Mannequin; Ease of Grasp; Principal Component Analysis
Human Age and Vehicle Speeds Affect on Vehicle Ingress Motion Pattern BIBAFull-Text 843-846
  Lars Hanson; Yong Li; Torbjörn Falkmer
The vehicle ingress and egress are important issues for the automotive industry, both for minimizing assembly work load and for maximizing end-users' comfort. Digital human modeling tools are used for evaluating and visualizing these issues. The assembler and end-user are more or less performing the very same entering task if the vehicles have identical geometrical prerequisites. The major difference is the vehicle speed; an assembler is entering a vehicle slightly moving forward on the assembly line with a speed of 5 meter/minute whereas the end user's vehicle is standing still. The human motion when entering a car is a complex biomechanical process, which affects many different body parts. Car ingress techniques, such as flopper, swiveler, and glider vary among humans; for which humans' agility may be one affecting factor. Agility is affected by joint diseases, which is more frequent among older people. There are several studies regarding ingress motion patterns[1,2], but studies on the differences in car ingress motion between car assemblers and end-users, or older and younger people are rare. Thus the purpose of the present study was to compare the ingress motion between younger versus older persons, and assemblers versus end-users.
Digital Human Model Based Participatory Design Method to Improve Work Tasks and Workplaces BIBAKFull-Text 847-855
  Kaj Helin; Juhani Viitaniemi; Jari Montonen; Susanna Aromaa; Timo Määttä
The objective of this research project was to improve manual work tasks and workplace design with a new digital human model based design method. The idea of the method was to make the design and analyze of work and workplaces easy for floor level development case. It also should to be exploitable in the context of participatory design approach. The developed method was implemented on a production design simulation platform. It was designed to be used in design of human factors, performance and functionality of a production concurrently. The implemented tool includes basic human motions which exploit real human motion data, effective work design features to easily generate variational solutions, embedded ergonomic analyses and checklists to help analyzing different work environment solutions, and to document the design outcome. Four industrial case studies were completed with the tool. The results show that the tool is feasible for individual and group design work, and has positive impacts on the design process and on the way how individuals can influence on her or his future work in production system.
Keywords: Computer aided ergonomics; workplace design; ergonomic analyses; participatory design; posture; motion analysis; digital human model
Investigation on Ergonomics Characteristics of Protective Clothing Based on Capture of Three-Dimensional Body Movements BIBAKFull-Text 856-864
  Huimin Hu; Li Ding; Chunxin Yang; Xiugan Yuan
The objective of this investigation is to measure and document any significant difference in motion performance between the partial pressure suit (PPS) and the common clothing (CC), and therefore to explore the ergonomics evaluation indexes and appraisal methods of protective clothing (PC). This paper presents the results of three human mechanics tests and two operational performance tests conducted on nine male subjects which made possible the comparative evaluation under these two different situations. The human mechanics tests included a range of motion (ROM) test, a grip strength test, and a torque test while the operational performance tests included a target-aiming test and a screwing nuts test. Significant difference was found between the two suits in the ROM test, the grip strength test as well as the target-aiming test. This study demonstrates that motion performances vary significantly between the two suits and ROM together with grip strength can serve as ergonomics evaluation indexes of PC.
Keywords: motion performance; ergonomics evaluation; range of motion (ROM); partial pressure suit (PPS); protective clothing (PC)
Strategy to Operate Cylindrical Interface-Operation Difference According to the Dimension of the Cylinder and That of the Hand BIBAKFull-Text 865-873
  Ohki Kanezashi; Natsuki Miyata; Jun Ota
In this article, we study how users determine the way to operate cylindrical interfaces (lever, switch, etc.) according to their dimensions, shape, and the user's hand dimensions. With a target of avoiding control failure, it is important to estimate user's intuitive operation of a given interface from design. Eight subjects were observed operating different cylinders with various height and diameter. The boundary between the tilting operation and other operations was found to be related to an aspect ratio; the ratio of the diameter to the height. The boundary between the sliding operation and rests was determined by a comparison of hand width with cylinder height. The boundary between the pushing and rotating operations was thought to be related to the length of the distal phalanxes of the fingers.
Keywords: Interface-design; Human-Model; Affordance; Ergonomics
Modeling of Human Head for Custom Wig Production BIBAFull-Text 874-883
  Youngjun Kim; Jungbum Cho; Bohyun Kim; Kunwoo Lee
We propose an innovative 3D wig designing system which would replace the traditional manual method. The customer's head is scanned by a 3D head scanner and the whole design process is computerized. After sending the design data to the wig-making factory through the internet, the data are reproduced by an NC milling machine to make a wig pattern. To realize our integrated 3D wig designing system, various CAD technologies are implemented: 3D scanning, triangular mesh generation, texture mapping, mesh smoothing, mesh splitting, mesh offsetting, 3D sketch using NURBS curve, tool-path generation, etc.
Evaluation of Navy Shipboard Habitability for a Warship Design Using Human Model BIBAKFull-Text 884-893
  Hongtae Kim; Jin H. Park; Hojin Hwang; Chang-Min Lee
Recently, ergonomic design is a key issue in the warship design. Ergonomic ship design aims to improve the safety and convenience of crew and passengers. In this paper, as a basis of analyzing and evaluating ergonomic design criteria and evaluation methods for a warship, existing military design guidelines and navy criteria in the fields of ergonomics were surveyed. Also, the methodology including an ergonomic human model is introduced. Finally, it is shown that the ergonomics evaluation of a design can be performed at the early stage of warship design using Navy Ergonomic Human Model based on Delmia's ERGO.
Keywords: Shipboard habitability; Human model; Warship design
Two Vibration Modes of a Human Body Sitting on a Car Seat -- The Relationship Between Riding Discomfort Affected by the Material Properties of the Seat Cushion and the Two Vibration Modes BIBAKFull-Text 894-903
  Mitsunori Kubo; Fumio Terauchi; Hiroyuki Aoki
The relationship between the properties of flexible polyurethane foam composing seat cushions for standard cars and the riding discomfort evaluated by subjects who sat on the seat were investigated. The properties of five kinds of polyurethane foam were measured using the DMA to define dynamical properties. Riding discomfort was subjectively evaluated by 17 subjects at four frequencies, and the correlation coefficients between the material properties and riding discomfort were analyzed. The results suggested that there were two relationships between material properties and riding discomfort, and that these relationships strongly relied on frequency. Furthermore, a digital human model was created to confirm the influence of frequency on these relationships, which suggested that the relationships affected sensitivity by the change in the vibration mode of the human body-seat vibration system.
Keywords: Riding Discomfort; Vibration Mode; Human Model
The Effects of Human Interaction on Biometric System Performance BIBAKFull-Text 904-914
  Eric P. Kukula; Stephen J. Elliott; Vincent G. Duffy
This paper discusses the impact of human interaction with biometric devices and its relationship to biometric performance. The authors propose a model outlining the Human-Biometric Sensor Interaction and discuss its necessity through case studies in fingerprint recognition, hand geometry, and dynamic signature verification to further understand the human-sensor interaction issues and underlying problems that they present to the biometric system. Human factors, human-computer interaction and digital human modeling are considered in the context of current and future biometric research and development.
Keywords: human-computer interaction (HCI); biometrics; human-biometric sensor interaction (HBSI); digital human modeling (DHM)
Design and Realization of Synthesis Assessment System for Cockpit Ergonomics BIBAKFull-Text 915-922
  Yinxia Li; Kaiying La; Xiugan Yuan
This paper emphasized on how to construct one kind of assessment system based on the standards and specifications for cockpit ergonomic synthesis assessment, and the knowledge of the aviation experts and the experienced pilots. It analyzed the necessity of developing the assessment system, and then presented the basic principal and the function demand of the assessment system. In addition, the key technologies for developing this assessment system were discussed in detail utilizing Visual FoxPro 6.0. This assessment system transforms the assessment model and process into the computer program by the mathematical model, enables the assessment process truly to be operational, and also can reduce the assessment cycle.
Keywords: Cockpit; Ergonomics; Human factors; Human engineering; Fuzzy
Development of a Test-Bed for Synthetical Ergonomics Evaluation of Pilot BIBAKFull-Text 923-928
  Wei Liu; Xiu-gan Yuan; Zhong-qi Liu; Rui Ma; Wei-yong Kang
The study of pilot perception has evolved from examining simple tasks executed in reduced laboratory conditions to the examination of complex, real-world behaviors. A test-bed for evaluating models of pilot behavior in which a set of infrared video-based eyetrackers to monitor subjects' eye movements while they perform a range of complex tasks such as driving, and manual tasks requiring careful eye-hand coordination was developed. The real cockpit platform is provided to subjects as they pilot in a virtual scene; a dual-haptic interface consisting of two touch-screen display devices and a shift allows free control within the cockpit.
Keywords: test-bed; eye tracking; haptic interface; ergonomics
Experimental Research of Evaluation of Temperature Ergonomics of EVA Spacesuit Glove BIBAKFull-Text 929-938
  Han Longzhu; Xiu-gan Yuan
The EVA spacesuit glove is one of the key components which can assure astronauts to achieve EVA tasks in security. Astronauts are subjected to the influence of low temperature when they are performing tasks outside the spaceship. To establish the standard of the ergonomics of the temperature of the glove work is very important. This paper studies the influence of low temperature on the ergonomics of the glove work when the skin surface temperature of the middle fingertip is at normal temperature, 15.60C and 100C respectively, in which the strength, fatigue, sensibility and flexibility are made as evaluation targets. The experiment indicates: the influence on the ergonomics of glove is not obvious when the temperature is controlled at 15.60C. Therefore the temperature of the middle fingertip skin should be controlled above 15.60C in glove design; the influence to the ergonomics of glove is relatively obvious when the temperature is about 100C. The influence on sensibility is the most obvious, and then the influence on fatigue, strength and flexibility is in descending order. The temperature standards of EVA spacesuit glove have practical meaning to design EVA spacesuit.
Keywords: hand; EVA spacesuit glove; ergonomics; low temperature
Digital Humans for Virtual Assembly Evaluation BIBAKFull-Text 939-948
  Dimitris Mavrikios; Menelaos Pappas; Marios Kotsonis; Vassiliki Karabatsou; George Chryssolouris
This paper studies the use of Virtual Reality and Human Simulation for the ergonomic evaluation of manual assembly processes. A virtual environment has been developed to represent the actual workspace where the assembly task took place. Into the virtual workspace, a digital human /mannequin was imported and programmed to simulate the task, in the same manner as it would be done by the actual worker. Based on the posture-based ergonomics analysis, each posture of the digital human has been "translated" into comfort scores, resulting in conclusions, related to the ergonomic efficiency of the process and in the design of the workstation. The conclusions that have been reached identify the critical points, during the assembly task, and lead to the necessary re-design actions in order for the worker's fatigue as well as the task's execution time to be reduced. A real-life assembly task of a commercial refrigerator has been implemented in order for the capabilities of the proposed process design evaluation method to be demonstrated.
Keywords: Virtual Reality; Digital Humans; Virtual Assembly; Process Design Evaluation; Ergonomics Analysis
Foot Digitalization for Last Design and Individual Awareness of Personal Foot Characteristics BIBAFull-Text 949-958
  Paolo Olivato; Manuela Morricone; Enrica Fubini; Alessandra Re
The aim of the present work was to gather data concerning the measurements and the shape of individuals' feet of Italians, to design more ergonomic shoe lasts. The unloaded feet of a sample of 316 participants of Italian ethnicity of 20 different towns located in northern, central, and southern Italy and the Italian islands were digitalized. Results showed significant differences by gender, age, and geographical area. The sample's degree of awareness concerning some of their own foot characteristics and interaction with footwear were also investigated. These findings will be used to design footwear that can provide a good fit for the feet of Italians and, consequently, a greater degree of comfort.
Can We Use Technology to Train Inspectors to Be More Systematic? BIBAKFull-Text 959-968
  Sajay Sadasivan; Anand K. Gramopadhye
Inspection quality is dependent on the ability of inspectors to weed out defective items. When inspection is visual in nature, humans play a critical role in ensuring inspection quality with training identified as the primary intervention strategy for improving inspection performance. However, for this strategy to be successful, inspectors must be provided with the needed tools to enhance their inspection skills. In this article we outline efforts pursued at Clemson University, focusing on the development of computer-based training systems for inspection training and discuss the results of some of the research briefly.
Keywords: Computer Based Training; Visual Inspection; Search Strategy
Enhancing Sense of Reality by Efficient and Precise Collision Detection in Virtual Environments BIBAKFull-Text 969-978
  Chuan-Jun Su
As the foundation of user-system interaction in virtual environments, collision detection is a time-consuming process and few real-time interactive algorithms for general objects developed. Most of the existing methods aim for reducing the computation time for some special cases. Collision detection algorithms developed are either not fast enough for practical applications or restricted to a class of specific model. In fact, a general analysis of the performance of collision detection algorithms is extremely difficult because performance is situation specific. The motivation of this work is to satisfy the real-time interaction and high precision requirements of a Virtual Environment (VE) for applications such as virtual design, virtual assembly, virtual training for manufacturing operations and maintenance.
Keywords: Collision Detection; Virtual Environment; virtual reality
Dynamic Generation of Human-Populated VR Models for Workspace Ergonomic Evaluation BIBAKFull-Text 979-987
  Tien-Lung Sun; Wen-Yang Feng; Chin-Jung Chao
Human-populated VR models have been employed by many researchers to evaluate workspace occupational health and safety (OHS) problems. Previous researches in VR-based ergonomic evaluation have taken a model-based, quantitative approach where human posture data are extracted from virtual space and sent to ergonomic models to calculate numeric results. Such model-based approach requires the VR model to be integrated with complex human models and ergonomic evaluation models. Construction of the virtual workspace thus becomes complicated and difficult, which often stops industrial adoption of the VR technology in ergonomic evaluation. To address this problem, this paper presents an easy-to-construct human-populated VR model to support visualization-based, qualitative workspace OHS evaluation. Details of the workspace layout design and the operation procedure design, and the dynamic VRML modeling to support the workspace design are discussed. Based on the proposed method, a human-populated virtual workspace is implemented to evaluate OHS problem associated with the design of a ship operation room.
Keywords: Virtual reality; VRML; virtual prototype; digital human; occupational health and safety
Effecting Validity of Ergonomics Analysis During Virtual Interactive Design BIBAKFull-Text 988-997
  Renran Tian; Vincent G. Duffy; John McGinley
This paper focuses on validating the performance of virtual interactive design (VID) environment with dynamic ergonomics analysis. Previous studies have only validated VID for posture-based static ergonomics analysis, and applied the methodology on several studies. While since dynamic information is important for ergonomics analysis, this study will investigate the performance of VID environment for ergonomics analysis considering dynamic information such as velocity, which uses motion instead of posture as analysis target.
Keywords: virtual interactive design; ergonomics analysis
Advanced Technology Training for Operating the Microlithography Panel Printer BIBAKFull-Text 998-1007
  Bharat Upadrasta; Mohammad T. Khasawneh; Sarah S. Lam
Electronics packaging plays a crucial role in the manufacturing of advanced microelectronics, with an increased interest in technology that produces greater power functionality in smaller spaces. The recent advances in this field have led to advanced manufacturing techniques, with the insertion of components in the micro- and nano-scales. In particular, the microlithography panel printer uses photolithography to create fine image patterns through reticles on substrate boards. The need for advanced features, updated software skills, and the high cost of human error places an increasing requirement for more efficient operator training at a reduced financial investment. Therefore, this research demonstrates the usefulness of virtual reality in modeling the microlithography machine using high fidelity simulations for training purposes. The development process and the structure of the training simulator is presented, with an outline of its effectiveness in supporting training needs, and a description of its reliability assessment through validation and testing.
Keywords: Virtual reality; electronics packaging; training; modeling; simulation
Ramsis -- The Leading Cad Tool for Ergonomic Analysis of Vehicles BIBAFull-Text 1008-1017
  Peter van der Meulen; Andreas Seidl
Early integration of ergonomics in the vehicle design process requires appropriate CAD tools. 15 years ago, the German car industry developed a new, three-dimensional tool for computer-aided ergonomics and occupant packaging, called RAMSIS. Its goal was to overcome the limitations of two-dimensional human templates, as well as to provide methods for predicting driver postures and comfort. The core of RAMSIS is a highly accurate three-dimensional human model that can be made to simulate occupants with a large variety of body dimensions and based on anthropometry databases from around the world. Extensive research was conducted on driver postures and comfort, which resulted in a probability-based posture prediction model. No subjective manikin manipulation by the user is necessary, so that fast, realistic and consistent analysis results are ensured at all times. An assessment of comfort allows designers to optimize packages with respect to driver comfort early in the design process. RAMSIS offers a number of other analysis tools, for example for vision, reach, force and seat belt studies. Over the years, new research projects have resulted in more sophisticated RAMSIS functions, such as a force-based posture and comfort prediction model, seat belt certification, compatibility with full body laser scanners, simulation of the interaction between seat and occupant and simulation of ingress and egress.
Using Multimodal Technologies to Enhance Aviation Maintenance Inspection Training BIBAKFull-Text 1018-1026
  Carl Washburn; Paris Stringfellow; Anand K. Gramopadhye
Recent collaborative efforts between Greenville Technical College's Aviation Maintenance Technology (Greenville, South Carolina, USA) training facility and Clemson University (Clemson, South Carolina, USA) have lead to significant improvements in Aviation Maintenance Technician training through the use of advanced computer technology. Such applications included: 2.5D and 3D virtual environments of a large-bodied aircraft cargo bay with interaction modalities ranging from fully immersive (using a head-mounted display and 6 degrees-of-freedom mouse) to semi-immersive (using a spatially-tracked suspended, touch-sensitive window display) to non-immersive (using a basic desktop computer and mouse); and 3D virtual environments of turbine engine blades where nondestructive inspection methods (e.g. borescoping) could be practiced. This paper discusses the integration of these technologies into an existing educational curriculum and provides insight as to how such programs might be implemented and evaluated.
Keywords: Education; Virtual Reality; Computer-Based-Training; Aviation Maintenance; Multimodal Instruction
Colored Petri Net Based Formal Airport Control Model for Simulation and Analysis of Airport Control Processes BIBAKFull-Text 1027-1036
  Bernd Werther; Christoph Möhlenbrink; Michael Rudolph
The development of the experimental Remote Tower Operation Human Machine Interface and the new Remote-Controller work position is supported by a cognitive work and task analysis (CWA) of the presently existing work environment and decision processes at airport Leipzig. This paper presents a formal approach for the description of the whole Human Machine System. It is shown how the results of a cognitive work analysis on a medium size airport are transferred into a formal executable human machine model for simulating the controllers work processes in relation to the airport processes. The model is implemented with Colored Petri Nets. The mathematical basis of Petri Nets allows a formal analysis of whole systems. Critical system states and inconsistencies in the human machine system are identified through comparison of knowledge states of the controllers with process states of the airport system by using State Space analysis. The represented formal work process model provides a valuable support for the communication between domain experts and system developers.
Keywords: Airport control model; Human Machine System; Colored Petri Net; State Space; Cognitive work analysis
Research on Modeling of Complicate Traffic Simulation System BIBAKFull-Text 1037-1046
  Jiankun Wu; Linpeng Huang; Jian Cao; Minglu Li; Dejun Wang; Mingwen Wang
With the increasing of traffic complexity, traffic simulation becomes an important approach to deal with the complicated traffic problems; meanwhile, system modeling plays a more and more important role in the simulation systems. Cellular automata provide a simple discrete deterministic mathematical model for physical, biological, and computational systems and are shown to be capable of complicated behavior and generate complex and random patterns, which are very suitable for the description of complicate traffic environment [7]. A simulation model based on agent technology, HLA/RTI technology and expanded cellular automaton is presented in this paper. The simulation model makes the platform expandable and flexible, at the same time, it can provide high-capable computing resources to solve the complex traffic issues. In the traffic entity model aspects, the expanded cellular automata and agent technology were adopted to model the behaviors of passengers, vehicles, traffic signal lights and so on. The optimal scheme for evacuation of traffic disaster, superintendence of large scale activities and design of traffic environment will be obtained through the simulation model.
Keywords: Traffic simulation; Agent; HLA/RTI; Complexity system; Cellular automata
Design and Implementation of Ergonomics Evaluation System of 3D Airplane Cockpit BIBAKFull-Text 1047-1055
  Libo Zhang; Xiugan Yuan; Lijing Wang; Dayong Dong
According to ergonomics factors referred by airplane design department and corresponding standards, structure and function of ergonomics evaluation system of 3D cockpit was designed. Digital human model, based on anthropometry database, comprises 66 segments, 65 joints and 131 degree of freedom. The ergonomics design of man-machine interface can be evaluated in terms of vision, reach and working posture comfort analysis methods and evaluation rules. Interior and exterior visual field of pilot can be achieved with the aid of vision analysis. The comfort of working posture and joints motion can be assessed by reference to joint angles for any selected posture. The details regarding system implementation with technology of OpenGL are discussed at last. The system can be computer-aided tool for airplane designer considering its convenience in using excellent model data interface with other 3D software.
Keywords: 3D airplane cockpit; Digital human model; Ergonomics; Working postural; Comfort
A Novel Method for Cloth-Body Collision Detection BIBAKFull-Text 1056-1063
  Xiaolong Zhu; Shihong Xia; Yong Yu; Tianlu Mao
This paper presents a novel cloth-body collision detection method by using the generalized cross-sectional contour technique, which has two main steps. During preprocessing step, the so-called skin hierarchical structure (Skin-H) of the body is constructed by using the improved generalized cross-sectional contour technique, which doesn't need to be updated in subsequent step. During runtime step, the cloth vertices are projected onto Skin-H structure efficiently, and then the exact collision detection can be done by a ray-triangle test technique at the lowest level of the structure. The simulation result demonstrates that the proposed method has some advantages in algorithm's efficiency, accuracy as well as practicability.
Keywords: Collision Detection; Hierarchical Approaches; Image-Based Methods; Cloth Simulation; Animation