bluuebunny/crossref_metadata_2025 huggingface dataset:
Optic-Flow Based Motion Analysis for Animation
Authors: Yuan Chunrong , Cheng Irene , Basu Anup , Mallot Hanspeter A.
Published: October 2019

Creating graphics animations is often a tedious process that requires days of content creation to make even a short video. In this work, we investigate the role of optic flow in making it easier to automate certain steps in creating animated clips. More specifically, we look into how optic flow can be used to detect and model natural events, such as, waterfall, rainfall, snowfall and so on. An algorithm that can not only detect 2D flow, but also track feature points reliably over video frames is described; followed by experimental results demonstrating its ability in motion analysis and motion synthesis. An example of the steps involved in creating a short animation is also outlined
Permutation Steganography for Polygonal Meshes Based on Coding Tree
Authors: Tu Shihchun , Hsu Hungwei , Tai Wenkai
Published: October 2019

We propose a coding tree for permutation steganography in polygonal meshes. Instead of conceptually building a complete binary tree for remaining embedding/extracting primitives to encode/decode bitstream, our method lengthens bitstream by exploiting the coding tree of the primitives, a binary tree which is a little bit skewed. The coding tree has higher levels than the complete binary tree so that as experimental results show, the average capacity of our approach is more about 0.39 bit/vertex than that of Bogomjakov et al. [5], and the improvement of the maximal capacity comes up to 40% of Bogomjakov et al. [5]. Still, our method has the minimal capacity same with Bogomjakov et al. [5], and is simple and easy to implement as well. This ordering is obtained based on the mesh connectivity [14], making our method robust to geometric affine transformations. Also, the primitive rearrangement does not distort the cover media and cause suspicion of the hidden message
Virtual Environment for an Ants-like Model
Authors: Hamada Mohamed
Published: October 2019

In this paper we introduce an integrated virtual environment of ants-like agents based on ants' behavior. Our system can simulate the behavior of ants-like agents under various conditions and environment changes. In our model the ants are moving in random on an environment that contains a randomly distributed source of food. Ants move with some simple rules and can change direction according to environmental information. We test this model with various situations and conditions of the environment to study how the system works with the pheromone information. In the aim of realizing the practical implication of our model, a web-based computer simulation is given. This simulation enables the study and test for the model under different circumstances of the environmental conditions
Empathy in Social Agents
Authors: Paiva Ana
Published: October 2019

Empathy is seen as the capacity to perceive, understand and experience others' emotions. This notion is often considered as one of the major elements in social interactions between humans. As such, when creating social agents, that are believable and able to engage users in social interactions, empathy needs to be addressed. Indeed, for the past few years, many researchers have been looking at this problem, not only in trying to find ways to perceive the user's emotions, but also to adapt to them, and react in an empathic way. This paper provides a small overview of this new challenging area of research, by analyzing empathy in the social relations established between humans and social agents, and providing a concrete model for the creation of empathic social agents.
Curvature-Dependent Reflectance Function for Interactive Rendering of Subsurface Scattering
Authors: Kubo Hiroyuki , Dobashi Yoshinori , Morishima Shigeo
Published: October 2019

Simulating sub-surface scattering is one of the most effective ways to realistically synthesize translucent materials such as marble, milk or human skin. We have developed a curvature-dependent reflectance function (CDRF) which mimics the presence of subsurface scattering. In this approach, we provide only a single parameter that represents the intensity of theincident light scattered in a translucent material. The parameter is not only provided by curve-fitting to a simulated data-set, but also manipulated by an artist. Furthermore, this approach is easily implementable on a GPU and does not require any complicated pre-processing and multi-pass rendering as is often the case in this area of research.
Persistent Wrinkles and Folds of Clothes
Authors: Kim Byung-Cheol , Oh Seungwoo , Wohn Kwangyun
Published: October 2019

We present a novel approach to woven-cloth simu-lation in order to generate persistent wrinkles and folds. For a couple of decades, our community has identified and mimicked non-linear buckling of cloth based on the mechanical measure-ment of cloth. It has, however, scarcely paid attention to another important aspect of the measurement, the hysteresis of cloth be-haviors, which is the lag of the amount of forces between stress and relaxation. Our interpretation of the measurement indicates that persistent wrinkles and folds develop in part from the hyste-resis of cloth and its associated energy loss. Thus, we establish an adaptive energy model which takes stiffness coefficients and rest posture values not as constants but as variables over time and behavior. As stiffness coefficients and rest posture values change in proportion to the amount of the energy loss, they appear as persistent wrinkles and folds. Consequently, the clothes simulated by our method bring more realism with respect to visual identi-fication for past behaviors of cloth.
Utilizing Roadmaps in Evacuation Planning
Authors: Rodriguez Samuel , Amato Nancy M.
Published: October 2019

In this paper we describe utilization of roadmaps in a general evacuation planning system for complex 3D environments. The problem consists of heterogeneous groups of agents whose behaviors and properties affect usage of the environment when creating evacuation plans. This planning system includes behaviors for those agents evacuating and directors that may be guiding the agents to improve evacuation. One aspect we focus on is modeling different forms of direction and communication between agents.
Methodology for Controlling Contact Forces in Interactive Grasping Simulation
Authors: Rusák Zoltán , Antonya Csaba , Horváth Imre
Published: October 2019

The paper proposes a new methodology to interactively simulate grasping of virtual product prototypes with the goal to evaluate the contact forces between the grasping hand and product as well as the load on the human arm. Interaction between product concepts and the users happens in a virtual environment, in which the user controls a virtual hand interactively. The contact between the virtual hand and the grasped product is simulated and visual feedback is provided to the user. Controlling the virtual hand interactively in real time holds many challenges. One of the challenges is mapping the motion of the user to contact forces, which then results in stable grasping of objects. In this paper we present a new methodology to convert and map the measured position of the real hand into contact forces so that the contact between the virtual hand and the object remains stable. Our approach applies a multi-objective optimization that takes into account the posture and anthropometric properties of grasping hand, as well as the penetration of the hand in the grasped virtual object in order to find the optimal arrangement of contact forces. The paper reports on the principle of our grasping control methodology as well as presents some test cases to show the advantages and disadvantages of the proposed approach.
An Information Model Based Framework for Virtual Micro Surgery
Authors: Cecil Joe , Pirela-Cruz Miguel
Published: October 2019

In this paper we discuss the creation of a virtual reality environment for micro surgery. An information model was developed and used as the basis to understand the complex domain of micro surgery. An information model using a modeling language is used to propel the various simulation activities in the virtual environment. An enterprise level surgical manager, surgical planner and other components work together to enable the functioning of the virtual environment for micro surgery. The creation of a virtual surgical environment will enable surgical residents to learn the appropriate way of managing various conditions with safety considerations to the residents (students) and patients.
Heterogeneous Remote Visualization Framework for Ubiquitous Product Development Activities
Authors: Opiyo Eliab Z. , Horváth Imre
Published: October 2019

Design office, as is known today, is a workplace where various experts gather and develop products. Traditionally, the trend in engineering product development has been to use desktop computers, virtual reality systems and other systems and devices placed in specific workplace locations. Clearly, these sorts of stationary support tools are desirable because they matchup the product development methodological frameworks that have prevailed over the past several decades. With the availability of a wide spectrum of improved mobile and wireless communication technologies coupled with increased network bandwidth and enhanced software for mobile data-communication networks, design researchers now have new opportunity of exploring and coming up with concrete recommendations on how these technologies should be utilized in product development. Therefore, the work reported in this paper aimed at investigating how to take advantage of these technologies and how the product developers can benefit from the capabilities provided by both portable and non-portable information and communication devices. The focus was specifically on the challenge of visualization of product data and models remotely. The main characteristic requirements for a remote product visualization environment have been formulated and used as the basis for creation of a generic framework. It has been shown that the proposed framework meets some of the key requirements.
Mixed Reality System for Ergonomic Assessment of Driver's Seat
Authors: Caruso Giandomenico
Published: October 2019

Virtual Reality techniques are more and more used to validate the design hypotheses during different phases of the product development. In the automotive field, however, there are some types of analyses that are unlikely to be performed by using only a Virtual Prototype (VP) of the vehicle. Therefore, the trend is to develop systems -called seating bucks- that enable engineers to integrate virtual and real objects to provide a tangible interface for the VP of the vehicle. This research aims at defining a new system and an evaluation protocol to improve, simplify and speed up the usual activities carried out for the ergonomic assessment of the driver's seat. In particular, we are interested in evaluating the ergonomics of car's dashboard with its knobs, buttons, display and other control systems. In this paper, we have described the development of this system by providing useful information about the physical issues, related to the seating buck structure, and about the development of the MR environment. The system and the evaluation protocol have been validated by performing several testing sessions with users. The tests confirm the effectiveness of our approach and have enabled us to achieve at interesting considerations.
Digital Analysis and Visualization of Swimming Motion
Authors: Kirmizibayrak Can , Honorio Jean , Jiang Xiaolong , Mark Russell , Hahn James K.
Published: October 2019

Competitive swimming is a demanding sport that requires rigorous training to achieve technical perfection. Research on computer simulations of flow have improved our understanding of how thrust and drag can be optimized for better performance. However, for a swimmer translating this information to technical improvement can be difficult. In this paper, we present an analysis and visualization framework for swimming motion that uses virtual reality to display 3-dimensional models of swimmers. The system allows users to digitize their motions from video sequences, create personalized virtual representations by morphing prototypical polygonal models, visualizing motion characteristics and comparing their motions to other competitors stored in a library. The use of virtual reality alleviates many problems associated by the current video-based visualization methods for analyzing swimming motion
Full Control of Virtual Objects Manipulation Based on the Images of Real Ones
Authors: Nini Brahim
Published: October 2019

This work deals with the virtual manipulation of a real object through its images. The results presented in this paper give a movie-based solution to the simulation process. We show how the simulation of infinite virtual views of a moving object can be reached using a finite number of object's taken images stored in an organized way. The basis of this solution is an analytical geometry-based method that links explicit applied user's actions, resulting in an object's views change, and images that match the best such views. This paper presents an overall solution for these three intertwined parts of the virtual manipulation that involves six degrees of freedom. Hence, a user is able to freely manipulate a virtual object in a scene in whatever manner s/he likes. In this case, the actions are transformed into rotations and/or translations which lead to some changes in object's appearance, both covered by two viewing features: zoom and/or rotations
Image Texture Feature Extraction Method Based on Regional Average Binary Gray Level Difference Co-occurrence Matrix
Authors: Yang Jian , Guo Jingfeng
Published: October 2019

Texture feature is a measure method about relationship among the pixels in local area, reflecting the changes of image space gray levels. This paper presents a texture feature extraction method based on regional average binary gray level difference co-occurrence matrix, which combined the texture structural analysis method with statistical method. Firstly, we calculate the average binary gray level difference of eight-neighbors of a pixel to get the average binary gray level difference image which expresses the variation pattern of the regional gray levels. Secondly, the regional co-occurrence matrix is constructed by using these average binary gray level differences. Finally, we extract the second-order statistic parameters reflecting the image texture feature from the regional co-occurrence matrix. Theoretical analysis and experimental results show that the image texture feature extraction method has certain accuracy and validity
A Virtual Touch Interaction Device for Immersive Applications
Authors: Gallotti Rodrigues Paulo , Raposo Alberto Barbosa , Soares Luciano Pereira
Published: October 2019

Traditional interaction devices such as computer mice and keyboards do not adapt very well to immersive envi-ronments, since they were not necessarily designed for users who may be standing or in movement. Moreover, in the current inte-raction model for immersive environments, based on wands and 3D mice, a change of context is necessary in order to execute non-immersive tasks. These constant context changes from im-mersive to 2D desktops introduce a rupture in user interaction with the application. The objective of this work is to study how to adapt interaction techniques from touch surface based systems to 3D virtual environments to reduce this physical rupture from the fully immersive mode to the desktop paradigm. In order to do this, a wireless glove (v-Glove) that maps to a touch interface in a vir-tual reality immersive environment was developed, enabling it to interact in 3D applications. The glove has two main functionalities: tracking the position of the user's index finger and vibrating the fingertip when it reaches an area mapped in the interaction space to simulate a touch feeling. Quantitative and qualitative analysis were performed with users to evaluate the v-Glove, comparing it with a gyroscopic 3D mouse.
A Collaborative Virtual Reality Oil and Gas Workflow
Authors: Dos Santos Ismael H. F. , Soares Luciano P. , Carvalho Felipe , Raposo Alberto
Published: October 2019

The current way of designing industrial plants relies on the communication among experts in the field, and on tools that allow the simulation of the site. Virtual reality (VR) tools are used to visualize and interact with complex 3D environments in real time, and several engineering simulations employ VR to foresee the results of complex industrial operations. The research project described here presents a Service Oriented Architecture aimed to create a collaborative environment, called CEE (Collaborative Engineering Environment) that integrates VR techniques into a system where the execution of different sequences of engineering simulations is modeled as scientific workflows. The focus of this research is on the oil and gas industry, particularly offshore engineering, where the project of a new production unit is a lengthy, expensive and usually is conducted by different specialists who are geographically distributed. Among the integrated engineering simulations are those involving structural calculus, hydrodynamics, naval engineering with mooring systems, meteo-oceanography, and others. The main objective is to improve the users' interpretation capacity and skills while providing visualization tools for a better understanding of the results.
Exploring Dynamic Character Motion Techniques for Games Development
Authors: Ismail Ismahafezi , Sunar Mohd Shahrizal , Suhaimi Yusof Cik
Published: October 2019

3D character development is very important part in the character animation. Currently, animation researchers try to control their virtual character joint and make their character motion more realistic and look like real human movement. Using motion capture technology, input data for character movement can be manipulated. This paper presents a current motion research in the real time animation character and focused in dynamic motion control considering physic for game development. From this paper, the researcher can get better understanding what is the main issues and relevant technique that used by the recent researchers in this area. This review focuses on three main parts in dynamic motion generation with physics consideration and control: skeleton hierarchy and kinematics, motion capture data animation, and active dynamic control.
Evaluation of Gesture Based Interfaces for Medical Volume Visualization Tasks
Authors: Kirmizibayrak Can , Radeva Nadezhda , Wakid Mike , Philbeck John , Sibert John , Hahn James
Published: October 2019

Interactive systems are increasingly used in medical applications with the widespread availability of various imaging modalities. Gesture-based interfaces can be beneficial to interact with these kinds of systems in a variety of settings, as they can be easier to learn and can eliminate several shortcomings of traditional tactile systems, especially for surgical applications. We conducted two user studies that explore different gesture-based interfaces for interaction with volume visualizations. The first experiment focused on rotation tasks, where the performance of the gesture-based interface (using Microsoft Kinect) was compared to using the mouse. The second experiment studied localization of internal structures, comparing slice-based visualizations via gestures and the mouse, in addition to a 3D Magic Lens visualization. The results of the user studies showed that the gesture-based interface outperform the traditional mouse both in time and accuracy in the orientation matching task. The traditional mouse was the superior interface for the second experiment in terms of accuracy. However, the gesture-based Magic Lens interface was found to have the fastest target localization time. We discuss these findings and their further implications in the use of gesture-based interfaces in medical volume visualization, and discuss the possible underlying psychological mechanisms why these methods can outperform traditional interaction methods
Developing Physics Simulation in Augmented Reality
Authors: Liu Damon Shing-Min , Yung Chun-Hao , Chung Cheng-Hsuan
Published: October 2019

Use of a physics engine to drive a virtual scene is becoming more common. Physics simulations aim to model the behaviors of objects in space so as to provide realistic motions in computer animation, thereby enriching the interaction and user experience in augmented reality. In this paper, we present a cross-platform environment in which handheld and desktop-computer users can collaborate with each other in a shared scene to accomplish physically realistic experiences during the course of interaction. In realizing the system, we explore and exploit several novel techniques, including bare-hand manipulation, a client/server computing framework, a tangible mobile phone interface, and a distributed scene graph structure. To demonstrate the effectiveness of the system, we developed JengAR, a simulation of the well-known tower building game
Touching the Void: Exploring Virtual Objects through a Vibrotactile Glove
Authors: Giannopoulos Elias , Pomes Ausias , Slater Mel
Published: October 2019

This paper describes a simple low-cost approach to adding an element of haptic interaction within a virtual environment. Using off-the-shelf hardware and software we describe a simple setup that can be used to explore physically virtual objects in space. This setup comprises of a prototype glove with a number of vibrating actuators to provide the haptic feedback, a Kinect camera for the tracking of the user's hand and a virtual reality development environment. As proof of concept and to test the efficiency of the system as well as its potential applications, we developed a simple application where we created 4 different shapes within a virtual environment in order to try to explore them and guess their shape through touch alone.
Do-It-Yourself Interface Device Prototyping for Virtual Reality
Authors: Wins Peter , Basu Aryabrata , Johnsen Kyle
Published: October 2019

the off-the-shelf virtual reality community is well aware of the wide variety of inexpensive and robust tracking and display technologies that have emerged from the entertainment industry in recent years. Alongside these developments, there has also been a vast improvement in the accessibility and usability of hobbyist-grade electronics components, which make incorporating lower-level sensing and actuation components into virtual reality systems feasible for even novices in electronics. Combined, these developments have formed the foundation for a renaissance of do-it-yourself interface device prototyping. Development of novel virtual reality interface devices has been simplified to the point that it can be commonplace in virtual reality system design, rather than an exception. This article discusses a variety of ways in which off-the-shelf electronics and devices can be leveraged and combined in virtual reality experiences, and the knowledge required to begin exploring possibilities, through case studies in prototyping virtual reality experiences.
Design and Implementation of Virtual Xinjiang Carpet Pattern Museum
Authors: Peng Hong , Zhang Mingmin
Published: October 2019

Xinjiang carpet design is the art treasure among the treasure house of Chinese culture. Virtual museum is the function carrier which collects and promotes the national culture. Through the analysis of the virtual experience interactive technical characteristic, the paper proposed "the scene roaming: interactive control operation: interactive content show" design method. And realized the interactive experience technology based on the users and the products through the unity3D, and also enriched the display mode of virtual Xinjiang carpet design museum.
A More Flexible Approach to Utilizing Depth Cameras for Hand andTouch Interaction
Authors: Butkiewicz Thomas
Published: October 2019

Many researchers have utilized depth cameras for tracking user's hands to implement various interaction methods, such as touch-sensitive displays and gestural input. With the recent introduction of Microsoft's low-cost Kinect sensor, there is increased interest in this strategy. However, a review of the existing literature on these systems suggests that the majority suffer from similar limitations due to the image processing methods used to extract, segment, and relate the user's body to the environment/display. This paper presents a simple, efficient method for extracting interactions from depth images that is more flexible in terms of sensor placement, display orientation, and dependency on surface reflectivity.
EDITORIAL The International Journal of Virtual Reality Vol.15 n°1
Authors: Richir Simon
Published: October 2019

Special Issue - Best Papers of Virtual Reality International Conference (VRIC'14)
Learning to replace a human: A virtual performing agent
Authors: McCormick John , Hutchison Steph , Nash Adam , Vincs Kim , Nahavandi Saeid , Creighton Douglas
Published: October 2019

In this paper we describe two artworks, Recognition, an outdoor interactive installation and Instrumental a live dance performance. In both works a performing agent has learnt sequences of movement from a dancer and uses these to stand in for a human performer. The agent uses an Artificial Neural Network to learn to dance from the human dancer and can perform in the human's stead. In Recognition the agent's movement is used when there are no humans present in order to keep continuity of the installation. In Instrumental the agent becomes a performing partner of a live human dancer, able to recognize the dancers movement and synthesize movement sequences based on the human dancer's movements.
Reflections on the state of developing virtual environments
Authors: Ray Andrew
Published: October 2019

Virtual environments (VEs) demonstrate the immense potential computer technology can provide to society. VEs have been created for almost two decades, but standardized tools and procedures for their creation do not exist. Numerous efforts to create tools for creating VEs have come and gone, but there is little consensus among tool creators for establishing a common subset of standard features that developers can expect. Currently, developers use one of many Virtual Reality (VR) toolkits to create a VE. However, VR toolkits are problematic when it comes to interoperability between applications and other VR toolkits. This paper investigates why the development tools are in this state. A discussion on the history of VR toolkits and developer experiences is used to show what developers face when they create a VE. Next, Three Dimensional Interaction Technique (3DIT) toolkits are introduced to show a new way of developing some parts of VEs. Lastly, a vision for the future of VE development that may help improve the next generation of toolkits is presented.
EDITORIAL The International Journal of Virtual Reality (2016)
Authors: Buche Cédric
Published: October 2019

Editorial IJVR 16-1
Eukaryo: An AR and VR Application for Cell Biology
Authors: Yuen Douglas , Santoso Markus , Cartwright Stephen , Jacob Christian
Published: October 2019

Eukaryo is a simulated bio-molecular world that allows users to explore the complex environment within a biological cell. Eukaryo was developed using Unity, leveraging the capabilities and high performance of a commercial game engine. Through the use of MiddleVR, our tool can support a wide variety of interaction platforms including 3D virtual reality (VR) environments, such as head-mounted displays, augmented reality (AR) headsets, and large scale immersive visualization facilities. Our interactive, 3-dimensional model demonstrates key functional elements of a generic eukaryotic cell. Users are able to use multiple modes to explore the cell, its structural elements, its organelles, and some key metabolic processes. In contrast to textbook diagrams and even videos, Eukaryo immerses users directly in the biological environment, giving a more effective demonstration of how cellular processes work, how compartmentalization affects cellular functions, and how the machineries of life operate.
DREAM Project: Decreasing REcurrent pain and Anxiety in Medical procedures on a pediatric population
Authors: Le May Sylvie , Paquin David , Bouchard Stéphane , Fortin Jean-Simon , Khadra Christelle
Published: October 2019

The DREAM project is a joint venture between the medical world, university professors and developers with one goal in mind: create an efficient distraction tool to reduce pain and anxiety in children receiving medical treatments. Growing evidence in the medical literature suggests that virtual reality is a very potent and effective way of creating distraction. In turn, distraction has been shown to reduce pain and anxiety in children who are receiving painful medical procedures. The pediatric population offers quite a challenge when it comes to pain control, especially the pain caused by medical procedure. Anxiety and anticipation greatly modulates pain perception and can often jeopardize a treatment if a child's collaboration cannot be obtained. With those premises in mind, our team is trying to create an efficient virtual reality game for distracting kids from their pain. The DREAM game has been tailored for the very specific needs and characteristics of our target population. The experience is optimized for the oculus rift and the controls have been simplified to work in various medical settings with minimal preparation time. Our main concern was to create a game that delivers a potent distractive effect while inciting almost no side effects or cyber sickness. The DREAM project is currently being tested on children with burn injuries. The objective of this paper is to present the methodology used to validate our hypotheses.
Worm Selector: Volume Selection in a 3D Point Cloud Through Adaptive Modelling
Authors: Dubois Emmanuel , Hamelin Adrien
Published: October 2019

3D point clouds are more and more widely used, especially because of the proliferation of manual and cheap 3D scanners and 3D printers. Due to the large size of the 3D point clouds, selecting part of them is very often required. Existing interaction techniques include ray/cone casting and predefined or free-form selection volume. In order to cope with the traditional trade-off between accuracy, ease of use and flexibility of these different forms of selection techniques in a 3D point cloud, we present the Worm Selector. It allows to select complex shapes while remaining simple to use and accurate. Using the Worm Selector relies on three principles: 1) points are selected by progressively constructing a cylinder-like shape (the adaptative worm) through the sequential definition of several sections; 2) a section is defined as a set of two contours linked together with straight lines; 3) each contour is a freely drawn closed shape. A user study reveals that the Worm Selector is significantly faster than a classical selection mechanism based on predefined volumes such as spheres or cuboids, while maintaining a comparable level of precision and recall.
Physiological Responses to Virtual Exergame Feedback for Individuals with Different Levels of Exercise Self-Efficacy
Authors: Cornick Jessica E. , Blascovich Jim
Published: October 2019

OBJECTIVE: Exercise videogames are increasingly popular as individuals seek to increase their activity. This study assessed the interaction of exercise self-efficacy (ESE) levels and perceived task demands of a virtual game on exercise and physiological reactions. Perceived task demands were manipulated by changing parameters of the participant's avatar in the exergame. METHODOLOGY: An experimental design was used with 89 female undergraduate students (Mean age=18.74+1.05, 18 to 21 years) who were randomly assigned to the high task demand condition (avatar weight remaining constant) or low task demand condition (avatar losing weight). Prior to the biking task, the Exercise Self-Efficacy scale was used to measure ESE. Participants biked on a stationary bike while immersed in a virtual environment with an avatar and were told the avatar would slim if they cycled fast enough. Only half of participants' avatars actually slimmed (high task demand manipulation). During biking, cardiovascular measures were assessed using a Biopac MP150 system with an Impedance Cardiograph and CNAP Monitor 500. One week after completion of the study, participants reported amount of exercise completed in the last week (in 15 minute increments) via the Physical Activity Questionnaire. Moderated regressions and moderated mediation models were used to examine the interaction of ESE levels, experimental condition and cardiovascular reactivity on amount of strenuous physical activity. RESULTS: Individuals with high ESE showed similar results in both task demand conditions with physiological reactivity patterns indicative of threat. Individuals with low ESE with a static avatar completed less exercise than those with low ESE with a slimming avatar. CONCLUSION: Results confirm that individuals with low ESE are particularly vulnerable to exercise demands.
Exploring Mixed-methods Instruments for Performance Evaluation of Immersive Collaborative Environments
Authors: Dupont Laurent , Pallot Marc , Morel Laure , Christmann Olivier , Boly Vincent , Richir Simon
Published: October 2019

Presently, there is a clear trend for both businesses and public institutions to move towards open or collaborative innovation. Nevertheless, engaging all stakeholders, especially users, for cocreating innovative solutions and usage scenarios is, as revealed in previous studies, not so obvious. We do believe that Immersive and Collaborative Environments (ICEs) based on the use of Virtual, Augmented and Mixed Reality technologies would be the right place for co-creating, exploring, experimenting and evaluating innovative ideas and concepts in order to quickly reach a common understanding. However, there is a need to design a proper method and instruments that would allow evaluating and comparing ICEs. Our previous paper presented the outcomes of an investigation to identifying and disentangling factors characterising a group immersion and collaboration in the context of co-creation. As a step further, this paper reports about our exploratory study towards the design of mixed methods quantitative and qualitative instruments for the evaluation of Immersive and Collaborative Environments (ICE) based on previously identified factors.
Towards a low-cost interactive system for motor self-rehabilitation after stroke
Authors: David Ludovic , Bouyer Guillaume , Otmane Samir
Published: October 2019

Virtual reality technologies have been experimented for several years for post-stroke motor rehabilitation, but there is too little diffusion of these systems among medical facilities and none among patients. Our objective is the development of an interactive system to assist motor rehabilitation of the upper limb after a stroke, which retains the medical benefits of traditional post-stroke methods while reducing human costs (usable with minimal supervision) and materials (general public), and facilitating active patient participation. System architecture, 3D interactions and virtual content are based on an iterative, user-centered design methodology with patients and therapists. The system allows users to perform repetitive and intensive tasks with the upper limb. The paretic hand is tracked with a low-cost depth sensor. Kinematic performance is monitored and visual feedbacks are proposed. Preliminary tests were conducted on a non-immersive prototype, with eight patients and a target pointing task. The results showed good usability and high acceptance from the users.
EDITORIAL - IJVR 17(3)
Authors: Buche Cédric
Published: October 2019

Editorial IJVR 17-3
An Agent-Aware Computing Based Mixed Reality Information System
Authors: Liu Charles Z. , Kavakli Manolya
Published: October 2019

In this paper, we present an agent- aware computing based collaborative information sys- tem scheme for MR applications. The HCI issues in VR, AR, and MR, have been discussed firstly. Besides the equipment, the lack of understanding of users also ac- counts for a significant bottleneck of improving user ex- perience and immersion during the interaction. Aiming at the issues, an agent-aware computing based scheme is proposed and implemented. The corresponding sys- tematic scheme is presented in the views of functional- ity, modules and system workflow and discussed in de- sign, implementation, and system synthesis. By means of the human-aware computing, system-aware comput- ing and human-system aware computing, issues such as mixed reality fusion, QoE-QoS management, confiden- tiality, and security, are addressed by the applying agent- aware computing based scheme into an implementation of the collaborative information system for mixed real- ity. Related modules along with their function and test results are given and discussed.
Effects of Interaction Level, Framerate, Field of View, 3D Content Feedback, Previous Experience on Subjective User eXperience and Objective Usability in Immersive Virtual Environment
Authors: Tcha-Tokey Katy , Loup-Escande Emilie , Christmann Olivier , Richir Simon
Published: October 2019

This paper investigates the effects of interaction level, framerate, field of view, 3D content feedback and previous experience on subjective User eXperience (i.e., presence, engagement, immersion, flow, emotion, skill, experience consequence, judgement, technology adoption) and objective usability in immersive virtual environment. Data were collected from a series of five sub- experiments (i.e., one for each influential factor) that involved a total of 152 individuals. The participants were asked to use the "Think and Shoot" immersive virtual environment and to complete a User eXperience questionnaire. Their subjective perceptions and objective measures were collected and analyzed. The results revealed that interactivity level and previous experience had an effect on subjective User eXperience and on objective usability. Framerate and field of view had an effect on objective usability. Finally, 3D content feedback had no significant influence on User eXperience. From these findings, key points for User eXperience practitioners are proposed.
EDITORIAL - IJVR 18(2)
Authors: Buche Cédric
Published: October 2019

Editorial IJVR 18-2
Hardware Design for an Electro-Mechanical Bicycle Simulator in an Immersive Virtual Reality Environment
Authors: Powell Jaemin , Stroh Oliver , Thomas Geb W.
Published: October 2019

Roughly 50,000 people are injured in bicycle collisions with motor vehicles each year. The Hank Bicycle Simulator provides a virtual environment to study and reduce this risk by safely investigating the interaction of bicycle riders and traffic, particularly for bicyclists crossing streets. The bicycle simulator design focuses on the bicycle and rider inertia, the predominant dynamic element for riders moving from a stopped position. The Hank Bicycle Simulator's flywheel provides instantaneous inertial response while a servomotor provides simulated wind resistance to pedaling. This work describes the simulator design and a validation experiment that compares the simulator performance to theoretical predictions. The Hank Bicycle Simulator achieved initial acceleration with less than 0.20% error at realistic rider weights. The observed terminal velocity achieved less than 3.75%, with smaller errors for heavier riders. This allowed the rider to cross a street with about a 60 ms time difference between the simulator and a real-life rider. The Hank Bicycle Simulator was also validated through various physical experiments measuring the system inertia, the time delay of the electrical components, and overall system performance. Such careful system validation for a mechanical feedback system is relatively rare in simulation research and is unique among previous reports of bicycle simulators.
ConVRgence (VRIC) Virtual Reality International Conference Proceedings
Authors: Richir Simon
Published: October 2019

Find the articles presented at the 3 days scientific conference ConVRgence (VRIC) which take place during Laval Virtual 2019 (April 20-22).
Identifying Cybersickness through Heart Rate Variability alterations
Authors: Garcia-Agundez Augusto , Reuter Christian , Caserman Polona , Konrad Robert , Göbel Stefan
Published: October 2019

Numerous users of Head Mounted Displays develop symptoms similar to motion sickness. This phenomenon is known as cybersickness. The current standard method to evaluate it is the Simulator Sickness Questionnaire (SSQ). Additionally, detection by methods such as biosignals is possible, but it requires sophisticated equipment and expertise. In order to detect early cybersickness symptoms, the availability of real-time detection by using simple equipment, such as a 2-lead ECG, would be highly useful. This contribution aims to analyze the feasibility of detecting cybersickness with a simple 2 lead ECG. A total of 13 participants played the VR game QuakeVR wearing an Oculus Rift DK2 for 15 minutes, during which a 2-lead ECG was recorded. Addiionally, pre- and post-SSQ questionnaires were given. Four of 13 participants had to end the experiment prematurely due to cybersickness. The difference in SSQ scores is statistically significant (p<.01), as is the ECG (p=.02), in these participants. This study shows the utility of a simple 2-lead ECG to detect cybersickness. These findings raise the possibility of real-time monitoring and prediction of cybersickness with simple devices and open the question of whether photoplethysmography could be used with the same purpose.
Politika i pozorište kao čuvari zajedničkog sveta
Authors: Kovačević Bojan
Published: October 2019

Autor zastupa tezu da u istoriji evropske drame i pozorišta leži originalan odgovor na pitanje odnosa između poretka i promene koje je u središtu preokupacija klasičnih političkih mislilaca. Pozorište ima temeljni zadatak očuvanja zajedničkog sveta bez koga i samo ostaje lišeno smisla postojanja. Gurnuvši nas isprva u provaliju zapitanosti nad smislom, veliki dramski pisci nas potom iz nje izvlače odgovorom koji je njihovoj mašti šapnulo doba u kojem su živeli. Oni među njima koji su postojeći poredak čuvali, poput Eshila, Molijera i Rasina, gledaocima su obznanjivali njegovu utemeljujuću ideju. Oni, poput Getea i Šilera, čiji je umetnički genij u istoriji prepoznao svrhoviti razvoj ka republici slobodnih građana, pozorište su koristili kao mesto estetskog poučavanja društvene elite od koje se očekuje da dolazak novog zajedničkog sveta ubrza. Za stvaraoce u revolucionarnim vremenima, poput Brehta i Pirandela, pozorišne daske služile su kao nadahnuće za radikalnu promenu svih postojećih društvenih i političkih ustanova. Konačno, autorima poput Euripida, Ibzena, Čehova i Strindberga pozorište je omogućilo da zavape za starim svetom koji je ostao bez svoje ideje o poretku i zato nestaje.
Geochronology and Geochemistry of Archean TTG and Tremolite Schist Xenoliths in Yemadong Complex: Evidence for Mesoarchean Continental Crustal Evolution in Kongling High-grade Metamorphic Terrane, Yangtze Craton, China
Authors: Wei Yunxu , Zhou Wenxiao , Hu Zhengxiang , Huang Xianxiao , Li Haiquan , Zhao Xiaoming
Published: October 2019

The origin and significance of the tonalite–trondhjemite–granodiorite (TTG) units and the familiar metabasite xenoliths they host in the Yangtze Craton, China, remain controversial, and resolving these issues is important if we are to understand the evolution of the early Yangtze Craton. We focused on biotite–tremolite schist xenoliths in the Archean TTG units of the Kongling high-grade metamorphic terrane, and U–Pb dating of their zircons yielded 207Pb/206Pb ages of ca. 3.00 Ga, which provides a minimum age for the formation of the pre-metamorphic basic igneous rock. The host TTGs and late intrusive granitic dikes yield three groups of upper intercept ages at 2.87–2.88, 2.91–2.94, and 3.07 Ga, and a concordant age at 2.94 Ga, which suggest that the Yangtze continental nucleus underwent three important metamorphic–magmatic events in the Mesoarchean at ca. 3.00, 2.94, and 2.87 Ga. The biotite–tremolite schists have high ratios of K2O/Na2O and high contents of CaO, Cr, and Ni, thus showing the characteristics of high-K calc-alkaline island-arc volcanic rocks (basalt–andesite) that form by the partial melting of subducted oceanic crust. The data also provide further proof that a Mesoarchean metamorphic basement exists in the Yangtze Plate. Derivation of the magmatic protoliths of the biotite–tremolite schist enclaves from an oceanic crust during slab subduction, and the presence of these xenoliths within the TTG suite, indicate the existence of the initiation of plate tectonics during the Mesoarchean (≤2.94 Ga).
Online Subspace Tracking of Sensors Data for Damage Propagation Modeling and Predictive Analytics
Authors: Khan Farhan
Published: October 2019

We analyze damage propagation modeling of turbo-engines in a data-driven approach. We investigate subspace tracking assuming a low dimensional manifold structure and a static behavior during the healthy state of the machines. Our damage propagation model is based on the deviation of the data from the static behavior and uses the notion of health index as a measure of the condition. Hence, we incorporate condition-based maintenance and estimate the remaining useful life based on the current and previous health indexes. This paper proposes an algorithm that adapts well to the dynamics of the data and underlying system, and reduces the computational complexity by utilizing the low dimensional manifold structure of the data. A significant performance improvement is demonstrated over existing methods by using the proposed algorithm on CMAPSS Turbo-engine datasets.
Quasi Cubic Trigonometric Curve and Surface
Authors: Zhang Guicang , Wang Kai
Published: October 2019

Firstly, a new set of Quasi-Cubic Trigonometric Bernstein basis with two tension shape parameters is constructed, and we prove that it is an optimal normalized totally basis in the framework of Quasi Extended Chebyshev space. And the Quasi-Cubic Trigonometric Bézier curve is generated by the basis function and the cutting algorithm of the curve are given, the shape features (cusp, inflection point, loop and convexity) of the Quasi-Cubic Trigonometric Bézier curve are analyzed by using envelope theory and topological mapping; Next we construct the non-uniform Quasi-Cubic Trigonometric B-spline basis by assuming the linear combination of the optimal normalized totally positive basis have partition of unity and continuity, and its expression is obtained. And the non-uniform B-spline basis is proved to have totally positive and high-order continuity. Finally, the non-uniform Quasi Cubic Trigonometric B-spline curve and surface are defined, the shape features of the non-uniform Quasi-Cubic Trigonometric B-spline curve are discussed, and the curve and surface are proved to be continuous.