BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons comb...BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.展开更多
Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strate...Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental immersion.However,the impact of virtual agent size and form on interaction performance remains unclear.Methods Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR environments.The first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent sizes.Participants,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a mouse.They completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and preferences.Results Results from the first experiment revealed that agents matching physical object size produced the best overall performance.The second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces immersion.To balance efficiency and immersion,frameless agents matching physical object sizes were deemed optimal.Conclusions Virtual agents matching physical entity sizes enhance user experience and interaction performance.Conversely,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual spaces.This study provides valuable insights for the future development of MR systems.展开更多
Nowadays,with the significant growth of the mobile market,security issues on the Android Operation System have also become an urgent matter.Trusted execution environment(TEE)technologies are considered an option for s...Nowadays,with the significant growth of the mobile market,security issues on the Android Operation System have also become an urgent matter.Trusted execution environment(TEE)technologies are considered an option for satisfying the inviolable property by taking advantage of hardware security.However,for Android,TEE technologies still contain restrictions and limitations.The first issue is that non-original equipment manufacturer developers have limited access to the functionality of hardware-based TEE.Another issue of hardware-based TEE is the cross-platform problem.Since every mobile device supports different TEE vendors,it becomes an obstacle for developers to migrate their trusted applications to other Android devices.A software-based TEE solution is a potential approach that allows developers to customize,package and deliver the product efficiently.Motivated by that idea,this paper introduces a VTEE model,a software-based TEE solution,on Android devices.This research contributes to the analysis of the feasibility of using a virtualized TEE on Android devices by considering two metrics:computing performance and security.The experiment shows that the VTEE model can host other software-based TEE services and deliver various cryptography TEE functions on theAndroid environment.The security evaluation shows that adding the VTEE model to the existing Android does not addmore security issues to the traditional design.Overall,this paper shows applicable solutions to adjust the balance between computing performance and security.展开更多
The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments...The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments and virtual sensor models. In the context of this, the present paper documents the development of a sensor model for depth estimation of virtual three-dimensional scenarios. For this purpose, the geometric and algorithmic principles of stereoscopic camera systems are recreated in a virtual form. The model is implemented as a subroutine in the Epic Games Unreal Engine, which is one of the most common Game Engines. Its architecture consists of several independent procedures that enable a local depth estimation, but also a reconstruction of a whole three-dimensional scenery. In addition, a separate programme for calibrating the model is presented. In addition to the basic principles, the architecture and the implementation, this work also documents the evaluation of the model created. It is shown that the model meets specifically defined requirements for real-time capability and the accuracy of the evaluation. Thus, it is suitable for the virtual testing of common algorithms and highly automated driving functions.展开更多
This paper presents research into applying virtual environment (VE) technology to supply chain management (SCM). Our research work has employed virtual manufacturing environments to represent supply chain nodes to sim...This paper presents research into applying virtual environment (VE) technology to supply chain management (SCM). Our research work has employed virtual manufacturing environments to represent supply chain nodes to simulate processes and activities in supply chain management. This will enable those who are involved in these processes and activities to gain an intuitive understanding of them, so as to design robust supply chains and make correct decisions at the right time. A framework system and its hierarchical structure for visualising and simulating supply chains in virtual environments are reported and detailed in this paper.展开更多
Collision avoidance decision-making models of multiple agents in virtual driving environment are studied. Based on the behavioral characteristics and hierarchical structure of the collision avoidance decision-making i...Collision avoidance decision-making models of multiple agents in virtual driving environment are studied. Based on the behavioral characteristics and hierarchical structure of the collision avoidance decision-making in real life driving, delphi approach and mathematical statistics method are introduced to construct pair-wise comparison judgment matrix of collision avoidance decision choices to each collision situation. Analytic hierarchy process （AHP） is adopted to establish the agents＇ collision avoidance decision-making model. To simulate drivers＇ characteristics, driver factors are added to categorize driving modes into impatient mode, normal mode, and the cautious mode. The results show that this model can simulate human＇s thinking process, and the agents in the virtual environment can deal with collision situations and make decisions to avoid collisions without intervention. The model can also reflect diversity and uncertainly of real life driving behaviors, and solves the multi-objective, multi-choice ranking priority problem in multi-vehicle collision scenarios. This collision avoidance model of multi-agents model is feasible and effective, and can provide richer and closer-to-life virtual scene for driving simulator, reflecting real-life traffic environment more truly, this model can also promote the practicality of driving simulator.展开更多
In this paper, we present a framework for the generation and control of an Internet-based 3-dimensional game virtual environment that allows a character to navigate through the environment. Our framework includes 3-di...In this paper, we present a framework for the generation and control of an Internet-based 3-dimensional game virtual environment that allows a character to navigate through the environment. Our framework includes 3-dimensional terrain mesh data processing, a map editor, scene processing, collision processing, and walkthrough control. We also define an environment-specific semantic information editor, which can be applied using specific location obtained from the real world. Users can insert text information related to the characters real position in the real world during navigation in the game virtual environment.展开更多
This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of ...This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs. This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs. Keywords Virtual environment - virtual testing - reconfigurable virtual reality Wenyan Wu graduated from Dalian University of Technology, China, with BSc and MSc in 1988 and 1991 respectively. She earned her PhD degree from University of Derby, UK, in 2002. She had taught and researched in Harbin Institute of Technology, China and De Montfort University, UK. She is currently a senior lecturer in simulation and virtual reality at Staffordshire University, UK. Her research interests include computer graphics, Virtual Reality and Augmented Reality system, advanced interface, modelling and simulation, distribution system.Zhengxu Zhao BSc, MSc, PhD, CEng, CITP, MBCS, full Professor in Applied Computing, Director of Virtual Reality Centre. He is also a Cheng Kong Scholar Project Professor in Virtual Reality Technology and Director of Virtual Reality Research Centre at the Southeast University, P R China. Professor Zhao’s research interests include computing graphics and VR systems, industrial process simulation, CIM and manufacturing management systems.展开更多
Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture ...Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.展开更多
On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi\|user, multi\|thread and intelli...On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi\|user, multi\|thread and intelligence and issues challenges to traditional GIS models and algorithms. The new advances in software and hardware technology lay a reliable basis for system design, development and application.展开更多
The multi-modal information presentation, integrated into the virtual environment （VE）, has potential for stimulating different senses, improving the user＇s impression of immersion, and increasing the amount of inf...The multi-modal information presentation, integrated into the virtual environment （VE）, has potential for stimulating different senses, improving the user＇s impression of immersion, and increasing the amount of information that is accepted and processed by the user＇s perception system. The increase of the useful feedback information may reduce the user＇s cognitive load, thus enhancing the user＇s efficiency and performance while interacting with VEs. This paper presents our creation of a multi-sensory virtual assembly environment （VAE） and the evaluation of the effects of multi-sensory feedback on the usability. The VAE brings together complex technologies such as constraint-based assembly simulation, optical motion tracking technology, and real-time 3D sound generation technology around a virtual reality workbench and a common software platform. The usability evaluation is in terms of its three attributes： efficiency of use, user satisfaction, and reliability. These are addressed by using task completion times （TCTs）, questionnaires, and human performance error rates （HPERs）, respectively. Two assembly tasks have been used to perform the experiments, using sixteen participants. The outcomes showed that the multi-sensory feedback could improve the usability. They also indicated that the integrated feedback offered better usability than either feedback used in isolation. Most participants preferred the integrated feedback to either feedback （visual or auditory） or no feedback. The participants＇ comments demonstrated that nonrealistic or inappropriate feedback had negative effects on the usability, and easily made them feel frustrated. The possible reasons behind the outcomes are also analysed by using a unifying human computer interaction framework. The implications, concluded from the outcomes of this work, can serve as useful guidelines for improving VE system design and implementation.展开更多
Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of hetero...Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.展开更多
This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatica...This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.展开更多
Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern...Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.展开更多
This paper first introduces a way to improve interactivity with high polygon count virtual objects through the "mixed" use of image-based representation within one object. That is, both 3D polygonal and imag...This paper first introduces a way to improve interactivity with high polygon count virtual objects through the "mixed" use of image-based representation within one object. That is, both 3D polygonal and image-based representations are maintained for an object, and switched for rendering depending on the functional requirement of the object. Furthermore, in order to reduce the popping effect and provide smooth and gradual transition during the object representation switch, the object is subdivided with the subdivided parts possibly represented differently, i.e., using 3D models or images. As for the image-based representation, the relief texture (RT) method is used. In particular, through the use of the mixed representation, a new way called TangibleScreen is pro-posed to provide object tangibility by associating the image-based representation with a physical prop (projecting the RTs) in a selective and flexible way. Overall, the proposed method provides a way to maintain an interactive frame rate with selective perceptual details in a large-scale virtual environment, while allowing the user to interact with virtual objects in a tangible way.展开更多
The sense of being within a three-dimensional （3D） space and interacting with virtual 3D objects in a computer-generated virtual environment （VE） often requires essential image, vision and sensor signal processing...The sense of being within a three-dimensional （3D） space and interacting with virtual 3D objects in a computer-generated virtual environment （VE） often requires essential image, vision and sensor signal processing techniques such as differentiating and denoising. This paper describes novel implementations of the Gaussian filtering for characteristic signal extraction and waveletbased image denoising algorithms that run on the graphics processing unit （GPU）. While significant acceleration over standard CPU implementations is obtained through exploiting data parallelism provided by the modern programmable graphics hardware, the CPU can be freed up to run other computations more efficiently such as artificial intelligence （AI） and physics. The proposed GPU-based Gaussian filtering can extract surface information from a real object and provide its material features for rendering and illumination. The wavelet-based signal denoising for large size digital images realized in this project provided better realism for VE visualization without sacrificing real-time and interactive performances of an application.展开更多
Studies the design of distributed virtual environments （DVEs） for tele-multi-robotics. The proposed design, incorporating two models （ distributlon-supported model and VE-supported model）, attempts to represent co...Studies the design of distributed virtual environments （DVEs） for tele-multi-robotics. The proposed design, incorporating two models （ distributlon-supported model and VE-supported model）, attempts to represent common functionality, communication issues, and requirements found in multi-operator DVEs. The distribution-supported model concentrates on the introduction of computer-supported collaborative work （CSCW） to realize the coordination of multi-operators, while the VE-supported model concentrates on the utilization of an object-oriented approach to strengthen the expandability and robustness of the system. Finally, the configuration anti running environments of the system are given.展开更多
Virtual environment has been widely applied in scientific research and considered as an important tool of exploring science. But constructing a real virtual environment is rather difficult. The difficulty cannot be co...Virtual environment has been widely applied in scientific research and considered as an important tool of exploring science. But constructing a real virtual environment is rather difficult. The difficulty cannot be compared with developing general software. It has a high demand for software technology. Obviously traditional methods are not competent for the job. Fortunately with the development of agent-oriented technologies, all problems seem to be solved. By classifying a virtual environment into four layers corresponding with real world and considering it as a collection of agents, the virtual objects can be mapped into agents and an agent model can be designed. Based on the idea that the state change of a system is caused by that of individuals and the mutual effect among them, a theory of agent behavior driven by event and belief is put forward. Such agent-oriented modeling method can cope with the demand for handling multi-dimension information. It is an effective technique for constructing a large and complex virtual environment.展开更多
The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtua...The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.展开更多
In this paper, the properties of distributed virtual environment (DVE) and the requirements on computer networks is briefly reviewed. A multicast protocol, called sender initiated grouping multicast protocol for DVE...In this paper, the properties of distributed virtual environment (DVE) and the requirements on computer networks is briefly reviewed. A multicast protocol, called sender initiated grouping multicast protocol for DVE (SIGMP), is proposed. This new multicast protocol is based on a novel concept, multicast group (MG), which divides all participants in a DVE system into groups, among which there is a multicast group trustee (MGT) node to manage the group. The protocol provides unreliable/reliable, totally ordered and multiple to multiple multicast transmission service for DVE systems without sacrificing the communication efficiency heavily. At the same time, reliable unicast and one to multiple multicast transmission services are also supported. The performance analysis of the new protocols is also presented. Based on SIGMP, a simple demonstration of DVE system is designed and implemented. This demo system is running on several SGI workstations connected by a FDDI and Ethernet network.展开更多
基金Supported by Hangzhou Medical and Health Technology Project,No.OO20191141。
文摘BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.
基金the Strategic research and consulting project of Chinese Academy of Engineering(2023-HY-14).
文摘Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)functionality.In MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental immersion.However,the impact of virtual agent size and form on interaction performance remains unclear.Methods Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR environments.The first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent sizes.Participants,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a mouse.They completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and preferences.Results Results from the first experiment revealed that agents matching physical object size produced the best overall performance.The second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces immersion.To balance efficiency and immersion,frameless agents matching physical object sizes were deemed optimal.Conclusions Virtual agents matching physical entity sizes enhance user experience and interaction performance.Conversely,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual spaces.This study provides valuable insights for the future development of MR systems.
基金This work was partly supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea Government(MSIT),(No.2020-0-00952,Development of 5G edge security technology for ensuring 5G+service stability and availability,50%)the Institute of Information and Communications Technology Planning and Evaluation(IITP)grant funded by the MSIT(Ministry of Science and ICT),Korea(No.IITP-2022-2020-0-01602,ITRC(Information Technology Research Center)support program,50%).
文摘Nowadays,with the significant growth of the mobile market,security issues on the Android Operation System have also become an urgent matter.Trusted execution environment(TEE)technologies are considered an option for satisfying the inviolable property by taking advantage of hardware security.However,for Android,TEE technologies still contain restrictions and limitations.The first issue is that non-original equipment manufacturer developers have limited access to the functionality of hardware-based TEE.Another issue of hardware-based TEE is the cross-platform problem.Since every mobile device supports different TEE vendors,it becomes an obstacle for developers to migrate their trusted applications to other Android devices.A software-based TEE solution is a potential approach that allows developers to customize,package and deliver the product efficiently.Motivated by that idea,this paper introduces a VTEE model,a software-based TEE solution,on Android devices.This research contributes to the analysis of the feasibility of using a virtualized TEE on Android devices by considering two metrics:computing performance and security.The experiment shows that the VTEE model can host other software-based TEE services and deliver various cryptography TEE functions on theAndroid environment.The security evaluation shows that adding the VTEE model to the existing Android does not addmore security issues to the traditional design.Overall,this paper shows applicable solutions to adjust the balance between computing performance and security.
文摘The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments and virtual sensor models. In the context of this, the present paper documents the development of a sensor model for depth estimation of virtual three-dimensional scenarios. For this purpose, the geometric and algorithmic principles of stereoscopic camera systems are recreated in a virtual form. The model is implemented as a subroutine in the Epic Games Unreal Engine, which is one of the most common Game Engines. Its architecture consists of several independent procedures that enable a local depth estimation, but also a reconstruction of a whole three-dimensional scenery. In addition, a separate programme for calibrating the model is presented. In addition to the basic principles, the architecture and the implementation, this work also documents the evaluation of the model created. It is shown that the model meets specifically defined requirements for real-time capability and the accuracy of the evaluation. Thus, it is suitable for the virtual testing of common algorithms and highly automated driving functions.
基金This work is partially sponsored by the Cheung Kong Scholars Programme of the People's Republic of China.
文摘This paper presents research into applying virtual environment (VE) technology to supply chain management (SCM). Our research work has employed virtual manufacturing environments to represent supply chain nodes to simulate processes and activities in supply chain management. This will enable those who are involved in these processes and activities to gain an intuitive understanding of them, so as to design robust supply chains and make correct decisions at the right time. A framework system and its hierarchical structure for visualising and simulating supply chains in virtual environments are reported and detailed in this paper.
基金supported by National Basic Research Program (973 Program,No.2004CB719402)National Natural Science Foundation of China (No.60736019)Natural Science Foundation of Zhejiang Province, China(No.Y105430).
文摘Collision avoidance decision-making models of multiple agents in virtual driving environment are studied. Based on the behavioral characteristics and hierarchical structure of the collision avoidance decision-making in real life driving, delphi approach and mathematical statistics method are introduced to construct pair-wise comparison judgment matrix of collision avoidance decision choices to each collision situation. Analytic hierarchy process （AHP） is adopted to establish the agents＇ collision avoidance decision-making model. To simulate drivers＇ characteristics, driver factors are added to categorize driving modes into impatient mode, normal mode, and the cautious mode. The results show that this model can simulate human＇s thinking process, and the agents in the virtual environment can deal with collision situations and make decisions to avoid collisions without intervention. The model can also reflect diversity and uncertainly of real life driving behaviors, and solves the multi-objective, multi-choice ranking priority problem in multi-vehicle collision scenarios. This collision avoidance model of multi-agents model is feasible and effective, and can provide richer and closer-to-life virtual scene for driving simulator, reflecting real-life traffic environment more truly, this model can also promote the practicality of driving simulator.
文摘In this paper, we present a framework for the generation and control of an Internet-based 3-dimensional game virtual environment that allows a character to navigate through the environment. Our framework includes 3-dimensional terrain mesh data processing, a map editor, scene processing, collision processing, and walkthrough control. We also define an environment-specific semantic information editor, which can be applied using specific location obtained from the real world. Users can insert text information related to the characters real position in the real world during navigation in the game virtual environment.
文摘This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs. This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs. Keywords Virtual environment - virtual testing - reconfigurable virtual reality Wenyan Wu graduated from Dalian University of Technology, China, with BSc and MSc in 1988 and 1991 respectively. She earned her PhD degree from University of Derby, UK, in 2002. She had taught and researched in Harbin Institute of Technology, China and De Montfort University, UK. She is currently a senior lecturer in simulation and virtual reality at Staffordshire University, UK. Her research interests include computer graphics, Virtual Reality and Augmented Reality system, advanced interface, modelling and simulation, distribution system.Zhengxu Zhao BSc, MSc, PhD, CEng, CITP, MBCS, full Professor in Applied Computing, Director of Virtual Reality Centre. He is also a Cheng Kong Scholar Project Professor in Virtual Reality Technology and Director of Virtual Reality Research Centre at the Southeast University, P R China. Professor Zhao’s research interests include computing graphics and VR systems, industrial process simulation, CIM and manufacturing management systems.
基金Funded by the National Natural Science Foundation of China (No.40341011) and the National 863 Program of China(No.2002AA135230)
文摘Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.
文摘On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi\|user, multi\|thread and intelligence and issues challenges to traditional GIS models and algorithms. The new advances in software and hardware technology lay a reliable basis for system design, development and application.
基金This work was supported in part by EPSRC(No.GR/M69333/01(P)).
文摘The multi-modal information presentation, integrated into the virtual environment （VE）, has potential for stimulating different senses, improving the user＇s impression of immersion, and increasing the amount of information that is accepted and processed by the user＇s perception system. The increase of the useful feedback information may reduce the user＇s cognitive load, thus enhancing the user＇s efficiency and performance while interacting with VEs. This paper presents our creation of a multi-sensory virtual assembly environment （VAE） and the evaluation of the effects of multi-sensory feedback on the usability. The VAE brings together complex technologies such as constraint-based assembly simulation, optical motion tracking technology, and real-time 3D sound generation technology around a virtual reality workbench and a common software platform. The usability evaluation is in terms of its three attributes： efficiency of use, user satisfaction, and reliability. These are addressed by using task completion times （TCTs）, questionnaires, and human performance error rates （HPERs）, respectively. Two assembly tasks have been used to perform the experiments, using sixteen participants. The outcomes showed that the multi-sensory feedback could improve the usability. They also indicated that the integrated feedback offered better usability than either feedback used in isolation. Most participants preferred the integrated feedback to either feedback （visual or auditory） or no feedback. The participants＇ comments demonstrated that nonrealistic or inappropriate feedback had negative effects on the usability, and easily made them feel frustrated. The possible reasons behind the outcomes are also analysed by using a unifying human computer interaction framework. The implications, concluded from the outcomes of this work, can serve as useful guidelines for improving VE system design and implementation.
文摘Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.
文摘This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.
文摘Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.
基金Project (No. R01-2006-000-11142-0) supported by the "Teukjung Gicho" Program of the Korea Science Foundation
文摘This paper first introduces a way to improve interactivity with high polygon count virtual objects through the "mixed" use of image-based representation within one object. That is, both 3D polygonal and image-based representations are maintained for an object, and switched for rendering depending on the functional requirement of the object. Furthermore, in order to reduce the popping effect and provide smooth and gradual transition during the object representation switch, the object is subdivided with the subdivided parts possibly represented differently, i.e., using 3D models or images. As for the image-based representation, the relief texture (RT) method is used. In particular, through the use of the mixed representation, a new way called TangibleScreen is pro-posed to provide object tangibility by associating the image-based representation with a physical prop (projecting the RTs) in a selective and flexible way. Overall, the proposed method provides a way to maintain an interactive frame rate with selective perceptual details in a large-scale virtual environment, while allowing the user to interact with virtual objects in a tangible way.
基金supported by Research Funding of Huddersfield University:GPU-based High Performance Computing for Signal Processing (No. 1008/REU117)
文摘The sense of being within a three-dimensional （3D） space and interacting with virtual 3D objects in a computer-generated virtual environment （VE） often requires essential image, vision and sensor signal processing techniques such as differentiating and denoising. This paper describes novel implementations of the Gaussian filtering for characteristic signal extraction and waveletbased image denoising algorithms that run on the graphics processing unit （GPU）. While significant acceleration over standard CPU implementations is obtained through exploiting data parallelism provided by the modern programmable graphics hardware, the CPU can be freed up to run other computations more efficiently such as artificial intelligence （AI） and physics. The proposed GPU-based Gaussian filtering can extract surface information from a real object and provide its material features for rendering and illumination. The wavelet-based signal denoising for large size digital images realized in this project provided better realism for VE visualization without sacrificing real-time and interactive performances of an application.
文摘Studies the design of distributed virtual environments （DVEs） for tele-multi-robotics. The proposed design, incorporating two models （ distributlon-supported model and VE-supported model）, attempts to represent common functionality, communication issues, and requirements found in multi-operator DVEs. The distribution-supported model concentrates on the introduction of computer-supported collaborative work （CSCW） to realize the coordination of multi-operators, while the VE-supported model concentrates on the utilization of an object-oriented approach to strengthen the expandability and robustness of the system. Finally, the configuration anti running environments of the system are given.
文摘Virtual environment has been widely applied in scientific research and considered as an important tool of exploring science. But constructing a real virtual environment is rather difficult. The difficulty cannot be compared with developing general software. It has a high demand for software technology. Obviously traditional methods are not competent for the job. Fortunately with the development of agent-oriented technologies, all problems seem to be solved. By classifying a virtual environment into four layers corresponding with real world and considering it as a collection of agents, the virtual objects can be mapped into agents and an agent model can be designed. Based on the idea that the state change of a system is caused by that of individuals and the mutual effect among them, a theory of agent behavior driven by event and belief is put forward. Such agent-oriented modeling method can cope with the demand for handling multi-dimension information. It is an effective technique for constructing a large and complex virtual environment.
文摘The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.
文摘In this paper, the properties of distributed virtual environment (DVE) and the requirements on computer networks is briefly reviewed. A multicast protocol, called sender initiated grouping multicast protocol for DVE (SIGMP), is proposed. This new multicast protocol is based on a novel concept, multicast group (MG), which divides all participants in a DVE system into groups, among which there is a multicast group trustee (MGT) node to manage the group. The protocol provides unreliable/reliable, totally ordered and multiple to multiple multicast transmission service for DVE systems without sacrificing the communication efficiency heavily. At the same time, reliable unicast and one to multiple multicast transmission services are also supported. The performance analysis of the new protocols is also presented. Based on SIGMP, a simple demonstration of DVE system is designed and implemented. This demo system is running on several SGI workstations connected by a FDDI and Ethernet network.
