LiveROMS: A virtual environment for ocean numerical simulations

LiveROMS is a bootable DVD that contains an Linux-based computer operating system which has a complete, functioning version of the ROMS ocean circulation model and an Octave version of ROMSTOOLS. It allows students and scientists to experiment with this ocean numerical model, with just a basic knowledge of Linux.     

Analyzing engineering simulations in a virtual environment

We present new results of ongoing research in developing a virtual environment for car-body engineering applications. Creating VRML scenes lets us use the Internet as a communication platform     

A virtual environment for network testing

The testing of network-based solutions demands a series of tedious tasks such as the deployment of the solution at different nodes and the configuration of different topologies. The manual execution of these tasks is very time consuming and a configurable environment to facilitate these tasks and consequently improve testing performance is desired. In this paper a virtual network environment that can be easily re-configured is presented to address this problem. The environment has been evaluated by a series of case studies: one dealing with the deployment and containment of a worm propagation attack and one dealing with detecting a denial of service attack. Three smaller case studies have also been developed. The results are a clear indication of the flexibility and usefulness of the virtual network environment.     

A nonparametric regression model for virtual humans generation

In this paper, we propose a novel nonparametric regression model to generate virtual humans from still images for the applications of next generation environments (NG). This model automatically synthesizes deformed shapes of characters by using kernel regression with elliptic radial basis functions (ERBFs) and locally weighted regression (LOESS). Kernel regression with ERBFs is used for representing the deformed character shapes and creating lively animated talking faces. For preserving patterns within the shapes, LOESS is applied to fit the details with local control. The results show that our method effectively simulates plausible movements for character animation, including body movement simulation, novel views synthesis, and expressive facial animation synchronized with input speech. Therefore, the proposed model is especially suitable for intelligent multimedia applications in virtual humans generation.     

A virtual studio environment for design integration

In this paper the authors attempt to stress the social dimension of design and the role of explicit support for human-level interaction during design systems integration. A human-centred approach is proposed by taking design integration as the collaborative use of design artefacts, and a virtual studio environment (VSE) framework is presented as an integration vehicle to link the social and technical dimensions. A VSE consists of two subsystems: the VSE base system and the domain resources. While common generic facilities for human–human interaction are embedded within the VSE base system, the domain-specific resources are loosely coupled into VSE via resource agents. A VSE prototype for the domain of building design is described, and a demonstration of the use of the VSE prototype is presented. This is then followed by some discussion on related research and further work. © 1998 Published by Elsevier Science Ltd. All rights reserved.     

A methodology for developing service in virtual manufacturing environment

Developing product related services in the context of virtual manufacturing environment to support manufacturing industry is considered as one of the main challenges for industrialised countries to improve their competiveness in the years to come. This is a complex servitization process that needs supports of appropriate models, methods and tools. This paper presents a methodological approach for the creation of the manufacturing service and service system along the engineering phases of a service life cycle. The proposed approach is developed under the frame of a FP7 European Integrated Project MSEE (Manufacturing Service Ecosystem). The methodology relates and federates a set of models, methods and tools through a structured approach. The experimentations of the methodology in industrial pilots showed that it allows the gain of time and consistency in a complex manufacturing servitization project.     

A collisions evaluation method in virtual environment for collaborativeassembly

Collision detection is critical for collaborative assembly simulation to assist design processing. However, collisions between polygonal models may not reflect collisions between real objects in reality because of polygonal approximation and designed tolerance. This problem reduces the reliability of simulation in collaborative assembly and sometimes even results in wrong conclusions. To solve the problem, we propose a novel collision evaluation algorithm based on generalized penetration depth, approximation information, and tolerance information. Given two interfered polygonal models, generalized penetration depth is calculated using relative motion information. Then two thresholds, which are based on approximation information and tolerance information, are integrated to evaluate collisions between polygonal models. In order to distinguish the status of collisions for further analysis, the collisions between polygonal models are categorized into three types by evaluation algorithm, namely real collision, potential collision, and fake collision. Computational efficiency and accuracy of the evaluation algorithm are verified in a virtual collaborative assembly environment.     

Model-based manufacturing integration: A paradigm for virtual manufacturing systems engineering

Current manufacturing system design methodologies produce multiple models of the eventual manufacturing system. These models reflect either the designers view of some subsystem, like materials handling, some level of abstraction, or some developmental stage in the design of the system. These models serve to break the complex system design into smaller, more manageable sized problems. This paper makes a case for the need to integrate these models before the physical system is constructed.     

A large-scale complex virtual environment for team training

Virtual environments that allow multiple participants to cooperatively interact present complex design problems. In this article, we describe the Close Combat Tactical Trainer (CCTT), a joint US Army-Loral project, which is the first fully distributed interactive simulation (DIS)-compliant training system development effort. This Army program's approach relies successfully on concurrent engineering, spiral development and usability engineering     

A virtual environment for multimedia intelligence data analysis

The article describes an experimental, exploratory information visualization system under development at the Pacific Northwest National Laboratory. The system aims to integrate multimedia data and help users visualize the contents of multimedia databases. The prototype, named Starlight, interactively generates information-dense 3D graphical representations of multimedia data interrelationships. Despite the richness and complexity of the information displays, they remain easy to understand. The prototype incorporates an experimental immersive interface intended to foster improved understanding of, and interactions with, 3D information visualizations. The interface is intended to be of practical use in a production-oriented information analysis environment. Although the existing prototype intentionally addresses a specific class of problems faced by intelligence analysts, the authors feel the general approach has broad applicability outside the intelligence community     

A new paradigm for urban surveillance with vehicular sensor networks

We consider a new application paradigm of vehicular sensor networks (VSN). Currently, vehicles are equipped with forward facing cameras to assist forensic investigations of events by proactive image-capturing from streets and roads. Due to content redundancy and storage imbalance in this in-network distributed storage system, how to maximize its storage capacity becomes a nontrivial challenge. In other words, how to maximize the average lifetime of sensory data (i.e., images generated by cameras) in the network is a fundamental problem to be solved. This paper presents, VStore, a cooperative storage solution in vehicular sensor networks for mobile surveillance, which has been designed to support redundancy elimination and storage balancing throughout the network. Compared with existing works, we propose a novel storage architecture for urban surveillance and deal with challenges in a mobile scenario. Field testing was carried out with a trace-driven simulator, which utilized about 500 taxis in Shanghai. The testing results showed that VStore can largely prolong the average lifetime of sensory data by cooperative storage.     

A methodology for solid modelling in a virtual reality environment

This paper presents a methodology for solid modelling in a virtual reality (VR) environment. Solid modelling in the VR environment is precisely performed in an intuitive manner through constraint-based manipulations. A hierarchically structured and constraint-based data model is developed to support solid modelling in the VR environment. Constraint-based manipulations are realized by allowable motions for precise 3D interactions in the VR environment. A mathematical matrix is presented for representing allowable motions. A procedure-based degree-of-freedom combination method for 3D constraint solving is presented for deriving the allowable motions from constraints. A rule-based constraint recognition engine is developed for both constraint-based manipulations and implicitly incorporating constraints into the VR environment. A prototype system has been implemented to testify the feasibility of the presented methodology.     

A framework for virtual organization creation in a breeding environment

Effectiveness in the process of creating virtual organizations (VO) is an important pre-condition for having a truly dynamic VOs, in response to collaboration opportunities in fast changing market contexts. A realistic approach to materialize agility in VO creation is defined under the assumption of a VO Breeding Environment (VBE), that guarantees the preparedness of its members to quickly get engaged in collaboration processes. After a survey of past approaches and a characterization of the VBE concept, a discussion of the process and suggested functionalities towards a VO creation framework are presented in this context. Finally a list of supporting tools is described and future research challenges are pointed out.     

一种虚拟人导航运动的路径规划算法

提出了一种虚拟人在复杂的3D障碍环境中根据导航目标快速进行最优路径规划的算法,该算法以使用栅格法表示虚拟环境为基础。首先,将虚拟环境中虚拟人高度范围内所有障碍物的几何形状映射到一个离散的2D位图,并对障碍物进行“膨胀”;然后,使用提出的算法规划出一条从初始位置到目标位置的最优路径,引导虚拟人在虚拟环境中进行导航运动。该方法可以在较少的内存代价和计算代价的情况下,快速规划出从虚拟人目前位置到目标位置的最优路径,算法的可行性和有效性经过实验验证。     

一种虚拟人追逐过程中的情绪博弈模型

追逐行为在人类社会生活中十分常见,模拟追逐过程中的情绪变化,有助于揭示情绪和运动的关系.在借鉴博弈论的基础上,研究了虚拟人围绕障碍物追逐的情绪博弈模型,依据追逐的剧情,拟定了虚拟人的情绪强度公式,定量描述了虚拟人的速度和体力的变化,提出了追逐过程中虚拟人情绪博弈策略.采用OpenSceneGraph图形库实现了虚拟人追逐动画,实验结果表明,该模型能很好地模拟追逐中虚拟人情绪的变化规律.     

A pipeline virtual environment architecture for multicore processor systems

We present a novel architecture to develop Virtual Environments (VEs) for multicore CPU systems. An object-centric method provides a uniform representation of VEs. The representation enables VEs to be processed in parallel using a multistage, dual-frame pipeline. Dynamic work distribution and load balancing is accomplished using a thread migration strategy with minimal overhead. This paper describes our approach, and shows it is efficient and scalable with performance experiments. Near linear speed-ups have been observed in experiments involving up to 1,000 deformable objects on a six-core i7 CPU. This approach’s practicality is demonstrated with the development of a medical simulation trainer for a craniotomy procedure.     

ADVICE: A virtual environment for Engineering Change Management

In this paper, we analyze Engineering Changes (EC), which are modifications in forms, fits, functions, materials, or dimensions in components constituting the design. We propose a new approach for processing these changes within a Virtual Collaborative Design Environment. This environment, named Active Distributed Virtual Change Environment (ADVICE) offers an Engineering Change Management solution by merging graphical and parametric data involved in the process into a virtual platform, which improves the comprehension of users and hence decreases the time required for review. ADVICE provides smart user support for predicting Engineering Changes to be triggered due to a specific change and for offering priorities to Engineering Change Requests. This is managed by employing Sequential Pattern Mining techniques to process captured Engineering Change history with Prioritization and Change Propagation mechanisms. For verifying these mechanisms, experiments involving synthetic data are conducted. The experiments present the capability of ADVICE to facilitate Engineering Change Management.     

A virtual disk environment for providing file system recovery

File system recovery (FSR) is a kind of recovery facility that allows users to roll back the file system state to a previous state. In this paper, we present a virtual disk environment (VDE) which allows previous write operations to a hard disk to be undone, and previous version of files to be recovered. It can be used to recover the file system quickly even when computer system suffers the serious disaster such as system crash or boot failure. The VDE is same as virtual disk in the virtual machine (VM) environment in some way, but it can be applied to the environment without VM supports. Algorithms for implementing the VDE are presented and its implementation on Windows platform is discussed. Based on the implementation, the experimental results of the VDE performance are analyzed. Comparing with other FSRs, the main advantage of the VDE is low overhead and high recovery speed.     

A self-configurable large-scale virtual manufacturing environment for collaborative designers

As manufacturing environments are getting distributed and increasing in size, the related virtual environments are getting larger and more closely networked together. This trend has led to a new paradigm—large-scale virtual manufacturing environment (LSVME). It supports networked and distributed virtual manufacturing to meet manufacturing system requirements. Since it contains a large number of virtual components, an effective data structure and collaborative construction methodology are needed. A metaearth architecture is proposed as the data structure for representing LSVME. This architecture consists of virtual space layer, mapping layer, library layer and ontology layers, which describe interaction among virtual components and has the ability to analyze the characteristics of virtual environment. In addition, it increases reusability of virtual components and supports self-reconfiguration for manufacturing simulation. A heuristic construction method based on graph theory is proposed using this architecture. It prevents redundant design of virtual components and contributes to an effective construction scheduling technique for collaborative designers.     

A 3D virtual environment for training soccer referees

Emerging digital technologies are being used in many ways by and in particular virtual environments provide new opportunities to gain experience on real-world phenomena without having to live the actual real-world experiences. In this study, a quantitative research approach supported by expert validation interviews was conducted to determine the availability of virtual environments in the training of soccer referees. The aim is to design a virtual environment for training purposes, representing a real-life soccer stadium to allow the referees to manage matches in an atmosphere similar to the real stadium atmosphere. At this point, the referees have a chance to reduce the number of errors that they make in real life by experiencing difficult decisions that they encounter during the actual match via using the virtual stadium. In addition, the decisions and reactions of the referees during the virtual match were observed with the number of different fans in the virtual stadium to understand whether the virtual stadium created a real stadium atmosphere for the referees. For this evaluation, Presence Questionnaire (PQ) and Immersive Tendencies Questionnaire (ITQ) were applied to the referees to measure their involvement levels. In addition, a semi-structure interview technique was utilized in order to understand participants’ opinions about the system. These interviews show that the referees have a positive attitude towards the system since they can experience the events occurred in the match as a first person instead of watching them from camera as a third person. The findings of current study suggest that virtual environments can be used as a training tool to increase the experience levels of the soccer referees since they have an opportunity to decide about the positions without facing the real-world risks.