合成虚拟实体对象复合行为状态

实现行为合成要求行为必须可重用,且行为由虚拟实体对象自主控制。文中提出一种基于ＳＣＰ模型合成复杂行为的方法,通过引入三种分别表示行为状态的顺序执行、并行执行以及重复执行的合成算子进行行为状态的运算,来合成复杂行为,构成复合行为状态,并通过扩充的Ｐｅｔｒｉ网予以实现。合成算子的引入增强了ＳＣＰ模型对复杂行为的描述能力,有利于虚拟实体对象行为的重用,并为复杂行为合成和行为建模研究提供新的思路。     

国防科大计算机学院工学博士学位论文摘要

虚拟世界行为建模技术的研究作者：郑援（１９９８．１０）导师：李思昆教授本文介绍了作者对虚拟世界行为建模技术几个热点问题的理论研究结果，以及在此基础上实现的虚拟实体对象建模语言ＳＣＰＬ，并给出了这些成果在工程实践中的应用和验证。本文提出了一种以控制论为...     

虚拟战场实体行为建模技术

行为建模是VR领域中的一个难点 ,文中分析了虚拟战场对实体对象行为的要求 ,提出了更加适应虚拟战场需求的实体对象行为模型ESCP。并给出了一个基于ESCP模型的计算机生成护航运输舰队实例。该实例详细介绍了虚拟实体对象的事件 /任务处理、复杂行为生成等。这些技术在分布式海战虚拟现实仿真环境中取得良好的实用效果。     

DVENET中计算机生成兵力的初步实现

计算机生成兵力（ＣＧＦ）是ＤＥＮＥＴ中的７种仿真实体之一，它由计算机程序（算法）控制实体的行为。计算机生成兵力的目的在于增加虚拟战场环境中仿真实体的数量，提高虚拟战场环境的复杂度和真实性。文中阐述了目前版本的ＤＶＥＮＥＴ中计算机生成兵力实体（歼击机和坦克）的部分低级智能行为的初步实现，并探讨了在后续课题中实现一个较为完善的计算机生成兵力系统的设想。     

在分布式VR系统中推算定位

文中基于行为模型ＳＣＰ提出一种分布式ＶＲ系统的推算定位方法。这种方法使用能够反映较长时间内动态实体对象行为状态进行推算定位,从而有效克服了已有推算定位方法行为误差较大、速度高时网络数据量大的缺点。逐渐逼近法的引入又使得平衡性较好。同已有两种推算定位文学实验比较的结果表明,这种方法具有状态失真度小、网络数据量较小的优点。     

软件配置管理系统HSCMS

在ＨＳＣＭＳ系统中，采用面向对象的观点组织软件实体，提供了对多种类型的软件实体进行统一管理的数据模型。ＨＳＣＭＳ系统以３类库为基础，实现了对软件实体的跟踪、控制，并提供了支持评审、释放管理，版本控制等配置管理功能的在线工具。此外，ＨＣＭＳ系统还提供同其它开发工具进行集成的接口     

基于VRML的三维虚拟校园漫游系统的研究

利用VRML(Virtual Reality Modeling Language)的虚拟建模语言的开发技术,提出解决三维虚拟校园场景实体建模方法,确定基于VRML感知器和Cortona VRML Client浏览器对场景中对象行为的控制,并对三维建模、纹理映射、碰撞检测、VRML场景优化技术等问题进行了探.     

一种多智能体系计算市场模型

本文针对网络信息服务问题提出一种多智能体ＭＡＳ（ｍｕｌｔｉ－ａｇｅｎｔ ｓｙｓｔｅｍ）计算市场模型，定义了计算市场，计算任务Ｃｏｎｓｕｍｅｒ和Ｓｅｒｖｅｒ实体；分析了实体在计算市场中的行为，证明存在针对任务的市场平衡；确定衡量市场效率的标准是市场运行造成的资源分配与最优分配的距离。     

虚拟制造技术

就“虚拟制造”的内涵与涉及到的关键技术进行了探讨，并介绍了国家ＣＩＭＳ工程技术研究中心（ＣＩＭＳＥＲＣ）正在建立的支持企业生产全过程的虚拟制造平台的框架及体系结构。     

最优预测理论在同步CSCW中的应用

运用现代控制论中的最优预测理论,对同步ＣＳＣＷ系统中的对象行为进行Ｋａｌｍａｎ预测,并通过这种方法来限制系统的带宽,同时给出了一个使用最优预测算法的,低带宽网的ＣＳＣＷ网络软件平台（ＣｏｎＷｏｒｋ）的设计方法及其实现,并提供了定量测试的数据,该系统运行以太网环境中。     

复杂行为的语言支持

文中面向复杂行为的虚拟环境应用需求在分析比较当前几种有代表性的建模语言的基础上,提出一个支持复杂行为的语言模型,该模型可以灵活定义行为之间的控制关系及其时间约束,并给出了面向复杂行为的虚拟环境计算算法。     

一个浏览器／服务器虚拟漫游环境

介绍了一个新开发的浏览器／服务器虚拟漫游环境VW3D。与目前较为通用的基于VRML的虚拟环境相比,VW3D采用基于SCPL语言的行为建模技术、灵活的软硬件驱动,因此有比较强的真实感和实时性,是一种很有前景的虚拟漫游系统。     

虚拟原型建模语言VPML

现有的模型描述语言难以满足基于虚拟原型的概念设计中产品模型描述的需求,基于扩充连接图思想,以基于虚拟原型的概念设计产品描述模型V－desModel为核心,提出了一种虚拟原型建模语言VPML,VPML是一种独立于领域与过程的面向机电产品概念设计的虚拟原型模型描述语言,具有较强的几何和行为建模能力,为多领域系统在概念设计阶段的协同设计、并行设计及联合仿真过程提供了一致的模型描述,VPML模型内嵌的虚拟特征生成算法,使得在概念设计阶段建立真实感很强的产品虚拟原型时设计信息不完备问题得到有效解决。     

Real-Time Depth-of-Field Rendering Using Anisotropically Filtered Mipmap Interpolation

This article presents a real-time GPU-based post-filtering method for rendering acceptable depth-of-field effects suited for virtual reality. Blurring is achieved by nonlinearly interpolating mipmap images generated from a pinhole image. Major artifacts common in the post-filtering techniques such as bilinear magnification artifact, intensity leakage, and blurring discontinuity are practically eliminated via magnification with a circular filter, anisotropic mipmapping, and smoothing of blurring degrees. The whole framework is accelerated using GPU programs for constant and scalable real-time performance required for virtual reality. We also compare our method to recent GPU-based methods in terms of image quality and rendering performance.     

基于多体动力学理论的赛车游戏引擎的设计与实现

运动车辆的实时建模、动力学行为仿真是赛车虚拟环境中的重要组成部分。论文设计并实现了一实时赛车游戏引擎,在引擎车辆建模中提出了一种基于多体动力学理论实时逼真的赛车建模方法,对赛车的真实受力状况进行简化,模拟车辆的各种动力学行为和车辆运动的真实感绘制。并实现了引擎中的碰撞检测技术、音效处理技术、虚拟环境的实时绘制技术。增强用户漫游虚拟环境的沉浸感。     

基于VRML-JAVA的网络交互式虚拟装配环境构建

虚拟现实建模语言(VRML)作为构建网络虚拟现实的国际标准，其应用得到了越来越多的关注。该文讨论了VRML虚拟场景与外界交互的手段和方法，着重研究了通过VRML外部编程接口EAI利用Java Applet来实现交互式网络虚拟装配环境的方法和实现过程，并给出了运行实例，通过该平台可以实现异地设计信息交流。     

Model transformations in simulation and planning: behaviorpreserving model simplifications

Reasoning tasks such as simulation and planning involve deriving behavior of a system from a model of the system. The information needed to solve such problems can be represented as model behavior pairs (MBPs). The problem can be stated as one or more incomplete MBPs. The problem-solving method can be expressed as a sequence of MBP completions and comparisons. A language for representing and manipulating models, behaviors, and MBPs is presented. It is independent of any specific modeling domain. An important class of model transformation operators is the behavior-preserving model transformation operators. Because they preserve behavior, they can be used to simplify a model without compromising its value for problem solving. This sort of operator can speed up computations significantly. It can be used either to select an appropriate sub-model for a specific problem or to decompose a problem into a sequence of subproblems. A behavior-preserving pruning operator is presented and shown to work in three modeling domains: discrete event simulation (DES), planning, and qualitative physics (QP). The significance of this work lies in the domain independence of the language and operators. It provides a representation midway between the computer-oriented concepts of programming languages (and knowledge representation schemes) and the problem oriented concepts of the real world. The benefits that can result from such a representation are easy mapping of problem-to-solution method, easy communication between solution methods (when more than one reasoning technique is required to solve a problem) and efficient solution of problems     

Threaded behavior protocols

Component-based development is a well-established methodology of software development. Nevertheless, some of the benefits that the component based development offers are often neglected. One of them is modeling and subsequent analysis of component behavior, which can help establish correctness guarantees, such as absence of composition errors and safety of component updates. We believe that application of component behavior modeling in practice is limited due to huge differences between the behavior modeling languages (e.g., process algebras) and the common implementation languages (e.g., Java). As a result, many concepts of the implementation languages are either very different or completely missing in the behavior modeling languages. As an example, even though behavior modeling languages are practical for modeling and analysis of various message-based protocols, they are not well suited for modeling current component applications, where thread-based parallelism, lock-based synchronization, and nested method calls are the essential building blocks. With this in mind, we propose a new behavior modeling language for software components, Threaded Behavior Protocols (TBP). At the model level, TBP provides developers with the concepts known from the implementation languages and essential to most component applications. In addition, the theoretical framework of TBP provides a notion of correctness based on absence of communication errors and a refinement relation to verify correctness of hierarchical components. The main asset of TBP formalism is that it links together the notion of threads as used in imperative object oriented languages and the notion of refinement. For instance, this allows reasoning about hierarchical components composed of primitive components implemented in Java without the need of bridging abstractions and simplifications enforced by the modeling languages.     

Using a trope-based foundational ontology for bridging different areas of concern in ontology-driven conceptual modeling

In recent years, ontology-driven reference models have gained much attention in the literature due to their potential key role in activities such as complex information modeling and semantic interoperability. The engineering process of these conceptual models should account for different phases addressing different areas of concern. In an initial phase of conceptual domain modeling, the target modeling artifacts should be constructed with the goal of maximizing quality attributes such as expressivity and truthfulness to the represented domain in reality. In a subsequent development phase, the resulting domain models can be used to guide the design decisions in the construction of different implementation artifacts addressing different computational concerns. In this paper, we present a philosophically sound, cognitively-oriented and formally characterized foundational theory of objects and tropes (property-instances). Moreover, we use this theory to bring about engineering contributions to both the aforementioned phases of ontology-driven conceptual modeling. Firstly, we show how this theory has been used to (re)design a system of modeling primitives underlying the conceptual domain modeling language OntoUML. Furthermore, we provide precise directives on how to map conceptual domain models in this language to their implementation in less-expressive computationally-oriented codification languages. In particular, we address here a mapping strategy to OWL (Web Ontology Language) that partially preserves the modal-temporal semantics of OntoUML. Finally, we discuss computational support for the proposed approach in terms of conceptual model construction, automatic transformation and temporal querying.