Xizhi Li's Personal Website

New: Xizhi Li. Synthesizing Real-time Human Animation by Learning and Simulation .work in progress 2005/01
Abstract: [preview]
Real-time human animation covers a wide range of applications such as virtual reality, video games, web avatars, etc. This paper presents a research framework aimed at synthesizing real-time humanoid animation by integrating the variables of the environment into the controllers of the human body and using a learning and simulation algorithm to calculate and memorize its motion. Both the environment and the human body can be partially or fully controlled by an external user; whereas the motion for the uncontrolled portion will be generated from an internal algorithm. To produce realistic animation, the environment and the body movements are first fully controlled until the animation system has discovered the patterns for the various combinations of the different parts of the body and the environment variables; then only the environment and selected parts of the human body are controlled, the system will generate the motion for the rest. The advantages of the framework are (1) the motion is fairly realistic since it is based on examples. (2) different parts of the human body may act less dependently; e.g. the top of the body might react to other environmental changes other than synchronizing with the bottom of the body. The animation system is included in a computer game engine we developed. Finally, how the research fits into the large context of automatic motion synthesis in the game engine will be discussed.

Xizhi Li and Qinming He. Scripting in Distributed Game Engine.2005/4
Abstract: [preview]
Since early 1990s, game engine has evolved to become a standard platform for constructing and running 3D virtual game worlds of high complexity and interactivity. People come to realize that game engine may evolve in to the most widely used virtual reality platform in the future. The research framework proposed in this paper is to exploit this possibility using scripting technologies and to redesign the computing paradigm in game engine to suit the need of highly dynamic networked virtual environment, where intelligent entities are situated and communicate with each other as well as human avatars. A framework design of the scripting system is proposed and implemented with supporting game demos.

Xizhi Li and Qinming He. Frame Rate Control in Distributed Game Engine. ICEC 2005. 2005/3
Abstract: [review]
Time management (or frame rate control) is the backbone system that feedbacks on a number of game engine modules to provide physically correct, interactive, stable and consistent graphics output. This paper discusses time related issues in game engines and proposes a unified time management (or more specifically frame rate control) architecture, which can be easily applied to existing game engines. The frame rate system has been used in our own distributed game engine and may also find applications in other multimedia simulation systems.

Xizhi Li. DHCI: an HCI Framework in Distributed Environment .HCI International 2005 (accepted for paper presentation) 2005/02
Abstract: [Full-length paper]
Due to web technologies, many software systems, from backbones to front ends, are migrating from standalone applications to cooperative ones. This transform impacts not only the way software works, but also how it looks, or its user interface with human operators. This article proposes DHCI, a framework of HCI , which generalizes a collection of programming and user interfaces in distributed environment . It may be adopted as the top-level interface in distributed software applications that call for extensive interactions with its users. The implementation is illustrated in two software systems we have been working at. One is called WAF, which is a multi - agent system (MAS) based application. The other is called NPL, which is the networking and scripting language used in our 3D computer game engine . They represent respectively two application domains of DHCI. The first is interface software for web users. The second is software development environment for programmers.

Xizhi Li and Hao Lin. A Proposal of Evaluation Framework for Higher Education .AIED 2005 (YRT papper) 2005/04
Abstract: [Full-length paper]
In traditional education evaluation system, the goal is to compress as much information as possible and try to use a few summative numbers, or one if possible, to represent the performance of different individuals. The regression formulae used to generate these numbers are scarcely convincing. An inadequate or unnecessary evaluation to the individual performance will lead to negative effect on the quality of its future work and the overall atmosphere among comparable people who work and learn together. In contrast, we believe a reasonable evaluation framework is to provide as much information about the individual as possible and reveal it in an ease-to-access manner to the individual as well as people who are interested in it. In the proposed web agent based evaluation framework, the focus of education evaluation shifts from information regression to information aggregation. Specifically, the work is motivated by our experiences in the CKC honors School of Zhejiang University, an honors program for elite undergraduate students.

Xizhi Li and Qinming He. WAF: an Interface Web Agent Framework . International Conference on Information Technology 2004
Abstract: [Short paper]
A trend in agent community or enterprises is that they are shifting from closed to open architectures composed of a large number of autonomous agents. One of its implications could be that interface agent framework is getting more important in multi-agent system (MAS); so that systems constructed for different application domains could share a common understanding in human computer interface (HCI) methods, as well as human-agent and agent-agent interfaces. However, interface agent framework usually receives less attention than other aspects of MAS. In this paper, we will propose an interface web agent framework which is based on our former project called WAF and a Distributed HCI template. A group of new functionalities and implications will be discussed, such as web agent presentation, off-line agent reference, reconfigurable activation map of agents, etc. Their enabling techniques and current standards (e.g. existing ontological framework) are also suggested and shown by examples from our own implementation in WAF.

Xizhi Li. Using Neural Parallel Language in Distributed Game World Composing. IEEE conf. Distributed Framework of Multimedia Applications' 05
Abstract: [Full-length paper]
Bringing networked virtual game worlds and game world logic to the open Internet will spawn new types of computer games . It usually deals with thousands of interactive entities among its web servers. Game engine practitioners have used scripting technology to add soft computing capabilities to a variety of their engine modules. This article proposes a unified approach of using Neural Parallel Language (NPL) in a computer game's scripting engine. We have implemented a reduced version of NPL and our own 3D game engine in a pair. We will show the effectiveness of such a programming language methodology by means of our released game demo. As the web is be coming more and more computable (the semantic web) and intelligent (agent technology), neural network based programming paradigm as described in this article is likely to become the solution to general purpose distributed software applications.

Xizhi Li, Li Tiecai. ECOMIPS: An Economic MIPS CPU Design on FPGA. IEEE proc. International Workshop on SOC' 04
Abstract: [Short paper]
In recently years, many traditional ASIC applications are moving towards a more flexible FPGA based design. To establish a complete application system, it often needs a separate processor to achieve some interactive system functionalities such as I/O operations and control-sensitive tasks. Modern chip producers (Xilinx, Altera, etc) are promoting economic, yet powerful FPGA chips that have the capacity of migrating a general DSP or Microprocessor into one FPGA chip. The trend is that both a general CPU module and the application specific circuit are to coexist on a single chip. This article introduces a MIPs CPU architecture or ECOMIPS to be implemented for that purpose. It focuses on economic resource utilization on modern chips (Xilinx Spartan 3 families). Traditional MIPs architecture was modified to avoid resource conflicts with the ASIC part. The key principles of designing such MIPs HDL IP cores are covered and analyzed with implementation results. As a second objective, ECOMIPS also tries to make itself a customizable and reusable architecture for bridging the gap between microprocessor and ASIC.

Xizhi Li. ParaEngine Reference Book. (book: 700 pages, 2004/8)
Introduction: [Email author to get it; I may make the game engine open source soon.]
ParaEngine is aimed to develop networked, cooperative, high-quality 3D games. Parallel World is a distributed game, built on top of ParaEngine. Player may have its own game world hosted like a personal website on its PC or other web servers. This reference book includes the game engine programming guide, tutorials by the Parallel World game and the complete API reference to date. The programming guide covers the use of the build-in scripting language (NPL) and runtime environment, animation system, 2D/3D GUI functions for scene object management, art resource tools, terrain engine and other miscellaneous functions. Tutorials include NPL source code segments used in the Parallel World game. API reference includes all class definitions and usage information in the game engine framework.

Xizhi Li. A General Outlook on Multi-Agent System. (overview article: 2003/8)
Abstract: [Download]
Multi-Agent System (MAS) is an emerging field of study and application that will constitute an indispensable part in the near future of mankind. It applies Artificial Intelligence (AI) related disciplines and theories to problems (or situations) for more intuitive and prospective solutions. The author has done a general research on Multi-Agent System. The paper contains a comprehensive and up-to-date overview and a conclusive outlook on MAS. It's hoped that this article will be helpful to those who have just decided to pick up, change or choose a subject that targets on Multi-Agent System.