Genuinity Signatures: Designing Signatures for Verifying 3D Object Genuinity

3D computer graphics models and digitally-controlled manufacturing have come together to enable the design, visualization, simulation, and automated creation of complex 3D objects. In our work, we propose and implement a framework for designing computer graphics objects and digitally manufacturing them such that no adversary can make imitations or counterfeit copies of the physical object, even if the adversary has a large number of original copies of the object, knowledge of the original object design, and has manufacturing precision that is comparable to or superior to that of the legitimate creator of the object. Our approach is to design and embed a signature on the surface of the object which acts as a certificate of genuinity of the object. The signature is detectable by a signature-reading device, based on methods in computer graphics and computer vision, which contains some of the secret information that was used when marking the physical object. Further, the compromise of a signature-reading device by an adversary who is able to extract all its secrets, does not enable the adversary to create counterfeit objects that fool other readers, thereby still enabling reliable copy detection. We implemented a prototype of our scheme end-to-end, including the production of the physical object and the genuinity-testing device.     

生产系统的计算机仿真研究

生产系统在设计与运行过程中面临着诸多的问题需要解决，计算机仿真技术作为一种有效验证生产系统设计合理性和辅助生产管理决策的手段，近年来在我国得到了越来越广泛的关注。该文系统总结了计算机仿真技术对生产系统的重要作用，利用Ithink5.0软件建立了简单生产过程的计算机仿真模型并进行了分析。     

A simulation system for a surface climbing robot

In order to reduce the cost of designing a new mechanism, it is desirable to use a simulation system that is able to provide a realistic representation of motions of the newly designed mechanism before actually manufacturing it. The modern computer graphics techniques have made it possible to realize this kind of simulation system. In this paper a simulation system with 2-D and 3-D was developed for design of a surface climbing robot with two legs, which can be used for inspections of nuclear power plants, ships, storage tanks, aircraft and tall buildings. This simulation/animation system was written in AutoLISP and implemented in a personal computer equipped with AutoCAD.     

CATC — A Computer Aided Tolerance Control system

Computer utilization in manufacturing systems is increasing at a rapid rate. Developments thus far have been disjointed. Much work needs to be done in the area of integrating computer aided design and computer aided manufacturing (CAD/CAM). Tolerance control is an important component in the integration of CAD and CAM. Selection of design tolerances affects the build-ability of a product. The selection of manufacturing processes and sequence of processes affects process tolerance stacking. Unexamined process tolerance stacking leads to scrap and rework. A computer aided tolerance control (CATC) system is presented in this paper. This system is based on the tolerance chart technique. The CATC system is interactive and uses computer graphics for information display. The system can be used for computer aided process planning (CAPP) and for CAD/CAM integration.     

Development of an Intelligent Wheelchair Using Computer Graphics Animation and Simulation

A new robot simulator JC-1 is used as a control software development tool in a project in progress where an intelligent wheelchair for a blind user is being developed. The intelligent wheelchair is planned to be able to fulfill simple symbolic commands like "follow wall" or "follow object" and using the JC-1 simulator an evaluation team which includes e.g. the user, a rehabilitation engineer and a software engineer, can check control algorithms and user interface routines before constructing a real wheelchair prototype. The JC-1 simulator models the environment using simplified boundary- representation where objects, robot sensors and actuators are presented as symbolic objects in the graphics data-base of the simulator. In the JC-1 simulator a robot controller under development controls the motion of the graphical model of the robot while simulator commands or other robot controllers can be used to control the movement of disturbing obstacles. Computer graphics animation and simulation help to find fundamental design errors at an early design stage and as this paper suggests, enable the user of the final product to take part in to the designing process of the robot controller. Benefits and difficulties of using computer graphics simulation in the wheelchair development process are discussed.     

Computer assisted plant layout using a graphics editor

Computer assisted plant layout has been available to industrial engineers, in one form or another, for a number of years. In this paper a semi-interactive computer graphics approach to layout planning is described. A graphics editor, CMASK, developed for designing integrated circuits was utilized to create plant-facility layout. The method based on a “layer by layer” approach to creating a layout is flexible and gives the layout designer a complete control to the layout generation process.     

Light Transport in Realistic Rendering: State-of-the-Art Simulation Methods

Programming and Computer Software - The modern realistic computer graphics is based on physically correct lighting simulation. One of the main and computationally difficult problems is the...     

Development of a user friendly gate-level logic simulator

A design of a digital logic simulator is developed and presented. BASIC on an IBM Personal Computer using interactive graphics tools is employed to make the simulator easy to use. The simulator can handle gate level logic circuits, and can be used for both logic verification and fault testing.

Efficient and correct simulation in a user-friendly environment was the main design objective. Concepts of interactive computer graphics are extensively applied to enable the drawing of the circuit. Menu structures have been used to simplify the interaction of user and computer. The foundation has been laid for a simulator that uses pattern recognition for circuit data acquisition.

The simulator permits the verification of the logic of a circuit without fault. The design also includes provision for inserting delays and simulating to detect hazards. Test sequences to detect the presence of faults in the circuit can be generated using deductive simulation. The design provides a reliable basis for further research into logic simulation.     

基于层次细节模型和分形理论的动态地形仿真

如何在PC机上生成具有动态特性的真实感地形图一直是计算机图形领域一个挑战性课题，该文在基于层次细节模型对同一场景或场景中的物体使用具有不同细节的描述而得到一组模型供绘制时选择使用的思想，运用分形绘图理论提出了一种动态地形仿真的方法，它具有重要的经济性和军事应用价值。     

分数维在自然景物仿真中的应用

计算机自然景物仿真具有广泛的应用领域,它是计算机图形学的一个重要分支.但自然景物形状复杂,不具有连续、光滑的数学性质,无法再用描述规则形体的欧氏几何来描述自然景物.文中介绍了分数维及分数维造型技术,这种技术可以有效解决不规则物体的造型问题,它能够逼真地描述自然界中存在的各种自然景物,从而获得满意的效果.最后用山作为分数维模拟自然景物的应用实例,试验结果证实了分数维在自然景物仿真中的有效性和实用性.     

计算机仿真及其在制造业中的应用

制造业是国民经济的支持性产业。ＣＩＭＳ是制造业新的生产模式，为实现ＣＩＭＳ．广泛应用了计算机仿真技术。本文是“计算机仿真与制造业发展”系列文章的第一篇，它主要介绍８０年代后期计算机仿真的几个大的转变，计算机仿真在制造业中的应用概况及我国研制的几个用于制造业的建模与仿真系统。     

Teaching computer game design and construction

Computer gaming is a key component of the rapidly growing entertainment industry. While building computer games has typically been a commercial endeavor, we believe that designing and constructing a computer game is also a useful activity for educating students about geometric modeling and computer graphics. In particular, students are exposed to the practical issues surrounding topics such as geometric modeling, rendering, collision detection, character animation and graphical design. Moreover, building an advanced game provides students exposure to the real-world side of software engineering that they are typically shielded from in the standard computer class. In this paper, we describe our experiences with teaching a computer science class that focuses on designing and building the best game possible in the course of a semester. The paper breaks down a typical game into various components that are suited for individual student projects and discusses the use of modern graphical design tools such as Maya in building art for the game. We conclude with a rough timeline for developing a game during the course of a semester and review some of the lessons learned during the three years we have taught the class.     

计算机显卡常见故障解析

显卡是计算机的视觉中枢,它可以将CPU处理后的数据信号翻译成显示器能显示的模拟信号,与显示器组成了电脑的显示系统。一般情况下,显卡出现的故障并不是很多,但是随着应用增多和性能的提高,显卡出现的故障率也在增长,给我们的正常使用带来了很多的不便。该文从五个方面分析了计算机显卡的常见故障,供计算机使用者维修参考。     

Manufacturing Models of Biomedical Objects via CAD/CAM and GKS

Picture generating methods like tomography have drastically improved the possibility for the conception of biomedical objects in living humans. They have proved to be of major significance in surgical planning. Computer Aided Design (CAD) methods based on tomography are in the research phase for the three-dimensional reconstruction and display using computer graphics for even better visualization. We provide a method beyond that by manufacturing physical three-dimensional models via the Graphical Kernel System (GKS) and Computer Aided Manufacturing (CAM) methods. This kind of method is very well suited for visualization in some application areas. Moreover it yields physical models which can be manipulated in the preoperative phase. Lastly a physical bone model can be a substitute for the original object.     

计算机仿真在制造车间设计中的应用

制造车间层的设计与车间中设备的利用率,产品的生产时间,车间的效率等密切相关,必须采取一种有效的方法。这是一个十分重要而又复杂的问题,也是目前仿真领域的研究热点之一。本文是“计算机仿真与制造业发展”系列文章中的第二篇,主要介绍了仿真技术在车间设计中的应用及几个可用于车间设计阶段的仿真软件,并且通过一个实例具体说明了如何使用仿真技术来辅助完成车间的设计工作。     

A simulation study of hierarchical clustering techniques for the design of cellular manufacturing systems

Forming part families and their associated machine groups remains one of the major concerns for companies changing from traditional batch manufacturing to cellular manufacturing. Cluster analysis is recognized as an appropriate procedure for forming the machine cells and part families necessary for the design of a cellular manufacturing system. In this paper, our concern is with using computer simulation to evaluate cluster analysis as a tool for designing cellular systems.     

Computer graphics in nuclear engineering education at Queen Mary College

Computer graphical display has been used in teaching nuclear engineering at Queen Mary College since 1971 and has assumed an increasingly important role in the modelling and simulation of engineering systems, not least nuclear engineering systems, for teaching purposes. The role of computer graphics is illustrated by means of examples selected from a suite of nuclear engineering programs in current use, indicating the highly flexible interaction and enhanced presentation of information which can be achieved. The facilities provided at Queen Mary College for the implementation of graphics-based teaching programs are described and the associated laboratory organisation indicated.     

The Computer Dictionary Project: an update

Since the mid-1980s, the IEEE Computer Society's Computer Dictionary Project has served the society, the IEEE, and computer professionals throughout the world by producing glossaries of computer-related terminology. The project's working group has finished one glossary for each of 10 computer science areas: the mathematics of computing, computer applications, modeling and simulation, image processing and pattern recognition, data management, computer graphics, computer networking, computer hardware, software engineering, and computer languages. A glossary with terms pertaining to artificial intelligence and robotics and another with terms pertaining to computer security and privacy are awaiting final approval and are scheduled to be published later. The working group is still studying terms pertaining to computation theory. The Computer Dictionary Project's work helps provide the type of clear, consistent terminology that clarifies definitions, standardizes term usage, and facilitates communication between computer professionals. The project's work attracts a particularly wide readership because the glossaries' 10,000 terms and definitions also appear in the popular IEEE Standard Dictionary of Electrical and Electronics Terms. Like all IEEE standards, the project's glossaries are subject to review and possible update every five years