A tolerant approach to reconstruct topology from unorganized trimmed surfaces

Presented in this paper is a topology reconstruction algorithm from a set of unorganized trimmed surfaces. Error-prone small geometric elements are handled to give proper topological information. It gives complete topology to topologically complete models, and it is also tolerant to incomplete models. The proposed algorithm is vertex-based in that clues for topological information are searched from the set of vertices first, not from that of edges.     

网格计算及其应用

网络计算给互联网带来了新的活力，它是一种新型的分布计算技术，致力于解决复杂度很高的新应用问题，文中简述了网格计算的定义、体系结构、关键问题、当前几个有代表性的网格系统以及网格应用实例，并分析了风格计算发展趋势。     

基于质粒的DNA计算模型研究

论文给出了一种基于环状质粒DNA计算的新方法,这种计算质粒包含一个特殊的插入DNA序列片断,每个片断定位在匹配的限制性内切位点,通过剪切和粘贴实现计算过程。论文同时给出了生物计算模型和相关的数学描述,这种模式的计算有待进一步研究。     

网格技术在广播电视中的应用

网格是继Internet和Web技术之后的第三个信息技术浪潮。简述了网格的定义、特点和基本体系结构 ,并且分析了网格技术在广播电视中的应用     

Trust for Ubiquitous,Transparent Collaboration

In this paper, trust-based recommendations control the exchange of personal information between handheld computers. Combined with explicit risk analysis, this enables unobtrusive information exchange, while limiting access to confidential information. The same model can be applied to a wide range of mobile computing tasks, such as managing personal address books and electronic diaries, to automatically provide an appropriate level of security. Recommendations add structure to the information, by associating categories with data and with each other, with degrees of trust belief and disbelief. Since categories also in turn confer privileges and restrict actions, they are analogous to rôles in a Rôle-Based Access Control system, while principals represent their trust policies in recommendations. Participants first compute their trust in information, by combining their own trust assumptions with others' policies. Recommendations are thus linked together to compute a considered, local trust assessment. Actions are then moderated by a risk assessment, which weighs up costs and benefits, including the cost of the user's time, before deciding whether to allow or forbid the information exchange, or ask for help. By unifying trust assessments and access control, participants can take calculated risks to automatically yet safely share their personal information.     

可编程光学二值双轨逻辑门

基于双轨逻辑,本文提出一种可级联的并行二值逻辑门。所有十六种二值逻辑运算可以采用偏振半波相延编程来实现。也提出了用电光晶体实现实时编程的方法。本文中给出了实验结果。     

Implementation of a vector quantization codebook design technique based on a competitive learning artificial neural network

We describe an implementation of a vector quantization codebook design algorithm based on the frequencysensitive competitive learning artificial neural network. The implementation, designed for use on high-performance computers, employs both multitasking and vectorization techniques. A C version of the algorithm tested on a CRAY Y-MP8/864 is discussed. We show how the implementation can be used to perform vector quantization, and demonstrate its use in compressing digital video image data. Two images are used, with various size codebooks, to test the performance of the implementation. The results show that the supercomputer techniques employed have significantly decreased the total execution time without affecting vector quantization performance.This work was supported by a Cray University Research Award and by NASA Lewis research grant number NAG3-1164.     

分形方法用于有噪图像边缘检测的研究

本文研究了加性高斯白噪声对于基于离散分数布朗随机场模型图像分形维数估计的影响，并将分形方法用于图像边缘检测，指出在加性高斯白噪声的情况下，分形方法用于图像边缘检测较之经典的基于梯度运算的边缘检测方法有好的抗噪性能，同时又能检测比较丰富的图像边缘细节。     

Fundamental solutions for half plane with an oblique edge crack

An elastic half plane with an oblique edge crack is considered in this paper. A pair of concentrated forces or point dislocations is assumed to act at an arbitrary point in the half plane. The half plane with an edge crack is first mapped into a unit circle by a rational mapping function so that the following analysis can be carried out on the mapped plane analytically. Then the complex stress functions are derived by separating the whole problem into two parts; one is the principal part corresponding to the infinite plane acted on by concentrated forces or dislocations, the other is the holomorphic part, which can be determined by making use of the property of regularity of complex stress functions. The stress intensity factors of the crack can be calculated with different inclined angles of the crack, and the displacement and stress components at an arbitrary position in the half plane can be expressed explicitly.     

客户机／服务器计算环境

本文介绍了客户机／服务器计算环境的基本概念和产生背景，阐述了客户机／服务器计算中操作系统的选择原则及企业级客户机／服务器计算环境的特点。