艺术教育建筑交往空间构成手法

艺术专业在教学中对交往、交流有着较高的要求,在目前的艺术教育建筑内,设计师也越来越多地考虑到这一点,在空间内部设置有各种形式的交往空间场所,然而空间之间的串联也是很重要的,对于各种形式的合理组合,也很好地决定了今后交往空间的使用。本文对于各种空间形式的串联提出一些方法。使得各种交往空间成为一个整体贯穿于建筑内部,这样各种交往空间得到更适宜的使用。     

浅谈视觉传达设计的教学理念与实践

面对市场的全球化,未来的设计师不仅需要深厚的文化底蕴,同时需要具有国际化的视野和迎接新挑战的能力。设计教育在知识经济的背景下面临新的机遇和挑战,如何在设计教学过程中解决问题,培养素质全面、质量合格的毕业生正是本文要探讨的问题。     

Timestamping messages and events in a distributed system using synchronous communication

Determining order relationship between events of a distributed computation is a fundamental problem in distributed systems which has applications in many areas including debugging, visualization, checkpointing and recovery. Fidge/Mattern’s vector-clock mechanism captures the order relationship using a vector of size N in a system consisting of N processes. As a result, it incurs message and space overhead of N integers. Many distributed applications use synchronous messages for communication. It is therefore natural to ask whether it is possible to reduce the timestamping overhead for such applications. In this paper, we present a new approach for timestamping messages and events of a synchronously ordered computation, that is, when processes communicate using synchronous messages. Our approach depends on decomposing edges in the communication topology into mutually disjoint edge groups such that each edge group either forms a star or a triangle. We show that, to accurately capture the order relationship between synchronous messages, it is sufficient to use one component per edge group in the vector instead of one component per process. Timestamps for events are only slightly bigger than timestamps for messages. Many common communication topologies such as ring, grid and hypercube can be decomposed into edge groups, resulting in almost 50% improvement in both space and communication overheads. We prove that the problem of computing an optimal edge decomposition of a communication topology is NP-complete in general. We also present a heuristic algorithm for computing an edge decomposition whose size is within a factor of two of the optimal. We prove that, in the worst case, it is not possible to timestamp messages of a synchronously ordered computation using a vector containing fewer than components when N ≥ 2. Finally, we show that messages in a synchronously ordered computation can always be timestamped in an offline manner using a vector of size at most . An earlier version of this paper appeared in 2002 Proceedings of the IEEE International Conference on Distributed Computing Systems (ICDCS). The author V. K. Garg was supported in part by the NSF Grants ECS-9907213, CCR-9988225, an Engineering Foundation Fellowship. This work was done while the author C. Skawratananond was a Ph.D. student at the University of Texas at Austin.     

Separation of synchronous and asynchronous communication via testing

One of the early results concerning the asynchronous π$\pi$-calculus which significantly contributed to its popularity is the capability of encoding the output prefix of the (choiceless) π$\pi$-calculus in a natural and elegant way. Encodings of this kind were proposed by Honda and Tokoro, by Nestmann and (independently) by Boudol. We investigate whether the above encodings preserve De Nicola and Hennessy’s testing semantics. In this sense, it turns out that, under some general conditions, no encoding of the output prefix is able to preserve the must testing. This negative result is due to (a) the non-atomicity of the sequences of steps which are necessary in the asynchronous π$\pi$-calculus to mimic synchronous communication, and (b) testing semantics’ sensitivity to divergence.     

On the Power of Las Vegas for One-Way Communication Complexity, OBDDs, and Finite Automata

The study of the computational power of randomized computations is one of the central tasks of complexity theory. The main goal of this paper is the comparison of the power of Las Vegas computation and deterministic respectively nondeterministic computation. We investigate the power of Las Vegas computation for the complexity measures of one-way communication, ordered binary decision diagrams, and finite automata.(i) For the one-way communication complexity of two-party protocols we show that Las Vegas communication can save at most one half of the deterministic one-way communication complexity. We also present a language for which this gap is tight.(ii) The result (i) is applied to show an at most polynomial gap between determinism and Las Vegas for ordered binary decision diagrams.(iii) For the size (i.e., the number of states) of finite automata we show that the size of Las Vegas finite automata recognizing a language L is at least the square root of the size of the minimal deterministic finite automaton recognizing L. Using a specific language we verify the optimality of this lower bound.     

基于agent的交易流程

从交易agent的行为特性出发,探讨了一典型交易流程的设计和实现。先给出交易流程图,然后再探讨交易环节中安全通信机制的框架和特征,接着针对具体环节深入探讨了其中的安全通信机制。最后给出流程支撑环境和结论。     

远程监控系统数据通信的分析与研究

论述一种分布式远程监控系统数据通信实现的方式,指出将多线程技术、Windows Sockets技术有机结合起来,比较理想地解决实时信息的通信问题。     

基于二总线结构的监测系统设计

介绍了二总线通信基本原理,并给出了基于二总线结构的监测系统的构成。该监测系统已在军事领域中得到应用。     

BCL-3: A High Performance Basic Communication Protocol for Commodity Superserver DAWNING-3000

1 IntroductionC1usters have been popu1ar platforms fOr high performance computing in receot years. They arewidely used in scientific and engineering computing business computing, and Internet informationservices. Communication perfOrmance is one of the most critical factors determining the perfOrmanceof a whole cluster system. So how to improve the performance of communication is a hot researchtopic in cluster computing. Meanwhile, bui1ding a cluster with commodity SMPs (CLUMPS) isbecorn…