SABUL: A Transport Protocol for Grid Computing

This paper describes SABUL, an application-level data transfer protocol for data-intensive applications over high bandwidth-delay product networks. SABUL is designed for reliability, high performance, fairness and stability. It uses UDP to transfer data and TCP to return control messages. A rate-based congestion control that tunes the inter-packet transmission time helps achieve both efficiency and fairness. In order to remove the fairness bias between flows with different network delays, SABUL adjusts its sending rate at uniform intervals, instead of at intervals determined by round trip time. This protocol has demonstrated its efficiency and fairness in both experimental and practical applications. SABUL has been implemented as an open source C++ library, which has been successfully used in several Grid computing applications.     

D-Index: Distance Searching Index for Metric Data Sets

In order to speedup retrieval in large collections of data, index structures partition the data into subsets so that query requests can be evaluated without examining the entire collection. As the complexity of modern data types grows, metric spaces have become a popular paradigm for similarity retrieval. We propose a new index structure, called D-Index, that combines a novel clustering technique and the pivot-based distance searching strategy to speed up execution of similarity range and nearest neighbor queries for large files with objects stored in disk memories. We have qualitatively analyzed D-Index and verified its properties on actual implementation. We have also compared D-Index with other index structures and demonstrated its superiority on several real-life data sets. Contrary to tree organizations, the D-Index structure is suitable for dynamic environments with a high rate of delete/insert operations.     

周期性脉冲流体对滴流床反应器性能的影响

用铜铬催化剂催化的过氧化氢分解反应作为液体限制反应的例子来研究周期性脉冲流体对滴流床反应器性能的影响.初步研究表明:当催化剂非完全润湿时,周期性脉冲流体能够提高反应器的性能;当催化剂完全润湿时,周期性脉冲流体不能提高反应器的性能,甚至还会产生不利影响.     

快淬贮氢合金的活化性能与寿命

主要讨论了快淬钛基合金具有良好活化性能及较差循环寿命的机理。研究结果表明:快淬钛基合金电极浸泡在碱液中,合金元素V、Zr、Ti、Mn、Ni以不同速度溶解,其中Ni的溶解速度最慢,使合金电极表面富Ni。富Ni电极表面具有良好的动力学性能,快淬钛基贮氢合金的放电容量急剧衰退与损失大量可吸氢的V、Zr元素密切相关。     

铅基板栅合金综合性能探析

在Pb-Ca-Sn-Al合金的基础上尝试添加第五种合金元素，测试其电化学性能，并在理论上讨论了其性能提高的原因。     

数字化自动控制系统性能指标的测量方法

针对传统的自动控制系统性能指标的测量方法中存在的测量过程复杂,手工操作带来的测量结果误差大等不足,本文提出一种新的基于数字化测量的控制系统性能指标测量方法,实验证明,该方法可有效降低测量过程的复杂度和主观因素,提高测量数据的精确度.     

几种不稳定滞后对象的预测PID 控制

针对几种不稳定滞后过程，给出一种预测PID控制器的结构形式．该控制器具有内环和外环两种控制器：内环控制器主要用于稳定系统；外环控制器具有预测PID控制的结构形式，主要用于消除输入干扰的影响和改善控制系统的动态性能．这种控制器结构简单，可调参数少，且参数的调节方便、直观．仿真结果表明，在干扰和模型失配的情况下，此类预测PID控制器仍具有良好的控制性能和鲁棒稳定性能．     

一种异构网络环境中的性能管理策略

文中针对一种特殊环境下的异构网络,研究其环境下的通信过程中所呈现的传输特征。利用在网络监测过程中得到性能参数的统计信息对网络传输性能进行分析,并对网络性能管理中性能参数的变化规律进行讨论,论述了统计分析基本原理在性能评估中的应用。提出了在测量和分析过程中需要考虑的因素以及进行分析的方法,为管理人员直观了解网络运行状况提供了依据。     

Memory Management for Real-Time Java: An Efficient Solution using Hardware Support*

This paper addresses the issue of improving the performance of memory management for real-time Java applications, building upon the real-time specification for Java (RTSJ) from the Real-Time Java Expert Group. In a first step, a collecting dynamic memory solution including both a real-time garbage collector and region-based memory management, is proposed. A thorough analysis of the parameters influencing the performance of write barriers in memory management, together with ways of improvement are then presented. Finally, the implementation of a memory management solution compliant with the RTSJ and integrating the proposed improvements is sketched.     

A Scalable Interconnection Network Architecture for Petaflops Computing

Extrapolating technology advances in the near future, a computer architecture capable of petaflops performance will likely be based on a collection of processing nodes interconnected by a high-performance network. One possible organization would consist of thousands of inexpensive, low-power symmetric multiprocessor (SMP) nodes. Each node will inject data into the interconnection network at a very large rate and consequently, the interconnect scheme is one of the most crucial design issues affecting system performance. This paper describes the 2D simultaneous optical multiprocessor exchange bus (2D SOME-Bus) which has the potential to become the basis of a high-end computer architecture capable of petaflops performance. It consists of N horizontal, N vertical 1D SOME-Bus networks, and N ² nodes. Each node is connected to one horizontal and one vertical 1D SOME-Bus. Each of N nodes connected to one 1D SOME-Bus has a dedicated broadcast channel and an input channel interface based on an array of N receivers monitoring all N channels and allowing multiple simultaneous broadcasts. In the 2D SOME-Bus, messages being broadcast on one Bus can be broadcast in a cut-through manner on one or more Buses in the other dimension. This paper describes the optoelectronic devices and technology which make the 2D SOME-Bus possible, and the network interface organization. It also presents simulation results which compare the performance of the 2D SOME-Bus, the 1D SOME-Bus, the crossbar and the torus under the message-passing paradigm.