3Y／4Y换相法变极绕组的实际应用

详细介绍了对于YD31 5 6 4双速电机采用 3Y 4Y换相法的变极设计方案 ,得到较为理想的绕组磁势波形 ,试验证明主要技术参数均达到较好的水平。     

SR电机电压斩波方式电磁力分析

本文基于SR电机线性模型和定子振动简化模型 ,对SR电机 ,PWM运行方式下的切向力和径向力进行了仿真计算 ,对非能量回馈 (NERVC)和能量回馈 (ERVC)两种不同续流方式下切向力和径向力的大小进行了比较。本文研究对进一步开展SR电机振动抑制策略研究有较大意义。     

EPr／TN网可达性分析的冗余并发后继标识

文中针对ＥＰｒ／ＴＮ网在可达性分析时出现的冗余发后继现象，从产生原因入手，给出一种解决算法，并由此深入这种扩展Ｐｅｔｒｉ网固有不完备性，最后提出了改进方法。     

基于协议引擎的协议实现方法研究

为了从实现的角度解决网络协议相似性和多样性的矛盾，以及不同协议不同实现方法对系统资源的消耗和协议管理维护的复杂性问题，文中在分析了基于ＯＳＩ协议实现的基本问题的基础上，提出用面向对象方法和虚拟概念解决通用性难题，并且提出了基于协议引擎的协议实现方法，分析了它的结构特点和应用时的几点考虑，认为效率是主要评价因素，文中还给出了Ｊａｖａ环境上应用协议引擎网络管理模块和网关路由器的实现方案。     

酒钢3~#焦炉计算机加热控制系统

介绍了酒泉钢铁公司新建3#焦炉计算机加热控制系统的方案，硬件和软件配置；系统实际运行情况。     

Extracting Schema from an OEM Database

While the schema-less feature of the OEM(Object Exchange Modl)gives flexibility in representing semi-structured data,it brings difficulty in formulating database queries. Extracting schema from an OEM database then becomes an important research topic.This paper presents a new approach to this topic with th following reatures.(1)In addition to representing th nested label structure of an OEM database,the proposed OEM schema keeps up-tp-date information about instance objects of the database,The object-level information is useful in speeding up query evaluation.(2)The OEM schema is explicitly represented as a label-set,which is easy to construct and update.(3)The OEM schema of a database is statically built and dynamically updated.The time complexity of building the OEM schems is linear in the size of the OEM database.(4)The approach is applicable to a wide range of areas where the underlying schema is much smaller than the database itself(e.g.data warehouses that are made from a set of heterogeneous databases).     

并行工程模式下企业管理决策的几个问题及其求解

针对并行工程模式下企业管理决策的典型问题,建立一组以省时为优化目标的数学模型。这些模型能较好地表现并行工程哲理的并行性、约束性和协调性特征。讨论了模型的求解,并给出一个算例。     

Post-pass partitioning of signal processing programs

Symmetric multiprocessor systems are increasingly common, not only as high-throughput servers, but as a vehicle for executing a single application in parallel in order to reduce its execution latency. This article presents Pedigree, a compilation tool that employs a new partitioning heuristic based on the program dependence graph (PDG). Pedigree creates overlapping, potentially interdependent threads, each executing on a subset of the SMP processors that matches the thread’s available parallelism. A unified framework is used to build threads from procedures, loop nests, loop iterations, and smaller constructs. Pedigree does not require any parallel language support; it is post-compilation tool that reads in object code. The SDIO Signal and Data Processing Benchmark Suite has been selected as an example of real-time, latency-sensitive code. Its coarse-grained data flow parallelism is naturally exploited by Pedigree to achieve speedups of 1.63×/2.13× (mean/max) and 1.71×/2.41× on two and four processors, respectively. There is roughly a 20% improvement over existing techniques that exploit only data parallelism. By exploiting the unidirectional flow of data for coarse-grained pipelining, the synchronization overhead is typically limited to less than 6% for synchronization latency of 100 cycles, and less than 2% for 10 cycles. This research was supported by ONR contract numbers N00014-91-J-1518 and N00014-96-1-0347. We would like to thank the Pittsburgh Supercomputing Center for use of their Alpha systems.     

提高工作站机群系统通信性能方法的研究

工作站机群系统是目前并行处理技术的研究特点之一，而春网络通信的性能又是机群系统的关键。本文在分析影响系统性能因素的基础上，从软、硬件两方面着重讨论了高速网络技术，精简通信协议和Ａｃｔｉｖｅ Ｍｅｓｓａｇｅ通信机制等提高网络通信性能的方法。     

贯流式水轮机线性调速器研究

采用常规ＰＩＤ控制的贯流式水轮机调节系统在弧立运行时难以稳定。本在分析ＰＩＤ控制的不足之后，提出了状态反馈优化控制，从而从根本上改善了贯流式水轮机调节系统的稳定性和动态品质。