尘粒光电脉冲信号的采集与多道处理技术

在检测净化或超净化场所的含尘浓度和含粒粒度分布方面提出了一种全新的多道处理方法，依光的散射理论及威尔金线性放线法，使得尘粒粒度与通道地址之间确定了一种对应关系，从而给尘粒光电脉冲信号的实时处理带来了极大的方便。     

基于多DSP的滤波系统设计

多处理器并行系统是数字信号处理器的重要发展方向之一。文中首先介绍了ADSP2106x的硬件结构和高速处理性能;然后在时域和频域中分析了滤波处理的不同情况,结合ADSP2106X的并行特点设计了滤波系统,利用芯片独特的链路口进行4片DSP互连确保处理器间的通信,同时将剩余的链路口作为数据的输出口汇总数据结果,从而避免了总线的竞争状态,使得数据的处理速度得到大幅的提高,具有广阔的应用前景。     

A multiprocessor using protocol-based programming primitives

A general strategy is presented for multiprocessing that combines programming technique, machine architecture, and performance estimation. The programmer decomposes an application into manipulations of protocol-based programming primitives (protocols) usingPlans andscenarios from software engineering. The programmer may select from generic protocols, which include shared-memory locations and messages, or may build his own. A system architecture that supports efficient emlation of protocols is presented along with a method of estimating program performance based on network characteristics. Results are given from a protocol-based operating system on the 64 processor BTL Hypercube multiprocessor.     

Exploring cache performance in multithreaded processors

Multithreading is a well known technique to hide latency in a non-blocking cache architecture. By switching execution from one thread to another, the CPU can perform useful work, while waiting for pending requests to be processed by the main memory. In this paper we examine the effects of varying the associativity and block size on cache performance in a reduced locality of reference environment, due to multithreading. We find that for associativity equal to the number of threads, the cache produces very low miss rate even for small sizes. Also by taking into account the increase in cycle time due to larger cache size or associativity we find that the optimum cache configuration for best processor performance is 16Kbytes direct mapped. Finally, with a constant main memory bandwidth, increasing the block size to more than 32 bytes, reduces the miss rate, but degrades processor performance.     

Adam: An Ada-based language for multiprocessing

Adam is a high-level language for parallel processing. It is intended for programming resource scheduling applications, in particular supervisory packages for run-time scheduling of multiprocessing systems. An important design goal was to provide support for implementation of Ada and its run-time environment. Adam has been used to implement Ada task supervision and also as a high-level target language for compilation of Ada tasking. Adam provides facilities corresponding to the Ada sequential constructs (including subprograms, packages, exceptions, generics). In addition, it provides specialized module constructs for implementation of packages that may be shared between parallel processes, and new predefined types for scheduling. The parallel processing constructs of Adam are more primitive than Ada tasking. Strong restrictions are enforced on the ways in which parallel processes can interact. A compiler for Adam has been implemented in MacLisp on DEC PDP-10 computers. Runtime support packages in Adam for scheduling (on a single CPU) and I/O are also provided. The compiler contains a library manipulation facility for separate compilation. The Adam compiler has been used to build an Ada compiler for most of the July 1980 Ada, including task types and rendezvous constructs. This was achieved by implementing the translation of Ada tasking into Adam parallel processing as a preprocessor to the Adam compiler. This present Ada compiler, which has been operational since December 1980, uses a procedure call implementation of tasking. It can be easily modified to other implementations. Compilation of Ada tasking into a high-level target language such as Adam facilitates studying questions of correctness and efficiency of various compilation algorithms, and code optimizations specific to tasking, e.g. elimination of unnecessary threads of control. This paper gives an overview of Adam and examples of its use. Emphasis is placed on the differences from Ada. Experience using Adam to build the experimental Ada system is evaluated. Design of a run-time supervisor in Adam is discussed in detail.     

Structured flowcharts for multiprocessing

We present a flowchart language for parallel processing: in addition to the “standard” components, our flowcharts contain fork, join and synchronizing nodes. Extending the work of Mills, we suggest restrictions on controlling computation flow and show that any proper program can be algorithmically transformed to an equivalent structured program.     

Comparison of five multiprocessor systems

This paper generalizes the traditional dataflow model of computation and defines the essential problems in multiprocessing: control implementation, program partitioning, scheduling, synchronization, and memory access. The paper assumes that these essential problems are axes of a multiprocessor design space and that the solutions to these problems are values on the axes. Each point in the space represents a multiprocessor including a computational paradigm that a user must follow to achieve high performance and efficiency on the particular machine. Thus, a classification of machines from the user's point of view is introduced naturally. Five well-known multiprocessors are compared using this classification scheme.     

An incremental garbage collection algorithm for multi-mutator systems

An elementary correctness proof for Ben-Ari's algorithm (1984) for incremental garbage collection is given. We give a new algorithm for systems in which there are multiple mutators and a proof of its correctness, which is a minor modification of the previous proof. Finally, we remark upon a way to implement these algorithms that may increase their performance on certain architectures. Carl Pixley holds B.S., M.S. and Ph.D. degrees in mathematics from the University of Omaha, Rutgers-The State University, and the State University of New York at Binghamton, respectively. His principal contributions are the Pixley-Roy construction of set-theoretic topology, a example in the selection theory of infinite-dimensional spaces, a decomposition theorem (with W. Eaton) in geometric topology, and the design and implementation of demanddriven arithmetic in a functional programming language. He is now a member of the technical staff of the VLSI Computer Aided Design Program of Microelectronics and Computer Technology Corporation (MCC) in Austin Texas, where he is investigating mathematical methods in the verification of hardware.     

Low-cost hardware platform for developing realtime 3D graphics

BRAD3D, a low-cost hardware platform for the development of a realtime 3D graphics software is presented. The BRAD3D configuration is derived from a generalization of 3D image synthesis. Three basic processes have been identified: the geometric process, dealing with the measurements of the scene; the topologic process, extracting visible information from the polygonal structure; and the scan-conversion process, producing pixel values on a frame buffer. BRAD3D is implemented as a three-stage pipeline and accommodates depth-list and scan-line hidden-surface-removal algorithms. Each stage of the pipeline can be implemented using different hardware solutions. A microprocessor-based solution is presented as a general prototyping approach.     

A real-time intelligent multiple fault diagnostic system

Modern manufacturing systems and their failure modes are very complex, and efficient fault diagnosis is essential for higher productivity. However, traditional fault diagnostic systems that perform sequential fault diagnosis can fail during diagnosis when fault propagation is very fast. This paper describes a real-time intelligent multiple fault diagnostic system (RIMFDS). This system deals with multiple fault diagnosis, and is based on multiprocessing by using a strata hierarchical artificial neural network (SHANN). If another fault occurs while an existing symptom is being diagnosed, the corresponding diagnosis module is triggered, and the fault diagnosis module of the new faulty unit begins to diagnose the faults in real time. RIMFDS can diagnose multiple faults with fast fault propagation and complex physical phenomena. The system consists of two main parts. One is a personal computer for remote signal generation and transmission, and the other is a host system for multiple fault diagnosis. The signal generator generates various faulty signals and image information and sends them to the host. The host has various modules and agents for efficient multiple fault diagnosis. A SUN workstation is used as a host for multiple fault diagnosis and graphic representation of the results.