基于顺序表查找的学生成绩查询功能的实现

顺序表是一种常见的,用一组地址连续的存储单元依次存储数据元素的线性结构.在顺序表上进行查找有多种方法,其中最生要的是顺序查找和二分查找两种方法.用这两种方法实现学生成绩查询功能各有优缺点.     

Nanoelectronic SET-based core for network-on-chip architectures

Nanoelectronics is a very promising step the world of electronics is taking. It is proved to be more efficient than the microelectronic approaches currently in use, mainly in terms of area and energy management. A Single-Electron Transistor (SET) is capable of confining electrons to sufficiently small dimensions, so that the quantization of both their charge and their energy is easily observable, making the SET's quantum mechanical devices. These features should allow building chips with a number of devices orders of magnitude greater than indicated by the roadmap still respecting area and power consumption restrictions. In this sense, Tera Scale Integrated (TSI) systems can be feasible in the future. A digital module, such as an arithmetic logic unit, completely implemented with SETs has already been proposed and validated by simulation. In this work a completely SET based network-on-chip (NoC) nanoelectronic core is proposed. Furthermore, a simple NoC architecture based on that nanoelectronic core is also evaluated. It is shown that the SET-based NoC has a promising performance considering parameters such as power consumption, area and clock frequency. A simple comparison of mesh NoC chip prototypes is shown.     

市话程控用户光端机的研制及应用前景

本文从实用化角度,根据今后综合业务数字网(ISDN)发展的需要,着重介绍了市话程控用户光缆中继系统中用户光端机的设计原理、技术特点以及在用户系统中的应用。     

再流焊接设备性能评估方法

再流焊接工艺是电子组装三大工序之一,其工艺的精确性直接决定了产品焊接质量。但由于再流焊接工艺的不可视化,使其成为工艺控制的难点。参考IPC-9853标准可对再流焊设备及工艺进行科学的量化评估,使其透明可视化,有助于工艺优化及控制。     

Efficient clustering algorithms for self-organizing wireless sensor networks

Self-organization of wireless sensor networks, which involves network decomposition into connected clusters, is a challenging task because of the limited bandwidth and energy resources available in these networks. In this paper, we make contributions towards improving the efficiency of self-organization in wireless sensor networks. We first present a novel approach for message-efficient clustering, in which nodes allocate local “growth budgets” to neighbors. We introduce two algorithms that make use of this approach. We analyze the message complexity of these algorithms and provide performance results from simulations. The algorithms produce clusters of bounded size and low diameter, using significantly fewer messages than the earlier, commonly used, Expanding Ring approach. Next, we present a new randomized methodology for designing the timers of cluster initiators. This methodology provides a probabilistic guarantee that initiators will not interfere with each other. We derive an upper bound on the expected time for network decomposition that is logarithmic in the number of nodes in the network. We also present a variant that optimistically allows more concurrency among initiators and significantly reduces the network decomposition time. However, it produces slightly more clusters than the first method. Extensive simulations over different topologies confirm the analytical results and demonstrate that our proposed methodology scales to large networks.     

Efficient modeling and analysis of energy consumption for 3D graphics rendering

This paper proposes new models of GPU energy consumption from the perspectives of hardware architects and graphics programmers by performing an architecture-independent analysis of the classical graphics rendering pipeline which is still in widespread use today. The detailed analysis includes graphics rendering workload, memory bandwidth and energy consumption . Although the models are derived from classical 3D pipeline, they are extensible to programmable pipelines. There are many factors that affect the performance and energy consumption of 3D graphics rendering, such as the number of textures, vertex sharing, level of details, and rendering algorithms. The proposed models are validated by our simulation study and used to guide our 3D graphics hardware design and 3D graphics programming in order to optimize performance and energy consumption of our GPU prototypes which have been successfully fabricated in SMIC 0.13 μm CMOS technology.     

空调机组性能系数浅析

介绍了当前应用较多的几种空调机组性能系数的现状,说明了各自的定义及应用,重点说明了蒸发冷却空调机组的性能特点,并通过具体的测试数据,说明了蒸发冷却空调机组的优势.     

A blind SNR estimator for digital bandpass signals

A subspace-based blind Signal-to-Noise Ratio （SNR） estimation algorithm for digital bandpass signals in Additive White Gaussian Noise （AWGN） channel is discussed. The lower bounds of the mean and variance of the estimation are derived, and simulations are performed for the commonly used digital bandpass signals, such as MPSK （M=2, 4, 8）, MFSK （M=2, 4） and MQAM （M=16, 64, 128, 256） signals. Theoretical analyses and simulation results indicate that the proposed algorithm is effective even when the SNR is below 0dB. Furthermore, the algorithm can provide a blind estimator in that it needs neither the parameters of the received signals, such as the carrier frequency, symbol rate and modulation scheme, nor the synchronization of the system.     

Packet loss analysis in optical packet-switched networks with limited deflection routing

We present an approximate analytical method for the evaluation of packet loss probability in synchronous optical packet-switched networks which operate under limited deflection routing with the contention resolution method based on priorities. Packets are lost because they are removed by nodes. They are removed because they experience too many deflections and stay prohibitively long in the network. Such packets have to be removed because they will be ignored by the transmission protocols (like TCP) and because the quality of their optical signal is unacceptable. Presented are results for the network in the topology of the torus of the two-dimensional grid, which operates at a steady state with the uniform load u, . The strength of our analysis is its novel mathematical approach, which is capable of providing very low packet loss probabilities. For the network composed of 100 nodes, we predict the packet loss probability as low as 10⁻⁹ or lower, while simulation provided results only at the order of 10⁻⁶. For a given permissible packet loss probability, our analysis provides the maximal network load and the number of allowed deflections. We verify the analysis with simulation in the cases for which simulation gave results.

Performance Bound for LDPC Coded Unitary Space–Time Modulation

This paper is concerned with the bit error probability (BEP) of coded unitary space–time modulation systems based on finite-length low density parity check (LDPC) codes. The union bound on the BEP of the maximum likelihood (ML) decoding is derived for any code rate, unitary space–time constellation and mapping. The tightness of the bound is checked with simulation results of the ordered statistic decoding (OSD). Numerical and simulation results show that the union bound is also close to the error performance of the sum–product (SP) decoding at low BEP levels when Gray mapping is employed. The derived bound is useful to benchmark the error performance of finite-length coded unitary space–time modulation systems, especially for those that employ short-to-medium length LDPC codes.