DS/FH通信系统Simulink仿真分析

利用Simulink工具构建了基于GMSK调制的DS／FH通信系统仿真模型,对系统性能进行仿真分析。仿真结果表明,GMSK作为一种理想的数字调制方式应用于DS／FH通信系统,可获得良好的频谱效益和抗干扰特性,能实现DS／FH通信系统的高速数据传输。     

烟草行业企业信息化管理研究

烟草信息化带来生产经营过程的集成化、数字化、智能化、电子化和网络化,使传统的烟草行业企业的管理形式发生了根本性变革,给烟草行业企业的信息化管理提出了严峻的挑战。本文分析了信息化管理的内涵,以及烟草行业企业进行信息化管理的必要性,最后提出了烟草行业企业进行信息化管理的策略。     

Software testing processes as a linear dynamic system

Software testing is essential for software reliability improvement and assurance, and the processes of software testing are intrinsically dynamic. However they are seldom investigated in a mathematically rigorous manner. In this paper a theoretical study is presented to examine the dynamic behavior of software testing. More specifically, a set of simplifying assumptions is adopted to formulate and quantify the software testing processes. The mathematical formulae for the expected number of observed software failures are rigorously derived, the bounds and trends of the expected number of observed software failures are analyzed, and the variance of the number of observed software failures is examined. On the other hand, it is demonstrated that under the simplifying assumptions, the software testing processes can be treated as a linear dynamic system. This suggests that the software testing processes could be classified as linear or non-linear, and there be intrinsic link between software testing and system dynamics.     

Test frame updating in CPM testing of Prolog programs

Category Partition Method (CPM) is a general approach to specification-based program testing, where test frame reduction and refinement are two important issues. Test frame reduction is necessary since too many test frames may be produced, and test frame refinement is important since during CPM testing new information about test frame generation may be achieved and considered incrementally. Besides the information provided by testers or users, implementation related knowledge offers alternative information for reducing and refining CPM test frames. This paper explores the idea by proposing a call patterns semantics based test frame updating method for Prolog programs, in which a call patterns analysis is used to collect information about the way in which procedures are used in a program. The updated test frames will be represented as constraints. The effect of our test frame updating is two-fold. On one hand, it removes “uncared” data from the original set of test frames; on the other hand, it refines the test frames to which we should pay more attention. The first effect makes the input domain on which a procedure must be tested a subset of the procedure’s input domain, and the latter makes testers stand more chance to find out the faults that are more likely to show their presence in the use of the program under consideration. Our test frame updating method preserves the effectiveness of CPM testing with respect to the detection of faults we care. The test case generation from the updated set of test frames is also discussed. In order to show the applicability of our method an approximation call patterns semantics is proposed, and the test frame updating on the semantics is illustrated by an example.

A single layer zero skew clock routing in X architecture

With its advantages in wirelength reduction and routing flexibility compared with conventional Manhattan routing, X architecture has been proposed and applied to modern IC design. As a critical part in high-performance integrated circuits, clock network design meets great challenges due to feature size decrease and clock frequency increase. In order to eliminate the delay and attenuation of clock signal introduced by the vias, and to make it more tolerant to process variations, in this paper, we propose an algorithm of a single layer zero skew clock routing in X architecture (called Planar-CRX). Our Planar-CRX method integrates the extended deferred-merge embedding algorithm (DME-X, which extends the DME algorithm to X architecture) with modified Ohtsuki’s line-search algorithm to minimize the total wirelength and the bends. Compared with planar clock routing in the Manhattan plane, our method achieves a reduction of 6.81% in total wirelength on average and gets the resultant clock tree with fewer bends. Experimental results also indicate that our solution can be comparable with previous non-planar zero skew clock routing algorithm. Supported in part by the National Natural Science Foundation of China (Grant No. 60876026), and the Specialized Research Fund for the Doctoral Program of Higher Education (Crant No. 200800030026)     

多重链路网络分区与QoS度量两级并行QoSR算法

在多重链路上联网络环境下,采用并行路由搜索的思想寻找最优路径,能够获得较好的路径寻优结果,并且算法的时间复杂度较低.给出一种两级并行QoSR算法,将多重链路环境按一定规则划分为若干分区,为每个分区分配一定数量的QoS度量并行处理器和1个分区处理器,在各个分区分别采用QPAS算法,由QoS度量并行处理器并行计算出各分区内的QoS度量Pareto最佳路径,最终由分区处理器调用最短路径并行算法完成分区间代价最小路径的计算.     

基于关键词设置的P2P信息检索

在分析以往结构化P2P基于单关键词分割的信息检索基础上,结合利用用户频繁出现的请求关键词的特点,提出结构化P2P中的一个基于请求关键词设置的索引框架KS-PIR。采用通过关键词联合的新特征项设置来扩充索引特征,并删节与特征项相关的索引记录表至恒定长度的方法,在检索质量提高的同时,又保证了可接受的带宽消耗,系统具有很好的扩展性。     

浅谈网上银行存在的问题及解决办法

网上银行支持在网络上进行交易的虚拟银行。只要能够上网,无论身在何处,都能够安全便捷地管理自己的资产和享受银行提供的服务。然而网上银行存在诸多的安全问题。本文就针对这些安全问题提出相应的解决办法。     

TS201 LINK口通信的关键设计与实现

针对DSP芯片TS201的LINK口互连在高速数据通信中存在数据错误、突发数据块传输不稳定等缺点,在分析其通信协议的基础上,并结合实际应用,提出了设计LINK口通信的关键要求,给出设计的要点,设计与实现了TS201的LINK口互连以及FPGA(Xilinx公司的XC4VFX60)与TS201 LINK口互连,得到了实际测试结果;结果表明,所设计的LINK口互连具备的优点有:1)DSP之间通信可以达到单向600MB/s,双向1.2GB/s;2)DSP与FPGA之间通信可以达到单向450MB/s,双向900MB/s;3)LINK口的通信具备稳定、突发数据块传输无错误等性能。     

Information-Driven Sensor Path Planning by Approximate Cell Decomposition

A methodology is developed for planning the sensing strategy of a robotic sensor deployed for the purpose of classifying multiple fixed targets located in an obstacle-populated workspace. Existing path planning techniques are not directly applicable to robots whose primary objective is to gather sensor measurements using a bounded field of view (FOV). This paper develops a novel approximate cell-decomposition method in which obstacles, targets, sensor's platform, and FOV are represented as closed and bounded subsets of an Euclidean workspace. The method constructs a connectivity graph with observation cells that is pruned and transformed into a decision tree from which an optimal sensing strategy can be computed. The effectiveness of the optimal sensing strategies obtained by this methodology is demonstrated through a mine-hunting application. Numerical experiments show that these strategies outperform shortest path, complete coverage, random, and grid search strategies, and are applicable to nonoverpass capable robots that must avoid targets as well as obstacles.