一种改进的基于遗传算法的测试调度方法

提出了一种改进的基于遗传算法的So C测试调度方法,通过该方法可以有效地优化测试总线的划分,合理调度各个IP核以实现并发测试,能够有效地缩短芯核测试时间。该算法把测试调度问题的可行解集用种群表示,逐代演化产生出越来越好的近似解。详细分析了该算法过程,对2002年国际测试会议(ITC’02)所提供的So C国际基准电路进行测试调度实验,实验结果表明,此算法比传统的整数线性规划(ILP)和遗传算法的结果要好。     

基于TAM分组策略的SoC测试多目标优化设计

在片上系统芯片（System-on-Chip ,SoC）测试优化技术的研究中,测试时间和测试功耗是相互影响相互制约的两个因素。在基于测试访问机制（Test Access Mechanism ,TAM ）分组策略的基础上,以测试时间和测试功耗为目标建立了联合优化模型,运用多目标遗传算法对模型进行求解。以ITC’02标准电路中的p93791电路为实例进行验证,表明此方法能够在测试时间和测试功耗的优化上获得较理想的解,且能提高TAM通道的利用率。     

基于遗传算法的NoC互连测试研究

针对互连测试难题的分析,提出一种基于遗传算法的NoC互连测试方案。该方案采用NoC重用测试机制的方法,在功耗限制条件下,选取合适的测试端口和最短测试路径,同时根据互连测试中实际存在的问题,对算法进行适当改进,建立基于遗传算法的NoC互连测试模型,旨在获取最优矢量集的同时,测试代价更小。当NoC的规模达到一定程度时,采用划分测试方法,缩短测试路径,降低测试时间,提高测试效率。以SoCIN结构电路为仿真平台,分别对不同规模的NoC进行实验仿真。实验结果表明,遗传算法能快速有效地收敛到最优解,在测试运行代数及测试生成时间上取得了良好的测试效果。     

基于IP核的芯片级测试结构研究

分析了芯片级测试的特点以及与传统板级测试区别,对SOC测试结构的核心部分测试访问机制(TAM)和Wrapper进行了详细的论述,分析了系统级芯片的测试结构及其优化.     

基于SoC芯片测试结构的研究

由于芯片规模的快速增长,给测试技术带来了新的挑战。结合系统芯片SoC测试结构的描述,对其核心部分测试外壳Wrapper和测试访问机制TAM做了论述,介绍了几类典型的测试访问机制TAM,分析其特点。同时对SoC的测试规划问题进行了讨论,指出了目前SoC测试面临的问题。     

单元测试中访问权限受限的成员函数的测试

本文详细介绍了在面向对象语言的单元测试中，访问权限受限的成员函数测试的必要性，并进一步讨论了在Java语言中利用反射机制突破访问权限的限制，完成受限函数测试的具体实现方法。解决了在正常情况下无法对访问权限受限的成员函数进行有效测试的问题，大大提高了开发速度和软件质量。     

结合DL-safe规则发现日志本体频繁模式的方法

为发现语义Web使用记录中所蕴含的有效信息,本文提出了一种挖掘日志本体频繁Web访问模式的方法。该方法引入应用访问规则集和观察集分别表示日志信息动态变化的语义规则和使用事实,并在DL安全的限定下将日志本体和应用访问规则集相结合构成一个推理过程可判定的混合知识库。在此基础上,利用日志本体中事件整分关系的语义构建访问模式学习的事务模型,并采用ILP的方法学习生成频繁用户访问模式树,解决了推理访问模式中非描述逻辑原子的问题。实验结果表明该方法的可用性和有效性。     

一种基于微处理器的SOC自测试方案

提出了一种基于片上微处理器和透明路径测试访问的SOC自测试方案。以片上微处理器为测试加载和响应收集比较的主体,构造透明路径并行传输测试数据,以嵌入程序控制测试过程。可以在提高测试速度的同时,降低对测试设备性能的依赖,并可以进行全速测试,所需额外面积开销较小。实验表明,该测试方案是有效的。     

温度约束下SoC测试总线分配算法研究

研究了SoC测试外壳与测试访问机制的设计,在温度约束条件下,提出了改进的测试总线分配算法。算法中应用了温度叠加模型,并针对温度约束,在算法中加入压缩过程。在严格的温度限制下,该算法能够找到测试时间更短的测试结构。     

基于BS架构的分布式文件数据并行访问方法

当前的分布式文件数据并行访问矩阵多为单结构,且访问的识别范围较小,导致访问耗时延长。为此,本文对基于BS架构的分布式文件数据并行访问方法进行设计与分析,根据实际的访问需求和标准,进行基础并行访问数据预处理;采用多阶的形式,扩大访问的识别范围,设计多阶交叉并行访问矩阵,构建BS架构分布式文件数据并行访问模型;采用自适应转换修正实现并访问处理。测试结果表明,对比于传统Spring分布式文件数据并行访问测试组、传统CP-ABE分布式文件数据并行访问测试组,此次设计的BS架构分布式文件数据并行访问测试组最终得出的分布式文件数据并行访问耗时均被较好地控制在0.2s以下,说明此种访问方法的针对性和稳定性更高,在BS架构的辅助下,可以加强对访问误差的控制,具有实际的应用价值。     

A Graph-Based Approach to Power-Constrained SOC Test Scheduling

The test scheduling problem is one of the major issues in the test integration of system-on-chip (SOC), and a test schedule is usually influenced by the test access mechanism (TAM). In this paper we propose a graph-based approach to power-constrained test scheduling, with TAM assignment and test conflicts also considered. By mapping a test schedule to a subgraph of the test compatibility graph, an interval graph recognition method can be used to determine the order of the core tests. We then present a heuristic algorithm that can effectively assign TAM wires to the cores, given the test order. With the help of the tabu search method and the test compatibility graph, the proposed algorithm allows rapid exploration of the solution space. Experimental results for the ITC02 benchmarks show that short test length is achieved within reasonable computation time.     

AFDX-TAP设备研究与实现

提出了一种串联植入式的AFDX网络TAP设备实现方法,从AFDX组网方式分析验证该TAP设备可以实现对AFDX网络的透明监测,并针对这种实现方式,提出软硬件解决方案,验证了该串联植入方式的TAP设备,可以有效地监测AFDX网络的工作状态和测试航空交换式以太网的可靠性与稳定性。     

OCDMA在光接入网中的应用方案

文章对光接入网（OAN）中光码分多址（OCDMA）方式进行了研究分析，并进行了计算机模拟，结果表明，在OAN中引入OCDMA技术，不需网络同步，在下行方向有很好的安全性，用户和业务可随机接入，可构成灵活的通用接入网传输平台。     

基于动态门限的战术数据链MAC协议

战术数据链（TDL）的作用就是在战场上能够更准确、有效和快速地传递战术情报。随着军事信息技术的发展,战场上的节点数量和传输数据呈现快速增长趋势。传统的战术数据链媒介访问控制（MAC）协议为了保证QoS,一般采用固定资源分配的多址访问算法,如TDMA,在面对大容量、高速率的需求时缺乏灵活性和有效性。为此,研究了基于统计优先级多址访问（SPMA）算法,提出了直接映射和差分趋势两种动态门限方法。仿真结果表明,动态门限比固定门限能够有效提高系统效率,更接近目标信道忙闲比设计,并且在相同负载下网络吞吐量也较固定门限高。     

Test Wrapper and Test Access Mechanism Co-Optimization for System-on-Chip

Test access mechanisms (TAMs) and test wrappers are integral parts of a system-on-chip (SOC) test architecture. Prior research has concentrated on only one aspect of the TAM/wrapper design problem at a time, i.e., either optimizing the TAMs for a set of pre-designed wrappers, or optimizing the wrapper for a given TAM width. In this paper, we address a more general problem, that of carrying out TAM design and wrapper optimization in conjunction. We present an efficient algorithm to construct wrappers that reduce the testing time for cores. Our wrapper design algorithm improves on earlier approaches by also reducing the TAM width required to achieve these lower testing times. We present new mathematical models for TAM optimization that use the core testing time values calculated by our wrapper design algorithm. We further present a new enumerative method for TAM optimization that reduces execution time significantly when the number of TAMs being designed is small. Experimental results are presented for an academic SOC as well as an industrial SOC.     

Two Auction-Based Protocols for Fair and Fast Resource Assignment in Wireless PCS

The Resource Auction Multiple Access (RAMA) protocol was recently proposed for fast resource assignment in wireless PCS networks. The protocol assigns communication resources to subscribers using a collision resolution method based on subscriber ID's. In each auction cycle, the subscriber with the highest ID will obtain the resource. Thus the RAMA protocol encounters the unfairness problem since subscribers with lower ID's might be delayed forever. In this paper, we propose two modifications to the RAMA protocol to solve the unfairness problem. The first modification forces the RAMA protocol to process requests in bursts, i.e., new requests are not processed until the current burst of requests are all satisfied. The second modification asks the base station to select subscribers randomly instead of the one with the highest ID. We derive mathematical models to compare the performances of proposed and original protocols. Performance results indicate that the modification of random selection is fairer than other protocols in terms of the waiting time distribution.     

A Priority MAC Protocol to Support Real-Time Traffic in Ad Hoc Networks

Carrier sense multiple access and its variants have been widely used in mobile ad hoc networks. However, most existing access mechanisms cannot guarantee quality for real-time traffic. This paper presents a distributed medium access control protocol that provides multiple priority levels for stations to compete for the wireless channel. One common channel is assumed to be shared by all stations. Stations are assumed to be able to hear each other (i.e., the network is fully connected). The channel is accessed by stations according to their priorities, and for stations with the same priority, they send frames in a round robin manner. The channel access procedure is divided into three stages: priorities classification period, ID initialization period, and transmission period. Simulation results indicate that our protocol provides high channel utilization and bounded delays for real-time frames.     

Downlink multiple access schemes for transmitted reference pulse cluster UWB systems

Transmitted reference pulse cluster (TRPC) signaling was recently proposed for low data rate ultra‐wideband communications. Compared with the conventional transmitted reference (TR), TRPC has a more compact and uniform spacing for the reference and data pulses and therefore solves the implementation problem posed by the long delay line requirement in the conventional TR. In this paper, downlink multiple access issue is further investigated for TRPC systems. According to the TRPC signaling structure, both code division multiple access (CDMA) and time division multiple access (TDMA) methods are discussed. Theoretical analysis and simulation results show that TDMA outperforms CDMA in both bit error rate performance and throughput. Copyright © 2010 John Wiley & Sons, Ltd.     

ITRI‐WiMAXT: A WiMAX conformance testing tool

The WiMAX Forum certifies and promotes the compatibility and interoperability of broadband wireless products where many testcases need to be developed for WiMAX procedures. In this paper, we develop a conformance test tool called ITRI‐WiMAXT based on the TTCN‐3 specifications. Then we show how WiMAX procedures are tested in ITRI‐WiMAXT. Based on ITRI‐WiMAXT, we have proposed several test procedures accepted by the WiMAX Forum. Copyright © 2009 John Wiley & Sons, Ltd.