Cell Broadband Engine Debugging for Unknown Events

The complexity of today's hundreds-of-million-transistor microprocessors all but guarantees imperfect first silicon, but leaves unanswered the question of what exactly will go wrong. This article describes features added to the cell broadband engine processor to enable debugging in the presence of such unknown events.     

人脸识别中的眼睛定位方法

眼睛是人脸部最重要的器官,因此眼睛准确定位在人脸识别中具有特殊重要的意义。基于灰度图像,提出一种改进的眼睛精确定位的方法。首先对图像进行光照和噪声的预处理,再利用积分投影和山谷法对图像进行分析,进而找出一系列的候选眼睛点,眼睛点的验证采用人脸的几何分布特征和眼睛模板匹配相结合的方法来进行最终眼睛对的确定。基于orl和yale人脸库的实验结果表明该算法对光照、旋转、遮挡不敏感,具有较高的定位准确率。     

三值光学计算机解码器亮度阈值自动测定技术

为了使三值光学计算机解码器对亮度各不相同的被解码图像都能做到准确解码,提出了根据灰度值对图像像素亮暗判定的阈值设定技术.其基本策略是找出各像素亮状态时的灰度最小值和暗状态时的灰度最大值,以亮状态灰度最小值下移10个灰度级为亮状态的判定阈值,以暗状态灰度最大值上移10个灰度级为暗状态的判定阈值.实验结果表明,以这样的两个阈值为判定标准,三值光学计算机解码器对光学处理器输出结果的判定准确度达到100％.     

一款可编程语音处理器的设计与应用

为了提高通信系统的保密性,降低制造成本,需要进行专用处理器的设计.该文基于SELP(Sinusoidal Excitation Linear Prediction)算法模型原理,设计了一款高质量多速率语音专用处理器芯片.芯片使用可重构体系结构和超长指令字系统设计方法,将复杂度高的子程序进行优化,能够显著提高指令并行度.仿真结果表明:在该芯片上实现语音压缩编码算法,执行效率高于相同工艺水平的通用数字信号处理器,并保持原有编码质量.该处理器能够实现多种类型的语音压缩算法,使语音算法可以达到高保密性、低复杂度和易开发性.     

基于程序行为特征比较的谓词切换排序

谓词切换（Predicate Switching）通过动态改变程序中的谓词判断语句状态观察程序运行结果的变化,分析可能与错误相关的关键谓词判断语句,从而实现辅助错误定位．谓词判断语句排序算法决定了谓词切换定位关键谓词判断语句的效率．已有的排序算法如LEFS算法定位效率较低;PRIOR算法虽然提高了定位效率,但必须首先做程序动态切片找寻与错误相关的谓词判断语句集合,而后建立程序依赖图以定义谓词判断语句的优先级,这个过程需要花费大量的时间,且算法复杂度较高．在这两种算法基础上提出一种新的改进排序算法,首先通过对比成功和失败的测试用例在运行中所展现出来不同程序行为特征,以此定义谓词判断语句的优先级,然后对不同优先级别的谓词根据执行先后顺序进行反向排序．基于基准测试集SiemensSuite的程序进行了实验,结果表明本文的排序算法与LEFS算法相比定位效率更高,与PRIOR算法相比减少定义谓词优先级的耗费,且算法更易于实现．     

MANET可用带宽测量和定位方法研究

MANET网络环境与有线网络不同,其可用带宽动态变化十分显著,目前基于传统有线网络理论的可用带宽的测量和定位方法不适用于MANET。在分析了现有带宽测量模型、工具和测量方法的基础之上,结合MANET无线带宽有限、动态多变等特点,提出了一种基于混杂包列的MANET可用带宽测量和定位方法。该方法结合了包对模型和包速率模型的思想,具有测量收敛时间短,测量负载小,测量精度高的特点,适用于MANET。最后通过仿真实验对该方法进行了模拟验证。     

IC卡在线检测的码号定位分割方法研究

针对IC卡的版面复杂性及版面质量，对IC卡在线检测中的码号定位分割问题进行了研究，提出了一种IC卡码号在线检测的定位分割方法。该方法采用预测样卡定位参数，结合初定位、宽区间定位、区间缩小精确定位对码号区定位，解决了不同版面、不同位置码号的IC卡定位问题。对定位方法进行了详细论述，采用求多投影直方图综合分割法对码号字符进行分割，有效地解决了IC卡在线检测中码号的定位分割问题。实验结果表明了方法的可行性与实用性。     

On a lower bound on the computational complexity of a parallel implementation of the branch-and-bound method

We study parallel complexity of the branch-and-bound method for optimization problems. We consider a standard implementation scheme for the branch-and-bound method on a parallel system, in which first only one processor is working, and then the resulting subtasks are given out to other processors. For this scheme, we give a lower bound on the parallel complexity independent of the problem. We study the complexity of this scheme for the Boolean knapsack problem. For a classical algorithmically hard example, we obtain parallel complexity bounds and show that these bounds coincide in order with each other and with the common lower bound on parallel complexity. Thus, we show that the common lower bound is achieved, in the order, for some optimization problems.     

Thread-Sensitive Instruction Issue for SMT Processors

Simultaneous Multi Threading (SMT) is a processor design method in which concurrent hardware threads share processor resources like functional units and memory. The scheduling complexity and performance of an SMT processor depend on the topology used in the fetch and issue stages. In this paper, we propose a thread sensitive issue policy for a partitioned SMT processor which is based on a thread metric. We propose the number of ready-to-issue instructions of each thread as priority metric. To evaluate our method, we have developed a reconfigurable SMT-simulator on top of the SimpleScalar Toolset. We simulated our modeled processor under several workloads composed of SPEC benchmarks. Experimental results show around 30% improvement compared to the conventional OLDEST_FIRST mixed topology issue policy. Additionally, the hardware implementation of our architecture with this metric in issue stage is quite simple.     

Simple and robust methods for support vector expansions

Most support vector (SV) methods proposed in the recent literature can be viewed in a unified framework with great flexibility in terms of the choice of the kernel functions and their constraints. We show that all these problems can be solved within a unique approach if we are equipped with a robust method for finding a sparse solution of a linear system. Moreover, for such a purpose, we propose an iterative algorithm that can be simply implemented. Finally, we compare the classical SV approach with other, recently proposed, cross-correlation based, alternative methods. The simplicity of their implementation and the possibility of exactly calculating their computational complexity constitute important advantages in a real-time signal processing scenario     

基于TMS320C6203的实时弱目标跟踪研究

介绍一种基于DSP实现弱目标跟踪的方法,该系统主要是以高速数字信号处理器TMS320C6203作为核心器件,并与FPGA和CPLD相结合跟踪弱目标。首先通过统计像素数的方法粗略计算目标位置,根据获得目标的位置和大小进行局部精确搜索,减少计算量,然后采用重心跟踪结合线性预测的方法对目标进行跟踪,通过串口通讯在显示器上我们可以看到跟踪结果。实验结果表明可以对目标进行准确定位,达到实时跟踪的目的。     

Graceful degradation in algorithm-based fault tolerantmultiprocessor systems

Algorithm-based fault tolerance (ABFT) is a technique which improves the reliability of a multiprocessor system by providing concurrent error detection and fault location capability to it. It encodes data at the system level and modifies the algorithm to operate on the encoded data in order to expose both transient and permanent faults in any processor. Work done till now in this area takes care of only the fault detection and location part of the problem. However, if spare processors are not available, then after a faulty processor has been located, the work initially assigned to it has to be mapped to some nonfaulty processors in the system in such a way that the fault tolerance capability of the system is still maintained with as small a degradation in performance as possible. In this paper, we propose an integrated deterministic solution to the above problem which combines concurrent error detection and fault location with graceful degradation. There exists no previous deterministic ABFT method for the design of general t-fault locating systems, even for the case of t=1. We propose a general method for designing one-fault locating/s-fault detecting systems. We use an extended model for representing ABFT systems. This model considers the processors computing the checks to be a part of the ABFT system, so that faults in the check computing processors can also be detected and located using a simple diagnosis algorithm, and the checks can be mapped to other nonfaulty processors in the system     

基于IXP1200入侵检测系统的流量分配器的研究

入侵检测系统是一种维护网络安全的手段。文章提出了基于网络处理器和处理机群的入侵检测系统的体系结构，详细讨论了利用网络处理器实现流量分配器功能，并对其中的关键算法进行了介绍。研究结果表明，经过算法优化，采用网络处理器IXP1200实现的流量分配器可以完成1000Mbps以上数据的实时采集，基于CAM技术的转发策略在维护信息完整性和降低处理复杂度两方面体现了很好的折中，达到了合理的流量分配。     

高效能ESCA协处理器验证技术研究

处理器结构的日益复杂使得对处理器功能进行有效验证变得越来越重要和关键。基于一款高效能计算协处理器ESCA,讨论了边界值验证、等价类验证和决策表验证等三类验证方法在ESCA处理器功能验证中的具体实现,并针对ESCA处理器中不同功能模块的基本特性提出了一种综合验证方法。实验结果表明,采用综合验证方法进行的ESCA处理器功能验证,不仅高效保证了验证案例集的生成,而且以较少的验证工作量实现了100%功能覆盖率,有效减少了ESCA处理器功能验证时间,提高了验证效率。     

龙芯3号板卡HT互联及内存故障诊断方法的设计与实现

龙芯3号处理器广泛应用于安全可靠领域,这类主板器件密度大,板贴程度高,故障检测难度大;需要在确保硬件高可靠的同时加强设备自检测和故障自诊断设计;基于龙芯3号计算机主板HyperTransport (HT)互联和内存出错两类常见的故障,提出了软件辅助故障诊断和可靠性增强的方法,为工厂的维修保障工作提供了有效的软件辅助定位故障的方法;经实验测试,该方法可以快速高效地定位龙芯3号主板故障,提高了维修保障效率。     

啤酒瓶凸性模号图像预处理算法

目前关于图像的锐化、二值化与图像分割的算法很多,而具体到实际工程当中所选择的算法则是千差万别。本文集中讨论了常用算法在啤酒瓶凸性模号识别系统中的特点,并选择Sobel算子法和方差分析法进行操作;并在图像分割过程中提出一种简便快速的字符定位方式,基本可以准确标定凸性字符位置,完成预处理过程。     

A fuzzy RISC processor

We describe application-specific extensions for fuzzy processing to a general purpose processor. The application-specific instruction set extensions were defined and evaluated using hardware/software codesign techniques. Based on this approach, we have extended the MIPS instruction set architecture with only a few new instructions to significantly speed up fuzzy computation with no increase of the processor cycle time and with only minor increase in chip area. The processor is implemented using a reconfigurable processor core which was designed as a starting point for application-specific processor designs to be used in embedded applications. Performance is presented for three representative applications of varying complexity     

PSO随机数参数设置的多目标定位方法研究

为了解决林业部门对森林防火安全监测系统中对多个声音目标的跟踪及定位问题,根据声音能量随距离衰减模型,提出了采用粒子群算法(PSO)的多目标定位与优化方法.通过利用极大似然法对声音强度模型的定位算法,采用惯性权重的粒子群算法,着重讨论了随机参数不同的设置方法对定位追踪精度性能的影响.通过仿真实验证明,粒子群算法中设置随机数参数为常数,可以有效提高目标定位精度,并减小搜索复杂度.     

基于TMS320DM6446的数字电影放映系统设计

在以数字多媒体处理器TMS320DM6446为核心的硬件平台上,采用达芬奇技术提出了一种新型数字电影放映系统的设计方案,并提出了应用达芬奇处理器开发数字视频产品的一般方法。该方案充分利用了达芬奇处理器高效性与编程灵活性的特点,通过使用达芬奇技术提供的系统组件和开发工具,极大地简化了数字电影放映系统软件开发的复杂性。     

啤酒瓶凸性模号图像预处理算法

目前关于图像的锐化、二值化与图像分割的算法很多,而具体到实际工程当中所选择的算法则是千差万别.本文集中讨论了在啤酒瓶凸性模号识别系统中的特点,并选择Sobel算子法和方差分析法进行操作.并且在图像分割过程中,提出一种简便快速的字符定位方式,基本可以达到准确标定凸性字符位置,完成预处理过程.