面向软硬件协同设计的性能优化框架

面对高性能计算机系统随着性能的提高其复杂性成倍增大的挑战,研究了复杂科学计算应用的优化,提出了一种面向软硬件特性设计的性能优化框架CPTF。该框架根据应用在运行时的剖析结果,结合应用的软件特性和平台的硬件特性,全局性地分析系统性能瓶颈及种类,并给出源码级的优化建议,并针对优化循环一类常见的问题,提出一种改进的循环合并算法。使用CPTF优化了一个物质点法粒子模拟应用,取得了近20%的性能提升。     

面向多处理器SoC设计的低功耗软硬件划分

提出了解决多处理器SoC的低功耗软硬件划分问题的方法--基于神经网络的禁忌搜索算法.其基本思想是:真实的生物神经元具有抑制重复激活的阻尼特性,这与禁忌搜索对重复搜索加以限制相类似,因此设计具有阻尼特性的神经网络实现禁忌搜索算法,受阻尼特性抑制的神经元对应禁忌活动.由于神经网络复杂的动态特性和禁忌搜索优秀的全局搜索能力,该算法能够有效地跳出局部最优解.对真实任务图的实验表明,与遗传算法相比,该算法不但具有搜索速度上的优势,而且所得到的绝大部分软硬件划分方案有更低的系统功耗.     

Optimal design and performance evaluation of a metal fiber filter for capturing radioactive aerosols

ABSTRACT

Conventional high-efficiency particulate air (HEPA) filters made of glass fiber media are prone to recycling problem and restrictions in extreme environmental condition such as high flow rate, high temperature, and fire. Therefore, metal fiber filters with minimal maintenance can replace conventional HEPA filters. The objective of the study is to evaluate the theoretical and experimental characteristics of a SUS316L metal fiber filter made from the fiber diameter of 8 µm. Theoretical modeling for predicting the collection efficiency of the radioactive aerosol is performed on the metal fiber as a function of particle size, filter thickness, and flow rate. Comparison between the experimental and theoretical results demonstrates that they are in good agreement. Consequently, the model is later utilized for performance optimization of the metal fiber filter. Also the metal filter for collecting the radioactive aerosol is optimized at the particle collection efficiency of 99.97% in most penetrating particle size (MPPS) of region 0.3 µm which complies with the standards established for conventional glass fiber HEPA filters.     

单轴转台控制系统软硬件设计与搭建

为满足惯导测试的综合需要,研究具有角位置、角速率、角振动三个功能的单轴转台控制系统的实现方法.根据功能要求,进行控制系统硬件总体方案设计和主要部件选型,进而建立转台的数学模型,进一步分析了电机伺服驱动原理和控制算法,给出了控制参数整定方法,并设计了上位机控制软件.经过坐标变换,三相永磁同步电机可转换为直流电机,即一个二...     

Optimal structural design under dynamic loads

This paper presents an algorithm for optimal design of elastic structures, subjected to dynamic loads. Finite element, modal analysis and a generalized steepest descent method are employed in developing a computational algorithm. Structural weight is minimized subject to constraints on displacement, stress, structural frequency, and member size. Optimum results for several example problems are presented and compared with those available in the literature.     

A hardware software co-design method for control transfer optimization in binary translation system

针对控制转移开销是影响二进制翻译和优化系统性能的主要因素,进行了提高二进制翻译优化系统性能的研究,提出并实现了硬件设计开销较小的基于硬件内容可寻址存储器(CAM)机制的软硬件协同设计方法.通过实验充分分析了CAM大小、软件替换算法对CAM命中率的影响,并根据分析提出了一种新颖的、软硬件结合的降低CAM访问缺失率的方法.该方法相对于传统的软件和硬件优化方法,硬件实现及验证复杂度低且优化效果明显.实验结果表明该方法使得二进制翻译系统整体性能提高了13.44％.该方法已实际应用于龙芯x86二进制翻译系统中.     

Combined hardware and software aspects of reliability

This paper presents the similarities and differences between hardware, software and system reliability. Relative contributions to system failures are shown for software and hardware and failure and recovery propensities are also discussed. Reliability, availability and maintainability (RAM) concepts have been broadly developed for software reliability than hardware reliability. Extending these software concepts to hardware and system reliability helps in examining the reliability of complex systems. The paper concludes with assurance techniques for defending against faults. Most of the techniques discussed originate in software reliability but apply to all aspects of a system. Also, the effects of redundancy on overall system availability are shown.     

软件系统安全性设计原则分析

软件系统安全缺陷是所有常见计算机安全性问题的根源，而其安全性又是一个涉及面广泛而又复杂的课题，其最大难题之一是：总有可能出现与所有已知模式完全不符合的新型安全性缺陷。因此，要保护免软件受各种可能类型，包括未知类型的攻击是不切实际的，但可以通过在设计和构建软件时运用合理的系统安全性原则来避免软件陷入容易被攻击的状况。本文对软件开发过程中的五项系统安全性设计原则进行了分析，包括保护最薄弱环节、纵深防御、故障保护、最小特权以及分隔原则。     

复合材料层合板及机翼格栅结构的动态特性优化设计

以复合材料层合板各单层连续变化的铺层角度为设计变量, 在有限元软件中对层合板结构的基频进行优化分析, 在四边简支和固支两种不同的边界条件下, 结构的基频分别提高了4.9%和16.2%, 并对优化前后结构的静力失效强度进行了对比分析。随后将这种优化方法应用到某无人机复合材料机翼格栅结构中, 针对格栅结构蒙皮和肋板共计24个纤维铺层角度进行了优化设计, 使结构基频提高了10.6%, 同时结构的承载能力也有了一定程度的提高。     

矿井WiFi视频传输系统软硬件设计与实现

针对矿井光线强度不够、瓦斯防爆、坑道弯曲多变等引起的多媒体信号获取困难与传输环境恶劣等问题,研制了高效的WiFi视频传输系统,并应用于矿井通信场合.采用嵌入式ARM处理器、红外CCD摄像头、WiFi模块等器件构造基本硬件传输处理平台,在软件上采用H.264视频编解码、RTP/UDP封装、WiFi快速切换等信息获取与传输机制,最终研制了满足煤矿多媒体监管所需的高效、低功耗井下无线多媒体终端系统.经工程实践验证,该系统适应井下弱光甚至全暗、防爆、低功耗、复杂链路等工作环境,并取得了较好的井下WiFi视频传输效果.因此,所设计的矿井WiFi传输系统能有效消除井下恶劣信道环境的影响,实现低成本实时宽带视频信息传输,可在矿井安全监控管理等场合广泛应用.     

计算机噪声仿真的软硬件设计方法

本文结合具体科研项目，提出两种实用计算机噪声仿真方法，方法之一是根据噪声分析程序提供时域波形数据文件，通过格式处理形成ＷＡＶ文件，然后在声卡上播放。另一种方法是在ＰＣ机的打印机接口处外接专门放音装置，这两种办法依据充分，方法切实可行，达到工程实用，对工业噪声的主要评价分析及噪声控制的研究提供了强有力的开发工具。     

Aviation software and hardware diagnostic unit for monitoring cross-country gas pipelines

The main components of a software and hardware diagnostic unit that makes it possible to perform remote laser probing of cross-country gas pipelines from on board an aircraft are considered. Results are provided for flying tests of the unit for a simulated gas leakage processed using special software. Translated from Izmeritel’naya Tekhnika, No. 2. pp. 41–44, February, 2009.     

火灾报警控制系统的优化设计

为了提高火灾报警控制系统的通用性及可靠性,分析了国内广泛使用的火灾报警控制系统的产品特性和目前设计中所存在的问题．利用各厂家产品在网络构成、设计、布线上的共通性,指出火灾报警控制系统通用性设计的必要性及可能性,提出了一种新的设计方法,使之能较合理可靠地适用于目前大多数的主流产品,极大地提高系统的可靠性,以满足建筑市场发展的需要．     

嵌入式设备电源控制系统的CAN通信软硬件设计

为解决电源监控系统中存在的数字化程度低、实时性差、准确度和可靠性低等问题,在研究CAN协议的原理及应用技术的基础上,采用外挂Microchip MCP2515 CAN控制器的设计思想,完成基于AVR单片机的CAN通信软硬件设计,满足电源控制系统策略的需要。该文给出CAN总线的整体结构及控制器、收发器等组成部分硬件及软件的设计与实现,并对系统进行网络负载分析及实时性分析。实际运行表明:该系统可实现报文的发送、接收等功能,可靠性强、通信实时性好。另外,电气隔离电路的设计,进一步提高系统的抗干扰能力;同时,软件设计部分采用自顶向下的模块化设计方法,增强系统的可移植性。     

Developments in hardware and software for computer controlled servohydraulic fatigue testing systems

During the last ten years digital computers have become increasingly important in the field of fatigue testing, not only replacing conventional single function electronic devices but also offering new possibilities in items of the organization and performance of materials testing equipment. This paper outlines typical ranges of applications for computers; the development of special hardware and software for use with servohydraulic fatigue test machines; and general trends regarding the use of computers in fatigue testing laboratories.     

Optimal design of a maintainable cold-standby system

This paper considers a framework to optimally design a maintainable cold-standby system. Not only the maintenance policy is to be determined, but also the reliability character of the components will be taken into account. Hence, the mean time to failure of the components and the policy time of good-as-new maintenances are proposed as decision variables. Following probability analyses, the system cost rate and the system availability are formulated as the optimization object and the constraint, respectively. Then, this optimization problem is directly resolved by recognizing its underlying properties. Moreover, the resolving procedure is found to be independent of the failure distributions of the components and the forms of the system cost, which is illustrated through a numerical example. As a conclusion, an exact method is successfully established to minimize the cost rate of a cold-standby system with the given maintenance facility.     

Fast-updating and nonrepeating Lissajous image reconstruction method for capturing increased dynamic information

We present a fast-updating Lissajous image reconstruction methodology that uses an increased image frame rate beyond the pattern repeat rate generally used in conventional Lissajous image reconstruction methods. The fast display rate provides increased dynamic information and reduced motion blur, as compared to conventional Lissajous reconstruction, at the cost of single-frame pixel density. Importantly, this method does not discard any information from the conventional Lissajous image reconstruction, and frames from the complete Lissajous pattern can be displayed simultaneously. We present the theoretical background for this image reconstruction methodology along with images and video taken using the algorithm in a custom-built miniaturized multiphoton microscopy system.