材料选择的集对分析方法及应用

基于集对论的原理，建立了零件材料选择的集对综合评价模型，主要考虑在零件设计时，如何在多种可用材料中合理地选出最佳的一种。该数学模型使材料选择的定性评价定量化、精细化、明朗化，提高了评价工作的可操作性和科学合理性。     

非正则LDPC码在DSP上的实现

首先简单介绍了非正则LDPC码的结构,给出了一种基于IEEE802.16e直接编码法生成的(576,288)非正则LDPC码的编译码原理。然后详细论述了其在TI定点DSP(TMS320C5510)上的定点化算法实现方式,并在经过C和部分汇编优化后将算法效率提高了70%以上,达到了实时系统要求。最后给出了该LDPC码与(2,1,7)卷积码在AWGN信道下的性能对比,表明这种中短码长的非正则LDPC码较卷积码有较大的纠错性能优势。     

基于集对分析理论的发电投资决策模型

在市场环境下,发电投资面临的诸多不确定因素将导致发电投资收益的不确定性,这需要发电投资决策评价方法来辅助发电商进行投资决策。为此首先分析了集对分析(set pair analysis,SPA)理论和发电投资的成本–效益问题;然后采用蒙特卡罗法对上网电价、煤炭价格和上网电量等不确定性因素进行模拟,得出发电投资的不确定性损失序列,并利用SPA对损失序列进行同、异、反特性描述,给出求解联系度系数的方法;在此基础上构建了基于SPA的发电投资决策模型,探讨了不确定数i的确定方法;最后通过算例证明了所构建模型的可行性,为发电商提供投资决策依据。     

一种基于随机混合坐标表示的防功耗分析标量乘法实现方法

提出了一种新的防功耗分析(包括简单和差分功耗分析simpleanddifferentialpoweranalysis)的椭圆曲线标量乘法实现方法,该方法实现简单,并且适合于各种不同有限域上椭圆曲线标量乘法的实现.该方法以模乘和模加减操作为最小调度单位,将标量乘法转换成完全随机的模乘和模加减操作序列;基于随机混合坐标表示实现点的加法和倍加操作,并随机地从点的加法和倍加操作序列中选取后续的模乘和模加减操作;任务调度与模乘和模加减操作的执行是并行的.另外,本文定量分析了该实现方法对于功耗分析的防护能力以及运算性能.     

A CLASS OF LDPC CODE’S CONSTRUCTION BASED ON AN ITERATIVE RANDOM METHOD

This letter gives a random construction for Low Density Parity Check （LDPC） codes, which uses an iterative algorithm to avoid short cycles in the Tanner graph. The construction method has great flexible choice in LDPC code＇s parameters including codelength, code rate, the least girth of the graph, the weight of column and row in the parity check matrix. The method can be applied to the irregular LDPC codes and strict regular LDPC codes. Systemic codes have many applications in digital communication, so this letter proposes a construction of the generator matrix of systemic LDPC codes from the parity check matrix. Simulations show that the method performs well with iterative decoding.     

Process-Based Software Engineering: Building the Infrastructures

A recent trend in software engineering is the shift from a focus on laboratory-oriented software engineering to a more industry-oriented view of software engineering processes. This complements preceding ideas about software engineering in terms of organization and process-orientation. From the domain coverage point of view, many of the existing software engineering approaches have mainly concentrated on the technical aspects of software development. Important areas of software engineering, such as the technical and organizational infrastructures, have been left untouched. As software systems increase in scales, issues of complexity and professional practices become involved. Software development as an academic or laboratory activity, has to engage with software development as a key industrialized process.This expanded domain of software engineering exposes the limitations of existing methodologies that often address only individual subdomains. There is, therefore, a demand for an overarching approach that provide a basis for theoretical and practical infrastructures capable of accommodating the whole range of modern software engineering practices and requirements. One approach is provided by Process-Based Software Engineering (PBSE); part of the more general trend towards a focus on process.This paper provides a review of process techniques for software engineering and a high-level perspective on PBSE. Typical approaches and techniques for the establishment, assessment, improvement and benchmarking of software engineering process systems are introduced in this paper, and many are developed further in other contributions to this volume.     

基于SPA的水文预测模型评估

为了对水文预测模型的可靠性和有效程度进行评定和检验,引入集对分析(Set Pair Analysis,SPA)方法,从同、异、反3个方面刻画预测模型的误差分布情况,利用联系度描述水文预测模型的预测精度,从而建立基于集对分析的水文预测模型评估方法。通过对水文预测中的TR模型和线性模型与实测系列之间联系度的对比,对2个模型的拟合结果和预测效果进行评价,结果表明,TR模型优于线性模型。与其他水文预测模型评估方法相比,集对评估方法具有评价信息全面、计算简便和实用的特点。     

The role of land abandonment in landscape dynamics in the SPA ‘Encinares del río Alberche y Cofio, Central Spain, 1984–1999

Land use has changed dramatically over the last 30–40 years throughout the Mediterranean. Much of this change has been driven by shifts in agricultural and socio-economic policy. This paper explores landscape dynamics in the SPA ‘Encinares del río Alberche y Cofio’ Central Spain between 1984 and 1999 in an area of approximately 83,000 ha. Categorical land cover maps, derived from three (1984, 1991 and 1999) remotely sensed Landsat images, are analyzed using a suite of landscape pattern metrics, and a simple transition matrix model of landscape change is developed. As with other landscapes in the Mediterranean a key trend is that of the abandonment of agricultural land and its subsequent succession to scrubland and woodland. Although there were significant composition changes in the landscape over the study period configurational changes are less evident. The transition matrix model suggests that there were differences in landscape dynamics between 1984–1991 and 1991–1999—most importantly an increase in the rate of land abandonment is evident. The model predicts a steady state landscape containing a higher abundance of scrubland and woodland, and a corresponding decline in pastureland and cropland. Finally, the underlying socio-economic and other drivers of landscape change in the Encinares del río Alberche y Cofio and some of the implications of recent changes are discussed in terms of increased wildfire risk. Sustainable management of landscapes to protect biodiversity requires the type of study described here. A necessary pre-requisite of such management activities or planning is an assessment of changes in landscape pattern and process, the social and economic pressures driving them, and their possible effects on ecosystem structure and function.     

基于改进CRITIC-GRA-SPA的“一带一路”基础设施PPP项目融资风险研究

为量化“一带一路”基础设施PPP项目的融资风险,构建包含政治、金融、社会、自然环境、建设、运营等方面的评价指标体系,用平均差代替标准差实现对传统CRITIC方法的改进,并将改进CRITIC方法与熵权法进行复合,对各层级指标进行赋权;运用GRA方法与SPA方法的耦合评价模型,综合考虑评价对象各指标因子的同一性、差异性和对立性,将联系度系数量化。结合实际案例,验证该模型的科学合理性,为未来“一带一路”基础设施PPP项目融资风险研究提供新思路。     

一种1553B总线远程终端的即插即用的设计

随着航天技术的不断发展,研制即插即用、低成本、小型化的卫星渐渐成为一种趋势,我国的星上数据管理系统使用1553B总线连接各个有数据交换需求的计算机与分系统,这些计算机与分系统也就成为1553B总线的远程终端;为了设计即插即用的1553B远程终端,对电子数据表单(Electronic data sheet,EDS)、龙芯1F中的1533B简易终端进行了研究,分析了电子数据表单的设计方法和使用方式,提出了应用EDS、1553B通信EDS的设计方法;分析了1553B简易终端对龙芯1F中测控接口的访问控制方式,在龙芯1F中添加了一个SPA(Space Plug-and-play Avionics)接口,与1553B简易终端联合使用,当龙芯1F作为1553B总线上的一个终端设备时,具有了即插即用的特征;由此说明1553B远程终端是可以实现即插即用的,同时把即插即用这一新的设计理念带入星载数据系统的设计中。