配置复杂度模型在系统运维中的应用

对配置复杂度进行概述,介绍目前的研究现状。提出改进后的配置复杂度模型,通过执行复杂度、参数复杂度、上下文复杂度、交互复杂度和并行复杂度5个指标度量配置信息系统的复杂程度。将该模型应用于实际应用系统的配置过程,寻找配置热点。给出降低复杂度的方法,通过使用XML语言描述配置过程,并且结合Web服务平台,使配置过程的复杂度得到一定程度的降低。     

面向对象类的复杂性的度量方法

简要分析了已有的几种面向对象软件复杂性度量方法,指出了这些方法在反映类复杂性方面存在的不足,运用软件复杂性分解的思想,提出了一种新的类复杂性度量方法。该方法将类复杂性分解为类成员复杂性、类成员关系复杂性和封装复杂性三个复杂性分量,对各分量分别度量,进而得出总复杂性。其中,类成员复杂性采用类所实现的成员的复杂性SIMC、类接口复杂性之和SCIC反映;类成员关系复杂性通过对文中提出的伪二部图进行分析反映;封装复杂性采用成员可见率反映。最后,通过实例验证了该方法的有效性和可行性。     

信息系统体系结构复杂性度量方法研究*

体系结构技术是进行信息系统设计的重要技术,其复杂性直接决定着建设信息系统的复杂性。研究了程序复杂性的度量方法,在复杂性概念研究的基础上,提出了将体系结构复杂性分为动态复杂性和结构复杂性分开进行度量的方法,并提出基于熵的动态复杂性和结构复杂性评估方法。通过对体系结构复杂性度量方法的研究,可以有效地度量体系结构的复杂性,为项目开发与决策提供有力的依据。     

图像复杂度研究综述

图像相关复杂度的研究领域很广泛,除了计算机科学领域,还延伸到医学、认知心理学等研究领域。在以上应用领域,与图像相关的复杂度的定义有很多,包括图像复杂度、视觉复杂度、场景复杂度,其中图像复杂度又可以进一步细分为颜色复杂度、纹理复杂度和形状复杂度。文中对以上这些复杂度的应用、定义和计算方法进行了归纳总结,并依据组成论中相关复杂度的定义,提出了一种研究图像复杂度的思路,即从图像组成元素的角度来研究图像复杂度。这种图像复杂度的定义只与图像本身所包含的元素、内容有关系,与图像处理任务和算法无关。同时,这种图像复杂度的定义符合一般意义下人对图像复杂性的感受和理解。图像元素可以分为颜色、形状、纹理三大类,它们又可以进一步用一些特征来表示。根据组成论,文中给出了定义这3种特征的广义集的方法。后续研究将进一步给出图像复杂度的计算算法,并通过与人工实验的相关性分析来验证计算结果是否与人的感受相一致。     

A granularity model for balancing the structural complexity of manufacturing systems equipment and layout

The structural complexity of a manufacturing system results primarily from the complexity of its equipment and their layout. The balance between both complexity sources can be achieved by searching for the best system granularity level, which yields a manufacturing system with the least overall structural complexity. A new system granularity complexity index is developed to sum up and normalize the complexity resulting from the system layout complexity and the equipment structural complexity. A previously developed layout complexity index together with a code-based structural complexity assessment are used to determine the structural complexity of standalone pieces of equipment and to arrive at a balance between the two sources of complexity. Cladistics analysis is used to hierarchically cluster required pieces of equipment and bundle them into more integrated equipment and machines and demonstrate the possible different system granularity levels. The new developed model is a useful tool to create specific system configuration and layout alternatives based on system components adjacency, and then select the system design with the least overall structural complexity among those alternatives. The results of the presented case study clearly demonstrated this trade-off where decomposing manufacturing systems into a highly granular configuration with standalone machines maximizes system layout complexity and minimizes equipment complexity, while at a low level of granularity pieces of equipment are bundled into complex integrated machines, lines or cells but with a very simple system layout.     

A Complexity Measure

This paper describes a graph-theoretic complexity measure and illustrates how it can be used to manage and control program complexity. The paper first explains how the graph-theory concepts apply and gives an intuitive explanation of the graph concepts in programming terms. The control graphs of several actual Fortran programs are then presented to illustrate the correlation between intuitive complexity and the graph-theoretic complexity. Several properties of the graph-theoretic complexity are then proved which show, for example, that complexity is independent of physical size (adding or subtracting functional statements leaves complexity unchanged) and complexity depends only on the decision structure of a program.     

Shape complexity

The complexity of 3D shapes that are represented in digital form and processed in CAD/CAM/CAE, entertainment, biomedical, and other applications has increased considerably. Much research was focused on coping with or on reducing shape complexity. However, what exactly is shape complexity? We discuss several complexity measures and the corresponding complexity reduction techniques. Algebraic complexity measures the degree of polynomials needed to represent the shape exactly in its implicit or parametric form. Topological complexity measures the number of handles and components or the existence of non-manifold singularities, non-regularized components, holes or self-intersections. Morphological complexity measures smoothness and feature size. Combinatorial complexity measures the vertex count in polygonal meshes. Representational complexity measures the footprint and ease-of-use of a data structure, or the storage size of a compressed model. The latter three vary as a function of accuracy.     

Measuring dynamic program complexity

A relative complexity technique that combines the features of many complexity metrics to predict performance and reliability of a computer program is presented. Relative complexity aggregates many similar metrics into a linear compound metric that describes a program. Since relative complexity is a static measure, it is expanded by measuring relative complexity over time to find a program's functional complexity. It is shown that relative complexity gives feedback on the same complexity domains that many other metrics do. Thus, developers can save time by choosing one metric to do the work of many     

Evaluating code complexity triggers,use of complexity measures and the influence of code complexity on maintenance time

Code complexity has been studied intensively over the past decades because it is a quintessential characterizer of code’s internal quality. Previously, much emphasis has been put on creating code complexity measures and applying these measures in practical contexts. To date, most measures are created based on theoretical frameworks, which determine the expected properties that a code complexity measure should fulfil. Fulfilling the necessary properties, however, does not guarantee that the measure characterizes the code complexity that is experienced by software engineers. Subsequently, code complexity measures often turn out to provide rather superficial insights into code complexity. This paper supports the discipline of code complexity measurement by providing empirical insights into the code characteristics that trigger complexity, the use of code complexity measures in industry, and the influence of code complexity on maintenance time. Results of an online survey, conducted in seven companies and two universities with a total of 100 respondents, show that among several code characteristics, two substantially increase code complexity, which subsequently have a major influence on the maintenance time of code. Notably, existing code complexity measures are poorly used in industry.     

面向信息安全的二维CAD工程图复杂度研究

针对二维CAD工程图的特点,研究了二维CAD工程图复杂度的度量方法。提出了实体复杂度、约束复杂度以及特征复杂度的定义,并分别给出了3种复杂度的计算方法。分析与讨论表明,上述3种复杂度能有效地对二维CAD工程图的复杂度进行度量。最后对二维CAD工程图复杂度在工程图内容加密以及数字水印中的应用进行了探讨。     

一种面向对象多态复杂性的度量方法

提出了一种类级多态复杂性和系统级多态复杂性的度量方法。该方法对强制多态、重载多态、类型参数化多态和包含多态这四种类型的多态进行分析,得出反映类的多态复杂性的量度,即强制多态复杂性（CCPP）、重载复杂性（CMC）、参数多态复杂性（CPMP）、包含多态复杂性（CCTP）;然后通过整合得到度量系统级的多态复杂性。实验证明,该方法能够正确有效地度量面向对象软件的多态复杂性。     

Comparison between conventional and digital nuclear power plant main control rooms: A task complexity perspective,Part II: Detailed results and analysis

Part II of this study aims to provide detailed, diagnostic information about the complexity difference between conventional and digital main control rooms (MCRs) in nuclear power plants. Complexity factors were classified according to task components and complexity dimensions. The effects of operator experience and plant type on complexity factors were statistically analyzed from three levels, i.e., task components, complexity dimensions, and individual factors. Interface management complexity factors were compared with other factors in digital MCRs. The results suggest that generally operator experience had effects on several task components and complexity dimensions only in abnormal/emergency situations. Plant type affected several task component and complexity dimensions in both abnormal/emergency and normal situations. Complexity factors in the affected task components and complexity dimensions had higher frequency, complexity, or impact in digital MCRs than those in conventional MCRs. Factors related to crew activity and the dimensions of overabundance, temporal demand, and variability had relatively high frequency, complexity, or impact. Compared with other factors, interface management complexity factors had marginally higher frequency, but significantly lower complexity and impact.Relevance to industryThis study quantitatively addresses the complexity difference between conventional and digital MCRs in detail. It may provide rich information for how to improve operator working environments in NPPs. It may also contribute to other applied domains, such as human reliability analysis and interface design.     

数值计算程序的存储复杂性分析

由于越来越多的技术用于缩小处理器与存储器之间的日益加大的速度差距,计算机的存储系统变得日趋复杂．现在,任何一个程序设计者,尤其是数值计算程序的设计者,若不考虑其所用计算平台存储系统的特点是很难获取高性能的．因此公用传统的算法评价方法,从时间复杂性和空间复杂性着手来解释一个算法的不同实现在同一计算平台上很大的性能差异,显然是不够的．计算平台存储系统的特点必须在分析算法的复杂性时加以考虑．孙家昶１９９     

GF(pm)上周期为pn序列的m紧错线性复杂度*

综合线性复杂度、k错线性复杂度、k错线性复杂度曲线和最小错误minerror(S)的概念,提出紧错线性复杂度的概念。在GF(pm)上周期为pn序列的k错线性复杂度快速算法的基础上,给出m紧错线性复杂度的快速算法。其中p是素数。 编程实现了该算法, 并给出实验结果。     

A spaceflight operation complexity measure and its experimental validation

A measure of operation complexity in spaceflight is proposed using a weighted Euclidean norm based on four factors: complexity of operation step size (COSS), complexity of operation logic structure (COLS), complexity of operation instrument information (COII), and complexity of space mission information (CSMI). The development of the operation complexity measure followed four steps. First, four factors were identified to be reflected in the operation complexity measure for spaceflight. Second, the entropy theory was adopted to measure the four factors. Then, the weights of the four factors were determined based on a questionnaire survey of 10 astronauts. Finally, the operation complexity values of spaceflight operations were determined by the weighted Euclidean norm of the four factors. To verify the validity of this complexity measure, a one-factor experiment was designed to test the proposed hypotheses. Ten subjects participated in the experiment and performed 179 trials. Both objective indexes (operation time and error rate) and subjective indexes (workload evaluated by NASA Task Load Index questionnaire and subjective complexity rating) were used in the experiment. The data analysis showed that the average operation time, subjective complexity rating, and subjective workload could be predicted well from the operation complexity value (R = 0.876, 0.802, and 0.698, respectively); and the error rate could only be partly explained by the operation complexity value (R = 0.343).

Relevance to industry

The proposed operation complexity measure can be used for ergonomics evaluation of spaceflight operation design. It can also be used for astronaut training planning. Training resources can be allocated to spaceflight tasks according to their operation complexity.     

若干二元周期序列的紧错线性复杂度

综合线性复杂度、k错线性复杂度、k错线性复杂度曲线和最小错误minerror（S）的概念,提出m紧错线性复杂度的概念。 序列S的m紧错线性复杂度是一个二元组（km,LCm）。序列S的k错线性复杂度曲线的第m个跃变点对应的km值和对应km错线性复杂度LCm,称为序列S的m紧错线性复杂度。通过使用简洁的cost二维结构,给出了周期为2n的二元序列的紧错线性复杂度算法,并证明具有Stamp-Martin模式的线性复杂度算法均可以简单地推广为求紧错线性复杂度的算法。与现有k错线性复杂度算法不同,该算法中省去了原来序列元素的运算。在王-张-肖算法基础上,通过使用cost二维结构,给出了周期为pn的二元序列的紧错线性复杂度算法,其中p是一个素数,2是一个模p2的本原根。     

Producing maintainable software

The increasing cost of software maintenance has resulted in greater emphasis on the production of maintainable software. One method used to enhance the development of maintainable software is to employ complexity metrics as a technique for controlling software complexity. In order to control complexity, it is imperative to plan for increases in complexity levels from code generation to code implementation. This paper presents a study of complexity increases during the testing and debugging phases of the software life cycle. The metrics used to measure complexity are lines of code, unique operators, unique operands, data difficulty, Halstead's effort and cyclomatic complexity.     

构件软件的回归测试复杂性度量

基于构件的软件构建方法目前被广泛使用在软件开发中,用于减少软件开发的工程成本和加快软件开发进度.在软件维护过程中,由于构件更新或者新版本的发布,基于构件的系统会受到影响,需要进行回归测试.对于指定的软件修改需求,维护者可以实施不同的修改手段.不同的修改手段会导致不同的回归测试复杂性,这种复杂性是软件维护成本和有效性的重要因素.目前的研究没有强调构件软件的回归测试复杂性问题.基于修改影响复杂性模型和度量,提出一种回归测试的复杂性度量框架.该度量框架包括两个部分:基于图的模型和形式化度量计算.该度量可以有效表示构件软件分别在构件和系统层面的回归测试复杂性因素,可视化地体现复杂性变化.然后根据模型,提出具体的度量计算方式.最后,通过实验研究,针对同一个构件软件的相同修改需求,利用若干个实验组进行独立修改实施,然后比较回归测试的复杂性.实验结果表明,所提出的度量方式是可行和有效的.     

The Monotone Circuit Complexity of Quadratic Boolean Functions

Several results on the monotone circuit complexity and the conjunctive complexity, i.e., the minimal number of AND gates in monotone circuits, of quadratic Boolean functions are proved. We focus on the comparison between single level circuits, which have only one level of AND gates, and arbitrary monotone circuits, and show that there is an exponential gap between the conjunctive complexity of single level circuits and that of general monotone circuits for some explicit quadratic function. Nearly tight upper bounds on the largest gap between the single level conjunctive complexity and the general conjunctive complexity over all quadratic functions are also proved. Moreover, we describe the way of lower bounding the single level circuit complexity and give a set of quadratic functions whose monotone complexity is strictly smaller than its single level complexity.