Multi-granularity evolution analysis of software using complex network theory

Software systems are a typical kind of man-made complex systems. Understanding their evolutions can lead to better software engineering practices. In this paper, the authors use complex network theory as a tool to analyze the evolution of object-oriented (OO) software from a multigranularity perspective. First, a multi-granularity software networks model is proposed to represent the topological structures of a multi-version software system from three levels of granularity. Then, some parameters widely used in complex network theory are applied to characterize the software networks. By tracing the parameters’ values in consecutive software systems, we have a better understanding about software evolution. A case study is conducted on an open source OO project, Azureus, as an example to illustrate our approach, and some underlying evolution characteristics are uncovered. These results provide a different dimension to our understanding of software evolutions and also are very useful for the design and development of OO software systems.     

A Priority-Based Negotiations Approach for Handling Inconsistencies in Multi-Perspective Software Requirements

Inconsistency of multi-perspective requirements specifications is a pervasive issue during the requirements process. However, managing inconsistency is not just a pure technical problem. It is always associated with a process of interactions and competitions among corresponding stakeholders. The main contribution of this paper is to present a negotiations approach to handling inconsistencies in multi-perspective software requirements. In particular, the priority of requirements relative to each perspective plays an important role in proceeding negotiation over resolving inconsistencies among different stakeholders. An algorithm of generating negotiation proposals and an approach to evaluating proposals are also presented in this paper, respectively.     

Symmetry in world trade network

Symmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network (WTN) has been rarely studied so far. In this paper, the authors systematically explore the symmetry in WTN. The authors construct WTN in 2005 and explore the size and structure of its automorphism group, through which the authors find that WTN is symmetric, particularly, locally symmetric to a certain degree. Furthermore, the authors work out the symmetric motifs of WTN and investigate the structure and function of the symmetric motifs, coming to the conclusion that local symmetry will have great effect on the stability of the WTN and that continuous symmetry-breakings will generate complexity and diversity of the trade network. Finally, utilizing the local symmetry of the network, the authors work out the quotient of WTN, which is the structural skeleton dominating stability and evolution of WTN. This research was supported by the National Natural Science Foundation of China under Grant No. 70371070; Shanghai Leading Academic Discipline Project under Grant No. S30504; and Key Project for Fundamental Research of STCSM under Grant No. 06JC14057.     

Asymptotic Solution of Activator Inhibitor Systems for Nonlinear Reaction Diffusion Equations

A nonlinear reaction diffusion equations for activator inhibitor systems is considered. Under suitable conditions, firstly, the outer solution of the original problem is obtained, secondly, using the variables of multiple scales and the expanding theory of power series the formal asymptotic expansions of the solution are constructed, and finally, using the theory of differential inequalities the uniform validity and asymptotic behavior of the solution are studied.     

A multiyear lags input-holding-output model on education with excluding idle capital

This paper develops a multi-year lag Input-Holding-Output (I-H-O) Model on education with exclusion of the idle capital to address the reasonable education structure in support of a sustainable development strategy in China. First, the model considers the multiyear lag of human capital because the lag time of human capital is even longer and more important than that of fixed capital. Second, it considers the idle capital resulting from the output decline in education, for example, student decrease in primary school. The new generalized Leonitief dynamic inverse is deduced to obtain a positive solution on education when output declines as well as expands. After compiling the 2000 I-H-O table on education, the authors adopt modifications-by-step method to treat nonlinear coefficients, and calculate education scale, the requirement of human capital, and education expenditure from 2005 to 2020. It is found that structural imbalance of human capital is a serious problem for Chinese economic development. This research was supporting by the Key Project of National Natural Science Foundation of China under Grant No. 60874119, Innovation Funds of Chinese Academy of Sciences, Research Fund for Humanities and Social Sciences in colleges under Grant No. 06BJY102, Key project in Jiangxi Soft Science Project under Grant No. [2006]188, Jiangxi Research Fund for Humanities and Social Sciences in colleges under Grant No. 03JJ01, and Henan Research Fund for Humanities and Social Sciences in colleges under Grant No. 2008-ZD-002.     

基于Agent的建模与仿真设计模式及软件框架

提出了一种基于Agent的建模与仿真设计模式——ABMS设计模式，阐述了ABMS设计模式的主要内容。该模式的提出有利于在建模与仿真领域以及软件开发界之间建立关于ABMS的对话联系与交流。然后设计了一种包含仿真服务模型和Agent仿真模型的ABMS分布仿真软件框架，该框架将最大限度实现仿真重用，并将支持大规模的基于Agent的复杂系统的分布仿真，包括军事对抗以及空间作战系统的仿真。该框架部分借鉴了HLA的思想，其中的ServerAgent提供底层的通用仿真服务。     

Agent- oriented Software Engineering

1　IntroductionAn increasing number of computer systems are being viewed in terms of autonomousagents.Agents are being espoused as a new theoretical model of computation that moreclosely reflects current computing reality than Turing Machines[1 ] .Agents are beingadvocated as a next generation model for engineering complex and distributed systems[2 ] .Agents are also being used as an overarching framework for bringing together thecomponent AI subdisciplines that are necessary to design and b…     

Web Services Composing by Multiagent Negotiation

Composing web services is gained daily attention in Service Oriented Computing. It includes the dynamic discovery, interaction and coordination of agent-based semantic web services. The authors first follow Function Ontology and Automated Mechanism Design for service agents aggregating. Then the problem is formulated but it is ineffective to solve it from the traditional global view. Because the complexity is NP-complete and it is dii~cult or even impossible to get some personal information. This paper provides a multi-agent negotiation idea in which each participant negotiates under the condition of its reservation payoff being satisfied. Numerical experiment is given and well evaluates the negotiation.     

FLOCKING OF MULTI-AGENT DYNAMIC SYSTEMS WITH GUARANTEED GROUP CONNECTIVITY*

This paper investigates distributed flocking problem where the information exchange among agents is modeled by the communication topology changing with time. Previous research on this problem establishes group stabilization by assuming that the dynamic topology is connected all the time, which however cannot be guaranteed by most proposed distributed control laws. In this paper, a distributed algorithm to distill a necessary subgraph of the initial communication topology is presented. This subgraph covers all the vertices of the communication topology and is proved to be connected as long as the initial communication topology is connected. A distributed control law is then designed to pursue the flocking motion while preserving all the edges in this subgraph. In this way, connectivity can be preserved all the time, and flocking problem is thus solved only provided the initial communication topology of multi-agent system is connected.     

The projective plane crossing numbers of circular graphs*

The authors give an upper bound for the projective plane crossing number of a circular graph. Also, the authors prove the projective plane crossing numbers of circular graph C （8, 3） and C （9, 3） are 2 and 1, respectively.     

On spectrum of networks based on matrix of link-state and its symmetry

This paper constructs a new spectrum of networks by means of the matrix of link-state of the network, which can reveal the characteristics of the correlation between the degrees of the network. Also, the computation of this spectrum of networks is usually more feasible and more efficient due to the much lower order of its matrix of link-state than its adjacent matrix in practice. Some estimates for the bounds of the key eigenvalues in the spectrum are obtained, the corresponding inequalities are presented and proved. For the sake of its application, the authors define spectrum of networks in two ways, and all theorems are given in parallel for both kinds of definition. In addition, the authors find a symmetry in the spectrum, which is relative to the characteristic of structure of its network to some extent. This research is supported by the Key Project for Fundamental Research of STCSM under Grant No. 06JC14057.     

基于面向对象贝叶斯网络的软件项目风险评估

针对软件项目的特点和软件项目风险定量评估任务,提出了基于面向对象贝叶斯网络的风险评估方法。该方法通过分析软件项目生命周期中的具体风险与风险因素之间的因果关系,建立面向对象贝叶斯网络拓扑结构;由专家判断和工程经验确定网络中的概率参数;采用概率推断工具,可定量估计风险的发生概率。给出了风险贝叶斯网络的建模过程,讨论了风险贝叶斯网络可以完成的风险管理任务。通过一个简单例子说明了该方法的应用。     

Energy flows in complex ecological systems: a review

Energy flow drives the complex systems to evolve. The allometric scaling as the universal energy flow pattern has been found in different scales of ecological systems. It reflects the general power law relationship between flow and store. The underlying mechanisms of energy flow patterns are explained as the branching transportation networks which can be regarded as the result of systematic optimization of a biological target under constraints. Energy flows in the ecological system may be modelled by the food web model and population dynamics on the network. This paper reviews the latest progress on the energy flow patterns, explanatory models for the allometric scaling and modelling approach of flow and network evolution dynamics in ecology. Furthermore, the possibility of generalizing these flow patterns, modelling approaches to other complex systems is discussed. This research is supported by Guozhi Xu Post Doctoral Research Foundation and the National Natural Science Foundation of China under Grant No. 60574068.     

Multi-agent aggregation behavior analysis: The dynamic communication topology*

The authors extend the Gazi＇s swarm model with local neighbor rules and the dynamic communication topology, and study its aggregation properties. Results of analysis show that all agents in the models aggregate and eventually form a cohesive cluster of finite size around the swarm center or the appointed point. Finally, simulations are provided to testify some of the results. Models in the paper are more applicable to the reality for the advantage that each agent only needs the partial information of the entire dynamic system when making motion decision.     

PRE-IMAGE ENTROPY OF NONAUTONOMOUS DYNAMICAL SYSTEMS*

The authors define and study topological pre-image entropy for the non-autonomous discrete dynamical systems given by a sequence {fi}i=1^∞ of continuous self-maps of a compact topological space. The basic properties and the invariant with respect to equiconjugacy of pre-image entropy for the non-autonomous discrete dynamical systems are obtained.     

设计模式在通信系统仿真软件中的应用

对大型、复杂系统性能评估的最好方法是系统仿真和建模,仿真软件的设计是实现仿真目的的关键。对于这种复杂软件的开发,目前最好的方法是利用软件工程的方法,而设计模式现在则成为软件工程中不可缺少的方法。目的在于对设计模式在仿真软件中的应用做一些探讨,利用设计模式来提高仿真软件的可靠性、安全性、可用性和可维护性。     

Robustness analysis of leader-follower consensus

In this paper, robustness properties of the leader-follower consensus are considered. For simplicity of presentation, the attention is focused on a group of continuous-time first-order dynamic agents with a time-invariant communication topology in the presence of communication errors. In order to evaluate the robustness of leader-follower consensus, two robustness measures are proposed: the L ₂ gain of the error vector to the state of the network and the worst case L ₂ gain at a node. Although the L ₂ gain of the error vector to the state of the network is widely used in robust control design and analysis, the worst case L ₂ gain at a node is less conservative with respect to the number of nodes in the network. It is thus suggested that the worst case L ₂ gain at a node is used when the robustness of consensus is considered. Theoretical analysis and simulation results show that these two measures are sensitive to the communication topology. In general, the “optimal” communication topology that can achieve most robust performance with respect to either of the proposed robustness measures is difficult to characterize and/or obtain. When the in-degree of each follower is one, it is shown that both measures reach a minimum when the leader can communicate to each node in the network. This work is supported by the National Natural Science Foundation of China under Grant No. 60774005.     

分布式仿真软件三层设计模式及应用

为了解决分布式仿真软件设计开发中的难题,提出了分布式仿真软件三层设计模式(ThreeLevel Design Pattern,TLDP).三层设计模式要求仿真软件按照用户服务层、应用服务层和数据服务层三层进行功能划分,进行分层设计和开发.对仿真软件设计中存在的问题进行了分析,介绍了三层设计模式的主要内容和设计开发规则,最后给出了两个应用实例.实践证明三层设计模式比较适用于具有复杂应用背景和软件环境的分布式仿真系统软件的设计与开发,能够有效提高设计开发效率.     

ON APPROXIMATION BY REPRODUCING KERNEL SPACES IN WEIGHTED L^p SPACES

In this paper, we investigate the order of approximation by reproducing kernel spaces on （-1, 1） in weighted L^p spaces. We first restate the translation network from the view of reproducing kernel spaces and then construct a sequence of approximating operators with the help of Jacobi orthogonal polynomials, with which we establish a kind of Jackson inequality to describe the error estimate. Finally, The results are used to discuss an approximation problem arising from learning theory.     

基于开源软件的有向图研究

从复杂网络的角度分析大型开源软件内部软件包依赖关系的复杂度和风险情况.以Gentoo Linux系统做为数据源,将系统中的软件包抽象成点,把软件包之间的依赖关系抽象成边,建立随机图,对此进行分析.除应用经典的随机图方法外,还定义了两个基于有向图的新参数:复杂度和风险度分布,用以量化地评估系统的复杂程度与风险性.通过应用两个新参数,观察到Gentoo系统的复杂度和风险度分布经历了一个快速增长的阶段.这种高速增长的原因来自系统中环状依赖结构.