利用框架技术构建Web应用

目前开发基于Java的Web应用正逐渐转向开源框架支持的轻量级开发架构,基于框架的Web应用具有高可靠性、可复用性,可扩展性和可维护性等优点.当前主流的开源框架有Struts、Spring和Hibernate,其中Struts是一个优秀的MVC框架,Spring是以AOP为基础并实现了IoC机制的轻量级框架,Hibernate是实现了对象/关系映射的持久化框架,它们三者的整合是目前一个比较流行的开发架构.分别介绍这3个框架,然后介绍整合了它们的一个开发架构,并通过一个实际的例子说明了在应用中将它们整合的方法.     

Impact analysis and change propagation in service-oriented enterprises: A systematic review

ContextThe adoption of Service-oriented Architecture (SOA) and Business Process Management (BPM) is fairly recent. The major concern is now shifting towards the maintenance and evolution of service-based business information systems. Moreover, these systems are highly dynamic and frequent changes are anticipated across multiple levels of abstraction. Impact analysis and change propagation are identified as potential research areas in this regard.ObjectiveThe aim of this study is to systematically review extant research on impact analysis and propagation in the BPM and SOA domains. Identifying, categorizing and synthesizing relevant solutions are the main study objectives.MethodThrough careful review and screening, we identified 60 studies relevant to 4 research questions. Two classification schemes served to comprehend and analyze the anatomy of existing solutions. BPM is considered at the business level for business operations and processes, while SOA is considered at the service level as deployment architecture. We focused on both horizontal and vertical impacts of changes across multiple abstraction layers.ResultsImpact analysis solutions were mainly divided into dependency analysis, traceability analysis and history mining. Dependency analysis is the most frequently adopted technique followed by traceability analysis. Further categorization of dependency analysis indicates that graph-based techniques are extensively used, followed by formal dependency modeling. While considering hierarchical coverage, inter-process and inter-service change analyses have received considerable attention from the research community, whereas bottom-up analysis has been the most neglected research area. The majority of change propagation solutions are top-down and semi-automated.ConclusionsThis study concludes with new insight suggestions for future research. Although, the evolution of service-based systems is becoming of grave concern, existing solutions in this field are less mature. Studies on hierarchical change impact are scarce. Complex relationships of services with business processes and semantic dependencies are poorly understood and require more attention from the research community.     

Quality models for web services: A systematic mapping

ContextQuality of Service (QoS) is a major issue in various web service related activities. Quality models have been proposed as the engineering artefact to provide a common framework of understanding for QoS, by defining the quality factors that apply to web service usage.ObjectiveThe goal of this study is to evaluate the current state of the art of the proposed quality models for web services, specifically: (1) which are these proposals and how are they related; (2) what are their structural characteristics; (3) what quality factors are the most and least addressed; and (4) what are their most consolidated definitions.MethodWe have conducted a systematic mapping by defining a robust protocol that combines automatic and manual searches from different sources. We used a rigorous method to elicitate the keywords from the research questions and a selection criteria to retrieve the final papers to evaluate. We have adopted the ISO/IEC 25010 standard to articulate our analysis.ResultsWe have evaluated 47 different quality models from 65 papers that fulfilled the selection criteria. By analyzing in depth these quality models, we have: (1) distributed the proposals along the time dimension and identified their relationships; (2) analyzed their size (visualizing the number of nodes and levels) and definition coverage (as indicator of quality of the proposals); (3) quantified the coverage of the different ISO/IEC 25010 quality factors by the proposals; (4) identified the quality factors that appeared in at least 30% of the surveyed proposals and provided the most consolidated definitions for them.ConclusionsWe believe that this panoramic view on the anatomy of the quality models for web services may be a good reference for prospective researchers and practitioners in the field and especially may help avoiding the definition of new proposals that do not align with current research.     

一种自适应信息集成方法

检测相似重复记录是信息集成中的关键任务之一,尽管已经提出了各种检测相似重复记录的方法,但字符串匹配算法是这些检测方法中的核心。在提出的自适应信息集成算法中,用一个综合了编辑距离和标记距离的混合相似度去度量字符串之间的相似度。为了避免由于表达方式的差异而造成的字符串之间的不匹配,字符串被分割成独立的单词后按单词的第一个字符进行排序。在单词的匹配中,对拼写错误和缩写有一定的容错功能。实验结果表明,自适应信息集成方法比用Smith Waterman和Jaro距离有更高的正确率。     

基于自适应算法的车载无人机的疲劳寿命分析

根据基本的疲劳分析理论和解非线性方程及方程组的数值分析的算法,设计了一种自适应算法对无人机在路面激励下的疲劳寿命进行预测。并应用该算法对一种车载无人机在典型任务剖面下的疲劳寿命进行了预测。     

SelfMotion: A declarative approach for adaptive service-oriented mobile applications

Modern society increasingly relies on mobile devices. This explains the growing demand for high quality software for such devices. To improve the efficiency of the development life-cycle, shortening time-to-market while keeping quality under control, mobile applications are typically developed by composing together ad-hoc developed components, services available on-line, and other third-party mobile applications. Applications are thus built as heterogeneous compositions, whose characteristics strongly depend on the components and services they integrate. To cope with unpredictable changes and failures, but also with the various settings offered by the plethora of available devices, mobile applications need to be as adaptive as possible. However, mainstream adaptation strategies are usually defined imperatively and require complex control strategies strongly intertwined with the application logic, yielding to applications that are difficult to build, maintain, and evolve. We address this issue by proposing a declarative approach to compose adaptive heterogeneous mobile applications. The advantages of this approach are demonstrated through an example inspired by an existing worldwide distributed mobile application, while the implementation of the proposed solution has been validated through a set of simulations and experiments aimed at illustrating its performance.     

基于遗传神经网络的自适应PID控制器的设计

提出了一种基于遗传算法和神经网络的自适应PID控制器的设计方法。该控制器主要由三个部分组成:利用遗传算法优化PID参数,和RBF神经网络结合,对被控对象逼近,搜索出一组准优的初始参数;RBF神经网络完成对被控对象Jacobian信息辨识;基于单神经元的自适应PID控制器,在线调整PID参数,以确保系统的响应具有最优的动态和稳态性能。仿真结果表明,控制器具有响应速度快,稳态精度高等特点,可用于控制不同的对象和过程。     

语音驱动自适应协同系统的决策方法

语音驱动的自适应协同系统应用日趋广泛,语音式任务目标具有的模糊性给自适应协同带来了挑战,自适应协同系统如何针对带有模糊性的语音进行任务决策是亟待解决的问题。为此,提出语音驱动的模糊自适应协同框架和决策方法。首先基于市场拍卖机制进行任务发布、投标和决策;然后把多属性的数据信息转化为二元语义并借助VIKOR方法进行排序;最后通过异构机器人自适应协同应用案例,说明了所提方法的决策步骤,表明了所提方法的有效性。     

A self-adaptive Model based on Multi-Objective Programming for Grid Resource Management

Abstract : The growing computational power requirements of grand challenge applications have positioned computational grid as promising next generation computing platform.However, resource management and application with varied requirements in grid environment continue to be a complex undertaking. In order to address complex resource management issues, we provide a self-adaptive model, which is based on multi-objective programming. The model make use of virtues of market mechanism efficiently, meanwhile, the shortcomings of market mechanism, such as too frequent fluctuations of price,are avoided by means of the method of changing prices after trading. Through using atom allocation of resource group, the cooperating allocation is improved, and some problems, such as deadlock of resource and inefficiently occupying resource, are solved. What' s more important, efficiently using various resources in grid system is guaranteed through importing multi-objective programming mechanism in our resource management solution. A frame of resource allocation is given at first, then, the mathematical model of the method is constructed. An algorithm is proposed to get the approximate solution in this paper.     

A service-oriented framework for agent-based simulations of collaborative supply chains

Current collaborative practices of supply chain management are limited to some known configurations where a dominant member sets the pace for the collaboration extent. Extending collaborative models to supply chains without a dominant member requires defining a fair assessment of costs and benefits and how they are distributed among members. To understand collaborative models and their mechanisms, simulation-based approaches are recommended as they can afford the complexity of real scenarios. However, building ad-hoc simulation models for studying complex supply chain interactions can be prohibitive in terms of both cost and time. Therefore, the availability of simulation frameworks, to be used easily by business managers and facilitating the development of those models, has a strong incentive in the quest of current business efforts to increase their supply chain performance. The objective of this work is to present a systematic and reusable serviceoriented framework for agent based simulation to support the analysis of collaborative interactions in supply chains. Results of a requirement analysis performed to this aim are described, and the fulfillment of identified requirements by the proposed framework, and capabilities thereof, are discussed.     

实时任务在异构集群中的自适应容错调度研究

异构集群由于良好的扩展性和可用性,逐渐成为当前并行计算的热点。在具有实时性要求的异构集群中,调度是提高系统性能的关键所在。在此提出了两种自适应调度算法SANOL和SAOL,在保证异构集群中任务的实时性和容错性的前提下,自适应地根据系统的负载情况动态地调整任务的服务级别,从而提高整个系统的灵活性、可调度性和资源利用率。通过实验将这两种算法与另外一种有效率的调度算法DYFARS算法进行比较,结果表明所提出的SAOL算法具有更好的性能。     

一种面向服务的异步消息中间件的设计

采用开放式标准的面向服务架构SOA是有效解决大规模企业应用集成的重要技术,但是SOA对异步传输和可靠为特征的复杂网络应用支持不足。传统消息中间件MOM虽具有松耦合和异步传输特性,但大多适用于企业内部集成,且其扩展性和灵活性不足,难以拓展到大规模网络环境。在全面吸收SOA和MOM的技术优点基础上,设计了一种面向服务的异步消息中间件体系结构,并研究了消息传输算法,服务重组和安全服务等关键技术。结合移动电子商务应用集成,验证了面向服务的异步消息中间件的扩展性、灵活性和有效性。     

基于GA-Vague集自适应PID控制器设计

提出了一种基于GA-Vague集相似度量推理的自适应PID控制器的设计方法。该控制器由三部分组成：（1）遗传算法对模糊推理规则的优化;（2）Vague集推理规则表精确量的计算;（3）基于Vague集相似度量的自适应PID设计。该控制器弥补了模糊PID控制器的不足,模糊变量隶属值难以确定,描述信息单一,又充分发挥了遗传算法的寻优能力,对推理规则表优化,得到最佳组合的PID控制,以确保系统的响应具有最优的动态和稳态性能。仿真结果表明,控制器具有响应速度快,稳态精度高等特点,可用于控制不同的对象和过程。     

Microservice transition and its granularity problem: A systematic mapping study

Microservices have gained wide recognition and acceptance in software industries as an emerging architectural style for autonomic, scalable, and more reliable computing. The transition to microservices has been highly motivated by the need for better alignment of technical design decisions with improving value potentials of architectures. Despite microservices' popularity, research still lacks disciplined understanding of transition and consensus on the principles and activities underlying that transition. In this paper, we report on a systematic mapping study that consolidates various views, approaches and activities that commonly assist in the transition to microservices. The study aims to provide a better understanding of the transition; it also contributes a working definition of the transition and technical activities underlying it. We term the transition and technical activities leading to microservice architectures as microservitization. We then shed light on a fundamental problem of microservitization: microservice granularity and reasoning about its adaptation as first-class entities. This study reviews state-of-the-art and -practice related to reasoning about microservice granularity; it reviews modeling approaches, aspects considered, guidelines and processes used to reason about microservice granularity. This study identifies opportunities for future research and development related to reasoning about microservice granularity.     

SCP2P：基于节点属性特征的自适应P2P模型

对等网络中的节点有其固有的属性特征。在以往的研究中,这些属性特征或是完全被忽略,或是仅仅简单、单一地被考虑。综合利用节点属性特征,提出了基于节点属性特征的自适应P2P模型。在模型中,节点按属性特征自适应组成集群。模型按实际需求驱动的模式动态调整和维护节点之间的连接,动态地调整节点的作用以及集群规模。     

A framework for context-aware self-adaptive mobile applications SPL

Mobile Applications are rapidly emerging as a convenient medium for using a variety of services. Over time and with the high penetration of smartphones in society, self-adaptation has become an essential capability required by mobile application users. In an ideal scenario, an application is required to adjust its behavior according to the current context of its use. This raises the challenge in mobile computing towards the design and development of applications that sense and react to contextual changes to provide a value-added user experience. In its general sense, context information can relate to the environment, the user, or the device status. In this paper, we propose a novel framework for building context aware and adaptive mobile applications. Based on feature modeling and Software Product Lines (SPL) concepts, this framework guides the modeling of adaptability at design time and supports context awareness and adaptability at runtime. In the core of the approach, is a feature meta-model that incorporates, in addition to SPL concepts, application feature priorities to drive the adaptability. A tool, based on that feature model, is presented to model the mobile application features and to derive the SPL members. A mobile framework, built on top of OSGI framework to dynamically adapt the application at runtime is also described.     

基于可拓学的自适应软件形式化方法

可拓学的核心是建立灵活变通地应对不确定变化和灵感涌现的适应性模型。讨论引入可拓理论去描述、分析和评价软件系统的自适应性质、范围和程度的可能性。用基元描述软件实体,将软件系统构造成基元网,利用拓展分析、可拓变换和优度评价等定性与定量相结合的方法揭示了自适应软件系统的动态性质,并形成了一种自适应软件形式化方法。     

矿用输送带双目视觉检测自适应标定方法

针对煤矿输送带纵向撕裂视觉检测中,传统的摄像机标定方法复杂、精度低等问题,提出了一种高效的双目视觉检测自适应标定方法。分析了摄像机数学模型与双目视觉基本原理,在线性模型的基础上引入非线性畸变参数,将输送带图像与7×7矩阵模型融合提取出的关键特征角点坐标值代入矩阵约束方程,求解出摄像机内外参数及结构参数、畸变参数,并对其进行非线性优化,得到精确值,最后采用贝叶斯误差估计方法对计算出的参数与Faugeras自标定方法所得结果进行对比分析。实验结果表明该方法精度高,可靠性好。     

基于.NET的Web应用框架的设计与应用

针对当前Web应用系统层次不够分明、结构不够清晰等不足,结合MVC设计模式和对象持久化技术,提出了一种基于.NET平台的Web应用框架.将传统的三层式的软件开发细化,在显示层将显示逻辑与应用逻辑相分离,将数据访问从业务逻辑中分离出来,使得基于框架的Web应用系统开发更加灵活,便于业务逻辑的测试、修改和重用,提高了系统的可移植性.最后,结合实例说明该框架的设计及应用.