A quality of service driven concurrency framework for object‐based middleware

Threads play a key role in object‐based middleware platforms. Implementers of such platforms can select either kernel or user‐level threads, but neither of these options are ideal. In this paper we introduce Application Scheduler Contexts (ASCs) which flexibly combine both types of thread and thereby attempt to exploit the advantages of each. Multiple ASCs can co‐exist, each with their own concurrency semantics and scheduling policy. ASCs also support quality of service (QoS) configurability, and define their own QoS schema. We show how ASCs can be efficiently implemented and how they can usefully be exploited in middleware environments. We also provide a quantitative evaluation that demonstrates the feasibility of the ASC concept in performance terms. Copyright © 2002 John Wiley & Sons, Ltd.     

Zorilla: a peer‐to‐peer middleware for real‐world distributed systems

The inherent complex nature of current distributed computing architectures hinders the widespread adoption of these systems for mainstream use. In general, users have access to a highly heterogeneous set of compute resources, which may include clusters, grids, desktop grids, clouds, and other compute platforms. This heterogeneity is especially problematic when running parallel and distributed applications. Software is needed which easily combines as many resources as possible into one coherent computing platform. In this paper, we introduce Zorilla: peer‐to‐peer (P2P) middleware that creates a single distributed environment from any available set of compute resources. Zorilla imposes minimal requirements on the resource used, is platform independent, and does not rely on central components. In addition to providing functionality on bare resources, Zorilla can exploit locally available middleware. Zorilla explicitly supports distributed and parallel applications, and allows resources from multiple sites to cooperate in a single computation. Zorilla makes extensive use of both virtualization and P2P techniques. We will demonstrate how virtualization and P2P combine into a simple design, while enhancing functionality and ease of use. Together, these techniques bring our goal a step closer: transparent, easy use of resources, even on very heterogeneous distributed systems. Copyright © 2011 John Wiley & Sons, Ltd.     

Agents in object‐oriented software engineering

Software engineers of multi‐agent systems (MASs) are faced with different concerns such as autonomy, adaptation, interaction, collaboration, learning, and mobility, which are essentially different from classical concerns addressed in object‐oriented software engineering. MAS developers, however, have relied mostly on object‐oriented design techniques and programming languages, such as Java. This often leads to a poor separation of MAS concerns and in turn to the production of MASs that are difficult to maintain and reuse. This paper discusses software engineering approaches for MASs, and presents a new method for integrating agents into object‐oriented software engineering from an early stage of design. The proposed approach encourages the separate handling of MAS concerns, and provides a disciplined scheme for their composition. Our proposal explores the benefits of aspect‐oriented software development for the incorporation of agents into object‐oriented systems. We also illustrate our aspect‐oriented approach through the Portalware multi‐agent system, a Web‐based environment for the development of e‐commerce portals. Copyright © 2004 John Wiley & Sons, Ltd.     

Developing an object‐oriented framework for content‐based image retrieval

Content‐based image retrieval (CBIR) is a process of retrieving images from an image database by exploiting the content of the images (typically the querying of an image). CBIR avoids many problems associated with traditional ways of retrieving images by keywords. Thus, a growing interest in the area of CBIR has been established in recent years. In this paper, a novel object‐oriented framework (CBIRFrame) is built for CBIR applications development. We discuss the motivations for CBIRFrame before discussing its design in detail. Two applications of CBIRFrame are also briefly discussed to show the effectiveness of applying CBIRFrame to real applications. Finally, we outline the possible uses of the design of CBIRFrame for other types of domains, such as content‐based retrieval of video clips. Copyright © 2003 John Wiley & Sons, Ltd.     

An integrated runtime QoS-aware middleware framework for distributed multimedia applications

Future-generation distributed multimedia applications are expected to be highly scalable to a wide variety of heterogeneous devices, and highly adaptive across wide-area distributed environments. This demands multiple stages of run-time support in QoS-aware middleware architectures, particularly, probing the performance of QoS parameters, instantiating the initial component configurations, and adapting to on-the-fly variations. However, few of the past experiences in related work have shown comprehensive run-time support in all of the above stages – they often design and build a middleware framework by focusing on only one of the run-time issues. In this paper, we argue that distributed multimedia applications need effective run-time middleware support in all these stages to be highly scalable and adaptive across a wide variety of execution environments. Nevertheless, the design of such a middleware framework should be kept as streamlined and simple as possible, leading to a novel and integrated run-time middleware platform to unify the probing, instantiation and adaptation stages. In addition, for each stage, the framework should enable the interaction of peer middleware components across host boundaries, so that the corresponding middleware function can be performed in a coordinated and coherent fashion. We present the design of such an integrated architecture, with a case study to illustrate how it is simple yet effective to monitor and configure complex multimedia applications.     

Distributed OSGi built over message‐oriented middleware

This paper describes key aspects of remote service invocation in federations of OSGi containers. It refers to the OSGi Remote Service Admin specification and describes its efficient implementation over message‐oriented middleware. Scalability problems of several different approaches to implementation are identified, and a solution in a form of innovative Remote Service Admin model extension is proposed. The extension, named On‐demand Remote Service Admin, is analyzed and validated in the context of a motivating scenario. Validation includes performance and scalability evaluation, which confirms that all assumed requirements have been satisfied by the constructed prototype. Finally, the presented research is compared with related works. Copyright © 2011 John Wiley & Sons, Ltd.     

中间件技术研究

中间件技术屏蔽了底层分布式环境的复杂性和异构性,简化了分布式应用程序的开发,使分布式应用程序的健壮性、可扩展性、可用性更好。本文介绍了中间件的定义、分类、主流中间件技术平台,能够隐藏底层网络环境的复杂性,处理平台之间的异构性,是分布式计算和系统集成的关键组件。本文介绍了中间件的基本概念,阐述了一种基于系统层次的分类方法,并详细讨论了现存各类中间件技术的特点、相关标准及发展应用情况。     

云计算环境下服务中间件动态管理框架的设计与实现

面向服务的软件开发过程会涉及不同种类以及层次的服务中间件,这一多层次、多种类、多依赖关系的服务中间件环境,在配置、管理与维护上均会给服务开发人员带来额外的开销与负担,直接影响开发效率。设计并实现了一个云计算环境下的服务软件设备动态管理框架,该框架可以根据开发人员需求,透明地完成服务中间件环境的配置与提供,并对服务中间件环境进行动态的健康管理与维护,保障服务中间件环境的稳定性与可靠性。     

JAMES: An object‐oriented Java framework for discrete optimization using local search metaheuristics

This paper describes the Java Metaheuristics Search framework (JAMES, v1.1): an object‐oriented Java framework for discrete optimization using local search algorithms that exploits the generality of such metaheuristics by clearly separating search implementation and application from problem specification. A wide range of generic local searches are provided, including (stochastic) hill climbing, tabu search, variable neighbourhood search and parallel tempering. These can be applied to any user‐defined problem by plugging in a custom neighbourhood for the corresponding solution type. Using an automated analysis workflow, the performance of different search algorithms can be compared in order to select an appropriate optimization strategy. Implementations of specific components are included for subset selection, such as a predefined solution type, generic problem definition and several subset neighbourhoods used to modify the set of selected items. Additional components for other types of problems (e.g. permutation problems) are provided through an extensions module which also includes the analysis workflow. In comparison with existing Java metaheuristics frameworks that mainly focus on population‐based algorithms, JAMES has a much lower memory footprint and promotes efficient application of local searches by taking full advantage of move‐based evaluation. Releases of JAMES are deployed to the Maven Central Repository so that the framework can easily be included as a dependency in other Java applications. The project is fully open source and hosted on GitHub. More information can be found at http://www.jamesframework.org . Copyright © 2016 John Wiley & Sons, Ltd.     

EASYLOCAL++: an object‐oriented framework for the flexible design of local‐search algorithms

Local search is a paradigm for search and optimization problems, which has recently evidenced to be very effective for a large number of combinatorial problems. Despite the increasing interest of the research community in this subject, there is still a lack of a widely‐accepted software tools for local search. We propose EASY LOCAL , an object‐oriented framework for the design and the analysis of local‐search algorithms. The abstract classes that compose the framework specify and implement the invariant part of the algorithm and are meant to be specialized by concrete classes that supply the problem‐dependent part. The framework provides the full control structures of the algorithms, and the user has only to write the problem‐specific code. Furthermore, the framework comes with some tools that simplify the analysis of the algorithms. The architecture of EASY LOCAL provides a principled modularization for the solution of combinatorial problems by local search and helps the user by deriving a neat conceptual scheme of the application. It also supports the design of combinations of basic techniques and/or neighborhood structures. The framework has been tested in some applicative domains and has proved to be flexible enough in the implementation of algorithms for the solution of various scheduling problems. Copyright © 2003 John Wiley & Sons, Ltd.     

A case study: productivity and quality gains using an object‐oriented framework

The Neuro‐Oncology Information System (NOIS) supports researchers and other personnel throughout the United States engaged in brain tumor research. Graphical user interfaces that allow data input into the NOIS have been evolving over several years. This paper describes the design and implementation of the NOIS Input Forms as they migrated from a procedural approach to a static object‐oriented approach, and finally to a framework approach in which not only static components were reused, but also the patterns of interaction among the components. The paper documents a significant gain in productivity and quality that was realized when using the framework design paradigm. Copyright © 1999 John Wiley & Sons, Ltd.     

Implementing a generic component‐based framework for telecontrol applications

The rapid growth of telecontrol systems is one of the major trends in today's network‐oriented community. The implementation of generic frameworks, consisting of reusable components that can form the basis for the development of such systems, is a necessity. There is a plethora of associated applications that can be developed in a distributed environment, such as audio/video teleconferencing, groupware and collaborative computing environments, remote controlled services, etc. In this paper we design and implement a generic framework of components that can be used for the realization of telecontrol applications. This category of applications focuses primarily on the issues of managing distributed units on remote end‐systems. Such applications contain remote units and administrators that are connected and exchange data and control messages. We analyse the outlined architecture of our framework and the most important system operations. We also describe the communication protocol used in message exchanges between the constituent components. Finally, we illustrate the usefulness of our framework by presenting two applications that were created by extending the basic software infrastructure. Copyright © 2007 John Wiley & Sons, Ltd.     

FC++: Functional tools for object‐oriented tasks

FC++ is a library for programming functionally in C++. Compared to other C++ functional programming libraries, FC++ is distinguished by its powerful type system which allows the manipulation of parametrically polymorphic functions (e.g., passing them as arguments to other functions and returning them as results). In this paper, we show how FC++ can be used in common object‐oriented programming tasks. We demonstrate FC++ implementations of several common design patterns (Adapter, Builder, Command, and more). Compared to conventional C++ implementations of these patterns, our implementations are either simpler (in that fewer classes/dependencies are needed), more efficient, or more type‐safe (thanks to parametric polymorphism and type inference). Copyright © 2002 John Wiley & Sons, Ltd.     

An object‐oriented design for graph visualization

Many applications, from everyday file system browsers to visual programming tools, require the display of network and graph structures. The Graph Visualization Framework (GVF) (available at http://www.cwi.nl/InfoVisu/GVF) is an architecture that supports the tasks common to most graph browsers and editors. This article gives a brief overview of the design of the GVF and focuses on the core classes that are used to represent and manipulate graphs. The design of the core classes is justified by the requirements for navigation and visualization. Copyright © 2001 John Wiley & Sons, Ltd.     

A cohesion measure for object‐oriented classes

In object‐oriented systems, cohesion refers to the degree of the relatedness of the members in a class and strong cohesion has been recognized as a highly desirable property of classes. We note that the existing cohesion measures do not take into account some characteristics of classes, and thus often fail to properly reflect the cohesiveness of classes. To cope with such a problem, we propose a new cohesion measure where the characteristics of classes are incorporated. Our cohesion measure takes into account the members that actually have impact on the cohesiveness of a class, and is defined in terms of the degree of the connectivity among those members. We develop a cohesion measurement tool for C++ programs, and perform a case study on a well‐known class library in order to demonstrate the effectiveness of our new measure. By performing principal component analysis, we also demonstrate that our measure captures a new aspect of class properties which is not captured by the existing cohesion measures. Copyright © 2000 John Wiley & Sons, Ltd.     

Role‐play virtual worlds for teaching object‐oriented design: the ViRPlay development experience

The use of game technology for building virtual learning environments is intended to improve the motivation and engagement of the student, borrowing such properties from their entertaining counterparts. Nevertheless, wrapping pedagogical contents in a virtual environment is no simple achievement, and requires a rigorous process of designing and validating the metaphors and mechanics included in the virtual learning system. In this paper we describe such design process exemplified in the construction of consecutive versions of ViRPlay, a 3D role play virtual environment for teaching object‐oriented design. We show how main mechanics were transferred from experiments in the real world and how such mechanics were evolved based on empirical evaluations. Copyright © 2011 John Wiley & Sons, Ltd.     

Obfuscation for object‐oriented programs: dismantling instance methods

Code obfuscation can help software developers protect technological secrets. Code readability is greatly enhanced with object‐oriented technology that represents dynamic binding using instance method invocation. Therefore, dismantling instance methods is proposed in this paper as a critical obfuscating technique for object‐oriented programs. The interception classes are interpolated first into the project. The static images and the up forwarders are then created. For each virtual function system and each interface function system, a respective dispatching function is set up. By properly arranging the class identifiers and binding identifiers, the switch statement in the dispatching function can be compiled into constant‐time low‐level code. After using dispatching functions to simulate virtual function system or interface function system invocations, all original instance methods in the project will be removed. Interception functions and export functions are indispensable in supporting the operation of callback methods. A prototype of our obfuscation system was implemented and successfully tested on some practical scale applications. Copyright © 2013 John Wiley & Sons, Ltd.     

消息中间件技术在煤矿井下通信系统中的应用

针对矿井TD-SCDMA通信系统易受环境影响而发生传输数据丢失或错误的问题,提出将消息中间件技术引入煤矿井下通信系统的方案,介绍了通信系统的4层架构,重点阐述了消息中间件技术在煤矿井下通信系统中的应用实现。消息中间件为通信系统各层之间提供同步和异步连接,通过使用"确保信息传输"技术、消息解析与过滤技术、异常处理技术以及Hibernate技术,实现了数据在传输过程中不丢、不错、不漏。测试结果表明,引入消息中间件技术后,煤矿井下通信系统的数据处理速度有了很大提高,出错率明显降低。