A style for integrating MS‐Windows software applications to client–server systems using Java technology

Developing software systems by integrating the existing applications/systems over the network has become an established and practical technique. The Microsoft (MS) Windows operating systems today support a huge number of software applications. If these commercial applications could be transformed to software components, this may accelerate the construction of new components. This paper proposes an architectural style to support a three‐phase process for integrating MS‐Windows applications in a distributed system using Java technologies. This style provides a solution with clear documentation and sufficient information that is helpful for the rapid integration of MS‐Windows applications. Finally, an exemplary graphical construction part management system that assembles two MS‐Windows applications was developed in this study to demonstrate the feasibility of this style. Copyright © 2006 John Wiley & Sons, Ltd.     

Migrating legacy scientific applications towards CORBA‐based client–server architectures

A distributed object is a reusable, self‐contained piece of software that cooperates with other objects on the same machine or across a network in a plug‐and‐play fashion via a well‐defined interface. The Numerical Propulsion System Simulation (NPSS) attempts to provide a collaborative aircraft engine design and simulation environment based on this concept. Many scientific applications in aerodynamics and solid mechanics are written in Fortran. Refitting this legacy Fortran code with distributed objects can increase code reusability. In this paper, we focus on the novel use of a remote variable scheme to help programmers migrate the Fortran code towards a client–server architecture. This scheme gives the client the capability of accessing variables at the server site and makes it easier for programmers to couple component engine code. Through the operator overloading features in C++, remote variables can be used in much the same way as traditional variables. The remote variable scheme adopts the lazy update approach and the prefetch method. Preliminary performance evaluation shows that communication overhead can be greatly reduced. Copyright © 2001 John Wiley & Sons, Ltd.     

A multi-layer client–server queueing network model with non-hierarchical synchronous and asynchronous messages

We analyze a multi-layered queueing network that models a client–server system where clients and servers communicate via synchronous and asynchronous messages. The servers are organized in groups such that they form a multi-layered structure. The messaging pattern is non-hierarchical, i.e., a client can send a message to a server belonging to any layer, and a server from a layer-i may issue messages to a server belonging to any higher layer, j>i. The queueing network is analyzed approximately using a decomposition algorithm. Numerical tests show that the approximation algorithm has a good accuracy.     

Design and implementation of a client‐server architecture for taxonomy manager

Taxonomy Manager (TM) is a computer‐based, full‐text method dedicated to represent biological knowledge allowing scientists to continuously revise and reorganize the conceptual framework of data and their interpretation. The system architecture distinguishes clients and a task oriented server. TM provides a distinct, precise, yet user‐friendly, formalism for knowledge specification by biologic experts and for factual knowledge input by general scientists on interactive interfaces. An incremental compiler translates and transforms new information specified within full‐text editors into an internal format and back again. A retrieval dialog allows access to the results of text analyses including information units and associated rules, and a browser offers free navigation through the network of data. External users can access the information contained within TM by a communication protocol. Copyright © 1999 John Wiley & Sons, Ltd.     

URNG: A portable optimization technique for software applications requiring pseudo-random numbers

Research software involving stochastic behaviour often requires millions of random numbers. In addition to the quality of the pseudo-random number generator (PRNG), the speed of the algorithm and the ease of its implementation are common practical aspects. In this work we will discuss how to optimize the access speed to random numbers independently from the generation algorithm. We propose an additional implementation technique in order to speed up any kind of PRNG taking into account the capacities of current computers and microcomputers. The speed of our solution stems from the classical unrolling optimization technique, it is named the URNG technique (unrolled random number generator). Random numbers are first generated in source code, then precompiled and stored inside the RAM of inexpensive computers at the executable loading time. With this technique random numbers need to be computed only once. The URNG technique is compliant with parallel computing. Limits and effects on speed and sensitivity are explored over four computer generations with a simple Monte Carlo simulation. Every research field using stochastic computation can be concerned by this software optimization technique which is currently limited to applications requiring not more than a few hundred millions of pseudo-random numbers.     

The software information base: A server for reuse

We present an experimental software repository system that provides organization, storage, management, and access facilities for reusable software components. The system, intended as part of an applications development environment, supports the representation of information about requirements, designs and implementations of software, and offers facilities for visual presentation of the soft-ware objects. This article details the features and architecture of the repository system, the technical challenges and the choices made for the system development along with a usage scenario that illustrates its functionality. The system has been developed and evaluated within the context of the ITHACA project, a technology integration/software engineering project sponsored by the European Communities through the ESPRIT program, aimed at developing an integrated reuse-centered application development and support environment based on object-oriented techniques.     

综合航电开放式软件设计技术

综合航电开放式软件设计技术是新一代航电系统支持平台机载实时容错分布式计算机系统的重点,它的设计直接或间接地关系到新一代综合航电系统的性能和成本.针对先进综合航电系统的特点、性能要求,对目前机载计算机软件系统存在的可靠性、安全性低,不易移植,成本高,层次分割不清晰,功能独立性差,对系统容错支持能力弱等缺陷,提出了"三层栈结构"的软件设计新思想,通过标准接口(物理接口和逻辑接口)使得层与层,模块与模块之间得以分开,实现了功能模块化、软硬件隔离性、软件的再利用性、可剪裁性、易维护性,以适应不断增长的航空电子系统任务能力需求,为新一代航电系统支持平台机载实时容错分布式计算机系统的开发、研制提供了可靠的保证.     

Interconnecting distributed virtual worlds using Metabots: performance evaluation against the traditional client‐server model

Virtual Worlds evolution is breaking the barriers of virtual isolation, thus allowing users to participate in geographically dispersed and culturally diverse places. At the same time, mobile agents have been established as a solid programming method for heterogeneous networking and computing environments. Our work focuses on the definition of a distributed Virtual World reference platform for enhanced users' experience. Towards interconnecting virtual worlds with mobile agents, we have further enriched the concept of a human‐like appearance avatar. We propose two distributed virtual world architectures, namely loose and tight. In parallel, we present a relevant implementation scheme along with experimental results that prove the performance enhancements achieved against the classic client/server model. Copyright © 2014 John Wiley & Sons, Ltd.     

A robotic software for intelligent applications

This study addresses the development of a novel intelligent robotic software system which can control a low-cost five DOF robotic arm and allows the robot to be able to play Tic-Tac-Toe, a simple board game. The paper first aims to introduce proposed software and then details the application developed, including image processing, and decision making steps.     

Client–server architecture for collaborative remote experimentation

Experience in teaching engineering related subjects has shown that a complementary approach combining theoretical and practical exercises is vital for effective learning. Increasingly, teaching institutions are offering remote access to distant laboratories as part of an overall e-learning strategy. However, the majority of remote access laboratories developed to date have suffered from a major deficiency, namely the provision of a web-based environment that accurately recreates the group working and tutor driven experience of traditional on-campus based laboratories. This paper addresses this issue and presents a client–server architecture, based on Web services and .NET remoting services, for an integrated learning environment for remote experimentation that allows students in disparate locations to simultaneously and collaboratively complete complex experimental exercises.     

A design medium for software

A design medium for software is proposed and illustrated. The medium, which employs rectangular, embedded contours, provides a high level of scale independence. Module specifications, logic design and program elements are easily intermixed in a design. The proposed module formalization includes interface specification, exceptions, logic design and effects in an order which will ultimately be exhibited by the program code as well.     

A generalized technique for simulating software reliability

Although several models have been proposed for assessing software reliability, none has emerged as the most effective predictor. The authors offer a general simulation technique that relaxes or removes many of the usual reliability-modeling assumptions and expends the reliability process to encompass the entire software life cycle     

一种面向无线传感器网络节点的软件更新技术

针对无线传感器网络节点资源受限、网络维护与软件更新困难的特点,以Contiki操作系统为开发平台,设计了一种可以满足无线传感器网络特点和应用的节点软件更新方法。通过连续分配和基于重定位信息的内存移动,设计了一种高利用率的内存使用策略;基于黑板模型的管理方法,实现了服务模块注册、更新和卸载的生命周期管理。实验结果显示：更新模块的大小与更新时间分别减小15％和13％,整个系统设计显著提高了传感器节点的能量和内存效率,延长了节点寿命。     

A framework for artificial intelligence applications software development

Despite the promise and prominence of artificial intelligence, successful widely-based applications have been rare. Much of previous artificial intelligence work has concentrated on the demonstration of techniques rather than the development of tools that can be used in systems design, analysis and operation. A systematic program of knowledge compilation in artificial intelligence is proposed where extensible function libraries can be used by professionals in various fields and non-programming specialists in developing artificial intelligence applications.     

Database systems: their applications to CAD software design

This paper concerns the application of database theories formulated mostly in the commercial and business area of data processing to CAD software design. The major approaches to database system design are analysed and examples of CAD software systems which have utilized them are indicated. An integraged approach to database system is proposed as an alternative for further investigations.     

Interactive dialogue model: a design technique for multichannel applications

Multichannel applications deliver the same content and a "similar interactive experience" using different devices and different technologies(e.g., web sites, palm held devices, car navigators, or interactive TVs). Various channels imply a number of differences, including screen (size), keyboard(size), pointing devices, output devices, performances, and the context of use (standing, sitting, walking, etc.). In most cases, today, applications for different channels are designed and implemented almost "independently", with ineffectiveness for the developers (high costs) and ineffectiveness for the users (loss of consistency across the different channels and the perception that they are "different applications"). This paper presents an interactive dialogue model (IDM), a novel design model specifically tailored for multichannel applications. The background research, moving from linguistic theories and practices, has led us to the development of a "channel-independent" design model (based on dialogue primitives). Design can start in a "conceptual", channel-independent fashion, and then proceed into a further "logical" design oriented toward specific channels of communication. Designing an interactive application in two steps (channel-independent first, and channel-dependent later) allows a number of advantages without making more cumbersome the overall design process. Beside the emphasis on multichannel, IDM has additional distinctive features: it is lightweight, providing a few set of primitives (and a simple graphic notation) which are easy to learn and teach. Moreover, it is suitable for brainstorming and generating ideas at early stage during design (or during the shift from requirements to design); finally, it is cost-effective (it requires little effort from designers) and modular (designers can take the part they wish, not being forced to "all or nothing"). IDM has been validated both in the academic and industry environments,providing excellent results so far.     

A CASE tool for software architecture design

This paper describes the Software Architect's Assistant, an automated visual tool for the design and construction of Regis distributed programs. Unlike conventional CASE tools and their supported methodologies, the Architect's Assistant supports a compositional approach to program development in which the software architecture plays a central role throughout the software life-cycle—from the early design stage through to system management and evolution.In its implementation, we have addressed some of the limitations of existing CASE tools, particularly in the degree of automated support offered to the human developer. Conscious effort has been made to maximise usability and efficiency, primarily by enhancing the level of automation and flexibility together with careful design of the user interface. Our objective is to provide a tool which automates all mundane clerical tasks, enforces program correctness and consistency and, at the same time, accommodates the individual working styles of its users.Although currently specific to the development of Regis programs, the Architect's Assistant embodies concepts and ideas which are applicable to CASE tools in general.     

Embedded software verification in hardware–software codesign

Concurrent Embedded Real-Time Software (CERTS) is intrinsically different from traditional, sequential, independent, and temporally unconstrained software. The verification of software is more complex than hardware due to inherent flexibilities (dynamic behavior) that incur a multitude of possible system states. The verification of CERTS is all the more difficult due to its concurrency and embeddedness. The work presented here shows how the complexity of CERTS verification can be reduced significantly through answering common engineering questions such as when, where, and how one must verify embedded software. First, a new Schedule-Verify-Map strategy is proposed to answer the when question. Second, verification under system concurrency is proposed to answer the where question. Finally, a complete symbolic model checking procedure is proposed for CERTS verification. Several application examples illustrate the usefulness of our technique in increasing verification scalability.     

Encapsulation of legacy software: A technique for reusing legacy software components

The following paper reviews the possibilities of encapsulating existing legacy software for reuse in new distributed architectures. It suggests wrapping as an alternative strategy to reengineering and redevelopment. It then defines the levels of granularity at which software can be encapsulated before going on to describe how to construct a wrapper and how to adapt host programs for wrapping. Some wrapping products are discussed and the state of the art summarized. The advantage of wrapping over conventional reengineering is the low cost and even lower risks involved. This is the driving force in the search for improved wrapping technology. This revised version was published online in June 2006 with corrections to the Cover Date.