A reasoning method for a ship design expert system

Abstract: The ship design process is a highly data‐oriented, dynamic, iterative and multi‐stage algorithm. It utilizes multiple abstraction levels and concurrent engineering techniques. Specialized techniques for knowledge acquisition, knowledge representation and reasoning must be developed to solve these problems for a ship design expert system. Consequently, very few attempts have been made to model the ship design process using an expert system approach. The current work investigates a knowledge representation–reasoning technique for such a purpose. A knowledge‐based conceptual design was developed by utilizing a prototype approach and hierarchical decompositioning. An expert system program called ALDES (accommodation layout design expert system) was developed by using the CLIPS expert system shell and an object‐oriented user interface. The reasoning and knowledge representation methods of ALDES are explained in the paper. An application of the method is given for the general arrangement design of a containership.     

BCOOPL: Basic concurrent object‐oriented programming language

A small, object‐oriented language is introduced: BCOOPL (Basic Concurrent Object‐Oriented Programming Language). This language is specifically targeted to support component‐oriented programming. The main design goal of BCOOPL was to provide a small, but powerful set of language features that supports the construction of high‐quality components through well‐established software engineering practices, which include the separation of interfaces and implementations, weakly‐coupled objects, and abstraction. A number of design patterns based on these principles is actually built in the language. In particular, the observer, the mediator and the bridge are supported directly. This provides a strong foundation on which higher level component specification languages can be built. BCOOPL has a long research history. Its roots can be traced back to path expressions, and the concurrent object‐oriented programming languages Procol and Talktalk. As a result, BCOOPL only integrates essential language features that blend well and have proven their value in practice. Copyright © 2000 John Wiley & Sons, Ltd.     

A framework for fuzzy knowledge based control

Two major problems appear during the design of a framework. The first is related to synthesizing generic elements for a family of applications and connecting them to an integrated control flow. The second lies in the design of a powerful, modular, reliable architecture that is easy to (re)use and understand. The fact of including design patterns in the architecture of frameworks minimizes the second problem. Indeed, design patterns provide proven, flexible, well‐engineered design solutions at a higher abstraction level than classes. Their associated documentation records information from experienced object‐oriented designers about solutions to recurrent problems, about contexts in which the patterns are applicable, about forces involved and consequences related to their use. This paper presents a number of the benefits of integrating design patterns in the development of an object‐oriented framework related to fuzzy logic control. It also reports on an object‐oriented design for Fuzzy Knowledge Based Control (FKBC) that includes design patterns to facilitate the development, maintenance and documentation of the FKBC framework. Copyright © 2000 John Wiley & Sons, Ltd.     

Designing generic algorithms for operations research

Design solutions have been proposed to implement generic data structures, however such techniques dedicated to algorithms are not well known. This article discusses various recurrent problems encountered when designing reusable, extensible algorithms for operations research. It explains how to use object‐oriented concepts and the notion of genericity to design algorithms that are independent of the data structures and the algorithms they use, but that can still interact deeply with them. An object‐oriented design is sometimes considered to be less efficient than a classical one, and operations research is one of these scientific fields where efficiency really matters. Hence, the main goal of this article is to explain how to design algorithms that are both generic and efficient. It also discusses specific recurring design issues for operations research software and proposes solutions that improve the genericity of the algorithms. Copyright © 2005 John Wiley & Sons, Ltd.     

Using interpreted CompositeCalls to improve operating system services

A large number of protection domain crossings and context switches is often the cause of bad performance in complex object‐oriented systems. We have identified the CompositeCall pattern which has been used to address this problem for decades. The pattern modifies the traditional client/server interaction model so that clients are able to build compound requests that are evaluated in the server domain. We implemented CompositeCalls for both a traditional OS, Linux, and an experimental object‐oriented μkernel, Off++ . In the first case, we learned about implications of applying CompositeCall to a non‐object‐oriented ‘legacy’ system. In both experiments, we learned when CompositeCalls help improving system performance and when they do not help. In addition, our experiments gave us important insights about some pernicious design traditions extensively used in OS construction. Copyright © 2000 John Wiley & Sons, Ltd.     

贯通面向对象分析、设计及实现方法的研究

本文探讨了面向对象分析与设计方法在实际软件开发中的优越性及存在的不足,文章主要就建立面向对象分析、设计、实现一致性平滑过渡的方法进行了具体的探讨,面向对象分析、设计、实现纵向一致性贯通问题的解决,将有助于面向对象方法由理论向实际应用的转换。     

A set‐oriented method definition language for object databases and its semantics

In this paper we propose a set‐oriented rule‐based method definition language for object‐oriented databases. Most existing object‐oriented database systems exploit a general‐purpose imperative object‐oriented programming language as the method definition language. Because methods are written in a general‐purpose imperative language, it is difficult to analyze their properties and to optimize them. Optimization is important when dealing with a large amount of objects as in databases. We therefore believe that the use of an ad hoc, set‐oriented language can offer some advantages, at least at the specification level. In particular, such a language can offer an appropriate framework to reason about method properties. In this paper, besides defining a set‐oriented rule‐based language for method definition, we formally define its semantics, addressing the problems of inconsistency and non‐determinism in set‐oriented updates. Moreover, we characterize some relevant properties of methods, such as conflicts among method specifications in sibling classes and behavioral refinement in subclasses. Copyright © 2003 John Wiley & Sons, Ltd.     

Object‐oriented distributed computing based on remote class reference

Java RMI, Jini and CORBA provide effective mechanisms for implementing a distributed computing system. Recently many numeral libraries have been developed that take advantage of Java as an object‐oriented and portable language. The widely‐used client‐server method limits the extent to which the benefits of the object‐oriented approach can be exploited because of the difficulties arising when a remote object is the argument or return value of a remote or local method. In this paper this problem is solved by introducing a data object that stores the data structure of the remote object and related access methods. By using this data object, the client can easily instantiate a remote object, and use it as the argument or return value of either a local or remote method. Copyright © 2003 John Wiley & Sons, Ltd.     

Engineering information integration using object‐oriented mediator technology

The mechanical product development process uses many different software systems to virtually simulate the behaviour of a design. The present work deals with flexible and efficient integration using object‐oriented mediator technology that provides transparent access to distributed engineering systems. The use of mediator technology is investigated for semi‐automatically integrating engineering information resident in computer aided design systems with a Common Object Request Broker Architecture based application programming interface. The purpose is to provide engineering analysis applications access to computer aided design system information and computational methods through a declarative query language. We conclude that the use of a declarative query language for developing engineering applications shows great potential in terms of flexibility, development productivity, performance, and ease of use, compared with using a procedural programming language. The work also shows new use of mediator technology, declarative queries, and active rules within engineering information integration that traditionally is accomplished using procedural programming. Copyright © 2004 John Wiley & Sons, Ltd.     

An approach for pattern oriented software development based on a design handbook

In many mature engineering disciplines, reuse of available design knowledge is helped by the presence of handbooks. These handbooks record the details of existing system components and help in the process of evaluating design alternatives while building new systems. In recent times, design patterns have been identified as fundamental components of an object oriented design. However, they are presented in a format that may not be best suited for systematic selection and use while evaluating design alternatives. This paper provides a procedure to construct a handbook based on design patterns. This handbook helps designers in methodical selection of design patterns. The construction of the handbook is based on the identification of a set of key attributes of a design pattern and quantification of these attributes using the principles of measurement theory. A new methodology for object oriented design which consults the handbook during the design process is also introduced. The proposed methodology along with the handbook helps in evaluating different design alternatives. This revised version was published online in June 2006 with corrections to the Cover Date.     

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.     

Automating the analysis of design component contracts

Software patterns are a new design paradigm used to solve problems that arise when developing software within a particular context. Patterns capture the static and dynamic structure and collaboration among the components in a software design. A key promise of the pattern‐based approach is that it may greatly simplify the construction of software systems out of building blocks and thus reuse experience and reduce cost. However, it also introduces significant problems in ensuring the integrity and reliability of these composed systems because of their complex software topologies, interactions and transactions. There is a need to capture these features as a contract through a formal model that allows us to analyze pattern‐based designs. In this paper, we provide an overview of a formal framework for ensuring the integrity of the compositions in object‐oriented designs by providing mathematically rigorous modeling and analysis techniques for object‐oriented systems comprising pattern‐based designs as the basic building blocks or design components. A case study related to a hypermedia Web‐based application has been presented to illustrate our approach in distributed systems. Copyright © 2005 John Wiley & Sons, Ltd.     

一种面向对象的形式化设计方法──从COOZ需求规格说明到设计

本文介绍了一种基于形式化规格说明语言ＣＯＯＺ的面向对象设计方法并给出实例。该方法用ＣＯＯＺ描述类的设计规格说明，实现了从形式化需求描述到形式化设计的平滑过渡。文中重点讨论了与设计方法有关的一些面向对象概念：对象类型和类的分开、子类型和继承的分开、灵活的消息传递和参数转换机制、主动对象和被动对象、根类的定义等。     

基于UML的图书管理系统分析与设计

图书管理系统是信息化时代有效管理图书的重要手段,根据不同的权限,读者、管理员、系统管理员可以完成各自的操作。文中借助UML技术对图书管理系统进行了面向对象分析与设计,在需求分析阶段给出了系统用例图,在类设计阶段给出了系统类图,在交互性设计阶段给出了借书时序图。     

A Function Point-Like Measure for Object-Oriented Software

We present a method for estimating the size, and consequently effort and duration, of object oriented software development projects. Different estimates may be made in different phases of the development process, according to the available information. We define an adaptation of traditional function points, called Object Oriented Function Points, to enable the measurement of object oriented analysis and design specifications. Tools have been constructed to automate the counting method. The novel aspect of our method is its flexibility. An organization can experiment with different counting policies, to find the most accurate predictors of size, effort, etc. in its environment. The method and preliminary results of its application in an industrial environment are presented and discussed.     

利用事件-状态图进行面向对象的系统设计

面向对象的一般概念并不保证系统设计的正确性、完整性和一致性 ,而且应用面向对象的方法 ,系统设计变得更为重要了。本文提出的事件状态图法是一种简捷有效的面向对象的系统设计方法。文章阐述了这一方法的具体应用 ,并讨论了识别现实系统的对象时应注意对状态变量的定义。文中最后还提出了一种包含 VBA编程的电子化版本的事件状态图     

Converting command‐line applications into binary components

A binary component is a separately compiled program that can be used as a part of a larger program. Binary components generally conform to an accepted technology such as JavaBeans or ActiveX, and generally support a rich program interface containing properties, methods and events. Binary components are generally used in a graphical user interface (GUI) environment. There are a number of benefits to be realized by converting command‐line software into binary components. The most important of these is that GUI environments are more popular and more familiar to most people than command‐line environments. Using binary components can greatly simplify a GUI implementation, to the point where it is only slightly more complicated than a typical command‐line implementation. However there are benefits that go beyond mere convenience. Binary components have much richer interfaces than command‐line programs. Binary components are service‐oriented rather than task‐oriented. A task‐oriented program has a main routine that is devoted to accomplishing a single task. A service‐oriented component has no main routine or main function, but instead provides a variety of services to its clients. Binary components can be easily integrated with one another, which permits a design where each major feature of an application is implemented in a different component. Such a design encourages software reuse at the component level and facilitates low‐impact feature upgrades. We first delineate a design‐pattern‐based methodology for converting command‐line programs into components. We then illustrate these principles using two projects, a simulation system for digital circuits, and a data generation system for software and hardware testing. Copyright © 2005 John Wiley & Sons, Ltd.     

Mapping the distribution of coral reefs and associated sublittoral habitats in Pacific Panama: a comparison of optical satellite sensors and classification methodologies

This research compared the ability of Landsat ETM+, Quickbird and three image classification methods for discriminating amongst coral reefs and associated habitats in Pacific Panama. Landsat ETM+ and Quickbird were able to discriminate coarse and intermediate habitat classes, but this was sensitive to classification method. Quickbird was significantly more accurate than Landsat (14% to 17%). Contextual editing was found to improve the user's accuracy of important habitats. The integration of object‐oriented classification with non‐spectral information in eCognition produced the most accurate results. This method allowed sufficiently accurate maps to be produced from Landsat, which was not possible using the maximum likelihood classifier. Object‐oriented classification was up to 24% more accurate than the maximum likelihood classifier for Landsat and up to 17% more accurate for Quickbird. The research indicates that classification methodology should be an important consideration in coral reef remote sensing. An object‐oriented approach to image classification shows potential for improving coral reef resource inventory.     

基于衍型的模式标注方法

设计模式在面向对象软件设计、开发和维护中发挥着非常重要的作用。为了克服现有设计模式标注方法的缺陷与不足,提出一种基于衍型的模式标注方法SBPN。基于UML衍型机制,SBPN不仅提供了一套规则用于精确标注结构图中类、方法或属性等模型元素的模式角色相关信息,还可以标注交互图中的模式信息。此外,SBPN为源代码中模式信息的标注也提供了相应的解决方案。给出了使用SBPN方法标注类图、交互图和源代码中的模式信息的实例,最后还将SBPN应用于一个较为复杂的排序系统。