In agriculture as in other domains, there exists a need for multifaceted and comprehensive decision support frameworks enabling the integration and use of different types of knowledge and information processing tools....
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In agriculture as in other domains, there exists a need for multifaceted and comprehensive decision support frameworks enabling the integration and use of different types of knowledge and information processing tools. The object-oriented paradigm provides a foundation for the construction of such general decision support frameworks. The objective of the described project was to build an object-oriented framework (called SAGE) for knowledge management and decision support in the area of agro-ecosystem management. The Smalltalk object-oriented programming system was the basic technology used to build the SAGE system. A Smalltalk-based object-oriented database management system was also used to provide persistence for Smalltalk objects. The result of the design and implementation effort is a library of Smalltalk classes that constitutes a framework onto which developers can build systems to represent agroecosystems and support the management of these systems. These classes are described and their design and implementation issues are discussed.
The modular design of products leads to a large number of different products by creating distinct combinations of modules and components. This can give each product distinctive functionality, features, and performance...
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The modular design of products leads to a large number of different products by creating distinct combinations of modules and components. This can give each product distinctive functionality, features, and performance levels. The design of modular products is of considerable importance in enabling companies to respond rapidly to changes in the market environment. This paper is concerned with the area of design with modules (DwM), which involves selecting the module combination to best satisfy the given set of requirements. The aim of this paper is to develop an approach for DwM, to meet customer requirements, using modules that come from suppliers that may be geographically separated and on differing computer platforms. An object-oriented approach for DwM, termed object-orienteddesign with modules (OODwM), is proposed where modules are represented as objects. The proposed OODwM approach is described and the approach is illustrated with an example involving the design of personal computers using the Internet as an implementation environment. The exchangeability inherent in OODwM is shown by exchanging the original selection object in the example implementation with a selection object that includes new constrained evolutionary algorithms. The use of an object-oriented approach for DwM offers several important potential advantages in that the model developed is readily computable, in the reusability of objects, and in the exchangeability of objects with similar interfaces. The main contributions of this paper are fourfold. First, an object-oriented approach to DwM is described. Second, a formalism for DwM using this object-oriented approach is presented. Third, the use of this formalism is illustrated with an Internet-based implementation showing how the formalism can be used for a specific problem, and how objects can be readily exchanged. Fourth, new constrained evolutionary algorithms are presented, together with some initial testing. (C) 1998 Elsevier Science Ltd.
The design and implementation of a knowledge elicitation tool for use in specifying real-time control system requirements with the Core method is presented. The tool uses pattern recognition based on a Holland classif...
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The design and implementation of a knowledge elicitation tool for use in specifying real-time control system requirements with the Core method is presented. The tool uses pattern recognition based on a Holland classifier to propose a control-system object space for subsequent manipulation, and it is in this area that emphasis is placed. Classifier systems in general are discussed, and an implementation using the Smalltalk-800 object-oriented programming environment is presented. Practical results are included.
The use of formal methods promises correctness, verifiability, robustness and reliability of operational software systems which have been developed so far. object-oriented methods enable easier development and mainten...
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The use of formal methods promises correctness, verifiability, robustness and reliability of operational software systems which have been developed so far. object-oriented methods enable easier development and maintenance of software application systems and promote the reuse of design and program code. Mapping formal specifications into an object-oriented application will therefore give a system that is not only correct and reliable, but easy to develop and enhance. In this paper, we show how specifications containing major decisions that financial managers typically make, can be expressed in the Z notation. These specifications are subsequently translated into pseudo object-oriented programs.
This paper describes the problems with conventional finite element analysis software and the potential solutions offered by object-oriented programs. It introduces the basic concepts of object-oriented programming and...
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This paper describes the problems with conventional finite element analysis software and the potential solutions offered by object-oriented programs. It introduces the basic concepts of object-oriented programming and of expandable applications. Finite element fundamentals are explained using a new perspective leading to the implementation of an object-oriented numerical analysis program. objects, classes, methods, and inheritance are illustrated using a graphical representation. implementation-independent descriptions are given for the internal operation of a generic class system, followed by some details regarding the design of object-oriented programs using class libraries from an expandable application framework. A theoretical foundation is laid for the implementation of an object-oriented program which uses isoparametric elements for the numerical analysis of two-dimensional linear problems in solid and structural mechanics. Class descriptions are given in parallel to a step by step formulation of the analysis solution. The analysis program is portrayed as an assembly of classes which control and organize, the solution process. The design, implementation, operation, validation, and maintenance of this program is compared to that of an equivalent procedural program to identify the advantages of the object-oriented approach. Practical applications of object-oriented finite element analysis are discussed with particular reference to the use of knowledge-based expert systems.
For an object-orienteddesign methodology to be effective, it is important to provide methods and tools for validating the design specification before going into the implementation phase. The paper proposes a design m...
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For an object-orienteddesign methodology to be effective, it is important to provide methods and tools for validating the design specification before going into the implementation phase. The paper proposes a design methodology and a related object-oriented specification language which allows the validation of specifications through simulated execution, or through automatic exhaustive simulation for a certain subset of the language. The paper also discusses the relation of this design methodology and language to other design methodologies which are in wide use, such as the entity-relationship model for databases, the ASN.1 notation used for Open systems Interconnection (OSI) communication protocols, as well as methodologies used in the standardization committees for the elaboration and description of various kinds of distributed systems standards. It is shown how these different approaches can be integrated into a single methodology and language, using the OSI Directory System as an example, which is explained in certain detail.
In this increasingly technological age, the need for parallel processing has never been greater than it is today. Parallelizing a particular program or system can increase the speed of the system by the number of proc...
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In this increasingly technological age, the need for parallel processing has never been greater than it is today. Parallelizing a particular program or system can increase the speed of the system by the number of processors (in the ideal case). A wide variety of parallel and distributed systems exist, and their efficiency may not be the same for different types of problems. In fact, the variation of real world systems and their possible implementation on an actual distributed system is enormous. In this paper, an inexpensive solution to parallelizing the determination of paths in a Petri net is presented. The system utilized is an IBM Local Area Network with four computers arranged as a parallel processing system. A three step generalized algorithm to accomplish the parallelization is given. The actual implementation, is facilitated by the use of objectoriented software design, in particular Turbo Pascal version 5.5 (which supports the creation of objects and their associated data sets and procedures). Finally, actual implementation and object creation of this system is accomplished.
Atomic transactions are now a familiar paradigm for distributed programming and have been provided in a number of object-oriented languages. Much effort has also been expended on developing open transaction processing...
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Atomic transactions are now a familiar paradigm for distributed programming and have been provided in a number of object-oriented languages. Much effort has also been expended on developing open transaction processing systems which support distributed transactions involving multi-vendor database systems. This paper addresses a number of issues that arise in combining object-oriented distributed programming with open transaction processing. We describe an approach to supporting transactions which can access objects and other resource types, such as files and records, consistently, and which is independent of the use of any particular object-oriented programming language. We discuss both the design of a generic run-time interface which provides language independent support for atomic objects and transactions and, following the X/Open model for open transaction processing, the design of an interface between the transaction manager and a resource manager which is suitable for the requirements of object-orientedsystems. We illustrate our approach by describing the transaction sub-system of the Amadeus/RelaX implementation of the Comandos platform which supports a number of popular object-oriented languages and has been integrated with an existing relational database system.
object-oriented modelling and design is a new way of thinking about problems, using models organised around real-world concepts. This paper presents an object-oriented approach to software development, based on modell...
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object-oriented modelling and design is a new way of thinking about problems, using models organised around real-world concepts. This paper presents an object-oriented approach to software development, based on modelling objects from a fire protection environment. The model is then used to build a language-independent design, organized around those objects. The paper also describes some object modelling techniques used in mapping the object-orienteddesign into an non-object-oriented programming language for constructing the system, a detailed evaluation and review of Microsoft Fortran is presented of this object-oriented application. The advantages of using the object-oriented methodology in the fire protection environment are reviewed, in terms of cost, speed, accuracy and long-term maintenance the software.
Experiences on the development of an advanced control system using the object-oriented programming (OOP) language Smalltalk-80 revealed that the language has many powerful features for rapid prototyping and simulating...
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Experiences on the development of an advanced control system using the object-oriented programming (OOP) language Smalltalk-80 revealed that the language has many powerful features for rapid prototyping and simulating advanced control systems, especially those involving intelligent features. In the development of an intelligent system identification supervisor (ISIS), Smalltalk-80 proved very suitable for incorporation into control-oriented simulation languages. Smalltalk 80's advantage lies in its portability, productivity, user interface and language. An overview of the development of ISIS is presented and the disadvantages of the language are described.
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