Workflow systems are receiving increased attention as they intend to facilitate the operations of enterprises by coordinating and streamlining business activities. The need for automated support and operational models...
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Workflow systems are receiving increased attention as they intend to facilitate the operations of enterprises by coordinating and streamlining business activities. The need for automated support and operational models that allow workflow applications to coordinate units of work across multiple servers-according to business defined rules and routes-is becoming critical for the proper management of such activities. In this paper, we describe a Transaction-oriented Workflow Environment (TOWE) for programming workflow activities. The novelty of our approach resides in the proposed unified abstraction, class libraries, to support workflow activities. The fundamental concept used in the TOWE system is based on the symbiosis of object-oriented programming and interprocess communication concepts. In TOWE, the concurrency abstractions are represented by process objects, active objects acting as processes, which involve asynchronous, location-independent, and application specific process invocations.
Our theoretical framework views programming as search in three problem spaces: rule, instance, and representation. The main objectives of this study are to find out how programmers change representation while working ...
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Our theoretical framework views programming as search in three problem spaces: rule, instance, and representation. The main objectives of this study are to find out how programmers change representation while working in multiple problem spaces, and how representation change increases the difficulty of programming tasks. Our theory of programming indicates that programming is similar to the way scientists discover and test theories. That is, programmers generate hypotheses in the rule space and test these hypotheses in the instance space. Moreover, programmers change their representations in the representation space when rule development becomes too difficult or alternative representations are available. We conducted three empirical studies with different programming tasks: writing a new program, understanding an existing program, and reusing an old program. Our results indicate that considerable cognitive difficulties stem from the need to change representations in these tasks. We conclude by discussing the implications of viewing programming as a scientific discovery for the design of programming environments and training methods.
User interfaces in interactive simulations convey the dynamic behavior of the modeled system and allow the analyst to interact with the executing simulation. Traditionally, the software to display system behavior and ...
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User interfaces in interactive simulations convey the dynamic behavior of the modeled system and allow the analyst to interact with the executing simulation. Traditionally, the software to display system behavior and to facilitate user interaction has been embedded in the simulation model. Such tight integrations make it difficult to maintain large simulations and impose unnecessary limitations on the development of interfaces to a simulation model. This article presents a portable, object-based architecture, called JADIS (Java-based Architecture for Developing Interactive Simulations), for developing interactive simulations. The architecture is implemented in Java and applies the Model-View-Controller paradigm to the development of interactive simulations. This article describes the JADIS architecture and presents its application to an aircraft repair time analysis problem in the domain of airbase logistics.
We present a Logical Machine (LM) system that can effectively support software environment migration and resource mapping. The Logical Machine Monitor provides a machine independent interface to the upper operating sy...
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We present a Logical Machine (LM) system that can effectively support software environment migration and resource mapping. The Logical Machine Monitor provides a machine independent interface to the upper operating systems. A mobile disk object with the mechanism of block migration on demand is implemented. It can be incorporated with the logical machine operating system migration facility to achieve job migration, i.e., the user can migrate the operating system and disk blocks to the place he or she desires. The mobile disk also simplifies the mechanism of parallel processing in some applications such as file striping among servers. With this approach, the system resources can be mapped more flexible, while transparency to the operating system is retained.
General purpose distributed object-oriented environments exist to allow for the efficient construction of client/server software systems, Standard network and distributed systems management environments exist for the ...
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General purpose distributed object-oriented environments exist to allow for the efficient construction of client/server software systems, Standard network and distributed systems management environments exist for the efficient operation of heterogeneous networked hardware and software systems. As distributed software systems get larger, the economies of systems development and the economies of software operation demand that we find an efficient way of integrating these two technologies, While the use of standardized distributed systems management for the management of distributed software applications seems reasonable, very little research has been done to confirm this, In this paper, we propose the integration of standardized distributed resource management technologies and distributed application software, In our work we have facilitated this integration using techniques based on mainstream object-oriented dynamic modeling, We will describe our techniques of integration as well as discuss the need for methodical engineered approaches when working in this area. (C) 1997 Elsevier Science B.V.
We have developed a cotton crop model, Cotton++. This model will eventually be coupled with an expert system to advise farmers when to irrigate, fertilize and harvest their crops. Cotton++ is written in the object-ori...
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We have developed a cotton crop model, Cotton++. This model will eventually be coupled with an expert system to advise farmers when to irrigate, fertilize and harvest their crops. Cotton++ is written in the object-oriented programming language C++. In this paper we discuss (1) the reasons we opted to adopt the object-oriented paradigm and (2) why we selected C++ over other available programming languages. (C) 1997 Elsevier Science B.V.
The objective of the European project STORMS' is to develop a software tool to be used for the design and the planning of the UMTS2 network. In this context the ParFlow method permits the simulation of outdoor rad...
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ISBN:
(纸本)3540628983
The objective of the European project STORMS' is to develop a software tool to be used for the design and the planning of the UMTS2 network. In this context the ParFlow method permits the simulation of outdoor radio wave propagation in urban environment, modeling the physical system in terms of the motion of fictitious microscopic particles over a lattice. This paper gives an overview of the ParFlow method, and reports the design and the implementation of ParFlow++, an object-oriented irregular parallel software for urban outdoor radio wave propagation prediction.
object-oriented programming (OOP) has changed significantly the way to produce software applications and allowed many problems that affected traditional programming to be overcome. Unfortunately several object-oriente...
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ISBN:
(纸本)0818678402
object-oriented programming (OOP) has changed significantly the way to produce software applications and allowed many problems that affected traditional programming to be overcome. Unfortunately several object-oriented frameworks misused OOP techniques, failed to address issues such as application extensibility, and have produced monolithic systems hard to manage and tailor. This paper describes Yasmin, a new object-oriented component-based architecture for software applications. It allows one to build applications which use system resources efficiently and which can be easily extended and configured in addition to being simple to program and to compose. This is achieved by means of droplets, a new type of software components that can be replaced and modified at runtime and by exploiting novel techniques such as collaboration and delegation.
We present an approach to migrate legacy systems to object-oriented platforms. The process consists of six sequential phases and encompasses reverse engineering and re-engineering activities. The aim of the reverse en...
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ISBN:
(纸本)081868013X
We present an approach to migrate legacy systems to object-oriented platforms. The process consists of six sequential phases and encompasses reverse engineering and re-engineering activities. The aim of the reverse engineering phases is to decompose programs into components implementing the user interface management and components implementing application domain objects. The identification of objects is centred around persistent data store and exploits object-oriented design metrics. Wrapping techniques are the core of the re-engineering activities They make new systems able to exploit existing resources, thus allowing an incremental and selective translation of the identified objects.
Component-based software development is associated with a shift from statement-oriented coding to system building by plugging together components. The idea is nor new and some progress has been made over the past deca...
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ISBN:
(纸本)081868271X
Component-based software development is associated with a shift from statement-oriented coding to system building by plugging together components. The idea is nor new and some progress has been made over the past decades. Nevertheless, today's software development practice is still far away from the vision. in recent years, the term componentware became the vogue in the software engineering community. The paper attempts to define the relevant terms by relating the definitions to the already well-defined terms of object technology. In particular, the focus lies on a discussion of the deficiencies of the object-oriented paradigm and how componentware might solve these short comings.
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