137,832 research outputs found
Towards a re-engineering method for web services architectures
Recent developments in Web technologies – in particular
through the Web services framework – have greatly enhanced the flexible and interoperable implementation of service-oriented software architectures. Many older Web-based and other distributed software systems will be re-engineered to a Web services-oriented platform. Using an advanced
e-learning system as our case study, we investigate central aspects of a re-engineering approach for the Web services platform. Since our aim is to provide components of the legacy system also as services in the new platform, re-engineering to suit the new development paradigm is as important as re-engineering to suit the new architectural requirements
Concurrent Lexicalized Dependency Parsing: A Behavioral View on ParseTalk Events
The behavioral specification of an object-oriented grammar model is
considered. The model is based on full lexicalization, head-orientation via
valency constraints and dependency relations, inheritance as a means for
non-redundant lexicon specification, and concurrency of computation. The
computation model relies upon the actor paradigm, with concurrency entering
through asynchronous message passing between actors. In particular, we here
elaborate on principles of how the global behavior of a lexically distributed
grammar and its corresponding parser can be specified in terms of event type
networks and event networks, resp.Comment: 68kB, 5pages Postscrip
Concurrent Lexicalized Dependency Parsing: The ParseTalk Model
A grammar model for concurrent, object-oriented natural language parsing is
introduced. Complete lexical distribution of grammatical knowledge is achieved
building upon the head-oriented notions of valency and dependency, while
inheritance mechanisms are used to capture lexical generalizations. The
underlying concurrent computation model relies upon the actor paradigm. We
consider message passing protocols for establishing dependency relations and
ambiguity handling.Comment: 90kB, 7pages Postscrip
Strategic Directions in Object-Oriented Programming
This paper has provided an overview of the field of object-oriented programming. After presenting a historical perspective and some major achievements in the field, four research directions were introduced: technologies integration, software components, distributed programming, and new paradigms. In general there is a need to continue research in traditional areas:\ud
(1) as computer systems become more and more complex, there is a need to further develop the work on architecture and design; \ud
(2) to support the development of complex systems, there is a need for better languages, environments, and tools; \ud
(3) foundations in the form of the conceptual framework and other theories must be extended to enhance the means for modeling and formal analysis, as well as for understanding future computer systems
Reasoning About a Service-oriented Programming Paradigm
This paper is about a new way for programming distributed applications: the
service-oriented one. It is a concept paper based upon our experience in
developing a theory and a language for programming services. Both the
theoretical formalization and the language interpreter showed us the evidence
that a new programming paradigm exists. In this paper we illustrate the basic
features it is characterized by
Communicating Java Threads
The incorporation of multithreading in Java may be considered a significant part of the Java language, because it provides udimentary facilities for concurrent programming. However, we belief that the use of channels is a fundamental concept for concurrent programming. The channel approach as described in this paper is a realization of a systematic design method for concurrent programming in Java based on the CSP paradigm. CSP requires the availability of a Channel class and the addition of composition constructs for sequential, parallel and alternative processes. The Channel class and the constructs have been implemented in Java in compliance with the definitions in CSP. As a result, implementing communication between processes is facilitated, enabling the programmer to avoid deadlock more easily, and freeing the programmer from synchronization and scheduling constructs. The use of the Channel class and the additional constructs is illustrated in a simple application
A survey of agent-oriented methodologies
This article introduces the current agent-oriented methodologies. It discusses what approaches have been followed (mainly extending existing object oriented and knowledge engineering methodologies), the suitability of these approaches for agent modelling, and some conclusions drawn from the survey
An Integrated Development Environment for Declarative Multi-Paradigm Programming
In this paper we present CIDER (Curry Integrated Development EnviRonment), an
analysis and programming environment for the declarative multi-paradigm
language Curry. CIDER is a graphical environment to support the development of
Curry programs by providing integrated tools for the analysis and visualization
of programs. CIDER is completely implemented in Curry using libraries for GUI
programming (based on Tcl/Tk) and meta-programming. An important aspect of our
environment is the possible adaptation of the development environment to other
declarative source languages (e.g., Prolog or Haskell) and the extensibility
w.r.t. new analysis methods. To support the latter feature, the lazy evaluation
strategy of the underlying implementation language Curry becomes quite useful.Comment: In A. Kusalik (ed), proceedings of the Eleventh International
Workshop on Logic Programming Environments (WLPE'01), December 1, 2001,
Paphos, Cyprus. cs.PL/011104
Improving the reuse possibilities of the behavioral aspects of object-oriented domain models.
Reuse of domain models is often limited to the reuse of the structural aspects of the domain (e.g. by means of generic data models). In object-oriented models, reuse of dynamic aspects is achieved by reusing the methods of domain classes. Because in the object-oriented approach any behavior is attached to a class, it is impossible to reuse behavior without at the same time reusing the class. In addition, because of the message passing paradigm, object interaction must be specified as a method attached to one class which is invoked by another class. In this way object interaction is hidden in the behavioral aspects of classes. This makes object interaction schemas difficult to reuse and customize. The focus of this paper is on improving the reuse of object-oriented domain models. This is achieved by centering the behavioral aspects around the concept of business events.Model; Models;
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