The remote method invocation (RMI) based Web database system is implemented for global environment models allocated on many servers on the Internet. These distributed environment models are regarded as the Web databas...
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The remote method invocation (RMI) based Web database system is implemented for global environment models allocated on many servers on the Internet. These distributed environment models are regarded as the Web database which is invoked remotely. We present a client-server architecture of the Web database from the viewpoint of object oriented programming. The global environment model is expressed by an autoregressive equation whose input and output are environment indices. We also present a graph theory based depth first search to obtain the model path which is a sequence of environment models from initial input to final output. The designed user interface of the Web database system is also shown.
Generic classes allow one, through type parameter instantiation, to obtain new classes that are adapted to different contexts. Therefore, genericity is an important support for class reuse. When the possibility of reu...
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Generic classes allow one, through type parameter instantiation, to obtain new classes that are adapted to different contexts. Therefore, genericity is an important support for class reuse. When the possibility of reusing a class to deal with elements of different domains arises, it is desirable to have the appropriated generic class. Nevertheless, the construction of generic classes is a task that must be planned in advance. Hence, the possibility of reusing a class in other domain can appear, but maybe the class is not prepared for this. In this paper, we present the definition of a class restructuring operator which allows one to obtain generic classes from non-generic classes. The operator is named “parameterize”. In particular, we present the operator definition for an environment that supports the reuse of Eiffel classes. First, we present briefly the operator and then we focus on those aspects concerned with how to obtain a restriction class to constrain generic parameters. All these aspects are introduced by using examples.
Symphony is an open and extensible Java-based framework for composition and manipulation of distributed legacy resources. Symphony allows users to compose visually a collection of programs and data by specifying dataf...
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Symphony is an open and extensible Java-based framework for composition and manipulation of distributed legacy resources. Symphony allows users to compose visually a collection of programs and data by specifying dataflow relationships among them and provides a client/server framework for transparently executing the composed application. Additionally, the framework is Web-aware and helps integrate Web-based resources with legacy resources. Symphony uses Sun Microsystems' JavaBeans component architecture for providing components that represent legacy resources. These components can be customized and composed in any standard JavaBeans builder tool. Executable components communicate with a server implemented using Java Remote Method Invocation mechanism, for executing remote legacy applications. Symphony enables extensibility by providing abstract components which can be extended by implementing simple interfaces. Beans implemented from the abstract beans can act as data producers, consumers or filters.
Despite the possibility of providing standard collection frameworks, object-oriented languages do not generally encourage a 'very high level' style of programming in which collection components are regarded as...
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Despite the possibility of providing standard collection frameworks, object-oriented languages do not generally encourage a 'very high level' style of programming in which collection components are regarded as first class citizens and in which different implementations for a collection can be exchanged without affecting the correctness of a program and with minimal change to the source code. This results both from weaknesses in the structure of the frameworks and from the poor degree of integration of collections into the languages. We present a new approach to the integration of collections in object-oriented languages in which collection types are part of the language but collection implementations are not. We also show how the integration of collection types allows automatic conversions which, among other advantages, provide a new solution to the problem of statically type-safe compatibility for collections.
In an object-oriented model, a class is considered to be a basic unit of testing. Methods (member functions) of a class can have different types of inter-method relationships. The causal relationships between methods ...
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In an object-oriented model, a class is considered to be a basic unit of testing. Methods (member functions) of a class can have different types of inter-method relationships. The causal relationships between methods specify the sequence in which the methods can be executed. We propose a class Petri net machine (CPNM) for specifying method sequence specification of a class and present a test-case generation technique based on Petri nets. In our technique, we discuss generating test cases for the method sequences of a class using coverage criteria.
We present a class based object oriented programming methodology, the Agent Class Methodology (ACM), a new kind of autonomous object generation methodology. The ACM specifies how to construct general purpose agents th...
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We present a class based object oriented programming methodology, the Agent Class Methodology (ACM), a new kind of autonomous object generation methodology. The ACM specifies how to construct general purpose agents that can be used to construct a communicating, distributed, concurrent system. We explain the ACM's autonomous control mechanism together with the four-layered class inheritance architecture of agent class, and we also describe the features of agent class to demonstrate that the ACM meets with the basic features of object orientation. As shown by our application of ACM, the traditional object oriented programming technique can be promoted to an agent oriented counterpart by the use of ACM.
The object-orientedprogramming language Java is an ideal companion to an object-oriented database system. This paper describes our approach to provide an almost seamless application programmer interface that allows J...
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The object-orientedprogramming language Java is an ideal companion to an object-oriented database system. This paper describes our approach to provide an almost seamless application programmer interface that allows Java programs to exchange objects with a database. Unlike other approaches that add persistence capabilities to Java, our approach does not change the Java language nor does it require changes to the Java Virtual Machine. We use reflection, i.e. self-inspection and change of a running program, to map Java classes to database classes, and to enable persistence. The result is a very flexible and efficient style of Java database access.
Advances in computational speed and memory make it now possible to do full scale 2D and 3D PIC simulations of laser and beam plasma interactions. However, the increased complexity of these codes and interactions make ...
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Advances in computational speed and memory make it now possible to do full scale 2D and 3D PIC simulations of laser and beam plasma interactions. However, the increased complexity of these codes and interactions make it necessary to apply modern programming approaches like objectoriented frameworks to the development of these codes. We report here on our progress in developing the objectoriented parallel PIC code OSIRIS that is implemented in Fortran 90. In its current state, the code can be used for 1D, 2D, and 3D simulations in Cartesian coordinates and for 2D simulations in cylindrically symmetric coordinates. We will present benchmarks of simulations done with this code for a proposed plasma wake field accelerator experiment.
This paper presents an overview of language approaches for the automation of distributed data parallel problem solutions. These data parallel problems are of interest to the oil industry and U.S. Federal Agencies invo...
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This paper presents an overview of language approaches for the automation of distributed data parallel problem solutions. These data parallel problems are of interest to the oil industry and U.S. Federal Agencies involved in the analysis of various kinds of telemetry data. Special emphasis is placed upon major language issues facing the development of the information power grid. The paper presents an example of the type of parallelism desired in the grid. The problem is specified in Descartes. A concurrent Java solution is then presented. The Java solution contains artifacts of the design of parallel solutions. The same problem is then recast in the high level language SequenceL, in which parallelisms are implied. The SequenceL approach seems to be a good candidate for a grid oriented language, in that the abstraction relieves the problem solver of much of the burden normally required in development of parallel problem solutions.
This paper addresses the process of deriving, implementing, and analyzing complex systems architecture. The top-level concerns that take precedence when performance constraints must be met invert the traditional order...
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This paper addresses the process of deriving, implementing, and analyzing complex systems architecture. The top-level concerns that take precedence when performance constraints must be met invert the traditional order and concerns within the design process. This paper presents a non-traditional view of systems architecture development which is motivated by the requirement to produce an architecture capable of predictably meeting its time constraints in addition to all the traditional correctness, quality, and maintainability concerns.
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