9321144
Using separation and composition of concerns to build multiuser virtual environments
Developing multiuser virtual environments (MUVE) is a very complex task since it involves several engineering domain aspects such as virtual reality, cooperative work and distributed systems. Furthermore, existing technologies like graphics capabilities, processing power and network bandwidth, are permanently evolving. For MUVE systems to be successfully developed, they must not only deal with all the different aspects that are inherent to these systems but also have the ability to deal with the continuous technology and requirements evolution. To cope with these problems, a software engineering separation of concerns approach is proposed. Concerns are identified for each of the different aspects of MUVEs. To obtain the necessary flexibility, each one of the concerns should abstract its possible variations in order to support the future system evolution. Moreover it is shown how concerns composition has the necessary expressive power to build multiuser virtual environments.
11562802
A Decision Support System for IST Academic Information
This article describes the Decision Support System (DSS) for Academic Information being developed at Instituto Superior Tecnico, the Engineering School of the Technical University of Lisbon. In Portuguese, this project has been given the acronym SADIA (Sistema de Apoio a Decisao da Informacao Academica). This paper focuses on the early phases of the DSS development process, i.e., the business requirements definition and the dimensional modelling. First, we show how the business requirements of the School drive the definition of the DSS dimensional model. Second, we detail the logical dimensional model for a selected business process, the IST Student Admission process. Third, the corresponding physical design decisions are reported. The results obtained from the three phases were successfully validated by business users.
203567
Separating replication from distributed communication: problems and solutions
Replication and distributed communication are usually tightly coupled. This code tangling forbids their independent reuse and adaptation. In this position paper, the problems resulting from coupling replication with distributed communication are discussed. In addition, a solution based on separation of concerns is proposed. The abstractions for each concern are presented, as well as their composition.
11594682
Framework, Design Patterns and Pattern Language for Object Concurrency
The development of concurrent applications is hard due to the diverse concerns involved and the non-determinism inherent to the implementation environment. In order to control such complexity developers can benefit from objectoriented frameworks providing application-independent solutions which can be specialized for the application-specific needs. A primary contribution of this paper is to describe a family of design patterns for object concurrency which are composed in a three-layered framework. In addition, a pattern language describing an incremental development process which is based on the framework and design patterns is also presented.
35073381
Service Logic Deployment and Distribution Configuration
The success of service providers in the competitive communications market of the future will be determined by the efficiency with which services are developed, and the quality levels at which services are provided. A service creation environment (SCE) should provide the service developer with solutions to these problems. In this paper we present two essential facilities that should be provided by an advanced SCE: a tool for the optimisation of the service logic deployment scheme and a distribution configuration language supporting the deployment and configuration of component-based distributed applications.
38014527
A Quality Design Solution for Object Synchronization
This paper presents a quality design solution, the Customizable Object Synchronization pattern, for object synchronization which decouples object synchronization from object concurrency and object functionality (sequential part). The solution described by this pattern provides encapsulation, extensibility, modularity and reuse of synchronization policies.
191535
Polymorphy and Hybridization in Genetically Programmed Networks
In this paper we discuss the polymorphic abilities of a new distributed representation for genetic programming, called Genetically Programmed Networks. These are inspired in a common structure in natural complex adaptive systems, where system functionality frequently emerges from the combined functionality of simple computational entities, densely interconnected for information exchange. A Genetically Programmed Network can be evolved into a distributed program, a rule based system or a neural network with simple adjustments to the evolutionary algorithm. The space of possible network topologies can also be easily controlled. This allows the fast exploration of various search spaces thus increasing the possibility of finding a (or a better) solution. Experimental results are presented to support our claims.
1719989
Empirical Evaluation of SysML through the Modeling of an Industrial Automation Unit
Industrial automation systems may include people, hardware, software and other elements necessary to produce the desirable results. The SysML modeling language is being proposed, by OMG and INCOSE, as a language that allows the system description correctly and consistently among various participants of the same project (software, mechanical, electrical and others engineers). The objective of this work is to evaluate the SysML proposal as a description language for industrial systems through the modeling of an industrial automation unit. A brief system description of the case study is included, the SysML diagrams will be presented during the system modeling and finally comments and considerations about the models and the modeling task are presented.
12874902
Behavioural Differential Equations and Coinduction for Binary Trees
We study the set TA of infinite binary trees with nodes labelled in a semiring A from a coalgebraic perspective. We present coinductive definition and proof principles based on the fact that TA carries a final coalgebra structure. By viewing trees as formal power series, we develop a calculus where definitions are presented as behavioural differential equations. We present a general format for these equations that guarantees the existence and uniqueness of solutions. Although technically not very difficult, the resulting framework has surprisingly nice applications, which is illustrated by various concrete examples.
7409552
Swarm optimisation as a new tool for data mining
This paper proposes the use of particle swarm optimisers as a tool for data mining. To evaluate its usefulness, we empirically compare the performance of three variants of the particle optimiser with another evolutionary algorithm, namely a genetic algorithm, in rule discovery for classification tasks. Such tasks are considered core tools for decision support systems in a widespread area, ranging from the industry, commerce, military and scientific fields. The data sources used here for experimental testing are commonly used and considered as a de facto standard for rule discovery algorithms reliability ranking. The results obtained in these domains seem to indicate that particle swarm optimisers are competitive with other evolutionary techniques, and can be successfully applied to more demanding problem domains.
12508242
MEGICO: An Intelligent Knowledge Management Methodology
In this paper, we describe a knowledge management system (KMS) design and construction methodology. For this purpose, section 1 gives a brief introduction that justifies the need for a genuine KMS methodology, like MEGICO. Section 2 very briefly presents MEGICO and section 3 discusses the results and conclusions of its use.