14281129
An abstraction for awareness management in collaborative virtual environments
This paper describes an object-oriented abstraction for the problem of awareness management in Collaborative Virtual Environments (CVEs). The described abstraction allows for different types of awareness information and awareness management policies to be used. It is also described how the defined abstraction was used to support the awareness management policies of two demo CVEs application.
16566221
Naming: design pattern and framework
Naming is an important, but frequently overlooked, aspect of software systems. Naming is usually combined with other issues, e.g. distributed communication technology. The paper treats naming in isolation. It presents a naming design pattern which abstracts several naming policies and an object-oriented framework that can be customized to support naming policies. An applications designer can choose the correct naming properties (relative, absolute, universal identifiers, etc.) to refer to specific objects.
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.
8086424
Dynamic evolution in workflow management systems
The environments where workflow management systems are typically used in are constantly changing. It is nearly impossible to foresee, at business process design stage, all the combinations of tasks needed to achieve the process' goals. Workflow management systems capable of supporting dynamic changes on executing instances in a flexible manner are thereby demanded. Former approaches have proposed a solution to this issue based on workflow type versioning and workflow instance migration. However, the operations that handle the modification of workflow types as well as the migration algorithm for workflow instances are tied to a particular representation of workflow types. This means that whenever the representation changes, the migration algorithms and the modification operations have to change accordingly. This is a current problem due to the uprising of different specifications for workflow definition languages, which are far away from stabilizing. In this paper, we address this problem by clearly decoupling the modification operations of workflow types from the internal structures and algorithms responsible for the instances' migration. In this manner we enable the use of different workflow definition languages while keeping the same internal structures and migration algorithms.
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.
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.
1918071
ESTWeb: bioinformatics services for EST sequencing projects
ESTWeb is an internet based software package designed for uniform data processing and storage for large-scale EST sequencing projects. The package provides for: (a) reception of sequencing chromatograms; (b) sequence processing such as base-calling, vector screening, comparison with public databases; (c) storage of data and analysis in a relational database, (d) generation of a graphical report of individual sequence quality; and (e) issuing of reports with statistics of productivity and redundancy. The software facilitates real-time monitoring and evaluation of EST sequence acquisition progress along an EST sequencing project.
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.
12270268
Mining Web Usage Data for Discovering Navigation Clusters
The analysis of a web site based on usage data is an important task as it provides insight into the organization of the site and its adequacy regarding user needs. This allows the relationship between prior categories and user browsing patterns to be explored. In this paper we propose an approach for discovering the profiles of visitor groups. To this end, we begin by mapping user interests into symbolic objects, which is the basis of the Symbolic Data Analysis and represents here a successful interaction of the user with the web site. We then identify groups of users with similar behavior by means of a dynamic clustering approach applying a context dependent dissimilarity measure. The method was applied to identify visitor groups of a web site in the educational domain and also to analyze the traces of different user behavior.
12195414
Evolving Controllers for Autonomous Agents Using Genetically Programmed Networks
This article presents a new approach to the evolution of controllers for autonomous agents. We propose the evolution of a connectionist structure where each node has an associated program, evolved using genetic programming. We call this structure a Genetically Programmed Network and use it to successfully evolve control systems with very different architectures, by making small restrictions to the evolutionary process. Experimental results of applying this method to evolve neural networks, distributed programs and rule-based systems capable of solving a common benchmark problem, the Ant Problem, are presented. Comparison with other known genetic programming based approaches, shows that our method requires less effort to find a solution.
15079292
Measuring similarity between collection of values
In this paper, we propose a set of similarity metrics for manipulating collections of values occuring in XML documents.
 Following the data model presented in TAX algebra, we treat an XML element as a labeled ordered rooted tree. Consider that XML nodes can be either atomic, i.e, they may contain single values such as short character strings, date, etc, or complex, i.e., nested structures that contain other nodes, we propose two types of similarity metrics: MAVs, for atomic nodes and MCVs, for complex nodes. In the first case, we suggest the use of several application domain dependent metrics. In the second case, we define metrics for complex values that are structure dependent, and can be distinctly applied for it and collections of values. We also present experiments showing the effectiveness of our method.