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.
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.
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.
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.
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.
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.
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.
15351818
Representing Web Data as Complex Objects
The popularization of the Web has made a huge volume of data available for a large audience. In a large number of Web sites, such as bookstores, electronic catalogs, travel agencies, etc., the pages constitute documents which are composed of pieces of data whose overall structure can be easily recognized. Such pages are called data-rich and can be seen as collections of complex objects. In this paper, we show how such objects can be represented by nested tables, which are simple, intuitive, and quite convenient for expressing their implicit structure. The assumption is that, for most sites of interest, only few examples are required to reveal the structure of the objects. To corroborate our assumption, we describe a data extraction tool that adopts this approach and present results of some experiments carried out with this tool.
7623756
Knowledge Management Systems Development: A Roadmap
This paper approaches the Knowledge Management Systems study, focusing not only in the establishment of essential development activities, but also in techniques, technologies, and tools for their support. Despite of the wide range of existing proposals for the development of this type of systems, none of them has achieved a level detailed enough to allow a direct application. This study is intended to be a palliative for the above-mentioned lack of detail by means of a development guide for Knowledge Management Systems. In this way, the proposed solution offers a clear definition concerning what has to be done and which type of mechanisms should be used for its development.