18811835
An Empirical Comparison of Particle Swarm and Predator Prey Optimisation
In this paper we present and discuss the results of experimentally comparing the performance of several variants of the standard swarm particle optimiser and a new approach to swarm based optimisation. The new algorithm, which we call predator prey optimiser, combines the ideas of particle swarm optimisation with a predator prey inspired strategy, which is used to maintain diversity in the swarm and preventing premature convergence to local suboptima. This algorithm and the most common variants of the particle swarm optimisers are tested in a set of multimodal functions commonly used as benchmark optimisation problems in evolutionary computation.
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.
6828563
A Particle Swarm Data Miner
This paper describes the implementation of Data Mining tasks using Particle Swarm Optimisers. The object of our research has been to apply such algorithms to classification rule discovery. Results, concerning accuracy and speed performance, were empirically compared with another evolutionary algorithm, namely a Genetic Algorithm and with J48 – a Java implementation of C4.5. The data sets used for experimental testing have already been widely used and proven reliable for testing other Data Mining algorithms. The obtained results seem to indicate that Particle Swarm Optimisers are competitive with other evolutionary techniques, and could come to be successfully applied to more demanding problem domains.
5929323
Agent-based modelling of product invention
This study describes a novel simulation model of the process of product invention. Invention is conceptualized as a process of directed evolutionary adaptation, on a landscape of product design possibilities, by a population of profit-seeking agents (inventors). The simulation experiments examine the sensitivity of the rate of advance in product fitness to the choice of search heuristics employed by inventors. The key finding of the experiments is that if search heuristics are confined to those which are rooted in past experience, or to heuristics which merely generate variety, limited product advance occurs. Notable product fitness advance only occurs when inventor's expectations as to the relative fitness of potential product inventions are incorporated into the model of invention. The results demonstrate the importance of human direction and expectations in invention. They also support the importance of formal product / project evaluation procedures in organizations, and the importance of market information when inventing new products.
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.
2626702
A Particle Swarm Model of Organizational Adaptation
This study introduces the particle swarm metaphor to the domain of organizational adaptation. A simulation model (OrgSwarm) is constructed to examine the impact of strategic inertia, in the presence of errorful assessments of future payoffs to potential strategies, on the adaptation of the strategic fitness of a population of organizations. The results indicate that agent (organization) uncertainty as to the payoffs of potential strategies has the affect of lowering average payoffs obtained by a population of organizations. The results also indicate that a degree of strategic inertia, in the presence of an election mechanism, assists rather than hampers adaptive efforts in static and slowly changing strategic environments.
8450178
Information Retrieval Aware Web Site Modelling and Generation
Design and maintenance of large corporate Web sites have become a challenging problem due to the continuing increase in their size and complexity. One particular feature present in the majority of this sort of Web sites is searching for information. However the solutions provided so far, which is based on the same techniques used for search in the open Web, have not provided a satisfactory performance to specific Web sites, often resulting in too much irrelevant content in a query answer. This paper proposes an approach to Web site modelling and generation of intrasite search engines, combining application modelling and information retrieval techniques. Our assumption is that giving search engines access to the information provided by conceptual representations of the Web site improves their performance and accuracy. We demonstrate our proposal by describing a Web site modelling language that represent both traditional modelling features and information retrieval aspects, as well as presenting experiments to evaluate the resulting intrasite search engine generated by our method.
12706002
Computer-Assisted Discrepancy Management - A Case Study in Research Transfer to Industry
This paper reports on the “repackaging” and transfer to industry of research results in ViewpointBased Requirements Engineering (VBRE). Our experience, as indicated here, is a particular case of the problems and solutions that small research groups can find in their transfer from theoretical work to practical application. In particular, starting with a formal approach for discrepancy management, we first developed a “light-weight version” of VBRE and empirically validated their most important claims. Then we developed a software tool (discRman) that encapsulates the main points of the approach and, finally, partner organizations used it in small projects. We think that this “theoretical-empirical-light-weight-tool” sequence can be applied in similar situations, especially by small research groups seeking for transfer of their results to industry. ACM Classification: D.2.1 (Software Engineering – Requirements/Specifications – Methodologies, Tools), D.2.8 (Software Engineering – Metrics – Performance measures), D.2.9 (Software Engineering – Management – Productivity)
14702137
A Multi-Neighbor-Joining Approach for Phylogenetic Tree Reconstruction and Visualization
The computationally challenging problem of reconstructing the phylogeny of a set of contemporary data, such as DNA sequences or morphological attributes, was treated by an extended version of the neighbor-joining (NJ) algorithm. The original NJ algorithm provides a single-tree topology, after a cascade of greedy pairing decisions that tries to simultaneously optimize the minimum evolution and the least squares criteria. Given that some sub-trees are more stable than others, and that the minimum evolution tree may not be achieved by the original NJ algorithm, we propose a multi-neighbor-joining (MNJ) algorithm capable of performing multiple pairing decisions at each level of the tree reconstruction, keeping various partial solutions along the recursive execution of the NJ algorithm. The main advantages of the new reconstruction procedure are: 1) as is the case for the original NJ algorithm, the MNJ algorithm is still a low-cost reconstruction method; 2) a further investigation of the alternative topologies may reveal stable and unstable sub-trees; 3) the chance of achieving the minimum evolution tree is greater; 4) tree topologies with very similar performances will be simultaneously presented at the output. When there are multiple unrooted tree topologies to be compared, a visualization tool is also proposed, using a radial layout to uniformly distribute the branches with the help of well-known metaheuristics used in computer science.
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.
30725726
An integrated MOLP method base package - A guided tour of tommix
Abstract An implementation of a MOLP interactive method base is presented in the form of a guided tour to a computer package. The MOLP method base (associated to a procedure toolbox) is a component of a decision support system framework which also integrates a dialogue base and a data management module. Besides providing the standard working of each method the interactive MOLP method base offers the possibility of method switching at any interaction with the decision maker (DM), in order to make the most of the potentialities of each method and support a “learning” process. Some key issues in the development of interactive MOLP approaches and computational tools are also discussed. Special attention is paid to the development of an user-friendly environment for interacting with the DM.