8920330
On the Evolution of Evolutionary Algorithms
In this paper we discuss the evolution of several components of a traditional Evolutionary Algorithm, such as genotype to phenotype mappings and genetic operators, presenting a formalized description of how this can be attained. We then focus on the evolution of mapping functions, for which we present experimental results achieved with a meta-evolutionary scheme.
10111787
Golomb Rulers: The Advantage of Evolution
In this paper we present a new evolutionary algorithm designed to efficiently search for optimal Golomb rulers. The proposed approach uses a redundant random keys representation to codify the information contained in a chromosome and relies on a simple interpretation algorithm to obtain feasible solutions. Experimental results show that this method is successful in quickly identifying good solutions and that can be considered as a realistic alternative to massive parallel approaches that need several months or years to discover high quality Golomb rulers.
12781827
On the influence of GVR in vehicle routing
A comparative study is made between a new evolutionary approach for the Vehicle Routing Problem (VRP) and a standard evolutionary model, based on Path Representation. Genetic Vehicle Representation (GVR) is the new two-level representational scheme designed to deal in an effective way with all the information needed by candidate solutions. Experimental results, obtained from a set of VRP instances, show performance improvements when GVR is used.
18592363
Evolving Golomb Rulers
A Golomb Ruler is defined as a ruler that has marks unevenly spaced at integer locations in such a way that the distance between any two marks is unique. Unlike usual rulers, they have the ability to measure more discrete measures than the number of marks they possess. Although the definition of a Golomb Ruler does not place any restriction on the length of the ruler, researchers are usually interested in rulers with minimum length. An Optimal Golomb Ruler (OGR) is defined as the shortest length ruler for a given number of marks [1].
11145016
Niching techniques: a study on the cluster geometry optimization problem
The cluster geometry optimization is one of these problems. The same cluster structure can be encoded in innumerable ways. A single translation or rotation performed in the cluster can lead to different genotypes for similar structures. A reliable similarity function can be computationally prohibitive or even impossible to define. We analyze the behavior of an alternative technique free of distance measures, the Spatially-Dispersed Genetic Algorithm [1] (sdGA), and its application on the cluster geometry optimization.
2344862
Busy Beaver - The Influence of Representation
The Busy Beaver is an interesting theoretical problem proposed by Rado in 1962, in the context of the existence of non computable functions. In this paper we propose an evolutionary approach to this problem. We will focus on the representational issues, proposing alternative ways of codifying and interpreting Turing Machines, designed to take advantage of the existence of sets of equivalent Turing Machines. The experimental results show that these alternatives provide improvement over the "standard" genetic codification.
10585259
Three-phase immiscible displacement in heterogeneous petroleum reservoirs
We describe a fractional-step numerical procedure for the simulation of immiscible three-phase flow in heterogeneous porous media that takes into account capillary pressure and apply it to indicate the existence of a so-called "transitional" wave in at least some multi-dimensional flows, thereby extending theoretical results for one-dimensional flows. The step procedure combines a second-order, conservative central difference scheme for a pertinent system of conservation laws modeling the convective transport of the fluid phases with locally conservative mixed finite elements for the associated parabolic and elliptic problems.
12511763
Modelling Divergent Production: A multi-domain approach
1 Departamento de Engenharia Informática Universidade de Coimbra Abstract This paper presents an ongoing Ph.D. work on the area of Cognitive Modelling and, more specifically, about computational applications of theories of creativity. Without making claims to psychological views or results related to the mentioned theories, this work is concerned with a search for “different” solutions in a heterogeneous knowledge base composed of structures from a variety of domains. These structures and work upon them, in addition to a computational model of creative production, which is derived from the theory of divergent production [4], form the basis of this work. Its first applicational goal is to implement a system that generates musical ideas recurring to high-level abstractions from other domains (visual arts, story plots, architecture). Part of this has already been implemented and first results obtained. The overall architecture is described in the present paper.
7429772
Experiments on Case-Based Retrieval of Software Designs
Software systems are becoming increasingly complex, demanding for more computational resources and better software development methodologies. The software engineer and the CASE tool must work like a team. For this to happen, the CASE tool must be able to understand the user, and to provide new functionalities, such as flexible retrieval of old designs. We think that Case-Based Reasoning can provide a reasoning framework capable of meeting these demands. One important task that a CASE tool based on Case-Based Reasoning can perform adequately, is the retrieval of relevant designs. These designs can be stored in a case library, central to the software development company, thus enabling knowledge sharing through out the company. In this paper we present an approach to case-based retrieval of software designs, and experimental results achieved with this approach.
5245012
A Conditional Random Field for Discriminatively-trained Finite-state String Edit Distance
The need to measure sequence similarity arises in information extraction, object identity, data mining, biological sequence analysis, and other domains. This paper presents discriminative string-edit CRFs, a finite-state conditional random field model for edit sequences between strings. Conditional random fields have advantages over generative approaches to this problem, such as pair HMMs or the work of Ristad and Yianilos, because as conditionally-trained methods, they enable the use of complex, arbitrary actions and features of the input strings. As in generative models, the training data does not have to specify the edit sequences between the given string pairs. Unlike generative models, however, our model is trained on both positive and negative instances of string pairs. We present positive experimental results on several data sets.
6376797
Sharing engineering information and knowledge
This paper describes an agent-based recommendation system developed to support knowledge acquisition and sharing processes. Its purpose is to aid the process of community building, specially in the early phase of peer search and recognition in a distributed engineering environment, where multidisciplinary teams must be established. In this kind of problem information about possible candidates to make up the teams must be gathered from all available channels, including the electronic ones. Due to privacy issues, Web based data mining systems are not efficient for the purpose of constructing candidate's profiles, even if they can offer some help; therefore a distributed solution that permits each candidate's workplace to be explored was developed. As a means of aggregating collected knowledge for sharing, a conceptual model, relating candidate's profiles and their knowledge domain was developed in the form of an ontology. This strategy allows the system to be specialised in terms of the candidates' main knowledge domain.