Using a unified measure function for heuristics, discretization, and rule quality evaluation in Ant-Miner

Ant-Miner is a classification rule discovery algorithm that is based on Ant Colony Optimization (ACO) meta-heuristic. cAnt-Miner is the extended version of the algorithm that handles continuous attributes on-the-fly during the rule construction process, while ?Ant-Miner is an extension of the algorithm that selects the rule class prior to its construction, and utilizes multiple pheromone types, one for each permitted rule class. In this paper, we combine these two algorithms to derive a new approach for learning classification rules using ACO. The proposed approach is based on using the measure function for 1) computing the heuristics for rule term selection, 2) a criteria for discretizing continuous attributes, and 3) evaluating the quality of the constructed rule for pheromone update as well. We explore the effect of using different measure functions for on the output model in terms of predictive accuracy and model size. Empirical evaluations found that hypothesis of different functions produce different results are acceptable according to Friedman’s statistical test

Investigating Evaluation Measures in Ant Colony Algorithms for Learning Decision Tree Classifiers

Ant-Tree-Miner is a decision tree induction algorithm that is based on the Ant Colony Optimization (ACO) meta- heuristic. Ant-Tree-Miner-M is a recently introduced extension of Ant-Tree-Miner that learns multi-tree classification models. A multi-tree model consists of multiple decision trees, one for each class value, where each class-based decision tree is responsible for discriminating between its class value and all other values present in the class domain (one vs. all). In this paper, we investigate the use of 10 different classification quality evaluation measures in Ant-Tree-Miner-M, which are used for both candidate model evaluation and model pruning. Our experimental results, using 40 popular benchmark datasets, identify several quality functions that substantially improve on the simple Accuracy quality function that was previously used in Ant-Tree-Miner-M

A mathematically assisted reconstruction of the initial focus of the yellow fever outbreak in Buenos Aires (1871)

We discuss the historic mortality record corresponding to the initial focus of the yellow fever epidemic outbreak registered in Buenos Aires during the year 1871 as compared to simulations of a stochastic population dynamics model. This model incorporates the biology of the urban vector of yellow fever, the mosquito Aedes aegypti, the stages of the disease in the human being as well as the spatial extension of the epidemic outbreak. After introducing the historical context and the restrictions it puts on initial conditions and ecological parameters, we discuss the general features of the simulation and the dependence on initial conditions and available sites for breeding the vector. We discuss the sensitivity, to the free parameters, of statistical estimators such as: final death toll, day of the year when the outbreak reached half the total mortality and the normalized daily mortality, showing some striking regularities. The model is precise and accurate enough to discuss the truthfulness of the presently accepted historic discussions of the epidemic causes, showing that there are more likely scenarios for the historic facts.Comment: 25 pages, 12 figure

Analytic approximation of solutions of parabolic partial differential equations with variable coefficients

A complete family of solutions for the one-dimensional reaction-diffusion equation $$u_{xx}(x,t)-q(x)u(x,t) = u_t(x,t)$$ with a coefficient $q$ depending on $x$ is constructed. The solutions represent the images of the heat polynomials under the action of a transmutation operator. Their use allows one to obtain an explicit solution of the noncharacteristic Cauchy problem for the considered equation with sufficiently regular Cauchy data as well as to solve numerically initial boundary value problems. In the paper the Dirichlet boundary conditions are considered however the proposed method can be easily extended onto other standard boundary conditions. The proposed numerical method is shown to reveal good accuracy.Comment: 8 pages, 1 figure. Minor updates to the tex

A Fast Chi-squared Technique For Period Search of Irregularly Sampled Data

A new, computationally- and statistically-efficient algorithm, the Fast $\chi^2$ algorithm, can find a periodic signal with harmonic content in irregularly-sampled data with non-uniform errors. The algorithm calculates the minimized $\chi^2$ as a function of frequency at the desired number of harmonics, using Fast Fourier Transforms to provide $O (N \log N)$ performance. The code for a reference implementation is provided.Comment: Source code for the reference implementation is available at http://public.lanl.gov/palmer/fastchi.html . Accepted by ApJ. 24 pages, 4 figure

Learning Multi-Tree Classification Models with Ant Colony Optimization

Ant Colony Optimization (ACO) is a meta-heuristic for solving combinatorial optimization problems, inspired by the behaviour of biological ant colonies. One of the successful applications of ACO is learning classification models (classifiers). A classifier encodes the relationships between the input attribute values and the values of a class attribute in a given set of labelled cases and it can be used to predict the class value of new unlabelled cases. Decision trees have been widely used as a type of classification model that represent comprehensible knowledge to the user. In this paper, we propose the use of ACO-based algorithms for learning an extended multi-tree classification model, which consists of multiple decision trees, one for each class value. Each class-based decision trees is responsible for discriminating between its class value and all other values available in the class domain. Our proposed algorithms are empirically evaluated against well-known decision trees induction algorithms, as well as the ACO-based Ant-Tree-Miner algorithm. The results show an overall improvement in predictive accuracy over 32 benchmark datasets. We also discuss how the new multi-tree models can provide the user with more understanding and knowledge-interpretability in a given domain

Els residus a Catalunya

Les questions concernant la dégradation de l'environnement et la pollution sont en train d'acquérir un rôle privilégié parmi les problèmes prioritaires des citoyens. C'est dans ce contexte qu'il faut placer la ajournée sur les déchets en Catalogne, qui s'est tenue à Tarragone le premier de décembre 1990 organisée par la Société Catalane d'Aménagement du Territoire. Les aspects traités autour du sujet central de la journée ont été les suivants: les politiques de gestion et de contrble, les déchets urbains, les approches de l'écologie, les déchets en tant que problbmes territoriaux et la gestion des déchets industriels.Among the different preoccupations which arouse the interest of the general public, questions involving contamination and destruction of the environment are acquiring a predominant position. In this context, seminar on «Waste products in Catalonia,, organized by the Catalan Society for Regional Planning was held on 1st December 1990 in Tarragona. Around the central theme, the following aspects were exarnined: management and control policies, urban residues, the contribution of ecology, spatial aspects of residues and the treatment of industrial waste.Entre las diversas problemáticas que el ciudadano siente cada vez mas como preocupación, las cuestiones que hacen referencia a la degradación del medio ambiente y a la contaminación están adquiriendo un lugar privilegiado. Es en este contexto que hemos de situar la jornada que sobre los «Residuos en Catalunya», se celebró el 1 de diciembre de 1990 en Tarragona, organizada por la Societat Catalana d'Ordenació del Territori. En torno al tema central de la jornada se trataron aspectos como: poiíticas de gestión y control, los residuos urbanos, aportaciones de la ecologia, aspectos territoriales de los residuos y la gestión de los residuos industriales.Entre les problematiques que van progressivament formant part del cataleg de preocupacions del ciutadi, les qüestions que fan referéncia a la degradaci6 del medi ambient i a la contaminació van adquirint un lloc privilegiat. És en aquest context que hem de situar la jornada que, sobre els «Residus a Catalunya», se celebra l'1 de desembre de 1990 a la ciutat de Tarragona, organitzada per la Societat Catalana d'Ordenació del Territori. Entorn el tema central de la jornada, es tractaren els aspectes següents: polítiques de gestió i control, els residus urbans, aportacions de l'ecologia, els residus com a element del territori i la gestió dels residus industrials