The Effect of Distinct Geometric Semantic Crossover Operators in Regression Problems

This paper investigates the impact of geometric semantic crossover operators in a wide range of symbolic regression problems. First, it analyses the impact of using Manhattan and Euclidean distance geometric semantic crossovers in the learning process. Then, it proposes two strategies to numerically optimize the crossover mask based on mathematical properties of these operators, instead of simply generating them randomly. An experimental analysis comparing geometric semantic crossovers using Euclidean and Manhattan distances and the proposed strategies is performed in a test bed of twenty datasets. The results show that the use of different distance functions in the semantic geometric crossover has little impact on the test error, and that our optimized crossover masks yield slightly better results. For SGP practitioners, we suggest the use of the semantic crossover based on the Euclidean distance, as it achieved similar results to those obtained by more complex operators

Which mechanism underlies the water-like anomalies in core-softened potentials?

Using molecular dynamics simulations we investigate the thermodynamic of particles interacting with a continuous and a discrete versions of a core-softened (CS) intermolecular potential composed by a repulsive shoulder. Dynamic and structural properties are also analyzed by the simulations. We show that in the continuous version of the CS potential the density at constant pressure has a maximum for a certain temperature. Similarly the diffusion constant, $D$, at a constant temperature has a maximum at a density $\rho_{\mathrm{max}}$ and a minimum at a density $\rho_{\mathrm{min}}<\rho_{\mathrm{max}}$, and structural properties are also anomalous. For the discrete CS potential none of these anomalies are observed. The absence of anomalies in the discrete case and its presence in the continuous CS potential are discussed in the framework of the excess entropy.Comment: 8 page

Revisiting the Sequential Symbolic Regression Genetic Programming

Sequential Symbolic Regression (SSR) is a technique that recursively induces functions over the error of the current solution, concatenating them in an attempt to reduce the error of the resulting model. As proof of concept, the method was previously evaluated in one-dimensional problems and compared with canonical Genetic Programming (GP) and Geometric Semantic Genetic Programming (GSGP). In this paper we revisit SSR exploring the method behaviour in higher dimensional, larger and more heterogeneous datasets. We discuss the difficulties arising from the application of the method to more complex problems, e.g., overfitting, along with suggestions to overcome them. An experimental analysis was conducted comparing SSR to GP and GSGP, showing SSR solutions are smaller than those generated by the GSGP with similar performance and more accurate than those generated by the canonical GP

Genetic Distance Based On Ssr And Grain Yield Of Inter And Intrapopulational Maize Single Cross Hybrids

The objective of this work was to correlate the genetic distances between the progenitors obtained by microsatellite markers with the grain yield of inter and intrapopulational maize single cross hybrids. Three S 0 populations derived from commercial single cross hybrids were used to obtain 163 hybrids (110 interpopulational and 53 intrapopulational). The two best hybrids and two worst hybrids of each the inter- and intrapopulational crosses were selected and their progenitors maintained through self-pollination of the second ear of each S 0 plant, genotyped with 47 SSRs. The Modified Roger's Distance (MRD) between each pair of S 1 inbred lines, the number of alleles and the polymorphic information content (PIC) of each primer were estimated. The genetic distances between progenitors were correlated with the grain yield of the inter- and intrapopulational hybrids. The number of obtained alleles was 186, with a mean of 3.96 alleles. The PIC varied from 0.49 to 0.80, with a mean of 0.65. The mean genetic distance between all S 1 inbred lines was 0.75, varying from 0.40 to 0.89, indicating the existence of variability between the S 1 inbred lines. The correlation between MRD and grain yield was high and significant for the interpopulational crosses (r = 0.84, P ≤ 0.01) and low and not significant (r = 0.18, P ≥ 0.05) for intrapopulational crosses.5103/04/15507513Ajmone Marsan, P., Castiglioni, P., Fu Sari, F., Kuiper, M., Motto, M., Genetic diversity and its relationship to hybrid performance in maize as revealed by RFLP and AFLP markers (1998) Theor. Appl. Genet., 96, pp. 219-227Árcade, A., Faivre-Rampant, P., Le Guerroué, B., Paques, L.E., Prat, D., Heterozigosity and hybrid performance in larch (1996) Theor. Appl. Genet., 93, pp. 1274-1281Barbosa, A.M.M., Geraldi, I.O., Benchimol, L.L., Garcia, A.A.F., Souza Jr., C.L., Souza, A.P., Relationship of intra and interpopulation tropical maize single cross hybrid performance and genetic distances computed from AFLP and SSR markers (2003) Euphytica, 87, pp. 87-99Benchimol, L.L., Souza Jr., C.L., Garcia, A.A.F., Kono, P.M.S., Mangolin, C.A., Barbosa, A.M.M., Coelho, A.S.G., Souza, A.P., Genetic diversity in tropical maize inbred lines: Heterotic group assignment and hybrid performance determined by RFLP markers (2000) Plant Breed., 119, pp. 491-496Boppenmaier, J., Melchinger, A.E., Brunklaus-Junt, E., Geiger, H.H., Genetic diversity for RFLP in European maize inbreds: Relation to performance of flint x dent crosses for forage traits (1992) Crop Sci., 32, pp. 895-902Butstein, D., White, M., Sholnick, M., David, R.W., Construction of a genetic linkage map in man using restriction fragment length polymorphisms (1980) Am. J. Hum. Genet., 32, pp. 314-331Cheres, M.T., Miller, J.F., Crane, J.M., Knapp, S.J., Genetic distance as a predictor of heterosis and hybrid performance within and between heterotic groups in sunflower (2000) Theor. Appl. Genet., 100, pp. 889-894Cruz, C.D., Shuster, I., (2004) GQMOL: Aplicativo Computacional para Análise de Dados Moleculares e de Suas Associações Com Caracteres Quantitativos. Versão 2004.2.1, , Viçosa. MGDhillon, B.S., Boppenmaier, J., Pollmer, R.G., Hermann, R.G., Melchinger, A.E., Relationship of restriction length polymorphisms among european maize inbreds with ear dry matter yield of their hybrids (1993) Maydica, 38, pp. 245-248Drinic, S.M., Trifunovic, S., Drinic, G., Konstantinov, K., Genetic divergence and its correlation to heterosis in maize as revealed by SSR base markers (2002) Maydica, 47, pp. 1-8Goodman, M.M., Stuber, C.W., Races of maize: VI. Isozyme variation among races of maize in Bolivia (1983) Maydica, 28, pp. 169-187Hallauer, A.R., Miranda Filho, J.B., (1988) Quantitative Genetics in Maize Breeding, 468p. , Iowa State University Press, AmesKruskal, J.B., Multidimensional scaling by optimizing goodness of fit to a no metric hypothesis (1964) Psychometrika, 29, pp. 1-27Lanza, L.L.B., Souza Jr., C.L., Ottoboni, I.M.M., Vieira, M.L.C., Souza, A.P., Genetic distance of inbred lines and prediction of maize single-cross performance using RAPD markers (1997) Theor. Appl. Genet., 94, pp. 1023-1030Le Clerc, V., Bazante, F., Baril, C., Guiard, J., Zhang, D., Assessing temporal changes in genetic diversity of maize varieties using microsatellite markers (2005) Theor. Appl. Genet., 110, pp. 294-302Lee, M., Godshalk, E.B., Lamkey, K.R., Woodman, W.W., Association of restriction fragment length polymorphisms among maize inbreds with agronomic performance of their crosses (1989) Crop Sci., 29, pp. 1067-1071Lu, H., Bernardo, R., Molecular marker diversity among current and historical maize inbreds (2001) Theor. Appl. Genet., 103, pp. 613-617Malécot, G., (1948) Les Mathématiques de l'Hérédite, , Masson et Cie, ParisMantel, N., The detection of disease clustering and a generalized regression approach (1967) Cancer Res., 37, pp. 209-220Melchinger, A.E., Genetic diversity and heterosis (1999) The Genetics and Exploitation of Heterosis in Crops, pp. 99-118. , J.G. Coors, S. Pandey (Eds.), Am. Soc. Agron. Madison WIMenkir, A., Melake-Berhan, A., Ingelbrecht, A.T., Adepoju, A., Grouping of tropical mid-altitude maize inbred lines on the basis of yield data and molecular markers (2004) Theor. Appl. Genet., 108, pp. 1582-1590Mille, M., (1997) TFPGA: Toll for Population Genetic Analysis, Version 1.3, , Northern Arizona UniversityPejic, I., Ajmone Marsan, P., Morgante, M., Kozumplick, V., Castiglioni, P., Taramino, G., Motto, M., Comparative analysis of genetic similarity among maize inbred lines detected by RFLPs, RAPDs, SSRs, and AFLPs (1998) Theor. Appl. Genet., 97, pp. 1428-11255Reif, J.C., Melchinger, A.E., Frisch, M., Genetical and mathematical properties of similarity and dissimilarity coefficients applied in plant breeding and seed bank management (2005) Crop Sci., 45, pp. 1-7Reif, J.C., Melchinger, A.E., Xia, X.C., Warburton, M.L., Hoisington, D.A., Vasal, S.K., Srinivasan, G., Frisch, M., Genetic distance based on simple sequence repeats and heterosis in tropical maize populations (2003) Crop Sci., 43, pp. 1275-1282Reif, J.C., Melchinger, A.E., Xia, X.C., Warburton, M.L., Hoisington, D.A., Vasal, S.K., Beck, D., Frisch, M., Use of SSRs for establishing heterotic groups in subtropical maize (2003) Theor. Appl. Genet., 107, pp. 947-957Rohlf, F.J., (2000) NTSYS-pc: Numerical Taxonomy and Multivariate Analysis System. Version 2.1, , Exeter Software. Setauket. NYSaghai-Maroof, M.A., Soliman, K.M., Jorgensen, R.A., Allard, R.W., Ribosomal DNA spacer length polymorphism in barley: Mendelian inheritance, chromosomal location, and population dynamics (1984) Proc. Natl. Acad. Sci. USA, 83, pp. 1757-1761(1998) SAS Language Guide for Personal Computers. Release 6.03 Ed., , SAS INSTITUTE, SAS Inst. Cary. NCSibov, S.T., Souza Jr., C.L., Garcia, A.A.F., Silva, A.R., Garcia, A.F., Mangolin, C.A., Benchimol, L.L., Souza, A.P., Molecular mapping in tropical maize (Zea mays L.) using microsattelite markers. 2. Quantitative trait loci (QTL) for grain yield, plant height, ear height and grain moisture (2003) Hereditas, 139, pp. 107-115Smith, O.S., Smith, J.S.C., Bowen, S.L., Tenborg, R.A., Wall, S.J., Similarities among a group of elite inbreds as measured by pedigree, F 1 heterosis, and RFLPs (1990) Theor. Appl. Genet., 80, pp. 833-840Steel, R.G.D., Torrie, J.H., (1980) Principles and Procedures of Statistics. 2. Ed., 633p. , New York: McGraw HillVaz Patto, M.C., Satovic, Z., Pêgo, S., Fevereiro, P., Assessing the genetic diversity of Portuguese maize germoplasm using microsatellite markers (2004) Euphytica, 137, pp. 63-72Xia, X.C., Reif, J.C., Hoisington, D.A., Melchinger, A.E., Frisch, M., Warburton, M.L., Genetic diversity among CIMMYT maize inbred lines investigated with SSR markers (2004) Crop Sci., 44, pp. 2230-2237Xu, S., Liu, J., Liu, G., The use of SSRs for predicting the hybrid yield and yield heterosis in 15 key inbred lines of Chinese maize (2004) Hereditas, 141, pp. 207-21

Gravitational field around a time-like current-carrying screwed cosmic string in scalar-tensor theories

In this paper we obtain the space-time generated by a time-like current-carrying superconducting screwed cosmic string(TCSCS). This gravitational field is obtained in a modified scalar-tensor theory in the sense that torsion is taken into account. We show that this solution is comptible with a torsion field generated by the scalar field $\phi$. The analysis of gravitational effects of a TCSCS shows up that the torsion effects that appear in the physical frame of Jordan-Fierz can be described in a geometric form given by contorsion term plus a symmetric part which contains the scalar gradient. As an important application of this solution, we consider the linear perturbation method developed by Zel'dovich, investigate the accretion of cold dark matter due to the formation of wakes when a TCSCS moves with speed $v$ and discuss the role played by torsion. Our results are compared with those obtained for cosmic strings in the framework of scalar-tensor theories without taking torsion into account.Comment: 21 pages, no figures, Revised Version, presented at the "XXIV- Encontro Nacional de Fisica de Particulas e Campos ", Caxambu, MG, Brazil, to appear in Phys. Rev.

Dynamically Driven Renormalization Group Applied to Sandpile Models

The general framework for the renormalization group analysis of self-organized critical sandpile models is formulated. The usual real space renormalization scheme for lattice models when applied to nonequilibrium dynamical models must be supplemented by feedback relations coming from the stationarity conditions. On the basis of these ideas the Dynamically Driven Renormalization Group is applied to describe the boundary and bulk critical behavior of sandpile models. A detailed description of the branching nature of sandpile avalanches is given in terms of the generating functions of the underlying branching process.Comment: 18 RevTeX pages, 5 figure

Wakes in Dilatonic Current-Carrying Cosmic Strings

In this work, we present the gravitational field generated by a cosmic string carrying a timelike current in the scalar-tensor gravities. The mechanism of formation and evolution of wakes is fully investigated in this framework. We show explicitly that the inclusion of electromagnetic properties for the string induces logarithmic divergences in the accretion problem.Comment: Revised version to be published in the Phys. Rev.

Irrigação por gotejamento com nitrogênio e potássio em tomateiro

Two levels of nitrogen and potassium were combined with drip irrigation system under edaphoclimatic conditions of "cerrado" soil in central Brazil to test their effect on the yield of 'Kada' tomato (Lycopersicum esculentum Mill). The water head was of 0.8, 1.0 and 1.2 levels of the class A evaporation tank settled on bare soil. Results showed no significant difference among treatments for the total fruit production per hectare. On the other hand, production of large fruits was different among treatments. It was observed that higher level of ammonium sulfate increased number and weight of fruits showing "blossom end rot", independently of the water head used. The combination of 0.8 water level with 1.400 kg/ha of ammonium sulfate and 918 kg/ha of potassium cloride proved to be the most effective in water utilization.Estudou-se o comportamento de tomateiro (Lycopersicum esculentum Mill) cultivar Kada, irrigado por gotejamento e adubado com dois níveis de nitrogênio e potássio, sob condições edafoclimáticas de cerrado do Brasil central. Aplicaram-se lâminas de irrigação correspondentes a 0,8, 1,0 e 1,2 da evaporação de um tanque classe A instalado sobre solo nu. Verificou-se não haver diferenças significativas entre tratamentos na produção total de frutos por hectare; entretanto, a produção de frutos graúdos diferiu entre os tratamentos estudados. Doses elevadas de sulfato de amônio aumentaram o número e o peso dos frutos com podridão estilar independentemente da lâmina de irrigação aplicada. A menor lâmina de irrigação combinada com as doses de 1.400 kg/ha de sulfato de amônio e 918 kg/ha de cloreto de potássio apresentaram melhor eficiência do uso de água

Schistosomiasis Mansoni In Urban Northeast Brazil: Influence Of Rainfall Regime On The Population Dynamics Of Biomphalaria Sp

Introduction: Our objective was to evaluate the infl uence of rainfall regime on the population dynamics of Biomphalaria in a potential urban focus of schistosomiasis in Aracaju, Brazil, during 2009-2010. Methods: Snails were collected monthly and were counted, measured and identifi ed; the level of infection and fecal contamination at the sampling sites was determined; rainfall data were obtained. Results: High levels of fecal contamination were observed, and the abundance of Biomphalaria glabrata increased during the rainy and post-rainy seasons. The snails' size was variable, and infected snails were identifi ed independently of rainfall. Conclusions: These results provide evidence of anthropogenic and climate interference in an urban focus of schistosomiasis in the Aracaju metropolitan area.465654657Pordeus, L.C., Aguiar, L.R., Quinino, L.R.M., Barbosa, C.S.A., Ocorrência das formas aguda e crônica da esquistossomose mansônica no Brasil no período de 1997 a 2006: Uma revisão de literatura (2008) Epidemiol Serv Saude, 17, pp. 163-175Souza, M.A.A., Barbosa, V.S., Wanderlei, T.N.G., Barbosa, C.S., Criadouros de Biomphalaria, temporários e permanentes, em Jaboatão dos Guararapes, PE (2008) Rev Soc Bras Med Trop, 41, pp. 252-256Araújo, K.C.G.M., Resendes, A.P.C., Souza-Santos, R., Silveira Jr., J.C., Barbosa, C.S., Análise espacial dos focos de Biomphalaria glabrata (Say, 1818) e de casos humanos de esquistossomose mansônica em Porto de Galinhas, Pernambuco, Brasil, no ano 2000 (2007) Cad Saude Publica, 23, pp. 409-417Lima, L.C., Família Planorbidae (1995) Tópicos em Malacologia Médica., pp. 90-112. , In: Barbosa FS, editor. Rio de Janeiro: Fundação Oswaldo Cruz(2005) Resolução CONAMA no 357, , http://www.cetesb.sp.gov.br/Agua/praias/res_conama_357_05.pdf, Conselho Nacional do Meio Ambiente (CONAMA). de 17 de março de. [Cited 2011 February 23]. Available fromSouza, M.A.A., Barbosa, V.S., Albuquerque, J.O., Bocanegra, S., Souza-Santos, R., Paredes, H., Aspectos ecológicos e levantamento malacológico para identificação de áreas de risco para transmissão da esquistossomose mansoni no litoral norte de Pernambuco, Brasil (2010) Iheringia Serie Zoológica, 100, pp. 19-24Barbosa, F.S., Barbosa, C.S., The bioecology of snails vectors for schistosomiasis in Brazil (1994) Cad Saude Publica, 10, pp. 200-209Fernandez, M.A., Thiengo, S.C., Susceptibility of Biomphalaria straminea from Peixe Angical dam, Tocantins, Brazil to infection with three strains of Schistosoma mansoni (2010) Mem Inst Oswaldo Cruz, 105, pp. 488-491Barbosa, C.S., Domingues, A.L.C., Abath, F., Montenegro, S.M.L., Guida, U., Carneiro, J., Epidemia de esquistossomose aguda na praia de Porto de Galinhas, Pernambuco, Brasil (2001) Cad Saude Publica, 17, pp. 725-728Rollemberg, C.V.V., Santos, C.M.B., Silva, M.M.B.L., Souza, A.M.B., Silva, A.M., Almeida, J.A.P., Aspectos epidemiológicos e distribuição geográfica da esquistossomose e geo-helmintos, no Estado de Sergipe, de acordo com os dados do Programa de Controle da Esquistossomose (2011) Rev Soc Bras Med Trop, 44, pp. 91-96Barbosa, C.S., Montenegro, S.M.L., Abath, F.G., Domingues, A.L.C., Eventos epidemiológicos relacionados à transmissão da esquistossomose em áreas rurais e urbanas de Pernambuco (2002) Mem Inst Oswaldo Cruz, 96, pp. 169-172Departamento de Vigilância Epidemiológica (2008) Vigilância e controle de moluscos de importância epidemiológica: Diretrizes técnicas., , Ministério da Saúde. Programa de Vigilância e Controle da Esquistossomose (PCE). 2nded. Brasília: Ministério da Saúd