18,410 research outputs found

    Handling Outlier in Two-Ways Table by Robust Alternating Regression of FANOVA Models: Towards Robust AMMI Models

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    AMMI (Additive Main Effect Multiplicative Interaction) model for interactions in two-way table provide the major mean for studying stability and adaptability through genotype × environment interaction (GEI), which modeled by full interaction model. Eligibility of AMMI model depends on that assumption of normally independentdistributederrorwithaconstantvariance. Nowadays,AMMImodelshavebeendevelopedforany conditionofMETdatawhich violencethenormality,homogeneityassumpion. Wecanmentioninthisclassof modelling as M-AMMI for mixed AMMI models, G-AMMI for generalized AMMI models. The G-AMMI was handling non-normality i.e categorical response variables using an algorithm of alternating regression. While in handling the non-homogeneity in mix-models sense, one may use a model called factor analytic multiplicative. The development of AMMI models is also to handle any outlier that might be found coincides withnon-homogeneityconditionofthedata. Inthispaper,wewillpresentofhandlingoutlierinmultplicative model by robust approach of alternating regression algorithm

    Existence of positive solutions for non local p-Laplacian thermistor problems on time scales

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    We make use of the Guo-Krasnoselskii fixed point theorem on cones to prove existence of positive solutions to a non local p-Laplacian boundary value problem on time scales arising in many applications. © 2007 Victoria University. All rights reserved.CEOCFCTFEDER/POCTISFRH/BPD/20934/200

    Noether's Theorem for Control Problems on Time Scales

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    We prove a generalization of Noether's theorem for optimal control problems defined on time scales. Particularly, our results can be used for discrete-time, quantum, and continuous-time optimal control problems. The generalization involves a one-parameter family of maps which depend also on the control and a Lagrangian which is invariant up to an addition of an exact delta differential. We apply our results to some concrete optimal control problems on an arbitrary time scale.Comment: This is a preprint of a paper whose final and definite form is published in International Journal of Difference Equations ISSN 0973-6069, Vol. 9 (2014), no. 1, 87--10

    Algoritmo AMMI ponderado para dados não replicados

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    The objective of this work was to propose a weighting scheme for the additive main effects and multiplicative interactions (AMMI) model, as well as to assess the usefulness of this W-AMMI model in the study of genotype x environment interaction (GxE) and quantitative trait locus x environment interaction (QxE) for nonreplicated data. Data from the 'Harrington' x TR306 barley (Hordeum vulgare) mapping population, with 141 genotypes evaluated in 25 environments, were used to compare the results from the AMMI model with those of two proposed versions of the W-AMMI model: equal weights per row and equal weights per column. The proposed W-AMMI columns algorithm is viable to analyze data with heterogeneous variance, when there are no replicates available. The use of the AMMI and W-AMMI models, in the indicated cases, improves QTL detection, besides providing a sound interpretation of GxE and a better understanding of QxE, which allows obtaining valuable information on increasing productivities in different environments. O objetivo deste trabalho foi propor um esquema de ponderação para o modelo de efeitos principais aditivos e interação multiplicativa (AMMI), bem como avaliar a utilidade deste modelo W-AMMI no estudo da interação genótipo x ambiente (GxA) e da interação de locos associados a caracteres quantitativos x ambiente (QxA) para dados não replicados. Utilizou-se a população de cevada (Hordeum vulgare) 'Harrington' x TR306, com 141 genótipos avaliados em 25 ambientes, para comparar os resultados do modelo AMMI com os de duas versões propostas do modelo W-AMMI: pesos iguais por linha e pesos iguais por coluna. O algoritmo W-AMMI de colunas proposto é viável para analisar informação com heterogeneidade de variâncias, quando não há repetições disponíveis. O uso dos modelos AMMI e W-AMMI, nos casos indicados, melhora a detecção de QTLs, além de propiciar uma intepretação adequada da GxA e um melhor entendimento da QxA, o que possibilita a obtenção de informações importantes para o aumento da produtividade em diferentes ambientes

    Analiza performansi novih eksperimentalnih genotipova ječma za prinos zrna pomoću AMMI biplota

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    Presence of GE interaction reduces the correlation between genotypic and phenotypic parameters and complicates progress of selection. Among several methods proposed for evaluation of the GE interaction, the AMMI model is one of the most commonly used. The objective of this study was to estimate the GE interaction in new barley lines using the AMMI model, and to identify winter barley genotypes with stable and high yield. Multi-location trials with 25 winter barley advanced lines were conducted at four locations. The AMMI model was used to estimate GE interaction. The AMMI analysis of variance indicated that the genotype, environment and GE interaction had significant influence (p lt 0,01) on barley grain yield. Based on AMMI method, G8 and G18 could be recommended for further testing due their high and stable yields.Interakcija GxE je izvor varijacije koji uključuje uticaj genotipa i faktora spoljašnje sredine, koji otežava izbor superiornih genotipova u procesu selekcije. AMMI analiza predstavalja metod koji se često koristi za ocenu interakcije genotip/sredina. Cilj ovog rada je ocena interakcije genotip/sredina pomoću AMMI modela, i identifikacija genotipova ozimog ječma sa visokim i stabilnim prinosom. Multilokacijski ogledi sa 25 superiornih linija ječma su posejani na četiri lokaliteta. AMMI analizom varijanse je utvrđeno da su genotip, sredina i interakcija genotip/ sredina imali signifikantan uticaj (p lt 0,01) na prinos ječma. Na osnovu AMMI analize, genotipovi G8 i G18 se mogu preporučiti za dalje testiranje usled njihovog visokog i stabilnog prinosa

    Optimal Control of Nonlocal Thermistor Equations

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    We are concerned with the optimal control problem of the well known nonlocal thermistor problem, i.e., in studying the heat transfer in the resistor device whose electrical conductivity is strongly dependent on the temperature. Existence of an optimal control is proved. The optimality system consisting of the state system coupled with adjoint equations is derived, together with a characterization of the optimal control. Uniqueness of solution to the optimality system, and therefore the uniqueness of the optimal control, is established. The last part is devoted to numerical simulations.Comment: Submitted 21-March-2012; revised 11-June-2012; accepted 13-June-2012; for publication in the International Journal of Contro

    KOREKSI METODE CONNECTED AMMI DALAM PENDUGAAN DATA TIDAK LENGKAP

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    Percobaan multilokasi mempunyai peranan penting dalam perkembangbiakan tanaman dan penelitian agronomi. Kajian mengenai interaksi antara genotipe dan lingkungan diperlukan dalam penyeleksian genotipe yang akan dilepas. Metode statistika yang biasa digunakan untuk mengolah data hasil percobaan multilokasi salah satunya adalah AMMI (Additive Main effect and Multiplicative Interaction). Metode ini menggabungkan analisis ragam aditif bagi pengaruh utama perlakuan dengan analisis komponen utama pada pengaruh interaksinya.Hambatan utama dalam menggunakan analisis AMMI adalah keseimbangan data. Sedangkan pada percobaan multilokasi kejadian data menjadi tidak seimbang peluangnya sangat besar. Agar setiap kombinasi genotipe dan lokasi memiliki jumlah ulangan yang sama, maka harus dilakukan pendugaan terhadap data yang tak lengkap. Pada kasus data tidak lengkap, diperlukan suatu metode pendugaan data untuk mempermudah analisis. Pada penelitian ini digunakan metode connected data dan algoritma EM-AMMI untuk menduga data yang tak lengkap dengan fungsi tujuannya adalah Mean Absolute Percentage Error (MAPE). Hasil simulasi menunjukkan bahwa semakin besar keragaman dari data maka semakin besar pula nilai MAPE semakin besar selaras juga dengan semakin tingginya persentas ketidaklengkapan data. Metode EM-AMMI memberikan MAPE yang lebih baik jika nilai awal dalam proses iterasi ditetapkan denga menggunakan metode Connected. Sehingga metode Connected –EM AMMI merupakan metode yang layak untuk dijadikan dasar pendugaan data tidak lengkap dalam analisis AMMI. Kata Kunci : AMMI, Connected AMMI, EM-AMM

    Mantle formation, coagulation and the origin of cloud/core-shine: II. Comparison with observations

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    Many dense interstellar clouds are observable in emission in the near-IR, commonly referred to as "Cloudshine", and in the mid-IR, the so-called "Coreshine". These C-shine observations have usually been explained with grain growth but no model has yet been able to self-consistently explain the dust spectral energy distribution from the near-IR to the submm. We want to demonstrate the ability of our new core/mantle evolutionary dust model THEMIS (The Heterogeneous dust Evolution Model at the IaS), which has been shown to be valid in the far-IR and submm, to reproduce the C-shine observations. Our starting point is a physically motivated core/mantle dust model. It consists of 3 dust populations: small aromatic-rich carbon grains; bigger core/mantle grains with mantles of aromatic-rich carbon and cores either made of amorphous aliphatic-rich carbon or amorphous silicate. We assume an evolutionary path where these grains, when entering denser regions, may first form a second aliphatic-rich carbon mantle (coagulation of small grains, accretion of carbon from the gas phase), second coagulate together to form large aggregates, and third accrete gas phase molecules coating them with an ice mantle. To compute the corresponding dust emission and scattering, we use a 3D Monte-Carlo radiative transfer code. We show that our global evolutionary dust modelling approach THEMIS allows us to reproduce C-shine observations towards dense starless clouds. Dust scattering and emission is most sensitive to the cloud central density and to the steepness of the cloud density profile. Varying these two parameters leads to changes, which are stronger in the near-IR, in both the C-shine intensity and profile. With a combination of aliphatic-rich mantle formation and low-level coagulation into aggregates, we can self-consistently explain the observed C-shine and far-IR/submm emission towards dense starless clouds.Comment: Paper accepted for publication in A&A with companion paper "Mantle formation, coagulation and the origin of cloud/core-shine: I. Dust scattering and absorption in the IR", A.P Jones, M. Koehler, N. Ysard, E. Dartois, M. Godard, L. Gavila
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