1,942 research outputs found

    A biological perspective on interpreting interaction effect

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    Factorial experiments are commonly employed in agricultural research as in other branches of applied sciences. In these experiments, inferences related to the interaction are essential. However, many researchers are still unable to analyze this type of experiment and interpret the results in the correct way. This is because researchers focus on interpreting the main effects although there is a significant interaction effect. Of course, meaningful main effects can exist even in the presence of an interaction, especially if interactions do not affect the main effects. Therefore, it is extremely important to understand thoroughly in which situations only the interaction effect(s), in which cases only the main effect(s), and in which cases the interpretation of the main effects will be meaningful although the interaction effect is significant. In this study, evaluating factorial experiments has been discussed in detail, especially in studies related to animal science. It has also been focused on the importance of considering both statistical and practical significance while interpreting the statistical analysis results

    Determination of depression risk factors in children and adolescents by regression tree methodology.

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    We used a regression tree method (RTM) to determine risks of depression in children/adolescents. The survey records of 4,143 children/adolescents in a study based in Mersin, Turkey served as data in this study, and multi-step, stratified, and cluster sampling were used. Effects of 24 variables (sex, smoking, parental problems, etc.) were evaluated on depression scores. The Child Beck Depression Inventory (CBDI) was used to determine the level of depression. Subjects were into 12 different groups based on magnitudes of mean depression scores. The interactions among 7 variables determined to be risk factors are shown on a schema. The STATISTICA (ver.6.0) package program was used for all computations. Although traditional statistical methods have often been used for analysis in this field, such approaches are associated with certain disadvantages such as missing values, ignorance of interaction effects, or restriction of the shape of the distribution. To avoid such disadvantages, we therefore suggest the use of the RTM in studies involving numerical-based outcome variables and for the investigation of a large number of variables and it may be more effective than traditional statistical methods in epidemiological studies which determine risk factors.</p

    Determination of water stress with spectral reflectance on sweet corn (Zea mays L.) using classification tree (CT) analysis

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    Abstract Water stress is one of the most important growth limiting factors in crop production. Several methods have been used to detect and evaluate the effect of water stress on plants. The use of remote sensing is deemed particularly and practically suitable for assessing water stress and implementing appropriate management strategies because it presents unique advantages of repeatability, accuracy, and cost-effectiveness over the ground-based surveys for water stress detection. The objectives of this study were to 1) determine the effect of water stress on sweet corn (Zea mays L.) using spectral indices and chlorophyll readings and 2) evaluate the reflectance spectra using the classification tree (CT) method for distinguishing water stress levels/severity. Spectral measurements and chlorophyll readings were taken on sweet corn exposed to four levels of water stress with 0, 33, 66 and 100 % of pot capacity (PC) before and after each watering time. The results demonstrated that reflectance in the red portion (600-700 nm) of the electromagnetic spectrum decreased and increased in the near infrared (NIR) region (700-900 nm) with the increasing field capacity of water level. Reflectance measured before the irrigation was generally higher than after irrigation in the NIR region and lower in the red region. However, when the four levels of PC and before or after irrigation only were compared, reflectance spectra indicated that water stressed corn plants absorbed less light in the visible and more light in the NIR regions of the spectrum than the less water stressed and unstressed plants. There was a similar trend to reflectance behaviour of water stress levels using chlorophyll readings that decreased over time. The CT analysis revealed that water stress can be assessed and differentiated using chlorophyll readings and reflectance data when transformed into spectral vegetation indices

    Avances en Informática y Automática. Duodécimo Workshop

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    Actas de los trabajos de TFM del Máster Universitario en Sistemas Inteligentes 2017-2018[ES]El Máster Oficial en Sistemas Inteligentes de la Universidad de Salamanca tiene como principal objetivo promover la iniciación de los estudiantes en el ámbito de la investigación. El congreso organizado por el Departamento de Informática y Automática que se celebra dentro del Máster en Sistemas Inteligentes de la Universidad de Salamanca proporciona la oportunidad ideal para que sus estudiantes presenten los principales resultados de sus Trabajos de Fin de Máster y obtengan una realimentación del interés de los mismos. La duodécima edición del workshop Avances en Informática y Automática, correspondiente al curso 2017-2018, ha sido un encuentro interdisciplinar donde se han presentado trabajos pertenecientes a un amplio abanico de líneas de investigación. Todos los trabajos han sido supervisados por investigadores de reconocido prestigio pertenecientes a la Universidad de Salamanca, proporcionando el marco idóneo para sentar las bases de una futura tesis doctoral. Entre los principales objetivos del congreso se encuentran: Ofrecer a los estudiantes un marco donde exponer sus primeros trabajos de investigación. Proporcionar a los participantes un foro donde discutir ideas y encontrar nuevas sugerencias de compañeros, investigadores y otros asistentes a la reunión. Permitir a cada estudiante una realimentación de los participantes sobre su trabajo y una orientación sobre las futuras direcciones de investigación. Contribuir al desarrollo del espíritu de colaboración en la investigación

    Creative destruction in science

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    Drawing on the concept of a gale of creative destruction in a capitalistic economy, we argue that initiatives to assess the robustness of findings in the organizational literature should aim to simultaneously test competing ideas operating in the same theoretical space. In other words, replication efforts should seek not just to support or question the original findings, but also to replace them with revised, stronger theories with greater explanatory power. Achieving this will typically require adding new measures, conditions, and subject populations to research designs, in order to carry out conceptual tests of multiple theories in addition to directly replicating the original findings. To illustrate the value of the creative destruction approach for theory pruning in organizational scholarship, we describe recent replication initiatives re-examining culture and work morality, working parents\u2019 reasoning about day care options, and gender discrimination in hiring decisions. Significance statement It is becoming increasingly clear that many, if not most, published research findings across scientific fields are not readily replicable when the same method is repeated. Although extremely valuable, failed replications risk leaving a theoretical void\u2014 reducing confidence the original theoretical prediction is true, but not replacing it with positive evidence in favor of an alternative theory. We introduce the creative destruction approach to replication, which combines theory pruning methods from the field of management with emerging best practices from the open science movement, with the aim of making replications as generative as possible. In effect, we advocate for a Replication 2.0 movement in which the goal shifts from checking on the reliability of past findings to actively engaging in competitive theory testing and theory building. Scientific transparency statement The materials, code, and data for this article are posted publicly on the Open Science Framework, with links provided in the article

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Search for stop and higgsino production using diphoton Higgs boson decays

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    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass
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