Revista Colombiana De Estadistica最新文献_第8页

Bayesian Estimation of the Limiting Availability in a Repairable One-Unit System 可修单单元系统极限可用性的贝叶斯估计

Revista Colombiana De Estadistica Pub Date : 2019-01-01 DOI: 10.15446/RCE.V42N1.66279

Víctor H. Salinas Torres, C. Vásquez, José S. Romeo

引用次数: 1

Using an Anchor to Improve Linear Predictions with Application to Predicting Disease Progression. 利用锚点改进线性预测及其在疾病进展预测中的应用。

Revista Colombiana De Estadistica Pub Date : 2018-07-01 DOI: 10.15446/rce.v41n2.68535

Alex Karanevich, Jianghua He, Byron J Gajewski

{"title":"Using an Anchor to Improve Linear Predictions with Application to Predicting Disease Progression.","authors":"Alex Karanevich, Jianghua He, Byron J Gajewski","doi":"10.15446/rce.v41n2.68535","DOIUrl":"https://doi.org/10.15446/rce.v41n2.68535","url":null,"abstract":"Linear models are some of the most straightforward and commonly used modelling approaches. Consider modelling approximately monotonic response data arising from a time-related process. If one has knowledge as to when the process began or ended, then one may be able to leverage additional assumed data to reduce prediction error. This assumed data, referred to as the \"anchor,\" is treated as an additional data-point generated at either the beginning or end of the process. The response value of the anchor is equal to an intelligently selected value of the response (such as the upper bound, lower bound, or 99th percentile of the response, as appropriate). The anchor reduces the variance of prediction at the cost of a possible increase in prediction bias, resulting in a potentially reduced overall mean-square prediction error. This can be extremely effective when few individual data-points are available, allowing one to make linear predictions using as little as a single observed data-point. We develop the mathematics showing the conditions under which an anchor can improve predictions, and also demonstrate using this approach to reduce prediction error when modelling the disease progression of patients with amyotrophic lateral sclerosis.","PeriodicalId":54477,"journal":{"name":"Revista Colombiana De Estadistica","volume":"41 2","pages":"137-155"},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6345390/pdf/nihms978249.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36902206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Artificial Neuronal Networks: A Bayesian Approach Using Parallel Computing 人工神经元网络：一种使用并行计算的贝叶斯方法

Revista Colombiana De Estadistica Pub Date : 2018-07-01 DOI: 10.15446/RCE.V41N2.55250

Eduardo Guzmán, Mario A. Vázquez, David del Valle, P. Pérez-Rodríguez

{"title":"Artificial Neuronal Networks: A Bayesian Approach Using Parallel Computing","authors":"Eduardo Guzmán, Mario A. Vázquez, David del Valle, P. Pérez-Rodríguez","doi":"10.15446/RCE.V41N2.55250","DOIUrl":"https://doi.org/10.15446/RCE.V41N2.55250","url":null,"abstract":"An Artificial Neural Network (ANN) is a learning paradigm and automatic processing inspired in the biological behavior of neurons and the brain structure. The brain is a complex system; its basic processing unit are the neurons, which are distributed massively in the brain sharing multiple connections between them. The ANNs try to emulate some characteristics of humans, and can be thought as intelligent systems that perform some tasks in a different way that actual computer does. The ANNs can be used to perform complex activities, for example: pattern recognition and classification, weather prediction, genetic values prediction, etc. The algorithms used to train the ANN, are in general complex, so therefore there is a need to have alternatives which lead to a significant reduction of times employed to train an ANN. In this work, we present an algorithm based in the strategy ``divide and conquer'' which allows to train an ANN with a single hidden layer. Part of the sub problems of the general algorithm used for training are solved by using parallel computing techniques, which allows to improve the performance of the resulting application. The proposed algorithm was implemented using the C++ programming language, and the libraries Open MPI and ScaLAPACK. We present some application examples and we asses the application performance. The results shown that it is possible to reduce significantly the time necessary to execute the program that implements the algorithm to train the ANN.","PeriodicalId":54477,"journal":{"name":"Revista Colombiana De Estadistica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.15446/RCE.V41N2.55250","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45544810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Form-Invariance of the Non-Regular Exponential Family of Distributions 非正则指数分布族的形式-不变性

Revista Colombiana De Estadistica Pub Date : 2018-07-01 DOI: 10.15446/RCE.V41N2.62233

S. Ghorbanpour, R. Chinipardaz, S. M. R. Alavi

引用次数: 0

Editorial 社论

Revista Colombiana De Estadistica Pub Date : 2018-07-01 DOI: 10.15446/rce.v41n2.73683

L. López Kleine, Ramón Giraldo Henao

引用次数: 0

On Reliability in a Multicomponent Stress-Strength Model with Power Lindley Distribution 具有幂Lindley分布的多组分应力强度模型的可靠性

Revista Colombiana De Estadistica Pub Date : 2018-07-01 DOI: 10.15446/RCE.V41N2.69621

Abbas Pak, Arjun K. Gupta, N. B. Khoolenjani

引用次数: 17

Construction of the Design Matrix for Generalized Linear Mixed-Effects Models in the Context of Clinical Trials of Treatment Sequences. 在治疗序列临床试验中构建广义线性混合效应模型的设计矩阵。

Revista Colombiana De Estadistica Pub Date : 2018-07-01 DOI: 10.15446/rce.v41n2.63332

Francisco J Diaz

{"title":"Construction of the Design Matrix for Generalized Linear Mixed-Effects Models in the Context of Clinical Trials of Treatment Sequences.","authors":"Francisco J Diaz","doi":"10.15446/rce.v41n2.63332","DOIUrl":"10.15446/rce.v41n2.63332","url":null,"abstract":"The estimation of carry-over effects is a difficult problem in the design and analysis of clinical trials of treatment sequences including cross-over trials. Except for simple designs, carry-over effects are usually unidentifiable and therefore nonestimable. Solutions such as imposing parameter constraints are often unjustified and produce differing carry-over estimates depending on the constraint imposed. Generalized inverses or treatment-balancing often allow estimating main treatment effects, but the problem of estimating the carry-over contribution of a treatment sequence remains open in these approaches. Moreover, washout periods are not always feasible or ethical. A common feature of designs with unidentifiable parameters is that they do not have design matrices of full rank. Thus, we propose approaches to the construction of design matrices of full rank, without imposing artificial constraints on the carry-over effects. Our approaches are applicable within the framework of generalized linear mixed-effects models. We present a new model for the design and analysis of clinical trials of treatment sequences, called Antichronic System, and introduce some special sequences called Skip Sequences. We show that carry-over effects are identifiable only if appropriate Skip Sequences are used in the design and/or data analysis of the clinical trial. We explain how Skip Sequences can be implemented in practice, and present a method of computing the appropriate Skip Sequences. We show applications to the design of a cross-over study with 3 treatments and 3 periods, and to the data analysis of the STAR*D study of sequences of treatments for depression.","PeriodicalId":54477,"journal":{"name":"Revista Colombiana De Estadistica","volume":"41 2","pages":"191-233"},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7100378/pdf/nihms-1050552.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37782716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simultaneous Confidence Bands for the Estimation of Expected Discounted Warranty Costs for Coherent Systems under Minimal Repair 最小维修条件下相干系统预期折扣保修成本估计的同步置信区间

Revista Colombiana De Estadistica Pub Date : 2018-01-01 DOI: 10.15446/RCE.V41N1.59929

C. Gómez, Nelfi Gertrudis González Alvarez

{"title":"Simultaneous Confidence Bands for the Estimation of Expected Discounted Warranty Costs for Coherent Systems under Minimal Repair","authors":"C. Gómez, Nelfi Gertrudis González Alvarez","doi":"10.15446/RCE.V41N1.59929","DOIUrl":"https://doi.org/10.15446/RCE.V41N1.59929","url":null,"abstract":"This paper develops simultaneous confidence bands using computer intensive methods based on resampling, for the expected discounted warranty costs in coherent systems under physical minimal repair, that is, when the system is observed at its components level and only the component that causes the fault is minimally repaired. For this purpose, it is shown that, under the framework of the Martingale processes and the central limit resampling theorem (CLRT) over stochastic processes, the discounted warranty cost processes satisfy the conditions set by the central limit resampling theorem (CLRT). Additionally, a simulation study is performed on the most relevant variables, such that the finite sample features of the proposed bands may be assessed, based on their actual coverage probabilities. The results in the considered scenarios show that resampling-based simultaneous confidence bands have coverage probabilities that are close to the nominal coverage. In particular, the agreement is good when there are 100 systems or more where a large number of resamples are used for the approximation.","PeriodicalId":54477,"journal":{"name":"Revista Colombiana De Estadistica","volume":"28 1","pages":"1-30"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83474421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Bivariate Model based on Compound Negative Binomial Distribution 基于复合负二项分布的二元模型

Revista Colombiana De Estadistica Pub Date : 2018-01-01 DOI: 10.15446/RCE.V41N1.57803

M. Omair, Fatimah E. Almuhayfith, A. Alzaid

引用次数: 8

Estimating dynamic Panel data. A practical approach to perform long panels. 估计动态面板数据。执行长面板的实用方法。

Revista Colombiana De Estadistica Pub Date : 2018-01-01 DOI: 10.15446/RCE.V41N1.61885

Romilio Labra Lillo, Celia Torrecillas

引用次数: 80