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991.
In this paper, we investigate the problem of determining the relationship, represented by similarity of the homologous gene configuration, between paired circular genomes using a regression analysis. We propose a new regression model for studying two circular genomes, where the Möbius transformation naturally arises and is taken as the link function, and propose the least circular distance estimation method, as an appropriate method for analyzing circular variables. The main utility of the new regression model is in identification of a new angular location of one of a homologous gene pair between two circular genomes, for various types of possible gene mutations, given that of the other gene. Furthermore, we demonstrate the utility of our new regression model for grouping of various genomes based on closeness of their relationship. Using angular locations of homologous genes from the five pairs of circular genomes (Horimoto et al. in Bioinformatics 14:789–802, 1998), the new model is compared with the existing models. 相似文献
992.
Francesca Bruno Fedele Greco Massimo Ventrucci 《Statistical Methods and Applications》2016,25(1):75-88
Methods to perform regression on compositional covariates have recently been proposed using isometric log-ratios (ilr) representation of compositional parts. This approach consists of first applying standard regression on ilr coordinates and second, transforming the estimated ilr coefficients into their contrast log-ratio counterparts. This gives easy-to-interpret parameters indicating the relative effect of each compositional part. In this work we present an extension of this framework, where compositional covariate effects are allowed to be smooth in the ilr domain. This is achieved by fitting a smooth function over the multidimensional ilr space, using Bayesian P-splines. Smoothness is achieved by assuming random walk priors on spline coefficients in a hierarchical Bayesian framework. The proposed methodology is applied to spatial data from an ecological survey on a gypsum outcrop located in the Emilia Romagna Region, Italy. 相似文献
993.
Mahdi Rasekhi Rahim Chinipardaz Sayed Mohammad Reza Alavi 《Statistical Methods and Applications》2016,25(3):375-394
The skew normal distribution of Azzalini (Scand J Stat 12:171–178, 1985) has been found suitable for unimodal density but with some skewness present. Through this article, we introduce a flexible extension of the Azzalini (Scand J Stat 12:171–178, 1985) skew normal distribution based on a symmetric component normal distribution (Gui et al. in J Stat Theory Appl 12(1):55–66, 2013). The proposed model can efficiently capture the bimodality, skewness and kurtosis criteria and heavy-tail property. The paper presents various basic properties of this family of distributions and provides two stochastic representations which are useful for obtaining theoretical properties and to simulate from the distribution. Further, maximum likelihood estimation of the parameters is studied numerically by simulation and the distribution is investigated by carrying out comparative fitting of three real datasets. 相似文献
994.
M. Giovanna Ranalli Antonio Arcos María del Mar Rueda Annalisa Teodoro 《Statistical Methods and Applications》2016,25(3):321-349
Survey statisticians make use of auxiliary information to improve estimates. One important example is calibration estimation, which constructs new weights that match benchmark constraints on auxiliary variables while remaining “close” to the design weights. Multiple-frame surveys are increasingly used by statistical agencies and private organizations to reduce sampling costs and/or avoid frame undercoverage errors. Several ways of combining estimates derived from such frames have been proposed elsewhere; in this paper, we extend the calibration paradigm, previously used for single-frame surveys, to calculate the total value of a variable of interest in a dual-frame survey. Calibration is a general tool that allows to include auxiliary information from two frames. It also incorporates, as a special case, certain dual-frame estimators that have been proposed previously. The theoretical properties of our class of estimators are derived and discussed, and simulation studies conducted to compare the efficiency of the procedure, using different sets of auxiliary variables. Finally, the proposed methodology is applied to real data obtained from the Barometer of Culture of Andalusia survey. 相似文献
995.
A visualization method measuring the performance of biomarkers for guiding treatment decisions 下载免费PDF全文
Biomarkers that predict efficacy and safety for a given drug therapy become increasingly important for treatment strategy and drug evaluation in personalized medicine. Methodology for appropriately identifying and validating such biomarkers is critically needed, although it is very challenging to develop, especially in trials of terminal diseases with survival endpoints. The marker‐by‐treatment predictiveness curve serves this need by visualizing the treatment effect on survival as a function of biomarker for each treatment. In this article, we propose the weighted predictiveness curve (WPC). Based on the nature of the data, it generates predictiveness curves by utilizing either parametric or nonparametric approaches. Especially for nonparametric predictiveness curves, by incorporating local assessment techniques, it requires minimum model assumptions and provides great flexibility to visualize the marker‐by‐treatment relationship. WPC can be used to compare biomarkers and identify the one with the highest potential impact. Equally important, by simultaneously viewing several treatment‐specific predictiveness curves across the biomarker range, WPC can also guide the biomarker‐based treatment regimens. Simulations representing various scenarios are employed to evaluate the performance of WPC. Application on a well‐known liver cirrhosis trial sheds new light on the data and leads to discovery of novel patterns of treatment biomarker interactions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
996.
魏丽 《西昌学院学报(社会科学版)》2016,(3):56-58
会官审录制度是明朝司法活动的重要组成部分之一,这一制度在明朝时期已经相当完善和成熟。会官审录制对加强明
朝中央集权统治,维护社会稳定发挥了重要作用。明朝会官审录的形式多样,内容丰富,在司法实践中体现出来的诸多特点和
蕴涵的精神意蕴对当今社会的法制建设仍有重大启示。 相似文献
997.
教育是非物质文化遗产保护和传承的主要途径。回顾近十年来我国非物质文化遗产教育研究的成果,发现它具有“三多三少”的特征。具体表现为:一是多强调正规教育(学校)在非物质文化遗产保护和传承中具有重要作用,少谈非正规教育的作用;二是多强调普通教育对非物质文化遗产人才的培养,少强调职业教育对非物质文化遗产人才的培养;三是多讨论各级各类学校的非物质文化遗产教育实践,少谈对非物质文化遗产教育的评价。思考我国非物质文化遗产教育研究现状,有利于充分发挥教育在非物质文化遗产保护和传承中的功能,切实提高非物质文化遗产教育的成效。 相似文献
998.
对近年来高强混凝土高温性能的研究成果进行了综述与分析,包括热工性、高温下和高温后力学性能以及高强高性能混凝土的爆裂性能。其中,高强混凝土热工性能方面的研究成果较少且研究结果离散性较大;高强混凝土力学性能方面的研究主要集中于抗压强度、抗拉强度、变形性能、弹性模量、泊松比、应力 应变关系等,而对高强混凝土结构、构件高温力学性能和温度场分析方面的研究较少;高强高性能混凝土爆裂方面的研究多集中于爆裂规律和爆裂抑制措施,对爆裂机理和微观结构的研究较少。本文分别从3个方面指出了高强混凝土高温性能研究中存在的问题和今后的研究方向,为深入研究高强混凝土的高温性能提供参考。 相似文献
999.
封龙山作为“燕赵文化名山”,有着悠久的历史传承和厚重的文化底蕴。封龙山文化的形成首先与毗邻曾为政治、经济、文化中心的特殊地理位置有关,其次是它对周边地区的广泛影响而形成了人才辈出群星璀璨的局面。封龙山作为中国古代传统文化的重要发祥地之一,为中华文明做出了卓越的贡献,并在以后封龙山文化在不断发展的过程中,表现出了极大的包融性,其丰富的文化内涵体现于三个方面:科学与信仰相容、 佛教与道教双修、修德与崇礼共存。 相似文献
1000.
在研究现有的几种发动机转速测量方法基础上,设计了一种以T型测速方法为原理,以DSPF2812为控制核心的发动机转速测量系统。给出了系统的测量原理以及实现发动机转速测量的软件编程方法和信号调理电路设计,同时应用LabVIEW软件实现对信号的监测和数据存储,最后对该测量系统进行了实验测试,在实际测试中取得了良好的效果。该系统具有测速精度高、测速范围广以及实时性强等特点,为汽车发动机性能研究、故障处理以及后续的分析提供了重要的参考依据,同时该系统还可以应用到电机测速等其它测速领域,具有较高的实用价值。 相似文献