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61.
The Consumer Price Indexes (CPI) are used in current economic systems to measure inflation. When constructing CPIs, however, official institutions have systematically overlooked the spatial dimension of elementary prices. Ignoring the fact that prices are collected at geographical locations implicitly implies considering prices as spatially independent, when in fact they are not. To solve this problem, this article proposes to weight basic price data by taking into account the spatial correlation they display. The weighted geometric and arithmetic means suggested generalize and improve the simple geometric and arithmetic means currently in use.  相似文献   
62.
Abstract

This paper proposes a new model for autoregressive time series of counts in terms of a convolution of Poisson and negative binomial random variables, known as Poisson–negative binomial (PNB) distribution. The corresponding first-order integer valued time series models are developed and their properties are discussed. The geometric PNB and the geometric semi PNB distributions are also introduced and studied.  相似文献   
63.
Some bootstrap and boosting methods for problems related to classification are introduced in this article. The first method chooses better boosting weights by using a bootstrap search algorithm. The second method is a good way to define a classification frontier. A new formulation for boosting in linear discriminant analysis is given. Since in this new formulation the uncertainty is represented by the weighted covariance matrix, it is more appropriate from the conceptual point of view. Simulation results show that the proposed methods perform well in data analysis.  相似文献   
64.
A data-driven technique is proposed to estimate the trend and relative growth rate of time series data. The method is based on the local linear regression smoother and the only assumption about the form of the trend and growth rate function is that they are smooth functions of time. We also extended the method for handling sudden shifts or changes in the trend or growth rate functions by adding dummy variables for the jumps. Simulation studies are carried out to see the performance of the proposed procedure. The method is applied to study the trend and growth rate of wheat production in India from 1951–2005.  相似文献   
65.
In this article, we investigated the bootstrap calibrated generalized confidence limits for process capability indices C pk for the one-way random effect model. Also, we derived Bissell's approximation formula for the lower confidence limit using Satterthwaite's method and calculated its coverage probabilities and expected values. Then we compared it with standard bootstrap (SB) method and generalized confidence interval method. The simulation results indicate that the confidence limit obtained offers satisfactory coverage probabilities. The proposed method is illustrated with the help of simulation studies and data sets.  相似文献   
66.
Copula models have become increasingly popular for modelling the dependence structure in multivariate survival data. The two-parameter Archimedean family of Power Variance Function (PVF) copulas includes the Clayton, Positive Stable (Gumbel) and Inverse Gaussian copulas as special or limiting cases, thus offers a unified approach to fitting these important copulas. Two-stage frequentist procedures for estimating the marginal distributions and the PVF copula have been suggested by Andersen (Lifetime Data Anal 11:333–350, 2005), Massonnet et al. (J Stat Plann Inference 139(11):3865–3877, 2009) and Prenen et al. (J R Stat Soc Ser B 79(2):483–505, 2017) which first estimate the marginal distributions and conditional on these in a second step to estimate the PVF copula parameters. Here we explore an one-stage Bayesian approach that simultaneously estimates the marginal and the PVF copula parameters. For the marginal distributions, we consider both parametric as well as semiparametric models. We propose a new method to simulate uniform pairs with PVF dependence structure based on conditional sampling for copulas and on numerical approximation to solve a target equation. In a simulation study, small sample properties of the Bayesian estimators are explored. We illustrate the usefulness of the methodology using data on times to appendectomy for adult twins in the Australian NH&MRC Twin registry. Parameters of the marginal distributions and the PVF copula are simultaneously estimated in a parametric as well as a semiparametric approach where the marginal distributions are modelled using Weibull and piecewise exponential distributions, respectively.  相似文献   
67.
The present study investigates the effects of different teaching strategies on student achievement using data from the so-called TALIS-PISA link created by the OECD. This is a recently developed instrument that allows for connecting data about teacher characteristics and practices collected in the TALIS (Teaching and Learning International Survey) survey with students’ academic performance measured in PISA (Programme for International Student Assessment). Our empirical strategy is based on an instrumental variable (IV) approach. Our results suggest that traditional teaching methods have a positive influence on students’ proficiency in mathematics, while the implementation of more innovative active learning strategies seem to have a negative impact on student achievement.  相似文献   
68.
Jose J. Rethinking social work ethics: what is the real question? Responding to Stephen Webb's ‘Against difference and diversity in social work’ Int J Soc Welfare 2010: 19: 246–252 © 2009 The Author(s), Journal compilation © 2009 Blackwell Publishing Ltd and the International Journal of Social Welfare. In his recent article, Stephen Webb argued that the real question for social work ethics concerns ‘recognising the Same and of restoring the principles of equality and social justice’. This argument also included raising questions about what should be considered an appropriate philosophical basis for progressive social work ethics. In his view, social work's emancipatory potential has been blunted by overstated and philosophically ill‐informed human rights claims about difference and diversity. He suggested that French philosopher Alain Badiou offers social workers a ‘set of conceptual devices for rethinking social work ethics’. I argue that pressing his points into Badiou's philosophical mould is unlikely to lead to a progressive social work practice, let alone solve the issues identified by Webb. Badiou's philosophical pronouncements about ethics are of questionable value and offer little or no assistance to social workers seeking to establish an ethical grounding for their professional practice.  相似文献   
69.
This paper reports a study designed to further validate a measure of quality of college life (QCL) of university students (Sirgy, Grzeskowiak, Rahtz, Soc Indic Res 80(2), 343–360, 2007). Two studies were conducted: a replication study and an extension study. The replication study involved surveys of 10 different college campuses in different countries. The results of the replication study provided additional nomological (predictive) validation support of the measure based on a theoretical model mapping out the antecedents and consequences of satisfaction with college life. With respect to the extension study, the focus was to further test the nomological validity of the QCL measure by arguing and empirically demonstrating that the consequence of QCL is life satisfaction. The extension study involved a survey of three college campuses in different countries. The results were also supportive of the nomological validity of the QCL measure.  相似文献   
70.
Pilates method is employed for physical and mental conditioning. Elderly people could be benefited from a patterned and regulated conditioning work based on Pilates method. We performed a systematic review to assess the evidence on the effects of Pilates method in physical fitness on older adults. Our search included the following databases: MEDLINE-PubMed, Scopus and CINAHL Plus with Full Text via EBSCO and SPORTDiscus databases (up to April 2014). A summary of the results was performed using a best evidence synthesis and was reported according to the systematic review method proposed by Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodology quality of selected studies. Seventeen experimental studies were included in this review. Fourteen were randomized controlled trials (RCT) and three clinical controlled trials (CCT). Quality scores according to PEDro indicate low quality of the included studies (range 1–6, mean 3.8?±?1.2). The most studied components related to physical fitness were neuromotor fitness (n?=?11), muscle strength (n?=?8), cardiorespiratory endurance (n?=?4), body composition (n?=?4) and flexibility (n?=?4). Results indicate that Pilates method seems to present positive effects in neuromotor fitness, especially in static and dynamic balance. Related to the other components of physical fitness (cardiorespiratory endurance, muscle strength, body composition and flexibility), contradictory results were observed. The Pilates method indicates to be an appropriate exercise modality in order to improve balance on older adults. Nevertheless, more intervention research is needed to build a solid knowledge base about the health benefits of Pilates method on older people, especially regarding the other components of physical fitness.  相似文献   
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