Monique Noirhomme‐Fraiture  Paula Brito 《Statistical Analysis and Data Mining》2011,4(2):157-170

This paper introduces symbolic data analysis, explaining how it extends the classical data models to take into account more complete and complex information. Several examples motivate the approach, before the modeling of variables assuming new types of realizations are formally presented. Some methods for the (multivariate) analysis of symbolic data are presented and discussed. This is however far from being exhaustive, given the present dynamic development of this new field of research. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 157–170, 2011  相似文献   

    

A. Douzal‐Chouakria  L. Billard  E. Diday 《Statistical Analysis and Data Mining》2011,4(2):229-246

One feature of contemporary datasets is that instead of the single point value in the p‐dimensional space ℜ^p seen in classical data, the data may take interval values thus producing hypercubes in ℜ^p. This paper studies the vertices principal components methodology for interval‐valued data; and provides enhancements to allow for so‐called ‘trivial’ intervals, and generalized weight functions. It also introduces the concept of vertex contributions to the underlying principal components, a concept not possible for classical data, but one which provides a visualization method that further aids in the interpretation of the methodology. The method is illustrated in a dataset using measurements of facial characteristics obtained from a study of face recognition patterns for surveillance purposes. A comparison with analyses in which classical surrogates replace the intervals, shows how the symbolic analysis gives more informative conclusions. A second example illustrates how the method can be applied even when the number of parameters exceeds the number of observations, as well as how uncertainty data can be accommodated. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 229–246 2011  相似文献   

    

Simona Korenjak‐erne  Vladimir Batagelj  Barbara Japelj Pave&#x;i&#x; 《Statistical Analysis and Data Mining》2011,4(2):199-215

  相似文献   

    

Judith Anzures‐Cabrera  Julian P. T. Higgins 《Research Synthesis Methods》2010,1(1):66-80

Meta‐analyses are fundamental tools for collating and synthesizing large amounts of information, and graphical displays have become the principal tool for presenting the results of multiple studies of the same research question. We review standard and proposed graphical displays for presentation of meta‐analytic data, and offer our recommendations on how they might be presented to provide the most useful and user‐friendly illustrations. We concentrate on graphs that specifically aim to present similar sorts of univariate results from multiple studies. We start with forest plots and funnel plots, and proceed to Galbraith (or radial) plots, L'Abbé (and related) plots, further plots useful for investigating heterogeneity, plots useful for model diagnostics and plots for illustrating likelihoods and Bayesian meta‐analyses. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

    

Ruggero G. Pensa  Jean‐Francois Boulicaut  Francesca Cordero  Maurizio Atzori 《Statistical Analysis and Data Mining》2010,3(1):38-55

In the generic setting of objects × attributes matrix data analysis, co‐clustering appears as an interesting unsupervised data mining method. A co‐clustering task provides a bi‐partition made of co‐clusters: each co‐cluster is a group of objects associated to a group of attributes and these associations can support expert interpretations. Many constrained clustering algorithms have been proposed to exploit the domain knowledge and to improve partition relevancy in the mono‐dimensional clustering case (e.g. using the must‐link and cannot‐link constraints on one of the two dimensions). Here, we consider constrained co‐clustering not only for extended must‐link and cannot‐link constraints (i.e. both objects and attributes can be involved), but also for interval constraints that enforce properties of co‐clusters when considering ordered domains. We describe an iterative co‐clustering algorithm which exploits user‐defined constraints while minimizing a given objective function. Thanks to a generic setting, we emphasize that different objective functions can be used. The added value of our approach is demonstrated on both synthetic and real data. Among others, several experiments illustrate the practical impact of this original co‐clustering setting in the context of gene expression data analysis, and in an original application to a protein motif discovery problem. Copyright © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 38‐55, 2010  相似文献   

    

Tung‐Ching Lin  Hsing Kenneth Cheng  Feng‐Sheng Wang  Kuei‐Jung Chang 《决策科学》2012,43(2):241-272

The study of consumers’ switching from one service provider to another has a long tradition in economics, information systems, and marketing. The emergence of electronic commerce presents new challenges in understanding consumers’ switching intentions in the context of e‐commerce in general and online auctions in particular. With the abundance of literature on online auctions, there is a surprising lack of research on auction sellers’ intentions to switch from one online auction platform to another. Using the competition between Yahoo!Kimo and Ruten_eBay, two leading auction platforms in Taiwan, as the backdrop, we developed a research model and collected empirical data based on this real case to study what factors influence auction sellers to switch to a competing service provider. We find that the higher the procedural switching costs, financial switching costs, relational switching costs, site design quality, or interaction quality, the lower the intention of an auction seller to switch to a competing auction service provider. A higher perceived transaction fee, however, leads to a higher switching intention.  相似文献   

    

Gene M. Grossman  Esteban Rossi‐Hansberg 《Econometrica : journal of the Econometric Society》2012,80(2):593-629

We propose a theory of task trade between countries that have similar relative factor endowments and technological capabilities, but may differ in size. Firms produce differentiated goods by performing a continuum of tasks, each of which generates local spillovers. Tasks can be performed at home or abroad, but offshoring entails costs that vary by task. In equilibrium, the tasks with the highest offshoring costs may not be traded. Among the remainder, those with the relatively higher offshoring costs are performed in the country that has the higher wage and the higher aggregate output. We discuss the relationship between equilibrium wages, equilibrium outputs, and relative country size.  相似文献   

    

Julio Dvila  Jay H. Hong  Per Krusell  Jos‐Víctor Ríos‐Rull 《Econometrica : journal of the Econometric Society》2012,80(6):2431-2467

We investigate the welfare properties of the one‐sector neoclassical growth model with uninsurable idiosyncratic shocks. We focus on the notion of constrained efficiency used in the general equilibrium literature. Our characterization of constrained efficiency uses the first‐order condition of a constrained planner's problem. This condition highlights the margins of relevance for whether capital is too high or too low: the factor composition of income of the (consumption‐)poor. Using three calibrations commonly considered in the literature, we illustrate that there can be either over‐ or underaccumulation of capital in steady state and that the constrained optimum may or may not be consistent with a nondegenerate long‐run distribution of wealth. For the calibration that roughly matches the income and wealth distribution, the constrained inefficiency of the market outcome is rather striking: it has much too low a steady‐state capital stock.  相似文献   

    

Daron Acemoglu  Vasco M. Carvalho  Asuman Ozdaglar  Alireza Tahbaz‐Salehi 《Econometrica : journal of the Econometric Society》2012,80(5):1977-2016

This paper argues that, in the presence of intersectoral input–output linkages, microeconomic idiosyncratic shocks may lead to aggregate fluctuations. We show that, as the economy becomes more disaggregated, the rate at which aggregate volatility decays is determined by the structure of the network capturing such linkages. Our main results provide a characterization of this relationship in terms of the importance of different sectors as suppliers to their immediate customers, as well as their role as indirect suppliers to chains of downstream sectors. Such higher‐order interconnections capture the possibility of “cascade effects” whereby productivity shocks to a sector propagate not only to its immediate downstream customers, but also to the rest of the economy. Our results highlight that sizable aggregate volatility is obtained from sectoral idiosyncratic shocks only if there exists significant asymmetry in the roles that sectors play as suppliers to others, and that the “sparseness” of the input–output matrix is unrelated to the nature of aggregate fluctuations.  相似文献   

    

Ulf von Lilienfeld‐Toal  Dilip Mookherjee  Sujata Visaria 《Econometrica : journal of the Econometric Society》2012,80(2):497-558

It is generally presumed that stronger legal enforcement of lender rights increases credit access for all borrowers because it expands the set of incentive compatible loan contracts. This result relies on an assumption that the supply of credit is infinitely elastic. In contrast, with inelastic supply, stronger enforcement generates general equilibrium effects that may reduce credit access for small borrowers and expand it for wealthy borrowers. In a firm‐level panel, we find evidence that an Indian judicial reform that increased banks' ability to recover nonperforming loans had such an adverse distributive impact.  相似文献