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191.
The decennial United States Census of Population determines not only political representation, but also how more than $185 billion of federal funds are allocated. Hence, there is intense interest in who responds, or does not respond, to Census queries. Both the popular media and the Bureau of the Census officials have developed a set of informal hypotheses which speak to who responds. Nine such hypotheses are identified and tested. For example, it is alleged that the elderly do not respond to the Census as often as others. Also, it is asserted that Republican politicians and talk show hosts diminished 2000 Census participation. No evidence is found to support these propositions. Empirical support is found for the media/Census view of the world in only two of nine cases and partial support in one. In two cases, the evidence neither supports nor rejects the hypotheses. In two cases, the evidence partially rejects the hypothesis, and in two cases, more strongly rejects the hypotheses. The results are sufficiently strong that they should inspire increased caution in media reporting and in the statements of Bureau of the Census officials.  相似文献   
192.
In this paper, sequential procedures for the surveillance of the covariance matrices of multivariate nonlinear time series are introduced. Two different types of control charts are proposed. The first type is based on the exponential smoothing of each component of a local measure for the covariances. The control statistic is equal to the Mahalanobis distance of this quantity with its in-control mean. In our second approach, the Mahalanobis distance is first determined and after that it is exponentially smoothed. We discuss three examples of local measures.

Several properties of the proposed schemes are discussed assuming the target process to be generated by a multivariate GARCH(1, 1) model. The generalization to the family of spherical distributions allows the modelling of frequently observed fat tails in financial data. Some results of an extensive Monte Carlo simulation study are provided in order to judge the performance of the presented control schemes. As a performance measure we use the average run length. An empirical example illustrates the importance of the fast detection of the changes in the covariance structure of the returns of financial assets.  相似文献   
193.
Canonical form plays a similar role in linear models to spectral decomposition in matrix analysis. Let X = (X 1,…, X n )′ be a random vector with expectation Aβ and the variance–covariance matrix σV, where V is positive definite and let rank(A) = r. Then there exists a nonsingular linear transformation from X to T = (T 1,…, T n )′, such that ET i  = η i , for i = 1,…, r and zero for i > r, while cov(T i , T j ) = δ ij σ. This canonical form, introduced by Ko?odziejczyk (1935 Ko?odziejczyk , S. ( 1935 ). On an important class of statistical hypotheses . Biometrika 27 : 161190 .[Crossref] [Google Scholar]), was used, among others, by Scheffé (1959 Scheffé , H. ( 1959 ). Analysis of Variance . New York : Wiley . [Google Scholar]) and by Lehmann (1959, 1986 Lehmann , E. L. (1959, 1986 ). Testing Statistical Hypotheses . New York : Wiley . [Google Scholar]). This technique is extended here for arbitrary (possibly singular) V and for simultaneous canonization of two models of this type.  相似文献   
194.
Using Zieliński's (1977 Zieliński , R. ( 1977 ). Robustness: a quantitative approach . Bull. Acad. Polon. Sci., Ser. Sci. Math. Astronom. Phys. 25 : 12811286 . [Google Scholar]) concept of robustness, B?a?ej (2007 B?a?ej , P. ( 2007 ). Robust estimation of the scale and weighted distributions . Appl. Math. (Warsaw) 34 : 3945 . [Google Scholar]) obtained the uniformly most bias-robust estimates (UMBREs) of the scale parameter for some statistical models, in a class of linear functions of order statistics. Violations of the models are generated by weight functions. In this article the UMBRE of the scale parameter, based on order statistics, a more general weighted model is derived. Extension of a result of B?a?ej (2007 B?a?ej , P. ( 2007 ). Robust estimation of the scale and weighted distributions . Appl. Math. (Warsaw) 34 : 3945 . [Google Scholar]) is given.  相似文献   
195.
In experiments in which the response to a treatment can be affected by other treatments, the interference model with neighbor effects is usually used. It is known that circular neighbor balanced designs (CNBDs) are universally optimal under such a model if the neighbor effects are fixed (Druilhet, 1999) or random (4 and 7). However, such designs cannot exist for every combination of design parameters. In the class of block designs with the same number of treatments as experimental units per block, a CNBD cannot exist if the number of blocks, b  , is equal to p(t−1)±1p(t1)±1, where p is a positive integer and t is the number of treatments. Filipiak et al. (2008) gave the structure of the left-neighboring matrix of E-optimal complete block designs with p  =1 under the model with fixed neighbor effects. The purpose of this paper is to generalize E-optimality results for designs with p∈NpN assuming random neighbor effects.  相似文献   
196.
Most research on the structural foundations of cultural consumption views tastes and practices as a better or worse emanation of social class or status. In contrast, this paper shows that cultural consumption is also embedded in a larger system of social networks. Not only does it examine whether having more diversified personal network translates into being involved in a wider range of cultural activities (omnivorousness), it also tests whether holding networks of different strength corresponds with different levels of cultural engagement (strong vs. weak). Based on the survey data collected in Poland in 2017, the analyses yield three main findings. First, cultural consumption continues to reflect social class divisions and is a potential mechanism for social exclusion. Second, network diversity is associated with cultural variety independently of class position. Third, the number of weak ties people hold is more strongly associated with the number of “weak” practices (that is practices of less frequency) and the number of strong ties is positively associated with the number of strong practices (voraciousness). These findings are discussed in terms of balance theory, interactional foci and weak versus strong culture. The implications of the article are that omnivorism both signifies class boundaries and indicates participation in different network structures.  相似文献   
197.
In migration research, the voice is usually given to those who move, but in this article, those who stay are at the centre of attention. The study aims to present the stayers’ practices of everyday life in transnational families in an attempt to highlight the experience of staying and understand the stayers’ role in the migration project. The study is based on semi-structured life story interviews conducted in 2020 with people who in the 1980s stayed in the northeastern part of Poland when their relatives migrated internationally. In the almost four-decade perspective, staying appears as a powerful condition and an active process, closely interrelated with migration. Also, the migration project does not appear dependent so much on the range and availability of communication technologies – limited in the 1980s – but on transnational families’ engagement in that project and desire to accomplish it.  相似文献   
198.
Public Organization Review - Sustainable development is usually investigated from a global or national rather than a regional or local perspective. However, it is local communes that decide on the...  相似文献   
199.
Journal of Combinatorial Optimization - We consider a number of parallel-machine scheduling problems in which jobs have variable processing times. The actual processing time of each job is...  相似文献   
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