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171.
172.
Blas Pelegrín Pascual FernándezMaría Dolores García Pérez Saúl Cano Hernández 《Omega》2012,40(2):149-158
We study the problem of locating new facilities for one expanding chain which competes for demand in spatially separated markets where all competing chains use delivered pricing. A new network location model is formulated for profit maximization of the expanding chain assuming that equilibrium prices are set in each market. The cannibalization effect caused by the entrance of the new facilities is integrated in the objective function as a cost to be paid by the expanding chain to the cannibalized facilities. It is shown that the profit of the chain is maximized by locating the new facilities in a set of points which are nodes or iso-marginal delivered cost points (points on the network from which the marginal delivered cost equals the minimum marginal delivered cost from the existing facilities owned by the expanding chain). Then the location problem is reduced to a discrete optimization problem which is formulated as a mixed integer linear program. A sensitivity analysis respect to both the number of new facilities and the cannibalization cost is shown by using an illustrative example with data of the region of Murcia (Spain). Some conclusions are presented. 相似文献
173.
Raphaël Mathieu Legault‐Laberge Mathilde Vanasse‐Pelletier 《Revue canadienne de sociologie》2021,58(1):65-85
This research explores the representations of two minority religions in United States, the Amish and the fundamentalist Mormons (FLDS), in two reality shows produced in 2013: Breaking Amish and Breaking the Faith. To which extent these reality shows contribute to reinforce stereotypes about these minority religions? The hypothesis postulates that there is a convergence in the representations of minority religions in these reality shows which contributes to the reproduction of stereotypes. Based on theories of identity construction and on the study of new religious movements, the analysis shows that the same guiding lines are recurrent in both reality shows. 相似文献
174.
Early acquisition of stereotypes that associate “blue” with boys and “pink” with girls can influence their preferences for these colors and also their choices in clothing, toys or objects in relation to gender stereotypes. In a Spanish sample (5–10-year olds, n = 614), this study reproduces the previous research conducted by Karniol (Sex Roles 65(1/2):119–132, 2011) for the purpose of analyzing whether gender-linked color preferences rule the choice of coloring booklets and if children’s choices of color are affected by their own gender. The results show that although boys used fewer female-stereotyped colors than girls, both genders colored in each figure with the stereotyped colors associated with them. This result indicates that boys and girls share similar gender stereotypes and use colors that agree with these stereotypes. 相似文献
175.
将邻域相关性的冗余第二代小波应用于滚动轴承信号降噪,用Hilhert包络解调法提取的故障特征频率,比较不
同转速和载荷下的提取效果,提出包络幅值峭度指标,并将其输入BP神经网络进行故障诊断。结果表明:基于邻域相关
性的冗余第二代小波降噪方法能很好的抑制噪声,保留原信号的信息;降噪后的故障信号经过Hilbert包络解调能找到
特征频率及其倍频,其效果优于原始信号的包络解调分析。工况会影响分析效果,且速度对提取效果的影响大于载荷。
包络幅值峭度指标能很好区分不同工况的故障信号,结合BP人工神经网络诊断正确率为100%。 相似文献
176.
Jean Cardinal Samuel Fiorini Gwenaël Joret 《Journal of Combinatorial Optimization》2008,16(4):361-377
We study an information-theoretic variant of the graph coloring problem in which the objective function to minimize is the
entropy of the coloring. The minimum entropy of a coloring is called the chromatic entropy and was shown by Alon and Orlitsky
(IEEE Trans. Inform. Theory 42(5):1329–1339, 1996) to play a fundamental role in the problem of coding with side information. In this paper, we consider the minimum entropy
coloring problem from a computational point of view. We first prove that this problem is NP-hard on interval graphs. We then
show that, for every constant ε>0, it is NP-hard to find a coloring whose entropy is within (1−ε)log n of the chromatic entropy, where n is the number of vertices of the graph. A simple polynomial case is also identified. It is known that graph entropy is a
lower bound for the chromatic entropy. We prove that this bound can be arbitrarily bad, even for chordal graphs. Finally,
we consider the minimum number of colors required to achieve minimum entropy and prove a Brooks-type theorem.
S. Fiorini acknowledges the support from the Fonds National de la Recherche Scientifique and GERAD-HEC Montréal.
G. Joret is a F.R.S.-FNRS Research Fellow. 相似文献
177.
178.
Raúl Fierro 《统计学通讯:理论与方法》2013,42(1):46-54
This work deals with hypothesis testing for some population models based on counting processes. An asymptotic hypothesis testing to find out certain homogeneity conditions about the parameters of these models is carried out. Some local alternatives are considered and these results are applied to prove homogeneity of the resistance level of susceptible individuals in a population which is subdivided into sub populations and is being attacked by an infectious disease. 相似文献
179.
Marc Tremblay Maude Letendre Louis Houde Hélène Vézina 《Revue europeenne de demographie》2009,25(2):215-233
European settlement in Quebec (Canada) began in the early 17th century, with the arrival of French pioneers. After the British
Conquest in 1760, immigrants from the British Isles began to settle in some parts of Quebec. Many of these immigrants were
Irish Catholics. Historians and genealogists have identified several names of Irish origin in the French Canadian population,
and many scholars have wondered about the importance of the integration of Irish migrants and their descendants within this
population. The purposes of this study are to identify and characterize the founders of Irish origin to estimate the importance
of their genetic contribution to the contemporary Quebec population, and to measure the variability of this contribution according
to the founders’ period of arrival and county of origin in Ireland. Data was obtained from a set of 2,223 ascending genealogies
going back as far as the early 17th century. The average genealogical depth is a little more than 9 generations, with many
branches reaching 16 or 17 generations. Although Irish founders explain less than 1% of the total Quebec gene pool, results
show that nearly 21% of the genealogies contain at least one Irish founder. These founders contributed to the peopling of
all regions of Quebec, but there are some important variations from one region to another. A majority of the Irish founders
immigrated during the 19th century, and most of them came from the counties of Southern Ireland. 相似文献
180.
Various nonparametric and parametric estimators of extremal dependence have been proposed in the literature. Nonparametric methods commonly suffer from the curse of dimensionality and have been mostly implemented in extreme-value studies up to three dimensions, whereas parametric models can tackle higher-dimensional settings. In this paper, we assess, through a vast and systematic simulation study, the performance of classical and recently proposed estimators in multivariate settings. In particular, we first investigate the performance of nonparametric methods and then compare them with classical parametric approaches under symmetric and asymmetric dependence structures within the commonly used logistic family. We also explore two different ways to make nonparametric estimators satisfy the necessary dependence function shape constraints, finding a general improvement in estimator performance either (i) by substituting the estimator with its greatest convex minorant, developing a computational tool to implement this method for dimensions \(D\ge 2\) or (ii) by projecting the estimator onto a subspace of dependence functions satisfying such constraints and taking advantage of Bernstein–Bézier polynomials. Implementing the convex minorant method leads to better estimator performance as the dimensionality increases. 相似文献