一类四阶非线性常微分方程的两点边值问题解的存在性与唯一性

本文利用Hammerstein型积分算子和上下解方法,研究了一类四阶非线性常微分方程的两点边值问题     

An upper bound for the distribution function of a positive definite quadratic form

In this paper the researchers are presenting an upper bound for the distribution function of quadratic forms in normal vector with mean zero and positive definite covariance matrix. They also will show that the new upper bound is more precise than the one introduced by Okamoto [4] and the one introduced by Siddiqui [5]. Theoretical Error bounds for both, the new and Okamoto upper bounds are derived in this paper. For larger number of terms in any given positive definite quadratic form, a rough and easier upper bound is suggested.     

费孝通的甘肃实践

费孝通教授为了重建他一生"志在富民"的学科,躬身来到"陇中苦甲天下"的甘肃定西,来到黄河上游,来到丝绸之路民族走廊的"小民族"中间。他在中央实施西部大开发伊始,又及时提出"西部大开发中人文资源的保护、利用和开发"的问题……。他想到,他说到,他身体力行,在实践中,他重建着中国的社会学、人类学学科。     

The historical roots of multicultural unity along the Upper Guinea Coast and in Guinea-Bissau

Lusofonia or lusophony is often defined as an identity shared by people in areas that were once colonised by Portugal, which in Africa include Angola, Cabo Verde, Guinea-Bissau, Mozambique and São Tomé and Príncipe. Lusofonia assumes that in these places people share something – a language, certainly, but also a history and culture rooted in the Iberian Peninsula. In some ways it is a re-articulation of Gilberto Freyre’s lusotropicalismo, the idea that Portuguese were more adaptable than other Europeans to tropical climates and cultures and created more multicultural colonial communities. Those who espouse lusofonia often have a political agenda – the strengthening of the Community of Portuguese-Speaking Countries. In this article, we argue that, like lusotropicalismo, lusofonia is a dream; it is not rooted in a historical reality. It is luso-centric in that it ignores the power and persistence of local cultures and gives undue weight to Portuguese influence. With regard to Africa, lusofonia’s agenda is elite driven and assumes the inevitability of modernity and globalisation. And we demonstrate that it was through Upper Guinean institutions and languages, and not colonial ones, that community and fellowship were most commonly fostered in the past, as they are fostered today. Those seeking the roots of lusofonia cannot, then, look to this period of Portuguese–African engagement in Upper Guinea. There Portuguese embraced “black ways.” They operated in a peculiar multicultural space in which people possessed fluid and flexible identities. Portugal did not create that space. Lusofonia has not been the foundation for cultural unity. Rather, unity has been found in localised institutions and in Crioulo. In Guinea-Bissau, lusofonia is not an indigenous movement. If it is anything, it is the stuff of elites and foreigners and is not rooted in any historical reality.     

An upper bound on the minimal total cost of the transportation problem with varying demands and supplies

In general cases, to find the exact upper bound on the minimal total cost of the transportation problem with varying demands and supplies is an NP-hard problem. In literature, there are only two approaches with several shortcomings to solve the problem. In this paper, the problem is formulated as a bi-level programming model, and proven to be solvable in a polynomial time if the sum of the lower bounds for all the supplies is no less than the sum of the upper bounds for all the demands; and a heuristic algorithm named TPVDS-A based on genetic algorithm is developed as an efficient and robust solution method of the model. Computational experiments on benchmark and new randomly generated instances show that the TPVDS-A algorithm outperforms the two existing approaches.     

Tolerance limits under Poisson regression based on small-sample asymptotic methodology

This article explores the calculation of tolerance limits for the Poisson regression model based on the profile likelihood methodology and small-sample asymptotic corrections to improve the coverage probability performance. The data consist of n counts, where the mean or expected rate depends upon covariates via the log regression function. This article evaluated upper tolerance limits as a function of covariates. The upper tolerance limits are obtained from upper confidence limits of the mean. To compute upper confidence limits the following methodologies were considered: likelihood based asymptotic methods, small-sample asymptotic methods to improve the likelihood based methodology, and the delta method. Two applications are discussed: one application relating to defects in semiconductor wafers due to plasma etching and the other examining the number of surface faults in upper seams of coal mines. All three methodologies are illustrated for the two applications.     

寻找快乐的家园——读王安忆长篇小说《上种红菱下种藕》

小说《上种红菱下种藕》表现了上海附近一个小镇上的特殊风景,这里的生活气息浓郁,且温情怡然,这里的人们质朴而善良,这些都是我们向往的最宝贵的东西。在现代化的进程中,经济的、科学技术的现代化一方面带来了富庶和繁荣,另一方面也刮走了精神中的营养。     

Coherent Frequentism: A Decision Theory Based on Confidence Sets

By representing fair betting odds according to one or more pairs of confidence set estimators, dual parameter distributions called confidence posteriors secure the coherence of actions without any prior distribution. This theory reduces to the maximization of expected utility when the pair of posteriors is induced by an exact or approximate confidence set estimator or when a reduction rule is applied to the pair. Unlike the p-value, the confidence posterior probability of an interval hypothesis is suitable as an estimator of the indicator of hypothesis truth since it converges to 1 if the hypothesis is true or to 0 otherwise.     

Comparison of One-Sided Tolerance Limits in Unbalanced One-Way Random Models

Cox's discrete logistic model was extended to the study of the life table by Thompson (1977) to handle grouped survival data. Inferences about the effect of grouping are studies byMonte Carlo methods. The results show that the effect of grouping is not substantial. This approach is applied to the grouped data on liver cancer. The computer program developed for grouped censored data with continuous and indicator covariates is of practical importance and is available fromThe Ohio State University     

Fast and rigorous: Configurational determinants of strategic decision-making balance

A longstanding debate in the strategic decision-making literature has focused on whether top management teams (TMTs) can effectively balance speed and comprehensiveness when making important decisions. In our research, we build on early insights and pivot from considering whether TMTs can engage indecision-making that balances these tensions to focus instead on when certain types of TMTs are able to achieve such balance. We employ a novel configurational analytical approach and a theoretical framework built from role theory to examine the CEO-TMT interface in a new way. In so doing, we are able to identify specific CEO-TMT constellations that support decision-making that is both fast and rigorous. Using a unique primary dataset and an abductive, configurational approach grounded in fuzzy set qualitative comparative analysis (fsQCA), we identify six specific leader-team configurations that each facilitate decision processes characterized by rigorous intra-team debate, meaningful reconciliation of divergent ideas, and fast decision speed (which we describe as strategic decision-making balance). The range of CEO-TMT configurations that emerge from our analyses contribute new theory and findings for the strategic decision-making and interface literatures more broadly, as well as the specific research streams on executive gender, humility, and TMT structure.