On bootstrapping periodic random arrays with increasing period

The aim of the paper is to determine when the periodic block bootstrap, procedure introduced by Chan et al. (Technometrics 46(2):215–224, 2004), can be applied to arrays of random variables. Formal consistency is obtained under α-mixing or m-dependence conditions together with the assumption that the length of the period tends to infinity. On the other hand, if the period is constant, inconsistency is shown. The performance of periodic block bootstrap is also compared in simulations with moving block bootstrap. It is suggested that for the case of long-period data the first method is more effective and much more stable with respect to the length of the block size.     

基于CPLD的正交磁通门传感器设计

简述了磁通门传感器技术中二次谐波法的原理,用软磁材料坡莫合金制作传感器探头磁芯,设计了基于CPLD的正交磁通门传感器。传感器能够实现水平载体的航向角数值,在0°³60°范围内航向角的测量精度可达1°,系统分辨率可达0.1°,可以满足水平定向导航的性能要求。     

浮选柱浮选金矿矿泥半工业试验研究

本文介绍了某金矿应用浮选柱浮选矿泥所进行的半工业试验过程及结果分析。通过试验及数据分析,表明了浮选柱适合该金矿浮选矿泥,并能够取得比较好的技术指标。     

Geodesic normal distribution on the circle

This paper is concerned with the study of a circular random distribution called geodesic normal distribution recently proposed for general manifolds. This distribution, parameterized by two real numbers associated to some specific location and dispersion concepts, looks like a standard Gaussian on the real line except that the support of this variable is [0, 2π) and that the Euclidean distance is replaced by the geodesic distance on the circle. Some properties are studied and comparisons with the von Mises distribution in terms of intrinsic and extrinsic means and variances are provided. Finally, the problem of estimating the parameters through the maximum likelihood method is investigated and illustrated with some simulations.     

A Case Study of Technological Switching and Technological Lock‐In in the French Fisheries Sector: Why is Sustainable Change so Difficult?

Many sectors such as the fishery show classic examples of technological lock‐in and path dependence, even though some economists might predict smooth switching toward technologies that are more cost effective and sustainable. We use ideas from the evolutionary economics and public choice literatures to explain why trajectories of technological change, especially in fisheries, may not be smooth at all, but rather punctuated. The interest of technological change and switching behavior for fisheries economists and managers stems from the fact that control of effective effort, often necessary for sustainable management of the resource, remains a central management problem for that sector worldwide, even in developed countries. However, various policies put in place by governments to support the fishing sector, and often put in place to “correct” for certain market failures, may inadvertently produce other “nonmarket” failures, which result in technological lock‐ins which are unsustainable. For example, the trawling technique was widely promoted in France in the 1970s and 1980s. Path dependency developed in such a way that the preferred choice of new entrants into the fishery was this technology. Technological lock‐in occurred on the trawling technique as the trawling sector also became more politically active, making it ultimately the most widely used technique in the French fisheries sector in the Atlantic. Switching away from this technology has not taken place even with poorer economic performance of that technology. This paper also discusses the influence of state subsidies on the adoption of trawling. Even if trawling was a major innovation in fisheries in the past, its potential for technological adaptations or minor innovations is limited now. These limitations are more obvious during periods of increasing energy prices, especially in the absence of state aid. However, due to collective choice phenomena, switches to more sustainable technologies will occur more slowly. Plusieurs secteurs, tel que celui des pêcheries, offrent des exemples de verrouillage technologique et de dépendances au sentier, alors même que les économistes s’attendent à un changement régulier vers une technologie plus efficace en termes de coûts et plus soutenable. Nous nous appuyons sur la littérature évolutionniste et des choix publics afin d’expliquer pourquoi les trajectoires du changement technologique, en particulier dans les pêcheries, peuvent ne pas être régulières, mais au contraire discontinues. L’intérêt des économistes et des gestionnaires pour le changement technologique et le comportement face au retour des techniques est lié au contrôle de l’effort réel, souvent nécessaire pour une gestion durable de la ressource. Le contrôle de l’effort reste le problème essentiel de la gestion des pêches à l’échelle mondiale, y compris dans les pays développés. Toutefois, de nombreuses mesures publiques mises en place par les gouvernements pour soutenir le secteur des pêcheries, afin de «contrecarrer» certaines défaillances du marché, peuvent déboucher involontairement sur d’autres défaillances «non marchandes», se traduisant par des verrouillages technologiques non‐soutenables. Par exemple, la technique du chalutage fut largement diffusé en France dans les années soixante‐dix et quatre‐vingt. Un sentier de dépendance s’est développé tel que les nouveaux entrants dans la pêcherie optaient pour cette technologie. Un verrouillage technologique s’est produit sur la technique du chalutage rendant ce secteur politiquement important, et finalement la technique la plus répandue parmi les pêcheries françaises de l’Atlantique. Un changement de technologie n’a donc pu survenir, même en présence de faibles performances économiques. L’article traite de l’influence des subventions étatiques liées à l’adoption du chalutage. Même si cette technologie fut une innovation majeure dans les pêcheries par le passé, les adaptations techniques potentielles ou les innovations mineures sont désormais limitées. Ces limites apparaissent clairement dans les périodes de coûts énergétiques croissants, notamment en l’absence d’aides étatiques. Toutefois, en raison du phénomène de comportements collectifs, les changements vers des technologies plus soutenables se déroulent avec lenteur.     

R&D Spillovers through Student Flows,Institutions, and Economic Growth: What can we Learn from African Countries?

Using modern panel cointegration estimation techniques, this paper examines whether tertiary student flows can effectively transmit technological knowledge from industrialized countries to African countries. The results obtained lend strong support to this hypothesis. In addition, this paper extends the analysis to include institutional variables such as the ease of doing business, legal origins, and religious majority to see if institutional characteristics have any impact on the way knowledge diffusion affecting total factor productivity (TFP). However, it is not clear that institutional differences are important factors that influence the degree of R&D spillovers and, hence, the TFP of African countries.     

Women’s Voice——A Deconstructive Interpretation of Gender in Absalom Absalom!

Absalom, Absalom! Faulkner＇ s eighth novel, published in 1936, is generally recognized as one of the greatest American novels ever written. Its center is the rise and fall of Thomas Sutpen, the ＂ruthless patriarch of a great southern family＂ （Byerman 129）, who aims to find wealth, then builds up a plantation and marries a daughter from a respectable family in Jefferson town in Yoknapatawpha County, Mississippi. All through his life,     

III. Weltwirtschaft und wirtschaft einzlner länderund und gebiete

Ohne Zusammenfassung     

Are family firms really superior performers?

Although international evidence suggests that families may be unhelpful to firm performance, recent analyses of U.S. public companies indicate that family firms outperform. This study probes these contrasting findings by investigating more fine-grained measures of family business in the U.S. Specifically, it makes a fundamental but neglected distinction between lone founder businesses in which no relatives of a founder are involved, and true family businesses that do include multiple family members as major owners or managers. The research also seeks to overcome issues of endogeneity and selection bias by examining both Fortune 1000 firms and a random sample of 100 much smaller public companies. The results show that findings are indeed highly sensitive both to the way in which family businesses are defined and to the nature of the sample. Fortune 1000 firms that include relatives as owners or managers never outperform in market valuation, even during the first generation. Only businesses with a lone founder outperform. Moreover neither lone founder nor family firms exhibited superior valuations within a randomly drawn sample of companies. Our results confirm the difficulty of attributing superior performance to a particular governance variable.     

东西经济走廊——机遇之门

建立东西经济走廊（EWEC），是越南在1998年12月于菲律宾马尼拉举行的东盟高级首脑会议中倡议的，属于河内行动计划的一个部分。东西经济走廊（EWEC）全长1450公里，跨越了越南、老挝、泰国和缅甸四个国家，连接了太平洋与印度洋。它始于越南岘港，并一直延伸到缅甸的毛淡棉港。在东南亚地区大湄公河次区域（GMS）中，东西经济走廊有着最优先发展的权利。