舵减横摇研究综述

舵减横摇系统是当今世界新发展起来的一种减摇系统,它具有结构简单,成本低廉,应用广泛等优点。本文就舵减横摇系统的可行性、数学模型和控制方法以及国内外研究和应用前景作了综合介绍和评价。     

An optimum t-test for the scale parameter of an extreme-value distribution

A Student's t-test proposed by Ogawa is considered for the hypothesis Ho: σ=σo against the alternative hypothesis H₁: σ ≠ σo, where σ is the scale parameter of the Extremevalue distribution of smallest values with known location parameter μ. The test is based on a few sample quantiles chosen from a large sample so as to give asymptotically maximum power to the test when the number of sample quantiles is fixed. A table which facilitates the computation of the test statistic is given. Several schemes for determining the ranks of the sample quantiles by the optimal spacings are compared and the effect of the bias of the estimate of σ on the test is investigated through a Monte Carlo study.     

Optimal sample size allocation for tests with multiple levels of stress with extreme value regression

In this article, we discuss the optimal allocation problem in a multiple stress levels life‐testing experiment when an extreme value regression model is used for statistical analysis. We derive the maximum likelihood estimators, the Fisher information, and the asymptotic variance–covariance matrix of the maximum likelihood estimators. Three optimality criteria are defined and the optimal allocation of units for two‐ and k‐stress level situations are determined. We demonstrate the efficiency of the optimal allocation of units in a multiple stress levels life‐testing experiment by using real experimental situations discussed earlier by McCool and Nelson and Meeker. Monte Carlo simulations are used to show that the optimality results hold for small sample sizes as well. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

基于设备贡献度的实时效能评估方法

为了实现对在线运行设备效能的实时评估,在深入研究线性和非线性指标聚合方法基础上,提出了一种基于设备效能贡献度的在线设备实时效能评估方法,给出了指标评定、权重计算和指标聚合方法.仿真结果表明,该方法克服了传统方法效能评估结果无法准确反映系统运行情况和设备故障情况的缺点,实现了对在线设备运行状态的快速、科学评估.     

AN ENDOGENOUS GROWTH MODEL OF CAPITAL AND ARMS ACCUMULATION

This paper attempts to examine the effect of an anticipated foreign military threat on the steady‐state growth rate and the transitional behavior of the economy. The modeling strategy follows the Sandler and Hartley (1995 Sandler, T. and Hartley, K. 1995. The Economics of Defense, Cambridge: Cambridge University Press.  [Google Scholar]) and Dunne et al. (2005 Dunne, J.P., Smith, R.P. and Willenbockel, D. 2005. Models of military expenditure and growth: a critical review. Defence and Peace Economics, 16: 449–461. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) viewpoints to emphasize the role of national defense in affecting growth from the perspective of both the demand and the supply sides. We thus combine the public capital version of endogenous growth with a framework of competitive arms accumulation. It is found that the key factor determining the steady state and the transitional effects of a rise in the foreign military threat on the home weapon–capital ratio, the consumption–capital ratio, and the rate of economic growth, is the degree of relative risk aversion.     

TERRORIST THREATS AND TRANSITIONAL DYNAMICS IN AN OVERLAPPING GENERATIONS MODEL

Previous research has shown that the duration of a civil war is in part a function of how it ends: in government victory, rebel victory, or negotiated settlement. We present a model of how protagonists in a civil war choose to stop fighting. Hypotheses derived from this theory relate the duration of a civil war to its outcome as well as characteristics of the civil war and the civil war nation. Findings from a competing risk model reveal that the effects of predictors on duration vary according to whether the conflict ended in government victory, rebel victory, or negotiated settlement.     

Endogenous Growth and Defense Expenditures: A New Explanation of the Benoit Hypothesis

This paper develops an endogenous growth model to examine the linkage between military expenditures and economic growth. We adopt the modeling strategy where both the supply side and the demand side effects of national defense are taken into considerations. Our result finds that a rise in military spending tends to stimulate the sustained growth rate, confirming Benoit's famous empirical findings.     

Optimum quantiles for the linear estimation of the parameters of the extreme value distribution in complete and censored samples

The present study is concerned with the determination of a few observations from a sufficiently large complete or censored sample from the extreme value distribution with location and scale parameters μ and σ, respectively, such that the asymptotically best linear unbiased estimators (ABLUE) of the parameters in Ref. [24] yield high efficiencies among other choices of the same number of observations. (All efficiencies considered are relative to the Cramér-Rao lower bounds for regular unbiased estimators.) The study is on the asymptotic theory and under Type II censoring scheme. For the estimation of μ when σ is known, it has been proved that there exists a unique optimum spacing whether the sample is complete, right censored, left censored, or doubly censored. Several tables are prepared to aid in the numerical computation of the estimates as well as to furnish their efficiencies. For the estimation of σ when μ is known, it has been observed that there does not exist a unique optimum spacing. Accordingly we have obtained a spacing based on a complete sample which yields high efficiency. A similar table as above is prepared. When both μ and σ are unknown, we have considered four different spacings based on a complete sample and chosen the one yielding highest efficiency. A table of the efficiencies is also prepared. Finally we apply the above results for the estimation of the scale and/or shape parameters of the Weibull distribution.     

小型旅馆消防安全现状及管理对策探讨

近年来,各地小型旅馆发展迅速,但由于其小而散使消防安全监管难度增大,从业人员消防安全意识淡薄,自身消防安全隐患较多,极易发生群死群伤火灾事故.介绍了小型旅馆的特点,分析了小型旅馆存在的消防安全隐患及消防监督管理工作存在的问题,探讨了加强小型旅馆消防安全管理的措施.