公安现役院校教学质量监控体系的建立与实践

教学质量是高等学校的生命线,是影响人才培养质量的最直接因素。依据本院在教学质量监控方面的探索与实践,提出建立一套适合公安现役院校特点的教学质量监控体系,用来指导和评价教学工作,加强教学管理,不断提高教学质量。     

新疆乡镇群众体育多元化服务体系的构建研究

本文通过对新疆乡镇群众体育服务体系的发展状况入手,分析新时期建立新疆乡镇群众体育多元化服务体系的意义.对如何构建新疆乡镇群众体育多元化服务体系的思路和框架进行探讨,以期望更好地为新疆的群众体育服务提供借鉴。     

Hilbert谱分析和平稳度

提出了本征模式函数IMF成员相应的幅度及频率时间函数的计算方法。由函数的Hilbert谱可获得相关的边缘谱,边缘谱确定了几乎连续的能量分布,从而提供了通过每个频率值测量总能量的方法。根据能量-频率-时间分布,就可以定量确定平稳性,平稳性是物理过程的一个复杂属性,其由平稳度DS和统计平稳度DSS进行度量,同时给出了DS和DSS的计算公式。     

基于半实物仿真的HLA／RTI关键技术研究

分析了基于HLA/RTI的半实物仿真中实践管理、数据收集能力、RTI通用性以及网络传输安全等问题,研究了新的时间管理策略,提出了合理设置lookahead的算法,设计了数据收集的层次框架,并制定了研发RTI的通用原则和安全有效的网络传输方案,为现代半实物系统仿真提供了理论借鉴。     

电子时间引信解除保险距离试验研究

通过测量弹丸炮口速度和引信解除保险时间的方法得出电子时间引信远解距离。在介绍某型电子时间引信实现远距离解除保险的方法和机构工作过程的同时,对远解距离进行理论分析,并对试验引信改装的实现方法作了详细说明。在此基础上,进行了电子时间引信解除保险距离测试试验并对试验结果作了分析。     

Dynamic lot‐sizing model with production time windows

We consider a dynamic lot‐sizing model with production time windows where each of n demands has earliest and latest production due dates and it must be satisfied during the given time window. For the case of nonspeculative cost structure, an O(nlogn) time procedure is developed and it is shown to run in O(n) when demands come in the order of latest production due dates. When the cost structure is somewhat general fixed plus linear that allows speculative motive, an optimal procedure with O(T⁴) is proposed where T is the length of a planning horizon. Finally, for the most general concave production cost structure, an optimal procedure with O(T⁵) is designed. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Exact expected values of variance estimators for simulation

We formulate exact expressions for the expected values of selected estimators of the variance parameter (that is, the sum of covariances at all lags) of a steady‐state simulation output process. Given in terms of the autocovariance function of the process, these expressions are derived for variance estimators based on the simulation analysis methods of nonoverlapping batch means, overlapping batch means, and standardized time series. Comparing estimator performance in a first‐order autoregressive process and the M/M/1 queue‐waiting‐time process, we find that certain standardized time series estimators outperform their competitors as the sample size becomes large. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

On valuing appreciating human assets in services

This paper derives optimal policies for when to hire, train, and lay off employees in service organizations when worker productivity appreciates deterministically or stochastically under constant, monotonic, and cyclic service demand. The model, an extension of the machine replacement problem from the engineering economy literature, uses infinite horizon linear programming to produce optimal personnel planning strategies and dual prices that characterize the workforce's economic value. The effect of employee attrition is also considered. In its valuation of human assets, unlike pure accounting approaches that only try to measure, this paper proposes an approach to capture the interaction between firm decisions pertaining to human resources and human resource value. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

On the effectiveness of top‐down strategy for forecasting autoregressive demands

We investigate the relative effectiveness of top‐down versus bottom‐up strategies for forecasting the demand of an item that belongs to a product family. The demand for each item in the family is assumed to follow a first‐order univariate autoregressive process. Under the top‐down strategy, the aggregate demand is forecasted by using the historical data of the family demand. The demand forecast for the items is then derived by proportional allocation of the aggregate forecast. Under the bottom‐up strategy, the demand forecast for each item is directly obtained by using the historical demand data of the particular item. In both strategies, the forecasting technique used is exponential smoothing. We analytically evaluate the condition under which one forecasting strategy is preferred over the other when the lag‐1 autocorrelation of the demand time series for all the items is identical. We show that when the lag‐1 autocorrelation is smaller than or equal to 1/3, the maximum difference in the performance of the two forecasting strategies is only 1%. However, if the lag‐1 autocorrelation of the demand for at least one of the items is greater than 1/3, then the bottom‐up strategy consistently outperforms the top‐down strategy, irrespective of the items' proportion in the family and the coefficient of correlation between the item demands. A simulation study reveals that the analytical findings hold even when the lag‐1 autocorrelation of the demand processes is not identical. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007.     

对一种混沌加密图像方法的破译研究

介绍了利用混沌映射系统进行保密通信的理论依据。分析了一种利用混沌动力学方程所形成的混沌序列来对图像进行加密的方案,并用程序语言予以实现。针对这种一维混沌加密算法,在加密方程、参数和初始值完全未知的前提下,运用相空间重构法和穷举法对其进行了破译研究并成功将其破译。总结了加密和破译方法的优缺点,提出了一种抗破译能力更强的加密方案。