Book reviews

Exporting Democracy: Fulfilling America's Destiny. By Joshua Muravchik, American Enterprise Institute (1991) ISSN 0–8447–3734–8. $12.95.

Generals in the Palacio. By Roderick Ai Camp. Oxford University Press, (1992), ISBN 0–19–507300–2, £45.

L'Armement en France. Genèse, Ampleur et Coût d'une Industrie By François Chesnais and Claude Serfati, Editions Nathan, Collection Economie/Sciences Sociales, Paris (1992), ISBN 2–09–190086–9.

The Têt Offensive. Intelligence Failure in War. By James Wirtz, Cornell University Press, New York (1991), ISBN 0–8014–2486–0. $38.50.

Restructuring of arms producton in Western Europe. Edited by Michael Brzoska and Peter Lock. Oxford University Press, Oxford (1992), ISBN 0–1982–9147–7. £25.00.

What is Proper Soldiering? A study of new perspectives for the future uses of the Armed Forces of the 1990s. By Michael Harbottle. The Centre for International Peacebuilding, Chipping Norton (1992), £3.50.

The Strategic Defence Initiative By Edward Reiss, Cambridge University Press, Cambridge (1992), ISBN 0–521–41097–5. £30.00.     

YBa_2Cu_3O_x超导薄膜水解前后的XPS分析

本文用X射线光电子能谱(XPS)方法研究了在ZrO_2(100)单晶衬底上用固相反应法制备的YBa_2Cu_3O_x超导薄膜的表面状态,组成和各成份元素的结合能,特别是超导薄膜水解前后表面状态和组成的变化。     

随机测定算法

本文研究计算机网的广播信道中测定算法结合使用随机预测树形算法的问题,并提出了一种高效算法。文章还应用随机过程理论推导了这种算法的有关分布和定理。业已证明,该算法是稳定的,并且有极高的吞吐率和良好的时延特性。仿真实验结果证实了理论上的结论。     

振动非平衡喷管流场的数值研究

从非定常的基本方程出发,采用时间相关法,利用带有平滑项的ＭａｃＣｏｒｍａｃｋ格式对以氮气为实验气体的一维振动非平衡喷管流场进行了数值计算。分析了不同条件下振动非平衡对流场的影响,确定了支配振动非平衡的主要因素。计算结果表明,对于一些实际应用的喷管条件,振动非平衡具有较为显著的影响。     

一种实用的有线电视加解扰方案

在分析了电视加扰技术中的模拟加扰方式和数字加扰方式后,对数字加扰时基处理中的行旋转、行置换、行变换等方法做了详细分析;为了保护有线电视加扰系统的安全,采用了随机数的产生、数据的加密等技术。最后详细介绍了一个包括加、解扰系统和用户控制的实验系统     

Estimating value in a uniform auction

Consider an auction in which increasing bids are made in sequence on an object whose value θ is known to each bidder. Suppose n bids are received, and the distribution of each bid is conditionally uniform. More specifically, suppose the first bid X₁ is uniformly distributed on [0, θ], and the i^th bid is uniformly distributed on [X_i?1, θ] for i = 2, …?, n. A scenario in which this auction model is appropriate is described. We assume that the value θ is un known to the statistician and must be esimated from the sample X₁, X₂, …?, X_n. The best linear unbiased estimate of θ is derived. The invariance of the estimation problem under scale transformations in noted, and the best invariant estimation problem under scale transformations is noted, and the best invariant estimate of θ under loss L(θ, a) = [(a/θ) ? 1]² is derived. It is shown that this best invariant estimate has uniformly smaller mean-squared error than the best linear unbiased estimate, and the ratio of the mean-squared errors is estimated from simulation experiments. A Bayesian formulation of the estimation problem is also considered, and a class of Bayes estimates is explicitly derived.     

关于烟雾对光电成像装备的干扰效果试验及其试验靶标

主题是如何通过外场试验定量评价烟雾对光电成像装备的干扰效果。提出一种综合靶标,可用于这种外场试验,也可考察光电成像装备抗烟雾干扰的能力。它适用于普通观瞄器材、照相侦察和摄像装备、微光夜视设备、热成像系统等。     

雷达目标回波信号的混沌、多重分形分析与识别

本文旨在将混沌、多重分形的理论和方法引入雷达信号处理，从混沌、分形动力学角度来揭示和刻划复杂目标散射机理，为进行有效信号处理和可靠目标识别寻找新的理论和技术实现方法。文中统计了五种飞机目标回波信号的Ｌｙａｐｕｎｏｖ指数分布情况，并计算了其多重分形维数，然后在此基础上，进行了目标识别的实验，获得了较高识别率。本文的研究表明，混沌、多重分形理论在目标特性及识别的研究中具有良好的应用前景。     

Callable products for an implicit time model with dependent demands

Capacity providers such as airlines and hotels have traditionally increased revenues by practicing market segmentation and revenue management, enabling them to sell the same capacity pool to different consumers at different prices. Callable products can enhance profits and improve consumers' welfare by allowing the firm to broker capacity between consumers with different willingness to pay. A consumer who buys a callable product gives the capacity provider the right to recall capacity at a prespecified recall price. This article studies callable products in the context of the model most commonly used in industry, which handles time implicitly imposing fewer restrictions on the nature of randomness compared to the Poisson arrival process favored in academia. In the implicit time model, capacity providers set booking limits to protect capacity for future high-fare demand. Our numerical study identifies conditions where callable products result in significant gains in profits.