Technical note: Finite-time regret analysis of Kiefer-Wolfowitz stochastic approximation algorithm and nonparametric multi-product dynamic pricing with unknown demand

We consider the problem of nonparametric multi-product dynamic pricing with unknown demand and show that the problem may be formulated as an online model-free stochastic program, which can be solved by the classical Kiefer-Wolfowitz stochastic approximation (KWSA) algorithm. We prove that the expected cumulative regret of the KWSA algorithm is bounded above by where κ₁, κ₂ are positive constants and T is the number of periods for any T = 1, 2, … . Therefore, the regret of the KWSA algorithm grows in the order of , which achieves the lower bounds known for parametric dynamic pricing problems and shows that the nonparametric problems are not necessarily more difficult to solve than the parametric ones. Numerical experiments further demonstrate the effectiveness and efficiency of our proposed KW pricing policy by comparing with some pricing policies in the literature.     

模糊偏序关系的一种信息集成方法

以模糊超过关系、模糊不协调关系为例,就模糊偏序关系给出了一种基于分组加权极大(极小)算子的信息集成方法,讨论了该方法的一致性、非独裁性等性质.     

生的激情 死的欲求——精神分析学说对马丁·伊登的心理分析

《马丁·伊登》是杰克·伦敦的半自传体小说，主人公马丁是伦敦塑造的超人形象。本文运用弗洛伊德的精神分析理论，从深层次上分析马丁·伊登的生的本能、死的本能、俄底浦斯情结（恋母情结）、施虐狂倾向、受虐狂倾向，探讨评论界一直争论不休的马丁·伊登的死因问题。分析结果表明正是马丁·伊登身上存在的死亡本能、施虐狂倾向、受虐狂倾向导致了他最终的自毁。     

采用瞬态球状热斗篷方法的浅层地下目标红外隐身技术

由于浅层地下目标与背景土壤的热物性不同,影响了整个区域表面的温度场分布,容易被敌方探测系统发现并击毁。针对这一问题,考虑太阳辐射、天空辐射以及风速的影响,建立了埋藏地下目标的区域温度分布传热模型,揭示了不同时段埋藏地下目标对区域表面温度场的影响。在变换热力学的基础上,通过坐标变换的方法,推导出球状瞬态热斗篷的导热系数的通解表达式。根据等效介质理论,对设计的热物性参数进行均质化,并通过数值实验方法验证了基于热斗篷地下目标红外隐身技术的可行性。     

基于分形的地图自动综合方法

为了较好地解决根据已知比例尺的地图通过自动综合生成满足不同比例尺需求的地图，利用地图边界所具有的分形特征及分形维数的不变性，提出了一种地图边界自动综合的方法——MADP。该方法不仅很好地保持了地图的形状特征和细节，而且较好地解决了公共边界的综合问题。实验表明，该方法具有较高的效率和公共边界综合能力。     

New inequalities for finite and infinite group problems from approximate lifting

In this paper, we derive new families of facet‐defining inequalities for the finite group problem and extreme inequalities for the infinite group problem using approximate lifting. The new valid inequalities for the finite group problem include two‐ and three‐slope facet‐defining inequalities as well as the first family of four‐slope facet‐defining inequalities. The new valid inequalities for the infinite group problem include families of two‐ and three‐slope extreme inequalities. These new inequalities not only illustrate the diversity of strong inequalities for the finite and infinite group problems, but also provide a large variety of new cutting planes for solving integer and mixed‐integer programming problems. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

清末不同政治力量对新军的思想控驭及其影响

清政府不仅从新军指挥体系入手强化中央集权,更注重利用思想控驭,加强对官兵"忠君"与"爱清"的教育,力图使新军成为大清王朝的护卫者.当清政府既不能应付外来挑战,又无法处理好国内问题时,许多新军官兵成为激进的民族主义者.这为革命党人在新军中的思想灌输大开方便之门.革命精神和"反满"情绪在大江以南的新军官兵中最为强烈,而北洋新军大部是忠于袁世凯的.这些都对清朝的统治构成致命打击.     

一种改进的事件驱动系统框架

在给出事件驱动系统安全漏洞的基础上,指出了产生漏洞的根本原因是:系统忽视了输入系统的事件序列之间存在的相关性;系统无条件信任任何事件源产生的事件.针对这两个原因,相应提出了事件序列形式安全分析模型及基于事件源的可信度评估模型,依据这两个模型,构建了一种改进的事件驱动系统框架.     

捷联惯导系统快速自对准误差模型的建立

通过对惯性制导系统两个基本方程的研究,求出了各状态矢量在各坐标系下的微分方程,然后以ψ角法所确立的平台为基准,分别推导得出惯性制导系统各主要状态的微分方程,从而建立了捷联惯性制导系统的误差模型.最后根据静基座捷联惯导系统初始对准的特点对其进行简化,得到了静基座捷联惯导系统快速自对准的误差模型.     

Weak aging properties for coherent systems with statistically dependent component lifetimes

As a relevant topic in reliability theory, the preservation of aging properties under the formation of various coherent structures contributes to improving system performance through better structure design and more effective system maintenance. The classical research in this line usually focuses upon coherent systems with independent component lifetimes. Recently, some authors discussed the preservation of IFR, NBU, and DMRL in the setting of dependent component lifetimes. This paper further investigates sufficient conditions for coherent systems with dependent component lifetimes to preserve aging properties including NBUC, NBU (2), DMRL, and their dual versions. Some examples are presented to illustrate coherent structures and typical copula functions fulfilling the present sufficient conditions as well.