高校多机位实况录像实践

基于多机位实况录像的基本原理,分析实况录像设备构成,讨论了几种实况录像系统设备配置方案,最后指出实况录像的注意事项。     

竞争市场上保修期与价格的联合质量信号传递作用

虽然顾客重视产品的质量（可靠性），但其在做出购买决策时往往不能完全掌握产品的质量信息。不同质量的产品可能具有不同生产和保修成本，因此保修期和销售价格可以成为传递产品质量的有效信号。考虑市场上存在相互竞争的两个生产商：在位者和新进者，顾客了解在位者的产品质量信息但不了解新进者的质量状况。研究并比较了仅保修期作为单质量信号、保修期和价格同时作为质量信号时，市场实现分离均衡的条件，以及新进者的保修期设计与定价决策。研究表明：在保修期作为单质量信号时，只要高质量新进者的单位时间保修成本小于低质量新进者，即可实现分离均衡；在保修期和价格同时作为质量信号时，当满足某些条件时也可实现分离均衡。相对于保修期作单质量信号的情形，当保修期和价格同作质量信号时，高质量新进者实现分离均衡所需提供的保修期更短、价格更低（信息租金更少），且能获得更高的市场份额和利润。最后，数值分析表明保修期和价格同作质量信号时所需满足的条件是比较宽松的，比保修期单独作质量信号时更容易实现分离均衡。     

基于前景理论的PPP项目投资者逆向选择问题研究

PPP项目中投资者逆向选择问题时有发生，严重制约我国PPP模式的可持续发展。为减少投资者逆向选择，在采购阶段对投资者合理筛选机制的设置至关重要。考虑到政府部门和投资者均为"有限理性"，本文基于前景理论，构建了PPP项目采购阶段双方之间的信号博弈模型。研究结果表明，低能力投资者的伪装成本是PPP市场实现分离均衡的决定性因素。为节约政府部门的检查成本，并使PPP市场更容易出现分离均衡，本文引入政府部门抽检模型，即对投资者报价的合理性进行抽检，进而得到最优抽检比例，可完全杜绝投资者逆向选择。通过数值模拟显示，政府部门最优抽检比例随着高能力投资者可获得合理利润率的增加而增加，但随着伪装成本、政府惩罚力度和高能力投资者折现率报价的增加而降低；且相比于收益，投资者对损失更为敏感，但随着收益和损失的增加，其敏感程度降低，符合前景理论。前景理论的引入，考虑了博弈过程中决策者的心理因素，使结果更接近真实情况。最后，为有效抑制投资者逆向选择，本文针对性提出了相关政策建议，为政府部门和投资者的决策提供参考和依据，助力完善PPP项目治理体系。     

Multi-attribute unit and group runs control chart to identify the process deterioration

Gadre and Rattihalli [Gadre, M.P. and Rattihalli, R.N., 2005a, A unit and group runs based chart to identify increases in fraction nonconforming. Journal of Quality Technology, 37, 199–209.] proposed a control chart called the unit and group runs (UGR) control chart to identify increases in fraction non-conforming. In this article, the concept of UGR chart is extended to the multi-attribute case to detect the process deterioration. It is illustrated that in multi-attribute cases also, the UGR chart gives a remarkable reduction in out-of-control average time to signal when compared with the multi-attribute np chart, the multi-attribute synthetic chart and the multi-attribute group runs chart recently developed by Gadre and Rattihalli [Gadre, M.P. and Rattihalli, R.N., 2005b, Some group inspection based multi-attribute control charts. Economic Quality Control, 20, 191–204.]. The steady state performance of the multi-attribute UGR chart is also excellent. The procedure of identifying the attributes causing signal is also described and illustrated.     

Bayesian Updating with Confounded Signals

We develop a Bayesian framework for estimating the means of two random variables when only the sum of those random variables can be observed. Mixture models are proposed for establishing conjugacy between the joint prior distribution and the distribution for observations. Among other desirable features, conjugate distributions allow Bayesian methods to be applied in sequential decision problems.     

企业现金股利政策影响因素的实证研究——以我国房地产上市公司为例

国内外学者对上市公司的分红政策研究较多,但大多基于所有沪深A股上市公司,对于一些小的细分行业缺乏其独有的分析。文章通过对2009—2011年沪深A股中136家上市房地产公司进行实证分析,探求决定公司现金股利政策的影响因素,研究结果显示,房地产企业的现金股利政策同持续分红政策、成长性和现金流情况正相关,而与偿债能力和周转性负相关,有效地验证了生命周期理论,部分验证了剩余股利和代理理论。而从公司分红多少来看,公司营业收入增长率、净资产收益率水平以及机构投资人持股比例越高,则公司进行现金分红的比例就越高。     

Evaluation of statistical methods for safety signal detection: a simulation study

Proactive evaluation of drug safety with systematic screening and detection is critical to protect patients' safety and important in regulatory approval of new drug indications and postmarketing communications and label renewals. In recent years, quite a few statistical methodologies have been developed to better evaluate drug safety through the life cycle of the product development. The statistical methods for flagging safety signals have been developed in two major areas – one for data collected from spontaneous reporting system, mostly in the postmarketing area, and the other for data from clinical trials. To our knowledge, the methods developed for one area have not been applied to the other one so far. In this article, we propose to utilize all such methods for flagging safety signals in both areas regardless of which specific area they were originally developed for. Therefore, we selected eight typical methods, that is, proportional reporting ratios, reporting odds ratios, the maximum likelihood ratio test, Bayesian confidence propagation neural network method, chi‐square test for rates comparison, Benjamini and Hochberg procedure, new double false discovery rate control procedure, and Bayesian hierarchical mixture model for systematic comparison through simulations. The Benjamini and Hochberg procedure and new double false discovery rate control procedure perform best overall in terms of sensitivity and false discovery rate. The likelihood ratio test also performs well when the sample sizes are large. Copyright © 2014 John Wiley & Sons, Ltd.     

M-estimator-based robust estimation of the number of components of a superimposed sinusoidal signal model

In this paper, we consider the problem of estimating the number of components of a superimposed nonlinear sinusoids model of a signal in the presence of additive noise. We propose and provide a detailed empirical comparison of robust methods for estimation of the number of components. The proposed methods, which are robust modifications of the commonly used information theoretic criteria, are based on various M-estimator approaches and are robust with respect to outliers present in the data and heavy-tailed noise. The proposed methods are compared with the usual non-robust methods through extensive simulations under varied model scenarios. We also present real signal analysis of two speech signals to show the usefulness of the proposed methodology.     

文化意识的二重性与价值观念的传承、建构

文化的重要特征是传承。而传承又主要是观念和信息意义上的。直接现实性的物质文化形态只有转化为间接的符号存在形式,才能以文化基因的方式不断复制自身并世代延续下去。以符号为载体的制度文化、观念文化表现为行为的模式和思想观念上认知和价值评价的二重反映形式,它们的传承具有不同特点。其中价值观念又构成了知行的中介环节。