Should sequels differ from original movies in pre-launch advertising schedule? Lessons from consumers' online search activity

Sequels have become a profitable strategy in the U.S. motion picture industry because of their strong name recognition. However, while the established positioning of a sequel may help insulate it from competing firms' advertising messages, its familiarity may cause moviegoers to be more easily satiated with advertising from the sequel. Therefore, this study examines how sequels differ from original concept movies in terms of their ad effectiveness. We focus our analysis on pre-launch periods, given these periods' importance in shaping the financial outcomes of motion pictures. We consider the weekly online search volume of a movie as a measure of consumer interest in it, and thus as an intermediate response to pre-launch advertising. We then develop a model that assumes ad effectiveness can decline, due to copy and repetition wearout, and increase, due to forgetting, over time. We find that copy wearout is greater for original movies, while repetition wearout and forgetting are greater for sequels. These findings suggest that sequels should allocate more in early pre-launch periods and less immediately before release, relative to originals, to maximize pre-launch consumer interest.     

Investor Pessimism and the German Stock Market: Exploring Google Search Queries

We analyze the relationship of retail investor sentiment and the German stock market by introducing four distinct investor pessimism indices (IPIs) based on selected aggregate Google search queries. We assess the predictive power of weekly changes in sentiment captured by the IPIs for contemporaneous and future DAX returns, volatility and trading volume. The indices are found to have individually varying, but overall remarkably high explanatory power. An increase in retail investor pessimism is accompanied by decreasing contemporaneous market returns and an increase in volatility and trading volume. Future returns tend to increase while future volatility and trading volume decrease. The outcome is in line with the conjecture of correction effects. Overall, the results are well in line with modern investor sentiment theory.     

基于混合K-中心点的Web客户聚类

通过对Web日志文件进行分析，该文提出了一种改进的K-中心点聚类算法对Wweb用户的行为进行分析的方法。该算法利用模糊相似度，并模仿遗传算法中计算适应度思想，另加了一层循环迭代，每次比较适应度，保留最佳适应度，使之有较好的性能，改进了其易局部最优化的缺点。     

我国经济发展水平与劳动力就业数量关系研究——兼论我国劳动力资源是否过剩

我国劳动力对经济发展而言，其生产率高于资本，因而经济发展对劳动力就业的促进作用逐渐减弱（经济增长的就业弹性逐渐变小）。据测算，我国2013年以前劳动力就业压力很大，2015年以后劳动力又会供不应求。所以，我国未来经济发展中，2014年前后应采用不同的产业结构调整策略来充分满足劳动力就业的要求。     

Lotus Domino/Notes的公开密钥加密机制

公开密钥加密技术在最近几年得到了极大的重视和发展。本文讨论了公钥加密技术的原理和实施技术，并结合公钥技术在Lotus Domino/Notes中的应用，着重探讨了Lotus系统内部用户校验和认证机制的建立和实施。     

Introducing Time‐to‐Educate in a Job‐Search Model

Transition patterns from school to work differ considerably across OECD countries. Some countries exhibit high youth unemployment rates, which can be considered an indicator of the difficulty facing young people trying to integrate into the labour market. At the same time, education is a time‐consuming process, and enrolment and dropout decisions depend on expected duration of studies as well as on job prospects with and without completed degrees. One way to model entry into the labour market is by means of job‐search models, where the job arrival hazard is a key parameter in capturing the ease or difficulty in finding a job. Standard models of job search and education assume that skills can be upgraded instantaneously (and mostly in the form of on‐the‐job training) at a fixed cost. This paper models education as a time‐consuming process, a concept which we call time‐to‐educate, during which an individual faces the trade‐off between continuing education and taking up a job.     

Conditioning as disintegration

Conditional probability distributions seem to have a bad reputation when it comes to rigorous treatment of conditioning. Technical arguments are published as manipulations of Radon–Nikodym derivatives, although we all secretly perform heuristic calculations using elementary definitions of conditional probabilities. In print, measurability and averaging properties substitute for intuitive ideas about random variables behaving like constants given particular conditioning information.
One way to engage in rigorous, guilt-free manipulation of conditional distributions is to treat them as disintegrating measures—families of probability measures concentrating on the level sets of a conditioning statistic. In this paper we present a little theory and a range of examples—from EM algorithms and the Neyman factorization, through Bayes theory and marginalization paradoxes—to suggest that disintegrations have both intuitive appeal and the rigor needed for many problems in mathematical statistics.     

Turbo码解码过程中的加权算法

本文通过调整迭代解码过程中系统位接收值的加权系数，提出了一种Turbo码加权迭代解码算法。该算法改变了迭代运算后Turbo码解码器输出软值中系统位接收值信息和它的外部估计信息的比重，使Turbo码无论在低信噪比或是在高信噪比时均具有优良的纠错性能。仿真结果显示，采用Turbo码加权迭代解码算法，不仅能提高Turbo码的收敛速度，而且能进一步降低Turbo码解码时的地板值，使Turbo码的比特误码率在高、低信噪比时都能够得到进一步改善。     

采用改进遗传算法的变压器优化设计

电力机车变压器的优化设计,采用遗传算法是比较好的选择,但传统遗传算法存在一些弊端,文章从编码方式、遗传操作等几个方面探讨了如何对其进行改进,并使用Visual C++编写了一套设计软件,实践证明这种改进是有效的。     

An effective step-down algorithm for the construction and the identification of nonisomorphic orthogonal arrays

In this paper we present an effective algorithm for the construction and the identification of two-level nonisomorphic orthogonal arrays. Using this algorithm, we identify and list a full catalogue of nonisomorphic orthogonal arrays with parameters OA(24,7,2,t), OA(28,6,2,t) and OA(32,6,2,t), t ≥ 2. Some statistical properties of these designs are also considered.