Media coverage and investment efficiency

We examine the effect of media coverage on firm-level investment efficiency. We find that media coverage reduces under-investment but increases over-investment. The negative effect of media coverage on under-investment is more pronounced in firms affected by greater information asymmetry and poorer corporate governance. The positive effect of media coverage on over-investment is driven by media-induced CEO overconfidence. Additional results show that both investment- and non-investment-related news coverage decrease under-investment, while non-investment-related news coverage is more influential in increasing over-investment. In general, higher news optimism is associated with less under-investment but more over-investment. Moreover, media coverage affects investment efficiency through its information dissemination rather than information creation function. Collectively, our results suggest that firms’ media visibility promotes more over-investment than under-investment.     

The Effect of Media Coverage on the Pricing of Seasoned Equity Offerings

This paper examines the role of media coverage and investor attention on the outcomes of seasoned equity offerings (SEOs). I use an archive of Thomson Reuters news articles to proxy for firm visibility and investor attention. I find that the volumes of news articles prior to the offerings are positively associated with the offer price discounts of SEOs. Furthermore, the volumes of news articles are negatively associated with the cumulative abnormal returns three days around the SEOs. I conclude that the costs of equity increase with media coverage prior to SEOs. Overall, the evidence is consistent with the hypothesis that media coverage affects investors' information processing in SEOs. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd.     

基于AD9361的掌上型LTE RRU设计与开发

当前小体积远端射频单元（Remote Radio Unit,RRU）主要是皮站级别的Pico-RRU，其重量和体积仍然难以满足掌上型的要求。为此，采用高集成度的AD9361芯片来实现长期演进（Long Term Evolution，LTE）宽带收发信机功能，配合时钟同步模块、放大器模块和控制接口电路等一起构建低成本的掌上型RRU。主要解决了基于AD9516的时钟同步、低相位噪声设计和高灵敏度接收机设计三个技术难点，成功实现了掌上型、高性能、低成本的设计目标。整个RRU样机尺寸为18 cm×10 cm×2 cm，质量约500 g，量产成本千元以内。测试表明，该RRU下行误差向量幅度（Error Vector Magnitude，EVM）小于3%，优于3GPP要求的8%；10 MHz带宽时上行接收机灵敏度优于3GPP要求的-93.5 dBm。     

高速移动数据传输新标准IEEE 802.20

介绍了未来高速移动通信新标准IEEE802．20的总体概况，具体分析了IEEE802．20的技术特性、系统参考结构以及系统的组成模型，并对IEEE802．20标准前景分析与展望进行了详细描述。     

An investigation of transformation-based prediction interval for the Weibull median life

Statistical inference based on the Weibull distribution, a distribution widely used in reliability and survival analysis, is usually difficult as it often involves numerical computation and approximation. However, this distribution can be transformed to near-normality by a simple power transformation. Based on this transformation, a prediction interval (PI) for its median can be easily constructed through an inverse transformation. The procedure for selecting the best power transformation through minimizing Kullback-Leibler information is described. The property of this transformation-based PI is investigated. Simple correction factors are also proposed. It is shown that the transformation-based PI with corrections performs well, irrespective of the sample size and parameter values. Simulation results show that the new PI generally outperforms the existing PI. Numerical examples are given for illustration.     

Quality Competition and Social Welfare in Markets with Partial Coverage: New Results*

We use a vertical product differentiation model under partial market coverage to study the social welfare optimum and duopoly equilibrium when convex costs of quality provision are either fixed or variable in terms of production. We show the following new results. First, under fixed costs, the social planner charges a uniform price for the single variant that just covers costs of quality provision. Like the duopoly equilibrium, this socially optimal pricing entails a partially uncovered market, but a smaller share of the market is served compared with the duopoly equilibrium. Second, for the variable cost case, it is socially optimal to provide both high‐ and low‐quality variants, but market shares need not be equal. This differs from the result in fully covered markets. Third, in the duopoly equilibrium, the quality spread is too wide under variable costs relative to the social optimum. Under fixed costs, the duopoly produces two variants, but quality is too low relative to the social optimum, which has only one variant.     

基于无线技术的仓储拣选作业流程再造方案分析

对传统的仓储拣选作业流程进行了研究分析,提出了基于无线技术的仓储拣选作业流程再造方案,并对两者进行了对比分析,阐述了再造后的拣选作业流程采用无线技术及其相关技术后的诸多优点及发展前景.     

MMS系统的原理结构与应用浅析

多媒体短信息服务(MMS)是目前短信息技术开发最高标准的一种.它最大的特色就是支持多媒体功能.MMS可即时实现终端到终端、终端到互联网或互联网到终端的信息传输,允许传输数据、文本、图像、音频、视频消息.本文对MMS的原理结构作了较为详细的分析,列举了MMS的几个其型应用例子.     

社会审计质量、国家审计监督与国企资产保值增值

在委托代理理论和协同理论框架下,选取2007—2017年中国A股国有上市公司为研究样本,实证检验社会审计质量对国企资产保值增值的影响以及社会审计与国家审计影响国企资产保值增值的替代效应。研究发现：高质量的社会审计有利于促进国企资产保值增值;社会审计与国家审计在促进国企资产保值增值中发挥了替代效应,而且这种替代效应主要体现在高质量的社会审计可以有效缓解国家审计扩大监督范围广度、提高目标实现深度与加强“监”的力度等方面的压力,但不会影响国家审计“督”的力度。研究结论对于国家审计机关合理利用社会审计资源、构建协同高效的审计监督体系、实现国企审计全覆盖、促进国企资产保值增值具有启示意义。     

Spread spectrum of knowledge network based on information integration environment

The concept and the characteristic of spread spectrum technology of knowledge network based on information integration environment are given at first. And the basic principle of the wireless network of knowledge and information is recommended. Then a project alternatives using the spread spectrum technology and wireless network is given to build a across-the abroad knowledge network system.