LT码新型度分布及其在电力线通信中的应用

Luby变换(Luby Transform,LT)码作为信道编码应用于电力线通信(Power Line Communication,PLC)，可实现电信号的可靠传输。度分布对LT码编译码性能的影响至关重要。为了得到更优的度分布，首先调整二进制指数分布(Binary Exponential Distribution,BED)中的度数比例，获得一种译码性能更优的改进的二进制指数分布(Improved BED,IBED)。然后，根据IBED在冗余度较小时译码成功率高，而冗余度增大后鲁棒孤子分布(Robust Soliton Distribution,RSD)的译码性能表现更佳的特点，通过求和归一化的方式将IBED与RSD两种度分布的优势进行有机结合，提出一种新型二进制鲁棒孤子分布(Binary RSD,BRSD)。仿真结果表明，与其他方法及传统的RSD相比，采用新度分布进行LT编码，可明显降低译码开销，并节约编译码耗时。将新型度分布应用于基于LT码的PLC系统中，能有效地抑制PLC信道中各种噪声对电信号的干扰，并提高通信效率。     

Communication and Comovement: Evidence from Online Stock Forums

We study investor communication and stock comovement using a novel data set from an active online stock forum in China. We find substantial comovement among the returns of a stock and its “related stocks,” which are frequently discussed in the subforum dedicated to the given stock. Comovement is greater when the discussion of related stocks is more intensive. Further, the effect of communication on comovement is stronger for stocks associated with higher information uncertainty. Codiscussed stocks are more actively traded and experience more correlated trading. A trading strategy that exploits communication‐driven comovement generates abnormal returns. Our findings highlight the impact of investor communication on asset comovement.     

Unemployment insurance benefits and income smoothing

Labor unemployment insurance reduces unemployment concerns. We argue that these benefits moderate incentives to smooth earnings to reduce employees’ concerns about unemployment risk. Using exogenous variations in unemployment insurance benefits, we find evidence consistent with this argument. We also find that the link between unemployment insurance benefits and income smoothing is stronger when there is higher unemployment risk and when the firm is likely to employ more low-wage workers, who find unemployment insurance benefits especially useful. Our paper contributes to the literature by showing that public policy decisions such as unemployment insurance have significant, albeit probably unintended, externalities on corporate financial reporting.     

国家助学贷款中信息不对称问题及其矫正

国家助学贷款工作的实施,为帮助贫困大学生顺利完成学业发挥着重要作用。但是由于助学贷款中的信息不对称所引起的逆向选择和道德风险问题使该项工作陷入了贷还两难的窘境。因此,必须通过建立完善的信用制度,健全法律法规,设计合理的还贷激励机制,构建风险分担体系,加大高校的工作投入,使助学贷款工作能够顺利实施,发挥更大的作用。     

C++对象布局分析

分析了目前最为流行的面向对象的开发工具C 的对象布局，并进一步分析了其形成原因。     

Getting the Most Out of a Mandatory Subordinated Debt Requirement

Recent advances in asset pricing—the reduced-form approach to pricing risky debt and derivatives—are used to quantitatively evaluate several proposals for mandatory bank issue of subordinated debt. We find that credit spreads on both fixed- and floating-rate subordinated debt provide relatively clean signals of bank risk and are not unduly influenced by nonrisk factors. Fixed-rate debt with a put is unacceptable, but making the putable debt floating resolves most problems. Our approach also helps to clarify several different notions of “bank risk.”     

缩小审计期望值差的办法

审计期望值差是审计研究中的重要问题,事关审计市场供求发展。此文以“审计七个基本前提假设”为基础,探讨了缩小审计期望值差的一些办法。     

鹿溪河漂流

“岸芷汀兰,郁郁青青……”．当我乘橡皮艇漂流在成都近郊鹿溪河上的时候,范仲淹的此句名言便一再地从我的脑海中欢快地蹦跳出来。此时正是初夏的五月．明丽的阳光透过两岸浓郁的林木,哗啦啦地照射在或急或缓的河流上,这条成都境内的岷江二级支流所凸现的波光粼粼,美仑美奂,着实让人心醉:散发着亲切泥土气息的河水涌动两岸倒     

董事利益保护刍议

董事会中心主义的确立，董事义务与责任体系的完备，使得对董事利益的保护成为公司经营管理效率提高的必要前提。如何建立符合中国实际的董事利益保护机制是摆在法学研究者面前一个紧迫而重要的课题。