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1.
We examine the link between the monitoring capacity of the board and corporate performance of UK listed firms. We also investigate how firms use the flexibility offered by the voluntary governance regime to make governance choices. We find a strong positive association between the board governance index we construct and firm operating performance. Our results imply that adherence to the board‐related recommendations of the UK Corporate Governance Code strengthens the board's monitoring capacity, potentially helping mitigate agency problems, but that investors do not value it correspondingly. Moreover, in contrast to prior UK findings suggesting efficient adoption of Code recommendations, we find that firms at times use the Code flexibility opportunistically, aiming to decrease the monitoring capacity of the board, which is followed by subsequent underperformance. This finding questions the effectiveness of the voluntary approach to governance regulation followed in the UK and in many countries around the world.  相似文献   
2.
为了加快低密度奇偶校验(LDPC)码的译码速度,有效改善LDPC码的译码性能,针对校验节点更新过程中的对数似然比(LLR)值的大小,设计了一种LDPC码的动态加权译码方法。以IEEE 802.16e标准的奇偶校验矩阵为例,根据LLR值的变化规律,利用增长因子和抑制因子对和积译码算法和最小和译码算法进行动态加权。仿真结果显示,基于动态加权的译码方法相对于传统译码方法误码率都有明显改进,译码复杂度也有所降低。  相似文献   
3.
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。  相似文献   
4.
Relative income gap is one of the most popular approaches for explaining the income–happiness relationship. We argue in this article that when people compare their incomes, they care about distributional fairness more than relative income disparity. It is difficult for us to explain China's income–happiness paradox if we simply compare the income gap and do not explore the income‐generation process leading to income inequality. We therefore employ an approach based on a responsibility‐sensitive theory of justice that decomposes individual income into fair and unfair components. As a proxy for distributional unfairness, unfair income is considered the main source of unhappiness. Using data from the Chinese Household Income Project survey, we find strong support for the negative relationship between income unfairness and happiness. We also find a significantly positive relationship between the relative income gap and income unfairness, which leads us to consider the income comparison hypothesis as the explanation for the income–happiness paradox in a new light. Sensitivity analyses confirm the robustness of our results.  相似文献   
5.
为进一步提升中短码长下准循环低密度奇偶校验(Quasi-cyclic Low-density Parity-check,QC-LDPC) 码的纠错性能,提出了一种综合短环数目和环连通性的QC-LDPC码构造方法。首先,采用Golomb规则构造QC-LDPC码,对基矩阵中的部分元素进行替换预处理,初步降低短环数目;其次,采用所提的利用近似环外信息度(Approximate Cycle Extrinsic message degree,ACE)的消环掩模算法来优化QC-LDPC码,使得掩模后的校验矩阵具有较大的ACE平均值,最终完成QC-LDPC码的构造。该构造方法简单、通用性强,在短环数目和连通性间进行了平衡。与只考虑减少短环数目、增大围长等方法相比,该方法构造的QC-LDPC码有更加优异的纠错性能。  相似文献   
6.
We examine the impact of governance reforms related to board diversity on the performance of European Union banks. Using a difference‐in‐difference approach, we document that reforms increase bank stock returns and their volatility within the first 3 years after their enactment. The type of reform matters, with quotas increasing return volatility. The effectiveness of reforms depends on a country's institutional environment. The impact of reforms on return volatility is found to be beneficial in countries more open to diversity, with common law system and with greater economic freedom. Finally, reforms play a bigger role in banks that have ex ante less heterogeneous boards.  相似文献   
7.
针对Radon-ambiguity变换(RAT)在估计多相码信号(Frank码、P1、P2、P3、P4码)调制参数时受噪声影响严重的问题,提出了基于平滑Radon变换的多相码信号参数估计方法。首先理论上分析了噪声影响多相码信号RAT估计性能的原因,进而通过二次平滑估计出信号RAT的噪声基底包络,最后在去除噪声基底的RAT平面中完成多相码信号调制参数的估计。仿真实验表明,该方法调频率和码元宽度估计的信噪比门限相比传统RAT方法分别降低了1 dB和4 dB。  相似文献   
8.
连续相位调制与低密度奇偶校验(LDPC)码编译码技术在提高频谱利用率的同时能够有效降低发射功率,然而这会增加通信系统的复杂度。为此,提出了一种低复杂度的联合迭代译码算法解决此问题。该算法以符号/比特的可靠度作为内外译码器之间的迭代信息。仿真结果表明,新的联合迭代译码算法的性能与概率域下的算法几乎没有差异,在总迭代次数相同的情况下,采用低复杂度联合迭代的性能相比于未采用联合迭代的性能有约0.75 dB的增益。  相似文献   
9.
This paper examines the initial impact of a ‘good governance’ code for charitable organisations that was promulgated in the Netherlands in 2005. Data are gathered from publicly available annual reports of 138 charities in the post‐implementation phase of the code (2005–2008). We first examine whether the code altered charities’ governance structures. Next, we investigate managerial pay as a key aspect of discharging financial accountability because prior literature focused on ‘excessive’ compensation. The findings indicate that a strengthened governance structure positively affects the likelihood of disclosing information concerning managerial pay, as well as mitigating managerial pay level.  相似文献   
10.
置信传播(BP)算法可以为系统极化码提供软信息作为判决依据,也可以为系统极化码在级联迭代译码中提供交换软信息。在详细描述基于信道极化结构的置信传播算法基础上,比较了系统极化码在软信息判决方法和极化编码判决方法下错误率性能的差异。仿真结果表明,软信息判决方法可以提高系统极化码的误比特率,在高信噪比下误帧率方面也略有提高。  相似文献   
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