利用ACE值构造QC-LDPC码

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。     

基于频率响应屏蔽技术的采样率变换新结构

介绍了频率响应屏蔽(FRM)技术在采样率变换技术中的应用,分析了FRM的简化结构——内插滤波器的设计方法。将此滤波器应用于采样率变换中,并结合多相滤波思想提出了一种高效的FRM采样率变换结构,此结构能极大降低采样率变换实现复杂度。最后通过设计实例,验证了此结构的高效性。     

Systematic risk estimation in the presence of large and many outliers

It is well recognized that the effect of extreme points on systematic risk estimates is not adequately captured through least squares estimation. This article uses the reweighted least median squares (RWLMS) approach, first proposed by Rousseeuw (1984), which accurately detects outlier presence. Using a large sample of 1350 NYSE/AMEX firms, the article demonstrates that least squares does indeed mask several potentially influential points, that this masking is very pervasive over the sample, and that it may persist even after conventional robust estimation techniques are applied. When these masked points are “unmasked” by RWLMS and zero weights assigned to such observations, the resulting RWLMS estimates of beta are on average 10%–15% smaller. However, a Bayesian treatment of such points (assigning a priori nonzero weights) is possible in both one and two factor market models.     

SC-CR Algorithms with informative masking

In this article, we present a significant improvement to the Self-Consistent, Competing Risks (SC-CR) Algorithms that have been published in the actuarial literature over the last several years. These algorithms were fairly flexible, admitting of any combination of partially masked risks and interval-censored failure times. However, we wish to show here that the SC-CR Algorithm can be further generalized to allow for each specific decrement to have its own distinct interval-censored range for any given individual observation. We have chosen to refer to this dynamic as ‘informative masking’ since additional information regarding the masking sets will be allowed to be incorporated. The enhancements will be applied to both the double-censored as well as interval-censored SC-CR Algorithms. Numerical examples that illustrate the usefulness of these enhancements will also be furnished.     

关于中枢掩蔽及掩蔽的临床应用探讨

探讨中枢掩蔽及掩蔽作用产生的机理,探索其对听觉器官的影响及有效的应用法。比较一组正常成年人在相同频率不同强度及相同强度不同频率的对侧掩蔽声(CAS)时听阈的变化,即中枢掩蔽效应(CME)的大小;同时测试一组神经性耳鸣患者掩蔽疗法的疗效。CME具有频率特异性及强度特异性,掩蔽疗法应可用于耳鸣的治疗。因中枢掩蔽的存在,如所用CAS40dBHL时,纯音听阈测试中,则需对测试结果进行修正;掩蔽疗法是治疗神经性耳鸣的一种安全、方便有效的疗法。     

基于Logistic映射的三种混沌保密通信方案

利用离散混沌信号的宽带类噪声特性实现信号的保密传输是混沌应用研究的重要方向。文章总结了Logistic及其改进型离散混沌映射的概率分布、均值、自相关和互相关等统计特性，阐明了将Logistic映射用于保密通信的有效性；分别介绍了基于Logistic离散混沌映射的混沌掩盖、混沌参数调制和混沌扩频等保密通信方案的原理和特点。     

The role of subordinate emotional masking in leader–member exchange and outcomes: A two-sample investigation

Recent developments in the leadership literature call for research that emphasizes the role of the follower as well as that of emotion in the leader–member exchange (LMX). In response to these calls, this research examines the relationship between subordinate emotional masking and LMX quality, as well as the mediating role of LMX quality in emotional masking/outcome relationships. We collect data from two samples of MBA students from the United States and China, respectively. In both samples, we find that emotional masking by subordinates is negatively related to LMX quality. The mediating role of LMX quality in the relationship between emotional masking and work-related outcomes is also supported. Suggestions for future research and practice are discussed.     

Disclosure Control of Business Microdata: A Density-Based Approach

For continuous key variables, a measure of the individual risk of disclosure is proposed. This risk measure, the local outlier factor, estimates the density around a unit. A selective masking method based on the nearest-neighbour principle and microaggregation is also introduced. Some results of an application to the Italian sample of the Community Innovation Survey are presented.     

业绩期望落差、市场竞争与企业开放式创新

基于业绩反馈理论和企业行为理论,以2015—2022年中国沪深A股上市公司为样本,运用OLS基准回归模型探讨市场竞争调节下,业绩期望落差持续性与范围性对企业开放式创新的影响。结果表明,业绩期望落差持续时间与涉及范围逐增致使企业创新开放动机与能力失衡,一致降低开放式创新绩效,强烈的外部市场竞争能够有效抑制其负向作用。机制分析发现,研发投入在业绩期望落差持续性和范围性对企业开放式创新的作用关系中发挥显著遮掩效应,主效应的部分影响被抵消。以上结论为推动业绩困境企业进行科学创新开放决策,打破“无知开放、盲目开放”陷阱提供经验借鉴。     

农地流转影响要素市场发育的机理与实证研究——基于面板中介效应模型的论证

[目的]要素市场化改革在我国农村市场化改革中相对滞后,农地流转作为完善要素市场发育的重要手段之一,其如何影响要素市场化水平是值得深入研究的问题,通过构建农地流转与要素市场化水平的分析框架,实证检验其中的作用机理。[方法]文章基于2005—2019年的省际面板数据,引入劳动力市场与农业资本市场的间接作用,运用面板中介效应模型进行实证分析。[结果]农地流转有利于提高要素市场化水平,农地流转率每上升1个百分点,要素市场化指数相应提高0.108,但存在显著的地域性差异。其中,劳动力市场在农地流转提高要素市场化水平过程中发挥部分中介效应作用,中介效应占比约为44.21%,农业资本市场发挥“遮掩效应”作用,遮掩效应占比约为3.72%。[结论]我国各要素市场是一个相互联动的交易体系,农地市场的发育水平能够影响劳动力市场与农业资本市场的发育水平。因此,需稳步推进农村各要素市场协同发展,尤其关注劳动力市场与农村金融市场的发育水平,发挥“1+1>2”的资源整合效应。