Deterministic construction of compressed sensing matrices based on semilattices

A central problem in compressed sensing is the construction of sensing matrices. In this paper, we show how to construct sensing matrices by using semilattices, and give many examples of sensing matrices constructed from specific semilattices. Moreover, we show that the new construction for some examples with small parameters gives better sensing matrices compared with previously known constructions.     

COVID-19疫情期间比特币与中国金融市场主要资产的关系研究

COVID-19疫情席卷全球,给国际金融行业带来了一场危机.由于对比特币关注度的提高及中国金融市场主要资产的不断发展,比特币市场与中国金融市场主要资产间的联系日益紧密,市场间的风险传导效应也在扩大.因此本文拟研究COVID-19疫情期间比特币与中国金融市场主要资产的相互作用,进而了解风险的作用机理.本文首先使用含有与疫情相关的虚拟变量的三个GARCH族模型,对比特币与中国金融市场主要资产之间是否存在杠杆效应进行研究.结果 显示,GJR-GARCH-t模型的拟合效果最好,意味着市场间存在杠杆效应.之后,通过计算VaR、CVaR和信息冲击曲线,对比特币与中国金融市场主要资产的风险关系进行研究.实证结果表明,基于Cornish-Fisher法计算的VaR和CVaR值对比特币风险的估计更合理;比特币在市场处于危机时风险会急剧加大,比特币的波动性对大部分资产的利空消息比利好消息更为敏感,因此需要合理配置资产来规避风险.     

Developing virtual team performance: an integrated perspective of social exchange and social cognitive theories

Review of Managerial Science - The emerging trend toward physically distributed work teams has necessitated a critical inquiry into the nature and roles of psychological contract and leadership in...     

Online MapReduce processing on two identical parallel machines

In this work we investigate the online over-list MapReduce processing problem on two identical parallel machines, aiming at minimizing the makespan. Jobs are revealed one by one, and each job consists of one map task and one reduce task. The map task can be arbitrarily split and processed on both machines simultaneously, while the reduce task has to be processed on a single machine and it cannot be started unless the map task has been completed. We first show that the general case of the problem reduces to the classical two machine online scheduling model with an optimal competitive ratio of 3/2. For a special case where the map task is at least as long as the reduce task, we prove that no online algorithm can be less than 4/3-competitive. An optimal Greedy algorithm with a matching competitive ratio is proposed as well.     

运营滞后与信用担保互换下的项目投资决策模型

在项目投资面临运营滞后以及债务融资约束的情形下，基于实物期权框架构建了企业家签订信用担保互换契约的两阶段投资决策模型。运用动态规划以及均衡定价方法，给出了企业家股权及期权价值的显示表达，得到了两个阶段担保成本满足的代数方程，并进一步分析了运营滞后和信用担保下企业家的最优投资决策问题。数值结果表明：外部运营时滞会提高杠杆率，导致企业家提前投资，同时会提高企业家第一阶段债务融资的担保成本，但会降低第二阶段债务融资的担保成本；随第一阶段投资额度逐渐增大，企业家的最优投资水平呈U型变化，第一阶段债务融资时的担保成本单调递减，而第二段债务融资时的担保成本呈现倒U型；企业家两个阶段的融资缺口对项目最优投资水平、最优破产水平以及担保成本有显著影响。     

Genetic distance,international experience and the performance of cross-border R&D for EMNEs

Cross-border R&D can contribute to the enhancement of independent innovation capabilities of emerging markets multinational enterprises (EMNEs) by benefiting from knowledge management. However, scant research exists examining the location impact of cross-border R&D for EMNEs on performance implications. This paper fills this important theoretical gap by building upon the literature of genetic distance in connection with knowledge management. We use a panel data of Chinese high-tech listed companies to empirically examine the impact of genetic distance on the performance of cross-border R&D and the role played by international experience. Our results reveal a positive relationship between genetic distance and the performance of cross-border R&D. Importantly, we highlight the motivation for cross-border R&D of EMNEs to acquire technical knowledge magnifies the positive effects of genetic distance and performance. Furthermore, our analysis indicates that international experience significantly enhanced the positive effect of genetic distance on cross-border R&D performance. We conclude this paper by discussing theoretical contributions to genetic distance, international management and knowledge management, as well as practical implications for cross-border R&D of EMNEs.     

战略科技人才培育路径仿真研究

采用文献综述和探索性因子分析相结合的方法,确定战略科技人才具有学识广、工作专注、品行优、使命感、战略思维5个主要特质。然后基于我国科技人才政策体系,通过问卷调查收集了116份样本数据,采用偏最小二乘法的结构方程建模(PLS-SEM),进行路径仿真,探讨了我国科技人才政策体系对战略科技人才特质的影响机理,共确定了22条培育战略科技人才的路径,在反映出我国科技人才政策体系严峻形势的同时,又为科技人才政策的改进和完善提供了一定理论指导。     

Cultural values and innovation: The mediating role of entrepreneurial learning capacity

Although both cultural values and innovation are widely acknowledged as collective embodiments of individual values and assets, little is known about the mechanisms through which cultural values influence the likelihood of innovation by some entrepreneurs rather than others. We argue that institutional pressures arising from cultural values affect entrepreneurial learning capacity which in turn impacts innovation activities. Our multi-level analysis of entrepreneurs from 19 countries between 2006 and 2011 suggests that entrepreneurial learning capacity serves as a mediator through which entrepreneurs maximize the innovation-related benefits of cultural values to their businesses.     

再论管理研究中的关系:“关”与“系”的交互视角

在系统回顾现有关系研究文献基础之上,结合关系研究和社会网络理论,区分双边联系(即“关”)和多边网络(即“系”)两大不同视角,重新梳理文献。在此基础上,对未来关系研究如何整合“关”视角和“系”视角提出了系统性建议,尤其是构建“关”与“系”二者整体性与动态性交互的核心机制体系,提出了包括信任转让、信任转化、“佛面”效应、多重结构四大交互机制,通过阐述“关”“系”互动机制,重新解读“关系”。     

Human Factors Analysis for Maritime Accidents Based on a Dynamic Fuzzy Bayesian Network

Human factors are widely regarded to be highly contributing factors to maritime accident prevention system failures. The conventional methods for human factor assessment, especially quantitative techniques, such as fault trees and bow-ties, are static and cannot deal with models with uncertainty, which limits their application to human factors risk analysis. To alleviate these drawbacks, in the present study, a new human factor analysis framework called multidimensional analysis model of accident causes (MAMAC) is introduced. MAMAC combines the human factors analysis and classification system and business process management. In addition, intuitionistic fuzzy set theory and Bayesian Network are integrated into MAMAC to form a comprehensive dynamic human factors analysis model characterized by flexibility and uncertainty handling. The proposed model is tested on maritime accident scenarios from a sand carrier accident database in China to investigate the human factors involved, and the top 10 most highly contributing primary events associated with the human factors leading to sand carrier accidents are identified. According to the results of this study, direct human factors, classified as unsafe acts, are not a focus for maritime investigators and scholars. Meanwhile, unsafe preconditions and unsafe supervision are listed as the top two considerations for human factors analysis, especially for supervision failures of shipping companies and ship owners. Moreover, potential safety countermeasures for the most highly contributing human factors are proposed in this article. Finally, an application of the proposed model verifies its advantages in calculating the failure probability of accidents induced by human factors.