空间目标的联合矩阵束极点估计

极点作为谐振区雷达目标的最主要电磁特性，具有很大的空间目标识别前景。但是在使用频域观测数据提取目标极点时，存在虚假极点和估计精度问题。针对上述问题，首先通过加窗和截断改进了后时响应信号的获取流程，抑制了虚假极点影响；然后采用最小描述长度法（MDL）估计极点个数，避免了定阶错误引起的虚假极点；最后采用联合矩阵束法估计极点，有效减少了单角度数据估计极点时存在的遗漏极点和虚假极点问题。FEKO软件验证表明，所提算法具有更高的精度和抗噪能力。     

Socio-demographics,political attitudes and informal sector employment: A cross-country analysis

In this paper, we empirically investigate the relationship between informal sector employment and micro-level socio-demographic characteristics, political acts and attitudes, and individual norms. Using self-reported individual micro-level data from the World Values Survey for seven developing countries (China, Ecuador, Egypt, Mexico, Peru, South Africa and Yemen), our cross-country regressions and principal component analysis reveal that socio-demographic characteristics of individuals are strong predictors of their informal sector employment. Our estimations further document that individual preferences for an economically strong, interventionist and egalitarian state and confidence in state and political institutions are positively and significantly correlated with informal sector employment, whereas variables associated with confidence in free market institutions and support for competition are negatively and significantly correlated with informal sector employment. We also show that individuals who participate either actively or inactively in peaceful and lawful political processes are significantly less likely to work in the informal sector. Finally, we document that individual norms, such as religiosity and tax morale, are negatively correlated with informal sector employment. Throughout our analysis, instead of having to rely on ad-hoc informality categorizations of third parties, we base our measurement of informal sector employment directly on the self-evaluation of individuals, who have the best information on the degree of their informality.     

Optimal investment with vintage capital: Equilibrium distributions

The paper concerns the study of equilibrium points, or steady states, of economic systems arising in modeling optimal investment with vintage capital, namely, systems where all key variables (capitals, investments, prices) are indexed not only by time but also by age. Capital accumulation is hence described as a partial differential equation (briefly, PDE), and equilibrium points are in fact equilibrium distributions in the variable of ages. A general method is developed to compute and study equilibrium points of a wide range of infinite dimensional, infinite horizon, optimal control problems. We apply the method to optimal investment with vintage capital, for a variety of data, deriving existence and uniqueness of equilibrium distribution, as well as analytic formulas for optimal controls and trajectories in the long run. The examples suggest that the same method can be applied to other economic problems displaying heterogeneity. This shows how effective the theoretical machinery of optimal control in infinite dimension is in computing explicitly equilibrium distributions. To this extent, the results of this work constitute a first crucial step towards a thorough understanding of the behavior of optimal paths in the long run.     

一般竞争战略理论论战、观点流派与研究展望——从割裂到融合

一般竞争战略理论对企业战略决策具有广泛而深远的影响。学者们对一般竞争战略的割裂观和融合观一直争执不休，众多研究呈现出多角度、多证据、结论矛盾和研究混乱的局面。文章通过对相关理论回顾和梳理，揭示出一般竞争战略理论割裂观存在的问题和困境，呈现融合观的理论与实证证据，提炼出混合战略的三个流派，并揭示混合战略研究的脉络和趋势。文章揭示出融合是竞争战略的趋势，实现不同战略类型的融合和竞争战略的多维体系构建，有助于厘清竞争战略研究的混乱和矛盾，打破根深蒂固的“骑墙战略”禁区思维，为企业的战略决策提供系统和多维的视角，并推动一般竞争战略从割裂化向融合化演进，特别是对现阶段的中国企业战略制定具有重要意义。     

新形势下高职后勤党建与社区党建共驻共建模式探讨

论文对高职后勤党建与社区党建共驻共建模式的背景及基础进行综述,分析加强社区党建的重要性以及社区党建工作的现状,论述高职后勤党建工作的基础、优势与促进社区共驻共建的重要性,提出高职后勤党建与社区党建共驻共建模式,并对这种共驻共建的模式提出优化思路,以期为现代党建工作提供思路,以供参考。     

Multidimensional brand equity and asymmetric risk

The authors investigate the extent to which central customer-based brand equity dimensions (Differentiation, Relevance, Esteem, Knowledge, and Energy) influence a firm’s systematic risk (i.e., beta) during both market upturns and downturns. The results demonstrate that aggregating upside and downside beta or different dimensions of brand equity masks the true associations which can be seen only in the disaggregate analyses. The authors find that Relevance and Knowledge play roles as stabilizers, showing negative relationships with both upside gains and downside risk, while Esteem plays the role of protector, showing a negative relationship with only downside losses and not influencing upside gains; Energy acts as a booster, being positively associated with a firm’s potential gains in a period of market growth without increasing the firm’s expected losses during a bad market. The positive relationship of Energy with aggregate risk could be misleading as it hides the beneficial effect of Energy as a booster. The authors also find that Relevance is the most important consideration when people make choices in bad market situations, while Energy becomes the most crucial deciding factor in good market situations. Taking advantage of the multidimensional constructs of brand equity while allowing for the asymmetrical characteristics of risk enables managers to capture the differential role of each brand equity dimension in influencing firm risks, which leads to more sophisticated strategic decisions regarding risk management. In addition to general brand strategy, the authors provide tailored brand strategies to firms from different industries or with different financial characteristics.     

跨行政区域协同创新界面管理研究

研究跨行政区域界面管理问题,对于实现协同目标、提升协同绩效具有重要意义。本文主要研究跨行政区域协同创新界面类型、成因,应对界面障碍策略等问题。结果表明,从协同创新演化及其协同机理来看,跨行政区域主体协同创新界面可以分为内外界面两类;跨行政区域协同创新形成的界面主要有制度、知识、技术、交易、组织和管理等表现形式,起因为界面对应的壁垒。最后提出通过构建协同创新平台来解决跨行政区域协同创新界面障碍的设想,设计了平台形式、结构及其运行机制。     

Weekday seasonality of stock returns: The contrary case of China

We document that Chinese stock returns exhibit early-in-the-week effects opposite-signed to those observed worldwide. The period of analysis is 2001–2016. Dominated by individual investors, Chinese stock markets offer unique out-of-sample insight regarding the source of weekday seasonality, ascribed elsewhere to institutional investors’ trading patterns. High returns to the market and to small, speculative stocks early-in-the-week pose a refuter to the mood explanation for the conventional (negative) Monday effect. A battery of tests suggests that the patterns in the Market, SMB, and RMW factors are jointly associated with Chinese individual investors whose demand is tilted towards small, speculative stocks. Our findings point to a potential role of dominant investor type in driving weekday patterns and the RMW premium.     

内外融资条件、融资约束与企业绩效——来自京津冀地区企业调查的新证据*

基于独特的京津冀地区企业调查数据和克服内生性的结构方程模型，本文对融资约束的成因及影响进行了实证分析。分析结果表明，企业自身条件和外部市场环境均对融资约束有重要影响，且企业自身条件对融资约束的影响更强。总的融资约束指标对企业绩效的影响不显著。在区分融资约束的不同维度后，本文发现，融资可得性提高显著促进了企业绩效提升，融资频率增加却降低了企业绩效，而融资获得速度（等待时间）对企业绩效没有统计上的显著影响。进一步的分析表明，无论是正规融资渠道，还是非正规融资渠道，上述结论仍然成立。利用多种政策提高企业的管理水平，改善企业的自身条件，是缓解融资约束的最有效办法。     

叶尔羌河平原绿洲土地生态安全预警演变与时空格局分析

[目的]探索叶尔羌河平原绿洲土地生态安全预警问题及其时空格局变化,旨在为叶尔羌河平原绿洲土地生态安全及可持续利用提供科学的参考依据。[方法]文章运用PSR模型构建预警指标体系,采用熵值法测算各指标权重,对2000—2016年叶尔羌河平原绿洲土地生态安全警情格局进行综合分析,并利用GIS技术分析其2000年、2005年、2010年和2016年土地生态安全空间格局变化,最后运用障碍度模型探索其障碍因子。[结果](1)2000—2016年叶尔羌河平原绿洲土地生态安全综合预警指数总体呈上升态势,生态预警状态由"较不安全"转为"临界安全",警度亦由"重警"变为"中警"。(2)从空间格局来看,空间上各县域土地生态安全水平差异明显,研究初期西部地区土地生态安全状态优于东部地区, 2016年呈现出中部高、东北—西南部低的态势。(3)近17年叶尔羌河平原绿洲各县域土地生态环境状况有所改善,安全状态经历了"极不安全—临界安全—较安全"的发展历程。(4)影响土地生态安全的主要障碍因子包括单位面积耕地农药负荷、人口密度、单位面积耕地化肥负荷、土地垦殖率、人口自然增长率和单位面积耕地地膜负荷等。[结论]研究期间叶尔羌河平原绿洲土地生态安全得到明显的提升与改善,并在良好的方向发展。