国家安全视角下的生物资源安全与保护制度研究

2014年习近平总书记提出了“总体国家安全观”理念,这是我国社会主义理论制度的又一伟大创新。本文从本次新冠疫情对于国家综合安全利益的影响出发,结合疫情对国家安全要素的扩张以及对国家安全利益的威胁等实际情况,探寻本次疫情暴露出的国家安全制度中存在的问题,以期完善我国以生物资源和公共卫生安全为代表的公共安全管理制度和疫情防控制度。     

基于PSO-SAS的联合侦察任务规划

针对联合侦察筹划中任务规划阶段机动侦察平台阵位与路线确定困难的问题，提出了一种基于粒子群优化-稀疏A星(Particle Swarm Optimization—Sparse A-star,PSO-SAS)算法的规划方法。该方法综合考虑侦察装备机动性能以及敌火力威胁、地形等因素，在侦察阵位规划上，建立了阵位综合评估模型，并利用粒子群算法进行阵位寻优；在路线规划上，采用稀疏A*算法进行航迹规划，通过将机动性能、安全距离、路程等约束引入搜索过程，缩短最优路线的计算时间。仿真试验验证了所提方法生成的侦察阵位和路线能够满足侦察任务要求。     

利用双正交小波变换优化G3-PLC系统性能

为了提高G3-PLC(G3-Power Line Communication)在复杂信道环境下通信的可靠性，提出了基于双正交小波变换的正交频分复用（Discrete Wavelet Transform-Orthogonal Frequency Division Multiplexing,DWT-OFDM）。通过双正交小波变换减小复杂信道环境下G3-PLC通信系统中OFDM载波间干扰，并通过合理减少循环前缀，优化传输效率，降低峰均比。在DWT-OFDM的G3-PLC系统中，通过不同小波基性能分析与对比，利用bior6.8双正交小波基进行系统性能优化。将DWT-OFDM的G3-PLC系统在实际电力线噪声库环境下进行实验分析，仿真结果表明，在平均误码率为10-3量级时，性能有5 dB左右提升，通信效率由40%提高至54%；结合限幅法，峰均比由11 dB降低至8 dB，通信性能极大优于基于FFT-OFDM的G3-PLC系统。     

服务贸易视角下中日韩贸易竞争与互补分析

作为东亚地区经济发展的核心,中日韩三国服务贸易的发展一直备受关注。日本服务贸易的竞争力水平是中日韩三国中最强的,其次是中国,最后是韩国。中国具有竞争力的行业主要是建筑、电信、计算机和信息以及其他商业服务,韩国具有竞争力的行业主要是旅游和建筑服务,日本具有竞争力的行业主要是运输、建筑、专业权利和特许服务以及政府服务。进一步对中日韩服务贸易的影响因素进行分析发现:人均国内生产总值、外商直接投资、货物贸易出口额和服务贸易开放水平与中日韩服务贸易竞争力水平都呈显著正相关关系,其中,服务贸易开放度水平对中日韩服务贸易竞争力水平的影响最大,外商直接投资对中日韩服务贸易竞争力水平的影响最小。     

Research on a stock-matching trading strategy based on bi-objective optimization

In recent years, with strict domestic financial supervision and other policy-oriented factors, some products are becoming increasingly restricted, including nonstandard products, bank-guaranteed wealth management products, and other products that can provide investors with a more stable income. Pairs trading, a type of stable strategy that has proved efficient in many financial markets worldwide, has become the focus of investors. Based on the traditional Gatev–Goetzmann–Rouwenhorst (GGR, Gatev et al., 2006) strategy, this paper proposes a stock-matching strategy based on bi-objective quadratic programming with quadratic constraints (BQQ) model. Under the condition of ensuring a long-term equilibrium between pairedstock prices, the volatility of stock spreads is increased as much as possible, improving the profitability of the strategy. To verify the effectiveness of the strategy, we use the natural logs of the daily stock market indices in Shanghai. The GGR model and the BQQ model proposed in this paper are back-tested and compared. The results show that the BQQ model can achieve a higher rate of returns.     

Data revisions to German national accounts: Are initial releases good nowcasts?

Data revisions to national accounts pose a serious challenge to policy decision making. Well-behaved revisions should be unbiased, small, and unpredictable. This article shows that revisions to German national accounts are biased, large, and predictable. Moreover, with use of filtering techniques designed to process data subject to revisions, the real-time forecasting performance of initial releases can be increased by up to 23%. For total real GDP growth, however, the initial release is an optimal forecast. Yet, given the results for disaggregated variables, the averaging out of biases and inefficiencies at the aggregate GDP level appears to be good luck rather than good forecasting.     

Beyond antitrust populism: Towards robust antitrust

The populist use of competition policies is on the rise again, associated with the growth of big-tech companies in the era of digital platforms. This article sees antitrust populism as a re-emerging force in the United States and Europe via greater politicisation of competition law enforcement. It addresses the basic tenets of antitrust populism in order to expose the fundamental problems that populist use of competition law entails. I argue for a rethink of antitrust policy on the intellectual foundations laid down by what Mark Pennington describes as ‘robust political economy’. We need greater regulatory humility and antitrust enforcement which takes both innovation and welfare seriously.     

Financial analyst coverage for U.S. firms facing foreign competition: Evidence from trade liberalization

This study examines financial analyst coverage for U.S. firms following an increase in foreign product market competition. To capture exogenous shocks to domestic firms' competitive environments, we exploit a quasi‐natural experiment from large import tariff reductions over the 1984 to 2005 period in the manufacturing sector. Using data for the years before and after large tariff reductions, our difference‐in‐differences analysis shows evidence of a significant decrease in analyst coverage for incumbent U.S. firms when they face greater entry threat from foreign competitors. We also find that analysts with less firm‐specific experience and less accurate prior‐period forecasts are more likely to stop following the domestic firm when foreign competition intensifies. Overall, the findings suggest that foreign product market competition from global trade liberalization is an important determinant of financial analysts' coverage decisions.     

Going green,going clean: Lean‐green sustainability strategy and firm growth

Despite the widespread recognition of the paybacks of “going green” and “going clean,” limited research has focused on the impact of lean‐green strategy on firm growth. In this study, we contribute to strategy and environmental sustainability literatures by investigating the possibility that the influence on lean‐green strategy and firm growth is driven by different levels of industry competition, managerial power, and family ties. Using panel data from 732 firms in four major industrialized economies (the United States, Germany, France, and the United Kingdom), we found that lean‐green strategy positively relates to firm growth and this relationship is amplified at higher levels of competition, managerial power, and family ties. Theoretical and practical implications of the study are also discussed.