金属类上市公司股权结构与经营绩效关系的研究

公司治理结构的改进是中国整个经济体制改革以及资本市场发展的一个非常重要的内容,股权结构是公司治理结构和经营绩效的基础,股权结构的不同在公司治理结构上表现出差异,从而对公司经营绩效产生影响。当前,我国金属上市公司经营绩效不佳,除了公司治理结构不合理和不完善外,上市公司股权结构不合理是一个关键因素。要提高我国上市公司的经营绩效,既要完善公司治理结构,也要优化上市公司的股权结构,使之趋于合理。     

基于多维频谱地图的干扰规避

针对复杂电磁环境下卫星移动通信系统可靠通信需求,利用频谱地图多维数据呈现优势,提出了基于多维频谱地图的干扰规避方法。通过建立卫星移动通信系统波束、时隙、子频带、干扰强度等多维信息关联的频谱地图,利用数据挖掘方法对频谱可用情况进行预测,基于预测结果及用户QoS(Quality of Service)需求生成干扰规避策略,通过星地联合频谱资源调配实现系统干扰规避。该方法为卫星移动通信系统干扰规避提供了一种全新的思路,可提升卫星移动通信系统干扰防护能力。     

The role of imports for exporter performance in Peru

Using highly disaggregated firm‐level customs data for imports and exports in Peru over the 2000–12 period, we explore the relationship between imports of intermediate inputs and firm export performance. The evidence shows that greater use, variety and quality of imported intermediate inputs are significantly correlated with higher export levels and growth, greater market diversification and higher export quality at the firm level, even after controlling for unobserved firm heterogeneity. Exporter–importers exposed to higher tariffs, and non‐tariff measures import less in total and exhibit lower import variety, whereas those using an advance customs clearance procedure designed to facilitate imports exhibit higher imports and a more diversified bundle of inputs.     

Costs of financial instability, household-sector balance sheets and consumption

Extant work on costs of financial instability focuses on fiscal costs and declines in aggregate GDP following banking crises. We estimate effects of banking and currency crises on consumption in 19 OECD countries, showing consumption plays an important role in the adjustment following a crisis, and effects are not captured solely by the impact of crises on standard consumption determinants, income and wealth. Additional effects, attributable to factors such as time-varying confidence, uncertainty and credit rationing, are aggravated by high and rising leverage, despite financial liberalisation easing liquidity constraints. High leverage implies that banking crises taking place now could have greater incidence than in the past.     

Stock markets, banks, and economic growth: Empirical evidence from the MENA region

Over the last four decades, a wide theoretical debate is concerned with the fundamental relationship between financial development and economic growth. Recent studies shed some light on the simultaneous effect of banks and financial system development on growth rather than a separate impact. The empirical study is conducted using an unbalanced panel data from 11 MENA region countries. Econometric issues will be based on estimation of a dynamic panel model with GMM estimators. Thus, peculiarities of MENA region countries will be detected. The empirical results reinforce the idea of no significant relationship between banking and stock market development, and growth. The association between bank development and economic growth is even negative after controlling for stock market development. This lack of relationship must be linked to underdeveloped financial systems in the MENA region that hamper economic growth. Then, more needs to be done to reinforce the institutional environment and improve the functioning of the banking sector in the MENA region. Based on these results, other regions at the same stage of financial development such as Africa, Eastern Europe or Latin America should improve the functioning of their financial system in order to prevent their economies from the negative impact of a shaky financial market.     

非寿险公司偿付能力额度和现金管理的研究

本文运用2001年～2006年20家保险公司的面板数据,比较分析了基于保险监管与基于比率法得到的最低偿付能力额度的差别,认为目前我国保险公司最低偿付能力额度制定过低,并且发现我国基于净赔款支出的方法在偿付能力额度制定中不能发挥作用;实证研究了保险公司现金持有量的影响因素,认为中资保险公司现金持有量主要受资产负债率、投资收益率、非投资资产率和流动资产率四个因素的影响,而外(合)资保险公司的现金持有量则主要受赔付率和非投资资产率的影响,差异较大。     

Segmentation and time-of-day patterns in foreign exchange markets

This paper sheds light on a puzzling pattern in spot foreign exchange markets: domestic currencies appreciate (depreciate) systematically during foreign (domestic) working hours. This phenomenon spans many years and several exchange rates, and overrides calendar effects. We argue that it is mainly due to liquidity and inventory patterns that emerge from the combination of two factors: domestic agents tend to be net buyers of foreign currency and to trade mostly in their country’s working hours. The prevalence of domestic (foreign) traders demanding the counterpart currency during domestic (foreign) working hours implies sell-price (buy-price) pressure on the domestic currency during domestic (foreign) working hours.     

Detecting jumps from Lévy jump diffusion processes

Recent asset-pricing models incorporate jump risk through Lévy processes in addition to diffusive risk. This paper studies how to detect stochastic arrivals of small and big Lévy jumps with new nonparametric tests. The tests allow for robust analysis of their separate characteristics and facilitate better estimation of return dynamics. Empirical evidence of both small and big jumps based on these tests suggests that models for individual equities and overall market indices require incorporating Lévy-type jumps. The evidence of small jumps also helps explain why jumps in the market index are uncorrelated with jumps in its component equities.     

航天测控信号处理平台的现状与发展趋势

航天测控信号处理平台是航天地面测控系统中不可或缺的核心处理设备。以近十年实际工作中开发交付的一系列航天测控信号处理平台为研究对象,通过对各平台架构、功能性能的系统分析,总结了航天测控信号处理平台的发展现状并梳理了航天测控信号处理平台的发展趋势。     

Analysing customers' reviews and ratings for online food deliveries: A text mining approach

The purpose of this study was to explore the relationship between online reviews and ratings through text mining and empirical techniques. An Indian food delivery portal ( Zomato.com ) was used, where 50 restaurants on Presence Across Nation (PAN) basis were selected through stratified random sampling. A total of 2530 reviews were collected, scrutinized, and analysed. Using the NVivo software for qualitative analysis, seven themes were identified from collected reviews, out of which, the ‘delivery’ theme was explored further for identifying sub-themes. Linear regression modelling was used to identify the variables affecting delivery ratings and sentiment analysis was also performed on the identified sub-themes. Regression results revealed that hygiene and pricing (delivery subthemes) demonstrated lower delivery ratings. These variables can be established as indicators for restaurants and related online food delivery services to build their business model around them. Similarly, negative sentiments were observed in pricing and hygiene sub-themes. Restaurants and online food services can enhance hygiene levels of their food delivery process in order to receive higher delivery ratings. Similarly, pricing of food items can be modified such that customers are not deterred from ordering the items—food and ordering service do not become cost-prohibitive. This study devised a standardized methodology for analysing vast amounts of online user-generated content (UGC). Findings from this study can be extrapolated to other sectors and service industries such as, tourism, cleaning, transportation, hospitals and engineering especially during the pandemic.