Complex Network of Aviation E-Services in the Belt and Road Initiative: A Heuristic Study of Small Data based on Block Modeling

ABSTRACT

The aviation e-service system is an important part of support for business communication in regions covered by Belt and Road initiative. In exploring the role of airline companies in this system, we examine the structure of the network, which consists of airlines interconnections based on small data of individual attributes of aviation companies in aviation e-services, and study these interconnections across different groups using block modeling. The heuristic solution of airline companies in development of international communication and cooperation is further discussed. Among our policy implications for global managers, we suggest the enhancement of cross-regional cooperation among airlines.     

EMPIRICAL PERFORMANCE OF GARCH MODELS WITH HEAVY‐TAILED INNOVATIONS

We introduce a new type of heavy‐tailed distribution, the normal reciprocal inverse Gaussian distribution (NRIG), to the GARCH and Glosten‐Jagannathan‐Runkle (1993) GARCH models, and compare its empirical performance with two other popular types of heavy‐tailed distribution, the Student's t distribution and the normal inverse Gaussian distribution (NIG), using a variety of asset return series. Our results illustrate that there is no overwhelmingly dominant distribution in fitting the data under the GARCH framework, although the NRIG distribution performs slightly better than the other two types of distribution. For market indexes series, it is important to introduce both GJR‐terms and the NRIG distribution to improve the models’ performance, but it is ambiguous for individual stock prices series. Our results also show the GJR‐GARCH NRIG model has practical advantages in quantitative risk management. Finally, the convergence of numerical solutions in maximum‐likelihood estimation of GARCH and GJR‐GARCH models with the three types of heavy‐tailed distribution is investigated.     

深圳市线路板蚀刻废液中铜、砷、铅、汞、镉含量调查

对深圳市60家线路板企业含铜蚀刻废液中铜、砷、铅、汞、镉含量的检测结果显示:酸、碱性蚀刻废液铜含量范围分别为38.6～167.9g/L、53.7～171.8g/L,,通过测量比重推算铜含量适用于碱性废液但不适合酸性废液.56个样品可检出砷(大于3mg/L).56个样品未检出铅(小于5mg/L),其余4个铅含量偏高.所有样品汞、镉均未检出,含量分别小于4mg/L、0.3 mg/L.将各样品砷、铅、汞、镉含量实测值换算为铜含量100ga.时的相对值后发现,上述四元素在蚀刻废液中的正常值分别为＜12mgAs/L、＜5 mg Pb/L、＜4 mg Hg/L、＜0.3 mg Cd/L.     

浅谈企业房地产价值信息的背离与披露

房地产交易中企业财务报告反映的房地产账面价值与实际市场价值的背离程度大,造成了企业资产价值的“低估”。该文试图分析引起企业房地产账面价值与实际市场价值背离的原因,提出了财务报告使用者了解企业房地产实际价值的几种可操作方法。     

A note on the existence of unique equivalent martingale measures in a Markovian setting

Simple sufficient conditions for the existence of a unique equivalent martingale measure are provided. Furthermore, these conditions give us a handle on situations where an equivalent martingale measure cannot exist. The existence of a unique equivalent martingale measure is of relevance to problems in mathematical finance. Two examples of models for which the question of existence was unresolved are studied. By means of our results existence of a unique equivalent measure up to an explosion time is proved.     

国际电子商务中的语言差异问题及其解决策略

在电子商务的全球化过程中，各地区的语言、文化差异。给国际电子商务展开带来了一定的障碍，本文论述了语言问题产生的根源，并提出了相应的解决策略，以期对国内企业的未来发展有所助益。     

An Average Derivative Estimation of Stochastic Frontiers

This paper utilizes the average derivative estimation of Stoker (1986) and the pesudo-likelihood estimation of Fan, Li, and Weersink (1996) to estimate a semiparametric stochastic frontier regression, y = g(x) + , where the function g(.)is unknown and is a composite error in a standard setting. The proposed semiparametric method of estimation is applied to data on farmers' credit unions in Taiwan. Empirical results show that the banking services of the farmers' credit unions is subject to economies of scale, but high degree of cost inefficiency in operation.     

我国危险品物流管理对策研究

通过对我国危险品物流的现状分析,指出了加强危险品物流管理的必要性,并阐述了加强危险品物流管理的意义。在对国外危险品物流管理方法进行总结的基础上,分析了我国政府和危险品物流企业在危险品物流管理中的作用和相互关系,并提出了加强危险品物流管理的一些具体对策和措施。     

一种城市物流分区配送方法的研究

提出了基于区位理论的城市物流分区配送的数学模型和算法实现方法，实验证明。该方法具有计算效率高，求解精度适中的特点。     

"按劳分配"在理论与实践中遇到的困难及其对策

文章在阐述我国个人收入分配制度确立的理论和实践依据的基础上，分析了“按劳分配”在理论与实践中遇到的难题，即“各尽所能”遇到的困难；劳动力成为商品与按劳分配的冲突；“劳”的理解问题；不同所有制、不同行业、不同职业、不同地区、城乡居民、高低收入群体收入差距不断拉大对按劳分配提出的挑战等，进而提出解决这些困难的主要对策。