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.     

Designs for estimating an extremal point of quadratic regression models in a hyperball

This paper is devoted to studying optimal designs for estimating an extremal point of a multivariate quadratic regression model in the unit hyperball. The problem of estimating an extremal point is reduced to that of estimating certain parameters of a corresponding nonlinear (in parameters) regression model. For this reduced problem truncated locally D-optimal designs are found in an explicit form. The result is a generalization of the results of Fedorov and Müller (1997) for onedimensional quadratic regression function in the unit segment. Received February 2002     

国外历史街区的保护

概述了联合国教科文组织和发达国家在历史街区保护的立法、行政管理、公众参与及资金筹集等方面的做法和经验;分析了城市建设与历史遗产保护之间的关系;认为二者是互为联系,互相促进的,处理好这一关系,城市将得以协调发展.     

公开市场业务与货币政策有效性——1997后中国货币政策传导梗阻的症结探析

1997年后我国一直实施“积极的”货币政策 ,但货币政策在传导过程中出现了梗阻 ,所起的作用远不尽如人意。公开市场业务是中央银行最重要的一个间接货币政策工具 ,作为公开市场业务主体的国债市场是央行公开市场操作的基本依托。我国国债市场在规模、流动性等方面发展滞后 ,仍是一个不成熟、不发达的市场 ,这使我国货币政策传导产生梗阻 ,严重抑制了货币政策效应的发挥     

粤港澳大湾区区块链应用研究--基于世界四大湾区对比分析

粤港澳大湾区作为我国经济最活跃、最开放、经济发展水平最高的区域之一,制造业和信息技术产业发达,具有率先发展区块链产业的优质土壤和先行条件。论文主要通过分析粤港澳大湾区区块链发展的现状,对比世界上其他三大湾区的科技、人才、投资机构等方面,挖掘粤港澳大湾区在对比分析下的发展潜能,分析存在的优劣势,补齐短板,抓住机遇,提出发展粤港澳大湾区区块链行之有效的策略。     

对我国医药企业自主创新演化机制的分析

自主创新是当前商业界和学术界研究比较热的话题。政府相应地制定了一系列的政策和法规来鼓励企业进行自主创新。在这种背景下,我国的医药企业也积极响应国家的政策进行自主创新。然而,医药企业创新在实际操作中的行动方向差异很大。针对这种差异,笔者将医药企业创新划分成新功能创新和新设计创新两种,并且通过对一系列的数据和资料分析后,发现我国的医药企业的创新并非实质上的自主创新即新功能创新,而是新设计创新。文中对产生这种局面的演化机制进行了分析。     

Robustness to the unavailability of data in block designs

We present general results for finding or boundingt _maxB , the maximum number of arbitrary whole blocks of observations which can be removed from a block design, and still leave all of the elementary treatment contrasts estimable. The block sizes may be larger than the number of treatments. The results are applied to BBDs, reinforced BIBDs and BBDs, BTIBDs, and a series of variance balanced incomplete block designs with two block sizes. Also given for most of these designs, are results fort _max, the maximum number of arbitrary, scattered observations that can become unavailable, and still leave all of the elementary treatment contrasts estimable.The work was undertaken while Dr. Whittinghill was visiting Ohio State University, and supported by a grant from the Natural Sciences Division, Colby College, Waterville, Maine.     

由临街地价推算区片价的方法探讨

如何利用临街样点地价推算区片平均地价及基准地价始终是城镇基准地价评估的一个难点。文章利用赤峰市的实际调查数据,分别采用临街贡献率和面积加权两种方法推算区片平均地价,并采用回归分析方法探讨区片价与临街地价之间的关系,结果证明两种方法所推算的区片平均价是基本一致的,而且区片价与临街地价之间呈“反S”曲线关系。     

Exact and approximate D-optimal designs in polynomial regression

If the sample sizen is large enough, then the exact polynomial regression designs obtained by rounding the weights of the approximate D-optimal design to integral multiples of 1/n are D-optimal. This was shown by alaevskiî (1966) and Gaffke (1987). In this note, an efficient algorithm to determine the minimum sample sizen _d for a polynomial model of degreed is derived from a condition given by Huang (1987). Under an additional assumption we show that the conditions of Gaffke and Huang are equivalent; we verify the additional assumption for polynomial degreed40.     

浅谈BM轻骨料连锁砌块施工技术

我国城镇化建设的持续推进和施工技术的飞速发展大大推动了新型建筑材料及其施工技术的发展和应用,例如砌筑、保温、防水等材料。文章以某大型商业楼工程为例,主要介绍了该工程砌体BM轻骨料连锁砌块的工程特难点、施工准备、施工要点及优缺点等内容,同时提出了施工建议。