大跨度天基数据链的TDD时隙调度分析与优化

针对天基数据链系统卫星间的传播时延较大且节点间距离变化较大等特点，提出了一种提高时频资源利用率、提升系统容量、减小时延的方法。在时分多址与空分多址相结合的接入方式下，进行了时隙调度的分析与优化，利用卫星星座的空间复用与大跨度传播时延特性，采用时隙编排、收发状态调整、帧格式优化等手段，将信道利用率和系统容量提升了1倍，将卫星节点在某一方向获得服务的平均等待时间缩短为原来的1/4，提高了天基数据链系统的服务质量。     

Public and private healthcare services: What drives the choice?

This paper has explored patients' propensity to consume private healthcare services. We based our analysis on the typical tangible and intangible (for instance, responsiveness, reliability, assurance and staff empathy) domains of the SERVQUAL and SERVPERF methods. These variables may influence patients' decision-making when they choose between the public and private sectors. We combined factor analysis (to obtain a set of latent factors related to perceived quality) and a partial proportional ordered logit model to estimate the probability that a patient would access private healthcare services. To test the main hypotheses, we used data from a stratified sample in Sardinia, a peripheral region of Italy. Findings revealed that private and public healthcare are substitutes, especially for primary/specialised services. Patients who used public healthcare frequently and had a low income were unlikely to change to private healthcare or to recommend private services. ‘Responsiveness’ and perceptions on ‘tangibles’ were key in determining the probability that a patient would choose and recommend private services. This paper offers a multifaceted framework that can be used in future research to generalise these findings, especially in insular regions that are constrained by mobility.     

信息不对称下的逆向供应链激励契约设计

文章运用委托一代理理论,研究了一个包含单一供应商和单一零售商的逆向供应链系统,讨论了逆向选择下此系统中零售商的激励扭曲问题,并求出了该情形下供应商用于协调逆向供应链的最优契约。     

郊区农村劳动力乡城迁移意愿研究——以广州市为例

依据农户抽样调查数据,运用逻辑回归模型,对特大城市郊区农村劳动力迁移决策的主要影响因素进行分析。     

Cash Management, Payment Patterns and the Demand for Money

We analyse cash management and payments behaviour using 1990–1994 panel data for Dutch households. The results largely confirm the transactions demand for money theory, including an income elasticity of substantially less than one, and they are consistent with the hypothesis of technology resulting in households' economizing on currency balances. The results indicate up to 40 per cent lower transactions balances in the future, which is affirmed by direct questioning on future expectations. The effect on total money outstanding is considerably lower, due to significant amounts of missing money in hoards, which are insensitive to new developments in the payments system.     

A GPS data-based analysis of built environment influences on bicyclist route preferences

This study examines the effects of built environment features, including factors of land use and road network, on bicyclists' route preferences using the data from the city of Seattle. The bicycle routes are identified using a GPS dataset collected from a smartphone application named “CycleTracks.” The route choice set is generated using the labeling route approach, and the cost functions of route alternatives are based on principal component analyses. Then, two mixed logit models, focusing on random parameters and alternative-specific coefficients, respectively, are estimated to examine bicyclists' route choice. The major findings of this study are as follows: (1) the bicycle route choice involves the joint consideration of convenience, safety, and leisure; (2) most bicyclists prefer to cycle on shorter, flat, and well-planned bicycle facilities with slow road traffic; (3) some bicyclists prefer routes surrounded by mixed land use; (4) some bicyclists favor routes which are planted with street trees or installed with street lights; and (5) some bicyclists prefer routes along with city features. This analysis provides valuable insights into how well-planned land use and road network can facilitate efficient, safe, and enjoyable bicycling.     

Free-Agency and the Competitiveness of Major League Baseball

I investigate whether the removal of the reserve clause in professional baseball affected the competitive nature of the industry in the context of whether the distribution of team wins has been affected by free-agency. Unlike previous studies which use the standard deviation of winning percentage, I use a more sensitive measure of parity. I calculate the deviations of the Herfindahl-Hirschman Index of team wins from the competitive ideal during 1920 to 1996 and relate them to player-talent distribution and structural changes in the industry. I isolate the structural effect of free-agency and find that it has adversely affected the parity of the American League but that it has had no statistical influence on the parity of the National League.     

基于Logit模型的视频流媒体用户付费意愿及其影响因素研究——以爱奇艺为例

爱奇艺作为国内头部视频流媒体之一,面临用户付费意愿薄弱的困境。基于整合型技术接受模型(UTAUT)和感知价值理论(CPV)的相关变量提出假设,构建研究模型。通过Logit模型展开实证研究,结果显示感知有用性、感知成本、社会影响、个人付费意识对爱奇艺用户的付费意愿有显著影响。对此,提出深耕优质内容IP、丰富价格体系、打造口碑营销、聚焦年轻人的情绪价值四点建议,为爱奇艺探索新的战略提供有针对性的对策建议。     

一种基于纠缠交换的远程量子链路建立策略

提出一种以纠缠交换作为核心技术的远程量子链路建立策略,建立了基于链路状态矩阵的量子链路模型并分析了纠缠交换的实现和矩阵表示。提出了链路协议栈以及端到端的建立策略,分析了矩阵控制下的纠缠交换和纠缠纯化流程,计算得出了在基于自动重传请求(ARQ)协议经典信息辅助下的链路时延和吞吐量与节点数、误帧率、平均距离、操作成功率之间的定量关系。仿真结果表明：处于同一状态区间内的链路性能随节点数呈现出较为一致和平缓的变化;不同区间内的链路性能差异较为显著,在节点平均距离为1 km、经典信息误帧率为0、纠缠保真度为0.98的情况下,当节点数分别为32、33和34时,链路时延分别为1.0770 ms、1.0903 ms和1.6690 ms,链路吞吐量分别为0.9285 kb/s、0.9172 kb/s和0.5992 kb/s。