矿山地质环境治理工程预算标准体系研究刍议

开展矿山地质环境治理工程预算标准体系研究,对于完善国土资源部部门预算管理制度,实现项目预算规范化、标准化、科学化意义重大。文章就矿山地质环境治理工程预算标准体系研究的背景及意义、原则及依据、内容及重点、思路及方法进行了探讨。     

基于全流程的进口B2C跨境电商商品质量风险评估体系构建

进口B2C跨境电商商品质量风险的有效评估是实现高质量监管的基础。文章基于进口B2C跨境电商活动全流程监管,对涉及商品质量的境外采购、仓储物流、平台销售、商品售后四个环节进行风险分析,构建了包括风险识别、评估指标体系、风险度量、风险等级划分以及风险原因追溯五个部分的进口B2C跨境电商商品质量风险评估系统,并以杭州市进口B2C跨境电商企业为例,进行实证研究。研究结果表明,杭州市进口B2C跨境电商企业的风险点主要集中于供应商资源、商品溯源、售后保障、商品质量标准认知四个方面,且不同规模企业的商品质量风险存在异质性。据此对企业和政府提出了相关政策建议。     

基于多传输手段的自组网路由协议研究

为了实现多手段通信资源的全局共用与优化使用,针对通信节点多传输手段的自组网特点,提出了一种基于节点MPR的OLSR路由协议（N-OLSR）。首先对HELLO报文格式进行修改,加入Port字段,根据通信手段的不同,对Willingnes字段的值做出修改,用接口索引来代替接口IP地址,将链路带宽大的信道用大索引号表示。以此为基础,从全局出发制定路由策略,将通信节点作为MPR的选举对象,改变传统方法在每个接口上进行MPR选举的机制。最后,通过仿真实验来测试N-OLSR路由协议的性能。结果表明,改进的协议完成了MPR从接口到节点的转移,降低了源节点将一跳邻居节点选为MPR的频率,从而减少TC报文的产生以及洪泛;改进的路由协议能够减少控制开销,降低丢包率,加快网络收敛速度。研究结果可为多传输手段的移动自组网提供一种可靠的路由协议方案,并且信道带宽越小越能发挥其性能。     

Assessing mainland Chinese tourists' satisfaction with Hong Kong using tourist satisfaction index

The purpose of this study is to test a two‐step tourist satisfaction index framework empirically. The first step estimates sectoral‐level satisfaction indexes based on a structural equation model, and the second obtains an overall tourist satisfaction index by conducting second‐order confirmatory factor analysis. This study is a pilot test of the theoretical framework based on three tourism‐related service sectors in Hong Kong. The results indicate that mainland Chinese tourists are most satisfied with the hotel sector in Hong Kong, followed by the retail sector, and least satisfied with local tour operators. The aggregate tourist satisfaction index is 74.04 out of 100. The results of this study have important practical implications for long‐term destination management. Copyright © 2010 John Wiley & Sons, Ltd.     

A Polarization Index for Overlapping Groups

The well‐known index of income bipolarization proposed by Wolfson (1994) requires two groups to be split according to the median income and, therefore, to be non‐overlapping. The aim of this paper is to propose a new polarization index in the spirit of the Wolfson index. It allows for any possible partition of the population in two or more (also overlapping) groups. The new index maintains the simplicity and immediate comprehension of the Wolfson index, though being much more flexible. An application is then provided for German and Italian income data.     

成都市国际化营商环境升级版战略研究--基于万博新经济研究院营商环境指数的分析

打造营商环境是促进经济的重要环节,提升营商环境是增强城市竞争力和吸引力的手段。论文通过引入万博新经济研究院发布的《后疫情时代中国城市营商环境指数评价报告(2020)》,多角度对比分析成都与国内先发城市,发现成都在营商环境方面的优势与短板,最后得出改进措施,旨在为成都打造国际化营商环境提供理论依据。     

基于超效率SBM模型的珠三角区域物流效率及影响因素分析

物流效率是反映物流绩效水平的重要指标.以珠三角城市群9个地市(不含香港特别行政区和澳门特别行政区)为研究对象,基于珠三角9个地市2010—2019年的面板数据,采用超效率SBM模型和GM L指数,测算珠三角城市群各地市的物流效率值及变动趋势.研究表明:技术进步是珠三角区域物流效率提升的主要因素,综合管理水平有待提高;珠三角区域的物流效率总体处于中等偏上效率水平且变化不大,深圳市物流效率水平提升较快且效率最高,东莞市物流效率最低,珠海市效率值起伏最为明显,整个测算期间呈"W"形走势.为进一步探讨外部因素对珠三角区域物流效率的影响程度,选取Tobit模型进行回归分析,发现区位优势对珠三角地区物流效率的提升起到了重要的作用.     

How to fight against southern pine beetle epidemics: An insurance approach

The southern pine beetle (SPB) is among the leading biological agents killing southern pine species in the eastern United States. In light of recognized spatiotemporal autocorrelation in SPB outbreaks, we devise a spatiotemporal block bootstrapping method that can be applied to analyze spatiotemporally dependent infestations. We also identify the relevant risk determinants and evaluate their impacts on the frequency of SPB outbreaks. For example, we find forest type, climate, and natural disasters like storm and forest management are all significantly associated with SPB risks. Using the results of a statistical model, we design a county-level group index insurance plan that generates estimates of actuarially fair premium rates for timber stands containing southern pine species. Given that no government-provided compensation scheme for SPB epidemics currently exists, application of this new insurance product could reduce forest owners losses. Our study offers an approach to analyzing and protecting against risks of other destructive pests affecting the timber sector.     

How Fast are Semiconductor Prices Falling?

The Producer Price Index (PPI) for the U.S. suggests that semiconductor prices have barely been falling in recent years, a dramatic contrast to the rapid declines reported from the mid‐1980s to the early 2000s. This slowdown in the rate of decline is puzzling in light of evidence that the performance of microprocessor units (MPUs) has continued to improve at a rapid pace. Over the course of the 2000s, the MPU prices posted by Intel, the dominant producer of MPUs, became much stickier over the chips' life cycle. As a result of this change, we argue that the matched‐model methodology used in the PPI for MPUs likely started to be biased after the early 2000s and that hedonic indexes can provide a more accurate measure of price change since then. MPU prices fell rapidly through 2004 on every price measure we present, with the PPI declining at an even quicker pace than the hedonic indexes. However, from 2004 to 2009, our preferred hedonic index fell faster than the PPI, and from 2009 to 2013 the gap widened further, with our preferred index falling at an average annual rate of 42 percent, while the PPI declined at only a 6 percent rate. Given that MPUs currently represent about half of U.S. shipments of semiconductors, this difference has important implications for gauging the rate of innovation in the semiconductor sector.     

基于县统筹财政分权视角下的地方义务教育公平研究 ——来自山东省的实例

由于基层政府长期存在财力事权上的不均衡,我国基层地区义务教育供给存在着差距。2001年的"以县为主"的县统筹财政制度开始实行,义务教育的负责主体变成了县级政府。借助2002年到2016年的山东省县级数据,运用泰尔指数作为分析工具,结合此期间山东省出台的教育改革措施,分析其对于缩小义务教育差异的影响。研究发现,政策制度仅仅改善了中等收入县级地区之间的差距,对于高收入和低收入地区并没有太好的效果,就目标而言,由于县级各地区上经济实力和义务教育规模的固有差距,导致无法取得理想中的效果。