叶尔羌河平原绿洲耕地利用转型与粮食产量耦合关系研究

［目的］为了解叶尔羌河平原绿洲耕地利用变化与粮食产量的耦合关系，以此优化粮食生产系统的指导方式，提高叶尔羌河平原绿洲粮食产量，协调叶尔羌河平原绿洲耕地利用转型与粮食产量的耦合关系，并为叶尔羌河平原绿洲的粮食安全保护提供一定的政策启示。［方法］文章运用熵值法，以粮食生产相关的“投入”指标为评价依据，耕地利用强度由地均化肥使用强度、有效灌溉比例、复种指数及地均农业机械化水平等4个指标构成，以及利用1990—2016年叶尔羌河平原绿洲粮食产量，分析其耕地利用转型和粮食产量耦合关系时空变化。［结果］(1)1990—2016年叶尔羌河平原绿洲各县耕地利用强度不断增大，并且区域时空格局差异明显，研究初期东北部地区的耕地利用程度强于西部地区，而2016年呈现出西南—中东部强，东北部弱的态势； 从粮食产量方面来看，叶尔羌河平原绿洲粮食产量整体有所增长，空间分异特征较不明显；(2)耕地利用强度—粮食产量耦合类型时空演化特征明显，高耦合值区增加，低耦合区值逐年减少； 从空间上看，叶尔羌河平原绿洲西部地区耕地利用转型与粮食产量耦合度越来越高。(3)耕地利用转型推动粮食生产格局不断演化，叶尔羌河平原绿洲耕地利用转型与粮食产量耦合度在1990—2016年呈现耦合度逐渐增加的趋势，耕地利用转型对保障区域粮食安全具有重要作用。［结论］叶尔羌河平原绿洲粮食产量随着耕地利用转型的不断深入而不断提高，耕地利用转型对粮食安全具有有利影响。     

Where to donate: The geographical distribution of corporate philanthropy in China

An emerging body of literature has demonstrated that corporate philanthropy can be an important part of a company’s business strategy. However, we know relatively little about how companies allocate philanthropic resources to achieve their strategic targets. Using geographical distribution data on corporate philanthropy in China from 2009 to 2016, we provide robust evidence of companies’ revenue-driven regional favoritism. Specifically, companies donate more to regions where they obtain revenue than to other regions. Further evidence suggests that this revenue-driven regional favoritism may have both reputational and political motivations. Further analysis suggests that China’s targeted poverty alleviation policy has compromised revenue-driven regional favoritism while increasing the amount of money donated to poor regions. Overall, we enrich understanding of decision-making on corporate philanthropy. We also demonstrate that companies can use the geographical distribution of corporate philanthropy strategically to obtain consumer and government favor in regions where they operate. The results also provide evidence at the micro company level of the effect of China’s implementation of a targeted poverty alleviation policy.     

SKU performance and distribution: A large-scale analysis of the role of product characteristics with store scanner data

This study investigates the relationship between distribution and market share across various consumer packaged goods (CPG) categories and specific stock keeping units (SKUs). The study identifies product-related characteristics that result in substantive deviations above or below market shares predicted by the distribution – market share relationship. The association of product price, brand (private label [PL] v. national brand [NB]) and pack size with above (or below) expected market share for a given distribution level is analysed. Results indicate larger pack sizes, PL and medium price levels result in market share above what would be predicted by an SKU’s distribution. This presents a source for competitive advantage in markets driven by push–pull dynamics.     

呼伦贝尔草原生态功能区土地利用变化及驱动力分析

[目的]土地利用作为地球表面与人类活动连接的纽带,明确其变化特征及驱动力对于土地利用格局的优化、区域生态环境的改善和土地利用率的提高等具有重要的指导意义。[方法]文章以呼伦贝尔草原生态功能区为例,从土地利用动态度和土地利用转移矩阵来探究研究区在1990—2015年土地利用变化特征。在此基础上,运用主成分分析对研究区土地利用的年际变化进行驱动力分析。[结果]2015年草地面积为329.52万hm~2,占总面积的81.17%,是呼伦贝尔草原生态功能区的主体土地利用类型, 1990—2015年草地总量略有减少,减幅为0.04%;湿地作为研究区第二大土地利用类型,呈现先减后增、整体减少的趋势,整体减幅为0.36%;其他土地面积减少1.39万hm~2,减幅为19.05%;面积增加的土地利用类型中,耕地面积整体上呈现增加趋势,增加8 480hm~2,增幅高达102.60%;人工表面面积增加6 075hm~2,增幅为29.47%;林地面积增加了2 908hm~2,增幅10.48%。草地、湿地和其他土地利用类型表现为净转入特征,耕地、林地和人工表面用地表现为净转出特征。区域经济和农畜因素是研究区土地利用变化的主要驱动力。[结论]草地与其他土地利用类型间的相互转换是呼伦贝尔草原生态功能区土地利用变化的主要特征,区域经济和农畜因素共同影响研究区不同土地利用类型的分布。     

基于POI提取的山地丘陵区乡村旅游空间分布研究*——以重庆市农家乐为例

［目的］通过大数据研究山地丘陵区乡村旅游的空间分布现状及规律，为乡村旅游规划提供参考借鉴。［方法］基于POI抓取技术，以2018年9月抓取到的重庆市1 644家农家乐为研究对象，结合各种地理基础数据资料，借助GIS分析手段，采用最近邻指数、K函数、核密度估计、Getis Ord Gi*热点分析和Moran′s I指数对重庆市农家乐空间分布特征进行研究。［结果］（1）重庆市农家乐分布整体呈现显著聚集趋势，空间自相关性显著； 主城区为聚集—随机分布，空间自相关性不显著； （2）市域范围农家乐聚集程度随空间尺度的增大而增强，主城区特征空间尺度为2139km； （3）农家乐在中部主城区集中连片分布，在主城外零散分布； （4）全市农家乐分布热点区域集中在中南部； （5）7044%的农家乐分布在距城市中心120km的范围内； （6）767%的农家乐分布在A级景区周边10km范围内，且倾向于分布在自然类景区和高等级景区周边； （7）中海拔地区为农家乐分布的主要区域。［结论］提出针对性的改善建议，以优化农家乐产业布局，促进乡村旅游发展与生态文明建设充分结合，更好助力乡村振兴。     

我国水稻产业供给侧结构性改革的思考

[目的]文章在供给侧改革视角下对水稻供需的结构性矛盾等方面进行梳理,分析基于供给侧改革战略的关键环节、实施路径和未来发展趋势,以期为制定我国水稻供给侧改革战略提供参考。[方法]采用文献分析法和调查研究法,从我国水稻生产供求结构、价格"天花板"和成本"地板"双重挤压、水稻生产的资源环境、市场调节等方面分析了我国水稻产业供给侧的现状和存在的问题;通过日本、泰国、中国五常大米政策特点和经验教训的启示,提出了我国水稻产业供给侧结构性改革的策略。[结果]在分析我国水稻产业供给侧现状的基础上,总结得出水稻产业供给侧改革措施:优化水稻产业空间和功能布局,以项目带动水稻产业结构调整,提高和优化稻米品种品质结构、审定标准向抗性优质专用水稻品种倾斜,因地制宜调减水稻生产面积,调整国家收储稻米标准,延长水稻全产业链等。[结论]加速我国水稻产业供给侧改革,能促进稻米产业结构快速升级,有效破解稻米产业的结构性矛盾,增强我国稻米产业可持续发展能力和国际竞争力。     

一种基于量子加密的软件定义网络南向安全防护策略

提出一种以量子加密技术为核心的软件定义网络（Software-defined Network，SDN）的南向安全防护策略，建立了基于量子密钥分发的SDN网络模型并分析了该模型下的身份认证、量子密钥分发和自适应免疫窃听流程。推导出了本策略下窃听攻击强度、用于检测窃听的量子态数目的比例α、系统发现窃听者的概率、密钥分发效率之间的定量关系。通过动态仿真分析确立了不同攻击强度下系统参数α的最优选值区间。SDN控制器可根据该仿真结果，动态地决策系统中α的取值进行自适应免疫密钥分发，实施更为精准的窃听免疫方案。     

中国东北三省与“一带一路”沿线国家贸易格局时空演变

利用2003年~2017年东北三省与"一带一路"沿线国家进出口贸易数据,采用地理集中度、位序变动指数、综合贸易份额指数、HM指数分析东北三省与沿线国家贸易格局及特征的变化。结果表明:东北三省与"一带一路"沿线国家的贸易往来日益密切,贸易总额大幅增加,尽管东北三省与东北亚地区的贸易份额有所下降,但东北亚地区始终是东北三省的贸易重心。东北三省与沿线国家贸易依赖度不断提高,具有明显的不对称性,表现出显著的单向依赖。从进出口商品结构来看,东北三省向沿线国家出口的资源密集型和劳动密集型商品占比下降,技术密集型商品占比有较大提升,出口商品更加多元化,附加值和科技含量进一步提高,进口商品结构相对稳定,主要为资源密集型和技术密集型商品。     

Tests of Normality of Functional Data

The paper is concerned with testing normality in samples of curves and error curves estimated from functional regression models. We propose a general paradigm based on the application of multivariate normality tests to vectors of functional principal components scores. We examine finite sample performance of a number of such tests and select the best performing tests. We apply them to several extensively used functional data sets and determine which can be treated as normal, possibly after a suitable transformation. We also offer practical guidance on software implementations of all tests we study and develop large sample justification for tests based on sample skewness and kurtosis of functional principal component scores.     

The performance of performance appraisal systems: understanding the linkage between appraisal structure and appraisal discrimination complaints

Abstract

Employee perceptions of the fairness of performance evaluations are critical to the success of any appraisal system. Research on performance management includes extensive studies on how bias emerges in the appraisal process. Despite this, there is no empirical evidence linking formal discrimination complaint filings – a key measure of bias - and performance appraisals. To close this gap, we conduct an empirical analysis using information on appraisal systems and discrimination complaints from the US federal government. Our findings suggest that agencies with better-designed appraisal systems will experience higher appraisal-related discrimination complaints, contrary to expectations. In particular, an expansion of training and voice opportunities are associated with an increase in appraisal discrimination complaints, while increased differentiation between performers is not consistently associated with complaints. For managers struggling with performance management, it may be better to spend time on improving performance-focused interpersonal communication rather than redesigning appraisal systems.