低山丘陵区高标准基本农田建设限制性因子识别与建设方向

[目的]识别低山丘陵区高标准基本农田建设的限制性因素。[方法]基于GIS平台,运用AHP-熵权法,以重庆市高标准基本农田建设的6个典型项目区为例,从田块禀赋、设施配套、投入产出水平、社会经济水平及生态环境等5方面选取15项指标,识别低山丘陵区高标准基本农田建设的限制性因素。[结果](1)低山丘陵区高标准基本农田建设限制性因素依次存在中低山缓坡区丘陵宽谷区河谷平坝区的趋势,且不同微地貌条件下的限制性因素存在一定差异。(2)从项目区评价分值来看,河谷平坝区耕地质量分值最高,为高标准基本农田重点建设区域;丘陵宽谷区建设条件与耕地质量较好,是高标准基本农田建设次重点区域;而中低山缓坡区限制性因子较多,高标准基本农田建设适宜性较差。(3)文章研究的AHP-熵权法可以适用于其他地貌类型单元下高标准基本农田建设限制性因素识别研究。[结论]因地制宜,科学合理安排低山丘陵区微地貌类型下的高标准基本农田建设内容与整治任务。     

多孔连续斜交框架桥顶进施工过程受力分析

城市道路下穿铁路框架桥顶进施工的关键是合理控制桥梁主体结构的受力。为了对框架桥顶进施工过程进行受力特性分析，采用Midas有限元软件模拟了框架桥在滑板上开始顶进、框架桥重心即将离开滑板、框架桥顶进即将就位三个施工阶段。结果表明，该框架桥的施工过程是安全可靠的，同时结合工程项目实际给出了顶进施工的注意事项。该方法可用来指导类似工程顶进施工过程的受力分析和施工控制。     

基于G1法的飞行签派员资质能力评估

为了强化飞行签派员的人员资质管理,提升签派员的运行控制能力,保证民航行业持续稳定安全,结合法规和国航西南分公司运行控制中心的考核制度,从知识、技能、从业经验、专业任职资格、业绩成果及工作态度等6个方面构建了飞行签派员能力评估体系,采用G1法确定指标权重并进行综合打分,以国航"7·10"误关组件导致座舱失压后继续飞行事件为例,对评估指标进行实例验证,为航空公司评估飞行签派员资质能力提供了一套实际可用的量化指标和系统化评估方法。     

叶尔羌河平原绿洲土地生态安全预警演变与时空格局分析

[目的]探索叶尔羌河平原绿洲土地生态安全预警问题及其时空格局变化,旨在为叶尔羌河平原绿洲土地生态安全及可持续利用提供科学的参考依据。[方法]文章运用PSR模型构建预警指标体系,采用熵值法测算各指标权重,对2000—2016年叶尔羌河平原绿洲土地生态安全警情格局进行综合分析,并利用GIS技术分析其2000年、2005年、2010年和2016年土地生态安全空间格局变化,最后运用障碍度模型探索其障碍因子。[结果](1)2000—2016年叶尔羌河平原绿洲土地生态安全综合预警指数总体呈上升态势,生态预警状态由"较不安全"转为"临界安全",警度亦由"重警"变为"中警"。(2)从空间格局来看,空间上各县域土地生态安全水平差异明显,研究初期西部地区土地生态安全状态优于东部地区, 2016年呈现出中部高、东北—西南部低的态势。(3)近17年叶尔羌河平原绿洲各县域土地生态环境状况有所改善,安全状态经历了"极不安全—临界安全—较安全"的发展历程。(4)影响土地生态安全的主要障碍因子包括单位面积耕地农药负荷、人口密度、单位面积耕地化肥负荷、土地垦殖率、人口自然增长率和单位面积耕地地膜负荷等。[结论]研究期间叶尔羌河平原绿洲土地生态安全得到明显的提升与改善,并在良好的方向发展。     

敦煌种业财务绩效评价研究

选择以农业上市公司敦煌种业为研究对象,以企业2014—2019年的报表数据为基础,采用功效系数法并以国务院国资委所编写的《企业绩效评价标准值》中国有企业绩效评价体系作为参考,构建对农业企业的财务指标评价体系,对敦煌种业2014-2019年企业财务指标的表现进行纵向分析,选择同行业中营业收入水平较高的北大荒进行横向对比,通过对比发现敦煌种业的问题主要体现在盈利能力和资产质量方面,对此提出了改进措施及建议。     

Intergenerational Earnings Inequality: New Evidence From Italy

Using an innovative dataset built by merging survey and administrative data, we provide new estimates of intergenerational earnings’ inequality between fathers and sons in Italy, extending previous evidence in several directions. We rely on the TSTSLS method to predict fathers’ earnings and compute intergenerational elasticities and imputed rank–rank slopes, trying to reduce estimation biases. Confirming previous evidence, we find that Italy is characterized by a high intergenerational inequality in cross-country comparison. Extending previous analyses, we show that the intergenerational association increases when sons at older ages and multi-annual averages of pseudo-fathers’ and sons’ earnings are considered. We also find that the intergenerational persistence differs across geographical macro-areas and is high also for daughters, especially when family earnings are considered. Furthermore, estimates where possible mediating factors of the parental influence are included among the covariates show that a high intergenerational association persists when sons’ education and occupation are controlled for.     

Application of evidential reasoning approach and OWA operator weights in road safety evaluation considering the best and worst practice frontiers

Data envelopment analysis (DEA) has recently become relatively popular with road safety experts. Therefore, various decision-making units (DMUs), such as EU countries, have been assessed in terms of road safety performance (RSP). However, the DEA has been criticized because it evaluates DMUs based only on the concept of self-assessment, and, therefore does not provide a unique ranking for DMUs. Therefore, cross efficiency method (CEM) was developed to overcome this shortcoming. Peer-evaluations in addition to self-evaluation have made the CEM to be recognized as an effective method for ranking DMUs. The traditional CEM is based only on the standard CCR (Charnes, Cooper and Rhodes) model, and it evaluates DMUs according to their position relative to the best practice frontier while neglecting the worst practice frontier. However, the DMUs can also be assessed based on their position relative to the worst practice frontier. In this regard, the present study aims to provide a double-frontier CEM for assessing RSP by taking into account the best and worst frontiers simultaneously. For this purpose, the cross efficiency and cross anti-efficiency matrices are generated.Even though a weighted average method (WAM) is most frequently used for cross efficiency aggregation, the decision maker's (DM) preference structure may not be reflected. For this reason, the present study mainly focuses on the evidential reasoning approach (ERA), as a nonlinear aggregation method, rather than the linear WAM. Equal weights are often used for cross efficiency aggregation; consequently, the effect of the DM's subjective judgments in obtaining the overall efficiency is ignored. In this respect, the minimax entropy approach (MEA) and the maximum disparity approach (MMDA) are applied for determining the ordered weighted averaging (OWA) operator weights for cross efficiency aggregation. The weighted cross efficiencies and cross anti-efficiencies are then aggregated using the ERA. Finally, the proposed method, called DF-CEM-ERA, is used to evaluate the RSP of EU countries as well as Serbian police departments (PDs).     

粤东西北与珠三角物流产业技术效率比较

运用DEA效率测度方法,通过对2013-2017年粤东西北与珠三角区域物流产业技术效率的对比研究,探索推动广东省区域物流协调发展的路径。结果显示:对比珠三角区域,粤东西北区域物流产业技术效率与珠三角区域存在较大差距,尤其是粤东与粤西地区,粤东区域物流产业技术效率值仅为0.4,粤西区域物流产业技术效率值为0.81,均远低于珠三角区域物流产业技术效率值0.94。纯技术效率低下是制约粤东西北地区物流产业技术效率提升的主要因素,应加强物流产业信息技术应用,推进物流技术装备现代化,提高技术创新能力水平。     

丝绸之路河西走廊物流业效率演化分析

构建了分析河西走廊物流业效率演化的指标体系,基于2009-2017年河西走廊物流业统计数据,运用DEA-Malmquist指数法测算了各市物流业效率和技术进步率,采用Tobit回归模型分析了该地区物流业效率的影响因素,并从省内、省域间、各经济区域间三个方面进行了对比分析。实证分析表明,相较于全国各省市地区,河西走廊物流业整体水平较低,物流业效率和技术进步率的强正相关性普遍存在,其物流业发展对政策偏向具有较强的依赖性;同时,技术进步率低下和基础设施匮乏也是制约物流业发展的重要因素。基于此,从政策照顾与资金投入、科技进步与管理水平和市场运营与体系建设三个方面,为河西走廊物流业发展提出了建议与改善措施。     

Foreign direct investment and economic growth: Is more financial development better?

We investigate the extent to which an increase in financial development affects the positive effect of foreign direct investment on economic growth. Although the financial sector is beneficial for economic growth, the effect of further financial development on growth is found to become insignificant. Using a dynamic panel threshold model on 62 middle- and high-income countries spanning the period 1987–2016, we re-examine the possible nonlinearity between finance, foreign direct investment, and growth. Consistent with the “vanishing effect” of financial development, we find significant evidence that foreign direct investment fosters growth in general, but the growth effect of foreign direct investment becomes negligible when the ratio of private sector credit to gross domestic product exceeds 95.6%. This finding is robust to different econometric methods, various subsamples and interaction analyses, and distinct financial development indicators.