A characterization of the extended serial correspondence

We study the problem of assigning objects to a group of agents. We focus on probabilistic methods that take agents’ ordinal preferences over the objects. Importantly, we allow for indifferences among objects. Katta and Sethuraman (2006) propose the extended serial correspondence to solve this problem. Our main result is a characterization of the extended serial correspondence in welfare terms by means of stochastic dominance efficiency, stochastic dominance no-envy and “limited invariance,” a requirement we adapt from Heo (2014a). We also prove that an assignment matrix is selected by the extended serial correspondence if and only if it satisfies “non-wastefulness” and “ordinal fairness,” which we adapt from Kesten et al. (2011).     

恶劣环境对船舶焊接的影响

在船舶建造过程中焊接工作量约占全部的30%~40%，焊接是保证质量的重中之重。焊接质量出问题，就可能造成严重的后果。我厂沿江堤而建，空气中湿度大，工作条件差。密集性气孔很严重。所以，在这种情况下，对我厂焊接质量控制提出更高的要求。     

浅谈测量员如何更好更快地提高业务水平

测量作为服务于国民经济建设的重要行业，随着传统测绘技术向数字化测绘技术转化，它表现出复杂性及多样性，当我们面对一项新的测量任务时，除了传统学习模式之外，我们该如何更好地提高自身地业务水平呢？本文结合作者工作经验论述了上述问题，为测量同行提供一些建议及指导。     

Understanding the impacts of ‘Grain for Green’ land management practice on land greening dynamics over the Loess Plateau of China

Land greening in China is regarded as contributing a great deal to greening of the Earth. The phenomenon is mainly attributed to climate change, arising atmospheric CO₂ and ‘Grain for Green’ (GFG) land management policies. However, limited knowledge is known how much land greening is from contributions of the GFG practice. Therefore, the study took the typical region of the GFG practice, the Loess Plateau, as the study area, and used 1982–2015 satellite-observed GIMMS3g normalized difference vegetation index (NDVI) data, ERA-Interim climatic variables (precipitation, temperature and solar radiation) and atmospheric CO₂ concentration data with the help of a developed TPRC-based NDVI model to derive GFG-induced NDVI after 1999. Furthermore, this study tracked the spatial-temporal dynamics of GFG-induced NDVI and assessed contributions of the GFG practice to regional vegetation changes. Results showed that satellite-observed NDVI and TPRC-based NDVI both exhibited an increasing spatial pattern from the northwestern to southeastern Loess Plateau, but their greening trends were separately 0.0022 and 0.0009 per year in 1982–2015 (p < 0.05). Note that the satellite-observed greening trend was much steeper with a slope of 0.0056 per year after 2006 (p < 0.05). The subsequent analyses documented that GFG-induced land greening were largely responsible for the steep trend. In space, evident greening patterns began to be observed in the central Loess Plateau from 2006 to 2008, afterwards expanded towards eastern and southwestern Loess Plateau. In 2011–2015, the increase magnitude of GFG-induced land greening in the Loess Plateau averagely accounted for 8.5 % in comparison to estimated TPRC-based NDVI, but in six natural zones were various, ranging from 3.2%–15.7%. In some regions of central Loess Plateau, GFG-induced NDVI contributed even more than 20 % to vegetation increase. This study highlights that land use management contributes more to land greening dynamics over the Loess Plateau compared to climate change and arising atmospheric CO₂ concentration. These findings likely provide some valuable information for curbing or enhancing specific-location vegetation changes in future regional land management and planning.     

供应商集中、公司治理与企业价值 ——基于我国A股制造业上市公司数据

本文通过选取2010—2017年我国A股制造业上市公司的数据,先研究公司供应商集中对于公司价值的直接影响,结论显示公司供应商集中对于企业价值有着负面的影响;然后在进一步研究中,探究了公司治理相关因素以及面临的融资约束情况对于公司供应商集中与公司价值关系的调节作用。实证结果显示,产权性质以及董事会独立性会对两者的关系产生影响;股东间的相互关联以及对于高管薪酬激励都对公司供应商集中与公司价值的关系有着负向的调节作用。与此同时公司面临的融资约束越小,公司供应商集中对于公司价值的负面效应越弱;最后利用多重中介效应模型探究了供应商集中的作用机制。     

Change or perish: Examining the role of human capital and dynamic marketing capabilities in the hospitality sector

Many researchers have endeavored to explain which factors contribute to sustainable competitive advantage. Toward this end, this study contributes to the marketing and hospitality management literature by providing empirical evidence on how human capital, dynamic marketing capabilities, and market dynamism influence competitive advantage in the hotel sector. We collected cross-sectional survey data from marketing and sales managers in 165 hotels, along with in-depth interviews in three hotels, based in four Gulf Cooperation Council (GCC) countries, namely, Saudi Arabia, Qatar, United Arab Emirates and Bahrain. The findings reveal that human capital directly, and indirectly through dynamic marketing capabilities, plays a critical role on developing competitive advantage. To contextualize this role, our research reveals that market dynamism moderates the mediated relationship between human capital and competitive advantage via market sensing capabilities. We discuss how the findings offer theoretical and managerial implications for the development of competitive advantage in the hotel sector.     

数量驱动或创新驱动：异质型人力资本对经济增长的机制演进

基于1987-2017年中国省际面板数据，运用SYS-GMM模型研究异质型人力资本对经济增长的影响。在区分高级与基本人力资本基础上，基于招生率和收入维度，从全局和阶段差异视角剖析异质型人力资本对经济提速的机制演进。研究发现：全局而言，两种测度下基础和高级人力资本各自以数量及创新方式驱动经济增长，并呈现以数量驱动为主，数量、创新双驱动的增长模式；从演进视角看，两种测度均表明，高级人力资本创新驱动是新常态阶段经济增长的核心动力，但相比旧常态阶段，基础人力资本数量驱动日趋弱化并呈异质性；进一步研究表明，产业结构、城镇化及开放程度均对创新驱动有不同程度激励效应，而城镇化是挤出数量驱动的主要推手。     

Co-ordination of land exploitation,exploitable farmland reserves and national planning in China

Land exploitation, as an important strategy to mitigate farmland loss and stabilize grain production, has been adopted to compensate farmland loss due to rapid urbanization in China. Bounded by the limited capacity and obvious spatial variations of national farmland reserves, it is essential to arrange land exploitation activities timely and reasonably. In this study, we propose an indicator for the status of regional land exploitation, the Exploitation Degree, to facilitate an overview of land exploitation programs in China at both provincial and prefectural levels based on project data from 2006 to 2012. To further our understanding of the regional features of land exploitation activities, we employ the Lasso model to identify and quantitatively assess influencing factors on land exploitation. Our study shows that: (1) contemporary land exploitation practices in China are significantly inconsistent across exploitable farmland reserves. Some areas are greatly over-exploited and such irrational land exploitation has been persistent; (2) related national land plans designed to guide land exploitation efforts centered on resource-rich regions and critical areas do not function as intended. Therefore, we suggest that China⿿s land exploitation policy shall be improved by reconsidering the orientation of land exploitation policy, coordinating land exploitation activities with productivity improvements and eco-system protection, and enhancing the power and scope of the plans in controlling and guiding land resource management.     

辽东湾沿海及内陆土地利用生态环境效应对比分析

以位于辽东湾北部的营口市和辽宁省内部的鞍山市为研究区,引用研究区土地利用图形数据,通过将景观斑块分类的方法,对辽东湾沿海及内陆城市的土地利用生态环境效应进行比较分析。结果表明:(1)辽东湾的优势景观为林地和旱地。(2)鞍山市的区域生态环境指数为0.43,营口市的区域生态环境指数为0.51。辽东湾沿海城市较内陆城市生态环境好。     

股权性质、环境不确定性与技术资本配置效率

技术转化为资本，资本创造价值已经成为共识，技术资本在不同公司创造价值的作用程度不同，根源是技术资本配置效率问题。选取沪深两市2008-2013年间制造业上市公司为样本，检验了基于不同股权性质的公司环境不确定性对企业技术资本配置效率和价值的影响，研究结果表明：①企业环境不确定性程度越高，技术资本配置效率越低，并且技术资本配置偏离度在国有公司中表现为配置过度，在非国有公司表现为配置不足；②在股权性质为国有的公司中，由环境不确定性引发的技术资本配置偏离将降低企业价值，在非国有控股公司中，由环境不确定性导致的技术资本配置偏离将增加企业价值。