Feature-based Groundwater Hydrograph Clustering Using Unsupervised Self-Organizing Map-Ensembles

Hydrograph clustering helps to identify dynamic patterns within aquifers systems, an important foundation of characterizing groundwater systems and their influences, which is necessary to effectively manage groundwater resources. We develope an unsupervised modeling approach to characterize and cluster hydrographs on regional scale according to their dynamics. We apply feature-based clustering to improve the exploitation of heterogeneous datasets, explore the usefulness of existing features and propose new features specifically useful to describe groundwater hydrographs. The clustering itself is based on a powerful combination of Self-Organizing Maps with a modified DS2L-Algorithm, which automatically derives the cluster number but also allows to influence the level of detail of the clustering. We further develop a framework that combines these methods with ensemble modeling, internal cluster validation indices, resampling and consensus voting to finally obtain a robust clustering result and remove arbitrariness from the feature selection process. Further we propose a measure to sort hydrographs within clusters, useful for both interpretability and visualization. We test the framework with weekly data from the Upper Rhine Graben System, using more than 1800 hydrographs from a period of 30 years (1986-2016). The results show that our approach is adaptively capable of identifying homogeneous groups of hydrograph dynamics. The resulting clusters show both spatially known and unknown patterns, some of which correspond clearly to external controlling factors, such as intensive groundwater management in the northern part of the test area. This framework is easily transferable to other regions and, by adapting the describing features, also to other time series-clustering applications.

     

西藏燕麦主要种植区灌溉定额空间分布及影响因素

燕麦为西藏自治区典型牧草之一,由于种植区地域辽阔,灌溉试验结果受限,西藏燕麦主要种植区的灌溉定额尚不明确。本文在西藏燕麦主要种植区内选取28个典型站点进行资料收集,遵循农业气候相似原则进行区域划分,基于水量平衡法揭示了西藏燕麦主要种植区灌溉定额的空间分布特征,并根据统计学原理分析了其影响因素。研究表明:燕麦主要种植区的灌溉定额呈由西藏中部至东部呈现先递增后递减的趋势,50%水文年下的燕麦灌溉定额在56~265 mm之间变化。降雨量是影响研究区内燕麦灌溉定额的主要因素(R²为0.515),ET₀次之(R²为0.152);其它气象因素中,日照时数对研究区燕麦灌溉定额影响较大(R²为0.462),且呈正相关关系;相对湿度对燕麦灌溉定额影响较小。西藏燕麦主要种植区的灌溉定额及其空间分布可为西藏自治区灌溉用水管理提供支撑。     

Optimal Water Allocation of Surface and Ground Water Resources Under Climate Change with WEAP and IWOA Modeling

Water Resources Management - The water evaluation and planning (WEAP) approach and the invasive weed optimization algorithm (IWOA) are herein employed to determine the optimal operating policies in...     

组织模块化对研究型大学技术转移绩效的影响

技术转移是将社会科技资源转化为实体经济效益的重要途径。当前，我国研究型大学技术转移渠道不畅、技术转移绩效不高、大学科技成果成功产业化“最后一公里”问题凸显。基于现实需求和研究缺口，构建组织模块化对研究型大学技术转移绩效影响的理论模型。在此基础上，收集我国38所研究型大学样本数据，采用SPSS24.0和AMOS软件进行结构方程路径分析，论证和检验组织模块化对于研究型大学技术转移绩效的影响机制。结果表明：组织模块化对研究型大学技术转移绩效具有显著正向影响；技术创新能力在组织模块化与技术转移绩效之间起显著中介作用；知识共享的调节作用主要体现在组织模块化独立性、响应性与技术创新能力之间的关系上，其对组织模块分工性与技术创新能力关系的影响作用不显著。     

Groundwater Level Simulation Using Soft Computing Methods with Emphasis on Major Meteorological Components

Water Resources Management - Precise estimation of groundwater level (GWL) might be of great importance for attaining sustainable development goals and integrated water resources management....     

房产税能否抑制实体经济"脱实向虚"——来自上海和重庆的经验分析

本文利用我国35个大中城市2006-2018年的平衡面板数据,基于上海和重庆在2011年实施的房产税试点政策,运用合成控制法检验房产税政策能否抑制实体经济"脱实向虚"发展的趋势.研究结果显示,房产税政策能够有效地遏制地区房地产业新增产值占GDP的比重的上升,促使实体企业回归主业,增加实体投资,实现促进实体经济朝着"脱虚返实"方向发展的作用.鉴于此,本文提出应加快推进房产税政策在全国范围内的实施,并在政府补贴、银行贷款等方面采取一系列配套措施鼓励实体企业进行更多的实体投资.     

Institutional dynamics and access to non-farm employment in rural China, 1950–1996

This article examines non-farm employment in the context of Chinese rural institutional change, based on evidence from discrete-time logistic models for event history analysis using the Life History and Social Change survey. We find the transition to non-farm sector rose rapidly during the Great Leap Forward and market reform, while the Cultural Revolution saw it reach the lowest ebb. While male advantage prevailed exclusively during the Cultural Revolution and early marketization, education possessed a stable positive effect in all historical periods. Although the returns to different kinds of political capital vary along with institutional dynamics, intergenerational reproduction was greatly reduced after the Cultural Revolution.     

团队科学创造力的提升需重视团队成就目标导向——被调节的中介效应

基于创造力成分等多维理论，构建以团队反馈寻求行为为中介变量，团队凝聚力为调节变量的被调节的中介效应模型，以期深入解释创新团队成就目标导向如何影响其团队科学创造力。基于129个理工科大学生科技创新团队数据，研究结果表明，团队学习目标导向和团队表现目标导向分别与团队科学创造力有显著的正向和负向关系；团队反馈寻求行为在团队成就目标导向与团队科学创造力间起部分中介作用；团队凝聚力负向调节团队反馈寻求行为与团队科学创造力间的关系，并弱化了团队成就目标导向通过团队反馈寻求行为对团队科学创造力的间接影响。结论对提高科技创新团队科学创造力有一定指导价值。