56 research outputs found
High Daytime and Nighttime Temperatures Exert Large and Opposing Impacts on Winter Wheat Yield in China
No full textJEL Codes: Q10, Q54We analyzed a provincial-scale data set of observed winter wheat yield, together with fine-scale daily weather outcomes from 1979 to 2011, to assess the responses of winter wheat yield in China to changes in the daytime temperature (Tmax) and the nighttime temperature (Tmin). Contrasting with the literature’s emphasis on a negative correlation between Tmin and wheat yield, we showed that winter wheat yield in China responded positively to higher Tmin, with the positive yield responses varying across wheat growing seasons. In line with the previous studies, we found that winter wheat yield exhibited negative responses to higher Tmax. These findings are useful for the development of China’s wheat-breeding programs and the design of efficient adaptation strategies in China’s grain sector to cope with future warming
Adaptive Figure-Ground Classification
No full textWe propose an adaptive figure-ground classification algorithm to automatically extract a foreground region using a user-provided bounding-box. The image is first over-segmented with an adaptive mean-shift algorithm, from which background and foreground priors are estimated. The remaining patches are iteratively assigned based on their distances to the priors, with the foreground prior being updated online. A large set of candidate segmentations are obtained by changing the initial foreground prior. The best candidate is determined by a score function that evaluates the segmentation quality. Rather than using a single distance function or score function, we generate multiple hypothesis segmentations from different combinations of distance measures and score functions. The final segmentation is then automatically obtained with a voting or weighted combination scheme from the multiple hypotheses. Experiments indicate that our method performs at or above the current state-of-the-art on several datasets, with particular success on challenging scenes that contain irregular or multiple-connected foregrounds. In addition, this improvement in accuracy is achieved with low computational cost.Computer Science, Artificial IntelligenceComputer Science, Interdisciplinary ApplicationsEngineering, Electrical & ElectronicEICPCI-S(ISTP)
Real-time rendering of light shafts on GPU
No full textIn the past, it is difficult to simulate light shafts effect in real-time. One major reason is the high computational expense to perform the physically-accurate computation of atmosphere scattering. Another is due to the limitation of computer resource, especially lack of power and programmability in the graphic hardware. Recently, with the advent, of more powerful graphic card in standard PC platform and the development of programmable stages in the graphic pipeline, a lot of computational expensive algorithms are made available in modern commercial games. In this paper, we propose a novel method of rendering light shafts with atmospheric scattering based on actual physical phenomena. The proposed method utilizes hardware frame buffer object and a mesh refinement pattern to achieve photorealistic effect at high frame rate.Computer Science, Artificial IntelligenceComputer Science, Software EngineeringComputer Science, Theory & MethodsCPCI-S(ISTP)
Notice of Retraction: Optimization on dynamic performance of constrained damping layer using nodal independent variable
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The research of carbon dioxide gas monitoring platform based on the wireless sensor networks
No full text多元化集团母公司心智图 对公司战略成效的影响：理论与案例分析
No full textabstract: 中国自80年代以来随着改革开放和经济发展潮流，一批批本土企业快速成长，已经从单一主业壮大成熟，完成资本积累并快速朝多元化、规模化发展。截止到2019年中国有129家企业进入世界500强，而该数量在2011年为69家 ，2005年为18家。这一数据反映了中国大型集团的增长速度之快、数量之多令人刮目相看。
然而，大型企业集团在经营规模上的庞大并不能掩盖其管理水平的低下与尴尬，这一点从多数企业的规模和利润比率就可窥见一斑。从战略管理角度看，集团企业在单一主业上的业务战略管理水平（竞争战略）经过30多年的发展和沉淀已经相对成熟，在某一行业领域也发展沉淀了很多成熟的职业经理人和专业人才。但是，国内至今很少有多元化集团战略管理（公司层面战略）的专题研究，且在多元化集团战略管理实践方面缺少经验和积累。多元化集团战略及管理领域的研究具有重要的现实意义和学术价值。
公司层面战略的研究起始于20世纪50年代，现有研究领域以西方学者为主，涉及公司层面战略的诸多领域，比如分部化、一般管理技能共用、协同效应、多元化、业务组合规划、基于价值的规划、重组、核心竞争力和资源共享、母合优势等全新和具有全球影响力的母公司管理概念。本文涉及的多元化集团公司战略三要素：母公司管理机制、业务组合、母子公司管控及子公司之间联接之前有西方学者作为独立课题都曾研究过，但作为整体性研究较少。中国目前研究该公司层面战略成果较少，市场上从事该领域的咨询机构也很少，少数咨询公司业务以多元化集团战略管控咨询方面为主。本文将从多元化集团母公司心智图对公司层面战略成效影响的研究作为核心内容，这项研究在中国乃至在世界范围内尚属初步尝试。
母公司心智图代表了某一时期多元化集团核心决策层的战略管理思维水平现状，是核心决策层对多元化集团公司战略三个核心要素及其相互关系的认知和掌握程度的集中体现。母公司心智图水平的测量可以从核心决策层的构成合理性及成员背景、核心决策层对行业及业务组合的认知水平、核心决策层对对母公司管理机制的认知水平、核心决策层对母子公司之间的联接及影响的认知水平以及核心决策层对多元化集团战略管理的综合能力水平这五个维度，共15个指标进行测量，总分100分。掌握了母公司的心智图就能够识别整个公司战略管理的现状及逻辑。母公司心智图决定了母公司管理机制、母子公司的联接影响方式（母公司如何影响和联接旗下业务）和业务组合（公司资金和管理的投向），而这三个核心要素的决策决定了公司层面战略的成效。母公司心智图的水平将很大程度上正面影响公司的战略成效。
本文将深入针对具有三个不同心智图水平的多元化集团进行案例分析，分别研究不同的母公司心智图水平如何通过影响业务组合决策、母公司管理机制建设、母子公司联接进而影响公司的战略成效。
关键词: 多元化集团、母公司心智图、心智图测量、公司层面战略管理三支柱、战略成效Dissertation/ThesisDoctoral Dissertation Business Administration 202
Efficient tree-structured SfM by RANSAC generalized Procrustes analysis
No full textThis paper proposes a tree-structured structure-from-motion (SfM) method that recovers 3D scene structures and estimates camera poses from unordered image sets. Starting from atomic structures spanning the scene, we build well-connected structure groups, and propose RANSAC generalized Procrustes analysis (RGPA) to glue structures in the same group. The grouping-aligning operations hierarchically proceed until the full scene is reconstructed. Our work is the first attempt of using GPA for modern 3D reconstruction tasks. RGPA is able to merge multiple structures at a time and automatically identify outliers. The reconstruction tree is much more compact and balanced than previous hierarchical SfM methods and has a very shallow depth. These advantages, along with the resulting removal of intermediate bundlCadjustments, lead to significantly improved computational efficiency over state-of-the-art SfM methods. The cameras and 3D scene can be robustly recovered in the presence of moderate noise. We verify the efficacy of our method on a variety of datasets, and demonstrate that our method is able to produce metric reconstructions efficiently and robustly. (C) 2017 Elsevier Inc. All rights reserved.National Natural Science Foundation (NSF) of China [61232014, 61421062, 61472010]; National Basic Research Program of China (973 Program) [2015CB351806]; National Key Technology R&D Program of China [2015BAKO1B06]; 973 Program [2015CB352502]; NSF of China [61625301, 61231002]; QualcommSCI(E)ARTICLE,SI179-18915
Change detection of land use and land cover of the southeast coastal area in Fujian, China
No full textNotice of Retraction: Structural-acoustic coupling and external sound pressure of a plate-ended cylindrical shell based on analytic method
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