基于GIS的精准农业信息流分析方法研究   总被引：1，自引：0，他引：1  

龙亮  谢高地  冷允法 《资源科学》2003,25(6):89-95

“精准农业”是基于农田内空间差异性信息和现代科学技术的作物生产管理系统。地理信息系统(GIS)是“精准农业”技术实践中的关键技术之一,它通过与GPS的结合,获取农田内空间差异性信息,建立农田环境要素信息数据库,运用GIS的各项功能对环境要素数据进行转换、处理和分析,最后形成各种指导农业生产的处方图形。该文以上海精准农业示范区为例,分析农田环境要素信息在GIS中的流动过程,信息流动主要环节的技术实现;空间插值方法是精准农业技术实现的重要方法,该文对常用于农田环境要素的空间插值方法做了初步研究。  相似文献   

Field dependence/independence cognitive style and problem posing: an investigation with sixth grade students     

Aristoklis Andreas Nicolaou  Xenia Xistouri 《教育心理学》2011,31(5):611-627

Field dependence/independence cognitive style was found to relate to general academic achievement and specific areas of mathematics; in the majority of studies, field-independent students were found to be superior to field-dependent students. The present study investigated the relationship between field dependence/independence cognitive style and problem-posing ability among sixth grade students. The 94 students’ sample was clustered into three groups, according to the cognitive-style field dependence/independence (field dependents, field mixed and field independents). The results suggest that field-independent participants outperformed field-mixed and field-dependent ones in both problem-posing ability and the complexity of the problems posed. It was also found that the content of the task influenced the differences between the three groups of students as regards the ability in problem posing and the complexity of the problems posed; while in the first (informal context), second and fourth task differences were found between the groups, in the third task (formal context), no differences were evident. The results are interpreted in consideration to the relevant literature findings. Some educational implications are discussed and directions for future research are drawn.  相似文献   

知识获取、路径依赖对企业创新能力的影响研究     

王向阳  卢艳秋  赵英鑫 《图书情报工作》2011,55(18):103-148

构建知识获取、路径依赖、渐进式创新和突破式创新之间的关系模型,运用SPSS和LISREL软件对收集的248份有效问卷进行实证分析。研究结果表明,中国企业的创新路径为知识获取-渐进式创新-突破式创新,知识获取对渐进式创新具有显著的影响,而对突破式创新的直接影响不显著;同时路径依赖对知识获取与企业渐进式创新之间的关系具有显著的调节作用。这为我国企业通过获取外部信息培育和发展创新能力提供了新的证据和启示。  相似文献   

Exploring geographic disparities in broadband access and use in rural southern Illinois: Who's being left behind?     

Tonny J. Oyana^{Author Vitae} 《Government Information Quarterly》2011,28(2):252-261

Recent literature about broadband telecommunications reveals two major areas that are not only globally gaining prominence, but are also demanding urgent attention from a research perspective. One of the key areas is related to the need to spatially evaluate the availability and deployment of broadband services, especially among urban versus rural communities. Another area of interest falls under the need for enabling broadband policies and strategies that address existing geographic disparities. These motivating factors shaped this research and provided a basis for defining three specific objectives, namely: (1) to identify locations with or without broadband access, (2) to identify underserved rural and inner-city markets, and (3) to determine whether university and community college towns can be used in the adoption and dispersion of broadband technologies in southern Illinois. Supply-side and demand-side data were collected and inputted into a Geographic Information System (GIS). Supply-side data included cable modem, digital subscriber lines (DSL), wireless, and fiber optic lines, while demand data included reported broadband requests from individuals without access (n = 439), students (n = 45,866), and higher education workforce (n = 5419). Using the GIS and statistical techniques, insightful maps of broadband infrastructure were created to illustrate areas of supply and demand so that governments and businesses can address existing gaps in consumer needs. Specifically, different levels of broadband access and use were mapped; different under-served rural and inner-city markets were identified so as to emphasize the dramatic economic impact on the business opportunities available to small business entrepreneurs. Also, different geographies of use and accessibility of broadband connectivity in the study region were synthesized to support decision-making. The resulting maps provided supply and demand marketing intelligence based on the geographic analyses of residential and enterprise sectors. These data can be used as a model to develop specific policy recommendations for a knowledge-based economy, specifically for the southern Illinois region or other rural communities in the United States.  相似文献   

消费级平板扫描仪的边界效应     

姚海根 《出版与印刷》2011,(2):2-6,48

由于光照的非均匀性和传感器对不同空间位置响应的差异,几乎所有的平板扫描仪都存在边界效应问题,以水平边界效应更为明显。本文测量了ScanMaker4850m扫描仪对未印刷白色静电复印纸的响应值,证明确实存在边界效应。  相似文献   

哲学视阈中的企业技术创新     

谈新敏  宋保林 《科技管理研究》2011,(3)

企业技术创新是企业持续增强自身竞争力的关键因素,从哲学高度审视企业技术创新,有利于拓展企业技术创新思路.哲学视阈中的企业技术创新包括三层含义:企业技术创新是技术路径依赖与技术路径创造相统一的过程;企业技术创新是技术社会化与社会技术化相统一的过程;企业技术创新过程是技术创新认知与技术创新实践相统一的过程.  相似文献   

Study of resonance-cone propagation in truncated hyperbolic metamaterial grids using transmission-line matrix simulations     

Omar F. Siddiqui  George V. Eleftheriades 《Journal of The Franklin Institute》2011,348(7):1285-1297

In this paper, we utilize transmission-line matrix simulations to study the electromagnetic properties of hyperbolic metamaterial grids, which are synthesized by arranging unloaded transmission lines over electrical ground planes, such that the unit cells are rectangular in shape. The hyperbolic grids support Bragg and Hyperbolic resonant modes that have rectangular and hyperbolic dispersion surfaces, respectively. We demonstrate the formation of these resonant modes in the hyperbolic grids and their refraction, and spatial scanning properties via circuit simulations. The simulation results are compared with experimental results of a two-layer anisotropic hyperbolic metamaterial.  相似文献   

ICT领域跨学科关联度的块段模型分析——基于我国校企合作申请的专利   总被引：1，自引：1，他引：0  

雷滔  陈向东 《中国软科学》2011,(1)

校企合作申请的发明专利能很好地反映高校科研成果供应与企业核心技术需求的对接。尝试以这类专利的主、次分类号为切入点,借助2009年OECD有关ICT领域的展望和政策,首次采用块段模型,分析该领域四大技术主题内部及其与非ICT领域间跨学科的技术关联,区别四大主题的技术路径依赖,挖掘技术平台,预测研发重点。助于我国ICT核心技术的把握和研发战略的布局,助于企业开展竞争情报分析,也为跨学科研究及其产业化提供了借鉴。  相似文献   

基于GIS的区域关键性生态用地空间结构识别方法探讨   总被引：10，自引：3，他引：7  

谢花林  李秀彬 《资源科学》2011,33(1):112-119

随着我国城镇化进程的加速,如何协调好城镇建设与地域生态系统的关系成为当前规划界的热点问题之一。本文基于GIS技术,从水资源安全、生物多样性保护、灾害规避与防护和自然游憩等4个方面,构建了空间尺度上的生态用地重要性综合指数和区域关键性生态用地空间结构识别方法,并进行了京津冀地区的实例研究。结果表明,京津冀地区核心型生态用地的面积为54943.87km2,占全区总面积的1/4,分布在西北部山区,主要是区域的河流水系、湿地、自然保护区、森林公园和风景名胜区的核心区,是维护区域生态安全的底线生态用地。识别结果能较好地反映关键性生态用地维护区域水、生物、灾害防护和游憩安全的空间特征。该识别方法将有利于指导我国土地的生态管理,开展生态保育和生态建设,维护区域生态系统健康与安全。  相似文献   

全球能源消费的空间差异及影响因素分析   总被引：1，自引：0，他引：1  

贾俊松  范英  吴晓华  孙德强 《资源科学》2011,33(5):796-805

选取全球主要国家和地区的能源系统为研究对象,对它们能源消费的规模、结构与效率在空间上的差异进行了分析,之后,采用递阶偏最小二乘(Hi_PLS)模型对能源消费量的主要影响因素进行了辨析,结果表明:①能源消费总量主要集中在北半球或北美、欧亚大陆及亚洲。人均能耗较高的国家则主要集中在油气资源丰富的区域或经济发达区;②结构方面,中东四国油气所占比例受其油气资源禀赋影响非常显著,它们除油气外的其它能耗几乎为0;③效率方面,能耗效率较高的国家主要分布在中南美、欧洲、欧亚大陆及亚太地区,而北美、中东和非洲地区的国家能耗效率则较低;④全球尺度,对能源消费量增长最重要的影响因素为交通业与信息产业的活动(包括基建),其次为医疗业及其它一般意义上的经济活动,最后就是人们投入研发以及从事农业等的活动。人口的自然增长及其结构因素与人们从事教育的活动对能源消费量增长的促进作用不大。据此,提出了一些减缓全球能源消耗,促进各国向低碳清洁的可持续发展模式转变的对策建议,供决策者参考。  相似文献