Tree health mapping with multispectral remote sensing data at UC Davis, California

Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Traditionally, this parameter has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the tree crown was classified as either healthy or unhealthy based on vegetation index values. At the whole tree scale, raster based statistical analysis was used to calculate tree health index which is the ratio of healthy pixels to entire tree pixels within the tree crown. The tree was classified as healthy if the index was greater than 70%. Accuracy was checked against a random sample of 1,186 trees. At the whole tree level, 86% of campus trees were classified as healthy with 88% mapping accuracy. At the pixel level, 86% of the campus tree cover was classified as healthy. This tree health evaluation approach allows managers to identify the location of unhealthy trees for further diagnosis and treatment. It can be used to track the spread of disease and monitor seasonal or annual changes in tree health. Also, it provides tree health information that is fundamental to modeling and analysis of the environmental, social, and economic services produced by urban forests.     

常德市区域可持续发展评价指标体系构建

区域可持续发展能力的评价 ,是实现区域可持续发展的关键与前提。利用层次分析法和主成分分析法 ,构建常德市区域可持续发展能力的评价指标体系 ,从总量规模和结构协调两个方面对常德市区域可持续发展能力进行评价 ,可为常德市区域可持续发展的实施提供科学的依据     

深圳经济发展的战略分析

本文对深圳经济后１５年发展具有长远意义的战略因素和战略措施进行分析和评论，并就经济发展的指导思想定位作了简要探讨。     

区域经济理论与青海经济协调发展

区域经济理论是一种新兴的经济理论,它通过区域经济的协调发展推动整个经济的腾飞,缩小地区间的发展差异,达到共同富裕的目标。文章以区域经济理论为指导,对青海经济的发展问题作了阐释,并提出了具体的对策。     

大力发展职业教育 促进地方经济发展

当前,我市正处于由农业主导型经济向工业主导型经济的转型期,各行各业对专业技术人才特别是高层次技能型人才的需求越来越大。我市高等职业教育的任务艰巨,前景广阔。大力发展高等职业教育成为促进地方经济发展的关键。     

An alternative to farmer age as an indicator of life-cycle stage: The case for a farm family age index

In studies of farming, the age of the principal decision-maker (PDM) has been associated with numerous farm structural and managerial features and has been widely accepted as a good indicator of the influence of life-cycle factors on decision-making. As such, it has become an important aspect of many quantitative studies of agricultural change. However, contemporary studies of family farming demonstrate that the concept of a single PDM in family farms is becoming an anachronism as alternative enterprises, pluriactivity and the scale of family farms force more diffuse management/operating systems. This raises questions concerning whether the age of the PDM can still be taken as representative of farm structure, strategy or life-cycle stage? Using a study conducted in the Grampian Mountains region of Scotland in 2003 this note investigates the impact of using an alternative index—compiled by averaging the age of family members working on the farm. It suggests that PDM age is a relatively poor indicator of farm structural and managerial features compared to a family age index and calls for researchers to think about alternative approaches to measuring ‘age’ as an indicator.     

渝西经济走廊县域产业结构:一些发现及解释

应用对应分析方法对渝西经济走廊各区市县的三次产业结构进行了实证研究,分析了该经济区产业结构及发展水平的县域差异,同时发现该经济区三次产业结构总体上呈"三足鼎立"的均衡格局,据此提出了调整产业结构、促进工业化与城镇化协同发展的四大策略:结构趋异、产业集群、人口聚集和商贸拓展。     

学科建设“诊断”的指标体系与评价方法

该文通过对学科建设内容的研究分析，运用模糊数学理论，建立了分层次模糊综合评判模型及其技术方法，有效地解决了对学科建设复杂因素定量化评价的问题。研究中创新性地提出学科建设优度的概念和计算公式，用来对学科建设的状况进行定量分析与评价，有利于找准学科存在的问题与不足，明确努力的方向，达到“以评促建设，以评促改革，以评促发展”的评价目的。在确定评价指标体系和指标分级标准的基础上，应用分层次模糊综合评判模型对不同研究领域的学科进行综合评价，其评价结果较充分地验证了该模型的科学性和实践性，对推进学科建设具有积极的意义。     

深化对劳动和劳动价值论问题的认识

深化对劳动和劳动价值论问题的认识 ,是由马克思主义与时俱进的理论品质和劳动价值论的地位决定的 ,是迎接理论挑战和实践挑战的需要。通过深化对生产劳动、科技劳动和经济管理劳动的认识 ,有利于丰富劳动概念的内涵 ,拓展生产劳动的范围 ,明确科技和经营管理劳动不仅是生产性劳动 ,而且在价值和社会财富的创造中发挥着巨大的作用。     

论社会主义市场经济的本质在于“四个坚持”

关于对社会主义市场经济的认识,一般人都从经济运行方式的角度去考察,揭示社会主义市场经济的运行规范和某些功能,而对于社会主义市场经济的本质问题缺乏哲学和理论思考,没有从根本上揭示社会主义市场经济的本质是什么。探讨社会主义市场经济不能只停留在社会主义市场经济的基本职能和功能,而不重视社会主义市场经济的本质问题;不能只停留在社会主义市场经济的基本表现,而忽视社会主义市场经济的本质特征。社会主义市场经济的本质在于“四个坚持”,即坚持社会主义道路、坚持无产阶级专政、坚持党的领导、坚持马列主义毛泽东思想。