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INTRODUCTION Land resources management and ecologicalenvironmental decision-making requires knowl-edge about the spatial distribution, and quantity andquality of soil resources. Soil maps have tradition-ally been made by interpretation of remotely sensedimagery supported by ground surveys. Thus, soilmapping becomes expensive, labor-intensive, andtime-consuming exercises. Moreover, it also issubjective, and may result in inconsistencies in theassignment of soil type boundaries or nam… 相似文献
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LI Guo-qi SHENG Huan-ye 《浙江大学学报(A卷英文版)》2007,8(4):638-643
Background knowledge is important for data mining, especially in complicated situation. Ontological engineering is the successor of knowledge engineering. The sharable knowledge bases built on ontology can be used to provide background knowledge to direct the process of data mining. This paper gives a common introduction to the method and presents a practical analysis example using SVM (support vector machine) as the classifier. Gene Ontology and the accompanying annotations compose a big knowledge base, on which many researches have been carried out. Microarray dataset is the output of DNA chip. With the help of Gene Ontology we present a more elaborate analysis on microarray data than former researchers. The method can also be used in other fields with similar scenario. 相似文献
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基于灰色聚类的专业设置评价体系 总被引：1，自引：0，他引：1
专业设置的影响因素错综复杂,从社会需求和办学资源两个角度建立专业设置适切性的综合评价系统,设计专业设置适切性的灰色聚类评价模型。通过实证分析,论述灰色系统理论应用于专业设置的基本过程,以定量定性相结合的方法对专业进行综合评价及分类,为专业设置提供决策依据。 相似文献
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综合污染指数法对漯河市蔬菜种植区土壤有机污染物环境质量评价 总被引：1，自引：0，他引：1
以临颍县、郾城区和舞阳县三个蔬菜种植基地的15个土壤样本的监测数据为基础,利用单项污染指数法和内梅罗综合污染指数法,对漯河市蔬菜种植区土壤有机污染物环境质量状况进行了分析与评价。结果显示,临颍县和郾城区的两块地污染等级均为清洁（安全）,舞阳县的一块地污染等级为轻度污染。 相似文献
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The development of group cohesion for small groups in face-to-face educational learning settings has been widely studied for decades. The calibre of group cohesion within these contexts is typically associated with increases in performance, resulting in a productive collaboration that helps drive knowledge building and innovation within a learning environment. However, understanding and measuring cohesion in technology-mediated learning experiences still requires additional research. This paper reports on a systematic literature review of small groups in technology-mediated learning settings to explore the definitions of cohesion and the methodologies used for the measurements that have been identified arising in this area. Furthermore, the review provides a characterisation of the factors that impact collaborative learning in computer-supported environments, highlighting two important aspects: i) there is a significant gap in measuring cohesion using unobtrusive methods, such as relying on log or trace data and ii) there is a lack of longitudinal approaches to understand the emergence of cohesion. Finally, we discuss implications for future research in studying group cohesion. 相似文献
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Şebnem Kandil İngeç 《International Journal of Science Education》2013,35(14):1897-1915
Concept mapping is a technique that paves the way to represent knowledge schematically. In this research, concept mapping was used as an assessment method on the impulse–momentum topic. The purpose of this study was to determine teacher candidates’ knowledge about understanding of the concepts of impulse and momentum by comparing and contrasting two different methods; namely, students’ concept maps and an achievement test. The mean of teacher candidates’ concept map scores are extremely low when compared with the scores of the achievement test. In addition, it was seen that although a great number of concepts were written down, not many relationships were established between these concepts. There is a weak correlation between the achievement test and the concept map scores since concept maps assess the students’ knowledge from a conceptual perspective while the achievement tests measure the level of students’ knowledge on the topic and his/her ability to apply this knowledge on different occasions. 相似文献
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In the structural design of tall buildings, peak factors have been widely used to predict mean extreme responses of tall buildings
under wind excitations. Vanmarcke’s peak factor is directly related to an explicit measure of structural reliability against
a Gaussian response process. We review the use of this factor for time-variant reliability design by comparing it to the conventional
Davenport’s peak factor. Based on the asymptotic theory of statistical extremes, a new closed-form peak factor, the so-called
Gamma peak factor, can be obtained for a non-Gaussian resultant response characterized by a Rayleigh distribution process.
Using the Gamma peak factor, a combined peak factor method was developed for predicting the expected maximum resultant responses
of a building undergoing lateral-torsional vibration. The effects of the standard deviation ratio of two sway components and
the inter-component correlation on the evaluation of peak resultant response were also investigated. Utilizing wind tunnel
data derived from synchronous multi-pressure measurements, we carried out a wind-induced time history response analysis of
the Commonwealth Advisory Aeronautical Research Council (CAARC) standard tall building to validate the applicability of the
Gamma peak factor to the prediction of the peak resultant acceleration. Results from the building example indicated that the
use of the Gamma peak factor enables accurate predictions to be made of the mean extreme resultant acceleration responses
for dynamic serviceability performance design of modern tall buildings. 相似文献
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During the 1980s a revolutionary type of computer software called Geographic Information Systems (GIS) was developed for integrating environmental data bases with automated map makers. Educational applications of GIS are presently gaining serious attention, and promise to impact US classrooms of tomorrow. Because technophiles focus initially on hardware and software issues, the expansion of educational technologies tends to outpace the associated knowledge base concerning learning and teaching. The emerging consensus is that systematic investigations of how technological innovations can support learning should precede the adoption of new educational practices. This study compared expert/novice-based problem-solving behaviors with a GIS program called ArcView. GIS problem-solving strategies described during reflective think-aloud sessions were evaluated through naturalistic research methods and were analyzed for the occurrence of thematic elements. Three GIS problem-solving typologies were identified. Experts relied on logical formulations to query the data base. Among the novice population, trial-and-error methods and midlevel cognitive strategies that relied on spatial analyses were most prevalent. As novices progressed through the problem set, higher-level cognitive operations were used more frequently. The findings suggest the importance of additional cognitive studies and classroom evaluations of various instructional models prior to the wholesale introduction of GIS technology into high school classrooms. © 1996 John Wiley & Sons, Inc. 相似文献
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数据挖掘是从大量的数据中提取知识。数据挖掘的主要功能有关联、分类、预测、聚类和时序分析等。文章对关联规则和分类规则这两种挖掘模式的存储方法进行研究,提出在关系数据库系统中使用主-子表来存储关联规则和分类规则的方法,继而将这种存储方法应用在其它类型的模式上,形成一种统一的数据挖掘模式的存储方法。 相似文献
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利用网络通信、数据库和仿真模拟等技术,将实践教学基地中各类资源有效重组,可以实现基地资源信息化管理.浙江机电职业技术学院在实践教学基地信息化建设过程中,开发信息管理平台,应用虚拟仿真技术,建设数字化制造实训车间,为更好地培养学生技能、提高教学资源使用效益创造了条件. 相似文献
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叶杰梅 《宁波教育学院学报》2006,8(4):77-79
生态化构建几何中解决线段比例问题的一个发展性平台为例,体现数学知识树的理念,促进学生在数学“双基”上寻求“发展”,以形成良好的认知结构以及对数学的感悟。 相似文献
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Shan-long Lu Xiao-hua Shen Le-jun Zoue Chang-jiang Li Yan-jun Mao Gui-fang Zhang Wen-yuan Wu Ying Liu Zhong Zhang 《浙江大学学报(A卷英文版)》2008,9(6):858-866
The classification of thematic mapper imagery in areas with strong topographic variations has proven problematic in the past using a single classifier, due to the changing sun illumination geometry. This often results in the phenomena of identical object with dissimilar spectrum and different objects with similar spectrum. In this paper, an integrated classification method that combines a decision tree with slope data, tasseled cap transformation indices and maximum likelihood classifier is introduced, to find an optimal classification method for thematic mapper imagery of plain and highland terrains. A Landsat 7 ETM＋ image acquired over Hangzhou Bay, in eastern China was used to test the method. The results indicate that the performance of the integrated classifier is acceptably good in comparison with that of the existing most widely used maximum likelihood classifier. The integrated classifier depends on hypsography （variation in topography） and the characteristics of ground truth objects （plant and soil）. It can greatly reduce the influence of the homogeneous spectrum caused by topographic variation. This integrated classifier might potentially be one of the most accurate classifiers and valuable tool for land cover and land use mapping of plain and highland terrains. 相似文献
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利用本体理论技术,以最终检索需求应用为导向,结合“技术的更新在科研文献上能得到很大程度的反映”这一假设对本体中的概念进行进化,结合分类主题词表及百科等通用的知识库中的概念,半自动构造了一个计算机技术领域的本体,消除了构建本体过程中细节的干扰从而实现机器智能,从而为Web信息检索提供建议． 相似文献
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Casey G. Cegielski L. Allison Jones‐Farmer 《Decision Sciences Journal of Innovative Education》2016,14(1):91-118
It is impossible to deny the significant impact from the emergence of big data and business analytics” on the fields of Information Technology, Quantitative Methods, and the Decision Sciences. Both industry and academia seek to hire talent in these areas with the hope of developing organizational competencies. This article describes a multi‐method research agenda that was executed to ascertain insights regarding which knowledge, skills, and abilities, (KSAs) are valued by employers seeking to hire entry‐level analytics professionals from schools of business. Current undergraduate business analytics programs are first examined to define the research scope. A triangulated mixed‐method research approach is then used to determine the knowledge, skills, and abilities that are in demand for entry‐level jobs in this area. Finally, the multi‐method triangulation of data is combined with experiences in building academic programs in business analytics at two nationally‐ranked state universities to offer insights for those seeking to develop academic programs in this area. 相似文献
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基于Web of Science中的SCI-E、SSCI数据库,立足于国际创业教育领域的研究文献,采用国际新兴的CiteSpace软件和可视化方法,将定量分析和定性研究相结合,在知识计量和谱图绘制的基础上,诠释国际创业教育的热点知识群,从而为国际创业教育领域开辟新的研究范式。研究发现,半个多世纪以来,国际创业教育的热点知识群可诠释为商业教育与管理教育,创业管理与商业模式,创业教育课程,创业教育预期、态度、模式与绩效,创业教育与方法,职业流动劳力和创业移民,创业者的人格与健康,青年创业者的支持与环境,创业专业选择、内科与初级保健护理,创业目的与成功,创业教育的调整与文化互渗,职业干预与决策,职业选择与创业自我评估等。 相似文献
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为掌握淮南市山南新区土壤中锌的含量现状,并为追踪研究该区城市化后土壤中锌的污染变化提供基础数据,对该区不同区域不同深度的土壤进行采样,用盐酸-硝酸-氢氟酸-高氯酸对土样进行全消解,用火焰原子吸收法对土壤中重金属锌的含量进行了测定,对测定结果进行了统计分析,并采用多种方法对该区土壤中重金属锌进行了环境质量评价。结果表明该区土壤中Zn的含量除个别数据外,大部分处于国内正常偏低的水平。 相似文献
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固体碱催化剂的研究进展 总被引：2，自引：0，他引：2
李俊鹏 《广东轻工职业技术学院学报》2007,6(3):13-17
介绍了固体碱的分类、固体碱催化剂的反应机制,概述了固体碱催化剂的最新研究进展,选择工业上一些以固体碱作为催化剂的反应来说明固体碱催化剂在工业上的应用,并做简短的论述.此外,展望了固体碱催化剂未来的研究方向. 相似文献