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41.
The purpose of this study is to find a theoretically grounded, practically applicable and useful granularity level of an algorithmically constructed publication-level classification of research publications (ACPLC). The level addressed is the level of research topics. The methodology we propose uses synthesis papers and their reference articles to construct a baseline classification. A dataset of about 31 million publications, and their mutual citations relations, is used to obtain several ACPLCs of different granularity. Each ACPLC is compared to the baseline classification and the best performing ACPLC is identified. The results of two case studies show that the topics of the cases are closely associated with different classes of the identified ACPLC, and that these classes tend to treat only one topic. Further, the class size variation is moderate, and only a small proportion of the publications belong to very small classes. For these reasons, we conclude that the proposed methodology is suitable to determine the topic granularity level of an ACPLC and that the ACPLC identified by this methodology is useful for bibliometric analyses.  相似文献   
42.
InCites Essential Science Indicators is becoming increasingly used to identify top-performing research and evaluate the impact of institutes. Unfortunately, our study shows that ESI indicators, as well as other normalized citation indicators, have the following flaws. First, the publication month and the online-to-print delay affect a paper’s probability of becoming a Highly Cited Paper (HCP). Papers published in the earlier months of the year are more likely to accumulate enough citation counts to rank at the top 1% compared with those published in later months of the year. Papers with longer online-to-print delays have an apparent advantage for being selected as HCPs. Research field normalizations lead to the third pitfall. Different research fields have different citation thresholds for HCPs, making research field classification important for a journal. In addition, the uniform thresholds for both articles and reviews in ESI affect the reliability of HCP selection because, on average, reviews tend to have higher citation rates than articles. ESI’s selection of HCPs provides an intuitive feel for the problems of normalized citation impact indicators, such as those provided in InCites and SciVal.  相似文献   
43.
通信信号的调制识别是目前研究的热点问题.本文给出一种新的数字调制信号识别方法.高速数字专用芯片ADSP2101是此方法具体实现的重要器件,这一方法在实际通信中有着广泛的应用.  相似文献   
44.
Handwriter identification aims to simplify the task of forensic experts by providing them with semi-automated tools in order to enable them to narrow down the search to determine the final identification of an unknown handwritten sample. An identification algorithm aims to produce a list of predicted writers of the unknown handwritten sample ranked in terms of confidence measure metrics for use by the forensic expert will make the final decision.Most existing handwriter identification systems use either statistical or model-based approaches. To further improve the performances this paper proposes to deploy a combination of both approaches using Oriented Basic Image features and the concept of graphemes codebook. To reduce the resulting high dimensionality of the feature vector a Kernel Principal Component Analysis has been used. To gauge the effectiveness of the proposed method a performance analysis, using IAM dataset for English handwriting and ICFHR 2012 dataset for Arabic handwriting, has been carried out. The results obtained achieved an accuracy of 96% thus demonstrating its superiority when compared against similar techniques.  相似文献   
45.
利用皖南两县五村社会调查资料,分析各类农民家庭的经济状况及其在收入和生活水准上的差别;考察农民对土地承包权的态度及其影响因素。结果表明,官方有关农民收入的数据,存在着低估的可能;农户不愿意放弃土地承包权的占大多数,但是如果国家征收土地时满足农民的一定要求,他们仍愿意放弃或出让。  相似文献   
46.
Data mining methods for classification and regression are becoming increasingly popular in various scientific fields. However, these methods have not been explored much in educational measurement. This module first provides a review, which should be accessible to a wide audience in education measurement, of some of these methods. The module then demonstrates using three real‐data examples that these methods may lead to an improvement over traditionally used methods such as linear and logistic regression in educational measurement.  相似文献   
47.
应收账款管理创新研究   总被引:1,自引:0,他引:1  
在传统应收账款管理方法的基础上,企业应运用维.帕累托(Vilfredo.Pareto)最优分析法对应收账款进行分类管理。即把已有客户分为核心客户、主要客户和一般客户,对他们实行不同的信用管理。对新客户运用稳健分析模型进行信用分析,然后做出销售决策。对销售人员确立应收账款管理目标,以应收账款质量提高作为目标管理的主要内容,企业销售人员的考核与应收账款质量的提高挂钩,建立应收账款管理的激励和约束机制。  相似文献   
48.
RS和GIS技术在城市绿地管理中的应用   总被引:3,自引:0,他引:3  
城市绿地管理是城市资源环境建设中的一个重要环节,文章主要从城市绿地调查、规划和监测三个方面探讨了遥感(RS)和地理信息系统(GIS)技术在城市绿地资源管理中的应用。  相似文献   
49.
梦是文学创作的一种特殊的表达方式。在小说《简爱》中,夏洛蒂.勃朗特通过梦的意象把女主人公简爱充满疑虑和矛盾的内心展现在读者面前。该文对小说中的梦境描写进行了归类并对其作了进一步分析,展示通过梦意象的运用产生了震撼人心的艺术效果,增强了思想感情表达的艺术张力。  相似文献   
50.
泉州湾湿地保护与生产活动的冲突和协调发展   总被引:3,自引:0,他引:3  
阐述了泉州湾河口湿地生物多样性价值及其保护对泉州近海环境的重要意义,但近年来人类活动的频繁干扰,如滩涂湿地过度养殖,工程建设占用湿地,海水污染,外来有害物种的蔓延使河口湿地逐渐退化,生物多样性减少,解决泉州湾河口湿地生产与保护的冲突应本着“善用湿地”这一宗,建立国家有自然保护区并成立相应的管理机构加强立法执法力度,恢复重建红树林群落,将养殖规模控制在理论规划范围内,严格控制污染源及加大对保护区的经济投入等。  相似文献   
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