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61.
基于数值仿真计算和微波网络理论,提出了一种多层介质中频率选择表面(FSS)等效电路的分析方法。该方法物理过程直观,计算量小,适用于二维任意形状FSS等效电路的精确求解。以方形贴片型FSS为例验证了等效电路模型的准确性,并分析了多层介质对其等效电路参数的影响规律。最后,基于滤波器理论与FSS等效电路模型设计了双层带通型FSS,计算结果表明全波仿真结果与理论计算结果基本一致,为多层FSS的综合设计提供了一种精确设计方法。 相似文献
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对基于高等师范学校古代汉语教学的语料库相关数据结果做了定量分析,阐述了语料库的用字概况,提出了字区划分的标准,研制了分区字频表。 相似文献
64.
《Enterprise Information Systems》2013,7(4):433-444
In today's business environment, enterprises are increasingly under pressure to process the vast amount of data produced everyday within enterprises. One method is to focus on the business intelligence (BI) applications and increasing the commercial added-value through such business analytics activities. Term weighting scheme, which has been used to convert the documents as vectors in the term space, is a vital task in enterprise Information Retrieval (IR), text categorisation, text analytics, etc. When determining term weight in a document, the traditional TF-IDF scheme sets weight value for the term considering only its occurrence frequency within the document and in the entire set of documents, which leads to some meaningful terms that cannot get the appropriate weight. In this article, we propose a new term weighting scheme called Term Frequency – Function of Document Frequency (TF-FDF) to address this issue. Instead of using monotonically decreasing function such as Inverse Document Frequency, FDF presents a convex function that dynamically adjusts weights according to the significance of the words in a document set. This function can be manually tuned based on the distribution of the most meaningful words which semantically represent the document set. Our experiments show that the TF-FDF can achieve higher value of Normalised Discounted Cumulative Gain in IR than that of TF-IDF and its variants, and improving the accuracy of relevance ranking of the IR results. 相似文献
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本文讲述了如何运用英语视频作为教学补充资料进行课堂英语教学。介绍了如何选择和准备视频素材,如何利用现实生活中的英语开展活动的过程,以及从中培养学生们听力、口语、词汇、语法的技能和对文化的理解。在本文中出现的一些议题,例如材料的难度、字幕和配音的问题,也将在文章中予以讨论和分析。 相似文献
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This research examines the important emerging area of online customer experience (OCE) using data collected from an online survey of frequent and infrequent online shoppers. The study examines a model of antecedents for cognitive and affective experiential states and their influence on outcomes, such as online shopping satisfaction and repurchase intentions. The model also examines the relationships between perceived risk, trust, satisfaction and repurchase intentions. Theoretically, the study provides a broader understanding of OCE, through insights into two shopper segments identified as being important in e-retailing. For managers, the study highlights areas of OCE and their implications for ongoing management of the online channel. 相似文献
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Product placement in sport video games is an emerging area of marketing and advertising communication, but it also raises controversial ethical issues. In order to investigate these issues from a consumer perspective, this study examines the perceptions of the acceptability of product placement in sport video games (SVGs). Data were gathered from 253 sport video gamers using an online survey. The results indicate that while sport video gamers generally have favorable attitudes toward product placement in sport video games, ethically-charged products such as alcohol, cigarettes, and guns are perceived as less acceptable than other products. Individual differences among sport video gamers are found based on their related attitudes, hours of playing sport video games, and gender. Also, sport video gamers who have favorable attitudes toward product placement, in general, are more likely to intend to purchase a product or brand which may be placed in sport video games. 相似文献
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固定镜头下视频序列中的运动汽车目标的检测、分割、跟踪及计数等底层视觉问题进行了研究,提出了计算交通流量的算法。仿真实现表明:此算法可以有效的去噪、检测目标并计数。 相似文献