文本分类中一种基于选择的二次特征降维方法

特征选择和特征抽取是文本分类中特征降维的主要方法.目前各种特征选择方法主要致力于度量特征与文本类别的相关性,却很少考虑特征之间的冗余性问题,从而影响特征降维的效果.本文提出一种基于选择的两步特征选择方法,既考虑一些类别信息较强的特征的选取,又减少一些类别判定方面的冗余特征,在尽量减少信息损失的前提下达到有效缩减特征维数的目的.对中文文本的分类实验结果表明,本文提出的特征降维方法在文本分类的准确率方面效果较好.     

海峡两岸土木工程专业术语初步对照与分析

鉴于海峡两岸土木工程学术交流日趋频繁,但两岸土木工程专业术语目前仍存在易混淆不清的问题(例如脚手架在台湾地区是鹰架),因此两岸在土木工程专业用语的术语差异性有必要进一步确认与整合。研究共查阅3 273笔两岸土木工程不同专业领域(包含土木、测量、交通、环境、岩土、结构及水利工程等)的术语资料,针对大土木及不同土木工程专业领域的专业术语差异性进行对照,并对专业术语容易混淆的程度给予评分。研究结果发现,在大土木的环境下,具有混淆程度的专业术语占27%,显示两岸土木工程人员在大土木的沟通上约有1/4的专业术语可能会被混淆或误解。此外,在上述的27%中,交通工程专业术语就占了19%,较其它专业领域占约8%左右要多,显示交通工程专业术语最容易混淆不清。     

Feminism, Patriarchy and Culture Dominance ——A review to "The Woman Warrior

1.Feminism and“The woman Warrior”Historically,thinking about gender happens in cultures where gender configurations-the socialmeaning systems that encode sexual difference-undergo changes or shifts.The same is true withthinking about race(thatrace as a constructbecomes apparentwhen ideas of race are shifting) or eco-nomics,or politics,etc.:all of these concepts are reevaluated when social practice(i.e.what peopledo) shifts.So gender,or masculine and feminine qualities,or male/female social …     

目标雷达散射截面(RCS)的高频预估方法

利用物理光学(PO)、几何绕射理论(GTDMEC)、物理光学+物理绕射理论(等效流)(PO+PTDMEC)等高频预估方法计算了平板的RCS.GTDMEC和P0+PTDMEC结果与实验结果和文献[1]吻合很好.     

对篮球技术偏利及克服办法之探讨

本文通过大量资料对偏利进行科学地探讨,揭示篮球技术偏利的形成因素和产生的不良影响,提出克服其有效办法。     

Contracts and Common Standards for Digital License Deals

Who should control and exploit digital rights in the publishing industry? For a precise definition and a discussion the publishing industry needs basic knowledge of how to purchase and sell electronic rights and extended standard agreements. This article is covering a definition of digital rights, purchase, and sale of digital rights, business models to sell digital content and terms with related conditions.     

多学科交叉融合的新生工科专业建设

新生工科专业是指由不同工程学科的交叉复合,或由工程学科与其他学科的交叉融合而产生的新的工科专业,新生工科专业建设是新工科建设中一项十分复杂的核心工作,对新工科中其它类型的学科专业建设,以及高等教育其它学科专业领域的新专业建设具有重要的参考和示范作用。新生工科专业建设内容主要包括专业设置、专业培养方案制定、课程体系建设、教学内容形成、实践教育教学体系构建、创新创业教育体系构建等方面。与此同时,在新生工科专业建设时还需要重视科学研究对新生工科专业建设和人才培养的支撑作用。本文以新生工科专业建设为主题,依次对上述六方面内容进行讨论和分析,以期为相关院校开展新工科建设提供参考和借鉴。     

跨文化意识培养与英语习语趣译

语言是文化的一个组成部分，又是文化的载体，语言学习不能独立于文化学习之外。文章分析了文化与语言之间相辅相成的关系，指出不同的语言承载各自不同的文化和习惯。认为跨文化意识不单纯是指文化风俗知识，它的含义包括政治、经济及日常生活，它体现在英语习语的趣译中。从而总结出成功的英语习语趣译，取决于跨文化意识的培养。     

环保技术创新的市场障碍及其跨越

有效供给和有效需求是环保技术创新实现的两个基本条件。当前我国环保技术创新供给与市场技术需求不相适应．这表明环保技术创新的市场化机制尚未形成。环保技术创新还缺乏良好的制度和政策环境。为此要把政府的干预与发挥市场的作用有机结合起来。加强制度建设。实施激活市场有效需求的政策。     

Effects of instructional strategies using cross sections on the recognition of anatomical structures in correlated CT and MR images

This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer‐based instructional strategies that use anatomical cross‐sections to enhance the interpretation of radiological images. These strategies include: (1) cross‐sectional images of the head that can be superimposed on radiological images, (2) transparent highlighting of anatomical structures in radiological images, and (3) cross‐sectional images of the head with radiological images presented side‐by‐side. Data collected included: (1) time spent on instruction and on solving test questions, (2) mental effort during instruction and test, and (3) students' performance to identify anatomical structures in radiological images. Participants were 28 freshmen medical students (15 males and 13 females) and 208 biology students (190 females and 18 males). All studies used posttest‐only control group design, and the collected data were analyzed by either t test or ANOVA. In self‐directed computer‐based environments, the strategies that used cross sections to improve students' ability to recognize anatomic structures in radiological images showed no significant positive effects. However, when increasing the complexity of the instructional materials, cross‐sectional images imposed a higher cognitive load, as indicated by higher investment of mental effort. There is not enough evidence to claim that the simultaneous combination of cross sections and radiological images has no effect on the identification of anatomical structures in radiological images for novices. Further research that control for students' learning and cognitive style is needed to reach an informative conclusion. Anat Sci Ed 1:75–83, 2008. © 2008 American Association of Anatomists.