基于互信息量的视频关键帧提取算法

关键帧提取技术是基于内容检索和视频分析的基础。关键帧的使用减少了视频索引的数据量,同时也为视频摘要和检索提供了一个组织框架。首先介绍了目前关键帧提取技术,然后提出了一种基于互信息量的关键帧提取方法,该算法以帧间互信息量来衡量两帧图像内容的相似性,可以对具体镜头按其特点自动提取出一个或多个关键帧。实验结果表明这种方法可以较好地概括视频内容。     

浅析视频技术的发展和应用

当前视频技术发展迅速且应用广泛,然而视频格式的不统一、编码技术的多样性却给视频的创建和使用带来了诸多不便。本文就各类视频文件的特点、应用和转换方式进行了深入的分析和探讨。     

神经网络在视频检索中的应用

随着计算机技术的发展,视频数据的容量以几何级数增长。如何在海量视频数据库中快速地检索到所需视频成为热门的研究课题。本文提出了一种基于反馈式神经网络的视频检索算法,对视频进行基于内容的分析和检索。实验表明用该方法检索的准确度比用基于关键帧的视频检索方法平均提高4%以上。     

典型实验教学视频案例制作的教学设计——以“乙酰水杨酸的制备”为例

典型实验教学视频案例为提高高校实验教学效果,促进实验教学改革起到重要推动作用。针对实验教学视频案例的制作,文章从教学设计的视角,以个案研究的方法,对典型实验教学视频案例的概念特点以及如何应用教学设计做了详细介绍。     

探析Hulu运营模式对卫视网站创新的借鉴

网络视频是一个受年轻用户青睐的新媒体新兴业务,但多数网络视频因其由用户自传而出现版权诉讼、内容删除、质量差和内容品位不高等问题,使一些视频网站看上去很热闹,赢利却很困难。本文通过对新兴视频网站Hulu的模式进分析,认为Hulu模式符合视频网站未来的发展趋势,值得各类视频网站借鉴。     

How to capture growth? – Video narratives as an instrument for assessment in teacher education

Portfolios are widely used as instruments for assessment in initial teacher education courses. They are claimed to present a comprehensive picture of student teachers' knowledge and performance. But what type of evidence is needed to safely say that an aspiring teacher has not only grasped essential notions and concepts from the teacher education course, but is also able to implement them in real world classroom situations? This paper reports on the design process of one portfolio assignment that has been developed specifically to capture students' classroom performance and development in their portfolio. Data from the portfolio entries of one student from a small-scale pilot conducted with the assignment are analyzed in detail followed by a discussion of the implications of the case study.     

Qualitative Differences Between Learning Environments Using Videos in Small Groups and Whole Class Discussions: A Preliminary Study in Physics

Interactivity, group learning and student engagement are accepted as key features of social constructivist learning theories. The challenge is to understand the interplay between such features in different learning environments. This study focused on the qualitative differences between two interventions—small-groups and whole-class discussions. In both interventions, three short video slices on the abstract topic ‘the physics of superconductivity’ were interspersed with the different discussion styles. The video slices are based on the Bruner stages. Twenty-nine first year university physics students completed a pre-test, underwent the intervention and completed a post-test. The remainder of the data were collected from student drawings, video recordings, observer notes and facilitator feedback. Results indicate that the use of the video slices in both interventions were successful in changing students’ understandings of superconductivity. However, the small groups treatment tended to facilitate questioning, meaning-making and subsequent changes of ideas more so than the whole class discussions. Implications for research and practice are discussed.     

对侦查讯问同步录音录像制度的反思

讯问同步录音录像制度对于遏制刑讯逼供、保护犯罪嫌疑人等都具有重要作用。任何制度的建立和运作都有赖于一系列相关制度作保障,我国在相关保障机制尚未建立健全的情况下就推行这一制度,不仅可能无法发挥该制度预期的作用,反而会造成相反的结果。解决问题的关键在于加强对侦查讯问过程的外部监督和制约,使得该制度得以真正发挥作用。     

网络教学视频素材应用研究

文章针对高校多媒体教学发展过程中主要瓶颈之一——教学视频素材的应用问题,以网络视频素材的应用过程为线索,从视频素材的来源、下载、格式转换、加工以及合理设计等多个方面入手,探索了一整套适合教学视频素材应用的方案和方法,为视频素材的应用及提高课堂教学效率提供了一种较好的模式。     

个体投资者网络信息搜寻行为:模式与特征

通过半结构化深度访谈,探讨投资者网络信息搜寻方式、选择不同方式的原因及相关因素对网络信息搜寻行为的影响。综合分析19位个体股票投资者(简称"投资者")的访谈数据,发现投资者网络信息行为具有不同特征:一些投资者仅通过浏览的方式获取信息,多数则通过浏览为主、搜索为辅的搜寻方式获取信息;大多数投资者在获取投资信息的过程中都倾向于后者;投资者的投资经验及投资模式一定程度上影响投资者信息搜寻方式的选择。