Equation based rate control scheme for video streaming over wireless channels with link level ARQ

INTRODUCTION Video streaming applications generally require continuous high bandwidth guarantees as well as stringent bounds on delays and jitters (Shen et al., 2004; Hassan and Krunz, 2004). Providing video streaming with acceptable quality degradation over wireless channels is fraught with challenges due to the adverse influence of bandwidth limitation, time variation, high error rate, and so on (Etoh and Yo- shimura, 2005; Shen et al., 2004; Chen and Zakhor, 2004; Hassan and Krunz, …     

Using video clubs to develop teachers’ thinking and practice in oral feedback and dialogic teaching

ABSTRACT

The authors report outcomes of an evaluation of a ‘video club’ intervention to improve the feedback and dialogic teaching practice of 91 teachers from 11 primary schools in England. Participating teachers worked collaboratively in a sequence of six video clubs over a six-month period. To understand teacher engagement they examine videos of video club meetings; online platform use metrics; surveys; selected videos of classroom practice; focus groups; and interviews. They evaluate change in teachers’ thinking and practice using survey results for participants compared to a comparison group of non-participating teachers at the intervention schools. The survey includes a new instrument for gathering evidence of teachers’ thinking and practice in feedback. The results suggested changes in thinking and practice for teachers who self-reported as engaging highly with the intervention. They conclude by discussing the potential of video technology within professional development and the challenges of researching changes in thinking and practice.     

An optimal quality adaptation mechanism for end-to-end FGS video transmission

In this paper, we propose a novel optimal quality adaptation algorithm for MPEG-4 fine granular scalability (FGS) stream over wired network. Our algorithm can maximize perceptual video quality by minimizing video quality variation and increasing available bandwidth usage rate. Under the condition that the whole bandwidth evolution is known, we design an optimal algorithm to select layer. When the knowledge of future bandwidth is not available, we also develop an online algorithm based on the optimal algorithm. Simulation showed that both optimal algorithm and online algorithm can offer smoothed video quality evolution.     

论华盛顿会议前后的全国国民外交大会

全国国民外交大会是华盛顿会议前夕在上海成立的一个全国性的民间外交团体。起初,代表们希望通过华会取消不平等条约,实现民族的独立,但是列强和北京政府的表现让他们大失所望。众多代表逐渐认识到列强不会轻易放弃在华特权,华会的结果不过是将中国置于共同剥削的对象,而腐败的北京政府也不可能取得外交的胜利,只有改造内政,才能挽救国家的危亡。这些认识在当时舆论界具有相当的代表性,促进了有利于国民革命的社会意识的形成。     

中共"七大"对党的作风建设的贡献

理论联系实际、群众路线、批评与自我批评这三大作风是我党长期革命建设实践的经验总结，是我党坚持理论创新、永葆革命生机的保证。60年前召开的中共七大正是党的三大作风成熟的重要体现，同时也是我党把三大作风进一步发扬光大的光辉典范。     

A bridge over troubled waters: Bridging organisations and entrepreneurial opportunities in emerging sectors

Bridging institutions or organisations are regarded as having positive effects in the Sectoral Systems of Innovation (SSI) literature, particularly in compensating for weaknesses in these systems. Yet, we know little about the organisational practices that make their role effective, or the types of innovation paths that they may facilitate within a system. This paper shows how bridging organisations may promote neglected areas of creativity and potential disruptive innovation. These blocked opportunities tend to emerge at the boundaries of SSI: where old sectors overlap and new trajectories form. We draw on the social networks, entrepreneurship and disruptive innovation literature and analyse an intervention in the UK electronic games industry: the evaluation of business propositions exploiting new gaming platforms such as mobile telephones, DVD and film. Using an innovative co-productive research design, the study shows how the effectiveness of bridging organisation activity depends on key design choices and brokerage capabilities.     

Mathematics teachers’ “learning to notice” in the context of a video club

This study examines changes in teachers’ thinking as they participated in a video club designed to help them learn to notice and interpret students’ mathematical thinking. First, we investigate changes in teachers’ talk about classroom video segments before and after participation in the video club. Second, we identify three paths along which teachers learned to notice students’ mathematical thinking in this context: Direct, Cyclical, and Incremental. Finally, we explore ways the video club context influenced teacher learning. Understanding different forms of teacher learning provides insight for research on teacher cognition and may inform the design of video-based professional development.     

Video as a tool for fostering productive discussions in mathematics professional development

This article explores the use of classroom video as a tool for fostering productive discussions about teaching and learning. The setting for our research is a 2-year mathematics professional development program, based on the Problem-Solving Cycle model. This model relies on video from the teachers’ own classrooms and emphasizes creating a community in which members feel comfortable learning from video. We describe our experiences carrying out the Problem-Solving Cycle model, focusing on our use of video, our efforts to promote a supportive and analytical environment, and the ways in which teachers’ conversations around video developed over a 2-year period.     

从加拿大第12次全国大都市会议看后经济危机背景下的加拿大多元文化主义

2010年3月在加拿大的蒙特利尔市举行的第12次全国大都市会议围绕社会文化融合、经济与劳动力市场协调、家庭及青少年问题、住房、社区、城乡环境、社会公正和安全保障等六项议题展开研讨,以此次会议的宗旨和要义为主线,审视独特的加拿大多元文化主义治国策略在后经济危机背景下所发挥的作用,分析新历史条件和国际形势对多元文化主义政策的要求和挑战,展望理解、宽容、和谐、共荣的加拿大社会理念的发展愿景,以及对人类社会整体进步的促进和推动。