H.264/AVC error resilience tools suitable for 3G mobile video services

The emergence of third generation mobile system （3G） makes video transmission in wireless environment possible, and the latest 3GPP/3GPP2 standards require 3G terminals support H.264/AVC. Due to high packet loss rate in wireless environment, error resilience for 3G terminals is necessary. Moreover, because of the hardware restrictions, 3G mobile terminals support only part of H.264/AVC error resilience tool. This paper analyzes various error resilience tools and their functions, and presents 2 error resilience strategies for 3G mobile streaming video services and mobile conversational services. Performances of the proposed error resilience strategies were tested using off-line common test conditions. Experiments showed that the proposed error resilience strategies can yield reasonably satisfactory results.     

2021年PISA数学——来自CCR的分析

数学是理解世界、公民身份和经济增长的基石。为了满足全社会对教育的需求,21世纪教育应该注重对知识理解的深度和多样性的培养。PISA关于数学能力的测试中,最重视学生运用数学推理来解决问题的能力。我们建议扩展数学过程的描述(表述、应用、解释、评估),并在PISA数学框架内确定这些处理过程为数学建模的主要组成部分,其中有七个最常用于寻找正确推理方法的推理工具:比较、比例推理、应用乘法量表、拆分、归并、由简入繁、概率推理和逻辑推理。PISA数学的素养领域涉及形状与空间、变化与关系、不确定性与数据、数量等,还要特别注意创造性思维能力、品格和元认知技能的培养。     

课堂教学中传统教具与信息化教具的适用度探讨

文章分析了传统教具和现代信息化教具各自的优势,对专业课课堂教学中如何合理地使用信息化教具和传统教具、并将二者有机结合的问题进行探讨.     

政策工具视角下《国家职业教育改革实施方案》的省级推进策略分析——以苏、浙、沪三省市政策文本为例

随着《国家职业教育改革实施方案》颁布以后,部分省市相继出台了各级层面的职业教育改革实施方案,分别针对区域实际制定了行动计划和具体标准。为了审视省级层面政策推进与落实情况,以罗斯维尔和泽福德的政策工具分类理论为基础,结合职业教育改革发展若干要素构建理论框架,对苏、浙、沪三省市的职业教育改革政策文本进行分析后发现:供给型政策工具使用适当,但内部结构失衡;环境型政策工具使用过溢,策略性措施成为主要手段;需求型政策工具使用不足,作用形式较为单一;职业教育改革发展维度覆盖较为全面,但内部分化。在此基础上,提炼出国家级方案的省级推进策略,包括国家政策的区域对应、区域状况的精准考察、省域政策的整体设计等三个环节,以此作为反馈的成功经验加以推广。     

An Investigation into a Digital Strategy for Industrial Design Education

As the number of digital natives increases and the range of digital design tools / media continues to expand, it is timely to examine the potential for an entirely digital industrial design process that can be employed in practice and education. Following a literature review, a draft Digital Industrial Design (DID) strategy that focuses on the core design activities of sketching, drawing, model making, and prototyping was generated. A paper‐based, theoretical model was established and presented to graduating students, academics and practitioners. The results indicated that, while graduating students were interested in employing an approach based entirely on digital methods, the majority had doubts about its capacity to replace conventional and hybrid methods. The removal of paper‐based sketching, the conventional hands‐on experience when model making, and the cost of digital tools were identified as primary concerns. Although academics believed that the future of industrial design programmes would become increasingly digital, it was identified that current programmes were failing to exploit the opportunities afforded by these technologies fully.     

Professional Development of Physics Teachers in an Evidence-Based Blended Learning Program

The present study examined continuity of learning between face-to-face and online environments in a “blended” professional development program designed for 16 physics teachers. The program had nine face-to-face meetings as well as continuous online exchanges between them through a website. The program focused on “knowledge integration” (KI) innovative activities in physics classes using an “evidence-based” approach: The teachers implemented the activities, collected and analyzed data about their practice and their students’ learning, and reflected on the evidence with their peers. Five reflective tools were used to promote continuity: Your Comments, Hot Polls, Smashing Sentences, Hot Reports, and Mini Research. Continuity was assessed with regard to the ideas discussed by the teachers and the reasoning patterns that they employed. Analysis of the online exchanges in relation to teachers’ face-to-face discourse revealed that the teachers discussed the same ideas (KI, evidence and learner-centered pedagogies), employed the same reasoning patterns (e.g., forming generalizations), and extended ideas in re-visitation. The online and face-to-face environments played different and complementary roles in the teachers’ learning. This study shows that appropriate use of an online environment in a blended program can lead to a continuous course of learning and can transform a “9 once-a-month-meetings” workshop into a “9-month” workshop.     

对股东代表诉讼制度的思考

从完善公司治理结构的角度,在我国建立股东代表诉讼制度,有利于减少和消除大股东和中小股东之间的利益冲突,有利于减少和消除股东和经营管理层之间的利益冲突,从而达到公司治理结构的平衡与完善。从股东代表诉讼制度构成要件的角度,探讨了股东同时所有股份原则,股东持股期间和持股比例,股东代表诉讼的被告范围和前置程序,公司在股东代表诉讼中的地位等问题。认为股东人格和公司人格应适当分离。     

微型学习现状调查与分析

依托移动学习终端的微型学习使随时随地的学习成为可能,并能够满足成人学习者短小、松散、实用的学习目的,是一种可以满足终身学习需求的非正式学习方式.为了更有针对性、有效地设计微型学习,本文对微型学习的国内外研究现状进行了调研,分析了微型学习所依托的移动学习终端、微型课程制作工具、微型学习通信方式等内容.     

Students' Perceptions of the Technological Supports for Problem-based Learning

This paper reports students' perceptions of the technological supports that assist problem-based learning (PBL). There are a number of tasks in the PBL processes, which can be supported by technological advances. A Web-based system has been developed to support the problem-based learning strategy. The system provides facilities to both teacher and students to facilitate learning and teaching. These include on-line teaching materials retrieval, a discussion area for problem analysis and brainstorming, a facility for project planning and monitoring, a private group area for the purposes of discussion, a facility for the submission of development work and learning resources, and a posting area to display good work to motivate students. The progress of the students can be monitored and feedback can be given to them. This paper presents a pilot study of student views of and preferences for various technological supports used to enhance learning effectiveness.     

The Complexity of Learning: Exploring the Interplay of Different Mediational Means in Group Learning with Digital Tools

The relationship between the different mediational means for supporting students’ learning with digital tools in science group work in a Norwegian lower-secondary school is examined. Analyses of teacher-student and student-student interactions are located in cultural-historical theory and draw on Galperin’s conceptualisation of learning processes. Findings show that digital tools, task design, peer collaboration, and teacher’s interventions dialectically interplay to shape how learners use mediational means: (1) digital tools are the resources that enable students to explicate their (mis)understandings; (2) compare-and-contrast tasks promote analytical thinking; (3) peers present themselves as resources who promote development of conceptual understanding; (4) the teacher guides learners’ attention towards the potential of the mediational resources, elicits, organises, and structures students’ knowledge. The dialectical interplay of these mediational means creates a system that supports and guides students’ learning.