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1.
Oyelami Olufemi Moses 《美中教育评论》2008,5(11):22-27
More recent motivational research focuses on the identification of effective techniques for enhancing instructional design and meeting the needs of diverse student populations （Wlodkowski R. J., 1981）. Learning-motivation researchers are applying some of the same theories and concepts found to be effective in industry to the development of motivational models that enhance the teaching-learning environment. One of such models is the Attention Relevance Confidence Satisfaction （ARCS） model of motivational design developed by John M. Keller （Small Ruth V., 2007）. The continuous improvement in handheld devices technologies has led to a new learning paradigm called mobile learning which involves the delivery of learning contents to learners utilizing mobile computing devices. Handheld devices, however, have constraints which limit their use for effective learning. Towards improving the effectiveness of mobile learning is a new mobile learning model proposed by Shih on which instructional designs for mobile learning can be based to facilitate mobile learning design and to achieve better mobile learning outcomes （Yushin E. Shih ＆ Dennis Mills, 2007）. Shih＇s model is based on Graphical User Interface （GUI）. This paper presents an enhanced Shih＇s model for effective mobile learning outcome in a university environment by making provision for instructional design to include online library search for both e-books and audio books using collaborative filtering algorithm to aid the search and posting and reading of testimonials about positive mobile learning outcomes so as to encourage other mobile learners. It also incorporates the use of Voice User Interface （VUI） to access the learning portal in order to overcome mobile devices interface limitations in addition to Graphical User Interface （GUI） proposed by Shih, so as to cater for the learning needs of the blind and the visually impaired. 相似文献
2.
INTRODUCTION Autonomous mobile robot is a machine able to extract information from its environment and use knowledge about its world to move safely in a meaningful and purposive manner, it can operate on its own without a human directly controlling it (Ehlert,1999). The primary task of a mobile robot is envi-ronmental navigation as basis for more useful tasks. In contrast to indoor mobile robots and industrial manipulation robots both working in relatively static and structured environme… 相似文献
3.
Tomi Kärki Heli Keinänen Anu Tuominen Marianna Hoikkala Eila Matikainen Hanna Maijala 《Technology, Pedagogy and Education》2018,27(2):251-263
The authors consider the use of mobile learning environment ActionTrack in teacher education. Pre-service class teachers’ (N = 277) experiences of the mobile learning environment were measured with a 7-point Likert-scale questionnaire based on seven attributes of meaningful learning. Students’ ratings for different attributes were analysed quantitatively. The authors conclude that, based on this analysis, it is possible to create meaningful learning experiences using ActionTrack. All the measured attributes of meaningful learning obtained positive values. In the mobile learning events of this study, three attributes arose as the essential features: mobile learning in the outdoors was primarily considered collaborative, active and contextual. 相似文献
4.
[1]Engebretsen,L.,Sudan,M.,2002.Harmonic Broadcasting is Bandwidth-Optimal Assuming Constant Bit Rate.Proc.Annual ACM-SIAM Symposium on Discrete Algorithms.San Francisco,CA,USA.
[2]ETSI,2005.IP Datacast over DVB-H:Content Delivery Protocols.ETSI Standard,Draft,V0.0.9.
[3]Horn,G.B.,Knudsgaard,P.,Lassen,S.B.,Luby,M.,Rasmussen,J.E.,2001.A scalable and reliable paradigm for media on demand.IEEE Computer,34(9):40-45.
[4]Hu,A.,2001.Video-on-Demand Broadcasting Protocols:A Comprehensive Study.Proc.IEEE Infocom.Anchorage,Alaska.
[5]Huang,C.,Janakiraman,R.,Xu,L.,2004.Loss-Resilient Media Streaming Using Priority Encoding.Proc.ACM International Conference on Multimedia (MM‘04).New York,USA.
[6]Jenka(c),H.,Stockhammer,T.,2005.Asynchronous Media Streaming over Wireless Broadcast Channels.Proc.of International Conference on Multimedia and Expo (ICME).Amsterdam,The Netherlands.
[7]Luby,M.,Gemmel,J.,Vicisano,L.,Rizzo,L.,Handley,M.,Crowcroft,J.,2002a.Asynchronous Layered Coding (ALC) Protocol Instantiation.RFC 3450,IETF.
[8]Luby,M.,Gemmel,J.,Vicisano,L.,Rizzo,L.,Handley,M.,Crowcroft,J.,2002b.Layered Coding Transport (LCT)Building Block.RFC 3451,IETF.
[9]Luby,M.,Vicisano,L.,Gemmel,J.,Handley,M.,Crowcroft,J.,2002c.Forward Error Correction (FEC) Building Block.RFC 3452,IETF.
[10]Luby,M.,Watson,M.,Gasiba,T.,Stockhammer,T.,Xu,W.,2006.Raptor Codes for Reliable Download Delivery in Wireless Broadcast Systems.Proc.Consumer and Communications Networking Conference (CCNC).Las Vegas,NV,USA.
[11]Paila,T.,Luby,M.,Lehtonen,R.,Roca,V.,Walsh,R.,2004.FLUTE-File Delivery over Unidirectional Transport.RFC 3926,IETF.
[12]Peltotalo,J.,Peltotalo,S.,Harju,J.,2005.Analysis of the FLUTE Data Carousel.Proc.10th EUNICE Open European Summer School.Colmenarejo,Spain.
[13]Shokrollahi,A.,2003.Raptor Codes.Tech.Rep.DR2003-06-001,Digital Fountain.
[14]TM-CBMS1361,2005.Proposal for Simulations for Evaluation of Application Layer FEC for File Delivery.
[15]Xu,L.,2001.Efficient and Scalable on-Demand Data Streaming Using UEP Codes.Proc.ACM International Conference on Multimedia (MM‘01).Ottawa,Ontario,Canada. 相似文献
5.
A fast motion estimation algorithm for mobile communications 总被引：1，自引：0，他引：1
CHEN Guo-bin 《浙江大学学报(A卷英文版)》2006,7(Z1)
The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder's performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware. 相似文献
6.
Precise navigation for a 4WS mobile robot 总被引：1，自引：0，他引：1
何波 《浙江大学学报(A卷英文版)》2006,7(2):185-193
INTRODUCTION Precise navigation is being researched and ap- plied in various fields, especially for outdoor mobile robots (Wang et al., 1998; Lee, 1997; Iida et al., 2000), such as those used in cargo container trans- portation at seaport, in precision agriculture, military vehicles, etc. As we know, applied sensors and rele- vant data processing basically determine the accuracy of navigation. In our research, GPS and encoders are used as navigation sensors. As an absolute positioning s… 相似文献
7.
A network model is proposed to support service differentiation for mobile Ad Hoc networks by combining a fully distributed admission control approach and the DIFS based differentiation mechanism of IEEE802.11. It can provide different kinds of QoS (Quality of Service) for various applications. Admission controllers determine a committed bandwidth based on the reserved bandwidth of flows and the source utilization of networks. Packets are marked when entering into networks by markers according to the committed rate. By the mark in the packet header, intermediate nodes handle the received packets in different manners to provide applications with the QoS corresponding to the pre-negotiated profile. Extensive simulation experiments showed that the proposed mechanism can provide QoS guarantee to assured service traffic and increase the channel utilization of networks. 相似文献
8.
Path tracking control of autonomous agricultural mobile robots 总被引：3，自引：0，他引：3
ZHU Zhong-xiang CHEN Jun YOSHIDA Toyofumi TORISU Ryo SONG Zheng-he MAO En-rong 《浙江大学学报(A卷英文版)》2007,8(10):1596-1603
In a tractor automatic navigation system, path planning plays a significant role in improving operation efficiency. This study aims to create a suboptimal reference course for headland turning of a robot tractor and design a path-tracking controller to guide the robot tractor along the reference course. A time-minimum suboptimal control method was used to generate the reference turning course based on the mechanical parameters of the test tractor. A path-tracking controller consisting of both feedforward and feedback component elements was also proposed. The feedforward component was directly determined by the desired steering angle of the current navigation point on the reference course, whereas the feedback component was derived from the designed optimal controller. Computer simulation and field tests were performed to validate the path-tracking performance. Field test results indicated that the robot tractor followed the reference courses precisely on flat meadow, with average and standard lateral devia- tions being 0.031 m and 0.086 m, respectively. However, the tracking error increased while operating on sloping meadow due to the employed vehicle kinematic model. 相似文献
9.
张小强 《重庆大学学报(英文版)》2005,(3)
1 Introduction 1 Both economic literature and legal literature have focused a great deal of attention on the phenomenon of network effects, or network externalities: “markets in which the value that consumers place on a good increases as others use the good.”[1] Network effects have important implications for structure and competitiveness of underlying market, as well as for regulation policy making. In China, theoretical developments of the concept have been introduced, but it still remains… 相似文献
10.
MOTIVATION The calculus of Mobile Ambients (MA) (Cardelli and Gordon, 1998) was proposed to model the mobile computation based upon the notion of ambient, a bounded location where computation takes place. It can also perform movements and carry mul-tiple processes and nested ambients within it: Primi-tive “in” and “out” allows the ambient to cross the computation boundary, and primitive “open” allows the boundary to dissolve and then to unleash the in-ternal processes. Later on, s… 相似文献
11.
ZHANG Xiao-qiang 《重庆大学学报(英文版)》2005,4(3):175-178
A model is proposed along with empirical investigation to prove the existence of network effects in China＇s mobile telecommunications market. Futhernore, network effects on China＇s mobile telecommunications are estimated with a dynamic model. The structural parameters are identified from regression coefficients and the results are analyzed and compared with another literature. Data and estimation issues are also discussed. Conclusions are drawn that network effects are significant in China＇s mobile telecommunications market, and that ignoring network effects leads to bad policy making. 相似文献
12.
INTRODUCTION Improvements in sensor and wireless commu-nication technology enable accurate, automated de-termination and dissemination of a user or object’sposition. There is great interest in exploiting thispositional data through location-based services (LBS)Because of the widespread use of relatively cheapcellular phones or other mobile devices, many loca-tion services will be based on tracking technology toreveal the mobile user’s “personal” location at anygiven time (Einar, 200… 相似文献
13.
YANG Rui-jun XIA Qi PAN Qun-hua WANG Wei-nong LI Ming-lu 《浙江大学学报(A卷英文版)》2006,7(4):493-501
INTRODUCTION Mobile ad hoc networks are under active research focused on issues such as routing, security (Venkatra- man and Agrawal, 2003) and data management (Fan and Zhang, 2004). People have proposes many kinds of security mechanisms such as SAR (Yi et al., 2002), SRP (Papadimitratos and Haas, 2002), ARAN (San- zgiri et al., 2002), ARIADNE (Hu et al., 2005) and SEAD (Hu et al., 2002) for networks. The resource consumptions of security mechanisms are always large in mobile … 相似文献
14.
Sports video appeals to large audiences due to its high commercial potentials. Automatically extracting useful semantic information and generating highlight summary from sports video to facilitate users‘ accessing requirements is an important problem, especially in the forthcoming broadband mobile communication and the need for users to access their multimedia information of interest from anywhere at anytime with their most convenient digital equipments. In this paper, a system to generate highlight summaries oriented for mobile applications is introduced, which includes highlight extraction and video adaptation. In this system, several highlight extraction techniques are provided for field sports video and racket sports video by using multi-modal information. To enhance users‘ viewing experience and save bandwidth, 3D animation from highlight segment is also generated. As an important procedure to make video analysis results universally applicable, video transcoding techniques are applied to adapt the video for mobile communication environment and user preference. Experimental results are encouraging and show the advantage and feasibility of the system for multimedia content personalization, enhancement and adaptation to meet different user preference and network/device requirements. 相似文献
15.
LI Mao-hai HONG Bing-rong LUO Rong-hua WEI Zhen-hua 《浙江大学学报(A卷英文版)》2006,7(6):937-944
INTRODUCTION A key prerequisite for a truly autonomous robot is that it can simultaneously localize itself and accu-rately map its surroundings (Kortenkamp et al., 1998), which is known as Simultaneous Localization and Mapping (SLAM), which, when phrased as a state estimation problem, involves a variable number of dimensions. Murphy and Russell (2001) adopted Rao-Blackwellized particle filters (RBPFs) as an effective way for representing alternative hypotheses on robot paths and ass… 相似文献
16.
This paper proposes novel multiple-mobile-robot collision avoidance path planning based on cooperative co-evolution, which can be executed fully distributed and in parallel. A real valued co-evolutionary algorithm is developed to coordinate the movement of multiple robots in 2D world, avoiding C-space or grid net searching. The collision avoidance is achieved by cooperatively co-evolving segments of paths and the time interval to pass them. Methods for constraint handling, which are developed for evolutionary algorithm, make the path planning easier. The effectiveness of the algorithm is demonstrated on a number of 2D path planning problems. 相似文献
17.
WAN Zheng PAN Xue-zeng CHEN Jian CUI Yu-zeng 《浙江大学学报(A卷英文版)》2006,7(12):2118-2126
INTRODUCTION Mobile IPv6 (MIPv6) (Johnson et al., 2004) was proposed to maintain network connectivity in the next generation Internet. However, communication quality of MIPv6 degrades because of the high signaling overhead and the long signaling delay when a mobile node (MN) performs handover. Hierarchical Mobile IPv6 (HMIPv6) (Soliman et al., 2005) was proposed to improve the performance of MIPv6, where the Mobility Anchor Point (MAP) handles mobility in- side the local domain… 相似文献
18.
ZHUANG Hui-zhong DU Shu-xin WU Tie-jun 《浙江大学学报(A卷英文版)》2006,7(4):516-524
INTRODUCTION Path planning of mobile robots is one of the key issues in robotics research on the problem of a robot finding a collision-free path from beginning to goal in the presence of obstacles. Depending on the envi- ronment surrounding the robot, it can be classified as follows: (1) Path planning for static obstacles in com- pletely known environment; (2) Path planning for static obstacles in un- known or partially known environment; (3) Path planning for dynamic obstacles in com- p… 相似文献
19.
This paper presents the findings of an investigation carried out in Sri Lanka to explore how mobile phones can support science teachers’ pedagogical practices throughout the teaching cycle of planning, teaching and evaluation. Data were collected using observation supported by audio and video recordings from both continuing professional development workshops where a group of teachers planned four science lessons that integrated mobile phones and the subsequent implementation of those lessons. Thematic network analysis, carried out on the data with the help of NVivo8 qualitative analysis software, showed how mobile phones were used and the issues involved. It concluded that mobile phones can support science teaching in a variety of ways, in particular with communication during planning lessons, with relating subject knowledge to authentic locations and activities during teaching and with image and data capture to support assessment and post-lesson reflection. The additional pedagogical practices and knowledge base required when integrating mobile phones into science lessons are discussed in the light of Shulman’s original model. 相似文献
20.
Education and Information Technologies - Using mobile applications in science education has proven to be effective as it adds multiple benefits including learning gains, motivation to learn, and... 相似文献