Due to large size and different popularity for different part of the video, most proxy caches for streaming medias cache only a part of the video. Thus, an accurate understanding on the internal popularity distributio...Due to large size and different popularity for different part of the video, most proxy caches for streaming medias cache only a part of the video. Thus, an accurate understanding on the internal popularity distribution of media objects in streaming applications is very important for the development of efficient cache mechanisms. This letter shows that the internal popularity of popular streaming media obeys a k-transformed Zipf-like distribution through analyzing two 6-month long traces recorded at different streaming video servers of an entertainment video-on-demand provider. This empirical model can be used to design an efficient cach- ing algorithm.展开更多
Aimed at the frozen soil arch reinforcement form of upside shed used for the shield machine launching in tunneling the internal force of the structure was calculated with the aid of the structural mechanics theory. Co...Aimed at the frozen soil arch reinforcement form of upside shed used for the shield machine launching in tunneling the internal force of the structure was calculated with the aid of the structural mechanics theory. Considering the space characteristics of the structure, this calculating method is suitable for practical engineering. Moreover, the behavior of the freezing arch reinforcement structure was analyzed combined with an engineering case.展开更多
This quantitative-oriented study investigates junior middle school EFL teachers’beliefs about motivational practices in the language teaching process.Grounded in self-determination theory,the study examined teachers...This quantitative-oriented study investigates junior middle school EFL teachers’beliefs about motivational practices in the language teaching process.Grounded in self-determination theory,the study examined teachers’beliefs in three basic psychological needs(relatedness,competence and autonomy)and the effect of their teaching experience on these beliefs.Data were obtained from 84 Chinese junior middle school English teachers through a questionnaire.Results suggested that teachers recognized motivational practices for relatedness and competence satisfaction while showing relatively low recognition of a few motivating practices for autonomy satisfaction.Teaching experience was found to have no influence on teachers’conception of needs-related motivational practices.Findings reveal that traditional activities like collective lesson preparations may have a negative influence on teachers’beliefs about motivational practices.They also present the necessity for adjustments on educational regulations,and for modern professional training to help teachers understand students’basic psychological needs,and to encourage new ideas to bolster students’intrinsic motivation for language learning.展开更多
Through questionnaire investigation, three major motivation types have been identified in less successful second year students (judged by the state exam CET4) in Hainan University: type A — integrative/intrinsic moti...Through questionnaire investigation, three major motivation types have been identified in less successful second year students (judged by the state exam CET4) in Hainan University: type A — integrative/intrinsic motivation (interest in culture and language), type B — job-related motivation (learning for better jobs), and type C — test-oriented motivation (learning to pass tests). Students with instrumental motivation (types B & C) far out-number those with integrative motivation (type A). Significant differences in test performance are found between type A and type C, and type B and type C. No significant difference is found between the test performance of type A students and that of type B students.展开更多
Based on the comparison with the Earth, using the LB magnetic field model, the distribution of O+ ion originating from the ionosphere in the Martian magnetosphere is theoretically studied under different conditions of...Based on the comparison with the Earth, using the LB magnetic field model, the distribution of O+ ion originating from the ionosphere in the Martian magnetosphere is theoretically studied under different conditions of the tail-like magnetic field. The results show that the tail-like magnetic field has influence on the O+ ion flux in the Martian magnetotail: (i) the O+ ion flux in the Martian tail will increase if the tail-like magnetic field increases; when the tail-like magnetic field increases from 5 nT to 20 nT, the O+ ion flux increases 3 times in the region of 2.8R m in the Martian tail; and (ii) the O+ ion flux decreases with increasing intrinsic moment; when the intrinsic moment increases about 5 times, the flux decreases to one fourth in the region of 2.8R m in the Martian tail. According to the data on the O+ ion flux and theoretical result in this paper, the deduced Martian intrinsic moment is about 2 ×1021 Gcm3. This is consistent with the most recent observation by the USA satellite MGS.展开更多
基金Supported by the National Natural Science Foundation of China (No.60302004), the Australian Research Council (Grant LX0240468) and Natural Science Foun-dation of Hubei, China (No.2005ABA264).
文摘Due to large size and different popularity for different part of the video, most proxy caches for streaming medias cache only a part of the video. Thus, an accurate understanding on the internal popularity distribution of media objects in streaming applications is very important for the development of efficient cache mechanisms. This letter shows that the internal popularity of popular streaming media obeys a k-transformed Zipf-like distribution through analyzing two 6-month long traces recorded at different streaming video servers of an entertainment video-on-demand provider. This empirical model can be used to design an efficient cach- ing algorithm.
基金Project 2002CB412704 supported by The National 973 Item
文摘Aimed at the frozen soil arch reinforcement form of upside shed used for the shield machine launching in tunneling the internal force of the structure was calculated with the aid of the structural mechanics theory. Considering the space characteristics of the structure, this calculating method is suitable for practical engineering. Moreover, the behavior of the freezing arch reinforcement structure was analyzed combined with an engineering case.
文摘This quantitative-oriented study investigates junior middle school EFL teachers’beliefs about motivational practices in the language teaching process.Grounded in self-determination theory,the study examined teachers’beliefs in three basic psychological needs(relatedness,competence and autonomy)and the effect of their teaching experience on these beliefs.Data were obtained from 84 Chinese junior middle school English teachers through a questionnaire.Results suggested that teachers recognized motivational practices for relatedness and competence satisfaction while showing relatively low recognition of a few motivating practices for autonomy satisfaction.Teaching experience was found to have no influence on teachers’conception of needs-related motivational practices.Findings reveal that traditional activities like collective lesson preparations may have a negative influence on teachers’beliefs about motivational practices.They also present the necessity for adjustments on educational regulations,and for modern professional training to help teachers understand students’basic psychological needs,and to encourage new ideas to bolster students’intrinsic motivation for language learning.
文摘Through questionnaire investigation, three major motivation types have been identified in less successful second year students (judged by the state exam CET4) in Hainan University: type A — integrative/intrinsic motivation (interest in culture and language), type B — job-related motivation (learning for better jobs), and type C — test-oriented motivation (learning to pass tests). Students with instrumental motivation (types B & C) far out-number those with integrative motivation (type A). Significant differences in test performance are found between type A and type C, and type B and type C. No significant difference is found between the test performance of type A students and that of type B students.
基金part of the research project "Correlation Between Interaction Patterns and Patterns of Meaning Construction in Undergraduate Asynchronous Online Discussion(HJSK2009-83)"supported by Scientific Research Fund of Hainan Provincial Education Department
基金This work was supported by the National Natural Science Foundation of China ( Grant No. 49884002) .
文摘Based on the comparison with the Earth, using the LB magnetic field model, the distribution of O+ ion originating from the ionosphere in the Martian magnetosphere is theoretically studied under different conditions of the tail-like magnetic field. The results show that the tail-like magnetic field has influence on the O+ ion flux in the Martian magnetotail: (i) the O+ ion flux in the Martian tail will increase if the tail-like magnetic field increases; when the tail-like magnetic field increases from 5 nT to 20 nT, the O+ ion flux increases 3 times in the region of 2.8R m in the Martian tail; and (ii) the O+ ion flux decreases with increasing intrinsic moment; when the intrinsic moment increases about 5 times, the flux decreases to one fourth in the region of 2.8R m in the Martian tail. According to the data on the O+ ion flux and theoretical result in this paper, the deduced Martian intrinsic moment is about 2 ×1021 Gcm3. This is consistent with the most recent observation by the USA satellite MGS.
