The spatial structure characteristics of landform are the foundation of geomorphologic classification and recognition.This paper proposed a new method on quantifying spatial structure characteristics of terrain surfac...The spatial structure characteristics of landform are the foundation of geomorphologic classification and recognition.This paper proposed a new method on quantifying spatial structure characteristics of terrain surface based on improved 3D Lacunarity model.Lacunarity curve and its numerical integration are used in this model to improve traditional classification result that different morphological types may share the close value of indexes based on global statistical analysis.Experiments at four test areas with different landform types show that improved 3D Lacunarity model can effectively distinguish different morphological types per texture analysis.Higher sensitivity in distinguishing the tiny differences of texture characteristics of terrain surface shows that the quantification method by 3D Lacu-narity model and its numerical integration presented in this paper could contribute to improving the accuracy of land-form classifications and relative studies.展开更多
Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure.Overl...Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure.Overlay routing has been used as an alternative to the default best effort Internet routing for the absence of end-to-end Quality of Service(QoS). While the former has recently been investigated, the conflict of QoS restraints and resource optimization remains unsolved. Recent studies have shown that overlay paths can give better latency, loss rate and TCP throughput. In this paper, a multi-dimensional QoS objective model based on the analysis of multiple QoS constraints has been presented, and a routing algorithm to optimise the overlay resource of its nodes and links is then proposed.In fact, the algorithm obtained multiple QoS values using probability theory to achieve the routing according to the multi-dimensional QoS objective vector of the QoS objective model. Simulation results reveals that the algorithm works better than other existing algorithms in balancing the network resources, and applications with stringent QoS requirements could be run.展开更多
The importance of teacher talk in EFL （English as a foreign language） class has aroused much attention in China since the late 1990s. On a basis of classroom discourse analysis, this paper has observed 14 courses wi...The importance of teacher talk in EFL （English as a foreign language） class has aroused much attention in China since the late 1990s. On a basis of classroom discourse analysis, this paper has observed 14 courses with 21 hours in total from advanced and fundamental grades in an English department. The classroom observation has been transcribed to analyze the features of teacher talk in various English courses in terms of five dimensions--discourse quantity, questioning types, feedback manners, interactional modification features, and conversation chains, It is found that on average there is significant difference in those five dimensions between fundamental and advanced courses. In terms of discourse quantity, the teacher talk has occupied more than 80% of the total talk amount and the total teacher talk in advanced courses is more than that in fundamental ones; the number of display questions is much more than that of referential questions; evaluative feedbacks are more than discursive ones; all of the teachers prefer to employ confirmation checks to modify students＇ answer, and half of the conversational chains are IRF （Initial-Response-Follow-up） structure while another half are full of complicated chains. The paper then provides some suggestions and implications for EFL teaching in the light of these findings.展开更多
基金Under the auspices of National Natural Science Foundation of China (No.40930531,41171320,41001301)
文摘The spatial structure characteristics of landform are the foundation of geomorphologic classification and recognition.This paper proposed a new method on quantifying spatial structure characteristics of terrain surface based on improved 3D Lacunarity model.Lacunarity curve and its numerical integration are used in this model to improve traditional classification result that different morphological types may share the close value of indexes based on global statistical analysis.Experiments at four test areas with different landform types show that improved 3D Lacunarity model can effectively distinguish different morphological types per texture analysis.Higher sensitivity in distinguishing the tiny differences of texture characteristics of terrain surface shows that the quantification method by 3D Lacu-narity model and its numerical integration presented in this paper could contribute to improving the accuracy of land-form classifications and relative studies.
基金supported by the National Natural Science Foundation of China under Grant No.61071126the National Science and Technology Major Projects of New Generation Broadband Wireless Mobile Communication Network under Grants No.2010ZX0300400201,No.2010ZX03003-001,No.2010ZX03004-001-01,No.2011ZX03002-001-02
文摘Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure.Overlay routing has been used as an alternative to the default best effort Internet routing for the absence of end-to-end Quality of Service(QoS). While the former has recently been investigated, the conflict of QoS restraints and resource optimization remains unsolved. Recent studies have shown that overlay paths can give better latency, loss rate and TCP throughput. In this paper, a multi-dimensional QoS objective model based on the analysis of multiple QoS constraints has been presented, and a routing algorithm to optimise the overlay resource of its nodes and links is then proposed.In fact, the algorithm obtained multiple QoS values using probability theory to achieve the routing according to the multi-dimensional QoS objective vector of the QoS objective model. Simulation results reveals that the algorithm works better than other existing algorithms in balancing the network resources, and applications with stringent QoS requirements could be run.
文摘The importance of teacher talk in EFL （English as a foreign language） class has aroused much attention in China since the late 1990s. On a basis of classroom discourse analysis, this paper has observed 14 courses with 21 hours in total from advanced and fundamental grades in an English department. The classroom observation has been transcribed to analyze the features of teacher talk in various English courses in terms of five dimensions--discourse quantity, questioning types, feedback manners, interactional modification features, and conversation chains, It is found that on average there is significant difference in those five dimensions between fundamental and advanced courses. In terms of discourse quantity, the teacher talk has occupied more than 80% of the total talk amount and the total teacher talk in advanced courses is more than that in fundamental ones; the number of display questions is much more than that of referential questions; evaluative feedbacks are more than discursive ones; all of the teachers prefer to employ confirmation checks to modify students＇ answer, and half of the conversational chains are IRF （Initial-Response-Follow-up） structure while another half are full of complicated chains. The paper then provides some suggestions and implications for EFL teaching in the light of these findings.
