A disorder situation of traffic operation always appears in on-ramp junction area of urban freeway,because the operation action for vehicles presents the weaving condition,especially for different vehicle types.Based ...A disorder situation of traffic operation always appears in on-ramp junction area of urban freeway,because the operation action for vehicles presents the weaving condition,especially for different vehicle types.Based on the analysis on the cellular automata theory,and combining with on-site survey data,several key parameters were defined,namely,cellular length,cellular speed,cellular acceleration,updating time interval.In addition,cellular acceleration rule,cellular deceleration rule,random rule,lane-changing rule and other micro-simulation rules were set,and cellular automaton micro-simulation model was set up.Further-more,a micro-simulation module was developed for traffic operation actions of on-ramp junction with Matlab toolbox.Finally,a simulation experiment for traffic operation reliability was done with this micro-simulation module,and the situation of change for on-ramp junction area was obtained under the conditions of different mainline design speed,acceleration lane length,vehicle generation probability and lane-changing probability.The results show that operation reliability for on-ramp junction is determined by the parameters of the probability of vehicle generation and the length of acceleration lane,especially for on-ramp.展开更多
The present study applies "Textual Patterns" like "general-specific" and "claim-counterclaim" to explore discourse coherence in Chinese students' English writing. The study confirms the function of the textual ...The present study applies "Textual Patterns" like "general-specific" and "claim-counterclaim" to explore discourse coherence in Chinese students' English writing. The study confirms the function of the textual patterns as macro-structures for discourse interpretation and production, and proves textual patterns as effective tools in identifying and solving problems with discourse coherence in Chinese EFL (English as a Foreign Language) learners' writing.展开更多
The paper presents the possibilities of implementing micro-simulation traffic tools in order to develop the evacuation plans. Well elaborated evacuation plans are the basis for alleviating the consequences resulting f...The paper presents the possibilities of implementing micro-simulation traffic tools in order to develop the evacuation plans. Well elaborated evacuation plans are the basis for alleviating the consequences resulting from emergencies. The simulation tools allow the design and verification of various evacuation planning scenarios with minimisation of costs and time. The paper provides detailed presentation of the basic characteristics of microscopic simulation of traffic flows, as well as examples of their implementation worldwide. The characteristics of the software tools are described through an overview of the basic settings ofPTV VISSIM (Planung Transport Verkehrin Stadten--Simulations model) program as one of the most significant representatives of these tools. The necessity of implementing the traffic tools in evacuation results from the crucial role of traffic in reducing the consequences of emergencies. These tools allow also a detailed analysis of the output data in order to select a suitable solution. The concluding part of the paper presents an example of evacuation of the population through the Jankomir node as part of the European project "preparedness for evacuation in case of a nuclear accident". The evacuation was performed through three scenarios in circumstances of higher or lower transport demand.展开更多
By the end of sixties, several satellites were launched to observe the earth; among them the Landsat missions have been important to study natural resources, especially in agriculture. Currently, Landsat 7, with some ...By the end of sixties, several satellites were launched to observe the earth; among them the Landsat missions have been important to study natural resources, especially in agriculture. Currently, Landsat 7, with some problems, and Landsat 5 are useful to evaluate crop development. A project called "Participatory multi-Level EO-assisted tools for Irrigation water management and Agricultural Decision-Support" (PLEIADES) was financed by the European Commission. This project considers eleven countries and 23 research institutions, Mexico being one of the selected countries. Landsat images are a basic tool of this project. Some of the results obtained in this study are presented in this article. By using w^getation indices obtained by the combinations of reflectances in different bands of the electromagnetic spectrum, it has been possible to estimate the behavior of several biophysical parameters of crops which are used to evaluate plant development, water stress, spatial soil variation, and the effect of plagues and crop diseases. To facilitate this process, a visor was developed, named SPIDER (System of Participatory Information Decision support and Expert knowledge for River basin management) whose use in this work is explained.展开更多
基金Project(HIT.NSRIF.2009102) supported by the Fundamental Research Funds for the Central Universities in ChinaProject(11541295) supported by the Scientific Research Fund of Heilongjiang Provincial Education Department of ChinaProject(20100471029) supported by China Postdoctoral Science Foundation
文摘A disorder situation of traffic operation always appears in on-ramp junction area of urban freeway,because the operation action for vehicles presents the weaving condition,especially for different vehicle types.Based on the analysis on the cellular automata theory,and combining with on-site survey data,several key parameters were defined,namely,cellular length,cellular speed,cellular acceleration,updating time interval.In addition,cellular acceleration rule,cellular deceleration rule,random rule,lane-changing rule and other micro-simulation rules were set,and cellular automaton micro-simulation model was set up.Further-more,a micro-simulation module was developed for traffic operation actions of on-ramp junction with Matlab toolbox.Finally,a simulation experiment for traffic operation reliability was done with this micro-simulation module,and the situation of change for on-ramp junction area was obtained under the conditions of different mainline design speed,acceleration lane length,vehicle generation probability and lane-changing probability.The results show that operation reliability for on-ramp junction is determined by the parameters of the probability of vehicle generation and the length of acceleration lane,especially for on-ramp.
文摘The present study applies "Textual Patterns" like "general-specific" and "claim-counterclaim" to explore discourse coherence in Chinese students' English writing. The study confirms the function of the textual patterns as macro-structures for discourse interpretation and production, and proves textual patterns as effective tools in identifying and solving problems with discourse coherence in Chinese EFL (English as a Foreign Language) learners' writing.
文摘The paper presents the possibilities of implementing micro-simulation traffic tools in order to develop the evacuation plans. Well elaborated evacuation plans are the basis for alleviating the consequences resulting from emergencies. The simulation tools allow the design and verification of various evacuation planning scenarios with minimisation of costs and time. The paper provides detailed presentation of the basic characteristics of microscopic simulation of traffic flows, as well as examples of their implementation worldwide. The characteristics of the software tools are described through an overview of the basic settings ofPTV VISSIM (Planung Transport Verkehrin Stadten--Simulations model) program as one of the most significant representatives of these tools. The necessity of implementing the traffic tools in evacuation results from the crucial role of traffic in reducing the consequences of emergencies. These tools allow also a detailed analysis of the output data in order to select a suitable solution. The concluding part of the paper presents an example of evacuation of the population through the Jankomir node as part of the European project "preparedness for evacuation in case of a nuclear accident". The evacuation was performed through three scenarios in circumstances of higher or lower transport demand.
文摘By the end of sixties, several satellites were launched to observe the earth; among them the Landsat missions have been important to study natural resources, especially in agriculture. Currently, Landsat 7, with some problems, and Landsat 5 are useful to evaluate crop development. A project called "Participatory multi-Level EO-assisted tools for Irrigation water management and Agricultural Decision-Support" (PLEIADES) was financed by the European Commission. This project considers eleven countries and 23 research institutions, Mexico being one of the selected countries. Landsat images are a basic tool of this project. Some of the results obtained in this study are presented in this article. By using w^getation indices obtained by the combinations of reflectances in different bands of the electromagnetic spectrum, it has been possible to estimate the behavior of several biophysical parameters of crops which are used to evaluate plant development, water stress, spatial soil variation, and the effect of plagues and crop diseases. To facilitate this process, a visor was developed, named SPIDER (System of Participatory Information Decision support and Expert knowledge for River basin management) whose use in this work is explained.