As the important complementary to terrestrial mobile communications, Internet via satellite can extend the coverage of communication and improve the continuity of data services. To build a space-terrestrial integrated...As the important complementary to terrestrial mobile communications, Internet via satellite can extend the coverage of communication and improve the continuity of data services. To build a space-terrestrial integrated communication system is the inevitable trend in the future. Taking into account combination of 5th generation(5G) terrestrial mobile communication system and satellite communication system, it is necessary to evaluate the promising 5G air interface waveform which can be adopted by satellite. In this paper, several non-orthogonal multi-carrier transmission schemes are evaluated and generalized frequency division multiplexing(GFDM) is advised as potential scheme of space-terrestrial integrated communication system. After the overview of GFDM, the implementation of GFDM transceiver is discussed respectively in time-domain and in frequency-domain. By deriving and comparing implementation complexity, GFDM modulation in time-domain is more suitable for satellite communication system. Then the properties of demodulation algorithms are specified. Based on designed pilot subcarriers, a new improved receiving algorithm is proposed in the end of the paper. The improved algorithm solves the problem of inter subcarriers interference(ICI) in matched filtering(MF) receiver and improves the re-ceiving symbol error rate(SER) obviously. The simulation and analysis prove that the proposed algorithm is effective.展开更多
Impact of Internet Technologies increases importance of changes in the system of social communication creating a stressful situation for the functioning of traditionally established social institutions. New phenomena ...Impact of Internet Technologies increases importance of changes in the system of social communication creating a stressful situation for the functioning of traditionally established social institutions. New phenomena such as priest＇s and saints＇ online pages, represent significant deviation from historical practice, bring certain dissonance to the activities of the church. On one hand, church has to use modern communication channel, on the other hand, effects of online translation of confessional relations are not predictable. Open global socieW requires certain universalization of education, but professional communications are faced not only with a problem of language barrier, but also with national culture. School of thought, formed in traditions of particular cultural outlook, risks losing its face to the loss of national characteristics of the education system. Institute of Administration is also experiencing certain amount of stress.展开更多
To increase the passenger transferring efficiency, the bus coordination holding control for transit hubs, which is as an important dynamic dispatching method for improving the service level of transit hubs, was studie...To increase the passenger transferring efficiency, the bus coordination holding control for transit hubs, which is as an important dynamic dispatching method for improving the service level of transit hubs, was studied in the framework of bus coordination dispatching mode. Firstly, the bus coordination holding control flow was studied based on Advanced Public Transportation Systems (APTS) environment. Then a control model was presented to optimize the bus vehicle holding time, and a genetic algorithm was designed as the solving method. In the end, an example was given to illustrate the effectiveness of the control strategy and the algorithm.展开更多
WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of...WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of nodes makes data dissemination a hard nut to crack. In this paper, we propose MSDD, a multiple mobile sinks data dissemination mechanism for solving the dissemination problem. The main ideas of MSDD are constructing a two-tier grid structure by a designated sink, exploiting a hierarchical monitoring mechanism, and employing a global agent to track the sink locations in order to make the emergencies reported to the sinks immediately, In addition, MSDD supports the query-driven data dissemination. Being compared with TTDD, MSDD is theoretically proved to have less communication overhead. We also validate MSDD outperforms TTDD in reliability and the emergency delivery latency bv simulations.展开更多
This paper conducts research on the algorithm to improve the location of Wireless Sensor Network （WSN） in Intelligent Transportation System （ITS）. The localization algorithm introduced an improved RSSI vehicle loc...This paper conducts research on the algorithm to improve the location of Wireless Sensor Network （WSN） in Intelligent Transportation System （ITS）. The localization algorithm introduced an improved RSSI vehicle localization algorithm based on multi-path effect and Gaussian white noise. The localization results under different values of Gaussian white noise and different density of beacon nodes are analyzes, and Kalman filtering algorithm is introduced to reduce the influence of signal noise. Finally, a simulation model of ITS is developed to test the algorithm based on mixed noise and Kalman filtering algorithm, which is used to simulate the localization of real vehicles. The simulation shows the algorithm has effect to improve location accuracy and to application展开更多
Addressing transportation planning, operation and investment challenges requires increasingly sophisticated data and information management strategies. ITS （intelligent transportation systems） and CV （connected veh...Addressing transportation planning, operation and investment challenges requires increasingly sophisticated data and information management strategies. ITS （intelligent transportation systems） and CV （connected vehicle） technologies represent a new approach to capturing and using needed transportation data in real time or near real time. In the case of Michigan, several ITS programs have been launched successfully, but independently of each other. The objective of this research is to evaluate and assess all important factors that will influence the collection, management and use of ITS data, and recommend strategies to develop integrated, dynamic and adaptive data management systems for state transportation agencies.展开更多
In this paper several kinds of high temperature molten salts were investigated experimentally on viscosity-temperature characteristics with high-temperature viscometer.The viscosities of the molten salts were measured...In this paper several kinds of high temperature molten salts were investigated experimentally on viscosity-temperature characteristics with high-temperature viscometer.The viscosities of the molten salts were measured and compared with those from references to verify the reliability of the viscometer and measuring methods,and a good agreement was observed from the comparisons.Then,two new high-temperature molten salts were made from the HITEC salt by some additives and the viscosity-temperature profiles of them were obtained by experiments.The results show that the new molten salts have much lower viscosities,thus suitable for reducing the flow resistance in transportation system of high-temperature solar thermal power generation.展开更多
文摘As the important complementary to terrestrial mobile communications, Internet via satellite can extend the coverage of communication and improve the continuity of data services. To build a space-terrestrial integrated communication system is the inevitable trend in the future. Taking into account combination of 5th generation(5G) terrestrial mobile communication system and satellite communication system, it is necessary to evaluate the promising 5G air interface waveform which can be adopted by satellite. In this paper, several non-orthogonal multi-carrier transmission schemes are evaluated and generalized frequency division multiplexing(GFDM) is advised as potential scheme of space-terrestrial integrated communication system. After the overview of GFDM, the implementation of GFDM transceiver is discussed respectively in time-domain and in frequency-domain. By deriving and comparing implementation complexity, GFDM modulation in time-domain is more suitable for satellite communication system. Then the properties of demodulation algorithms are specified. Based on designed pilot subcarriers, a new improved receiving algorithm is proposed in the end of the paper. The improved algorithm solves the problem of inter subcarriers interference(ICI) in matched filtering(MF) receiver and improves the re-ceiving symbol error rate(SER) obviously. The simulation and analysis prove that the proposed algorithm is effective.
文摘Impact of Internet Technologies increases importance of changes in the system of social communication creating a stressful situation for the functioning of traditionally established social institutions. New phenomena such as priest＇s and saints＇ online pages, represent significant deviation from historical practice, bring certain dissonance to the activities of the church. On one hand, church has to use modern communication channel, on the other hand, effects of online translation of confessional relations are not predictable. Open global socieW requires certain universalization of education, but professional communications are faced not only with a problem of language barrier, but also with national culture. School of thought, formed in traditions of particular cultural outlook, risks losing its face to the loss of national characteristics of the education system. Institute of Administration is also experiencing certain amount of stress.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 70601022)the National Basic Research Program of China (Grant No.2006CB705505)
文摘To increase the passenger transferring efficiency, the bus coordination holding control for transit hubs, which is as an important dynamic dispatching method for improving the service level of transit hubs, was studied in the framework of bus coordination dispatching mode. Firstly, the bus coordination holding control flow was studied based on Advanced Public Transportation Systems (APTS) environment. Then a control model was presented to optimize the bus vehicle holding time, and a genetic algorithm was designed as the solving method. In the end, an example was given to illustrate the effectiveness of the control strategy and the algorithm.
基金This work was supported in part by China National Natural Science Foundation under Grant 61271185,and the Fundamental Research Funds for the Central Universities
文摘WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of nodes makes data dissemination a hard nut to crack. In this paper, we propose MSDD, a multiple mobile sinks data dissemination mechanism for solving the dissemination problem. The main ideas of MSDD are constructing a two-tier grid structure by a designated sink, exploiting a hierarchical monitoring mechanism, and employing a global agent to track the sink locations in order to make the emergencies reported to the sinks immediately, In addition, MSDD supports the query-driven data dissemination. Being compared with TTDD, MSDD is theoretically proved to have less communication overhead. We also validate MSDD outperforms TTDD in reliability and the emergency delivery latency bv simulations.
文摘This paper conducts research on the algorithm to improve the location of Wireless Sensor Network （WSN） in Intelligent Transportation System （ITS）. The localization algorithm introduced an improved RSSI vehicle localization algorithm based on multi-path effect and Gaussian white noise. The localization results under different values of Gaussian white noise and different density of beacon nodes are analyzes, and Kalman filtering algorithm is introduced to reduce the influence of signal noise. Finally, a simulation model of ITS is developed to test the algorithm based on mixed noise and Kalman filtering algorithm, which is used to simulate the localization of real vehicles. The simulation shows the algorithm has effect to improve location accuracy and to application
文摘Addressing transportation planning, operation and investment challenges requires increasingly sophisticated data and information management strategies. ITS （intelligent transportation systems） and CV （connected vehicle） technologies represent a new approach to capturing and using needed transportation data in real time or near real time. In the case of Michigan, several ITS programs have been launched successfully, but independently of each other. The objective of this research is to evaluate and assess all important factors that will influence the collection, management and use of ITS data, and recommend strategies to develop integrated, dynamic and adaptive data management systems for state transportation agencies.
基金supported by the National Natural Science Foundation Key Project of China (Grant No. 50736005)the National Basic Research Program of China ("973" Program) (Grant No. 2010CB227103)
文摘In this paper several kinds of high temperature molten salts were investigated experimentally on viscosity-temperature characteristics with high-temperature viscometer.The viscosities of the molten salts were measured and compared with those from references to verify the reliability of the viscometer and measuring methods,and a good agreement was observed from the comparisons.Then,two new high-temperature molten salts were made from the HITEC salt by some additives and the viscosity-temperature profiles of them were obtained by experiments.The results show that the new molten salts have much lower viscosities,thus suitable for reducing the flow resistance in transportation system of high-temperature solar thermal power generation.
