Metropolitan cities in China are commonly confronted with unresolved traffic congestion issues, primarily due to rapidly increasing traffic demand. Group disparity between commuting mode choice and its spatial distrib...Metropolitan cities in China are commonly confronted with unresolved traffic congestion issues, primarily due to rapidly increasing traffic demand. Group disparity between commuting mode choice and its spatial distribution on road networks has enabled us to examine the factors that give rise to the discrepancies and the fundamental spatial causes of traffic congestion. In recent years, mi- cro-perspective, individual, and behavior-based spatial analysis have mushroomed and been facilitated with effective tools such as tem- poral geographic information systems （T-GIS）. It is difficult to study the interrelations between transport and space on the basis of commuting mode choice since the mode choice data are invisible in a specific space such as a particular road network. Therefore, in the field of transport, the classical origin destination （OD） four-stage model （FSM） is usually employed to calculate data when studying commuting mode choice. Based on the relative principles of T-GIS and the platform of ArcGIS, this paper considers Guangzhou as a case study and develops a spatio-temporal tool to examine the daily activities of residents. Meanwhile, the traffic volume distribution in rush hours, which was analyzed according to commuting modes and how they were reflected in the road network, was scrutinized with data extracted from travel diaries. Moreover, efforts were made to explain the relationship between traffic demand and urban spatial structure. Based on the investigation, this research indicates that traffic volumes in divergent groups and on the road networks is driven by： l） the socio-economie characteristics of travelers; 2） a jobs-housing imbalance under suburbanization; 3） differences in the spatial supply of transport modes; 4） the remains of the Danwei （work unit） system and market development in China; and 5） the transition of urban spatial structure and other factors.展开更多
Referring to research on the Heterogeneous Network （Het-Net） application scenario and technique characters in IMT-Advaneed （The 4th Generation Mobile Communications） cellular system, this paper provides further an...Referring to research on the Heterogeneous Network （Het-Net） application scenario and technique characters in IMT-Advaneed （The 4th Generation Mobile Communications） cellular system, this paper provides further analysis on main technique aspects of Heterogeneous Network, discussion on interference issue due to multi-layer building by access points and their corresponding solutions from standardization and engineering implementation. The proposed solution can effectively solve the interference problem in IMT-advanced Het-Net, and also improves the networking performance dramaticaUy for future mobile communication systems.展开更多
This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer an...This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer and a control law for the systems in the absence of any finite data-rate communi- cation channel. Based on the observer and the control law, the authors constructs an encoder/decoder pair and provides a sufficient condition, including suitable sampling period and data rate, which will guarantee the stability of the closed-loop systems when a finite data-rate communication channel is introduced.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.40971098)National High Technology Research and Development Program of China(No.2012AA121402)
文摘Metropolitan cities in China are commonly confronted with unresolved traffic congestion issues, primarily due to rapidly increasing traffic demand. Group disparity between commuting mode choice and its spatial distribution on road networks has enabled us to examine the factors that give rise to the discrepancies and the fundamental spatial causes of traffic congestion. In recent years, mi- cro-perspective, individual, and behavior-based spatial analysis have mushroomed and been facilitated with effective tools such as tem- poral geographic information systems （T-GIS）. It is difficult to study the interrelations between transport and space on the basis of commuting mode choice since the mode choice data are invisible in a specific space such as a particular road network. Therefore, in the field of transport, the classical origin destination （OD） four-stage model （FSM） is usually employed to calculate data when studying commuting mode choice. Based on the relative principles of T-GIS and the platform of ArcGIS, this paper considers Guangzhou as a case study and develops a spatio-temporal tool to examine the daily activities of residents. Meanwhile, the traffic volume distribution in rush hours, which was analyzed according to commuting modes and how they were reflected in the road network, was scrutinized with data extracted from travel diaries. Moreover, efforts were made to explain the relationship between traffic demand and urban spatial structure. Based on the investigation, this research indicates that traffic volumes in divergent groups and on the road networks is driven by： l） the socio-economie characteristics of travelers; 2） a jobs-housing imbalance under suburbanization; 3） differences in the spatial supply of transport modes; 4） the remains of the Danwei （work unit） system and market development in China; and 5） the transition of urban spatial structure and other factors.
文摘Referring to research on the Heterogeneous Network （Het-Net） application scenario and technique characters in IMT-Advaneed （The 4th Generation Mobile Communications） cellular system, this paper provides further analysis on main technique aspects of Heterogeneous Network, discussion on interference issue due to multi-layer building by access points and their corresponding solutions from standardization and engineering implementation. The proposed solution can effectively solve the interference problem in IMT-advanced Het-Net, and also improves the networking performance dramaticaUy for future mobile communication systems.
文摘This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer and a control law for the systems in the absence of any finite data-rate communi- cation channel. Based on the observer and the control law, the authors constructs an encoder/decoder pair and provides a sufficient condition, including suitable sampling period and data rate, which will guarantee the stability of the closed-loop systems when a finite data-rate communication channel is introduced.
