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Disruption tolerant networks (DTNs) are characterized by low node density, unpredictable node mobility, and lack of global network information. Most of current research efforts in DTNs focus on data forwarding, but only limited work has been done on providing efficient data access to mobile users. In this paper, we propose a novel approach to support cooperative caching in DTNs, which enables the...
Opportunistic mobile networks consist of personal mobile devices which are intermittently connected with each other. Data access can be provided to these devices via cooperative caching without support from the cellular network infrastructure, but only limited research has been done on maintaining the freshness of cached data which may be refreshed periodically and is subject to expiration. In this...
3G networks are currently facing severe traffic overload problems caused by excessive demands of mobile users. Offloading part of the 3G traffic through other forms of networks, such as Delay Tolerant Networks (DTNs), WiFi hotspots, and Femtocells, is a promising solution. However, since these networks can only provide intermittent and opportunistic connectivity to mobile users, utilizing them for...
Disruption Tolerant Networks (DTNs) are characterized by low node density, unpredictable node mobility and lack of global network information. Most of the current research efforts in DTNs focus on data forwarding, but only limited work has examined the problem of providing effective access of fused information to mobile users. In this paper, we examine a QoI metric — provenance (“to come from”) —...
Wireless sensor network (WSN) is considered as one of the most important techniques in the 21st century. However, wireless sensor network operating system (WSNOS) is the core and also the essential part of the WSN system, and its high efficiency and flexibility directly impact on the performance of the real-time system. Our Liaoning Provincial Key Embedded Technology Institute has achieved great results...
With the development of air traffic transportation industry, present design capacity can not meet future demand. Multi-airport system is the research object of this paper. The main influencing factor of multi-airport system capacity is partial route legs have less capacities. This paper combines the restricted optimization method of simultaneous perturbation stochastic approximation (SPSA) and hierarchical...
In this paper, we propose a method for DS-CDMA delay estimation through the use of the downlink channel character. This method is based on Independent Component Analysis using the conjugate descent algorithm to estimate the multi-path mixture matrix and find the delay information which is embodied by the column vector of the mixture matrix using both the independence of information source and the...
Air traffic delay is a critical and expensive problem for multi-airport systems. One strategy for reducing total delay cost is to optimize the flight schedule. The SIMMOD software developed by FAA can be used to build simulation model for the multi-airport system. Based on the restricted SPSA optimization algorithm and the theory of multi-level programming model, an area multi-airport system simulation...
A new adaptive predictive control method based on delay parameter identification is proposed in this paper to control time-varying processes with dominant and variable delay. By minimizing the error between the process output and the process predictive model output, the variable delay parameter is identified. Then, a new directly regressive method is designed to gain the predictive output of the system...
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