Small cells have been regarded as an appealing technique to boost resource reuse ratio. On the other hand, their large-scale and self-organised tendency would complicate the interference environment of mobile networks...Small cells have been regarded as an appealing technique to boost resource reuse ratio. On the other hand, their large-scale and self-organised tendency would complicate the interference environment of mobile networks. Meanwhile, traffic class is booming in recent years, which leads to higher demand for net- work designers on Quality of Service （QoS） provision, and therefore users＇ diverse re- quirements may not be guaranteed in sucff＇an interference limited scenario. To maximise the number of users with QoS demands as well as resource reuse ratio, we formulate the resource allocation problem into a multi-objective l0 norm form. It is shown to be NP hard, and an iterative method is employed to approach the optimal solution. Because of its limit of being not adaptive to large-scale networks, we also design a heuristic method based on chordal graph, which, however, could result in per- formance loss when the size of networks is small. Finally, by combining these two meth- ods, we devise a hybrid algorithm such that the allocation performs both efficiently and effectively. Simulation results illustrate the performance of our proposed methods in terms of outage probability and resource reuse ratio.展开更多
Mobile block system is a new type of block technology based on the theory of interval block. This article focuses on the analysis of safety key points, the efficient use of emergency time, the maximum efficiency of mo...Mobile block system is a new type of block technology based on the theory of interval block. This article focuses on the analysis of safety key points, the efficient use of emergency time, the maximum efficiency of mobilizers, to reduce the loss of emergency incidents and casualties.展开更多
This paper applies new maximum-power-point tracking （MPPT） algorithm to a hybrid renewable energy system that combines both Wind-Turbine Generator （WTG） and Solar Photovoltaic （PV） Module （SPVM）. In this paper...This paper applies new maximum-power-point tracking （MPPT） algorithm to a hybrid renewable energy system that combines both Wind-Turbine Generator （WTG） and Solar Photovoltaic （PV） Module （SPVM）. In this paper, the WTG is a direct-drive system and includes wind turbine, three-phase permanent magnet synchronous generator, three-phase full bridge rectifier, and buck-bust converter, while the SPVM consist of solar PV modules, buck converter, maximum power tracking system for both systems, and load. Several methods are applied to obtain maximum performances, the appropriate and most effective method is called gradient-approximation method for WTG approach, because it enables the generator to operate at variable wind speeds. Furthermore MPPT also is used to optimized the achieved energy generated by solar PV modules.Matlab / Simulink approach is used to simulate, discuss, and optimized the generated power by varying the duty cycle of the converters, and tip speed ratio of the WTG system.展开更多
Because of its landscape heterogeneity,Koshi Basin（KB） is home to one of the world＇s most abundant,diverse group of species.Habitat change evaluations for key protected species are very important for biodiversity p...Because of its landscape heterogeneity,Koshi Basin（KB） is home to one of the world＇s most abundant,diverse group of species.Habitat change evaluations for key protected species are very important for biodiversity protection in this region.Based on current and future world climate and land cover data,MaxE nt model was used to simulate potential habitat changes for key protected species.The results shows that the overall accuracy of the model is high（AUC 0.9）,suggesting that the MaxE nt-derived distributions are a close approximation of real-world distribution probabilities.The valley around Chentang Town and Dram Town in China,and Lamabagar and the northern part of Landtang National Park in Nepal are the most important regions for the protection of the habitat in KB.The habitat area of Grus nigricollis,Panax pseudoginseng,and Presbytis entellus is expected to decrease in future climate and land cover scenarios.More focus should be placed on protecting forests and wetlands since these are the main habitats for these species.展开更多
基金ACKNOWLEDGEMENT First, thanks for the invitation from the organ- isers of IEEE/CIC ICCC 2013 held in Xi＇an, China. This work was supported by the Na- tional Natural Science Foundation of China under Grants No. 60972047, No. 61231008 the National Science and Technology Major Project under Grams No. 2011ZX03005-004, No. 2011ZX03004-003, No. 2011ZX03005- 003-03, No. 2013ZX03004007-003+4 种基金 the Shannxi 13115 Project under Grant No. 2010ZDKG-26 the National Basic Research Program of China （973 Program） under Grant No. 2009CB320404 the Program for Changjiang Scholars and Inn- ovative Research Team in University under Gr- ant No. IRT0852 the 111 Project under Grant No. B08038 and the State Key Laboratory Fou- ndation under Grants No. ISN1002005, No. ISN090305.
文摘Small cells have been regarded as an appealing technique to boost resource reuse ratio. On the other hand, their large-scale and self-organised tendency would complicate the interference environment of mobile networks. Meanwhile, traffic class is booming in recent years, which leads to higher demand for net- work designers on Quality of Service （QoS） provision, and therefore users＇ diverse re- quirements may not be guaranteed in sucff＇an interference limited scenario. To maximise the number of users with QoS demands as well as resource reuse ratio, we formulate the resource allocation problem into a multi-objective l0 norm form. It is shown to be NP hard, and an iterative method is employed to approach the optimal solution. Because of its limit of being not adaptive to large-scale networks, we also design a heuristic method based on chordal graph, which, however, could result in per- formance loss when the size of networks is small. Finally, by combining these two meth- ods, we devise a hybrid algorithm such that the allocation performs both efficiently and effectively. Simulation results illustrate the performance of our proposed methods in terms of outage probability and resource reuse ratio.
文摘Mobile block system is a new type of block technology based on the theory of interval block. This article focuses on the analysis of safety key points, the efficient use of emergency time, the maximum efficiency of mobilizers, to reduce the loss of emergency incidents and casualties.
文摘This paper applies new maximum-power-point tracking （MPPT） algorithm to a hybrid renewable energy system that combines both Wind-Turbine Generator （WTG） and Solar Photovoltaic （PV） Module （SPVM）. In this paper, the WTG is a direct-drive system and includes wind turbine, three-phase permanent magnet synchronous generator, three-phase full bridge rectifier, and buck-bust converter, while the SPVM consist of solar PV modules, buck converter, maximum power tracking system for both systems, and load. Several methods are applied to obtain maximum performances, the appropriate and most effective method is called gradient-approximation method for WTG approach, because it enables the generator to operate at variable wind speeds. Furthermore MPPT also is used to optimized the achieved energy generated by solar PV modules.Matlab / Simulink approach is used to simulate, discuss, and optimized the generated power by varying the duty cycle of the converters, and tip speed ratio of the WTG system.
基金National Natural Science Foundation of China(41371120)Tibet Key Science and Technology Program(2015XZ01G72)The Australian Government-funded Koshi Basin Programme at the International Centre for Integrated Mountain Development(ICIMOD)
文摘Because of its landscape heterogeneity,Koshi Basin（KB） is home to one of the world＇s most abundant,diverse group of species.Habitat change evaluations for key protected species are very important for biodiversity protection in this region.Based on current and future world climate and land cover data,MaxE nt model was used to simulate potential habitat changes for key protected species.The results shows that the overall accuracy of the model is high（AUC 0.9）,suggesting that the MaxE nt-derived distributions are a close approximation of real-world distribution probabilities.The valley around Chentang Town and Dram Town in China,and Lamabagar and the northern part of Landtang National Park in Nepal are the most important regions for the protection of the habitat in KB.The habitat area of Grus nigricollis,Panax pseudoginseng,and Presbytis entellus is expected to decrease in future climate and land cover scenarios.More focus should be placed on protecting forests and wetlands since these are the main habitats for these species.
