The Experts below are selected from a list of 36324 Experts worldwide ranked by ideXlab platform

Sheng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • prolonging wsn lifetime with an actual Charging Model
    Wireless Communications and Networking Conference, 2018
    Co-Authors: Sheng Zhang
    Abstract:

    Recent breakthroughs in wireless power transfer make it possible to charge sensors over a long distance. Existing works have mainly focused on maximizing network lifetime, optimizing Charging efficiency, and optimizing Charging quality. All these works use a linear superposition Charging Model, which may not be accurate in real life situations. We use the actual Charging Model, which has a nonlinear super-position and we consider the Charging scheduling problem (CSP): given multiple chargers and a group of sensor nodes, how can the chargers be optimally scheduled so that the total Charging time is minimized and each sensor node has at least energy E? We prove that CSP is NP-hard, and propose a weight-greedy algorithm to solve the problem. Unlike the algorithm proposed before, ours does not need to calculate all charger groups utility in advance, which reduces the complexity. Extensive simulations demonstrate that the performance of our algorithm with sparse network is almost as good as the optimal algorithm. In general cases, our algorithm outperforms the random algorithm. Furthermore, our algorithm obtains the best solution in two special cases.

  • WCNC - Prolonging WSN lifetime with an actual Charging Model
    2018 IEEE Wireless Communications and Networking Conference (WCNC), 2018
    Co-Authors: Sheng Zhang
    Abstract:

    Recent breakthroughs in wireless power transfer make it possible to charge sensors over a long distance. Existing works have mainly focused on maximizing network lifetime, optimizing Charging efficiency, and optimizing Charging quality. All these works use a linear superposition Charging Model, which may not be accurate in real life situations. We use the actual Charging Model, which has a nonlinear super-position and we consider the Charging scheduling problem (CSP): given multiple chargers and a group of sensor nodes, how can the chargers be optimally scheduled so that the total Charging time is minimized and each sensor node has at least energy E? We prove that CSP is NP-hard, and propose a weight-greedy algorithm to solve the problem. Unlike the algorithm proposed before, ours does not need to calculate all charger groups utility in advance, which reduces the complexity. Extensive simulations demonstrate that the performance of our algorithm with sparse network is almost as good as the optimal algorithm. In general cases, our algorithm outperforms the random algorithm. Furthermore, our algorithm obtains the best solution in two special cases.

I S Osadko - One of the best experts on this subject based on the ideXlab platform.

  • auger ionization and tunneling neutralization of single cdse zns nanocrystals revealed by excitation intensity variation
    Journal of Physical Chemistry C, 2016
    Co-Authors: Yu I Eremchev, I S Osadko, A V Naumov
    Abstract:

    The dependence of the average times in on- and off-states of the fluorescence of a single semiconductor colloidal core/shell nanocrystal (so called quantum dot) on the intensity of the continuous laser excitation was studied. The mathematical expressions for the intensity dependence for on- and off-average times are obtained in the framework of a modified Charging Model, taking into account both the Auger ionization and tunnel neutralization mechanisms for transitions between neutral (on-state) and the ionized (off-state). The experiment with a single nanocrystal CdSe/ZnS shows that average on-time is proportional to 1/I2, whereas the average off-time is nearly independent of the intensity, I. These results agree with processes of Auger ionization and tunneling neutralization of the core in core/shell nanocrystals.

  • two types of the relation between the intensity and the life time of photoluminescence of core shell semiconductor quantum dots important role of coulomb field and tunneling transitions
    Journal of Chemical Physics, 2014
    Co-Authors: I S Osadko
    Abstract:

    It has been recently found [Gh. Galland, Y. Ghosh, A. Steinbruck, M. Sykora, J. A. Hollingsworth, and V. I. Klimov, Nature (London)479, 203 (2011)] that semiconductor core/shell nanocrystals (NCs) with blinking photoluminescence (PL) can be of “A” or “B” type. NCs of A-type exhibit correlation between the intensity of PL and the life time. In NCs of B-type such correlation is absent. Simple Model based on combination of the Charging Model and the two-level system Model is proposed for describing emissive properties of NCs of both types. The Model invokes fluctuations of emission ability γ em of NC to explain the emissive properties of NCs of B-type. Our combined Model is also in agreement with anticorrelation between the duration τ off of off intervals and PL life time t off in off intervals found recently for NCs of A-type in the experiment [A. A. Cordones, T. J. Bixby, and S. R. Leone, Nano Lett.11, 3366 (2011)].

Decun Dong - One of the best experts on this subject based on the ideXlab platform.

  • A Cost-Oriented Optimal Model of Electric Vehicle Taxi Systems
    Sustainability, 2018
    Co-Authors: Ning Wang, Decun Dong
    Abstract:

    This paper presents a cost optimal Model of electric vehicle taxi systems based on the cost of electric vehicle taxi companies, Charging or battery swap stations, passengers’ time, and emission costs. Considering the requirement of meeting passengers’ travel demands, an electric taxi demand Model using transportation elasticity is formulated to optimize the number of electric taxis. The electric taxi demand Model constitutes the measure of electric taxis, the cruise range, the amount of Charging or battery swap stations, and other related factors. Simultaneously, to meet the Charging requirements of electric taxis, a layout optimal Model of EVSE (electric vehicle supply equipment) is designed using a Voronoi polygon method aimed at the cost of Charging or battery swap stations and the range cost for changing. Finally, these aforementioned Models are mixed to calculate the scale of electric taxis, the allocation of vehicle Models, the optimizing level, and the site distribution of Charging or battery swap stations. The key findings include the following: (1) the cost of the BEV(battery electric vehicle) taxi system is lower in the Charging Model than in the battery swap Model, (2) the cost of the PHEV taxi system is lower than the BEV taxi system in the Charging Model, (3) in the Tongzhou District of Beijing, five Charging or battery swap stations required being found to meet the Charging demands of 5557 BEVs in the Charging Model or 5316 BEVs in the battery swap Model, (4) according to the passengers’ travel demands and traffic conditions in Tongzhou, the BEV’s cruise range ought to be 250 km and BEV’s battery capacity should be 42.5 kW, the price of PHEV should be under 24,000 RMB and the electric-powered cruise range needs to be under 100 km, the daily operating time of EVs is around 16 h and the daily operating range is controlled under 380 km, and (5) a carbon tax is suggested to be imposed on ICEVs but the price should be under 20 RMB per ton.

Ning Wang - One of the best experts on this subject based on the ideXlab platform.

  • A Cost-Oriented Optimal Model of Electric Vehicle Taxi Systems
    Sustainability, 2018
    Co-Authors: Ning Wang, Decun Dong
    Abstract:

    This paper presents a cost optimal Model of electric vehicle taxi systems based on the cost of electric vehicle taxi companies, Charging or battery swap stations, passengers’ time, and emission costs. Considering the requirement of meeting passengers’ travel demands, an electric taxi demand Model using transportation elasticity is formulated to optimize the number of electric taxis. The electric taxi demand Model constitutes the measure of electric taxis, the cruise range, the amount of Charging or battery swap stations, and other related factors. Simultaneously, to meet the Charging requirements of electric taxis, a layout optimal Model of EVSE (electric vehicle supply equipment) is designed using a Voronoi polygon method aimed at the cost of Charging or battery swap stations and the range cost for changing. Finally, these aforementioned Models are mixed to calculate the scale of electric taxis, the allocation of vehicle Models, the optimizing level, and the site distribution of Charging or battery swap stations. The key findings include the following: (1) the cost of the BEV(battery electric vehicle) taxi system is lower in the Charging Model than in the battery swap Model, (2) the cost of the PHEV taxi system is lower than the BEV taxi system in the Charging Model, (3) in the Tongzhou District of Beijing, five Charging or battery swap stations required being found to meet the Charging demands of 5557 BEVs in the Charging Model or 5316 BEVs in the battery swap Model, (4) according to the passengers’ travel demands and traffic conditions in Tongzhou, the BEV’s cruise range ought to be 250 km and BEV’s battery capacity should be 42.5 kW, the price of PHEV should be under 24,000 RMB and the electric-powered cruise range needs to be under 100 km, the daily operating time of EVs is around 16 h and the daily operating range is controlled under 380 km, and (5) a carbon tax is suggested to be imposed on ICEVs but the price should be under 20 RMB per ton.

  • Cost–benefit assessment and implications for service pricing of electric taxies in China
    Energy for Sustainable Development, 2015
    Co-Authors: Ning Wang, Gangzhan Fu, Yun Li
    Abstract:

    Abstract This paper presents a methodology to assess the cost–benefit and develop the service pricing strategy of electric taxies in Shanghai, China. There are 4 kinds of electric taxi Models being structured. The total life cycle cost Model for cost–benefit assessment is developed with consideration of purchase cost, usage cost, and other operation cost. Three scenarios are defined, including gasoline price increasing, electricity price increasing, and battery cost decreasing. Then the service pricing Model is proposed. The results indicate that the profitability of battery-swapping Model is higher than that of the Charging Model. The taxi Models with longer driving range have greater profitability than those with shorter driving range. With annually increasing rate of 8% of gasoline price, the electric taxi will obtain the same profit with the gasoline taxi in 5 years. With annually increasing rate of 20% of electricity price, the service price of electric taxies will rise by 1%. When the battery cost decreases by 49%, the service price of electric taxies will be 4% lower than that of gasoline taxies.

  • The Economic Benefit of Electric Taxi Based on Total Ownership Cost Model
    Advanced Materials Research, 2013
    Co-Authors: Ning Wang, Yun Li
    Abstract:

    To analyze the economic benefit of electric taxi in two different Models: battery Charging Model (ETC) and swapping Model (ETS), this paper built total ownership cost Model based on purchase and used cost, and equaled the total ownership cost of electric and conventional taxi in the nominal lifetime to get the maximum affordable battery Charging price and battery swapping price respectively, which is 1.1 RMB yuan/kWh and 0.54 RMB yuan/km. The results show that ETS has economic advantage over ETC. Adjust the Charging and swapping price to 0 RMB yuan, the equilibrium year of ETS is only 0.8 years, compared to ETCs 2.8 years.

Xia Chen - One of the best experts on this subject based on the ideXlab platform.

  • Research on telecom service providers’ network charge strategy based on two-sided market theory
    Cluster Computing, 2018
    Co-Authors: Xuanqi Ou, Tingjie Lv, Xia Chen
    Abstract:

    Against the background of increasingly mature mobile internet eco-system, internet companies have been continuing pursuing the innovation of internet applications. The action has brought about not only more clicks from the netizens but also gave rise to mounting network burden. Telecom service providers are now faced with the dual pressure from both the soaring broadband building and maintenance costs as well as the declining traditional operating revenues. They wish to find a way to abolish the previous unified pricing Model and shift it into the differential Charging Model by offering graded data flow services. Consequently, the controversy over “net neutrality” has been aroused in the whole society. In this article we analyze the optimum prices in different stages of the internet eco-system, and establish two-sided market Model for further research.