Internet Exchange Point(IXP)is a system that increases network bandwidth performance.Internet exchange points facilitate interconnection among network providers,including Internet Service Providers(ISPs)andContent Del...Internet Exchange Point(IXP)is a system that increases network bandwidth performance.Internet exchange points facilitate interconnection among network providers,including Internet Service Providers(ISPs)andContent Delivery Providers(CDNs).To improve service management,Internet exchange point providers have adopted the Software Defined Network(SDN)paradigm.This implementation is known as a Software-Defined Exchange Point(SDX).It improves network providers’operations and management.However,performance issues still exist,particularly with multi-hop topologies.These issues include switch memory costs,packet processing latency,and link failure recovery delays.The paper proposes Enhanced Link Failure Rerouting(ELFR),an improved mechanism for rerouting link failures in software-defined exchange point networks.The proposed mechanism aims to minimize packet processing time for fast link failure recovery and enhance path calculation efficiency while reducing switch storage overhead by exploiting the Programming Protocol-independent Packet Processors(P4)features.The paper presents the proposed mechanisms’efficiency by utilizing advanced algorithms and demonstrating improved performance in packet processing speed,path calculation effectiveness,and switch storage management compared to current mechanisms.The proposed mechanism shows significant improvements,leading to a 37.5%decrease in Recovery Time(RT)and a 33.33%decrease in both Calculation Time(CT)and Computational Overhead(CO)when compared to current mechanisms.The study highlights the effectiveness and resource efficiency of the proposed mechanism in effectively resolving crucial issues inmulti-hop software-defined exchange point networks.展开更多
This study investigates the steam generating potential of a solar steam generation system and the potential for utility scale implementation in Libya oil for steam demanding enhanced oil recovery (EOR) methods. The pr...This study investigates the steam generating potential of a solar steam generation system and the potential for utility scale implementation in Libya oil for steam demanding enhanced oil recovery (EOR) methods. The proposed system uses parabolic troughs as solar collectors. The technology is proved to be technically feasible. Solar EOR should be seen as an add-on to existing plants due to the abundance of solar energy in Libya. The System Advisor Model (SAM) model system, developed by the National Office of Renewable Energy (NRE), was used to assess the plant’s active and economic performance.展开更多
An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more...An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more importantly its high cost.The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP).Analysis based on pinch technology can be helpful to optimal heat recovery operation.In this paper,temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology.The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds.Dynamic characteristic(time factor)of adsorption refrigeration system is the main resistance for heat recovery.The effect of pinch point temperature difference on the system COP is not distinct.Furthermore,when the driving temperature is 90°C,the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system.Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed,four-bed,mass recovery,et al.).展开更多
1 Introduction Let r be a natural number, P<sub>r</sub>（t）=（t-t<sub>j</sub>）, t<sub>j</sub>∈R, j=1,…, r, and P<sub>r</sub>（D）（D=-d/（dt）） be the induced diffe...1 Introduction Let r be a natural number, P<sub>r</sub>（t）=（t-t<sub>j</sub>）, t<sub>j</sub>∈R, j=1,…, r, and P<sub>r</sub>（D）（D=-d/（dt）） be the induced differential operator of P<sub>r</sub>（t）. Let 1≤p, q, s≤∞. We introduce some new classes of smooth functions defined on R as follows: W<sub>pqs</sub>（P<sub>r</sub>）=:{f∈L<sub>S</sub>（R）; f<sup>（r-1）</sup> is locally absolutely continuous on R and ‖P<sub>r</sub>（D）f‖<sub>pq</sub>≤1}. Here the norm ‖·‖<sub>pq</sub> as in Ref. [1] is defined展开更多
文摘Internet Exchange Point(IXP)is a system that increases network bandwidth performance.Internet exchange points facilitate interconnection among network providers,including Internet Service Providers(ISPs)andContent Delivery Providers(CDNs).To improve service management,Internet exchange point providers have adopted the Software Defined Network(SDN)paradigm.This implementation is known as a Software-Defined Exchange Point(SDX).It improves network providers’operations and management.However,performance issues still exist,particularly with multi-hop topologies.These issues include switch memory costs,packet processing latency,and link failure recovery delays.The paper proposes Enhanced Link Failure Rerouting(ELFR),an improved mechanism for rerouting link failures in software-defined exchange point networks.The proposed mechanism aims to minimize packet processing time for fast link failure recovery and enhance path calculation efficiency while reducing switch storage overhead by exploiting the Programming Protocol-independent Packet Processors(P4)features.The paper presents the proposed mechanisms’efficiency by utilizing advanced algorithms and demonstrating improved performance in packet processing speed,path calculation effectiveness,and switch storage management compared to current mechanisms.The proposed mechanism shows significant improvements,leading to a 37.5%decrease in Recovery Time(RT)and a 33.33%decrease in both Calculation Time(CT)and Computational Overhead(CO)when compared to current mechanisms.The study highlights the effectiveness and resource efficiency of the proposed mechanism in effectively resolving crucial issues inmulti-hop software-defined exchange point networks.
文摘This study investigates the steam generating potential of a solar steam generation system and the potential for utility scale implementation in Libya oil for steam demanding enhanced oil recovery (EOR) methods. The proposed system uses parabolic troughs as solar collectors. The technology is proved to be technically feasible. Solar EOR should be seen as an add-on to existing plants due to the abundance of solar energy in Libya. The System Advisor Model (SAM) model system, developed by the National Office of Renewable Energy (NRE), was used to assess the plant’s active and economic performance.
基金supported by the National Natural Science Foundation of China(Grant No.51906136)the Institute of Advanced Studies(IAS)of the University of Warwick in the UK(Grant No C5E3X56470T)Shanghai Sailing Program(Grant No.19YF1423100)。
文摘An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more importantly its high cost.The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP).Analysis based on pinch technology can be helpful to optimal heat recovery operation.In this paper,temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology.The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds.Dynamic characteristic(time factor)of adsorption refrigeration system is the main resistance for heat recovery.The effect of pinch point temperature difference on the system COP is not distinct.Furthermore,when the driving temperature is 90°C,the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system.Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed,four-bed,mass recovery,et al.).
基金Project supported by the National Natural Science Foundation of China.
文摘1 Introduction Let r be a natural number, P<sub>r</sub>（t）=（t-t<sub>j</sub>）, t<sub>j</sub>∈R, j=1,…, r, and P<sub>r</sub>（D）（D=-d/（dt）） be the induced differential operator of P<sub>r</sub>（t）. Let 1≤p, q, s≤∞. We introduce some new classes of smooth functions defined on R as follows: W<sub>pqs</sub>（P<sub>r</sub>）=:{f∈L<sub>S</sub>（R）; f<sup>（r-1）</sup> is locally absolutely continuous on R and ‖P<sub>r</sub>（D）f‖<sub>pq</sub>≤1}. Here the norm ‖·‖<sub>pq</sub> as in Ref. [1] is defined
