The scheduling efficiency of the tracking and data relay satellite system（TDRSS）is strictly limited by the scheduling degrees of freedom（DoF）,including time DoF defined by jobs＇ flexible time windows and spatial ...The scheduling efficiency of the tracking and data relay satellite system（TDRSS）is strictly limited by the scheduling degrees of freedom（DoF）,including time DoF defined by jobs＇ flexible time windows and spatial DoF brought by multiple servable tracking and data relay satellites（TDRSs）.In this paper,ageneralized multiple time windows（GMTW）model is proposed to fully exploit the time and spatial DoF.Then,the improvements of service capability and job-completion probability based on the GMTW are theoretically proved.Further,an asymmetric path-relinking（APR）based heuristic job scheduling framework is presented to maximize the usage of DoF provided by the GMTW.Simulation results show that by using our proposal 11%improvement of average jobcompletion probability can be obtained.Meanwhile,the computing time of the time-to-target can be shorten to 1/9 of the GRASP.展开更多
Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduli...Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.展开更多
Self-powered photovoltaic windows,which integrate photovoltaic with electrochromic devices,have attracted widespread attention of scholars since they can generate electricity in situ and reduce building energy consump...Self-powered photovoltaic windows,which integrate photovoltaic with electrochromic devices,have attracted widespread attention of scholars since they can generate electricity in situ and reduce building energy consumption by modulating the transmitted solar radiation.However,previous studies mainly focused on the material development and performance characterization,lack of comfort assessment and energy saving potential of its application to buildings.To address this issue,an adjustable semi-transparent photovoltaic(ATPV)window which integrates CdTe-based photovoltaic and WO3-based electrochromic,was taken as the research object,and a novel rule-based control strategy taking the beam solar radiation luminous efficacy(CtrlEff)as decision variable was proposed for the first time.The ATPV window model was established in WINDOW software based on the measured data,and then it was exported to integrated with a medium office building model in EnergyPlus for performance evaluation including the visual comfort,thermal comfort,net energy consumption,and net-zero energy ratio.The results of a case study in Changsha(E 112°,N 28°)indicated that the ATPV window under the CtrlEff strategy can effectively reduce the southward and westward intolerable glare by 86.9%and 94.9%,respectively,and increase the thermal comfort hours by 5%and 2%,compared to the Low-E window.Furthermore,the net-zero energy consumption can be decreased by 58.7%,65.7%,64.1%,and 53.8%for south,west,east,and north orientations,and the corresponding net-zero energy ratios are 65.1%,54.6%,62.7%,and 61.6%,respectively.The findings of this study provide new strategies for the control and optimization of the adjustable window.展开更多
基金Supported by the National Natural Science Foundation of China(91338101,91338108,61132002,6132106)Research Fund of Tsinghua University(2011Z05117)Co-innovation Laboratory of Aerospace Broadband Network Technology
文摘The scheduling efficiency of the tracking and data relay satellite system（TDRSS）is strictly limited by the scheduling degrees of freedom（DoF）,including time DoF defined by jobs＇ flexible time windows and spatial DoF brought by multiple servable tracking and data relay satellites（TDRSs）.In this paper,ageneralized multiple time windows（GMTW）model is proposed to fully exploit the time and spatial DoF.Then,the improvements of service capability and job-completion probability based on the GMTW are theoretically proved.Further,an asymmetric path-relinking（APR）based heuristic job scheduling framework is presented to maximize the usage of DoF provided by the GMTW.Simulation results show that by using our proposal 11%improvement of average jobcompletion probability can be obtained.Meanwhile,the computing time of the time-to-target can be shorten to 1/9 of the GRASP.
基金supported by the National Natural Science Foundation of China(6113200291338101+3 种基金91338108)the National S&T Major Project(2011ZX03004-001-01)the Research Fund of Tsinghua University(2011Z05117)the Co-innovation Laboratory of Aerospace Broadband Network Technology
文摘Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.
基金the National Natural Science Foundation of China(No.51978252)the High-tech Industry Technology Innovation Leading Plan of Hunan Province(2020GK2076)+2 种基金the Science and Technology Innovation Program of Hunan Province(2020RC5003)the Hunan Province Innovation Development Program(2020RC4045)the Hunan Province Key R&D Program(2021SK2045).
文摘Self-powered photovoltaic windows,which integrate photovoltaic with electrochromic devices,have attracted widespread attention of scholars since they can generate electricity in situ and reduce building energy consumption by modulating the transmitted solar radiation.However,previous studies mainly focused on the material development and performance characterization,lack of comfort assessment and energy saving potential of its application to buildings.To address this issue,an adjustable semi-transparent photovoltaic(ATPV)window which integrates CdTe-based photovoltaic and WO3-based electrochromic,was taken as the research object,and a novel rule-based control strategy taking the beam solar radiation luminous efficacy(CtrlEff)as decision variable was proposed for the first time.The ATPV window model was established in WINDOW software based on the measured data,and then it was exported to integrated with a medium office building model in EnergyPlus for performance evaluation including the visual comfort,thermal comfort,net energy consumption,and net-zero energy ratio.The results of a case study in Changsha(E 112°,N 28°)indicated that the ATPV window under the CtrlEff strategy can effectively reduce the southward and westward intolerable glare by 86.9%and 94.9%,respectively,and increase the thermal comfort hours by 5%and 2%,compared to the Low-E window.Furthermore,the net-zero energy consumption can be decreased by 58.7%,65.7%,64.1%,and 53.8%for south,west,east,and north orientations,and the corresponding net-zero energy ratios are 65.1%,54.6%,62.7%,and 61.6%,respectively.The findings of this study provide new strategies for the control and optimization of the adjustable window.
