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Efficiency analysis of numerical integrations for finite element substructure in real-time hybrid simulation 被引量:4
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作者 Wang Jinting Lu Liqiao Zhu Fei 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第1期73-86,共14页
Finite element(FE) is a powerful tool and has been applied by investigators to real-time hybrid simulations(RTHSs). This study focuses on the computational efficiency, including the computational time and accuracy... Finite element(FE) is a powerful tool and has been applied by investigators to real-time hybrid simulations(RTHSs). This study focuses on the computational efficiency, including the computational time and accuracy, of numerical integrations in solving FE numerical substructure in RTHSs. First, sparse matrix storage schemes are adopted to decrease the computational time of FE numerical substructure. In this way, the task execution time(TET) decreases such that the scale of the numerical substructure model increases. Subsequently, several commonly used explicit numerical integration algorithms, including the central difference method(CDM), the Newmark explicit method, the Chang method and the Gui-λ method, are comprehensively compared to evaluate their computational time in solving FE numerical substructure. CDM is better than the other explicit integration algorithms when the damping matrix is diagonal, while the Gui-λ(λ = 4) method is advantageous when the damping matrix is non-diagonal. Finally, the effect of time delay on the computational accuracy of RTHSs is investigated by simulating structure-foundation systems. Simulation results show that the influences of time delay on the displacement response become obvious with the mass ratio increasing, and delay compensation methods may reduce the relative error of the displacement peak value to less than 5% even under the large time-step and large time delay. 展开更多
关键词 real-time hybrid simulation computational efficiency numerical integration storage optimization time delay
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A Study of Energy Conversion Efficiency Versus Plasma Density by Lower Hybrid Current Drive in HT-7 Tokamak
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作者 丁伯江 匡光力 +14 位作者 刘岳修 刘登成 单家方 刘甫坤 沈慰慈 石跃江 吴振伟 林建安 俞家文 徐汉东 商连全 张晓东 刘小宁 赵燕平 李建刚 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第3期1269-1274,共6页
Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieve... Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieved during the ramp-up phase. The study of the dependence of conversion efficiency on plasma density shows that the conversion efficiency is affected by the driven current, which is mainly dominated by the competition of impurity concentration with wave accessibility condition. In addition, the effect of current profile may play an important role in determining the conversion efficiency. 展开更多
关键词 LHCD In A Study of Energy Conversion efficiency Versus Plasma Density by Lower Hybrid Current Drive in HT-7 Tokamak HT
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Shoot and root traits in drought tolerant maize(Zea mays L.) hybrids 被引量:3
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作者 ZHAO Jin XUE Qing-wu +7 位作者 Kirk E Jessup HOU Xiao-bo HAO Bao-zhen Thomas H Marek XU Wen-wei Steven R Evett Susan A O'Shaughnessy David K Brauer 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第5期1093-1105,共13页
This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency(WUE) in drought tolerant(DT) maize(Zea mays L.) hybrids under full and deficit irrigated condition... This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency(WUE) in drought tolerant(DT) maize(Zea mays L.) hybrids under full and deficit irrigated conditions. A two-year greenhouse study was conducted with four hybrids(one conventional hybrid, 33D53AM, two commercial DT hybrids, P1151 AM, N75H, and an experimental hybrid, Exp HB) grown under two water regimes(I(100) and I(50), referring to 100 and 50% of evapotranspiration requirements). Under water stress, the hybids P1151 AM, N75, and Exp HB showed more drought tolerance and had either greater shoot dry weight or less dry weight reduction than the conventional hybrid(33 D53 AM). However, these three hybrids responded to water stress using different mechanisms. Compared with the conventional hybrid, the two commercial DT hybrids(P1151 AM and N75H) had a smaller leaf area, shoot dry weight, and root system per plant. As a result, these hybrids used less water but had a higher WUE compared with the conventional hybrid. In contrast, the experimental hybrid(ExpHB) produced more shoot biomass by silking stage at both irrigation levels than all other hybrids, but it had relatively lower WUE. The hybrids demonstrated different drought response mechanisms that may require different irrigation management strategies. More investigation and validation are needed under field conditions and in different soil types. 展开更多
关键词 drought tolerant hybrid rooting characteristics water use water use efficiency
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Enhanced Reliability in Network Function Virtualization by Hybrid Hexagon-Cost Efficient Algorithm
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作者 D.Jeyakumar C.Rajabhushanam 《Computer Systems Science & Engineering》 SCIE EI 2022年第12期1131-1144,共14页
In this,communication world, the Network Function Virtualization concept is utilized for many businesses, small services to virtualize the network nodefunction and to build a block that may connect the chain, communi... In this,communication world, the Network Function Virtualization concept is utilized for many businesses, small services to virtualize the network nodefunction and to build a block that may connect the chain, communication services.Mainly, Virtualized Network Function Forwarding Graph (VNF-FG) has beenused to define the connection between the VNF and to give the best end-to-endservices. In the existing method, VNF mapping and backup VNF were proposedbut there was no profit and reliability improvement of the backup and mapping ofthe primary VNF. As a consequence, this paper offers a Hybrid Hexagon-CostEfficient algorithm for determining the best VNF among multiple VNF and backing up the best VNF, lowering backup costs while increasing dependability. TheVNF is chosen based on the highest cost-aware important measure (CIM) rate,which is used to assess the relevance of the VNF forwarding graph.To achieveoptimal cost-efficiency, VNF with the maximum CIM is selected. After the selection process, updating is processed by three steps which include one backup VNFfrom one SFC, two backup VNF from one Service Function Chain (SFC),and twobackup VNF from different SFC. Finally, this proposed method is compared withCERA, MinCost, MaxRbyInr based on backup cost, number of used PN nodes,SFC request utility, and latency. The simulation result shows that the proposedmethod cuts down the backup cost and computation time by 57% and 45% compared with the CER scheme and improves the cost-efficiency. As a result, this proposed system achieves less backup cost, high reliability, and low timeconsumption which can improve the Virtualized Network Function operation. 展开更多
关键词 Network function virtualized(NFV) hybrid hexagon-cost efficient algorithm(HH-CE) cost-aware important measure(CIM) RELIABILITY network services
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Mathematical model of absorption and hybrid heat pump 被引量:1
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作者 Grazia Leonzio 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第10期1492-1504,共13页
Recovering waste heat from industrial processes is bene ficial in order to reduce the primary energy demands and heat pumps can be used to this purpose.Absorption heat pumps are energy-saving and environment-friendly ... Recovering waste heat from industrial processes is bene ficial in order to reduce the primary energy demands and heat pumps can be used to this purpose.Absorption heat pumps are energy-saving and environment-friendly because use working fluids that do not cause ozone depletion and can reduce the global warming emissions.The hybrid heat pump processes combine the conventional vapor-compression and the absorption heat pump cycles.Studies about the simulations and modeling of hybrid heat pumps are few in literature.In this research a mathematical model for single effect absorption and hybrid heat pump is carried out with Chem Cad? 6.0.1.LiBr–H_2O is used as working fluid while electrolytic NRTL and electrolytes latent heat are used as thermodynamic model due to the better results.Binary parameters of activity coef ficients are regressed from experimental vapor pressure data while default constants are used for the solubility expressions.A design of heat pumps is developed and a new modeling of generator is analyzed.The coef ficient of performance of absorption heat pump and hybrid heat pump is equal to 0.7 and 0.83 respectively.For absorption heat pump a sensitivity analysis is carried out to evaluate the effect of temperature and pressure generator,the concentration of Li–Br solution on coef ficient of performance,cooling capacity and working fluid temperature.For hybrid heat pump,the different coef ficients of performance,the primary energy ratio,the generator heat,and the compressor power are analyzed for different values of compressor proportion.Results show that comparing the two systems the hybrid pump allows to save more primary energy,costs and carbon dioxide emissions with respect to absorption heat pump with the increasing of compressor proportion parameter.Future researches should focus on the construction of this heat pumps integrated in chemical processes as a biogas plant or trigeneration systems. 展开更多
关键词 Absorption heat pumps Hybrid heat pumps LiBr–H2O modeling Energy efficiency Process simulation Mathematical model
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Highly Efficient and Stable Hybrid White Organic Light Emitting Diodes with Controllable Exciton Behavior by a Mixed Bipolar Interlayer
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作者 侯媛媛 李江红 +3 位作者 冀晓翔 吴亚锋 范玮 Igbari Femi 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期170-173,共4页
Highly efficient and stable hybrid white organic light-emitting diodes (HWOLEDs) with a mixed bipolar interlayer between fluorescent blue and phosphorescent yellow emitting layers are demonstrated. The bipolar inter... Highly efficient and stable hybrid white organic light-emitting diodes (HWOLEDs) with a mixed bipolar interlayer between fluorescent blue and phosphorescent yellow emitting layers are demonstrated. The bipolar interlayer is a mixture of p-type diphenyl (l0-phenyl-lOH-spiro [acridine-9,9'-fluoren]-3Lyl) phosphine oxide and n-type 2',2- (1,3,5-benzinetriyl)-tris(1-phenyl-l-H-benzimidazole). The electroluminance and Commission Internationale de l'Eclairage (CIE1931) coordinates' characteristics can be modulated easily by adjusting the ratio of the hole- predominated material to the electron-predominated material in the interlayer. The hybrid WOLED with a p-type:n-type ratio of 1:3 shows a maximum current efficiency and power efficiency of 61.1 ed/A and 55.8 lm/W, respectively, with warm white CIE coordinates of (0.34, 0.43). The excellent efficiency and adaptive CIE coordi- nates are attributed to the mixed interlayer with improved charge carrier balance, optimized exciton distribution, and enhanced harvesting of singlet and triplet excitons. 展开更多
关键词 with is of by Highly Efficient and Stable Hybrid White Organic Light Emitting Diodes with Controllable Exciton Behavior by a Mixed Bipolar Interlayer in
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Energy Management Strategy for Hybrid Electric Vehicle Based on System Efficiency and Battery Life Optimization
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作者 YANG Yang SU Ling +2 位作者 QIN Datong GONG Hui ZENG Jianfeng 《Wuhan University Journal of Natural Sciences》 CAS 2014年第3期269-276,共8页
A novel method to calculate fuel-electric conversion factor for full hybrid electric vehicle(HEV)equipped with continuously variable transmission(CVT)is proposed.Based on consideration of the efficiency of pivotal... A novel method to calculate fuel-electric conversion factor for full hybrid electric vehicle(HEV)equipped with continuously variable transmission(CVT)is proposed.Based on consideration of the efficiency of pivotal components,electric motor,system efficiency optimization models are developed.According to the target of instantaneous optimization of system efficiency,operating ranges of each mode of power-train are determined,and the corresponding energy management strategies are established.The simulation results demonstrate that the energy management strategy proposed can substantially improve the vehicle fuel economy,and keep battery state of charge(SOC)change in a reasonable variation range. 展开更多
关键词 hybrid electric vehicle energy management strategy efficiency optimization battery state of charge fuel-electric conversion factor
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Performance evaluation of a WDM/OCDM based hybrid optical switch utilizing efficient resource allocation
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作者 Ahmed Nabih Zaki Rashed Abd-Elnaser A. Mohammed Osama M.A. Dardeer 《Chinese Optics Letters》 SCIE EI CAS CSCD 2014年第5期5-10,共6页
A hybrid optical switch (HOS) with physical layer of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) scheme is proposed. An additional feature to the HOS than optical cross conne... A hybrid optical switch (HOS) with physical layer of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) scheme is proposed. An additional feature to the HOS than optical cross connect (OXC) is that the controller can process requests for both circuit establishment and burst scheduling. In our study, the measurement criteria of HOS are the blocking probability, probability of error, and probability of outage. To simplify the analysis, no distinction is made between a circuit in progress and a burst in progress. Moreover, a minimum fit (MinF) resource allocation strategy is applied in order to increase the bandwidth efficiency and control the multiplexing interference of the OCDM. A 2D Markov model for the HOS is presented using the MinF strategy. Numerical results reveal that the code parameters and the resource allocation strategy greatly affect the performance. Certain periority can be achieved by assigning shorter codes to high periority users and longer codes to low periority users. Also, the probability of error and outage are reduced bv aonling the MinF strategy. 展开更多
关键词 WDM Performance evaluation of a WDM/OCDM based hybrid optical switch utilizing efficient resource allocation
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