To study the gating kinetics of voltage dependent K + channel in clonal pheochromocytoma (PC12) cells, the inward currents of K channel in PC12 cells were recorded using cell attached patch clamp technique. The fracta...To study the gating kinetics of voltage dependent K + channel in clonal pheochromocytoma (PC12) cells, the inward currents of K channel in PC12 cells were recorded using cell attached patch clamp technique. The fractal features of the open and closed time distributions were determined. The fractal dimensions and kinetic setpoints for the open and closed durations were estimated. It was found that the fractal dimension D was independent of voltage and the logarithm logA of the setpoint A was inversely proportional to the pipette potential (Vp) for the closed durations. While for the open durations the fractal dimension D was inversely proportional to the pipette potential and the logarithm logA of the setpoint A was independent of voltage. Thus, for this channel the open and closed durations and voltage dependence of the gating could be well described by the fractal model.展开更多
Recent studies have shown that office building systems do not adapt well to partial occupancy(e.g.,from teleworking)and thus perform suboptimally.As a result,this study aims to assess office building performance adapt...Recent studies have shown that office building systems do not adapt well to partial occupancy(e.g.,from teleworking)and thus perform suboptimally.As a result,this study aims to assess office building performance adaptability by investigating the impact of four different technologies,including occupancy-based lighting,smart plugs(occupancy-based plug load),demand-controlled ventilation(DCV),occupancy-based thermostat,and their cumulative effect in office buildings in six different Canadian climates.A three-story office building is simulated in EnergyPlus version 9.3.0 under five occupancy scenarios,including 0%occupancy,100%occupancy,50%uniformly distributed occupancy across the floor,50%consolidated occupancy scenario where occupants work in core zones,and 50%consolidated occupancy scenario where occupants work in perimeter zones.The results are compared using energy use intensity(EUI),energy use intensity per occupant(EUP),and the corresponding greenhouse gas(GHG)emissions.A total of 180 simulations demonstrate the occupancy-adaptive technologies are generally most beneficial for low occupancy scenarios and milder climates.The results also show the cumulative impact of all these technologies on the potential energy savings is significant in the climates under consideration.Overall,the results show office buildings can improve their performance adaptability during partial occupancy by implementing the studied technologies.Aside from filling in the current knowledge gap in the literature on partial occupancy,the for the first time results of this study systemically demonstrate how each technology performs under different partial occupancy scenarios and how they perform together at each climate.展开更多
Conversion of hourly dispatch cases derived using DC optimal power flow(DCOPF)to AC power flow(ACPF)case is often challenging and requires arduous human analysis and intervention.This paper proposes an automated two-s...Conversion of hourly dispatch cases derived using DC optimal power flow(DCOPF)to AC power flow(ACPF)case is often challenging and requires arduous human analysis and intervention.This paper proposes an automated two-stage approach to solve ACPF formulated from DCOPF dispatch cases.The first stage involved the use of the conventional Newton Raphson method to solve the ACPF from flat start,then ACPF cases that are unsolvable in the first stage are subjected to a hotstarting incremental method,based on homotopy continuation,in the second stage.Critical tasks such as the addition of reactive power compensation and tuning of voltage setpoints that typically require human intervention were automated using a criteriabased selection method and optimal power flow respectively.Two datasets with hourly dispatches for the 243-bus reduced WECC system were used to test the proposed method.The algorithm was able to convert 100%of the first set of dispatch cases to solved ACPF cases.In the second dataset with suspect dispatch cases to represent an extreme conversion scenario,the algorithm created solved ACPF cases that satisfied a defined success criterion for 77.8%of the dispatch cases.The average run time for the hotstarting algorithm to create a solved ACPF case for a dispatch was less than 1 minute for the reduced WECC system.展开更多
This paper studies sampled-data proportional-integral(PI)control for a basic class of nonlinear uncertain systems.The authors claim that a process with the first-order dynamics can achieve zero steady-state error thro...This paper studies sampled-data proportional-integral(PI)control for a basic class of nonlinear uncertain systems.The authors claim that a process with the first-order dynamics can achieve zero steady-state error through a sampled-data PI controller whenever the sampling period T<T_(0)(k_(p),k_(i),L),where T_(0)(k_(p),k_(i),L)is a number determined by the parameters kp,ki and the Lipschitz constant L of the system.On the other hand,once the sampling period T is given,the two parameters kp and ki of the sampled-data PI controller are apparently restricted by T,or the setpoint tracking error diverges.展开更多
It has been found in recent years that using setpoint temperatures based on adaptive thermal comfort models is a successful method of energy conservation.Recent studies using adaptive setpoint temperatures incorporate...It has been found in recent years that using setpoint temperatures based on adaptive thermal comfort models is a successful method of energy conservation.Recent studies using adaptive setpoint temperatures incorporate international models from ASHRAE Standard 55 and EN16798-1.This study,however,has instead considered a regional Brazilian adaptive comfort model.This study investigates the energy demand arising from the use of a local Brazilian comfort model in order to assess the energy implications from the use of the worldwide ASHRAE Standard 55 adaptive model and various fixed setpoint temperatures.All of Brazil’s climate zones,full air-conditioning,mixed-mode building operating modes,present-day climate change scenarios,and future scenarios—specifically Representative Concentration Pathways(RCP)2.6,4.5,and 8.5 for the years 2050 and 2100—have all been taken into account in building energy simulations.The use of adaptive setpoint temperatures based on the Brazilian local model considering mixed-mode has been found to significantly reduce energy consumption when compared to static setpoint temperatures(average energy-saving values ranging from 52%to 58%)and the ASHRAE 55 adaptive model(average values ranging from 15%to 21%).Considering climate change and the mixed-mode Brazilian model,the overall energy demand for the three groups of climatic zones(annual average outdoor temperatures≤21℃,>21 and≤25℃and>25℃)ranged between 2%decrease and 5%increase,4%and 27%increase,and 13%and 45%increase,respectively.It is concluded as a consequence that setting setpoint temperatures based on the Brazilian local adaptive comfort model is a very efficient energy-saving method.展开更多
基金It is supported by the National Natural science Foundation of China(No.3 9170 2 2 2 )
文摘To study the gating kinetics of voltage dependent K + channel in clonal pheochromocytoma (PC12) cells, the inward currents of K channel in PC12 cells were recorded using cell attached patch clamp technique. The fractal features of the open and closed time distributions were determined. The fractal dimensions and kinetic setpoints for the open and closed durations were estimated. It was found that the fractal dimension D was independent of voltage and the logarithm logA of the setpoint A was inversely proportional to the pipette potential (Vp) for the closed durations. While for the open durations the fractal dimension D was inversely proportional to the pipette potential and the logarithm logA of the setpoint A was independent of voltage. Thus, for this channel the open and closed durations and voltage dependence of the gating could be well described by the fractal model.
文摘Recent studies have shown that office building systems do not adapt well to partial occupancy(e.g.,from teleworking)and thus perform suboptimally.As a result,this study aims to assess office building performance adaptability by investigating the impact of four different technologies,including occupancy-based lighting,smart plugs(occupancy-based plug load),demand-controlled ventilation(DCV),occupancy-based thermostat,and their cumulative effect in office buildings in six different Canadian climates.A three-story office building is simulated in EnergyPlus version 9.3.0 under five occupancy scenarios,including 0%occupancy,100%occupancy,50%uniformly distributed occupancy across the floor,50%consolidated occupancy scenario where occupants work in core zones,and 50%consolidated occupancy scenario where occupants work in perimeter zones.The results are compared using energy use intensity(EUI),energy use intensity per occupant(EUP),and the corresponding greenhouse gas(GHG)emissions.A total of 180 simulations demonstrate the occupancy-adaptive technologies are generally most beneficial for low occupancy scenarios and milder climates.The results also show the cumulative impact of all these technologies on the potential energy savings is significant in the climates under consideration.Overall,the results show office buildings can improve their performance adaptability during partial occupancy by implementing the studied technologies.Aside from filling in the current knowledge gap in the literature on partial occupancy,the for the first time results of this study systemically demonstrate how each technology performs under different partial occupancy scenarios and how they perform together at each climate.
基金This work was supported by the ERC Program of the National Science Foundation and DOE under NSF Award Number EEC-1041877the CURENT Industry Partnership Program,and the Bredesen Centre,University of Tennessee,Knoxville.
文摘Conversion of hourly dispatch cases derived using DC optimal power flow(DCOPF)to AC power flow(ACPF)case is often challenging and requires arduous human analysis and intervention.This paper proposes an automated two-stage approach to solve ACPF formulated from DCOPF dispatch cases.The first stage involved the use of the conventional Newton Raphson method to solve the ACPF from flat start,then ACPF cases that are unsolvable in the first stage are subjected to a hotstarting incremental method,based on homotopy continuation,in the second stage.Critical tasks such as the addition of reactive power compensation and tuning of voltage setpoints that typically require human intervention were automated using a criteriabased selection method and optimal power flow respectively.Two datasets with hourly dispatches for the 243-bus reduced WECC system were used to test the proposed method.The algorithm was able to convert 100%of the first set of dispatch cases to solved ACPF cases.In the second dataset with suspect dispatch cases to represent an extreme conversion scenario,the algorithm created solved ACPF cases that satisfied a defined success criterion for 77.8%of the dispatch cases.The average run time for the hotstarting algorithm to create a solved ACPF case for a dispatch was less than 1 minute for the reduced WECC system.
基金supported in part by National Key R&D Program of China under Grant No.2018YFA0703800the National Natural Science Foundation of China under Grant No.U21B6001the China Postdoctoral Science Foundation under Grant No.2021TQ0352。
文摘This paper studies sampled-data proportional-integral(PI)control for a basic class of nonlinear uncertain systems.The authors claim that a process with the first-order dynamics can achieve zero steady-state error through a sampled-data PI controller whenever the sampling period T<T_(0)(k_(p),k_(i),L),where T_(0)(k_(p),k_(i),L)is a number determined by the parameters kp,ki and the Lipschitz constant L of the system.On the other hand,once the sampling period T is given,the two parameters kp and ki of the sampled-data PI controller are apparently restricted by T,or the setpoint tracking error diverges.
基金This study was funded by the Urban Innovative Actions initiative(European Commission),under the research project UIA04-212 Energy Poverty Intelligence Unit(EPIU),the Spanish Ministry of Science and Innovation,under the research project PID2021-122437OA-I00“Positive Energy Buildings Potential for Climate Change Adaptation and Energy Poverty Mitigation(+ENERPOT)”the Andalusian Ministry of Development,Articulation of the Territory and Housing,under the research project US.22-02“Implicaciones en la mitigación del cambio climático y de la pobreza energética mediante nuevo modelo de confort adaptativo para viviendas sociales(ImplicAdapt)”.The authors also acknowledge the support provided by the Thematic Network 722RT0135“Red Iberoamericana de Pobreza Energética y Bienestar Ambiental(RIPEBA)”financed by the call for Thematic Networks of the CYTED Program for 2021.
文摘It has been found in recent years that using setpoint temperatures based on adaptive thermal comfort models is a successful method of energy conservation.Recent studies using adaptive setpoint temperatures incorporate international models from ASHRAE Standard 55 and EN16798-1.This study,however,has instead considered a regional Brazilian adaptive comfort model.This study investigates the energy demand arising from the use of a local Brazilian comfort model in order to assess the energy implications from the use of the worldwide ASHRAE Standard 55 adaptive model and various fixed setpoint temperatures.All of Brazil’s climate zones,full air-conditioning,mixed-mode building operating modes,present-day climate change scenarios,and future scenarios—specifically Representative Concentration Pathways(RCP)2.6,4.5,and 8.5 for the years 2050 and 2100—have all been taken into account in building energy simulations.The use of adaptive setpoint temperatures based on the Brazilian local model considering mixed-mode has been found to significantly reduce energy consumption when compared to static setpoint temperatures(average energy-saving values ranging from 52%to 58%)and the ASHRAE 55 adaptive model(average values ranging from 15%to 21%).Considering climate change and the mixed-mode Brazilian model,the overall energy demand for the three groups of climatic zones(annual average outdoor temperatures≤21℃,>21 and≤25℃and>25℃)ranged between 2%decrease and 5%increase,4%and 27%increase,and 13%and 45%increase,respectively.It is concluded as a consequence that setting setpoint temperatures based on the Brazilian local adaptive comfort model is a very efficient energy-saving method.
