Effects of High Temperature and High Humidity on the Degree of Ocular Damage Caused by 60 GHz Millimeter Wave Exposure Masami Kojima1,2,Takafumi Tasaki3,4,Toshio Kamijo5,Aki Hada5,Yukihisa Suzuki5,Masateru Ikehata6,Hi...Effects of High Temperature and High Humidity on the Degree of Ocular Damage Caused by 60 GHz Millimeter Wave Exposure Masami Kojima1,2,Takafumi Tasaki3,4,Toshio Kamijo5,Aki Hada5,Yukihisa Suzuki5,Masateru Ikehata6,Hiroshi Sasaki1,2(1.Division of Vision Research for Environmental Health,Medical Research Institute,Kanazawa Medical University,Kahoku,Japan;2.Department of Ophthalmology,Kanazawa Medical University,Kahoku,Japan;3.Division of Protein Regulation Research,Medical Research Institute;4.Department of Medical Zoology,Kanazawa Medical University,Kahoku,Japan;5.Department of Electrical Engineering and Computer Science,Graduate School of Systems Design,Tokyo Metropolitan University,Tokyo,Japan;6.Comfort Science and Engineering Laboratory,Human Science Division,Railway Technical Research Institute,Tokyo,Japan)Abstract:Millimeter waves(MMW)are pervasive in society;however,studies on the biological effects of MMWexposure are usually performed in laboratory settings not reflecting global environmental diversity.We investigated the effects of a 6 min exposure to 60 GHz MMW(wavelength,5.0 mm)at incident power densities of 200 and 300 mW cm-2 in eyes(exposed right eyes vs.unexposed left eyes)under various ambient temperature/relative humidity environments(24℃/50%,45℃/20%,and 45℃/80%)using an in vivo rabbit model.Correlations were examined with adverse ocular events,including corneal epithelial damage(assessed using fluorescein staining),corneal opacity(evaluated by slit-lamp microscopy)。展开更多
Vehicle suspension design includes a number of compromises to provide good leveling of stability and ride comfort. Optimization of off-road vehicle suspension system is one of the most effective methods, which could c...Vehicle suspension design includes a number of compromises to provide good leveling of stability and ride comfort. Optimization of off-road vehicle suspension system is one of the most effective methods, which could considerably enhance the vehicle stability and controllability. In this work, a comprehensive optimization of an off-read vehicle suspension system model was carried out using software ADAMS. The geometric parameters of suspension system were optimized using genetic algorithm (GA) in a way that ride comfort, handling and stability of vehicle were improved. The results of optimized suspension system and variations of geometric parameters due to road roughness and different steering angles were presented in ADAMS and the results of optimized and conventional suspension systems during various driving maneuvers were compared. The simulation results indicate that the camber angle variations decrease by the optimized suspension system, resulting in improved handling and ride comfort characteristics.展开更多
An active pipe-embedded building envelope, which is an external wall or roof with pipes embedded inside, was presented. This structure may utilize the circulating water in the pipe to transfer heat or coolth inside di...An active pipe-embedded building envelope, which is an external wall or roof with pipes embedded inside, was presented. This structure may utilize the circulating water in the pipe to transfer heat or coolth inside directly. This kind of structure is named ＂active pipe-embedded building envelope＂ due to dealing with the thermal energy actively inside the structure mass by circulating water. This structure not only deals with thermal energy before the external disturbance becomes cooling/heating load by using the circulating water, but also may use low-grade energy sources such as evaporative cooling, solar energy, and geothermal energy. In the meantime, this structure can also improve the indoor thermal comfort by tempering the internal wall surface temperature variation due to the thermal removal in the mass. This work further presents the thermal performance of this structure under a typical hot summer weather condition by comparing it with that of the conventional external wall/roof with numerical simulation. The results show that this pipe-embedded structure may reduce the external heat transfer significantly and reduce the internal wall surface temperature for improving thermal comfort. This work also presents the effects of the water temperature and the pipe spacing on the heat transfer of this structure. The internal surface heat transfer may reduce by about 2.6 W/mE when the water temperature reduces by 1℃ as far as a brick wall with pipes embedded inside is concerned. When the pipe spacing reduces by 50 mm, the internal wall surface heat flux can also reduce by about 2.3 W/m2.展开更多
To explore the thermal responses under the non-thermal equilibrium cold environmental conditions,a laboratory study was conducted in climate chamber.The local skin temperatures and thermal sensation of 20 subjects wer...To explore the thermal responses under the non-thermal equilibrium cold environmental conditions,a laboratory study was conducted in climate chamber.The local skin temperatures and thermal sensation of 20 subjects were recorded at 10 min intervals for 90 min under air temperatures of 7.4,9.1,11 and 15 °C.The results show that both local skin temperatures and mean skin temperature decrease not only with the drop of ambient air temperature but also with the exposure time.Local thermal sensation and overall the thermal sensation have the similar temperature-varying and time-varying characteristics.Predicted mean vote(PMV) model cannot correctly predict the thermal sensation under non-thermal equilibrium cold environment.The correlation between local thermal sensation and local skin temperatures shows that thermal sensation is closely related to skin temperature.Skin temperature is an effective indicator of thermal sensation.A linear relationship model between overall thermal sensation and mean skin temperature,considering both ambient temperature and exposure time,was established in the non-thermal equilibrium cold environment,which makes the evaluation of thermal sensation more objective.展开更多
Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototyp...Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver's seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level.展开更多
The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential...The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential buildings in Xi’an,China.A total of 2069 valid questionnaires,along with indoor environmental parameters were obtained.The results indicated occupants’thermal comfort requirements varied with seasons.The neutral temperatures were 17.9,26.1(highest),25.2,and 17.4℃(lowest),and preferred temperatures were 23.2,25.6(highest),24.8,and 22.4℃(lowest),respectively for spring,summer,autumn,and winter.The neutral temperature and preferred temperature in autumn are close to the neutral temperature in summer,while the neutral temperature and preferred temperature in spring are close to that in winter.Besides,the 80%and 90%acceptable temperature ranges,adaptive thermal comfort models,and thermal comfort zones for each season were established.Human’s adaptability is related to his/her thermal experience of the current season and the previous season.Therefore,compared with the traditional year-round adaptive thermal comfort model,seasonal models can better reflect seasonal variations of human adaptation.This study provides fundamental knowledge of the thermal comfort demand for people in this region.展开更多
To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three...To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three similar offices at temperatures of 24,26 and 28 ℃ respectively. A thermal comfort questionnaire survey was conducted. It is demonstrated that air-conditioner energy consumption at the set temperature of 28 ℃ is 113% and 271% lower than at 26 ℃ and 24 ℃,respectively. A linear relationship exists between air-conditioner energy consumption and the indoor and outdoor temperature difference. When comfortably dressed,over 80% of research participants accept the set temperature of 28 ℃. The regression analysis leads to a neutral temperature of 26.2 ℃ and an acceptable temperature of 28.2 ℃ for over 80% of the research participants subjects,indicating that the current 26 ℃ set temperature for offices in summer,required by Chinese General Office of the State Council,can be increased to 28 ℃. Moreover,analysis of predicted mean vote(PMV) index shows that a set temperature of 27 ℃,not 26 ℃,is sufficiently comfortable for office staff wearing long-sleeve shirts,long pants and leather shoes.展开更多
The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating p...The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating panel typically applied to apartments in South Korea with the forced-convection cooling system using improved fan coil unit. The subjective warm/cool-feeling responses to the combined radiant-floor and convective cooling system in the questionnaire survey conducted among the test subjects were analyzed to establish the basic data for the combined cooling system. The results show that in the thermal-equilibrium condition, the vertical air temperature difference in the model living room is larger in the forced-convection-cooling condition. Most of the subjects feel a proper warm/cool feeling on their entire body, but they feel colder on the foot and lower body in the combined-cooling condition.展开更多
Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influ...Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influence of the hypoxic environment on the plateau on the thermal comfort of short-term sojourners in Tibet,China,oxygen generators were used to create oxygen-enriched environments,and physiological and psychological reactions of subjects were compared under different oxygen partial pressures(p_(O_(2)))and air temperatures(t_(a)).The results showed that subjects’thermal sensation,thermal comfort and mean skin temperature decreased with a decrease in the oxygen partial pressure.When t_(a)=17℃,the influence of oxygen partial pressure was more pronounced,compared to p_(O_(2))=16.4 kPa,the thermal sensation of subjects under p_(O_(2))=13.7 kPa decreased by 33%.The rate of subjects feeling comfortable decreased by 25%,and the mean skin temperature decreased by 0.7℃.The hypoxic environment of the plateau exacerbates human discomfort.Therefore,it is necessary to fully understand the actual thermal requirements of sojourners in Tibet,China.The results of this study would have implications for a better understanding of thermal comfort characteristics in the hypoxia environment in plateau.展开更多
Physiological parameters of people and enact assessment standard of indoor thermal environment that are appropriate to our national conditions were explored from the perspective of physiology. From December 2005 to Ja...Physiological parameters of people and enact assessment standard of indoor thermal environment that are appropriate to our national conditions were explored from the perspective of physiology. From December 2005 to January 2006, nerve conduction velocities and skin temperatures of 20 healthy students were tested with questionnaire investigation. The results show that the nerve conduction velocities as well as skin temperatures present an obvious decline trend in a continuous draught, and that the nerve conduction velocities and skin temperatures have a definite linear relationship. Draught velocity is an important factor in winter that affects body comfort, and the subjects are sensitive to air velocity.展开更多
Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buil...Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.展开更多
A field study on thermal comfort was conducted in university dormitories in Chongqing,China,which was transverse with monthly from August 2008 to April 2009. A total of 1 572 returned questionnaires were collected. Th...A field study on thermal comfort was conducted in university dormitories in Chongqing,China,which was transverse with monthly from August 2008 to April 2009. A total of 1 572 returned questionnaires were collected. Thermal comfort variables were measured,at the same time students answered a survey on their indoor climate sensation. The thermal environment parameters,i.e.,indoor air temperature,air relative humidity,air velocity and outdoor air temperature were measured. The subjective survey investigated thermal sensation and preference using subjective scales. Objective data analysis shows that the indoor environments in university dormitories in Chongqing cannot meet 80% acceptability criteria prescribed by ASHRAE Standard 55. The ranges of accepted temperature are 21.5?28.5 ℃ in summer and 14.1?23.4 ℃ in winter. The preferred temperature is 22.8 ℃. It is observed that during summer season people prefer somewhat cooler condition than neutral,but in the winter season people prefer somewhat warmer condition than neutral. The relationship between air movement preference and thermal sensation indicates that even without a cooling requirement related to thermal comfort,people appear to welcome air movement.展开更多
A field study and analysis about the thermal comfort was carried out in the waiting room at Beijing West Rail Station in Chinese cold region.Passengers' TSV(thermal sense vote)was obtained using statistical method...A field study and analysis about the thermal comfort was carried out in the waiting room at Beijing West Rail Station in Chinese cold region.Passengers' TSV(thermal sense vote)was obtained using statistical method on the basis of more than 1 200 questionnaires.The linear regression between TSV and indoor temperature indicates that thermal neutral temperature is 25.2 ℃.According to the percentage of satisfaction among all passengers under different indoor temperatures,the acceptable temperature range in the waiting room is 24.2～30.2℃.It is also found that passengers' temporary stay should be taken into consideration for the thermal comfort analysis.Passengers' TSV is not a constant value after they enter the waiting room.In fact,ΔTSV increases as passengers are waiting for the train,and the growing rate is dependent on indoor-outdoor temperature difference.The greater the temperature difference,the faster ΔTSV increases.At last,a linear regression between indoor comfortable temperature and outdoor temperature was generated as the adaptive comfort model.展开更多
The present building facility management status in China resulted in many problems such as high energy consumption,failure of automation control,services failure and poor indoor air quality.Based on questionnaires and...The present building facility management status in China resulted in many problems such as high energy consumption,failure of automation control,services failure and poor indoor air quality.Based on questionnaires and interviews to professional engineers and building users,a comprehensive evaluation index system was established on facility management of high-rise office buildings.A Fuzzy AHP based upon hierarchy criteria system was established.A Fuzzy AHP Evaluation Model on Facility Management System was set up;α-cut analysis was introduced and incorporated with expert knowledge together,which made up the optimism index λ.The fuzzy optimum crisp weight of each criterion was resulted from data-mining.Case investigations were processed in high-rise office buildings in Shenyang.The results illustrated that indoor air quality,thermal comfort and life cycle cost were the most important indexes in the evaluation of Facility Management System of high rise office buildings.Residents in high-rise buildings in Shenyang pay less attention to maintenance management and environment protection.By comparison with the analysis result of Export Choice,Fuzzy AHP-based evaluation model could act as a scientific reference for the establishment of governmental standards in facility management area in building.展开更多
To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the dis...To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the distribution of the indicators of indoor air in the gymnasium to check the air-conditioning parameters reasonable or not. And there was a questionnaire for audiences and staff about the acceptance and satisfaction of the thermal comfort,simultaneously,some environmental parameters were monitored. Then an experiment was carried out in gymnasium with the plate sedimentation to the biological aerosol in the air. Finally,the thermal comfort and IAQ in the gymnasium were assessed based on the results of above questionnaire survey and measurements. The results show that most parameters of the environmental are within the standard limits of thermal comfort and IAQ in the monitored period,and the biological contaminants initially come from human beings. The main species in the gymnasium are streptobacillus,coccus,cladosporium,penicillium and neurospora.展开更多
To study the effects of perceived control on human thermal sensation and thermal comfort in heated environments,a psychological experiment was conducted.In total,24 subjects participated in an experiment.The experimen...To study the effects of perceived control on human thermal sensation and thermal comfort in heated environments,a psychological experiment was conducted.In total,24 subjects participated in an experiment.The experiment consisted of two cases in which the indoor temperature was set at 18℃ with different cold radiation temperatures.The experiment lasted for 120 min and was divided into three phases,adaptation,without perceived control and perceived control.In the second phase,the subjects were told in advance that the indoor temperature could not be adjusted.In the third phase,subjects were told that they could adjust the indoor temperature to meet their own thermal expectations,but the indoor temperature could not actually be changed.The results showed that the effect of perceived control on thermal sensation was related to the thermal expectation.For people with strong expectations for a neutral environment,perceived control improved their thermal sensation by satisfying their thermal expectations.For people with low thermal expectations,perceived control reduced their thermal tolerance to the environment,eventually leading to thermal discomfort.These new findings provide more supports for the importance of psychological effects and a reference for the personal control of heating temperatures.展开更多
文摘Effects of High Temperature and High Humidity on the Degree of Ocular Damage Caused by 60 GHz Millimeter Wave Exposure Masami Kojima1,2,Takafumi Tasaki3,4,Toshio Kamijo5,Aki Hada5,Yukihisa Suzuki5,Masateru Ikehata6,Hiroshi Sasaki1,2(1.Division of Vision Research for Environmental Health,Medical Research Institute,Kanazawa Medical University,Kahoku,Japan;2.Department of Ophthalmology,Kanazawa Medical University,Kahoku,Japan;3.Division of Protein Regulation Research,Medical Research Institute;4.Department of Medical Zoology,Kanazawa Medical University,Kahoku,Japan;5.Department of Electrical Engineering and Computer Science,Graduate School of Systems Design,Tokyo Metropolitan University,Tokyo,Japan;6.Comfort Science and Engineering Laboratory,Human Science Division,Railway Technical Research Institute,Tokyo,Japan)Abstract:Millimeter waves(MMW)are pervasive in society;however,studies on the biological effects of MMWexposure are usually performed in laboratory settings not reflecting global environmental diversity.We investigated the effects of a 6 min exposure to 60 GHz MMW(wavelength,5.0 mm)at incident power densities of 200 and 300 mW cm-2 in eyes(exposed right eyes vs.unexposed left eyes)under various ambient temperature/relative humidity environments(24℃/50%,45℃/20%,and 45℃/80%)using an in vivo rabbit model.Correlations were examined with adverse ocular events,including corneal epithelial damage(assessed using fluorescein staining),corneal opacity(evaluated by slit-lamp microscopy)。
文摘Vehicle suspension design includes a number of compromises to provide good leveling of stability and ride comfort. Optimization of off-road vehicle suspension system is one of the most effective methods, which could considerably enhance the vehicle stability and controllability. In this work, a comprehensive optimization of an off-read vehicle suspension system model was carried out using software ADAMS. The geometric parameters of suspension system were optimized using genetic algorithm (GA) in a way that ride comfort, handling and stability of vehicle were improved. The results of optimized suspension system and variations of geometric parameters due to road roughness and different steering angles were presented in ADAMS and the results of optimized and conventional suspension systems during various driving maneuvers were compared. The simulation results indicate that the camber angle variations decrease by the optimized suspension system, resulting in improved handling and ride comfort characteristics.
基金Project(51178201) supported by the National Natural Science Foundation of China Project(2011CDB292) supported by the Natural Science Foundation of Hubei Province,China
文摘An active pipe-embedded building envelope, which is an external wall or roof with pipes embedded inside, was presented. This structure may utilize the circulating water in the pipe to transfer heat or coolth inside directly. This kind of structure is named ＂active pipe-embedded building envelope＂ due to dealing with the thermal energy actively inside the structure mass by circulating water. This structure not only deals with thermal energy before the external disturbance becomes cooling/heating load by using the circulating water, but also may use low-grade energy sources such as evaporative cooling, solar energy, and geothermal energy. In the meantime, this structure can also improve the indoor thermal comfort by tempering the internal wall surface temperature variation due to the thermal removal in the mass. This work further presents the thermal performance of this structure under a typical hot summer weather condition by comparing it with that of the conventional external wall/roof with numerical simulation. The results show that this pipe-embedded structure may reduce the external heat transfer significantly and reduce the internal wall surface temperature for improving thermal comfort. This work also presents the effects of the water temperature and the pipe spacing on the heat transfer of this structure. The internal surface heat transfer may reduce by about 2.6 W/mE when the water temperature reduces by 1℃ as far as a brick wall with pipes embedded inside is concerned. When the pipe spacing reduces by 50 mm, the internal wall surface heat flux can also reduce by about 2.3 W/m2.
基金Project(50838009) supported by the National Natural Science Foundation of China
文摘To explore the thermal responses under the non-thermal equilibrium cold environmental conditions,a laboratory study was conducted in climate chamber.The local skin temperatures and thermal sensation of 20 subjects were recorded at 10 min intervals for 90 min under air temperatures of 7.4,9.1,11 and 15 °C.The results show that both local skin temperatures and mean skin temperature decrease not only with the drop of ambient air temperature but also with the exposure time.Local thermal sensation and overall the thermal sensation have the similar temperature-varying and time-varying characteristics.Predicted mean vote(PMV) model cannot correctly predict the thermal sensation under non-thermal equilibrium cold environment.The correlation between local thermal sensation and local skin temperatures shows that thermal sensation is closely related to skin temperature.Skin temperature is an effective indicator of thermal sensation.A linear relationship model between overall thermal sensation and mean skin temperature,considering both ambient temperature and exposure time,was established in the non-thermal equilibrium cold environment,which makes the evaluation of thermal sensation more objective.
基金Projects(51078087, 51178158) supported by the National Natural Science Foundation of ChinaProject(11040606Q39) supported by the Natural Science Foundation of Anhui Province, ChinaProjects(2012HGQC0015, 2011HGBZ0945) supported by the Fundamental Research Funds for the Central Universities
文摘Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver's seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level.
基金Project(51325803)supported by the National Science Foundation for Distinguished Young Scholars of ChinaProject(2020M673489)supported by China Postdoctoral Science FoundationProject(2020-K-196)supported by the Science and Technology Project of Ministry of Housing and Urban-Rural Development,China。
文摘The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential buildings in Xi’an,China.A total of 2069 valid questionnaires,along with indoor environmental parameters were obtained.The results indicated occupants’thermal comfort requirements varied with seasons.The neutral temperatures were 17.9,26.1(highest),25.2,and 17.4℃(lowest),and preferred temperatures were 23.2,25.6(highest),24.8,and 22.4℃(lowest),respectively for spring,summer,autumn,and winter.The neutral temperature and preferred temperature in autumn are close to the neutral temperature in summer,while the neutral temperature and preferred temperature in spring are close to that in winter.Besides,the 80%and 90%acceptable temperature ranges,adaptive thermal comfort models,and thermal comfort zones for each season were established.Human’s adaptability is related to his/her thermal experience of the current season and the previous season.Therefore,compared with the traditional year-round adaptive thermal comfort model,seasonal models can better reflect seasonal variations of human adaptation.This study provides fundamental knowledge of the thermal comfort demand for people in this region.
基金Project(50838009) supported by the National Natural Science Foundation of ChinaProjects(2006BAJ02A09,2006BAJ02A13-4) supported by the National Key Technologies R & D Program of China
文摘To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three similar offices at temperatures of 24,26 and 28 ℃ respectively. A thermal comfort questionnaire survey was conducted. It is demonstrated that air-conditioner energy consumption at the set temperature of 28 ℃ is 113% and 271% lower than at 26 ℃ and 24 ℃,respectively. A linear relationship exists between air-conditioner energy consumption and the indoor and outdoor temperature difference. When comfortably dressed,over 80% of research participants accept the set temperature of 28 ℃. The regression analysis leads to a neutral temperature of 26.2 ℃ and an acceptable temperature of 28.2 ℃ for over 80% of the research participants subjects,indicating that the current 26 ℃ set temperature for offices in summer,required by Chinese General Office of the State Council,can be increased to 28 ℃. Moreover,analysis of predicted mean vote(PMV) index shows that a set temperature of 27 ℃,not 26 ℃,is sufficiently comfortable for office staff wearing long-sleeve shirts,long pants and leather shoes.
基金Project(NRF-2013RIA2A1A01014020)supported by the National Research Foundation of Korea
文摘The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating panel typically applied to apartments in South Korea with the forced-convection cooling system using improved fan coil unit. The subjective warm/cool-feeling responses to the combined radiant-floor and convective cooling system in the questionnaire survey conducted among the test subjects were analyzed to establish the basic data for the combined cooling system. The results show that in the thermal-equilibrium condition, the vertical air temperature difference in the model living room is larger in the forced-convection-cooling condition. Most of the subjects feel a proper warm/cool feeling on their entire body, but they feel colder on the foot and lower body in the combined-cooling condition.
基金Project(U20A20311)supported by the State Key Program of National Natural Science Foundation of ChinaProject(52008329)supported by the National Natural Science Foundation of ChinaProject(2018BSHYDZZ14)supported by the Postdoctoral Research Foundation of Shaanxi Province,China。
文摘Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influence of the hypoxic environment on the plateau on the thermal comfort of short-term sojourners in Tibet,China,oxygen generators were used to create oxygen-enriched environments,and physiological and psychological reactions of subjects were compared under different oxygen partial pressures(p_(O_(2)))and air temperatures(t_(a)).The results showed that subjects’thermal sensation,thermal comfort and mean skin temperature decreased with a decrease in the oxygen partial pressure.When t_(a)=17℃,the influence of oxygen partial pressure was more pronounced,compared to p_(O_(2))=16.4 kPa,the thermal sensation of subjects under p_(O_(2))=13.7 kPa decreased by 33%.The rate of subjects feeling comfortable decreased by 25%,and the mean skin temperature decreased by 0.7℃.The hypoxic environment of the plateau exacerbates human discomfort.Therefore,it is necessary to fully understand the actual thermal requirements of sojourners in Tibet,China.The results of this study would have implications for a better understanding of thermal comfort characteristics in the hypoxia environment in plateau.
基金Project(CSTC 2004AA7008) supported by the State I mportant Project of the Science and Technology
文摘Physiological parameters of people and enact assessment standard of indoor thermal environment that are appropriate to our national conditions were explored from the perspective of physiology. From December 2005 to January 2006, nerve conduction velocities and skin temperatures of 20 healthy students were tested with questionnaire investigation. The results show that the nerve conduction velocities as well as skin temperatures present an obvious decline trend in a continuous draught, and that the nerve conduction velocities and skin temperatures have a definite linear relationship. Draught velocity is an important factor in winter that affects body comfort, and the subjects are sensitive to air velocity.
基金Project(2018YFC0704500)supported by the National Key R&D Program of ChinaProjects(51838007,52130803)supported by the National Natural Science Foundation of China。
文摘Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.
基金Projects(50838009, 50678179)supported by the National Natural Science Foundation of ChinaProjects(2006BAJ02A09, 2006BAJ02A13-4)supported by the National Key Technologies R & D Program of China
文摘A field study on thermal comfort was conducted in university dormitories in Chongqing,China,which was transverse with monthly from August 2008 to April 2009. A total of 1 572 returned questionnaires were collected. Thermal comfort variables were measured,at the same time students answered a survey on their indoor climate sensation. The thermal environment parameters,i.e.,indoor air temperature,air relative humidity,air velocity and outdoor air temperature were measured. The subjective survey investigated thermal sensation and preference using subjective scales. Objective data analysis shows that the indoor environments in university dormitories in Chongqing cannot meet 80% acceptability criteria prescribed by ASHRAE Standard 55. The ranges of accepted temperature are 21.5?28.5 ℃ in summer and 14.1?23.4 ℃ in winter. The preferred temperature is 22.8 ℃. It is observed that during summer season people prefer somewhat cooler condition than neutral,but in the winter season people prefer somewhat warmer condition than neutral. The relationship between air movement preference and thermal sensation indicates that even without a cooling requirement related to thermal comfort,people appear to welcome air movement.
基金Supported by National Natural Science Foundation of China(20676154)
文摘A field study and analysis about the thermal comfort was carried out in the waiting room at Beijing West Rail Station in Chinese cold region.Passengers' TSV(thermal sense vote)was obtained using statistical method on the basis of more than 1 200 questionnaires.The linear regression between TSV and indoor temperature indicates that thermal neutral temperature is 25.2 ℃.According to the percentage of satisfaction among all passengers under different indoor temperatures,the acceptable temperature range in the waiting room is 24.2～30.2℃.It is also found that passengers' temporary stay should be taken into consideration for the thermal comfort analysis.Passengers' TSV is not a constant value after they enter the waiting room.In fact,ΔTSV increases as passengers are waiting for the train,and the growing rate is dependent on indoor-outdoor temperature difference.The greater the temperature difference,the faster ΔTSV increases.At last,a linear regression between indoor comfortable temperature and outdoor temperature was generated as the adaptive comfort model.
文摘The present building facility management status in China resulted in many problems such as high energy consumption,failure of automation control,services failure and poor indoor air quality.Based on questionnaires and interviews to professional engineers and building users,a comprehensive evaluation index system was established on facility management of high-rise office buildings.A Fuzzy AHP based upon hierarchy criteria system was established.A Fuzzy AHP Evaluation Model on Facility Management System was set up;α-cut analysis was introduced and incorporated with expert knowledge together,which made up the optimism index λ.The fuzzy optimum crisp weight of each criterion was resulted from data-mining.Case investigations were processed in high-rise office buildings in Shenyang.The results illustrated that indoor air quality,thermal comfort and life cycle cost were the most important indexes in the evaluation of Facility Management System of high rise office buildings.Residents in high-rise buildings in Shenyang pay less attention to maintenance management and environment protection.By comparison with the analysis result of Export Choice,Fuzzy AHP-based evaluation model could act as a scientific reference for the establishment of governmental standards in facility management area in building.
基金Project(2006BAJ02A10) supported by the National Key Technologies R & D Program of China
文摘To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the distribution of the indicators of indoor air in the gymnasium to check the air-conditioning parameters reasonable or not. And there was a questionnaire for audiences and staff about the acceptance and satisfaction of the thermal comfort,simultaneously,some environmental parameters were monitored. Then an experiment was carried out in gymnasium with the plate sedimentation to the biological aerosol in the air. Finally,the thermal comfort and IAQ in the gymnasium were assessed based on the results of above questionnaire survey and measurements. The results show that most parameters of the environmental are within the standard limits of thermal comfort and IAQ in the monitored period,and the biological contaminants initially come from human beings. The main species in the gymnasium are streptobacillus,coccus,cladosporium,penicillium and neurospora.
基金Project(2018YFC0704500)supported by the National Key R&D Program of China during the 13th Five-Year Plan Period。
文摘To study the effects of perceived control on human thermal sensation and thermal comfort in heated environments,a psychological experiment was conducted.In total,24 subjects participated in an experiment.The experiment consisted of two cases in which the indoor temperature was set at 18℃ with different cold radiation temperatures.The experiment lasted for 120 min and was divided into three phases,adaptation,without perceived control and perceived control.In the second phase,the subjects were told in advance that the indoor temperature could not be adjusted.In the third phase,subjects were told that they could adjust the indoor temperature to meet their own thermal expectations,but the indoor temperature could not actually be changed.The results showed that the effect of perceived control on thermal sensation was related to the thermal expectation.For people with strong expectations for a neutral environment,perceived control improved their thermal sensation by satisfying their thermal expectations.For people with low thermal expectations,perceived control reduced their thermal tolerance to the environment,eventually leading to thermal discomfort.These new findings provide more supports for the importance of psychological effects and a reference for the personal control of heating temperatures.
