scholarly journals Experimental Study of Thermal Comfort Based on Driver Physiological Signals in Cooling Mode under Summer Conditions

2021 ◽  
Vol 11 (2) ◽  
pp. 845
Author(s):  
Yunchan Shin ◽  
Jeonggyun Ham ◽  
Honghyun Cho
Keyword(s):  
Thermal Comfort ◽  
Stress Index ◽  
Total Power ◽  
Cooling Mode ◽  
Left Hand ◽  
Temperature Conditions ◽  
Air Temperatures ◽  
Cabin Temperature ◽  
Cooling Function ◽  
Electroencephalogram Eeg

In this study, electroencephalogram (EEG), photo-plethysmography (PPG), and surface temperature measurements of subjects were taken while performing a driving simulation when the cabin and vent discharge air temperature in summer were changed from discomfort to comfort conditions. Additionally, subjective questionnaires were used to analyze the subject’s thermal comfort under the various driving environments. As a result, the surface temperatures of the forehead, left hand, right hand, and abdomen of the subject during driving were reduced by 2, 0.97, 2.18, and 5.86 °C, respectively, by operating a 12.5 °C vent cooling function at a cabin temperature of 35 °C. As a comprehensive analysis of the subjective survey, PPG, and EEG results, total power (TP), the standard deviation of N-N interval (SDNN), and the root mean square of successive differences (RMSSD) of subjects increased and stress index decreased at cabin and vent discharge air temperatures of 30–27.5 °C and 16.5–18.5 °C, respectively. Furthermore, the relative sensory motor rhythm (SMR) wave and concentration index (CI) of the frontal lobe tended to increase under the same temperature conditions. Accordingly, it was confirmed that these temperature conditions provided a pleasant driving environment for the driver and increased concentration on driving.

scholarly journals Measuring thermal comfort in a built environment: A case study in a Central Business District, Jakarta

2021 ◽  
Vol 918 (1) ◽  
pp. 012024
Author(s):  
N A Putri ◽  
R Hermawan ◽  
L Karlinasari
Keyword(s):  
Built Environment ◽  
Thermal Comfort ◽  
Open Space ◽  
Positive Impact ◽  
Central Business District ◽  
High Humidity ◽  
Open Spaces ◽  
Temperature Conditions ◽  
Air Temperatures ◽  
Business District

Abstract It is obvious that an increase in the built environment in many major cities is not balanced with the availability of green open space causing environmental problems such as an increase in accumulative city temperature (e.g., urban heat island). Therefore, many initiatives have been implemented to integrate more green open spaces in an effort to deal with increasing air temperatures in cities, but baseline information on the positive impact on the built environment is still lacking. The objective of this study was to identify thermal comfort in green open spaces and built environments in a central business district. Basic microclimate variables and thermal humidity index (THI) were analyzed in three sites representing the district by also considering the distribution of green open spaces, buildings, and traffics. Results showed that in the morning, the average temperature at the three sampling points have a low temperature (T=27.77-28.50°C) with high humidity (RH=77.21-80.97%) and the THI value is quite comfortable (THI=26.72-27.22°C), while during the daytime, the temperature conditions at the three sites have high temperatures (T=31.37-33.04°C) with low humidity (RH=63.30-65.80%) and high THI values (THI=29.22-30.62°C). In the afternoon, the temperature conditions at the three sample points have a high enough temperature (T=29.70-30.61°C) and high humidity (RH=67.36-71.02%), while the THI value is only in point two, which is close to the quite comfortable category (THI=27.98°C), while other locations have a value THI=28.60°C and 28.62°C. The results of this study mark the presence of green open space with the trees in the district has a positive effect on decreasing air temperature and hence increasing environmental comfort. The addition and enrichment of trees can be done to increase thermal comfort in the built environment.

scholarly journals Research on vehicle cabin temperature and thermal comfort optimal control based on fuzzy PID

2021 ◽  
Vol 1865 (3) ◽  
pp. 032039
Author(s):  
Changhao Piao ◽  
Weiwei Wang ◽  
Ziyang Liu ◽  
Cunxue Wu ◽  
Rongdi Yuan
Keyword(s):  
Optimal Control ◽  
Thermal Comfort ◽  
Fuzzy Pid ◽  
Vehicle Cabin ◽  
Cabin Temperature

scholarly journals Analysis of EEG, Cardiac Activity Status, and Thermal Comfort According to the Type of Cooling Seat during Rest in Indoor Temperature

2020 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
Yunchan Shin ◽  
Minjung Lee ◽  
Honghyun Cho
Keyword(s):  
Thermal Comfort ◽  
Human Body ◽  
Cold Water ◽  
Cardiac Activity ◽  
Satisfaction Level ◽  
Water Cooling ◽  
Indoor Temperature ◽  
Sensorimotor Rhythm ◽  
Electroencephalogram Eeg ◽  
Wave Reduction

In this study, electroencephalogram (EEG) and cardiac activity status of the human body while using various types of seats during rest were analyzed in indoor summer conditions. Thermal comfort was also evaluated through a subjective survey. The EEG, cardiac activity status, and subjective survey during rest indicated that the use of ventilation and cold water-cooling seats was effective. This effectiveness was because of the θ-wave and α-wave activation, sensorimotor rhythm, β-wave reduction, and left hemisphere activation, demonstrating that the conditions applied were suitable for rest. According to the analysis of the subjective questionnaire survey, the use of ventilation and cold water-cooling seats provided a more pleasant state than the basic seat, improving the subject’s warmth and comfort, and also the concentration. In addition, the use of a cold water-cooling seat provided the highest satisfaction level, being the most favorable condition for rest.

STATE OF AUTONOMIC REGULATION OF HEART RHYTHM IN YOUNG AND AGED RATS BEFORE AND AFTER APPLICATION OF DIFFERENT REGIMENS OF RHYTHMIC EXTREME COOLING

2020 ◽  
pp. 436-443
Author(s):  
В. В. Кулик ◽  
В. Г. Бабийчук
Keyword(s):  
Heart Rate ◽  
Metabolic Regulation ◽  
Experimental Studies ◽  
Autonomic Regulation ◽  
The Body ◽  
Total Power ◽  
Aged Rats ◽  
Cooling Mode ◽  
Adaptive Capabilities ◽  
Extreme Cold

В работе изучено влияние разных режимов ритмических экстремальных холодовых воздействий на состояние вегетативной регуляции сердечного ритма у молодых и старых крыс. По данным спектрального анализа вариабельности сердечного ритма установлено, что у молодых крыс использование температурных режимов ритмических экстремальных холодовых воздействий, РЭХВ (-120 °С; -120 °С; -120 °С) и (-60 °С; -120 °С; -120 °С) значительно повышало адаптационные возможности организма за счет активации собственных гомеостатических регуляторных систем. При этом комбинированный режим РЭХВ (-60 °С; -120 °С; -120 °С) оказался наиболее оптимальным для старых животных, поскольку его применение не сопровождалось чрезмерной активацией симпатико-адреналовой системы на ранних этапах экспериментальных исследований в отличие от режима (-120 °С; -120 °С; -120 °С). Кроме того, использование данного режима охлаждения способствовало статистически значимому увеличению показателей общей мощности спектра нейрогуморальной регуляции не столько за счет повышения активности гуморально-метаболического звена регуляции, преобладание которого характерно для пожилого возраста, сколько благодаря увеличению тонуса вегетативных центров, причем парасимпатические влияния на миокард превалировали над симпатическими. The influence of various rhythmic extreme cold effects on the state of autonomic regulation of heart rate in young and aged rats was studied. According to the spectral analysis of heart rate variability, it has been found that in young rats, using rhythmic extreme cold exposures (RECE) temperature regimens of (-120 °С; -120 °С; -120 °С) and (-60 °С; -120 °С; -120 °С) significantly increased adaptive capabilities of the body due to the activation of its own homeostatic regulatory systems. At the same time, the combined regimen of RECE (-60 °С; -120 °С; -120 °С) occurred to be the most optimal for aged animals, since its use was not accompanied with an excessive activation of sympathoadrenal system at the early stages of experimental studies, in contrast to the regimen (-120 °С; -120 °С; -120 °С). In addition, the use of this cooling mode contributed to a statistically significant increase in the total power of spectrum of neurohumoral regulation not so much due to a rise in activity of humoral-metabolic regulation link, the prevalence of which is characteristic of an old age, but due to an increase in the tone of vegetative centers, herewith the parasympathetic effects on the myocardium prevailed sympathetic ones.

scholarly journals The Street Air Warming Phenomenon in a High-Rise Compact City

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 402 ◽  
Author(s):  
Xiaoxue Wang ◽  
Yuguo Li ◽  
Xinyan Yang ◽  
Pak Chan ◽  
Janet Nichol ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Urban Climate ◽  
Pollutant Dispersion ◽  
Urban Morphology ◽  
Air Temperatures ◽  
Significant Difference ◽  
Sensitivity Studies ◽  
Weather Stations

The street thermal environment is important for thermal comfort, urban climate and pollutant dispersion. A 24-h vehicle traverse study was conducted over the Kowloon Peninsula of Hong Kong in summer, with each measurement period consisting of 2–3 full days. The data covered a total of 158 loops in 198 h along the route on sunny days. The measured data were averaged by three methods (direct average, FFT filter and interpolated by the piecewise cubic Hermite interpolation). The average street air temperatures were found to be 1–3 °C higher than those recorded at nearby fixed weather stations. The street warming phenomenon observed in the study has substantial implications as usually urban heat island (UHI) intensity is estimated from measurement at fixed weather stations, and therefore the UHI intensity in the built areas of the city may have been underestimated. This significant difference is of interest for studies on outdoor air temperature, thermal comfort, urban environment and pollutant dispersion. The differences were simulated by an improved one-dimensional temperature model (ZERO-CAT) using different urban morphology parameters. The model can correct the underestimation of street air temperature. Further sensitivity studies show that the building arrangement in the daytime and nighttime plays different roles for air temperature in the street. City designers can choose different parameters based on their purpose.

scholarly journals The Connection between Architectural Elements and Adaptive Thermal Comfort of Tropical Vernacular Houses in Mountain and Beach Locations

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7427
Author(s):  
Hermawan Hermawan ◽  
Jozef Švajlenka
Keyword(s):  
Thermal Comfort ◽  
Mixed Method ◽  
Rainy Season ◽  
Qualitative Methodology ◽  
Dry Season ◽  
Architectural Elements ◽  
Air Temperatures ◽  
Adaptive Thermal Comfort ◽  
Architectural Features ◽  
Study Results

Passive thermal comfort has been widely used to test the thermal performance of a building. The science of active thermal comfort is important to be connected with the science of architecture. The currently developing active thermal comfort is adaptive thermal comfort. Vernacular houses are believed to be able to create thermal comfort for the inhabitants. The present study seeks to analyze the connection between the architectural elements of vernacular houses and adaptive thermal comfort. A mixed method was applied. A quantitative approach was used in the measurement of variables of climate, while a qualitative methodology was employed in an interview on thermal sensations. The connection between architectural elements and adaptive thermal comfort was analyzed by considering the correlation among architectural features, the analysis results of thermal comfort, and the Olgyay and psychrometric diagrams. At the beginning of the rainy season, residents of exposed stone houses had the highest comfortable percentage of 31%. In the middle of the rainy season, the highest percentage of comfort was obtained by residents of exposed brick and wooden houses on the beach at 39%. The lowest comfortable percentage experienced by residents of exposed stone houses at the beginning of the dry season was 0%. The beginning of the dry season in mountainous areas has air temperatures that are too low, making residents uncomfortable. The study results demonstrate that adaptive thermal comfort is related to using a room for adaptation to create thermal comfort for the inhabitants.

scholarly journals Temperature conditions in the RBMK spent fuel pool in the event of disturbances in its cooling mode

2021 ◽  
Vol 7 (1) ◽  
pp. 9-13
Author(s):  
David A. Hakobyan ◽  
Victor I. Slobodchuk
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Maximum Temperature ◽  
Spent Fuel ◽  
Cooling Mode ◽  
Temperature Conditions ◽  
Fuel Assemblies ◽  
Spent Fuel Pool

The problems of reprocessing and long-term storage of spent nuclear fuel (SNF) at nuclear power plants with RBMK reactors have not been fully resolved so far. For this reason, nuclear power plants are forced to search for new options for the disposal of spent fuel, which can provide at least temporary SNF storage. One of the possible solutions to this problem is to switch to compacted SNF storage in reactor spent fuel pools (SFPs). As the number of spent fuel assemblies (SFAs) in SFPs increases, a greater amount of heat is released. In addition, no less important is the fact that a place for emergency FA discharging should be provided in SFPs. The paper presents the results of a numerical simulation of the temperature conditions in SFPs both for compacted SNF storage and for emergency FA discharging. Several types of disturbances in normal SFP cooling mode are considered, including partial loss of cooling water and exposure of SFAs. The simulation was performed using the ANSYS CFX software tool. Estimates were made of the time for heating water to the boiling point, as well as the time for heating the cladding of the fuel elements to a temperature of 650 °С. The most critical conditions are observed in the emergency FA discharging compartment. The results obtained make it possible to estimate the time that the personnel have to restore normal cooling mode of the spent fuel pool until the maximum temperature for water and spent fuel assemblies is reached.

Applying the Passivhaus standard to a terraced house in a hot and humid tropical climate – Evaluation of comfort and energy performance

2020 ◽  
Vol 41 (3) ◽  
pp. 247-260
Author(s):  
Roy Candra Sigalingging ◽  
David Chow ◽  
Steve Sharples
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Best Practice ◽  
Natural Ventilation ◽  
Tropical Climate ◽  
Energy Performance ◽  
Tropical Region ◽  
Humid Tropical Climate ◽  
Air Temperatures

In a hot and humid tropical climate, natural ventilation brings high levels of moisture into dwellings that, together with occupant activity, can result in very elevated internal relative humidity levels. Coupling these high relative humidities with high internal air temperatures creates occupant thermal discomfort, which is typically ameliorated in the tropics using energy-intensive air conditioning systems. This paper has investigated the potential benefits for thermal comfort and energy usage of applying the German Passivhaus standard to tropical dwellings. By creating a super insulated and air-tight envelope, the Passivhaus standard reduces fabric heat transfer, controls air infiltration and provides low-energy comfort. Applying this approach to a tropical terraced house might be effective but could, potentially, have an adverse impact on mechanical cooling demand. This study took an actual terraced property in Jakarta, Indonesia and thermally modelled its performance as insulation and airtightness levels were incrementally improved up to the Passivhaus standard. Field measurements in the dwelling of air temperature and relative humidity were used to validate the thermal model of the existing house. The validated model then tested the feasibility of meeting the Passivhaus energy standard for cooling in the modified tropical house. Simulation allowed the effects of air conditioning (AC) and dehumidifiers on thermal comfort and cooling loads to be investigated. The research develop the Passivhaus building model that had the floor insulation removed to let the ground floor act as a thermal sink and potentially provide radiant cooling. Analysis revealed that the building’s predicted air temperatures were affected in a beneficial way by having the Passivhaus without floor insulation. Practical application: Cooling in hot and humid tropical region is an energy-intensive approach. Design approaches that can bring comfort and save energy for the occupant are essential. The success of Passivhaus standard in mild climate might be transferable to bring comfort in tropical housing. Best practice can be developed by analysing the Passivhaus building performance in hot and humid tropical region.

scholarly journals The Cooling Effect of Large-Scale Urban Parks on Surrounding Area Thermal Comfort

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3904 ◽  
Author(s):  
Farshid Aram ◽  
Ebrahim Solgi ◽  
Ester Higueras García ◽  
Amir Mosavi ◽  
Annamária R. Várkonyi-Kóczy
Keyword(s):  
Thermal Comfort ◽  
Large Scale ◽  
Urban Parks ◽  
Cooling Effect ◽  
Urban Park ◽  
P Value ◽  
Cognitive State ◽  
Physiological Equivalent Temperature ◽  
Air Temperatures ◽  
Cooling Effects

This empirical study investigates large urban park cooling effects on the thermal comfort of occupants in the vicinity of the main central park, located in Madrid, Spain. Data were gathered during hot summer days, using mobile observations and a questionnaire. The results showed that the cooling effect of this urban park of 125 ha area at a distance of 150 m could reduce air temperatures by an average of 0.63 °C and 1.28 °C for distances of 380 m and 665 meters from the park. Moreover, the degree of the physiological equivalent temperature (PET) index at a distance of 150 meters from the park is on average 2 °C PET and 2.3 °C PET less compared to distances of 380 m and 665 m, respectively. Considering the distance from the park, the correlation between occupant perceived thermal comfort (PTC) and PET is inverse. That is, augmenting the distance from the park increases PET, while the extent of PTC reduces accordingly. The correlation between these two factors at the nearest and furthest distances from the park is meaningful (p-value < 0.05). The results also showed that large-scale urban parks generally play a significant part in creating a cognitive state of high-perceived thermal comfort spaces for residents.

scholarly journals Motor Imagery EEG Classification Using Capsule Networks

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2854 ◽  
Author(s):  
Kwon-Woo Ha ◽  
Jin-Woo Jeong
Keyword(s):  
Motor Imagery ◽  
Learning Approaches ◽  
Eeg Signals ◽  
Left Hand ◽  
Computer Interfaces ◽  
Conventional Machine ◽  
Short Time ◽  
Electroencephalogram Eeg ◽  
Target Data

Various convolutional neural network (CNN)-based approaches have been recently proposed to improve the performance of motor imagery based-brain-computer interfaces (BCIs). However, the classification accuracy of CNNs is compromised when target data are distorted. Specifically for motor imagery electroencephalogram (EEG), the measured signals, even from the same person, are not consistent and can be significantly distorted. To overcome these limitations, we propose to apply a capsule network (CapsNet) for learning various properties of EEG signals, thereby achieving better and more robust performance than previous CNN methods. The proposed CapsNet-based framework classifies the two-class motor imagery, namely right-hand and left-hand movements. The motor imagery EEG signals are first transformed into 2D images using the short-time Fourier transform (STFT) algorithm and then used for training and testing the capsule network. The performance of the proposed framework was evaluated on the BCI competition IV 2b dataset. The proposed framework outperformed state-of-the-art CNN-based methods and various conventional machine learning approaches. The experimental results demonstrate the feasibility of the proposed approach for classification of motor imagery EEG signals.

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