scholarly journals Thermal Comfort-Based Personalized Models with Non-Intrusive Sensing Technique in Office Buildings

2019 ◽  
Vol 9 (9) ◽  
pp. 1768 ◽  
Author(s):  
Siliang Lu ◽  
Weilong Wang ◽  
Shihan Wang ◽  
Erica Cochran Hameen
Keyword(s):  
Surface Temperature ◽  
Skin Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Correlation Coefficients ◽  
Hvac Systems ◽  
Recall Score ◽  
Support Vector ◽  
Linear Kernel ◽  
Related Factors

Heating, ventilation and air-conditioning (HVAC) systems play a key role in shaping the built environment. However, centralized HVAC systems cannot guarantee the provision of a comfortable thermal environment for everyone. Therefore, a personalized HVAC system that aims to adapt thermal preferences has drawn much more attention. Meanwhile, occupant-related factors like skin temperature have not had standardized measurement methods. Therefore, this paper proposes to use infrared thermography to develop individual thermal models to predict thermal sensations using three different feature sets with the random forest (RF) and support vector machine (SVM). The results have shown the correlation coefficients between clothing surface temperature and thermal sensation are 11% and 3% higher than those between skin temperature and thermal sensation of two subjects, respectively. With cross-validation, SVM with a linear kernel and penalty number of 1, as well as RF with 50 trees and the maximum tree depth of 3 were selected as the model configurations. As a result, the model trained with the feature set, consisting of indoor air temperature, relative humidity, skin temperature and clothing surface temperature, and with linear kernel SVM has achieved 100% recall score on test data of female subjects and 95% recall score on that of male subjects.

Study on Thermal Environment of Direct Gain Solar and Heating Rooms

2013 ◽  
Vol 291-294 ◽  
pp. 1101-1106
Author(s):  
Lin Bo Chen ◽  
Jia Ping Liu ◽  
Wei Hua Zhang
Keyword(s):  
Relative Humidity ◽  
Surface Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Human Action ◽  
The South ◽  
The North ◽  
Inner Surface ◽  
Indoor And Outdoor

The indoor thermal environment usually is measured in the condition of heating or cooling. This paper studies the thermal environment in direct gain solar and heating rooms. The indoor and outdoor temperature and relative humidity, inner surface temperature, human action, and times of opening door per day, are field tested and analyzed. PMV index is used to evaluate thermal environment. The results show that the relative humidity in direct gain solar and heating rooms is too low to comfortable. The curtain from closed to open, the window inner surface temperature decreases 13.9 °C in north orientation room, and decrease 10.3 °C in south orientation room. The indoor air temperature, relative humidity and inner surface temperature at the height of 1.5 m change a little by normal opening door. Thermal environment evaluation proves that in cloudy day, north orientation room is more comfortable than the south orientation room, while in sunny day, their difference of thermal sensation decreases. So we suggest that in order to keep thermal comfort, the curtain should be closed on the condition of no solar energy, the relative humidity should be designed during heating design, and the facing correction factors should be revised, so that the south orientation room is comfort in cloudy day. For energy conservation, the north exterior window should be smaller than the south exterior window.

The effects of firefighting boots and personal protective equipment load on foot thermal comfort

2021 ◽  
pp. 004051752110265
Author(s):  
Miao Tian ◽  
Xianghui Zhang ◽  
Xumei Tang
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Personal Protective Equipment ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Whole Body ◽  
Protective Equipment ◽  
Human Foot ◽  
Physiological Variables ◽  
Psychological Scales

Maintaining foot comfort is important as it influences the overall comfort of the human body. Shoe microclimate and foot skin temperature have been suggested to contribute to the thermal sensation of the foot. Considering the thermal environment and personal protective equipment (PPE) used for structural and proximity firefighting, climatic chamber tests with 13 male participants were conducted during standing and walking. Four test conditions – unloaded with training shoes, loaded with training shoes, unloaded with firefighting boots, and loaded with firefighting boots – were designed to investigate the effects of firefighting boots and PPE load on the thermal comfort of the human foot. Physiological variables of in-shoe and foot skin temperature at the whole and local regions of the foot were measured and subjective responses were gathered using psychological scales. The results showed that wearing firefighting boots may elevate the thermal sensation of wearers. The PPE load increased the in-shoe and foot skin temperature as well as subjective ratings. Subjective sensations of the foot were strongly correlated with in-shoe and skin temperature in the plantar regions. Correlation analysis of thermal sensation at the whole and local foot regions indicated that the sensation at the forefoot was closest to the whole foot, followed by the midfoot and heel. The findings address the relationship of physiological and subjective variables as well as the thermal sensation of whole and local foot regions, which can be considered for footwear design and thermal comfort prediction of the foot and whole body.

scholarly journals Assessment of Thermal Environment in a Kitchen with a New Ventilation System

2019 ◽  
Vol 111 ◽  
pp. 02034 ◽  
Author(s):  
Sumei Liu ◽  
Xiaojie Zhou ◽  
Xuan Liu ◽  
Xiaorui Lin ◽  
Ke Qing ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Great Influence ◽  
Comfort Level ◽  
Whole Body ◽  
Body Parts

Chinese kitchen environment is usually hot and humid in summer and cold in winter, while housewife spends considerable time there. This investigation developed a new ventilation system for Chinese kitchens to improve thermal comfort level. To assess the thermal performance of the ventilation system, 32 cooks were asked to prepare the same dishes in the kitchen with or without the system in summer in Changsha, China. The assessment was carried out by subjective questionnaire survey on thermal sensation vote (TSV) and objective on-site measurements of the indoor air temperature and cook’s skin temperature. The indoor air temperature was measured at different locations in the kitchen. The skin temperature was measured at 18 body parts of the cooks. The results show that the thermal environment in the kitchen was non-uniform and local thermal sensation had a great influence on the whole body sensation. Without the new ventilation system, the cooks complained that the hottest parts were thorax, head and face areas. Reasonably good correlation existed between the cooks’ skin temperatures and their thermal sensation votes. The increase of cooks’ skin temperature with the ventilation system was lower than that without the ventilation system. TSV was improved with the new ventilation system.

Study on Thermal Environment of Sports Field in Different Materials

2013 ◽  
Vol 361-363 ◽  
pp. 538-541
Author(s):  
Yong Qiang Xiao ◽  
Ying Xue Cao
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Early Summer ◽  
Artificial Turf ◽  
Environmental Characteristics ◽  
Thermal Discomfort ◽  
Instrumental Measurement ◽  
Cooling Methods

Natural lawn and artificial turf, which have a great difference on practical function and thermal environment characteristics, are widely used in sports field. In order to obtain the quantitative differences on thermal environment in summer, instrumental measurement and questionnaires are used in this paper to investigate the thermal environmental characteristics of natural lawn and artificial turf, respectively. Meanwhile human thermal sensation in the two lawns was also evaluated. The results show that the foliar surface temperature and mean air temperature in artificial turf is significantly higher than that of natural lawn in early summer. Due to thermal discomfort and the potential hurt for athletes on artificial turf field, cooling methods such as sprinkle are recommended.

scholarly journals Estimating Water Vapor Using Signals from Microwave Links below 25 GHz

2021 ◽  
Vol 13 (8) ◽  
pp. 1409
Author(s):  
Kun Song ◽  
Xichuan Liu ◽  
Taichang Gao ◽  
Peng Zhang
Keyword(s):  
Water Vapor ◽  
Weather Forecasting ◽  
Water Cycle ◽  
Correlation Coefficients ◽  
Support Vector ◽  
Vapor Density ◽  
Measurement Resolution ◽  
Sensing Model ◽  
Numerical Weather Forecasting ◽  
Mean Square Errors

Water vapor is a key element in both the greenhouse effect and the water cycle. However, water vapor has not been well studied due to the limitations of conventional monitoring instruments. Recently, estimating rain rate by the rain-induced attenuation of commercial microwave links (MLs) has been proven to be a feasible method. Similar to rainfall, water vapor also attenuates the energy of MLs. Thus, MLs also have the potential of estimating water vapor. This study proposes a method to estimate water vapor density by using the received signal level (RSL) of MLs at 15, 18, and 23 GHz, which is the first attempt to estimate water vapor by MLs below 20 GHz. This method trains a sensing model with prior RSL data and water vapor density by the support vector machine, and the model can directly estimate the water vapor density from the RSLs without preprocessing. The results show that the measurement resolution of the proposed method is less than 1 g/m3. The correlation coefficients between automatic weather stations and MLs range from 0.72 to 0.81, and the root mean square errors range from 1.57 to 2.31 g/m3. With the large availability of signal measurements from communications operators, this method has the potential of providing refined data on water vapor density, which can contribute to research on the atmospheric boundary layer and numerical weather forecasting.

scholarly journals Workflow to build a continuous static elastic moduli profile from the drilling data using artificial intelligence techniques

2021 ◽  
Author(s):  
Osama Siddig ◽  
Salaheldin Elkatatny
Keyword(s):  
Young’S Modulus ◽  
Elastic Moduli ◽  
Young's Modulus ◽  
Correlation Coefficients ◽  
Wellbore Stability ◽  
Machine Learning Techniques ◽  
Support Vector ◽  
Ann Model ◽  
Weight On Bit ◽  
Data Points

AbstractRock mechanical properties play a crucial role in fracturing design, wellbore stability and in situ stresses estimation. Conventionally, there are two ways to estimate Young’s modulus, either by conducting compressional tests on core plug samples or by calculating it from well log parameters. The first method is costly, time-consuming and does not provide a continuous profile. In contrast, the second method provides a continuous profile, however, it requires the availability of acoustic velocities and usually gives estimations that differ from the experimental ones. In this paper, a different approach is proposed based on the drilling operational data such as weight on bit and penetration rate. To investigate this approach, two machine learning techniques were used, artificial neural network (ANN) and support vector machine (SVM). A total of 2288 data points were employed to develop the model, while another 1667 hidden data points were used later to validate the built models. These data cover different types of formations carbonate, sandstone and shale. The two methods used yielded a good match between the measured and predicted Young’s modulus with correlation coefficients above 0.90, and average absolute percentage errors were less than 15%. For instance, the correlation coefficients for ANN ranged between 0.92 and 0.97 for the training and testing data, respectively. A new empirical correlation was developed based on the optimized ANN model that can be used with different datasets. According to these results, the estimation of elastic moduli from drilling parameters is promising and this approach could be investigated for other rock mechanical parameters.

Toe Temperatures During Dartmoor Training

1988 ◽  
Vol 74 (3) ◽  
pp. 181-186
Author(s):  
S. P. L. Travis
Keyword(s):  
Surface Temperature ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Air Temperature ◽  
Factors Associated ◽  
Recording Period ◽  
Exposure To Cold ◽  
Main Factors ◽  
Minimum Air Temperature

AbstractThe surface temperature of eight Royal Marine recruits was monitored in the field during Autumn training on Dartmoor (minimum air temperature 4.5°C). The lowest skin temperature recorded was 6.1°C. One subject experienced a toe temperature below 10° for 5.5 hours and below 15°C for 12.6 hours during a 24 hour recording period. Ambient temperature and inactivity during exposure to cold were the main factors associated with low toe temperatures but individual responses varied widely.

A Conformable Two-Dimensional Resistance Temperature Detector for Measuring Average Skin Temperature

2021 ◽  
Author(s):  
Laura Namisnak ◽  
Sepideh Khoshnevis ◽  
Kenneth R. Diller
Keyword(s):  
Surface Temperature ◽  
Skin Temperature ◽  
Infrared Thermography ◽  
Single Point ◽  
Wearable Sensors ◽  
Two Dimensional ◽  
Nonuniform Temperature ◽  
Resistance Temperature Detector ◽  
Temperature Detector ◽  
Average Skin

Abstract Various medical procedures are accomplished by manipulating skin temperature in a nonuniform pattern. Skin temperature monitoring is essential to assess conformance to protocol specifications and to prevent thermal injury. Existing solutions for skin temperature monitoring include single point sensors, such as thermocouples, and two-dimensional methods of sensing surface temperature, such as infrared thermography, and wearable technology. Single point sensors cannot detect the average temperature and consequently their measurements cannot be representative of average surface temperature in a nonuniform temperature field. Infrared thermography requires optical access, and wearable sensors may require complex manufacturing processes and impede the heat exchange with a source by introducing a layer of insulation. Our solution is a two-dimensional resistance temperature detector (2D RTD) created by knitting copper magnet wire into custom shapes. The 2D RTDs were calibrated, compared to one-dimensional sensors and wearable sensors, and analyzed for hysteresis, repeatability, and surface area conformation. Resistance and temperature were correlated with an R2 of 0.99. The 2D RTD proved to be a superior device for measuring average skin temperature exposed to a nonuniform temperature boundary in the absence of optical access such as when a full body thermal control garment is worn.

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