• Title/Summary/Keyword: Thermal discomfort

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A Comparative Analysis of Energy Simulation Results and Actual Energy Consumption on Super High-rise Apartments (초고층 공동주택의 세대별 냉난방부하 시뮬레이션 결과 및 에너지 실사용량과의 비교 분석)

  • Suh, Hye-Soo;Kim, Byung-Seo
    • Journal of the Korean Solar Energy Society
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    • v.31 no.4
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    • pp.34-40
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    • 2011
  • Apartment Housing has been increasing steadily, particularly our current super high-rise apartment houses that represent the culture has become a trend in Korea. These super high-rise apartment houses' curtain wall system increases heating and cooling loads, it is expected to vary by each unit's thermal properties. In this study, measured indoor environment and energy simulation results were compared to actual energy consumption. As a result, the various factors that affect heating and cooling loads, such as direction, plan type and glazing area, influence each unit's load characteristic. In particular, according to the electricity costs savings behavior, the occupant's thermal discomfort is expected to be large in summer. Therefore, to reduce heating and cooling load for each unit requires a reasonable plan.

A Study on a Heat-load of IT Equipments for the Thermal Environment Control in the Data Center (데이터센터의 합리적인 환경제어를 위한 장비 발열기준에 대한 연구)

  • Cho, Jin-Kyun;Hong, Min-Ho;Jeong, Cha-Su;Kim, Byung-Seon
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.938-943
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    • 2006
  • The primary purpose of a computer room of data center and associated infrastructure is to support the operation of critical IT equipment. Traditionally, most owners of large critical data centers have been more than willing to accept a reasonable amount of computer room worker discomfort if necessary to support critical IT systems. All electrical equipment produces heat, which must be removed to prevent the equipment temperature from rising to an unacceptable level. Most information technology equipment and other equipment found in a data center or network room is air-cooled. Sizing a cooling system requires an understanding of the amount of heat produced by the equipment contained in the enclosed space, along with the heat produced by the other heat sources typically encountered.

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An application to HVAC control system based on occupants' thermal response in office buildings (공조제어 적용을 위한 재실자 온열반응 데이터의 유효성 분석에 관한 연구)

  • Han, Hyesim;Kim, Jonghun;Jeong, Hakgeun;Jang, Cheol-Yong
    • KIEAE Journal
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    • v.14 no.4
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    • pp.111-117
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    • 2014
  • In South Korea, the government has recently enforced regulations associated with buildings. Temperature restriction in indoor environment is one of the common ways of energy reduction in order not to dissipate heating and cooling energy; however the people who are in restricted temperature feels uncomfortable. Furthermore, occupants cannot feel the same thermal sensation even they are in the same place. For the reason, occupants should express their thermal sensation and HVAC system should be able to apply their demand. It is proved by an adaptive principle. The adaptive model means that people react in ways which tend to restore their comfort, when change occurs such as to produce discomfort. In order to design HVAC control strategies based on adaptive model, we designated an existing office building as a reference building to gather data from actual field. Furthermore, we gathered occupants' thermal sensation and clothing insulation in real-time. We filtered the data with Kalman's filter method. The data was reasonable when there is an alarm messages for asking questionnaire. The response ratio were different in occupants' thermal condition. In conclusion, the filtered occupants' thermal sensation can be used as a real time HVAC control and input value of HVAC control.

Potential Efficacy of Multiple-shot Long-pulsed 1,064-nm Nd:YAG in Nonablative Skin Rejuvenation: A Pilot Study

  • Kim, Young-Koo;Lee, Hae-Jin;Kim, Jihee
    • Medical Lasers
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    • v.9 no.2
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    • pp.159-165
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    • 2020
  • Background and Objectives The ultimate goal in current skin rejuvenation practice is to achieve a good result with minimal pain and downtime. Nonablative skin rejuvenation (NSR) is one technique. The efficacy of the long-pulsed 1064 nm Nd:YAG laser (LPNDY) has not been assessed in NSR. Materials and Methods Three target areas were selected (bilateral cheeks and glabellar region) in six volunteer subjects. A LPNDY with an integral skin temperature monitor delivered three stacked shots to each target area (1064 nm, 12 mm spot, 13 J/cm2, 1 Hz) without any skin cooling or anesthesia. The skin temperature was recorded before, during, and after each set of shots using the system monitor and in real-time using a high-sensitivity (±0.001℃) near-infrared video camera. The skin reaction was observed with the naked eye, and pain and discomfort were assessed by the subjects during and after treatment. Results The subjects reported a mild feeling of heat with no discomfort during or after the test treatments. Mild erythema was observed around the treatment areas, without noticeable edema. A series of three ascending skin temperature stepwise peaks, with a decrease in skin temperature towards the baseline after the third shot, was observed consistently. The mean temperatures for shots 1, 2, and 3 for the cheeks were 39.5℃, 42.0℃, and 44.4℃, respectively, and for the glabella, 40.8℃, 43.9℃, and 46.2℃, respectively. Similar ranges were indicated on the system integral temperature monitor. Conclusion A set of three stacked pulses with the LPNDY at a low fluence achieved ideal dermal temperatures to achieve some dermal remodeling but without any downtime or adverse events. The temperature data from the integral thermal sensor matched the video camera measurements with practical accuracy for skin rejuvenation requirements. These data suggest that LPNDY would satisfy the necessary criteria to achieve effective NSR, but further studies will be needed to assess the actual results in clinical practice.

Mobility and Thermal Comfort Assessment of Personal Protective Equipment for Female Healthcare Workers: Impact of Protective Levels and Body Mass Index (감염병 대응 개인보호복의 동작성 및 열적 쾌적성: 보호 수준 및 여성 착용자 체격의 영향)

  • Do-Hee Kim;Youngmin Jun;Ho-Joon Lee;Gyeongri Kang;Cho-Eun Lee;Joo-Young Lee
    • Fashion & Textile Research Journal
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    • v.26 no.1
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    • pp.123-136
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    • 2024
  • This study aimed to assess the mobility and thermal comfort of personal protective equipment (PPE) among female healthcare workers, taking into account wearers' physique and PPE protection levels. A total of 16 participants (age: 26.3 ± 8.3 y, height: 161.5 ± 7.3 cm, body weight: 57.1 ± 11.0 kg, BMI: 21.9 ± 3.6), representing diverse body types, underwent four PPE conditions: L (Low_Plastic gown ensemble), M (Medium_Tyvek 400), H (High_Tyvek 800J with Powered Air Purifying Respirator [PAPR]), and E (Extremely high_Tychem 2000 with PAPR, Bib apron, and Chemical-resistant gloves). The mobility protocol consisted of 10 different tasks in addition to donning and doffing. The 10 tasks were repeated twice at an air temperature of 24.3 ± 0.1℃, 59±4%RH. Findings revealed a disproportionate relationship between PPE protection and wearer discomfort. Significant differences in clothing microclimate and total sweat rate were observed between the lowest (L) and highest (E) protection levels (p < 0.01), while distinctions among medium levels were inconclusive. Subjective evaluations favored conditions H and L over M and E (p < 0.05), indicating reduced heat, and humidity, increased comfort, and lower exertion. Instances of mobility discomfort, specially in the small body type group, underscored the need for a suitable PPE size system for Korean adult female medical workers. Furthermore, enhancements in gloves, shoe cover, and PAPR hood designs are essential for improving ease of movement and preventing hindrance.

Study of Summer Season High Temperature Events in Busan (부산지역의 하계 도시열환경의 특성에 관한 연구)

  • Lee, Kwi-Ok;Lee, Hyun-Ju;Lee, Hwa-Woon
    • Journal of Environmental Science International
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    • v.16 no.5
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    • pp.593-602
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    • 2007
  • The frequency of tropical nights and tropical days in Busan during summer season (June-August) from 1995 to 2004 were investigated. When air temperature higher than $25^{\circ}C$ continuously maintains at night in summer, it is called the occurrence of tropical night. Tropical day is defined that maximum air temperature is higher than $30^{\circ}C$, In Jin-Gu and Daeyeon-dong shows a lot of frequency of tropical day and tropical night because there were located in downtown. Relatively, the areas where are located in seaside and riverside show very low frequency. This can be explained the cooling effects of sea and river. The main meteorological characteristics during tropical nights and tropical days is proved pattern of reverse tendency through wind rose. We analyzed heat index and discomfort index during tropical night and tropical day. This study is useful to understand the aspect of urban thermal environment but need some more observation to quantify.

Rewarming Intervention Program for Abdominal Surgery Patients (복부 수술 환자의 저체온 예방 중재 프로그램)

  • Ahn, Hye-Young;Eom, Mi-Ran
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.17 no.2
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    • pp.220-230
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    • 2010
  • Purpose: This study was done to identify differences in three groups of operative patients (Forced Air Warming, Electrical Blanketrol, Control) for discomfort and pattern of body temperature during surgery and post operatively. Methods: The sample consisted of 3 randomized 3 groups of abdominal surgery patients admitted to an university hospital in D-city : The Bair Hugger and upper body blanket were used with the first group, electrical blanketrol with PVC Film with the second, and the third group was the control. ANOVA was used with the WIN SPSS 17.0 program to analyze the data. Results: Significant differences were found among the three groups for tympanic and esophageal body temperature at 1 hour after starting surgery. There was significant difference in tympanic body temperature during the 15 minute stay in the post anesthetic room. There were no significant differences in thermal discomfort while in the post anesthetic room. or There among the three groups for serum cortisol during surgery. Conclusion: According to the results of this study, application of a Bair Hugger or electrical blanketrol improves maintenance of body temperature of operative patients as well as body temperature of post operative patients, and is a clinically significant warming method providing a more consistent body temperature.

Evaluation of the Wear Comfort of Outdoorwear by Skin Wettedness Analyses (Skin Wettedness 분석을 통한 아웃도어웨어의 착용 쾌적성 평가)

  • Jeong, Jeong-Rim;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.11 no.6
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    • pp.947-952
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    • 2009
  • The purpose of this study is to analyze skin wettedness($w$) used as the rate index of thermal comfort, and to evaluate the wear comfort of outdoorwear. Skin wettedness is widely used to express the degree of thermal comfort. If skin wettedness exceeds a certain threshold, the body feels damp and discomfort. An experiment which consisted of rest(30 min), exercise(30 min) and recovery(20 min) periods was administered in a climate chamber with 10 healthy male participants. Two kinds of outdoorwears made of 100% cotton fabrics (Control) and specially engineered fabrics having feature of quick sweat absorbency and high speed drying fabric (Functional) were evaluated in the experiment. The condition of climate chamber was controlled according to the thermal insulation of 4 kinds of experimental ensembles(E1~E4). Total sweat loss, sweat loss absorbed into clothing and skin temperature were measured. Skin wettedness was calculated from the ratio of evaporative rate to the maximal evaporative capacity. Skin wettedness of 'Functional' was lower than 'Control' in the 3 kinds of ensembles(E1, E2, E4) because the materials of 'Functional' were composed of quick sweat absorbency and high speed drying fabrics, water vapour permeability and waterproof fabrics.

Thermographic assessment on temperature change of skin surface in frame fitting point (열화상 카메라를 활용한 frame fitting point의 표면 온도 분석)

  • Joo, Byung Hyuk;Park, Chang Won
    • Journal of Korean Clinical Health Science
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    • v.9 no.1
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    • pp.1462-1468
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    • 2021
  • Purpose; The purpose of this study is to objectively identify and quantify the wearer's feelings of wearing glasses. Methods: The temperature of the skin on the nose ridges and ear, and the area where the glasses were seated, was measured using a thermal imaging camera. Results: Before wearing the glasses, the temperature of the skin surface on the nasal ridge was 34.908 ± 0.875 ℃ and the temperature of the ear region was determined as 31.981 ± 0.549 ℃. The changed temperature measured at 5 minutes later after taking off the glasses showed that the nasal ridge was determined as 35.467 ± 0.342 ℃ and the ear area was determined as 32.994 ± 0.412 ℃ (p<0.05). Conclusions: In this experiment, it was revealed that the glasses cause discomfort and heat in the fitting area. It was the first attempt to study objectively and scientifically. Analysis of frame fitting points by using thermal camera is expected to be helpful when consulting a sensitive person about changes in the fit of glasses.

Framework for improving the prediction rate with respect to outdoor thermal comfort using machine learning

  • Jeong, Jaemin;Jeong, Jaewook;Lee, Minsu;Lee, Jaehyun
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.119-127
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    • 2022
  • Most of the construction works are conducted outdoors, so the construction workers are affected by weather conditions such as temperature, humidity, and wind velocity which can be evaluated the thermal comfort as environmental factors. In our previous researches, it was found that construction accidents are usually occurred in the discomfort ranges. The safety management, therefore, should be planned in consideration of the thermal comfort and measured by a specialized simulation tool. However, it is very complex, time-consuming, and difficult to model. To address this issue, this study is aimed to develop a framework of a prediction model for improving the prediction accuracy about outdoor thermal comfort considering environmental factors using machine learning algorithms with hyperparameter tuning. This study is done in four steps: i) Establishment of database, ii) Selection of variables to develop prediction model, iii) Development of prediction model; iv) Conducting of hyperparameter tuning. The tree type algorithm is used to develop the prediction model. The results of this study are as follows. First, considering three variables related to environmental factor, the prediction accuracy was 85.74%. Second, the prediction accuracy was 86.55% when considering four environmental factors. Third, after conducting hyperparameter tuning, the prediction accuracy was increased up to 87.28%. This study has several contributions. First, using this prediction model, the thermal comfort can be calculated easily and quickly. Second, using this prediction model, the safety management can be utilized to manage the construction accident considering weather conditions.

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