• Advances in Energy Research
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• v.5 no.4
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• pp.289-304
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• 2017

Large glazed surfaces and windows become common features in modern buildings. The spread of these features was influenced by the dependence of designers on mechanical and artificial systems to provide occupants with thermal and visual comfort. Countries with hot summer and cold winter conditions, like Jordan, require maximum shading from solar radiation in summer, and maximum exposure in winter to reduce cooling and heating loads respectively. The current research aims at designing optimized double-positioned external shading device systems that help to reduce energy consumption in buildings and provide thermal and visual comfort during both hot and cold seasons. Using energy plus, a whole building energy simulation program, and radiance, Lighting Simulation Tool, with DesignBuilder interface, a series of computer simulations for energy consumption and daylighting performance were conducted for offices with south, east, or west windows. The research was based on comparison to determine the best fit characteristics for two positions of adjustable horizontal louvers on south facade or vertical fins on east and west facades for summer and winter conditions. The adjustable shading systems can be applied for new or retrofitted office or housing buildings. The optimized shading devices for summer and winter positions helped to reduce the net annual energy consumption compared to a base case space with no shading device or with curtains and compared to fix shading devices.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.8
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• pp.1042-1050
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• 2003

A heating flow discharged from a 4-way ceiling type indoor unit has been investigated to determine the design parameters for the optimal flow control. The flow was measured by a PIV(particle image velocimetry) system and an experimental model of 1/10 scale with a transparent room was devised by satisfying the Archimedes number. This similarity is generally used in cases where the forced convection has similar magnitude of the natural convection. To optimize the heating flow, several vane angles and vane control algorithms of cross and right angle controls were considered. Regarding the vane angle, experimental results show that 30$^{\circ}$is an optimal angle to avoid re-suction flows without significant increase in flow noise. Temperature distribution measured in the environmental chamber ensures the increased thermal comfort when compared to the case, 60$^{\circ}$angle. At the optimal angle, applying open/close control gives rise to more uniform distribution of the heating flow than without control. Especially, the cross-control seems to be satisfactory for thermal comfort.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.153-159
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• 2014

This study evaluates the changes of the subjective hand, preference, comfort and mechanical properties of tricot based artificial suede made from sea-island type micro fibers according to raising condition. The subjective hand and the preference of raised suede for jacket were rated by the 20's and 30's women experts according to raising cycles. Comfort properties were evaluated by air permeability, water vapor transmission, and thermal transmission. Mechanical properties were measured by the KES-FB system. The subjective hand of artificial suede was categorized into three hand factors: smoothness, warmness and thickness. Smoothness, warmness and thickness perception increased with raising cycles which affected hand preference and luxuriousness perception. The thickness and wale density of suede increased with the number of raising. Suede became more compact and less pliable and less stretchable due to increased fabric thickness; in addition, the surface of suede became smoother and compressive since the surface evenness of suede improved with smaller fiber fineness and an increased amount of naps covered the base fabric. Furthermore, water vapor transmission decreased and thermal insulation increased. The best raising conditions for artificial suede was four cycles in which artificial suede was preferred without changes in physical properties.

• International Journal of Costume and Fashion
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• v.9 no.1
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• pp.34-43
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• 2009

This study compared the thermal comfort of indoor clothing from Tencel material that is getting higher in demand due to being eco-friendly with superior wettability, with that from Polyester material that despite being most widely used for indoor clothing, rapidly discharges body sweat due to low wettability. The experiments were performed in the two manners, objective evaluation under the conditions of an artificial climate chamber and subjective evaluation of wearing the given clothes at home followed by filling in the questionnaire. Subjects were 8 healthy elderly women in their 60's who spend majority of their time at home rather than in social activities, and comparison was made on skin temperature and humidity inside clothing at exercise and relaxation states under early summer environment. Based on these results, wearing Tencel material clothing maintained cooler temperatures under warm environment rather than when wearing Polyester material clothing, thus enabling activities under more comfortable state. Regarding humidity inside clothing, parts with twofold clothing did not show difference between Tencel and Polyester, but the onefold arm showed lower when wearing Tencel. With this results, Tencel is regarded as more comfortable and nicer than Polyester.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.3
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• pp.410-425
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• 1997

Buildings are mostly under part load conditions causing an inefficient system operation in terms of energy consumption. It is critical to operate building air-conditioning system with a scientific or optimal manner which minimizes energy consumption and maintains thermal comfort by matching building sensible and latent loads. Little research has been performed in developing general methodologies for the optimal operation of air-conditioning system. Based on this research motivation, system simulation program was developed by adopting various equipment operating strategies which are energy efficient especially for humidity control in summer. A numerical optimization technique was utilized to search optimal solution for multi-independent variables and then linked to the developed system simulation model within a mam program. The main goal of the study is to provide a systematic framework and guideline for the optimal operation of air-conditioning system focusing on air-side. For given cooling loads and ambient outdoor conditions the optimal operating strategies of a commercial building are determined by minimizing a constrained objective function by a nonlinear programming technique. Desired space setpoint conditions were found through evaluating the trade-offs between comfort and system power consumption. The results show that supply airflow rate and compressor fraction play main roles in the optimization process. It was found that variable setpoint optimization technique could produce lower indoor humidity level demanding less power consumption which will be benefits for building applications of humidity problem.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.513-522
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• 2010

The aim of this study is to investigate the actual state for the development of the thermally comfortable uniform for workers on a low temperature storage. Observation, interview and survey were executed focusing on the environment, clothing, and human factors which have effects on the comfort of workers. Of 400 distributed, 253 questionnaires were analyzed through descriptives, frequency, ANOVA, t-test, multi-response analysis, correlation analysis with SPSS 12.0. The results are following. Coming and going between a selling area and cold storages, the workers showed to experience a big temperature gap. They indicated to feel cold on face and hands which were not covered by clothing and have got sick because of low temperature. The workers wanted the uniform made of functional fabrics, especially heat insulation fabrics. Female workers rather than male workers, the older, and the longer their working period were, the more uncomfortable they revealed to feel. The workers who works on the daily products part or mainly on the freezer appeared to feel cold more than any other workers. In conclusion, it was found that the uniform which consider steady state and unsteady state heat transfer together must be developed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.11
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• pp.761-769
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• 2007

The purpose of this study is to present a simplified model of predicted mean vote (PMV) using multiple regression analysis. We performed the experiments and the numerical calculations in the lecture room during summer and winter to simplify PMV. And the multiple regression analysis on PMV was conducted to estimate the contribution of independent variables toward PMV. From the multiple regression analysis, we found that the effect of independent variables on PMV followed in order, clo value>air temperatur>air velocity>mean radiant temperature>relative humidity. And the simplified PMV was proposed through a few assumptions and then was compared with original PMV. They had a good agreement with each other. Additionally, we compared the simplified PMV with EDT. We expected that the simplified PMV can be more useful than EDT to evaluate the thermal comfort in the place, where radiation is dominant. But the comfort range of the simplified PMV should be adjusted to predict the exact thermal comfort in the future.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.261-266
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• 2015

This study was conducted to examine the effect of tree density of Pinus koraiensis forest on the thermal comfort and the physiological response of human body in summer season. As the indicators of thermal comfort were used the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), while the heart rate variability was used for the physiological indicator of subjects. The subjects were 15 physically healthy men and women in their 20s ($23.7{\pm}1.7$ years old). The subjects sat in each site to measure HRV for 5 minutes and the thermal comfort of each site was measured. As a results, it was proven by PMV and PPD that the Pinus koraiensis forest with 120% tree density was thermally more comfortable than the Pinus koraiensis forest with 80% tree density. In case of the subjects' physiological response, the Pinus koraiensis forest with 120% tree density showed significantly higher HF of HRV than the Pinus koraiensis forest with 80% tree density and significantly lower LF/HF. Therefore, the findings of this study scientifically proved that the Pinus koraiensis forest with 120% tree density is thermally more comfortable and physiologically more relaxing than the Pinus koraiensis forest with 80% tree density.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.21-22
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• 2003

여름철 더운환경과 냉방환경에서 안감소재별 6종의 원피스 드레스의 주관적 착용감을 평가한 결과, 안감소재에 따라 원피스 드레스의 주관적 착용감은 유의한 차이를 나타내어 고온환경에서는 레이온 안감이, 냉방환경에서는 아세테이트 안감의 착용감이 좋은 것으로 나타났다. 여름철 환경에서는 의복기후보다 주관적 착용감이 쾌적감에 더 큰 영향을 미치는 요인을 나타났다.

• Fashion & Textile Research Journal
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• v.2 no.3
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• pp.253-264
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• 2000

The purpose of this study was to examine the thermal comfort characteristics of the garments for school, textile and bank worker's uniform. The garments selected for this study were frequently used in Taegu area in terms of design and material used for making garments by the survey for the study The human subject tests were performed to determine the thermal comfort characteristics of garments including thermal, humidity, and wearing sensation and the data were analysed statistically. The results of the study were as follows: 1. According to the result of the survey jacket was mostly used as a school uniform for both male and female high school students. The survey showed that 93% of male students wore 'neck T-shirts' and dimensional fitness for the school uniform got suitable at 2~3 grade high school students. In terms of human subject tests, most students rated 'uncomfortable' in wearing sensation of their school uniform. One of this reason was due to the humidity sensation and air velocity sensation. Level of significance of the thermal sensation for gender difference was higher in hands and feet of the subjects than in chest and thigh of them. 2. According to the result of the survey jacket with zipper was mostly used as a textile worker's uniform. The result of the survey indicated that some textile workers are wearing their inner wear (38.7% for upper and 46.6% for lower). In the human subject tests, about 50% of subjects rated 'comfortable to slightly comfortable' for wearing sensation of the textile worker's uniform. It showed that the female subjects of the humidity sensation was rated higher than the male subjects of the humidity sensation, while the male subjects of the thermal sensation was rated higher than the female subjects of the thermal sensation. There was a closer correlation with the subjective thermal sensation for textile worker's uniform in center parts of the subjects such as back and waist than exposed parts. 3. The result of the survey showed that 70% and 23% of the female banker uniform were blouse and jacket, respectively and 75% and 25% of the male banker uniform were jacket and T-shirt, respectively. All interviewee rated trousers and skirts that were used for their lower. 4. The result indicated that 50% male and 67.7% female subjects for the banker uniform rated 'slightly comfortable for the comfort' sensation. 50% male subjects rated 'neutral' and about 50% female subjects rated 'slightly warm to neutral' for the thermal sensation. In addition, The result showed that 75% male subjects for both upper and lower rated 'neutral' for the humidity sensation and also 75% female subjects rated 'neutral to slightly dry'. Thus, there was no significant different between gender. 5. In the thermal sensation of the subjects for the banker's uniform by parts, 50% subjects rated 'neutral' for their body parts, including head, neck, back, waist, hip, lower arm, and thigh. The extremely cold parts were hands and feet for both male and female subjects.