• 한국신뢰성학회지:신뢰성응용연구
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• 제13권3호
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• pp.207-216
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• 2013

This paper, we classified LED failure mechanisms that occur due to the delamination and analyzed each of the mechanism that gives the LED PKGs the effect. Usually, the LED is composed of several materials which are LED chips, gold wire, phosphor, epoxy resin, adhesive, reflector and lead frame. These different materials are usually delaminated in trouble conditions which are huge temperature difference, hot and humid or mechanical shocked. When the components are delaminated, a luminance will be lost and moisture be absorbed easily, a thermal resistance be increased attendantly. In this paper, we experimented to investigate failure mechanism of the thermal resistance and failure mechanism of the decrease of luminance that occur due to the delamination. A thermal shock test was performed to reproduce this phenomena by subjecting samples to a cold-hot cyclling process between $-30^{\circ}C$(15min) and $110^{\circ}C$(15min). The samples were inspected at 200, 600 and 1,000 cycles. We measured feature of LED using the spatial analyzer, optical microscope, thermal resistance, photometer, scanning electron microscope (SEM). As a result, the progression of the crack and the thermal resistance and decrease in luminance are proportional to number of thermal shock.

• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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• pp.1435-1441
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• 2017

Objective: The objective of this study was to determine the effect of adding water to total mixed ration (TMR) on fresh water intake, nutrient digestibility, wool cortisol, and blood indices in Corriedale ewes under hot and humid conditions. Methods: Nine non-pregnant Corriedale ewes (ave. body weight = $41{\pm}3.5kg$) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a triplicate $3{\times}3$ Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment, 27 replications). Treatments were TMR (crude protein [CP] = 16.1, total digestible nutrients = 69.1%) moisture levels for 40%, 50%, and 60%. Results: No differences were found in body weight gain among all treatment groups (p>0.05). Nitrogen balance including digestible N, retained N, and urinary and fecal N showed no change among the treatment groups (p>0.05). Fresh water intake was the lower in 50% TMR moisture group than in the other groups (p<0.05). Other than ether extract which was higher in 60% TMR moisture group (p<0.05) the differences among nutrient digestibilities including CP, organic matter, dry matter, neutral detergent fiber, acid detergent fiber, and non-fiber carbohydrate were not significant (p>0.05). No significant difference was observed for serum protein, blood urea nitrogen, glucose, and triglyceride among the treatment groups (p>0.05). Wool and blood cortisol were not different among the treatment groups (p>0.05). Blood hematology including red blood cell, white blood cells, hemoglobin, hematocrit, basophils, and eosinophils were not different among the treatment groups (p>0.05). Conclusion: It is concluded that TMR moisture at 40%, 50%, and 60% had no effects on N balance parameters, and nutrient digestibilities except for the ether extract under hot and humid conditions. Additionally there were no effects on stress conditions include wool cortisol, as well as blood cortisol levels of ewes.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.72-96
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• 1997

To investigate the difference of sweating reaction on somato types. We measured total sweat rate, locl sweat rate, skin temperature, physiological reactions and psyschological reactions at $25{\pm}1^{\circ}C$ and $25{\pm}1^{\circ}C$ under laboratory conditions. Nine healthy adult females were divided into three somato types (slender(3), normal(3) and obese type(3)). The results were as follows; Total sweat rate was highest in obese type, and then comes normal type and slender type in order. Local sweat rate was highest in infrascapular area, and then breast, the back of the hand, upperarm, ant. leg, and ant. thigh in order in all somato types. Mean skin temperature was highest in slender type, and then normal type and obese type in order. Rectal temperature, blood pressure and pulse rate were highest in boese type. Psychological reactions were appeared 'hot' 'humid' 'sweat' as ambient temperature go up. And somato types make little difference in psychological reactions.

• 설비공학논문집
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• 제10권4호
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• pp.381-388
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• 1998

Hot and humid weather in summer generally brings about discomfort. Experiments on which relative humidity makes effects on the comfort sensation were performed to the young and the aged using sensation vote. From July to October 1996, seven college students and eleven aged people were exposed for 2 hours under six different conditions in the Pukyong National University test chamber so as to determine the effects of relative humidity on thermal and comfort sensations. Subjects were wearing same clothes, and the mean clo value was 0.5. The mean radiant temperature was equal to the air temperature and air velocity in the occupied zone around 0.lm/s. In the experiments, it was found that discomfort could be largely reduced when the humidity is controlled to low values in the settled high temperature.

• 패션비즈니스
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• 제3권1호
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• pp.125-137
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• 1999

The present study aims to reveal the sweating reaction of male adults, focused on athletes. With six subjects (3 athletes and 3 non-athletes) in two different conditions of ambient temperature (I : $25\pm1.0^{\circ}C$, II : $29.5\pm1.0^{\circ}C$), their total sweat rate, local sweat rate, skin temperature, physiological reaction (rectal temperature, blood pressure, and pulse rate), and psychological reaction (thermal, moisture, comfort, and perceptive sweat sensations) were measured. The comparison gave the following results: Total sweating rate was greater in non-athletes, while the two groups had more perspiration in ambience II. Local sweating rate in both ambiences was the greatest in the central breast area (athletes) and the infrascapular area (non-athletes). The mean skin temperature had more changes of increase and decrease in athletes. As to physiological reaction, non-athletes had lower rectal temperature and blood pressure as well as higher pulse rate. As for psychological reaction in Ambience II, the 4 sensations were mostly 'hot', 'humid', 'uncomfortable', and 'sweaty'.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.1-6
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• 1996

Cellulose fiber reinforced cement composites manufactured by the slurry-dewatering process have found broad applications in thin cement products as replacement for asbestos cement. This paper focuses on the durability characteristics of these composites under different aging conditions. The effects of wetting-drying and freezing-thaw cycles, carbonation, and exposure to hot and humid environments on the structure and properties of cellulose fiber-cement composites were investigated. The predominant mechanisms of aging in the composites were identified through investigation of structure-property relationships. Measures to control these aging mechanisms were diversed and evaluated. Refined cellulose fiber-cement composites are shown to possess excellent durability characteristics under the effects of various aging processes.

• Asian-Australasian Journal of Animal Sciences
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• 제19권8호
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• pp.1111-1119
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• 2006

The aim of this study was to analyze post-weaning reproductive performance of Large White sows in relation to season, parity and their lactation performance under tropical conditions in Guadeloupe (French West Indies, $16^{\circ}$ Lat. N, $61^{\circ}$ Long. W.). This work was based on data recorded in the experimental unit of INRA from January 1993 to December 2003. Two seasons were determined a posteriori from climatic parameters recorded continuously in a station close to the experimental unit. Mean ambient temperature was higher during the hot season than the warm season ($26^{\circ}C$ vs. $24^{\circ}C$) but relative humidity was comparable for both seasons (i.e. 87% on average). Season had a significant effect on all reproductive parameters analyzed. Primiparous sows weaned in the hot season had a higher probability of a prolonged weaning to estrus interval, WEI (odds ratio was 4.1; p<0.01) but multiparous sows were not affected. A higher probability of a prolonged weaning to conception interval, WCI (odds ratio >2.5, p<0.01) and a lower subsequent farrowing rate (-10%, p<0.01) were found for sows weaned in the hot season. A higher daily feed intake during lactation reduced the probability of a prolonged WEI (p<0.05). Body weight and average back-fat thickness at farrowing affected WEI and WCI (p<0.05), whereas body weight and average backfat thickness change in lactation did not. This study confirms the negative effects of the hot season on primiparous reproductive performance. It also indicates that lactation performance influences sow non-productive period.

• Architectural research
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• 제25권4호
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• pp.73-84
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• 2023

Indoor thermal conditions greatly affect the health and comfort of humans who occupy the space in it. The purpose of this research is to analyze the influence of water and vegetation elements as a microclimate modifier in buildings to obtain thermal comfort through the study of thermal environment models. This research covers two objects, namely public buildings and housing in Makassar City, South Sulawesi Prov-ince - Indonesia. Quantitative methods through field surveys and measurements based on thermal and personal variables. Data analysis based on ASHRAE 55 2020 standard. The data was processed with a parametric statistical approach and then simulated with the Computational Fluid Dynamics (CFD) simulation method to find a thermal prediction model. The model was made by increasing the ventilation area by 2.0 m2, adding 10% vegetation with shade plant characteristics, moving water features in the form of fountains and increasing the pool area by 15% to obtain PMV + 0.23, PPD + 8%, TSV-1 - +0, Ta_25.7℃, and relative humidity 63.5 - 66%. The evaluation shows that the operating temperature can analyze the visitor's comfort temperature range of >80% and comply with the ASHRAE 55-2020 standard. It is concluded that water elements and indoor vegetation can be microclimate modifiers in buildings to create desired comfort conditions and adaptive con-trols in buildings such as the arrangement of water elements and vegetation and ventilation systems to provide passive cooling effects in buildings.

• 한국작물학회지
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• 제38권2호
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• pp.166-173
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• 1993

하대두는 추대두에 비하여 생육특성상 고온다습의 조건에서 성숙하는 관계로 미이라병의 종자감염이 높아 적정입모를 확보하기 위해서는 종자소독의 필요성이 요구된다. 따라서 본 시험은 입중을 달리한 하대두 계통에서 종자소독에 의한 입모율 향상이 후기생육 및 수양에 미치는 영향과 미이라병의 감염정도에 따른 종자소독제의 처리효과를 구명코자 하였다. 1. 입중을 달리한 하대두 계통에 종자소독제를 분의 처리하여 파종하면 무처리에 비하여 발아율이 향상되었고 배축장이 길었으며 약제처리의 약효는 대립종에서 높고 소립종에에서 낮은 경향이였다. 2. 종자소독제를 처리했을때 후기생육, 주당엽수, 백립중 및 수양은 무처리와 비교하여 큰 차이가 없었다. 3. 동일품종내에서 미이라병의 가시적 감염증세가 경미하면 종자소독제의 처리효과는 적었고 심할수록 약제처리에 의하여 발아율과 발아세가 현저히 향상되었는데 그 정도는 대립종에서 높았다.

• 한국가금학회지
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• 제48권2호
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• pp.59-67
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• 2021

This study investigated the morphological features, growth, and meat yield performance of Pekin (P), Nageswari (N), and their reciprocal F₁ crossbreds (P♂×N♀ and N♂×P♀). A total of 301-day-old ducklings were reared in four different pens up to 20 weeks of age under intensive management conditions. Feeding and management practices were similar for all individuals throughout the experimental period. The morphology and plumage pattern of F₁ crossbreds were similar to those of indigenous Nageswari ducks because of the dominant inheritance of the extended Black allele (E locus). Genotype had significant differences (P<0.05) among the four genotypes in morphometric measurements, except wing and shank length. Growth performance was highly significant among the four genotypes (P<0.001) from one-day to 12 weeks of age. The average live weights of P, N, P♂×N♀ and N♂×P♀ crossbred genotypes at 12 weeks of age were 2038.35±29.74, 1542.44±33.61, 1851.85±28.59 and 1691.08±27.80 g, respectively. Meat yield parameters varied significantly (P<0.05) among the different genotypes for all studied traits, except for liver and gizzard weight. Moreover, no significant differences (P>0.05) were observed between P and P♂×N♀ crossbred for important meat yield traits such as hot carcass weight, dressing%, back half weight, drumstick with thigh weight and breast meat weight. Remarkably, the P♂×N♀ crossbreed possesses 50% native inheritance, which contributes to better adaptation in a hot-humid environment. Our results revealed that the P♂×N♀ genotype could be suitable for higher meat production with better adaptability in the agro-climatic conditions of Bangladesh.