• 한국재료학회지
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• 제28권8호
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• pp.435-439
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• 2018

MA Al alloys are examined to determine the effects of alloying of Mg and Cu and rolling on tensile deformation behavior at 748 K over a wide strain rate range($10^{-4}-10^3/s$). A powder metallurgy aluminum alloy produced from mechanically alloyed pure Al powder exhibits only a small elongation-to-failure(${\varepsilon}_f$ < ~50%) in high temperature(748 K) tensile deformation at high strain rates(${\acute{\varepsilon}}=1-10^2/s$). ${\varepsilon}_f$ in MA Al-0.5~4.0Mg alloys increases slightly with Mg content(${\varepsilon}_f={\sim}140%$ at 4 mass%). Combined addition of Mg and Cu(MA Al-1.5%Mg-4.0%Cu) is very effective for the occurrence of superplasticity(${\varepsilon}_f$ > 500%). Warm-rolling(at 393-492 K) tends to raise ${\varepsilon}_f$. Lowering the rolling-temperature is effective for increasing the ductility. The effect is rather weak in MA pure Al and MA Al-Mg alloys, but much larger in the MA Al-1.5%Mg-4.0%Cu alloy. Additions of Mg and Cu and warm-rolling of the alloy cause a remarkable reduction in the logarithm of the peak flow stress at low strain rates (${\acute{\varepsilon}}$< ~1/s) and sharpening of microstructure and smoothening of grain boundaries. Additions of Mg and Cu make the strain rate sensitivity(the m value) larger at high strain rates, and the warm-rolling may make the grain boundary sliding easier with less cavitation. Grain boundary facets are observed on the fracture surface when ${\varepsilon}_f$ is large, indicating the operation of grain boundary sliding to a large extent during superplastic deformation.

• 한국제4기학회지
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• 제18권2호통권23호
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• pp.23-31
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• 2004

Temperature variations, and carbon dioxide and methane concentrations are summarized during the past 400,000 years. Atmospheric temperature varied approximately within $10^{\circ}C$ during the past 400,000 years. Most of the time during the past 400,000 years, temperature was lower than today except 410000, 320000, 250000, and 125000 years ago. Temperature was slightly higher or at least similar to today during the time period of 410000. 320000, 250000, and 125000 years ago. The carbon dioxide concentration varied between 180 and 300 ppm, and the methane concentration varied between 40 and 700ppb. The present atmospheric concentration of carbon dioxide is 375 ppm and methane is 1750 ppb. Temperature was 5-$7^{\circ}C$ lower than today during the Last Glacial Maximum(18,000 years ago) and the Younger Dryas(10,000 years ago). Temprature was varied within $1^{\circ}C$ during the past 10,000 years. Especially Middle Holocene Climatic Optimum(6,000 years ago), Medieval Warm Period (500-1,000 years ago), and Little Ice Age(100-500 year ago) were global climatic events. In general, mechanism for the Middle Holocene Climatic Optimum, Medical Warm Period, and Little Ice Age can be explained by the solar insulation, however their exact mechnism is not well known. Carbon dioxide concentration during the past 400,000 years never reached the current value of 375 ppm. Furthermore, the current methane concentration never reached during the past 20Ma. However, current temperature value has happened several times during the past 400,000 years. The implication of this is unsolved question so far. This should be challenged in the near future.

• 한국산림과학회지
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• 제99권1호
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• pp.57-61
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• 2010

본 연구는 난대산림연구소의 제주시험림에 있는 붉가시나무(Quercus acuta)에 대한 개체목의 수간곡선식 추정 및 간재적을 추정하기 위하여 수행되었다. 최적의 추정식을 선택하기 위하여 Max and Burkhart식, Kozak식 및 Lee식을 적용하여 각 식의 직경 추정에 대한 검정 통계량 및 실측치와 추정치간의 오차분포를 검증하였다. 그 결과 Max and Burkhart식 및 Lee식이 특정 구간에서 과대치 또는 과소 추정치를 보인데 반하여 Kozak식은 전구간에서 고른 분포를 보였다. 추정력이 가장 좋은 Kozak식을 활용하여 수피포함 재적표를 작성하였다.

• 한국도로학회논문집
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• 제18권2호
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• pp.29-36
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• 2016

PURPOSES: The objective of this study is to determine the milling temperature that minimizes the binder-induced damage to the aggregate; this is achieved by evaluating the temperature dependence of the viscosity of the asphalt binder, with the aim of developing an effective heating process for warm in-place recycling. METHODS : The validity of the indoor test was confirmed by conducting an internal heating test based on the on-site heating test. In addition, the adhesive power of the binder was measured at various temperatures ($30^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, $60^{\circ}C$, $70^{\circ}C$) via three types of measuring methods. RESULTS: The surface temperature spectrum of field test was slight different with that of laboratory test. But, the spectra of inner temperature between the field and the laboratory was almost similar. Also, the adhesion of the asphalt binder was measured from $30^{\circ}C$ to $70^{\circ}C$. The adhesion of the binder was significantly decreased from $60^{\circ}C$. Contrary to other temperature, the adhesion was slightly changed from $60^{\circ}C$ to $70^{\circ}C$. Also the inner temperature between two different heating methods was shown similar temperature spectra. CONCLUSIONS: The pavement heating temperature spectrum of hot in place recycling method was simulated by a laboratory test. Based on this study, the optimum temperature was $60^{\circ}C{\sim}70^{\circ}C$ for reducing aggregate damage during milling process. The susceptibility heating method developed in this study can be maintained the optimum inner temperature range.

• Journal of Plant Biotechnology
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• 제31권1호
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• pp.31-35
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• 2004

멸종위기에 직면한 피뿌리풀 (Stellera roseaN.)의 기내증식법을 개발하고자 액아 마디를 MS 배지에 BAP와 zeatin을 처리하여 다경 (multiple shoot)를 유도하고 기내발근에 미치는IBA및 NAA처리 효과를 조사하였다. 액아 마디로부터 다경유도는 BA가 현저히 양호한 반면 줄기의 생장은 zeatin이 BA보다 효과적이었다. 증식된 줄기로부터 기내 발근은 오옥신 처리로 가능하였으나 발근율은 대체로 저조하였고 오옥신의 전처리 기간에 따라 차이를 보였다. IBA가 NAA보다 다소 좋은 발근효과를 보였고 1.0mg/L 농도로 15일간 배양시 30%까지 발근되었다. NAA역시 처리농도 및 처리기간에 따라 발근율에 차이를 보였다. 발근묘는 인공토양에서 51%가 활착되어 정상생장이 가능하였다. 이상의 결과는 발근 및 순화조건을 좀더 개선하면 피뿌리풀의 효율적인 기내번식이 가능함을 시사해준다.

• 가정과삶의질연구
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• 제16권4호
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• pp.1-16
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• 1998

this study examined the correlates of adult attachment focused on internal working models of 201 housewives. Findings indicated that 68.3% of subjects were classified as secure whereas 27.5% as avoidant and 4.2% as anxious. Greater security was associated with slightly less avoidance while greater anxiousness was associated with slightly greater avoidance. That is subjects who possessed more security tended to be less avoidant while subjects who possessed more anxiousness tended to be more avoidant. The primary characteristics classifying subjects into those three attachment styles were feelings about closeness dependence and anxiousness in relationships with others. Adult attachment was related in theoretically expected ways to one's history of attachment and parenting. Secure subjects were more likely to report warm/responsive parental caregiving style than insecure styles. Insecure subjects in comparison with secure subjects perceived their mothers as cold inconsistent and ot very responsive. Anxious subjects dscribed their fathers as cold and rejecting. The secure attachment style in comparsion with insecure styles was associated with positive mental models of self and social world indicating greater self-esteem positive beliefs about self and others positive relationships with their children greater marital satisfaction and greater secure attachment to their husbands. These results suggest that internal working model offers a useful perspective on adult attachment.

• 한국의류산업학회지
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• 제3권3호
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• pp.265-270
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• 2001

Korea and Japan, neighboring two nations, have similar cultural background and complicated relations in terms of their culture and constitution. In this study, clothing microclimate and subjective sensation of Korean and Japanese subjects for Hanbok, traditional costumes of Korea, were assessed and investigated differences between them. The results of the study were as follows. For Hanbok, the temperature within clothing at the chest have significant correlations with the variables of race and elapsed time with p<0.001. At the thigh, correlations with elapsed time were significant (p<0.001). For the humidity within clothing at the chest of Hanbok, correlations with variables of race were significant (p<0.001). At the thigh, correlations with race and elapsed time were significant(p<0.001). For Hanbok, Korean group reported 'slightly warm' whereas Japanese group reported 'hot' in the thermal sensation. For the humid sensation, Korean group reported 'neutral' and Japanese group reported 'humid'. For the comfort sensation, Korean group reported 'slightly uncomfortable' and Japanese group reported 'uncomfortable'. Japanese group reported high relation with comfort sensation and humidity of microclimate.

• KIEAE Journal
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• 제7권5호
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• pp.65-71
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• 2007

The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

• 패션비즈니스
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• 제21권4호
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• pp.144-158
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• 2017

Fur garment has long been the conventional symbol for luxury, or conspicuous consumption. However, as fashion items began to diversify as part of overall fashion trend, fur items are now more about individual taste and style than just lavishness. Synthetic fur is especially emerging as a new promising fashion material, with a touch almost like natural fur at an affordable price. Along with the emergence of 'Vegan Fashion' trend, synthetic fur is establishing itself as a popular fashion textile. This study is an attempt to investigate subjective evaluation and physical properties of natural and synthetic furs, whose results will further serve as basic data in developing synthetic fur materials. Sensory and emotional evaluations are carried out on natural and artificial furs. For analysis, factors such as weight, thickness, air permeability, gloss and compressibility were surveyed to observe how they influence the physical properties. According to the subjective evaluation, natural and artificial fur samples do not differ in conspicuous ways in appearance. Experiments on physical properties, specifically warm/cool touch experiment, show that natural fur has a slightly higher warm sensation than artificial fur. Luster analysis by using a microscope revealed that there are subtle qualitative differences between natural and artificial fur. During the subjective evaluation, subjects found it hard to state distinct quantitative differences in luster. A survey as a means of assessing qualitative differences in gloss seems to be necessary to complement the evaluation. Results from this study will potentially serve as resources for diversification of fashion product designs using synthetic fur.

• Asian-Australasian Journal of Animal Sciences
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• 제14권9호
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• pp.1221-1227
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• 2001

Young lambs (Suffolk wethers, n=18), which were 22 to 26 kg average BW, were chronically exposed to temperatures of +1 to +$4^{\circ}C$ (cold) or +21 to +$24^{\circ}C$ (warm) during 10 wk experimental periods. The sheep were closely shorn and were housed in individual metabolism crates in controlled environment rooms. Sheep consumed pelleted diets ad libitum, which consisted of mainly barley grain and brome grass, and contained 7, 11, or 14% CP. The experimental design consisted of a $2{\times}3$ factorial with a single crossover of environment treatment. Feed intake, BW, feces, and urine excretion were measured. Apparent digestibilities were not affected by diet CP concentration or temperature treatments; however, voluntary intake per kg BW was increased (p<0.05) by diet CP content in both environments. Growing lambs gained weight slightly faster in a cold environment when N intake was above 27 g/d. Nitrogen excretion and N balance were positively related (p<0.01) with diet CP content, and fecal N excretion was significantly increased (p<0.05) in the cold environment. Therefore, dietary CP content strongly influenced N metabolism; however, cold exposure did alter only fecal N excretion. The higher DM intake per kg BW at 11% CP diet in the cold environment permitted ADG comparable to 14% CP diet in the warm environment. The results of this study do support the hypothesis that lambs are better able to utilize a moderate reduction in the CP content of the diet in a cold environment.