• 한국대기환경학회지
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• 제15권3호
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• pp.317-325
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• 1999

The demand of diesel engine on the construction equipment has been rapidly increased because of high thermal efficiency and fuel economy. The exhaust emission from nonroad vehicles equipped with diesel engine such as construction equipment, ship, and agricultural equipment, etc. Which are known to be harmful to human health and environment, has not been regulated in our country. But the regulation for nonroad vehicle has been already progressed in advanced country. So we investigated the contribution ratio of air pollution by construction equipment in order to establish the exhaust emission management strategy for nonroad vehicle. Based on the statistical data for construction equipment, 5 kinds of equipment are selected and tested in the engine dynamometer to determine the emission factor. And the amount of air pollutant from construction equipment are calculated by using of the emission factor and recommended exhaust emission standard for construction equipment.

• 한국대기환경학회지
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• 제6권2호
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• pp.135-146
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• 1990

The purpose of the study was to identify sources of particulate matters statistically and to estimate the mass contribution quantitatively in the Pusan metropolitan area. Then, the study has used the TTFA (target transformation factor analysis) model, a receptor model, to apportion aerosol mass with the raw data of 106 ambient samples characterized by 24 heavy metal variables. The TTFA was extensively applied to generate source profiles and their aerosol mass contributions. Though a couple of sources were not identified, four to seven sources were able to be extracted at 3 different sites (Jang Rim-Dong, Kwang Bok-Dong, and Kwang An-Dong) in Pusan area and finally mass conributions could be calculated.

• Biomolecules & Therapeutics
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• 제28권1호
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• pp.45-57
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• 2020

In the neurovascular unit, the neuronal and vascular systems communicate with each other. O₂ and nutrients, reaching endothelial cells (ECs) through the blood stream, spread into neighboring cells, such as neural stem cells, and neurons. The proper function of neural circuits in adults requires sufficient O₂ and glucose for their metabolic demands through angiogenesis. In a central nervous system (CNS) injury, such as glioma, Parkinson's disease, and Alzheimer's disease, damaged ECs can contribute to tissue hypoxia and to the consequent disruption of neuronal functions and accelerated neurodegeneration. This review discusses the current evidence regarding the contribution of oxygen deprivation to CNS injury, with an emphasis on hypoxia-inducible factor (HIF)-mediated pathways and Notch signaling. Additionally, it focuses on adult neurological functions and angiogenesis, as well as pathological conditions in the CNS. Furthermore, the functional interplay between HIFs and Notch is demonstrated in pathophysiological conditions.

• 한국환경과학회지
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• 제17권3호
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• pp.315-323
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• 2008

Based on the result of extraction of common factors executed in order to elucidate the visual attributes of street scenery by types through the rotation of 23 adjective variables by Varimax, the visual attributes expressed after the construction of the facilities using street scenery were anylized to be 4 factors including factor 1 through factor 4. Theexplanation of the 4 factor groups to explain the entire distribution was 65.3% and these factor groups are the psychological attributes felt when using facilities are constructed by securing the street spaces in downtowns and the factors were named as naturalness(factor 1), locality(factor 2), identity(factor 3) and clarity(factor 4) respectively. Based on the result of one-way layout distribution analysis, the preferences for street scenery by types were found out to show considerable differences at 1 % significance level. Based on the result of multiple regression analysis, all of the factors explaining preferences including factor 1 through factor 4 were significant at 1 % significance level. In case other conditions are constant, if the values of the adjective variables related to locality(factor 2) increase by 1 unit, the preferences which are the values of dependent variables will increase by 0.709. The variable with the largest relative contribution among the 4 factor groups was the locality(factor 2) factor group and on the contrary, it was found that the independent variable with least influences was the clarity(factor 4) factor group.

• Tribology and Lubricants
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• 제10권4호
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• pp.13-26
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• 1994

Effects of resin contents, number of carbonization, graphitization, sliding speed, and oxidation on friction and wear behavior of carbon/carbon composite materials were investigated. Friction and wear tests were carried out under various sliding conditions. An experimental setup was designed and built in the laboratory. Stainless steel disks were used as the counterface material. Friction coefficient, emperature, and wear factor were measured with a data acquisition system. Wear surfaces were observed by the scanning electron microscope. It has been shown that the average friction coefficient was increased with the sliding speed in the range of 1.43~6.10 m/s, but it as decreased in the range of 6.10~17.35 m/s. Specimens prepared by different numbers of carbonization. showed variations in friction coefficient and friction coefficient of the graphitized specimen was the highest. Friction coefficients depended on contribution of the plowing and adhesive components. As the number of carbonization was increased, wear factor was reduced. Wear factor of the graphitized specimens dropped further. In the case of graphitized specimens, sliding speed had a large influence on wear behavior. When the tribological experiments were conducted in nitrogen atmosphere, the wear factor was decreased to two thirds of the wear factor obtained in air. It is obvious that the difference was affected by oxidation. Results of friction and wear tests were applied to a neural network system based on the backpropagation algorithm. A neural network may be a valuable tool for prediction of tribological behavior of the carbon/carbon composite material if ample data are present.

• 대한가정학회지
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• 제41권6호
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• pp.119-129
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• 2003

This study was peformed to establish the standard size system to be required for the production of brassiere. The subject were 155 Korean twenties-aged women and were directly measured anthropometrically. From 27 measurements, 5 factors were extracted through factor analysis. The accumulative contribution ratio is 76.92％. Factor 1 indicates the degree of obesity around the chest, factor 2 is the drooping degree of breast, factor 3 is the contours and prominence, factor 4 is the breast breadth and breadth of bust point, factors 5 is the volume of breast. The subject were classified into 3 cluster as their breast types through cluster analysis. Type 1 is the closest to the ideal breast shape and not too droopy. This group belonged to 75A. Type 2 has small breast and belonged to 70AA group. Type 3 is the obesest and has the biggest and droopy breast. This group belonged to 75B. The distribution of size of brassiere had 3 sections from 70 to 80 showing a rate of 81.94% and the sin of the cup had 4 sections from AAA cup to B cup showing a rate of 89.70％. The production ratio of each brassiere size, it was found that the brassiere size of highest production ratio was 75A(16.39％) in type 1,70AA(16.27%) in type 2, and 75B(13.72％) in type 3. This suggests that it is necessary to adjust for the production rate of brassieres.

• 한국항만경제학회지
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• 제23권4호
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• pp.49-69
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• 2007

본 연구의 목적은 한국의 항만물류산업의 성장회계분석을 통하여 경제성장의 기여요인을 분석하는 것이다. $1990{\sim}2003$년간 항만물류산업은 전 산업 평균에 비하여 총요소생산성과 노동의 기여도는 높고 자본스톡 기여도는 낮다. 외환위기 전후로 항만물류산업의 성장 패턴은 크게 변화하였다. 외환위기 이전, $1990{\sim}1998$년간 항만물류산업의 경제성장률은 14.1%로 전 산업 평균 경제성장률 7.7%보다 크게 높고 그 주된 기여요인도 자본스톡과 총요소생산성으로 나타나지만 이들의 기여도는 전 산업 평균에 미치지 못하였다. 외환위기 이후, $1998{\sim}2003$년간 항만물류산업의 경제성장률은 5.4%로 전 산업 평균(10.1%)에 크게 미치지 못하였고 경제성장에 대한 기여도는 자본스톡 13.1%, 노동 57.0%, 총요소생산성(성장률) 29.9%로 노동에 의존한 성장패턴이 총요소생산성의 성장률 저하와 함께 경제성장률을 격감시키는 결과를 초래하였다.

• 한국초지조사료학회지
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• 제41권1호
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• pp.47-55
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• 2021

본 연구는 기후요인과 토양요인이 알팔파 건물수량에 어느 정도 영향을 미치는지를 기여도로 평가할 목적으로, 기상변수와 토양물리성변수를 고려하여 일반선형모형으로 수량예측모델을 구축하였다. 알팔파 수량예측모델 구축과정은 알팔파, 기상 및 토양자료수집, 가공, 통계분석 및 모델구축 순이었다. 수량예측모델은 알팔파와 양적자료인 기상변수를 선택하기 위한 다중회귀분석과 질적자료인 토양물리성변수도 고려하기 위해서 일반선형모형을 사용하였다. 그 결과 DMY에 영향을 미치는 기상변수는 적산온도와 생육일수이었으며, 토양물리성변수는 점토함량이 선택되었다. DMY에 영향을 미치는 변수별 기여도는 점토함량(63%), 적산온도(21%) 및 생육일수(11%)순 이었으며 요인별 기여도는 기후요인(적산온도, 21%와 생육일수, 11%)이 32%, 토양요인(점토함량)이 63%로 나타나 토양요인이 기후요인보다 알팔파 건물수량에 더 기여하는 것으로 평가하였다. 본 연구에서 이용한 알팔파 자료는 토성, 시비수준 및 품종이 제한되어 있어 앞으로 이들 요인을 고려한 다양한 조건의 재배실험을 통하여 보다 많은 자료축적이 요구된다.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.600-608
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• 2013

Amide analogs of tridecapeptide ${\alpha}$-factor (WHWLQLKPGQPMYCONH$_2$) of Saccharomyces cerevisiae, in which Trp at position 1 and 3 were replaced with other residues, were synthesized to ascertain whether cooperative interactions between two Trp residues occurred upon binding with its receptor. Analogs containing Ala or Aib at position 3 of the peptide $[Ala_3]{\alpha}$-factor amide (2) and $[Aib_3]{\alpha}$-factor amide (5) exhibited greater decreases in bioactivity than analogs with same residue at position one $[Ala^1]{\alpha}$-factor amide (1) and $[Aib^1]{\alpha}$-factor amide (4), reflecting that $Trp^3$ may plays more important role than $Trp^1$ for agonist activity. Analogs containing Ala or Aib in both position one and three 3, 6 exhibited complete loss of bioactivity, emphasizing both the essential role and the combined role of two indole rings for triggering cell signaling. In contrast, double substituted analog with D-Trp in both positions 9 exhibited greater activity than single substituted analog with D-Trp 8 or deleted analog 7, reflecting the combined contribution of two tryptophane residues of ${\alpha}$-factor ligand to activation of Ste2p through interaction with residue $Tyr^{266}$ and importance of the proper parallel orientation of two indole rings for efficient triggering of signal G protein coupled activation. Among ten amide analogs, $[Ala^{1,3}]{\alpha}$-factor amide (3), $[Aib^{1,3}]{\alpha}$-factor amide (6), [D-$Trp^3]{\alpha}$-factor amide (8) and [des-$Trp^1,Phe^3]{\alpha}$-factor amide (10) were found to have antagonistic activity. Analogs 3 and 6 showed greater antagonistic activity than analogs 8 and 10.

• Journal of Photoscience
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• 제3권3호
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• pp.147-151
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• 1996

Dynamics of contact ion-pair between 1, 2, 4, 5-tetracyanobenzene anion and cation of biphenyl derivatives was investigated on the picosecond time scale. Solvent effect on the electron transfer was observed and electron transfer rates were examined using Marcus equation which contains distance dependence of the electron transfer rate in the frequency factor, along with the consideration of molecular shape. From the discussion based on disk model for molecular shape, contribution of interring torsional motion of biphenyl to the inner-sphere reorganization energy is strongly suggested, which leads to the physical explanation for the observed solvent effect on the rate of electron transfer.