• 천문학회보
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• 제45권1호
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• pp.70.4-71
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• 2020

One of the distinctive characteristics of the evolution of binary systems would be mass transfer. Close binary systems experience so-called Case A mass transfer during the main-sequence. We have performed calculations of the evolution of massive Case A (with the initial period 1.5 ~ 4.5 days) binary systems with the initial mass of 10 ~ 20 solar masses and mass ratio 0.5 ~ 0.95 using the MESA code. We find that in some systems, after the first mass transfer, the secondary stars evolve faster than the primary stars and undergo so-called 'reverse' mass transfer. Such phenomena tend to occur in relatively low-mass (initial mass < 16 solar masses) and close (initial period < 3 day) systems. Unless a system enters the common-envelope phase, the primary star would become a single helium star after the secondary star ends its life if the system were unbound by the neutron star kick. We find the various evolutionary implications of the remaining primary stars. In addition to the evolution into the compact single helium star progenitor, there is a possibility that the remaining primary star could evolve into a helium giant star, which could be a promising candidate for Type Ibn supernova progenitor, depending on the core mass. Further, we find that some primary stars satisfy the conditions for the formation of electron-capture supernova progenitor.

• 한국의류산업학회지
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• 제21권6호
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• pp.789-799
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• 2019

This study classified and analyzed the upper body types of 7-13 years old elementary school boys, using 3D data from the 6th Size Korea. The results of this study are as follows. Seven factors were extracted from the factorial analysis as an independent factor for a cluster analysis. The cluster analysis generated four body types. Type 1 has large ratio of front and back depth as well as circumference, with a front protrusion. In Type 2, the vertical value of upper torso is longer than average; in addition, its flatness is the largest and produces a thin body type. Type 3 has a smaller flatness in the bust, waist, abdomen and hip than other types, while also having the largest BMI. Type 4 is characterized by a greater shoulder angle than other types and its other factors are close to average. As a result of the logistic regression analysis, the prediction model used eight variables to generate and its accuracy is 88.679%. The classification of upper body types from this study can be used as basic data to improve patternmaking for each body type. The generated prediction model is also expected to be used as a method to help classify upper body types using the eight variables.

• 대한기계학회논문집
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• 제16권7호
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• pp.1363-1372
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• 1992

본 연구에서는 고속 냉간 압연유를 개발하기 위한 기초 연구로써 압연유의 기본이 되는 기유의 종류와 압연유에 첨가되는 각종 첨가제중 고속, 고압하 압연에서 가장 문제가 되는 히트 스크래치를 방지하는 역할을 하는 극압제의 종류 및 함량이 압연유의 윤활성과 내소부성에 어떠한 영향을 주는가를 소다식 진자형 마찰계수 시험 기, Falex 시험기 그리고 Four Ball 시험기와 같은 실험실적 평가방법과는 달리 실제 롤과 스트립 사이의 접촉조건이 상사한 시험압연기를 사용한 윤활성 및 내소부성 평가 실험을 통하여 검토하였다. 본 평가 실험에 사용된 시험압연기는 압하배분, 압연 채 터링(chattering), 장력 제어, 압연윤활 특성, 압연재 형상 제어, 이주속 압연특성 등 을 시험할 수 있는 다목적 냉간압연기로써 그 구조와 제원을 Fig.1과 Table 1에 나타 내었다. 또한 극압제를 함우하고 있는 압연유와 스트립 표면간의 화학반응에 의한 극압막의 존재여부를 확인하기 위하여 EDS(energy dispersive spectrometer) 분석법과 ESCA (electron spectroscopy for chemical analysis) 분석법을 이용하여 분석하였다.

• 자원환경지질
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• 제33권6호
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• pp.491-504
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• 2000

Environmental isotope $^{18}O$, $^{2}H$, $^{3}H$,$^{13}C$, $^{34}S$and $^{87}Sr/^{86}Sr$) studies on ${CO_2}$-rich waters in the Kangwon Province were carried out to elucidate the origin, residence time, water-rock interaction and mixing process of their. ${\delta}^{18}O$ and ${\delta}D$ data indicate that ${CO_2}$-rich waters were derived from the local meteoric water. It also shows that each type of ${CO_2}$-rich water has distinct isotopic composition and Na-${HCO_3}$ type water (-10.8 to -12.1${\textperthousand}$, ${\delta}^{18}O$ ) is lighter than other type waters. These depleted isotopic values supposedly indicate that, considering the altitude effect of isotope in Korea, the recharge area of Na-${HCO_3}$ type water can be estimated to be relatively higher in elevation than those of Ca-${HCO_3}$ and Ca-Na-${HCO_3}$ type waters. Tritium contents close to zero are observed in the Na-${HCO_3}$ type water, confirming a long residence time and the possibility of a ${CO_2}$ inflow into the aquifer at great depth. These isotope data also show that the Ca-${HCO_3}$ type water has undergone mixing process with surface water during ascending at depth, whereas Na-${HCO_3}$ type water was less mixed with surface waters. The carbon isotope data (-8.8 to ＋0.8 ${\textperthousand}$ ${\delta}^{13}C$) indicate that dissolved carbon in the ${CO_2}$-rich waters was possibly derived from deep seated ${CO_2}$ gas. The high ${\delta}^{34}S$ values (up to 38.1${\textperthousand}$) of dissolved sulfates suggest that sulfate reduction by microbial activity had occurred at depth. Strontium isotopic data ($^{87}Sr/^{86}Sr$) of ${CO_2}$-rich waters indicate that the chemistry of the ${CO_2}$-rich waters is determined by water-rock (granite) interaction.

• 한국의류학회지
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• 제30권6호
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• pp.971-980
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• 2006

The colors of apparel have a close relationship with the facial color types of consumers. To extract the favorable colors that flatter to consumer's facial color types, the facial colors of Korean females were analyzed. With color meter JX-777, 2 points of face were measured and classified into 3 clusters that had similar hue, value and chroma. Other new 10 college girls were measured and 3 subject among them were selected by the criteria that choose new subjects who have the classified facial color types. 175 respondents answered the degree of becomingness of color samples on three subjects. Data were analyzed by K-means cluster analysis, ANOVA and Duncan multiple range test using SPSS Win. 12. Findings were as follows: 1) 324 subjects who had YR facial colors were classified into 3 facial color groups. The average facial color Type 1 was 4.82YR 6.47/3.70 and composed 48.88% among total observations. Type 2 was 5.99YR 6.12/4.12 and 30.25%. Type 3 was 5.15YR 7.07/4.97 and 20.99% respectively. 2) Favorable colors for Type 1 were 18 colors that belonged to 'a' group from among colors that were divided into a, b, c group by Duncan post hoc test. 3) Type 2 showed that this type had many unfavorable colors. Unfavorable colors were 18 colors that belonged to 'c' by Duncan test. 4) Type 3 showed that black is the most favorable color and 18 colors were at middle level, which belonged to 'b' from among 18 colors that were divided into a, b, and c by Duncan test.

• 한국주거학회논문집
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• 제21권3호
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• pp.11-21
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• 2010

The purpose of this study is to gather baseline data on perceived priority of residential choice and housing satisfaction rates among consumers with the aim of using this information for future planning. Self-administered questionnaires were provided to 196 studio-type multi-family housing dwellers in the City of Gwangju from 2009 Apri 5th to 29th. The collected data was used to conduct comparative and descriptive statistical analysis: factor analysis, t-test, one-way ANOVA, correlation analysis. The main findings obtained are as follows: Firstly, in relation to perceived priority of residential choice, dwellers identified seven factors as important. Secondly, in terms of housing satisfaction about a unit room, the respondents identified five factors as important. This study confirmed that there existed passive correlation between priority of residential choice and housing satisfaction among residents in studio-type multi-family housings in Gwangju. It is very necessary to project a studio-type multi-family housing close to transportation for easy access, avoiding commercial districts. Delicate interior and design will attract more female residents as well as fully-equipped parking lots for people who drive to their workplace. According to research on a degree of housing satisfaction, all respondents expressed dissatisfaction with "noise". Therefore, in dealing with construction plans of studio apartment units, from now on, sound proofing facilities are required to reduce the acoustic invasion of privacy, especially, for units with more than two people. In order to satisfy all the demand of residents in studio apartment units, we have to pursue systematic and succeeding research about a studio-type multi-family housing well-fitted for the actual circumstances of local area and suitable for longer stay. To sum up, more research and development will be required for high-class studio-type multiplex housing for sale in dealing with households with financial stability such as two-paycheck couples, so-called DINK, or a professional single person, in the future.

• 한국광학회지
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• 제19권1호
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• pp.31-35
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• 2008

결합효율이 높고 정렬오차 발생 시 결합효율의 저하가 작은 광통신용 비구면 렌즈 시준기를 설계하였다. 비구면 시준 렌즈는 GRIN 렌즈와 작동거리와 두께가 유사하고 외경이 동일한 원통형 막대 형태로 설계해 GRIN 렌즈를 대체할 수 있도록 하였다. 결합효율의 저하는 시준렌즈의 구면수차에 의해 주요하게 발생하므로, 비구면 렌즈 시준기가 볼 렌즈, GRIN 렌즈 및 C-렌즈 시준기보다 높은 결합효율을 가지도록 비구면 계수를 최적화 해 구면수차를 낮추었다. 설계한 비구면 렌즈 시준기의 결합효율은 기존 시준기들보다 높았으며 정렬오차에 따른 결합효율의 감소도 작았다.

• 한국패류학회지
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• 제12권1호
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• pp.1-17
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• 1996

Morphological and histochemical characteristics of the cells in posterior tentacle antenna of Korean slug, Incilaria fruhstorferi were observed with light microscope. The epithelium of the posterior tentacle antenna was composed of supporting cells, sensory neurons and type-a clear cell. The columnar supporting epithelium was widely distributed in the posterior tentacle antenna, and the upper end of the cell was covered with acidic mucopolysaccharide. Nerve endings of the sensory neuron were distributed between type-a clear cells. It was usually located in tentacular knob, and the number of them gradually decrdased as close as tentacular stalk. Several cilia were observed on the nerve ending. Type-a clear cells were very brightly stained with all staining used, and the neutral mucous guanules distributed in the cytoplasm. Collar cells, type-b clear cell and various types of secrdtory cells distributed in the connective tissue. The collar cells were clustering in connective tissue, and the cytoplasm were filled with neutral mucous guanules. The cells and granules were stained with dark brown by silver nitrate stain. Type-b clear cells were irregular in shape and their cytoplasms were brightly stained wth many stains used. Ten types of secretory cells evenly distributed in the connective tissue and muscle layers of the posterior tentacle antenna. The five types of the secretory cells(A, B, E, J and L)seemed to secrete acidic mucopolysaccharide, and the other five type of the cell(C, D, F, H, and L)seemed to secrete neutral mucopolysaccharide. Muscular tissue composed of well-developed thick longitudinal muscle layers and thin circular muscle layers. Type-L secretory cells clustered only in muscular layers and they contained acidic mucopolysaccharides.

• 한국작물학회지
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• 제28권2호
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• pp.233-239
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• 1983

종전에는 Brassica napus에서 성분이 개량되지 않은 유채의 일반 품종들의 Winter type만을 대상으로 춘파성 정도를 분류하고 추태로서 분류기준을 삼았으나 본 시험에서는 같은 B. napus인 Summer type까지를 포함하고 성분이 개량된 양질유ㆍ양박 품종을 공시하여 임실여부로서 분류기준을 삼는 새로운 분류를 시도하여 춘파성 정도를 조사하였던 바 그 결과를 요약하면 다음과 같다. 1. 현재 목포지장에서 보유하고 있는 양질유ㆍ양박 유채(Brassica napus) 품종 및 육성계통들은 8단계 group으로 춘파성 정도를 분류할 수 있었고 춘파성 정도 제Ⅶ group는 Summer type의 계통들이 이에 속하였으며 이들 계통은 Oro, Midas 등의 Summer type의 품종과 교배하여 선발된 계통들이었다. 2. 춘파 파종기에 따른 성숙기변화는 춘파시기가 늦을수록 성숙기는 지연되는 경향이었고 춘파성 정도가 높음에 따라 생육일수와 적산온도가 줄어드는 경향이었다. 3. 춘파성 정도와 내한성 관계는 춘파성 정도가 높을수록 내한성이 낮았으며 춘파성 정도와 초성간에는 춘파성이 높을수록 초성에서 I형에 가깝고 주경의 신장이 분지보다 빈약한 바 이들 모든 상호관계는 고도의 부상관으로 나타났다. 4. 월동에 안전한 추파재배용계통은 춘파성 정도가 낮은 0, I, II group로서 공시품종중 59 품종이 이에 속하였다.

• 치과방사선
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• 제28권1호
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• pp.111-126
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• 1998

In this study, radiographic evaluation was made using panoramic radiography and cross-sectional tomography of SCANORA/sup (R)/ in male and female adults in their 20's on the relationship between the maxillary sinus floor and the apex of the maxillary molar, to test the accuracy and effectiveness of the cross-sectional tomography, and to use this information in the assessment of preop. and postop. root canal treatment, apical surgery, extraction and implantology. Forty-one adults with an average age of 24.4 years were studied using panoramic radiography and cross-sectional tomography. In panoramic view and cross-sectional view, the position of the apices of maxillary molars were classified as separated, contacted, or protruded type; the general shape of the maxillary sinus floor was evaluated horizontally and vertically from cross-sectional tomography. The accuracy of each radiography was tested using maxilla from 5 fresh cadavers from the Anatomy Lab at Yonsei University Dental College, and panoramic view and cross-sectional tomography were taken in the same condition as with the patients. The results were as follows: 1. Panoramic view and cross-sectional view were taken in the maxilla specimen, and the actual distance between the maxillary sinus floor and the tooth apices were measured in the specimen; the median values of the distance from the tooth apices to the maxillary sinus floor in the panoramic view, cross-sectional view and in the actual maxilla specimen were 2.83 mm, 4.51mm, and 4.l5mm, respectively. In the cross-sectional view, the measured distance was close to the actual distance but in the panoramic view, the measured distance was far from the actual distance. 2. When the results of the panoramic view and cross-sectional view were compared, 40.5％ of the results agreed with each other in the two radiographic methods and buccal roots of the 2nd molar were the closest to the maxillary sinus floor in the cross-sectional tomography. 3. In cross-sectional view, when the vertical relationship of the maxillary sinus floor and maxillary roots was assessed, in 1st molars, type II (the sinus floor that extends down to the buccolingual furcation area) was predominant, while in 2nd molars, type I (the sinus floor located above the level connecting the buccal and lingual apices) was predominant. In the horizontal relationship, in 1st molars, type II (the lowest floor of the maxillary sinus located in between the buccal and lingual roots) was predominant; in 2nd molars, type I (the lowest floor of the maxillary sinus located on the buccal side of the buccal roots) and type II appeared in similar frequency. In conclusion, the SCANORA/sup (R)/ cross-sectional tomography was more effective than the frequently used panoramic view, in that the relationship of the maxillary molars and maxillary sinus floor can be evaluated more accurately and the buccolingual cross-sectional view can also be observed. And maxillary sinus floor that was close to maxillary 2nd molar had tendency to be located on buccal side than that close to 1st molar. Therefore, cross-sectional tomography is an effective and accurate method to evaluate the position of the teeth in relation to the sinus floor preoperative and can be easily used to diagnose localized periapical lesions. Also, the image quality obtained was quite satisfactory.