고온에서 HAN 계열 추진제 액적의 거동에 대한 연구

황창환(Chang Hwan Hwang),백승욱(Seung Wook Baek),한조영(Cho Young Han),김수겸(Su Kyum Kim),전형열(Hyung Yeol Jeon) 한국연소학회 2012 KOSCOSYMPOSIUM논문집 Vol.- No.45

The droplet behavior of 83.9 wt.% HAN water solution was investigated experimentally with various ambient temperature and nitrogen environment. At the initial stage of evaporation under thermal decomposition temperature of HAN, gradual decreasing of droplet diameter was observed. After that, the droplet started to expand due to the internal pressure build up by water nucleation inside the droplet. The micro explosion was observed at higher temperature than the decomposition temperature of HAN and the remaining droplet showed similar behavior of single composition droplet. The decreasing rate was augmented as the ambient temperature increasing.

한강하구지역에서 월동하는 재두루미(Grus vipio)의 개체군 감소

이화수(Hwa-Su Lee),신주열(Ju-Yeol Shin),이시완(Si-Wan Lee),강태한(Tae-Han Kang),윤순영(Soon-Young Yoon),김정수(Jungsoo Kim) 한국조류학회II 2012 한국조류학회지 Vol.19 No.4

김포시와 고양시 일대의 한강하구 지역은 우리나라에서 재두루미의 가장 중요한 월동지 및 중간기착지로 알려져 있지만, 이 지역의 조류 서식환경은 심각한 개발압력과 인간의 간섭으로 인해 지속적으로 나빠지고 있다. 따라서 본 연구에서는 2007-2008년과 2011-2012년의 월동시기에 본 지역에 도래하는 재두루미를 대상으로 월동 개체군 크기 변화와 월동지역 내에서 과거와 현재의 취식지역 이용 현황 등을 조사하여 개발행위가 이들의 서식에 미치는 영향을 확인하였다. 본 지역에서 월동하는 재두루미 개체군은 평균 124.9개체(2007-2008년)에서 59.0개체(2011-2012년)로 감소하였으며, 주요 취식지역에서 확인된 개체수는 평균 77.7개체에서 24.1개체로 감소하여 월동개체군의 감소폭에 비해 주요 취식지역의 이용 개체수의 감소폭이 더 크게 나타났다. 유형별 분석에서는 가족군에 비해 무리군의 개체수가 많이 감소한 것으로 나타났으나, 홍도평 지역의 가족군 이용 개체수는 변화가 나타나지 않았다(Mann-Whitney test. Z=-0.26, p=0.979). 그리고 과거 다수의 재두루미가 주요 취식지역으로 이용하였던 송포동과 평동지역은 2012-2013년 조사에서는 거의 이용하지 않는 것으로 나타났다. 이는 위 지역의 개발행위(예: 제 2자유로 건설 등)와 깊은 연관성이 있는 것으로 생각된다. Han-river estuary in Gimpo and Goyang city is well known as one of the most important wintering and stopover sites for migrating White-naped Crane (Grus vipio) in Korea. Nowadays, habitat quality of this area is getting worse due to serious development pressure and high human disturbances. So, we wanted to know whether development actions affected total wintering population change in Han-river estuary and feeding group pattern of White-naped Crane in main feeding habitats between the 2007-2008 and 2011-2012 wintering period. Average wintering population was decreased 124.9 to 59.0 and population of main feeding site also decreased 77.7 to 24.1. But decrease rate of main feeding site population was higher than total wintering population. Non-family feeding population was more decrease than family feeding population in the flock type analysis. But family feeding population of Hongdopyong was maintained from past and present (Mann-Whitney test. Z=-0.26, p=0.979). However, almost all White-naped Crane din not use both feeding sites, Pyong-dong and Songpo-dong, where were deteriorated habitat quality by human act.

교과 어휘 학습을 위한 교수 학습 방법 일고(一考)

한은수 ( Eun Su Han ) 근역한문학회 2011 한문학논집(漢文學論集) Vol.33 No.-

52% of elementary schools throughout Korea have been teaching Chinese characters as the schools` regular curriculum(subjective, discretion activity, and special activity), and 57% included the Chinese education in the category of extra curricular activities (Morning Self-studies, After school study program). Elementary students in Korea generally complete the goals and content that is required in the education process of a textbook. Although current textbooks are only inscribed in Han-geul, most of the Han-geul vocabulary was based in Chinese characters, and therefore brings big trouble to one`s studies when one can not comprehend the meaning of the Chinese character vocabulary. So for elementary students to faithfully complete their academic studies, they essentially need a deep understanding of the Chinese character vocabulary related to the vocabulary of a subject. And in this manuscript, we will examine the actual situation of vocabulary used in subject textbooks and observe how teaching and learning was done at the scene of education. As a result, we discovered that an elementary 1st Grader needs to understand the meaning of 70 Chinese characters to complete one subject, and some subjects required understanding up to 300 Chinese characters. This type of subject vocabulary deepens more as the academic year rises. For example, for 6th grade Korean and Social Studies, a student needs to understand 1300 vocabularies to understand the subject. Since it is difficult for elementary learners to understand the numerous vocabularies above, it is necessary to at least concentrate on the concept of vocabularies. At the elementary school scene, the Chinese script was studied mainly through various Chinese character study methods of reading, writing, and activity. However, the teaching and learning methods of Chinese vocabulary has not been researched or exercised compared to the active studies done at elementary schools. This manuscript examined the Chinese characters vocabulary teaching and learning methods regarding the study of coined words, finding synonyms*antonyms studies, word puzzle playing studies, drawing a semantic network map studies and etc.. And through an analysis of some of the Chinese character teaching and learning methods, the outcome of these methods were rough and the content was slow. The practice of Chinese characters through subject studies of elementary school learners is not a study of the script, and the meaning of Chinese characters can differ according to the vocabulary. Therefore further research is recommended in this area to ensure internal stability to the studies of subject vocabulary that are in the mainstream of each academic subject.

Equivalent Circuit Analysis of Induction Motors Considering Magnetic Saturation for Automotive Applications

Su‑Jin Lee,김성일,Pil‑Wan Han,김창업 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

This paper deals with the characteristics analysis of 3-phase induction motors for electric power steering applications by combining fnite element analysis with an equivalent circuit model. Induction motors for automobiles have high magnetic saturation due to size limitations. Accordingly, to improve the accuracy of the equivalent circuit analysis, it is necessary to consider the magnetizing reactance according to the magnetizing current. An equivalent circuit analysis method that takes into account the magnetic saturation of 3-phase induction motors is proposed and verifed through a test.

Comparative analysis of bovine maternal corpus luteum microRNAs with aberrant and normal developed cloned fetus at late gestation

Xiaohu Su,Shenyuan Wang,Guangqi Gao,Xinyu Zho,Lidong Han,Guanghua Su,Jiaqi Zhang,Wanfu Bai,Xiuying Wang,Guangpeng Li,Li Zhang 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background The development efficiency of cloned cattle is extremely low (< 5%), most of them were aborted at late gestation. Based on our previous studies, some recipient cows with a cloned fetus would present as engorged uterine vessels and enlarged umbilical vessels randomly. Abortion involves both maternal and fetal factors. Objective Our aim was to explore this phenomenon by microRNAs expression profile analysis of maternal corpus luteum (CL), which was related to pregnancy maintenance. Methods The present study provided the comparison of maternal CL miRNAs expression of abnormally and normally developed cloned bovine fetus at late gestation (~ 210 days) using RNA-Seq technology. Results We selected two abnormally pregnant cows (abnormal group, AG) and three normally pregnant cows (normal group, NG) and acquired valid reads of 9317,261–12,327,185 (~ 84.53–91.28%) from five libraries. In total, we identified 981 conserved miRNAs and 223 novel miRNAs. 1052 miRNAs were co-expressed, 124 miRNAs were uniquely expressed in AG, and 93 miRNAs were uniquely expressed in the NG. Compared with NG, 11 were significantly overexpressed, and 22 were downregulated (p < 0.05) at AG among 1052 co-expressed miRNAs. The differentially expressed miRNAs-targeted genes were further analyzed by Gene Ontology and KEGG pathway analysis. Notably, the steroid biosynthesis pathway was a significantly enriched term (p < 0.01), which may affect the secretion of progesterone. Conclusion Our research suggested that abnormal miRNAs expression of bovine maternal CL may affect the pregnant status at late gestation.

자연과학적 데이터를 활용한 풍납토성 백제토기의 분류 방안 연구

문은정 ( Eun Jung Moon ),강희준 ( Hee Jun Kang ),한민수 ( Min Su Han ),이한형 ( Han Hyoung Lee ) 백제학회 2011 백제학보 Vol.0 No.5

본 연구는 풍납토성 출토 백제토기를 대상으로 현장에서 소성온도에 따라 토기를 분류할 수 있는 외형관찰 기준을 마련하는데 자연과학적 데이터를 활용하고자 하는 연구이다. 소성온도는 토기의 경도, 밀도 풍을 포함한 다양한 물리화학적 특성에 영향을 미친다. 이 중 현장에서 측정이 가능하고 유용한 것이 경도이다. 그러므로 우리나라의 발굴현장에서 적용하고 있는 경도 측정기준을 적용하여 토기를 분류하고, 자연과학적 분석을 통하여 이들 토기의 마이크로비커스 경도, 밀도, 흡수율, 조직의 유리질화도, 광물학적 특성 등을 측정하여 현장에서 적용하는 경도분류 기준과의 상관관계를 비교연구하였다. 그 결과, 발굴현장에서 동전의 긁힘에 의해 주로 행해지던 연질과 경질의 이분법적 분류는 연질과 연경질, 경질의 세 단계로 세분됨을 알 수 있었다. 소성 온도 추정 결과, 연질은 1,000˚C 이하, 연경질은 1,000~1,100˚C, 경질은 1,200˚C 이상에서 소성되었을 것으로 판단된다. 한편, 3단계로 분류되는 토기들의 각 단계별 외형적 공통점을 추출하여 자연과학적인 정밀분석 없이 육안관찰만으로 토기를 3단계로 분류할 수 있는 관찰기준의 제시를 시도하였다. 이러한 기준은 파괴분석을 하지 않고도 토기의 외형적 특징을 이용하여 토기의 대략적인 물성과 소성온도 추정을 가능하게 할 것으로 기대된다. 단, 이러한 기준은 풍납토성에서 출토된 한성백제시기의 토기 중에서 배류와 호류 등 색상이 단조로운 제한된 기종을 중심으로 한 결과라는 한계를 가진다. 따라서 추가적으로 여러 기종의 다양한 색상을 가진 토기들을 대상으로 풍납토성 출토 토기의 경도별 분류가 가능하도록 수정·보완하는 연구를 진행할 예정이다. Observation methods of appearance were studied to establish a systemized classification criteria according to the firing temperatures of excavated earthenware from the Pung-Nap Mud Castle. A firing temperature has an impact on various physical and chemical properties including hardness and density of earthenware. Of all the properties, hardness can be measured in situ. Therefore, the earthenware were categorized according to the measurement method of hardness which can be applied and useful method for archaeological sites. In addition, the correlation between the measurement method and micro Vickers hardness, absorptance, degree of vitrescence and mineralogical properties of the earthenware were studied by means of a natural scientific analysis. The result suggests that the dichotomous way of classification based on a scratching method determining whether it is hard or soft should be categorized into three stages; soft, soft/hard and hard. According to the presumption of the firing temperature, it is believed that the earthenware were fired at below 1,000℃, 1,000~1,100℃ and 1,200℃ respectively. The systemized observation method was proposed to enable the earthenware to be categorized into three stages using visual observation without a detailed scientific analysis. The method will make it possible to estimate roughly the physical properties and firing temperature of the earthenware with only visual observation. However, it has limits as it was established focusing on certain types such as Cups and Jars among the Han-Sung Baek-Je earthenware. Therefore, a further study is planned to be carried out on various objects excavated from Pung-Nap Mud Castle in order to enable categorization on the basis of hardness of the earthenware.

가로변 건물 외장 재료의 구성과 이미지에 관한 연구 : 전주시를 중심으로

한상수,남해경,박한규 대한건축학회 2004 대한건축학회논문집 Vol.20 No.12

This study aims to find out the composition of the architectural materials for the exterior design of the urban buildings and their facade Image. To carry out this study, the field survey for the buildings of the 5 main streets in Chonju area was done And each one of the exterior building materials of the selected 15 buildings were investigated by a specialist group and non-specialist group They were analyzed as their built age, function, story and materials and their image It is concluded as followings 1 The tiles are mostly used as the building facade materials 2 As the built age, the tiles are chiefly used in the buildings that were built from 1970 to 1980, the granite and glass are more widely used in the recent buildings 3 As the function, the tiles are largely used in the kinds of daily life buildings and hospital buildings, and the glasses are in the office buildings 4 As the building story, the tiles are generally used In the lower story buildings, however in the middle story buildings granite and glasses are generally used. And in the higher story buildings, the glass is mostly used The compositional proportion of the buildings, as its used materials, are 70%, 23% and 7% respectively It is shown that the image of cool and modernness is taken with the buildings of glass, steel, timber and aluminum made And the buildings of red brick, tile, dry-bite and concrete have their own Images of warm together with the images of physical properties In the process of architectural design, the design of its exterior materials will be applied as its physical properties and images

니트섬유강화 복합재료의 기계적 성질에 관한 연구

한길영,이동기,최병기,오환교,신용욱,전수영 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

Using conventional textile techniques such as weaving, braiding, knitting and stitching it is possible to produce a wide range two and three dimensional fiber preforms. However, so far only a limited attention has been given to knitted fabrics in composite industry. This is mainly due to the opinion that knitted fabric reinforced composites posses low mechanical properties owing to their looped fiber architecture. But it is possible to obtain desired mechanical properties by selecting proper knitted fabric structure. In this paper, tensile failure load and displacement of one yarn, four yarns and knitted fabrics of ten yarns of kevlar fiber were determined experimentally in the unidirection. Mechanical properties of plain weft knitted fabrics reinforced composite intrusion beam for car side door application were investigated experimentally, which compared with desire value of American Fedral Motor vehicles Safety Standard (FMVSS) and presented the results.

PLD 박막의 물리적 성질

한용진,조봉균,정재훈,이수빈,박해윤,이태기,채희백,홍진수 순천향대학교 기초과학연구소 1998 순천향자연과학연구 논문집 Vol.4 No.2

Thin amorphous carbon films were deposited by a Q-switched Nd;YAG 532nm with beam power density of ?? on the high purity graphite (99.7%). The pressure of vacuum chamber was ?? Torr. In order to estimate the quality of the Pulsed Laser Deposition films one of the most important optical properties, bandgap energy, was characterized by transmission and reflection in the range of the visible, and an optical direct bandgap energy of 2.45eV and indirect bandgap energy 0.36eV were obtained. Surface morphology of amorphous film was investigated by AFM (Atomic Force Microscopy). Its surface roughness is 70nm. Comparing our results with the published values in the literature we have confidence that our films show the good quality for optical properties.

가로변 건물의 외장재료 구성에 관한 연구

한상수,박한규 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(계획계)

This study aims to find out the composition of the architectural materials for the exterior design of the buildings in the city. To carry out this study, the field survey for the buildings of the 5 main streets in Chonju area was done. They are analyzed as their built age, function, story and materials. It is concluded that ; 1. The tile is mostly used as the architectural material in the buildings in the city. 2. As the built age, the tile is most used in the buildings that were built from 1970 to 1980, the granite and glass are more widely used in the recent buildings. 3. As the function, the tile is largely used in the kind's of daily life buildings and hospital buildings, and the glass is in the office buildings. 4. As the building story, the tile is generally used in the lower story buildings, in the middle story buildings it is chiefly used granite and glass, and in the higher story buildings, the glass is mostly used. The elevational proportion of the building, as its used materials, the 1st main material by 70%,: the 2nd material by 23,:and the 3rd material by 7% in the buildings are composed.