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WATER MASERS FROM THE PROTOSTELLAR DISK AND OUTFLOW IN THE NGC 1333 IRAS 4 REGION

  • Park, Geum-Sook;Choi, Min-Ho
    • 천문학회지
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    • 제40권4호
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    • pp.123-125
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    • 2007
  • NGC 1333 is a nearby star forming region, and IRAS 4A and IRAS 4BI are low-mass Class 0 protostars. IRAS 4A is a protobinary system. The NGC 1333 IRAS 4 region was observed in the 22 GHz water maser with a high resolution (0.08") using the Very Large Array. Two groups of masers were detected: one near A2 and the other near BI. Most of the masers associated with A2 are located very close (< 100 AU) to the radio continuum source. They may be associated with the circumstellar disk. Since no maser was detected near AI, the A2 disk is relatively more active than the Al disk. Most of the masers in the BI region are distributed along a straight line, and they are probably related with the outflow. As in many other water maser sources, the IRAS 4 water masers seem to trace selectively either the disk or the outflow. Considering the outflow lifetimes, the disk-outflow dichotomy is probably unrelated with the evolutionary stage of protostars. A possible explanation may be that both the outflow-maser and the disk-maser are rare phenomena and that detecting both kinds of maser around a single protostar may be even rarer.

블루스 전통에서 바라본 제니스 조플린의 위반 : 공연을 중심으로 (Janis Joplin's transgression in blues tradition: focusing on blues performance)

  • 최하영
    • 영미문화
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    • 제14권1호
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    • pp.287-310
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    • 2014
  • While Janis Joplin is generally known as a hippie rock star of an untimely death to Korean audience, she is more strongly evoked in the image of blues mama in American context. Blues, definitely based on African-American vernacular tradition, is defined as a matrix, which is "a point of ceaseless input and output, a web of intersecting, crisscrossing impulses always in productive transit," to borrow Houston A. Baker's expression. This article explores how her life and music can be understood in blues tradition, especially in terms of personal and social transgression for which she was criticized, focusing on her blues performance. First of all, born and growing up in southern Texas between 1940s and 1960s, she expressed her innate suspicion against segregation and white supremacy, actively embracing rich black musical heritage of the area. Second, against the normative social and moral expectation of a middle class white woman to be a suburban housewife, she sought her own desire, whether it was professional ambition or sexual possibility. Third, beyond the selling image of a heterosexually lascivious blues mama, she dared to be a homosexual and bisexual, while it was not publically acknowledged. Along with her alcohol and drug dependence, such transgressions against normative social expectation were not made without her inner conflict, leaving a trace of trauma, hesitation, and the blues. While she was "buried alive in the blues," as a sacrifice at the altar of the 1960s, she still remains "alive" provoking "fire inside of everyone of us."

협동 제품개발 실습에서 참가자 기여도 평가를 위한 Product Data Analytics 기반 정량적 평가 시스템 적용 (Applying a Product Data Analytics-based Quantitative Contribution Evaluation System for Participants to Collaborative Projects in Product Development Practices)

  • 도남철
    • 공학교육연구
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    • 제22권4호
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    • pp.61-70
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    • 2019
  • As product development process becomes complex, it becomes more important for engineering students to experience collaborative product development. Especially the collaboration experience based on Product Data Management (PDM) systems is useful, since participants are likely to use the same environment for their professional product development. However, instructors have difficulties to evaluate contribution of each participant to their projects during the practices, since it is hard to trace personal activities for collaborative design processes. To solve this problem, this study suggests a data-driven objective method that analyses product data accumulated in PDM databases to evaluate numerically calculated contributions of participants to their class projects. As a result, the quantitative measures provided by the data-driven analysis with qualitative measures for project results can improve the fairness and quality of evaluation of contributions of participants to collaborative projects. This study implemented the proposed evaluation method with an information system and discussed the result of the application of the system to product development practices.

A Variable Protostar, EC 53

  • Lee, Yong-Hee;Lee, Jeong-Eun;Johnstone, Doug;Herczeg, Gregory J.;Mairs, Steve;Varricatt, Watson;Contreras, Carlos
    • 천문학회보
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    • 제44권2호
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    • pp.68.2-68.2
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    • 2019
  • Most of the stellar mass accretes during the early evolutionary stage of protostars. However, the accretion process in protostars is in a veil of the thick envelope. Monitoring the submillimeter emission from the envelope is a way to trace the accretion process in protostars since the submillimeter emission linearly responses to the temperature of the envelope, which is heated by the accretion process at the center. In the JCMT transient Survey, we detected a submillimeter variable, EC 53. EC 53 is a Class 1 protostar that was known to have a periodic variation at NIR. EC 53 has been monitored with United Kingdom InfraRed Telescope (UKIRT), Liverpool telescope, and JCMT/SCUBA-2 since we detected the 850 ㎛ flux enhancement in the JCMT transient survey. We also adopt the photometric data sets of Wide-field Infrared Survey Explorer (WISE). Over all wavelengths from NIR to submillimeter, we see two modes of variation, a 1.5-years periodic variation and a long-term increase. We present the light curves of EC 53 at multi-wavelengths and discuss the cause of variability in EC 53.

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전남지역에서 출토된 고대 도자기의 태토조성과 소성온도 (Body Composition and Firing Temperature of Ancient Pottery Excavated in Chonnam Province)

  • 강경인;정창주
    • 보존과학회지
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    • 제6권1호
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    • pp.15-30
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    • 1997
  • 전남지역 도요지에서 출토된 토기, 시유도편, 녹청자와 청자편의 제조기술과 산지추정은 X선회절분석, 유도결합 플라즈마 발광분석, 열기계적 분석을 통한 물리화학적 성질의 검토로 이루어졌다. 도편의 사용원료는 점토, 석영, 장석광물로 유사하지만 그 함량비는 출토지에 따라 약간의 차이가 있으며, 철분함량에서 토기, 흑갈유, 녹갈유 도편은 $4\~7\%$, 녹청자 및 청자편은 $2\~3\%$로 기종에 따라 두드러진 차이를 나타내고 있다 흑갈유, 녹청자의 구성광물은 $\alpha-Quartz$, mullite와 일부 tridymite, cristobalite로 이루어졌으며, 청자는 $\alpha-Quartz$, mullite만으로 구성되어 있다. 도편의 소성온도는 토기가 $1000\~1100^{\circ}C$, 흑갈유, 녹갈유, 녹청자 청자가 $l130\~1200^{\circ}C$ 정도로 추정되었다. 도편에 대한 출토지의 구분은 분석된 21개의 미량원소중 14개의 원소가 매우 근접되어 불가능하였으며, 도자기제조에 사용된 원료의 지질학적인 특성이 유사한 것으로 판단하였다. 이들 지역에서 출토된 도편의 특성원소는 Rb, Sr, V, Zr, Y, Nd, Sc, La, Ce, Nb, Sm, Eu, Dy, Yb로 14개이다. 영암의 도편은 Zn과 Fe원소에 의해 다른 지역에서 출토된 도편들과 명확히 구분되었고, 출토지가 다른 녹청자, 청자편은 동일한 범위에 군집되는 특징을 나타내어 사용원료가 비슷한 것으로 추정된다.

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대학 강의실에서 글리터의 분포 연구 (A study on the distribution of glitter particles from an university building)

  • 홍성욱;조형우;손다솜;이슬비
    • 분석과학
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    • 제28권4호
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    • pp.288-298
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    • 2015
  • 대학교의 한 강의동에 있는 16개 강의실에 비치되어 있는 의자 1,000개를 피전사체(potential recipient)로 선정해 미세증거물의 한 종류인 글리터의 분포를 연구하였다. 강의실에 비치된 의자의 인체와 접촉하는 표면을 테이프로 전사하고 테이프를 현미경으로 관찰한 결과 조사 대상으로 삼은 16개 강의실의 68.8 %에 해당하는 11개 강의실의 의자에서 12점의 글리터가 발견되었다. 이는 1,000개 의자의 1.1%에 해당하는 11개 의자에서 12점의 글리터가 발견되었다고도 해석할 수 있는 결과로서 이런 결과를 볼 때 글리터는 다른 사건현장에서도 나타날 가능성이 높은 미세증거물인 것을 알 수 있다. 발견된 각각의 글리터는 육안 및 현미경으로 모양, 크기, 두께, 색상, 홀로그램 존재여부를 검사하였고 검사가 끝난 글리터는 적외선분광광도계로 옮겨서 양쪽 면의 코팅성분을 화학적으로 분석함으로서 12점의 글리터 중 서로 동일한 글리터가 있는지 확인하였다. 확인 결과 발견된 12점의 글리터 중 2점은 동일시기에 동일물체에서 탈락된 특성이, 2점은 동일한 생산라인에서 만들어진 동일한 종류의 글리터로 볼 수 있는 특징이 나타났고, 8점은 서로 다른 글리터로 밝혀졌다. 동일한 생산라인에서 만들어진 글리터가 두 개의 다른 강의실 의자에서 발견된 결과를 해석하기 위해 강의실을 이용한 학생들의 이동경로를 추적한 결과 두 강의실은 동일수업을 수강하는 학생들이 이용한 강의실인 것으로 밝혀졌다. 이 결과는 미세증거물의 증거가치를 판단할 때에는 사건관계자의 이동경로를 함께 고려해야 한다는 것을 말해주는 것이다.

시대 변천에 따른 속옷에 관한 연구(I) -고대를 중심으로- (A Study on the Changes of the Ancient Underclothes)

  • 김주애
    • 복식문화연구
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    • 제5권4호
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    • pp.12-31
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    • 1997
  • This is a study on the changes of the ancient underclothes. Underclothing includes all such articles, worn by either sex, as were completely or mainly concealed from the spectator by the external costume. Functions of underclothes are follow ; to protect the body from cold, to support the shape of the costume, to cleanliness, to erotic use of underclothes and as a method of class distinction. Linen is the oldest as materials and cotton came into general use after the Restoration of 1660. We must suppose that woolen petticoat was at least as old as the Middle Ages and silk was rarely used until late in Victorian times. Until the middle of the last century underclothes were necessarily hand-made, and the absence of fit was noticeable until the introduction of man\`s drawers, fitting the leg, at the close of the eighteen century. Strings and ribbons were the fastenings for underclothes until the middle of the seventeenth century, when they were replaced by buttons. One outstanding example of the first type of figures is a Babylonian girl of about 3000 BC from Sumeria who wears that today would immediately be described as briefs. Female statues show no trace of anything being worn under the chiton, but there is literary evidenced that the Greeks. A band of linen of kid was bound round the waist and lower torso to shape and control it. It was known as the Zone or girdle. The apodesmos, meaning a band, breast band, occurs in a fragment of Aristophanes. A Roman mosaic shows female athletes wearing a bikini-briefs and bra in the fourth century AD. A similar band, called the mastodeton, or breast band, was also worn round the bust, apparently to flatten or minimise it, as in the 1920s, and not, to stress its curves. In Rome, too, women sometimes wore bands of material round the hips and bust-a cestus or girdle is referred to by the poet Martial and seems to have been similar to the zone, but wider, and the strophium, or breast band, is mentioned by Cicero.

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30kW급 LFG 가스터빈 발전용 연료화 정제시스템 개발 (Development of Fuel Conditioning System for 30 kW-class LFG Gasturbine Power Generation)

  • 허광범;박정극;임상규;이정빈
    • 신재생에너지
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    • 제6권1호
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    • pp.29-37
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    • 2010
  • Biogas is a carbon neutral energy and consists of mostly methane and carbon dioxide, with smaller amounts of water vapor, and trace amounts of $H_2S$, Siloxane and other impurities. Hydrogen sulfide and Siloxane usually must be removed before the gas can be used for generation of electricity or heat. The goals of this project are to develope the Fuel conditioning system of Land Fill Gas for 30kW-Micro Gas Turbine co-generation system. The fuel conditioning system mainly consists of $H_2S$ removal system, Land Fill Gas compressor, Siloxane removal system and many filtering systems. The fuel requirement of 30kW MGT is at least 32% of $CH_4$, $H_2S$ (<30 ppm), Siloxane (<5ppb) and supply pressure (> 0.6 MPa) from LFG compressor. Main mechnical charateristics of Micro Gas Turbine system by using LFG have the specific performance; 1) high speed turbine speed (96,000 rpm) 2) very clean emmission NOx (<9 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for LFG fuel conditioning system. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of Land Fill Gas (LFG), this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

프레데릭 로 옴스테드의 도시공원관에 대한 재해석 (Reinterpreting Frederick Law Olmsted's Idea of Urban Parks)

  • 조경진
    • 한국조경학회지
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    • 제30권6호
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    • pp.26-37
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    • 2003
  • Urban park are indispensable elements of contemporary cities. However, the structure and culture of contemporary cities is currently changing. There are prevalent discourses that Olmstedian parte are no longer relevant to our new societies and cultures. New kinds of parks have emerged with different forms and functions. In order to propose a new paradigm for parks in the 21st century, we need to look back to the origin of modem parks, which is to say, Olmstedian parte. This paper aims to trace the background of park movements in the 19th century America and to identify and describe Olmsted's idea of urban parks. In addition, the paper will clarify the limitations and reinterpret the meaning of Olmsted's idea of urban parks. One idea behind the development of urban parte was to mitigate urban problems such as public health, alcoholism violence and class conflicts in 19th century industrial cities. The aim of urban park was partially achieved at that time. However, those parse did not serve the use of diverse classes. Olmstedian parks were designed for passive and civilized recreation, and lower classes were more attracted by active theme parks and areas such as Coney Island and John Wood. The strengths of Olmsted's idea of urban parte can be outlined as follows: First, designing parte goes beyond shaping physical lands to embrace social reforms. This means that park designers should have a critical understanding of society and culture. Also, landscape designers should have a bold vision for the future. Without such a vision and social agenda, landscape architects cannot postulate alternative possibilities through engaging in new practices. Second, Olmsted successfully adapted British landscape aesthetic ideas such as the picturesque, the sublime and the beautiful into an American context. Finally, his vision and idea of urban parks show us that landscape architecture is not just technical work, but that it can create a locus to engage a new cultural praxis by inventing cultural products - parks.

조선시대 체산자(砌山子)에 대한 연구 (A Study on Chesanja(Qìshānzǐ, The Looping stitch) of Joseon Dynasty)

  • 양수정
    • 복식
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    • 제66권7호
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    • pp.89-108
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    • 2016
  • The purpose of this study is not only to trace the examples of 'Chesanja' from the texts and artifacts, but also to restore the terminology of the lost traditional Joseon embroidery technique. 'Chesanja' came on Mongolia and Yuan period affected embroidery techniques of the neighboring countries. Therefore, this study will focus on investigate the process of changing 'Chesanja' into Guya(Goya) through ${\ll}Barktonsa{\gg}$ the foreign language transcriptions of the Chosun dynasty, and examine the generation, fashion, and destruction of this technique with the social technical usage. Around the 16th century of the Joseon Dynasty, 'Chesanja' had been actively used as a decorative techniques to dairy products as well as a Buddhist memorial goods embroidered. Accor- dingly, in the "Beonnyeok-Baktongsa"(1515) appeared together written records with 'Chesanja' 'Gwiyeo[귀여]' the Eonhae(Korean annotation) only had emerged in the Joseon Dynasty. It was still a technique to decorate the edges of royal pillow in the mid-17th century. And we have checked from the text "Baktongsaeonhae"(1677) also. Despite this by the mid-18th century, the term in "Baktongsa-sinseok"(1765) and "Baktongsa-sinseok-eonhae"(1765) had disappeared. This phenomenon suggests the possibility that the production and utilization of 'Chesanja' required the sophisticated process for the ruling class had been declined with the custom of embroidery based on the gradation by colorful threads as the preferred technique. Therefore, 'Chesanja' and 'Gwiyeo'[귀여] disappeared from the records but they can be found in the artifacts of the royal family of 19th century. So Chesanja is calls Guya(Goya) and exists as unique technic only in the royal family.