• 제목/요약/키워드: Re-Entry

검색결과 138건 처리시간 0.028초

차단막을 이요한 치조골재생의 장기적 평가 (Long-term evaluation of the bony regeneration following the guided tissue regeneration)

  • 최점일;김성조;김태규
    • Journal of Periodontal and Implant Science
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    • 제26권2호
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    • pp.350-355
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    • 1996
  • The present study was performed to evaluate the amount of bony regeneration following the guided tissue regeneration(GTR). Re-entry procedure has been performed at 1 year following the GTR with Gore-tex membranes on the furcal defects and the amount of bony regeneration was measured. Sites treatedwith open flap procedures were used as controls. The results reveated that significant amount of bone could be regenerated through the GTR procedures compared with convention flap procedures.

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Investigation of Single Phase Frictional Pressure Loss in Circular Micro Tubes

  • Han Dong-Hyouck;Lee Kyu-Jung
    • Journal of Mechanical Science and Technology
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    • 제20권8호
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    • pp.1284-1291
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    • 2006
  • Single phase pressure drops in micro tubes were investigated through an experimental measurement and a numerical simulation. Experimental Po was obtained in circular micro tubes with 87 and $118{\mu}m$ diameter with distilled water. Experiments were carried out in laminar flow region with varying the Re 15-450 for the $87{\mu}m$ diameter tubes and 60-1300 for the $118{\mu}m$ diameter tube. No early transition from laminar to turbulent flow was detected for the experimental range. The computational estimation of pressure drop in the $87{\mu}m$ diameter tube was performed with the aid of CFD software. Boundary conditions from experiments were used for the numerical simulation. The results of experimental and numerical studies showed a good agreement with the conventional macro theory.

A Study on the Enhancement of Detection Performance of Space Situational Awareness Radar System

  • Choi, Eun-Jung;Lee, Jonghyun;Cho, Sungki;Moon, Hyun-Wook;Yum, Jea-Myong;Yu, Jiwoong;Park, Jang-Hyun;Jo, Jung Hyun
    • Journal of Astronomy and Space Sciences
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    • 제35권4호
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    • pp.279-286
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    • 2018
  • Radar sensors are used for space situational awareness (SSA) to determine collision risk and detect re-entry of space objects. The capability of SSA radar system includes radar sensitivity such as the detectable radar cross-section as a function of range and tracking capability to indicate tracking time and measurement errors. The time duration of the target staying in a range cell is short; therefore, the signal-to-noise ratio cannot be improved through the pulse integration method used in pulse-Doppler signal processing. In this study, a method of improving the signal-to-noise ratio during range migration is presented. The improved detection performance from signal processing gains realized in this study can be used as a basis for comprehensively designing an SSA radar system.

A New Grid-Based Monte Carlo Code for Raman Scattered He II: Preliminary Results

  • Chang, Seok-Jun;Choi, Bo-Eun;Lee, Hee-Won
    • 천문학회보
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    • 제44권1호
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    • pp.85.2-85.2
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    • 2019
  • We developed a new grid-based Monte Carlo code to trace far UV He II line photons that are incident on a thick H I region and subsequently transferred through Rayleigh and Raman scattering with atomic hydrogen. In particular, we consider a neutral region that is moving away from the He II emission source which is either monochromatic or is described by a Gaussian profile. The resultant Raman scattered He II line profiles from a monochromatic source are characterized by a double peaked core part with an extended Raman red tail that is attributed to multiple re-entry events. Complicated behaviors are observed in the case of a Gaussian He II source including the formation of a secondary red peak near the Balmer center dependent on the H I column density. A preliminary application of our results to the CFHT data of the planetary nebula IC 5117 is presented.

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A Study of the Flow Phenomenon of Water in a Channel with Flat Plate Obstruction Geometry at the Entry

  • Khan, M.M.K.;Kabir, M.A.;Bhuiyan, M.A.
    • Journal of Mechanical Science and Technology
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    • 제17권6호
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    • pp.879-887
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    • 2003
  • The flow in a parallel walled test channel, when obstructed with a geometry at the entrance, can be forward, reverse and stagnant depending on the position of the obstruction. This interesting flow phenomenon has potential benefit in the control of energy and various flows in the process industry In this experiment, the flat plate obstruction geometry was used as an obstruction at the entry of the test channel. The parameters that influence the flow inside and around the test channel were the gap (g) between the test channel and the obstruction geometry, the length (L) of the test channel and the Reynolds number (Re). The effect of the gap to channel width ratio (g/w) on the magnitude of the velocity ratio (V$\_$i/ / V$\_$o/ : velocity inside/ velocity outside the test channel) was investigated for a range of Reynolds numbers. The maximum reverse flow observed was nearly 20% to 60% of the outside velocity for Reynolds number ranging from 1000 to 9000 at g/w ratio of 1.5. The maximum forward velocity inside the test channel was found 80% of the outside velocity at higher g/w ratio of 8. The effect of the test channel length on the velocity ratio was investigated for different g/w ratios and a fixed Reynolds number of 4000. The influence of the Reynolds number on the velocity ratio is also discussed and presented for different gap to width ratio (g/w). The flow visualisation photographs showing fluid motion inside and around the test channel are also presented and discussed.

해양 과학시추 50년 (1968-2018): 한국의 성과 및 미래 방향 (Fifty Years of Scientific Ocean Drilling (1968-2018): Achievements and Future Direction of K-IODP)

  • 김길영
    • 한국해양학회지:바다
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    • 제24권1호
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    • pp.30-48
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    • 2019
  • 2018년은 해양 과학시추가 시작된 지 50년이 되는 해이다. 그럼에도 불구하고 우리는 지구의 대양저보다 달의 표면을 더 많이 알고 있을 정도로 지구내부에 대한 정보가 많지 않다. 대양저에 관한 연구는 해양 과학시추로부터 얻어진 시료를 통해서 알 수 있다. 이러한 심해의 시료획득은 50년 전인 1968년 8월 11일 미연방차원에서 지원된 심해저시추계획(DSDP: Deep Sea Drilling Project)에서 글로마 챌린저(Glomar Challenger)호를 이용한 멕시코 만 시추로부터 시작되었다. 이후 해저지각시추프로그램(ODP: Ocean Drilling Program), 통합해저지각시추프로그램(old IODP: Integrated Ocean Drilling Program), 그리고 국제해양시추탐사프로그램 (new IODP: International Ocean Discovery Program)으로 이어져 오고 있다. 해양 과학시추로부터 얻어진 가장 큰 성과는 두 가지 기술적인 성과와 다양한 과학적인 성과로 나눠진다. 첫 번째 기술적인 성과는 시추선이 시추위치를 벗어나지 않고 연속적으로 시추코어를 획득할 수 있도록 위치를 유지시켜주는 동적위치유지 시스템(dynamic positioning system)이다. 다른 하나는 시추동안 드릴 비트를 교체한 후 동일한 시추공에 드릴비트가 쉽게 투입될 수 있도록 해주는 재투입 콘(re-entry cone)의 개발이다. 이러한 기술적인 혁신 외에도 다양한 과학적 성과 즉 판구조론 증명, 지구의 역사 규명, 그리고 심해 퇴적물 내 생명체의 발견 등이 있다. 2013년 10월 시작된 국제해양시추탐사프로그램(new IODP)은 2023년까지 계속될 예정이고, 2023년 이후 다음 단계를 위해 참여 회원국들은 새로운 과학계획 수립과 더불어 미래의 해양 과학시추 50년을 준비하고 있다. 우리나라도 이러한 국제적인 동향에 발맞추어 회원국가로서 지속적인 참여와 다음단계를 위한 준비가 필요한 시점이다.

경력단절여성의 복지정책에 관한 연구 (A Study on the Welfare Policy of Career Interrupted Women)

  • 이경화
    • 미래기술융합논문지
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    • 제1권2호
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    • pp.57-62
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    • 2022
  • 경력단절 여성들이 노동시장으로 재진입하는 것을 지원하기 위해서는 유망직업을 발굴하여 선정하는 것 뿐만이 아니라, 선정된 유망직종에 대한 객관적이고 정확한 직업정보를 제공하여 경력단절 여성들이합리적인 직업선택을 할 수 있도록 지원할 필요성이 제기된다. 정부지원과정이 일반과정에 비해 수강료의 부담이 없고, 교육 내용의 충실도가 높기 때문에 교육생 모집과정에서 경쟁을 통하여 취업의지가 높은 교육생을 선발할 수 있다는 점을 들 수 있다. 그리고 정부지원과정이 상대적으로 양질의 프로그램과 강사진을 확보하여 교육생의 집중도와 만족도, 취업에 대한 의지를 높인다는 점, 직무소양 및 취업대비 교육의 의무화, 취업상담을 통한 직업설계 지원 및 지속적인 사후지원 체제도 작용한다. 이에 따라 경력단절 여성을 위한 유망직종의 선정 및 교육훈련 프로그램의 설계과정에서 체계적이고 지속적인 개발과 지원이 이루어진다면 경력단절 여성들의 노동시장 재진입도 좀 더 활성화될 것으로 기대된다

Southeast Asian Studies: Insiders and Outsiders, or is Culture and Identity a Way Forward?

  • King, Victor T.
    • 수완나부미
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    • 제8권1호
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    • pp.17-53
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    • 2016
  • Debates continue to multiply on the definition and rationale of Southeast Asia as a region and on the utility of the multidisciplinary field of area studies. However, we have now entered a post-colonialist, post-Orientalist, post-structuralist stage of reflection and re-orientation in the era of globalization, and a strong tendency on the part of insiders to pose these issues in terms of an insider-outsider dichotomy. On the one hand, the study of Southeast Asia for researchers from outside the region has become fragmented. This is for very obvious reasons: the strengthening and re-energizing of academic disciplines, the increasing popularity of other non-regional multidisciplinary studies, and the entry of globalization studies into our field of vision. On the other hand, how has the local Southeast Asian academy addressed these major issues of change in conceptualizing the region from an insider perspective? In filling in and giving substance to an outsider, primarily Euro-American-Australian-centric definition and vision of Southeast Asia, some local academics have recently been inclined to construct Southeast Asia in terms of the Association of Southeast Asian Nations (ASEAN): a nation-state-based, institutional definition of what a region comprises. Others continue to operate at a localized level exploring small-scale communities and territories, while a modest number focus on sub-regional issues (the Malay-Indonesian world or the Mekong sub-region are examples). However, further reflections suggest that the Euro-American-Australian hegemony is a thing of the past and the ground has shifted to a much greater emphasis on academic activity within the region. Southeast Asia-based academics are also finding it much more important to network within the region and to capture, understand, and analyze what Chinese, Japanese, and Korean scholars are saying about Southeast Asia, its present circumstances and trajectories, and their increasingly close involvement with the region within a greater Asia-Pacific rim. The paper argues that the insider-outsider dichotomy requires considerable qualification. It is a neat way of dramatizing the aftermath of colonialism and Orientalism and of reasserting local priorities, agendas, and interests. But there might be a way forward in resolving at least some of these apparently opposed positions with recourse to the concepts of culture and identity in order to address Southeast Asian diversities, movements, encounters, hybridization, and hierarchies.

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공연의 형식에 따른 현대공연장 공간구성 특성에 관한 연구 (A Study on the Characteristics of Space Forms in Performing Arts Centers for Performance Types)

  • 김성기
    • 한국실내디자인학회논문집
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    • 제21권1호
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    • pp.195-202
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    • 2012
  • This study aimed to analyze the types and characteristics of space forms according to performance types in the space of performing arts centers through the cases of modern performing arts centers. As for the space forms according to the performance forms, the performing arts centers devoted to dramas made a small space or turned into multi-purpose ones entering the modern days. Added to the proscenium, the main stage, was the back stage for the stage background. The area of the stage and auditorium grew similar with some kind of separation between the stage and audience. The concert halls have close relationships with the audience and their stage contacts the auditorium on many sections. The stage space is smaller than the auditorium and usually either the complex or entry type. In the opera theater, they commonly create a space for social gathering in addition to the main stage of proscenium, back stage, side stage and auditorium. They're also distinct from other performing centers for having an orchestra pit between the stage and audience. The stage is twice as big as the auditorium and the separate type. In today's performing arts centers, the sizes of the stage and auditorium can vary widely, and the performances of many different genres are put to multiple purposes.

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문헌과 이탈 귀순자 설문조사를 통해 본 북한인의 보건영양상태 (Assessment of Health and Nutritional Status of North Koreans Utilizing an Exhaustive Literature Search and Survey)

  • 장남수
    • Journal of Nutrition and Health
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    • 제31권8호
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    • pp.1338-1346
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    • 1998
  • North Korea has been experiencing a serious food shortage. However, the extent and magnitude of malnutrition and health problems are virturally unknown because a nationwide food and nutritional survey has never been conducted. To get a better udnerstanding of the situation., an exhaustive literature search on the health and nutritiona conditions of North Koreans was performed. We also obtained anthropometric data on 274 North Korean Defectors who are recently resettlers in the South. Some(137) measurements were taken at the time of entry to the South, and the remaining data was from the health and nutrition mail survey conducted by us on North Korean refugeee re-settlers. Health and inutritional status of North Koreans was found to be less than desirable as shown in high infant mortality rates, high mortality and morbidity rates of malnutriton-related infectious deseases, and smaller body sizes. Striking differences were noted in all of the above health and nutrition indicators between north and South Koreans. Considering the fact that North and South Koreans are homogeneous in their genetic back-ground, ours study results clearly demonstrate that the health and nutrition of North Koreas has deteriorated with the dhronic food shortage, which might have sorsened with a recent food crissi. The smaller and thinner adult stature proevailing in North Korea could play a significant negative role in the country's economy, since lower lean body mass has been associated with reduced work productivity that could hinder economic growth and development.

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