• 제목/요약/키워드: Stable region

검색결과 1,098건 처리시간 0.024초

부정교합 아동의 성장에 따른 연조직 측모의 변화 (A LONGITUDINAL STUDY ON THE SOFT TISSUE FACIAL PROFILE CHANGES - Study report from 9 to 13 years of age -)

  • 장병천;김정민;경희문;권오원;성재현
    • 대한치과교정학회지
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    • 제19권3호
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    • pp.87-97
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    • 1989
  • 연조직 측모의 연령증가에 따른 변화양상을 정확히 규명하고자 정상적인 안모 및 교합을 가졌다고 생각되는 9세 아동 남자 29명, 여자 26명을 대상으로 2년 간격으로 3차례에 걸쳐 얻어진 두부방사선 규격사진을 분석하여 다음과 같은 결론을 얻었다. 남녀별 각 계측항목의 연령에 따른 평균치 및 표준편차를 산출하였다. 연조직 측모의 평가에서 soft tissue facial angle, total facial convexity angle은 연령증가에 따른 약간의 변화를 보여 주었으며 기타 항목에서는 큰 변화를 보이지 않았다. 연조직 후경은 연령증가에 따른 증가를 보여 주었으며 두안부의 하안면부(point B, pog) 보다는 구순부(point A, LS, LI)에서의 증가량이 더 크게 나타났다. 안면고경의 바율은 GL'-Sn/Sn-Me' 1:1, Sn-St/St-Me' 0.51:1, Sn-LI/LI-Me' 0.82 : 1 로 연령증가에 따른 큰 변화가 없었다.

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ANALYSIS OF HCCI COMBUSTION CHARACTERISTICS BASED ON EXPERIMENTATION AND SIMULATIONS-INFLUENCE OF FUEL OCTANE NUMBER AND INTERNAL EGR ON COMBUSTION

  • Iijima, A.;Yoshida, K.;Shoji, H.;Lee, J.T.
    • International Journal of Automotive Technology
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    • 제8권2호
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    • pp.137-147
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    • 2007
  • Homogenous Charge Compression Ignition (HCCI) combustion systems can be broadly divided for the process applied to 4-stroke and 2-stroke engines. The former process is often referred to as simply HCCI combustion and the latter process as Active Thermo-Atmosphere Combustion (ATAC). The region of stable engine operation tends to differ greatly between the two processes. In this study, it was shown that the HCCI combustion process of a 4-stroke engine, characterized by the occurrence of autoignition under a high compression ratio, a lean mixture and wide open throttle operation, could be simulated by operating a 2-stroke engine at a higher compression ratio. On that basis, a comparison was made of the combustion characteristics of high-compression-ratio HCCI combustion and ATAC, characterized as autoignited combustion in the presence of a large quantity of residual gas at a low compression ratio and part throttle. The results showed that one major difference between these two combustion processes was their different degrees of susceptibility to the occurrence of cool flame reactions. Compared with high-compression-ratio HCCI combustion, the ignition timing of ATAC tended not to change in relation to different fuel octane numbers. Furthermore, when internal EGR was applied to high-compression-ratio HCCI combustion, it resulted in combustion characteristics resembling ATAC. Specifically, as the internal EGR rate was increased, the ignition timing showed less change in relation to changes in the octane number and the region of stable engine operation also approached that of ATAC.

두개의 전위차계를 이용한 모듈형 완구의 동작 저장 및 반복 재생 동작의 구현 (Record and Replay Motion Implementation to Modular Toys using Two Potentiometers)

  • 이진규;이보희;김종태;박지엽;공정식
    • 융합정보논문지
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    • 제7권2호
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    • pp.59-65
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    • 2017
  • 창의적 모듈형 완구의 동작 구현을 위하여 동작을 기록하고 또한 읽어서 반복 동작하는 방식의 움직임이 요구된다. 이 때 완구 동작용 모터 출력축에는 전위차계를 사용하여 절대 회전각을 읽어서 제어를 수행하게 된다. 하지만 전위차계의 감지 영역의 불안정한 부분이 일정 영역에 존재하게 되는데 이로 인한 모터 제어의 불안정을 가져올 수 있다. 본 논문에서는 2개의 전위차계를 한 축에 장착시켜 안정된 영역을 각각 읽어서 1회전 절대각을 찾는 알고리즘을 제안한다. 그리고 다중 회전을 수행 시 필요로 하는 보정 알고리즘에 대해서도 기술하였다. 제안된 방식은 실제 토포보 모듈라 완구에 적용하여 동작을 기록하고 반복 동작을 수행하여 효과적으로 동작됨을 보였다. 아울러 다 회전 동작을 기록하고 동작 시켜 제안된 방식의 유용성을 제시하였다. 향 후 다양한 동작을 통하여 기록과 재생의 기능을 확대해 나갈 것이다.

중력모형을 이용한 일본의 CPTPP 교역 효과 분석 (Analysis of Japan's CPTPP Trade Effect Using Gravity Model)

  • 김종인;황성혁
    • 산업융합연구
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    • 제21권5호
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    • pp.43-50
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    • 2023
  • 우리 정부는 2022년에 아시아·태평양 지역 내 안정적인 공급망 구축 등을 위해 CPTPP 가입을 추진한다는 계획을 발표하였다. CPTPP는 아시아·태평양 지역의 경제통합 기치 아래 예외 없는 관세 철폐와 새로운 통상규범 정립 등을 목표로 일본이 주도하고 있으며 2018년에 11개국 간 타결되어 출범하였다. 본고의 분석에 따르면 CPTPP 발효 이후 일본과 회원국 간 교역 증진 효과가 확인되었고, 1인당 GDP가 많고 거리가 짧을수록 그 효과가 더욱 컸으며 관세 철폐 및 감축이 예정대로 진행된다면 교역 증진 효과는 점차 확대될 것으로 예상된다. 반면, 일본과 CPTPP 회원국 간 교역 확대는 비회원국과의 교역이 상대적으로 위축될 수도 있다는 것을 시사하므로 아시아·태평양 지역 내에서 안정적인 공급망을 구축해야 하는 우리나라 산업 측면에서는 위협 요인으로 작용할 수도 있다. 일본은 우리나라의 네 번째 무역 상대국으로 주요 교역 파트너인 만큼 CPTPP가 향후 일본과 회원국 간 교역에 미치는 영향에 대한 면밀한 검토 등을 토대로 우리나라의 CPTPP 참여 여부 및 협상 내용 관련 논의가 이루어져야 할 것이다.

깊이정보를 이용한 케스케이드 방식의 실시간 손 영역 검출 (Real-time Hand Region Detection based on Cascade using Depth Information)

  • 주성일;원선희;최형일
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제2권10호
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    • pp.713-722
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    • 2013
  • 본 논문에서는 깊이정보를 이용하여 케스케이드 방식에 기반한 실시간 손 영역 검출 방법을 제안한다. 실험 환경 조명 조건의 변화로부터 빠르고 안정적으로 손 영역을 검출하기 위해 깊이정보만을 이용한 특징을 제안하며, 부스팅과 케스케이드 방법을 이용한 분류기를 통해 손 영역 검출 방법을 제안한다. 먼저, 깊이정보만을 이용한 특징을 추출하기 위해 입력영상의 중심 깊이 값과 분할된 블록의 평균 깊이 값의 차이를 계산하고, 모든 크기의 손 영역 검출을 위해 중심 깊이 값과 2차 선형 모델을 이용하여 손 영역의 크기를 예측한다. 그리고 손 영역으로부터의 특징 추출을 통한 학습 및 인식을 위해 케스케이드 방식을 적용한다. 본 논문에서 제안한 분류기는 정확도를 유지하고 속도를 향상시키기 위하여 각 스테이지를 한 개의 약분류기로 구성하고 검출율을 만족하면서 오류율이 가장 낮은 임계값을 구하여 과적합 학습을 수행한다. 학습된 분류기를 이용하여 손 영역을 분류하고, 병합단계를 통해 최종 손 영역을 검출한다. 마지막으로 성능 검증을 위해 기존의 다양한 아다부스트와 정량적, 정성적 비교 분석을 통해 제안하는 손 영역 검출 알고리즘의 효율성을 입증한다.

역내 해양협력 및 신뢰증진을 위한 한국 해군의 기여방안 (ROK Navy's Role for a Confidence Building and Mutual Cooperation on the East Asian Sea)

  • 박영준
    • Strategy21
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    • 통권30호
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    • pp.143-176
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    • 2012
  • We are witnessing the growing maritime tension on the East Asian sea these days. Each naval powers in the region are competing each other to acquire more advanced naval capabilities. Based upon the rapid economic development, China is actively beefing up its naval capabilities and expand its boundary of naval activities all over the East Asian region. Chinese Navy already unveiled its expansive naval strategy replacing the traditional concept of 'Near-Sea Defense' with the new concept of 'Far-Sea Defense' strategy. In response to potential rival's naval build up, the U.S. is redeploying its naval forces focusing on the Asia-Pacific region. The U.S. enhances its joint naval exercises with the countries in the region, such as Japan, India, Australia and so on. In addition, Washington is devising new naval strategy under the concept of 'Air-Sea Battle' to deter Peking's so-called 'Anti-Access/ Area Denial(A2AD)' strategy. As a close ally of the U.S., Japan also disclosed its clear intention to strengthen the Maritime Self Defense Force(MSDF)'s capabilities by introducing the new concept of 'Dynamic Defense Force' in 2011. Under the new concept, JMSDF is pursuing the additional acquisition of submarines, quasi-aircraft carriers, Aegis-equipped destroyers, etc. Under the new president's strong leadership, Russia is also invigorating the naval build-up. Especially, Russia is fortifying the Pacific Fleet's naval assets by deploying new-type of naval ships such as the Mistral which was imported from France. In the midst of competitive naval build-up among the major naval powers in the region, we are observing the growing maritime conflicts on the East China Sea as well as South China Sea. Those naval conflicts can pose severe threats to our national interests. Maritime conflicts on the East or South China Sea can imperil our sea lanes which will be indispensible for national economic development. Neighboring countries' maritime conflicts also will cast an uncertainty on the path to mobilize international cooperation to resolve the North Korean issues. We should contribute to ease the maritime tension in the region by various ways. First, we should actively galvanize the bilateral maritime dialogue among the major naval powers in the region. Second, we also should take the lead to form a multilateral maritime cooperation mechanism in the region. Above all, we should set the aim to be a peaceful maritime power who can contribute to a building of stable maritime order in the region with a considerable naval power.

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韓國 煙草載培地域의 地理學的 硏究 (A geographical study of the Korean Tobacoo forming region)

  • 김광자
    • 대한지리학회지
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    • 제21권
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    • pp.16-37
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    • 1980
  • The purpose of this study is to clarify how the Korean tobacco farming region has been geographically formed by natural and cultural environments, and to examine and cultural environments, and to examine whether it can be recognized as a major part of agricultultural regions. The questions asked in this study are associated with the spatial diffusion of tobacco cultivation, the patterns and processes of the farming region from 1900 to 1960, and the regional characteristics of the concentrated farming area since 1960. The study is inductively approached and most data used were collected from old records and field works. The delineation of the tobacco farming region was derived by applying the concept of the uniform region. Tobacco was introduced through Japan during the years of Kwang Hae Kun (1616-1622). According to the old records, three places, Waekwan, Dongrae, and Ulsan, were the first tobacco raising areas. In the 1700's the well-known tobacco farming regions were scattered all around the nation in places like Jinan, Samdeung, Seongcheon, Gangdong, Yeongweol and Yeongyang. This distributon pattern suggests that tobacco farming in Korea developed spatially along main traffic routes before the 1700's. Untill the 1920's the pattern of tobacco regions was relatively static. Since the 1920's, it has shown a pattern of concentration in the Choongbuk province, where the new highly productive yellow tobacco has been introduced. It was not until the 1960's that yellow tobacco instead of the native variety came to be cultivated all over the country. In the 1960's, the tobacco farming region tended to be concentrated and localized in north western Choongnam, northern Cheonbuk, Choongbuk, and Kyeongbuk including Cheongsong, Andong, and Yeongyang. Since 1970, tobacco production has declined in some of the former major areas of cultivation in terms of its density, while there have appeared highly concentrated areas in Cheongsong and Andong, centered around Yeongyand. There has also emerged a secondary major concentrated area along the coast including such places as Kochang, Yeongkwang and Mooan. The appearance of the Yeongyang tobacco area as the most important core region can be described as follows; at first this area has the disadvantage of being in competition with other places for selling cash crops besides tobacco, because it is located in a mountain zone and it is far from the major metropolises of Seoul and Pusan. Thus has been formed the farming mentality that agricultural management makes the most profit on farming tobacco because tobacco is stable in price and selling routes. As a result of this longstanding belief, these areas (Yeongyang, Cheongsong and Andong) have developed into tobacco concentrated regions. Finally, the tobacco concentrated regions of Korea have changed through time. The factors affecting this change have been the kind of tobacco grown, the monopoly system, agricultural techniques and the expansion of arable land through the clearing of slopes. In conclusion, the research indicates that the localized and concentrated patterns of tobacco cultivation are geographically typical. Thus, recognition of tobacco farming region is important to understanding the agricultural region of Korea as a whole.

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3차원 테크놀러지를 이용한 여성용 수영복의 가슴부위 외관 및 패턴 기능성 향상에 관한 연구 (3D Pattern Development of Functional Women's Swimwear To Improve the Appearance and Stability of Chest Region)

  • 유정자;홍경희
    • 한국생활과학회지
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    • 제21권2호
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    • pp.285-298
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    • 2012
  • Considerable number of women are enjoying swimming, however, the chest-region of swimsuits including cup inserts are not stable during swimming. The purpose of this study was to explore alternate designs and methods of stabilizing the breast cup to the swimmer's body by using 3D technology to design and position the pad and cup pattern of the swimming suit. To position the pad optimally, a 3D pattern of a nude woman was divided into blocks and different reduction rates were applied to blocks around the outlines of the breast. Two types of 3D patterns were developed. The first, referred to as the 'basic 3D pattern' provided for the curved surface of the breast point to be maintained with the remaining slack distributed evenly along the neckline, armhole and side seam. The second, referred to as the '1/3 shoulder moved 3D pattern' ignored the curved nature of the breast point by overlapping, with the resulting position of the shoulder strip moved toward the center. Three women of corresponding size and body shape evaluated the two 3D pattern designs as well as the conventional 2D pattern style of swimsuit. Respondents rated the'the basic 3D pattern' design highest in terms of stability and easy of movement in the chest region.

유도전동기의 극 저속도 운전을 위한 MRAS방식 순시속도 관측기에 관한 연구 (A study on MRAS(Model Reference Adaptive System) Method Instantaneous Speed Observer for Very Low Speed Drive of Induction Motors)

  • 황락훈;나승권;정남길;김영복
    • 한국항행학회논문지
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    • 제16권6호
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    • pp.1123-1133
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    • 2012
  • 논문에서는 극저속 영역 및 저속 영역에서 안정적이고 동특성이 우수한 벡터제어 시스템을 구성하여, 축소차원 상태관측기를 이용한 순시속도 관측기와 극 저속 제어, 회전자 속도를 추정하는 벡터제어 시스템에 관한 방법을 제안하였다. 본 시스템에서 제안된 관측기는 축소차원 상태관측기를 부하토크 추정에 적용하여 속도추정에 이용함으로서 시스템구성을 간단히 구현 하면서도 극 저속 영역에서 정확한 순시속도 추정이 가능하였다. 또한, 시스템 잡음에 의한 영향을 줄이고, 관측기의 극을 변화시키는 일 없이 부하외란 이나 모델화 오차, 측정 잡음 등에 강인한 유도전동기 속도제어 시스템을 제시하였다.

미연혼합기의 난류특성과 이중분류버너화염의 연소특성에 관한 실험적 연구 (An experimental study on turbulence characteristics of mixture and combustion characteristics of doubled jet burner flames)

  • 최경민;장인갑;최병륜
    • 대한기계학회논문집B
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    • 제21권2호
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    • pp.213-223
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    • 1997
  • Premixed flame is better than diffusion flame to accomplish a high loading combustion. Since the turbulent characteristics of unburned mixture has a great influence on the flame structure, it is general that many researchers realize a high loading combustion with strengthening turbulent intensity of unburned mixture. Because turbulent premixed flame reacts efficiently on the condition of distributed reaction region, we made high turbulent premixed flame in the doubled impingement field. We investigated turbulent characteristics of unburned mixture with increasing shear force and visualized flames with direct and Schlieren photographs. And the combustion characteristics of flame was elucidated by instantaneous temperature measurement with a thermocouple, by ion currents with a micro electrostatic probe, by radical luminescence intensity and local equivalence ratio. Extremely strong turbulent of small scale is generated by impingement of mixture, and turbulent intensity of unburned mixture increased with the mean velocity. As a result of direct photographs, visible region of flame became longer due to increasing central direction flux. But as strengthed turbulent intensity, visible region of flame turned to shorter and reaction occurred efficiently. As strengthened turbulent intensity of mixture with increasing flux of central direction, maximum fluctuating temperature region moved to radial direction and fluctuation of temperature became lower. The reason is influx of central direction which caused flame zone to move toward radial direction, to maintain flame zone stable and to make flame scale smaller.