• 제목/요약/키워드: Existence Needs

검색결과 194건 처리시간 0.027초

초소형 촉매 이상 분해 반응기 해석 모델 개발 (Development of Analysis Model for Down Scaled Two Phase Catalytic Reactor)

  • 이대훈;권세진
    • 대한기계학회논문집B
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    • 제28권1호
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    • pp.24-30
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    • 2004
  • Analysis model for the two-phase catalytic reactor is presented. With the progress in development of micro thermofluidic devices, needs fur understanding of the phenomena in two phase reaction in cm scale has been arisen. To investigate thermal and reactive performance of down scaled two phase reactor simple analysis model that is a kind of lumped flow model is proposed. Analysis model presented is based on the experiment on mm scale model reactor. Target experiment is catalytic decomposition of 70wt% hydrogen peroxide with existence of perovskite L $a_{0.8}$S $r_{0.2}$Co $O_3$ catalyst. It is composed of balance equations of mass and energy. Each phase is considered to be a species fur the simplicity. Axial diffusion and transversal distribution of properties are neglected. Two phase catalytic reaction is modeled as successive gasification of liquid lump around catalyst and reaction in gas phase. Heat transfer is modeled by model function ofNu number. Modeled Nu is expressed as Nu=N $u_{0}$ (1+ $a_1$( $a_2$ $T^{-}$ $a_3$)exp( $a_4$ $T^{-1}$)exp( $a_{5}$ z). Transfer coefficients are determined by the comparison of experimental results. With the model, heat transfer characteristics are investigated. Also by the mass transfer coefficient, characteristics in mass transfer is investigated. With the result basic understanding on design and analysis of mm scale two-phase reactive device is obtained. Also it can be further applied to micro scale reactive device fabricated by micromachining.ing..

국내의 경근(經筋) 연구동향에 대한 고찰 (An Analysis of the Study Tendency on Meridian Muscle)

  • 이상민;이종수
    • 척추신경추나의학회지
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    • 제4권2호
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    • pp.211-223
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    • 2009
  • Objectives : The aim of this research is to analyze the current trend of the studies about eridian muscle and to provide background for further studies. Methods : Reviewing 33 domestic oriental medical studies about meridian muscle, and comparative analysis was made. These studies were classified by method, theme and subtitle. Results : 1. According to the classification by study method, number of literary studies are 22(67%), which is more than half, number of experimental studies are 5(15%) and clinical studies are 6(18%). 2. According to the classification by study theme in literary study, percentage of 'Structure amp; Movement of Meridian Muscle' took 64%, Theory study of Meridian Muscle' took 14%, 'Application of Concept of Meridian Muscle' took 14%, 'Treatment of Meridian Muscle disorder' took 9% arranged in order. 3. In 'Theory study of Meridian Muscle', there were not only literary approaches but also Deficiency-Excessiveness(虛實) and historical approaches. Study about 'Structure & Movement of Meridian Muscle' includes analysis of muscle and Myofascial pain syndrome. On this background, it is necessary to recognize the linkage and motion analysis of Meridian Muscle. Therefore, studies were changed into interpretation about Anatomy trains, analysis of motion. The study about 'Treatment of Meridian Muscle disorder' provided the various treatment method-Acupuncture, Manual therapy, Ashi(阿是)-point therapy, CHUNA therapy etc.- in literary study. The study about the 'Application of Concept of Meridian Muscle' has been performed in relation to Embedding Therapy, Kyungkuen chuna, Ki-gong therapy. 4. Experimental Studies were all Anatomical Studies. Studies were done in trial of discovering the actual existence, but revealed problem in interpretating the meaning of Meridian Muscle. 5. Clinical Studies based on Ashi(阿是)-point therapy CHUNA Muscles Along Meridians Release Therapy etc, were performed. Experimental studies about Meridian Muscle were assessed as low grade according to Jadad Scale. There were no studies which were based on well-organized Meridian Muscle theory. Conclusions : There needs to be more discussion about concept of Meridian Muscle and proceed more reliable experimental studies with organized Meridian Muscle theory. Further objective studies about treatment of Meridian Muscle should be done.

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영아반 보육실습 체험에 대한 의미 (Meaning of Student Teaching Experiences in Daycare Centers for Toddler)

  • 천혜정;서영숙
    • 한국보육지원학회지
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    • 제6권1호
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    • pp.177-199
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    • 2010
  • 본 연구는 어린이집 영아반 보육실습에서 예비보육교사들이 어떠한 체험을 하는지, 그 체험의 의미가 무엇인지를 드러내어, 예비보육교사들의 영아반 보육실습에 대한 이해를 제공하는데 연구목적이 있다. 연구방법은 서울의 A대학 유아교육과 3학년 학생 4명의 보육실습 체험을 8개월간 수집한 내러티브 연구이다. 예비보육교사들의 영아반 보육실습의 체험은 개인마다 다양하였으며 실습을 통하여 교사가 되어가는 것의 가치와 영아에 대한 이해, 영아보육에 대한 이해를 나타내고 있다. 영아반보육실습의 의미는 예비보육교사가 보육실습에서 자기존재를 확인하고 교사로서 자신을 돌아보는 자기성찰의 태도를 통하여 자기정체성을 형성해 나가는 과정이고, 가르치는 일에 행복함을 체험하는 과정이었다. 또한 영아보육교사의 역할은 영아들의 삶에 진정으로 마음을 다하여 함께 하는 돌봄의 자세임을 알아가고 있다.

역정규 손실함수를 이용한 기대손실 관리도의 개발 (A Development of Expected Loss Control Chart Using Reflected Normal Loss Function)

  • 김동혁;정영배
    • 산업경영시스템학회지
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    • 제39권2호
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    • pp.37-45
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    • 2016
  • Control chart is representative tools of statistical process control (SPC). It is a graph that plotting the characteristic values from the process. It has two steps (or Phase). First step is a procedure for finding a process parameters. It is called Phase I. This step is to find the process parameters by using data obtained from in-controlled process. It is a step that the standard value was not determined. Another step is monitoring process by already known process parameters from Phase I. It is called Phase II. These control chart is the process quality characteristic value for management, which is plotted dot whether the existence within the control limit or not. But, this is not given information about the economic loss that occurs when a product characteristic value does not match the target value. In order to meet the customer needs, company not only consider stability of the process variation but also produce the product that is meet the target value. Taguchi's quadratic loss function is include information about economic loss that occurred by the mismatch the target value. However, Taguchi's quadratic loss function is very simple quadratic curve. It is difficult to realistically reflect the increased amount of loss that due to a deviation from the target value. Also, it can be well explained by only on condition that the normal process. Spiring proposed an alternative loss function that called reflected normal loss function (RNLF). In this paper, we design a new control chart for overcome these disadvantage by using the Spiring's RNLF. And we demonstrate effectiveness of new control chart by comparing its average run length (ARL) with ${\bar{x}}-R$ control chart and expected loss control chart (ELCC).

비자성 증기발생기 전열관의 원격장와전류 탐상 가능성 연구 (Feasibility Study of Remote Field Eddy Current Testing for Nonmagnetic Steam Generator Tubes)

  • 신영길
    • 비파괴검사학회지
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    • 제21권5호
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    • pp.518-525
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    • 2001
  • 증기발생기 전열관이 노후화 됨에 따라 새롭고 판단이 애매한 결함이 발생되기 시작하고 있다. 대부분의 결함은 전열관 외부에서 발생되어 진전된다. 일반 와전류탐상에서는 외부결함으로부터의 신호가 표피효과로 인해 내부결함으로부터의 신호보다 매우 약하기 때문에, 본 논문에서는 자성체 관 검사에서 내부 및 외부결함에 거의 같은 민감도를 보인 바 있는 원격장와전류 탐상을 비자성체인 전열관의 검사에 적용하기 위한 연구를 수행하였다. 유한요소 모델링을 통한 연구결과는 비자성체인 전열관에서 원격장와전류 효과가 나타나려면 탐상주파수가 수백 kHz가 되어야 하며, 여자코일과 센서코일간의 간격은 자성 관 검사시의 절반인 관 외경의 1.5배 정도가 되어야 함을 보였다. 이렇게 설계된 탐촉자를 사용하여 예측한 결함신호들은 이 검사방법이 내부 및 외부결함에 동일하게 민감하며, 위상신호의 세기와 결함깊이간에는 선형적인 비례관계가 존재함을 보여 주었다. 이러한 결과들은 비자성 증기발생기 전열관이라 할지라도 원격장와전류 탐상이 가능함을 말해 주고 있다.

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창의성 요인에 대한 통계적 실증연구: 서울특별시 소방서를 대상으로 (An Empirical Research on Creativity Factors - Focusing on Seoul Fire Stations -)

  • 한민채;권인규
    • 한국화재소방학회논문지
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    • 제26권2호
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    • pp.32-39
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    • 2012
  • 본 연구는 소방조직에서의 창의성 촉진 요인을 탐색하여 조직 창의성의 증진방법을 모색하고 있다. 기후변화 등과 더불어 시민의 소방서비스의 욕구증대로 인하여 소방서에 대한 기대가 점증하여 전통적인 화재 구조 구급 업무수행뿐 아니라 환경변화에 조응하는 적절한 방식의 변화를 통하여 정당성과 영속성을 확보하여야 한다. 이러한 관점에서, 창의성이라는 주제는 소방서의 영속성을 담보하는 주요한 변수이다. 본 연구에서는 총 5개의 가설을 설정하여 비전, 폐기학습 및 긍정적 피드백과 같은 변수들이 실제로 조직 창의성을 고양할 수 있는지를 검증하였다. 서울시 소방공무원 155명을 대상으로 실시한 설문결과를 통계적으로 검증하여 위의 언급한 변수들이 조직 창의성과 관련이 있음을 밝혀내었다. 이러한 검증결과에 따라, 창의성 촉성을 위한 몇 가지 정책적 함의를 도출하였다.

광탄성 측정 기법을 이용한 입상체 초기 조건의 얕은 기초 지지력에 대한 영향 평가 (Evaluation of the Effect of Initial Condition of the Granular Assembly on the Bearing Capacity of the Shallow Foundation using Photoelastic Measurement Technique)

  • 신상영;정영훈
    • 대한토목학회논문집
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    • 제36권3호
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    • pp.471-491
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    • 2016
  • 고전적인 한계 평형 해석에서 얕은 기초의 지지력은 토체 내부의 파괴면을 가정하여 시작한다. 하지만 입상체 역학의 관점에서 토체의 파괴는 접촉력 사슬 구조의 국부적인 좌굴에 의해 시작된다. 본 연구에서는 모형 토립자를 이용하여 구성한 입상체 상부에 얕은 기초 하중을 재하하여 파괴 시까지 입상체 내부의 접촉력 사슬 분포가 어떻게 변화하는지 관찰하였다. 초기 결함이 없이 규칙적인 구조를 가지는 조건과 입상체 하부에 초기 국부적인 불완전성이 있는 조건을 가진 두 가지 종류의 입상체를 준비하여 실험하였다. 입상체 내부에서 발생하는 접촉력 사슬 구조의 방향 분포는 초기 불완전성의 여부에 따라 매우 큰 차이를 보였다. 초기 불완전성이 있는 입상체는 결함이 없는 입상체가 견딘 하중의 67%만을 견딜 수 있었다.

최근 우리나라 e-Learning 시장의 주요 동향 및 향후 전망 (Some Problems of e-Learning Market in Korea)

  • 윤영한
    • 통상정보연구
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    • 제9권2호
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    • pp.103-120
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    • 2007
  • The knowledge based economy requires more and more people to learn new knowledge and skills in a timely and effective manner. These needs and new technology such as computer and Internet are fueling a transition in e-learning. According to specialist's opinion, imagination experience studying is generalized, and learning environment that language barrier by studying, multi-language studying Machine that experience past things that disappear through simulation, and travel area, and experience future changed state disappears is forecasting to come. This is previewing finally that it may become future education that education and IT, element of entertainment is combined. Already, became story that argument for party satellite of e-Learning existence passes one season already. e-Learning is utilized already in all educations that we touch by effectiveness by corporation's competitive power improvement and implement of lifelong education in educational institutions through present e-Learning. It is obvious that when see from our viewpoint which is defining e-Learning by one industry and rear by application to education as well as one new growth power about these, e-Learning industry becomes very important means that can solve dilemma of growth real form. Only, special quality of digital industry that e-Learning is being same with other digital industry and repeat putting out a fire rapidly, and is repeating sudden change that these evolution is not gradual growth of accumulation and improvement of technology that is appearing consider need to. In the meantime, we need to observe about evolution of Information Technology. Because there is some scholars who e-Learning's concept foresees to evolve by u-Learning.(although, a person who see that these concept is not more in marketing terminology by some scholars' opinion is). This u-Learning's concept means e-Learning that take advantage of ubiquitous technology as Ubiquitous-Learning's curtailment speech. Ubiquitous, user means Information-Communication surrounding that can connect to network freely regardless of place without feeling network or computer. There is controversy about introduction time regarding these direction, but e-Learning is judged to evolve by u-Learning necessarily. Because keep in step and age that study all contents that learner wants under environment of 3A (any time, any whrer, any device) by individual order thoroughly is foreseen to come in ubiquitous learning environment that approach more festinately.

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지역공동체 형성전략연구 -천안시를 중심으로- (Strategy on the Formation of the Regional Community -focus on the case of Cheonan-)

  • 박종관
    • 한국콘텐츠학회논문지
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    • 제12권7호
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    • pp.183-193
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    • 2012
  • 본 연구는 효과적인 갈등해소를 위한 공동체 형성 전략을 도출하는데 그 목적을 두고 있다. 지역공동체 관련 이론의 정립과 더불어 천안지역주민 조사를 통하여 전략방안을 모색해 보았다. 연구결과, 공동체의식과 주민참여의 상관성에서는 충족감, 연대감, 소속감이 높은 유의관계를 보였으며, 이중 소속감이 사회참여의 욕구에 크게 작용한다는 것을 알 수 있었다. 지역공동체 형성의 요건은 다음과 같다. 첫째, 다양한 지역의 특성과 주민들의 요구에 대응할 수 있는 지역공동체형성 전략의 적용이다. 둘째, 지역공동체의 형성을 위하여 지자체들의 적극적인 지원, 지역공동체의 자체적인 노력과 지역주민들의 협력과 이해가 필요하다. 우리가 생각하는 이상적인 지역공동체란 물적 풍요와 사회구조의 평등실현 뿐만 아니라 성숙된 관계를 이끌어가는 건전한 사고의 각성이 어우러져서 성립된다.

구강 편평세포암종에서의 암줄기세포 이론과 최신 지견 (Cancer stem cell theory and update in oral squamous cell carcinoma)

  • 김덕훈;윤준용;이주현;김성민;명훈
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제37권2호
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    • pp.97-108
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    • 2011
  • Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.