• 제목/요약/키워드: relativity

검색결과 288건 처리시간 0.028초

실온동작 세라믹 가스센서의 제작 및 특성 (Fabrication of Ceramic Gas Sensors at Room Temperature and Characteristics)

  • 정재업;윤여경;이성필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.814-817
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    • 2003
  • As additive Pt of a little to $SnO_2$ that gas sensing property is superior oxide-semiconductor material to fabricate gas sensor that operation is possible at room temperature and fabricated ceramic gas sensing devices. And, the change amount and sintering temperature of addition material investigated gas sensitivity by change of operation temperature, humidity relativity, Long-term stability and hysteresis. And achieved SEM and XRD analysis for characteristics searching examination of devices.

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등가재령에 의한 시멘트 모르터의 응결시간 예측 (Prediction of Setting Time of the Cement Mortar Considering Equivalent Age)

  • 최현규;손호정;백대현;임춘근;한민철;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.331-332
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    • 2010
  • 본 연구에서는 등가재령에 의한 적산온도방법을 이용하여 혼화재를 치환한 시멘트 모르터의 응결시간을 예측하는 방법을 제시하였다. 혼화재치환에 따른 시멘트 모르터의 겉보기 활성화에너지를 등가재령식에 대입한 결과 양생온도별로 거의 유사한 값으로 나타나 응결시간 예측에 적산온도 개념의 적용이 적합한 방법인 것으로 나타났다.

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유체파동에의 상대성이논 적용 (Relativistic View in Hydrodynamic Waves)

  • 김훈철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.193-196
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    • 2002
  • The relativistic theory has not been properly taken up by the marine hydrodynamicists. To take on a relativistic view, we confine ourselves to a simple vector case of a wave train in spacetime, to be shown to represent a sound wave or a surface wave, and bring in an observer who is travelling on another platform. We are interested in relative position of each event on these two worldlines. It, then, will be shown that the velocity, the acceleration, the encounter frequency, the group velocity, and the time and the space distance between the wave and the observer on the worldlines should all be derivable in principle. This is interpreted to mean that we really have the relativistic events taking place with different values of time dilation in the sense of 'spacetime', and that the well-known ${\lceil}special Theory of Relativity{\rfloor}$ applies just as well in hydrodynamic waves.

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Testing Gravity with Cosmic Shear Data from the Deep Lens Survey

  • Sabiu, Cristiano G.;Yoon, Mijin;Jee, M. James
    • 천문학회보
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    • 제43권1호
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    • pp.62.2-62.2
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    • 2018
  • From the gaussian, near scale-invariant density perturbations observed in the CMB to the late time clustering of galaxies, CDM provides a minimal theoretical explanation for a variety of cosmological data. However accepting this explanation, requires that we include within our cosmic ontology a vacuum energy that is ~122 orders of magnitude lower than QM predictions, or alternatively a new scalar field (dark energy) that has negative pressure. Alternatively, modifications to Einstein's General Relativity have been proposed as a model for cosmic acceleration. Recently there have been many works attempting to test for modified gravity using the large scale clustering of galaxies, ISW, cluster abundance, RSD, 21cm observations, and weak lensing. In this work, we compare various modified gravity models using cosmic shear data from the Deep Lens Survey as well as data from CMB, SNe Ia, and BAO. We use the Bayesian Evidence to quantify the comparison robustly, which naturally penalizes complex models with weak data support. In this poster we present our methodology and preliminary constraints on f(R) gravity.

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콘크리트의 초기 강도발현에 미치는 혼화제의 영향 (Influence of Chemical Admixture on the Strength Development of Concrete at Early Age)

  • 황인성;나운;이승훈;류현기;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.741-744
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    • 2003
  • In this study, the influence of chemical admixture on early strength development of concrete is discussed. According to the results, fluidity with variation of kinds of chemical admixture is lower in the case of acceleration type than in the case of normal type. Setting time of naphthalene acceleration type is shortened by I hour, and that of melamine is nearly same, but that of polycarbonic acid is somewhat retarded in comparison with that of naphthalene normal type. Early compressive strength gains 5MPa in about 18hours regardless of the kinds of chemical admixture. But as time elapses, compressive strength is higher in order of polycarbonic acid, naphthalene and melamine type. The relativity between compressive strength and the rebound value of P-type schmidt hammer is also favorable at early age, and compressive strength of 5MPa is estimated at the rebound value of 22.

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완화(palliation)의 개념분석 (Concept Analysis of Palliation)

  • 윤수진;최의순
    • 여성건강간호학회지
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    • 제12권1호
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    • pp.5-11
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    • 2006
  • Purpose: The purpose of this study was to analyze the concept, palliation, in order to enhance understanding of palliative care and ultimately lead to the provision of timely quality palliative care. Method: This study used Walker and Avant s methods for concept analysis. Result: The defining attributes of palliation identified in this study were 1) being limited, 2) responsiveness, 3) leading to positive effects, 4) relativity, and 5) being unsettled. The antecedents of palliation were 1) a problematic condition, 2) appropriate management for the problematic condition, and 3) interaction between the problematic condition and the appropriate management. The consequences of palliation included 1) improvement of a problematic condition and 2) dependency on a management of the problematic condition. Conclusion: Although further studies are required to refine the diverse attributes of the concept of palliation, according to this concept analysis of palliation, palliative care should be introduced at the early stage of disease and constantly provided for the improvement of its negative symptoms.

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자기유사성을 갖는 데이터 트래픽의 통계적인 특성 (Statistical Characteristics of Self-similar Data Traffic)

  • 구혜련;홍경호;임석구
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2005년도 춘계 종합학술대회 논문집
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    • pp.410-415
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    • 2005
  • Recent measurements of local-area and wide-area traffic have shown that network traffic exhibits at a wide range of scales - Self-similarity. Self-similarity is expressed by long term dependency, this is contradictory concept with Poisson model that have relativity short term dependency. Therefore, first of all for design and dimensioning of next generation communication network, traffic model that are reflected burstness and self-similarity is required. Here self-similarity can be characterized by Hurst parameter. In this paper, when different many data traffic being integrated under various environments is arrived to communication network, Hurst Parameter's change is analyzed and compared with simulation results.

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성인 여성의 체형 특성에 따른 웨딩드레스 디자인 선호도 연구 (A Study of Preference about Wedding Dress Design according to Body Shape for Adult Women)

  • 박진희;서미아
    • 복식문화연구
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    • 제14권4호
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    • pp.625-634
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    • 2006
  • The purpose of this study is to preview artistic presentation, factors of designing and ornamentation, to provide useful information to the wedding dress industry in developing consumer-oriented design of wedding dress. Also, this study is to investigate relativity between individual characteristics, such as demographic character and body figures, and preference of consumers, in order to learn if there is any pattern of consumers decision making, and to help consumers by giving tips for their wedding dress shopping. According to this study, I can see that when modern South-Korean adult women choose their wedding dress, they consider many factors just like silhouette, detail, fabric material and so on, then they select their own best dress by grasping their body characteristics.

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Reconsidering the Formal Accounts of Continuity in the Theory-Change from Newtonian to Einsteinian Physics

  • Yang, Kyoung-Eun
    • 논리연구
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    • 제12권2호
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    • pp.171-199
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    • 2009
  • 본 논문은 형식적인 조건을 통하여 뉴턴 물리학에서 아인슈타인 물리학으로의 이론변화의 연속성을 이해하려는 과학이론에 대한 진보적 견해를 비판적으로 고찰한다. '상응 원리'이나 '공변 원리'와 같은 형식적인 측면이 이 이론변화에서 중요한 정보를 담고 있는 것은 부정할 수 없지만, 이 형식적 속성은 뉴턴역학에서 아인슈타인의 특수 그리고 일반 상대성 이론으로의 발전에 대한 진화적 견해를 위한 본질적 요소를 제공하기에는 충분치 않다.

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원전 사고연계 시스템의 사이버보안성 분석환경 개발방안에 관한 연구 (A Study on Establishment of Simulation Test Facility for Analysing Relativity of NPP Accidents)

  • 변예은;김현두;김시원
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2016년도 추계학술발표대회
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    • pp.243-245
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    • 2016
  • 2008년 미국 Hatch 발전소에서 제어시스템 소프트웨어 업데이트로 인한 비상정지, 2010년 이란 원자력시설에서 악성코드 스턱스넷(Stuxnet) 감염을 통한 원심분리기 1,000여개 파괴 등 원자력시설에 대한 사이버공격이 점차 증가하고 있는 상황에서 우리나라도 이와 같은 사고를 예방하기 위한 방안을 강구하여야 한다. 이미 우리나라 원자력시설에서 사용되는 시스템들이 아날로그 방식에서 디지털로 교체되고 있는 등 사이버공격에 용이하게 변화되고 있다. 이에 원전 사고연계 시스템들의 보안성을 평가할 수 있는 환경을 구축함으로써 사이버공격에 대한 보안대책 마련 및 근본적인 방어 체계를 수립하고자 한다.