• Title/Summary/Keyword: relativity

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

  • Jung, Jae-Eop;Yoon, Yeu-Kyung;Lee, Sung-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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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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Prediction of Setting Time of the Cement Mortar Considering Equivalent Age (등가재령에 의한 시멘트 모르터의 응결시간 예측)

  • Choi, Hyun-Kyu;Son, Ho-Jung;Baek, Dae-Hyun;Lim, Choon-Keun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.331-332
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    • 2010
  • This paper present a method to estimate the setting time of cement mortar incorporating admixtures under various curing temperature conditions by appling maturity based on equivalent age. It is indicated that equivalent age using setting time can be a proper method to predict setting time and it also exhibited comparable relativity between prediction value and measurement value.

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Relativistic View in Hydrodynamic Waves (유체파동에의 상대성이논 적용)

  • Kim Hun Chol
    • Proceedings of the KSME Conference
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    • 2002.08a
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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
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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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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Influence of Chemical Admixture on the Strength Development of Concrete at Early Age (콘크리트의 초기 강도발현에 미치는 혼화제의 영향)

  • 황인성;나운;이승훈;류현기;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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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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Concept Analysis of Palliation (완화(palliation)의 개념분석)

  • Yoon, Soo-Jin;Choi, Euy-Soon
    • Women's Health Nursing
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    • v.12 no.1
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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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Statistical Characteristics of Self-similar Data Traffic (자기유사성을 갖는 데이터 트래픽의 통계적인 특성)

  • Koo Hye-Ryun;Hong Keong-Ho;Lim Seog-Ku
    • Proceedings of the Korea Contents Association Conference
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    • 2005.05a
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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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A Study of Preference about Wedding Dress Design according to Body Shape for Adult Women (성인 여성의 체형 특성에 따른 웨딩드레스 디자인 선호도 연구)

  • Park, Jin-Hee;Suh, Mi-A
    • The Research Journal of the Costume Culture
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    • v.14 no.4
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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
    • Korean Journal of Logic
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    • v.12 no.2
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    • pp.171-199
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    • 2009
  • This essay will consider evolutionary views that attempt to capture the continuity of theory-change from Newtonian to Einsteinian physics via the formal aspects of these theories. Although it cannot be denied that the formal aspects such as 'correspondence principles' and 'covariance principles' provide important information concerning this theory-change, these formal properties are not sufficient to capture the essential elements of any evolutionary account of the development of Einstein's special and general theories of relativity from Newtonian mechanics.

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

  • Byun, Ye-Eun;Kim, Hyun-Doo;Kim, Si-Won
    • Proceedings of the Korea Information Processing Society Conference
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    • 2016.10a
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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.