• Title/Summary/Keyword: Metric

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A Study on the Improvement of Accuracy for Deformation Measurement of Circular Structures by Multiple Method (Multiple-Method에 의한 원형구조물 변형측정의 정확도 향상에 관한 연구)

  • Raymond J. Hintz;Mook, Kang-Joon;Jin, Oh-Won
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.6 no.1
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    • pp.13-24
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    • 1988
  • The determination of three-dimensional positions on a circular or cylindrical surface covers a variety of applications. As an example, consider the monitoring of structures, which is an important topic in the broad category of deformation analysis. The use of convergent photography in determination of these positions has the many advantages over survey based procedures. This paper illustrates results from bundle adjustments derived from convergent photography of a cylindrical object, with both metric and non-metric cameras utilized in the test. In addition to standard error comparisons resulting from the error analysis provided by the bundle adjustments, object space coordinates resulting from metric and non-metric camera network geometries will also be compared.

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A Study on the Evaluation Unit of a Military Aircraft Noise (군용항공기 소음평가 단위에 관한 연구)

  • Lee, Jun-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.5 s.98
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    • pp.550-557
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    • 2005
  • Korean 'Law of Aviation' and 'Test Method of Measuring Noise and Vibration' designate to use WECPNL metric based on $L_{max}$ measurement for the accessment of aircraft noise in Korea. However, time duration of noise event can not be considered in $L_{max}$ metric in principle, compensation on the duration has been utilized. A study was done recently to evaluate appropriate duration compensation for the accessment of military aircraft noise under current metric of WECPNL and $L_{max}$. This study was carried out to evaluate what metric is the most appropriate to express aircraft noise including time duration of single noise event, computing and comparing noise exposure with 1 second noise measurement data of military aircraft in $L_{max}$, $L_{Aeq,\;T}$ and SEL. This study shows SEL is the most appropriate noise metric for the evaluation of noise exposure with time duration such as aircraft noise without compensation. It is suggested to use SEL noise metric instead of $L_{max}$ noise metric with duration compensation for the aircraft noise accessment either military aircraft or civilian aircraft.

Estimation of evapotranspiration in South Korea using Terra MODIS images and METRIC model (Terra MODIS 위성영상과 METRIC 모형을 이용한 전국 증발산량 산정)

  • Kim, Jin Uk;Lee, Yong Gwan;Chung, Jee Hun;Kim, Seong Joon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.103-103
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    • 2019
  • 본 연구에서는 Terra MODIS 위성영상과 Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) 모형을 이용하여 2012년부터 2017년까지 한반도 전국의 증발산량을 산정하고 플럭스 타워 실측 증발산량과 비교하였다. METRIC은 전 세계에 널리 적용된 바 있는 에너지 수지 기반의 Surface Energy Balance Algorithm for Land (SEBAL) 모형의 개념과 기술을 기반으로 현열(Sensible Heat Flux) 추정 모듈을 개선한 모형이다. 본 연구에서 METRIC 모형은 기존 C#으로 개발되어 있던 SEBAL 코드에서 현열 추정 모듈을 수정하였고 연산 속도 개선을 위해 Python으로 재작성하였다. METRIC 모형의 위성 자료로 Terra MODIS 위성의 MOD13A2(16day, 1km) NDVI, MOD11A1(Daily, 1km) Land Surface Temperature (LST) 및 MCD43A3(Daily, 500m) Albedo를 구축하였으며 500m 공간해상도의 Albedo는 1000m 해상도로 resample하여 활용하였다. 기상자료는 기상청 기상관측소의 풍속, 풍속측정높이, 습도, 10분 간격 이슬점 온도, 일사량 자료를 위성 자료와 같은 공간해상도로 내삽(Interpolation)하여 구축하였다. 모형결과 검증을 위해 국내 플럭스 타워 (설마천, 청미천, 덕유산) 증발산량 관측 자료와의 결정계수(Coefficient of determination, $R^2$), RMSE(Root mean square error) relative RMSE (RMSE%), Nash-Sutcliffe efficiency (NSE) 및 IOA(Index of Agreement)를 산정하고, 기존 SEBAL 모형 결과와의 비교를 통해 본 모형의 개선점을 보이고자 한다.

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Mesh distortion, locking and the use of metric trial functions for displacement type finite elements

  • Kumar, Surendra;Prathap, G.
    • Structural Engineering and Mechanics
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    • v.29 no.3
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    • pp.289-300
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    • 2008
  • The use of metric trial functions to represent the real stress field in what is called the unsymmetric finite element formulation is an effective way to improve predictions from distorted finite elements. This approach works surprisingly well because the use of parametric functions for the test functions satisfies the continuity conditions while the use of metric (Cartesian) shape functions for the trial functions attempts to ensure that the stress representation during finite element computation can retrieve in a best-fit manner, the actual variation of stress in the metric space. However, the issue of how to handle situations where there is locking along with mesh distortion has never been addressed. In this paper, we show that the use of a consistent definition of the constrained strain field in the metric space can ensure a lock-free solution even when there is mesh distortion. The three-noded Timoshenko beam element is used to illustrate the principles. Some significant conclusions are drawn regarding the optimal strategy for finite element modelling where distortion effects and field-consistency requirements have to be reconciled simultaneously.

GRAY CURVATURE IDENTITIES FOR ALMOST CONTACT METRIC MANIFOLDS

  • Mocanu, Raluca;Munteanu, Marian Ioan
    • Journal of the Korean Mathematical Society
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    • v.47 no.3
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    • pp.505-521
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    • 2010
  • Alfred Gray introduced in [8] three curvature identities for the class of almost Hermitian manifolds. Using the warped product construction and the Boothby-Wang fibration we will give an equivalent of these identities for the class of almost contact metric manifolds.

COMMON FIXED POINT THEOREMS FOR HYBRID MAPS IN NON-ARCHIMEDEAN FUZZY METRIC SPACES

  • Samanta, T.K.;Mohinta, Sumit
    • Journal of applied mathematics & informatics
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    • v.31 no.1_2
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    • pp.155-164
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    • 2013
  • In this paper, we have established some common fixed point theorems for two pairs of occasionally weakly compatible hybrid maps sat-isfying a strict contractive condition in a non-archimedean fuzzy metric space. Our result extend, generalized and fuzzify several fixed point theo-rems on metric space.

HALF LIGHTLIKE SUBMANIFOLDS OF A SEMI-RIEMANNIAN SPACE FORM WITH A SEMI-SYMMETRIC NON-METRIC CONNECTION

  • Jin, Dae Ho
    • The Pure and Applied Mathematics
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    • v.21 no.1
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    • pp.39-50
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    • 2014
  • In this paper, we study screen quasi-conformal irrotational half lightlike submanifolds M of a semi-Riemannian space form $\tilde{M}(c)$ admitting a semi-symmetric non-metric connection, whose structure vector field ${\zeta}$ is tangent to M. The main result is a classification theorem for such Einstein half lightlike submanifolds of a Lorentzian space form admitting a semi-symmetric non-metric connection.

COMMON FIXED POINT THEOREM AND INVARIANT APPROXIMATION IN COMPLETE LINEAR METRIC SPACES

  • Nashine, Hemant Kumar
    • East Asian mathematical journal
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    • v.28 no.5
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    • pp.533-541
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    • 2012
  • A common fixed point result of Gregus type for subcompatible mappings defined on a complete linear metric space is obtained. The considered underlying space is generalized from Banach space to complete linear metric spaces, which include Banach space and complete metrizable locally convex spaces. Invariant approximation results have also been determined as its application.

HALF LIGHTLIKE SUBMANIFOLDS OF AN INDEFINITE TRANS-SASAKIAN MANIFOLD WITH A QUARTER-SYMMETRIC METRIC CONNECTION

  • Jin, Dae Ho
    • East Asian mathematical journal
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    • v.33 no.5
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    • pp.543-557
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    • 2017
  • Jin [10] studied lightlike hypersurfaces of an indefinite trans-Sasakian manifold with a quarter-symmetric metric connection. We study further the geometry of this subject. The object of this paper is to study the geometry of half lightlike submanifolds of an indefinite trans-Sasakian manifold with a quarter-symmetric metric connection.