• 제목/요약/키워드: closed forms

검색결과 223건 처리시간 0.023초

슬롯 개구를 통한 평행평판 도파관 내부로의 전자파 펄스 결합문제 해석 (Analysis of Electromagnetic Pulse Coupling Via a Slot Aperture into Parallel-Plate waveguide)

  • 이영순;박의준
    • 한국전자파학회논문지
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    • 제11권7호
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    • pp.1204-1210
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    • 2000
  • 슬롯 개구를 통해 평향평판 도파관 내부를 결합되어지는 전자파 펄스(EMP)의 과도 응답을 해석하기 위한 방법을 제안하였다. 개구의 미지 등가 면 자기전류밀도에 대한 혼합 포텐셜 적분 방정식(MPIE)을 세웠고 평행평판 도파관 영역에서의 백터 및 스칼라 포텐셜 그린함수를 개선된 북소영상법을 사용하였을 때 closed form 그림함수를 사용한 결과를 계산시간을 현저히 줄일 수 있었고 본 논문이 제안한 방법의 타당성을 확인하기 위해 기존 방법의 해석결과와 비교해 보았을때 본 논문의 해석결과와 비교적 잘 일치함을 알 수 있었다.

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Characteristics of Optical Current Sensors by Sensor Design

  • Kim, Young-Min;Park, Jung-Hwan;Lee, Kwang-Sik;Kim, Jung-Bae;Park, Won-Zoo
    • 조명전기설비학회논문지
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    • 제21권4호
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    • pp.80-87
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    • 2007
  • This paper will suggest that the 1 cross orthogonal loop type sensor improves on the orthogonal loop form sensor-head, which is available a calibration of the linear birefringence, when a fiber optic current sensor was composed. An output characteristics of the 1 cross orthogonal loop form, a general closed loop form, the orthogonal loop form are compared by the IEC(International Electrotechnical Commission) 60044-8 standard, and the state of polarization is compared with three forms. As a result, when the closed loop form was changed to the orthogonal loop form, retardation decreased 15.3[%]. When the closed loop form was changed to the 1 cross orthogonal loop type, the retardation decreased 33.8[%]. As a result of the Faraday Effect measurement, the 1 cross orthogonal loop form has the highest output characteristic and the lowest error ratio. It met the 0.5 class of the IEC 60044-8 standard. Thus, in application of the 1cross orthogonal loop form, the possibility to develop high reliability fiber optic current sensors that have a high output and stable error ratio rises is increased.

잠수체의 구획 분류 및 체적 계산을 위한 구획 결정 알고리즘 (An Algorithm for Automatic Determination and Calculation of Volumetric Spaces of Submerged Bodies)

  • 박인하;남종호
    • 대한조선학회논문집
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    • 제51권2호
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    • pp.148-153
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    • 2014
  • Submerged bodies such as autonomous underwater vehicles (AUV) or remotely operated vehicles (ROV) are widely used in various fields of exploring underseas. Those bodies keep ballasting and deballasting for stable navigation and operation. Identifying the internal volumetric spaces of the bodies is a primary step for such an operation. Unfortunately, most CAD models given to the engineer do not properly represent the compartments since each face of a compartment exists as an independent entity rather than as a face that belongs to the compartment. In this paper, an algorithm that automatically identify the faces as a group that forms a closed volumetric space, i.e., a compartment is presented. A submerged body is sliced into a number of cross sections. Each sliced section is analyzed to yield closed loops that are sections of the compartment. Then, the associated closed loops are gathered along the longitudinal direction to form a compartment. The algorithm presented is shown to provide a practical and reasonable solution that can readily be used in various applications.

SOLUTION TO ${\bar{\partial}}$-PROBLEM WITH SUPPORT CONDITIONS IN WEAKLY q-CONVEX DOMAINS

  • Saber, Sayed
    • 대한수학회논문집
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    • 제33권2호
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    • pp.409-421
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    • 2018
  • Let X be a complex manifold of dimension n $n{\geqslant}2$ and let ${\Omega}{\Subset}X$ be a weakly q-convex domain with smooth boundary. Assume that E is a holomorphic line bundle over X and $E^{{\otimes}m}$ is the m-times tensor product of E for positive integer m. If there exists a strongly plurisubharmonic function on a neighborhood of $b{\Omega}$, then we solve the ${\bar{\partial}}$-problem with support condition in ${\Omega}$ for forms of type (r, s), $s{\geqslant}q$ with values in $E^{{\otimes}m}$. Moreover, the solvability of the ${\bar{\partial}}_b$-problem on boundaries of weakly q-convex domains with smooth boundary in $K{\ddot{a}}hler$ manifolds are given. Furthermore, we shall establish an extension theorem for the ${\bar{\partial}}_b$-closed forms.

독일베르크분트 가구의 특성분석 (Significant Characteristics of Furniture in Deutsche Werkbund)

  • 조숙경
    • 한국가구학회지
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    • 제15권2호
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    • pp.63-71
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    • 2004
  • Deutsche Werkbund, founded in 1907 and closed by Nazis in 1934, is affected on German economic growth and industry The purpose of the association was the improvement of industrial materials as emphasizing the close relationship between artists and industrialists. The group is developed within the contrast idea of Hermann Muthesius who wanted the standardization of industries and of Henry van der Velde who wanted the freedom of artistic expression based on individualism. The furniture of DWB in terms of function exemplifies remarkable structures compare to furniture existed eyer before. The use of such functional elements as shelves, casters and drawers in rectangular forms is notable. And the form make it possible to utilize in small spaces. Thus, the furniture of DWB represents such standards in industrial design as simple, and geometric forms without any ornamentation.

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Optimal Structural Design for Flexible Space Structure with Control System Based on LMI

  • Park, Jung-Hyen;Cho, Kyeum-Rae
    • Journal of Mechanical Science and Technology
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    • 제16권1호
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    • pp.75-82
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    • 2002
  • A simultaneous optimal design problem of structural and control systems is discussed by taking a 3-D truss structure as an object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider a minimum weight design problem for structural system and disturbance suppression problem for the control system. The structural objective function is the structural weight and the control objective function is $H_{\infty}$ norm from the disturbance input to the controlled output in the closed-loop system. The design variables are cross sectional areas of the truss members. The conditions for the existence of controller are expressed in terms of linear matrix inequalities (LMI) By minimizing the linear sum of the normalized structural objective function and control objective function, it is possible to make optimal design by which the balance of the structural weight and the control performance is taken. We showed in this paper the validity of simultaneous optimal design of structural and control systems.

Slit 近傍의 Stokeslet 에 의한 2次元의 느린 粘性流動 (Two-Dimensional Slow Viscous Flow Due to a Stokeslet Near a Slit)

  • 고형종;김문언
    • 대한기계학회논문집
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    • 제7권4호
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    • pp.386-391
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    • 1983
  • Two-dimensional slow viscous flow due to a stokeslet near a slit is investigated on the basis of Stokes approximation. Velocity fields and stream function are obtained in closed forms by finding two sectionally holomorphic functions which are determined by reducing the problem to Riemann-Hilbert problems. The force exerted on a small cylinder is calculated for the arbitrary position of the cylinder translating in an arbitrary direction. The features of fluid flow are also investigated.

Lp-ESTIMATES FOR THE ${\bar{\partial}}$-EQUATION WITH EXACT SUPPORT ON q-CONVEX INTERSECTIONS

  • Khidr, Shaban
    • 대한수학회지
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    • 제55권1호
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    • pp.29-42
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    • 2018
  • We construct bounded linear integral operators that giving solutions to the ${\bar{\partial}}$-equation in $L^p$-spaces and with compact supports on a q-convex intersection ($q{\geq}1$) with ${\mathcal{C}}^3$ boundary in $K{\ddot{a}}hler$ manifolds, and we apply it to obtain a Hartogs-like extension theorems for ${\bar{\partial}}$-closed forms for some bidegree.

APPROXIMATE FIBRATIONS IN TOPOLOGICAL CATEGORY AND PL CATEGORY

  • Young, Won-Huh;Im, Ho;Woo, Ki-Mun
    • 대한수학회지
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    • 제33권3호
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    • pp.641-650
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    • 1996
  • Let G denote an upper semicontinuous(usc) decomposition of an (n + k)-manifold M into closed, connected n-manifolds. What can be said about the decomposition space B = M/G\ulcorner What regularity properties are possessed by the decomposition map $p : M \to B \ulcorner$ Certain forms of these questions have been addressed by D. Coram and pp. Duvall [C-D].

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MOMENTS OF VARIOGRAM ESTIMATOR FOR A GENERALIZED SKEW t DISTRIBUTION

  • KIM HYOUNG-MOON
    • Journal of the Korean Statistical Society
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    • 제34권2호
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    • pp.109-123
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    • 2005
  • Variogram estimation is an important step of spatial statistics since it determines the kriging weights. Matheron's variogram estimator can be written as a quadratic form of the observed data. In this paper, we extend a skew t distribution to a generalized skew t distribution and moments of the variogram estimator for a generalized skew t distribution are derived in closed forms. After calculating the correlation structure of the variogram estimator, variogram fitting by generalized least squares is discussed.