• 제목/요약/키워드: single integral

검색결과 317건 처리시간 0.024초

산란음장 해석을 위한 적분방정식에 대한 연구 (A study of integral equations for the analysis of scattered acoustic field)

  • Wonju Jeon;Lee, Duck-Joo
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.1016-1019
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    • 2002
  • This paper deals with a fundamental and classical scattering problem by a finite strip. For the analysis of scattered acoustic field, a “single” integral equation is derived. Firstly, the complexity by considering the effect of the mean flow is alleviated by the introduction of Prandtl-Glauert coordinate and the new dependent variable. Secondly, the difficulty of solving the resultant strongly-coupled integral equations which always appear in this kind of 3-part mixed boundary value problem is solved by observing some good properties of the functions in complex domain and manipulating the equations and variables for the use of those properties. The solution can be obtained asymptotically in terms of gamma function and Whittaker function. One aim of this study is the improvement of methodology for the research using integral equations. The other is the basic understanding of scattering by a finite strip related to the linear cascade model of rotating fan blades.

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유연관절로봇의 모터 동역학을 정확하게 재설정하기 위한 적분매니폴드 피드백제어 개발 (Exact Reshaping of Motor Dynamics in Flexible-Joint Robot using Integral Manifold Feedback Control)

  • 박영진;정완균
    • 로봇학회논문지
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    • 제9권1호
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    • pp.20-27
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    • 2014
  • In this paper, an exact reshaping method for the motor dynamics of a flexible-joint robot is proposed using an integral manifold approach. Obtaining the exact model for both motor-side and link-side dynamics of a flexible-joint robot is difficult due to its under-actuated nature and complex dynamics. Despite the simple structure of the motor-side dynamics, they are difficult to model accurately for a flexible-joint robot due to motor disturbances, especially when speed reducers such as harmonic drives are installed. An integral manifold feedback control (IMFC) is proposed to reshape the motor dynamics. Based on the integral manifold approach, it is theoretically proved that the IMFC reshapes motor dynamics exactly even with bounded disturbances such as motor friction. The performance of the proposed IMFC is verified experimentally using a single degree-of-freedom flexible-joint robot under gravity conditions.

Single-Layer 포텐셜과 가중함수를 이용한 응력강도계수의 계산 (Calculation of Stress Intensity Factors Using Single-Layer Potential and Weight Function)

  • 이형연;홍창선
    • 대한기계학회논문집
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    • 제19권4호
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    • pp.981-989
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    • 1995
  • A new weight function approach to determine SIF(stress intensity factor) using single-layer potential has been presented. The crack surface displacement field was represented by one boundary integral term whose kernel was modified from Kelvin's fundamental solution. The proposed method enables the calculation of SIF using only one SIF solution without any modification for the crack geometries symmetric in two-dimensional plane such as a center crack in a plate with or without an internal hole, double edge cracks, circumferential crack or radial cracks in a pipe. The application procedure to those crack problems is very simple and straightforward with only one SIF solution. The necessary information in the analysis is two reference SIFs. The analysis results using present closed-form solution were in good agreement with those of the literature.

지구양위탕과 가미지구양위탕의 항암제에 의해 손상된 위장관의 회복효과에 관한 연구 (Protective and Healing Effects of both Jiguyangwi-tang and Gamijiguyangwi-tang on Gastric Mucosa Injuries induced by Cyclophosphamide in Mice)

  • 권오희;류기원;류봉하;윤상협;백태현
    • 대한한의학회지
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    • 제22권2호
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    • pp.84-93
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    • 2001
  • This research was to find out the protective and healing effects of both the Jiguyangwi-tang and the Gamijiguyangwi-tang on the gastric mucosa injuries by cyclophosphamide. At first, Jiguyangwi-tang and Gamijiguyangwi-tang extract were administered to the mice before one week, and then integral administration of those two drugs(each herbal extract and cyclophosphamide) were followed for another one week, respectively. After finishing those treatments, I have examined the state of the both ulcer and inflammation on the damaged gastric mucosa cell and watched the level of proliferating cell nuclear antigen(PCNA), Bcl-2, and apoptosis. These results were as follows, 1. Gastric mucosa inflammation have more significantly reduced in groups of integral administration of Jiguyangwi-tang plus cyclophosphamide, Gamijiguyangwi-tang plus cyclophosphamide and cyclophosphamide then in group of single cyclophosphamide. 2. Gastric ulcer have been reduced in groups of integral administration of Jiguyangwi-tang plus cyclophosphamide, Gamijiguyangwi-tang plus cyclophosphamide and cyclophosphamide then in group of single cyclophosphamide. But the significance have not shown. 3. PCNA level have more significantly elevated in integral administration of Jiguyangwi-tang plus cyclophosphamide and Gamijiguyangwi-tang plus cyclophosphamide and cyclophosphamide then in group of single cyclophosphamide. 4. The significance of both apoptosis induction and bcl-2level have not noticed among all groups. 5. Between Jiguyangwi-tang and Gamijiguyangwi-tang, the differance of effect was not admitted in statistically From these results, it is suggested that Jiguyangwi-tang and Gamijiguyangwi-tang are useful medicines in protecting gastric inflammation and ulcer, that is gastrointestinal side-effect of cyclophosphamide. The preventing effect of Jiguyangwi-tang and Gamijiguyangwi-tang may be through the 'affecting the period of cell division', but not the inhibition of apoptosis.

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P-version 균열모델에 의한 J-적분해석 (J-integral Analysis by P-version Crack Model)

  • 이채규;우광성;윤영필
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1994년도 가을 학술발표회 논문집
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    • pp.38-45
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    • 1994
  • P-version finite element model for the computation of stress intensity factors in two dimensional cracked panels by J-integral method is presented. The proposed model is based on high order theory and hierarchical shape function. The displacements fields are defined by integrals of Legendre polynomials which can be classified into three part such as basic mode, side mode, integral mode. The stress intensity factors are computed by J-integral method. The example models for validating the proposed p-version model are centrally cracked panel, single and double edged crack in a rectangular panel under pure Mode I. And the analysis results are compared with those by the h-version of FEM and empirical solutions in literatures. Very good agreement with the existing solution are shown.

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끌줄 및 부이줄에 있어서 Pode 해석에 의한 줄 함수의 이용 (use of Cable Functions by Pode's Analysis in a Towing Cable or a Buoy Cable)

  • 박해훈
    • 수산해양기술연구
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    • 제35권4호
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    • pp.353-358
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    • 1999
  • Tabulated results by Pode are used for computing the cable shape and cable tension in static equilibrium. This paper describes a technique using the integral form by Pode to give a simplified calculation of the cable functions at any desired value because in most practical cased the points of interest on the cable are not the points of reference on which the tables are based. Solving the nondimentional tension, $\tau$, defined by Pode in closed form reduces the integral in cable functions to a single integral. The technique using the integral form enables us to calculate the cable functionsin at any critical angle and at any point in case of a towing cable or certain cable-buoy systems.

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3D 집적 영상을 이용한 인터렉티브 시스템 (Interactive system using 3D integral imaging technique)

  • 신동학;김은수
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2008년도 추계종합학술대회 B
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    • pp.503-506
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    • 2008
  • 3D 집적 영상 기술은 연속적인 시점, 완전 시차와 풀칼라 영상을 공중에 표현하는 유망한 기술이다. 본 논문에서는 한 대의 카메라를 이용한 새로운 형태의 인터렉티브 3D 집적영상 시스템을 제안한다. 이 장치는 기존의 3D 집적 영상 디스플레이 시스템에 단순한 한대의 카메라를 추가적으로 사용하여 유저 인터페이스가 구현될 수 있다. 제안하는 시스템의 가능성을 보이기 위해서, 실험적인 장치 구현을 수행하고 기초적인 실험 결과를 보고한다.

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Utkin 정리의 단일입력 불확실 적분 선형 시스템에 대한 증명 (A Poof of Utkin's Theorem for the SI Uncertain Integral linear Case)

  • 이정훈
    • 전기학회논문지
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    • 제60권4호
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    • pp.843-847
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    • 2011
  • In this note, a proof of Utkin's theorem is presented for the SI(Single Input) uncertain integral linear case. The invariance theorem with respect to the two transformation methods so called the two diagonalization methods are proved clearly and comparatively for SI uncertain integral linear systems. With respect to the sliding surface transformation, the equation of the sliding mode, the sliding surface is invariant. Both the applied control inputs have the same gains. By means of the two transformation methods the same results can be obtained. Through an illustrative example and simulation study, the usefulness of the main results is verified.

ON EULERIAN q-INTEGRALS FOR SINGLE AND MULTIPLE q-HYPERGEOMETRIC SERIES

  • Ernst, Thomas
    • 대한수학회논문집
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    • 제33권1호
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    • pp.179-196
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    • 2018
  • In this paper we extend the two q-additions with powers in the umbrae, define a q-multinomial-coefficient, which implies a vector version of the q-binomial theorem, and an arbitrary complex power of a JHC power series is shown to be equivalent to a special case of the first q-Lauricella function. We then present several q-analogues of hypergeometric integral formulas from the two books by Exton and the paper by Choi and Rathie. We also find multiple q-analogues of hypergeometric integral formulas from the recent paper by Kim. Finally, we prove several multiple q-hypergeometric integral formulas emanating from a paper by Koschmieder, which are special cases of more general formulas by Exton.

Energy Efficiency Improvement of Vanadium Redox Flow Battery by Integrating Electrode and Bipolar Plate

  • Kim, Min-Young;Kang, Byeong-Su;Park, Sang-Jun;Lim, Jinsub;Hong, Youngsun;Han, Jong-Hun;Kim, Ho-Sung
    • Journal of Electrochemical Science and Technology
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    • 제12권3호
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    • pp.330-338
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    • 2021
  • An integral electrode-bipolar plate assembly, which is composed of electrode, conductive adhesive film (CAF) and bipolar plate, has been developed and evaluated for application with a vanadium redox flow battery (VRB) to decrease contact resistance between electrode and bipolar plate. The CAF, made of EVA (ethylene-vinyl-acetate) material with carbon black or CNT (Carbon Nano Tube), is applied between the electrode and the bipolar plate to enable an integral assembly by adhesion. In order to evaluate the integral assembly of VRB by adhesive film, the resistivity of integral assembly and the performance of single cell were investigated. Thus, it was verified that the integral assembly is applicable to redox flow battery. Through resistance and contact resistance of bare EVA and CAF films on bipolar plate were changed. Among the adhesive films, CAF film coated with carbon black showed the lowest value in through resistance, and CAF film coated with CNT showed the lowest value in contact resistance, respectively. The efficiency of VRB single cell was improved by applying CAF films coated with carbon black and CNT, resulting in the reduced overvoltage in charging process. Therefore, the energy efficiency of both CAF films, about 84%, were improved than that of blank cell, about 79.5 % under current density at 40 mA cm-2. The energy efficiency of the two cells were similar, but carbon black coated CAF improved the coulomb efficiency and CNT coated CAF improved the voltage efficiency, respectively.