• Title/Summary/Keyword: 평형 오차

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Prediction of Sorption Characteristics by Mass Balance Concept (함량비례 개념에 의한 수분흡습 특성의 예측)

  • Yoon, Heeny H.N.;Kim, H.;Shin, Y.D.;Yoo, M.Y.
    • Korean Journal of Food Science and Technology
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    • v.18 no.2
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    • pp.77-81
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    • 1986
  • The water sorption isotherms of individual insoluble components of corn starch, isolated soybean protein (ISP) and casein and their binary mixtures of corn starch-lSP and corn starch-casein were measured and analyzed. BET monolayer values and Smith plot parameters from the results of sorption isotherms were calculated by mass balance concept . The comparisons between experimental and predicted values resulted in an error of 2.29% for equilibrium moisture content and an error of 2.95% in monolayer value for the mixture 50% corn starch-50% ISP. On the other hand , for the mixture 50% corn starch-50% casein the errors were 2.66% and-5.34%, respectively.

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The Prediction of Vapor-Liquid Equilibrium Data for Cyclohexanol-Cyclohexanone System at Subatmospheric Pressure (감압하에서 2성분 Cyclohexanol-Cyclohexanone계에 대한 기-액평형치의 추산)

  • Shim, Hong-Seub;Kim, Jong-Shik
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.677-681
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    • 1999
  • For the binary cyclohexanol-cyclohexanone system the vapor-liquid equilibrium data, which are the necessary ones for the design of the distillation columns in separation process of volatile liquid-mixtures, are measured at subatmospheric pressure of 150, 300 and 500 mmHg. An empirical relation between logarithmic values of relative volatility(log $\alpha$) and liquid phase composition(x), which predicts the vapor-liquid equilibrium data, is obtained from above measured data of 150, 300 and 500 mmHg and the published ones of 30, 100, 200, 395 and 750 mmHg. The predicted data are compared with the measured and published ones to be in good agreement.

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The Realization of State-Space Digital Filters with Minimum Output Error Variance by Weighted Function (가중함수에 의한 최소 출력오차 분산을 갖는 상태공간 디지틀 필터 실현)

  • 김정화;정찬수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.9
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    • pp.909-917
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    • 1992
  • This paper proposes the realization of state-space digital filters with minimum output error variance. The algorithm is transforms of controllability and observability gramian in linear time invariant systems by weighted function and can improve performance of the digital filters by reducing the put error variance for state space coeffient variation. A numerical example shows that algorithm structure has much lower output error variance than that of other four structures(canonical, parallel, statistical sensitivity, balanced).

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Balance plate system to monitor and analysis the center of pressure(COP) of the body (인체 압력중심 계측과 분석을 위한 평형판 시스템의 개발)

  • Cha, Eun-Jong;Song, Chun-Hee;Lee, Tae-Soo;Lee, Kyung-Moo;Kim, Nam-Kyun;Kim, Yeon-Hee
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.63-67
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    • 1995
  • 신체 자세균형의 안정도를 반영하는 압력중심(COP)을 계측하기 위해 정삼각형 모양의 평형판 시스템을 설계, 제작하였고 그 유용성을 평가하였다. 재질로는 강도와 가공성이 뛰어난 듀랄루민을 사용하였고 압력중심(COP)의 위치를 계측하는 힘센 서로는 공업용 로드셀 3개를 사용하였다. COP신호를 검출하는 전자회로를 제작하여 실험한 결과 평형판의 COP 위치측정 오차는 2% 미만이었다. 시스템의 임상응용가능성을 평가하기 위하여 정상인 10명과 이학적 평가가 정상인 환자 4명을 대상으로 임상실험을 수행하였다. 자세안정도를 반영할 척도로써 COP신호의 표준편차($SD_x,\;SD_y,\;SD_r$)를 설정하여 자세가 불안정해짐에 따라, 그리고 시각의 영향이 배제됨에 따라 이 값들이 증가하는 것을 관찰하였다. 또한 환자의 경우에는 정상인과 현저한 차이를 보였다. 즉, 본 평형판시스템이 자세안정도를 정량적이고 예민하게 계측할 수 있음을 확인하였고 임상적 실용성을 검증하였다.

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Study of Effects of Measurement Errors in Damage Detection (동적 측정오차가 손상탐지에 미치는 영향에 관한 연구)

  • Kim, Ki-Ook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.3
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    • pp.218-224
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    • 2011
  • A modal method is presented for the investigation of the effects of measurement errors in damage detection for dynamic structural systems. The structural modifications to the baseline system result in the response changes of the perturbed structure, which are measured to determine a unique system in the inverse problem of damage detection. If the numerical modal data are exact, mathematical programming techniques can be applied to obtain the accurate structural changes. In practice, however, the associated measurement errors are unavoidable, to some extent, and cause significant deviations from the correct perturbed system because of the intrinsic instability of eigenvalue problem. Hence, a self-equilibrating inverse system is allowed to drift in the close neighborhood of the measured data. A numerical example shows that iterative procedures can be used to search for the damaged structural elements. A small set of selected degrees of freedom is employed for practical applicability and computational efficiency.

The Grinding Machining Characteristics of $ZrO_2$ Ceramics Ferrule in the Chucking Alignment Error (척킹 평형 정렬 오차에 따른 지르코니아 세라믹스 페룰의 연삭 가공 특성)

  • Lee S.W.;Kim G.H.;Choi Y.J.;Choi H.Z.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.19-22
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    • 2005
  • As the optical communication industry is developed, the demand of optical communication part is increasing. $ZrO_2$ ceramic ferrule is very important part which can determines the transmission efficiency and information quality to connect the optical fibers. In general $ZrO_2$ ceramic ferrule is manufactured by grinding process because the demands precision is very high. And the co-axle grinding process of $ZrO_2$ ceramic ferrule is to make its concentricity all of uniform before centerless grinding. When co-axle grinding of ferrule supported by two pin, pin chucking alignment accuracy is very important. This paper deals with the analysis of the chucking alignment experiment with parallel error on the micro feeding equipment. Thus, if possible be finding highly good the chucking alignment of two pin.

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Determination of an Optimum Initial Cable Tension Force for Cable-Stayed Bridges using the Least Square Method (최소자승법을 이용한 사장교의 적정 케이블 장력 결정)

  • Park, Yong Myung;Cho, Hyun Jun
    • Journal of Korean Society of Steel Construction
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    • v.17 no.6 s.79
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    • pp.727-736
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    • 2005
  • This study presents a method of determining the optimum cable tension forces for the proper initial equilibrium state of a cable-stayed bridge using the least square method. The proposed method minimizes the errors, i.e., the differences, such as the deflection and the moments of the girder and the tower, between the target values from a continuous beam by considering the cable anchor point as supports of the girder and the responses obtained from the analysis of the entire cable-stayed bridge system. Especially, the proposed method can selectively control the adjustment of the tower moment, the girder moment, and the deflections by introducing the weighing matrix. Through numerical analysis and comparisons with existing studies, the usefulness and validity of the proposed method was verified.

Analysis of Frictional Contact Problems of Nonlinearly Deformable Bodies by Using Contact Error Vector (접촉 오차 벡터를 이용한 비선형 변형체의 마찰접촉 해석)

  • Lee, Kisu;Kim, Bang-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.3
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    • pp.305-319
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    • 2000
  • Numerical solution lot frictional contact problems of nonlinearly deformable bodies having large deformation is presented. The contact conditions on the possible contact points are expressed by using the contact error vector, and the iterative scheme is used to reduce the contact error vector monotonically toward zero. At each iteration the solution consists of two steps : The first step is to revise the contact force by using the contact error vector given by the previous geometry, and the second step is to compute the displacement and the contact error vector by solving the equilibrium equation with the contact force given at the first step. Convergence of the iterative scheme to the correct solution is analyzed, and the numerical simulations we performed with a rigid-plastic membrane and a nonlinear elastic beam.

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Initial Equilibrium State Analysis of Cable Stayed Bridges Considering Axial Deformation (축방향 변형을 고려한 사장교의 초기평형상태 해석)

  • Kim, Je Choon;Chang, Sung Pil
    • Journal of Korean Society of Steel Construction
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    • v.14 no.4
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    • pp.539-547
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    • 2002
  • The study proposed the initial equilibrium state analysis method that considers axial deformation, in order to accurately determine the initial shape of a cable-stayed bridge. Sepecifically, the proposed method adopted the successive iteration method. In order to evaluate appropriate initial cable force introduced in the initial equilibrium state analysis, parametric studies were performed and a useful linear analysis method proposed. The geometrically nonlinear static behaviors of cable-stayed bridges were considered, using three-dimensional frame element and elastic catenary cable element. The usefulness and applicability of the analytic method proposed in this study were demonstrated using numerical examples, including a real cable-stayed bridge. The algorithm, is applicable in cases wherein axial deformation is not adopted in the fabrication camber, or final cable force is adjusted to eliminate construction and fabrication errors occurring during construction.

Investigation of Control Theory on Pressure Drop Characteristics of Pneumatic Regulator for Gas Supply (공압 레귤레이터의 공급압력 강하 제어이론에 대한 고찰)

  • Cho, Nam-Kyung;Chung, Yong-Gahp;Cho, In-Hyun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.15 no.2
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    • pp.74-83
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    • 2011
  • For launcher applications, different from other applications, very high flow rate is required which can lead to supply pressure drop against required setting pressure. The supply pressure decrease is closely related to regulator characteristics. In this paper, supply pressure offset is investigated considering regulators as kinds of control systems. Pressure offset of self-operated regulator is analyzed with sensitive parameter defined as the ratio of valve travel to pressure offset. It is shown that pressure offset of self-operating regulator can be improved by incorporating proportional and integral controls and they can be materialized with pilot regulator systems.