• Title/Summary/Keyword: spline function

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Development of a reduced-order distillation model and real-time tuning using the extended kalmen filter (증류공정 차수감소 모델의 개발 extended kalmen filter에 의한 실시간대에서의 조정)

  • 정재익;최상열;이광순
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.466-470
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    • 1988
  • A tunable reduced-order distillation model is proposed for real-time applications. To develop the model, a binary distillation column with MaCabe-Thiele assumptions was considered first and then the governing equations for the column were reduced to a simplified vector differential equations using the collocation method combined with cubic spline interpolation function. The final reduced-order model has four tuning parameters, relative volatilities and liquid holdups for rectifying and stripping sections, respectively. To assess the applicability of the developed model,the real-time adjustment of the model was tried by recursively updating the tuning parameters using the BKF algorithm. As a result, it was found that the reduced-model follows the simulated distillation process very closely as the parameters are improved.

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Development of overall efficiency measurement automation system for hydraulic motor (유압모터의 전효율 측정 자동화 시스템개발)

  • 김형의;함영복;정동수;김진욱;이일영;김명환
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.928-933
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    • 1991
  • In this study, the authors developed a hydraulic motor performance test system which automatically accomplishes the procedure of basic performance test and represents the data obtained in the test as performance curves. The software is made as conversation style between a computer and a user, so even to novices it is very easy to use. The most important point of this study is to get desirable isoefficiency curves. As some defined number of data are obtained at actual test, additional data necessary for desirable isoefficiency curves are generated numerically by interpolation. Basis spline function is used to get more smooth representative performance curves.

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Shape Optimization of a Rotating Cantilever Beam Considering Its Modal and Stress Characteristics (회전 외팔보의 진동 및 응력 특성을 고려한 형상 최적화)

  • Yun, Yeong-Hun;Yu, Hong-Hui
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.4
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    • pp.645-653
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    • 2001
  • It is well known that natural frequencies increase when a cantilever beam rotates about the axis perpendicular to its longitudinal axis. Such phenomena that are caused by centrifugal inertia forces are often referred to as the stiffening effects. Occasionally it is necessary to control the variation of a natural frequency or the maximum stress of a rotating beam. By changing the thickness of the rotating beam, the modal or the stress characteristics can be changed. The thickness of the rotating beam is assumed to be a cubic spline function in the present work. An optimization method is employed to find the optimal thickness shape of the rotating beam. This method can be utilized for the design of rotating structures such as turbine blades and aircraft rotary wings.

The Analysis of Mode Shape using 2 Dimensional Continuous Scanning (2차원 연속 Scanning을 이용한 진동모드 해석)

  • Yoon, Sang-Yol;Ryu, Je-Kil;Park, Kyi-Hwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.531-535
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    • 2000
  • If the displacement of the structure is obtained by integrating the signal from accelorometer and laser, the vibration mode can be examined. This conventional method, however, has the disadvantage of the necessity of multiple accelerometers and many data processing steps such as frequency response function(FRF). In order to get smooth mode shape, we should also use algorithms of cubic spline or others. In this paper, we propose a method which gets the mode shape by using the velocity signal directly obtained from the plane scanning. In this method, we just use coefficients and phases for specific frequency.

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Effective Computation for Odds Ratio Estimation in Nonparametric Logistic Regression

  • Kim, Young-Ju
    • Communications for Statistical Applications and Methods
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    • v.16 no.4
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    • pp.713-722
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    • 2009
  • The estimation of odds ratio and corresponding confidence intervals for case-control data have been done by traditional generalized linear models which assumed that the logarithm of odds ratio is linearly related to risk factors. We adapt a lower-dimensional approximation of Gu and Kim (2002) to provide a faster computation in nonparametric method for the estimation of odds ratio by allowing flexibility of the estimating function and its Bayesian confidence interval under the Bayes model for the lower-dimensional approximations. Simulation studies showed that taking larger samples with the lower-dimensional approximations help to improve the smoothing spline estimates of odds ratio in this settings. The proposed method can be used to analyze case-control data in medical studies.

Shape Optimization of a Rotating Cantilever Beam Considering Its Modal Characteristics (진동 특성을 고려한 회전 외팔보 형상의 최적화)

  • Yun, Young-Hoon;Yoo, Hong-Hee
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.643-648
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    • 2000
  • It is well known that natural frequencies increase when a cantilever beam rotates about the axis perpendicular to its longitudinal axis. Such phenomena that are caused by centrifugal inertia forces are often referred to as the stiffening effects. Occasionally it is necessary to control the variation of a natural frequency of a rotating beam. By changing the thickness of the rotating beam, the modal characteristics can be changed. The thickness of the rotating beam is assumed to be a cubic spline function in the present work. An optimization method is employed to find the optimal thickness shape of the rotating beam. This method can be utilized usefully for the design of rotating structures such as turbine blades and aircraft rotary wings.

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Syntatic Pattern recognition of the ECG (심전도 신호의 신택틱 패턴인식)

  • Nam, Seung-Woo;Lee, Byung-Cha;Sin, Kun-Su;Lee, Jae-Jun;Lee, Myung-Hoo
    • Proceedings of the KOSOMBE Conference
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    • v.1991 no.11
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    • pp.129-132
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    • 1991
  • This paper describes the ECG pattern recognition using the syntatic pattern recognition algorithm. The algorithm uses the BNF rule wi th the semantic evaluation which has the structural Information of the ECG. This algorithm is constructed with (1) removing the baseline drift by the Cubic spline function and exract the significant point by the line-approximation algorithm, (2) syntatic peak recognition algorithm with the extracted significant point, (3) produce the token which is used pattern recognition, (4) pattern recognition of the ECG by the syntatic pattern recognition algorithm, (5) extract the parameter with the pattern recognized ECG signal.

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Negative Binomial Varying Coefficient Partially Linear Models

  • Kim, Young-Ju
    • Communications for Statistical Applications and Methods
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    • v.19 no.6
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    • pp.809-817
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    • 2012
  • We propose a semiparametric inference for a generalized varying coefficient partially linear model(VCPLM) for negative binomial data. The VCPLM is useful to model real data in that varying coefficients are a special type of interaction between explanatory variables and partially linear models fit both parametric and nonparametric terms. The negative binomial distribution often arise in modelling count data which usually are overdispersed. The varying coefficient function estimators and regression parameters in generalized VCPLM are obtained by formulating a penalized likelihood through smoothing splines for negative binomial data when the shape parameter is known. The performance of the proposed method is then evaluated by simulations.

Trajectory Planning of Articulated Robots with Minimum-Time Criterion (최소시간을 고려한 다관절 로봇의 궤적계획)

  • Choi, J.S.;Yang, S.M.;Kang, H.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.6
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    • pp.122-127
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    • 1996
  • The achievement of the optimal condition for the task of an industrial articulated robot used in many fields is an important problem to improve productivity. In this paper, a minimum-time trajectory for an articulated robot along the specified path is studied and simulated with a proper example. A general dynamic model of manipulator is represented as a function of path distance. Using this model, the velocity is produced as fast as possible at each point along the path. This minimum-time trajectory planning module together with the existing collision-free path planning modules is utilized to design the optimal path planning of robot in cases where obstacles present.

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A Study on Reverse Design of Cam Mechanism using NURBS (NURBS를 이용한 캠 기구의 역설계에 관한 연구)

  • 김상진;신중호;김대원;윤호업
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.920-924
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    • 2002
  • This paper presents the reverse design of a cam mechanism using NURBS(Nonuniform Rational B-spline curve). Cam is very difficult to make the accurate shape on the design and the manufacture. Because the cam shape is commonly made in order to move in special functions. The reverse design can be used to check accuracy between the designed data and the manufactured data of the cam shape and also reproduce the cam without the design data. The reverse design procedures consist of motion analysis and curve fitting. The motion analysis is used the central difference method and the relative velocity method to find the displacement and velocity. The curve fitting is used NURBS to develope the whole curve. The central difference method is derived in the 3 dimensional space.

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