• Title/Summary/Keyword: Inverse transformation

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Different estimation methods for the unit inverse exponentiated weibull distribution

  • Amal S Hassan;Reem S Alharbi
    • Communications for Statistical Applications and Methods
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    • v.30 no.2
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    • pp.191-213
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    • 2023
  • Unit distributions are frequently used in probability theory and statistics to depict meaningful variables having values between zero and one. Using convenient transformation, the unit inverse exponentiated weibull (UIEW) distribution, which is equally useful for modelling data on the unit interval, is proposed in this study. Quantile function, moments, incomplete moments, uncertainty measures, stochastic ordering, and stress-strength reliability are among the statistical properties provided for this distribution. To estimate the parameters associated to the recommended distribution, well-known estimation techniques including maximum likelihood, maximum product of spacings, least squares, weighted least squares, Cramer von Mises, Anderson-Darling, and Bayesian are utilised. Using simulated data, we compare how well the various estimators perform. According to the simulated outputs, the maximum product of spacing estimates has lower values of accuracy measures than alternative estimates in majority of situations. For two real datasets, the proposed model outperforms the beta, Kumaraswamy, unit Gompartz, unit Lomax and complementary unit weibull distributions based on various comparative indicators.

(J,J')-lossless factorization and $H^{\infty}$ control in discrete-time systems (이산시간 시스템에서 (J,J')-lossless 분해와 $H^{\infty}$ 제어)

  • 정은태;이재명;박홍배
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.5
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    • pp.65-72
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    • 1994
  • We resolve the suboptimal $\infty$ control problem using (J,J')-lossless coprime factorization by transforming the linear fractional transformation (LFT) into chain scattering description (CSD) in discrete-time systems. The condition transformed LFT into CSD is that the inverse matrix of $P_{21}$ of standard plant exists. But, this paper presents the method of transforming LFT into CSD for 4-block problem in case that the inverse matrix of $P_{21}$ of standard plant does not exist and parameterization of the all suboptimal $\infty$T controllers using (J,J')-lossless coprime factorization. It is shown that this method can resolve the suboptimal $\infty$ control problem solving only two Riccati equations in discrete-time systems.

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Inverse Dynamic Analysis for Various Drivings in Kinematic Systems (기구학적 시스템에 있어서 구동방법에 따른 역동역학 해석)

  • Lee, Byung Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.9
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    • pp.869-876
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    • 2017
  • Analysis of actuating forces and joint reaction forces are essential to determine the capacity of actuators, to control the mechanical system and to design its components. This paper presents an algorithm that calculates actuating forces(or torques), depending on the various types of driving constraints, in order to produce a given system motion in the joint coordinate space. The joint coordinates are used as the generalized coordinates of a kinematic system. System equations of motion and constraint acceleration equations are transformed from the Cartesian coordinate space to the joint coordinate space using the velocity transformation method. A numerical example is carried out to verify the algorithm proposed.

Dimension reduction for right-censored survival regression: transformation approach

  • Yoo, Jae Keun;Kim, Sung-Jin;Seo, Bi-Seul;Shin, Hyejung;Sim, Su-Ah
    • Communications for Statistical Applications and Methods
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    • v.23 no.3
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    • pp.259-268
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    • 2016
  • High-dimensional survival data with large numbers of predictors has become more common. The analysis of such data can be facilitated if the dimensions of predictors are adequately reduced. Recent studies show that a method called sliced inverse regression (SIR) is an effective dimension reduction tool in high-dimensional survival regression. However, it faces incapability in implementation due to a double categorization procedure. This problem can be overcome in the right-censoring type by transforming the observed survival time and censoring status into a single variable. This provides more flexibility in the categorization, so the applicability of SIR can be enhanced. Numerical studies show that the proposed transforming approach is equally good to (or even better) than the usual SIR application in both balanced and highly-unbalanced censoring status. The real data example also confirms its practical usefulness, so the proposed approach should be an effective and valuable addition to usual statistical practitioners.

Imaging an Unknown Velocity Target in Inverse SAR (Inverse SAR에서 속도를 모르는 움직이는 물체의 이미징 알고리즘)

  • 양훈기;김은수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.5
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    • pp.796-804
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    • 1994
  • This paper presents Inverse SAR imaging algorithm for a unknown velocity target and a real ISAR data is processed and applied to the algorithm. The real ISAR data is obtained by transmitting a number of pulse modulated by a stepped-frequency method and the received data are undersampled. We present a method applicable for the case of a undersampled data base. In this method, the original echoed signal is mixed with a reference signal to make it unaliased, followed by being interpolated. Target`s velocity required for the algorithm is estimated via subaperture processing and after the coordinate transformation into squint-mode SAR with the estimated velocity, a recently proposed SAR/ISAR imaging algorithm derived without any approximation is utilized to produce the output image. We also propose an ISAR image scheme that is usable when a target changes its velocity during ISAR data acquisition time.

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New techniques for the transformation of the logic diagram (논리도변환의 새로운 기법)

  • 조동섭;황희융
    • 전기의세계
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    • v.28 no.8
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    • pp.57-65
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    • 1979
  • This paper is concerned with not only the transformation of the logic diagrams to the NAND and the NOR forms but also the inverse transformation deriving the simple Boolean function from a logic diagram. The conversions of the algebraic expression from the AND, OR and NOT operations to the NAND and the NOR operations are usually quite complicated, because they involve a large number of repeated applications of De Morgan's Theorem and the other logic relations. For the derivation of the Boolean function, it becomes difficult because the Boolean function is determined from the De Morgan's theorem in consecutive order until the output is expressed in terms of input variables (9). But, these difficulties are avoided by the use of new techniques, called the TWO-NOTs method and the MOVING-NOT method, that are presented in this paper.

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Generalized Kinematics Modeling of Wheeled Mobile Robots (바퀴형 이동로봇의 기구학)

  • Shin, Dong-Hun;Park, Kyung-Hoon
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.5
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    • pp.118-125
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    • 2002
  • The previous kinematic analysis of wheeled mobile robots(WMRs) is performed in an ad-hoc manner, while those of the robot manipulators are done in a consistent way using the coordinate system assignment and the homogeneous transformation matrix. This paper shows why the method for the robot manipulators cannot be used directly to the WMRs and proposes the method for the WMRs, which contains modeling the wheel with the Sheth-Uicker notation and the homogeneous transformation. The proposed method enable us to model the velocity kinematics of the WMRs in a consistent way. As an implementation of the proposed method, the Jacobian matrices were obtained for conventional steered wheel and non-steered wheel respectively and the forward and inverse velocity kinematic solutions were calculated fur a tricycle typed WMR. We hope that our proposed method comes to hold an equivalent roles for WMRs, as that of the manipulators does for the robot manipulators.

An Development of Landscape Lighting Power Control System with Solar Cell Generator Equipment for Energy Saving (에너지절감을 위한 태양광발전설비 연계형 경관조명 전력제어시스템의 개발)

  • Kim, Dong-Wan;Park, Sung-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.364-371
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    • 2010
  • In this paper, we propose the landscape lighting power control system with solar sell generator equipment for energy saving, and also which is included the landscape lighting power transformation device. The power transformation device can check inverse current in the power of the solar cell module and control the power of the battery. And we present the design of landscape lighting power control system. The power control system uses microprocessor with charging system and power transformation device. And also it can control the power of loads under consideration intensity of illumination. The landscape lighting loads are composed of LED(Lighting Emitting Diode) and HID(High Intensity Discharge)lamps. To evaluate property, we installed the solar cell array which generate three kilo watt power. Experimental results show that the proposed system can have stability and energy saving on the mixed configuration of electric loads with DC and AC lamps.

A Curve Lane Detection Method using Lane Variation Vector and Cardinal Spline (차선 변화벡터와 카디널 스플라인을 이용한 곡선 차선 검출방법)

  • Heo, Hwan;Han, Gi-Tae
    • KIPS Transactions on Software and Data Engineering
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    • v.3 no.7
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    • pp.277-284
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    • 2014
  • The detection method of curves for the lanes which is powerful for the variation by utilizing the lane variation vector and cardinal spline on the inverse perspective transformation screen images which do not required the camera parameters are suggested in this paper. This method detects the lane area by setting the expected lane area in the s frame and next s+1 frame where the inverse perspective transformation and entire process of the lane filter are adapted, and expects the points of lane location in the next frames with the lane variation vector calculation from the detected lane areas. The scan area is set from the nextly expected lane position and new lane positions are detected within these areas, and the lane variation vectors are renewed with the detected lane position and the lanes are detected with application of cardinal spline for the control points inside the lane areas. The suggested method is a powerful method for curved lane detection, but it was adopted to the linear lanes too. It showed an excellent lane detection speed of about 20ms in processing a frame.