• Title/Summary/Keyword: single variable

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Study of a Variable Single-tracked Crawler for Overcoming Obstacles (가변형 단일 궤도를 이용한 장애물 극복방법에 관한 연구)

  • Kim, Jee-Hong;Lee, Chang-Goo
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.4
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    • pp.391-395
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    • 2010
  • In our paper, we propose an asymmetric single-tracked wheel system, and describe its structure and the method for maintaining the length of a transformable track system. And the method is reducing the gap of lengths. Therefore, we propose an efficient structure for transforming and explain motions with kinematics. Our transformable shape single-tracked mobile system has an advantage to overcome an obstacle or stairs by the variable arms in the single unity track system. But we will make the variable shape of tracked system get a drive that has a force to stand against a wall. In this case, we can consider this system to a rigid body and have a notice that this single tracked system is able to get vary shape with the variable arm angle. Considering forces balance along x-axis and y-axis, and moments balance around the center of the mass we have. If this rigid body is standing against a wall and doesn't put in motion, the force of flat ground and the rigid body sets an equal by a friction. In the same way, the force of a wall and the rigid sets an equal by a friction.

Efficient estimation and variable selection for partially linear single-index-coefficient regression models

  • Kim, Young-Ju
    • Communications for Statistical Applications and Methods
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    • v.26 no.1
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    • pp.69-78
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    • 2019
  • A structured model with both single-index and varying coefficients is a powerful tool in modeling high dimensional data. It has been widely used because the single-index can overcome the curse of dimensionality and varying coefficients can allow nonlinear interaction effects in the model. For high dimensional index vectors, variable selection becomes an important question in the model building process. In this paper, we propose an efficient estimation and a variable selection method based on a smoothing spline approach in a partially linear single-index-coefficient regression model. We also propose an efficient algorithm for simultaneously estimating the coefficient functions in a data-adaptive lower-dimensional approximation space and selecting significant variables in the index with the adaptive LASSO penalty. The empirical performance of the proposed method is illustrated with simulated and real data examples.

Single-Phase Self-Excited Induction Generator with Static VAR Compensator Voltage Regulation for Simple and Low Cost Stand-Alone Renewable Energy Utilizations Part I : Analytical Study

  • Ahmed, Tarek;Noro, Osamu;Soshin, Koji;Sato, Shinji;Hiraki, Eiji;Nakaoka, Mutsuo
    • KIEE International Transactions on Power Engineering
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    • v.3A no.1
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    • pp.17-26
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    • 2003
  • In this paper, the comparative steady-state operating performance analysis algorithms of the stand-alone single-phase self-excited induction generator (SEIG) is presented on the basis of the two nodal admittance approaches using the per-unit frequency in addition to a new state variable de-fined by the per-unit slip frequency. The main significant features of the proposed operating circuit analysis with the per-unit slip frequency as a state variable are that the fast effective solution could be achieved with the simple mathematical computation effort. The operating performance results in the simulation of the single-phase SEIG evaluated by using the per-unit slip frequency state variable are compared with those obtained by using the per-unit frequency state variable. The comparative operating performance results provide the close agreements between two steady-state analysis performance algorithms based on the electro-mechanical equivalent circuit of the single-phase SEIG. In addition to these, the single-phase static VAR compensator; SVC composed of the thyristor controlled reactor; TCR in parallel with the fixed excitation capacitor; FC and the thyristor switched capacitor; TSC is ap-plied to regulate the generated terminal voltage of the single-phase SEIG loaded by a variable inductive passive load. The fixed gain PI controller is employed to adjust the equivalent variable excitation capacitor capacitance of the single-phase SVC.

Variable Step Size Maximum Power Point Tracker Using a Single Variable for Stand-alone Battery Storage PV Systems

  • Ahmed, Emad M.;Shoyama, Masahito
    • Journal of Power Electronics
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    • v.11 no.2
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    • pp.218-227
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    • 2011
  • The subject of variable step size maximum power point tracking (MPPT) algorithms has been addressed in the literature. However, most of the addressed algorithms tune the variable step size according to two variables: the photovoltaic (PV) array voltage ($V_{PV}$) and the PV array current ($I_{PV}$). Therefore, both the PV array current and voltage have to be measured. Recently, maximum power point trackers that arc based on a single variable ($I_{PV}$ or $V_{PV}$) have received a great deal of attention due to their simplicity and ease of implementation, when compared to other tracking techniques. In this paper, two methods have been proposed to design a variable step size MPPT algorithm using only a single current sensor for stand-alone battery storage PV systems. These methods utilize only the relationship between the PV array measured current and the converter duty cycle (D) to automatically adapt the step change in the duty cycle to reach the maximum power point (MPP) of the PV array. Detailed analyses and flowcharts of the proposed methods are included. Moreover, a comparison has been made between the proposed methods to investigate their performance in the transient and steady states. Finally, experimental results with field programmable gate arrays (FPGAs) are presented to verify the performance of the proposed methods.

The method to produce GRM coefficient using single transform matrix (단일변수 변환 행렬을 이용한 GRM 상수 생성 방법)

  • 이철우;김영건
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.807-810
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    • 1998
  • This paper propose the method to produce GRM(Generalized Reed-Muller)expansion. The general method to obtain GRM expansion coefficient for p valued n variable is derivation of single variable transform matrix and expand it n times using Kronecker product. In this case the size of matrix increases depending on the augmentation of variables. In this paper we propose the simple algorithm to produce GRM coefficient using a single variable transform matrix.

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Analysis of Design and Part Load Performance of a Modified Regenerative Cycle Gas Turbine (수정된 재생사이클 가스터빈의 설계 및 부분부하 성능해석)

  • Hwang, Sung-Hoon;Kim, Tong-Seop
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.467-472
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    • 2005
  • Characteristics of a Modified regenerative cycle gas turbine has been investigated. In the cycle, the turbine expansion is divided into two parts and the regenerator locates between them. Two types of mechanical design are assumed: two-shaft and single-shaft. In particular, optimal pressure ratio division between the high and low pressure turbines is evaluated for the single shaft configuration. The part load analyses have been carried out with the aid of off-design models. In addition to the general fuel only control, a variable speed control is assumed as the part load operating strategy of the single shaft configuration. Obvious advantage with the alternative cycle is observed in the variable speed operation of the single shaft design.

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A Study on Speed Variable Proportional Resonant Current Controller of Single-Phase PMSM (단상 영구자석 동기전동기의 속도 가변형 비례공진 전류제어에 관한 연구)

  • Lee, Won-Seok;Hwang, Seon-Hwan;Park, Jong-Won
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.954-960
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    • 2020
  • This paper proposes a speed variable proportional resonant current control method for a single-phase permanent magnet synchronous motor(PMSM). Due to the electromagnetic characteristics of a single-phase PMSM, negative and zero torques are generated in the part corresponding to the phase difference between the stator current and the back electromotive force. In addition, overcurrent limitation is required because of the low stator resistance and inductance in sensorless operation. When using the vector control for current control of single-phase PMSM under these conditions, processes of coordinate transformation, inverse coordinate transformation, and generation of virtual dq-axis components are required. However, the proposed variable speed proportional resonant current control method does not need the coordinate transformation used for AC motors. In this paper, we have confirmed stable maneuverability by using variable proportional resonant current control algorithm, and proposed sensorless control based on a mathematical model of a single-phase PMSM without a position sensor when reaching a constant speed. The usefulness of the current control method was verified through several experiments.

Revised KS Standards for Acceptance Sampling By Attribute and By Variable Based On OC Curve (OC 곡선에 기초한 규준형 샘플링 검사 규격)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
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    • 2008.11a
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    • pp.505-515
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    • 2008
  • This paper introduces six single and sequential acceptance sampling plans based on OC( Operating Characteristic) curve. Revised KS standards for acceptance sampling by attribute and by variable such as KSA 3102 : 1996, 3103 : 2005, KSA ISO 14560 : 2006, 8422 : 2001, 8423 : 2001 are presented.

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Revised KS Standards for Acceptance Sampling By Attribute and By Variable Based On Switching Rule (전환규칙을 적용한 조정형 샘플링 검사의 종류)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
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    • 2008.11a
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    • pp.517-526
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    • 2008
  • This paper introduces fourteen single, double, multiple and sequential acceptance sampling plans based on switching rule. Revised KS standards for acceptance sampling by attribute and by variable such as KSA ISO 2859-0, 1:2001 2859-2:2001, 8422:2001, 3951:2006, 8423:2001, MIL-STD-105E:1989, 414:1968 and ANSI/ASQ Z1.4, Z1.9:2003 are presented.

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The Decoupling And Design Of Linear Multivariable Control Systems By State Variable Feedback (상태변수피이드백에 의한 선형다변수제어시스템의 분할식설계에 관한 연구)

  • 황창선
    • 전기의세계
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    • v.23 no.2
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    • pp.46-54
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    • 1974
  • The purposes of this paper are to deal with the design of m-input, m-output linear systems by the state variable feedback, and to extend the design capability of the state variable feedback design. The design requirements are decoupling and the exact realigation of desired transfer functions. Some methods are proposed to insert series compensators in the fixed plant in the cases when series compensators are needed to meet the input-output transfer matrix specification. The method for adding series compensators to the input channels of the fixed plant is shown by examples to lead both to the loss of the ability to decouple the augmented plant by the state variable feedback, and to the loss of desired zeroes. A method which avoids these two hazards is developed in which series compensators are put on the output channels of the fixed plant: it is proved that the augmented plant is F-invariant. By treating each subsystem individually, the designer can apply some of the previous developed knowledge of the state variable design of single-input, single-output systems.

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