• Wind and Structures
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• 제11권1호
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• pp.19-33
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• 2008

This research investigates the adaptive input estimation method applied to the multilayer shearing stress structure. This method is to estimate the values of wind load inputs by analyzing the active reaction of the system. The Kalman filter without the input term and the adaptive weighted recursive least square estimator are two main portions of this method. The innovation vector can be produced by the Kalman filter, and be applied to the adaptive weighted recursive least square estimator to estimate the wind load input over time. This combined method can effectively estimate the wind loads to the structure system to enhance the reliability of the system active performance analysis. The forms of the simulated inputs (loads) in this paper include the periodic sinusoidal wave, the decaying exponent, the random combination of the sinusoidal wave and the decaying exponent, etc. The active reaction computed plus the simulation error is regard as the simulated measurement and is applied to the input estimation algorithm to implement the numerical simulation of the inverse input estimation process. The availability and the precision of the input estimation method proposed in this research can be verified by comparing the actual value and the one obtained by numerical simulation.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1031-1036
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• 2015

Proportional-integral-derivative (PID) controllers are widely used in industrial sites. Most tuning methods for PID controllers use an empirical and experimental approach; thus, the experience and intuition of a designer greatly affect the tuning of the controller. The representative methods include the closed-loop tuning method of Ziegler-Nichols (Z-N), the C-C tuning method, and the Internal Model Control tuning method. There has been considerable research on the tuning of PID controllers for single-input single-output systems but very little for multi-input multi-output systems. It is more difficult to design PID controllers for multi-input multi-output systems than for single-input single-output systems because there are interactive control loops that affect each other. This paper presents a tuning method for the PID controller for a two-input two-output system. The proposed method uses a real-coded genetic algorithm (RCGA) as an optimization tool, which optimizes the PID controller parameters for minimizing the given objective function. Three types of objective functions are selected for the RCGA, and each PID controller parameter is determined accordingly. The performance of the proposed method is compared with that of the Z-N method, and the validity of the proposed method is examined.

• 제어로봇시스템학회논문지
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• 제2권3호
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• pp.165-173
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• 1996

It is not desirable to have too large control input in control systems, because there are usually a limitation for the input magnitude and cost for the input energy. Previous papers in the iterative learning control did not considered on these points. In this paper, an iterative learning control method is proposed for a class of nonlinear systems with consideration on input magnitude by adopting a concept of cost function consisting of the output error and the input magnitude in quadratic form. We proposed a new input update law with an input penalty function. If we choose a reasonable input penalty function, the two control objectives, good command following and small input energy, can be achieved. The characteristics of the proposed method are shown in the simulation examples.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1259-1263
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• 1999

In this paper, a method to guarantee system continuity is developed, which can be applied to discontinuity problem in the time domain of restructurable control system. This method can be summarized as input alternation using weight change considering convergence speed of system mode. Input is changed from 'system continuity guarantee input,' which is defined as a input that minimizes the change of state variables, to 'alternative controller input,' which is selected by Neil's PI/EAM[3]. AIDC aircraft model is used for simulation. By showing the waveform of system input and state variable, we can sure that this method is effective for depression of system shock like jerk.

• Structural Engineering and Mechanics
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• 제34권1호
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• pp.1-14
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• 2010

The innovative intelligent fuzzy weighted input estimation method which efficiently and robustly estimates the unknown time-varying input force in on-line is presented in this paper. The algorithm includes the Kalman Filter (KF) and the recursive least square estimator (RLSE), which is weighted by the fuzzy weighting factor proposed based on the fuzzy logic inference system. To directly synthesize the Kalman filter with the estimator, this work presents an efficient robust forgetting zone, which is capable of providing a reasonable compromise between the tracking capability and the flexibility against noises. The capability of this inverse method are demonstrated in the input force estimation cases of the plate structure system. The proposed algorithm is further compared by alternating between the constant and adaptive weighting factors. The results show that this method has the properties of faster convergence in the initial response, better target tracking capability, and more effective noise and measurement bias reduction.

• 디자인융복합연구
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• 제16권4호
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• pp.115-126
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• 2017

지능형제품은 모체제품이라고 불리는 기존 제품에 상호작용성이 더해진 제품으로, 제품 속성에 따라 유희, 즐거움 등의 쾌락적 속성을 모체제품에 추가한 쾌락적 지능형제품과 모체제품의 기능 수행에서 요구되는 사용 행위를 자동화함으로써 실용적 속성을 부여하는 실용적 지능형제품으로 구분될 수 있다. 실용적 지능형제품의 경우, 모체제품을 사용하는 과정에서 지능화를 통해 지원되어야 하는 사용행위를 발굴하여, 이를 자동화하면 되는 반면, 쾌락적 지능형제품은 쾌락적 속성을 부여할 수 있는 다양한 감성적 가치를 발굴하여 사용자 경험을 디자인할 수 있다. 이에 본 연구에서는 쾌락적 지능형 제품의 인터랙션디자인에 초점을 두어, 쾌락적 지능형제품의 효과적인 입력 제어 방식에 대해 탐구하였다. 입력 제어 방식은 모체제품의 기존 사용자 행위가 적용된 모방 입력 방식과 사용자 행위를 변형하여 적용한 응용 입력 방식으로 구분된다. 입력 제어 방식에 따른 사용자 인식을 알아보기 위해 실험을 실시하였고 소비자 수용도를 평가하였다. 그 결과, 응용 입력 방식이 모방 입력 방식에 비해 신규성과 흥미도에서 더 높은 평가를 받았다. 또한, 응용 입력 방식이 모방 입력 방식에 비해 높은 제품선호도를 나타냈다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2393-2398
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• 2003

In this paper, we proposes a new fuzzy inference system for modeling nonlinear systems given input and output data. In the suggested fuzzy inference system, the number of fuzzy rules and parameter values of membership functions are automatically decided by using the kernel-based method. The kernel-based method individually performs linear transformation and kernel mapping. Linear transformation projects input space into linearly transformed input space. Kernel mapping projects linearly transformed input space into high dimensional feature space. The structure of the proposed fuzzy inference system is equal to a Takagi-Sugeno fuzzy model whose input variables are weighted linear combinations of input variables. In addition, the number of fuzzy rules can be reduced under the condition of optimizing a given criterion by adjusting linear transformation matrix and parameter values of kernel functions using the gradient descent method. Once a structure is selected, coefficients in consequent part are determined by the least square method. Simulated result illustrates the effectiveness of the proposed technique.

• Journal of Power Electronics
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• 제19권6호
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• pp.1380-1392
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• 2019

Input filters are very important to matrix converters (MCs). They are used to improve grid side current waveform quality and to reduce the input voltage distortion supplied to the grid side. Due to the effects of the input filter and the output power, the grid side power factor (PF) is not at unity when the input power factor angle is zero. In this paper, the displacement angle between the grid side phase current and the phase voltage affected by the input filter parameters and output power is analyzed. Based on this, a new grid side PF unity compensation method implemented in the indirect space vector pulse width modulation (ISVPWM) method is presented, which has a larger compensation angle than the traditional compensation method, showing a higher grid side PF at unity in a wide output power range. Simulation and experimental results verify that the analysis of the displacement angle between the grid side phase current and the phase voltage affected by the input filter and output power is right and that the proposed compensation method has a better grid side PF at unity.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.768-773
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• 2004

This work deals with the synthesis of discrete-time nonlinear controller for input time-delay existing nonlinear system and proposes a new effective method to compensate the influence of input time-delay. The controller is synthesised by using input/output linearization. Under the circumstance that input time-delay exist, controller have to produce future value that will be needed for system. On account of this reason described, a weighted average predictor of combined states is adopted. Using the discretization via Euler method, numerical simulations about Van der Pol system are performed to evaluate performance of the proposed method.

• 대한인간공학회지
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• 제17권3호
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• pp.61-70
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• 1998

The purpose of this paper is to evaluate the input methods of the numeric keypads that are widely used in various types of consumer and industrial electronic products. Three methods to enter numerals using keypads were compared: (1) Machine Intelligence, (2) + 100 key, and (3) Enter key input methods. Experiments were conducted to compare these three input methods for the channel selection of TV. Experimental prototypes which simulate TV user interfaces were developed using $RAPID^{TM}$ for usability testings. In the experiment, data on subject performance such as completion time, operational errors, and user interaction were collected through auto-logging method and video recording. After each test session, subjective preference was also asked using a questionnaire. In order to analyze the type of operation errors and the error causation, operation sequences were analyzed from the collected data. The Enter key input method showed better performance than other input methods. Based on these results. we can conclude that the input method using numeric keypads should be compatible with generic number counting(to input ch 7, it would be better to input 7 directly than to input 07 or 007) and should switch the channel as quickly as possible. This conclusion can be applied to the design of user interfaces which require numeral inputs.