• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.75-79
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• 1993

본 논문에서는 변화가 심한 음원파형을 추정하는 새로운 순차처리 알고리듬을 제안한다. 먼저, 1) 기존의 순차처리 분석법중 대표적인 분석법인 RLS(recursive least square)의 문제점들을 검토하고, 2) 이를 개선하기 위해서 관측행렬(observation matrix)을 최적차수의 SVD(reduced-rank singular value decomposition)로 재구성하고, 3) 이에 견실개념(robustness concept)을 적용해서 최적의 성도변수(vocal tract parameter)를 찾아내고 역필터를 적용해서 음원(voice source)을 효과적으로 구분해낸다. 본 논문에서 제안된 방법으로 음원을 추정할 경우, 변화가 심한 음원파형을 잘 추정할 수 있으며, 음원의 특성을 구분해낸 성도 파라미터도 효과적으로 추정할 수 있다. 본 연구내용은 음성합성에서 자연성 개선 및 개인성 구현을 위해서 필수적이며, 다양한 형태의 음성을 표현하기 위해 사용되어질 수 있다. 또한, 음성코딩, 화자인식, 음성인식에서도 사용되어질 수 있다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.311-314
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• 2003

In radar tracking, since the sensor measures range, azimuth and elevation angle of a target, the measurement equation is nonlinear and the extended Kalman filter (EKF) is applied to nonlinear estimation. The conventional EKF has been widely used as a nonlinear filter for radar tracking, but the considerably large measurement error due to the linearization of nonlinear function in highly nonlinear situations may deteriorate the performance of the EKF. To solve this problem, a fuzzy-model-based Kalman filter (FMBKF) is proposed for radar tracking. The FMBKP uses a local model approximation based on a TS fuzzy model instead of a Jacobian matrix to linearize nonlinear measurement equation. The hybrid GA and RLS method is used to identify the premise and the consequent parameters and the rule numbers of this TS fuzzy model. In two-dimensional radar tracking problem, the proposed method is compared with the conventional EKF.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.984-990
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• 2013

This paper develops a new Intelligent Electronic Device (IED), and then presents an application method of a monthly load forecasting algorithm on the smart IEDs. A Multiple Linear Regression (MLR) model implemented with Recursive Least Square (RLS) estimation is established in the algorithm. Case Study proves the accuracy and reliability of this algorithm and demonstrates the practical meanings through designed screens. The application method shows the general way to make use of IED's smart characteristics and thereby reveals a broad prospect of smart function realization in application.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.551-551
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• 1989

In general, a remotely operated vehicle(ROV) operates at deep sea. The control system of ROV is composed of two local loops; the first loop placed on the surface vessel monitors and manipulates the attitude of the ROV using joystick, and the second part on the ROV automatically controls thrusters and acquires positional data. This paper presents a position control simulation of a ROV using an adaptive controller and discusses the control effects of two different conditions. The design of an adaptive control system is obtained by the application of a self-tuning controller with the minimization of an appropriate cost function. The parameters of the control system are estimated by a recursive least square method(RLS). In the simulation, a Runge-Kutta method is used for the numerical integration and the generated outputs are obtained by adding measurement errors. Additionally, this paper discusses the mathematical modelling of a ROV and make a survey of control systems.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.51-58
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• 1989

In general, a remotely operated vehicle(ROV) operates at deep sea. The control system of ROV is composed of two local loops; the first loop placed on the surface vessel monitors and manipulates the attitude of the ROV using joystick, and the second part on the ROV automatically controls thrusters and acquires positional data. This paper presents a position control simulation of a ROV using an adaptive controller and discusses the control effects of two different conditions. The design of an adaptive control system is obtained by the application of a self-tuning controller with the minimization of an appropriate cost function. The parameters of the control system are estimated by a recursive least square method(RLS). In the simulation, a Runge-Kutta method is used for the numerical integration and the generated outputs are obtained by adding measurement errors. Additionally, this paper discusses the mathematical modelling of a ROV and make a survey of control systems.

• Smart Structures and Systems
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• v.11 no.6
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• pp.569-587
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• 2013

This paper evaluates the closed loop performance of the reaching law based discrete sliding mode controller with multisensor data fusion (MSDF) in real time, by controlling the first two vibrating modes of a piezo actuated structure. The vibration is measured using two homogeneous piezo sensors. The states estimated from sensors output are fused. Four fusion algorithms are considered, whose output is used to control the structural vibration. The controller is designed using a model identified through linear Recursive Least Square (RLS) method, based on ARX model. Improved vibration suppression is achieved with fused data as compared to single sensor. The experimental evaluation of the closed loop performance of sliding mode controller with data fusion applied to piezo actuated structure is the contribution in this work.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.117-119
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• 1995

서울대학교 의공학과에서는 부분적인 심부전 판자의 보조 및 치료장비로 전기유압식 좌심실 보조 장치를 개발하고 있다. 이 장비의 경우 인체의 좌심방 및 대동맥에 직접 연결되므로 실제적으로 좌심실 보조 장치의 박출량을 센서를 통하여 알아내는 데에는 여러가지 어려움이 따른다. 이러한 필요성에 비추어 전기유압식 좌심실 보조 장치의 박출량을 시스템을 ARX모델로 모델링하여 RLS(Recursive Least Square) 알고리듬을 이용하여 추정하였다. 그 결과 비교적 높은 정착도로 박출량이 추정됨을 볼 수 있었다. 하지만, ARX모델의 특성상 원래 본 연구의 시작과정에서 분석한 시스템의 동적 특성을 완전하게 반영할 수 없었다. 앞으로 시스템의 파라미터 추정 과정에서 이미 주어진 동적 특성은 고정시키고 나머지 파라미터들만을 추정하는 알고리듬을 개발하는 것도 흥미로운 과제라 할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5C
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• pp.506-513
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• 2003

Most existing space-time coding (STC) schemes have been developed for flat fading channels. To obtain antenna diversity gain, they rely on channel state information (CSI) required at the receiver through channel estimation techniques. This paper proposes a new decision feedback decoding scheme for Alamouti-based space-time block coding (STBC) transmission over time-selective fading channels. In wireless channels, time-selective fading effects arise mainly due to Doppler shift and carrier frequency offset, Modelling the time-selective fading channels as the first-order Gauss-Markov processes, we use recursive algorithms such as Kalman filtering, LMS and RLS algorithms for channel tracking. The proposed scheme consists of the symbol decoding stage and channel tracking algorithms. Computer simulations confirm that the proposed scheme shows the better performance and robustness to time-selectivity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4C
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• pp.384-391
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• 2003

Blind channel identification and equalization attempt to identify the communication channel and to remove the inter-symbol interference caused by a communication channel without using any known trainning sequences. In this paper, we propose a blind adaptive channel identification and equalization algorithm with phase offset compensation for single-input multiple-output (SIMO) channel. It is based on the one-step forward multichannel linear prediction error method and can be implemented by an RLS algorithm. Phase offset problem, we use a blind adaptive algorithm called the constant modulus derotator (CMD) algorithm based on condtant modulus algorithm (CMA). Moreover, unlike many known subspace (SS) methods or cross relation (CR) methods, our proposed algorithms do not require channel order estimation. Therefore, our algorithms are robust to channel order mismatch.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1146-1148
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• 1996

In this paper, uncertain parameters of the heat transfer model of a Dynamically Tuned Gyroscope (DTG) are estimated by the Recursive Least Squares (RLS) method. Also, using this model, a temperature controller for a DTG is designed. As the temperature controller, a PI controller is used. It is presented that a controller can be easily designed when the heat transfer model of a DTG is used. By simulations and experiments, it is shown that the estimated heat transfer model is appropriate and the desired performance of the temperature controller is satisfied.