• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.102.4-102
• /
• 2002

A deadzone compensator is designed for a positioning system using fuzzy logic. The classification property of fuzzy logic systems make them a natural candidate for the rejection of errors induced by the deadzone, which has regions in which it behaves differently. A tuning algorithm is given for the fuzzy logic parameters, so that the deadzone compensation scheme becomes adaptive, guaranteeing small tracking errors and bounded parameter estimates, formal nonlinear stability proofs are given to show that the tracking error is small. The fuzzy logic deadzone compensator is implemented on a positioning system to show its efficacy. 1. Deadzone Compansation 2. XY positioning table 3. Fuzzy Logic 4. Actuator nonlinearity

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.331-336
• /
• 1989

Under the condition of stable inverse a billinear model predictive control method for SISO and MIMO system with time delay is derived. For processes subject to a bounded disturbance the proposed control method with a classical recursive adaptation algorithm was shown to be stable in the sense of the convergence of parameter estimates and the boundedness of the control error. Several simulation results demonstrate the characteristics of the proposed bilinear model predictive control method.

• 제어로봇시스템학회:학술대회논문집
• /
• 1988.10b
• /
• pp.1045-1050
• /
• 1988

The problem of applying the linear integral filter in analysis and parameter estimation of linear continuous systems is discussed. A discrete-time model, which is equivalent to that obtained using the bilinear z transformation, is derived and employed to predict system output. It is shown that the output error can be controlled through the sampling interval. In order to obtain unbiased estimates, an instrumental variable (IV) method is proposed, where the instrumental variables are constituted using adaptive filtering. Some problems on implementation of the recursive IV algorithm are discussed. Both theoretical analysis and simulation study are given to illustrate the proposed methods.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.313-316
• /
• 2003

This paper proposes a new measurement method of face region size for real-time serveillance systems. The proposed method consists of three steps. In the first step, it detects global face area based on the block-based difference images. In the second step, it measures the face region size using face color information. In the third step, it estimates the face position in the next input image using the trajectory of face regions. The experimental results have shown that the proposed algorithm measures the face size within 20％ relative error on average, which is a]towable for most surveillance systems.

• ETRI Journal
• /
• v.38 no.3
• /
• pp.510-517
• /
• 2016

Recent developments in the field of separation of mixed signals into music/voice components have attracted the attention of many researchers. Recently, iterative kernel back-fitting, also known as kernel additive modeling, was proposed to achieve good results for music/voice separation. To obtain minimum mean square error (MMSE) estimates of short-time Fourier transforms of sources, generalized spatial Wiener filtering (GW) is typically used. In this paper, we propose an advanced music/voice separation method that utilizes a generalized weighted ${\beta}$-order MMSE estimation (WbE) based on iterative kernel back-fitting (KBF). In the proposed method, WbE is used for the step of mixed music signal separation, while KBF permits kernel spectrogram model fitting at each iteration. Experimental results show that the proposed method achieves better separation performance than GW and existing Bayesian estimators.

• ETRI Journal
• /
• v.34 no.4
• /
• pp.625-628
• /
• 2012

In this letter, a novel method for localizing a user in a smart home environment is presented. We propose a two-level structure, in which the first level determines an occupant's location in the block level using RSSI in a ZigBee network, while the second level accurately estimates the occupant's location using a particle filter to handle the variations in the signal strength measurement. We devise an experimental setup with people performing significant tasks in the smart home. The results obtained from the testbed indicate that the proposed model leads to an improvement in the mean distance error.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.5
• /
• pp.1363-1371
• /
• 1996

This paper presents the design, fabrication, and testing of polysilicon electrostatic microactuators that resonate in the direction parallel to the silicon susbstrates. A set of six different designs has been developed using a theoretical model and design formulae developed for the mocroactuators. Microactuator prototypes are fabricated from a 2.1 $\mu{m}$-thick LPCVD polysilicon film, using a 4-mask surface-micromachining process. The prototypes are tested under a d.c. bias voltage of 45V with an a.c. drive voltage amplitude of 20 v.Measured resorant frequencies are in the ranges of 40-60 kHz, showing a good agreement to their theoretical estimates within error bounds of .$\pm$.5%. Important issues inthe design and microfabrication of the microactuators are discussed, together with potential applicaitons of the key technology involved.

• Proceedings of the KSPS conference
• /
• 2003.10a
• /
• pp.101-104
• /
• 2003

In this paper, speech quality is improved by removing abrupt noise intervals and then substituting the gaps with estimates of the previous speech waveform. An abrupt noise detection signal has been proposed as a prediction error signal by utilizing LP coefficients of the previous frame. Abrupt noise intervals are estimated by using spectral energy. After removing estimated noise intervals, we applied several waveform substitution techniques such as zero substitution, previous frame repetition, pattern matching, and pitch waveform replication. To prove the validity of our algorithm, the LPC spectral distortion test and the recognition test are executed and, the results show that the speech quality is fairly well improved.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.401-406
• /
• 1992

When a velocity-aided strapdown inertial navigation system is loaded into a torpedo subjected to an extraneous force by the current, odometer measurement errors occur seriously. In order to compensate for navigation errors induced by large odometer biases, the Kalman Filter with separate bias estimator is applied, which separately estimates an unknown bias, and corrects the state estimate produced by the bias-free Kalman Filter to reflect the effect of the bias estimate.

• Journal of the Semiconductor & Display Technology
• /
• v.8 no.4
• /
• pp.7-13
• /
• 2009

The slender device(long length and thin width) manufactured by stereolithography process suffers from large curl distortion. This paper adapts two control parameters such as a critical exposure and a penetration depth. The measurement of the test parts dimension are carried out by reverse engineering method with the optical 3-dimensional measurement equipment. We investigate how each parameter contributes to the part accuracy and estimates the optimal set of parameters which minimizes the dimensional error of the test parts. Finally, As being an the RAM slot as being an example of the slender device, the RAM slot is made with the optimal values of control parameter and the results are investigated