• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.287-287
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.195-195
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• 2004

리니어 모터는 큰 이송속도와 정밀한 위치제어가 가능하여 고정밀도가 요구되는 분야에서 널리 사용되고 있으며, 이에 대한 연구도 활발히 진행되고 있다. 그 중 리니어 모터의 정밀도를 저해하는 요인 및 측정 방법에 대해서도 연구가 점차로 많이 진행되고 있으며, 현재 시스템이 가지고 있는 기하학적 오차에 관한 연구와 열변형에 관한 연구가 보고되었다. 특히 기하학적 오차는 가공물의 정밀도를 결정하는 중요한 지표이며, 가공된 물체를 결정하는 기본요소이기 때문에 가장 많이 연구되었으며, 이에 대한 다양한 해석 방법과 보상에 관한 연구가 이루어졌다.(중략)

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.2 s.308
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• pp.12-18
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• 2006

This paper presents a method to extract a good high-resolution image from a low-resolution video in an automatic manner. Since a high-resolution image reconstruction method utilizing several low-resolution input images works better than a conventional interpolation method utilizing single low-resolution input image only if the input images are well registered onto a common high-resolution grid, low-resolution input images should be carefully chosen so that the registration errors can be carefully considered. In this paper, the statistics obtained from the motion-compensated low-resolution images are utilized to evaluate the feasibility of the input image candidates. Maximum motion-compensation error is estimated from the high-resolution image observation model. U the motion-compensation error of the input image candidate is greater than the estimated maximum motion-compensation error, the input image candidate is discarded. The number of good input image candidates and the statistics of the motion-compensation errors are used to choose final input images. The final input images chosen from the input image selection block are given to the following high-resolution image reconstruction block. It is expected that the proposed method is utilized to extract a good high-resolution image efficiently from a low-resolution video without any user intervention.

• Journal of Broadcast Engineering
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• v.19 no.6
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• pp.896-906
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• 2014

In this paper, a real-time dual-mode temporal synchronization and compensation method based on a new reliability measure in stereoscopic video is proposed. The goal of temporal alignment is to detect the temporal asynchrony and recover synchronization of the two video streams. The accuracy of the temporal synchronization algorithm depends on the 3DTV contents. In order to compensate the temporal synchronization error, it is necessary to judge whether the result of the temporal synchronization is reliable or not. Based on our recently developed temporal synchronization method[1], we define a new reliability measure for the result of the temporal synchronization method. Furthermore, we developed a dual-mode temporal synchronization method, which uses a usual texture matching method and the temporal spatiogram method[1]. The new reliability measure is based on two distinctive features, a dynamic feature for scene change and a matching distinction feature. Various experimental results show the effectiveness of the proposed method. The proposed algorithms are evaluated and verified through an experimental system implemented for 3DTV.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.123-129
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• 2014

This paper presents an altitude detection accuracy for long range and multifunction radar. The accuracy is difficult to estimate because it is affected by an time varying atmosphere refractivity. We analyze altitude accuracy with a raytracing simulator with atmosphere refractivity. An altitude error is simulated with measured and modeled refractivity, and the modeled refractivity is used for compensate an altitude accuracy. As a result, the error is modeled with normal distribution function, and analyzed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.9
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• pp.617-625
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• 2022

This study investigates the use of movable calibration target for gyroscopic and accelerometer bias compensation of inertial measurement units for firing lane alignment. Calibration source is detected with the help of vision sensor and its information in fused with other sensors on launcher for error correction. An algorithm is proposed and tested in simulation. It has been shown that it is possible to compensate sensor biases in firing launcher in few seconds by accurately estimating the location of calibration target in inertial frame of reference.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.143-148
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• 2020

In the case of a system that detects and controls the phase of an alternating voltage, the analog control method compensates the phase offset part by filtering for the detected phase and applies it to the control. However, in the digital control method, precise control cannot be achieved due to an error between the operating frequency of the microprocessor or the microcontroller and the input phase time when controlled using such phase detection. In general, when the method used is a certain time, the accumulated error is compensated and adjusted at random. To solve this problem, a method of detecting a zero point in real time and compensating for the operating frequency of the microprocessor is needed. Therefore, the research to be performed in this paper to reduce these errors and apply them to precise digital control is as follows. 1) Research on how to implement Zero Crossing Detection algorithm through simulation modeling to compensate the zero point to match the operating frequency through detection. 2) A study on the method of detecting zero points in real time through the Zero Crossing Detection design using a microcontroller and compensating for the operating frequency of the microprocessor. 3) A study on the estimation of the rotor position of BLDC motors using the Zero Crossing Detection circuit.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.1861-1868
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• 2014

In wireless communication systems, a frequency offset exist at the received signal due to the transmitter-receiver oscillator mismatch and Doppler effect in mobile environments. Those offsets rotate the received signal's phase and degrade the receiver performance. Hence, estimation and compensation of the frequency offset is crucial at the receiver. This paper proposes a new frequency offset estimation technique based on partial correlation. The proposed method requires less computational complexity than that of the conventional method. In addition, since the proposed one can estimate a wide range of frequency offset without estimation accuracy loss, the application of the method is desirable for the communication environments that have a large frequency offset. In order to verify the performance of our proposed scheme, a series of computer simulations have been carried out and compared against those of the conventional method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.10
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• pp.1413-1421
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• 1993

It is possible to weaken the undesirable effect of a bounded control input signal to the plant and done by setting up an additional correction loop which compensates for the suppresed portion of the control input signal. The design and analysys of stability of state controller is used by the Kalman-Szego-Lemma and as the result of this method is made possible to take advantage of the control input to the plant even for small error signals.

• The Journal of the Acoustical Society of Korea
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• v.12 no.5
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• pp.38-46
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• 1993

스피커는 입력이 전기신호이고 출력이 소리인 전기 음향 장치로서, 고유의 전달함수를 갖는 하나의 시스템으로 생각할 수 있다. 일한 스피커 시스템의 전달함수는 여러 가지 원인으로 인해 주파수 영역에서 평탄한 특성을 가지지 못하며 선형위상의 조건을 만족시키기가 힘들다. 음색을 변화시키는 스피커의 전달함수를 선형이라고 가정할 때 스피커의 앞단에서 스피커의 선형 전달함수의 역에 해당하는 선형 필터를 추가함으로쏘, 음색의 왜곡은 보정할 수 있다. 본 연구에서는 이러한 스피커의 선형왜곡을 보상하기 위한 선형필터로서 FIR 필터를 사용하였으나, 2장에 제시되어 있는 기존의 알고리듬과는달리 귀의 청감특성을 이용하여 가청주파수 대역에 대해 몇 개의 대역으로 나눈 후, 각 대역마다 보상 할 주파수 해상도를 달리하는 새로운 알고리듬에 대해 기술하였다. 이러한 다해상도 선형왜곡 보상시스템은 각 대역마다 다른 해상도로 보상한다는점에서는 필터뱅크 보상 시스템과 유사하지만, 대역통과필터가 아닌 저역통과필터만을 이용하여 설계의 복잡서응ㄹ 줄였으며 각 대역마다 독립적으로 보상하는 필터뱅크 보상시스템과는 달리 1차 대역에서 보상하지 ath한 오차를 2차, 3차에서 보상하는 새로운 기법을 이용하였다. 본 알고리듬을 적용한 모의실험을 통하여 성능을 평가한 결과 가청음대역에서 ±6dB의 왜곡을 보인 스피커가 실효 tap수를 272로 했을 때 ±0.5dB의 리플을 보이는 양호한 결과를 얻었다.