• 한국통신학회논문지
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• 제21권8호
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• pp.1885-1896
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• 1996

This paper describes the implementation of the AVT(Automatic video Tracker) using ASIC. The basic tracking algorithm is based on the spatio-temporal gradient method, and adaptive window sizing, track state decision algorithm were also realized. Newly developed ASIC performs recursive image filtering, extraction of spatio-temporal gradient/gradient functions of image in field rate. Using the FPGA/ASIC, the tracker was simply realized in one board type which can be easily applied to various image system. We conformed ASIC operation by computer simulation and tested the system in real tracking situations. From the result, the system can track the moving target which has a velocity of 2-3 pixel/field and a size of varying from 2 to 128 pixes. Also fast refresh rateof motion estimation(60Hz) improves the characteristics of servoing system which forms feedback loop with the tracker.

• 전기학회논문지
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• 제61권2호
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• pp.276-283
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• 2012

In this paper, a practical quasi-optimal DOA(direction of arrival) estimator is proposed in order to develop a one-axis gimbaled ultrasonic source tracker for mobile robot applications. With help of the gimbal structure, the ultrasonic moving source tracking problem can be simply reduced to the DOA estimation. The DOA estimation is known as one of the representative long-pending nonlinear filtering problems, but the conventional nonlinear filters might be restrictive in many actual situations because it cannot guarantee the reliable performance due to the use of nonlinear signal model. This motivates us to reformulate the DOA estimation problem in the linear robust state estimation setting. Based on the assumption that the received ultrasonic signals are noisy sinusoids satisfying linear prediction property, a linear uncertain measurement model is newly derived. To avoid the DOA estimation performance degradation caused by the stochastic parameter uncertainty contained in the linear measurement model, the recently developed NCRKF (non-conservative robust Kalman filter) scheme [1] is utilized. The proposed linear DOA estimator provides excellent DOA estimation performance and it is suitable for real-time implementation for its linear recursive filter structure. The effectiveness of the suggested DOA estimation scheme is demonstrated through simulations and experiments.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.189-192
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• 2009

We present a novel head tracking system for stereoscopic displays that ensures the viewer has a high degree of movement. The tracker is capable of segmenting the viewer from background objects using their relative distance. A depth camera is used to generate a key signal for head tracking application. A method of the moving parallax barrier is also introduced to supplement a disadvantage of the fixed parallax barrier that provides observation at the specific locations.

• 대한전자공학회논문지
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• 제24권4호
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• pp.684-695
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• 1987

In this paper, an improved matching method using subtemplate of moving region and 3-step search algorithm is proposed. It reduces heavy computational load of the conventional method and also can continuously track the target even with occlusion. The proposed method is applied to an automatic target tracker using high speed 16bit microprocessor in order to track one moving target in real time. Experimental results show that the proposed method has better performance over the conventional method in spite of greately reducing the computational load, even in case with complex background and/or with occlusion.

• 전자공학회논문지
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• 제53권4호
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• pp.129-135
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• 2016

본 논문에서는 이동 창 함수 추적기라는 새로운 추적 알고리즘을 제안한다. 본 논문에서는 이동표적의 궤적을 효율적으로 추정하기 위해 과거 궤적의 정보를 포함하는 이동 구간이 선형이라는 가정을 한 선형 창 함수를 적용하여 구현한다. 제안된 알고리즘의 창 함수의 파라메터는 측정 잡음의 영향을 줄이기 위해 그리고 알파-베터 추적기와 비교하여 더 적은 계산량 증가로 빠른 이동 표적 추적을 구현하기 위해 적절하게 선택할 수 있다. 본 논문에서 제안한 창 함수 추적기를 검증하기 위해 잡음상황에서 선형과 비선형 궤적에 대한 컴퓨터 모의실험을 수행했다. 또한 제안된 창 함수 추적기는 초기값에 대한 둔감한 특성과 예측할 수 없는 시변 측정 환경에서 창 함수 추적기를 사용할 경우 더 높은 자유도를 가짐을 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.335-337
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• 1994

The correlation tracker developed by John M. Fitts in 1979 is the most complex to mechanize but provides the best tracking performance in a low SNR condition. Correlation tracker would rewove the requirements for optimizing threshold and has no need to know information about the target. But if the displacement of the target is large, the tracking error of the correlation tracker tends to diverge. In this paper, we suggest a precision image tracking algorithm which improves the tracking performance via iterative application of the matched filter estimation algorithm.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1987년도 춘계학술발표회 논문집
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• pp.42-45
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• 1987

In this paper a target tracking algorithm of the centroid extraction from moving edges is proposed, It aims to avoid the difficulty of imahe segmentation in case of the centroid extraction from one frame. The performance of the proposed algorithmfor noisy and occluded images is discussed Finally it is also applied to a real time target tracker.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1987년도 춘계학술발표회 논문집
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• pp.52-55
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• 1987

In tihis paper an improved matching method using subtemplate of moving region and 3-step search algorithm is proposed It reduces heavy computational load of the conventional method. The proposed method is applied to an automatic target tracker using high speed 16 bit microprocessor in order to track one moving target in real time. Expericmental results show that the proposed method has better performance over the conventional methodin spite of greately reducing the computational load, even in came complex background.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.478-481
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• 1996

Tracking a target of versatile maneuver recently demands a stable adaptation of tracker, and the multiple model techniques are being developed because of its ability to produce useful information of target maneuver. This paper presents the way to apply the multiple model method in a moving-target and moving-platform scenario, and the estimation and prediction results better than those of single Kalman filter.

• 방송공학회논문지
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• 제17권5호
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• pp.817-826
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• 2012

본 논문에서는 이동형 패럴랙스 배리어 방식의 모바일 3D 디스플레이를 위해 급격한 조명 변화에도 강인한 시청자 시역위치 추정 알고리즘을 제안한다. 기존의 비올라-존스 검출기와 옵티컬-플로우를 선형 결합한 시역 위치 추정 알고리즘[1]은 급격하게 조명이 변하는 경우 잘못된 시역 위치를 추정하는 문제가 있음을 확인하였고, 특히 이러한 급격한 조명의 변화 문제는 모바일 환경에서 흔히 발생하는 환경조건이다. 그리고 어두운 공간에서 3D 디스플레이를 시청하는 경우 디스플레이 조명이 시청자의 얼굴에 비치기 때문에 조명 변화가 매우 크게 발생할 수 있다. 급격한 조명의 변화에 대한 문제점을 해결하기 위해 본 논문에서는 매 프레임마다 정확하게 옵티컬-플로우 얼굴 검출기의 정확도를 판단할 수 있는 방법을 새롭게 제안하고, 다양한 실험을 통해 그 효과를 검증한다. 조명의 변화등에 의해 옵티컬-플로우가 잘못된 추적 결과를 출력하는 경우, 기존의 두 알고리즘(비올라-존스 얼굴검출기+옵티컬-플로우 특징점 추적기)을 선별적으로 선택함으로써 강인한 얼굴검출 및 추적이 이루어지도록 하고, 다양한 실험 결과를 통해 그 효과를 검증한다.