• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.4
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• pp.223-229
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• 2017

An angle error is a factor obstructing to track accurate position in tracking radars. And the noise incurring the angle error can be divided as follows; thermal noise and glint. In general, Extended Kalman filter used in tracking radars is designed with considering thermal noise only. The Extended Klaman filter uses a fixed measurement error covariance when updating an estimate state by using ahead state and measurement. But, a noise power varies according to the range. Therefore we purposes the adaptive Kalman filter which changes the measurement noise covariance according to the range. In this paper, we compare the performance of the Extended Kalman filter and the proposed adaptive Kalman filter by considering KSLV-I (Korean Satellite Launch Vehicles).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1096-1102
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• 2014

In remote gaze tracking system using infra-red LEDs, calibrating the position of reflected light is essential for computing pupil position in captured images. However, there are limitations in reducing errors because variable locations of head and unknown radius of cornea are involved in the calibration process as constants. This study purposes a gaze tracking method based on pupil-corneal reflection that does not require user-calibration. Our goal is to eliminate the correction process of glint positions, which require a prior calibration, so that the gaze calculation is simplified.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.48-63
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• 2015

In this study, we introduce various hyperspectral data processing techniques for the monitoring of shallow and coastal waters to enlarge the application range and to improve the accuracy of the end results in Korea. Unlike land, more accurate atmospheric correction is needed in coastal region showing relatively low reflectance in visible wavelengths. Sun-glint which occurs due to a geometry of sun-sea surface-sensor is another issue for the data processing in the ocean application of hyperspectal imagery. After the preprocessing of the hyperspectral data, a semi-analytical algorithm based on a radiative transfer model and a spectral library can be used for bathymetry mapping in coastal area, type classification and status monitoring of benthos or substrate classification. In general, semi-analytical algorithms using spectral information obtained from hyperspectral imagey shows higher accuracy than an empirical method using multispectral data. The water depth and quality are constraint factors in the ocean application of optical data. Although a radiative transfer model suggests the theoretical limit of about 25m in depth for bathymetry and bottom classification, hyperspectral data have been used practically at depths of up to 10 m in shallow and coastal waters. It means we have to focus on the maximum depth of water and water quality conditions that affect the coastal applicability of hyperspectral data, and to define the spectral library of coastal waters to classify the types of benthos and substrates.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.456-459
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• 1993

CADET is used to analyze the performance of the missile. Miss distance is calculated for a given lateral fin force saturation level due to the aerodynamic characteristics, target acceleration, and glint and fading noises which is assumed as Gaussian noises. As .alpha.-.betha. filter is studied to attenuate the noises, the results are compared with those of without filter. For the easy simulation, the transfer function of a discrete .alpha.-.betha. filter is converted into the continuous model. Simulation results show that the results of CADET simulation is similar to those of Monte-Carlo simulation. Moreover CADET is the better in computing time demand.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.309-312
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• 2003

기존 홍채 인식 시스템의 접안식 영상 획득상 불편한 사항을 해결하고 인식의 정확도를 높이기 위해서는 원격으로 영상을 획득할 수 있어야 하며, 홍채의 경계선을 정확하게 검출할 수 있어야 한다. 또한 기존 홍채 영역 검출 방법의 문제점인 홍채를 원으로 가정하는 방식을 개선할 필요성이 있다. 따라서 본 논문에서는 조명에 의한 glint 정보와 intensity gradient를 이용하여 홍채의 경계를 산출하였으며, 아울러 스테레오스코픽 카메라를 이용하여 홍채 경계의 3차원 좌표를 획득함으로써, 카메라를 기준으로 하는 홍채의 주시각을 찾아 홍채의 원형 변환에 활용하도록 하였다.

• ICROS
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• v.3 no.2
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• pp.20-25
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• 1997

이 글에서는 전술유도무기체계에서 호밍유도의 PNG 다음으로 많이 채택하고 있는 시선지령유도의 유도루우프 설계기술에 대해 논하고자 한다. 이를 위해 유도루우프를 구성하고 있는 부체계인 표적추적장치, 오차보상기, feedforward 보상기에 대해 살펴보고 유도루우프를 설계할 때 고려해야 할 유도오차를 발생시키는 요인인 표적의 기동, glint noise 등의 영향에 대해 분석한다. 또한 유도탄의 기동력과 지령수신기의 수신감도에 따라 결정되는 명중영역의 산출과 시선유도의 발전추세에 대해 언급하고자 한다.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2124-2127
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• 2003

This paper suggests user interface method with wearable computer by means of detecting gaze under HMD, head mounted display, environment. System is derived as follows; firstly, calibrate a camera in HMD, which determines geometrical relationship between monitor and captured image. Second, detect the center of pupil using ellipse fitting algorithm and represent a gazing position on the computer screen. If user blinks or stares at a certain position for a while, message is sent to wearable computer. Experimental results show ellipse fitting is robust against glint effects, and detecting error was 6.5％, and 4.25％ in vertical and horizontal direction, respectively.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.78-78
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• 2004

• Korean Journal of Remote Sensing
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• v.26 no.2
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• pp.175-188
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• 2010

A new correction method is required for the Geostationary Ocean Color Imager (GOCI), which is the world's first ocean color observing sensor in geostationary orbit. In this paper we introduce a new method of atmospheric and the Bidirectional Reflectance Distribution Function(BRDF) correction for GOCI. The Spectral Shape Matching Method(SSMM) and the Sun Glint Correction Algorithm(SGCA) were developed for atmospheric correction, and BRDF correction was improved using Inherent Optical Property(IOP) data. Each method was applied to the Sea-Viewing Wide Field-of-view Sensor(SeaWiFS) images obtained in the Korean sea area. More accurate estimates of chlorophyll concentrations could be possible in the turbid coastal waters as well as areas severely affected by aerosols.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.83-86
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• 2003

This paper suggests user's interface with computer by means of detecting gaze under HMD, head mounted display, environment. System is derived as follows; firstly, calibrate a camera in HMD, which determines geometrical relationship between monitor and captured image. Second, detect the center of pupil using algorithm of the center of mass and represent a gazing position on the computer screen. If user blinks or stares at a certain position for a while, message is sent to computer. Experimental results show the center of mass is robust against glint effects, and detecting error was 7.1%. and 4.85% in vertical and horizontal direction, respectively. To adjust detailed movement of a mouse takes 0.8 sec more. The 98% of blinking is detected successfully and 94% of clicking detection is resulted.