• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.265-279
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• 2010

A color image requires at least three color channels to obtain the full color image. However the image sensor obtains only the intensity of the brightness, that is, three image sensors are required for every pixel to capture the full color image. Since the image sensor is quiet expensive, most of digital still cameras adopt single image sensor array with color filter array (CFA) to reduce the size and the cost. Since the image obtained using single sensor array has only one color component per pixel, we need to reconstruct the missing two color components to obtain the full color image. We call this process as color filter interpolation or demosaicking. In this paper, demosaicking algorithm composed of two large step is proposed. Proposed algorithm is combined with several different algorithms such as Edge-directed demosaicking, Second-order gradients as correction terms, Smooth hue transition Interpolation, etc. The simulation results show that the proposed algorithm performs much better than the state-of-the-art demosaicking algorithms in terms of both subjective and objective qualities.

• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.493-500
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• 2002

Fingerprint recognition is concerned with fingerprint acquisition and matching. Our research was focused on a fingerprint matching method using an inkless fingerprint input sensor at the fingerprint acquisition step. Since an inkless fingerprint sensor produces a digital-image-processed fingerprint image, we did not consider noise that can happen while acquiring the fingerprint. And making the user attempt fingerprint input as random, we considered image distortion that translation and rotation are included as complex. NJTC algorithm is used for fingerprint identification and verification. The method to find the center of the fingerprint is added in the NJTC algorithm to supplement discrimination of fingerprint recognition. From this center point, we decided the optimum cropping size for effective matching with pixels and demonstrated that the proposed method has high discrimination and high efficiency.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.109-117
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• 2012

Recently, large-scale multi-hazards have been occurred in the various areas of the world. A variety of Earth observation sensors such as satellite EO, aerial and terrestrial LiDAR have been utilized for global natural disaster monitoring. Especially, commercial satellites which observe the Earth regularly and repeatedly, and acquire images with cm-level high spatial resolution enable its applications to extend in the fields of disaster management from advanced disaster monitoring to timely recovery. However, due to existing satellite operation systems with some limitations in almost real-time and wide regional disaster response, close international collaborations between satellite operating organizations like NASA, JAXA, KARI etc. have been required for collecting satellite images in time through a satellite platform with multi-sensors or satellite constellation. For responding domestic natural disaster such as heavy snowfall and extreme rainfall in 2011, this paper proposes a disaster management system for timely decision-making; rapid acquisition of satellite imagery, data processing, GIS analysis, and digital mapping through cooperation with NDMI in Korea and International Charter-Space and Major disasters.

• Composites Research
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• v.28 no.4
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• pp.143-147
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• 2015

This paper proposes laser ultrasonic technique for the impact damage inspection of hydrogen fuel tank and proves that the impact damage can be visualized using an ultrasonic wave propagation imager with an easy detachable sensor head as an impact damage inspection tool for hydrogen fuel tanks. Also the performances of the proposed ultrasonic propagation imager support it can be implemented in real-world technology when the hydrogen car becomes popular.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.19-25
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• 2012

GEO-KOMPSAT2 shall provide higher quality of image than the COMS and uses star tracker instead of earth sensor, which requires precise onboard orbit information. This requires precise on-ground orbit determination. For COMS, orbit determination is performed using the ranging data obtained from tracking system located in DAEJON. For accurate orbit determination of GEO-KOMPSAT2, KARI is building a secondary tracking station in CHUUK Islands. In this paper, the achievable accuracy of table based onboard orbit parameter generator which interpolates orbit data obtained from on-ground orbit determination using tracking data collected from two ground stations. Two types of approaches have been applied; covariance analysis and numerical analysis. By combining two analysis results, total orbit error has been estimated.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.704-705
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• 2016

스마트아이 기술은 기존의 재난 감시 및 관리 서비스가 사람에 의한 단순 모니터링 기반의 대응을 제공하는 데 비해, 무인기를 활용해 사람의 사각에서 발생하는 재난 상황을 촬영하여 감시 및 분석을 하며, 무인기에 탑재된 다중 복합 센서 데이터의 실시간 처리 분석을 통해 국지적 산불 재난의 감지 예측 및 상황대응을 지원하고, 통합경보 시스템과 연동하여 대국민 재난 정보 전달 서비스 제공하는 서비스이다. 현재 본 서비스를 제공할 수 있는 Front to End 시스템이 개발 완료되어 실험실 테스트를 진행하였으며, 이와 더불어 실제 필드에서의 재난 감시 및 예측 성능을 검증하기 위한 필드 테스트를 준비 중에 있다. 이에 본 논문에서는 현재 구축하고 있는 스마트아이 재난 관리 플랫폼 실험실 테스트의 진행상황을 간단히 소개하고, 재난 영상의 획득, 분석, 및 예측을 수행하는 통합 플랫폼의 주요 기능들에 대해서 논한다.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.517-528
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• 2011

In this paper, we propose an indoor navigation system that can do walk safely to the destination for visually impaired persons. The proposed system analyzes images taken with the camera finds the ID of the marker to identify the absolute position of the pedestrian. Using the distance and angle obtained from IMU(Inertial Measurement Unit) accelerometer sensor and a gyro sensor, the system decides the relative position of a pedestrian for the previous position to determine the next direction. At the same time, we simplify a complex spatial structure in front of user by means of ultrasonic sensors and determine an avoidance direction by estimating the patterns. Then, it uses a few IR(Infrared Rays) sensors to detect stair. Our system offers position of visually impaired persons incorporating multiple sensors and helps users to arrive to destination safely.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2262-2270
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• 1999

In this paper, we describe gesture recognition algorithm using computer vision sensor and HMM. The automatic hand region extraction has been proposed for initializing the tracking of the tele-operation gestures. For this, distance informations(disparity map) as results of stereo matching of initial left and right images are employed to isolate the hand region from a scene. PDOE(positive difference of edges) feature images adapted here have been found to be robust against noise and background brightness. The KNU/KAERI(K/K) gesture instruction set is defined for tele-operation in atomic electric power stations. The composite recognition model constructed by concatenating three gesture instruction models including pre-orders, basic orders, and post-orders has been proposed and identified by discrete HMM. Our experimental results showed that consecutive orders composed of more than two ones are correctly recognized at the rate of above 97%.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.169-172
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• 2010

유비쿼터스 화재 방재 시스템은 온도, 습도, 조도, 가속도, CO2, 등의 다양한 센서로부터 얻는 값을 이용해 화재를 판별하여 관리자에게 전달하고 시스템 설정 값에 따라 소화설비를 동작시키는 지능형 화재 탐지 시스템이다. 기존 화재 판별 기법은 크게 영상인식, 퍼지추론, 베이지안 추론으로 나뉠 수 있다. 본 논문에서는 앞선 기술들을 분석하고, ARM9 S3C2440/SHT-75를 이용한 센서기반 유비쿼터스 화재 방재 시스템 최적의 화재 판별 기술로서 가속도 알고리즘과 벡터 랜덤변수 표본공간 영역을 이용한 패턴인식 기술을 사용한 복합 화재 판별 방법을 제안한다.

• Korean Journal of Remote Sensing
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• v.20 no.6
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• pp.419-425
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• 2004

This study has proposed a data fusion method based on the Dempster-Shafer evidence theory The Dempster-Shafer fusion uses mass functions obtained under the assumption of class-independent Gaussian assumption. In the Dempster-Shafer approach, uncertainty is represented by 'belief interval' equal to the difference between the values of 'belief' function and 'plausibility' function which measure imprecision and uncertainty By utilizing the Dempster-Shafer scheme to fuse the data from multiple sensors, the results of classification can be improved. It can make the users consider the regions with mixed classes in a training process. In most practices, it is hard to find the regions with a pure class. In this study, the proposed method has applied to the KOMPSAT-EOC panchromatic image and LANDSAT ETM+ NDVI data acquired over Yongin/Nuengpyung. area of Kyunggi-do. The results show that it has potential of effective data fusion for multiple sensor imagery.