• 한국정보통신학회논문지
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• 제19권10호
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• pp.2292-2300
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• 2015

자동차 후방카메라 시스템은 후진시 차량 후방을 모니터 영상으로 보여주어 안전 운전과 주차 편리를 위한 서비스를 제공한다. 본 논문에서는 우리나라가 개발한 개인용 무선통신 Binary CDMA 신기술을 이용하여 유선의 제약없이 설치가 자유롭고 설치비용을 절감할 수 있는 자동차 후방카메라 시스템의 구현방법 및 기술에 관해 연구하였다. 본 연구를 통해 시제품을 제작하였고, 무선영상 전송기와 중계기의 카메라 입력 및 모니터 출력, Bianry CDMA를 이용한 무선 통신, 영상전송기와 중계기 응용프로그램의 핵심 구현에 대해 연구하였다.

• International Journal of Computer Science & Network Security
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• 제23권3호
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• pp.94-100
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• 2023

The primary goal of any communication spacecraft is to provide communication in variety of frequency bands based on mission requirements within the Indian mainland. Some of the spacecrafts operating in S-band utilizes a 6m or larger aperture Unfurlable Antenna (UFA for S-band links and provides coverage through five or more S-band spot beams over Indian mainland area. The Unfurlable antenna is larger than the satellite and so the antenna is stowed during launch. Upon reaching the orbit, the antenna is deployed using motors. The deployment status of any deployment mechanism will be monitored and verified by the telemetered values of micro-switch position before the start of deployment, during the deployment and after the completion of the total mechanism. In addition to these micro switches, a camera onboard will be used for capturing still images during primary and secondary deployments of UFA. The proposed checkout system is realized for validating the performance of the onboard camera as part of Integrated Spacecraft Testing (IST) conducted during payload checkout operations. It is designed for acquiring the payload data of onboard camera in real-time, followed by archiving, processing and generation of images in near real-time. This paper presents the architecture, design and implementation features of the acquisition, processing and Image generation system for Camera onboard spacecraft. Subsequently this system can be deployed in missions wherever similar requirement is envisaged.

• 한국통신학회논문지
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• 제40권6호
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• pp.1102-1106
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• 2015

사회 안전망 제공을 위한 실시간 영상 기반의 협동적 스마트 카메라 네트워크에서는 상황인지 추론 및 처리를 위하여, 스마트 카메라 간에 상황 인지 및 대응을 위한 데이터를 저장 및 전달한다. 특정 이벤트에 대해 카메라가 측정한 값을 다른 상황 데이터 및 추론 결과와 함께 RDB(Relational Data Base)에 저장하고, 해당 정보가 필요한 주변 카메라에 전달한다. 일부 RDB를 온톨로지 RDF(Resource Description Framework) 파일로 변환해 그 결과를 상황인지 추론에 이용한다. 스마트 카메라 간 연동은 ONVIF(Open Network Video Interface Forum) 표준을 따르며, 협동적인 지능형 관제시스템을 이룬다. 데이터 저장 및 전달에 있어서 기밀성과 무결성을 보장하기 위하여 정보보호 기술을 도입하며, 이를 적용한 프로토타입 시스템을 구현하여 오버헤드에 대한 분석을 수행하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1011-1016
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• 2015

Gas piping systems in power plants and factories are always influenced by the mechanical vibrations of rotational machines such as pumps, blowers, and compressors. Unusual vibrations in a gas piping system influence possible leakages of liquids or gases, which can lead to large explosive accidents. Real-time measurements of unusual vibrations in piping systems in situ prohibit them from being possible leakages owing to the repeated fatigue of vibrations. In this paper, a non-contact 3-dimensional measurement system that can detect the vibrations of a solid body and monitor its vibrational modes is introduced. To detect the displacements of a body, a stereoscopic camera system is used, through which the major vibration types of solid bodies (such as X-axis-major, Y-axis-major, and Z-axis-major vibrations) can be monitored. In order to judge the vibration types, an artificial neural network is used. The measurement system consists of a host computer, stereoscopic camera system (two-camera system, high-speed high-resolution camera), and a measurement target. Through practical application on a flat plate, the measured data from the non-contact measurement system showed good agreement with those from the original vibration mode produced by an accelerator.

• 한국통신학회논문지
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• 제42권4호
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• pp.816-818
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• 2017

본 논문에서는 화상인식서버 기반의 감시 카메라 네트워크 시스템에서 프레임 폐기율 및 서버의 활용도에 기반한 성능분석을 수행한다. 각 감시 카메라에 대하여 인식상태 및 유휴상태로 나누어 다른 프레임 전송률을 적용함으로서 서버의 처리용량을 기준으로 한 최적의 화상 프레임 수 및 수용 가능한 카메라 수 등의 파라미터들에 대하여 분석한다. 분석된 결과는 화상 감시 카메라 네트워크의 효율적인 운영을 위하여 유용하게 활용될 것으로 판단된다.

• 한국지능시스템학회논문지
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• 제21권6호
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• pp.743-748
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• 2011

본 논문에서는 지능형 영상 감시 시스템을 위한 다수의 네트워크 카메라를 이용한 협동 추적 알고리즘을 제안한다. 이를 위하여 각의 카메라는 모션 템플릿 기법을 통하여 영상내의 움직임 물체를 추출하고, 추출된 움직임 물체의 이동방향을 추정한다. 움직임 물체가 추출되면 칼만 필터를 이용하여 움직임 물체의 정확한 좌표를 추정한다. 움직임 물체의 이동방향과 카메라의 상태를 이용하여 가장 효율적인 협동추적 카메라를 선정하고, 각 카메라의 공간정보를 이용하여 PTZ 변수를 설정하고 협동요청을 한다. 협동요청을 받은 카메라는 설정된 PTZ 변수를 이용하여 움직임 물체를 협동 추적하고 확대영상을 획득한다. 실험을 통하여 제안된 협동추적 알고리즘의 성능분석 및 그 응용 가능성을 확인한다.

• 로봇학회논문지
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• 제13권4호
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• pp.230-236
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• 2018

3D depth perception has played an important role in robotics, and many sensory methods have also proposed for it. As a photodetector for 3D sensing, single photon avalanche diode (SPAD) is suggested due to sensitivity and accuracy. We have researched for applying a SPAD chip in our fusion system of time-of-fight (ToF) sensor and stereo camera. Our goal is to upsample of SPAD resolution using RGB stereo camera. Currently, we have 64 x 32 resolution SPAD ToF Sensor, even though there are higher resolution depth sensors such as Kinect V2 and Cube-Eye. This may be a weak point of our system, however we exploit this gap using a transition of idea. A convolution neural network (CNN) is designed to upsample our low resolution depth map using the data of the higher resolution depth as label data. Then, the upsampled depth data using CNN and stereo camera depth data are fused using semi-global matching (SGM) algorithm. We proposed simplified fusion method created for the embedded system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.566-571
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• 1994

This paper presents in image-based visual servo control scheme for tracking a workpiece with a hand-eye coordinated robotic system using the fuzzy-neural-network. The goal is to control the relative position and orientation between the end-effector and a moving workpiece using a single camera mounted on the end-effector of robot manipulator. We developed a fuzzy-neural-network that consists of a network-model fuzzy system and supervised learning rules. Fuzzy-neural-network is applied to approximate the nonlinear mapping which transforms the features and theire change into the desired camera motion. In addition a control strategy for real-time relative motion control based on this approximation is presented. Computer simulation results are illustrated to show the effectiveness of the fuzzy-neural-network method for visual servoing of robot manipulator.

• 제어로봇시스템학회논문지
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• 제4권4호
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• pp.487-493
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• 1998

Camera calibration is the process of determining the coordinate relationship between a camera image and its real world space. Accurate calibration of a camera is necessary for the applications that involve quantitative measurement of camera images. However, if the camera plane is parallel or near parallel to the calibration board on which 2 dimensional objects are defined(this is called "ill-conditioned"), existing solution procedures are not well applied. In this paper, we propose a neural network-based approach to camera calibration for 2D images formed by a mono-camera or a pair of cameras. Multi-layer perceptrons are developed to transform the coordinates of each image point to the world coordinates. The validity of the approach is tested with data points which cover the whole 2D space concerned. Experimental results for both mono-camera and stereo-camera cases indicate that the proposed approach is comparable to Tsai's method［8］. Especially for the stereo camera case, the approach works better than the Tsai's method as the angle between the camera optical axis and the Z-axis increases. Therefore, we believe the approach could be an alternative solution procedure for the ill -conditioned camera calibration.libration.

• 대한전기학회논문지
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• 제43권6호
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• pp.1010-1019
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• 1994

It is shown that there exists a nonlinear mapping which transforms image features and their changes to the desired camera motion without measuring of the relative distance between the camera and the object. This nonlinear mapping can eliminate several difficulties occurring in computing the inverse of the feature Jacobian as in the usual feature-based visual feedback control methods. Instead of analytically deriving the closed form of this mapping, a Fuzzy Membership Function-based Neural Network (FMFNN) incorporating a Fuzzy-Neural Interpolating Network is used to approximate the nonlinear mapping. Several FMFNN's are trained to be capable of tracking a moving object in the whole workspace along the line of sight. For an effective implementation of the proposed FMF network, an image feature selection process is investigated. Finally, several numerical examples are presented to show the validity of the proposed visual servoing method.