• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.540-543
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• 2007

The modulation transfer function (MTF) in a camera system is a measurement of how well the system will faithfully reproduce the original scene. The electro-optical camera system consists of optics, an array of pixels, and an electronics which is related to the image signal chain. The system MTF can be cascaded with each element's MTF in the frequency domain. That is to say, the electronics MTF including the detector MTF can be recalculated easily by the acquired system MTF if the well-known test optics is used in the measuring process. A Time-Delay and Integration (TDI) detector can make a signal increase by taking multiple exposures of the same object and adding them. It can be considered the various methods to measure the MTF of the TDI camera system. This paper shows the actual and practical MTF measuring methods for the detector and electronics in the TDI camera. The several methods are described according to the scan direction as well as the TDI stages such as the single line mode and the multiple-lines mode. The measuring is performed in the in the static condition or dynamic condition to get the point spread function (PSF) or the line spread function (LSF). Especially, the dynamic test bench is used to simulate on track velocity to synchronize with TDI read out frequency for the dynamic movement.

• 제어로봇시스템학회논문지
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• 제7권9호
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• pp.790-797
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• 2001

A simple computer vision technology to measure the middle-ranged depth with a mono camera and a plain mirror is proposed. The proposed system is structured with the rotating mirror in front of the fixed mono camera. In contrast to the previous stereo vision system in which the disparity of the closer object is larger than that of the distant object, the pixel movement caused by the rotating mirror is bigger for the pixels of the distant object in the proposed system. Being inspired by such distinguished feature in the proposed system, the principle of the depth measurement based on the relation of the pixel movement and the distance of object is investigated. Also, the factors to influence the precision of the measurement are analysed. The benefits of the proposed system are low price and less chance of occlusion. The robustness for practical usage is an additional benefit of the proposed vision system.

• 한국생산제조학회지
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• 제24권6호
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• pp.605-612
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• 2015

Three dimensional (3D) position determination and motion recognition using a 3D depth sensor camera are applied to a developed penguin-shaped robot, and its validity and closeness are investigated. The robot is equipped with an Asus Xtion Pro Live as a 3D depth camera, and a sound module. Using the skeleton information from the motion recognition data extracted from the camera, the robot is controlled so as to follow the typical three mode-reactions formed by the operator's gestures. In this study, the extraction of skeleton joint information using the 3D depth camera is introduced, and the tracking performance of the operator's motions is explained.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.1-6
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• 2006

Single-Camera Stereoscopic Vision three-dimensional measurement system has been developed based upon 30-PTV algorithm. The system consists of one camera $(1k\times1k)$ and a host computer. To attain three-dimensional measurements a plate having stereo holes has been installed inside of the lens system. Three-dimensional measurements was successfully attained by adopting the conventional 30-PTV camera calibration methods. As applications of the constructed measurement system, a water droplet mixed with alcohol was constructed on a transparent plastic plate with the contacted fluid diameter 4mm, and the particles motions inside of the droplet have been investigated with the constructed measurement system. The measurement uncertainty of the constructed system was 0.04mm, 0.04mm and 0.09mm for X, Y and Z coordinates.

• 한국전자통신학회논문지
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• 제17권6호
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• pp.1025-1032
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• 2022

본 논문에서는 기존 유선기반 CCTV 감시시스템과 IP 카메라 시스템에서 발생되는 구축비용에 대한 부담을 절감하고자 무선 통신기술을 활용한 TDMA기반 PoE 무선 다중 IP 카메라 전송시스템 개발이며, 국산 무선통신기술을 활용한 고화질 영상의 원거리 무선 전송 기술에 대해 설계 및 구현 하고자 한다. 제안 관련 기술에 대한 선 IP 전송 시스템의 송수신 프로토타입과 무선 다중 IP 카메라 전송 단말장치 및 영상 수집 장치(SB-200)에 대해 기술하였다.

• Physical Therapy Rehabilitation Science
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• 제13권1호
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• pp.106-112
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• 2024

Objective: This study aimed to evaluate the validity of a depth camera-based system for monitoring physical function, assessing its feasibility for accurately monitoring activities of daily living. Design: A cross-sectional study. Methods: Twenty-three participants were enlisted to perform fifteen activities of daily living within a living laboratory designed to simulate a home environment. Activities were monitored using a depth camera system capable of classifying actions into standing, sitting, and lying down, with a conventional video camera employed for activity recording. The duration of each activity, as measured by the system, was compared to direct observations made by a physical therapist which were analyzed using a motion analysis software. The association between these two measurement approaches was assessed through correlation analysis, coefficient of determination, intraclass correlation coefficient (ICC), and Bland-Altman plots. Results: Our findings indicated that standing activities exhibited the highest correlation (r=0.847) between the system measurements and physical therapist observations, followed by sitting (r=0.817) and lying down (r=0.734), which demonstrated lower correlations. However, the ICC and Bland-Altman plots revealed notable variances between the two measurement methods, particularly for activities involving lying down. Conclusions: In this study, the depth camera-based physical monitoring system showed promise feasibility in distinguishing standing, sitting, and lying down activities at home environments. However, the current study also underlined some necessities of enhancements in capturing lying down activities.

• 한국정보전자통신기술학회논문지
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• 제12권6호
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• pp.537-546
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• 2019

본 논문에서는 휴대하기 편하고 3D 콘텐츠 제작이 용이한 트윈 카메라 모듈 시스템을 구현하고자 하였다. 제안한 트윈 카메라 모듈 시스템은 2D 스테레오 카메라로 부터 입력되는 영상을 변환하여 3차원 영상으로 출력할 수 있는 시스템이다. 본 눈문에서 제안한 시스템의 성능평가를 위해 Test Platform을 이용하여 좌, 우 두 개의 렌즈로 촬영된 스테레오 입체 영상의 좌, 우 영상 간의 시차에 따른 회전(Rotation), 기울기(Tilt)에 대한 보정을 평가하였다. 또한 SIFT(Scale Invariant Feature Transform) 알고리즘을 이용하여 3D 입체 영상의 거리오차(Depth Error)를 검증하여 트윈 카메라 모듈 시스템의 효율성을 검증하고자 하였다. 본 논문에서 제안한 트윈 카메라 모듈 시스템은 촬영된 영상을 3D 입체 영상과 준비 영상으로 변화하여 외부에 출력하면 각기 다른 3D 입체 영상 제작 방식에 따른 출력장치에 맞춰 디스플레이가 가능하다. 또한 생성된 영상을 준비 영상과 입체 영상을 각기 다른 채널을 통해 출력하여 많은 제품에 적용하기 쉽고 간편하게 3D 입체 영상 콘텐츠를 제작하는데 이용할 수 있을 거라 기대한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.407-412
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• 2009

In the present work, vibration control performance of active camera mount system for unmanned aero vehicle (UAV) is evaluated. An active mount featuring inertia type of piezostack actuator is designed and manufactured. Then, vibration control performances are experimentally evaluated. A camera mount system with four active mounts is constructed and mechanical model is established. The governing equation for the camera mount system is obtained and control model is constructed in state space model. Sliding mode controller which has inherent robustness to external disturbance is designed and implemented to the system. Vibration control performances are evaluated at each mount and center of gravity point. Effective vibration performances are obtained and presented in time and frequency domains.

• 제어로봇시스템학회논문지
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• 제8권12호
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• pp.1036-1040
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• 2002

To process data of digital linescan camera, the frame grabber is essential to handle the data in low-level and in high speed more than 30 MHz stably. Traditional approaches to the development of hardware in vision system for the special purpose are mai y based on PC system, and are expensive and gigantic. Therefore, there are many difficulties in applying those in the field. So we investigate, in this paper, the implementation of FPGA for real-time processing of digital linescan camera. The system is not based on PC, but electronic device such as micropncessor. So it is expected that the use of FPGAs for low-level processing represents a fast, stable and inexpensive system. The experiments are carried out on the web guiding system in order to show the efficiency of the new image processor.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1565-1567
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• 2004

Various defects are found in FPD (Flat Panel Display) manufacturing process. So detecting these defects early and reprocessing them is an important factor that reduces the cost of production. In this paper, the bare glass inspection system for the FPD which is the early process inspection system in the FPD manufacturing process is designed and implemented using the high performance and accuracy CCD line scan camera. For the preprocessing of the high speed line image data, the Image Processing Part (IPP) is designed and implemented using high performance DSP (Digital signal Processor), FIFO (First in First out), FPGA (Field Programmable Gate Array) and the Data Management and System Control part are implemented using ARM (Advanced RISC Machine) processor to control many IPP and cameras and to provide remote users with processed data. For evaluating implemented system, experiment environment which has an area camera for reviewing and moving shelf is made.