• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.27-33
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• 2004

The Noise generation mechanisms of propane laminar premixed flames on a slot burner have been studied experimentally. The sound levels and frequencies were measured for various mixture flow rates (velocities) and equivalence ratios. The primary frequency of self-induced noise increases with the mean velocity of mixture as $f{\;}{\propto}{\;}U_f^{1.144}$ and the measured noise level increases with the mixture flow rate and equivalence ratio as $p{\;}{\propto}{\;}U_f^{1.7}$$F^{8.2}$. The nature of flame oscillation and the noise generation mechanisms are also investigated using a high speed CCD camera and a DSRL camera. The repetition of sudden extinction at the tip of flame is evident and the repetition rates are identical to the primary frequencies obtained from the FFT analysis of sound pressure signals. CH chemiluminescence intensities of the oscillating flames were also measured by PMT with a 431 nm(10 FWHM) band pass filter and compared to the pressure signals.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.177-180
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• 2002

In this paper, we has been studied self controlled mobile robot system with CCD camera. This system consists of TMS320F240 digital signal processor, step motor, RF module and CCD camera. 2-axis compass and magnetic sensor, we used wireless RF module for movable command transmiting between robot and host PC. This robot go straight until 95 percent filled screen with white color both side from input image. And the robot recognizes obstacle about 95 percent filled something, so it could turn for avoid the obstacle and conclude new path plan. it could get turning angle from 2-axis compass and magnetic sensor.

• Korean Journal of Geomatics
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• v.4 no.1
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• pp.9-16
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• 2004

An object-oriented design was carried out for the digital photogrammetric processes. Classes were identified and implemented to develop an integrated digital photogrammetry system using a 3 dimensional self-calibration model for CCD cameras. This integrated system is deemed to be a significant progress from the conventional photogrammetric system which is a series of discrete processes. Object oriented methodology was selected for the implementation of the integrated photogrammetric system because it would be a very complex task to get the same result using a procedural programming language. Besides the simplification of development effort, object oriented methodology has further benefits of better management of program in case when updates to parts of the program are necessary. Using the classes designed in this study, a 3 dimensional self-calibration model was developed for a CCD camera. Classes for data input and image handling as well as classes for bundle adjustment were implemented. The bundle adjustment system was further enhanced with member functions to handle additional parameters for principal point coordinates and focal length, thereby, enabling the application to non-metric CCD cameras.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.297-298
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• 2019

본 논문에서는 드론용 오픈 소스 API를 이용하여 셀프 카메라 촬영이 가능한 드론용 앱을 설계한다. 특히, 딥러닝 기반의 YOLO 객체 탐지 기술을 적용하여 배경 속에서 사람을 탐지하여 개인 및 단체 사진 촬영이 가능하도록 설계한다. 개발하는 셀프 카메라 앱은 기체의 자동 회전 및 선회 기반 연속 촬영 기능을 포함하여 다양한 형태의 인물 사진 촬영이 가능하다. 개발된 앱 기술을 기반으로 선회 및 회전을 통한 경비 구역의 침입자 촬영을 위한 시스템 및 드론 제어 기술에 활용하고자 한다.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.2
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• pp.131-138
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• 2020

In this paper, we analyze the delay phenomenon that can occur when controlling an unmanned aerial vehicle using a camera and describe a solution to solve the phenomenon. The group of pictures (GOP) value is changed in order to reduce the delay according to the frame data size that can occur in the moving image data transmission. The appropriate GOP values were determined through experimental data accumulation and validated through camera self-test, system integration laboratory (SIL) verification test and system integration test.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.133-137
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• 2002

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.511-518
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• 2012

It is well-known that non-metric digital cameras have to be calibrated for the close-range photogrammetry. But, the self-calibration is still not an easy task because it requires rather a large calibration site of accurate control points, multiple image acquisitions in different positions, and accurate image point measurements that are quite labor-intensive and time-consuming. Based on the premise, this study carried out check point accuracy analysis from self-calibration of different control point designs and photo combinations. The test results showed that the calibration using three photos covering three-dimensional control points produced high accuracy, but control points on a plane could attain the comparable accuracy with four photos including a 90-degree rotated photo. We then compared the target accuracy of on-site self-calibration using flat control points to that of laboratory-self calibration and observed comparable results.

• Journal of Sensor Science and Technology
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• v.27 no.1
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• pp.6-12
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• 2018

In this paper, a 32-variable pulse position modulation (32-VPPM) scheme is proposed to support a red-green-blue light-emitting-diode (RGB-LED)-based optical camera communication (OCC) system. Our proposed modulation scheme is designed to enhance the OCC data transmission rate, which is targeted for the wearable biomedical data monitoring system. The OCC technology has been utilized as an alternative solution to the radio frequency (RF) wireless system for long-term self-healthcare monitoring. Different biomedical signals, such as electrocardiograms, photoplethysmograms, and respiration signals are being monitored and transmitted wirelessly from the wearable biomedical device to the smartphone receiver. A common 30 frames per second (fps) smartphone camera with a CMOS image sensor is used to record a transmitted optical signal. Moreover, the overall proposed system architecture, modulation scheme, and data demodulation are discussed in this paper. The experimental result shows that the proposed system is able to achieve > 9 kbps using only a common smartphone camera receiver.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3856-3863
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• 2012

A 3D reconstruction technique from stereo images that requires minimal intervention from the user has been developed. The reconstruction problem consists of three steps of estimating specific geometry groups. The first step is estimating the epipolar geometry that exists between the stereo image pairs which includes feature matching in both images. The second is estimating the affine geometry, a process to find a special plane in the projective space by means of vanishing points. The third step, which includes camera self-calibration, is obtaining a metric geometry from which a 3D model of the scene could be obtained. The major advantage of this method is that the stereo images do not need to be calibrated for reconstruction. The results of camera calibration and reconstruction have shown the possibility of obtaining a 3D model directly from features in the images.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.254-260
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• 2019

Recently, a self-camera that generates and distributes a large amount of moving images has been rapidly increasing due to the appearance of SNS such as Facebook, Instagram, and Tweet using mobile. In particular, the amount of SNS connections using mobile phones is significantly increasing in terms of usage, number of connections, and usage time. However, the use of a self-recording system using a smartphone by itself is extremely limited not only in terms of usage but also in frequency of use. In addition, the conventional unattended recording system is a very expensive system that automatically records and tracks an object to be photographed using an infrared signal. Therefore, this paper developed a low cost unmanned recording system using mobile phone. The system consists of a commercial mobile camera, a servomotor for moving the camera from side to side, a microcontroller for controlling the motor, and a commercial wireless Bluetooth earset for video audio input. And it is an unmanned automation system using mobile, and anyone can record image by self image tracking.