• 전기전자학회논문지
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• 제26권3호
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• pp.396-400
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• 2022

본 연구에서는 해저에서 발견한 인체를 해수면까지 운반하는 인양백을 기반으로 수중구조를 위한 ICT 기반 수중통신 모니터링 장치를 구현한다. 인양백은 에어를 주입하는 리프트백, 사이드백, CO₂ 카트리지 등으로 패키지화 되어 있다. 모니터링 시스템은 휴대하기 용이한 구조로 모바일 방식으로 개발한다. 수중 초음파 센서 신호는 USB 포트를 사용하여 공급되며, O/S는 리눅스로 구성한다. 수중통신동시험은 동해안에서 수심 6m~40m까지 실시간으로 측정 시험을 진행한다. 초음파 음향센서는 2,400bps로 변환되어 2원화에 따라 전송오차를 검증한다. 센서에서 모니터링까지 통신속도는 115,200bps, 제어기에서 수신부까지 통신속도는 2,400bps를 사용한다. 리프팅 장치의 상용화 단계에서 로우엔드 타입 개발이 용이하고 호환성이 넓도록 한다.

• 한국전자통신학회논문지
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• 제19권1호
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• pp.11-18
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• 2024

본 논문에서는 Chebyshev 다항식을 이용해서 차량용 근거리 레이다에서 사용하는 70GHz 대역 배열안테나를 최적 설계하였다. SRR(: Short Range Radar)에서는 근거리 내에 물표를 검출하면서 높은 FoV(: Field of View)를 확보하기 위한 빔폭과 낮은 SLL(: Side lobe level)을 가져야 한다. 최적 설계된 안테나는 76~81GHz에서 동작하며 안테나의 크기를 소형으로 하기 위해 12개의 패치를 직렬로 배열하여 구성하였고, 78GHz에서 SLL - 10dB이하, 안테나의 이득 15.4dB를 만족하고 빔폭 112.5o, 입력반사계수 -10dB이하의 성능을 갖는다. 본 논문에서는 Chebyshev 다항식을 이용해서 SRR을 위한 안테나의 설계를 진행하고 이를 기반으로 MRR과 LRR에 사용될 안테나 구조 설계를 위한 최적 설계법을 제시한다.

• 한국멀티미디어학회논문지
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• 제15권12호
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• pp.1506-1516
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• 2012

In a ship block logistics application, acquisition of locations is required in order to identify location of the ship blocks. A Smart device equipped with a GPS sensor can be used as a mobile client for a ship block logistics application. However the precision of GPS components on a commercial smart device is not high enough. Therefore, using the GPS for localization may produce significant positioning errors in a ship block logistics system. This paper proposes a method to reduce errors in measuring locations using a smart device. Based on the knowledge of how the location information is used in a ship block logistics application, and the predictability of the client's moving line based on geographical layout of a shipyard area, our proposed technique enables a better prediction of the ship blocks location. Performance evaluation shows that the proposed technique can significantly reduce the positional error.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.703-704
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• 2009

Natural gas Hydrate is an ice-like crystal containing natural gas it. Natural gas hydrate is studied as a new energy resource and a factor for seafloor slope stability and global warming. The unique pressure and temperature stability conditions of natural gas hydrate have challenged the research efforts. In this study, a new tool to study hydrate-bearing sediments and the preliminary results are introduced. The device can sustain 20MPa of the fluid pressure and apply 5MPa of the vertical effective stress under the temperature control. Cell can be scanned by X-ray CT scanner and also has the capability of multi-sensor data acquisition. Preliminary results suggests various application of the cell to hydrate-bearing research.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.946-949
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• 2006

With repeated coverage, spaceborne SAR (Synthetic Aperture Radar) instruments provide the most efficient means to monitor and study the changes in important elements of the marine environment. Due to highresolution of SAR data, the coverage of SAR sensor is always limited, especially for a repeat cycle. With more SAR sensors from various satellites, new data products such as ocean surface drift can be derived when two SARs' tracks overlap in a short time over coastal areas. Currently, there are two SAR sensors on different satellites with almost the exactly same path. That is, ERS-2 is following ENVISAT with a 30-minutes delay, which will be a good timing for ocean mesosclae feature tracking. For another application, a mystery ship near a big eddy with strong ship wake has been tracked between ERS-2 and ENVISAT SAR images to estimate its ship speed.

• International Journal of Ocean System Engineering
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• 제3권4호
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• pp.218-224
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• 2013

This paper describes the design and control of a hovering AUV test-bed and analyzes the dynamic performance of the vehicle using simulation programs. The main purpose of this vehicle is to carry out fundamental tests of its station keeping, attitude control, and desired position tracking. Its configuration is similar to the general appearance of an ROV for underwater operations, and its dimensions are $0.75m{\times}0.5m{\times}0.5m$. It has four 450-W thrusters for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring the water depth and a magnetic compass for measuring its heading angle. The navigation of the vehicle is controlled by an onboard Pentium III-class computer, which runs with the help of the Windows XP operating system. This provides an appropriate environment for developing the various algorithms needed for developing and advancing a hovering AUV.

• 대한조선학회논문집
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• 제48권4호
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• pp.336-341
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• 2011

Ship infrared signature is the cause of detection and tracking by infrared sensor and anti-ship missile seeker. Recent warships have been applied the infrared stealth technology to reduce own ship infrared signature and tested to validate own ship infrared signature level. This study describes the two issues. Firstly, we describe the infrared measurement concept and infrared signature level establishment method that have been performed. Secondly, we compare and analyze the error components between the infrared measurement and simulation result.

• 융합신호처리학회논문지
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• 제19권2호
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• pp.35-41
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• 2018

The analysis of plankton species distribution in sea or fresh water is very important in preserving marine ecosystem health. Since manual analysis is infeasible, many automatic approaches were proposed. They usually use images from in situ towed underwater imaging sensor or specially designed, lab mounted microscopic imaging system. Normally they assume that only single plankton is present in an image so that, if there is a clumping among multiple plankton of same species (homogeneous clumping) or if there are multiple plankton of different species scattered in an image (heterogeneous interspersion), they have a difficulty in recognition. In this work, we propose a deep learning based method that can detect and recognize individual plankton in images with homogeneous clumping, heterogeneous interspersion, or combination of both.

• 한국컴퓨터정보학회논문지
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• 제20권12호
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• pp.29-36
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• 2015

In this paper, we propose the horizontal line detection using the Haar-like features and linear regression in infrared images. In the marine environment horizon image is very useful information on a variety of systems. In the proposed method Haar-like features it was noted that the standard deviation be calculated in real time on a static area. Based on the pixel position, calculating the standard deviation of the around area in real time and, if the reaction is to filter out the largest pixel can get the energy map of the area containing the straight horizontal line. In order to select a horizontal line of pixels from the energy map, we applied the linear regression, calculating a linear fit to the transverse horizontal line across the image to select the candidate optimal horizontal. The proposed method was carried out in a horizontal line detecting real infrared image experiment for day and night, it was confirmed the excellent detection results than the legacy methods.

• 대한임베디드공학회논문지
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• 제9권3호
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• pp.165-171
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• 2014

In this paper, we propose the hardware and software of a test-bed of a hovering AUV (autonomous underwater vehicle). Test-bed to develop as the underwater robot for the hovering -type is planning to apply for marine resource development and exploration for deep sea. The RTU that controls a azimuth thruster and a vertical thruster of test-bed is a intergrated-type thruster. The main control unit that collects sensor's data and performs high-speed processing and controls a movement of test-bed is a underwater hybrid navigation system. Also it transfers position, posture, state information of test-bed to the host PC of user using a wireless communication. The host PC checks a test-bed in real time by using a realtime monitoring system that is implemented by LabVIEW.