• Journal of Multimedia Information System
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• 제4권4호
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• pp.195-204
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• 2017

Mobile robots are used for years as a valuable research and educational tool in form of available open-platform designs and Do-It-Yourself kits. Rapid development and costs reduction of Unmanned Air Vehicles (UAV) and ground based mobile robots in recent years allowed researchers to utilize them as an affordable research platform. Despite of recent developments in the area of ground and airborne robotics, only few examples of Unmanned Surface Vehicle (USV) platforms targeted for research purposes can be found. Aim of this paper is to present the development of open-design USV drone with integrated multi-level control hardware architecture. Proposed catamaran - type water surface drone enables direct control over wireless radio link, separate development of algorithms for optimal propulsion control, navigation and communication with the ground-based control station. Whole design is highly modular, where each component can be replaced or modified according to desired task, payload or environmental conditions. Developed USV is planned to be utilized as a part of the system for detection and identification of marine and lake waste. Cameras mounted to the USV would record sea or lake surfaces, and recorded video sequences and images would be processed by state-of-the-art computer vision and machine learning algorithms in order to identify and classify marine and lake waste.

• Journal of Advanced Marine Engineering and Technology
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• 제36권4호
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• pp.484-489
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• 2012

본 논문은 선박의 주 추진기관으로 사용가능한 육상 운송수단에 탑재되어있는 대형 디젤엔진에서 배출되는 입자상 물질과 질소산화물의 배출특성을 ESC mode에 적용시켜 분석하는데 초점을 두었다. 입자상 물질은 엔진의 고부하 영역에서 다량으로 배출되는 특성을 확인 할 수 있었으며 질소산화물의 경우 배기가스 온도 측정형태와 동일한 경향으로 배출되었다. 매연여과장치를 부착하여 입자상 물질의 배출특성을 분석한 결과 mode별 1/100~1/1,000배까지 저감되었다. 그러나 급격한 엔진 부하 변동 시 저감효과는 떨어졌으며 고속-고부하 영역에서는 매연여과장치내부의 온도상승으로 일부 재생현상이 발생하여 입자상 물질의 배출 증가 결과를 초래하는 현상이 발생하였다. 시험엔진에서 배출되는 입자상 물질의 입경분포를 분석한 결과 대부분 100nm 이하의 크기를 가지는 나노 입자가 배출되었으며 매연여과장치를 부착 및 탈착하여 측정한 결과 배출수준에는 차이가 있지만 입자상 물질의 입경분포는 비슷한 경향으로 분석되었다.

• 한국항해항만학회지
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• 제36권5호
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• pp.379-385
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• 2012

본 논문에서는 수상 및 수중운동체의 안정성 및 안정화기법에 관해 고찰한다. 선박이 운동을 하게 되면 부가질량이 변하게 되고 대칭인 시스템행렬이 비대칭이 된다. 비대칭성에 따라 시스템의 안정성해석방법도 달라지는데 예를 들어 가속도 피드백을 통해 비대칭요소를 제거하여 대칭으로 변환시키는 것이 가장 대표적인 해석 및 안정화 기법이다. 시스템 모델자체는 어디까지나 모델이기 때문에 대상시스템을 명확하게 수식으로 표현할 수 없으므로 피드백에 의한 비대칭요소를 소거시키는 방법은 타당하지 못하다. 따라서 본 논문에서는 대칭행렬이 비대칭행렬로 변하는 제약에 구애받지 않는, 보다 일반성을 갖는 안정성해석법을 제안하였다. 그리고 시스템 안정성 조건을 행렬부등식으로 변환하여 나타내었다. 이것은 안정성 해석 및 안정화를 위한 제어이득을 효율적으로 계산할 수 있는 방법으로 다양한 제약조건에도 유연하게 대응할 수 있다. 시뮬레이션을 통해 제안한 기법의 유효성을 검증하였다.

• 해양환경안전학회지
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• 제19권3호
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• pp.264-269
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• 2013

This paper is to investigate propagation path characteristics of GPS potential jamming signal. To do this, the spherical ground diffraction model is applied to the potential jamming scenario referred to the GPS jamming events occurred in recent years. The fundamental theory on the propagation path loss is discussed and a specific model is applied to several vehicles types which have own heights of antennas in order to compare their propagation path loss values at same 2-D location. The transmitting powers are appropriately given as the ordinary GPS jamming events. And then the received powers in dBW are obtained with given transmitting powers and the estimated total loss. The result of received jamming power at various locations due to the given scenario was distinct. For example, propagation loss values were estimated as -147 ~ -142dBW and -167 ~ -162dBW in $10^6W$ and $10^4W$, respectively. This computation result of the loss can be seriously considered with the tolerable jammer power against L1- C/A GPS receiver under any real jamming situations.

• Journal of Advanced Marine Engineering and Technology
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• 제27권1호
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• pp.82-90
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• 2003

Nowadays, many components used in machinery industry is required lightness and high strength. The shot-peening method is used in order to improve the fatigue life of spring steel(JIS G SUP-9) which is used in suspension of automobile. The compressive residual is induced in this shot-peening process. This paper investigated the effect of the residual compressive stress on the fatigue crack growth characteristics. Main results are summarized as follows. 1. The fatigue crack growth rate on stage II is conspicuous with the level of compressive residual stress and is dependent on Paris equation. 2. Although the maximum compressive residual stress is deeply and widely formed from surface, it does not improve the fatigue life comparing when maximum compressive residual stress is formed in surface. 3. The threshold stress intensity factor range is increased with increasing compressive residual stress. 4. In fracture surface of fatigue crack growth it is investigated that compressive residual stress remarkably retards fatigue crack growth.

• Journal of Advanced Marine Engineering and Technology
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• 제35권1호
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• pp.102-107
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• 2011

에너지 절감을 위한 백색 LED 기반 조명은 자유공간상의 광 무선통신 분야를 개척하는 기회를 제공하였다. 가시광 통신을 위한 트랜시버는 LED와 포토다이오드로 구성되므로 높은 대역폭과 신뢰성, 저 전력 등의 장점이 있어 기존의 무선통신과 양립할 수 있는 기술로 주목받고 있다. 그러나 기존의 건축물이나 배와 자동차와 같은 구조물에 조명을 이용한 통신 네트워크를 설치한다는 것은 쉬운 일이 아니다. 본 연구에서는 자동차 또는 선박의 통신망으로 갖춰진 CAN 기반의 LED 통신시스템을 제안한다. 실내무선 네트워크를 위한 CAN 인터페이스 모듈과 트랜시버를 조명 시스템에 적용 가능함을 보였다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.195-199
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• 2005

As vehicles are recently becoming more important in our life, the study for engine capacity has been conducted for many years. Specially, the study on lubrication in the engine is needed to develop engine capacity. The role of lubrication is to reduce fraction, manage the temperature and protect from corrosion etc. At the view point of the engine, lubrication and cooling of the engine have an effect on the life and efficiency, so we have to study this problem. Ball check valve is located in the inlet of the Oil Jet. Ball check valve is used to control the flow rate of the engine oil, which cools and lubricates the engine. Flow rate at the oil jet is very important, so the study for this problem is needed to conduct researches. The point of this study is to compute the flow rate and the flow in oil jet. The results of this study is that the mass flow rate is satisfied with the research which is obtained at the experiment.

• 대한조선학회논문집
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• 제45권6호
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• pp.579-589
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• 2008

In the past few years, there are many studies and researches of the underwater vehicles which are carried out its mission using sonar sensors. MSCL(Marine System Control Lab.) at Inha University developed test-bed small ROV, ISRO. ISRO is an open-frame type and has 4 thrusters. ISRO can control 4 motions i.e surge, sway, yaw and heave with sonar sensors. ISRO is developed for inspection of ship hull, marine structure, plant of lake or river and so on. When ROV ISRO inspects something, it is necessary to control the position of ROV ISRO's for the movement and anti-collision with structures in the underwater. In this paper, we deal with the development of a small ROV and verification of the position control system via simulation and experiment using sonar sensors.

• 수산해양교육연구
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• 제29권2호
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• pp.354-364
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• 2017

This study tries to evaluate the effect of ITT introduction in Busan New Port. The study used the estimation model of the number of vehicles required in accordance with the backhaul rate. The model used big data, COPINO e-document for one year in 2015. COPINO recorded the event such as truck ID, container ID, ATA, damage etc when truck arrived at gate. The study finds important information to estimate the required number of trucks for handling current ITT containers in Busan New Port: Daily throughput in Busan New Port is 1650 vans, especially night throughput recorded peak level in 1800 hours to 2400 hours, the throughput between adjacent terminals recorded high, i.e PNIT to HPNT. The transportation capability for 6 hours between terminals is from 4 vans to 7 vans. The required trucks are estimated 89 currently without considering peak level. If we change the back haul rate from current 20% to 40%, 60% and 80%, how much would the cost drop? It was discovered that, if it is raised to 40%, 60% and 80%, the number of vehicle required will be reduced from 89 (current) to 76, 65 and 59. It was also discovered that the total savings will reduce down to 12%, 25% and 34%.

• 한국해양환경ㆍ에너지학회지
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• 제13권1호
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• pp.47-52
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• 2010

근해에 설치되는 3차원 착저식 OWC 파력발전 챔버 구조물의 파 에너지 흡수효율과 구조물에 작용하는 1차 및 시간 평균 2차 파랑하중의 해석기법을 보였다. 쌍동형 OWC챔버 내부의 변동압력을 각 챔버의 내부 자유표면 경계조건에 도입하였으며 챔버 내부는 Rankine, 외부는 유한수심 3차원 자유표면 Green함수에 연계된 하이브리드 적분방정식을 사용하여 포텐셜 유동을 해석하였다. 수치실험 결과로서 3차원 착저식 OWC 파일럿 플랜트의 파력발전 1차변환 효율과 구조물에 작용하는 반복 및 지속적인 파랑하중을 제시하였다.