• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.277-285
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• 2020

A differential drive wheeled robot is a kind of mobile robot suitable for indoor navigation. Model predictive control is an optimal control technique with various advantages and can achieve excellent performance. One of the main advantages of model predictive control is that it can easily handle constraints. Therefore, it deals with realistic constraints of the mobile robot and achieves admirable performance for trajectory tracking. In addition, the intention of the robot can be properly realized by adjusting the weight of the cost function component. This control technique is applied to the local planner of the navigation component so that the mobile robot can operate in real environment. Using the Robot Operating System (ROS), which has transcendent advantages in robot development, we have ensured that the algorithm works in the simulation and real experiment.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.4
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• pp.256-265
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• 2023

This paper describes the results of the development of the submarine Free Running Model (FRM). First, the goal of development was set based on the test conditions and the test environment, and the system was obtained accordingly. The target submarine, Joubert BB2 submarine, was selected with a scale of 18.35 in accordance with the development goal. In order to conduct a submarine FRM test underwater, where communication is impossible, the FRM must operate at least semi-autonomously. For this purpose, an Extended Kalman Filter (EKF) based underwater integrated navigation system and control system using a sailplane and an X-shaped sternplane were designed respectively. In addition, a ballast system was designed to enable the model to float to the water surface in case of an emergency. To verify its propulsion, navigation, and control performance, the FRM tests were conducted in both indoor and outdoor basins. As a result, the relationship between propeller RPM and vehicle speed was derived, and it was confirmed that the navigation and control performance met the target value.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.174-192
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• 2021

The LIDAR sensor, which provides higher cognitive performance than cameras and radar, is difficult to apply to ADAS or autonomous driving because of its high price. On the other hand, as the price is decreasing rapidly, expectations are rising to improve existing autonomous driving functions by taking advantage of the LIDAR sensor. In level 3 autonomous vehicles, when a dangerous situation in the cognitive module occurs due to a sensor defect or sensor limit, the driver must take control of the vehicle for manual driving. If the driver does not respond to the request, the system must automatically kick in and implement a minimum risk maneuver to maintain the risk within a tolerable level. In this study, based on this background, a LIDAR-based LKS MRM algorithm was developed for the case when the normal operation of LKS was not possible due to troubles in the cognitive system. From point cloud data collected by LIDAR, the algorithm generates the trajectory of the vehicle in front through object clustering and converts it to the target waypoints of its own. Hence, if the camera-based LKS is not operating normally, LIDAR-based path tracking control is performed as MRM. The HAZOP method was used to identify the risk sources in the LKS cognitive systems. B, and based on this, test scenarios were derived and used in the validation process by simulation. The simulation results indicated that the LIDAR-based LKS MRM algorithm of this study prevents lane departure in dangerous situations caused by various problems or difficulties in the LKS cognitive systems and could prevent possible traffic accidents.

• Proceedings of the KOR-KST Conference
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• 2003.02a
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• pp.3-18
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• 2003

본 논문은 ATMS와 ATIS에서 요구되는 교통관리 및 정보제공의 효과분석을 위해, 운전자의 주행 및 경로선택 의사결정과 교통제어에 대한 반응등 운전자 행태를 모의실험에 반영함으로써 교통시스템의 실시간 특성을 모사할 수 있는 모형을 구축하고 이를 기반으로 하는 미시적 교통 모의실험기를 개발하는 것을 목적으로 하였다. 본 연구에서는 운전자, 차량, 교통망, 검지 및 신호시스템, 교통정보제공시스템 등을 교통시스템의 주요 구성요소로 설정하였으며 운전자 및 차량특성, 차두시간분포와 차량발생모형, 차량주행모형, 차로변경 및 간격수락모형, 경로선택모형을 주모의실험모형을 구성하는 부모형으로 결정하였다. 따라서 본 논문에서는 각각의 부모형들에 대한 최근의 연구결과들을 검토하고, 현실모사 능력과 함께 다른 부모형들과의 연계, 모의실험기의 구현상에서의 적합성 등을 고려하여 적정모형의 선정 및 수정, 새로운 부모형의 구축을 수행하였다. 구축된 부모형을 통합하여 교통모의실험기를 개발하였으며 구축된 모형의 타당성 및 적용성 검토를 위해 현장자료 및 가상자료를 이용한 검증을 수행하였다. 검증결과 모형의 목적인 교통제어 및 정보제공등의 시스템 대안의 평가에 이용 가능한 것으로 나타났다. 또한 본 논문의 연구결과는 교통제어 및 정보제공전략 대안의 평가뿐만 아니라 차량추종 및 차로변경 등의 미시적 교통모형 연구, 동적기종점 통행량 추정, 동적통행배정의 연구에도 활용할 수 있을 것으로 판단된다. 본 논문의 연구모형은 현단계에서는 현실의 모사 및 분석을 위한 도구보다는 새로운 대안들간의 비교평가를 위한 도구로 활용할 수 있을 것으로 판단된다. 이에 따라 현실모사의 정확도를 확보하기 위한 검증 및 개선이 필요할 것이며, 각 부모형들에 대한 계속적인 연구와 새롭게 발표되는 연구결과를 수용한 지속적인 개발이 필요할 것이다.유기적인 연계에 있음을 밝히고 있다. 건설을 위한 정책적 시사점과 동북아 연구개발정보 Portal 및 APEC APGrid 연구망 등의 구체적인 정보인프라 구축방안을 도출하였다.술 주기를 도출하고, 산업 내 평균 권리 청구 항목 수를 이용하여 각 산업의 기술 범위를 비교하였다. 각각의 동적 분석을 통해 시간에 따른 변화 양상이 관찰하였고, ANOVA 분석을 이용하여 통계적 유의성을 검증하였다. 본 연구는 현재의 기술 패러다임 내에서 Pavitt이 제시한 산업 분류의 근거를 보충 설명하였고 특허 정보를 이용하여 기술혁신의 산업별 유형에 대한 폭넓은 분석방법을 제시하였다.별 시간대별 효과분석을 통하여 정책의 시행여부가 결정되어야 할 것이다. 한편, 화물전용차선의 설치로 인한 물류비용의 절감을 보다 효과적으로 달성하기 위해서는 종합류류 전산망의 시급한 구축과 함께 화물차의 적재율을 높이고 공차율을 낮출 수 있는 운송체계의 수립이 필요한 것으로 판단된다. 그라나 이러한 화물전용차선의 효과는 단기적인 치유책일 수밖에 없기 때문에 물류유통 시설의 확충을 위한 사회간접자본의 구축을 서둘러 시행하여야 할 것이다.으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압주입시험에서도 확인된다.. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9%

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.99-111
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• 2021

The connected farm that agricultural land, agricultural machinery and farmer are connected with an IoT gateway is in the commercialization stage. That has increased productivity, efficiency and profitability by intimate information exchange among those. In order to develop the educational program of intelligent agricultural machinery and the agricultural machinery safety education performance indicator, this study analyzed patent trends of agricultural machine with unmanned technology used in agriculture and efficiency technology applied advanced technologies such as ICT, robots and artificial intelligence. We investigated and analyzed patent trends in agricultural machinery of Korea, the USA and Japan as well as the countries in Europe. The United States is an advanced country in the field of unmanned technology and efficiency technology used in agriculture. Agricultural automation technology in Korea is insufficient compared to developed countries, which means rapid technological development is needed. In the sub-fields of field automation technology, path generation and following technology and working machine control technology through environmental awareness have activated.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.56-76
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• 2024

We for the first time made a successful longest continuous sectional observation in the East Sea by an underwater glider during 95 days from September 18 to December 21 2020 in the Korea along the 106 Line (129.1 °E ~ 131.5 °E at 37.9 °N) of the regular shipboard measurements by the National Institute of Fishery Science (NIFS) and obtained twelve hydrographic sections with high spatiotemporal resolution. The glider was deployed at 129.1 °E in September 18 and conducted 88-days flight from September 19 to December 15 2020, yielding twelve hydrographic sections, and then recovered at 129.2 °E in December 21 after the last 6 days virtual mooring operation. During the total traveled distance of 2550 km, the estimated deviation from the predetermined zonal path had an average RMS distance of 262 m. Based on these high-resolution long-term glider measurements, we conducted a comparative study with the bi-monthly NIFS measurements in terms of spatial and temporal resolutions, and found distinguished features. One is that spatial features of sub-mesoscale such as sub-mesoscale frontal structure and intensified thermocline were detected only in the glider measurements, mainly due to glider's high spatial resolution. The other is the detection of intramonthly variations from the weekly time series of temperature and salinity, which were extracted from glider's continuous sections. Lastly, there were deviations and bias in measurements from both platforms. We argued these deviations in terms of the time scale of variation, the spatial scale of fixed-point observation, and the calibration status of CTD devices of both platforms.