• Journal of Institute of Control, Robotics and Systems
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• v.20 no.12
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• pp.1204-1208
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• 2014

As required performance of UAV (Unmanned Aerial Vehicle) becomes more complex and complicated, required positioning accuracy is becoming more and more higher. GPS is a reliable world wide positioning providing system. Therefore, UAV generally acquires position information from GPS. But when GPS is not available such as too weak signal or too less GPS satellites environments, UAV needs alternative positioning system such as network positioning system. RSSI (Received Signal Strength Indicator) based positioning, which is one method of network positioning technologies, determines its position using RSSI measurements containing distance information from AP (Access Point)s. In that method, a selected AP's configuration has strong and tight relationship with its positioning errors. In this paper, for, we additionally account AP's configuration information by adopting DOP (Dilution of Precision) into AP selection procedures and provide more accurate RSSI based positioning results.

• Journal of Korea Multimedia Society
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• v.23 no.8
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• pp.1088-1098
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• 2020

This paper proposes an obstacle avoidance method using a depth polar grid. Depth information is a crucial factor for determining the safe path for collision-free navigation of unmanned aerial vehicles (UAVs) as it can perceive the distance to the obstacles effectively. However, the existing depth-camera-based approaches for obstacle avoidance require computational y expensive path planning algorithms. We propose a simple navigation method using the polar-grid of the depth information obtained from the camera with narrow field-of-view(FOV). The effectiveness of the approach was validated by a series of experiments using software-in-the-loop simulation in a realistic outdoor environment. The experimental results show that the proposed approach successfully avoids obstacles using a single depth camera with limited FOV.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.84.2-84.2
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• 2015

Growing market of electric vehicles such as hybrid, plug-in hybrid, and bare electric vehicles in the world is accelerating the significance of Li-ion batteries as a renewable green energy. According to such market flow, the developing components such as cathode, anode, electrolyte, and separator, composing the Li-ion batteries, is significantly important tasks for the commercialization. In particular, development of the cathode material having high capacity and stable thermal stability is essential for long-distance electric vehicle in the near future. Herein we introduce various applications of Li-ion batteries such as portable electronics, electric vehicles, and energy storage system, and also its research trend, in particular on the cathode materials.

• IE interfaces
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• v.15 no.3
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• pp.316-324
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• 2002

Automated Guided Vehicles are widely used as an essential material handling system for FMS to provide flexibility and efficiency. We suggest a new dispatching rule based on priority function which considers urgency and empty vehicle travel time under finite buffer capacity. We evaluate the performance of the proposed rule by comparing the performance of Shortest Travel Time/Distance(STT/D) rule in terms of machine utilization, throughput and WIP level using simulation. The simulation results show that the suggested dispatching rule is robust and provides better machine utilization, throughput with comparable WIP level compared to STT/D rule.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.110-113
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• 2003

Most traffic accidents are caused by drivers' carelessness and lack of information on the surrounding objects. In this paper we proposed a model of human intention recognition through case-base learning and to build up an experiment system. The system can help us recognize object's intention (e.g. turn left, turn right or straight) by using detected data about human's motion, speed of the car and the distance between the car and the intersection. Furthermore, we included an example using case-base learning in this paper to improve the precision of recognition as well as an example to explain the use of the system. PC can be used to predict the driving reaction beforehand and send a warning signal to the driver in time if there is any danger.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.134-139
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• 2002

Motorcycle industry, for its competitive position, depends on part design technology. This part design has a bulky amount of data and asks the accumulation of advanced technical skill and experience, and fragmentary technical application is not enough to get to the kernel of a problem. Therefore, the improvement of proper productivity - the starting point of engineering design - and useful Design Methodology for products manufacturing are needed. Thus this paper is aimed to create a program that outputs dynamic characteristics of a vehicle when the data from fully understanding on motorcycle's brake system and induced formula for brake design are inputted.

• Journal of the korean Society of Automotive Engineers
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• v.18 no.6
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• pp.63-68
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• 1996

차량의 자동제어는 컴퓨터, 통신, 기계, 계측등의 하드웨어와 자동제어 기술, 통신망 운영, 컴퓨터 운영등의 소프트웨어 기술의 응용을 바탕으로 하는 지능형 차량은 단순히 차량 상호간, 차량과 도로에 설치된 컴퓨터와의 통신으 통한 정보교환 기능과 더불어 운전기능 자체를 스스로 행하는 기능을 포함하고 있다. 지능형 차량 개발은 운전자 인식증진 기술, 사고회피 기술, 피해확산 방지기술, ITS(Intelligent Transport System) 연계 및 관련 Infrastructure 기술, Human-Machine Interface 기술, Sensor Fusion 기술, 레이더 기술 등을 꼽을 수 있다. 이중에서 차량의 지능화를 구현하는 가장 핵심적인 세부 기술은 CCD 카메라, 레이저 레이더, 밀리파 레이더, 생체 센서등을 들 수 있다. 본 원고에서는 위와 같이 차량의 지능화, 특히 차량 거리검지 장치를 구현코자 사용되고 있는 센서의 종류와 응용에 대하여 고찰하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.393-396
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• 2007

EGR is well established and efficient means to reduce NOx emissions. The increase of EGR rate affects the ignition delay of the combustion due to the lower oxygen availability. The increasing of the ignition delay period causes large combustion noise. In this study, the effects of EGR and Induction Point on combustion noise are investigated by measuring cylinder pressure and noise. As a result, The Combustion noise is markedly increased under the application of EGR. The increased premixed distance by displacing EGR Induction point in flow direction causes the uniform EGR distribution and the modulation level of the combustion noise is reduced slightly.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.5
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• pp.407-415
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• 2002

In this paper, mutual coupling effect between antennas mounted on UAV(Unmanned Air Vehicle), operating In different frequency bands, is calculated for supposing efficient arrangement. For the calculation, FDTD method is used, simulation parameters are confined to distance between antennas, height of antennas, types of ground, etc. The simulation data are compared with those of other numerical method to confirm accuracy of the results. It is appeared that the critical factor of mutual coupling is height of an antenna relative to that of the other antenna.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.101-110
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• 2003

Motorcycle industry, for its competitive position, depends on part design technology. This part design has a bulky amount of data and asks the accumulation of advanced technical skill and experience, and fragmentary technical application is not enough to get to the kernel of a problem. Therefore, the improvement of proper productivity - the starting point of engineering design - and useful Design Methodology for products manufacturing are needed. Thus this paper is aimed to create a program that outputs dynamic characteristics of a vehicle when the data from fully understanding on motorcycle's brake system and induced formula for brake design are inputted. This paper is intended to show a creative design method by the thermal analysis data through FEM study and using shape design parameters derived from our programs.