• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.558-565
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• 2017

Recently, there has been a tendency to lead the private sector in the launch vehicle market, and as the market has become saturated, efforts are being made to reduce the launch cost. Advanced countries in space development have promoted manned long-range space exploration plans. As oxygen/methane is more efficient, lower cost, and eco-friendly than typical propellants, and can be produced locally on an alien planet, it is the most suitable next-generation propellant to meet this trend. Now methane engine development is accelerating due to changes in international conditions and corporate environment. It is also expected to develop a methane engine in order to survive in this global trend and to keep up with the launch vehicle market in the future.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.548-553
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• 2019

Along with advanced vehicle to vehicle (V2V) communication technologies, platooning is regarded as one of the most promising form of autonomous driving solutions in order to increase road capacity. In this paper, we propose a novel V2V transmission scheme for safety message dissemination in platooning. The proposed scheme enhances the efficiency of channel access and multi-vehicle orthogonal frequency division multiple access (OFDMA) transmission by taking advantage of triggered uplink access technique and null data packet feedback report protocol introduced in the sixth generation WLAN standard, IEEE 802.11ax. The simulation results prove that the proposed scheme outperforms the conventional IEEE 802.11 transmission scheme throughout all measured vehicle density range.

• The KIPS Transactions:PartD
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• v.11D no.6
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• pp.1231-1238
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• 2004

By virtue of the advanced Internet technology, there are lots of research works for e-Logistics which means virtual business activities or service architecture based on the Internet among the logistics companies. Because e-Logistics environment requires more dynamic and global service area, conventional vehicle monitoring and control technologies innate many problems in terms of Integrating, storing and sharing the location data. It needs the development of the moving object technology in order to resolve efficiently the limitations. In this paper, we propose the whole components of the moving object management system which supports the advanced sharing the location information as well as the integration of location data. We are sure the suggested system can be adopted to construct the next generation-logistics vehicle monitoring and control system by reducing the overall cost and time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.457-467
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• 2020

Increasing environmental concerns have prompted countries around the world to tighten regulations on greenhouse gases and fuel efficiency. Research is being done using advanced driver assistance systems to improve fuel economy and for the convenience of drivers. Research on systems such as adaptive cruise control (ACC), LKAS, and AEB is active. The purpose of ACC is to control the longitudinal speed and distance of the vehicle and minimize the driver's load, which is considered useful for accident prevention. From this point of view, research has used a mathematical method of safety evaluation as a function of distances and scenarios while considering domestic road environments. A vehicle is tested with a simulation in a proposed scenario. The purpose of the analysis is to verify the functional safety of ACC by comparing the theoretical calculations using theoretical equations, the relative distances in the simulation, and an actual vehicle test. These methods are expected to enable many companies to use scenarios, formulas, and simulations as safety verification methods in the development of ACC.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.44-50
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• 2017

Vehicle Holding Device(VHD) has a role that holding the launch vehicle on its launch pad until the engine therust reaches a steady condition. The analytical study of shape parameters and dynamic characteristics of hydraulic cylinders is carried out. The contraction of cylinder is considered as the major factor of releasing mechanism. Through the analysis, the decreasing of cylinder slit size and increasing initial charging pressure increase the contraction force. Through the transient analysis, cylinder load, displacement and inner pressure distribution are confirmed. The cylinder contraction force is converged to the cylinder external force when the cylinder starts to move. Also, the pressure distribution in the hydraulic cylinder is constant.

• Proceedings of the KOR-KST Conference
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• 1996.12a
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• pp.7-16
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• 1996

In this paper a modeling paradigm is described for answering the following questions: What would be the economic impact A, the social impact B, the demographic impact C, the land-use impact D, the environmental impact E and the user benefit F, over geographic scale G for a transport investment H at time T. The paradigm is illustrated for two ITS technologies: Advanced Transportation Management System (ATMS)and Advanced Vehicle Control Systems (AVCS).

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.4
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• pp.80-86
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• 1993

This paper presents an advanced AC drive system used in electric vehicles. The system consists of a drive motor, a PWM transistorized inverter, a PCL-812PG data card, and a controller. This paper describes a design method for RSPWMSS and PID controller. This controller system is implemented on computer and applied to drive motor(induction motor), yielding satisfactory result.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2108-2111
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• 2003

This paper introduces a new local feature extraction method and image matching method for the localization and classification of targets. Proposed method is based on the block-by-block projection associated with directional pattern of blocks. Each pattern has its own eigen-vertors called as CEBs(Classified Eigen-Blocks). Also proposed block-based image matching method is robust to translation and occlusion. Performance of proposed feature extraction and matching method is verified by the face localization and FLIR-vehicle-image classification test.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.4
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• pp.149-161
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• 2021

This study proposes a methodology for mission/path planning of an unmanned aerial vehicle (UAV) using an artificial potential field with the Markov Decision Process (MDP). The planning problem is formulated as an MDP. A low-resolution solution of the MDP is obtained and used to define an artificial potential field, which provides a continuous UAV mission plan. A numerical case study is conducted to demonstrate the validity of the proposed technique.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.130-132
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• 2019

본 논문에서는 위상 천이 풀 브릿지 컨버터와 공진형 하프 브릿지 컨버터를 통합한 구조에서 새로운 센터탭 클램프 회로를 적용하였다. 하프 브릿지 컨버터가 통합되어 있는 구조를 통하여 기존 위상 천이 풀 브릿지 컨버터가 가지고 있는 여러 단점을 개선할 수 있으며, 또한 제안하는 클램프 회로를 통해 이차측 전압 스트레스 및 출력 커패시터의 사이즈 측면에서 개선점을 갖는다. 이러한 장점들을 통해 효율과 비용 측면에서 큰 효과를 갖는다. 3.3 kW 의 프로토타입을 통해 실험으로 검증하였다.