• Journal of Aerospace System Engineering
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• v.18 no.3
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• pp.27-33
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• 2024

According to the success of the Nuri Space Launch Vehicle (KSLV-II) and the development goal of the next generation space launch vehicle (KSLV-III), it is expected that the domestic geostationary satellite capability will be increased from (1 to 3.7) ton. Also, it is predicted that substantial ability of about 1 ton can be provided for the space exploration of the Moon, Mars, asteroids, etc. The Goheung space launch site is optimized for sun-synchronous small satellites, and due to the essential precondition that the launch trajectory does not impinge another country's sovereign airspace, it is not satisfactory as a geostationary satellite launching site. Its latitude also requires more energy to shape the rotating orbital plane from the initial injection status. This results in a decreasing factor of economic feasibility, including the operating complexity. Therefore, in parallel with the development of a next generation space launch vehicle, the practical process for acquisition of oversea land or sea space launch site near the Earth's equator and research for the optimization of orbiting methods of geostationary satellite injection must be continued.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.101-108
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• 2006

• The Journal of Korea Robotics Society
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• v.3 no.1
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• pp.1-8
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• 2008

Automatic parking assist system is one of the key technologies of the future automobiles. Control problem of a car-like vehicle is not easy due to the nonholonomic constraints. In this paper, a practical solution for planning a car-parking path is proposed according to the proposed motion space (M-space) approach. The M-space is the extension of the conventional configuration space (C-space). A collision-free, nonholonomic feasible path can be directly computed by the M-space conversion and a back-propagation of reachable regions from the goal. The proposed planning scheme provide not a single solution, but also a candidate solution set, therefore, optimization of the parking path can be easily carried out with respect to performance criteria such as safety, maneuvering, and so on. Presented simulation results clearly show that the proposed scheme provides various practical solutions.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.1003-1013
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• 2016

This paper proposes a framework of superpixel-based vehicle detection method using plane normal vector in disparity space. We utilize two common factors for detecting vehicles: Hypothesis Generation (HG) and Hypothesis Verification (HV). At the stage of HG, we set the regions of interest (ROI) by estimating the lane, and track them to reduce computational cost of the overall processes. The image is then divided into compact superpixels, each of which is viewed as a plane composed of the normal vector in disparity space. After that, the representative normal vector is computed at a superpixel-level, which alleviates the well-known problems of conventional color-based and depth-based approaches. Based on the assumption that the central-bottom of the input image is always on the navigable region, the road and obstacle candidates are simultaneously extracted by the plane normal vectors obtained from K-means algorithm. At the stage of HV, the separated obstacle candidates are verified by employing HOG and SVM as for a feature and classifying function, respectively. To achieve this, we trained SVM classifier by HOG features of KITTI training dataset. The experimental results demonstrate that the proposed vehicle detection system outperforms the conventional HOG-based methods qualitatively and quantitatively.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.2
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• pp.71-79
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• 2014

To enhance success probability of a system development project, its overall risk level should be minimized through systematically managing schedules, costs, and technical performances. However, Attempts to manage technical performance compared to numerous efforts to control costs and schedules in such projects are deficient. Particularly, a space launch vehicle, a large complex system, development project is much less likely to meet its technical performance objectives due to its technological difficulty, along with schedule delay and cost overrun. The technical performance management (TPM) is a method for tracking and managing technical progress in order to achieve technical performance targets within schedule and budget. In this paper, we investigate applications of the TPM in several space launch vehicle development projects. Then we propose and validate the TPM process to achieve a successful mission in such projects.

• ETRI Journal
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• v.37 no.6
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• pp.1220-1230
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• 2015

An autonomous valet parking (AVP) system is designed to locate a vacant parking space and park the vehicle in which it resides on behalf of the driver, once the driver has left the vehicle. In addition, the AVP is able to direct the vehicle to a location desired by the driver when requested. In this paper, for an AVP system, we introduce technology to recognize a parking space using image sensors. The proposed technology is mainly divided into three parts. First, spatial analysis is carried out using a height map that is based on dense motion stereo. Second, modelling of road markings is conducted using a probability map with a new salient-line feature extractor. Finally, parking space recognition is based on a Bayesian classifier. The experimental results show an execution time of up to 10 ms and a recognition rate of over 99%. Also, the performance and properties of the proposed technology were evaluated with a variety of data. Our algorithms, which are part of the proposed technology, are expected to apply to various research areas regarding autonomous vehicles, such as map generation, road marking recognition, localization, and environment recognition.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.1
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• pp.56-63
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• 2023

For the success of system development, it is necessary to systematically manage the requirements that are the basis of system development and its verification results. In order to follow the principles of SE(Systems Engineering)-based V&V(Verification&Validation) process, requirements can be managed by securing the requirements and their establishments, design compliances, and verification compliances according to the system development lifecycle. Especially, in a large-complex system research and development project, such as a space launch vehicle development project, many participants establish, verify, and validate numerous requirements together during the project. Therefore, logical and systematic requirements management, including guarantee of data integrity, change history, and traceability, is very important for multiple participants to utilize numerous requirements together without errors. This paper introduces the practical requirements and verification management for the requirements-based development process in the space launch vehicle development project.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.139-155
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• 2016

Present paper introduces the recent advances in space launch vehicle technologies. A brief survey is given for the space development programs in civil sector with their business model and key technologies. Advances in key technologies were reviewed in detail with more emphasis on the electric pump cycle engine for low cost high performance small launch vehicle, Electron, under development by Rocketlab Ltd., since their contributions would give good lessons for rocket scientists.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.185-188
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• 2009

The rocket motor of the space launch vehicle offers thrust for satellite to enter into the orbit. Characters of the solid propellant for rocket motors are affected by the space conditions such as vacuum and space radiation. The solid propellant used for such a purpose should not undergo physical, internal ballistic and energetic changes when exposed to vacuum and space radiation. This study describes the development of the solid propellant composition for the rocket motor of the space launch vehicle. Also, experimental study was conducted on supersonic diffuser in order to verify the performance of the solid propellant composition which was applied to standard motor on the ground in the vacuum condition.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.551-564
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• 2016

High-speed flight vehicles (HSFVs) such as space launch vehicles and missiles undergo severe dynamic loads which are generated during the launch and in in-flight environments. A typical vehicle is composed of thin plate skin structures with high-performance electronic units sensitive to such vibratory loads. Such lightweight structures are then exposed to external dynamic loads which consist of random vibration, shock, and acoustic loads created under the operating environment. Three types of dynamic loads (acoustic loads, rocket motor self-induced excitation loads and aerodynamic fluctuating pressure loads) are considered as major components in this study. The estimation results are compared to the design specification (MIL-STD-810) to check the appropriateness. The objective of this paper is to study an estimation methodology which helps to establish design specification for the dynamic loads acting on both vehicle and electronic units at arbitrary locations inside the vehicle.