• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1559-1565
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• 2013

This study aims to investigate the dynamic interaction characteristics between Maglev vehicles and an elevated guideway. A more detailed model for the dynamic interaction of the vehicle/guideway is proposed. The proposed model incorporates a 3D full vehicle model based on prototyping, flexible guideway by a modal superposition method, and levitation electromagnets including the feedback controller into an integrated model. The proposed model was applied to an urban transit Maglev developed for a commercial application to analyze the dynamic response of the vehicle and guideway, and the effect of the surface roughness of the rail, mid-span guideway deflections, and air gap variations are then investigated from the numerical simulation.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.269-278
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• 2018

Railway obstacle detecion system has been introduced with high-speed railway in 2004 to prevent accidents by obstacles such as landslide, rockfall and things fallen from the gauntry over the railway. But existing system has some limitation for landslide or fallen obstacle over railway. Therefore, In this study, we suggest new advanced obstacle detection system introducing the OTDR, optical fiber fences and detection cameras. This system can detect depression degree by the force to the fences and video for the specific region as well as detection wire Off condition. We produce and functional tests for fiber fence and OTDR, which are the core parts of the development system, and results were obtained to demonstrate improved detection capabilities. Several functions also been tested to verify the advanced detection performance and got some satisfactory results. Further we will conduct environment tests and field test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.101-103
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• 2022

CCTV is mainly used as a real-time detection system for critical facilities. In the case of CCTV, although the accuracy is high, the viewing angle is narrow, so it is used in combination with a sensor such as a radar. LiDAR is a technology that acquires distance information by detecting the time it takes to reflect off an object using a high-power pulsed laser. In the case of lidar, there is a problem in that the utilization is not high in terms of cost and technology due to the limitation of the number of simultaneous processing sensors in the server due to the data throughput. The detection method by the optical mesh sensor is also vulnerable to strong winds and extreme cold, and there is a problem of maintenance due to damage to animals. In this paper, by using the 1550nm wavelength band instead of the 905nm wavelength band used in the existing lidar sensor, the effect on the weather environment is strong and we propose to develop a system that can integrate and control multiple sensors.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.261-284
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• 2018

The current international legal system does not provide a safeguard against the militarization and the weaponization of outer space. Although the term "peaceful use of outer space" in the 1967 Outer Space Treaty(OST) appears in official government statements or in multilateral space treaties, it is still without an authoritative definition in reviewing national practices. The ambiguous ban on weapons in Article IV of the OST allows countries to loophole on the deployment of other weapons other than nuclear weapons. Meanwhile "Draft Treaty on the Prevention of the Placement of Weapon in Outer Space and of the Threat or Use of Force against Outer Space Objects(PPWT)" to Conference on Disarmament (CD) commissioned by the UN General Assembly's Special Session jointly submitted by China and Russia in 2008 and later revised in 2014, attempting to define and prohibit the proliferation of weapons in outer space and provided definitions of prohibited weapons, are opposed by the US on the grounds that currently there is no arms race in outer space. Some experts support a hard law approach in which binding laws aimed at ultimately creating integrated and binding legal instruments in all aspects of the use of outer space should be adopted to regulate the military use of space. However as a temporary measure the soft law guidelines should be developed for the non liquiet, a situation where there is no applicable law. The soft law could be used to create support for the declaration of the treaties and to create international customary law. For example, the 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space that regulates the activities of the state in the exploration and use of the universe, and the 1992 Principles Relevant to the Use of Nuclear Power Sources in Outer Space will illustrated. While substantial portions of the former was codified later in the 1967 OST, the latter which, although written in somewhat mandatory terms, have been consistently complied with by states, have arguably become part of customary international law. On November 12, 1974, the General Assembly reaffirmed that the development of international law may be reflected inter alia, by declarations and resolutions of the General Assembly which may to that extent be taken into consideration by the International Court of Justice.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.459-464
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• 2001

Leaf disks from cultivar 'Kennebec' and one selection line (ND 860-2) were cultured on Murashige-Skoog medium with various combinations of indole acetic acid (IAA) and zeatin riboside. Shoots, roots and callus were induced at various combinations of plant growth regulator levels. The medium containing $3.5mg{\cdot}L^{-1}$ IAA and $4.0mg{\cdot}L^{-1}$ zeatin riboside produced the most plantlets. Rooted regenerants were grown in the greenhouse. The growth of regenerated plants obtained from the MS medium supplemented with $7.0mg{\cdot}L^{-1}$ IAA and $3.0mg{\cdot}L^{-1}$ zeatin riboside was significantly greater than those grown from nodal expalnts. In ND 860-2, a leaf chimera with chlorophyll deficient (light yellow) sectors was found in plants regenerated fiom leaf disks (grown on MS medium supplemented with $3.5mg{\cdot}L^{-1}$ IAA and $3.0mg{\cdot}L^{-1}$ zeatin riboside) but not in plants grown from nodal explants. The phenotypic variability was also observed in the tuber number, size and weight.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.127-136
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• 2010

In multi-view video, illumination disharmony between neighboring views can occur on account of different location of each camera and imperfect camera calibration, and so on. Such discrepancy can be the cause of the performance decrease of multi-view video coding by mismatch of inter-view prediction which refer to the pictures obtained from the neighboring views at the same time. In this paper, we propose an efficient histogram-based prefiltering algorithm to compensate mismatches between the luminance and chrominance components in multi-view video for improving its coding efficiency. To compensate illumination variation efficiently, all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching. A Cosited filter that is used for chroma subsampling in many video encoding schemes is applied to each color component prior to histogram matching to improve its performance. The histogram matching is carried out in the RGB color space after color space converting from YCbCr color space. The effective color conversion skill that has respect to direction of edge and range of pixel value in an image is employed in the process. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with other methods.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.661-669
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• 2007

Eyer since the Prandtl's experiment in 1934 and X-21 airjet test in 1950 both attempting to reduce drag, it was found that controlling the velocities of surface for extremely fast-moving object in the air through suction or injection was highly effective and active method. To obtain the right amount of suction or injection, however, repetitive trial-and error parameter test has been still used up to now. This study started from an attempt to decide optimal amount of suction and injection of incompressible Navier-Stokes by employing optimization techniques. However, optimization with traditional methods are very limited, especially when Reynolds number gets high and many unexpected variables emerges. In earlier study, we have proposed an algorithm to solve this problem by using step by step method in analysis and introducing SQP method in optimization. In this study, we propose more effective and robust algorithm and techniques in solving flow optimization problem.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.111-119
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• 2013

It is essential and fundamental to extract boundary information of target object via massive three-dimensional point data acquired from laser scanner. Especially extracting boundary information of manmade features such as buildings is quite important because building is one of the major components consisting complex contemporary urban area, and has artificially defined shape. In this research, extended ${\chi}$-algorithm using geometry information of point data was proposed to extract boundary information of building from three-dimensional point data consisting building. The proposed algorithm begins with composing Delaunay triangulation process for given points and removes edges satisfying specific conditions process. Additionally, to make whole boundary extraction process efficient, we used Sweep-hull algorithm for constructing Delaunay triangulation. To verify the performance of the proposed extended ${\chi}$-algorithm, we compared the proposed algorithm with Encasing Polygon Generating Algorithm and ${\alpha}$-Shape Algorithm, which had been researched in the area of feature extraction. Further, the extracted boundary information from the proposed algorithm was analysed against manually digitized building boundary in order to test accuracy of the result of extracting boundary. The experimental results showed that extended ${\chi}$-algorithm proposed in this research proved to improve the speed of extracting boundary information compared to the existing algorithm with a higher accuracy for detecting boundary information.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.166-168
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• 2003

본 논문은 실시간 옷감 애니메이션을 생성하기 위한 기법을 설명한다. 이 논문에서는 질량 스프링 모델에 기반한 물체를 가상현실 환경에서 실시간에 움직이기 위한 수치적분 기술을 다루고 있다. 많은 연구자들이 옷감과 같이 객체의 움직임과 외형을 표현하기 위한 다양한 기법들을 제안했지만. 옷감 객체를 가상 현실 환경에서 실시간으로 움직이게 하는 일은 여전히 어려운 문제이다. 옷감 애니메이션의 가장 큰 문제는 옷감의 움직임을 표현하는 운동 방정식을 수치 적분하는 것이 안정적으로 수행되지 않는다는 것이다. 1990년 Baraff의 논문에서 제시된 것과 같이 암시적 적분법이 이러한 안정성 문제를 해결해 주기는 하지만, 암시적 적분법은 수치적분 문제를 선형시스템 풀이 문제로 바꾸기 때문에 사실적인 외형을 가진 복잡한 모델의 애니메이션을 실시간 혹은 상호작용적으로 생성하는 문제에는 그대로 적용할 수가 없다［1］. 암시적 적분법의 이러한 문제점들을 해결하고 실시간 흑은 상호작용적 애니메이션을 얻기 위해 몇 가지 근사 기법들이 제안되었다. 하지만. 이러한 근사 기법들은 지나친 근사에 기초하고 있기 때문에 실제 옷감의 움직임과 같은 사실적인 동작을 생성하지 못하였다 이 논문에서 소개할 기법은 사실적인 옷감 주름을 생성할 수 있을 정도로 복잡한 옷감 모델을 다루면서도, 이전의 근사 기법들이 생성할 수 없었던 사실적인 움직임을 얻을 수 있다. 따라서, 본 논문의 기법은 가상 현실 환경에서 시스템 전제의 상호작용성을 해치지 않으면서도 매우 사실적인 옷감 모델을 포함할 수 있도록 해 준다. 제안된 기법은 수치적분의 안정성을 위해 암시적 적분법에 기반하고 있으면서도, 선형 시스템의 해를 효과적이면서도 사실성을 해치지 않도록 근사하여 실시간 옷감 애니메이션을 생성한다.한다.수행하였다. 분석에서는 제품의 효율성뿐만 아니라 보안성을 중요하게 생각하였으며, 앞으로 보안 관련 소프트웨어 개발에 사용될 수 있는 도구들이 가이드 라인에 대한 정보를 제공한다.용할 수 있는지 세부 설계를 제시한다.다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아이에서 그 주산기사망률(周産基死亡率)이 각각 가장 낮았다. 2. 사산(死産)과 초생아사망(初生兒死亡)을 구분(區分)하여 고려해 볼때 사산(死産)은 모성(母性)의 임신력(

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.387-394
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• 2016

A stereo matching method is one of the ways to obtain a depth value from two dimensional images. This method estimates the depth value of target images using stereo images which have two different viewpoints. In the result of stereo matching, the depth value is represented by a disparity value. The disparity means a distance difference between a current pixel in one side of stereo images and its corresponding point in the other side of stereo images. The stereo matching in a homogeneous region is always difficult to find corresponding points because there are no textures in that region. In this paper, we propose a novel matching equation using the distance transform to estimate accurate disparity values in the homogeneous region. The distance transform calculates pixel distances from the edge region. For this reason, pixels in the homogeneous region have specific values when we apply this transform to pixels in that region. Therefore, the stereo matching method using the distance transform improves the matching accuracy in the homogeneous regions. In addition, we also propose an adaptive matching cost computation using a kernel of one dimensional array depending on the characteristic of regions in the image. In order to aggregate the matching cost, we apply a cross-scale cost aggregation method to our proposed method. As a result, the proposed method has a lower average error rate than that of the conventional method in all regions.