• Title/Summary/Keyword: 이준익

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Attitude Control using Quantitative Feedback Theory of a Quad-Rotor Vehicle with Plant Parametric Uncertainty (플랜트 파라미터의 불확실성을 포함한 4-회전익(Quad-Rotor) 비행체의 정량적 궤환 이론을 이용한 자세 제어)

  • Lee, ByungSeok;Heo, Moon-Beom;Lee, Joon Hwa
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.3
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    • pp.243-253
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    • 2014
  • This paper deals with the Quantitative Feedback Thoery(QFT) guaranteeing robustness in spite of the plant parametric uncertainty. In the frequency domain, the QFT guarantees the robustness of the design specification on the uncertainty of plant parameters and disturbance. In order to use the QFT, a selected plant is a Quad Rotor Vehicle(QRV) which has excellent maneuverability and possibility of vertical take-off and landing like the helicopter. And attitude control is examined the possibility satisfied the requirement specification under the setting parametric uncertainty of motors driving 4-blades. Additionally, in an attitude control, the pre-filter considering parameter range and operating range of a QRV was used. For these purpose, in this paper, by using QFTCT, that is the QFT Control Toolbox designing the controller in MATLAB by the QFT, each design phases are introduced.

Vortex Shedding Frequency for a 2D Hydrofoil with a Truncated Trailing Edge (뒷날이 잘린 2차원 수중익의 와도 흘림 주파수)

  • Lee, Seung-Jae;Lee, Jun-Hyeok;Suh, Jung-Chun
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.6
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    • pp.480-488
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    • 2014
  • Vortex shedding which is the dominant feature of body wakes and of direct relevance to practical engineering problems, has been intensively studied for flows past a circular cylinder. In contrast, vortex shedding from a hydrofoil trailing edge has been studied to much less extent despite numerous practical applications. The physics of the problem is still poorly understood. The present study deals with $K{\acute{a}}rm{\acute{a}}n$ vortex shedding from a truncated trailing-edge hydrofoil in relatively high Reynolds number flows. The objectives of this paper are twofold. First, we aim to simulate unsteady turbulent flows past a two dimensional hydrofoil through a hybrid particle-mesh method and penalization method. The vortex-in-cell (VIC) method offers a highly efficient particle-mesh algorithm that combines Lagrangian and Eulerian schemes, and the penalization method enables to enforce body boundary conditions by adding a penalty term to the momentum equation. The second purpose is to investigate shedding frequencies of vortices behind a NACA 0009 hydrofoil operating at a zero angle of attack.

Exploit Tool Implementation for Secure USB Drive: Based on the Password Authentication of Product F (보안 USB 취약점 익스플로잇 도구 개발: F 제품 비밀번호 인증을 기반으로)

  • Suwan Go;Seunghee Kwak;Junkwon Lee;Jaehyuk Lee;Kyungroul Lee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2023.05a
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    • pp.176-177
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    • 2023
  • 최근 USB 저장장치의 데이터 노출 및 탈취 문제를 해결하기 위하여, 보안 USB 저장장치가 등장하였으나, 데이터를 보호하기 위한 다양한 보안기술을 적용함에도 불구하고, 사용자 인증 우회나 비밀번호 노출과 같은 취약점으로 인하여, 보안 USB에 저장된 중요한 자료나 민감한 정보가 노출되는 문제점이 지속해서 발견되는 실정이다. 이에 따라, 보안 USB의 취약점 연구도 지속적으로 연구되고 있지만, 보안 USB 취약점을 분석하는 것은 수동적이고, 많은 노력과 시간이 소요되므로, 취약점을 자동으로 진단하고 분석하는 도구가 요구된다. 따라서, 본 논문에서는 자동화된 취약점진단 및 분석 도구를 제작하기 위하여, F 제품을 대상으로, 해당 제품에서 제공하는 비밀번호인증에서 발생하는 취약점을 분석하고 실증하며, 그 결과를 기반으로 최종적으로는 보안 USB 취약점 익스플로잇 도구 프로토타입을 개발한다.

Effects of Sublethal Doses of Chlorpyrifos-methyl on the Following Generation of the Beet Armyworm, Spodoptera exigus (Hubner) (아치사량의 chlorpyrifos-methyl이 파밤나방(Spodoptera exigua(Hubner)) 차세대형성에 미치는 영향)

  • 이준익;김용균
    • Korean journal of applied entomology
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    • v.36 no.3
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    • pp.277-282
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    • 1997
  • Chemosterilant effect of chlorpyrifos-methyl (CPM) on the beet armyworm, Spodoptera e.rigua (Hubner) was investigated, using topical application. Egg fecundity and fertility were analyzed in the adults reared from the fifth instar larvae which were treated with sublethal doses of CPM. Though CPM reduced fecundity a little, it gave significant negative effect on egg fertility in a dose-dependent manner. Genetic analysis was performed by reciprocal crosses between treated (100 Wgllarva) and untreated individuals and showed a dominant lethal effect of CPM on egg fecundity and fertility. This results indicate that chlorpyrifos-methyl may act as a chemosterilant as well as a well-known neurotoxicant, and suggest that it can be used in genetic control program.

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Study for the development of assembly type joint boxes for extra high voltage power cables (초고압 전력 케이블용 조립식 접속상의 개발을 위한 연구)

  • Seo, J.Y.;Park, J.S.;Lee, H.S.;Oh, E.J.;Han, B.S.;Hahn, K.M.;Lee, K.C.;Jeon, S.I.;Han, M.K.;Lee, J.H.;Shin, P.S.
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.925-927
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    • 1992
  • Since that the portion of failures caused by mis-installation of accessories is about 50% of whole failures in power transmission lines, the necessity of assembly type joint boxes, which have excellent installation capability and which can be electrically tested before installation, is gradually increasing. In this paper, we presented the results from the study from the point of design and the results of experiments using models. With the results of study, we could make it clear that the possibility of practical use of assembly type joint boxes instead of conventional molding type joint boxes is very high.

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Development of a Mobile Application using J2ME and EJB (J2ME와 EJB 기술을 활용한 무선 어플리케이션 개발)

  • 이종섭;이준수;최정욱;오동익
    • Proceedings of the Korea Multimedia Society Conference
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    • 2002.05d
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    • pp.690-694
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    • 2002
  • 무선 인터넷의 성장에 대한 높은 기대에도 불구하고 이를 위한 컨텐츠의 제공은 아직까지 부족한 상태로, 무선 인터넷 시장이 보다 활성화되기 위해서는 많은 양질의 컨텐츠가 제공되어야 한다. 이러한 많은 양질의 컨텐츠를 확보하기 위해서는 기존의 유선 인터넷 컨텐츠를 그대로 활용하면서 프리젠테이션 로직만을 분리하여 단말기에 탑재하는 방식이 유용하다. 또한, 분리된 프리젠테이션 로직과 기존의 유선 인터넷 측의 로직을 연결하기 위해서는 여러 단말기에서 지원되며 다양한 인터넷 접속 방식을 제공하는 Java 기술이 유리하다. 본 연구에서는 이러한 Java의 장점들을 활용하여 무선환경에서 작동하는 티켓 예약 응용시스템을 개발하였고, 이를 통해 효율적인 무선 응용 시스템 구축 방법의 모델을 제시하고자 한다. 본 연구에서 활용한 방식을 따르면 보다 효율적이고 마르게 무선 응용 시스템을 구축할 수 있으며, 기존의 유선 인터넷 컨텐츠를 활용함으로써 다양한 양질의 컨텐츠를 쉽게 확보할 수 있어, 무선 인터넷의 활성화에 도움이 될 수 있을 것으로 기대한다.

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Implementation of Object Tracking for IR Images Using PowerPC based System (PowerPC 기반의 IR 영상 객체 추적기 구현)

  • Lee, Jae-Ik;Lee, Jun-Haeng;Park, Chang-Han
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.213-214
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    • 2007
  • In this paper, we implement one tracking scheme based on the block matching using PowerPC system. We implement tracking algorithm uses the information from Infrared (IR) sensor for tracking object. When a occlusion occurs, the proposed algorithm predicts movements of an object using the historical tracking information and it can keep the object tracking.

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Rewriting Male-identity Narratives, Possibilities & Limitations - Focusing on & - (새로운 남성 정체성의 모색, 가능성과 한계 - <라디오 스타>와 <즐거운 인생>을 중심으로 -)

  • Hwang, Hye-Jin
    • The Journal of the Korea Contents Association
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    • v.8 no.12
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    • pp.131-140
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    • 2008
  • It has been a major agenda in criticism that there have been a dominant tendency of male-centered narratives in Korean mainstream films after . These kinds of narratives could be accept as a result of searching process in virtual realm for understanding the social changes. I suggest $H.Lef\acute{e}bvre's$ very familiar concept 'quotidienne', which influences the conditions to constitute male-identity as a fundamental base of male-centered narratives, to analyze and . It seems meaningful these texts tried to reconstitute male-identity through distinguish potential energy of 'quotidienne' from repressive everyday-life. The result of analysis has lied two ambivalent dimensions, nevertheless, it would be required further studies to argue on male-centered narratives and discourses of male-identity as which results could represent interactions between various social contradictions.

A Study on the Filed Application of Environmental Friendly Porous Concrete For Planting (환경친화 식생용 포러스콘크리트의 현장적용성에 관한 연구)

  • Kim Jeong Hwan;Lee Nam Ik;Lee Young Hee;Kwon Hyuk Jun;Lee Jun;Park Seung Bum
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.769-772
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    • 2005
  • The river environments of many streams in korea have been deteriorate through the rapid industrialization and urbanization since the 1960s. In Germany and Japan, on the other hand, much efforts on the research and project have been made for the restoration of the deteriorated streams to close-to-nature. in order to restore the deteriorated streams, therefore, it is necessary to investigate such advanced technologies and materials. In view of this requirement, various research paths are being taken focusing on coarse aggregates to make multi-functional porous concrete having continuous voids so as to improve water and air permeability, acoustic absorption, water purification, and applicability to vegetation. The Purpose of this study is to investigate the method for recovery of the environment in the streams area using porous concrete block. the porous concrete block applies for test in the cheonggae-cheon have been monitored planting during six month. after 6 months, plant grows flourishing and reconstructed in state such as nature rivers.

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