• 제목/요약/키워드: Ground mode

검색결과 645건 처리시간 0.03초

항공기 구조물의 동적 거동 시험/해석 절차 (An Integrated Approach to the Dynamic Testing of Aerospace Structures)

  • 이상엽
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.348-357
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    • 2006
  • Ground Vibration Tests (GVT) are needed on au new aircraft types and as part of certification. Its first objective is to verify models used for the calculation and prediction of the dynamic behavior of the structure. The main objectives of this paper are to introduce 'the integrated approach of dynamic testing for aerospace structure' in detail and 'The research projects in which LMS participated in aerospace structural dynamic area'

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Penman 식과 기상요소를 이용한 증발산모델에 관하여 (On the Evapotranspiration Model derived from the Meteorological Elements and Penman equation)

  • 이광호
    • 물과 미래
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    • 제6권2호
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    • pp.6-11
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    • 1973
  • This paper include the hydrometeorological analyses of evapotranspiration which is import factor concerning the estimate of water budgest over a certain basin. Evapotranspiration model mode by the multiple regression analysis between the evapotranspiration measured on various kinds of ground cover (water, bare soil and lawn) and the other meteorological elements affecting the evapotranspiration process, and the simple regression analysis between the evapo transpiration measured on each ground cover and the evapotranspiration on water and vegetables calculated from the Penman equation. It is expected that the evapotranspiration models are a very useful formulae estimating ten days amounts or a month's amounts.

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The First Multi-Frequency Synthesis Space-VLBI Observations of 0059+581 with Radioastron

  • Alexey Rudnitskiy;Mikhail Shchurov;Taehyun Jung;Marcello Giroletti
    • 천문학회지
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    • 제56권1호
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    • pp.91-96
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    • 2023
  • In this paper, we describe the first multi-frequency synthesis observations of blazar 0059+581 made with the Radioastron space-ground interferometer in conjunction with the Korean VLBI Network (KVN), Medicina and Torun ground telescopes. We conducted these observations to assess the spaceground interferometer multi-frequency mode capability for the first time.

배전계통 접지전극의 접지효과 분석 연구 (Comparison the grounding effect of a grounding rods and a grounding copper band in the Distribution System)

  • 강문호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 A
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    • pp.509-511
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    • 2004
  • Grounding rods as a discharge path are normally used to ensure the safety of human beings and facilities from the over-voltages and the over·current. Each grounding mode class 1, class 2, class 3, special class 4- has prescribed ground resistance values which are kept by the utilities. However, in the distribution system, it is very difficult for grounding rods to obtain the prescribed ground resistance values because of the limits of installation space. Therefore, in this paper, the grounding effects of the grounding copper bands which are recently developed to use efficiently in small area and the grounding rods are compared by testing the ground resistance values, ground potential rise(GPR), and step voltage in various cases.

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위그선 연구현황과 전산유체역학의 응용 (State-of-the-Art of WIG(Wing-In-Ground Effect) Ships and Application of the Computational Fluid Dynamics)

  • 강국진
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2005년도 춘계 학술대회논문집
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    • pp.14-19
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    • 2005
  • The paper introduces the state-of-the art of WIG ship and application field of the CFD to WIG ship development. WIG ships are highly efficient and fast transport vehicles which take advantage of benefits of ground effect. Chapter 1 describes the characteristics of WIG ship. Chapter 2 reviews the research works of Russia, German, Chinese, Korea and etc. Chapter 3 explains the kind of WIG ship categorized by the main operational mode and take-off system. Chapter 4 describes about the application field of CFD to WIG ship development procedure.

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Polarimetric Parameters Extraction to Understand the Scattering Behavior of NASA/JPL AIRSAR Data

  • Yang, Min-Sil;Moon, Wooil-M.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.442-447
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    • 2002
  • When a SAR system operates in a full-polarimetic mode, the amount of the information one can extract is so complex that the effective presentation of the information is important. However, the information acquired from the polarimetric SAR data is often difficult to interpret by itself, because it is consisted of both the amplitude information and the phase information. Polarimetric parameters are the good way of representing the polarimetric SAR information in a quantitative manner. Also they can characterize the scattering behavior of the ground scatterer. In this research, extraction of polarimetric parameters, evaluation and interpretation of the scattering behavior of the ground with respect to polarimetric SAR signal are carried out. Using the NASA/JPL AIRSAR data, we estimated the polarimetric parameters and compared them in terms of the ground features. In general, extracted parameters well represent the characteristics of the different features on the ground.

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연약지반 개량 PBD 복합천공기 리더의 구조 안전성 평가 (Structural Safety Evaluation of PBD Composite Perforator's Leader for Soft Ground Improvement)

  • 김민호
    • 한국기계기술학회지
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    • 제20권6호
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    • pp.894-900
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    • 2018
  • Among the soft ground improvement methods, PBD is the most common construction method because it is cheap and construction is fast. However, if the ground is rigid, additional work is required. In this study, the structural safety, natural vibration, and safety angle of the steel vertical tower structure were evaluated in the development of the PBD composite perforator which can be combined with drilling work and PBD construction. Structural safety was assessed when the wind load of 20 m/s was simultaneously applied to the PBD construction load of 20 tons, the perforating operation of 25 tons, and the wind speed of 50 m/s was applied only to the wind load. The natural frequencies were evaluated up to the sixth mode, and the safety angle was evaluated for static and dynamic safety angles.

초기 유도용 수동추적 필터 (A passive tracking filter in a capture guidance mode)

  • 엄태윤;안조영;송택렬
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.99-104
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    • 1989
  • A practical filter is suggested for ground-Dasea missile tracking in a capture guidance mode, utilizing angle-only measurements from a passive sensor and its performance is evaluated by a realistic system simulation study. Also suggested is a missile acceleration model that provides inputs to the filter. The suggested filter has a decoupled structure of independent azimuth and elevation channels with efficiency in commutation time and memory requirements.

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Investigation of the Reaction Coordinate for Dissociation in $Cr(CO)_6$ Using Resonance Raman Spectroscopy

  • 유수창;고석범;J. B. Hopkins
    • Bulletin of the Korean Chemical Society
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    • 제16권11호
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    • pp.1043-1045
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    • 1995
  • The overtone of the ν2 vibrational mode in Cr(CO)6 are observed for the first time in cyclohexane and methanol at both the 266 and 213 nm excitations. The appearance of the overtones due to the displacement of the electronic excited state with respect to the ground state along the ν2 vibrational mode is interpreted in terms of wavepacket concept and molecular orbital (MO) theory. Our Raman results suggest a new interpretation for the excited state potential.

지반조건, 굴착특성 및 지층구성을 고려한 터널굴착 유발 지반변위 거동분석 (Analysis of Ground Movements due to Tunnel Excavation Considering Ground Conditions, Excavation Characteristics, and Ground Layer Formations)

  • 손무락;윤종철
    • 대한토목학회논문집
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    • 제29권5C호
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    • pp.239-250
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    • 2009
  • 본 논문에서는 지반의 지반조건, 굴착특성 및 지층구성을 고려한 터널굴착 유발 주변지반의 침하 및 수평변위에 대한 거동특성을 수치해석적 방법으로 조사하였다. 이를 위해서 먼저 지반변위 예측방법에 관한 관련 사례조사 및 문제점분석을 수행하고, 이를 바탕으로 한 수치해석적 매개변수연구를 수행하였다. 이러한 사례조사의 분석결과는 지반조건에 따른 주변 지반변위의 특성을 일차적으로 파악하기 위해 이용되며, 또한 기존방법의 문제점을 파악함과 동시에 수치해석적 매개변수연구를 위한 기초자료로서 활용된다. 수치해석적 매개변수연구는 먼저 굴착유발 주변 지반변위 계측이 신뢰성 있게 측정된 사례를 토대로 시뮬레이션을 실시하여 수치해석상 필요한 접근방법 및 적합한 지반모델을 설정하고, 이를 토대로 지반조건, 굴착 특성 및 지층구성을 달리한 매개변수 연구를 수행하였다. 이러한 과정을 수행한 후 굴착으로 인한 주변지반의 침하 및 수평 지반변위가 변해가는 과정을 종합적으로 분석하여 그 거동을 파악하였다.