• 제목/요약/키워드: Ground length

검색결과 1,148건 처리시간 0.026초

접지면의 슬롯을 이용한 마이크로파 집적회로용 가변 감쇠기의 설계 (A Design of Variable Attenuator for MMIC using Slot in the Ground Plane)

  • 김기래
    • 한국정보통신학회논문지
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    • 제7권6호
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    • pp.1109-1114
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    • 2003
  • 마이크로스트립 선로의 접지면에 슬롯이 있는 SGPS (Split Ground Plane Structure) 구조는 등가적으로 병렬공진 특성을 갖는다. 슬롯의 길이가 특정 주파수의 반파장과 같으면 큰 감쇠특성을 나타낸다. 본 연구에서는 SGPS 구조의 슬롯 중앙에 저항을 두고 저항 값을 가변하면 공진주파수에서 감쇠특성이 변하는 원리를 이용하여 MMIC용 가변 감쇠기를 설계하였다. 이 감쇠기에서 저항대신 PIN 다이오드를 이용하면 송수신기에서 자동이득조절 (AGC) 회로에 응용할 수 있다.

일반 물질과 접지면으로 구성된 AMC 위의 다이폴 안테나 특성 분석 (Characteristics of a dipole on AMC consisting of a normal material and a ground plane)

  • 이동현;우대웅;김기호;지정근;성원모;박위상
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.347-348
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    • 2008
  • We investigate the characteristics of a dipole antenna on an artificial magnetic conductor (AMC) constructed of a normal material and a ground plane. We studied how the antenna performance is affected by changes in the dipole length and the distance between the dipole and the ground plane. The relation between the reflection phase of the AMC and the input resistance of the dipole for input impedance matching is also verified.

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보행속도가 보행특성모수 및 지면반발력에 미치는 영향에 관한 연구 (A study of the effect of walking speed upon gait parameters and foot-ground reaction forces)

  • 황규성;정민근;이동춘
    • 대한인간공학회지
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    • 제11권1호
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    • pp.93-101
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    • 1992
  • Gait parameters for the Korean normal adults were compared with sex and age. Time-distance measurements and ground reaction force parameters were studied in relation to walking speed. Regression analysis was performed to establish functional relations between walking speed and various gait parameters. It is found that cardence and stride length varied linearly with walking velocity whereas time of double support was inversely proportional to walking velocity. The amplitude of ground reaction force was increased with increasing velocities of gait due to the greater heel-strike force and toe-off forces associated with these higher velocities. The results of this study can be usefull utilized as basic data to design and evaluate prosthetic devices, and to detect abnormal gait performances.

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연직 마이크로파일이 설치된 조밀한 모레지반의 지지력 증가에 관한 연구 (A Study on Increase of Bearing Capacity of Dense Sandy Ground installed by Vertical Micropiles)

  • 최상민;임종철;이태형;공영주
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.355-362
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    • 2001
  • Since micropiles were conceived in Italy in the early 1950s, which have been widely used for In-situ reinforcement, bearing pile or the concept of combination in the world-wide. The meaning of micropiles usually differs from that of a general deep foundation. Because the load capacity of it was mainly affected by skin friction. Also, it could be obtained the improvement effects of load capacity or ground's rigidity by the unitary behavior of ground and micropiles. In this study, The model tests were peformed on the dense sand where micropiles are set to the vertical direction. Strip footing was used in it. Steel bars of dia. 2 and 4㎜ were used in model tests of which the sand was attached on the surface, and the length of it was changed as 2B to 6B(where, B is width of strip footing) Through this process, the load capacity were analyzed from the test results in the relationship between load and displacement.

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최적 보행 동작 구현을 위한 시뮬레이션 기반 Jansen Mechanism 활용 보행 로봇 설계 및 구현

  • 김승하;이수홍
    • EDISON SW 활용 경진대회 논문집
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    • 제6회(2017년)
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    • pp.534-538
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    • 2017
  • There are three types of robots that move on the ground classified as drivetrain. Wheels, tracks and Legs. Wheels and tracks are much easier to construct and control, but they have problems passing through obstacles like people. This paper discusses the design of line tracing using Theo Jansen, one of multi-legged walking mechanism. In order to increase the moving speed, the Jansen mechanism is designed by maximizing the objective variable as GL (Ground Length), GAC (Ground Angle Coefficient). In this project, only three sensors were attached and Arduino was used for optimal control of the motor using the sensor values.

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연속 프리플렉스 합성형교의 내진해석에 관한 연구 (A Study on the Seismic Analysis of Continuous Preflex Composite Bridges)

  • 구민세;정재운;김훈희
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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    • pp.241-248
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    • 1999
  • Structural damage during an earthquake is caused by the response of the structure to the ground motion input at its base. The dynamic force produced in the structure are due to the inertia of its vibrating elements. The response of the structure exceeds the ground motion and this dynamic magnification depends on the duration and frequency content of the ground vibration, the soil properties at the site, distance from the epicenter and the dynamic characteristics of the structure. Earthquake load used in this study as a input data was artificially simulated with the design spectrum diagram in the Korean Earthquake Resistant Design Code. This paper presents the seismic analysis of the continuous preflex composite girder bridges according to variation of pier's height and span's length.

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토목섬유를 사용한 무처리 연약지반과 성토사이의 수평배수층 (Geotextiles Horizontal Drain between Earth Fills and Natural Soft Ground)

  • 이형규;공길용;김현태
    • 한국농공학회지
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    • 제44권4호
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    • pp.129-138
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    • 2002
  • This paper presents a study on the discharge capacity of geotextiles as a horizontal drain layer placed between the layers of earth fill and natural soft ground. Required discharge capacity of geotextiles as drain layers estimated by consolidation analysis is proportional to the consolidation coefficient of the ground soils and the width of the earth fills. The field discharge capacity of the geotextiles are measured by the hydraulic transmissivity test. And the results show wide variation according to the material characteristics of geotextiles, water content of the soils, vertical pressure, and etc. For the short horizontal drain length, geotextile filter mat can be used for the horizontal drain layer. And f3r the long drain($25{\sim}55m$), it is used for the drain together with Bord Drain.

연약지반용 스마트 앵커 공법 (A Method of SMART Anchor for a Weaked Ground Condition)

  • 박대웅;정종기;김정열
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.1334-1337
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    • 2009
  • A SMART anchor is a kind of friction mount anchor, the load is diffused and applied to the various parts of the distributed bond length, having less impact on the grout strength, and being able to secure necessary anchoring force in relatively soft grounds. Smart anchor can have strong loads in soft and weak grounds as in rock beds.

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역 T형 노치를 가진 4세대 이동통신용 평면형 폴디드 모노폴 안테나 (A Planar Folded Monopole Antenna with Inverted T-Shape Notch in Ground Plane for 4G Mobile Communication)

  • 신호섭;최인태
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2013년도 추계학술대회
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    • pp.893-895
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    • 2013
  • 본 논문에서는 접지면에 역 T형 노치를 넣은 평면형 폴디드 모노폴 안테나를 제안하였다. 제안된 안테나에서는 대역폭을 늘리기 위하여 내부 패치와 외부 패치의 폭들을 점차 넓히는 방향으로 변화를 주었고, 그라운드에 가로와 세로 slit의 길이가 비슷하고 폭은 약 2배 정도 차이가 있는 노치를 넣어 설계 및 모의실험을 하였다.

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근접굴착 시 기존건물의 영향을 받는 터널의 거동 (Behavior of the tunnel under the influence of a existing building during the adjacent ground excavation)

  • 이종민
    • 한국터널지하공간학회 논문집
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    • 제20권3호
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    • pp.609-623
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    • 2018
  • 건물하중의 영향을 받는 상태의 기존터널에 근접해서 터널보다 깊은 심도로 지반을 굴착하는 경우에 흙막이벽체의 거동이 기존터널의 존재로 인해 큰 영향을 받는 것으로 알려져 있다. 그런데 지상 구조물에 의해 받는 영향에 대한 연구 예가 많지 않다. 따라서 본 연구에서는 기존터널에 근접하여 지반을 굴착할 때 기존터널이 상부구조의 영향을 받는 상태에서 건물 위치에 따른 터널의 거동을 대형모형실험과 수치해석을 실시하여 측정하였다. 이를 위해 지표면에 건물하중이 없는 경우와 건물하중이 3가지 이격거리에 위치한 경우(0 m, 1D, 2D)에 대하여 각각 대형모형실험을 수행하였다. 본 논문에서는 흙막이벽체와 기존구조물의 영향을 받고 있는 터널의 거동에 대하여 연구하였다. 1 : 10의 축척으로 2.0 m (폭)${\times}$6 m (높이)${\times}$4.0 m (길이)의 크기를 가진 대형토조에서 실험을 수행하였다. 그 결과 흙막이벽체 배면에 있는 인접터널의 안정성은 근접굴착에 의해 뚜렷하게 영향을 받는 것으로 나타냈다.