• Title/Summary/Keyword: Driving-point impedance

Search Result 14, Processing Time 0.016 seconds

Reactance Loaded Dipole Antennal Elements for Beam Tilting with Forced Resonance (리액턴스 장하 강제 공진형 지향성 틸트 다이폴 안테나 소자)

  • 김기채;권익승;서영석;박용완
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.11 no.2
    • /
    • pp.278-285
    • /
    • 2000
  • This paper presents the basic characteristics of the beam tilting dipole antenna element in which one reactance element is used for the impedance matching at the feed point. The radiation pattern is tilted by the properly determined driving point position, and the loading reactance is used to obtain forced resonance without great changes in tilt angle. The numerical results demonstrate that the reactance element should be loaded in the region where the driving point is placed to obtain forced resonance of the antenna with little changes in beam tilt angle. In case the proposed forced resonant beam tilting antenna with $0.8\lambda$ length is driven at $0.2\lambda$ from the center, the main beam tilt angle o.5 57.7 degrees, the highest power gain of 8.6 dB are obtained.

  • PDF

Mathematical Model Development of Whole-body Vertical Vibration, Using a Simulated Annealing Method (Simulated Annealing 기법을 이용한 인체 수직 전신 진동 모델의 파라미터 선정)

  • Choi, Jun-Hee;Kim, Young-Eun;Baek, Kwang-Hyun
    • Proceedings of the KSME Conference
    • /
    • 2000.11a
    • /
    • pp.381-386
    • /
    • 2000
  • Simple spring-damper-mass models have been widely used to understand whole-body vertical biodynamic response characteristics of the seated vehicle driver. However, most previous models have not considered about the non-rigid masses(wobbling masses). A simple mechanical model of seated human body developed in this study included the torso represented by a rigid and a wobbling mass. Within the 0.5-20Hz frequency range and for excitation amplitudes maintained below $5ms^{-2}$, this 4-degree-of-freedom driver model is proposed to satisfy the measured vertical vibration response characteristics defined from a synthesis of published data for subjects seated erect without backrest support. The parameters are identified by using the combinatorial optimization technique, simulated annealing method. The model response was found to be provided a closer agreement with the response characteristics than previously published models.

  • PDF

Development of Human Body Vibration Model Including Wobbling Mass (Wobbling Mass를 고려한 인체 진동 모텔의 개발)

  • 김영은;백광현;최준희
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.10 no.2
    • /
    • pp.193-200
    • /
    • 2002
  • Simple spring-damper-mass models have been widely used to investigate whole-body vortical biodynamic response characteristics of the seated vehicle driver. Most previous models have not considered the effect of wobbling masses; i.e. heart, lungs, liver, intestine, etc. In this study, 4 -DOF seated driver model including one non-rigid mass representing wobbling visceral mass, 5-DOF model including intestine, and 10-DOF model including five lumbar vertebral masses were proposed. The model parameters were identified by a combinatorial optimization technique. simulated annealing method. The objective function was chosen as the sum of error between model response of seat-to-head transmissibility and driving point mechanical impedance and those of experimental data for subjects seated erect without backrest support. The model response showed a good agreement with the experimental response characteristics. Using a 10-DOF model, calculated resonance frequency of lumbar spine at 4Hz was matched well with experimental results of Panjabi et al.

A fast fault location method using modal decomposition technique of traveling wave (진행파 모드 분해 기법을 이용한 고속 고장점 표정)

  • 조경래;홍준희;김성수;강용철;박종근
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.45 no.2
    • /
    • pp.167-174
    • /
    • 1996
  • In this paper, a fault location algorithm is presented, which uses novel signal processing techniques and takes a new paradigm to overcome some drawbacks of the conventional methods. This new method for fault location on electric power transmission lines uses only one-terminal fault signals. The main feature of the method is hat it uses the high frequency components in fault signal and considers the influence of the source network by using a traveling wave propagation characteristics. As a result, we can develop a high speed, good accuracy fault locator.

  • PDF