• Title/Summary/Keyword: 2 order system

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Reliability Analysis of Cantilever Retaining Wall Using Multiple Failure Modes (다중거동함수에 의한 T형 옹벽의 신뢰도 해석)

  • Park, Chun-Su;Song, Yong-Seon;Kim, Yeong-Pil
    • Geotechnical Engineering
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    • v.4 no.2
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    • pp.15-24
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    • 1988
  • To identify the stability of cantilever retaining wall in safe state by the deterministic method, these potential modes of such geotechnical failures as bearing capacity, horizontal sliding and overturning are analysed using Advanced First Order Second Moment (AFOSM) method. All design variables are assumed of the normal distribution and to be statistically independent. Considering the correlations between the single modes, structural system reliability index is 2. 05. Even if the safety factors are larger than the required value in the codes' by the conventional deterministic method, the system reliability of this structure may not be Judged to be safe state since the system reliability index is much lower than general value of 3.

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Development of Land Suitability Classification System for Rational Agricultural Land Use Planning (농지이용계획의 합리적 책정을 위한 농지적성 평가기법의 개발)

  • 황한철;최수명
    • Journal of Korean Society of Rural Planning
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    • v.3 no.2
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    • pp.102-111
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    • 1997
  • For rational agricultural land use planning, it is quite necessary to get hold of land suitability precisely and to make decision on land use patterns accordingly. In the methodological viewpoint, objective and scientific evaluation techniques for land suitability classification should be supported for the systematic land use planning. As one of technical development approaches to rational land use planning, this study tried to frame a land suitability evaluation system for agricultural purposes. Evaluation unit is defined as a tract of land bounded by road, other land units and topographical features. And quantification theory was applied in the determination works of evaluation criteria. The administrative area of Namsa-myon(district), Yongin-si(city), Kyunggi-do(province) was selected for the case study. In order to check the feasibility of the evaluation system developed in the study, field check team, consisting of 2 government officers and 2 representative farmers, carried out evaluation works by observation on 148 sample land units, 10% of total 1,480 ones. Between estimated and observed results, there showed very good relationship of its multiple correlation coefficient, R=0.9467.

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2DOF PID Controller by the new method of adjusting parameters (새로운 파라미터 조정법에 의한 2자유도 PID제어기)

  • Lee, Chang-Ho;Kim, Jong-Jin;Ha, Hong-Gon
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2006.06a
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    • pp.85-88
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    • 2006
  • Many control techniques have been proposed in order to improve the control performance of the discrete-time domain control system. In the position control system, the output of a controller is generally used as the input of a plant but the undesired noise is include in the output of a controller. In this paper, the neuro-network 2-DOF PID Controller is designed by a neural network and the gains of this controller are adjusted automatically by the back-propagation algorithm of the neural network when the response characteristic of system is changed under a condition.

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A Study on the Performance Improvement of PZT Actuator Controller for Metal Jet (메탈젯용 PZT 액츄에이터 제어기 성능향상에 관한 연구)

  • Yun, So-Nam;Jo, Jeong-Dae;Lee, Taek-Min
    • 연구논문집
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    • s.33
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    • pp.81-88
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    • 2003
  • A metal jet printing system based on ink jet printing technique is one of the effective equipments for manufacturing elements of display devices, electrical devices, information processing systems, and so on. In order to develop an actuator of the metal jet printing system, bimorph type PZT actuator(length 25.2mm, width 7.2mm, thickness 0.5mm, shim thickness 0.2mm) and its controller(voltage range $\pm24v$, built-in fast recovery diode) were suggested and investigated. Performance tests and characteristic analysis, such as displacement, force, hysteresis and frequency, were carried out. The results show that the suggested actuator and controller are suitable for the metal jet printing system.

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Clinical Study of Two Cases of Facial Diplegia with Continued Facial Palsy (편측 안면마비가 잇따라 발병한 양측 안면마비 환자 2례에 대한 임상적 고찰)

  • Yang, Gi-Young;Lee, Byung-Ryul;Kim, Young-Il
    • Journal of Acupuncture Research
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    • v.25 no.5
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    • pp.205-211
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    • 2008
  • Objectives : This study is designed in order to evaluate oriental medical treatment of facial diplegia with continued facial palsy. Methods : The authors observed patients by Yanagihara's unweighted grading system for operated acupuncture treatment, herbal medicine treatment and physiotherapy. Results & Conclusions : 1. Both facial grade had different scores in Yanagihara's unweighted grading system for 2 cases when the facial palsy occured. 2. Both cases were diagnosed in wind-cold(feng-han) type. 3. The left and right side of face took different amount of time to recover. 4. Facial diplegia was significantly improved.

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A Study on the Empirical Cases of Electronic Democracy Focused on Internet Voting for the G2C(Government to Customer) Environment (G2C 환경을 위한 인터넷 선거 중심의 전자민주주의의 사례 연구)

  • 양광모;김형진
    • Journal of the Korea Safety Management & Science
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    • v.5 no.3
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    • pp.121-131
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    • 2003
  • This study centers on how the electronic democracy which is expected to be a political system of information society may increase civic participation and develop political system. On the other hand, critics of internet voting claim that the technology required to properly authenticate voters and assure the accuracy and integrity of the election system either does not exist or is not widespread enough in society to be equitable and effective. In order to capture the potential that this new technology offers, it must be implemented correctly, upon a well-conceived framework of standards and procedures. At the same time, government must seek the advice of industry leaders as well as social activists so as to avoid the many obstacles that will undoubtedly arise.

A Study for Controller Design Using 2-Degree of Freedom(DOF) Structure In A Magnetically Suspended System (자기부상시스템의 2-DOF 구조를 이용한 제어기 설계에 관한 연구)

  • Baek, Seung-Koo;Lee, Chang-Young;Chang, Seok-Gahk;Kwon, Sung-Tae
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1430-1435
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    • 2006
  • This study deals with the problem of balance beam system to stabilize about static and sinusoidal disturbance. wherein the design objectives are to keep the gap deviation from static and sinusoidal disturbance. In this paper propose the 2-Degree of Freedom(DOF) structure and a simple first-order controller which is designed by Characteristic ratio assignment (CRA) method. Matlab simulation result verify stabilization of balance beam system despite of disturbance. Hybrid simulation between digital controller and analog plant is presented by Matlab Simulink.

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A Study on Micro-step of 2-phase Hybrid Type Linear Stepping Motor (2상 하이브리드형 리니어 스텝핑 전동기의 미세스텝에 관한 연구)

  • Oh, Hong-Seok;Kim, Dong-Hui;Lee, Sang-Ho
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.5
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    • pp.358-363
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    • 2000
  • In this paper, a voltage equations, a thrust force equations and kinetic equation are derived from the basic structure of a 2-phase hybrid type linear stepping motor(HLSM). And a micro-stepping method in order to eliminate effectively the resonant phenomena and to increase the positional resolution of the HLSM was proposed. The proposed micro-stepping method can divide one step into the maximum 128 micro-steps under simple control system. The dynamic characteristics of proposed micro-stepping method were analyzed by the ACSL(Advanced Continuous Simulation Language) with the voltage equations, the thrust force equations and the kinetic equation, and were measured by laser experimental system. As the result, the justice of theory was confirmed, and the resonant phenomena, the positional resolution and dynamic thrust were improved by the proposed micro-stepping method.

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Construction and Evaluation of Oxidation System for Superconductor Thin Film (초전도 박막 제작을 위한 산화 시스템 구축 및 평가)

  • 임중관;박용필;송경용
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.2
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    • pp.163-167
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    • 2003
  • Ozone is strong and useful oxidizing gas for the fabrication of oxidation thin films. In order to obtain high quality thin film, the ozone concentration must be increased. An ozone condensation system is evaluated in the viewpoint of an ozone supplier for oxidation thin film growth. Ozone is condensed by the adsorption method and ozone concentration reaches 8.5 mol% by 2.5 h after the beginning of the ozone condensation is negligible if the condensed ozone is transferred between the ozone condensation system and the film growth chamber within a few minutes. CuO peak which is the result of the obtained Cu-films using condensed ozone appears by XRD patterns.

A Optical System Design of LED Marine Lanterns Based on a TIR Collimator Lens (전반사 렌즈를 이용한 LED 등명기 광학계 설계)

  • Go, Dong Hyun;Lee, Yoon Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.11
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    • pp.1-5
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    • 2015
  • In this paper, we propose the optical system design for a medium sized LED marine lanterns which simplifies the multi-layer structure into a single structure. In order to satisfy the target fixed intensity(35,000cd) and vertical divergence($-2.5^{\circ}{\sim}-4.0^{\circ}$, $+2.5^{\circ}{\sim}+4.0^{\circ}$), we use the total internal reflection collimator lens. And a Monte Carlo simulation has been utilized to optimize a condition of a LED package, TIR lens and outside lens. The computer simulation results indicated that this LED marine lanterns can produce of a fixed intensity(35,382cd) and vertical divergence($-3.1^{\circ}{\sim}+2.5^{\circ}$). Using the this optical system, we achieve the target value of LED lanterns.