• Title/Summary/Keyword: Characteristic Equation

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Estimation of Load Characteristic Factor Considering The Load Pattern and Seasonal Characteristic for Consumer (수용가의 형태와 계절별 특성을 고려한 부하특성계수 재 산정)

  • Hwang, H.M.;Jang, S.I.;Kim, K.H.;Kim, J.E.;Rho, D.S.;Jeong, I.J.
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.450-453
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    • 2003
  • This paper presents the estimation on Load Characteristic Factor(k) which is considered to load pattern and seasonal characteristic of consumer. We can calculate the loss of distribution networks through the equation composing of Load Factor(LF), Loss Load Factor(LLF) and load characteristic factor(k). This equation is similar to the method of Regulator-General Victoria, Australia. Generally, the conventional method for calculating the distribution losses uses k with a constant value from 0.1 to 0.3. However, the k which is a relationship between LF and LLF can be varied by load pattern and seasonal characteristics. It is necessary to estimate the k according to load characteristics. This paper shows the result for recalculating k using the KEPCO's SOMAS data measured in distribution networks.

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Complex Quadruplet Zero Locations from the Perturbed Values of Cross-Coupled Lumped Element

  • Um, Kee-Hong
    • International journal of advanced smart convergence
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    • v.6 no.4
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    • pp.33-40
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    • 2017
  • In this paper, complex quadruplet zeros of microwave filter systems are investigated. For the cascaded systems the chain matrices are most conveniently used to derive the voltage transfer function of Laplace transform with cascaded two-port subsystems. The convenient relations of transfer function and chain matrix are used in order to find the transmission zeros. Starting from a ladder network, we introduced a crossed-coupled lumped element, in order to show the improved response of bandpass filter. By solving the transmission zero characteristic equation derived from the cascaded subsystems, we found the zeros of filter system with externally cross-coupled lumped elements. With the cross-coupled elements of capacitors, the numerator polynomial of system transfer function is used to locate the quadruplet zeros in complex plane. When the two pairs of double are on the zeros -axis, with the perturbed values of element, we learned that the transition band of lowpass filter is improved. By solving the characteristic equation of cascaded transfer function, we can obtain the zeros of the cross-coupled filter system, as a result of perturbed values on lumped element.

Adaptive Design of IIR Digital Filters Using Output Error Method with Adaptive Compensator (적응 보상기를 가지는 출력오차 방법을 이용한 IIR 다지탈 필터의 적응적 설계)

  • 배현덕;이종각
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.9
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    • pp.685-690
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    • 1987
  • Adaptive design of IIR digiral filters using equation error method has been studied. In this paper, a design technique of IIR digital filters using output error method with adaptive compensator is presented. In computer simulation results, it is shown that flat response characteristic in pass-band, below-40[dB] attenuation characteristic in stop-band, sharf cut-off characteristic in transition-band, and phase characteristic is linearin pass-band.

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Design and Characteristic Analysis of Vaccum Pump Using Moving Magnet type Linear Oscillatory Actuator (가동 영구자석형 리니어 진동 액츄에이터를 이용한 진공 펌프의 설계 및 특성해석)

  • Cho, Sung-Ho;Kim, Duk-Hyun;Kim, Gyu-Tak
    • Proceedings of the KIEE Conference
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    • 2002.04a
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    • pp.61-63
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    • 2002
  • This paper deals with the design of vaccum pump using moving magnet type linear oscillaory actuator based on the design procedure and the characteristic analysis. To improve the starting characteristic, the optimum spring constant is detected and redesigned. The parameter was calculated by Finite Element Method(FEM). In order to dynamic characteristic analysis. Time difference method with voltage and kinetic equation is used.

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Transient Response of The Optimal Taper-Flat Head Slider in Magnetic Storage Devices

  • Arayavongkul, R.;Mongkolwongrojn, M.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.990-994
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    • 2004
  • This paper presents a method to predict the transient characteristic of the air lubricated slider head in a hard disk drive by using optimization technique. The time dependent modified Reynolds equation based on the molecular slip flow approximation equations was used to describe the fluid flow within the air bearing and the implicit finite difference scheme is applied to calculate the pressure distribution under the slider head. The exhaustive search combined with the Broyden-Fletcher-Goldfarb-Shanno method were employed to obtain optimum design variables which are taper angle, rail width and taper length in order to keep the forces and moments acting on the slider head in dynamic equilibrium. The results show that the optimal head slider of the magnetic head has good stability characteristic that can reach the steady state within 0.5 microsecond.

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Using Structural Equation Modeling to Fit a Model of Student Background, Teacher Background, Home Environment, and a School Characteristic to Mathematics Achievement on the TIMSS

  • Cho, Gyu-Pan
    • Research in Mathematical Education
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    • v.7 no.4
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    • pp.247-270
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    • 2003
  • The purpose of this study is to build a model that explains the relationship between and among five variables that are student background, teacher background, home environment, school characteristic, and student mathematics achievement, using structural equation modeling. Another purpose of this study is to compare the relationships of these variables between the United States and Korea in 7th and 8th grades mathematics. Student, teacher, and school background files from population 2 in the TIMSS were selected for this study. The result of the study provides practical information for teachers, parents, school principals, and other people who are interested in improving student achievement, and also provides the information that may explain differences and similarities between the US and Korea in mathematics achievement.

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Vibration Characteristics of a 1-3 Piezoelectric Composite Arrayed on a Cylindrical Surface (원통면에 배열된 1-3 압전 복합체의 진동 특성)

  • Kim, Dae-Seung;Kim, Jin-Oh
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.93-96
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    • 2007
  • This paper presents a theoretical approach to describe the vibration characteristics in the 1-3 piezoelectric composite arrayed on a cylindrical surface. By homogenizing the composite composed of a piezoelectric ceramic and a polymer the physically useful parameters were defined and then used to derive the governing equation of radial motion for the cylindrical 1-3 piezoelectric composite. Applying mechanical and electric boundary conditions has yielded a characteristic equation for radial vibration of the composite. Theoretical calculations of the resonance frequency have been compared with those obtained by the finite-element analysis and have shown a good agreement.

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Vibration of Elevator Rope with a Spring-mass System at the Tip (끝 단에 스프링-질량계가 연결된 엘리베이터 로프의 진동)

  • Kwak, Moon K.;Han, Sangbo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.4
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    • pp.317-323
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    • 2014
  • This study is concerned with the free vibration analysis of an inextensible uniform rope with a spring-mass system at the tip. The rope is hanged vertically in a gravitational field. This problem is related to the free vibration of an elevator rope connected to an elevator cage. The equation of motion and the corresponding boundary conditions are derived by using the Hamilton's principle. The general solution of the governing equation of motion is expressed in terms of Bessel functions. The characteristic equation was derived by applying the boundary conditions. The characteristic values which are in fact non-dimensionalized natural frequencies were obtained numerically. The effects of mass and spring constant were investigated. The numerical results show how the tip mass and spring affect the natural frequencies of the rope.

Stability for Active Vibration Magnetic Bearing - Main Spindle of a Machine Tool (공작기계 자기베어링 - 주축 시스템의 능동진동 안정성 연구)

  • 김재실
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.04a
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    • pp.697-703
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    • 2000
  • In design step of an active vibration control system, the stability analysis is required for obtaining a stable control region so that the system is protected from it violent natural vibration. This paper describes the procedure of stability simulation for the active magnetic bearing-main spindle of a machine tool. The characteristic equation of the overall system is derived by assembling the dynamic equation of a flexible shaft and the transfer functions of feedback components. And the stable region is obtained by calculating the eigenvalues of the characteristic equation. The simulated control stable region is good agreement by comparing the experiment. Therefore the stable control gain is selected in this paper.

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Vibration Characteristics Analysis of a Piezoelectric Disc or Torsional Transducers (비틀림 진동 변환기용 압전 원판의 진동특성 해석)

  • Lee, Jung-Hyun;Kim, Jin-Oh
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.12 s.105
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    • pp.1416-1421
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    • 2005
  • This paper presents an analytical approach for the vibration characteristics of a piezoelectric disc for torsional vibration transducers. The characteristic equation of the piezoelectric annular disc has been derived from Gibbs' free energy equations and mechanical and electrical equilibrium. With an anisotropic material properties of the disc, the characteristic equation has yielded resonance frequencies. Numerically-calculated results have been compared with the results obtained by the finite element analysis and experiments and have confirmed the validity of the theoretical analysis.