• 제목/요약/키워드: zeroes

검색결과 21건 처리시간 0.019초

THE EXACT BERGMAN KERNEL AND THE EXTREMAL PROBLEM

  • Jeong, Moonja
    • Korean Journal of Mathematics
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    • 제13권2호
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    • pp.183-191
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    • 2005
  • In this paper we find the Laurent series expansions representing the reproducing kernels. Also we find the number of zeroes of the exact Bergman kernel via parallel slit domain in order to relate the exact Bergman kernel to an extremal problem.

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EXISTENCE OF A MULTIVORTEX SOLUTION FOR ${SU(N)_g}{\times}U(1)_l$ CHERN-SIMONS MODEL IN ${R^2}/{Z^2}$

  • Yoon, Jai-Han
    • 대한수학회논문집
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    • 제12권2호
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    • pp.305-309
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    • 1997
  • In this paper we prove the existence of a special type of multivortex solutions of $SU (N)_g \times U(1)_l$ Chern-Simons model. More specifically we prove existence of solutions of the self-duality equations for $(\Phi(x), j =1, \cdots, N$ has the same zeroes. In this case we find that the equation can be reduced to the single semilinear elliptic partial differential equations studied by Caffarelli and Yang.

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영과잉 포아송 회귀모형에 대한 베이지안 추론: 구강위생 자료에의 적용 (Bayesian Analysis of a Zero-inflated Poisson Regression Model: An Application to Korean Oral Hygienic Data)

  • 임아경;오만숙
    • 응용통계연구
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    • 제19권3호
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    • pp.505-519
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    • 2006
  • 셀 수 있는 이산 자료(discrete count data)에 대한 분석은 여러 분야에서 활용되고 있지만 영(zero)을 과도하게 포함하고 있는 영과잉 자료는 자료의 성격상 포아송 분포를 따르지 못할 때가 있어 분석에 어려움이 따른다. Zero-Inflated Poisson(ZIP)모형은 이런 어려움을 극복하기 위하여 영에 대한 점확률을 가지는 분포와 포아송 분포를 합성하여 과도한 영과 영이 아닌 자료를 설명하는 모형이다. 설명 변수가 존재할 때는 포아송 분포 부분에서 반응변수의 평균과 공변량사이에 로그선형 연결함수를 사용한 Zero-Inflated Poisson Regression(ZIPR)모형이 사용될 수 있다. 본 논문에서는 Markov Chain Monte Carlo 기법을 이용한 ZIPR모형의 베이지안 추론방법을 제안하고, 이를 실제 구강위생 자료에 적용하며 다른 모형들과 비교한다. 그 결과 베이지안 추론 방법을 적용한 영과잉 모형의 추정오차가 다른 모형들의 추정오차보다 작았고, 예측치가 더 정확했다는 점에서 우수함을 알 수 있었다.

상태변수피이드백에 의한 선형다변수제어시스템의 분할식설계에 관한 연구 (The Decoupling And Design Of Linear Multivariable Control Systems By State Variable Feedback)

  • 황창선
    • 전기의세계
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    • 제23권2호
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    • pp.46-54
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    • 1974
  • The purposes of this paper are to deal with the design of m-input, m-output linear systems by the state variable feedback, and to extend the design capability of the state variable feedback design. The design requirements are decoupling and the exact realigation of desired transfer functions. Some methods are proposed to insert series compensators in the fixed plant in the cases when series compensators are needed to meet the input-output transfer matrix specification. The method for adding series compensators to the input channels of the fixed plant is shown by examples to lead both to the loss of the ability to decouple the augmented plant by the state variable feedback, and to the loss of desired zeroes. A method which avoids these two hazards is developed in which series compensators are put on the output channels of the fixed plant: it is proved that the augmented plant is F-invariant. By treating each subsystem individually, the designer can apply some of the previous developed knowledge of the state variable design of single-input, single-output systems.

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저소음 저배압을 위한 다중모드 지능제어 배기계에 관한 연구 -음향관 모델의 모델차수 결정방법- (The study on the multi-mode muffler by intelligent control for low noise and low backpressure)

  • 손동구;김흥섭;오재응
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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    • pp.142-147
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    • 1996
  • For prediction and control of sound, acoustic systems must be modeled. Because sound systems like exhaust systems are very difficult to calculate mathematically, this study presents a method to determine experimentally the order of poles by transfer function. When designing a control system by traditional methods the exact model order and coefficient of the system to be controlled must be determined. But in acoustic systems, where systems to be controlled are very complex, mathematical interpretation is almost always impossible. Therefore transversal filters using trial and error methods to determine model order of a system are used to design a system. Compared to mathematical models with poles, transversal filters, in which the model order becomes relatively large, have the disadvantage of prolonged processing time and marked time delay. This study presents a method to determine experimentally the order of poles in a system model with poles and zeroes. Also, the validity of this method was verified mathematically and confirmed by application in general simple models and acoustic tube simulators.

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FMCW 레이더용 타입-3 PLL의 설계 가이드 (A Design Guide to Type-3 PLLs for FMCW Radars)

  • 황인덕;김창환
    • 한국ITS학회 논문지
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    • 제11권4호
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    • pp.70-79
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    • 2012
  • FMCW 레이더에서 주파수 램프 신호를 발생시키기 위하여 필요한 타입-3 PLL의 설계 가이드를 제시하였다. 그러기 위해서 개루프 전달함수의 크로스오버 주파수를 1 Hz로 정규화 한 조건에서 Pspice 시뮬레이션을 통하여 폐루프 특성을 비교하였다. 결론적으로 타입-3 PLL의 1) 위상여유는 45도로 하고, 2) 두 개의 영점은 같도록 하며, 3) PLL 차수를 높이기 위한 극점은 개루프 전달함수의 크로스오버 주파수보다 10배 정도 크게 할 것을 권한다.

접지된 유전체층 위에 변하는 저항율을 갖는 저항띠 격자구조에서의 전자파산란 해석 -한쪽 모서리에서 0이고 다른쪽 모서리로 가면서 무한대로 변하는 경우- (Analysis of the Electromagnetic Scattering by a Resistive Strip Grating Tapered Resistivity On a Grounded Dielectric Plane -from Zeores at One Edge to Infinite at the Other Edge-)

  • 윤의중
    • 정보학연구
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    • 제8권2호
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    • pp.77-84
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    • 2005
  • In this paper, electromagnetic scattering problems by a resistive strip grating with tapered resistivity on a grounded dielectric plane according to strip width and spacing, relative permittivity and thickness of dielectric layers, and incident angles of a electric wave are analyzed by applying the Fourier-Galerkin Moment Method known as a numerical procedure. The boundary conditions are applied to obtain the unknown field coefficients and the resistive boundary condition is used for the relationship between the tangential electric field and the electric current density on the strip. The resistivity of resistive strips in this paper varies from zeroes at one edge to infinite at the other edge, then the induced surface current density on the resistive strip is expanded in a series of Jacobi polynomials of the order ${\alpha}=0.2,\;{\beta}=-0.2$ as a orthogonal polynomials. The numerical results of the geometrically normalized reflected power in this paper are compared with those for the existing perfectly conducting strip. The numerical results of the normalized reflected power for conductive strips case with zero resistivity in this paper show in good agreement with those of existing papers.

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Robust Active LED Driver with High Power Factor and Low Total Harmonic Distortion Compatible with a Rapid-Start Ballast

  • Park, Chang-Byung;Choi, Bo-Hwan;Cheon, Jun-Pil;Rim, Chun-Taek
    • Journal of Power Electronics
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    • 제14권2호
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    • pp.226-236
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    • 2014
  • A new active LED driver with high power factor (PF) and low total harmonic distortion (THD) compatible with a rapid-start ballast is proposed. An LC input filter is attached to the ballast to increase PF and reduce THD. A boost converter is then installed to regulate the LED current, where an unstable operating region has been newly identified. The unstable region is successfully stabilized by feedback control with two zeroes. The extremely high overall system of the 10th order is completely analyzed by the newly introduced phasor transformed circuits in static and dynamic analyses. Although a small DC capacitor is utilized, the flicker percentage of the LED is drastically mitigated to 1% by the fast controller. The proposed LED driver that employs a simple controller with a start-up circuit is verified by extensive experiments whose results are in good agreement with the design.