• Title/Summary/Keyword: Green's method

Search Result 1,065, Processing Time 0.03 seconds

An Accurate Closed-form Green's Function for the Planar Structure with General Sources (일반적인 전원을 포함하는 평판구조에 대한 정확한 Closed-form 그린함수)

  • Kang Yeon-Duk;Lee Taek-Kyung
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.41 no.6 s.324
    • /
    • pp.79-86
    • /
    • 2004
  • In the integration of Sommerfeld type for space domain Green's function, a accurate closed-from Green's function method provides more exact solution than the typical complex image method and two-level method. The accurate closed-form Green's function method is applied to obtain the space domain Green's functions of planar structures with general sources. Please put the abstract of paper here.

On a Symbolic Method for Fully Inhomogeneous Boundary Value Problems

  • Thota, Srinivasarao
    • Kyungpook Mathematical Journal
    • /
    • v.59 no.1
    • /
    • pp.13-22
    • /
    • 2019
  • This paper presents a symbolic method for solving a boundary value problem with inhomogeneous Stieltjes boundary conditions over integro-differential algebras. The proposed symbolic method includes computing the Green's operator as well as the Green's function of the given problem. Examples are presented to illustrate the proposed symbolic method.

Approximate Method of Multi-Layer Green's Function Using FDTD Scheme and Rational Function Approximation (FDTD 방법과 분수 함수 근사법을 이용한 다층 구조에서의 Green 함수 근사화)

  • Kim, Yong-June;Koh, Il-Suek;Lee, Yong-Shik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.22 no.2
    • /
    • pp.191-198
    • /
    • 2011
  • In this paper, a method to approximate a multi-layer Green's function is proposed based on a FDTD scheme and a rational function approximation. For a given horizontal propagation wavenumber, time domain response is calculated and then Fourier transformed to the spectral domain Green's function. Using the rational function approximation, the pole and residue of the Green's function can be estimated, which are crucial for a calculation of a path loss. The proposed method can provide a wideband Green's function, while the conventional normal mode method can be applied to a single frequency problem. To validate the proposed method, We consider two problems, one of which has a analytical solution. The other is about multi-layer case, for which the proposed method is compared with the known normal mode solution, Kraken.

Analysis of Waveguid Filter Using Green′s Absorbing Layer in three Dimension TLM Method (3차원 TLM 법에서 그린 흡수층을 이용한 도파관 필터의 해석)

  • 김병수;전계석
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.5 no.5
    • /
    • pp.1001-1010
    • /
    • 2001
  • In TLM method, Discrete Green's function ABC have been used when improved the exactness of analyzing in wide frequency band. But this technology has a complicated process to apply absorbing boundary, which means it needs additional numerical analyzing process to obtain discrete Green's function data. so, In this paper, we propose new Green's absorbing layer for simple process to apply absorbing boundary. newly proposed Green's absorbing layer is produced by applying of loss operation, loading discrete Green's function with attenuation. A state of optimum absorbing would be obtained by relation between increasing rate of loss, attenuation constant and length of green's absorbing layer. and then Analysts of waveguide BPF is carried out using Green's absorbing layer within state of optimum absorbing, then this result is in corrective agreement with the result applying traditional discrete Green's function ABC.

  • PDF

A Study on the Microbial Quality Control of Chicken Meat Salad by Adding Green Tea Extracts in Foodservice Operations (급식소에서 생산되는 닭고기 샐러드의 녹차추출물 첨가에 따른 미생물적 품질 평가)

  • Kim, Heh-Young;Ko, Sung-Hee
    • Journal of the Korean Society of Food Culture
    • /
    • v.20 no.6
    • /
    • pp.675-682
    • /
    • 2005
  • This study was aimed to determine microbiological quality by adding green tea extracts to chicken meat salad. For this study, Chicken meat salad were prepared with two production method. (method 1: addition of green tea extracts to boiling phase, method 2: addition of green tea extracts to salad dressing) Microbiological effects of green tea extracts were assessed during production process by measuring process time, temperature, pH and Aw and determining total plate counts and coliforms. Effects of green tea extracts on total plate counts and coliforms were observed during holding at 3, 10, $25{\pm}1^{\circ}C$ for 12 hours. Green tea extracts improved the microbiological quality and showed antibacterial properties when they are added to chicken meat salad.

Prediction of Sound Field Inside Duct with Moving Medium by using one Dimensional Green's function (평균 유동을 고려한 1차원 그린 함수를 이용한 덕트 내부의 음장 예측 방법)

  • Jeon, Jong-Hoon;Kim, Yang-Hann
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.11a
    • /
    • pp.915-918
    • /
    • 2005
  • Acoustic holography uses Kirchhoff·Helmholtz integral equation and Green's function which satisfies Dirichlet boundary condition Applications of acoustic holography have been taken to the sound field neglecting the effect of flow. The uniform flow, however, changes sound field and the governing equation, Green's function and so on. Thus the conventional method of acoustic holography should be changed. In this research, one possibility to apply acoustic holography to the sound field with uniform flow is introduced through checking for the plane wave in a duct. Change of Green's function due to uniform flow and one method to derive modified form of Kirchhoff·Heimholtz integral is suggested for 1-dimensional sound field. Derivation results show that using Green's function satisfying Dirichlet boundary condition, we can predict sound pressure in a duct using boundary value.

  • PDF

Steady Stokes flow analysis using Axial Green's Function Formulation (축그린함수법을 이용한 정상상태의 스톡스유동해석)

  • Kim, D.W.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.256-258
    • /
    • 2011
  • Using the axial Green's function method for Steady Stokes flows, we introduce a new pressure correction formula to satisfy the incompressibility condition, in which the pressure is related to the integral of the second order derivatives of the velocity. Based on this formula, we propose the iterative method for solving the Stokes flows in complicated domains. Even if the domain is complex, this method maintains the second order of convergence for the velocity.

  • PDF

Singularity-Circumvented Computation of Green's Functions for 2D Periodic Structures in Homogeneous Medium

  • Kahng, Sung-Tek
    • Journal of electromagnetic engineering and science
    • /
    • v.7 no.2
    • /
    • pp.59-63
    • /
    • 2007
  • This paper suggests a novel method to efficiently calculate the spatial-domain Green's functions of 2D electromagnetic problems Briefly speaking, this method combines spectral and spatial domain calculation schemes and prevents the Green's functions from poor convergence due to the singularities that complicate the process of the Method of Moment(MoM) applications For the validation of this proposed method, fields will be evaluated along the spatial distance including zero distance for 2D free-space and periodic homogeneous geometry The numerical results show the validity of the prosed method and correspondng physics.

Quantitative analysis of oral disease-causing bacteria in saliva among bacterial culture, SYBRgreen qPCR and MRT-PCR method (타액내 구강질환 원인 균의 세균배양법, SYBR green qPCR법, MRT-PCR법 간의 정량분석)

  • Park, Yong-Duk;Oh, Hye-Young;Park, Bok-Ri;Cho, Ara;Kim, Dong-Kie;Jang, Jong-Hwa
    • Journal of Korean society of Dental Hygiene
    • /
    • v.17 no.2
    • /
    • pp.319-330
    • /
    • 2017
  • Objectives: The purpose of this study was to compare SYBR Green qPCR, TaqMan, and bacterial selective medium cultures for accurate quantitative analysis of oral microorganisms. Methods: The SYBR Green method is widely used to analyze the total amount of oral microorganisms in oral saliva. However, in this study, MTR-PCR method based on TaqMan method was performed using newly developed primers and probes. In addition, it was designed to confirm the detection agreement of bacteria among bacteria detection method. Results: As a result of MRT-PCR and SYBR Green qPCR analysis, more than 40 times (0.9-362.9 times) bacterium was detected by MRT-PCR. In addition, more bacteria were detected in saliva in the order of MRT-PCR, SYBR Green qPCR, and bacterium culture, and the results of MRB-PCR and SYBR Green qPCR showed the highest agreement. The agreement between the three methods for detecting P. intermedia was similar between 71.4 and 88.6%, but the agreement between MRT-PCR and SYBR Green qPCR was 80% for S. mutans. Among them, the number of total bacteria, P. intermedia and S. mutans bacteria in saliva was higher than that of SYBR Green qPCR method, and bacterium culture method by MRT-PCR method. P. intermedia and S. mutans in saliva were detected by MRT-PCR and MRT-PCR in 88.6% of cases, followed by the SYBR Green qPCR method (80.0%). Conclusions: The SYBR Green qPCR method is the same molecular biology method, but it can not analyze the germs at the same time. Bacterial culturing takes a lot of time if there is no selective culture medium. Therefore, the MRT-PCR method using newly developed primers and probes is considered to be the best method.

Site-Specific Ground Motions based on Empirical Green`s Function modified for the Path Effects in Layered Media (층상구조에서 지진파 전파경로를 고려하여 수정된 경험 Green 함수를 이용한 지반운동 모사)

  • 조남대;박창업
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 2001.09a
    • /
    • pp.19-27
    • /
    • 2001
  • Seismic parameters fur computation of ground motions in Southern Korea are obtained from recently recorded data, and site-independent regional and site-dependent local strong ground motions are predicted using efficient computational techniques. For the computation of ground motions, we devised an efficient procedure to compute site-independent $x_{q}$ and dependent $x_{s}$ values separately. The first step of this procedure is to use the coda normalization method far computation of site independent Q or corresponding $x_{q}$ value. The next step is the computation of $x_{s}$, values fur each site separately using the given $x_{q}$ value. For computation of ground motions the empirical Green's function (EGF) is modified to account fur the depth and distance variations of subevents on a finite fault plane using the theoritical Green's function. It is computed using wavenumber integration technique in layered media. The site dependent ground motions at seismic stations in southeastern local area were properly simulated using the modified empirical Green's function method in layered medium. The proposed method and procedures fur estimation of site dependent seismic parameters and ground motions could be efficiently used in the low and moderate seismicity regions.ons.s.ons.

  • PDF