• Title/Summary/Keyword: Green's Functions

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Efficient Computation of the Impedance Matrices for Layered Medium Problems Using the Spline-type Divided-difference Interpolation Technique (스플라인형 분할차분 보간법을 이용한 다층구조 문제의 임피던스 행렬의 효율적 계산)

  • 강승택;최재훈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.2
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    • pp.257-266
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    • 1999
  • In this paper, a spline-type divided-difference interpolation technique is proposed to efficiently evaluate the impedance matrix elements in the MoM analysis of layered medium problems. This method is combined with the fast computational method of the basis-expanded and tested dyadic Green's functions (expressed in the spectral domain integrals) in a recent literature. For the sake of its validity, the proposed method is applied to analyze the characteristics of a microstrip gap discontinuity, a microstrip filter, and an aperture coupled patch antenna. Numerical results obtained by this approach are in good agreement with those of other approaches.

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Analysis of Electromagnetic Interference of a Parallel Plate with Apertures using the SDDI Technique (SDDI 기법을 이용하는 개구를 가지는 평행평판 구조의 전자파 간섭 해석)

  • 강승택;최재훈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.1
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    • pp.63-67
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    • 2000
  • In this paper, the electromagnetic interference of a parallel plate with apertures is characterized by the method of moment(MoM), using the Spline-type Divided-Difference Interpolation(SDDI) technique. Particularly, for the solution of the problem, the application of the SDDI technique is extended to the calculation of the summation-type Green's functions. It improves numerical efficiency, having accuracy and saving the overall computational time required in the MoM application. For validating the proposed method, the electric fields on the apertures are calculated and compared to those of the literature. The numerical results show good agreement with them.

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SOLUTIONS OF STURM-LIOUVILLE TYPE MULTI-POINT BOUNDARY VALUE PROBLEMS FOR HIGHER-ORDER DIFFERENTIAL EQUATIONS

  • Liu, Yuji
    • Journal of applied mathematics & informatics
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    • v.23 no.1_2
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    • pp.167-182
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    • 2007
  • The existence of solutions of the following multi-point boundary value problem $${x^{(n)}(t)=f(t,\;x(t),\;x'(t),{\cdots}, x^{(n-2)}(t))+r(t),\;0 is studied. Sufficient conditions for the existence of at least one solution of BVP(*) are established. It is of interest that the growth conditions imposed on f are allowed to be super-linear (the degrees of phases variables are allowed to be greater than 1 if it is a polynomial). The results are different from known ones since we don't apply the Green's functions of the corresponding problem and the method to obtain a priori bounds of solutions are different enough from known ones. Examples that can not be solved by known results are given to illustrate our theorems.

Visual Preference in Green Roof Sites (옥상 녹화지의 시각적 선호도)

  • Lee, Gwan-Gyu
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.5 s.118
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    • pp.32-38
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    • 2006
  • Roof greening in a city can contributes to not only providing network opportunities for dispersed greenspace patches but also bringing more greenspaces into a city. In addition, it can help to flooding and microclimate control in the city. Recently, a number of roof greening projects have been introduced, mainly to public buildings and schools. Roof peening need to offers both ecological functions and convenience and satisfaction for urban residents. This study aims to provide directions for improving ecological benefits and visual preference of roof greening. Twelve scene slides were adopted to measure people's visual preference. The survey results show that landscape images can be categorized into naturalness, visual diversity, uniqueness, and spatial flexibility. Physical scenes can be classified into type I mostly greened by plants, type II mixed between convenience facilities and plants, and type III constructed with pond. People show high preferences to type I and type II when visual diversity is high. The results of this study suggest to enhance the visual preference by considering visual diversity when applying the ecological design methods to improve naturalness for roof greening.

Successful replantation of an avulsed frontal scalp through microvascular anastomoses of only one artery and one vein: a case report

  • Dongjin Kim;Somin Oh;Woo Shik Jeong
    • Archives of Craniofacial Surgery
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    • v.25 no.2
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    • pp.95-98
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    • 2024
  • Scalp avulsion is a devastating injury. The best possible procedure is replantation. Several successful scalp replantations with anastomoses of several vessels in large defects have been reported. In this report, we present a case of replantation of a large scalp avulsion using revascularizing with only one artery and vein. Despite the initial signs of flap congestion, we could predict the survival of the replanted scalp and terminate the procedure after detecting good perfusion and washout with indocyanine green fluorescence imaging. The procedure was successful following the patient's recovery of sensory and sweating functions without complications such as flap necrosis or infection. Several important factors for successful scalp replantation with positive esthetic and functional outcomes were considered.

Determination of Optimal Unit Hydrographs and Infultration Rate Functions from Single Rainfall-Runoff Event (단순 강우-유출 사상으로부터 최적단위도와 침투율의 결정)

  • An, Tae-Jin;Ryu, Hui-Jeong;Jeong, Gwang-Geun;Sim, Myeong-Pil
    • Journal of Korea Water Resources Association
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    • v.33 no.3
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    • pp.365-374
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    • 2000
  • This paper is to present the determination of the optimal Joss rate parameters and urnt bydrographs from the observed single rainfall-runoff event using optimization models coupled with a stochastic technique for the global solution. Two kinds of the linear program models are formulated to derive the optimal unit hydrographs and loss rate parameters for gaged basins; one mimmizes the summation of the absolute residual between predlCted and observed runoff ordinates and the other, the maximum absolute residuaL Multistart algorithm which is one or stochastic techniques for the global optimum is adopted to perturb the parameters of the loss rate equations. Multistart efficiently searches the feasIble region to identify the global optimlUll for loss rate parameters, which yields the optimal loss rate parameters and unit hydrograph for Kostiakov's, Plulip's, and Horton's equation. The unique unit hydrograph ordinates for a gIven rainfall-runoff event iS exclusrvely obtained WIth $\Phi$ index, but unit hydrograph ordinates depend upon the parameters [or each loss rate equations. The parameters of Green-Ampt's are determined through a trial and error method. In this paper the single rainfall-nmoff event observed from a watershed is considered to test the proposed method. The optimal unit hydrograph herein found has smaller deviations than the ones reported previously by other researchers.

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An Expression Levels Analysis of the Bitter Taste Receptors in the Murine Exocrine Glands

  • Ki, Su-Young;Cho, Young-Kyung;Chung, Ki-Myung;Kim, Kyung-Nyun
    • International Journal of Oral Biology
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    • v.43 no.1
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    • pp.5-11
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    • 2018
  • Recent findings indicate that Type 2 taste receptors (T2Rs) are expressed outside the gustatory system, including in the gastrointestinal tracts and the exocrine glands, such as the submandibular (SM), parotid (P), lacrimal (L) glands and pancreas (PC). Specifically, T2Rs are found in some of the gastrointestinal endocrine cells, and these cells secreted peptide hormones in response to stimulation by bitter-tasting compounds. The results show that T2Rs may have significant physiological roles besides bitter taste reception. The functions of the T2Rs in the exocrine glands remain poorly understood. An expression levels analysis of T2Rs will help to determine those functions in the exocrine glands. The expression levels of the T2Rs in the exocrine glands were discovered via the qPCR. C57BL/6J mice of 42~60-day-old were used. Messenger RNAs were extracted from S, P, L and PC. Cloned DNAs were synthesized by reverse transcription. Quantitative PCRs were performed using the SYBR Green method. The expression levels of the T2Rs were calculated as relative expression levels to that of the GAPDH. The statistical significance among the observed exocrine glands was tested using the variance analysis (ANOVA test). Tas2r108, out of murine 35 T2Rs, was the most highly expressed in every observed exocrine gland. This finding was similar to previous results from tongue papillae, but the expression levels were lower than those of the tongue papillae. Tas2r137 of SM, P, L and PC were expressed a little lower than that of tongue papillae. The T2Rs in the exocrine glands may play slightly different roles from those in the tongue. We suggest that physiological studies such as a patch clamp and functional $Ca^{2+}$ imaging of acinar cells are necessary for understanding the Tas2r108 functions.

Color Arrangement Evaluation on Working Clothes for Safety and Integrated Environment Harmony in Machinery Industry Fields (기계 산업 분야의 통합 환경 조화와 안전을 위한 작업복 색채 배색 평가)

  • Park, Hyewon;Yang, Junghee
    • Journal of Fashion Business
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    • v.16 no.5
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    • pp.207-219
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    • 2012
  • It is intended to study the colors of work environment and the working clothes colors between humans and environment with application of the arrangement of working clothes colors to domestic machinery companies that play pivotal roles in the industry of Korea. The purpose of this study is to provide the foundation of color plan for the integrated environmental harmonization and the safety of industrial sites by analyzing the photographs of working clothes in the sires in consideration of the functions of colors (clearness, attention-getting, and safety) using the Faber Birren's Color Harmony and by analyzing the result of a questionnaire survey. The study was conducted by the method to shoot a worksite using a digital camera after wearing 24 sets of uniforms, which were developed by the color plan established in a previous study, in the same worksite. The shooting place was an outdoor steel sheet inspection site of D company, a machinery company in Changwon-si, Gyeongnam, and the intensity of illumination was 2400lux. 24 pieces of images were printed in 5x7 inch size and a questionnaire survey was performed at 5-point scale. The questionnaire survey was performed for 13 subjects consisting of 6 field professionals having more than 30 years of experiences, 4 clothes color professionals, and 3 industrial engineering professionals. The result of the survey was statistically analyzed by the method of frequency analysis using IBM SPSS Statistics 20 Program. As the result of assessment of basic four colors (yellow green, sky blue, blue, and violet) of working clothes, yellow green, sky blue, and blue showed high mean values in (Tint)+(Shade)+(Tone)+(Gray) equation indicating that its is a harmonized equation.

Surface wave Tomography of the Korean Peninsula by Noise Cross-correlation Method (잡음 상호상관 기법을 이용한 한반도의 표면파 토모그래피에 대한 연구)

  • Cho, Kwang-Hyun;Kang, Ik-Bum
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.133-136
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    • 2007
  • Cross correlation of seismic-background motions (Campillo and Paul, 2003; Shapiro et al., 2005) is applied to observations from the Korean Meteorological Administration seismic network to estimate the short-period Rayleigh and Love wave dispersion characteristics of the region. Standard processing procedures are applied to the cross correlation, except that signal whitening is used in place of one-bit sampling to equalize power in signals from different times. Multiple-filter analysis is used to extract the group velocities from the estimated Green's functions, which are then used to image the spatially varying dispersion at periods between 0.5 and 20 sec. The tomographic inversion technique used inverts all periods simultaneously to provide a smooth dispersion curve as a function of period in addition to the usual smooth spatial image for a given period. The Gyeongsang Basin in the southeastern part of the peninsula is clearly resolved with lower group velocities.

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IMAGING THE UPPER CRUST OF THE KOREAN PENINSULA BY SURFACE WAVE TOMOGRAPHY (표면파 토모그래피를 이용한 한반도 상부지각의 이미지)

  • Cho, Kwang-Hyun;Herrmann, Robert B.;Lee, Kie-Hwa
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.41-50
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    • 2006
  • The crustal structure of Korean Peninsula have been investigated by analyzing group velocity dispersion data of surface wave. Cross.correlation of seismic background motions (Campillo and Paul, 2003; Shapiro et al., 2005) has been applied to estimate the short.period Rayleigh. and Love.wave group velocity dispersion characteristics of the region. Standard processing procedures were applied to the cross.correlation, except that signal whitening was used in place of one.bit sampling equalize power in signals from different times. Multiple.filter analysis was used to extract the group velocities from the estimate Green's functions, which were then use to image the spatially varying dispersion at periods between 0.5 and 20 seconds. The tomographic inversion technique used inverted all periods simultaneously to provide a smooth dispersion curve as a function of period in addition to the usual smooth spatial image for a given period. The Gyeongsang Basin in the southeastern part of the peninsula is clearly resolved with lower group velocities.

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