• Title/Summary/Keyword: Green's Functions

Search Result 205, Processing Time 0.027 seconds

Spectral Domain Analysis of Resonant Frequency in Rectangular Microstrip Patch Antenna on Uniaxial Substrates with Airgap and Superstrate (공기 갭과 덮개층을 갖는 이방성 매질 위의 사각 마이크로스트립 패치 안테나 공진 주파수의 파수 영역 해석)

  • Lee, Sang-Mok;Yoon, Joong-Han;Kim, Heung-Soo
    • Journal of IKEEE
    • /
    • v.5 no.1 s.8
    • /
    • pp.91-99
    • /
    • 2001
  • Spectral domain of resonant frequency rectangular microstrip patch antenna on anisotropic substrates and superstrate with airgap are analyzed. First, we derive dyadic Green function for selected anisotropic material by constitutive relation and then formulate integral equations of electric fields using Fourier transform in space region. Using Galerkin's moment method, we discretize the electric field integral equations Into the matrix form and select sinusoidal functions as basis functions. We verify the validity of numerical results and compare the results with existing ones in showing a good agreement between them. The resonant frequencies in the variation of air gap, patch length and permittivity of superstrate anisotrpy ratio of anisotrpic superstrate are presented and analyzed.

  • PDF

Harmonic seismic waves response of 3D rigid surface foundation on layer soil

  • Messioud, Salah;Sbartai, Badredine;Dias, Daniel
    • Earthquakes and Structures
    • /
    • v.16 no.1
    • /
    • pp.109-118
    • /
    • 2019
  • This study, analyses the seismic response for a rigid massless square foundation resting on a viscoelastic soil layer limited by rigid bedrock. The foundation is subjected either to externally applied forces or to obliquely incident seismic body or surface harmonic seismic waves P, SV and SH. A 3-D frequency domain BEM formulation in conjunction with the thin layer method (TLM) is adapted here for the solution of elastodynamic problems and used for obtained the seismic response. The mathematical approach is based on the method of integral equations in the frequency domain using the formalism of Green's functions (Kausel and Peck 1982) for layered soil, the impedance functions are calculated by the compatibility condition. In this study, The key step is the characterization of the soil-foundation interaction with the input motion matrix. For each frequency the impedance matrix connects the applied forces to the resulting displacement, and the input motion matrix connects the displacement vector of the foundation to amplitudes of the free field motion. This approach has been applied to analyze the effect of soil-structure interaction on the seismic response of the foundation resting on a viscoelastic soil layer limited by rigid bedrock.

Determination of Optimal Unit Hydrographs and Infiltration Rate Functions at the site of the Su-Jik Bridge in the HwangGuJichen River (황구지천 수직교 지점에서의 최적 단위도 및 침투율의 결정)

  • Ahn, Taejin;Cho, Byung Doon;Lyu, Heui Jeong
    • Journal of Wetlands Research
    • /
    • v.7 no.3
    • /
    • pp.57-66
    • /
    • 2005
  • This paper is to present the determination of the optimal loss rate parameters and unit hydrographs from the observed single rainfall-runoff event using optimization model. The linear program models has been formulated to derive the optimal unit hydrographs and loss rate parameters for the site of the Su-Jik Bridge in the HwangGuJichen River; one minimizes the summation of the absolute residual between predicted and observed runoff ordinates. In the perturbation stage of parameters the trial and error method has been adopted to determine the loss rate parameters for Kostiakov's, Philip's, Horton's, and Green-Ampt's equation. The unique unit hydrograph ordinates for a given rainfall-runoff event is exclusively obtained with ${\Phi}$ index, but unit hydrograph ordinates depend upon the parameters for each loss rate equations. In this paper the single rainfall-runoff event observed from the sample watershed is considered to test the proposed method. The optimal unit hydrograph obtained by the optimization model has smaller deviations than the ones by the conventional method.

  • PDF

A Study on the Design Characteristic of Outdoor Spaces in the Apartment Complex - Focused on the Good Design Awarded Apartment Complex in the Past Decade - (국내 아파트 단지 외부공간의 디자인 특성 분석 - 최근 10년간 굿 디자인(Good Design) 수상 아파트 단지를 대상으로 -)

  • Jung, Hyun-Won;Oh, Jung-Ah
    • Korean Institute of Interior Design Journal
    • /
    • v.24 no.1
    • /
    • pp.160-168
    • /
    • 2015
  • The subject of this research is to analyze the design characteristics of outdoor spaces in Good Design awarded apartment complexes in the past decade. The results are as follows. First, the overall outdoor space design theme, one of the conceptual elements, is focused on both 'nature' and 'story of various subject' that are similar to each other. Second, the case study object with the visual openness, which is secured between apartment blocks, is shown frequently in case box-shaped apartment blocks are arranged in a row. However, in case of Y-shaped block arrangement, the visual openness secured within an apartment complex is considered more important. Third, according to the result of circulation/ inner path element, the most frequently appeared inner path form is a grid pattern with straight path emphasis. While apartment complexes with the parking lot on the ground are only 3 out of 18 cases, it with circulation path for vehicle on the ground level are over 61%. Fourthly, the design characteristic of social space of physical outdoor design appears to be 'central link facility type'. In this case, the central community facilities are more likely to be combined with various functions, such as green, water, and social connection. Fifthly, in case of natural space, most of the apartment cases are shown over 45% green area ratio with wide green and water space provision. Especially, the differentiation is to provide the space where can stimulate a resident's participation.

New UWB 1:2 Power Divider with Flat In-Band Splitting and Bandpass Filtering Functions

  • Duong, Thai Hoa;Kim, Ihn-Seok
    • Journal of electromagnetic engineering and science
    • /
    • v.10 no.1
    • /
    • pp.28-34
    • /
    • 2010
  • This paper introduces a new U.S. ultra-wideband(UWB: 3.1~10.6 GHz) 1:2 power divider based on a single section Wilkinson type configuration. The divider provides very flat in-band power splitting, high isolation, low insertion loss, sharp roll-off bandpass filtering, and DC blocking characteristics. The circuit consists of a $\lambda$/4 Y resonator, three capacitively coupled $\lambda$/2 short-circuited lines, and a resistor between the two output ports. The circuit structure was simulated with ADS and HFSS, and realized with low-temperature co-fired ceramic(LTCC) green tape, which has a dielectric constant of 7.8. $|S_{11}|$ better than 10 dB, $|S_{21}|$ and $|S_{31}|$ less than 3.2 dB, with both $|S_{22}|$ and $|S_{32}|$ measured as better than 12 dB for the whole UWB band. Measurement results agree closely with HFSS simulation results. The power divider has a compact size of $4\times9\times0.6mm^3$.

Quantum Transport Simulations of CNTFETs: Performance Assessment and Comparison Study with GNRFETs

  • Wang, Wei;Wang, Huan;Wang, Xueying;Li, Na;Zhu, Changru;Xiao, Guangran;Yang, Xiao;Zhang, Lu;Zhang, Ting
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.14 no.5
    • /
    • pp.615-624
    • /
    • 2014
  • In this paper, we explore the electrical properties and high-frequency performance of carbon nanotube field-effect transistors (CNTFETs), based on the non-equilibrium Green's functions (NEGF) solved self - consistently with Poisson's equations. The calculated results show that CNTFETs exhibit superior performance compared with graphene nanoribbon field-effect transistors (GNRFETs), such as better control ability of the gate on the channel, higher drive current with lower subthreshold leakage current, and lower subthreshold-swing (SS). Due to larger band-structure-limited velocity in CNTFETs, ballistic CNTFETs present better high-frequency performance limit than that of Si MOSFETs. The parameter effects of CNTFETs are also investigated. In addition, to enhance the immunity against short - channel effects (SCE), hetero - material - gate CNTFETs (HMG-CNTFETs) have been proposed, and we present a detailed numerical simulation to analyze the performances of scaling down, and conclude that HMG-CNTFETs can meet the ITRS'10 requirements better than CNTs.

A Study on Symbolism of Man's Neckwear (남성용 네트웨어에 나타난 상징성)

  • 유태순
    • Journal of the Korean Society of Costume
    • /
    • v.31
    • /
    • pp.203-214
    • /
    • 1997
  • The neck is the human body is closely con-nected with the life and properties of keeping warm as one of the opening part in clothes. In ancient times it was put on necklace for the protection of neck and in Rome it was worn muffler called focale for the protection of neck throat. in addition cravat directly originated in necktie today was primarily worn for the protection of soldier's neck and has been turned into decorative purpose until today. As the ornament is developed to vari-ous kinds of form the neck decoration is changed and grown again and again. Therefore this thesis studies history of the neckwear and various the symbolic factor. The first factor is the social. The neckwear shows the social position class and status and does social mutual interaction as conversation starters. The second factor is the mental It express individuality fondness attitude and is felt to be indignity by being forced to be worn. The third factor is the political. it shows political tendency by indicating the royal sign or part's sign in necktie like the French royal-ist's green muffler The forth factor is the man's sexual. I expresses wearing stock being brave symbol-izing independence. The sixth factor is the traditional. It is worn with appearing traditionand custom and one of cultural movements. The seventh factor is the ideological. It symbolizes the freedom of suffragettes and emancipation of woman. The social factor is the most extensive among them. The neckwear is various in the way of expression like its kinds and is generalized, It functions as a independent part of clothes.

  • PDF

The Conditions of Tourist Attractions and Its Planning Directions in Rural Villages Based on City-dweller's Preferences (도시민의 선호를 바탕으로 한 농촌마을의 관광자원 실태와 정비방향)

  • Jeon, Yeong-Mi;Im, Sang-Bong;Han, Kyung-Soo;Park, Yoon-Ho;Jang, Eun-Sook;Kim, Bum-Soo
    • Journal of Korean Society of Rural Planning
    • /
    • v.9 no.1 s.18
    • /
    • pp.55-64
    • /
    • 2003
  • The objective of the study is to suggest planning directions for practical use and to find the conditions of tourist attractions in rural villages founded on city-dweller's preference. Both a questionnaire and a field survey were used for the study. Selected were four villages such as Oryan-ri, gachun-ri, Junggi-ri, and Gyochon-ri. The results of the study are as follows: City-dweller's valued on natural environment resources in rural tourism and felt uncomfortable to accommodations. The scoring system reflecting functions of six resources showed that common problems encountered in rural tourism were lacks of people's organization, and human exchange mind, and tourism-related leasure places and facilities. Based upon the results, some measures to develop villages were suggested.

Planting Improvement and Contribution to Greenspace Function by Use of Roadside Buffer Greens;In the Case of Songpadearo and Nambusunwhanno in Songpa-gu, Seoul (도심 도로변 완충녹지의 주변 토지이용을 고려한 녹지기능 재설정 및 식재방안;서울시 송파구 송파대로, 남부순환로틀 대상으로)

  • Kim, Yeong-Yong;Lee, Kyong-Jae;Choi, Jin-Woo;Han, Bong-Ho
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.36 no.3
    • /
    • pp.39-51
    • /
    • 2008
  • This study focuses on the reconstruction of buffer greens which were installed to reduce environmental effects on roadsides constructed in the 1980s, in order to supplement various urban green functions. The subjects were buffer greens installed along the Songpadaero and Nambusunwhanro in Songpa-gu. Planting was suggesting to strengthen the buffer, landscape, shading and ecological function according to the use of the buffer green surroundings. The surroundings of the green axis subjects are high-rise apartment areas, neighboring commercial areas, commercial working areas, transportation facility areas, urban support facility areas, schools, parks, etc. However, the structure of the buffer greens were uniformed with Plantanus occidentalis and Ginkgo biloba and Zelkova serrata in the canopy layer and with Forsythia koreana and Ligustrum obtusifoliumin the shrub layer in lineal or alternate order, functioning only as buffer space. Therefore, the buffer greens need to be reconstructed, supplementing various functions according to land use, in order to improve the pedestrian walk area in terms of landscape and use of greens. In line with that, the planting improvement plans according to the land use patterns, and physical and ecological structure were classified into buffer and landscape, landscape and buffer, buffer and shading, and buffer and ecological function. In addition, improving planting function, species and facilities are suggested.

Health Educational Program for Women's Health in Women's Health Care Center (여성건강교육 프로그램 개발에 관한 연구 - 여성건강간호센터에서의 교육을 중심으로 -)

  • Lee, Eun-Hee;Choi, Sang-Soon;So, Ae-Young
    • Women's Health Nursing
    • /
    • v.6 no.1
    • /
    • pp.67-81
    • /
    • 2000
  • The purpose of this study was to analyze women's health problems using Green & Kreuter's(1991) PRECEDE model and to develop health education program for women's health. The subjects were recruited women from Wonju city 18 years or older. 1. The results showed that about 50% of the women were satisfied with their lives as women, 23% of the sample felt there was a need for a women's health care center. The mean number of health problems was 3.1 and the prevalence rate, 44.4%. 2. We developed on educational program according to group differences related to health problems, diagnosis of disease, variables influencing health promotion behavior, and programs which each group wanted. Also we stressed self-efficacy and self-help group for the management of individual health to all groups. 3. The diagnoses of diseases that were experienced premarital over the past year were gastritis, bronchitis, spinal disk, and fracture, for the childbearing/rearing group, gastritis, vaginitis and cervicitis, cervical cancer and cystitis and nephritis and arthritis and for the middle-aged/elderly group arthritis, gastritis, vaginitis and cervicitis, and spinal disk. Of the sample 30.5% did not have a health exam in the past year, and only 10% of the premarital group, 12.5% of the childbearing/child-rearing group, and 18.3% of the middle aged-elderly group were concerned about their health and did something for their health. 4. The average score on the HPLP was 2.41. the HPLP was scores according to group were found to have significant differences. self-efficacy, family functions, health attention and were considered important variables in the premarital group, in the childbearing/child-rearing group self-efficacy, family functions, internal locus of control, health attention, and health perception and power others locus of control and then for the middle aged-elderly group self-efficacy, health attention, internal locus of control, family functions and health perception. 5. There are a few educational programs in the city provided by the Wonju Health Center and by community health nurse practitioners. The premarital group requested the educational programs on diet, health exercise, family health and stress management. Also the childbearing/child-rearing group wanted programs on diet, family health, stress management, and health exercise, and the middle-aged/elderly group wanted that of family health, diet, climacteric changes stress management and health exercise. The program suggested that this program should be applied to women in the community to insure adequate management of women's health. Follow-up research with PROCEED is needed to analyze health outcomes, also, a women's health nursing specialist system is required to develop health promotion, and improve the quality of life for women.

  • PDF