• Title/Summary/Keyword: Green's function

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Nonlinear Localized Modes in Photonic Crystals

  • Park, Q-Han
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.96-99
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    • 2002
  • We give a brief overview of nonlinear localized modes in photonic crystals. We explain how photonic crystals can potentially be important in making small scale active devices which operate in an all optical way. Two models to approach nonlinear photonic crystals, the coupled mode theory and the discrete lattice theory using a Green's function, are explained.

An Introduction of Park-Based Mixed Use District around Urban Large Parks and Green Spaces - With Special Reference to the Application of Landscape Urbanism to Mixed-Use Development -

  • Cho, Se-Hwan;Lee, Jeung-Eun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.5_2
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    • pp.135-143
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    • 2010
  • The 21st century is currently undergoing an era of urban regeneration. The purpose of this research is to secure and expand the green infrastructure with zoning regulation in the context of urban regeneration. This objective also seeks a way of urban regeneration through the use of existing large parks by employing park-based mixed use districts around the periphery of large urban parks and green spaces. This research examines the limits, problems of existing single- and mixed-use zoning districts for securing of green infrastructure by book review. This research finally advocates introducing a another type of urban mixed-use districts, namely park-based mixed use district and its characteristics and functions, by using landscape ecology and landscape urbanism as a theoretical basis. The results of this research suggested that large parks and green spaces should be considered as one of patch in landscape ecology. This research also discusses the possibility that, as patches have ecotones with greater biodiversity in the peripheral areas of it, the green infrastructure can be constructed around the periphery of large urban large parks and green spaces by introducing cultural ecotone of nature's convergence with the city. As a result, the green infrastructure and high density of land use and using behaviour can be increased. Park-based mixed use districts encourage the convergence of parks and the city, with the park being used as the main function; residential, commercial, business and cultural uses etc. are partial functions. In order for the park-based mixed use districts to be designated, the size of large urban parks and green spaces, as well as location, city function and condition of the peripheral areas all need to be considered. The necessity to examine the designated width of the park-based mixed use districts and the form of the peripheral area was also discussed. This research, which is based on investigative research results, suggests that further in-depth and comprehensive analysis of the actual condition of urban large parks and peripheral areas needs to be completed. Specialists and other interested parties, analysis and investigation on related plans and designs are also needed for the institutional practice.

A Study on the Application of Criteria of the Indoor Environment through the Case of Green Building Certification Criteria for School (사례분석을 통한 학교건축 친환경 인증기준의 실내환경 평가항목 적용현황에 관한 연구)

  • Eun, So-jin;Lee, Jong-kuk
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.9 no.1
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    • pp.23-31
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    • 2010
  • Recently, there are effects such as commercial investment and introducing new technology by introducing a BTL project. As a result, School's conditions are getting better and Numbers of certified schools are increasing, because the Green Building Certification Criteria was created in 2002 and expanded to schools in March, 2005. But the certificated schools just get the minimum score for certificate level 'good' about 65 points and there is no certificated school level 'very good'. The users of school stay in long time in the facility cause of the unique function of school. It means Indoor Environment Quality Criterion of the school is very important than any other criteria. Therefore, this study aims to analyze the indoor environment factor for the plan of the certificated school by green building rating systems. And this study also wants make the basement of a substantial technical application and development of the criteria in the plan for sustainable green school.

Relationships Between Ecological and Utilizational Effectiveness of Green Roof Sites (옥상녹화지의 생태적 효과와 이용 효과의 상관성)

  • Kim, Hyun;Lee, Gwan-Gyu
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.2
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    • pp.114-122
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    • 2008
  • Roof greening recently emerged to be an important issue of environmental policies in a city. To cover roofs of buildings with green vegetation gives chances not only to improve urban environmental function but also provides the opportunities of environmental learning and convenience for users in the building. This study aimed to give directions for roof greening plan to designers by acknowledging the relationships between ecological and utilizational effectiveness. 10 sites and 15 variables were adopted to measure the relationships. As a result, no positive correlations was found between them. One of the results in correlation analysis among variables, however, showed that the roof gardens have high utilizational effectiveness only when a green roof was made by focusing on ecological functions in addition to the concepts that will guarantee user's convenience such as accessibility, entrance and exit, facilities for convenience and learning. The results implies that a green roof has to be designed considering multi-functional effects. Correlation between species of vegetation and the number of daily users, average staying hours, and attending level for environment educational programs were not significant. These findings imply that when a green roof has to be take high utilizational effectiveness, both plentiful vegetation species and design concepts for users' convenience are should be considered.

Vibration mitigation of composite laminated satellite solar panels using distributed piezoelectric patches

  • Foda, M.A.;Alsaif, K.A.
    • Smart Structures and Systems
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    • v.10 no.2
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    • pp.111-130
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    • 2012
  • Satellites with flexible lightweight solar panels are sensitive to vibration that is caused by internal actuators such as reaction or momentum wheels which are used to control the attitude of the satellite. Any infinitesimal amount of unbalance in the reaction wheels rotors will impose a harmonic excitation which may interact with the solar panels structure. Therefore, quenching the solar panel's vibration is of a practical importance. In the present work, the panels are modeled as laminated composite beam using first-order shear deformation laminated plate theory which accounts for rotational inertia as well as shear deformation effects. The vibration suppression is achieved by bonding patches of piezoelectric material with suitable dimensions at selected locations along the panel. These patches are actuated by driving control voltages. The governing equations for the system are formulated and the dynamic Green's functions are used to present an exact yet simple solution for the problem. A guide lines is proposed for determining the values of the driving voltage in order to suppress the induced vibration.

The Recognition of Commercial Business Men and Employers and Pedestrian on the Existence Effect of Roadside Green Spaces in Local City - Chungju City to - (지방도시 가로 녹지의 존재효과에 대한 보행자와 상업종사자의 의식 연구 - 충주시 가로수를 대상으로 -)

  • Kim, Bum-Soo;Shin, Won-Sop
    • Journal of Environmental Science International
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    • v.16 no.2
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    • pp.159-169
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    • 2007
  • The overall purpose of this study was to investigate pedestrians and commercial business men and employers' recognition on management of street trees and green spaces along street sides. The followings were main results of this study. Both pedestrians and commercial business men and employers mostly perceived positive influence of street trees on urban environment and their business. In addition, pedestrians gave higher scores of positive influence of trees function than those of commercial business men and employers. Pedestrians showed strong intention to participate management activities of street trees or green spaces. This study indicated that negative perception on street trees came from improper management rather than existence of street trees. Therefore, more intensive management actions are needed.

On the Improved Green Integral Equation applied to the Water-wave Radiation-Diffraction Problem

  • Do-Chun,Hong
    • Bulletin of the Society of Naval Architects of Korea
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    • v.24 no.1
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    • pp.1-8
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    • 1987
  • It is shown that irregular frequencies in the source and doublet distribution method, can be eliminated if the Green function associated with Kelvin's source of pulsating strength, is modified only in the region inside the body at the level of the undisturbed free surface. The system of the resulting Green integral equation is augmented without loss of the square-integrable property of its kernel so hat the discretisation yield N linearly independent equations for N unknown variables. From the solution, the potential and velocity at any point on the wetted surface of a surface-piercing body can be found using the properties of the double layer composed of the source and normal doublet distribution.

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In Vitro Combinatorial Mutagenesis of the 65th and 222nd Positions of the Green Fluorescent Protein of Aequarea victoria

  • Nakano, Hideo;Okumura, Reiko;Goto, Chinatsu;Yamane, Tsuneo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.5
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    • pp.311-315
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    • 2002
  • By the in vitro combinatorial mutagenesis, which is a sequential reaction of PCR mutagenesis and in vitro coupled transcription/translation with Escherichia coli S30 extract, S65 and E222 of green fluorescent protein of Aequarea victoria were comprehensively changed to all possible combinations of amino acids, thus totally 400 mutant (including a wild type) proteins were simultaneously produced and their fluorescent properties were analyzed. Although a few mutations had been reported so far at the 222nd position, replacement E222 to all other19 amino acids gave fluorescent signal to the mutants by changing Ser 65 to Ala together. Among the mutants, replacement to G, A, S, Q, H and C gave relatively high fluorescence. The in vitro combinatorial mutagenesis, therefore, has been proved valuable for comprehensive structure-function studies of proteins.

Development of Green's Functions for Fatigue Damage Evaluation of CANDU Reactor Coolant System Components (CANDU형 원전 주요기기의 피로손상 평가를 위한 그린함수 개발)

  • Kim, Se Chang;Sung, Hee Dong;Choi, Jae Boong;Kim, Hong Key;Song, Myung Ho;Nho, Seung Hwan
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.7 no.4
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    • pp.38-43
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    • 2011
  • For the efficient and safe operation of nuclear power plant, evaluating quantitatively aging phenomenon of major components is necessary. Especially, typical aging parameters such as stresses and cumulative usage factors should be determined accurately to manage the lifetime of the plant facility. The 3-D finite element(FE) model is generated to calculate the aging parameters. Mechanical and thermal transfer functions called Green's functions are developed for the FE model with standard step input. The stress results estimated from transfer functions are verified by comparing with 3-D FE analyses results. Lastly, we suggest an effective fatigue evaluation methodology by using the transfer functions. The usefulness of the proposed fatigue evaluation methodology can be maximized by combining it with an on-line monitoring system.