• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.241-248
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• 2004

In general, the salient features if the floating breakwater have excellent regulation of sea-water keeping the marine a1ways clean, up and dorm free movement with the incoming and outgoing tides, capable of being installed without considering the geological condition of sea-bed at any water depth, This study discusses the three dimensional wave transformation of the floating breakwater moored by catenary. Numerical method is based at the Green function method and eigenfunction expansion method. The validity of the present is confirmed by comparing it with the result of Ijima et a1.(1975) fer tensile maxed floating breakwater. According to the numerical results, drift and width of the floating breakwater affect at the wave transformation greatly, and incident wave of long period is well transmitted to the rear of the floating breakwater.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.201-207
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• 2010

본 논문에서는 대규모 공공관리시스템에 그린IT 개념을 적용한 성능개선을 제안, 개발, 구현하여 관리, 비용, 인력 분야에 대하여 탁월한 성과를 도출하였다. 현재 운영 중인 시스템에 대하여 공공기관의 사용자들이 제시한 성능개선 사항을 분석하여 절감효과를 유발할 수 있는 리소스 중에서 그린IT 개념이 적용 가능한 항목을 선정하여 개선방안을 제시하고 시험운영을 거쳐 실제 시스템에 적용하는 절차로 구현하였다. 대규모 공공관리시스템으로는 국가자격 관리시스템을 대상으로 하여 기존의 개인별 시험용 저장장치를 보안처리를 강화한 온라인 처리과정으로 전환하여 비용 및 인력절감 효과와 관리상의 효율성을 확보하였다. 기존 운영시스템과 비교하여 볼 때 운영인력, 장애처리, 유지보수, 관리비용에서 2배에서 최대 12배의 효율성이 도출되었으며 년 간 최대 500만개의 개인 배포용 저장장치를 절감하였다.

• 대한기계학회논문집A
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• 제26권4호
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• pp.775-786
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• 2002

A Mixed Volume and Boundary Integral Equation Method is applied for the effective analysis of elastic wave scattering problems and plane elastostatic problems in unbounded solids containing general anisotropic inclusions and voids or isotropic inclusions. It should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of anisotropic inclusions and voids or isotropic inclusions. In the formulation of this method, the continuity condition at each interface is automatically satisfied, and in contrast to finite element methods, where the full domain needs to be discretized, this method requires discretization of the inclusions only. Finally, this method takes full advantage of the pre- and post-processing capabilities developed in FEM and BIEM. Through the analysis of plane elastostatic problems in unbounded isotropic matrix with orthotropic inclusions and voids or isotropic inclusions, and the analysis of plane wave scattering problems in unbounded isotropic matrix with isotropic inclusions and voids, it will be established that this new method is very accurate and effective for solving plane wave scattering problems and plane elastic problems in unbounded solids containing general anisotropic inclusions and voids/cracks or isotropic inclusions.

• 통상정보연구
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• 제14권4호
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• pp.89-107
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• 2012

최근 녹색기후기금 (GCF, Green Climate Fund) 사무국의 한국유치를 계기로 기존에 한국이 주도해 설립한 글로벌녹색성장센터 (GGGI)와 녹색기술센터 (GTC)와 더불어 한국은 글로벌 녹색성장을 선도하는 전 세계 녹색성장의 허브로 자리매김하게 되었다. 그러나 이와 같은 선진경제로의 도약을 위해서는 무엇보다 한국경제가 모범적인 녹색성장의 정책 추진이 필수적이라 할 것이다. 이는 최근 이산화탄소배출량의 성장률에 있어 중국에 이어 세계 2위의 불명예스런 한국의 입장에서 더욱 절실히 요구되는 상황이라 하겠다. 특히 이와 같은 녹색성장의 지속적인 경쟁력 우위를 주도하기 위해서는 무엇보다 낙후된 한국의 물류산업에 대한 전면적인 개편이 필요하다고 할 것이다. 이는 운송산업이 전세계 이산화탄소배출량의 21%정도를 차지하는 가장 전략적으로 중요하면서도 취약한 분야이기 때문이다. 이에 따라 물류 및 운송산업에 대해 녹색 생산성을 실증분석하고 이에 기초한 전략적 대안을 제시하는 것은 한국의 통상정책의 가장 중요하고도 의미가 있는 연구라 할 것이다. 이를 위해 본 연구는 기존의 전통적 생산성개념에 환경오염변수를 고려한 방향적 거리함수(directional distance function)와 Malmquist 지수 (ML지수) 가운데에서도 가장 최근에 새롭게 제시된 총체적 ML지수 (Global Malmquist-Luenberger Index, GML) 연구 모형을 기초로 환경 보호와 경제개발을 조화롭게 추진하기 위한 녹색생산성의 실질적인 정책 방향의 패러다임을 제시하고 있다.

• Journal of applied mathematics & informatics
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• 제30권5_6호
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• pp.773-785
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• 2012

In this paper, we establish sufficient conditions for the existence and uniqueness of solutions to a general class of three-point boundary value problems for a coupled system of nonlinear fractional differential equations. The differential operator is taken in the Caputo fractional derivatives. By using Green's function, we transform the derivative systems into equivalent integral systems. The existence is based on Schauder fixed point theorem and contraction mapping principle. Finally, some examples are given to show the applicability of our results.

• 대한기계학회논문집A
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• 제36권6호
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• pp.665-672
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• 2012

면외 기계적 하중 및 면내 전기적 하중하의 횡등방성 이종 압전재료에 대한 계면균열문제를 해석하였다. 복소함수를 도입하여 문제를 수식화 하고, 이로부터 Hilbert 문제를 구성하였다. Hilbert 문제를 풀므로써, 일반해를 얻었다. 일반해를 사용하여, 반무한 균열 혹은 한 개 유한균열 및 두 개 유한균열에 대한 폐형 해를 각각 구하였다. 이때 하중은 한 개의 집중 기계하중 및 전기적하중이 균열면에 작용한다. 이 문제는 기하조건만 동일하면, 임의의 하중에 대해서도 해를 얻을 수 있는 Green 함수로서 사용될 수 있다.

• Journal of Mechanical Science and Technology
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• 제20권5호
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• pp.658-667
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• 2006

Fractional derivative models, which are used to describe the viscoelastic behavior of material, have received considerable attention. Thus it is necessary to put forward the analysis solutions of dynamic systems containing a fractional derivative. Although previously reported such kind of fractional calculus-based constitutive models, it only handles the particularity of rational number in part, has great limitation by reason of only handling with particular rational number field. Simultaneously, the former study has great unreliability by reason of using the complementary error function which can't ensure uniform real number. In this paper, a new approach is proposed for an analytical scheme for dynamic system of a spring-mass-damper system of single-degree of freedom under general forcing conditions, whose damping is described by a fractional derivative of the order $0<{\alpha}<1$ which can be both irrational number and rational number. The new approach combines the fractional Green's function and Laplace transform of fractional derivative. Analytical examples of dynamic system under general forcing conditions obtained by means of this approach verify the feasibility very well with much higher reliability and universality.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.78-83
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• 2003

General algorithm is developed for the prediction of internal flow-induced noise. This algorithm is based on the integral formula derived by using the General Green Function, Lighthills acoustic analogy and Curls extension of Lighthills. Novel approach of this algorithm is that the integral formula is so arranged as to predict frequency-domain acoustic signal at any location in a duct by using unsteady flow data in space and time, which can be provided by the Computational Fluid Dynamics Techniques. This semi-analytic model is applied to the prediction of internal aerodynamic noise from a throttle valve in an automotive engine. The predicted noise levels from the throttle valve are compared with actual measurements. This illustrative computation shows that the current method permits generalized predictions of flow noise generated by bluff bodies and turbulence in flow ducts.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.997-1008
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• 2012

This work provides an alternative derivation of third order response functions in four wave mixing spectroscopy of multichromophoric macromolecular systems considering only single exciton states. For the case of harmonic oscillator bath linearly and diagonally coupled to exciton states, closed form expressions showing all the explicit time dependences are derived. These expressions can provide more solid physical basis for understanding 2-dimensional electronic spectroscopy signals. For more general cases of system-bath coupling, the quantum master equation (QME) approach is employed for the derivation of multistep time evolution equations for Green function-like operators. Solution of these equations is feasible at the level of 2nd order non-Markovian QME, and the new approach can account for inter-exciton coupling, dephasing, relaxation, and non-Markovian effects in a consistent manner.

• 한국주거학회논문집
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• 제10권3호
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• pp.165-173
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• 1999

The current regulations and laws related to landscaping facilities within apartment estates stipulate the proportion of the estate lot allocated to green area and landscaping. These regulations define the criteria for landscaping, the density of trees and other related matters. In fact. the selection and locations of trees are determined by the builder. The builder first decides the location of the building and then allocates the residual land to landscaping. So landscaping within apartment complexes is often unmet to residents' need and ecological growth and function of trees and plants. This study was designed to examine the variety of trees and their location as an aspect of their function within each area of the YS and DK apartment complexes. As the results, the difference in the two estates is striking in aspects of quantity and quality. Even though the regulations for landscaping within apartment estate is met. the real landscaping is often unmet to residents and general people.