• Journal of the Society of Naval Architects of Korea
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• v.42 no.1 s.139
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• pp.18-23
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• 2005

The transmission and reflection coefficiencies of a BBDB-type floating breakwater in water of finite depth are studied taking account of fluctuating air pressure in the air chamber. The wave potential is calculated by a hybrid integral equation consisting of a Green integral equations associated with the Rankiue Green function inside the BBDB and the Kelvin Green function outside. The transmission and reflection coefficients of the breakwater are obtained directly from the potential solution in the outer region.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.2
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• pp.77-85
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• 1998

Propagation of elastic surface waves in anisotropic media is considered in this study. An analytical technique is proposed to study the scattering of surface waves at the interface between two anisotropic quarter-spaces. The Green's function technique is used to derive a system of equations which can determine the scattering coefficients at the interface. A numerical study is carried out and the trade-offs between the material anisotropy and inhomogeneity are studied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.1
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• pp.143-149
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• 1993

An approach is presented for efficient numerical integration of the Sormnerfeld type integrals pertinent to the microstrip surface Green's function arising in the problem of an electric current point source on an infinite planar grounded dielectric substrate. This approach, valid for both lossless and lossy dielectric substrates, is based on the deformation of the integration contour via a coordinate transformation and Cauchy's residue theory, and identifies clearly the effects of surface waves. I ts useful application is in a rigorous moment method analysis of micros trip antenna arrays and microstrip guided wave structures. The efficiency and the usefulness of the present approach are emphasized through some numerical calculations of the impedance matrix elements with associated CPU times.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.201-206
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• 2014

GCM(Green Chain Management) is being spread by that companies which apply with eco-friendly concept in entire SCM(Supply Chain Management) perspective is being increased for resolving some recent environmental problems. There are reasons that numerous companies focus on GCM. At first various governments began to directly manage components and material contents about various noxious substances. Second, environment problem management in the entire logistics process from procurement of product materials to distribution of product became to be important according to introduction of certification system that evaluate the environmental impact throughout life-cycle of products. Purposes of this paper are 1) to analyze the GCM process whose important is more increasing in the recent logistics environment change, 2) to comprehend places and sources that generate environmental elements like energy consumption and greenhouse gas emissions in elements of logistics function, and 3) to construct integrated GCM system for observing activity of logistics function throughout life-cycle of products.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.8
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• pp.1438-1445
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• 1992

A new and efficient method is presented to evaluate contact force and motion of an electric railway simple catenary-pantograph system. Overhead lines are regarded as simple strings, and hangers connected to the strings are replaced with concentrated forces acting on them. The displacement of strings due to concentrated forces caused by hangers and pantograph is expressed using Green's function. A system of linear algebraic equations in terms of unknown forces is derived based upon the compatibility requirement at the location of hangers and pantograph. This procedure is more analytic in formulation compared to the existing methods such as finite difference method or normal modes method, and it is expected to be more accurate. Present method has additional advantage that it requires neither numerical differentiation nor system eigenvalues.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.2
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• pp.11-18
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• 1988

The radiation problem for an oscillating cylinder advancing under the free surface with a constant horizontal velocity is studied using the Green integral equation in the frequency domain. The Green function expressed in terms of the complex exponential, is derived using the damped free surface condition. Special attention is given to the behavior of the numerical solution in the vicinity of the critical Brard number ${\gamma}_c=\omega{\cdot}u/g=0.25$ where $\omega$ is the circular frequency of encounter, u the advancing speed and g the gravitational acceleration. It is shown that the solution is finite in the vicinity of ${\gamma}_c$ although the Green function becomes singular at ${\gamma}_c$. It is also shown that the computed hydrodynamic coefficients agree well with those obtained from the solution of the same problem formulated in the time domain.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.6
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• pp.37-49
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• 2002

The objective of this research was an investigation of the important green spaces in Daegu and to present the basic frame of green network in Daegu. Present the condition of the significant green spaces is as follows: In the 3km radius of the city center, the isolation and discontinuation of the green spaces was extensive, caused by crowding of houses and funeral parlours. Consequently, the isolation relaxation which leads to the additional creation of the green spaces and a buffering plan were demanded. In the transfer area of a 3∼6km radius, which is located between the city center's congested area and the suburb green spaces, the significant green spaces had high connection and buffering characteristic, but in the northwest and the south, serious discontinuation appeared between the suburb green spaces and the city conte green spaces. In the 6∼9km radius, the suburb important green spaces accomplished the function which extended the back core green spaces to the city center area. But creation of buffering green spaces was necessary in part because of proximity to the resident area. The results suggest a connection between green spaces on the base of the distribution of the important green spaces, were as follows: In the 3km radius, irregular direction lines appeared while a schedule one direction line appeared in 3∼6km and 6∼9km radius. The discontinued parts of the green network were caused by industrial complexes, house crowding, and cultivation areas. Consequently, reservation and creation plans of green spaces in response to this were demanded. Through the additional creation of green spaces in the discontinued parts, the basic frame of green network in Daegu was the radiation annular form. And it was suitable to activate the parks and the general green spaces.

• Honam Mathematical Journal
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• v.44 no.4
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• pp.485-503
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• 2022

In this work, a discontinuous singular Dirac system is studied. For this system, a spectral function is constructed. Finally, by using the spectral function, a spectral expansion formula is given.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.233-243
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• 2013

As companies were concerned with developing green logistics and environment, most logistics concerned functions like packaging, loading, storage, transportation and IT studies are active in study. Even if active in research studies, companies still recognized that logistics cost increases as green concepts are applied. For the efficient execution of green logistics management, it is absolutely necessary but difficult to build an optimal logistics system where each function is smoothly interacted through the proper integration and the link of various logistics functions and partners. This study aims to development of green logistics through integration of supply chain functions and partners. With this aim of study, case studies with analysis of embodiment, planning and operations for supply chain of companies are carried out.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.2
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• pp.153-159
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• 2004

This paper preliminary discussed the important function and faced problems of suburb green space during the process of urban development. As well as it points out the contradiction of protection and making use of. In this paper it takes the green space system planning in Wuxi as an example. Through introducing the classification, distribution, arrangement principles, overall arrangement tactics and concrete protective measures of suburb green space in Wuxi, the paper also puts forward the correct disposal principles for the relationship between protection and making use of toward the suburb green space to realize 'both-win' of them.