• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.99-104
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• 2009

Creep characteristic is an important failure mechanism when evaluating engineering materials that are soft as polymers or used as mechanical elements at high temperatures. One of the popular thermo-elastic plastics, Polyethylene(PE) which is used broadly for engineering purposes, as it has good properties and merits compared to other plastics, was studied for creep characteristic at various level of stresses and temperatures. From the experimental results, the creep limit of PE at room temperature is 75% of tensile strength. Also the creep limits decreased exponentially as the temperatures increased, up to 50% of the melting point. Also the secondary stage among the three creep stages was nonexistent nor was there any rupture failure which occurred for many metals.

• Korean Institute of Interior Design Journal
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• v.14 no.2 s.49
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• pp.46-54
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• 2005

This study is about the polyphony music proportion which appears today in the Architecture space. In the field of interior architecture, there have been many tries of applying characteristics of music, such as abstraction and nature of time for users of space to have new experience. It has been possible because architecture and music have similarities in many ways. Regarding using proportional characteristic in architecture and music, the both fields are enormously related in some ways. The purpose of this study is explaining of possibility of architectural expression in music and suggesting a way of analysing architectural design based on musical elements emphasizing proportional characteristic. Therefore, it is going to analyse Counterpoint of Bach, which is well expressed in music and compare it with proportional characteristic of space through this study.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.1250-1256
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• 1995

In this paper, shielded suspended coplanar waveguide with multiple anisotropic substrates is analyzed by the point matching method in the quasi-TEM mode appoximation. The characteristic impedance and the effective dielectric constant are calculated by varying the width of center strip and gap between the center strip and the ground strip. And also the characteristic parameters are calculated as a function of ${\varepsilon}_{x}/{\varepsilon}_{y}$) and a permitivity of the support substrate. Approaching the ground strip to infinity, the values of the characteristic parameters are found to be in good agreement with the other results by variational method.

• Korean Institute of Interior Design Journal
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• v.20 no.4
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• pp.63-73
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• 2011

In the middle of that a information form is being formlessly changed to diverse deirections, a design and a space as physical consequence show not only a allegory but mutually relational charicteristic meaning a nonboundary and nonlinear form by development of modem digital culture. Following development of the modern digital culture, a design and space which are physical results, show a point of correlative specificity, allegory, nonlinear and nonboundary, Not only a design and culture but also various circles handle a hypertext as a representative pivot in this change. this has same contexts as rhizome possessing a asignifiante and nomadic characteristic said by Felix Guattari and Gilles Deleuze. An ideal of rhizome space shows historical decisions, unexpected accidents, a concepts, an individual. a group, social compositions above an contrifugal exterior force, This study examines into surroundings designed by a hypertext and rhizome through a case accordingly and infers an ultramodern characteristic in conventional precognition with synthesizing a peculiarity of the digital generation space.

• 한국전산유체공학회:학술대회논문집
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• 1999.11a
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• pp.48-58
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• 1999

The Characteristic Flux Difference Splitting (CFDS) scheme designed to adapt the characteristic boundary conditions at the wall and inflow/outflow boundary planes satisfies Roe's property U, although the CFDS Jacobian matrix is decomposed by a product of elaborate transformation matrices and explicit eigenvalue matrix. When the CFDS algorithm, thus a variant of Roe's scheme, is applied straightforwardly to hypersonic flows over a blunt body, the strong bow shock gradually breaks down near the stagnation point. This numerical instability is widely observed by many researchers employing flux-difference method, known in the literature as the carbuncle phenomenon. Many remedies have been proposed and resulted in partial cures. When the idea of Sanders et al. which identifies the minimum eigenvalues near the discontinuity present is applied to CFDS method, it is shown that the instability problem can be controlled successfully. A few flux splitting methods have also been tested and results are compared against the Nakamori's Mach 8 blunt body flow.

• KIEAE Journal
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• v.13 no.2
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• pp.157-162
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• 2013

To deal with the water pollution arising from the construction site, this study raises the issues of management and laws and it suggest the efficient way to reduce water pollution by through the case studies. In order to study, seven cases were selected from "Construction Environmental Management Best Practice Competition" co - sponsored by Construction Association of Korea and Construction Environment Association. As a study result, there are problems that depending on the characteristic of the construction site environment simple alone settling facilities can not handle muddy and dirty water generated by the construction site. However, when the construction site applied improved water pollution control facilities with reflecting the characteristic of muddy and dirty water. The problem can be solved moreover it can achieve exceeded emission standard. Therefore new regulations and management with water pollution control facilities considering characteristic of environment is needed to cope with water pollution arising from the construction site.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.78-85
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• 2010

Creep characteristic is an important failure mechanism when evaluating engineering materials that are soft material as polymers or used as mechanical elements at high temperatures. One of the popular thermo-elastic polymers, Polycarbonate(PC) which is used broadly for engineering polymer, as it has excellent mechanical and thermal properties compared to other polymers, was studied for creep characteristic at various level of stresses and temperatures. From the experimental results, the creep limit of PC at room temperature is 85 % of tensile strength. which is higher than PE (75%)at room temperature. Also the creep limits decreased exponentially as the temperatures increased, up to 50 % of the melting point($267^{\circ}C$). Also the first and third stage among the three creep stages was non-existent nor was there any rupture failure which occurred for many metals.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.12
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• pp.1403-1410
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• 2011

Creep characteristic is an important failure mechanism when evaluating engineering materials that are soft material as polymers or used as mechanical elements at high temperatures. One of the popular thermo-elastic polymers, Polymethyl methacrylate(PMMA) which is used broadly for engineering polymer, as it has excellent mechanical and thermal properties compared to other polymers, was studied for creep characteristic at various level of stresses and temperatures. From the experimental results, the creep limit of PMMA at room temperature is 85 % of tensile strength. which is higher than that of PE (75%)at room temperature. Also the creep limits decreased to nil linearly as the temperatures increased, up to $120^{\circ}C$ of the melting point($267^{\circ}C$). Also the first and third stage among the three creep stages were non-existent nor were there any rupture failure which occurred for many metals at high temperatures.

• Progress in Superconductivity and Cryogenics
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• v.8 no.3
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• pp.49-53
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• 2006

A high temperature superconductor (HTS) has been developed for power applications such as power cables, fault current limiters and superconducting magnetic energy storage devices. For such applications it is required to understand the DC voltage-current characteristic of the HTS. which is important in analyzing AC loss and flux flow loss quantitatively. In this work, we have experimentally investigated influence of several factors, e.g. critical current density. degradation and AC external magnetic field, on the DC voltage-current characteristic. The measured results have been discussed in engineering application point of view.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.401-407
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• 2006

In this paper, we present a small-sized and light weighted dual-band antenna for an access point of 2.4/5 GHz dual-band WLAN(Wireless Local Area Network). The antenna for WLAN should show the characteristic of omni-directional radiation pattern. First, to obtain the omni-directional radiation pattern the proposed dual-band antenna has an orthogonal inverted triangular type element at the center and locates four resonating elements symmetrically around it. Also, for the purpose of easy manufacturing and miniaturization of the antenna, we changed the central element which had the orthogonal inverted triangular type structure into the plate type. Measured $S_{11}$ for the proposed dual-band plate type antenna showed characteristic which was less then -12.8 dB for WLAN frequency bands. Measured results for the maximum gain showed 3.17 dBi at 2.44 GHz, 5.38 dBi at 5.77 GHz with omni-directional radiation pattern. The implemented antennas showed applicable performances for the access point of WLAN.