• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.567-571
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• 2005

The slender rectangular cantilever beam has vef interesting to study dynamic behaviors of the harmonic base excitation of a cantilever beam shows many nonlinear dynamics due to unstability , energy transfer and mode coupling. Nonlinear phenomenon shows superharmonic, subharmonic, super subharmonic and chaotic motions of the cantilever beam. Experimental observation and verification of these phenomenon carry much importance for the theoretical study as well as in it self. In the experimental cantilever beam, the chaotic motions of the beam appear as a pink noise signal in FFT analysis and as a torus structure in the oscilloscope analyzed to eventually give information of chaotic motions of the cantilever beam.

• Journal of The Korean Astronomical Society
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• v.44 no.1
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• pp.13-21
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• 2011

We model dust around Herbig Ae/Be stars using a radiative transfer model for multiple isothermal circumstellar dust shells to reproduce the multiple broad peaks in their spectral energy distributions (SEDs). Using the opacity functions for various types of dust grains at different temperatures, we calculate the radiative transfer model SEDs for multiple dust shells. For eight sample stars, we compare the model results with the observed SEDs including the Infrared Space Observatory (ISO) and AKARI data. We present model parameters for the best fit model SEDs that would be helpful to understand the overall structure of dust envelopes around Herbig Ae/Be stars. We find that at least four separate dust components are required to reproduce the observed SEDs. For all the sample stars, two innermost dust components (a hot component of 1000-1500 K and a warm component of 300-600 K) with amorphous silicate and carbon grains are needed. Crystalline dust grains (corundum, forsterite, olivine, and water ice) are needed for some objects. Some crystalline dust grains exist in cold regions as well as in hot inner shells.

• Fire Science and Engineering
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• v.13 no.4
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• pp.30-37
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• 1999

In this study, reduced-scale experiments as the alternative to a real-scale fire test were conducted to understand fire properties in atrium space. The scaling laws were derived from $\pi$-parameters which were deduced by dimensional analysis of governing equations (continuity, conservation of momentum and conservation energy). The 1/50 scale experiment simulated the real-scale fire test in SIVANS atrium at Japan were conducted under the scaling laws. And this results were compared with real-scale experiment results. Furthermore these results were visualized by video recording system using laser light sheet.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.7
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• pp.127-133
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• 2001

The effects of triangular and rectangular discharge current waveforms on anode erosion in wire electric discharge machining is investigated based on heat transfer analysis of half-space subject to time and space-dependent heat flux. The thermal load on the anode is simulated by a hear flux that is calculated from time-dependent discharge channel radius and energy. Evolution of the melting front during discharge, the molten volume at the experimental result for qualitative verification of the analysis. It is demonstrated that the triangular current waveform is more efficient in eroding the anode than the rectangular one.

• Journal of Astronomy and Space Sciences
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• v.8 no.1
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• pp.11-23
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• 1991

The dynamical evolution of globular clusters is studied using the orbit-averaged multicomponent Fokker-Planck equation. The original code developed by Cohn(1980) is modi-fied to include the effect of stellar evolutions. Plommer's model is chosen as the initial density distribution with the initial mass function index $\alpha$=0.25, 0.65, 1.35, 2.35, and 3.35. The mass loss rate adopted in this work follows that of Fusi-Pecci and Renzini(1976). The stellar mass loss acts as the energy source, and thus affects the dynamical evolution of globular clusters by slowing down the evolution rate and extending the core collapse time Tcc. And the dynamical length scale $$R_c, $$R_h is also extended. This represents the expansion of cluster due to the stellar mass loss.

• Korean Institute of Interior Design Journal
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• no.38
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• pp.91-99
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• 2003

In the philosophical sense, aZen teacher would probably say there is no answer to the Question. Whatnis Zen\ulcorner Zen is an approach to life, a way of being , rather then a philisophy or set doctrine. Modern living people quest for peace and tranquility has led designers and decorators to look to East to the natural harmony and blance of Asian home and to the simpicity of their art and design. Zen style interiors are simplicity and serenity. These imply the paring down of a cluttered environment and concentration on creating harmony. balance, touch, and texture. By achieving these things you can create a place where the spiritual or inner needs can be addressed and where you can indulge in calming or stimulating the senses with light, space, and free flow of energy In Zen interior we approach 'Homoㆍaesthetcus' by feeling and' Homoㆍreligious' by mind. "Less is more", this phrase has made the pared down environment an interior form.

• Korean Institute of Interior Design Journal
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• no.38
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• pp.14-20
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• 2003

In 1923, El. Lissitzky designed ‘Proun Raum’ to realize his spatial experiment in paintings that are called 'Proun'. For this, Lissitzky taken Pome 'element' to construct his imaginary space that combine time with space. Especially, Quadrangle make an important role by the reason of its potential energy. In other words, alteration of its four corners turn Quadrangle to rectangle or square, etc, and describe some force, motion and location as itself. Analyzing 'Proun' and 'A and Pangeometry' that describes his spatial concept, spatial characteristics of 'Proun Raum' are comprehended, and the significance of spatial construction method in 'Proun Raum' are summarized as follows; occurrence of spectator's visual guide by elements, secession of afterimage, do-construction of the border.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.05a
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• pp.106-111
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• 2004

The purpose of this study is finding the spatial character for autogenous space design through the violation of Nam-dae-mun market. The violation is defined as the possession of space in excess of one's property. In Nam-dae-mun market, the violation is sanctioned by usage. Through the violation, Nam-dae-mun market naturally acquires autogenous energy and pliability. According to three steps, this research proceed. 1. To investigate the limitation of modern architecture and the meaning of the violation. 2. To research the present condition of Nam-dae-mun market and the process of spatial formation. 3. To compare 'F' building in Nam-dae-mun with Sam-ik fashion building which was redeveloped.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.756-761
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• 2007

This papered is concerned with the crashworthiness characteristics analysis of the non-step bus when it is crashed or roll-over analysis. Computer simulations is implemented using LS-Dyna explicit code which can effectively analysis dynamic response with the lapse of time. We construct a FEM model of the non-step bus under development according to the safety rules used in Europe for composite non-step buses. The crash energy and absorption rate are evaluated to understand crashworthiness characteristic of the composite non-step bus. Body deformation is also examined whether the survival space is secured for passengers.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.156.2-156.2
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• 2011

본 연구에서는 일단 수성가스전이반응 (Single stage water gas shift reaction)을 위해 높은 활성을 가진 백금 담지 촉매를 함침법 (Incipient wetness impregnation method)으로 제조하여 높은 공간 속도 (Gas hourly space velocity) $45,515h^{-1}$에서 담체에 따른 촉매 활성을 평가하였다. 담체는 $CeO_2$, $ZrO_2$, MgO, MgO-$Al_2O_3$ (MgO = 30 wt%) 그리고 $Al_2O_3$를 사용하였으며 백금의 담지량은 1 wt%로 고정하였다. BET, XRD, TPR, CO-chemisorption 분석을 통하여 담체의 구조적 특성이 촉매 활성에 미치는 영향에 대하여 조사하였다.