• Journal of Astronomy and Space Sciences
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• v.31 no.3
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• pp.241-246
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• 2014

The Amon-Ra instrument is the main optical payload of the proposed EARTHSHINE satellite. It consists of a visible wavelength instrument and an IR energy channel instrument to measure a global Earth albedo. We report a new sensitivity technique for efficient alignment of the visible channel instrument. Whilst the sensitivity table method has been widely used in the alignment process, the straightforward application of the method tends to produce slow process convergence because of shop floor alignment practice uncertainties. We investigated the error sources commonly associated with alignment practices and used them when estimating the Zernike polynomial coefficients. Aided with single center field wavefront error (WFE) measurements and their corresponding Zernike polynomial coefficients, the method involves the construction and use of an experimental, instead of simulated, sensitivity table to be used for alignment state estimations. A trial alignment experiment for the Amon Ra optical system was performed and the results show that 71.28 nm in rms WFE was achieved only after two alignment iterations. This tends to demonstrate its superior performance to the conventional method.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.5
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• pp.45-51
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• 2002

The characteristics of nonlinear seismic behavior and failure mechanism of RC space frame in railroad viaducts have been studied by the numerical analysis in time domain. The structure concerned is modeled in 3 dimensional extent and the RC frame elements consisting of fibers are employed for the columns. The fibers are characterized as RC zone and PC one to distinguish the different energy release after cracking resulted from the bond characteristic between concrete and re-bar. Due to the deviation of the mass center and the stiffness center of the entire structure the complex behavior is shown under seismic actions. The excessive shear force is concentrated on the column beside flexible one relatively, which leads to the failure of bridge concerned.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.207-217
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• 2000

A fire fighting characteristic by a single evaporating droplet in the case of a fire of military enclosure space was studied experimentally. Transient cooling of solid surface by water droplet evaporation has been investigated through controlled experiments using a heated brass cylinder. Quantitative predictions of droplet evaporation time and in-depth transient temperature distribution in solid have been made. The particular interest was in the removal of thermal energy from the heated cylinder by evaporative cooling. A $10{\mu}1$ single droplet is deposited on a horizontal brass surface with initial temperatures in the range of $90^{\circ}C{\sim}130^{\circ}C.$ The results can be summarized as follows; Evaporating droplet was divided into three different configuration. Evaporation time was predicted as a function of initial surface temperature ($t_c=492.62-6.89T_{s0}+0.0248T_{s0}^2).$ The contact temperature was predicted as a function of initial surface temperature( $T_{i}$=0.94 $T_{s0}$+1.4), The parameter ${\beta}_o$ was predicted as a function of initial surface temperature( ${\beta}_0$ : 0.O0312 $T_{s0}+0.932$)>)>)

• Journal of Agricultural Extension & Community Development
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• v.14 no.2
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• pp.417-436
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• 2007

The purpose of this study was to prepare for developing rural house remodeling techniques utilizing the traditional residence factor. The study was carried out through both literature research and on-site research. The traditional residence space factors were identified through literature research and on-site research was carried out through analysis of the rural house remodeling cases. The results of this study was as follows ; 1) Traditional space factors were derived by literature research i. e. space arrangement (topography, direction, plane arrangement), exterior factors; walls, madang, interior factors; roofs, ondol, floors, colours. 2) The traditional residence factor utilizations of remodeling were applied a result through investigation case and analysis. Five rural houses in Namsa village, Danseong-myeon, Sangcheong-gun, Gyeongsangnam-Do were analyzed as remodeling cases including traditional residence factors. There were limitation of budget problems and material selection in the traditional residence factor utilizations of remodeling. The researchers have chosen target rural houses which applied for traditional residence factors to remodel the rural houses, and the most important factor to consider was harmony with rural unique characteristics. The researchers suggested considerations should be placed on development with energy savings and convenience in rural house remodelling.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.53.2-53.2
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• 2017

Stochasitc gravitational wave background (SGWB) is expected to be contributed by primordial sources (e.g. inflation signature) and astrophysical sources (e.g., incoherent superposition of a large numbers of compact binary inspirals throughout in the Universe). Theoretically, SGWB is predicted to span in a broad frequency range between less than nHz up to kHz. Many gravitational-wave (GW) detectors such as LIGO or LISA aim to detect or constrain SGWB in different frequency band that is most sensitive for each detector. In this talk, we focus on the prospectives of constraining the energy density of SGWB between 0.1-10 Hz. We introduce the characteristics of SGWB and representative models for primordial and astrophysical sources. Then, we propose a signal extraction scheme to detect SGWB using one or several omni-directional GW detectors such as SLGT(Superconducting Low-frequency Gravitational-wave Telescope). Considering SLGT sensitivity, we discuss how to observe SGWB in 0.1-10 Hz if we have SLGT network. Finally, we highlight interesting SGWB models that can be constrained in 0.1-10 Hz with SLGT.

• Fire Science and Engineering
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• v.11 no.4
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• pp.3-14
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• 1997

The smoke filling process for the atrium space containing a fire source is simulated using two types of deterministic fire model : Zone model and Field model. The zone model used is the CFAST(version 1.6) model developed at the Building and Fire Research Laboratories, NIST in the USA. The field model is a self-developed frie field model based on Computational Fluid Dynamic (CFD) theories. This article is focused on finding out the smoke movement and temperature distribution in atrium space which is cubic in shape. For solving the liked set of velocity and pressure equation, the PISO algorithm, which strengthened the velocity-pressure coupling, was used. Since PISO algorithm is a time-marching procedure, computing time si very fast. A computational procedure for predicting velocity and temperature distribution in fire-induced flow is based on the solution, in finite volume method and non-staggered grid system, of 3-dimensional equations for the conservation of mass, momentum, energy, species and so forth. The fire model i.e Zone model and Field model predicted similar results for clear heights and the smoke layer temperature.

• Journal of Communications and Networks
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• v.6 no.3
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• pp.258-268
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• 2004

We demonstrate rotationally invariant space-time (ST) trellis codes with a 4-D rectangular signal constellation for data transmission over fading channels using two transmit antennas. The rotational invariance is a good property to have that may alleviate the task of the carrier phase tracking circuit in the receiver. The transmitted data stream is segmented into eight bit blocks and quadrature amplitude modulated using a 256 point 4-D signal constellation whose 2-D constituent constellation is a 16 point square constellation doubly partitioned. The 4-D signal constellation is simply the Cartesian product of the 2-D signal constellation with it-self and has 32 subsets. The partition is performed on one side into four subsets A, B, C, and D with increased minimum-squared Euclidian distance, and on the other side into four rings, where each ring includes four points of equal energy. We propose both linear and nonlinear ST trellis codes and perform simulations using an appropriate multiple-input multiple-output (MIMO) channel model. The 4-D ST codes constructed here demonstrate about the same frame error rate (FER) performance as their 2-D counterparts, having however the added value of rotational invariance.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.128-135
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• 2010

In this paper, traditional residential architecture in South Korea appear to approach environmental regulation as part of ecological architecture of regional climate controlled environment, according to the characteristics and spatial arrangement, and material to the environment was described as a controlled manner. The scope of this study was not large scale housing construction from traditional chusagotaek, yunjeunggotaek, yangjindang, dokrakdang target was the case. Focusing on examples extracted from Korea first eco-friendly characteristics of traditional residential architecture is an extension of nature to explore space and yard space, and South Korea by way of environmental control that appears in traditional architecture, waterproof, moisture, solar radiation, sunlight, ventilation and air Attributes such as environmental regulation and environmental regulation of space, place and manner of materials were described. Korea's research through more traditional residential architecture of the environmental control and a wide range of environmentally friendly eco-construction was that appeared natural to use energy efficiently, it had been available. Later appeared on the Korea traditional architecture through research on environmental control of environmentally friendly ways to navigate and take advantage of the elements, through continuous research and eco-friendly construction to realize the traditional South Korea could provide a prototype of the modern, I thought I'd had.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.117-124
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• 2006

Korean urban traditional housing abandoned by the social apathy promptly disappearing form our sight, or ruining. It tells that the strategies we are using today are impossible to fulfill socio-economic needs of residents here. So it needed to find out the strategies which can change this place better to live in. Consolidating the street parking lots fer cars can be one of the important solutions to the area. By using cul-de-sac, after setting up small unit of communities, we will have chance to have a small public space, and at the same time it can help to set up our tradition of people's intimacy inside the community. Most people have their own cars, and the need of parking lots becomes more serious. So, a meeting place like public well in the past must replace parking lots. On the other hand, it is important to re-consolidate existing land to obtain appropriate land size for other uses. Today, the use of private space (house, private lots, etc..)and public space(streets, local offices) is very important. NIMBY (Not In My Back Yard) attitude should also be reconsidered. All these negative social aspects come from negative social relationship, thus we should consider them with care and deep understandings. The traditional housing of Korea should not be abandoned as slum, but this should be transformed in terms of the conservation since it is superior in its ecological and energy conservation aspect.

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.267-271
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• 2000

The influence of photoexcited nonequilibrium carriers on domain switching and photovoltaic current was investigated in two kinds of poled La-modified PbTiO$_3$ferroelectric ceramics, (Pb$_{0.85}$La$_{0.15}$)TiO$_3$and (Pb$_{0.76}$La$_{0.24}$)TiO$_3$, under illumination in the absence of external electric field. Both photovoltaic current and cumulative AE event counts increased with illumination time. The observed nonsteady-state photovoltaic current could be explained on the basis of the cycles of a series of physical events consisting the establishment of space charge field by photoexcited carriers trapped at the grain boundaries, the photoinduced domain switching, and the increase in the remanent polarization. An analysis of energy distribution of the observed AE signals also revealed that the space charge field in (Pb$_{0.85}$La$_{0.15}$)TiO$_3$allowed both 18$0^{\circ}C$ and 90$^{\circ}$domains to be switched during illumination.