• Archives of design research
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• v.19 no.5 s.67
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• pp.351-362
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• 2006

Currently, finding one's way in the underground spaces associated with subway stations in large cities is becoming a serious problem, and an environment that facilitates wayfinding is becoming more important. This study investigated interior treatments that function as visual cues in the subway stations of Seoul, Tokyo, and Taipei in order to develop design guidelines that would improve the place-cognition environment. A theoretical study has shown that there are three categories of visual cue for place cognition: marked trails, regional differentiation, and landmarks. The case study showed that marked trails involve treatments like vertical markers, confrontational positioning, and subway color codes. Regional differentiation involves patterns on the floors and walls, and accent colors on the walls and columns. Landmarks include treatments such as super graphics, symbolic features, artistic decoration and special lights. In the cases of Seoul, marked trails and regional differentiation were predominant. In addition, the Olympic symbol 'Hodori' and the ancient Korean character "Hunminjungeum" were used as landmarks. In the cases of Tokyo, regional differentiation predominated over marked trails because of the complexity of the spatial structure and subway line connection system. In the cases of Taipei, simple, unified images predominated, and there was minimal dependence on marked trails and landmarks. The need for regional differentiation was weak, because the stations studied have open structures that guarantee an open field of view. The results of this research could be used as design guidelines, after further experimental verification, that would help to improve the public environment in terms of wayfinding.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.507-518
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• 2020

With the rapid development of rail transit, rail transit noise needs to be paid more and more attention. In order to accurately and effectively analyze the characteristics of low-frequency noise, a prediction model of vibration of box girder was established based on the hybrid FE-SEA method. When the train speed is 140 km/h, 200 km/h and 250 km/h, the vibration and noise of the box girder induced by the vertical wheel-rail interaction in the frequency range of 20-500 Hz are analyzed. Detailed analysis of the energy level, sound pressure contribution, modal analysis and vibration loss power of each slab at the operating speed of 140 km /h. The results show that: (1) When the train runs at a speed of 140km/h, the roof contributes more to the sound pressure at the far sound field point. Analyzing the frequency range from 20 to 500 Hz: The top plate plays a very important role in controlling sound pressure, contributing up to 70% of the sound pressure at peak frequencies. (2) When the train is traveling at various speeds, the maximum amplitude of structural vibration and noise generated by the viaduct occurs at 50 Hz. The vibration acceleration of the box beam at the far field point and near field point is mainly concentrated in the frequency range of 31.5-100 Hz, which is consistent with the dominant frequency band of wheel-rail force. Therefore, the main frequency of reducing the vibration and noise of the box beam is 31.5-100 Hz. (3) The vibration energy level and sound pressure level of the box bridge at different speeds are basically the same. The laws of vibration energy and sound pressure follow the rules below: web

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.82-89
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• 2013

The phase in digital technology expedited low-budget digital film productions in the Korean film industry; hence the international film festivals circuit became the launching pad for Korean directors as they built their reputation and careers around the critical acclaim. Pieta (Kim Ki-Duk)'s Claim on Golden Lion prize at the Venice Film Festival in 2012 would be one of the splendid achievements - the festival is considered to be one of the top the international film festival. However, the increased volume of the low-budget digital film productions are not necessarily proportional to the growth in the quality of the productions. The drawbacks to the production system appeared to be the underlying cause. In attempt to approach the issue, this article explores the production system from 2000 until now. It is illustrated that the value chain model has been transformed from general ones into vertical & horizontal integrated ones. A notable example of successful indie bands-around Hongik university area-, as well the analysis on the low-budget hit productions, especially from the mid-2000's, are introduced as the case studies. The strategies that led the success, such as subsidies policy, the tax benefits on investment firms and production companies, and the aid in international film festival submissions on low-budget digital film productions, are thus examined with further suggestions.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.145-148
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• 2003

The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7； flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5； flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3； cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2； flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.103-114
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• 2011

In this study, we discuss a fatal accident severity model obtained from the analysis of 112 crash sites collected since 2000, and the resulting relationship between fatal accidents and roadway geometry design. From the 720 times computer simulations for improving driving safety, we then reached the following conclusions:. First, the result of cross and frequency-analyses on the car accident sites showed that 43.7% of the accidents occurred on the curved roads, 60.7% on the vertical curve section, 57.2% on the roadways with radius of curvature of 0 to 24m, 83.9% on the roads with superelevation of 0.1 to 2.0% and 49.1% on the one-way 2-lane roads; vehicle types involved are passenger vehicles (33.0%), trucks (20.5%) and buses (14.3%) in order of frequency. The results also show that the superelevation is the most influencing factor for the fatal accidents. Second, employing the Ordered Probit Model (OPM), we developed a severity model for fatal accidents being a function of on various road conditions so as to the damages can be predicted. The proposed model possibly assists the practitioners to predict dangerous roadway segments, and to take appropriate measures in advance. Third, computer simulation runs show that providing adequate superelevation on the segment where a fatal accident occurred could reduce similar fatal accidents by at least 85%. This result indicates that the regulations specified in the Rule for Road Structure and Facility Standard (description and guidelines) should be enhanced to include more specific requirement for providing the superelevation.

• Korean Journal of Optics and Photonics
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• v.11 no.4
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• pp.271-278
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• 2000

We have fabricated and analyzed the lasing characteristics of 1.3$\mu\textrm{m}$ Spot-Size-Converter (SSC) integrated Fabry-Perot (FP) laser diodes, which are very promising light sources for optical subscriber networks. SSC-LDs has been developed by BIB (buttjoint-built-in) coupling and selective MOVPE growth. High-performances were achieved such as the slope efficiency from the SSC facet of 0.23-0.32 mW/mA, the full-width at the half maximum of the far-field pattern (FFP) of 9.5$^{\circ}$~12.3$^{\circ}$, the alignment tolerances of $\pm$2.3$\mu\textrm{m}$ and $\pm$2.5$\mu\textrm{m}$ within the extra-coupling loss of 1 dB for the vertical and parallel directions, respectively. These experimental results were compared to theoretical ones in order to clarify the operational problems and give a good design direction of the fabricated SSC-LDs. It was revealed that an asymmetric output power from the facets, an irrelevancy of FFP and the waveguide structure around SSC facet region, and a poor temperature characteristics were originated from the scattering in the BIB and SSC sections and SHB effect in the active section for the first time.t time.

• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.511-523
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• 1995

The elastic open activator is one of the modified myodynamic activator. The reduced size of the appliance mass motivates the patients' comfort and longer time of wearing. Its peculiarities in loose fitting and the lack of appliance stabilization in the mouth draws the tongue and the surrounding functional matrices on close interaction with the appliance, consigns the physiologic exertion to target structures, and eventually makes it feasible to the inland of non-extraction treatment In the context of the sagittal malocclusion, the orthodontic trench is dependent upon the growth of basal structure aimed, therefore, it is contemplated to grabble the effects of Elastic Open Activator upon the class II malocclusion of growing child retrospectively. The cephalometric headfilms and study models of nine Class II malocclusion of growing child retrospectively. The cephalometric headfilms and study models of nine class II division 1 and five division 2 patients were evaluated and analyzed, and the following observations were drawn, 1. The maxilla maintained a normal growth pattern in both groups. 2. The mandible grew anteroinferiorly in both groups. 3. The upper incisors tipped ligually in Class II division 1 and tipped labially in Class II division 2 and anterior vertical alveolar growth was interrupted in both groups. 4. The lower incisors tipped labially. 5. There was an arch expansion in both groups and increase of available space in Class II division 2

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.1
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• pp.6-13
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• 2001

By using a vertical Bridgeman method, single crystalline structures of $Mg_xZn_{1-x}Te(0{\le}X{\le}0.48)$ were grown for various Mg mole compositions. With the increasing Mg fraction, the lattice constant is linearly increased from 6.103 to 6.239$\AA$ for the range of $0{\le}X{\le}0.48$ and the lattice constant of zincblende MgTe was linearly extrapolated to the value of 6.433$\pm$0.002$\AA$. The optical properties of the crystalline structure were characterized with photocurrent measurements. As a results of photocurrent spectra, the single crystalline $Mg_xZn_{1-x}Te$ show the energy bandgap of 2.380 and 2.260eV at 4.2 and 294 K, respectively. The photocurrent peak blueshifts with increasing Mg mole fraction and show the linear dependence of energy bandgap, $E_g$(X)=b+(0.8)X. The extrapolation shows the energy bandgaps of MgTe of 3.18 and 3.06eV at the temperatures of 4.2 and 294K, respectively. Furthermore, the photocurrent peaks redshifts with increasing temperature and the temperature coefficient is given to the value of $dE_g$/dT=-(5.6~$6.1){\times}10^{-4}$eV/K. for the temperature range above 100K.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.73-85
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• 2006

Array observations of the vertical component of microtremors are frequently conducted to estimate a subsurface layered-earth structure on the assumption that microtremors consist predominantly of the fundamental mode Rayleigh waves. As a useful tool in the data collection, processing and analysis, the spatial autocorrelation (SPAC) method is widely used, which in practice requires a circle array consisting of M circumferential stations and one centre station (called "M-station circle array", where M is the number of stations). The present paper considers the minimum number of stations required for a circle array for efficient data collection in terms of analytical efficacy and field effort. This study first rearranges the theoretical background of the SPAC algorithm, in which the SPAC coefficient for a circle array with M infinite is solely expressed as the Bessel function, $J_0(rk)$ (r is the radius and k the wavenumber). Secondly, the SPAC coefficient including error terms independent of the microtremor energy field for an M-station circle array is analytically derived within a constraint for the wave direction across the array, and is numerically evaluated in respect of these error terms. The main results of the evaluation are: 1) that the 3-station circle array when compared with other 4-, 5-, and 9-station arrays is the most efficient and favourable for observation of microtremors if the SPAC coefficients are used up to a frequency at which the coefficient takes the first minimum value, and 2) that the Nyquist wavenumber is the most influential factor that determines the upper limit of the frequency range up to which the valid SPAC coefficient can be estimated.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.3
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• pp.132-138
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• 2003

A stoichiometric mixture for $CdIn_2Te_4$ single crystal was prepared from horizontal electric furnace. The $CdIn_2Te_4$ single crystal was grown in the three-stage vertical electric furnace by using Bridgman method. The $CdIn_2Te_4$ single crystal was evaluated to be tetragonal by the power method. The (001) growth plane of oriented $CdIn_2Te_4$ single crystal was confirmed from back-reflection Laue patterns. The carrier density and mobility of $CdIn_2Te_4$ single crystal measured with Hall effect by van der Pauw method are $8.61\times 1016 \textrm {cm}^{-3}$ and 242 $\textrm{cm}^2$/V.s at 293 K, respectively. The temperature dependence of the energy band gap of the $CdIn_2Te_4$ single crystal obtained from the absorption spectra was well described by the Varshni's relation, $1.4750ev - (7.69\times10^{-3})\; ev/k)\;T^2$/(T + 2147k).The crystal field and the spin-orbit splitting energies for the valence band of the $CdIn_2Te_4$ single crystal have been estimated to be 0.2704 eV and 0.1465 eV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the $\Delta$so definitely exists in the $\Gamma_7$ states of the valence band of the $CdIn_2Te_4$ single crystal. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1-} B_{1-}$ and Cl-exciton peaks for n = 1.