• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.229-235
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• 2019

Currently, Korean society has seen a rapid increase in international marriages since the mid-1990s, and the number of their children entering school age has been increasing every year in recent years. With the growing number of students with parents from various social and cultural backgrounds in our society, the difficulties they face are emerging as a new social problem that we should pay attention to and solve. Although the difficulties they are experiencing vary depending on their parents' nationality, social, economic status, and attitude toward raising their children, it is generally reported that they are suffering from language barriers in elementary school, study barriers in high school, and friendship barriers in middle school. In particular, the school started this research based on the problem that when students from multi cultural families did not mix well with ordinary students and could not narrow the distance between them, they could become adults and enter society in the future, causing social conflict.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.468-472
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• 1997

The effect of the surface state on the quantum efficiency of underlying GaAs/AlGaAs multi-quantum well(MQW) structures consisting of three GaAs quantum wells with different thickness, is studied by low temperature photoluminescence(PL). The structure was grown by molecular beam epitaxy(MBE) on (100) GaAs substrate. The thickness of three GaAs quantum wells was 3, 6 and 9 nm, respectively. The MQWs were placed apart from 50 nm AlGaAs edge-barriers including two inner-barriers with 15 nm in thickness. The samples used in this study were prepared with different growth temperatures. Particularly, the hydrogen passivation effect to the 9 nm quantum well located at near surface appeared much stronger than any others. Transition energy and optical gain related to the hydrogen passivation effects on the multi-quantum well structure was calculated by transfer matrix method.

• Journal of Soil and Groundwater Environment
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• v.21 no.1
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• pp.1-5
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• 2016

Capillary barriers, consisting of relatively fine-over-coarse materials, have been suggested as an alternative to traditional compacted soil covers. So, We were analysed to capillary barrier effect according to five cases of multi-layer cover systems. Water balance simulation was conducted with unsaturated flow model HELP to assess unsaturated hydraulic parameters such as hydraulic conductivity, climate affecting the performance of capillary barriers. Simulation were conducted for 5 Cases in the Ulsan area. Result of simulation indicated that three cases was formed unsaturated condition and capillary barrier effect.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.757-761
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• 2001

In order to study noise barriers of complex shapes and to assess their efficiency, precise prediction model is required. For instance, geometrical approaches cannot deal with complex diffraction effects. So that in this paper, the time domain numerical computation method(Computational Aeroacoustics method) is applied to estimate noise reduction by diffraction and finite impedance condition. The CAA method can be used to calculate exactly the pressure of complex barrier shape with different impedance condition, such as T-shape, cylindrical edge and multi-edge noise barriers.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.40-44
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• 2019

Experimental studies have been carried out to investigate characteristics of gas explosion using a multi layered water gel barrier in a vented explosion chamber. The chamber is consisted of 1600 mm in length, with a square cross-section of $100{\times}100mm^2$. The gel concentration of inner layer of MLWGB ranged from 10% to 90% with intervals of 10% by weight of gel. Displacement of the MLWGB was photographed with a measured using a high-speed video camera, and pressure development was measured using a data acquisition system. It was found that MLWGBs with 10 ~ 20% inner layer concentrations were ruptured during the explosions. As the concentrations of inner layer increased from 30% to 90%, the barriers were not ruptured. As the gel concentrations of the inner layer increased, the displacement increased toward the chamber exit and the pressure decreased for the ruptured barriers. It was found that the pressure attenuation obtained from the MLWGB was higher than that of the single water gel barrier. For the cases of non-ruptured barriers, the pressure inside the chamber less increased with increasing gel concentrations of the inner layer. It was also found that the displacement moved back into the chamber for non-ruptured MLWGBs, and it was sensitive to the gel concentrations.

• Elastomers and Composites
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• v.46 no.2
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• pp.94-101
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• 2011

The conventional radiation barriers may show some disadvantages such as heavy weight and possibility of poisoning human bodies because they are composed of lead plates or resin plates containing large amounts of lead powders. Another disadvantage may be direct penetration of radiation through small pin holes. In this article, technologies of multi-layered polymer barriers against radiation, which has been extensively focused recently, will be introduced. A new concept of radiation protection as well as improving endurance with employing nano-layered inorganic particles is introduced.

• Journal of Information Technology Applications and Management
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• v.21 no.2
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• pp.15-29
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• 2014

This study analyzes the influence factors of IPTV users on the purchase of paid contents. This study carries out a web-log analysis of the actual users of the service provided by the domestic IPTV providers and classifies the influence factors on the purchase of paid contents largely into VOC, switching barriers, and content consumption pattern to conduct an empirical analysis. As analysis procedure, first, this study analyzes the preceding researches related to the core influence factors and content-purchasing patterns, and second, conducts a basic statistics analysis of the distribution of basic characteristics of the logs used, as presented in the above. Third, this study carries out a multiple regression analysis as an estimating equation of the number of purchasing the paid content depending on switching barriers of IPTV service, VOC, and content consumption pattern. As a statistical package, Stata version 11.2 was used. Through the empirical analysis, this study found that of the service use logs, VOC and content consumption pattern had a multi-dimensional impact on the purchase of premium contents. On the other hand, this study also found that the impact of switching barriers such as combination state with other products and current status of holding a point did not have a significant impact on the purchase of paid contents.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.105-108
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• 2006

We investigated the fluidic gas-driven carbon-nanotube motor based on multi-wall carbon nanotubes and fluidic gas flow. Since the origination of the torque was the friction between the carbon nanotube surface and the fluidic gases, the density and the flow rate of the working gas or liquid were very important for the carbon nanotube motor. Molecular simulation results showed that multi-wall carbon nanotubes with very low rotating energy barriers could be effectively used for fluidic gas-driven carbon-nanotube motors.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5791-5797
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• 2012

Introduction: Return-to-work (RTW) can be a problematic occupational issue with detrimental impact on the quality of life of previously-employed breast cancer survivors. This study explored barriers and facilitators encountered during the RTW process in the area of cancer survivorship. Materials and Methods: Six focus groups were conducted using a semi-structured interview guide on 40 informants (employed multiethnic survivors). Survivors were stratified into three groups for successfully RTW, and another three groups of survivors who were unable to return to work. Each of the three groups was ethnically homogeneous. Thematic analysis using a constant comparative approach was aided by in vivo software. Results: Participants shared numerous barriers and facilitators which directly or interactively affect RTW. Key barriers were physical-psychological after-effects of treatment, fear of potential environment hazards, high physical job demand, intrusive negative thoughts and overprotective family. Key facilitators were social support, employer support, and regard for financial independence. Across ethnic groups, the main facilitators were financial-independence (for Chinese), and socialisation opportunity (for Malay). A key barrier was after-effects of treatment, expressed across all ethnic groups. Conclusions: Numerous barriers were identified in the non-RTW survivors. Health professionals and especially occupational therapists should be consulted to assist the increasing survivors by providing occupational rehabilitation to enhance RTW amongst employed survivors. Future research to identify prognostic factors can guide clinical efforts to restore cancer survivors to their desired level/type of occupational functioning for productivity and wellbeing.

• Wind and Structures
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• v.20 no.2
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• pp.213-236
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• 2015

For high-speed railways (HSR) in wind prone regions, wind barriers are often installed on bridges to ensure the running safety of trains. This paper analyzes the effect of wind barriers on the running safety of a high-speed train to cross winds when it passes on a bridge. Two simply-supported (S-S) PC bridges in China, one with 32 m box beams and the other with 16 m trough beams, are selected to perform the dynamic analyses. The bridges are modeled by 3-D finite elements and each vehicle in a train by a multi-rigid-body system connected with suspension springs and dashpots. The wind excitations on the train vehicles and the bridges are numerically simulated, using the static tri-component coefficients obtained from a wind tunnel test, taking into account the effects of wind barriers, train speed and the spatial correlation with wind forces on the deck. The whole histories of a train passing over the two bridges under strong cross winds are simulated and compared, considering variations of wind velocities, train speeds and without or with wind barriers. The threshold curves of wind velocity for train running safety on the two bridges are compared, from which the windbreak effect of the wind barrier are evaluated, based on which a beam structure with better performance is recommended.