• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.486-492
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• 2020

The method for preparing a perovskite-type bismuth ferrite (BFO) photocatalyst which reacts to visible LED light and the characteristics of visible light photocatalysis were investigated. BFO was prepared according to the sol-gel method. The prepared BFO consisted mainly of BiFeO₃ structure and formed a nano-sized crystal including Bi₂₄Fe₂O₃₉ structure. The BFO nano crystallines were identified from the UV-visible diffuse reflectance spectra to absorb UV and visible light up to about 600 nm. The bandgap of the BFO determined from the diffuse reflectance spectrum was about 2.2 eV. Formaldehyde was decomposed by the photoreaction of BFO photocatalysts with the visible light LED lamps with wavelengths of 585 nm and 613 nm. The narrow bandgap of BFO led to elicit BFO photocatalytic activity in visible LED light.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.190-200
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• 2011

Different from visible horror elements that confront the characters directly and do physical harms, invisible horror elements are expressed through suggestion and imagination and their realities are not disclosed. For the disclosure of the realities of invisible horror elements, they are expressed through the overturned relation between the subject and victim of horror as in 'The Others' or through body snatching as in 'The Happening' and 'Paranormal Activity'. The overturn of relation and body snatching are connected to cannibalism in that the former causes a sudden change of personality and the latter takes the body of others. Cannibalism and the change of personality belong to the formalization and illogic of lower order resulting from cannibalism. The meaning of invisible horror elements in films seems to be contradictory to the original meaning of cannibalism, which is entering the sphere of utopian freedom, but considering that the reversed role resolves conflicts and tensions from terror and gives relief from fear, the meaning may be consistent with the spirit of cannibalism, namely, entering 'the sphere of freedom. In this study, the author attempted to analyze how the expression and plot of films showing invisible horror elements are related with cannibalism.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2006.05a
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• pp.286-292
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• 2006

가시오가피와 더덕 추출물을 첨가한 발효유가 마우스의 면역 기능에 미치는 영향을 알아보기 위하여 선발된 수컷 마우스를 대상으로 하여 발효유에 가시오가피와 더덕 열수 추출 건조물(가시오가피:더덕=8:2)을 혼합하여 투여한 그룹 1mg/mL(A), 3mg/mL(B), 9mg/mL(C)의 3 그룹으로 나누어 임상 적용 경로인 경구 투여를 선택하여 발효유를 각각 3mL/kg씩 위내로 직접 투여하였다. 대조군은 발효유만 먹인 그룹(D)과 식염수만 먹인 그룹(E)을 두었다. 실험 결과 모든 그룹에서 마우스의 증체량과 체중 증가는 유의성이 없었고, 7주와 10주령에 안락사 시킨 마우스의 각 장기인 간, 신장, 심장, 폐, 고환의 무게에서도 유의성이 없었다. 비장 계수는 7주령에서는 B군에서 유의성 있는 차이를 보였고 10주령에는 C군에서 유의성 있는 증가가 관찰되었다(p<0.05). 비장 계수는 식이 지속 기간이 길어질수록 증가되었고, 흉선 계수는 B군에서 유의성 있는 증가가 관찰되었다(p<0.05). 항체 생산 세포수는 가시오가피와 더덕을 급여 한 군 모두에서 대조군에 비해 증가하였으며, 특히 A, C군에서는 유의성(p<0.05)이 있었다. 모든 그룹에서 항체 생산 세포수는 10주령에서 7주령에 비하여 감소하는 경향을 보였다. 항원에 대한 항체 생성량을 알아보기 위하여 혈구 응집 반응을 실시한 결과 가시오가피와 더덕을 급여한 군에서 대조군에 비하여 증가하는 경향을 보였고 7주령 A, C 군에서는 유의성 있는 차이를 보였으나 10주령 에서는 C군에서만 유의성있는 차이가 나타났다(p<0.05).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.92-106
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• 2017

The adverse weather is known as a factor that interrupts traffic flow and causes traffic accidents and traffic congestion by lowering visibility of drivers. Especially, in case of fog unlike any other weather conditions, traffic accidents lead to serious accidents and the fatality of the accidents is known to be high. This paper aims to analyze uninterrupted traffic flow characteristics under foggy conditions among adverse weathers. The traffic volumes and speeds under foggy and normal conditions were analyzed. Results indicated that fog with low visibility causes the most insignificant reduction in traffic volumes. On the other hand, the reduction in the speeds due to low visibility was evident. In addition, the relationship between flow, speed, and density in fog were analyzed. Analysis results showed that the fog with less than 200m visibility had clear impact on traffic flow.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.39-43
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• 2020

In this paper, we propose the multi-channel interference cancellation algorithm for visible light communication (VLC) in smart building. The VLC system is communication technology using visible rays that come out in Light Emitting Diode (LED) device. It has energy curtailment effect and possible to use in ubiquitous network service applications. When a large number of users communicate indoors, the performance can be reduced due to channel interference. To remove interference, at the first, the minimum mean square error (MMSE) scheme as interference cancellation methods used, and then the successive interference cancellation (SIC) is applied to obtain additional diversity gain and improve interference cancellation performance. Indoor VLC channel model is employed. The performance is evaluated in terms of bit error rate (BER). From the simulation results, it is confirmed that the proposed scheme has better BER performance compared to the previous systems. As a result, the proposed interference cancellation improves the signal quality of VLC systems by effectively removing the channel noise. The results of the paper can be applied to VLC for smart building and general communication systems.

• Korean Journal of Construction Engineering and Management
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• v.18 no.1
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• pp.83-89
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• 2017

Temporary structures provide the accessible working area when building a permanent building structure in the construction operation. Executed in a natural environment, the temporary structure is prone to the external influence factors of underground water, soil conditions, etc. These factors should be carefully considered in designing the temporary structure. The objective of this study is to apply the external influence factors in designing a more reliable earth retaining wall. The research methodology is based on the Taguchi method that has been studied to improve product quality in the industry. An orthogonal array was developed to analyze the interaction between the external influence factors and the internal influence factors. A sample case study demonstrated that the Taguchi method can be used in planning a more reliable temporary structure for earth retaining walls.

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.147-152
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• 2010

The Internet has become a major channel of business marketing and sales, and there is a core competitive object between websites for a high position ranking in search engine results. There are various ways to maintain the high position ranking of website involving the development of componental coding or the expensive investment for the search engine optimization. The purpose of this paper is proposed to identify and rank the negative elements of website visibility to get rid of those elements when website designer designs the webpage. Website can be removed from indices of search engines when they are not satisfied for search engine optimization. The proposed experiments that are identified and ranked the negative elements of website visibility in this paper are based on the theories and experiments of existing website visibility models. The experimental analyses in this paper are scored and normalized based on methodologies of those models and 10 highest negative elements are ranked through the analyses. Therefore when website is designed, these highest negative elements should be avoided so website can not be removed in the indices of search engines.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.167-172
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• 2017

In this paper, we propose a variable RGB interleaving technique for efficient data transmission in LED based visible light communication system. Visible light communication systems that utilize light as a resource for data transmission are affected by the nature of light and the three primary colors of light. However, the nature of light, such as light reflection, diffraction, and superposition, causes interference of the data to be transmitted, causing burst errors in the data. Such a problem causes the BER performance of the visible light communication system to degrade. To solve these problems, this paper attempts to utilize the variable RGB interleaving technique. Through variable RGB interleaving, data burst errors can be reduced and inter channel interference in a visible light communication system can be reduced. In addition, if the proposed system is applied to meet the QoS that depends on the importance of data or the requirements of the user, it can provide QoS requested by the user and enable efficient data transmission.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.673-677
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• 1997

It has been reported that E. senticosus is effective for strengthening the liver, reduction of blood sugar levels, antistress and rainforcement of stamina. However, most of the extraction from this medicinal plant is imported from foreign countries. Therefore, farmers have tried to grow it in this country even though it is difficult to propagate by seeding method. This study was carried out to improve seeding propagation using seeds in National Honam Agricultural Experinment Station from '92 to '93. The seeds of E. senticosus were immature embryo at the time of gathering seeds in autumn, and needed wet stratification treatment for after-ripening. Embryo elongated slowly for a few days after stratification treatment, and cotyledon started to develop from 40 days after treatment. There were significantly positive correlation between after-ripening period and the ratio of embryo length. Dehiscence was the highest in the ratio of embryo length of 60∼70％, and percentage of dehiscent seed after treatment for 150 days was 76.5％.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.563-565
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• 2010

LED is low power and pro-environment semiconductor element. That can be used not only as the lighting function but also for Visible Light Communication(VLC). The VLC is the communication technology that can send data by blinking a fluorescent or LED using visible spectrum. That velocity of blinking can not be usually recognized by eyesight. Visible Light Communication using LED can be used in many fields. In the field of ITS(Intelligent Transportation System), Under construction on the road, Emitting traffic signs can be applied to transfer the vehicle information. In this paper, Emitting traffic signs in addition to the VLC give information about road condition, safety distance and the lane change. We design Communication protocol to provide safety service and verify protocol by experiment.