• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.55-56
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• 2022

본 논문에서는 유·아동의 독서활동을 돕고자 기존에 있는 동화책과 가상현실 기술을 결합한 몰입형 동화 콘텐츠를 제안한다. VR 환경은 3D 입체 환경을 통한 중다감각적 상호작용을 가능하게 하여 학습자로부터 동기를 유발시킨다. 프로그램이 시작되면 컨트롤러가 활성화되며 동화보기, 미니게임 등 동화에 직접적으로 참여하여 즐길 수 있는 콘텐츠로, 향후 유·아동의 교육적인 면에서도 더욱 효과적일 것으로 기대된다.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.44-54
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• 2008

In this paper, an iterative multiple symbol differential detection for turbo coded differential unitary space-time modulation using a posteriori probability (APP) demodulator is investigated. Two approaches of different complexity based on linear prediction are presented to utilize the temporal correlation of fading for the APP demodulator. The first approach intends to take account of all possible previous symbols for linear prediction, thus requiring an increase of the number of trellis states of the APP demodulator. In contrast, the second approach applies Viterbi algorithm to assist the APP demodulator in estimating the previous symbols, hence allowing much reduced decoding complexity. These two approaches are found to provide a trade-off between performance and complexity. It is shown through simulation that both approaches can offer significant BER performance improvement over the conventional differential detection under both correlated slow and fast Rayleigh flat-fading channels. In addition, when comparing the first approach to a modified bit-interleaved turbo coded differential space-time modulation counterpart of comparable decoding complexity, the proposed decoding structure can offer performance gain over 3 dB at BER of $10^{-5}$.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.357-363
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• 2013

This study aims to establish and apply a mobile office app for approving the achievements of tasks assigned to each person to investigate resulting satisfaction. This is done first by implementing the app for approval in a company with smart phones to enable tasks to be carried out any time and anywhere while the mobile office environment changes the method of carrying out tasks. More efficient work environment is expected if the system implemented in this study is improved in cooperation with customer's requirements. Matters for improving work efficiency added to the approval management system through this app will contribute to efficiently and continuously improving the mobile office environment to enhance productivity and efficiency of a company.

• Journal of Internet Computing and Services
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• v.16 no.4
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• pp.25-37
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• 2015

This study has developed a mobile AR contents Builder (MARB) featuring the augmentation of virtual objects, e. g. 2D images, 3D models and videos on user-preferred markers in mobile environment and with connected interaction events. The developed MARB is capable of augmenting multiple virtual objects on markers preferred by users, and selectively supporting many marker-specific interaction events. The MARB is also developed as a mobile App for convenience of use in the mobile environment. This makes users to implement AR contents by a GUI-based authoring procedure on the mobile device. The developed MARB allows App developers and general users to author mobile contents easily and can be applied to various field by those who wish to use diverse mobile AR contents. Moreover, the MARB will provide solutions for the expansion of mobile AR market, by overcoming the difficulties of mobile AR content development.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.197-199
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• 2016

일반적으로 네비게이션은 차를 이용하는 것으로 발전한 것이 대부분이며, 지형이나 지도 또는 정보를 저장했다가 사용하는 로드뷰를 이용하여 개발되고 있다. 본 연구에서는 증강현실 기술과, 스마트폰의 카메라, 센서 등을 이용하여 실제의 길과 주변 환경을 스마트폰에 보여주고, 실제 길 위에 찾고자 하는 목적지까지 길을 안내해주며 다양한 부가 정보를 제공하는 도보 길찾기 앱을 개발하고자 한다. 기존의 앱과 다른 점은 증강현실 기술을 활용하는 것이다. 기존 네이게이션에서 2D나 3D로 그래픽 처리되어 있는 것을 실제 화면을 적용하여 직관적으로 길을 찾을 수 있고, 부가적으로 주변의 정보들을 실시간으로 표현할 수 있는 이점이 있다.

• Biomolecules & Therapeutics
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• v.29 no.3
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• pp.290-294
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• 2021

Extracellular beta amyloid (Aβ) plaques are the neuropathological hallmarks of Alzheimer's disease (AD). Accordingly, reducing Aβ levels is considered a promising strategy for AD prevention. 3'-O-acetyl-24-epi-7,8-didehydrocimigenol-3-O-β-D-xylopryranoside significantly decreased the Aβ production and this effect was accompanied with reduced sAPPβ production known as a soluble ectodomain APP fragment through β-secretases in HeLa cells overexpressing amyloid precursor proteins (APPs). This compound also increased the level of sAPPα, which is a proteolytic fragment of APP by α-secretases. In addition, 3'-O-acetyl-24-epi-7,8-didehydrocimigenol-3-O-β-D-xylopryranoside decreased the protein level of β-secretases, but the protein levels of A disintegrin and metalloproteinase (ADAM) family, especially ADAM10 and ADAM17, are increased. Thus, 3'-O-acetyl-24-epi-7,8-didehydrocimigenol-3-O-β-D-xylopryranoside could be useful in the development of AD treatment in the aspect of amyloid pathology.

• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.467-468
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• 2014

• Journal of Digital Contents Society
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• v.14 no.3
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• pp.381-390
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• 2013

Almost all the mobile phone users already moved or are now moving away to smartphones for their various applications like games. If we are to speak about game applications, due to the performance limits of smartphones, 2D games are predominant over 3D games in every app. store. In this paper, we implement a 3D cube game application by porting an existing visual c++ irrlicht cube application to android platform library using the android Native Development Kit. After the porting is done, we add a few new features for more fun. Because the android NDK makes the existing C/C++ codes run directly on the android operating systems, we found by real execution tests that our 3D cube app. is well executed on a low-end android smartphone without any performance problem.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.45-49
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• 2006

Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.147-154
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• 2020

It is difficult to educate the overall operation of public and private blockchains with different characteristics. Recently, most education for blockchain is targeted at public blockchains such as Bitcoin and Ethereum. However, in an actual business environment, a private blockchain such as HyperLedger Fabric is used because access to corporate data is controlled through user authentication. In the case of HLF-based education, it is necessary to understand various components that are not in the public blockchain, such as peers, orderers, and channels. In this paper, a lab framework for HLF is designed for an efficient and systematic understanding of the functions and operations. The framework consists of HLF network, chaincode, and decentralized software control functions. Through the framework, the network configuration, distribution and activation of chaincode, and dApp execution process were checked step by step, and it was very easy to understand the overall flow for blockchain services. In addition, it is expected that a systematic understanding of the overall flow will be possible even in future network expansion.