• Journal of Astronomy and Space Sciences
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• 제37권4호
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• pp.219-228
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• 2020

A CubeSat platform has become a popular choice due to inexpensive commercial off-the-shelf (COTS) components and low launch cost. However, it requires more power-efficient and higher-data rate downlink capability for space applications related to remote sensing. In addition, the platform is limited by the size, weight and power (SWaP) constraints as well as the regulatory issue of licensing the radio frequency (RF) spectrum. The requirements and limitations have put optical communications on promising alternatives to RF communications for a CubeSat platform, owing to the power efficiency and high data rate as well as the license free spectrum. In this study, we analyzed the performance of optical downlink communications compatible with CubeSat platforms in terms of data rate, bit error rate (BER) and outage probability. Mathematical models of BER and outage probability were derived based on not only the log-normal model of atmospheric turbulence but also a transmitter with a finite extinction ratio. Given the fixed slot width, the optimal guard time and modulation orders were chosen to achieve the target data rate. And the two performance metrics, BER and outage data rate, were analyzed and discussed with respect to beam divergence angle, scintillation index and zenith angle.

• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.232-237
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• 2021

Pre-Corona cultural content was largely formed face to face. For example, the service was great while visiting tourist attractions, visiting performances to see K-Pop, or visiting lectures to learn K-Beauty. However, after the coronation, the virtual world-centered Metaverse began to take the spotlight as non-face-to-face services changed. IT and cultural contents have been combined and developed into various digital services. In that sense, Metaverse, which breaks the boundaries between real-world space and virtual space, has the potential to escape from physical time and space constraints. However, Korea still lacks a Metaverse platform for cultural content. In particular, it is necessary to match each other's necessary services by providing Metaverse -oriented cultural contents that users want, including experienced cultural contents such as K-pop and K-beauty, away from cultural contents that are developed around history museums. Therefore, in this paper, we would like to propose a Metaverse-based cultural content matching platform where users can experience cultural content directly or indirectly.

• Journal of Astronomy and Space Sciences
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• 제32권2호
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• pp.151-159
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• 2015

The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD) to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.

• 한국지능시스템학회논문지
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• 제19권1호
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• pp.115-121
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• 2009

Web 2.0 has become the face next generation Web among the business world and research community. Web 2.0 is instant superficial gratification of people. On the other hand, Semantic Web is deep, meaningful and lasting relationship with data. So, it is difficult to apply the Semantic Web to the real world. In this paper, a platform for educational services using the Semantic Web and Web 2.0 is proposed. The proposed platform is based mix of the Semantic Web and Web 2.0, so it is useful to apply in the real world applications. Two services are presented, one is a semantic email system and the other is a cyber study space. The cyber study space adjusted each student is presented. The study environment is called iStudySpace that has personal scheduler, study status plan table, personalized search engine and several gadgets. Finally characteristics and limitations of the Semantic Web and Web 2.0, the organization and components of the platform, evaluation of iStudySpace are shown.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.863-864
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• 2005

In recent years, we use overdriving scheme to improve the response time of the liquid crystal. Since conventional overdriving scheme uses memory to perform ideal processing, it is desired to reduce system cost by decreasing the data stored in these SDRAMs. As a general compression method, quantization, sub-sampling and Block Truncation Coding ( BTC ) are used, which process data in block base and cause block effect. So we proposed new data compression method by color space conversion. Because this method compresses luminance and chrominance signal by different ratio, it can efficiently reduce error of block effect in decompression image.

• 한국멀티미디어학회논문지
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• 제23권3호
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• pp.499-507
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• 2020

This paper is one of the types of 'sharing economy', a social economic model that borrows and shares things, spaces, and services from the development of the 4th Industrial Revolution. Through sharing of empty space and time in the city, I would like to suggest a way to reduce the closure of small business owners in order to create jobs, which is one of urban problems in the community. We also build a platform that utilizes the free time and space of buildings through space sharing, one of the types of sharing economy, and provides education programs for start-up education, promotion, marketing, and consulting by matching small business owners with building owners. Therefore, in this paper, by sharing the space and time, the landlord and the small business can share the profits of the small business by reducing the business owner's closure and the job creation plan. Coaching urban regeneration was proposed.

• 정보화정책
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• 제25권4호
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• pp.108-120
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• 2018

전 세계 4차 산업혁명의 도래에 맞춰 한국은 적극적으로 국가적 대응계획 I-Korea 4.0을 수립하여 2017년 11월에 발표하였다. 이 계획은 국가성장을 위한 산업혁신과 사회문제 해결을 목표로 하고 있다. 부동산산업도 예외는 아니며 산업혁신을 위해서는 스마트환경에서 주거, 상업, 업무, 복합 등 다양한 가용공간의 효과적 활용이 선행되어야 한다. 이를 위해서는 효율적 의사결정이 필요하고 이는 공간수요자 행태의 실시간 정보와 정확한 예측이 이루어 질 때 가능하다. 이에, 본 연구는 빅데이터 기반 스마트 스페이스 플랫폼을 제안하고 플랫폼의 구조와 서비스를 구체화 시키고자 한다. 스마트 스페이스 플랫폼도 스마트 트래픽, 스마트 시티, 스마트 헬스 등 다양한 스마트환경 적용사례처럼 급속히 발전하고 있는 정보통신기술(ICT)을 이용해 빅데이터의 효율적 저장, 접근, 분석, 활용이 가능하다. 스마트 스페이스 플랫폼의 구조는 6개 레이어 즉, Collection layer, Transfer layer, Storage layer, Service layer, Application layer, Management layer로 구성된다. 이 플랫폼은 의사결정자들이 행위기반(activity-based), 시장기반(market-based), 정책기반(policy-based) 빅데이터를 Searching, Mining, Integrating, Storing, Analyzing, Visualizing 할 수 있는 서비스체계를 가지고 있다.

• 한국게임학회 논문지
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• 제10권6호
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• pp.89-96
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• 2010

본 연구는 소셜네트워크와 활발하게 연계되고 있는 스마트폰 플랫폼을 기반으로 한 농장경영 게임의 특성을 파악하기 위하여, 게임 내의 소셜 네트워크 플레이 경험이 스마트폰 플랫폼에서 보여지는 농장경영게임의 공간과 어떻게 연관되는가를 분석하고자 하였다. 스마트폰 플랫폼을 기반으로 한 SNS 농장경영게임의 플레이 경험은 주로 세 개의 모듈, 정작 모듈, 환경 배치 모듈, 공간 확장 모듈을 중심으로 이루어진다. 본 연구에서는 농장경영게임의 특성을 분석하기 위하여 공간경험이론을 바탕으로 외적 투시공간, 내부조망 공간, 상징적 기획 공간으로 나누어 각 공간에서 일어나는 플레이 경험을 중심으로 살펴보았다. 농장경영게임에서 플레이어는 고정된 시정을 통해 공간을 인식하고, 모듈을 재해석하여 재배치하는 데 있어 자신의 공간을 소셜 네트워크의 기본단위로 삼게 된다. 이러한 과정에서 공간은 단순한 배정이 아닌, 소셜 네트워크 게임에서 필수적인 협력 플레이를 일으키도록 하는 주체적 역할을 수행한다.

• Journal of Astronomy and Space Sciences
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• 제31권1호
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• pp.91-99
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• 2014

The atmospheric flow in the 3-Cell model of global atmosphere circulation is described by the Lagrange's equation of the non-inertial frame where pressure force, frictional force and fictitious force are mixed in complex form. The Coriolis force is an important factor which requires calculation of fictitious force effects on atmospheric flow viewed from the rotating Earth. We make new Mathematica platform to solve Lagrange's equation by numerical analysis in order to analyze dynamics of atmospheric general circulation in the non-inertial frame. It can simulate atmospheric circulation process anywhere on the earth. It is expected that this pedagogical platform can be utilized to help students studying the atmospheric flow understand the mechanisms of atmospheric global circulation.

• Steel and Composite Structures
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• 제24권3호
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• pp.383-391
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• 2017

The goal of this study is to investigate structural analysis and behaviors of an innovative aerial work platform truss frame whose ductility is improved by using high strength-steel UL-700. The present space truss frame can move or stop through tunnels for maintenance constructions by automatic facilities and workmanship within standardized limited building lines of tunnel. Most of all, this method overcomes problematic, which is to block cars during construction periods, seriously, of typical methods like as using truck and scaffolds for tunnel maintenance. According to evaluated appropriate design results of space truss frames of numerical examples by using a commercial MIDAS GEN program, it is verified that design parameters such as layered size, cross-sectional size, and steel material of the present space truss frame are determined to depend on characteristics such as lanes or shape of road tunnels.