• Journal of Korea Multimedia Society
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• v.20 no.5
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• pp.808-826
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• 2017

Most of conventional DSS's(Digital Signage Systems) have been built based on LAMP framework. Recent researches have shown that MEAN or MERN stack framework is simpler, more flexible, faster and more suitable for web-based application than LAMP stack framework. In this paper, we propose a design and implementation of MEARN (ME(A+R)N) stack-based real-time digital signage system, MR-DSS, which supports handing real-time tasks like urgent/instant messaging, system status monitoring and so on, efficiently in addition to conventional digital signage CMS service tasks. MR-DSCMS, CMS of MR-DSS, is designed to provide most of its normal services by REST APIs and real-time services like urgent/instant messaging by Socket.IO base under MEARN stack environment. In addition to architecture description of components composing MR-DSS, design and implementation issues are clarified in more detail. Through experimental testing, it is shown that 1) MR-DSS works functionally well, 2) the networking load performance of MR-DSCMS's REST APIs is better compared to a well-known open source Xibo CMS, and 3) real-time messaging via Socket.IO works much faster than REST APIs.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.382-384
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• 2012

클라우드 컴퓨팅 기술의 발전과 함께 많은 기업들이 관련 기술 연구를 통해 여러 플랫폼들을 제안하고 있다. 이러한 상황은 클라우드 컴퓨팅 플랫폼 발전에 도움이 되지만, 통합되지 않은 다수의 플랫폼으로 인한 문제점도 존재한다. 왜냐하면 클라우드 컴퓨팅 환경에 대해 처음 접하는 사용자의 경우, 플랫폼 선택시 합리적인 선택을 하기 어렵기 때문이다. 따라서 본 논문에서는 가장 많은 업체들이 제공하고 있는 오픈소스 기반의 플랫폼인 OpenStack, Eucalyptus, CloudStack, OpenNebula를 비교 및 분석한다. 분석 결과에서 알 수 있듯이, 각 플랫폼은 지원 가상화 기술, 스케줄링 기법, 배치 기법, 호환성 등 여러 가지 특성들 차이로 인한 장단점이 존재한다. 분석 결과를 바탕으로, 사용자들은 플랫폼들의 특성을 파악해 상황에 맞는 플랫폼을 합리적으로 선택할 수 있다.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.129-134
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• 2002

In this study, the experimental open-tube and close-tube thermoacoustic apparatuses were constructed. In order to determine the optimum length of resonant tube, frequency and the optimum length of stack, the resonant characteristics of thermoacoustic apparatuses were investigated, The length of resonant tube varies from 400mm to 850 mm. The experimental frequency varies from 100 Hz to 1000 Hz. In case of first harmonic, the maximum temperature difference of the open-tube thermoacoustic apparatus is 41$^{\circ}C$)resonator length: 500 mm), and the maximum temperature difference of the close-tube thermoacoustic apparatus is 42$^{\circ}C$ (resonator length : 850 mm).

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.384-387
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• 2010

HONS(Hybrid Open Networking Stack) 는 다양한 무선 센서들을 하나의 네트워크로 서비스할 수 있는 시스템이다. IEEE 802.15.4 표준의 Open 패킷 구조를 정의하여, 다양한 센서를 저전력 멀티-홉 네트워크로 구성할 수 있다. HONS 네트워크는 라우터와 무선 센서로 구성된다. 라우터는 전원을 사용하여 멀티-홉 네트워크의 기본 백본을 형성하며, 무선 센서는 배터리로 저전력 동작을 하여, 라우터가 구성하는 멀티-홉 네트워크에 참여한다.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.2
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• pp.144-154
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• 2016

HT-PEMFC (high temperature polymer electrolyte membrane fuel cell) using PA (phosphoric acid) doped PBI (polybenzimidazole) membrane has been researched for extending the lifetime. However, the existing work on durability of HT-PEMFC focuses on identifying degradation causes of lab scale. The short life time of HT-PEMFC is still the problem for its commercialization. In this paper, an operating method to maximize life time of 5kW HT-PEMFC stack are proposed. The proposed method includes major steps such as minimization of OCV (Open Circuit Voltage) exposure, control of the proper stack temperature, and N2 purging for the stack. This long life operating method was based on the fragmentary results of degradation from previous research works. Experimentally, the 5 kW homemade HT-PEMFC stack was operated for a long time based on the proposed method and the stack successfully can operate within the desired degradation rate for the target life time.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.459-462
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• 2008

The fact that the major cases of life casualties are from smoke in the fire accidents and the expected steep increase of skyscrapers, huge spaces, multiplexes and huge scaled underground spaces demand establishment of efficient smoke countermeasure. The architectural factors affecting the pressure field of building should be examined for the successful design and operation of smoke management system and the stack effect is one of the important factors. The field experiments on stack effect in stairwells of high-rise building with regard to open/close condition of door are carried out to evaluate the features of pressure applied to door between each compartments, i.e, stair, lobby and accommodation. The procedures and results of experiments are presented.

• Journal of Digital Convergence
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• v.14 no.7
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• pp.373-383
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• 2016

With mobile-epoch and emerging of Fin-tech, Bio-recognition technology utilizing bio-information in secure method has spread. Specially, In order to change convenient payment services and transportation cards, the combination of biometrics and mobile services are being expanded. The basic concept of authentication such as access control, IA&A, OpenID, OAuth 1.0a, SSO, and Biometrics techniques are investigated, and the protocol stack for security API platform, FIDO, SCIM, OAuth 2.0, JSON Identity Suite, Keystone of OpenStack, Cloud-based SSO, and AIM Agent are described detailed in aspect of application of AIM. The authentication technology in domestic and foreign will accelerate technology development and research of standardization centered in the federated FIDO Universal Authentication Framework(UAF) and Universal 2 Factor Framework(U2F). To accommodate the changing needs of the social computing paradigm recently in this paper, the trends of various authentication technology, and design and function of AIM framework was defined.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.152-158
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• 2016

In this paper, we implemented the full stack platform design with MongoDB database of open source platform Raspberry PI 3 model. We experimented the triggering of event driven with acceleration sensor data logging with wireless communication. we captured the image of USB Camera(MS LifeCam cinema) with 28 frames per second under the Linux version of Raspbian Jessie and extended the functionality of wireless communication function with Bluetooth technology for the purpose of making Android Mobile devices interface. And therefore we implemented the functions of the full stack platform for recognizing the event triggering characteristics of detecting the acceleration sensor action and gathering the temperature and humidity sensor data under IoT environment. Especially we used MEAN Stack for developing the performance of full stack platform because the MEAN Stack is more akin to working with MongoDB than what we know of as a database. Afterwards, we would enhance the performance of full stack platform for IoT clouding functionalities and more feasible web design with MongoDB.

• Smart Media Journal
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• v.7 no.4
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• pp.70-78
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• 2018

Current trends in information system have led many companies to adopt security solutions. However, even with a large budget, they cannot function properly without proper security monitoring that manages them. Security monitoring necessitates a quick response in the event of a problem, and it is needed to design appropriate visualization dashboards for monitoring purposes so that necessary information can be delivered quickly. This paper shows how to visualize a security log using the open source program Elastic Stack and demonstrates that the proposed method is suitable for network security monitoring by implementing it as a appropriate dashboard for monitoring purposes. We confirmed that the dashboard was effectively exploited for the analysis of abnormal traffic growth and attack paths.

• Journal of the Korean Ceramic Society
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• v.44 no.8
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• pp.407-411
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• 2007

A 3-cell stacked anode-supported solid oxide fuel cell was designed and fabricated to achieve a complete gas seal and the facile stacking of components. The stack was assembled with a unit cell with $10{\times}10cm^2$ area, and each cell was interconnected by a stainless steel 430 separator using a proprietary sealant sheet. The stack performance was examined at various gas flow rates of $H_2+3.5vol%\;H_2O$, and air at a fixed temperature of $800^{\circ}C$. No gas leakage was found from the sealing between cells and inter-connects within a measurement system in this research during a prolonged time of 500 h in operation. The test resulted in an open circuit voltage of 3.12 V, a peak power of 149 W, and a power density of $0.61W/cm^2$, while the long term durability of the power showed 19.1% degradation during the prolonged time of 500 h when tested at $800^{\circ}C$.