• Applied Chemistry for Engineering
• /
• v.3 no.4
• /
• pp.535-546
• /
• 1992

The molten carbonate fuel cell(MCFC) has been under Intensive development for the last decade as a second generation fuel cell. The advantages of the MCFC over the phophoric acid fuel cell are higher efficiency, its ability to accept CO and $H_2$ as a fuel, lower material costs, and high operating temperature making internal reforming possible. These features, along with low atmospheric emissions, will open up a significant market as an attractive means of developing highly efficient power plant. This article reviews a status of the MCFC research and development, a principle of the MCFC, and cell and stack technology including the status of electrodes, matrices and electrolytes. Several technical difficulties which must be resolved to be commercialized art mainly focused.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2018.05a
• /
• pp.12-15
• /
• 2018

비정형 데이터를 효율적으로 처리하기 위한 대표적인 오브젝트 스토리지로 OpenStack Swift가 있다. 하지만, 오브젝트 스토리지의 일관성 지원은 동기화 지연을 발생시키고 전체 성능에 영향을 미친다. 이런 문제는 기존 시스템에서 발생하는 페이지 스왑, 데이터 중복을 비휘발성 메모리를 사용함으로써 제거할 수 있고 오브젝트 서버의 성능 하락을 완화할 수 있다. 하지만, 비휘발성 메모리를 효율적으로 사용하기 위해서는 비휘발성 메모리 장치별 특성을 고려한 효율적인 데이터 배치가 필요하고 본 논문에서는 이를 위한 마이그레이션 기법을 제안한다. 마이그레이션 기법에서 사용하는 점수식은 First In First Out (FIFO)보다 정확도를 약 11% 향상시켰고, 기존 기법들보다 실행 시간은 42% 감소, 마이그레이션 횟수는 최대 24배 감소, 에너지 소비량은 9% 정도 절약하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.04a
• /
• pp.167-169
• /
• 2015

기존 그리드 및 클러스터 환경과 달리 클라우드 컴퓨팅 환경에서는 하나의 물리 호스트 위에 다수의 가상 머신 인스턴스가 할당 및 운용됨에 따라 가상 머신 간섭 (Virtual Machine Interference)에 의한 응용 처리 성능 저하가 발생한다. 본 논문에서는 클라우드 오픈소스 플랫폼인 오픈스택 (OpenStack)을 기반으로 하여 가상 머신 인스턴스 위에서 Montage 워크플로우 응용을 처리할 때 가상 머신 간섭이 처리 성능에 미치는 정도를 분석하고 이를 해결하기 위한 자원 할당 정책을 논의한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.10a
• /
• pp.284-286
• /
• 2015

최근 첨단과학응용 분야에서 클라우드 기반의 실험 환경을 구축하는 사례가 늘어가고 있다. 이러한 연구 환경의 패러다임 변화와 관련하여 연구망에서도 고성능 백본 망을 활용한 데이터 공유 서비스에 대한 필요성이 대두되고 있다. 본 논문에서는 데이터 공유 모델의 설계에 앞서 실험적 연구로 공개 소프트웨어 클라우드 운영체제인 OpenStack의 Swift 서비스를 이용하여 오브젝트 스토리지 실험 테스트 베드를 구축하고, 대용량의 데이터 전송 시 발생하는 트래픽을 분석한다. 분석 결과, 리플리카의 생성, 배치 및 선택 등에 따른 유의한 트래픽 발생의 변화를 관찰할 수 있었고, 이러한 결과는 광역 규모의 분산된 데이터 공유 모델 설계 및 망에 대한 요구사항 등으로 활용될 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.637-638
• /
• 2014

This paper proposes a new visualization method based on Vitualization technique which uses internal relationship of user correlation and external information of social network to visualize user relationship hierarchy. The proposed method use hadoop on virtual machine of OpenStack for distribution and parallel processing which the result of calculation visualizes hierarchy graph to analyze link nodes of Social Network Services for users.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.11a
• /
• pp.148-151
• /
• 2013

가상화 기반 클라우드 컴퓨팅 환경은 비용 효율성과 자원 활용 측면에서 강점을 갖고 있으나 주어진 응용의 행태에 따른 적절한 자원할당 방법이 필요한 상황이다. 그러므로 클라우드 컴퓨팅 환경에서 다양하게 구성된 가상클러스터와 응용 특성을 서로 비교 분석해야 한다. 이를 위해 본 논문의 목적은 OpenStack 기반 가상화 자원을 사용하여 생성된 클러스터 환경을 상태분석 도구인 Ganglia를 이용하여 분석한다. 분석에 사용되는 Utility 함수의 결과는 각 응용에서 요구되는 성능을 클라우드 컴퓨팅 환경이 만족시키는지 판단할 수 있는 자료가 될 것이다.

• Journal of the Semiconductor & Display Technology
• /
• v.22 no.2
• /
• pp.11-16
• /
• 2023

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, without operating system, we have implemented an EtherCAT master with an open source EtherCAT master stack SOEM on STM32 Nucleo-144 board with an STM32F767 microcontroller. And its jitter performance has been evaluated at the output of the network port to include all the effects of the entire system in the results. The results show that the implemented EtherCAT master has precise control performance for control frequencies from 1KHz to 8KHz and relatively superior jitter performance compared to the EtherCAT masters with real-time patched Linux operating system.

• Journal of The Geomorphological Association of Korea
• /
• v.27 no.4
• /
• pp.53-70
• /
• 2020

Silgyeong sansuhwa (Realistic landscape paintings) are drawn in Korea since 17th century. It has characteristics of more realistic description of landscape than painting from previous periods. Kim Hong Do's 'Haedong Myeongsan docheop (The album of paintings of famous mountains in Korea)' has been recognized as fine example of realistic description of geomorphic landscapes. Kim Hong Do and Kim Eung hwan did official travel to Gwandong and Geumgangsan area by order of King Jeongjo in 1788. As a result of that travel they draw about 100 piece of landscape painting. About 60 pieces of the paintings are still remaining. These are open to public by Korea National Museum in 1996. 14 pieces of painting, Daegwanryeong and Gangneung, Gyeongpo-dae, Hohae-jeong, Gahak-jeong, Cheonggan-jeong, Mun-am, Mangyang-jeong, Wolsong-jeong, Neungpa-dae, Naksan-sa, Mureung-gye, Gyejo-gul, and Hyeonjong-am, are analysed in this study. Coastal depositional landforms, like lagoon, sand beach and spit or barriers, erosional forms, like sea stack, sea cliff and sea cave, depicted in the paintings are analysed. In addition, structural landforms, colluvial landform and bedrock incision form by the running water in mountain area were analysed and weathered forms of granite and excursion to karst cave also discussed. It is found that sea arch in the printing destroyed since 1788, though exact position and reason is still unknown. There are strong need for discovery and identification of geomorphic landscape resources, for applied geomorphological studies and for prepare educational materials for non-face-to-face education. It also be emphasized that it can be used of the course work materials for future education using augmented reality and virtual reality technology.

• Korean Institute of Interior Design Journal
• /
• v.23 no.4
• /
• pp.240-247
• /
• 2014

This study is aimed to examine the characteristics of library space, in which user experiences and social networking are central in its design. Today, a library is a place to provide diverse accesses and experiences to information networks, where various individuals and user groups come and share mutual understanding and experiences. Library users developed social ties and a sense of community through library experiences. As a multipurpose space of a community, a library has the characteristics of urban public space like sidewalks and plazas. The eight case studies of libraries are analyzed from the viewpoint of each factor of library experience, including landscape, sidewalk, and plaza experience. The study drew its conclusions as follows. First, a library is a regional landmark for the users. Thus, it tends to be designed to allow transparency on its surface which introduces inner and outer landscape into the inside of the building. Second, the users experience a library similarly as they experience an urban street where they interface, browse, and interact with people and information. As they interact and share experiences, they develop solidarity and social ties among them. A library is designed to preserve continuity to adjacent streets, which increases accessibility to the building and hosts street activities into the building. Third, a library today is designed to be a flexible open space with information networking as well as community networking which allows library users diverse activities within it. For example, a multipurpose grand stairs in the middle of the main circulation of a building allows the users diverse activities. A large open stack with reading areas gives the users the feeling of an urban plaza where they can move vertically and horizontally. In conclusion, all findings of this study imply a user-oriented design for a library building.

• Korean Journal of Remote Sensing
• /
• v.26 no.2
• /
• pp.99-108
• /
• 2010

According to the recent trend on advancement of web computing technologies and diversification of spatial data types to be processed, designing and implementing of web-based applications using open sources has been regarded as one of important users-needs. In this study, a kind of geo-browser model composed of client-middleware-DBMS stack is suggested, and the prototype implementation are performed. Especially, modularization of user interfaces is contributed to increase both applicability for a certain target system and accessibility for web users. In middleware, it has functions to decrease erroneous factors on spatial data registration processes, and provides spatial data the form of OGC WxS standards. It is thought that this system is helpful to utilize as basic architecture and the related implementation model for web-based geo-spatial services and their applications.