• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.614-618
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• 2002

파일 공유를 위한 방법으로 FTP, NFS나 최근 P2P기술 등이 많이 제안되었지만, 현재까진 아직 FTP를 많이 사용하고 있다. 본 논문에서는 거의 기존 파일 전송 서비스 환경의 변경을 하지 않으면서도 고용량의 데이터를 보다 효율적으로 공유할 수 있는 방법으로써 Distributed File Server(DFS)방식을 제안한다. DFS의 특징은 기존 서버 클라이언트 방식의 FTP 환경을 변경하지 않고, 단지 다수의 서버들과 클라이언트 사이에 DFS를 설치함으로써 클라이언트에게 고용량 파일 저장 장소를 가진 FTP서버를 제공할 수 있다는 것이다. RedHat7.2 상에서 DFS 기능의 검증을 위한 프로토타입 구현을 통해 최근 대두되고 있는 고용량 데이터들로 인한 파일 시스템의 부족등의 문제점을 해결할 수 있음을 보였다.

• International Journal of Contents
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• 제10권1호
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• pp.62-67
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• 2014

Usually, cloud storage systems are developed based on DFS (Distributed File System) for scalability and reliability reasons. DFSs are designed to improve throughput than IO response time, and therefore, they are appropriate for batch processing jobs. Recently, cloud storage systems have been used for update intensive applications such as OLTP and so on. However, in DFSs, in-place update operations are not carefully considered. Therefore, when updates are frequent, I/O performance of DFSs are degraded significantly. DFSs with RAID techniques have been proposed to improve their performance and reliability. Their performance degradation caused by frequent update operations can be more significant. In this paper, we propose an in-place update method for DFS RAID exploiting a differential logging technique. The proposed method reduces the I/O costs, network traffic and XOR operation costs for RAID. We demonstrate the efficiency of our proposed in-place update method through various experiments.

• Fisheries and Aquatic Sciences
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• 제13권3호
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• pp.231-235
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• 2010

The effects of various natural antioxidant sources on oxidation of olive flounder (Paralichthys olivaceus) and fish diet during storage was determined. Juvenile fish were distributed among 18 flow-through tanks (40 fish per tank). Six experimental diets were prepared in triplicate: control (CT), antitox (AT), green tea extract (GE), fig extract (FE), Haeroc product (HP) and by-product of green tea (BG). The experimental diets were stored at two temperatures: room temperature ($26.8^{\circ}C$) for 14 days and frozen ($-30^{\circ}C$) for 16 weeks. Thirty fish were sampled from each tank at the end of the 8-week feeding trial. Whole bodies of fish were homogenized and stored in a home freezer ($-9.6^{\circ}C$) for 24 weeks. Acid values (AVs) and peroxide values (POVs) of the diets and frozen fish during storage were monitored. AVs of the experimental diets tended to increase with the storage period except for that of the HP diet at room temperature. POVs from FE, CT, and BG diets peaked at day 7 and then decreased through the remainder of the experiment. AVs of the experimental diets and fish increased with time at $-30^{\circ}C$ and $-9.6^{\circ}C$. Results of this study show that by-products of green tea and Haeroc product seem to have potential as antioxidants in fish feed to inhibit oxidation of both the feed and fish during storage.

• 한국식생활문화학회지
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• 제30권5호
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• pp.596-610
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• 2015

This study is on the alcohol beverage utensils represented on the Chinese tomb mural paintings of Song, Liao, Jin, and Yuan those countries had foreign exchange with Koryo Dynasty. These mural paintings are distributed in the areas such as Hebei, Henan, Inner mongolia, Shanxi, Shaanxi, Peijing. etc. The Alcohol beverage vessels were classified mainly into storage vessel, pouring vessel, drinking vessel and ladles according to the purpose. The storage vessels of Song, Liao and Jin were called Jiuping, Jingping, Jiuzun as well as Meiping. Pouring vessels are basically one set of Zhuzi, Wenwan and Jiuzhu, or Zhuhu and Zhuwan. On the mural paintings of Yuan Dynasty, Meiping as storage vessels disappear, and a variety of shapes of pouring vessels such as Mayu and Yuhuchunping appear. This trend indirectly indicates the new arrival of distilled liquor, which seems to have affected transition of the alcohol beverage utensils.

• Journal of Plant Biology
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• 제37권3호
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• pp.293-299
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• 1994

Developing rice endosperm cells display two morphologically distinct rough endoplasmic reticulum (ER) membranes, the cisternae ER (C-ER) and theprotein body ER (PB-ER), the latter delimiting the prolamine protein bodies. We (Li et al., 1993) have recently shown that the storage protein mRNAs are not randomly distributed on these ER types; the C-ER is enriched for glutelin mRNAs, whereas the PB-ER harbors predominantly prolamine transcripts. To address whether these ER types have differnet capacities to translate these mRNAs and translocate their proteins into the lumen, a microsomal fraction enriched in C-ER vesicles was prepared from devleoping rice seeds. When present in an in vitro translatin system, the microsomes were able to proteolytically remove the signal peptide and internalize both preproglutelin and preprolamine within the microsomal vesicles. Of the two species, preprolamine was more effectively translocated and processed. These results suggest that the C-ER has the capacity to recognize and bind both storage protein mRNAs during protein synthesis. Moreover, efficient translocation and processing of glutelin requires additional factors that are deficient or absent in the in vitro system.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.57-60
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• 2008

As the technology of a large scale battery have advanced, it's application to the electric power network have been active in foreign country. By providing the electric power energy stored in the electric power storage system when needed, there are many advantages that it is able to reduce the gap between the electric power demand and supply for day and night to increase capacity factor, to upgrade the electric power quality degraded from the unbalance between power demand and supply and to compensate the fluctuation of wind power plant and photovoltaic power generation. In this study, the current application of electric power storage system using battery is introduced in detail, and I have thought out it's application fields based on the foreign examples. These are demand side response, upgrade of the power quality, stabilization of fluctuation of renewable energy and distributed generation for filling elapse.

• 한국정보시스템학회지:정보시스템연구
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• 제27권2호
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• pp.95-114
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• 2018

Purpose The recent concern over environmental problems such as greenhouse gas emission and fine dust contributes increasing interest in renewable energies. However the intrinsic characteristics of renewable energies, intermittent and stochastic generation, might cause serious problems to the stability and controllability of power grid. Therefore countermeasures such as virtual power plant (VPP) must be prepared in advance of the spread of uncontrollable distributed renewable energy resources to be one of major energy sources. Design/methodology/approach This study deals with the design concept of the VPP platform. we proposed as a technology solution for achieving the stability of power grid by guaranteeing a single power profile combining multiple distributed power sources with ICT. The core characteristics of VPP should be able to participate in the grid operation by responding to operation instructions from the system operator, KPX, as well as the wholesale electricity market. Findings Therefore this study includes energy storage device(ESS) as a controllable component as well as renewable energy resources such as photovoltaic and wind power generation. Based on this configuration, we discussed core element technologies of VPP and protype design of VPP solution platform according to system requirements. In the proposed solution platform, UX design for the integrated control center and brokerage system were included as well as ancillary service function to respond to KPX's operation instruction with utilizing the capability of ESS. In addition, a simulator was suggested to verify the VPP operations.

• 한국통신학회논문지
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• 제41권12호
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• pp.1684-1691
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• 2016

최근 분산 저장 시스템에 erasure code를 활용하여 저장소 효율성을 높이려는 연구가 활발히 진행되고 있다. 재생 부호(regenerating codes)는 erasure code의 일종으로, 높은 저장소 효율성과 네트워크 효율성을 가지는 코드이다. (n,k,d)-재생 부호는 n개의 저장소 노드를 가지며, 손실된 노드가 발생하였을 때, 해당 노드는 d개의 살아남은 노드로부터 정보를 다운로드받아 복구될 수 있다. 하지만 일반적인 재생 부호는 노드 복구 시 정확히 d개의 도움 노드들을 사용해야 하며, 노드 손실이 빈번하거나, 노드 간 접속이 불안정한 환경에서, d개 이하의 노드들에만 접속 가능할 경우에 유연하게 대처할 수 없다. 본 논문에서는 약간의 복구 대역폭의 희생을 통하여, $$k{\leq_-}{\bar{d}}{\leq_-}d$$의 다양한 도움 노드의 수 ${\bar{d}}$개로 노드를 복구할 수 있는 유연한 코드 운용 방식을 제안하였다.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1369-1375
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• 2017

This paper presents an optimal operation scheduling algorithm for a smart home with energy storage system, electric vehicle and distributed generation. The proposed algorithm provides the optimal charge and discharge schedule of the EV and the ESS. In minimizing the electricity costs of the smart home, it considers not only the cost of energy purchase from the grid but also the life cost of batteries. The life costs of batteries are calculated based on the relation between the depth of discharge and life time of battery. As the life time of battery depends on the charge and discharge pattern, optimal charge and discharge schedule should consider the life cost of batteries especially when there is more than one battery with different technical characteristics. The proposed algorithm can also be used for optimal selection of size and type of battery for a smart home.

• 정보과학회 논문지
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• 제41권12호
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• pp.1126-1135
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• 2014

최근 대규모 RDF 데이터를 효과적으로 분산 저장 및 관리하기 위해 RDF 분할 기법의 연구가 진행되고 있다. 본 논문에서는 지속적으로 데이터의 추가 및 변경이 발생하는 동적 환경에서 부하 분산을 지원하는 RDF 동적 분할 기법을 제안한다. 제안하는 기법은 그래프 분할을 수행하기 위한 기준으로 질의에 의해 사용된 RDF 데이터의 사용 빈도에 따라 클러스터와 서브 클러스터 그룹을 생성한다. 생성된 클러스터와 서브 클러스터는 분산된 서버의 부하 및 저장되는 데이터 크기를 고려하여 분할을 수행한다. 이를 통해 지속적인 데이터 변경 및 추가로 인해 특정 서버에 대한 데이터 집중을 해결하고 서버들간에 효율적인 부하 분산을 수행한다. 성능평가를 통하여 분산 서버에서 제안하는 기법이 기존 분할 기법에 비해 질의 수행 시간이 크게 향상됨을 보인다.