• 한국콘텐츠학회논문지
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• 제16권5호
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• pp.251-258
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• 2016

최근 클라우드 컴퓨팅, 사회 관계망 서비스 등의 분야에서 고속 저장 장치에 대한 수요가 크게 증가하고 있다. 성능이 우수한 고속 저장 장치가 개발되고 있지만 현재 리눅스 운영체제의 입출력 스택은 하드 디스크 드라이브를 고려해서 설계되었기 때문에 고속 저장 장치를 충분히 활용하고 있지 못하다. 이 논문에서는 고속 저장 장치의 입출력 대역폭과 입출력 지연시간을 최대로 활용할 수 있는 최적화된 입출력 스택을 제안한다. 이를 위해 기존 리눅스의 블록 입출력 계층을 새로운 인터페이스를 가지는 입출력 계층으로 대체하고 최적화한다. 제안된 입출력 계층은 기존의 하드 디스크 드라이브를 고려한 블록 계층을 우회하고 디바이스 드라이버를 최적화하여 고속 저장 장치의 성능을 최대한 이용할 수 있게 해준다. 또한, 리눅스의 ext2/ext4 파일 시스템을 제안된 입출력 계층 위에서 동작할 수 있도록 최적화하였고, 벤치마크 실험 결과를 통해서 제안하는 입출력 스택은 기존 리눅스 입출력 스택과 비교하여 1.7배 정도의 성능 향상이 있음을 확인할 수 있었다.

• 정보관리연구
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• 제42권4호
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• pp.59-74
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• 2011

디지털자료가 증가하고 있음에도 불구하고, 과학기술정보 수입국으로서 정보의 자립도를 높이기 위하여 인쇄자료의 수집과 보존공간의 확보는 국가차원에서 여전히 중요하다. 본 연구는 한국과학기술정보연구원(KISTI)의 사례를 통하여 과학기술 인쇄자료 보존공간의 문제를 분석한 후, 확충방안을 제안 하였다. 국내외 표준 서고공간을 제시하고, KISTI의 서고공간 현황을 분석한 후, 유형별 자료 증가분에 근거하여 2020년까지 시나리오별 필요 서고보존공간을 연차별로 예측하였다. 부족한 보존공간의 확충방안을 개별도서관과 협력을 통한 공동보존서고 운영방안으로 나누어 제시하였다. 본 연구는 KISTI 사례 분석을 통하여 기관에 필요한 보존공간을 산출하고 확충방안을 제시함으로써, 다른 도서관이나 정보센터에 유사한 문제가 발생하였을 때 도움이 되고자 하였다.

• 한국인쇄학회지
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• 제29권1호
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• pp.61-74
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• 2011

Critical environmental elements for long term preservation of a paper are temperature, humidity, dust, light, contaminants in air, and mold. Especially, temperature and humidity need special care, because they can not only directly degrade paper but also affect the degradation of the other elements. Therefore methods to monitor variation of temperature and relative humidity were studied. One of the methods was to use preservation index for evaluating preservation environment. Since the evaluation for preservation environment of a stack room investigated firstly by D. K. Sebera, PI(preservation index) and TWPI(Time-Weighted Preservation Index) by IPI is made to evaluate relatively preservation environment in a stack room. T. Padfield developed method which could calculate easy PI and TWPI. In this study, the preservation environment of stack rooms for paper storage in NAK(National Archives Korea) was evaluated by PI and TWPI. PI and TWPI of stack rooms for paper storage in NAK maintained good condition but PI depended on season. Then the preservation environment of stack rooms for paper storage in NAK was required to maintain continuously PI and TWPI regardless of season change.

• 한국포장학회지
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• 제23권2호
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• pp.97-101
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• 2017

Fruits are subjected to a variety of vibration stress during the transportation from a production area to markets. Vibration inputs are transmitted from the transporting vehicle through the packaged fruit. And the steady state vibration input may cause serious internal damage of fruit. Product quality of fruits declines by various factors while they are stored right after harvesting and among the substance in charge of post ripening action, ethylene ($C_2H_4$) biosynthesis increases fruits' respiration process after harvesting and decreases storage expectancy. Ethylene production of apples rapidly increases while storage duration becomes longer. This tendency is much clearer for the apples with vibration stress at input acceleration level. When there was no vibration stress, change in ethylene production level of apples are not very large during storage. Ethylene production rates inside the gas collecting container increased significantly ($p{\leq}0.05$) after 24 hours storage, particularly for apples with vibration stress ($0.7{\mu}l/kg{\cdot}hr$ (1st stack), $0.78{\mu}l/kg{\cdot}hr$ (2nd stack), $0.96{\mu}l/kg{\cdot}hr$ (3rd stack)); whereas less ethylene was produced in control apples ($0.18{\mu}l/kg{\cdot}hr$ during storage. Also ethylene production rates of apples according to the stack position were significantly different ($p{\leq}0.05$). The vibration stress clearly accelerated the degradation of apple quality during storage, resulting in increased ethylene production.

• 전기의세계
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• 제31권4호
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• pp.281-287
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• 1982

PASCAL has a recursive nested structure and uses deep binding of identifiers. This paper studies the problems and techniques in storage management for PASCAL on the IBM 370 system, and presents run-time storage administration algorithms which use stack scheme and heap efficiently on the view of storage. The stack-scheme was used to implement the feature of recursive nested structure and the heap was used to implement the feature of the dynamic allocation procedure and pointer variable, allowing an additional dynamic storage recovery procedure.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.61-67
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• 2020

This paper is to propose a hybrid memory adaptor using next-generation nonvolatile memory devices such as phase-change memory to improve the performance limitations of OpenStack-based object storage systems. The proposed system aims to improve the performance of the account and container servers for object metadata management. For this, the proposed system consists of locality-based dynamic page buffer, write buffer, and nonvolatile memory modules. Experimental results show that the proposed system improves the hit rate by 5.5% compared to the conventional system.

• 반도체디스플레이기술학회지
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• 제8권1호
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• pp.13-17
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• 2009

In PRAM applications, the devices can be made for both binary and multi-state storage. The ability to attain intermediate stages comes either from the fact that some chalcogenide materials can exist in configurations that range from completely amorphous to completely crystalline or from designing device structure such a way that mimics multiple phase chase phenomena in single cell. We have designed stack-structured phase change memory cell which operates as multi-state storage. Amorphous $Ge_xTe_{100-x}$ chalcogenide materials were stacked and a diffusion barrier was chosen for each stack layers. The device is operated by crystallizing each chalcogenide material as sequential manner from the bottom layer to the top layer. The amplitude of current pulse and the duration of pulse width was fixed and number of pulses were controlled to change overall resistance of the phase change memory cell. To optimize operational performance the thickness of each chalcogenide was controlled based on simulation results.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.253-259
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• 2020

Most of today's large-scale cloud systems and enterprise data centers are distributing resources to improve scalability and resource utilization. NVMe-over-Fabric protocol allows submitting NVMe commands to a remote NVMe SSD through RDMA (Remote Direct Memory Access) network. It is attracting attention recently because it is possible to construct a disaggregation storage system with low latency through the protocol. However, the current I/O stack of NVMe-over-Fabric has an inefficient structure for maintaining compatibility with the traditional I/O stack. Therefore, in this paper, we propose a new mechanism to reduce I/O latency and CPU overhead by modifying I/O path of NVMe-over-Fabric to pass through legacy block layer. According to the performance evaluation results, the proposed mechanism is able to reduce the I/O latency and CPU overhead by up to 22% and 24% compared to the existing NVMe-over-Fabrics protocol, respectively.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.381-382
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• 2007

• 전기화학회지
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• 제10권2호
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• pp.104-109
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• 2007

연료 전지의 소형화를 위하여 흑연(graphite)를 기본으로 하는 분리판을 실리콘분리판으로 대체하였으며, 실리콘 분리판과 active area가 $4cm^2$인 MEA (membrane electrode assembly)와 결합하여 단위 전지를 제작하였다. 단위 전지에 공급되는 수소와 산소의 공급량은 고정하고 가습기의 구동 온도만을 변화시키면서 단위 전지의 성능을 확인하고 최적의 가습 조건을 결정하였다. 또한 가습 조건이 실리콘으로 제작된 연료 전지 스택에 미치는 영향을 알아보기 위하여 실리콘 분리판과 2개의 MEA로 이루어진 스택을 제작하여 가습 조건의 영향을 알아보고 실리콘 분리판으로 제작된 연료전지 스택의 문제점 및 특징을 알아보았다.