• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.1-2
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• 2020

응용프로그램의 응답성을 향상시키기 위해서는 저장장치 시스템의 데이터 처리 능력이 중요하다. 한편, 차세대 메모리(NVDIMM)는 DRAM과 SSD 중간 정도의 성능 특성과 저장 용량을 갖는다. NVDIMM을 저장장치의 캐시로 사용함으로써 메모리와 저장장치의 격차는 많이 줄게 된다. 본 논문에서는 경량의 재사용 거리 측정 기법을 이용하여 효율적으로 디스크를 캐싱하는 기법을 제안한다. 제안 기법은 경량의 재사용 거리 측정 기법을 바탕으로 계산된 CFD(Computational Fluid Dynamics)값에 따라 디스크 캐시에 해당 데이터 적재 여부를 결정한다. 결과적으로 제안 기법을 적용한 디스크 캐시를 운용함에 따라 캐시의 히트율을 향상시켰다.

• Journal of the Korea Computer Industry Society
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• v.5 no.1
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• pp.101-108
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• 2004

As the dependency to network system and demands of efficient storage systems rapidly grows in every networking filed, the current trends initiated by explosive networked data grow due to the wide-spread of internet multimedia data and internet requires a paradigm shift from computing-centric to data-centric in storagesystems. Furthermore, the new environment of file systems such as NAS(Network Attached Storage) and SAN(Storage Area Network) is adopted to the existing storage paradigm for Providing high availability and efficient data access. We describe the design issues and system components of SANiqueTM, which is the cluster file system based on SAN environment. SANiqueTM has the capability of transferring the user data from the network-attached SAN disk to client applications directly We, especially, present the protocol and functionality of the global buffer manager in our cluster file system.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.690-691
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• 2011

제주 스마트그리드 실증사업은 기기 설치, 시험운전 단계에서 실증운전 단계로 넘어가는 과정 중에 있다. 제주 가상전력시장기반 하에서 수요측 자원의 본격적인 Full-Scale 전력거래가 시작될 예정이며, 거래 수익 최대화를 위해서는 에너지저장장치의 적절한 운영이 필수적으로 요구된다. 당사에서는 에너지저장장치의 시간대별 운영 패턴 도출을 통해 가상전력시장에 참여할 수 있는 에너지저장장치 운영 프로그램을 개발하였다. 본 논문에서는 가상전력시장의 개요, 에너지저장장치 운영 프로그램의 개념과 실행 스케쥴, 그리고 입출력 데이터와 Flow Chart 등에 대하여 기술하였다. 향후 실증단계 진행 중에 신뢰할 만한 Raw Data와 거래 reference를 확보, 분석하고 적용하는 과정을 거치면서 운영 알고리즘을 조금 더 개선해야 할 필요가 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1037-1043
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• 2006

In this paper, we introduce a two-dimensional modulation code for holographic data storage systems(HDSS), which is a candidate for the next generation data storage system. The two-dimensional(2D) intersymbol interference(ISI) induces higher bit error rate(BER). The balanced number of zeros(dark) and ones(light) in each page reduces inter-page interference(IPI). The code rate is 519. Although the proposed code has higher code rate than other 2D code with rate 4/9, the BER performances of two codes are similar.

• Proceedings of the Korea Database Society Conference
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• 2002.10a
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• pp.321-353
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• 2002

대부분의 기업에서 100 메가바이트 데이터는 1백만 달러로 평가. 재난을 치룬 회사 중 43%는 다시 일어서지 못했고, 그 중 29%가 2년 내에 폐업함(McGladrey and Pullen). 500개의 데이터 센터 중 1개 꼴로 매년 한 건의 심각한 재난을 겪을 것으로 추정됨(McGladrey and Pullen) (중략)

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2501-2503
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• 2005

탐침형 정보 저장 장치는 원자 현미경의 원리를 이용한 차세대 고밀도 저장장치로 여겨진다. 정보의 크기가 수십 나노미터 이하이므로 정밀한 위치 제어 알고리즘이 필수적이다. 본 논문에서는 별도의 위치 센서없이 복수개인 탐침을 이용하여 원하는 데이터 위치로 이동하는 servo algorithm, 정보 추종을 위한 tracking algorithm 및 위치 검출용 탐침의 수를 줄이고 최적 제어기 설계를 위한 노이즈 특성 안정화를 위한 servo code 설계법을 제안하고 제어기 설계법을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.401-409
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• 2013

Recently, almost all data has stored and managed in the shape of digital as development of IT infrastructure. Digital data is able to store the huge data in very small space. but if the disk should be stolen or lost, it would have many secure problems such as data leakage. Currently, digital data is protected by encryption method to prevent data leakage. However, the encryption method is not enough to protect data because the performance of attack system is higher and the attack methods is various. Therefore, there is a need for a new advanced data protection method. To solve secure problems, many research has been progressed like Cloud Shredder, which distributes data and then store. In this paper, We found out the problem of the Cloud Shredder and proposed an advanced method of digital data protection to solve those problem.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.9-14
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• 2021

In computing systems that require high reliability, the method of predicting the lifetime of a storage device is one of the important factors for system management because it can maximize usability as well as data protection. The life of a solid state drive (SSD) that has recently been used as a storage device in several storage systems is linked to the life of the NAND flash memory that constitutes it. Therefore, in a storage system configured using an SSD, a method of accurately and efficiently predicting the lifespan of a NAND flash memory is required. In this paper, a method for optimizing the lifetime prediction of a flash memory-based storage device using the frequency of NAND flash memory failure is proposed. For this, we design a cost matrix to collect the frequency of defects that occur when processing data in units of Drive Writes Per Day (DWPD). In addition, a method of predicting the remaining cost to the slope where the life-long finish occurs using the Gradient Descent method is proposed. Finally, we proved the excellence of the proposed idea when any defect occurs with simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.77-82
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• 2014

SD memory cards are widely used in portable digital devices, and most of them exploit NAND flash memory as their storage, so that they have a feature of storing users' important data safely with low costs. In case of using NAND flash memory as storage, however, there is no method to store users' data if memory capacity is insufficient when transferring a large volume of data. This paper proposes a virtual SD memory card system. It used a SD memory card device driver to process data requested from a host by exploiting external storage rather than by exploiting flash memory as a memory core for storing data to the SD memory card. For experiment, it used the FPGA-based SD card slave controller IP on the SMC controller with a S3C2450 ARM CPU to test.

• Journal of Internet of Things and Convergence
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• v.10 no.3
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• pp.19-24
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• 2024

Recent advances in large-scale data processing technologies such as big data, cloud computing, and artificial intelligence have increased the demand for high-performance storage devices in data centers and enterprise environments. In particular, the fast data response speed of storage devices is a key factor that determines the overall system performance. Solid state drives (SSDs) based on the Non-Volatile Memory Express (NVMe) interface are gaining traction, but new bottlenecks are emerging in the process of handling large data input and output requests from multiple hosts simultaneously. SSDs typically process host requests by sequentially stacking them in an internal queue. When long transfer length requests are processed first, shorter requests wait longer, increasing the average response time. To solve this problem, data transfer timeout and data partitioning methods have been proposed, but they do not provide a fundamental solution. In this paper, we propose a dual queue based scheduling scheme (DQBS), which manages the data transfer order based on the request order in one queue and the transfer length in the other queue. Then, the request time and transmission length are comprehensively considered to determine the efficient data transmission order. This enables the balanced processing of long and short requests, thus reducing the overall average response time. The simulation results show that the proposed method outperforms the existing sequential processing method. This study presents a scheduling technique that maximizes data transfer efficiency in a high-performance SSD environment, which is expected to contribute to the development of next-generation high-performance storage systems