• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1172-1181
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• 1997

A militimedia data is a data mixed of formatted data like an audio and video. Multimedia data has characteristics that it need large amount of storage,wide network bandwith andreal time responsibolity. Because of these characteristocs, the VOD server and continous media storage server have a disk stripe structure or disk stripe sructure or disk array structure(RAID).In the parallel disk access system,high-speed play-back of continous media using segment interleavung may not ensure Qos pf other cioents because of the concentrated load within some disks. The load concentration of disks is related to both the number of disks in the system and playback rate of contimous media.In this paper. we describe that high-speed playback scheme,which is independent of the number of disk and plyback rate can be achieved by technique of changing the in-teval of access to segnent location.We show the experimental result of this technique in this pater.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.811-820
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• 1997

Disk arrays are using to enhance data trandfer rate and I/O performance in multimedia applications which need a high-performance storage device with large storage capacity and high-speed network.As performance varies with configuration and data layout scheme,disk array characteristic variables must be approrpriately deter-mined in desibning disk array archetecture for a speciffic applicatoin. In this paper,in order to design a disk array architecturte as a storage server of a small-scale VOD system,we evaluate performance of a disk array to chose the number of disks in the array,disk array cinfiguration,a degree of declustering for a given data block size of continous media file system and I/D request size through simulation.Simulation result shows that RAID level 5 with 5 disks ios a suitable candidate for the disk array architecture which privides MPEG-2 files with a rate of 6 Mbps,Moreover,we whow that stripe unit is 64 KB and a layout scheme is contigous placement.

• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.106-111
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• 2000

Real-time applications as multimedia file transfer, it is necessary to use a disk array as a system. For Providing requested service to much more clients at the same time in a multimedia storage server considerable varied strategies in a several parts. But especially it is important to various parameters for disk array such as relation of striping block size as a system environmental characteristics of video data. In this paper we evaluated the suitable storage system architecture implementing them applying synthetically generated workloads that varied in the parameters interest in real environment of multimedia server.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.25-30
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• 1999

This paper covers the development of a highly portable and low cost SPOT image data receiving system. We followed two design approaches. One is the software-based approach by which most of the real-time processing is handled by software. With the complete software-based design, it is simple to add a function for receiving any additional satellite data. Satellite-specific format handlers including error correction, decompression and decryption can easily be accommodated. On the other approach. we used a general hardware platform, IBM-PC and a low cost SCSI RAID (Redundant Away of Independent Disks), and therefore, we can make a low cost system.

• Proceedings of the KIEE Conference
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• summer
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• pp.572-574
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• 2004

The configuration of Distribution Automatic System(BAS) is dual servers and raid 5(redundant arrays of inexpensive disks) clustering dual HDD. The DAS has the distributed object-oriented architecture using middleware software(BASEstar), so the number of client nodes has no limitation. Because the DAS is scalable, it can be configured using various application programs and be upgraded easily. The DAS has competitive to export because there are system development and accumulation of technology that coincide in International Standard, using common 05 and DB. This paper describes the structure of DAS hardware and software separately and proposes to improve program to share real time DB efficiently at each node.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.75-84
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• 2017

It becomes more and more more important for the storage that supports high speed recording and stable access from network environment. As one field of basic science which produces massive astronomical data, VLBI(: Very Long Baseline Interferometer) is now demanding more data writing performance and which is directly related to astronomical observation with high resolution and sensitivity. But most of existing storage are cloud model based for the high throughput of general IT, finance, and administrative service, and therefore it not the best choice for recording of big stream data. Therefore, in this study, we design storage system optimized for high performance of I/O and concurrency. To solve this problem, we implement packet read and writing module through the use of libpcap and pf_ring API on the multi core CPU environment, and build a scalable storage based on software RAID(: Redundant Array of Inexpensive Disks) for the efficient process of incoming data from external network.

• KIISE Transactions on Computing Practices
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• v.21 no.7
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• pp.470-475
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• 2015

Openstack is an open source software that enables developers to build IaaS(Infrastructure as a Service) cloud platforms. Openstack can virtualize servers, networks and storages, and provide them to users. This paper proposes the structure of Openstack cloud storage system applying Infiniband to solve bottlenecking that may occur between server and storage nodes when the server performs an I/O operation. Furthermore, we implement all flash array based high-performance Cinder storage volumes which can be used at Nova virtual machines by applying distributed RAID-60 structures to three 8-bay SSD storages and show that Infiniband storage networks applied to Openstack is suitable for virtualizing high-performance storage.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.33-35
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• 1998

본 논문에서는 형식론적 모델링 및 모의 실험 방법을 사용하여 병렬 디스크의 성능 예측 및 영상 데이터용 비선형 편집기의 개발을 위한 여러 형태의구조에 대해서 모의 실험한 결과 및 성능에 영향을 미치는 요소들에 대해 다루고 있다. 컴퓨터가 발전하기 전에는 테이프를 이용한 선형 편집기를 사용하였으나. 컴퓨터가 발전하고 또한 입출력 장치의 성능이 향상되면서 RAID(Redundant Array of Inexpensive Disk)가 개발되었고, 이것을 이용한 비선형 편집기가 개발되었다. 병렬디스크는 비선형 편집기뿐만 아니라 VOD(Video On Demand)나 데이터 서버등 응용분야가 많고, 요구되는 성능에 따라서 다양한 구조의 병렬디스크가 사용된다. 매우 큰 대역폭이 요구되는 병렬디스크의 경우에는 다양한 버스와 버퍼를 사용한 복잡한 계층적 구조가 요구된다. 그러나 이렇게 복잡한 병렬디스크를 개발하기 에 적당한 개발 도구가 없어 필요한 성능에 꼭 맞는 시스템을 개발하기가 어렵다. 특히 디스크의 성능을 수학저으로 쉽게 구할 수 없다. 또한 시스템이 실물로 완성되기 전에는 디스크의 운영 알고리즘의 개발 및 파일 시스템의 개발이 쉽지 않다. 그래서 쉬운 소프트웨어 개발과 디스크의 성능을 쉽게 측정하기 위해서 객체 지향 성능 예측시스템(OOPPS :Objet Oriented Performance Prediction System)을 개발하였고, 이것을 이용하여 HDTV용 비선형 편집기의성능을 예측하고, 필요한 성능을 만족하는 구조를 선택하여 실물로 개발하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.817-828
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• 2017

It is very hard to find the system which processes single 10Gbps stream, and the related application is also rare. But in the field of science such as physics and astronomy, these high speed systems have been widely used and now more upgraded performance is expected. For this reason, high speed network based storage which captures and records 10Gbps level of packets was developed for the support of small astronomical company in KASI. But for the use of the system in research, system performance should be not only evaluated but also optimized. In this paper, we first implement system environment for the performance evaluation and discuss the experiment procedure and solution to acquire numerical results.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.1-7
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• 2011

In this paper, we design rectifing circuits at 910MHz, which is used for passive RFID system, for wireless power transmission system by using two types of schottkey diodes HSMS_2822 and HSMS 2852, and the RF-DC conversion efficiencies for the curcuits are compared and analyzed in terms of input power and load resistance. When the input power is -20 to 17dBm, the conversion efficiency for HSMS_2852 is larger than in case of HSMS_2822. The output voltage and current at the load of the fabricated rectifying circuit are measured through a dipole antenna when input power is transmitted by a RFID reader and the diatance varies. The measured ouput volatge and current for the distance of 50cm are 2.5V and 5.75mA.