• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3026-3049
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• 2016

Cloud computing promises high performance and cost-efficiency. However, most cloud infrastructures operate at a low utilization, which greatly adheres cost effectiveness. Previous works focus on seeking efficient virtual machine (VM) consolidation strategies to increase the utilization of virtual resources in production environment, but overlook the under-utilization of backup virtual resources. We propose a heuristic time sharing policy of backup VMs derived from the restless multi-armed bandit problem. The proposed policy achieves increasing backup virtual resources utilization and providing high availability. Both the results in simulation and prototype system experiments show that the traditional 1:1 backup provision can be extended to 1:M (M≫1) between the backup VMs and the service VMs, and the utilization of backup VMs can be enhanced significantly.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.4
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• pp.455-469
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• 2003

Recently, as new technologies such as SAN and NAS come into wide use to deal with a large amount of data, an efficient backup software for SAN and NAS is very required. In this paper, we design and implement a backup software for SAN that fully supports NDMP. The NUMP is an open standard protocol for network-based backup. The proposed backup software has various unique features such as SAN based tan free backup, automatic and manual backup, on-line backup by using snap shot, file-system, raw-device, database backup and so on. The proposed backup software also can be configured as a backup center that uses SAN as a backup media.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.1
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• pp.1-17
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• 2008

Recently, the object based storage devices systems(OSDs) have been actively researched. They are different from existing block based storage systems(BSDs) in terms of the storage unit. The storage unit of the OSDs is an object that includes the access methods, the attributes of data, the security information, and so on. The object has no size limit and no influence on the internal storage structures. Therefore, the OSDs improve the I/O throughput and the scalability. But the backup systems for the OSDs still use the existing backup techniques for the BSDs. As a result, they need much backup time and do not utilize the characteristics of the OSDs. In this paper, we design and implement a new object based backup system that utilizes the features of the OSDs. Our backup system significantly improves the backup time over existing backup systems because the raw objects are directly transferred to the backup devices in our system. It also restores the backup data much faster than the existing systems when system failures occur. In addition, it supports various types of backup and restore requests.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.159-171
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• 2005

It has been increased to use the SAN with increasing the size of storage device. In this paper, we design and implement a backup system to support the tape and disk based backup with devices and media in SAN cluster. Our backup system provides device and media management for efficiently managing a number of devices and media in SAN cluster. It also supports script management to process an additional tasks requested by clients and monitoring to control and manage tasks in execution. In addition, it supports reporting to offer backup and restore information to clients.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.177-184
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• 2002

In these day, the storage capacity has been growing and the informations increase in geometrically progression in a modem information age. At present the situation is required that the exchanges and access of the informations is available without regard to time and space. In this paper we present a effective backup systems to backup the information of server that continuously has to be accessible in 365's days. There are two backup cases. one is a file-base backup and the other is a block-based backup. In general, a block-based backup has a good performance than a file-based backup but it is difficult to implement a block-based systems. First, we introduce the technique of backup and methods, on-line backup. Next, we present our backup systems based on client-server model and have a snapshot facility. Finally we introduce SCSI-Protocol in order to increase the data transfer rate.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.4
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• pp.88-95
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• 2010

As the development of IT technologies, storages stored very sensitive data which should not be damaged, too. It increased the importance of data backup and makes the time need to backup data important issues. Snapshot is one of the backup technologies which needs short downtime to maintain consistency of data during backup data. In this paper, we studied two kinds of snapshots, local file system based snapshot and network file system based snapshot. In the local file system based snapshot part, we propose the PSnap which is a snapshot library for non-snapshot file system as like Ext2, Ext3 and XFS. In another part, network file system based snapshot, we propose the GlorySnap which snapshot utilities for GloryFS is a distributed file system was made by ETRI.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.270-278
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• 2014

The stability and security management of IT data becomes more important because information security threats increases rapidly in Big Data era. The operational policy of the data backup considering information security threats is required because the backup policy is the fundamental method that prevents the damage of security threats. We present an economic approach for a data backup system with information security threats which damage the system. The backup operation consists of the differential backup and the batch backup. We present a stochastic model considering the occurrence of information security threats and their damage. We analyze the stochastic model to derive the performance measures for the cost analysis. Finally we analyze the average cost of the system and give numerical examples.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.67-72
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• 2006

Because computer system is complex gradually from fast growth of the Internet and sudden increase of Internet user and scale is growing, and dependence for computer system is rising gradually, data damage by mistake or disaster is big enough to can not imagine. Usually is continuous if wish to inform through internet and must update data stably, we should manage so that precious data is not erased from sudden problem through periodic backup. Plan to protect data safely for this should be readied. This paper proposes system that can make effective backup environment because consider environment and achievement method in these data management side. That is, implements system that achieve data backup and restore selectively in internet. Backup and restore about data had stored through browser even if disconnect directly to server because it is possible connect in internet by advantage of proposing system are available. Also, This system can manage data stored to server more efficiently by using selectively both backup and restore two methods.

• Structural Engineering and Mechanics
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• v.38 no.1
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• pp.99-123
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• 2011

Brick veneer over steel stud backup wall is lighter and easier to construct compared to brick veneer over concrete masonry backup wall. However, due to the relatively low stiffness of the steel stud backup, the brick veneer tends to crack under wind load. This paper briefly introduces a new panelized brick veneer with steel frame backup wall system that is developed to potentially address this problem. The experimental study of the performance of this system under simulated wind loading is discussed in detail. The test setup details and the test specimens are introduced, results of major interests are presented, and performance of the new system is evaluated based on the test results.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.524-527
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• 2010

As the GPS(Global Positioning System) vulnerabilities were introduced, alternative systems to GPS backup have been studied for several years. Enhanced Loran(eLoran) as the worldwide ground-based supplementary radio navigation system was recommended as the cost effective alternative to GPS backup. Many efforts on adoption of eLoran as GPS backup have been presented. The US has been the leading role and announced that 70% enhancement for eLoran was established last year. However, the Obama administration cut off the eLoran budget on the fiscal year 2010 budget proposal while GAO's reports submitted that GPS service gap would be possible just some years later. Besides the US's condition, there are still many positive opinions on eLoran to GPS backup. This paper introduces the historical and technical aspects of eLoran and Korea's research topics.