• Transactions of the Society of Information Storage Systems
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• v.10 no.1
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• pp.7-13
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• 2014

The Blu-ray Disc Recordable(BD-R) is one of strong candidates for archival application among optical media formats, because of its large capability. However, the well-defined accelerated aging test conditions and evaluation criteria have not yet been fully confirmed for BD-R. In this study, the data stability and degradation aspect of BD-R were analyzed by the random-symbol error rate(R-SER) measurement after the accelerated aging test. And a reasonable test condition of accelerated aging for BD-R and the appropriate evaluation criterion using R-SER measurement were discussed.

• Journal of Korean Library and Information Science Society
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• v.34 no.2
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• pp.187-207
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• 2003

With the rapidly evolving information technologies and the Internet, a network-based storage management system is required that can efficiently save, search, modify, and manage digital contents which are increasing by geometric progression. Recently, the SAN became highlighted as a solution to such issues as the integrated data management for heterogeneous systems, the effective utilization of storage systems, and the limitation of data transfer. SAN allows for effective management and sharing of bulk data by directly connecting the storage systems, which used to be independently connected to servers, to the high-speed networks such as optical channels. In this study, I researched on the technologies, standardization and market trends of storage management systems, and performed comparative analyses of the structures, components, and performances for achieving the integration of diverse system storage systems as well as the virtualization of storage systems.

• Transactions of the Society of Information Storage Systems
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• v.6 no.2
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• pp.47-51
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• 2010

We investigate misalignment characteristics of 5/8 modulation code for holographic data storage. The 5/8 modulation code does not have any isolated patterns that is the most unwanted problem for holographic data storage. As the results, the 5/8 modulation code showed a strong side of misalignments, and the code has the best performance among uncoded, 5/9, and 6/8 modulation codes when there are large misalignments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2851-2873
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• 2016

Cloud storage as a service provides high scalability and availability as per need of user, without large investment on infrastructure. However, data security risks, such as confidentiality, privacy, and integrity of the outsourced data are associated with the cloud-computing model. Over the year's techniques such as, remote data checking (RDC), data integrity protection (DIP), provable data possession (PDP), proof of storage (POS), and proof of retrievability (POR) have been devised to frequently and securely check the integrity of outsourced data. In this paper, we improve the efficiency of PDP scheme, in terms of computation, storage, and communication cost for large data archives. By utilizing the capabilities of JAR and ZIP technology, the cost of searching the metadata in proof generation process is reduced from O(n) to O(1). Moreover, due to direct access to metadata, disk I/O cost is reduced and resulting in 50 to 60 time faster proof generation for large datasets. Furthermore, our proposed scheme achieved 50% reduction in storage size of data and respective metadata that result in providing storage and communication efficiency.

• The KIPS Transactions:PartA
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• v.10A no.6
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• pp.657-664
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• 2003

Supporting the availability, integrity, and confidentiality of the information is crucial. The survivability storage systems require to encode and distribute data over multiple storage nodes or data base to survive failures and malicious attacks Information dispersal scheme is one of the most efficient schemes allowing high availability and security with reasonable overhead. In this paper, we propose an algorithm determining the optimal (m, n)-lDS in terms of availability, given a set of IDS's. The proposed algorithm will be very useful for designing a highly available and secure storage system since many factors such as node number, storage space, operation speed, etc. interact with each other and thereby finding an optimal information dispersal scheme is very difficult.

• Transactions of the Society of Information Storage Systems
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• v.11 no.1
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• pp.1-5
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• 2015

The selective frequency analysis method is suggested in the holographic data storage system with the nyquist aperture to reduce the size of hologram. The image filter was designed with many different methods to improve the bit error rate caused by the nyquist aperture. In previous the methods of image restoration for HDS, an iteration time and a highly precise point spread function were necessary. In this paper, we describe the optical system with analytic method. Thereby, we expect our result help the researchers to design the filter.

• Transactions of the Society of Information Storage Systems
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• v.8 no.2
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• pp.67-71
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• 2012

Page-oriented holographic data storage (HDS) is very sensitive to the tilt error. Therefore, tilt error should be measured and compensated. Especially, mechanical tilt measurement method cannot cope with tilt error measurement because photopolymer medium has shrinkage problem. Therefore, the method to solve this problem is using the reconstructed image which can represent both tilt and shrinkage effect. In this paper, we suggest disc tilt measurement algorithm using image pattern of retrieval data.

• Journal of the Korea Society of Computer and Information
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• v.24 no.9
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• pp.1-8
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• 2019

In this paper, we propose a performance isolation of shared space for virtualized SSD based storage systems, to solve the weakness in a VSSD framework. The proposed scheme adopts a CFQ scheduler and a shared space-based FTL for the fairness and the performance isolation for multiple users on virtualized SSD based storage systems. Using the CFQ scheduler, we ensure SLOs for the storage systems such as a service time, a allocated space, and a IO latency for users on the virtualized storage systems. In addition, to improve a throughput and reduce a computational latency for garbage collection, a shared space-based FTL is adopted to maintain the information of SLOs for users and it manages shared spaces among the users. In our experiments, the proposal improved the throughput of garbage collection by 7.11%, on average, and reduced the computational latency for garbage collection by 9.63% on average, compared to the previous work.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.340-367
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• 2018

Storage services integration can be done for achieving high availability, improving data access performance and scalability while preventing vendor lock-in. However, multiple services environment management and interoperability have become a critical issue as a result of service architectures and communication interfaces heterogeneity. Storage federation model provides the integration of multiple heterogeneous and self-sufficient storage systems with a single control point and automated decision making about data distribution. In order to integrate diverse heterogeneous storage services into a single storage pool, we are proposing a storage service federation framework named BoxBroker. Moreover, an automated decision model based on a policy-driven data distribution algorithm and a service evaluation method is proposed enabling BoxBroker to make optimal decisions. Finally, a demonstration of our proposal capabilities is presented and discussed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.3
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• pp.25-35
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• 2011

In the Semantic Web, storage models are required to efficiently store and retrieve metadata and ontology represented using OWL that can provide expressive power and reasoning support. In this paper, we propose an OWL storage model that can store and retrieve many restrictions and semantic relations defined on ontology with metadata. In addition, we propose some methods and rules to improve query processing efficiency of the proposed storage model. The proposed storage model can store and process large amounts of ontology and metadata because it consists of tables based on the relational database. And the proposed model can quickly provide more accurate results to users because of performing two different types of ontology reasoning and using the prime number labeling scheme to easily identify hierarchy relationships between classes or properties. The comparative evaluation results show that our storage model provides better performance than the existing storage model.