• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.765-774
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• 2001

In this paper, we proposed the striping policy for the storage nodes in the Linux-based parallel media stream server. We newly developed a storage clustering architecture, and named it as a system RAID architecture. In this system, many storage cluster nodes are grouped to operate as a single server. This system uses unique striping policy to distribute multimedia files into the parallel storage nodes. If a service request occurs, each storage cluster node transmits striped files concurrently to the clients. This scheme can provide the fair distribution of the preprocessing load in all storage cluster nodes. The feature of this system is a relative striping policy based on the file types, service types, and the number of storage nodes to provide the best service.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.71-76
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• 2022

Buffer cache bridges the performance gap between memory and storage, but its effectiveness is limited due to periodic flush, performed to prevent data loss in smartphones. This paper shows that selective flushing technique with small persistent memory can reduce the flushing overhead of smartphone buffer cache significantly. This is due to our I/O analysis of smartphone applications in that a certain hot data account for most of file writes, while a large proportion of file data incurs single-writes. The proposed selective flushing policy performs flushing to persistent memory for frequently updated data, and storage flushing is performed only for single-write data. This eliminates storage write traffic and also improves the space efficiency of persistent memory. Simulations with popular smartphone application I/O traces show that the proposed policy reduces write traffic to storage by 24.8% on average and up to 37.8%.

• Journal of the Korean Society for information Management
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• v.40 no.1
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• pp.149-173
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• 2023

This study examines email records management patterns of undergraduate students and their perceptions of university email policy. The research collected data from 317 undergraduate students using a survey based on the five essential elements of email records management: common elements, email creation, email management, email preservation, and perception. Also, an in-depth interview was conducted with 6 undergraduate students, according to the method of university email service: Google, Microsoft, and in-house webmail. As a result, undergraduate students used email as an address book, cloud storage, file storage, and collaboration tool, and they had difficulties in systematically managing the email records according to the records lifecycle. Also, there was a tendency to prefer using an external email platform that can use additional functions to in-house webmail that has limitations in mobile service and preservation of attachments. Thus, this study suggests ways to help undergraduate students manage their email records, including maintaining graduates' email accounts, providing sufficient email storage, and providing email records management training and guidelines for undergraduate students.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.5
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• pp.322-330
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• 2009

In order to utilize NAND flash memory as storage media which does not allow update-in-place and limits the number of block erase count, various garbage collection policies supporting wear-leveling have been investigated. Conventional garbage collection policies require cleaning-index calculation for the entire blocks to choose a block to be garbage-collected to support wear-leveling whenever a garbage collection is required, which results in performance degradation of system. This paper proposes a garbage collection policy which supports wear-leveling using a threshold value, which is in fact a variance of erase counts and by the maximum erase count of all blocks, without calculating the cleaning-index. During garbage collection, the erase cost is minimized by using the Greedy Policy if the variance is less than the threshold value. It achieves wear-leveling by excluding the block with the largest erase count from erase target blocks if the variance is larger than threshold value. The proposed scheme shows that a standard deviation approaches to zero as the erase count of blocks approaches to its upper limit and the measured speed of garbage collection is two times faster than the conventional schemes.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.15 no.1
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• pp.43-67
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• 2004

The purpose of this study is to design semantic web and policy direction for national knowledge and information management. The paper describes all the components needed to accomplish the objective: 1) creating unchangeable and unique identifiers for metadata elements, resources, and ontology classes and properties; 2) recommending active use of XML namespaces; 3) establishing metadata and application profile standards for national integrated searching; 4)developing a metadata registry to promote semantic interoperability among metadata; 5) discussing the need of creating ontologies using W3C OWL and ISO Topic Maps; 6) providing intelligent search services based on metadata; and 7) presenting future directions and tasks of national knowledge and information management.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.235-242
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• 2014

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. In this paper we suggested an Asterisk-based Internet telephony system which can be easily scalable. Most current systems use text files to manage their configuration: SIP users, dialplans, IVR service and etc. But we designed the management system which introduces database tables for efficiency and scalability. It also supports web-based functions developed by using Asterisk, Apache, MySQL, jQuery, PHP and open source softwares.

• Journal of Digital Convergence
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• v.10 no.5
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• pp.267-273
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• 2012

The semantic relationship structures hierarchically the huge amount of document objects which is usually not formatted. However, it is very difficult to structure relevant data from various distributed application domains. This paper proposed a new object management method to service the distributed domain objects by using semantic reference relationship. The proposed mechanism utilized the profile structure in order to extract the semantic similarity from application domain objects and utilized the joint matrix to decide the semantic relationship of the extracted objects. This paper performed the simulation to show the performance of the proposed method, and simulation results show that the proposed method has better retrieval performance than the existing text mining method and information extraction method.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.651-654
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• 2010

본 연구는 국내사업체 수에서 87.9% 이상을 차지하고 있는 소상공인들의 창업과 경영애로 분야에서 가장 시너지효과가 크다고 보여지는 소상공인 조직화부분에 대하여 실증적 연구를 실시하였다. 본연구은 소상공인 조직화를 위하여 소상공인 조직화를 프랜차이즈, 공동브랜드, 업종별 협회, 시 군 구에 등록된 상인회로 구분하였다. 소상공인들의 내적인 면에서 경영전략 선정에 있어서 어떠한 가치관을 가지는 지에 대하여 국내 최초로 군집분석에 의한 실증적인 분석을 시도하였다. 연구결과 소상공인의 인구통계적인 유형에서 성별, 학력, 연령, 업종별로 유의한 조직화 인지와 조직화 효과 그리고 최종적인 경영성과에 차이가 있음을 밝혀냈다. 또한 소상공인들이 경영전략 가치관에 대하여 군집분석을 실시한 결과 가격경쟁지향과 마케팅경쟁지향, 무개념 경영등 3가지 유형의 프로파일을 도출할 수 있었다. 이러한 소상공인 조직화에 대한 프로파일 도출과 조직화 인식도에 따른 경영 성공과 실패의 상호관계에 대한 연구 결과가 의미하는 바는, 향후 정부에서는 소상공인에 대하여 시설 개선과 현대화 사업 추진 못지않게 조직화 개발과 같은 조직관리에 대한 경영현대화 사업에 더욱 많은 노력을 경주하여야 하는 필요성을 밝혀 주었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1743-1749
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• 2011

The multimedia data for video-on-demand(VOD) service has large, continuous and real time characteristics. The frequent disk I/O operations takes much time and decrease the system performance in multimedia services. Therefore the efficient buffer management is needed in order to reduce the disk accesses to multimedia data. This paper addresses how to increase the buffer hit ratio and the number of users in a multimedia service like VOD by increasing the utility of buffer. This paper also simulated various resource management algorithms and strategies and evaluated, compared and analyzed their performances.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.426-434
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• 2001

Striping is a scheme that partitions data into blocks and distributes the blocks on different servers in a well defined order and thus could improve system capacity through load balance. In this paper, we propose a parallel VOD server and striping policies for load balancing when extra storage nodes are attached to a parallel VOD server for insufficient disk space in that VOD server. When new video data is stored on the attached storage node, the node may be overloaded. Since it decreases the system bandwidth, appropriate striping policies are required. We therefore present three striping policies that move some block of data o existing nodes into the new node and distribute the new data across all the storage nodes including the new node. Our experiment result shows that FSM bi-direction is the most effective technique.