• Title/Summary/Keyword: file management

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A Comparison of Retrieval Effectiveness between Image File and Text File (이미지 화일과 텍스트 화일의 검색효율성 비교)

  • 임영선;이두영
    • Proceedings of the Korean Society for Information Management Conference
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    • 1996.08a
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    • pp.15-18
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    • 1996
  • 본 논문은 본문 전체가 기계가독형 화일로 구성된 텍스트 전문데이터베이스와 이미지화일로 구성된 이미지 전문데이터베이스와의 검색효율성을 비교함으로써 도서관과 최종이용자의 입장에서 바람직한 전문데이터베이스가 어떤 것인지를 제안하고자 한다.

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A Flash Memory Management Method for Enhancing the Recovery Performance (복구 성능 향상을 위한 플래시 메모리 관리 기법)

  • Park, Song-Hwa;Lee, Jung-Hoon;Cho, Sung-Woo;Kim, Sang-Hyun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.5
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    • pp.235-243
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    • 2018
  • NAND flash memory has been widely used for embedded systems as storage device and the flash memory file systems such as JFFS2, YAFFS/YAFFS2 have been adopted by these embedded systems. The flash memory file systems provide the high performance and overcome the limitations of flash memory. However, these file systems don't solve the slow mount time problem when a sudden power failure happens. In this paper, we proposed a flash memory management method for enhancing the recovery performance. The proposed method manages the flash memory block type and stores the block type information at recovery image block. When file operations are occurred, our method stores the file information at the metadata block before and after the file operation. When mounting the flash memory, our method only scans the recovery image blocks and metadata blocks. The proposed method reduces the mount time by seeking the metadata block locations fast by using the recovery image blocks. We implemented the proposed method and evaluation results show that our method reduces the mount time 13 ~ 46 % compared with YAFFS2.

A Problem Solving Method for Non-Admittable Characters of a Windows File Name in a Directory Index Anti-Forensic Technique (디렉토리 인덱스 안티포렌식 기법에서 Windows 파일명에 사용할 수 없는 문자 문제의 해결방법)

  • Cho, Gyusang
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.11 no.4
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    • pp.69-79
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    • 2015
  • This research proposes a modified data hiding method to hide data in a slack space of an NTFS index record. The existing data hiding method is for anti-forensics, which uses traces of file names of an index entry in an index record when files are deleted in a direcotry. The proposed method in this paper modifies the existing method to make non-admittable ASCII characters for a file name applicable. By improving the existing method, problems of a file creation error due to non-admittable characters are remedied; including the non-admittable 9 characters (i. e. slash /, colon :, greater than >, less than <, question mark ?, back slash ${\backslash}$, vertical bar |, semi-colon ;, esterisk * ), reserved file names(i. e. CON, PRN, AUX, NUL, COM1~COM9, LPT1~LPT9) and two non-admittable characters for an ending character of the file name(i. e. space and dot). Two results of the two message with non-admittable ASCII characters by keyboard inputs show the applicability of the proposed method.

Estimation of the Utilization of a File with Distributed Free Space (분산된 저장 구조를 지닌 파일에서의 파일 활용성 산정)

  • Kim, Seong-Eon
    • Asia pacific journal of information systems
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    • v.2 no.2
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    • pp.71-84
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    • 1992
  • Analysis for the file with distributed free space such as a VSAM has been done. Birth and death process has been adopted to describe the status changes of control intervals in a VSAM file. File utilization is calculated as a function of the number of control intervals which contain different number of records in them. Effect of the control interval sizes and the loading factors are analyzed over the time horizon.

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A File System for Embedded Multimedia Systems (임베디드 멀티미디어 시스템을 위한 파일 시스템의 설계 및 구현)

  • Lee Minsuk
    • Journal of Information Technology Applications and Management
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    • v.12 no.1
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    • pp.125-140
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    • 2005
  • Nowadays, we have many embedded systems which store and process multimedia data. For multimedia systems using hard disks as storage media such as DVR, existing file systems are not the right choice to store multimedia data in terms of cost. performance and reliability. In this study we designed a reliable file system with very high performance for embedded multimedia applications. The proposed file system runs with quite simple disk layout to reduce time to initialize and to recover after power failures, uses a large data block to speed up the sequential accesses, incorporates a time-based indexing scheme to improve the time-based random accesses and boosts reliability by backing up the important meta data on a small NVRAM. We implemented the file system on a Linux-based DVR and verified the performance by comparing with existing file systems.

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Metadata Structrues of Huge Shared Disk File System for Large Files in GIS (GIS에서 대용량 파일을 위한 대용량 공유 디스크 파일시스템의 메타데이터 구조)

  • 김경배;이용주;박춘서;신범주
    • Spatial Information Research
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    • v.10 no.1
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    • pp.93-106
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    • 2002
  • The traditional file system are designed to store and manage fur small size files. So. we cannot process the huge files related with geographic information data using the traditional file system such as unix file system or linux file system. In this paper, we propose new metadata structures and management mechanisms for the large file system in geographic information system. The proposed mechanisms use dynamic multi-level mode for large files and dynamic bitmap for huge file system. We implement the proposed mechanisms in the metadata structures of SANtopia is shared disk huge file system for storage area networks(SAN).

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An Arbitrary Disk Cluster Manipulating Method for Allocating Disk Fragmentation of Filesystem (파일시스템의 클러스터를 임의로 할당하여 디스크를 단편화하기 위한 방법)

  • Cho, Gyu-Sang
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.16 no.2
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    • pp.11-25
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    • 2020
  • This study proposes a method to manipulate fragmentation of disks by arbitrarily allocating and releasing the status of a disk cluster in the NTFS file system. This method allows experiments to be performed in several studies related to fragmentation problems on disk cluster. Typical applicable research examples include testing the performance of disk defragmentation tools according to the state of fragmentation, establishing an experimental environment for fragmented file carving methods for digital forensics, setting up cluster fragmentation for testing the robustness of data hiding methods within directory indexes, and testing the file system's disk allocation methods according to the various version of Windows. This method suggests how a single file occupies a cluster and presents an algorithm with a flowchart. It raises three tricky problems to solve the method, and we propose solutions to the problems. Experiments for allocating the disk cluster to be fragmented to the maximum extent possible, it then performs a disk defragmentation experiment to prove the proposed method is effective.

The Effects of Trust on Customer Satisfaction and Re-use Intention in P2P File Sharing (P2P파일공유에서 신뢰가 고객만족과 재이용의도에 미치는 영향)

  • Cho, Chul-Ho;Kang, Byung-Suh
    • Journal of Korean Society for Quality Management
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    • v.34 no.2
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    • pp.33-47
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    • 2006
  • This study was designed to examine the casual relationships among trust evaluation factors, trust, customer satisfaction, and re-use intention in the P2P file sharing service. We applied structural equation model to test the hypotheses and research model. As a result of this study, trust evaluation factors affect trust and customer satisfaction and both of trust and customer satisfaction affect re-use intention respectively and significantly. Also trust affects customer satisfaction significantly. Specifically, trust was empirically confirmed as one of the important factors preceding customer satisfaction and re-use intetion in the P2P file sharing service. Therefore, this study shows that trust is important factor that P2P companies have to emphasize to raise user satisfaction and performance.

IFCXML Based Automatic Data Input Approach for Building Energy Performance Analysis

  • Kim, Karam;Yu, Jungho
    • Journal of Construction Engineering and Project Management
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    • v.3 no.1
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    • pp.14-21
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    • 2013
  • To analyze building energy consumption, the building description for building energy performance analysis (BEPA) is required. The required data input for subject building is a basic step in the BEPA process. Since building information modeling (BIM) is applied in the construction industry, the required data for BEPA can be gathered from a single international standard file format like IFCXML. However, in most BEPA processes, since the required data cannot be fully used from the IFCXML file, a building description for BEPA must be created again. This paper proposes IFCXML-based automatic data input approach for BEA. After the required data for BEPA has been defined, automatic data input for BEPA is developed by a prototype system. To evaluate the proposed system, a common BIM file from the BuildingSMART website is applied as a sample model. This system can increase the efficiency and reliability of the BEPA process, since the data input is automatically and efficiently improved by directly using the IFCXML file..