• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1542-1552
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• 1996

This paper presents a design and implementation of an extended directory system in manage and provide an effective search operation of the DFR(Document Filing and Retrieval) Object's attributes. For this, the design and implementation of a configuration model for interworking between the DFR and directory systems, an association mechanisms between two application's operation, extended directory schema and extended DIT(Directory Information Tree) are described. In a distributed environment, the interworking between the DFR and directory system implemented by using QUIPU 8.0 of ISODE(ISO Development Environment) directory system is tested. based on the result of this paper, an extended model of the directory system is proposed for proving search operation of various application's objects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1356-1364
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• 1997

This paper presents a modelling and implementation scheme of a multi directory which provides location and supplementary information of multiple applications in distributed environments. An extrended directory schema and extended DIT(Directory Information Tree) model is proposed for the multi directory. For implementation scheme, an implementation example adapted for the DFR(Document Filing and Retrieval) is shown. In addition, a configuration model for interworking between the DFR and the multi directory, an association mechanisms between two application's operations are also described. In a distributed environment, the interworking between the DFR and a multi directory implemented by using QUIPU 8.0 of ISODE(ISO Development Environment) directory system is tested. Based on the result of this paper, an extended model ofthe directory system is proposed for providing search operation of various application' objects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1397-1402
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• 2021

The overlay2 file system is one of the union file systems that mounts multiple directories into one. The source directory used for this overlay2 file system mount has a characteristic that it operates independently of the write-able layer after mounting, so it is often used for container platforms for application delivery. However, the overlay2 file system has a security vulnerability that the write-able layer is also modified when file in the source directory is modified. In this study, I proposed the overlay2 file system protection technology to remove the security vulnerabilities of the overlay2 file system. As a result of empirically implementing the proposed overlay2 file system protection technology and verifying the function, the protection technology proposed in this study was verified to be effective. However, since the method proposed in this study is a passive protection method, a follow-up study is needed to automatically protect it at the operating system level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.445-446
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• 2021

Union file system is a technology that can be used as a single file system by integrating various files and directories. It has the advantage of maintaining the source file/directory used for integration, so it is used in many applications like container platform. When using the union file system, the user accesses the write-able layer, to which the security technology provided by the operating system can be applied. However, there is a disadvantage in that it is difficult to apply a separate security technology to the source file and directory used to create the union file system. In this study, we intend to propose an access control mechanism to deny security threats to source file/directory that may occur when using the union file system. In order to verify the effectiveness of the access control mechanism, it was confirmed that the access control mechanism proposed in this study can protect the source file/directory while maintaining the advantages of the union file system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.2
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• pp.73-90
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• 2015

When we apply file commands on files in a directory, the directory as well as the file suffer changes in timestamps of MFT entry. Based on understanding of these changes, this work provides a digital forensic analysis on the timestamp changes of the directory influenced by execution of file commands. NTFS utilizes B-tree indexing structure for managing efficient storage of a huge number of files and fast lookups, which changes an index tree of the directory index when files are operated by commands. From a digital forensic point of view, we try to understand behaviors of the B-tree indexes and are looking for traces of files to collect information. But it is not easy to analyze the directory index entry when the file commands are executed. And researches on a digital forensic about NTFS directory and B-tree indexing are comparatively rare. Focusing on the fact, we present, in this paper, directory timestamp changes after executing file commands including a creation, a copy, a deletion etc are analyzed and a method for finding forensic evidences of a deletion of directory containing files. With some cases, i.e. examples of file copy and file deletion command, analyses on the problem of timestamp changes of the directory are given and the problem of finding evidences of a deletion of directory containging files are shown.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2684-2686
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• 2001

In order to utilize cache in multiprocessor system, cache coherence problem must be handled. Central directory scheme is one of hardware-assisted cache coherence solutions. The goal of this paper was not only to propose some special methods needed to apply central directory scheme to the specific multiprocessor system based on Intel486 microprocessors but also to design central directory unit for cache coherence of the target system. The problems of arbitrating several requests from processors, storing the cache information, and generating control signals for cache line fill and snoop cycle were solved.

• Journal of the Semiconductor & Display Technology
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• v.8 no.1
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• pp.39-42
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• 2009

In this paper an attempt for realizing a storage system which works as a part of human brain has been discussed. The system is expected to be able to coordinate with human brain. And current storage may have inherent problem due to an intrinsic attribute of storage, exclusiveness. Directory structure in it must be a source of confusion, if it used out side of the range of limitation. Adapting multidimensional annotation of file name extension and directory-less file system, a new storage system able to associate and coordinate with human brain may be available near future. This paper showed that the limitation of current storage system clearly exists, because of human brain limitation to memorize directory name.

• The KIPS Transactions:PartC
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• v.10C no.2
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• pp.199-208
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• 2003

LDAP (Lightweight Directory Access Protocol) Directory Service provides information for locating resources like files and devices over the network such as Internet or Intranet. Since LDAP is widely accepted as one of the standard directory service structure for the Internet, it is desirable that a group of LDAP servers works transparently and continuously even if the related network partitions temporally, through maintaining replicated directory information among those LDAP servers. In this paper, we describe the design and implementation of a robust LDAP sewer, which runs as a process group in JACE group communication system, and the associated LDAP service provider which enables Java applications to use the developed LDAP directory service.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.8-16
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• 2022

In this paper, we propose a method of reconstructing the file system to obtain digital forensics information from the APFS file system when meta information that can know the structure of the file system is deleted due to partial damage to the disk. This method is to reconstruct the tree structure of the file system by only retrieving the B-tree node where file/directory information is stored. This method is not a method of constructing nodes based on structural information such as Container Superblock (NXSB) and Volume Checkpoint Superblock (APSB), and B-tree root and leaf node information. The entire disk cluster is traversed to find scattered B-tree leaf nodes and to gather all the information in the file system to build information. It is a method of reconstructing a tree structure of a file/directory based on refined essential data by removing duplicate data. We demonstrate that the proposed method is valid through the results of applying the proposed method by generating numbers of user files and directories.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.1
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• pp.215-234
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• 2009

This study aims to perform an evaluation of directory services provided by major Korean search portals: Naver, Daum, Yahoo-Korea, and Empas. A directory service of Open Directory is also compared. These directory services are evaluated in terms of the coverage, category creation criteria, site selection criteria, breadth and depth of hierarchy, clarity and currency of category names, order of category listing, and overall classification system. The results of this study can be implemented for the development and improvement of portal's directory services. Users can refer to the results of this study in choosing directory services from search portals.