• Journal of KIISE
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• v.44 no.12
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• pp.1245-1251
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• 2017

In this study we present a novel directory architecture that can dynamically allocate a directory entry for a cache block on demand at runtime only when the block is shared by more than one core. Thus, we do not maintain coherence for private blocks, substantially reducing the number of directory entries. Even for shared blocks, we allocate directory entry dynamically only when the block is actively shared, further reducing the number of directory entries at runtime. For this, we propose a new directory architecture called dynamic directory table (DDT), which is implemented as a cache of active directory entries. Through our detailed simulation on PARSEC benchmarks, we show that DDT can outperform the expensive full-map directory by a slight margin with only 17.84% of directory area across a variety of different workloads. This is achieved by its faster access and high hit rates in the small directory. In addition, we demonstrate that even smaller DDTs can give comparable or higher performance compared to recent directory optimization schemes such as SPACE and DGD with considerably less area.

• 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 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.

• 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.

• 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.

• Journal of Korean Library and Information Science Society
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• v.37 no.2
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• pp.255-272
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• 2006

This study was investigated to the geography services and geographical directories through Internet in order to develop a geographical directory. Research method was the examination of different type of geography services through internet and geographical directories on the Internet search engines. The results show principles for a geographical directory construction: use both geographical names and subject names on the initial directory screen, repeated use the names through directory hierarchy, locality use on bottom directory as a geographical name, and fit use of the number of directories.

• Journal of the Korean Society for information Management
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• v.18 no.2
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• pp.143-164
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• 2001

The purpose of this study is to suggest the guidelines for organizing and maintaining their subject directory search engines which serve effective search results of web documents. The methods of this study are to review and analyze some directory search engines for finding problems of them and review literatures concerned with classification theory and previous studies. As results, this study suggests the guidelines for preparing the systematic subject directory scheme that is adapted to the internet directory search engines related to general andlor special subject fields through using the above guidelines.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.259-264
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• 2014

The web server is configured to display the list of files contained in this directory. This is not recommended because the directory may contain files that are not normally exposed through links on the web site. The directory list have some serious vulnerability to show internal files and directory to outsider attackers. Therefore, the proposed countermeasure of directory list is presented to prevent unnecessary valuable information from outsider attackers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1143-1152
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• 2000

As being various user telephone number after entry of new telecommunication enterprise, management of systematic Directory Assistance Service is required. Also through providing competition of Directory Assistances Service, enhancement of Service quality and development of new Service are induced. In this study, there is researched the overall view of present Directory Assistance Service in priority Korean Telecom and the oversea's Directory Assistance Service for U.S.A, England, Australia, Japan. As result of study, we want to suggest the appointment of unified Directory Database Management Company and outsourcing of Directory Assistance Service to that company but in reality, there may be other idea also with regard to various circumstances.

• The Journal of Society for e-Business Studies
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• v.9 no.1
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• pp.83-104
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• 2004

Recently, information systems that require storage and retrieval of huge amount of data are becoming used widely. Accordingly, research efforts have been made to develop Linux cluster file systems in the SAN environment in which clients themselves can manage metadata and access data directly. Also a semi-flat directory structure based on extendible hashing has been proposed to support fast retrieval of files[1]. In this research, we have designed and implemented the semi-flat extendible hash directory under the Linux system. In order to evaluate the practicality of the directory, we have also implemented the B+-tree based directory and experimented the performance. According to the performance comparisons, the extendible hash directory has the better performance at insert, delete, and search operations. On the other hand, the B+-tree directory is better at sorting files.