• Journal of the Korean Operations Research and Management Science Society
• /
• v.21 no.1
• /
• pp.31-50
• /
• 1996

In this paper we prescribe a replication server scheme with an algorithm DRF (Differential Refresh File) to refresh multiple materialized views and replicas in distributed environments. Before sending relevant tuples in server sites to client sites, an effective tuple reduction scheme is developed as a preprocessor to reduce the transmission cost. Because it utilizes differential files with out touching base relations, the DRF scheme can help to minimize the number of locks, which enhances the system's performance.

• Convergence Security Journal
• /
• v.6 no.2
• /
• pp.1-11
• /
• 2006

The files of intellectual property on computer systems have increasingly been exposed to such threats that they can be flowed out by internal users or outer attacks through the network. The File Outflow Protection System detects file outflow when users not only copy files on client computers into storage devices, but also print them. This Protection system has been designed to Win32 API hooking by I/O Manager in kernel level if files are flowed out by copying. As a result, the monitoring system has exactly detected file outflows, which is proved through testing.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.12
• /
• pp.1858-1860
• /
• 2016

In this paper, a modified YARA software architecture that can perform pattern matching for multi-rule files is proposed. Based on a improved scanning thread algorithm, the new design reduces memory loading time of rule files for pattern matching. Therefore, the proposed architecture can reduce operation time for pattern matching while it requires an increased memory in proportion to the number of rule files.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10a
• /
• pp.4-6
• /
• 2001

In this paper, we designed a system that can mine user's traversal patterns from web log files. The system cleans an input data, transactions of a web log file, and finds traversal patterns from the transactions, each of which consists of one user's access pages. The resulting traversal patterns are shown on a web browser, which can be used to analyze the patterns in visual form by a system manager or data miner. We have implemented the system in an IBM personal computer running on Windows 2000 in MS visual C++, and used the MS SQL Server 2000 to store the intermediate files and the traversal patterns which can be easily applied to a system for knowledge discovery in databases.

• Restorative Dentistry and Endodontics
• /
• v.28 no.1
• /
• pp.41-49
• /
• 2003

There are increasing usage of Nickel-Titanium rotary files in modern clinical endodontic treatment because it is effective and faster than hand filing due to reduced step. This study was conducted to evaluate the effect of canal preparations using 3 different rotary Nickel-Titanium files that has different cross sectional shape and taper on the maintenance of canal curvature. Simulated resin block were instrumented with Profile(Dentsply, USA), GT rotary files(Dentsply, USA), Hero 642(Micro-Mega France), and Pro-Taper(Dentsply, USA). The image of Pre-instrumentation and Post-instrumentation were acquired using digital camera and overspreaded in the computer. Then the total differences of canal diameter, deviation at the outer portion of curvature, deviation at the inner portion of curvature, movement of center of the canal and the centering ratio at the pre-determined level from the apex were measured. Results were statistically analyzed by means of ANOVA, followed by Scheffe test at a significance level of 0.05. The results were as follows； 1. Deviation at the outer portion of curvature, deviation at the inner portion of curvature were showed largest in Pro-Taper so also did in the total differences of canal diameter(p＜0.05). 2. All the groups showed movements of center Profile combined with GT rotary files and Hero 642 has no difference but Pro-Taper showed the most deviation(p＜0.05). 3. At the 1, 2, 3mm level from the apex movements of center directed toward the outer portion of curvature, but in 4, 5 mm level directed toward the inner portion of curvature(p＜0.05). As a results of this study, it could be concluded that combined use of other Nickel-Titanium rotary files is strongly recommended when use Pro-Taper file because it could be remove too much canal structure and also made more deviation of canal curvature than others.

• Journal of the Korea Convergence Society
• /
• v.10 no.3
• /
• pp.7-14
• /
• 2019

With the development of information and communication technology, we have been able to access and manage documents containing corporate information anytime and anywhere using smart devices. As the work environment changes to smart work, the scope of information distribution is expanded, and more efforts are needed to manage security. This paper proposes a file sharing system that enables users who have smart devices to manage and share files through mutual cooperation. Proposed file sharing system, the user can add a partner to share files with each other when uploading files kept by spliting the part of the file and the other uses an algorithm to store on the server. After converting the file to be uploaded to base64, it splits it into encrypted files among users, and then transmits it to the server when it wants to share. It is easy to manage and control files using dedicated application to view files and has high security. Using the system developed with proposed algorithm, it is possible to build a system with high efficiency even for SMEs(small and medium-sized enterprises) that can not pay much money for security.

• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.53-60
• /
• 2018

With the development of information and communication technology, we have been able to access and manage documents containing corporate information anytime and anywhere using smart devices. As the work environment changes to smart work, the scope of information distribution is expanded, and more efforts are needed to manage security. This paper proposes a file sharing system that enables users who have smart devices to manage and share files through mutual cooperation. Proposed file sharing system, the user can add a partner to share files with each other when uploading files kept by spliting the part of the file and the other uses an algorithm to store on the server. After converting the file to be uploaded to base64, it splits it into encrypted files among users, and then transmits it to the server when it wants to share. It is easy to manage and control files using dedicated application to view files and has high security. Using the system developed with proposed algorithm, it is possible to build a system with high efficiency even for SMEs(small and medium-sized enterprises) that can not pay much money for security.

• Journal of Internet Computing and Services
• /
• v.21 no.3
• /
• pp.93-102
• /
• 2020

In order for data obtained through all stages of digital crime investigation to be recognized as evidence capability, it must satisfy legal / technical requirements. In this paper, we propose a mechanism and implement software to provide digital forensic evidence by automatically recovering files by scanning / inspecting the unallocated area inside the storage disk block without relying on information provided by the file system. The proposed technique checks / analyzes the RAW disk data of the system under analysis in 512-byte block units based on information on the storage format / file structure of various files stored on the disk without referring to the file system-related information provided by the operating system. The file carving process was implemented, and a smart carving mechanism was proposed to intelligently restore deleted or damaged files in the storage device. As a result, we have provided a block based smart carving method to intelligently identify fragmented and damaged files in storage efficiently for forgery analysis on digital forensic investigation.

• The KIPS Transactions:PartB
• /
• v.9B no.1
• /
• pp.67-76
• /
• 2002

MP3 audio format has good quality and high compression rate ; therefore, the use of MP3 format increases. The requirement of keeping the extra information such as author and lyrics in MP3 files increases. And the tagging systems designed to meet this requirement are suggested. ID3 vl tag and Lyrics3 v2 tag are two most widely used tagging systems. But ID3 vl tag and Lyrics3 v2 tag are the last things to arrive when the file is being streamed. Therefore, users cannot get the tag information until the entire audio file is downloaded. Moreover information synchronized with audio stream may lose its feature. In this paper, a system searching and playing audio files based on tag information in MP3 files is implemented. This system solves the problem that the tag information is ignored when an MP3 files is played on internet. An audio object is described in an XML document, and timing and synchronization between elements in that In document is provided in HTML+TIME style using XSL.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.1 s.39
• /
• pp.107-117
• /
• 2006

Java language creates class files through Java compiler. Class files include informations involved with achievement of program. We can do analysis and optimization for efficient codes by analyzing class files. This paper analyzes bytecodes using informations of Java class files. We translate stack-based Java bytecodes into 3-address codes. Then we translate into static single assignment form using the 3-address codes. Static single assignment form provides a compact representation of a variable's definition-use information. Static single assignment form is often used as an intermediate representation during code optimization. Static sing1e assignment form renames each occurrence of a variable such that each variable is defined only once.