• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.5.1-5.9
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• 2018

Objectives: This study evaluated the amount of remaining root canal filling materials after retreatment procedures performed by undergraduate students using manual, rotary, and reciprocating techniques through micro-computed tomographic analysis. The incidence of instrument fracture and the instrumentation time were also evaluated. Materials and Methods: Thirty maxillary single rooted teeth were prepared with Reciproc R25 files and filled with gutta-percha and AH Plus sealer by the continuous wave of condensation technique. Then, the specimens were assigned to 3 groups (n = 10), according to the retreatment technique used: manual, rotary, and reciprocating groups, which used K-file, Mtwo retreatment file, and Reciproc file, respectively. Retreatments were performed by undergraduate students. The sample was scanned after root canal filling and retreatment procedures, and the images of the canals were examined to quantify the amount of remaining filling material. The incidence of instrument fracture and the instrumentation time were recorded. Results: Remaining filling material was observed in all specimens regardless of the technique used. The mean volume of remaining material was significantly lower in the Reciproc group than in the manual K-file and Mtwo retreatment groups (p < 0.05). The time required to achieve a satisfactory removal of canal filling material and refinement was significantly lower in the Mtwo retreatment and Reciproc groups (p < 0.05) when compared to the manual K-file group. No instrument fracture was observed in any of the groups. Conclusions: Reciproc was the most effective instrument in the removal of canal fillings after retreatments performed by undergraduate students.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.178-192
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• 2021

File system forensics typically focus on the contents or timestamps of a file, and it is common to work around file/directory centers. But to recover a deleted file on the disk or use a carving technique to find and connect partial missing content, the evidence must be analyzed using cluster-centered analysis. Forensics tools such as EnCase, TSK, and X-ways, provide a basic ability to get information about disk clusters, but these are not the core functions of the tools. Alternatively, Sysinternals' DiskView tool provides a more intuitive visualization function, which makes it easier to obtain information around disk clusters. In addition, most current tools are for Windows. There are very few forensic analysis tools for MacOS, and furthermore, cluster analysis tools are very rare. In this paper, we developed a tool named FACT (Forensic Analyzer based Cluster Information Tool) for analyzing the state of clusters in a HFS+ file system, for digital forensics. The FACT consists of three features, a Cluster based analysis, B-tree based analysis, and Directory based analysis. The Cluster based analysis is the main feature, and was basically developed for cluster analysis. The FACT tool's cluster visualization feature plays a central role. The FACT tool was programmed in two programming languages, C/C++ and Python. The core part for analyzing the HFS+ filesystem was programmed in C/C++ and the visualization part is implemented using the Python Tkinter library. The features in this study will evolve into key forensics tools for use in MacOS, and by providing additional GUI capabilities can be very important for cluster-centric forensics analysis.

• Korean Journal of Digital Imaging in Medicine
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• v.11 no.2
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• pp.69-77
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• 2009

This study gives an account of the collateral standards in IEC 60601-1-3: 2008 specifying the general requirements for basic safety and essential performance of diagnostic X-ray equipment regarding radiation protection as it pertains to the production of X-rays. The collateral standards establish general requirements for safety regarding ionization radiation in diagnostic radiation systems and describe a verifiable evaluation method of suitable requirements regarding control over the lowest possible dose equivalent for patients, radiologic technologists, and others. The particular standards for each equipment can be determined by the general requirements in the collateral standard and the particular standard is followed in the risk management file. The guidelines for radiation safety of diagnostic radiation systems is written up in ISO 13485, ISO 14971, IEC 60601-1-3(2002)1st edition, medical electric equipment part 1-3, and the general requirements for safety-collateral standards: programmable electrical medical systems. Therefore the diagnostic radiation system protects citizens' health rights with the establishment and revisions of laws and standards for diagnostic radiation systems as a background for the general requirements of radiation safe guards applies, as an international trend, standards regarding the medical radiation safety management. The diagnostic radiation system will also assure competitive power through a conforming evaluation unifying the differing standards, technical specifications, and recognized processes.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.4
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• pp.39-49
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• 2001

Application of information system to hospital would bring innovative improvement on efficiency of business management and provide high quality services toward patients as well as the retrenchment of operating funds. PACS(Picture Archiving and Communication System) including X-ray film that manages the medical image information effectively, has drawn considerable attention to essential structural elements to the sophisticated information system for hospital. PACS system should be connected to the network after making a form of standard medical image file from different style of image information obtained from various medical instruments. In this paper, to solve this problem, we construct Mini-PACS that converts the form of Non-DICOM file to the form of standard file by designing the DICOM converter. This system is designed to be managed under Web environment. Comparing with the existed Mini-PACSs, consisting of the client and server module, our system is designed and implemented with integration of these functions in order to be strongly combine strongly between system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.10 s.241
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• pp.1353-1360
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• 2005

Injection-molded products serve a wide range of applications in our modem lives and their significance is ever increasing. However, difficulty of communication among related companies under the present system results in increase of lead time and decrease of production efficiency. The objective of this paper is the development of a web-based draft verification system in mold design processes. Although several commercial CAD systems offer draft verification functions, those systems are very expensive and inadequate to perform collaborative works. For collaborative work under the distributed environment, the proposed system uses native file transforming of CAD data into optimal format by using the ACIS kernel and InterOp. Functions of draft verification modules are constructed over the ActiveX control using the visual C++ and OpenGL. Therefore, collaborators related to the development of a new product are able to verify the draft and undercut over the Internet without commercial CAD systems. The system helps to reduce production cost, errors and lead-time to the market. Performance of the system is confirmed through various case studies.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.135-138
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• 2005

Java Virtual Machine이 기반이 되는 플랫폼 사용으로 모바일 폰 Java는 C/C++로 컴파일 된 Binary File에 비해 속도가 떨어지고 고성능의 프로세서를 필요로 하기 때문에 가격이 비싸질 수밖에 없다. Native Binary를 사용하는 Nano-X Window System Graphic Engine은 저 사양 프로세서에서 사용가능한 모바일 플랫폼으로써 Java Virtual Machine 보다 빠른 속도를 구현할 수 있고 GPL License를 따르기 때문에 생산단가도 절약할 수 있어 저가형 핸드폰의 대량 생산으로 인해 현재 떠오르고 있는 신흥시장에서 보다 경쟁력을 높일 수 있을 것으로 기대된다. 본 논문에서는 기존의 모바일 플랫폼과 Nano-X window System을 비교해보고 모바일 플랫폼으로써의 개발 방향에 대해 논해 보려 한다.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.4
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• pp.29-37
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• 2010

The change detection of XML documents is a major research area. However, though XML becomes a file format for Hangul documents, research on change detection of Hangul documents based on the characteristics of Hangul documents is rather scarce. Since format data in Hangul documents are very large, which is different from ordinary XML documents, it is not proper to apply general XML change detection algorithms such as X-treeDiff+ to Hangul documents without any change. In this paper, we propose new contents-based matching algorithm and implement it in X-treeDiff+. The result of our testing shows better performance for most documents in editing process.

• Journal of the Korean Wood Science and Technology
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• v.26 no.2
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• pp.29-37
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• 1998

An image analysis program with the function of measuring various quantitative characteristics in the transverse surface of wood was developed using Delphi 2.0. Data on pore characteristics (conditions for image processing, proportion of pores in relationship to other elements, tangential diameter, area, tangential and radial diameter, x and y coordinates of pore center, and geometric coefficients) were saved in text file format. In addition, the pore area histogram in the tangential and radial directions was saved as a BMP (bitmap) type file. Analyses indicated that quantitative characteristics such as the relative radial distribution of pores in a growth ring, pore tangential area histogram, and proportion of pore in lumen area appear to be useful in separating four diffuse-porous woods and four ring-porous woods on the species level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.197-200
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• 2019

File Transfer Protocol (FTP) is a protocol for transferring files between computers, FTPS with TLS, and SFTP based on similar SSH. The keynote to apply one-time password (OTP) has been diffused to resolve identity and password theft cases. In this paper, it has been confirmed that both data transmission and identity authentication using OTP at TLS level are possible without significant change in user client.

• Journal of Sensor Science and Technology
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• v.11 no.5
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• pp.263-272
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• 2002

In this paper, we investigate the potential for retrieval of morphometric data from three dimensional images of conducting bronchus obtained by X-ray Computerized Tomography (CT) and to explore the potential for the use of rapid prototype machine to produce physical hollow bronchus casts for mathematical modeling and experimental verification of particle deposition models. We segment the bronchus of lung by mathematical morphology method from obtained images by CT. The surface data representing volumetric bronchus data in three dimensions are converted to STL(streolithography) file and three dimensional solid model is created by using input STL file and rapid prototype machine. Two physical hollow cast models are created from the CT images of bronchial tree phantom and living human bronchus. We evaluate the usefulness of the rapid prototype model of bronchial tree by comparing diameters of the cross sectional area bronchus segments of the original CT images and the rapid prototyping-derived models imaged by X-ray CT.