• Proceedings of the KACD Conference
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• 2003.11a
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• pp.599-599
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• 2003

Endodontic rotary NiTi(Nickel-Titanium) files have several advantages, but they also have some problems. Fracture of instrument is the one of the problems. Cyclic fatigue fracture may not give a previous sign(ex, bending or distortion of the files) before it happen. It is affected by various factors. This study investigated time which takes for cyclic fatigue fracture to happen and fracture patterns with regard to different NiTi files and pecking motion.(omitted)

• Journal of Korean Society of Archives and Records Management
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• v.13 no.3
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• pp.7-39
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• 2013

Some records have to be classified not according to their business function but according to their case because of the characteristics of the organization's business. Examples of this are case files, criminal files, lawsuit files, personal files, medical files, and project files. The case files are made according to standard business processes. Case files are filled with records of a series of activities and these records, which are made while carrying out various functions, reenact the multilevel process of a case. This study organized the implications of managing case files by examining the composition of lawsuit records and deducting characteristics in management. To do this, first, this study analyzed the composition of the lawsuit records that Korea Legal Aid Corporation produced and managed. Second, this study confirmed how the characteristics of case files are reflected in the lawsuit records of Korea Legal Aid Corporation. Third and lastly, this study searched how the lawsuit files are managed and used through the example of Korea Legal Aid Corporation.

• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.25.1-25.10
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• 2018

Objectives: To evaluate the mechanical properties and metallurgical characteristics of the M3 Rotary and M3 Pro Gold files (United Dental). Materials and Methods: One hundred and sixty new M3 Rotary and M3 Pro Gold files (sizes 20/0.04 and 25/0.04) were used. Torque and angle of rotation at failure (n = 20) were measured according to ISO 3630-1. Cyclic fatigue resistance was tested by measuring the number of cycles to failure in an artificial stainless steel canal ($60^{\circ}$ angle of curvature and a 5-mm radius). The metallurgical characteristics were investigated by differential scanning calorimetry. Data were analyzed using analysis of variance and the Student-Newman-Keuls test. Results: Comparing the same size of the 2 different instruments, cyclic fatigue resistance was significantly higher in the M3 Pro Gold files than in the M3 Rotary files (p < 0.001). No significant difference was observed between the files in the maximum torque load, while a significantly higher angular rotation to fracture was observed for M3 Pro Gold (p < 0.05). In the DSC analysis, the M3 Pro Gold files showed one prominent peak on the heating curve and 2 prominent peaks on the cooling curve. In contrast, the M3 Rotary files showed 1 small peak on the heating curve and 1 small peak on the cooling curve. Conclusions: The M3 Pro Gold files showed greater flexibility and angular rotation than the M3 Rotary files, without decrement of their torque resistance. The superior flexibility of M3 Pro Gold files can be attributed to their martensite phase.

• Journal of Digital Contents Society
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• v.13 no.2
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• pp.141-150
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• 2012

As various smartphones users are increasing rapidly, the more contents they keep in their devices, however, the larger necessity for the effective and easy management of their files they want. To satisfy this need, we propose an integrated multimedia files management system, H5Station. By using H5Station client, users can connect to the H5Station server running on their own PC, and manage their multimedia files effectively, and enjoy every file they have. The H5Station client is developed by using HTML5 standard technology. Therefore H5Station client can run on any HTML5-supported browser. Main functions of the H5Station are as follows: configuring user settings, charting the distribution of user files, upload/download/deletion of files, synchronizing files' metadata between client and server, playing user-selected files, searching files users want, and finally creating user-customized buttons. Through these functions, users can easily find, play, and manage their multimedia contents at any place and anytime.

• Restorative Dentistry and Endodontics
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• v.29 no.3
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• pp.267-272
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• 2004

The purpose of this in vitro study was to evaluate the effect of surface defects and cross-sectional configuration of NiTi rotary files on the fatigue life under cyclic loading. Three NiTi rotary files ($K3^{TM},{\;}ProFile^{\circledR},{\;}and{\;}HERO{\;}642^{\circledR}$) with ＃30/.04 taper were evaluated. Each rotary file was divided into 2 subgroups : control (no surface defects) and experimental group (artificial surface defects), A total of six groups of each 10 were tested. The NiTi rotary files were rotated at 300rpm using the apparatus which simulated curved canal (40 degree of curvature) until they fracture. The number of cycles to fracture was calculated and the fractured surfaces were observed with a scanning electron microscope. The data were analyzed statistically. The results showed that experimental groups with surface defects had lower number of cycles to fracture than control group but there was only a statistical significance between control and experimental group in the $K3^{TM}$ (p<0.05), There was no strong correlation between the cross-sectional configuration area and fracture resistance under experimental conditions. Several of fractured files demonstrated characteristic patterns of brittle fracture consistent with the propagation of pre-existing cracks. This data indicate that surface defects of NiTi rotary files may significantly decrease fatigue life and it may be one possible factor for early fracture of NiTi rotary files in clinical practice.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.6.1-6.10
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• 2021

Objectives: The aim of this study was to evaluate the corrosion resistance of heat-treated (Reciproc and WaveOne) and non-heat-treated (ProTaper and Mtwo) superelastic nickel-titanium endodontic files when immersed in a 5.25% sodium hypochlorite solution. Materials and Methods: Anodic polarization curves were obtained with potential sweeps that began at the open circuit potential or corrosion potential (E_corr). The pitting potential (E_pit) was identified on the anodic polarization curve as the potential at which a sudden increase in current was observed. The micromorphology of the 28 tested files was analyzed before and after the electrochemical assay using scanning electron microscope (SEM). The data were analyzed using 1-way analysis of variance with the post hoc Bonferroni test (for E_corr) and the Student t-test for independent samples (for E_pit). Results: The mean E_corr values were 0.506 V for ProTaper, 0.348 V for Mtwo, 0.542 V for Reciproc, and 0.321 V for WaveOne files. Only WaveOne and Protaper files exhibited pitting corrosion, with E_pit values of 0.879 V and 0.904 V, respectively. On the SEM images of the ProTaper and WaveOne files, cavities suggestive of pitting corrosion were detected. Conclusions: Signs of corrosion were observed in both heat-treated and non-heat-treated files. Of the evaluated files, WaveOne (a heat-treated file) and ProTaper (a non-heat-treated file) exhibited the lowest corrosion resistance.

• Proceedings of the Korean Society for Information Management Conference
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• 1994.12a
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• pp.151-154
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• 1994

Historical background of computer files is briefly outlined. Descriptive examples of phisical area of computer files revealed in existing cataloging rules and manuals are examined and analyzed in terms of consistency identification and term standardization. An analysis of examples may provide the basis for enhancing organizing computer file.

• Progress in Medical Physics
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• v.28 no.3
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• pp.129-133
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• 2017

The machine log files recorded by a scanning control unit in proton beam therapy system have been studied to be used as a quality assurance method of scanning beam deliveries. The accuracy of the data in the log files have been evaluated with a standard calibration beam scan pattern. The proton beam scan pattern has been delivered on a gafchromic film located at the isocenter plane of the proton beam treatment nozzle and found to agree within ${\pm}1.0mm$. The machine data accumulated for the scanning beam proton therapy of five different cases have been analyzed using a statistical method to estimate any systematic error in the data. The high-precision scanning beam log files in line scanning proton therapy system have been validated to be used for off-line scanning beam monitoring and thus as a patient-specific quality assurance method. The use of the machine log files for patient-specific quality assurance would simplify the quality assurance procedure with accurate scanning beam data.

• Asia pacific journal of information systems
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• v.14 no.3
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• pp.169-187
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• 2004

Self-maintainability of data warehouse(DW) views is an ability to maintain the DW views without requiring an access to (i) any underlying databases or (ii) any information beyond the DW views and the delta of the databases. With our proposed method, DW views can be updated by using only the old views and the differential files such as different files, referential integrity differential files, linked differential files, and backward-linked differential files that keep the truly relevant tuples in the delta. This method avoids accessing the underlying databases in that the method achieves self-maintainability even in preparing auxiliary information. We showed that out method can be applicable to the DW views that contain joins over relations in a star schema, a snowflake schema, or a galaxy schema.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1181-1186
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• 2002

This system is controlled by PC application programs through USB interface. PC application programs make image files, user's files , sound files and option files. And these files are downloaded to external memory card of this system. The other PC application programs monitor status of DARC, GPS, LED module of this system. The PC application programs help user manage this system efficiently.