• Restorative Dentistry and Endodontics
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• v.42 no.4
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• pp.316-323
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• 2017

Objectives: This study compared the amount of apically extruded bacteria during the glide-path preparation by using multi-file and single-file glide-path establishing nickel-titanium (NiTi) rotary systems. Materials and Methods: Sixty mandibular first molar teeth were used to prepare the test apparatus. They were decoronated, blocked into glass vials, sterilized in ethylene oxide gas, infected with a pure culture of Enterococcus faecalis, randomly assigned to 5 experimental groups, and then prepared using manual stainless-steel files (group KF) and glide-path establishing NiTi rotary files (group PF with PathFiles, group GF with G-Files, group PG with ProGlider, and group OG with One G). At the end of canal preparation, 0.01 mL NaCl solution was taken from the experimental vials. The suspension was plated on brain heart infusion agar and colonies of bacteria were counted, and the results were given as number of colony-forming units (CFU). Results: The manual instrumentation technique tested in group KF extruded the highest number of bacteria compared to the other 4 groups (p < 0.05). The 4 groups using rotary glide-path establishing instruments extruded similar amounts of bacteria. Conclusions: All glide-path establishment instrument systems tested caused a measurable apical extrusion of bacteria. The manual glide-path preparation showed the highest number of bacteria extruded compared to the other NiTi glide-path establishing instruments.

• Restorative Dentistry and Endodontics
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• v.38 no.3
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• pp.167-171
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• 2013

Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.29-37
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• 1996

In this study, PC controlled CNC automatic cutting system is developed. Technological introduction of the control process and the computer programming has made possible not only the automatic control for cutting processing unit but also the easy-to-use graphic software that enables the cutting process. This program involves shape part drawing and amendment, pattern reading and saving, reading Autocad file, nesting process, kerf compensation, automatic cutting path generation, NC file conversion and motor control. Software is devided into 3 modules for easy work. First step enables drawing, amendment and pattern making, followed by automatic nesting and cutting path generation with kerf compensation. In the final step, drawing data is transmitted for the resulting automatic cutting processes. This software would be applicated in gas cutting and textile cutting so that it improves the productivity of cutting process.

• Korean Journal of Computational Design and Engineering
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• v.18 no.4
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• pp.243-249
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• 2013

This paper presents a tool-path generation methods for an automated robotic system for skull drilling, which is performed to access to some neurosurgical interventions. The path controls of the robotic system are classified as move, probe, cut, and poke motions. The four motions are the basic motion elements of the tool-paths to make a hole on a skull. Probing, rough cutting and fine cutting paths are generated for skull drilling. For the rough cutting path circular paths are projected on the offset surfaces of the outer top and the inner bottom surfaces of the skull. The projected paths become the paths on the top and bottom layers of the rough cutting paths. The two projected paths are blended for the paths on the other layers. Syntax of the motion commands for a file format is also suggested for the tool-paths. Implementation and simulation results show that the possibility of the proposed methods.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.6
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• pp.327-333
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• 2023

Existing studies on the UAV (Unmanned Aerial Vehicle)-based CPS (Cyber Physical System) environment lack forest fire monitoring and forest fire reconnaissance using real-world UAVs. So, it is necessary to monitor forest fires early through CPS based on real-world UAVs with high reliability and resource management efficiency. In this paper presents an MFG (Misstion File Generater) that automatically generates a flight path of an UAV for forest fire monitoring in a CPS environment. MFG generates flight paths based on a hiking trail with a high fire probability due to a true story of an entrant. We have confirmed that the flight path generated by MFG can be applied to the UAV. Also, we have verified that the UAV flies according to the flight path generated by MFG in simulation, with a negligible error rate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1295-1298
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• 2004

Selective Laser Sintering(SLS) method is one of Rapid Prototyping(RP) technologies. It is used to fabricate desirable part to sinter powder and stack the fabricated layer. To develop this SLS machine, it needs effective scanning path and the development of scanning device. This paper shows how to make fast scanning path with respect to scan spacing, laser beam size and scanning direction from 2-dimensional sliced file generated in commercial CAD/CAM software. Also, we develop the scanning device and its control algorithm to precisely follow the generated scanning path. Scanning path affects precision and total machining time of the final fabricated part. Sintering occurs using infrared laser which has high thermal energy. As a result, shrinkage and curling of the fabricated part occurs according to thermal distribution. Therefore, fast scanning path generation is needed to eliminate the factors of quality deterioration. It highly affects machining efficiency and prevents shrinkage and curling by relatively lessening the thermal distribution of the surface of sintering layer. To generate this fast scanning path, adaptive path generation is needed with respect to the shape of each layer, and not simply x, y scanning, but the scanning of arbitrary direction must be enabled. This paper addresses path generation method to focus on fast scanning, and development of scanning system and control algorithm to precisely follow generated path.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2333-2340
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• 2017

Recently industry is suffering severe losses of important internal information, and most of the leaks result from the insiders. Thus, various technological counter measures are being studied in order to protect private organization information. In this paper, among various internal information leakage path protection mechanisms, we propose a technique for preventing files which are defined as confidential from being copied or moved through USB. The implemented confidential file loss prevention system is composed of both signature insert manager and confidential file detect manager. The signature insert manager allows a system administrator to insert a special pattern specifying a classified confidential file, while the confidential file detect manager protects confidential file leakage when a user attempts to move or copy a confidential file to the USB memory. This results would be contributed to reducing the damage caused by leakage of confidential files outside of the company via USB.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.3
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• pp.75-81
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• 2003

Pocket machining is metal removal operation commonly used for creating depressions in machined parts. Numerically controlled milling is the primary means for machining complex die surface. These complex surfaces are generated by a milling cutter which removes material as it traces out pre-specified tool paths. To machine, a component on a CNC machine, part programs which define the cutting tool path are needed. This tool path is usually planned from CAD, and converted to a CAM machine input format. In this paper I proposed a new method for generating NC tool paths. This method generates automatically NC tool paths with dynamic elimination of machining errors in 2$\frac{1}{2}$ arbitrary shaped pockets. This paper generates a spiral-like tool path by dynamic computing optimal pocket of the pocket boundary contour based on the type and size of the milling cutter, the geometry of the pocket contour and surface finish tolerance requirements. This part programming system is PC based and simultaneously generates a G-code file.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.687-692
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• 1993

This paper deals with the generation of laser scan path for manufacturing 3-dimensional body using StereoLithography. The purpose of this study is to develop one module of the StersoLithography system(SLA) for Rapid Protyping and Manufacturing. AutoCAD system is used to supply CAD information from model. The X-Y controller which was made for a special purpose is used to test this system. The system software developed is composed of 3 main modules, the first module is calculating the boundary point os laser scan path. The scound module is generating final output file which is used to down load on the controller. The result of this study shows a good algorithm to generate laser scan path on the basis of simple mathematical background.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.190-193
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• 2004

This paper presents studies on the creation time of scanning path using rapid prototype device. In the case of Jewellery, it needs to take time too much at the whole process of rapid prototype in accordance with heigh of the multi-layered. When increases the number of polygon by heigh of the Multi-layered, it has proper influence on the creation time of scanning path. Therefore, we can get the spending time and the number of polygon for the creation during increase the heigh of the multi-layered. These values are showed by the quantitative. We try to analyze relation between these and heigh of the multi-layered.