• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.22.1-22.10
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• 2020

Objectives: This study investigated the influence of glide path size and operating kinetics on the time to reach the working length and the fracture resistance of Twisted File (TF) and Endostar E3 files. Materials and Methods: A total of 120 mandibular single-rooted premolars were selected. Two methods of kinetic motion (TF adaptive and continuous rotary motion) and file systems (TF and Endostar E3) were employed. The files were used in root canals prepared to apical glide path sizes of 15, 20, and 25. The time taken to reach the working length and the number of canals used before the instrument deformed or fractured were noted. Fractured instruments were examined with scanning electron microscopy. Results: The TF system took significantly more time to reach the working length than the Endostar E3 system. Both systems required significantly more time to reach the working length at the size 15 glide path than at sizes 20 and 25. A greater number of TFs than Endostar E3 files exhibited deformation, and a higher incidence of instrument deformation was observed in adaptive than in continuous rotary motion; more deformation was also observed with the size 15 glide path. One TF was fractured while undergoing adaptive motion. Conclusions: No significant difference was observed between continuous rotary and adaptive motion. The TF system and adaptive motion were associated with a higher incidence of deformation and fracture. Apical glide path sizes of 20 and 25 required significantly less time to reach the working length than size 15.

• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.31-37
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• 2005

The aim of this study was to evaluate the effectiveness of sealer placement in simulated root canal extensions. Forty resin blocks were attained from the Endo-training Bloc. In each block. The simulated root canal was made with $\#20$, 80taper GT file. After each block was longitudinally split into two halves, a standardized groove was prepared on one canal wall of two halves to simulate the canal extensions with various irregularities. The two halves of each block were assembled and all simulated root canals were obturated by single cone method with AH26 sealer. Four different methods of sealer placement were used: group A, $\#20$ K-file; group B, ultrasonic file; group C, lentulo spiral; group D, EZ-Fill bi-directional spiral. All obturated blocks were stored in $100\%$ humidity at $37^{\circ}C$ for 1 week, Using a low speed saw, each block was sectioned horizontally. Images of the sections were taken using a stereomicroscope at $\times$ 30 magnification and a digital camera. The amount of the sealer in the groove was evaluated using a scoring system, a higher score indicated better sealing effectiveness. The data was statistically analysed by Fisher's Exact Test. The sealing score was the lowest, specially at the middle area of canal extensions in group A, and that was statistically significant difference from other groups. In conclusion, the ultrasonic file, lentulo spiral and EZ-Fill bi-directional spiral were effective methods of sealer placement in simulated canal extensions. The K file was the least effective method, specially at the middle area of canal extensions.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.635-645
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• 2003

One of very important features that are necessarily supported by clustered parallel computer systems is a single I/O system image in which users can access both the local and remote I/O resources transparently. In this paper, we propose an efficient disk sharing technique supporting a single disk I/O system image architecture. The design separates the I/O subsystem of a cluster into the file system and a set of virtual hard disk drivers. The virtual hard disk driver deals with a hard disk in the remote node as a local hard disk. All services provided by it are performed in the device driver level without any modification of file systems. Users can, therefore, access all the disks in the cluster regardless of their locations. Our virtual hard disk driver is implemented under the linux, and also tested in a linux cluster system. We find by experiments that it can successfully support a single disk I/O space, and at the same time it shows better performance than NFS. We are sure that this paper can be a guideline for single I/O space of other devices to be easily constructed.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.4
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• pp.213-221
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• 2022

Purpose: The efficacy of the amount of sealer in the root canal and two retreatment NiTi file systems in removing filling materials. Materials and Methods: Extracted premolars with a single root canal were selected for this study. After access opening and root canal preparation up to size #40/.06, the specimens were randomly divided into four groups. Gutta percha (GP) tapers of .06 or .04 were used for each group and filled using a single-cone filling technique with CeraSeal, a calcium silicate-based sealer. Each group was retreated either using the ProTaper Universal Retreatment System (PTUR) or the Hyflex Remover (HR). The time taken to remove the filling material, the amounts of apically extruded debris, and canal cleanliness were measured and compared. Results: The amount of sealer did not affect the efficiency when removing the filling materials. However, the filling material was removed faster in the HR group than in the PTUR group. Two types of NiTi files showed similar retreatment effects in the amounts of apically extruded debris and in the degree of canal cleanliness. Conclusion: The amount of sealer in canal filling had no significant effect on retreatability. Retreatment with HR removed filling materials is faster than PTUR. There was no difference in other removal efficiencies according to the type of retreatment NiTi file.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.3
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• pp.171-180
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• 2009

Slowly, but surely, we are seeing the emergence of a variety of embedded systems that are employing Storage Class RAM (SCRAM) such as FeRAM, MRAM and PRAM, SCRAM not only has DRAM-characteristic, that is, random byte-unit access capability, but also Disk-characteristic, that is, non-volatility. In this paper, we propose a new software architecture that allows SCRAM to be used both for main memory and for secondary storage simultaneously- The proposed software architecture has two core modules, one is a SCRAM driver and the other is a SCRAM manager. The SCRAM driver takes care of SCRAM directly and exports low level interfaces required for upper layer software modules including traditional file systems, buddy systems and our SCRAM manager. The SCRAM manager treats file objects and memory objects as a single object and deals with them in a unified way so that they can be interchanged without copy overheads. Experiments conducted on real embedded board with FeRAM have shown that the SCRAM driver indeed supports both the traditional F AT file system and buddy system seamlessly. The results also have revealed that the SCRAM manager makes effective use of both characteristics of SCRAM and performs an order of magnitude better than the traditional file system and buddy system.

• Restorative Dentistry and Endodontics
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• v.31 no.1
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• pp.11-19
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• 2006

The purpose of this study was to compare and evaluate the shaping abilities of various hybrid instrumentation method using constant tapered file systems with $ProTaper\^{(R)}$ S1 and the difference between experts and inexperienced clinicians in use of NiTi file. Three hybrid methods used in this study were composed of $ProTaper\^{(R)}\;S1\;and\;K-Flexofile\^{(R)}\;(group S),\;ProTaper\^{(R)}\;S1\;and\;HeroShaper\^{(R)}\;(group\;H),\;and\;ProTaper\^{(R)}\;S1\;and\;ProFile\^{(R)}\;(group\;P)$respectively. The $ProTaper\^{(R)}$-alone method (group C) was introduced as a control group. After canal preparation, the lapse of time was recorded. The images of pre- and post-operative canal were scanned and superimposed. Amounts of instrumented canal widths and centering ratio were measured at apical 1, 2 and 3 mm levels and statistical analysis was performed In this study. both of the group C and S took more time to prepare canals than other groups, Inexperienced operators required more time for the entire preparation with the groups C and H than the experienced (p<0.05). And the centering ratio of group P were preferable to $ProTaper\^{(R)}$-alone method or the hybrid technique using stainless steel files. As such, within experienced operators, group H also showed better results in addition to the group P. Under these condition, the hybrid methods of each the $ProFile^{(R)}$ system and $HeroShaper^{(R)}$ with ProTaper are recommendable comparative to $ProTaper\^{(R)}$-alone method. According to the results, the hybrid instrumentation method is a more appropriate method of canal preparation than single file system for narrow or curved canals.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.6 s.261
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• pp.635-643
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• 2007

As many engineers and technicians are involved in the design process of large scale and/or complex products, there are a lot of miss matches and interferences due to designers' faults and several kinds of CAD systems. Recently, CAD systems are applied to verify and check the assembly process. Digital Mock-Up(DMU) system, a tool to build a virtual mock-up in the design stage, has been used to prevent the interferences and miss matches during precision design processes. Using the virtual assembly tool, engineers are able to design precision and interference free parts without physical mock-ups. Instead of a single CAD source, several CAD systems are used to design a complex product. Several organizations are involved in the distributed design environment for heterogeneous multi-CAD assembly. XML and the lightweight CAD file are proposed for the multi-CAD assembly. XML data contains hierarchy of the heterogenenous multi-CAD assembly. STEP PDM schema and STEP ISO 10303-28 formations are applied to construct the XML data. The lightweight CAD file produced from various CAD files through ACIS kernel and InterOp not only contains mesn, B-Rep and topological data, but also is used to visualize CAD data and to verify dimensions. Developed system is executed on the desktop computers. It does not require commercial CAD systems to visualize 3D assembly data. Real-time interference and fitness checks, dimensional verification, and design and assembly verification are performed on the developed system. Assembly of heterogeneous models for a car is conducted to verify the effectiveness of the developed DMU system on the Internet.

• Journal of Biomedical Engineering Research
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• v.14 no.4
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• pp.327-332
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• 1993

Automatic transmission of data from the blood analyzer to the request site is one of the most important part in hospital computerization. We have developed a system that transmits data from the arterial blood gas analyzer to the request site automatically In this system HOST computer, FILE server,'LAN(Local Area Network) , 3270 Emulator and bfulti-port card are integrated with 3 blood gas analyzers(NOVA Inc., USA) which are connected to a single multi-port card in a personal computer. When specimen are collected from tramp)inly sites, they are transferee to the laboratory In the Yonsei Cardiovascular Center After analysis, the result is transmitted to the personal computer via serial commnunication between machine and multi-port card using interrupt method. Then, the patient's information (Name, Patient ID No., etc.) is obtained from the HOST computer througth the emulator. The combined data (patient information & lab data) is transmitted to each request site via LAN automatically These results are stored in the File Server for one year and they can be reviewed anytime. Also, it could be used for the various statistics and the flow chart for clinical research. Additionally, we found thal this system reduces the personal labor.

• Journal of radiological science and technology
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• v.23 no.1
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• pp.103-111
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• 2000

In recent years, medical procedures have become more complex, while financial pressures for shortened hospital stays and increased efficiency in patient care have increased. As a result, several shortcomings of present film-based systems for managing medical images have become apparent. Maintaining film space is labor intensive and consumes valuable space. Because only single copies of radiological examinations exist, they are prone to being lost or misplaced, thereby consuming additional valuable time and expense. In this paper, MINI-PACS for image archiving, transmission, and viewing offers a solution to these problems. Proposed MINI-PACS consists of mainly four parts such as Web Module, Client-Server Module, Internal Module, Acquisition Module. In addition, MINI-PACS system includes DICOM Converter that Non-DICOM file format converts standard file format. In Client-Server Module case, Proposed system is combined both SCU(Service Class User: Client) part and SCP(Service Class Provider: Server)part therefore this system provides the high resolution image processing techniques based on windows platform. Because general PACS system is too expensive for Medium and Small hospitals to install and operate the full-PACS. Also, we constructed Web Module for database connection through the WWW.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.3
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• pp.197-212
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• 1990

This paper present a new design concept of a single chip 16-bit data path using the concept of modular design, the whole system is divided into several blocks which can be operated as an independent system itself. Making the internal blocks can act as a subsystem, it is possible to shorten design turn-around time, to be redesigned effectively, and to optimize the system performance. The designed system is data path. The data path is to manipulate 16-bit integer data. It is composed of aritmetic logic unit, register file, barrel shifter and bus circuit. The widths and lengths of gate in the circuit were determined using SPICE2. The results of circuit simulation were in good agreement with expected circuit characteristics.