• Advances in pediatric surgery
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• v.13 no.2
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• pp.112-118
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• 2007

Ingested foreign bodies are common occurrences in the pediatric population. From October 2002 to April 2006, eight patients (6 male, mean age: $30.9{\pm}14.4$ months, range: 7~45 months) who had ingested metallic foreign bodies, such as bar magnets, coin-type magnets, screws, metal beads, and disk batteries, were selected for foreign body removal using a magnetic device under floroscopic control. A 1-cm-long cylindrical magnet (6 mm in diameter) was placed at the end of a 150-cm-long plastic tube from an IV set. The magnet was passed through the mouth into the stomach. Under fluoroscopic control, the magnet was maneuvered so that it attached to the metallic foreign bodies. The forgeign body was then easily removed by retracting the magnet with the metallic object attached. This procedure was successful in six patients of 8 patients. This procedure is a minimally-invasive and may avoid the use of anesthesics, endoscopy or surgery.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.4
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• pp.1-10
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• 1993

This paper presents the designing/manufacturing scheme of the diplexer for satellite transponder which is composed of 2-channel bandpass filters, coupled with E-plane T-junction, having symmetrical waveguide E-plane step discontinuity structures. The 2-channel bandpass filters of the diplexer are designed by the scheme of connecting ${\lambda}_{g}$/2 shunt stub to the waveguide E-plane, playing the role of heat sinks without attaching a special heat sinks and to give the profitable productivity and allow the low-cost manufacturing at mass production, tuning screws are eliminated which have been used to compensate the operating characteristics of manufactured filters. The 2 channel bandpass filters of manufactured 14/12 GHz diplexer for domestic Ku-band satellite transponder have the return loss of 25 dB, insertion loss of 0.3 dB in passband, and below-50 dB of stopband characteristics (T$_{x}$ : f$_{o}{\pm}$250 MHz, R$_{x}$ : f$_{o}{\pm}$220 MHz) at room temperature.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.93-98
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• 2010

The metal fastening method is the new technology to repair cracks in the casting material using specially designed reverse screws. In this study, we conduct the finite element analysis to analyze the pulling force characteristic of a reverse screw, the core component of the metal fastening method, with respect to the change of the applying torque, frictional coefficient and front screw angle. The simplified analysis model with single screw pitch is proposed for convergency of the non-linear contact analysis. As a results, the pulling force of a reverse screw increase in proportion to the applying torque but exponentially decrease according to frictional coefficient. And also we can find the optimum front screw angle with the largest pulling force is $20^{\circ}$.

• Journal of Applied Reliability
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• v.11 no.3
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• pp.305-318
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• 2011

In the statement of logistics reliability prediction methodology, all components should be managed as the analysis objectives. However, in some reliability prediction of weapon systems, fastening parts, e.g., screws, bolts and nuts, have been frequently ignored because some organizations related to weapon systems have emphasized that those parts are not significant in their failures rate and functions. In this paper, failure rates, modes, and distributions were presented to prove that fastening parts should be included in reliability prediction objectives. Also, failure rate prediction methods of fastening parts are presented and compared.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.143-146
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• 2001

Servomotors, especially linear brushless servomotors have numerous advantages over ball screws, timing belts, rack/pinion drives and friction drives compared wi th rotary servomotors This paper proposes an linear regression method as the estimated ion of unknown parameters from the linear brushless DC motor The estimated parameters are used to tune the gain of controller. In order to agree with this purpose, Digital Signal Processor (TMS320F240), developed for implementation of the motor control, is adopted in this study. The processor playing an important role in controller has A/D converters, PWM generators, riched I/O ports internally.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.435-444
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• 1997

Many of the problems which are faced to the edentulous patients are related to a minimal amount of available mandibular bone volume and height. Most of the patients with mild atrophy of the mandible are treated using endosseous implant prosthodontics. TMI(Trans-mandibular Implant) can be used in case of severe mandibular atrophy, poor bone quality, atrophy of the mandible with exposed of inferior alveolar nerve, osteoporosis and the fracture of the atrophic mandible. Also it can eliminate the need for bone grafting and vestibuloplasty. The TMI is a rigid box frame structure which controls and distribute the masticatory force over the severely resorbed mandible. The box frame structure consist of a superstructure, baseplate, 4 transosseous posts, and 5 cortical screws. This is a case report that also describes about the transmandibular implant reconstruction system.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.1
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• pp.47-54
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• 2003

The radiating multislotted antennas widely used in the antennas technique are rather prospective for the application in industrial installations for microwave heating. In this paper, the model of such an antenna is experimentally investigated. The model under investigation presents a section of the waveguide Inn 340 whose broad wall contains 15 movable slotted plates. This design allows to experimentally define a location of all the slots providing the necessary distribution of radiating power along the waveguide with minimal SWR of all the system. The variants of power uniform distribution along the waveguide as well as the power decreasing to the waveguide end are examined. The application of plates with different thickness allowed to estimate the influence of the walls thickness on the Power distribution. The possibility of system extra-tuning with the help of tuning screws located in the vicinity of each slot is considered. Obtained results are compared to the conducted theoretical calculations and data in references.

• Tribology and Lubricants
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• v.20 no.3
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• pp.140-144
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• 2004

Water-lubrication ball bearings are required to install in aqueous medium where water is used as coolant or working fluid. However water-lubricated frictional characteristics of stainless steel ball bearing is not will known compared to oil-lubricated frictional characteristics. Furthermore study on friction at high temperature is rare because bearing maintenance strategy for water-lubricated or chemicals-lubricated bearings of equipment is mostly based on change of failed bearings and parts. Ball bearings and ball screws are used to transmit power in the control rod drive mechanism for an integral reactor and are lubricated with high temperature and high pressure chemically-controlled water. Bearings and power transmitting mechanical elements for a nuclear reactor require high reliability and high performance during estimated lifetime, and their performance should be verified. In this paper, experimental research results of frictional characteristics of water-lubricated ball bearing are reported.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2006.11a
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• pp.84-84
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• 2006

• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.188-193
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• 2004

The purpose of this paper is concerned with a development of an air-powered handpiece for surgical operation. The handpiece is the tool of surgical instruments and it can be used to interchange multiple attachments for drilling, pinning, sawing, driving screws and reaming. Most of domestic medical instruments bring in overseas and the air-powered handpiece imported from foreign countries at 100％ too. Therefore we develop new air powered handpiece. we research in 2D and 3D modeling, design of air line, analyze structure. The air-powered handpiece composes of body, power supply air-line, elements for mechanical power transmission, attachment, and surgical tools. The handpiece is developed by several processes that 3D design, machining, heat treatment and coating. The developed handpiece is experimented to confirm check the efficiency.