• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.2
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• pp.26-30
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• 2016

This paper presented an optimum design of a perpendicular PMDSLSM (Permanent Magnet Double-sided Linear Synchronous Motor) to minimize the detent force. As an optimum method, the response surface method was used and 3D finite element method for the calculation. The design variables of the machine were the primary core width and thickness, and magnet width, thickness and length. Object functions were to minimize the detent force and maximize the thrust of the basic model. The results showed that the thrust force of the optimum design increased from 82.1N to 90.2N and detent force decreased from 15.2N to 2.8N, respectively, compared to the basic model.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.1
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• pp.49-55
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• 1996

In this paper, the characteristics of a double-sided linear pulse motor (DLPM) with permanent magnet are analysed using the method which combined the coenergy method and the equivalent magnetic circuit method. In the process of computation, the magnetic material nonlinealities of the permanent magnet, the primary and the secondary core are interpolated by the cubic spline method. Then, the equivalent magnetic circuit modelled by the permeance method including airgap reluctance, which is a function of displacement, is obtained. The static thrust which is the derivative of coenergy is computed by Newton Raphson method at each dispacement. And, in order to investigate the characteristics of the DLPM, the thrust shows as a function of displacement, input current and air gap. The simulation resuls are compared with experimental ones obtained from the DLPM with 2 phase and 4 poles.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.9
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• pp.572-577
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• 2000

This paper describes the test results of a single phase 3kVA high temperature superconducting power transformer. The tapes are made with Bi-2223 and have silver alloy as the matrix. Four double pancake windings are used. Among them two double pancake windings are connected in series for high voltage winding and the others are connected in parallel for low voltage winding. The rated voltage and current of primary winding and secondary winding are 220/110V. 13.7/27.3A. Fundamental characteristics are obtained through short circuit and no load test. The over load capability and characteristics are investigated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.9
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• pp.62-73
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• 2013

In this paper, a new linear synchronous motor - permanent magnet double-sided synchronous motor with perpendicular arrangement (PMDLSM), was proposed. It was designed to account for the drawbacks of conventional linear motors, such as the normal force and end effects. The detent force and the thrust were analyzed for different combinations of primary core modules and magnet poles of the machine, and the optimum combination was made. The characteristics of the perpendicular PMDLSM were analyzed by finite element method, and the experiments agreed well with the analysis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.12
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• pp.1050-1057
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• 2015

This paper presents the characteristics of broadband double-cone antennas. The antenna is used to measure electromagnetic fields(2~5 GHz) radiated from a primary or a secondary electrode of a pole-transformer when partial discharge occurs inside the pole-transformer. The theoretical analysis is conducted using commercial software based on a finite difference time domain(FDTD) method. The parameters are a radius, and a height of the broadband double-cone antennas, and the number of posts on a ground plane. This paper examines influences of structural parameters of the broadband double-cone antennas on return loss. The results show that a condition for an optimum structure of broadband double-cone antennas exists. It also shows that the broadband double-cone antennas have radiation patterns similar to those of a dipole antenna. Therefore the broadband double-cone antennas are appropriate for the measurement of radiated electromagnetic fields from the pole-transformer. To verify the theoretical analysis, computed results are compared to experimental results.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.383-387
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• 2000

Fusion is defined as union of two separate tooth buds at some stage in their development with confluence of dentin and characterized by separate root canal and large single crown, while gemination is defined as an attempt of the single tooth bud to incompletely divide and usually result in a single root with one root canal and two completely or incompletely separated crowns. It is sometimes difficult to decide whether an abnormally large tooth is the result of fusion of a normal and a supernumerary tooth, or of gemination; use of the term 'Double tooth' may make the clinicians avoid this difficulty(Brook & Winter). Commonly there are no symptoms, but the problems associated with these anomalies include esthetics, possible loss of arch length and delayed or ectopic eruption of the permanent teeth, caries along the line of demarcation, and periodontal disease. Commonly, it dose not need to be treated in primary dentition but in case of permanent dentition, it may be requested to be treated due to esthetics and other problems. In our case, a 8 years old girl showed a Double tooth, we attained the favorable results by performing hemisection with apexification.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.2
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• pp.95-99
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• 2011

The development of different entities of soft tissue sarcoma in one patient is rare. It usually affects head and neck or abdominal region, whereas those affecting the extremities are much rarer. We describe a patient with double primary presentation of liposarcoma and Ewing's sarcoma in extremity. This case implies that sarcoma patients are at increased risk of a second malignancy, and this implies a need to search for occult tumors during follow up.

• Progress in Superconductivity
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• v.5 no.2
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• pp.149-152
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• 2004

The design and the fabrication of a 1 MVA single-phase HTS transformer are presented in this paper, The rated voltages are 22.9 ㎸ for primary and 6.6 ㎸ for secondary, and the rated currents are 44 A and 152 A respectively. The transformer has HTS double pancake type windings. This type of winding has many advantages such as ease of fabrication and maintenance, good distribution of surge voltage and insulation of windings. Single HTS wire was used for primary winding and four HTS parallel wires were used for secondary winding. These windings are arranged reciprocally with the shell type iron core. An FRP cryostat with room temperature bore was fabricated to isolate the iron core from the coolant. The winding will be cooled down to 65 K with sub-cooled liquid nitrogen using a GM-cryocooler. The sub-cooled liquid nitrogen has advantages of good insulation because of no bubbles as well as increased current capacity of HTS wire.

• Journal of Chest Surgery
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• v.38 no.11 s.256
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• pp.791-794
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• 2005

After esophagectomy, the stomach is used most commonly for the method of reconstruction. However, the stomach may not be large enough to be reached the site of anastomosis when it is above the pharynx. We experienced a double primary cancer of the lower esophagus and the larynx. Total laryngectomy and total esophagectomy were done with cervical pharyngojejunogastrostomy for reconstruction. Free jejunal graft is interposed between the oropharyngeal stump and the stomach is pulled-up. We could restore the alimentary track without tension at the anastomotic site and obtain sufficient blood supply.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.329-337
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• 2015

PURPOSE. This retrospective study aims at the evaluation of implant-supported overdentures (IODs) supported by ceramo-galvanic double crowns (CGDCs: zirconia primary crowns + galvano-formed secondary crown). MATERIALS AND METHODS. In a private practice, 14 patients were restored with 18 IODs (mandible: 11, maxilla: 7) retained by CGDCs on 4 - 8 implants and annually evaluated for technical and/or biological failures/complications. RESULTS. One of the 86 inserted implants failed during the healing period (cumulative survival rate (CSR) implants: 98.8%). During the prosthetic functional period (mean: $5.9{\pm}2.2years$), 1 implant demonstrated an abutment fracture (CSR-abutments: 98.2%), and one case of peri-implantitis was detected. All IODs remained in function (CSR-denture: 100%). A total of 15 technical complications required interventions to maintain function (technical complication rate: 0.178 treatments/patients/year). CONCLUSION. Considering the small sample size, the use of CGDCs for the attachment of IODs is possible without an increased risk of technical complications. However, for a final evaluation, results from a larger cohort are required.