• The Journal of the Korean dental association
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• v.36 no.5 s.348
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• pp.344-352
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• 1998

아무리 총의치를 완벽하게 만들고자 해도 환자는 불만을 표시하게 된다. 총의치 환자에서 가장 많이 나타나는 문제는 동통(pain)이 있거나, 유지력 혹은 안정성 부족으로 의치가 헐거움,씹기가 어렵거나 씹을때 소리가 나는 것, 구토,발음,심미성 부족 등이다. 이같은 문제는 장착 직후부터 수 개월 후까지 언제든지 나타날수 있다. 이에 대한 원인과 해결책을 간략하게 살펴보고자 한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.188-189
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• 2013

본 논문에서는 산업현장과 교육시설에서의 가정용 소형 단상변압기의 규격품 사용 여부와 운영상의 안전성 실태를 분석하였다. 전기용품 안전 관리법에 따른 법정인증을 받지 않은 제품이 5개 조사되었으며, 단자 체결형 변압기의 경우 전원선 접속 불량(헐거움), 설치 및 고정 불량, 접지 미체결(누락), 전압조정 핸들 파손, 변압기 상부 가연물 방치가 주요 불합리 항목으로 조사되었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.895-902
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• 2007

Rotating machinery has two typical faults with clearance, one is partial rub and the other is looseness. Due to these faults, non-linear and non-stationary signals are occurred. Therefore, time-frequency analysis is necessary for exact fault diagnosis of rotating machinery. In this paper newly developed time-frequency analysis method, HHT(Hilbert-Huang Transform) is applied to fault diagnosis and compared with other method of FFT, SFFT and CWT. The results show that HHT can represent better resolution than any other method. Consequently, the faults of rotating machinery are diagnosed efficiently by using HHT.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.224-235
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• 2013

A passively fitting prosthesis is an essential prerequisite to attain long-lasting success and maintenance of osseointegration. However, true "passive fit" can not be achieved with the present implant-supported prosthesis fabrication protocol. Many clinical situations are suitably treated with cantilevered implant-supported fixed restorations. The purpose of this study was to compare the stress distribution pattern and magnitude in supporting tissues around ITI implants with cantilevered, implant-supported, screw-retained fixed prosthesis according to the fitness of superstructures. Photoelastic model was made with PL-2 resin (Measurements, Raleigh, USA) and three ITI implants (${\phi}4.1{\times}10mm$) were placed in the mandibular posterior edentulous area distal to the canine. Anterior and posterior extended 4-unit cantilevered FPDs were made with different misfit in the superstructures. 4 types of prosthesis were made by placing a $100{\mu}m$ gap between the abutment and the crown on the second premolar and/or the first molar. Photoelastic stress analysis were carried out to measure the fringe order around the implant supporting structure under simulated loading conditions (30 lb).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.686-686
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• 2013

Automotive turbochargers have become common in gasoline engines as well as diesel engines. They are excellent devices to effectively increase fuel efficiency and power of the engines, but they unfortunately cause several noise problems. The noises are classified into mechanical noises induced from movement of a rotating shaft and aerodynamic noises by air flow in turbochargers. In addition to, there is a mechanical noise caused from movement of an actuator, electronically controlling a wastegate valve. It is called as valve rattle noise. The actuator is connected to a valve through a linkage. The noise occurs only if the valve is open, where the linkage is freely contact to neighbor structures without being constrained by any external forces. This condition allows impacts by the pulsation of exhaust gas, and the vibration from the impacts spreads out through turbine housing, causing the rattle noise. The noise is not in mechanical operating wastegate turbochargers because the linkage of an actuator is strongly connected by actuating force. For the electronic wastegate turbocharger, this paper proposed a test device to show the noise generating mechanism with a small vibration motor having an unbalanced shaft. It also shows how to reduce the noise - reduction of linkage clearances, inserting wave washers into a connection, and applying loose fitting in bushing embracing a valve lever to turbine housing.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.239-245
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• 2016

Purpose: The purpose of this study was to identify clinical complications in removable partial denture (RPD) with implant-supported surveyed prostheses, and to analyze the factors associated with the complications such as location of the implant, splinting adjacent prostheses, the type of retentive clasps, Kennedy classification, and opposing dentition. Materials and Methods: A retrospective clinical study was carried out for 11 patients (7 male, 4 female), mean age of 67.5, who received RPD with Implant-supported surveyed prostheses between 2000 and 2016. The mechanical complications of 11 RPDs and 37 supporting implant prostheses and the state of natural teeth and peripheral soft tissue were examined. Then the factors associated with the complications were analyzed. Results: The average of 3.4 implant-supported prostheses were used for each RPD. Complications found during the follow-up period of an average of 42.1 months were in order of dislodgement of temporary cement-retained prostheses, opposing tooth fracture/mobility, screw fracture/loosening, clasp loosening, veneer porcelain fracture, marginal bone resorption and mobility of implant, artificial tooth fracture. Complications occurred more frequently in anterior region compared to posterior region, non-splinted prostheses compared to splinted prostheses, surveyed prostheses applied by wrought wire clasp compared to other clasps, and natural dentition compared to other removable prostheses as opposing dentition. There were no significant differences in complications according to the Kennedy classification. Conclusion: All implant-assisted RPD functioned successfully throughout the follow-up. However, further clinical studies are necessary because the clinical evidences are still not enough to guarantee the satisfactory prognosis of implant-assisted RPD for long-term result.