• 구강회복응용과학지
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• 제24권2호
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• pp.193-201
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• 2008

하악 완전 무치악 환자의 보철수복에 있어 임플란트 식립 후 피개의치의 제작은 첫 번째 치료 옵션으로 고려되어질 수 있다. 임플란트 지지 텔레스코프 피개의치를 제작하는 경우 인공치 및 유지 장치의 배열을 위한 악간 공간이 필요하다. 임플란트 상부 보철물의 passive한 fit은 보철물의 기계적 실패를 막는 중요한 요소이다. Gold electroforming system을 이용하여 제작한 telescopic attachment는 우수한 마진 적합도 및 passive한 fit을 보이며 얇은 코핑 두께로 인하여 좁은 악간 공간에서도 사용이 가능한 장점이 있다. 본 증례에서는 4개의 임플란트 식립 후 Gold electroforming system을 이용하여 telescopic overdenture를 제작하여 기능 및 심미적으로 좋은 결과를 나타내었다.

• 한국공작기계학회논문집
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• 제15권1호
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• pp.8-16
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• 2006

The communication through optical fiber is taking an important role of the expansion of communication network with excellent transmitting rate and quality. As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement of the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1215-1220
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• 2004

Cell adhesion to any material surface is considered to be fundamental and important phenomenon in the fields of tissue engineering. Cell adhesion molecules, mechanism, and attachment force have been studied and described a lot. However, the effects of mechanical stimuli on the adhesive forces still have been left much to be investigated. In this study, to investigate the changes in cell adhesive force due to resting time period during the intermittent hydrostatic pressurizing (IHP), cells were cultured under the IHP with various resting times. Then the cell adhesive forces were measured quantitatively utilizing a cell detachment test system and immunofluorescent staining was performed using fluorescent microscopy. In the results, immediately after mechanical stimuli (150 minutes after seeding) and one hour later (210 minutes after seeding), the average adhesive force of experimental group 5 (resting time: 15min) compared with that of control group at same culture time was increased significantly (p<0.05). The results indicated that IHP can contribute in improving cell adhesive force and some of time intervals were required for the expression of cell response.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1676-1681
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• 2003

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline. and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application. as the attaching force ortho vehicle can be affected by its posture.

• 한국정밀공학회지
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• 제31권9호
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• pp.791-797
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• 2014

Abstract Scaffold used as a carrier of the cell has been actively conducted using plenty of technology in tissue engineering. ${\beta}$-tricalcium phosphate (${\beta}$-TCP) material has shown good biocompatibility and osteoconductive ability when it was implanted as a bone graft substitute in osseous defect in human and animal studies for bone regeneration. In this study, we fabricated the blended polycaprolactone (PCL) and ${\beta}$-TCP scaffold by the polymer deposition system (PDS). The PCL/${\beta}$-TCP scaffold was fabricated at a temperature of $110^{\circ}C$, pressure of 650 kPa, and scan velocity of 100 mm/sec. The Overall geometry and size of the scaffold were fixed circle type with a diameter of 10 mm and a height of 4 mm. PCL/${\beta}$-TCP scaffold was observed by scanning electron microscopy. Cell attachment and proliferation of the scaffold containing 30 wt% ${\beta}$-TCP was superior to those containing 10 wt% and 20 wt% ${\beta}$-TCP.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.81-86
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• 2005

As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement to the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

• 한국정밀공학회지
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• 제21권9호
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• pp.77-84
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• 2004

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline, and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application, as the attaching force of the vehicle can be affected by its posture.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.476-481
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• 2001

In a vacuum circuit breaker mechanism, a spring-actuated linkage system is used to satisfy the desired opening and closing characteristics of electric contacts. Because the opening dynamics of electric contacts is determined by such a linkage system, the stiffness, free length and attachment points of a spring become the important design parameters. In this paper, based on the energy conservation that the total system energy is constant throughout the operating range of a mechanism, a systematic design procedure of determining the spring design parameters is presented. The proposed procedure is applied to the design of an opening spring for satisfying the specified opening characteristics.

• 한국생산제조학회지
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• 제9권2호
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• pp.138-143
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• 2000

The establishment of a practical ultra-precision grinding technique using Diamond and CBN wheels is one of the major key technolo-gies to improve production techniques for machine-to-difficult materials without finishing process such as lapping and polishing. But the special efficient dressing technique for ultra-fine grit type grinding wheels to stabilize the grinding ability was not developed. Recently electrolytic in-process dressing technique is proposed to ultra-fine grit type metal bonded diamond wheels to protrude abra-sives continuously from the tool surface. This technology can be widely used to surface grinding and cylindrical grinding but cannot be used efficiently to internal grinding because of the electrode attachment trouble. This paper describes the effect of interval type electrolytic dressing as proposed newly to cast iron bonded diamond wheel for efficient internal grinding with mirror type high quality ground surface.

• The Journal of Advanced Prosthodontics
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• 제3권1호
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• pp.37-42
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• 2011

Partial edentulism has multiple implications in relation to function, esthetics and future rehabilitative treatment. This case report illustrates the management of a patient with extreme consequences of partial edentulism. The main clinical findings were unopposed remaining teeth, overeruption of the remaining teeth, loss of vertical dimension of occlusion, and significant disfigurement of the occlusal plane. Following the diagnostic procedure, a well-coordinated prosthodontic treatment involving liaison with other dental disciplines was indicated. The management involved an innovative combination of fixed and removable prostheses in conjunction with crown lengthening surgery and strategic implant placement. Series of provisional prostheses were applied to facilitate the transition to the final treatment.