• 대한치과보철학회지
• /
• 제42권6호
• /
• pp.679-684
• /
• 2004

Statement of problem. There have been few studies about the marginal fit of Auro Galvano Crowns. Purpose. The purpose of this study was to compare the marginal fit of the anterior single restorations. Material and methods. The in vitro marginal discrepancies of metal-ceramic, Auro Galvano Crown and coping were evaluated and compared. The Auro Gavano Crowns were made from one extracted maxillary central incisor prepared by milling machine. 30crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. Results. Mean marginal gap dimensions and standard deviations at the marginal opening for the anterior single crowns were $74{\pm}21{\mu}m$ for the control (metal-ceramic restoration), $45{\pm}11{\mu}m$ for Auro Galvano Crown coping, and $51{\pm}9{\mu}m$ for the Auro Galvano Crown. Conclusions. Auro Calvano Crown showed significantly smaller (P<.05) marginal gap than the control. Ceramic application did not significantly affected the marginal fit of Auro Galvano Crown. (P>.05)

• The Journal of Advanced Prosthodontics
• /
• 제7권3호
• /
• pp.257-263
• /
• 2015

PURPOSE. In this study, we aimed to evaluate the amount of marginal gap with two different substructure materials using identical margin preparations. MATERIALS AND METHODS. Twenty stainless steel models with a chamfer were prepared with a CNC device. Marginal gap measurements of the galvano copings on these stainless steel models and Co-Cr copings obtained by a laser-sintering method were made with a stereomicroscope device before and after the cementation process and surface properties were evaluated by scanning electron microscopy (SEM). A dependent t-test was used to compare the mean of the two groups for normally distributed data, and two-way variance analysis was used for more than two data sets. Pearson's correlation analysis was also performed to assess relationships between variables. RESULTS. According to the results obtained, the marginal gap in the galvano copings before cementation was measured as, on average, $24.47{\pm}5.82{\mu}m$ before and $35.11{\pm}6.52{\mu}m$ after cementation; in the laser-sintered Co-Cr structure, it was, on average, $60.45{\pm}8.87{\mu}m$ before and $69.33{\pm}9.03{\mu}m$ after cementation. A highly significant difference (P<.001) was found in marginal gap measurements of galvano copings and a significant difference (P<.05) was found in marginal gap measurements of the laser-sintered Co-Cr copings. According to the SEM examination, surface properties of laser sintered Co-Cr copings showed rougher structure than galvano copings. The galvano copings showed a very smooth surface. CONCLUSION. Marginal gaps values of both groups before and after cementation were within the clinically acceptable level. The smallest marginal gaps occurred with the use of galvano copings.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 춘계학술대회논문집
• /
• pp.338-341
• /
• 2005

This paper proposes a control system for a Galvano meter which can be used in angle multiplexing for a holographic data storage. Due to the small angle multiplexing selectivity and the exposure/delay time of a CCD camera, the system needs to be controlled to satisfy the performance specification. First, the mathematical model is derived by combining the electrical and mechanical dynamic equations. Then, the obtained model was tuned by the experiments. Finally, a PID controller using DSP was designed and was applied the holographic system. From this approach, we successfully meet the performance specification.

• 동력기계공학회지
• /
• 제3권2호
• /
• pp.79-83
• /
• 1999

We implemented a system that can change laser beam directions rapidly by controlling the galvano-mirror, on which a mirror is mounted, with a computer. We show that a laser projection can be realized by programming our system properly, and that it can also be used for multiplexing 2-dimensional image information in the data storage of holographic memories efficiently.

• 한국기계가공학회지
• /
• 제9권5호
• /
• pp.70-75
• /
• 2010

In this paper, laser marking systems dedicated to cylinderical parts was developed. We first develop the marking device which consists of Nd-Yag laser, galvano scanner and additional rotational axis, then develop algorithm for supporting the digital image with bmp data format. Additional rotational axis is so attached as to rotate the cylinderical parts for marking its whole surface. The image is separated into line by line and the separated line image is sent to galvano scanner while rotating the additional axis simultaneously. CxImage library, famous open source code, is employed for the image processing. The developed method was tested with various images and shows that it reduces marking time significantly without reducing marking quality.

• 정보저장시스템학회논문집
• /
• 제2권1호
• /
• pp.43-49
• /
• 2006

Fractal/angle multiplexing is a $LiNBO_3$ crystal using a X-Y Galvano mirror, and the random access concept in fractal/angle multiplexing are discussed in this paper. First, the brief introduction of the designed holographic digital data storage system is presented. Then, the average access time concept for the storage system is newly defined, and the comparison of the average access time between the holographic storage and a conventional optical disk is performed. Second, the basic simulation and experiment to find the X-Y Galvano mirror dynamics are conducted. From this analysis, we find that the average access time in our HDDS which has 6 degree scan angle is about 5 msec. This result is very high performance when it compared with the average access time of a conventional optical disk. Finally, some recording results using fractal/angle multiplexing are presented, then, the relationship between bit error rate and angle mismatch for the each multiplexing are discussed.

• 대한치과기공학회지
• /
• 제28권1호
• /
• pp.215-219
• /
• 2006

• 정보저장시스템학회논문집
• /
• 제7권2호
• /
• pp.85-89
• /
• 2011

In retrieving process in angle multiplexing Holographic Data Storage(HDS), It is important to search the exact recording angles. In this paper, we propose the retrieving angle searching method using pre-scan. Pre-scan method is means that rotating the galvano mirror before the retrieving process. Therefore, retrieving signals are maximized when between the galvano mirror and recoded angle are exactly matched. Through the measured signals, we will find the exact angle and compensate tangential tilt angle. The experimental results shows propose method is enough to apply the HDS.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 춘계학술대회 논문집
• /
• pp.453-454
• /
• 2010

• 대한치과보철학회:학술대회논문집
• /
• 대한치과보철학회 2001년도 추계학술대회
• /
• pp.42-42
• /
• 2001