• 한국CDE학회논문집
• /
• 제21권2호
• /
• pp.204-214
• /
• 2016

Shipbuilding process takes a long time for producing final products, and needs many different resources. Because of these characteristics, it has been studied about shipyard simulation and virtual manufacturing that is able to implement the virtual manufacturing process. However, among the previous researches, it requires considerable time and effort to construct simulation model since the systematic methodology has not been used for simulation modeling. Also, reusability of constructed simulation model was low. Therefore, this research defines the method to construct shipyard simulation system using the process-centric simulation modeling methodology and shipyard simulation framework. This paper also validates the utility of this methodology through applying to construct simulation model for the shipyard master plan validation.

• The Journal of Advanced Prosthodontics
• /
• 제10권5호
• /
• pp.367-373
• /
• 2018

PURPOSE. To evaluate the fit of a crown produced based on a 3D printed model and to investigate its clinical applicability. MATERIALS AND METHODS. A master die was fabricated with epoxy. Stone dies were fabricated from conventional impressions (Conventional stone die group: CS, n=10). Digital virtual dies were fabricated by making digital impressions (Digital Virtual die group: VD, n=10). 3D data obtained from the digital impression was used to fabricate 3D printed models (DLP die group: DD, n=10, PolyJet die group: PD, n=10). A total of 40 crowns were fabricated with a milling machine, based on CS, VD, DD and PD. The inner surface of all crowns was superimposed with the master die files by the "Best-fit alignment" method using the analysis software. One-way and 2-way ANOVA were performed to identify significant differences among the groups and areas and their interactive effects (${\alpha}=.05$). Tukey's HSD was used for post-hoc analysis. RESULTS. One-way ANOVA results revealed a significantly higher RMS value in the 3D printed models (DD and PD) than in the CS and DV. The RMS values of PD were the largest among the four groups. Statistically significant differences among groups (P<.001) and between areas (P<.001) were further revealed by 2-way ANOVA. CONCLUSION. Although the fit of crowns fabricated based on the 3D printed models (DD and PD) was inferior to that of crowns prepared with CS and DV, the values of all four groups were within the clinically acceptable range (<$120{\mu}m$).

• 대한치과기공학회지
• /
• 제34권4호
• /
• pp.369-377
• /
• 2012

Purpose: The aim of study was to compare the dimensional stability of digitized dental stone replica using different color of gypsum materials using a white light scanner with three-dimensional software. Methods: A master model(500B-1, Nissin dental product, Japan) with the prepared lower full arch tooth was used. Several type IV stones(white, yellow, green) were used for 30 stone casts(10 casts each) duplicated a master model of mandible. The master model and the replicas were digitized with the non-contacting white light scanner to create 3-dimensional digital models. The linear distance between the reference points were measured and analyzed on the Delcam Copycad$^{(R)}$(Delcam plc, UK) 3D graphic software. One-way analysis of variance(ANOVA) combined with a Tukey multiple-range test were used to analysis the data(${\alpha}$=0.05). Results: There were considerable differences in mean values between gypsum materials within each color(white, yellow, green), and this difference was statistically significant, p=0.001. Conclusion: Digitization of dental materials on optical scanner was affected by color. Three different color of gypsum materials showed clinically acceptable accuracies of full arch digital model produced by them. Besides, these results will have to be confirmed in further clinical studies.

• 대한치과보철학회지
• /
• 제33권3호
• /
• pp.539-549
• /
• 1995

The purpose of this study was to determine the accuracy of 3 implant impression methods by using strain gauge. The models used for this study were partially edentulous mandibular acrylic resin casts Model A, with two abutment analogs in #46,47 extraction site, represented two implant parallel to to the adjacent natural tooth. Model B represent an anterior implant parallel to the adjacene natural tooth and a posterior implant exhibiting a 15-degree lingual inclination. Master framework were fabricated on the master model, and 3 strain gauges were attached to a master framwork to determine the passivity of fit of the framework to sample casts made by the three impression techniques. The master framework was attached to each sample cast with gold screws, which were tightened with the torque driver to ensure a consistent toque application of 10 Ncm. Universal Digital Measuring System UCAM-5BT was used for strain measuring. Impression techniques studid were : 1. unsplinted tapered impression coping, polyvinyl siloxane, stock tray 2. unsplinted squared impression coping, polyether, custom tray 3. squared impression coping splinted with Duralay resin, polyether, custom tray Through analysis on data from this study, the following conclusions were obtained. 1. There were no statistically significant differences between the mean strain recorded from the sample casts made with the tree impression. But only strain values of model A(parallel group) Y-axis was signifcantly differed between Technique 1 and 3(P<0.05). 2. There was no statistically significant difference between model A(parallel group) and model B(15-degree divergent group).

• 한국산학기술학회논문지
• /
• 제12권11호
• /
• pp.5314-5320
• /
• 2011

현재 설계교육에서 디지털 기술매체는 새로운 디자인 매체로 재인식되어 설계 커리큘럼에도 적지 않은 영향을 주고 있다. 산업적으로도 비정형 설계가 증가하면서 디지털 디자인의 가능성을 실험하는 진보적 건축 그룹들이 등장해서 실질적인 디지털 설계교육으로 전환을 촉구하고 있다. 국내 설계교육에서도 디지털 관련 과목이 다양하게 개설되어 운영되고 있지만, 기존 설계스튜디오를 보조하는 교과과정으로 운영되는 형편이다. 따라서 국내의 설계교육에서도 실무분야의 디지털 설계 전문가를 양성할 수 있는 교육모델이 제시되고 운영되어야 하며, 더불어 건축설계에서 디지털 패러다임의 적용 가능성을 탐구할 필요가 있다. 이런 배경에서 본 연구는 디지털 설계의 이론적 고찰과 교육 사례 고찰을 통해 건축설계 교육에 적용 가능한 디지털 설계 커리큘럼 모델을 제안하고자 한다.

• 구강회복응용과학지
• /
• 제36권1호
• /
• pp.29-40
• /
• 2020

목적: Encoded healing abutment와 scan body를 이용한 디지털 인상과 pick-up 인상용 코핑을 이용한 인상 채득법의 정확도를 다른 임플란트 식립 각도에서 비교 연구하고자 하였다. 연구 재료 및 방법: 3D 프린터를 이용해 주모형을 제작하고 0°, 10° 및 20°의 근심경사로 3개의 임플란트를 위치 시켰다. 각각의 임플란트에 지대주를 체결하고 주모형을 스캔하여 참조 모델을 만들었다. P군 모델은 pick-up 인상용 코핑을 사용하여 15개의 석고 모형을 만들고 지대주를 장착 후 스캔하여 제작하였다. E군과 S군의 모델은 각각 encoded healing abutment와 scan body를 주모형에 체결하고 구내 스캐너를 이용해 15회씩 인상채득을 하여 제작하였다. 각각의 실험군 STL 파일은 best fit alignment를 이용해 참조 모델과 중첩하였고 root mean square (RMS) 값을 분석하였다. 결과: RMS 값은 P군에서 가장 작았고(25.56 ± 2.53 ㎛), 그다음 S군(35.27 ± 2.56 ㎛), E군(38.29 ± 4.12 ㎛) 순 이었다. S군과 E군 사이에는 유의차가 없었고, P군은 S군과 E군 보다 작았다(P < 0.05). 임플란트 각도와 RMS 값의 상관관계는 E군에서 유의하였다(P < 0.05). 결론:Pick-up 인상용 코핑 방법은 encoded healing abutment와 scan body 인상 채득 방법에 비해 더 높은 정확도를 보였고 encoded healing abutment와 scan body 인상 방법은 정확도에서 유의한 차이가 없었다. Encoded healing abutment의 임상적 사용은 가능하나 경사진 임플란트의 인상의 경우 주의하여 사용해야 할 것으로 사료된다.

• 한국문헌정보학회지
• /
• 제36권4호
• /
• pp.49-67
• /
• 2002

학교도서관은 질적으로 우수한 교육을 실현하기 위한 핵심 시설이며, 우리나라의 제7차 교육과정에서도 학생 스스로가 문제를 해결하는 자율적이며, 창조적인 인재 양성을 강조함으로써 학교도서관의 중요성이 더욱 증대하고 있다. 이러한 시대적 요청에 부응하여 교육인적자원부에서는 2001년부터 학교도서관 디지털자료실 설치 사업을 추진하고 있으며, 최근에는 학교도서관 활성화 종합방안을 발표한 바 있다. 그러나 학교도서관 디지털자료실은 설치 기준이나 지침 그리고 객관적인 모형에 의존하기보다는 학교 현장의 상황에 따라서 다양한 형태로 설치, 운영되고 있는 실정이다. 따라서 본고에서는 학교도서관 디지털자료실이 갖추어야 할 적정 규모와 공간 구성 요소를 분석하고, 각급 학교의 현황을 고려하여 4개의 규모별 시설$\cdot$설비 모형(A형, B형)을 제시하고자 한다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
• /
• pp.251-254
• /
• 2008

The German radar satellite TerraSAR was launched in 2007. In this study, interferogram is generated using TerraSAR-X data and DEM (Digital Elevation Model). Coregistration procedures used with SAR images (i.e. master and slave) in traditional method results in serious errors for high resolution TerraSARX data because of the mutual shift of the master and slave images due to topography. This error becomes more serious in mountainous areas in which the coherence between interferometric pairs is relatively low. Here we processed a geometric coregistration with DEM exploiting height information. Through the method, interferometry processing is fulfilled to generate a qualified interferogram and coherence is improved. This approach will help high resolution X-band SAR interferometry in mountainous area.

• Journal of Mechanical Science and Technology
• /
• 제15권1호
• /
• pp.1-9
• /
• 2001

The recent spread of scaled telemanipulation into microsurgery and the nano-world increasingly requires the identification of the possible operation region as a main system specification. A teleoperation system is a complex cascaded system since the human operator, master, slave, and communication are involved bilaterally. Hence, a small time delay inside a master and slave system can be critical to the overall system stability even without communication time delay. In this paper we derive an upper bound of the scaling product of position and force by using Llewellyns unconditional stability. This bound can be used for checking the validity of the designed bilateral controller. Time delay from the sample and hold of computer control and its effects on stability of scaled teleoperation are modeled and simulated based on the transfer function of the teleoperation system. The feasible operation region in terms of position and force scaling decreases sharply as the sampling rate decreases and time delays inside the master and slave increase.

• The Journal of Advanced Prosthodontics
• /
• 제9권1호
• /
• pp.1-13
• /
• 2017

PURPOSE. The purpose of this study was to compare the fit of cast gold crowns fabricated from the conventional and the digital impression technique. MATERIALS AND METHODS. Artificial tooth in a master model and abutment teeth in ten patients were restored with cast gold crowns fabricated from the digital and the conventional impression technique. The forty silicone replicas were cut in three sections; each section was evaluated in nine points. The measurement was carried out by using a measuring microscope and I-Soultion. Data from the silicone replica were analyzed and all tests were performed with ${\alpha}$-level of 0.05. RESULTS. 1. The average gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. 2. In marginal and internal axial gap of cast gold crowns, no statistical differences were found between the two impression techniques. 3. The internal occlusal gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. CONCLUSION. Both prostheses presented clinically acceptable results with comparing the fit. The prostheses fabricated from the digital impression technique showed more gaps, in respect of occlusal surface.