• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.294-302
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• 2015

PURPOSE. The purpose of this study was to verify the clinical-feasibility of additive manufacturing by comparing the accuracy of four different manufacturing methods for metal coping: the conventional lost wax technique (CLWT); subtractive methods with wax blank milling (WBM); and two additive methods, multi jet modeling (MJM), and micro-stereolithography (Micro-SLA). MATERIALS AND METHODS. Thirty study models were created using an acrylic model with the maxillary upper right canine, first premolar, and first molar teeth. Based on the scan files from a non-contact blue light scanner (Identica; Medit Co. Ltd., Seoul, Korea), thirty cores were produced using the WBM, MJM, and Micro-SLA methods, respectively, and another thirty frameworks were produced using the CLWT method. To measure the marginal and internal gap, the silicone replica method was adopted, and the silicone images obtained were evaluated using a digital microscope (KH-7700; Hirox, Tokyo, Japan) at 140X magnification. Analyses were performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (${\alpha}=.05$). RESULTS. The mean marginal gaps and internal gaps showed significant differences according to tooth type (P<.001 and P<.001, respectively) and manufacturing method (P<.037 and P<.001, respectively). Micro-SLA did not show any significant difference from CLWT regarding mean marginal gap compared to the WBM and MJM methods. CONCLUSION. The mean values of gaps resulting from the four different manufacturing methods were within a clinically allowable range, and, thus, the clinical use of additive manufacturing methods is acceptable as an alternative to the traditional lost wax-technique and subtractive manufacturing.

• 한국안전학회지
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• 제14권4호
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• pp.93-99
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• 1999

A try was carried out to reduce lead time of die manufacturing. That is to make manual machining and finishing work time shorter by improving CAD/CAM modeling methods, so called with "separate modeling" and "relief modeling". The manual machining and finishing manual work time were reduced adapting the novel CAD/CAM modeling methods. Ultimately we accomplished much reduction of the lead time of die manufacturing.f die manufacturing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.555-560
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• 2002

This paper addresses the methodologies for manufacturing systems design. While a number of design methods are used in product or part design, methods for manufacturing systems design are rarely known. Two approaches, simulation and axiomatic design theory, are discussed with respective case examples. The usual purpose of using simulation is to identify the bottleneck of a manufacturing system or to evaluate its performance with the aim of configuring the manufacturing system. The simulation typically proceeds in steps such as problem definition, model building, numerical experimentation, analysis and evaluation. The axiomatic design method transforms customer attributes into functional requirements and repeats mapping processes between functional domain and physical one until a satisfactory level of refinement of the functional requirements and the design parameters is reached. Possible design alternatives are evaluated by applying the independence axiom as well as the information axiom.

• 경영과학
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• 제16권1호
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• pp.137-156
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• 1999

Flexibility is a competitive weapon in the changing environment. In order to pursue the flexibility, Korean manufacturing companies must define the flexibility dimension clearly, build the appropriate manufacturing infrastructures and measure the right flexibility performance indicators. This paper found out as follows. First, Korean manufacturing companies' flexibility strategy groups were formed three types. They are flexibility superior group, middle flexibility group and flexibility inferior group. Second, when different types of flexibility strategy group measured their performances, the degree of importance of flexibility performance indicators were different among groups. Third, when different types of flexibility strategy group were pursued, the different manufacturing methods such as product/process design technology, analysis technology, production system management technology and non technological factors were used. Lastly, when different types of flexibility strategy group were pursued, the actual flexibility performances were different among groups.

• 산업경영시스템학회지
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• 제15권25호
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• pp.41-51
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• 1992

Most of the planing models for automated manufacturing systems are based on the assumption that for each part there is only one process method available Really. for a part to be manufactured in an automated manufacturing system, a number of different process methods can be generated, each of which may require specific types of tools and auxiliary devices such as fixtures, grippers and feeders. In this paper, An optimal algorithm for the selection of a set of process methods with the minimum corresponding manufacturing cost and minimal number of tools and auxiliary devices Is proposed. The proposed optimal algorithm is based on branch and bound method which is one of the optimal solution methods.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1711-1714
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• 2007

Various manufacturing methods are analyzed by using manufacturing metrics to validate which method would be applicable to flexible microelectronics. Among others, Roll-to-Roll method is revealed to inherently have an excessive WIP resulting in long cycle time and limited diversity as well as low equipment efficiency.

• 산업공학
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• 제18권1호
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• pp.94-103
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• 2005

Digital Manufacturing is a technology to facilitate effective product developments and agile productions by digital environments representing the physical and logical schema and the behavior of real manufacturing system including manufacturing resources, processes and products. A digital factory as a well-designed and integrated environment is essential for successful applications of this technology. In this research, we constructed a sophisticated digital factory of an automotive company’ general assembly shop by measuring and 3-D CAD modeling using parametric methods. Specific parameters of each objects were decided by object-oriented schema of the general assembly shop. It is expected that this method is very useful for constructions of a digital factory, and helps to manage diverse information and re-use 3D models.

• 한국인터넷방송통신학회논문지
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• 제19권5호
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• pp.219-227
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• 2019

제조업의 생산 방법은 노동집약적인 방법에서 제조설비 중심의 기술집약적인 방법으로 변경되어가고 있다. 사람의 노동력을 제조설비가 대체하게 되면서 제조설비의 모니터링과 관리의 중요성이 강조되고 있다. 또한, 최근 빅데이터 기술은 한정된 데이터에서 새로운 가치를 찾아내는 중요한 기술로 등장하였다. 따라서 제조업의 변화는 기존 제조 공장에 사물인터넷(IoT), 정보통신기술, 센서 데이터, 빅데이터를 융합한 스마트팩토리의 필요성을 증대시켰다. 본 논문에서는 제조설비 데이터를 몽고DB에 실시간으로 분산 저장 및 처리하는 기술과 R 프로그래밍을 사용한 시각화를 통해 기존 국내 제조업 공장이 빅데이터 기반의 스마트팩토리가 되기 위한 전략을 제시하고자 한다.

• The Journal of Advanced Prosthodontics
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• 제14권2호
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• pp.122-132
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• 2022

PURPOSE. This in-vitro analysis aimed to compare the intaglio trueness, the antagonist's wear volume loss, and fracture load of various single-unit zirconia prostheses fabricated by different manufacturing techniques. MATERIALS AND METHODS. Zirconia crowns were prepared into four different groups (n = 14 per group) according to the manufacturing techniques and generations of the materials. The intaglio surface trueness (root-mean-square estimates, RMS) of the crown was measured at the marginal, axial, occlusal, and inner surface areas. Half of the specimens were artificially aged in the chewing simulator with 120,000 cycles, and the antagonist's volume loss after aging was calculated. The fracture load for each crown group was measured before and after hydrothermal aging. The intaglio trueness was evaluated with Welch's ANOVA and the antagonist's volume loss was assessed by the Kruskal-Wallis tests. The effects of manufacturing and aging on the fracture resistance of the tested zirconia crowns were determined by two-way ANOVA. RESULTS. The trueness analysis of the crown intaglio surfaces showed surface deviation (RMS) within 50 ㎛, regardless of the manufacturing methods (P = .053). After simulated mastication, no significant differences in the volume loss of the antagonists were observed among the zirconia groups (P = .946). The manufacturing methods and simulated chewing had statistically significant effects on the fracture resistance (P < .001). CONCLUSION. The intaglio surface trueness, fracture resistance, and antagonist's wear volume of the additively manufactured 3Y-TZP crown were clinically acceptable, as compared with those of the 4Y- or 5Y-PSZ crowns produced by subtractive milling.

• 한국생산제조학회지
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• 제24권4호
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• pp.455-462
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• 2015

A feature line is a visually noticeable creased line on outer automotive panels. Feature lines play an important role in creating a good impression of a car. Even though the manufacturing quality of feature lines is important, it is difficult to achieve the designed shape owing to the springback of sheet metal. The current study presents five methods of making samples that will be used in a visual experiment to discover a quality control quantitative manufacturing allowance for feature lines. Measurement and inspection methods for the samples are also presented. The results show that plunge machining is the most accurate way to make the desired shape, and that wrapping the machined surface with sheet film is an appropriate way to emulate the roughness and visual texture of the painted outer panels of a car.