• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.14-19
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• 2017

In this paper, a fused illumination mechanism for detecting surface defects in steel plates was designed by applying the discriminant function that can differentiate the contrast of defects and non-defects. There is low contrast, non-uniformity, and no feature characteristics in steel plate surfaces. The fused illumination mechanism is devised, based on those characteristics. Optimum parameters of the fused illumination mechanism are determined by applying the discriminant function after acquiring the defect image in steel plate surfaces. The performance of the proposed mechanism is verified by experminets.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.179-182
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• 2002

Rapid Prototyping (RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys' Fused Deposition Modeling (FDM) is a typical RP process that can fabricate prototypes out of plastic materials, and the parts made from FDM were often used as load-carrying elements. Because FDM deposits materials in about $300\mutextrm{m}$ thin filament with designated orientation, parts made from FDM show anisotropic material properties. This paper proposes an analytic model to predict the tensile strength of FDM parts. Applying the Classical Lamination Theory, which was developed for laminated composite materials, a computer code was implemented. Tsai-Wu failure criterion was added to the code to predict the failure of the FDM parts. The tensile strengths predicted by the analytic model were compared with experimental data. The data and prediction agreed reasonably well to prove the validity of the model. In addition, a web-based advisory service was developed to provide to strength prediction and design rules for FDM parts.

• Korean Journal of Computational Design and Engineering
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• v.7 no.2
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• pp.96-101
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• 2002

Rapid Prototyping (RP) technology has been advanced to fabricate initial prototypes from various materials. Stratasys′ Fused Deposition Modeling (FDM) is one of the typical RP processes that provide functional prototypes of ABS plastic. In order to predict the behavior of final ABS parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on the FDM part. In this paper, we seek to characterize the properties of ABS parts fabricated by the FDM 1650. Using the Design of Experiment (DOE) approach, the process parameters of FDM, such as raster orientation, air gap, bead width, color, and model temperature were examined. Tensile strengths of crisscross specimens, 〔45°/-45°〕, cross specimens, 〔0°/90°〕, and directionally fabricated tensile specimens (〔0°〕 and 〔90°〕) were measured and compared with the injection molded FDM-ABS P400 material. For the FDM parts made with a -0.003"air gap, the typical tensile strength ranged between 50 percent and 83 percent of the strength of injection molded ABS P400. From the experiments, a couple of build rules for designing FDM parts were obtained.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.10
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• pp.42-50
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• 2000

We show that both cross and bar states with high extinction ratios larger than 30dB can be achieved at eh same ends of ultra-short fused vertical directional coupler switches with two sections by changing the refractive indices of cores and inner cladding layers less than 1%. Based on the calculation of extinction ratios of cross state and bar state for various refractive index and thickness of inner cladding layer and core using the improved coupled mode theory and beam propagation method, the guidelines for design to achieve large tolerances in refractive indices of core and inner cladding layer in fused vertical directional coupler switches are presented.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.1
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• pp.33-39
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• 2022

As 3D printer-related patents expire and major technologies are disclosed, the price of 3D printers is dropping, creating an environment where you can easily find the product you want. In particular, the cheapest FDM (Fused Deposition Modeling) 3D printer is being used in various fields. The FDM method can be manufactured without collapsing of the shape only by attaching a support under certain conditions when outputting the shape. When printing a shape without a support, the irregular surface that occurs at a certain angle is a defect in the product, but it is considered that it can be used as another fun factor in terms of arts and crafts. In this paper, to obtain such an irregular surface, factors that can affect the output were controlled and only the output angle was tested as a displacement factor. As a result of the experiment, it was possible to obtain an irregular surface without the filament flowing down when printing at an angle of 62° to 70° from the vertical. Also, artificially irregular surfaces were applied to craft products.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1352-1358
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• 2009

As the demand for a convergence between construction technologies and IT is on the rise, as seen in the visualization of U-City construction, studies on the ways in which IT in should be utilized in the building and construction field have been continuously and actively performed. However, there has been almost no development of standardized technology criteria relating to the life cycle of a building (planning, design, construction, and maintenance). That is, there are almost no examples of efforts made to combine construction technology and IT in a fundamental way, considering the environment, the facility, its spatial characteristics, engineering, materials, and structure, aspects that are commonly required not only for interior spaces but also for exterior construction of U-City. Despite the fact that a state-of-the-art infrastructure has been built, and the competency of users with the cutting-edge technology, composite studies on technologies, facilities, services and spaces are still lacking, and basic research on the composite operation method including compatibility and linkage between facilities and services within a U-City has been insufficient as well. It is generally known that by fusing IT with construction technologies, the total period of construction taken can be reduced and construction expenses can be curtailed, while construction quality can be improved. For this reason, it is vital to prepare a standardized base to connect cutting-edge IT with the construction technologies. In preparing such a base, the most urgent issue is to develop standardized technology criteria. The ultimate objective of this research is to establish the technological criteria system required to apply construction-IT fused technologies to U-Cities, and to develop the technological criteria for the design, construction and maintenance of the U-Cities. This paper, whose objective is to establish development strategies for construction-IT fused technologies by way of analyzing the criteria for conventional construction projects, the necessity of criteria for construction-IT fused technologies, and the current status of U-Cities' development, is the underlying research for this purpose. The strategies established are expected to be utilized in establishing the system of criteria for construction-IT fused technologies, and to contribute to a knowledge base in the construction-IT field. In addition, based on the strategies established, criteria for construction-IT fused technologies, such as design criteria and construction standards, will be developed, and by applying these criteria and standards, the ultimate objectives of U-Cities, which are the enhancement of urban competitiveness and the satisfaction of residents, will be attained

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.31-37
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• 2008

A variety of the porcelain fused to gold(PFG) have been developed to which porcelain can be fused. PFG alloys developed for this purposed have a high melting point and do not discolor when combined with porcelain. The design of the compositions of PFG is very important to esthetic restorative materials applying to porcelain. The purpose of this study is on the change of physical and mechanical characteristics in PFG 18K alloy by the small additional elements. Principal results are as follows. The high Au alloy containing 18Karat gold contents is respectively Au(75%), Pd(10%), Pt(4%), Ag(4%), In(2%), Sn(2%), Cu(2%), Ti(1%). These alloys are composed mainly of gold, platinum, silver and palladium with a few percent of the additional elements. By the addition of small amounts of elements such as In, Sn, Ti, the fine grain castings are produced in gold alloy and the small addition of platinum is very effective in increasing of hardness and strength. These gold alloys are representative of the changes to be expected as a result of heat treatment. These changes in strength and hardness values are sufficient to demonstrate a significant difference in performance between a as-casted and a heat-treated. These alloys have mechanical properties characteristics of Type and Type gold alloys. These alloys are useful to porcelain-metal restorations and dental laboratory. Also the porcelain fused to metal(PFM) alloys containing gold are commonly use for dental purposes in dental laboratory.

• Progress in Superconductivity and Cryogenics
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• v.26 no.2
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• pp.19-23
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• 2024

3D printing has the advantage of being able to process various types of parts by layering materials. In addition to these advantages, 3D printing technology allows models to be processed quickly without any special work that can be used in different fields to produce workpieces for various purposes and shapes. This paper deals to not only increase the utilization of 3D printing technology, but also to revitalize 3D printing technology in applications that require similar cryogenic environments. The goal of this study is to identify the mechanical properties of polylactic acid and photopolymer resin processed by Fused Deposition Modeling (FDM) and Digital Light Processing (DLP) respectively. The entire process is meticulously examined, starting from getting the thermal contraction using an extensometer. A uniaxial tensile test is employed, which enables to obtain the mechanical properties of the samples at both room temperature (RT) and cryogenic temperature of 77 K. As the results, photopolymer resin exhibited higher tensile properties than polylactic acid at RT. However, at cryogenic temperatures (77 K), the photopolymer resin became brittle and failure occurred due to thermal contraction, while polylactic acid demonstrated superior tensile properties. Therefore, polylactic acid is more suitable for lower temperatures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.13
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• pp.119-126
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• 1973

In order to investigate the effects of phosphorous fertilizer such as fused Phosphate, compound fertilizer and triple phosphate on barley(growth and yield at the fixed level of nitrogen and potassium, 4 level of hosphorous) has been tested at Suwon. Iri. Kwangju ani Daegu with randomized completeblock design. The results obtained could be summarized as follows. 1. In four locations. increased application of phosphorus have brought earlier maturity in barley regardless the type of fertilizer but fused phosphate considered to have more effects on stimulation of maturity of barley compare with the others. 3. Fused phosphate increased yield higher by-8kg/10a application compare with the same level of compound fertilizer and triple phosphate but there was no differences in yield at 12kg/10a phosphate but there was no differences in yield at 12kg/l0a application among the fertilizers except Kwangju and Suwon. 3. Grain weight was considerably higher in application of fused phosphate Thus are considered effects phosphate. 4. Optimum amount of phosphorous fertilizer was considered 8kg/l0a. Application of 4kg per 10a produced lower yield than 8kg and slightly or no increased yield was observed in 12kg application. 5. Among the 4kg/10a applied condition of phosphorous fertilizers, yield was decreased at fused phosphate treatment compare with the others and this fact resulted supposedly due to the lower portion of valid phosphorus in fused phosphate because of its citric acid solubility. At level of 12kg/10a application fused phosphate was considered more effective in yield increment.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.101-108
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• 2017

Recently, the patent rights for 3D printing technology have expired, while 3D printers with RP (Rapid Prototyping or Additive Manufacturing) and 3D printing technologies are receiving attention. In particular, the development of 3D printers is rapid in Korea, thanks to the increasing sales and popularity of FDM (Fused Deposition Modeling or Fused Filament Fabrication) 3D printers. However, the quality and productivity of the FDM 3D Printer are not good, so customers prefer the DLP (Digital Light Processing) method to avoid these shortcomings. The DLP method has high quality and productivity. However, because of the stereolithography equipment, it has few studies compared to optimal values for elements then FDM 3D printing study. In this study, to find the optimal conditions for 3D printing with the DLP method, the aim is to obtain the optimal values (strength, final time, quality) by changing the light exposure time, layer thickness, and z-axis speed.