• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.79-82
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• 1995

The problem of temperature control for rapid thermal processing (RTP) in semiconductor manufacturing is discussed in this paper. Among sub=micron technologies for VLSI devices, reducing the junction depth of doped region is of great importance. This paper investigates existing methods for manufacturing wafers, focusing on the RPT which is considered to be good for formation of shallow junctions and performs the wafer fabrication operation in a single chamber of annealing, oxidation, chemical vapor deposition, etc., within a few minutes. In RTP for semiconductor manufacturing, accurate and uniform control of the wafer temperature is essential. In this paper, a robustr controller is designed using a recently developed optimization technique. The controller designed is then tested via computer simulation and compared with the other results.

• 한국시뮬레이션학회논문지
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• 제8권1호
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• pp.63-76
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• 1999

Recently in manufacturing environment, manufacturing order is characterized by unstable market demand, shorter product life cycle, a variety of product and shorter production lead time. In order to adapt this manufacturing order, flexible manufacturing systems(FMS) in manufacturing technology advances into the direction that machines become further versatile functionally and that tools are controlled by fast tool delivery device. Unlike conventional FMS to mainly focus on part flow, it is important to control tool flow in single-stage multimachine systems(SSMS), consisting of versatile machines and fast tool delivery device. This research is motivated by the thought that exact estimation of tool competition at part release in SSMS enhances the system performance. In this paper, in SSMS under dynamic tool allocation strategy to share tools among machines, we propose real-time part release and tool allocation algorithms which can apply real factory and which can improve system performance.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 춘계학술대회 논문집
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• pp.60-64
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• 1999

Recently in manufacturing environment, manufacturing order is characterized by unstable market demand, shorter product life cycle, a variety of product and shorter production lead time. In order to adapt this manufacturing order, flexible manufacturing system(FMS) in manufacturing technology advances into the direction that machines become further versatile functionally and that tools are controlled by fast tool delivery device. Unlike conventional FMS to mainly focus on part flow, it is important to control tool flow in single-stage multimachine systems(SSMS), consisting of versatile machines and fast tool delivery device. In this paper, in SSMS under dynamic tool allocation strategy to share tools among machines, we propose real-time part release and tool allocation algorithms which can apply real factory and which can improve system performance.

• 한국항공운항학회지
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• 제13권1호
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• pp.43-49
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• 2005

There are several ways to mold the complex material, and it is divided to vacuum pack mold, compression mold, and hand lay up for a high molecular substance as a basic material. Moreover, it can be divided to general manufacturing (Single form) and mold manufacturing(Mold form) under normal temperature for Firefly. Firefly was manufactured with hand lay up and general manufacturing that using the foam core, glass fabric, and template without mold. However, mold manufacturing that is producing the surface by semi-sandwich using thin foam core and glass fabric then reinforce the inside with spar and rib is on developing. Mold manufacturing can make easy to production, standardize the quality, and possible to mass producing. In this paper, we present the mold producing process for canard aircraft "Firefly", and the problems and solutions during producing Firefly. Moreover, it complements the defect that the problems caused by master manufacturing error when produce several masters of a large part, and make the manufacturing process to be shortened by the replacement from the supplementary plate to the foam that is installed when producing lay up mold.

• 한국기계가공학회지
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• 제21권5호
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• pp.1-8
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• 2022

Fused deposition modeling (FDM), based on stacking a continuous filament of polymer or composite materials, is well matured and is thus widely used in additive manufacturing technology. To advance FDM-based 3D printing technology, the mechanical properties of additively manufactured composite materials must be improved. In this study, we proposed a novel FDM 3D printing process using metal wire-polymer composites, enabling enhanced mechanical properties. In addition, we developed a new type FDM filament of copper wire wrapped in nylon material for stable 3D printing without thermal damage during the printing process. After FDM printing of the copper wire-nylon composite filament, we conducted a tensile test to investigate the mechanical behavior of the printed composite materials. The experimental results confirmed that the tensile strength of the 3D-printed metal wire-polymer composites was higher than that of the conventional single polymer material. Thus, we expect that the FDM printing process developed in this study may be promising for high-load-bearing applications.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.541-542
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• 2009

We have developed an image reversal photoresist with high thermal stability and electric insulating properties for the single isolation structure of OLEDs. The thermal stability and electric insulating properties are investigated and compared with those of conventional insulator and cathode separator materials. The single isolation structure using the image reversal photoresist reduces the fabrication process steps and cuts down the manufacturing cost.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권2호
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• pp.143-149
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• 2017

Purpose: In recent years, weight reduction for improving fuel efficiency of the vehicle and cost reduction have been developed. The structure of suspension link is widely used as a single plate press structure which can reduce process and weight compared to existing pipe welding method. However, it was found that the lifetime of a single plate press structure is determined by initial defects that occurred during initial manufacturing rather than fatigue damage caused by driving. Methods: I research the mechanism of failure phenomenon of the single plate press assist arm of rear wheel. In addition, I investigate durability effect parameters to determine the link lifetime in inserting bush into single plate press process through durability test. Conclusion: I discover significant durability effect parameter in inserting bush into single plate press process. It is expected that the durability can be improved by suggesting a bush inserting process inspection guide for similar suspension link like single plate press structure.

• 대한안전경영과학회지
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• 제14권4호
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• pp.291-301
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• 2012

Quality management activities are an important factor that they could be regarded as a most significant drive to prompt growth of a corporation. From this research as core strategy of the enterprise single ppm wants to emphasize the importance of the quality management activity. The Empirical results are summarized as follows, for successful Single PPM, leadership and corporate culture should be based on. As Single PPM activities factor, Customer Management significantly affects Single PPM Performance. Therefore, to the success of quality management activities, internal corporate leadership and corporate culture must be formed. And for customer management, should take advantage of a variety of the company's internal and external information strategically.

• Current Optics and Photonics
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• 제1권4호
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• pp.364-371
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• 2017

Compared to one made of glass, an aluminum mirror features light weight, compact design, low cost, and quick manufacturing. Reflective mirrors and supporting structures can be made from the same material, to improve the athermal performance of the system. With the rapid development of ultraprecise machining technologies, the field of applications for aluminum mirrors has been developed rapidly. However, most of them are rotationally symmetric in shape, and are used for infrared applications. In this paper, the design and manufacture of an off-axis aluminum mirror used for a three-mirror-anastigmat (TMA) optical system at visible wavelengths is presented. An optimized, lightweight design provides a weight reduction of more than 40%, while the surface deformation caused by earth's gravity can meet the required tolerance. The two pieces of an off-axis mirror can be diamond-turned simultaneously in one setup. The centrifugal deformation of the off-axis mirror during single-point diamond turning (SPDT) is simulated through the finite-element method (FEM). The techniques used to overcome centrifugal deformation are thoroughly described in this paper, and the surface error is reduced to about 1% of the original value. After post-polishing, the form error is $1/30{\lambda}$ RMS and the surface roughness is better than 5 nm Ra, which can meet the requirements for visible-light imaging.

• 대한금속재료학회지
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• 제50권2호
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• pp.107-115
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• 2012

Direct laser melting (DLM) is a powder-based additive manufacturing process to produce parts by layer-by-layer laser melting. As the properties of the manufactured parts depend strongly on the deposited laser-melted bead, deposited layers obtained by the DLM process were characterized in this study. This investigation used a 200 W fiber laser to produce single-line beads under a variety of different energy distributions. In order to obtain a feasible range for the two main process parameters (i.e. laser power and scan rate), bead shapes of single track deposition were intensively investigated. The effects of the processing parameters, such as powder layer thickness and scan spacing, on geometries of the deposited layers have also been analyzed. As a result, minimum energy criteria that can achieve a complete melting have been suggested at the given powder layer thickness. The surface roughnesses of the deposited beads were strongly dependent on the overlap ratio of adjacent beads and on the energy distributions of laser power. Through microstructural analysis and hardness measurement, the morphological and mechanical properties of the deposited layers at various overlapped beads have also been characterized.