• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1125-1128
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• 2007

The laminating technique for developing flexible liquid crystal display was demonstrated by using a thin UV curable polymer film and a plastic substrate with patterned polymer wall structure. We adopted the rigid wall structure to provide a solid mechanical support for the stable molecular alignment of liquid crystals (LCs) in the device. The cover film was prepared to have an ability of aligning LC molecules by patterning a micro-groove structure using the soft-lithographic process. These two substrates can be assembled tightly by the laminating and one-step UV irradiation process because of the adhesive nature of the used UV curable polymers. Proposed method can be used to fabricate the flexible LC display with simplicity and also be applicable for a cost-effective roll-to-roll process.

• 한국군사과학기술학회지
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• 제12권3호
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• pp.290-298
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• 2009

This paper proposes a novel process which can develop the system requirements in defense R&D programs. As the weapon systems become more complicated, the success and effectiveness of R&D outcome heavily depend on the application and tailoring of systems engineering process and methods. And, the accuracy and quality of system requirements are essential prerequisite to leverage the systems engineering process. To produce the artifacts of systems engineering such as OCD, ORD, and the systems requirements, the system user can write out requirement document using the proposed implementation process and templates without expending heavy work loads.

• Transactions on Electrical and Electronic Materials
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• 제8권1호
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• pp.11-14
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• 2007

Consumables used in Chemical Mechanical Polishing (CMP) have been played important role to improve quality and productivity. Since the properties of consumables constantly change with various reasons, such as shelf time, manufactured time, lot to lot variation from supplier and so on, CMP results are not constant during the process. Also, CMP process results are affected by multiple sources from wafer, conditioner, pad and slurry. Therefore, multiple sensing systems are required to monitor CMP process variation. In this paper, the authors focus on development of monitoring system for CMP process which consist of force, temperature and displacement sensor to measure the signal from CMP process. With monitoring systems mentioned above, complex CMP phenomena can be investigated more clearly.

• 한국기계가공학회지
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• 제19권2호
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• pp.55-62
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• 2020

In this study, a PDMS-based low-elasticity magnetorheological elastomer (MRE) was fabricated and the Taguchi method was used to identify the factors affecting the elastic modulus. The mixing entropy was calculated using optical microscopy to confirm particle dispersion, which was referenced in the process establishment. In the MRE process, four parameters, namely the curing agent, particle type, particle fraction, and applied magnetic field, were divided into three levels. The elastic modulus of the specimen was compared at the off-state and at 0.2 T using compression tests, and the obtained signal to noise ratio indicated that the softness and change in the elastic modulus of the MRE was mainly affected by the curing agent and the particle fraction.

• 한국주조공학회지
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• 제32권1호
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• pp.16-23
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• 2012

In this study, we develop the lower pressure die casting with rheo-forming process of A356 aluminum alloy and vacuum system which can control the crystal size and obtain the high strengthened-light material. Using this process, we fabricate the thin plate for bipolar plate through the low pressure die casting with electromagnetic stirring and vacuum-evacuation which can control the crystal grain by electromagnetic stirring. Thin plate ($110mm{\times}130mm{\times}1mm$) is fabricated by this process. The average Vickers hardness of thin plate is about 77 HV.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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• pp.513-516
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• 2004

Evolutionary operation is useful to improve on-line full-scale manufacturing processes by systematically changing the levels of the process variables while meeting production schedule. Evolutionary operation was developed using two or three process variables for process operators who are not good at statistics. Recently, when a product is developed, it is very important for the engineers to make the production line stable as soon as possible. And there are many causes which have influences to the product performance. This paper presents an evolutionary operation procedure with many process variables using saturated two level fractional factorial designs including Plackett-Burman design.

• 한국생산제조학회지
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• 제25권6호
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• pp.421-425
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• 2016

Micro-EDM is one of the recent fine-machining technologies. Micro-EDM is widely used in precision processes because products manufactured via EDM are free from workpiece hardness. However, the debris produced during the process cause many problems such as reduced precision of the process. The first solution of this problem involves using the milling hole process. Micro-EDM hole process involves an electrode moving rapidly in the vertical direction via a servo system to disperse debris. However, this process can cause reduced work efficiency owing to contact between the electrode and workpiece. In this study, ultrasonic vibration is added to micro-EDM channel machining. Ultrasonic vibration removes the debris during machining and enables precision machining. Consequently, a clean work environment for the subsequent processes is maintained.

• Journal of Welding and Joining
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• 제28권4호
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• pp.81-86
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• 2010

In resistance spot welding, regardless of the optimal condition, bad weld quality was still produced due to complicated manufacturing processes such as electrode wear, misalignment between the electrode and workpiece, poor part fit-up, and etc.. Therefore, the goal of this study was to measure the process signal which contains weld quality information, and to develop the process fault monitoring system. Welding force signal obtained through variety experimental conditions was analyzed and divided into three categories: good, shunt, and poor fit-up group. And then a monitoring algorithm made up of an artificial neural network that could estimate the process fault of each different category based on pattern was developed.

• 한국분말재료학회지
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• 제24권2호
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• pp.153-163
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• 2017

Transparent conducting electrodes (TCEs) are attracting considerable attention as an important component for emerging optoelectronic applications such as liquid crystal displays, touch panels, and solar cells owing to their attractive combination of low resistivity (<$10^{-3}{\Omega}cm$) and high transparency (>80%) in the visible region. The solution-based process has unique properties of an easy fabrication procedure, scalability, and low cost compared to the conventional vacuum-based process and may prove to be a useful process for fabricating TCEs for future optoelectronic applications demanding large scale and flexibility. In this paper, we focus on the introduction of a solution-based process for TCEs. In addition, we consider the powder materials used to fabricate solution-based TCEs and strategies to improve their transparent conducting properties.

• Design & Manufacturing
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• 제10권1호
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• pp.31-35
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• 2016

In sheet metal forming process, drawing is typical process. And the key factor of drawing is blank holding force (BHF) A low BHF can cause wrinkling, whereas a high BHF can cause fracture during a deep drawing process. Thus, formability can be influenced by application appropriate BHF. In this study, a variable blank holding force (VBHF) is applied to extend the forming limit by avoiding both wrinkling and fracture. To determine VBHF in drawing process, numerical simulations and statistical analysis are carried out using commercial FEM software.