• Journal of the Korean Society for Precision Engineering
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• v.33 no.2
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• pp.149-155
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• 2016

In this study, we investigated the adhesive strength by molecular weight, mixture ratio, coating thickness, lamination temperature and aging condition of adhesive in manufacture process of Nylon-Aluminum for secondary aluminum pouch. It found that as the molecular weight of adhesive gets lower, the adhesive strength increases. In the mixture ratio, as the content of hardener get higher and as the content of solvent get lower, the adhesive strength increases. Also, as the coating thickness of adhesive get thicker, the adhesive strength increase. In addition, the adhesive strength is higher at 90 degrees of lamination temperature. So, it found that 90 degrees of lamination temperature is appropriate. In the aging condition when aged for 5 days, it found that the reaction and curing of adhesive is sufficient by measuring the adhesive strength.

• Journal of the Korea Furniture Society
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• v.16 no.2 s.30
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• pp.59-65
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• 2005

As physical condition of students improves, there is a need to develop human body-friendly desk and chair for students. In this study, desks and chairs were manufactured with curved veneer lamination under high frequency heating and pressing, using ten wood species such as Japanese red pine, Korean pine, pitch pine, Japanese larch, yellow poplar, black locust, oak, radiata pine, beech, and birch. The performance of these products were evaluated. The results obtained were summarized as follows; With high frequency heating, the turned lamination of veneers with full size sheet ($3{\times}6\;feet$) prepared by rotary lathe peeling was successfully applied for making the members of desk top, leg frames of desk and chair. Bending strengths of desk tops were relatively greater for yellow poplar, black locust and red pine, which were similar to those of beech and birch. Bending strengths of desk legs were classified into greater species group (red pine, yellow poplar, larch) and lower species group (radiata pine, Korean pine, pitch pine). Compressive strengths of chair legs in parallel direction to the lamination were greater in black locust and larch. On the other hand, differences between outer and inner gap at the top and drawer bottom of desk top were rather larger for the laminations of birch and beech, and less for those of yellow poplar and pitch pine, showing greater stability of open drawer space. In results, yellow poplar, larch, pitch pine and red pine showed good appearance and strength properties at the curved veneer lamination. Accordingly, it was believed that these domestic woods were able to substitute for birch which was being imported for the use of veneer-laminates type furniture.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.47-52
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• 2011

In this study, an accurate 2-noded hybrid-mixed element for continuous fiber-reinforced laminated beams is newly proposed. The present element including the effect of shear deformation is based on Hellinger-Reissner variational principle, and introduces additional consistent node less degrees for displacement field interpolation in order to enhance the numerical performance. The micromechanical and lamination theory are employed in the finite element description to consider the effects of the laminate stacking sequences, material orthotropy, and fiber volume fraction, etc. The element stiffness matrix can be explicitly derived through the stationary condition and static condensation using Mathematica program. Several numerical examples confirm the accuracy of the present hybrid-mixed element and also show in detail the effects of the continuous fiber volume fraction, stacking sequences and boundary condition on the bending behavior of laminated beams.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.9-9
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• 2008

Recently, the thickness of solar cell gets thinner to reduce the quantity of silicon. And the reduced thickness make it easy to be broken while PV module fabrication process. This phenomenon might make PV module's maximum power and durability down. So, when using thin solar cell for PV module fabrication, it is needed to optimize the material and fabrication condition which is quite different from normal thick solar cell process. Normally, gel-content of EVA sheet should be higher than 80% so PV module has long term durability. But high gel-content characteristic might cause micro-crack on solar cell. In this experiment, we fabricated several specimen by varying curing temperature and time condition. And from the gel-content measurement, we figure the best fabrication condition. Also we examine the crack generation phenomenon during experiment.

• Proceedings of the KIEE Conference
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• summer
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• pp.1465-1467
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• 2004

In this paper, deduced manufacturing condition of glass/glass curtain wall module and metal curtain wall module. From the results. lamination condition of glass/glass curtain wall module deduced optimum in pumping $time-120^{\circ}C$ 23min, slow $press-120^{\circ}C$. 300mmHg. 3min. standard $press-120^{\circ}C$. 200mmHg. 0.5min. fast $press-120^{\circ}C$. 100mmHg. 0.3min and $curing-140^{\circ}C$, 6min, and lamination condition of metal curtain wall module deduced optimum in pumping $time-120^{\circ}C$. 8min, slow $press-120^{\circ}C$, 700mmHg. 0.5min, standard $press-120^{\circ}C$, 600mmHg, 0.5min. fast $press-120^{\circ}C$, 100mmHg. 1.5min and $curing-140^{\circ}C$. 6min. This time. power uniformity of glass/glass curtain wall module and metal curtain wall module showed each ${\pm}2.7\%,\;{\pm}2.12\%$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.910-913
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• 2001

Rapid Prototyping(RP) techniques have unique characteristics according to their working principle: the stair-stepped surface of a part due to layer-by-layer stacking, low building speed, and additional post-processing to improve surface roughness. A new RP process, Variable Lamination Manufacturing by using expandable polystyrene foam(VLM-S), has been developed to overcome the unfavorable characteristics. The objective of this study is to investigate the thermal characteristics and skeleton size effects as the hotwire cuts EPS foam sheet in order to improve dimensional accuracy of the parts, which is produced by VLM-S. Empirical and analytical approaches are performed to find the relationship between cutting speed and heat input, and the relationship between maximum available cutting speed and heat input. In addition, empirical approaches are carried out to find the relationship between cutting error and skeleton size, and cutting deviation and skeleton size. Based on these results, the optimal hotwire cutting condition and available minimum skeleton size are derived. The outcomes of this study are reflecting in the enhancement of VLM-S input data generation S/W.

• Journal of KSNVE
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• v.8 no.4
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• pp.632-642
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• 1998

A method based on finite element discretization is developed for optimizing the polarization profile of PVDF film to create the modal transducer for specific modes. Using this concept, one can design the modal transducer in two-dimensional structure having arbitrary geometry and boundary conditions. As a practical means for implementing this polarization profile without repoling the PVDF film the polarization profile is approximated by optimizing electrode patterns, lamination angles, and poling directions of the multi-layered PVDF transducer. This corresponds to the approximation of a continuous function using discrete values. The electrode pattern of each PVDF layer is optimized by deciding the electrode of each finite element to be used or not. Genetic algorithm, suitable for discrete problems, is used as an optimization scheme. For the optimization of each layers lamination angle, the continuous lamination angle is encoded into discrete value using binary 5 bit string. For the experimental demonstration, a modal sensor for first and second modes of cantilevered composite plate is designed using two layers of PVDF films. The actuator is designed based on the criterion of minimizing the system energy in the control modes under a given initial condition. Experimental results show that the signals from residual modes are successfully reduced using the optimized multi-layered PVDF sensor. Using discrete LQG control law, the modal peaks of first and second modes are reduced in the amount of 12 dB and 4 dB, resepctively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.126-129
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• 2003

The electrical properties of a ZnO-based multilayered chip varistor (abbreviated as MLV) were studied as functions of firing condition and the degree of lamination. The fundamental varistor characteristics such as nonlinear coefficient and breakdown voltage were independent of the degree of lamination. As the number of the laminated ceramic sheets increased, however, not only the energy handling capability but also the capacitance and the leakage current which are relevant to delayed response to the voltage surge and the pre-breakdown energy loss, respectively, increased. With the increase of firing temperature between $950^{\circ}C$ and $1150^{\circ}C$, both the capacitance and the leakage current of the MLV increased due mainly to the grain growth of ZnO and the volatilization of $BiO_2O_3$. High performance MLVs with clear electrode pattern were obtained at the firing temperature range of $l000{\sim}1050^{\circ}C$ in this experiment.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.1
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• pp.15-22
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• 2002

We received 2 types flexible packaging films from two companies that laminated PET $16{\mu}m/dry$ lamination/aluminium foil $7{\mu}m/dry$ lamination/CPP $80{\mu}m$ films. For the reason of hot sealing's trouble through filling process, We separated each layer and compared thicks, film types and tested IR, DSC and sensory test. At the result, one sample's thick is different but film types is same between samples. Optimum hot-sealing conditions between two samples is $195^{\circ}C\;and\;210^{\circ}C$. The difference is $15^{\circ}C$. According to test of direct filling packaging process by four face fluid filling machine, two sample's sealing strength of hot-sealing is $4.76kg/cm2/15mm$(sample of optimum hot-sealing condition is $195^{\circ}C$) and $3.84kg/cm2/15mm(210^{\circ}C)$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.20-21
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• 2006

In this paper, we studied the influence of EVA sheet gel content on photovoltaic module durability. Depending on thermal curing temperature and time during lamination, there are dramatic changes on chemical and physical characteristics. To find the optimum PV module process condition, Glass/EVA/Back Sheet scheme was made. Gel Content, FT-IR spectrum and SEM were used for the detail analysis. From these results, $110^{\circ}C/6min$ and $130^{\circ}C/4min$ lamination condition could be suggested for the best one for durable PV module processing. The further analysis is described in the following paper.