• Journal of Welding and Joining
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• v.27 no.4
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• pp.44-48
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• 2009

In automotive company, a lot of researchers have investigated for the spatterless welding process during last two decades. A spatter influences on the product quality such as strength and surface states. In this paper, a hollow tip is proposed for spatterless process. An optimal size of electrode hole is obtained from a weldability evaluation of each hole diameter. Through the cross section analysis, a phenomenon that molten metal moves in the hole which located between two workpiece is observed, and this makes spatterless welding process even though current is higher. Finally, widely acceptable weld area in lobe curve is obtained by using hollow tip as compare with conventional no hollow tip. In this paper, spatterless resistance spot welding with improvement weldability and productivity is proposed by using hollow tip.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.35
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• pp.179-219
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• 2007

Cross-border supply chains undergone complexity in the global trade process, unpredictability and continually evolving regulations and information requirements. Under these circumstances, longer lead time inhibiting quick response to market demands, unanticipated supply chain costs eroding product cost savings, compliance and documentation errors causing delays and fines are challenging global trade companies when they execute global business. These problems are mainly caused by unautomated, unintegrated process which lead to longer and more unpredictable lead times, slower cash flow, cost overruns, and ultimately lower profits and less satisfied customers. Complex and unpredictable global trade environment requires global trade companies of global trade management functions to automate and control this complex environment for driving out cost, time and risk from their business. Global trade management allows cost savings, supply chain efficiencies and improved compliance through improving global supply chain visibility, facilitating cash flow by supply chain financing, enhancing supply chain security and risk management.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.503-521
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• 2005

Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for muliple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^{++}$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other,

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.371-373
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• 2015

Today, 3D printer is all the more impressive because it is reducing complex product process than other existing methods (e.g. CNC) fast handling customer's various demands. If 3D printer become popular, that can shift industrial production methods and consumption patterns. Therefore 3D printer cross lips as the second industrial Revolution. This paper will classify the various kind of 3D printers among their properties, analyze merits and demerits of each ones, and proposed the direction of 3D printers future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.63
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• pp.1-12
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• 2001

When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in consideration of the correlations among the characteristics. To solve the issue on the optimal design for multiple quality characteristics, this study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of the terms. The model will be used to determine the global optimal design parameters where there exists the conflict among the characteristics, which shows difference in optimal design parameters for the individual characteristics. Also, when an adjustment factor exists for each m performance characteristics, this research propose a method by minimizing the expected loss after adjustment.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.69-79
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• 2004

Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for multiple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^{++}$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1301-1303
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• 1996

A new automatic frequency control(AFC) tracking algorithm, which we call a rotational decision directed AFC(RDDAFC) is proposed for QPSK demodulation at the digital direct broadcasting satellite(DBS). In order to prevent the presence of the residual phase difference between symbols received at k and k-l by the CPAFC[1] as well as the AFC based on $tan^{-1}$ circuit[2], the RDDAFC rotates the decision boundary for the kth received symbol by the frequency detector output of the (k-1)th received symbol before passing through the cross product discriminator. Test results show that the total pull-in time of the RDDAFC and PLL was 0.13msec under a carrier frequency offset of 2.4MHz when S/N equals 2dB.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.2
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• pp.178-183
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• 2009

This paper introduces experimental investigates of an accident pattern for the distributing cross linking-polyethylene(XLPE) cable terminations considering product liability(PL) law environment. The influence of defects such as thickness and length decrease of XLPE, an impurity on XLPE and the gap between stress-con of housing and semi-conductor on insulating properties of the termination have been studied. The thickness and length decrease of XLPE decrease ac breakdown strengths. Breakdown traces of XLPE that is damaged by knife displayed ellipse shape. The gap of between stress-con and semiconductor deteriorates dielectric strength of XLPE seriously.

• Transactions of Materials Processing
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• v.23 no.3
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• pp.145-150
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• 2014

Precision control of the slab is crucial for product quality and production economy in hot strip mills. The current study presents a new model for predicting width spread of a slab with a rectangular cross section during roughing. The model is developed on the basis of the extremum principle for a rigid plastic material and a three dimensional admissible velocity field. This model incorporates the effect of process variables such as the shape factor and the ratio of width to thickness. We compare the results of this model to 3-D finite element (FE) process simulations and also to results from a previous study.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.401-405
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• 1999

Reflective silver films with high quality were prepared on polyester substrate by using sputter deposit on techniques. Best reflectivity thin films of silver were produced with process parameters of $10^{-6}$ Torr as base pressure, 50 W as R.F. power, 5 mTorr as working pressure, and 10 sccm as Ar flow rate. Being deposited with an R.F. power of 50 W, Ag films revealed the highest 96.3 % reflectance as illuminated with a light of 700 nm wavelength. The adhesion of sample films showed as high as 14 to $20{\;}kg/\textrm{cm}^2$, which is suitable for industrial purposes. Their film crystallinity and orientation resulted in the planes of (111) and (200) for the growth with a preferred orientation of <111>, in general. The cross-sections of thin film specimens showed columnar structures. It is noted that columns became coarsened and less dense as R.F. power increased, resulting in a low reflectivity for the product film.