• Journal of Korean Society for Quality Management
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• v.41 no.1
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• pp.39-52
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• 2013

Purpose: The purpose of this study was to investigate if purchasing companies' efforts of supplier development activities to supplier companies have positive impacts on the purchasing companies' performance as the first step. In the second step, we tried to confirm if the concept of Supply Chain Corporate Social Responsibility activities and Coexistence activities take the roles of moderate variable on relationship between supplier development and three performances respectively. Methods: The collected data through survey were analysed using multiple regression for the first step of the study and moderate regression for the second one of it. Results: The results of this study are as follows; supplier development efforts effect on all three performances positively. Moreover, Supply Chain CSR has significant moderate effect on relationship between supplier management and corporate performances, while Coexistence does between supplier management and logistics performances. In the case of relationship between supplier management and production performances, both Supply Chain CSR and Coexistence show significant moderate effect. Conclusion: Manufacturing companies in Korea need to make effort of supplier development in selective way when they want to practice Supply Chain CSR and Coexistence concurrently considering strategies and objectives.

• Tribology and Lubricants
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• v.31 no.4
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• pp.170-176
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• 2015

As a continuation of Part I, which developed a design formula of the minimum corner radius (R_min) for restraining tribological failures, Part II investigates design parameters such as material properties and contact force. As design examples, Al 7075-T651, SST 304 and HT-9 are chosen for the materials and 1, 10 and 100 kN are used for the forces. The results show that the difference in R_min decreases as either the elastic modulus increases or the contact force decreases. Given the same material and force, the permissible R_min decreases as the flat region increases and vice versa. Because the R_min values obtained from the examples are very small, the dimensions of the corner radius normally designed in engineering structures are regarded acceptable. The von Mises stress evaluated for a typical example, which is far below the yield strength, confirms this interpretation. Nevertheless, the present work can provide a design criterion as well as a guideline for quality control in the manufacturing of, in particular, contact corners, which has not been attempted before to the best of the author’s knowledge. In addition, this paper considers the problem of a step that may be formed in the contact contour by using a similar approach. The result shows that no size of the step is permissible.

• Korean Journal of Health Education and Promotion
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• v.20 no.2
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• pp.1-18
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• 2003

The purpose of this study was to develop game style courseware in oral health instruction for elementary school children. The manufacturing equipment and languages which were used to develop the courseware were： Photoshop version 7.0, Illustrator version 10.0, HTML, Dream Weaver MX, Editplus, CSS and Java - script. The data base was built up by using PHP and mySQL over Internet Explorer version 4.0. The contents of courseware for oral health education were based on the list of oral health affaires of the Department of Health and Welfare, 2002. The story of the game ‘Saving Hayani locked down in a castle of a cavity man’ was developed for the learners to learn oral health by inducing learning motivation. A character named ‘Chan i’ was introduced to the learners to be more friendly with the program while they were learning. As the game was made of three step education levels, the learner most pass the prepared test given at each step to advance to a higher level. A database connected to web was constructed to store the scores the learners earned at each step. In conclusion, the courseware will help the elementary school children learn oral health care efficiently through the internet regardless of time and space.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.845-851
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• 2013

In this paper, a robust optimization approach is applied to the two-axes stage using a piezoelectric actuator for precise motion tracking. Robust control is based on LQG/LTR (linear quadratic Gaussian control with loop transfer recovery) control. Further, an LMI (linear matrix inequality) is used to find the optimal parameter in the loop transfer recovery step, instead of a trial and error method. A decoupler in the shape of FIR filter is added to reduce the coupling effect between the motions of the two axes, and hence, the feedback control loop is designed independently for each axis motion. The experimental result shows that the proposed control scheme can be applied effectively for motion control of the two-axes stage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.44-44
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• 2009

Fault detection is necessary for yield enhancement and cost reduction in semiconductor manufacturing. Sensory data acquired from the semiconductor processing tool is too large to analyze for the purpose of fault detection and classification(FDC). We studied the techniques of fault detection using statistical method. Multiple regression analysis smoothly detected faults and can be easy made a model. For real-time and fast computing time, the huge data was analyzed by each step. We also considered interaction and critical factors in tool parameters and process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.65-72
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• 2000

This paper presents the study of the tension control in a web transfer system. In this study the sliding mode controller is applied to a time-varying nonlinear mathematical model. The model was derived to consider the effects of changing the roll radius in tension variation during winding and unwinding. The uncertainty in modeling may be due to unmodelled dynamics, on variations in system model. Designed sliding mode controller made the system error always staying in the suggested surface from the beginning. Through this, system is maintained to be robust against a disturbance and uncertainty. To verify the designed controller has a good performance, various inputs such as desired velocity, step input, and trapezoidal input are applied. When the sliding mode controller was used, the system(the tension control) performance was improved comparing to the PID controller. The robustness of the controller with respect to an estimation error was verified through simulations.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.119-126
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• 2000

Recently, according to the various taste of consumers, the design of a product is changed variously and complicatedly. The complicated product is not usually constructed with one path but multi-path. By the way, in machining, higher precision and the reduction of leading and machining time is required. But, for the multi-patch sculptured surface, the amount of machining data becomes large. This means the increase of leading and machining time. In this study, the tool path generation method with reparameterization is proposed for multi-patch sculptured surface and variable step size using NURBS is used to satisfy the precision and to reduce leading and machining time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04a
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• pp.443-448
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• 1994

As a basic step of interfacing CAD and CAM, it is required to convert thedrawing data into manufacturing information automatically. In this study the developed system carries out feature recognition from the orthographic views of press mold containing various pockets. Using rhe recognized output data, 3 dimension- al model is built using ADS and AME in order to check the result of recognition. The system consists of 4 main parts, suchas, Preprocessing, Coordinate handling, Feature recognition and 3D-modeling. The system shows a good application example which can interface the design and manufacturing stage in CAD/CAM system on PC level

• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.221-225
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• 2014

Although gold wire bonding techniques have already matured in semiconductor manufacturing, weakly bonded wires in semiconductor chip assembly can jeopardize the reliability of the final product. In this paper, weakly bonded or failed aluminum bonding pads are analyzed using X-ray photoelectron spectroscopy (XPS), Auger electron Spectroscopy (AES), and energy dispersive X-ray analysis (EDX) to investigate potential contaminants on the bond pad. We found the source of contaminants is related to the dry etching process in the previous manufacturing step, and fluorocarbon plasma etching of a passivation layer showed meaningful evidence of the formation of fluorinated by-products of $AlF_x$ on the bond pads. Surface analysis of the contaminated aluminum layer revealed the presence of fluorinated compounds $AlOF_x$, $Al(OF)_x$, $Al(OH)_x$, and $CF_x$.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.211-221
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• 1998

It is very important to have a satisfactory measurement system, since it is useless to try to improve the manufacturing process without an adequate measurement system. Therefore, evaluation of the measurement system is the first step for the quality improvement of the manufacturing process. To estimate the measurement error we must conduct a controlled gage repeatability and reproducibility(gage R&R) study. Many manufacturers use a gage or instrument to measure multiple dimensions for the overall quality of the manufactured parts. In this case, it is necessary to estimate the gage R&R for multiple dimensions. When a gage measures a large number of dimensions of a part, it is very time-consuming and costly to measure all the dimensions. In this paper we propose the use of the principal component analysis method to identify a few principal components out of the original multivariate measurement capability to explain most of the measurement system variation pattern.