• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.178-187
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• 2009

Six Sigma emphasizes KPI and establishes the present level as well as the goal level through statistical calculation and tries to achieve management innovation through process improvement. But in the area of new product development or service, sufficient data for statistical measurement may not be secured. On the other side, looking for contradictions through problem analysis, TRIZ is a methodology that stresses the process of solving these problems. TRIZ also has its own problems: it is hard to define its initial task, to objectify the measurement of effect, and to optimize the drawn out idea. The purpose of this report is to give a comprehensive understanding about each methodology (Sigma Six and TRIZ) through its analysis, to confirm the need of linking both methodologies, and to suggest a model for this linking process. Also, they will be verified through examples, and the synergy effect will be discussed.

• Journal of Welding and Joining
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• v.13 no.4
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• pp.113-121
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• 1995

This study deals with the quality and the optimum range of laser cutting process. Cold rolled steel sheets for automobile application were cut by a high power CO$_{2}$ laser system with beam quality of TEM$_{\infty}$ mode. Both process parameters such as travel speed and assist gas pressure, and quality factors were considered to optimize the laser cutting. It was revealed that the thinner the sheet thickness, the less effect of oxidation energy for contributing the cutting process. High speed photographs demonstrated that molten spot on the cut surface moved in a random and vigorous manner according to its viscosity and the flowing direction of assist gas, which resulted in so called striation. Laser cutting produced a very smooth surface of average roughness(Ra) about less than 1.5.mu.m at the optimum range. It was also shown that the characteristics of dross formation was influenced by the flowing durection of assist gas and the fluidity of molten metal drop..

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.269-272
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• 2006

The hydroforming processing is a relatively new technology in comparison with conventional stamping process. The hydroforming processing makes torsion beam in rear suspension of automobile. The durability of torsion beam is very important characteristic that operate in an automobile. In order to optimize the hydroforming process and satisfy the durability, the hydroforming simulation which could control an axial compression and high internal pressure with computer simulation has to be operated. This paper is about an optimum design to improve the kinematic and compliance characteristics of a torsion-beam of suspension system. The result from finite element analysis shows that the forming and the durability are optimized. If there is effect of First pressure in hydroforming processing that gap is in the die tool, the prototype of tube is not satisfied on the durability test.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.121-128
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• 2012

The optimization of cooling system parameters for designing injection mold is very important to acquire the highest part quality. In this paper, the integration of computer simulations of injection molding and Analysis of Variance(ANOVA) with orthogonal array was used as a design tool to optimize the cooling system parameters aimed at minimizing the part warpage. The design optimizer was applied to find the optimum levels of cooling system parameters for a dustpan. This optimization resulted in more uniform temperature distribution over the part and significant reduction of a part warpage, showing the capability of present method as an effective design tool. The whole optimization process was performed systematically in a proper number of cooling simulations. The design optimizer can be utilized effectively in the industry practice for designing mold cooling system with less cost and time.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.1
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• pp.48-56
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• 2009

This paper presents the results of miniaturized micro milling machine tool development for micro precision machining process. Finite element analysis has been performed to know the relationship between design dimensional variables and structural stiffness in terms of static, dynamic, thermal aspects. Design optimization has been performed to optimize the design variables of micro machine tool to minimize the volume, weight and deformation of machine tool structure and to maximize the stiffness in terms of static, dynamic, and thermal characteristics. This study presents the assessment of the technology incentive for the minimization of machine tool in the quantitative context of static, dynamic stiffness, thermal resistance and thus the accuracy implications. This study can also be provided a basic knowledge for further research of micro factory development.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.74-80
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• 2011

In this study, a variety of welding experiments were carried out to optimize root-pass welding process using GMA process. Based on the experimental results, optimal welding conditions were selected after analyzing correlation between welding parameters and back-bead geometry. Then, effectiveness of empirical models developed was compared and analyzed, and optimized empirical models were finally developed for predicting back-bead by analyzing the main effect of each factor which affects back-bead geometry and their influence on interaction. Also, functions proper for expressing the surface of back-bead were selected using diverse quadratic functions, and back-bead geometry was visualized using empirical models developed and quadratic functions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.842-847
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• 2012

The Response Surface Method(RSM) is used as optimal design technique of experimental conditions. In Al7075-T0 turning operation, the principle cutting force and the Center-line averaged roughness are measured to optimize machining process. In variation of feed, depth of cut and cutting speed, three cutting parameters are evaluated. The optimal cutting conditions of Al7075-T0 turning are suggested by RSM. As a main result, feed is the dominant cutting parameter in this turning process considering surface roughness and cutting force.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.5
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• pp.547-553
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• 2008

Multi Progress Planning System problem in a multi-stage manufacturing system have a complexity and peculiarity different from other kinds of production system. World leading company has invested much cost and effort into a Real-Time Planning System and intelligent manufacturing field to obtain their own competitiveness. Especially Real-Time Planning System for ship production process as a part of intelligence for a shipyard. Real-Time Planning System, simulation based system, or virtual manufacturing system is an approach to achieve a such goal. It is expected that the Real-Time Planning System will contribute to the improvement of the productivity in working process at a shipyard. Also, This Real-Time Planning System will optimize the entire shipbuilding process in a multi progress planning environment for the delivery.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1997-2001
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• 2010

Generally, railroad soil around turnout was caused by leakage of lubricant oils during its maintenance. So, TPH concentration in soil was much higher than standard in Soil Envirnment Law. In additiont, railroad site was still difficult to assess due to railcar operation. This research was conducted to investigate the effect on electrolyte concentration during the Electrokinetic-Fenton process for contaminated soil around railroad turnout. As a result, experimental result shows that TPH removal in soil and amount of EOF were changed depending on electrolyte concentration. In future, the removal efficiency can be enhanced to optimize concentration in EK-Fenton Process.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.1-8
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• 2003

In this study, the high performance BCD device structure which satisfies the high voltage and fast switching speed characteristics is devised. Through the process and device simulation, optimal process spec. & device spec. are designed. We adapt double buried layer structure, trench isolation process, n-/p-drift region formation and shallow junction technology to optimize an electrical property as mentioned above. This I.C consists of 20V level high voltage bipolar npn/pnp device, 60V level LDMOS device, a few Ampere level VDMOS, 20V level CMOS device and 5V level logic CMOS.