• Journal of Aerospace System Engineering
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• v.14 no.4
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• pp.25-31
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• 2020

The development of manufacturing technology for braided composites has led to farther extension of the applications in aerospace structures. Since the mechanical characteristics of braided composites are affected by various materials and manufacturing parameters, it is important to determine the parameters required to appropriately design the braided composite structures. In this study, we proposed a geometric model of RUC (repeating unit cell) for 2D braided composites, and predicted the mechanical properties according to the change of fiber volume fraction, fiber filament size, braiding angle, and gap between adjacent yarns by the yarn slicing technique and stress averaging method. Finally, we analyze the characteristics of mechanical properties according to each manufacturing parameter of the braided composite material.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.225-232
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• 1999

The effect of manufacturing parameters such as molding and curing conditions on friction characteristics of friction materials was studied using a pad-on-disk type friction tester. Friction materials containing 15 ingredients were investigated for an optimal manufacturing condition for the best friction characteristics employing Taguchi robust experimental design. The main effects were different for mechanical properties and friction characteristics and were strongly influenced by manufacturing conditions. An optimum manufacturing condition was obtained to achieve the best friction characteristics concerning mechanical properties(hardness, porosity, wear resistance), friction stability, and change of rotor temperature.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.42-51
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• 2021

Investigations of process parameters are essential when fabricating high-quality parts using additive manufacturing. This study investigates the change in the mechanical characteristics of a SUS316L specimen fabricated using selective laser melting based on the energy density and bead overlap ratio. The SUS316L powder particles were spherical and 35 ㎛ in size. Single-bead and hexahedral shape deposition experiments were performed sequentially. A single bead experiment was performed to obtain the bead overlap ratios for different laser parameters utilizing laser power and scan speed as experimental parameters. A hexahedral shape deposition experiment was also performed to observe the difference in mechanical properties, such as the internal porosity, surface roughness, and hardness, based on the energy density and bead overlap ratio of the three-dimensional printed part. Laser power, scan speed, overlap ratio, and layer thickness were chosen as parameters for the hexahedral shape deposition experiment. Accordingly, the energy density applied for three-dimensional printing, and the experimental parameters were calculated, and the energy density and bead overlap ratio for fabricating parts with good properties have been suggested.

• Tribology and Lubricants
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• v.18 no.2
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• pp.127-132
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• 2002

The Taguchi method, a robust experimental design, was used to optimize manufacturing parameters of a brake lining during hot pressing and heat treatment. A friction material containing 15 ingredients was employed fur this experiment and friction and wear tests were carried out by using a pad-on-disk type tribotester. Sixteen brake linings with different manufacturing conditions were examined according to a parameter design. From the results of the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA), the cause and effect of the manufacturing parameters on physical properties (hardness and porosity) and friction and wear characteristics of brake linings was obtained.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.625-632
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• 2012

Optimization of process parameters in polymer extrusion is an important task to reduce manufacturing cost. To determine the optimum values of the process parameters, it is essential to find their influence on the strength of polymer breathable thin film. The significance of six important process parameters namely, extruder cylinder temperature, extruder speed, extruder dies temperature, cooling roll temperature, stretching ratio, stretching roll temperature on breathable film strength of polymer extrusion was determined. Moreover, this paper presents the application of Taguchi method and analysis of variance (ANOVA) for maximization of the breathable film strength influenced by extrusion parameters. The optimum parameter combination of extrusion process was obtained by using the analysis of signal-to-noise ratio. The conclusion revealed that extruder speed and stretching ratio were the most influential factor on the film strength, respectively. The best results of film strength were obtained at higher extruder speed and stretching ratio.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.386-393
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• 2015

A study is carried out on investigation on pattern costs, identification of geometric parameters for the cost, and development of cost estimation models for casting patterns. Pattern costs for machine tool structures are collected and analyzed to identify the important geometric parameters that affect the costs. The parameters are used for the development of the costing models. It is found that the geometric parameters can be easily obtained from a CAD system and then the costing models estimate a pattern cost in a minimum time. The models are verified with the structures whose pattern cost was used for this study. It is expected that this costing models can evaluate the cost of casting structures of machine tools in search of a near-optimal design based on manufacturing cost and, for example, weight at the design stage.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.18-23
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• 2006

Cutting by a high speed laser cutting machine is one of most effective technologies to improve productivity. This paper has presented the cutting characteristics and optimal cutting conditions in a high speed feeding type laser cutting machine by using Tacuchi method in the design of experiment. An L9(34) orthogonal array is adopted to study the effect of adjustment parameters. The adjustment parameters consist of cutting speed, laser power, laser output duty and assistant gas pressure. The surface roughness of sheet metal is regarded as a quality feature. Analysis of variance is performed in order to evaluate the effect of adjustment parameters on the quality feature of laser cutting process.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.247-254
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• 1999

The effect of manufacturing parameters such as molding and curing conditions on friction characteristics of friction materials were studied using a pad-on-disk type friction tester. The optimal manufacturing rendition for the best friction characteristics were investigated using friction materials containing 15 ingredients employing Taguchi robust design experiment. The friction characteristics were strongly affected by pressing time, pressing temperature, pressing pressure, curing time, curing temperature.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.82-86
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• 2004

To cope with the challenge from global market characterized by frequent changes in requirements, manufacturing enterprise should be able to promptly adjust its manufacturing system accordingly. Therefore, it is important to provide manufacturing system designer with an appropriate methodology to (re-)design a manufacturing system subject to requirements change. Axiomatic design theory focuses design activity mainly on functional consideration rather than physical, and has been known as effective especially in the conceptual design phase. This paper introduces an approach to apply the axiomatic design principle to manufacturing system design. It is shown that a new design solution can be reached quickly by finding design parameters for the added or revised functional requirements and thus achieving a set of functional requirements as well as design parameters that satisfy the independence axiom. Some illustrative examples are also given.

• Korean Journal of Computational Design and Engineering
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• v.13 no.1
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• pp.67-75
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• 2008

In spite of rapidly increasing interests in digital manufacturing, there still lacks of a systematic approach in manufacturing line flow analysis via modeling and simulation; currently, the parameters for designing manufacturing line are defined by being solely based on engineers experiences. The paper proposes an application of the genetic algorithm to a discrete event line simulation finding optimal set of parameters for manufacturing line balancing problem. The proposed method has been applied to two example problems-one is a simple manufacturing model and the other for shipyard industry-in order to demonstrate its validity and usefulness.