• Journal of Welding and Joining
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• v.23 no.5
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• pp.30-36
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• 2005

In this part, thermal finite element analysis(FEA) is conducted for the experiments in part 1. The molten area of base metals are analyzed by FEA results and compared with experimental ones. Temperature data from FEA results are used to calculate the IMC layer thickness analytically at the interface. IMC layer is established as a function of time and temperature when there is an interaction between solid steel and molten aluminum. The IMC layer thickness is obtained by cumulative computations using the time-temperature data from FEA results.

• Transactions of Materials Processing
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• v.12 no.7
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• pp.615-622
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• 2003

In the automobile industry, the design of optimal blank shape becomes a significant part of the stamping. It provides many evident advantages, sush as enhancement of formability, reduction of material cost and product development period. However, the nesting process, required for the optimal usage of materials in the blanking becomes more complicated as the blank shape becomes complicated, like most optimal blank shape. In this study, stamping process optimization system for the optimal usage of material has been developed through the integration of optimal blank design and optimal nesting. For optimal blank design, a radius vector method, the modified version of the initial nodal velocity method, the past work of the present author, have been proposed. Both the optimal blank design and optimal nesting programs have been developed under the GUI environment for the convenience of engineers. The efficiency of the optimization system has been verified with some chosen problems.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.52-59
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• 2004

Recently the high speed end-milling processing is demanded the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. The working factors of high speed end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to analyze the working factors to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on distance of cut, feed rate, revolution of spindle and depth of cut. By design of experiment, it is effectively represented shape characteristics of surface roughness in high speed end-milling. And determination($R^2$) coefficient of regression equation had a satisfactory reliability of 76.3% and regression equation of surface roughness is made by regression analysis.

• Journal of Fashion Business
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• v.6 no.3
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• pp.60-68
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• 2002

Fashion has been affected by the change of periodic conditions. A good example is found in the relationship between fashion and periodic conditions before and after World War I in the U.S. During the pre-wartime, the artificial silhouette achieved through using devices like the corset was popular and then women's dresses were very decorative and gorgeous using a wide variety of details. S-curved silhouettes and Paul Poiret's style will be reviewed as distinctive shapes of pre-war fashion in the beginning of the 20th Century. Through the war, women's rights improved enormously, the use of the automobile increased tremendously, and various kind of sports, the movie industry and ready-to-wear market developed very much. Women's clothes also changed to be much more practical and functional in post-war fashion. It seems that fashion is affected by the change of periodic conditions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.17-24
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• 1995

The classification of quality costs by item is essencial to sum up the entire quality cost but the reality of classifying the quality cost by the firm is facing with difficulty in terms of grouping the concerned items. Meanwhile, the classification of items and calculating method of quality costs should be prepared in adcance with a certain standards and or regulations to figure out the accurate quality costs successfuly. This case study provides the contents of quality costs calulated by item and the method of calculation in detail which is applicable to automobile component industry md, also introduce how to set up the computing system of quality costs.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.131-137
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• 2016

In unlimited competition era changed rapidly, productivity improvement and raw cost reduction by working improvement are very important for the survival of middle and small-sized companies. At this moment, middle and small-sized companies are cleary important in domestic industry. Therefore, this researcher applied TPS(Toyota production system) 7 wastes by experiment planning method for wastes of lots of working processes at the manufacturing site of automobile assembly manufacturing company, D company, analyzed current system of D company applied so as to verify if value creation works and factors were minimized during the production and drew results by analyzing experimental planning for analyzing waste elimination.

• Elastomers and Composites
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• v.54 no.3
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• pp.175-181
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• 2019

The research and development of high-performance polymer materials with excellent gas barrier properties has gained considerable attention from the viewpoint of expanding their applications in various fields, including tire automobile parts and the polymer film industry. Natural rubber (NR) has been widely used as a rubber material in real-life, but its application is limited owing to its poor gas barrier properties. In this paper, we study the gas barrier properties of NR, epoxidized natural rubber (ENR), and their blend compositions by using molecular simulation. The results show that ENR-50 has superior oxygen barrier properties than those of NR. Moreover, the oxygen barrier properties of a blend of NR/ENR-50 improve with increasing volume fraction of ENR-50. The trend of improved oxygen barrier properties of NR, ENR-50, and their blend is in good agreement with experimental observations.

• Journal of IKEEE
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• v.23 no.1
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• pp.346-349
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• 2019

Product liability is an important regulation factor in automotive industry. ISO 26262 international standard was established as an exemption clause of product liability. In autonomous car, product liability becomes more important, and ISO/PAS international standard was additionally established, but it can be applied to only sensing stage, which can partly make the autonomous car companies exempt the product liability but not completely. Therefore, reform of current legal system is absolutely necessary to commercialize autonomous car until a new international standard is established as a complete exemptions clause.

• Steel and Composite Structures
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• v.33 no.2
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• pp.299-306
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• 2019

The natural fibre composites are termed as bio-composites. They have shown a promising replacement to the current carbon/glass fibre reinforced composites as environmental friendly materials in specific applications. Natural fibre reinforced composites are potential materials for various engineering applications in automobile, railways, building and Aerospace industry. The natural fibre selected to fabricate the composite material is plant-based fibre e.g., sisal fibre. Sisal fibre is a suitable reinforcement for use in composites on account of its low density, high specific strength, and high hardness. Epoxy is a thermosetting polymer which is used as a resin in natural fibre reinforced composites. Hand lay-up technique was used to fabricate the composites by reinforcing sisal fibres into the epoxy matrix. Composites were prepared with the unidirectional alignment of sisal fibres. Test specimens with different fibre orientations were prepared. The fabricated composites were tested for mechanical properties. Impact test, tensile test, flexural test, hardness test, compression test, and thermal test of composites had been conducted to assess its suitability in industrial applications. Scanning electron microscopy (SEM) test revealed the microstructural information of the fractured surface of composites.

• Advances in nano research
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• v.15 no.2
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• pp.141-153
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• 2023

The main objective of this paper is to develop the finite element study on the nonlinear free vibration of functionally graded nanocomposite spherical shells reinforced with graphene platelets under the first-order shear deformation shell theory and von Kármán nonlinear kinematic relations. The governing equations are presented by introducing the full asymmetric nonlinear strain-displacement relations followed by the constitutive relations and energy functional. The extended Halpin-Tsai model is utilized to specify the overall Young's modulus of the nanocomposite. Then, the finite element formulation is derived and the quadrilateral 8-node shell element is implemented for finite element discretization. The nonlinear sets of dynamic equations are solved by the use of the harmonic balance technique and iterative method to find the nonlinear frequency response. Several numerical examples are represented to highlight the impact of involved factors on the large-amplitude vibration responses of nanocomposite spherical shells. One of the main findings is that for some geometrical and material parameters, the fundamental vibrational mode shape is asymmetric and the axisymmetric formulation cannot be appropriately employed to model the nonlinear dynamic behavior of nanocomposite spherical shells.