• Journal of Welding and Joining
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• v.29 no.1
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• pp.115-122
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• 2011

This study is to propose an in-process monitoring system for micro resistance spot welding processes using minute accelerometer. A minute accelerometer is mounted on the upper moving electrode tip holder. With its high sensitivity and frequency response characteristics, accelerometer output signal has been successfully recorded and integrated twice to reflect electrode expansion during micro spot welding processes. The analysis of electrode expansion pattern was attempted to find its correlation with spot weld quality. Major previous findings1-6) regarding spot weld quality assessment with the electrode expansion signal in large scale resistance spot welding processes were proved to be true in this in-process monitoring system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.3
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• pp.58-63
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• 2004

In the present work a finite element formulation using dynamic-explicit time integration scheme is used for numerical analysis of multi-stage stamping processes. The lumping scheme is employed for the diagonal mass matrix and dynamic explicit formulation Multi-Stage stamping is analyzed by using dynamic-explicit finite element method. Further, the simulated results for the panel stamping processes are shown and discussed. Its application is being increased especially in the stamping industrial area for the cost reduction, weight saving, and improvement of strength.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.90-96
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• 2013

During the cold forming, due to high working pressure acting on the die surface, failure mechanics must be considered before die design. One of the main reasons of die failure in industrial application of metal forming technologies is wear. Die wear affects the tolerances of formed parts, metal flow and costs of process etc. The only way to control these failures is to develop methods which allow prediction of die wear and which are suited to be used in the design state in order to optimize the process. In this paper, the wear experiments to obtain the wear coefficients and the upsetting processes was accomplished to observe the wear phenomenon during the cold forming process. The analysis of upsetting processes was accomplished by the rigid-plastic finite element method. The result from the deformation analysis was used to analyse the die wear during the processes and the predicted die wear profiles were compared with the measured die wear profiles.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.2
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• pp.131-144
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• 1992

Even though nonhomogeneous Markov Decision Processes subsume homogeneous Markov Decision Processes and are more practical in the real world, there are many results for them. In this paper we address the nonhomogeneous Markov Decision Process with objective to maximize average reward. By extending works of Ross [17] in the homogeneous case adopting the result of Bean and Smith [3] for the dicounted deterministic problem, we first transform the original problem into the discounted nonhomogeneous Markov Decision Process. Then, secondly, we transform into the discounted deterministic problem. This approach not only shows the interrelationships between various problems but also attacks the solution method of the undiscounted nohomogeneous Markov Decision Process.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.116-122
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• 1996

In forming processes, die failure must be considered before die design. One of the main reasons of die failure in industrial application of metal forming technologies is wear. The die wear affects the tolerances of formed parts, metal flow and costs of processes etc. The only way to control these failures is to develop methods which allow prediction of the die wear and which are suited to be used in the design state in order to optimize the process. In this paper, wire drawing processes were simulated using the rigid-plastic finite element method and its results were used for predicting the die wear by Archard's wear model. The effects of the temperature rising on the wear profiles of die were also investigated. The simulation results were compared with the measured die profiles.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.67-70
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• 2005

The static implicit finite element method is applied effectively to analyze total roof panel stamping processes, which include the forming stage. complicated and abnormal Large size roof panel was analyzed by using commercial program called AutoForm. Analysis results examining possibility and validity of the AutoForm software and the factor study are presented. Further, the simulated results for the total roof panel stamping processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.17-22
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• 2017

This review deals with scale-up strategies for optimized chemical processes particularly for micron and submicron products. The method of finding scale-up factors was also introduced for two systems, a system with chemical reaction and a system without chemical reaction. This review is expected to serve as an initial guideline for process engineers who are to scale up their current chemical processes for small products of micron or submicron size.

• Textile Coloration and Finishing
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• v.17 no.6 s.85
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• pp.20-26
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• 2005

For developing digital printing textiles, special pretreatment processes are necessary. These processes include developing formulation of coating agent and coating processes. The pretreatment were investigated with the variation concentration of anti-migration agent, fixation chemical etc.. The printing qualities according to pretreatment conditions were studied with color yield, printed capital letter sharpness and washing fastness. It was observed that the concentration of anti-migration agent, fixation agent(alkali) was closely related to printing qualities. For developing industrial technology of cellulosic digital printing textiles, optimum viscosity of pretreatment coating formulation is very important factor.

• Journal of Information Processing Systems
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• v.16 no.6
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• pp.1271-1280
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• 2020

The yield and quality of a micromanufacturing process are important management factors. In real-world situations, it is difficult to achieve a high yield from a manufacturing process because the products are produced through multiple nanoscale manufacturing processes. Therefore, it is necessary to identify the processes and equipment that lead to low yields. This paper proposes an analytical method to identify the processes and equipment that cause a defect in the plastic ball grid array (PBGA) during the manufacturing process using logistic regression and stepwise variable selection. The proposed method was tested with the lot trace records of a real work site. The records included the sequence of equipment that the lot had passed through and the number of faults of each type in the lot. We demonstrated that the test results reflect the real situation in a PBGA manufacturing process, and the major equipment parameters were then controlled to confirm the improvement in yield; the yield improved by approximately 20%.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.7-14
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• 2022

The presented research is devoted to the problems of achieving the goals of sustainable development, which will contribute to the development of industrial parks and their transformation into eco-industrial parks. The importance of the functioning of industrial parks and their transformation into eco-industrial ones in the direction of achieving sustainable development goals is substantiated. The development of industrial parks and their transformation through the coordination of dynamic development processes and the establishment of a system of mutually beneficial relations, due to the peculiarities of their functioning aimed at achieving sustainable development goals ensure the achievement of sustainable spatial development. Transformation of industrial parks will contribute to: increasing tax revenues of local budgets, increasing employment in the regions, raising public awareness of the need for environmentally friendly, energy efficient production, increasing the balance and harmony of social, economic and environmental development, modernization of territorial communities and regional enterprises resources and increase entrepreneurial initiative, rational use of available resources, intensification of small and medium enterprises, including innovation. The authors' scientific achievements are the substantiation of the principles of functioning of industrial parks in order to achieve the goals of sustainable development, which are based on a systematic approach and provide for the transformation into eco-industrial parks.