• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.213-217
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• 1999

An expert system is developed for rational and efficient design of multi-component injection molding which is a fairly new manufacturing technique to produce plastic parts by injecting two or more materials sequentially using multiple injection units in a single machine into a single rotary mold. The knowledge base used in the present design system is primarily composed of two parts ; knowledge from domain expert and knowledge from CAE analysis. The present expert system has hour main modules ; general design guidelines for injection molding specific guidelines for multi-component injection molding redesign guidelines from the result of the CAE analysis and finally troubleshooting for multi-component injection molding. To show the validity of the present design methodology two shop floor design problems were tested ; design and fabrication of timing belt cover and power window's assist knob by using multi-component injection molding.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.273-277
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• 2003

A general process of electronic assembly is composed of a series of geometric alignments and bonding/screwing processes. After assembly, the function is tested in a following process of inspection. However, assembly of micro-optic devices requires both processes to be performed in equipment. Coarse geometric alignment is made by using vision and optical function is improved by the following fine motion based on feedback of tunable laser interferometer. The general system is composed of a precision robot system for 3D assembly, a 3D vision guided system for geometric alignment and an optical feedback system with a tunable laser. In this study, we propose a new fast alignment algorithm of micro-optic devices for both of visual and optical alignments. The main goal is to find a fastest alignment process and algorithms with state-of-the-art technology. We propose a new approach with an optimal sequence of processes, a visual alignment algorithm and a search algorithm for an optimal optical alignment. A system is designed to show the effectiveness and efficiency of the proposed method.

• Industrial Engineering and Management Systems
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• v.7 no.2
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• pp.160-170
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• 2008

This paper proposes a mathematical model for converting conveyor assembly line to cellular manufacturing in complex production environments. Complex production environments refer to the situations with multi-products, variant demand, different batch sizes and the worker abilities varying with work stations and products respectively. The model proposed in this paper aims to determine (1) how many cells should be formatted; (2) how many workers should be assigned in each cell; (3) and how many workers should be rested in shortened conveyor line when a conveyor assembly line should be converted, in order to optimize system performances which are defined as the total throughput time and total labor power. We refer the model to a new production system. Such model can be used as an evaluation tool in the cases of (i) when a company wants to change its production system (usually a belt conveyor line) to a new one (including cell manufacturing); (ii) when a company wants to evaluate the performance of its converted system. Simulation experiments based on the data collected from the previous documents are used to estimate the marginal impact that each factor change has had on the estimated performance improvement resulting from the conversion.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.3
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• pp.25-43
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• 2010

We consider a multi-objective balancing and sequencing problem in mixed model assembly lines, which is important for an efficient use of the assembly lines. In this paper, we present a neighborhood symbiotic evolutionary algorithm to simultaneously solve the two problems of balancing and model sequencing under multiple objectives. We aim to find a set of well-distributed solutions close to the true Pareto optimal solutions for decision makers. The proposed algorithm has a two-leveled structure. At Level 1, two populations are operated : One consists of individuals each of which represents a partial solution to the balancing problem and the other consists of individuals for the sequencing problem. Level 2, which is an upper level, works one population whose individuals represent the combined entire solutions to the two problems. The process of Level 1 imitates a neighborhood symbiotic evolution and that of Level 2 simulates an endosymbiotic evolution together with an elitist strategy to promote the capability of solution search. The performance of the proposed algorithm is compared with those of the existing algorithms in convergence, diversity and computation time of nondominated solutions. The experimental results show that the proposed algorithm is superior to the compared algorithms in all the three performance measures.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.369-372
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• 2006

Optimal engineering design is challenging because nonlinear objective functions need to be evaluated in a high-dimensional space. This paper presents a data-mining aided optimal design method. The method is employed in designing an optimal multi-station fixture layout. Its benefit is demonstrated by a comparison with currently available optimization methods.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.47-52
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• 2002

There are many factors in machine tool error. These are thermal deformation, geometric error, machine's part assembly error, error caused by tool bending. Among them thermal error is 70% of total error of machine tool . Prediction of thermal error is very difficult. because of nonlinear tendency of machine tool deformation. In this study, we tried thermal error prediction by using multi regression analysis.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.649-652
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• 2005

The camera cellular phone has a large portion of cellular phone market in recent year. The variety of a customer demand makes a fast model change and the spatial resolution is changed from VGA to multi-mega pixel. The 1.3 mega pixel (MP) camera cellular phone was first released into the Korean market in October 2003. The major cellular phone companies released a 2MP camera cellular phone that supports zoom function and a 2MP camera cellular phone is settled down with the Korea cellular phone market. It makes a keen competition in price and demands automation for phone camera module. There is an increasing requirement for the automatic assembly to correspond to a fast model change. The hard automation techniques that rely on dedicated manufacturing system are too inflexible to meet this requirement. Therefore in this study, this system is designed with the flexibility concept in order to cope with phone camera module change. The system has a same platform that has X-Y-Z motion or X-Z motion with ${\mu}m$order accuracy. It has a special gripper according to the type of a component to be put together. If the camera model changes, the gripper may be updated to fit for the camera module. The controller of this system acquires the data sets that have the information about the assembly part by the tray. This information is obtained ahead of an inspection step. The controller excludes an inferior part to be assembled by using this information to diminish the inferior goods. The assembly jig used in this system has a function of self adjustment that reduces the tact time and also diminish the inferior goods. Finally, the intelligent assembly system for phone camera module will be designed to get a flexibility to meet model change and a high productivity with a high reliability.

• Journal of the Korean Geographical Society
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• v.50 no.6
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• pp.621-639
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• 2015

The aim of this study is to consider the physical distribution system of assembly supplied from $1^{st}$ supplier and module corporation to automobile assembly plant through analysis of existing literatures and interview survey. The major findings of this study are as follows. Parts supply of automobile are to bind together with many regional parts supplier than using multi frequency and small delivery of JIT. Regional physical distribution center of joint parts and integrated physical distribution information center is to be installed in neighboring region of automobile assembly plant in order to reduce the transport cost by designating and activating multiple physical distribution and transport companies in each automobile assembly plant and turning into effective high volume shipping system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.631-634
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• 2001

In this study, the graphic simulation system of multi joint manipulator is developed to analyze and optimize the remote handling processes for the spent fuel assembly. This system consists of a 3-D graphical modeling system, a device assembling system, and a motion simulation system. To analyze and optimize the processes involved in multi-joint manipulator operation such as NFBC transportation process and bottom nozzle removal process, the virtual work place is implemented using a computer graphic technology. This virtual workcell is exactly same as that of the real environment. This graphic simulation system of the multi-joint manipulator can be effectively used for designing the main processes and maintenance processes of the spent fuel management.

• 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.