• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.93-101
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• 2021

The purpose of this study is to analyze the adequacy of production capacity of the assembly process system of mobile bath vehicle's top box panel and process design through a simulation analysis. Towards this end, the layout of the facility designed with pre-verification job using a simulation modeling and an experiment, and facility, logistics process, and personnel input method were made into a simulation model, and the design system's adequacy was evaluated through an experiment. To produce 120 mobile bath vehicles annually, it was analyzed that 14 general workers and seven skilled workers were adequate through the experiment. It was also identified that three painting process lines carried out through outsourcing were adequate. Production lead time was 201.7 hours on average and it was 230 hours maximum. To meet customer delivery service level of 95% within the deadline when establishing a customer order and vehicle delivery plan, it was analyzed that more than 215 hours of lead time is needed minimum. If the process cycle time is reduced to 85% upon system stabilization and skillfulness improvement, it was analyzed that annual output of 147 vehicles can be achieved without additional production line expansion.

• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.103-103
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• 1997

• Macromolecular Research
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• v.9 no.4
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• pp.185-196
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• 2001

The self-assembly of block copolymers can lead to a variety of ordered structures on a nanometer scale. In this article, the self-assembling behaviors of triblock copolymers in the melt and the selective solvent are described with the results obtained from the computer simulations. With the advances of computing power, computer simulations using molecular dynamics and Monte Carlo techniques make it possible to study very complicated phenomena observed in the self-assembly of triblock copolymer. 13king full advantage of the computer simulation based on well-defined model, the effects of various structural and thermodynamic parameters such as the copolymer composition, the block sequence, the pairwise interaction energies, and temperature on the self-assembly are discussed in some detail. Some simulation results are compared with experimental ones End analyzed by comparing them with the theoretical treatment.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.514-518
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• 1990

This paper describes an experimental Knowledge-Based Control System, named KBCS, for manufacturing and assembly. The KBCS of five parts and function : data-base, knowledge acquisition, optimization, and graphic monitoring. The KBCS is utilized for a FMS which is of five machine centers and automatic assembly lines. Each machine can perform almost all manufacturing functions which some difference in efficiency. Buffers store temporarily the incoming components and the outing components. Parts arrive at assembly lines after many steps of manufacturing, and the transfer path and time are determined by procedural knowledge of control systems. Nine different incoming components are set up. The total control system is expected to perform four algorithms, timing algorithm ,sequencing algorithm, penalty algorithm, and cart algorithm. The construction of controller require basic components of manufacturing systems in which knowledges are formulated on the base of the results and the repeated simulation of KBCS with graphic monitoring system. Simulation results by KBCS are compared with those by the other rules of manufacturing.

• Korean Journal of Computational Design and Engineering
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• v.10 no.3
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• pp.199-209
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• 2005

In this paper, a digital simulation model for an automotive assembly line is constructed by adapting a digital manufacturing methodology. Applied methodology is a simulation for a plant level of the assembly production line. The first significance of this methodology is a validation of the production planning based on various scenarios. The second is pre-verification for the new production plan or production method. The third is a visualization of the production process. Several models were implemented and those models were verified. Then, it was possible to find a most efficient production scenario and production method.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.75-79
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• 2016

A helical nanosturctrue can be obtained by self-assembly method. Utilizing DPD simulation coarse-grained model, we patterned 2D layer nanosheets with repeated diagonal defects and grafts, and programed to self-roll into hollow helix structure. The defected pattern side caused anisotropy, and formed helix or helix-like structure. This opens the possibility to control the helix pitch or cavity radius. In this work, we designed several patterns about diagonal defect with a variety of defect side densities and defect widths and then simulation was carried out. Thus, our results have that parameters are affecting self-assembly of nanosheets and their conformation.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.4
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• pp.330-337
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• 2015

A bucket-brigade is a way of transporting items where items are passed from one person to the next. The operation of the bucket brigade imitates the cooperative behavior of ants when brood, food or other resources are moved. Koo (2009) presented a bucket brigade-based assembly cell where each worker follows a simple rule: perform assembly operations on a product until the next worker downstream takes it over; then go back to the previous worker upstream to take over a new assembly job. In this way, the flow line is self-balanced without any predetermined job assignment. However, there are some productivity losses related to hand-off and blocking. This paper examines the hand-off and blocking losses and presents a new bucket brigade-based assembly cell where working areas for each assembler is restricted with the help of buffer interfaces. Simulation experiments are used to validate the performance of the new assembly system.

• Journal of Korean Society for Quality Management
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• v.22 no.4
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• pp.79-101
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• 1994

In modern manufacturing, a product consists of many components created by different processes. Variations in the individual component dimensions and in the processes may result in unacceptable final assemblies. Thus, engineers have increased pressure to properly set tolerance specifications for individual components and to control manufacturing processes. When a proper variation stack-up analysis is not performed for all of the components in a functional system, all component parts can be within specifications, but the final assembly may not be functional. Thus, in order to improve the performance of the final assembly, a proper variation stack-up analysis is essential for specifying dimensional tolerances and process control. This research provides a detailed case example of the use of variation stack-up analysis using a Monte Carlo simulation method to improve the defect rate of a complex process, which is the commutator brush track undercut process of an armature assembly of a small motor. Variations in individual component dimensions and process mean shifts cause high defect rate, Since some dimensional characteristics have non-normal distributions and the stack-up function is non-linear, the Monte Carlo simulation method is used.

• Journal of the Korea Society for Simulation
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• v.14 no.2
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• pp.25-34
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• 2005

Determination of component mounting sequence on printed circuit board assembly process is a typical NP-hard problem. It is a kind of traveling salesman problems, but it has one more hard to meet constraint of matching component type per mounting position as well as searching the shortest path. An efficient method is developed by separation of crowed area and allowing up to two slots per component type. A simulation model is constructed using Visual C++ for evaluation of the suggested heuristic.

• IE interfaces
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• v.5 no.1
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• pp.35-46
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• 1992

This paper deals with analysis of material handling system efficiency of a heat-exchanger manufacturing line. This line is a typical flow shop type assembly line which consists of 10 steps of assembly stations. Each station have one or two workers who assemble and move components for the job, and no special transporters for component's movement. Therfore, all the workers are involoved in unnecessary moving activities which decrease overall production efficiencies of the line. To improve productivities, production outputs and worker's job performances for this assembly line, the several alternatives are considered such as installing new conveyor lines and automatic guided vehicle(AGV) system. Analyzing economic feasibilities and responses of the system alternatives, an experimental simulation model is built suing SIMAN Ver. 3. 5 simulation language with CINEMA package for animation of the process flow. Through this animation process a vivid picturial analysis could performed on the process flow.