• 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.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.4
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• pp.1-8
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• 2003

It is well known that design cost is only about 5% of final product cost but over 70% of it is determined during design stage. Earlier in the product design and development cycle the design changes occur, more economic they become. Therefore, it is recommended that the manufacturing time and cost of product are considered in steps involved in designing and manufacturing a product as early as possible. In this study, it is proposed a possible way that cm be available for estimating manufacturing time of parts, which are manufactured by conventional material removal processes (e.g. turning, milling and drilling). For it to be useful in the early design stage, the minimum number of informations on dimension shape, and design features of part will be used in this method.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.275-278
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• 2000

In this paper, we carried out fundamental experiments to use steel manufacturing slag as a concrete aggregate. Generally, there are two types of slag, the blast-furnace slag and the steel manufacturing slag. The latter is classified by the difference of manufacturing method of steel into the convertor slag and the electric-furnace slag. The steel manufacturing slag mainly contains $SiO_2$ and CaO as the chemical composition. The reaction with water and a little of free CaO in the steel manufacturing slag made the expansion of volume change, Therefore, we primarily investigated physical properties, expansion mechanism, pH value, aging effect and aging methods in the steel manufacturing slag, Then compressive strength of concrete with steel slag aggregate is measured.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.168-176
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• 2008

In an environment where manufacturing conditions such as product lines keep changing, manufacturing control systems need to be continually maintained and upgraded according to the change. This requires an effective system implementation methodology. In this paper, a methodology based on the multi-criteria similarity comparison of manufacturing processes is proposed. A newly introduced process is compared with existing ones based on the multi-criteria similarity, and candidates for software reuse are selected from stored modules according to the overall process characteristics. The proposed methodology has been tested for an electronics manufacturing company's manufacturing control system, and the result has been satisfactory in that it can save time and efforts for system implementation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.311-315
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• 2008

Currently, in automobile industry. the efforts to reduce the manufacturing cost by changing the process of manufacturing are continually performed. In this paper, we proposed a new manufacturing process, the roll bending of a ring plate of automotive fuel tank instead of conventional press blanking process to reduce material loss and manufacturing cost. Finite element analysis was used to optimize the roll bending process to assure rectangular cross-section of the ring plate. Also, spring-back analysis after the roll bending was performed and dimension of the bending die considering spring-back was analyzed. Finally, we verified a possibility for realization of the proposed method shape with prototypes.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.4
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• pp.143-151
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• 1996

The concept of cellular manufacturing is to decompose a manufacturing system into subsystems, which are easier to manage than the entire manufacturing system. The objective of cellular manufacturing is to group parts with similar processing requirements into part families and machines into cells which meet the processing needs of part families assigned to them. This paper presents a methodology for cell formation based on genetic algorithm which produces improved cell formation in terms of total moves, which is a weighted sum of both intercell moves and intracell moves. A sample problem is solved for two, three and four cells with an approach based on genetic algorithms.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.63-72
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• 2011

In recent years, hot-stamped components are more increasingly used in the automotive industry in order to reduce weight and to improve the strength of vehicles. In hot stamping process, blank is hot formed and press hardened in a tool. However, in hot stamping without cooling channel, temperature of the tool increases gradually in mass production thus cannot meet the critical cooling rate to obtain high strength over 1500MPa. Warpage occurs in the hot stamped component due to non-uniform stress state caused by unbalanced cooling. Therefore, tools should be uniformly as well as rapidly cooled down by the coolant which flows through cooling channel. In this paper, optimal design method of cooling channel to obtain uniform and high strength of the component is proposed. Optimized cooling channel is applied to the hot press V-bending process. As a result of measuring strength, hardness and microstructure of the hot formed parts, it is known that the design methodology of cooling channel is effective to the hot stamping process.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.25-29
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• 2001

There are so many researches about the search method for the most compatible dispatching rule to a manufacturing system state. Most of researches select the dispatching rule using simulation results. This paper touches upon two research topics: the clustering method for manufacturing system states using simulation, and the search method for the most compatible dispatching rule to a manufacturing system state. The manufacturing system state variables are given to ART II neural network as input. The ART II neural network is trained to cluster the system state. After being trained, the ART II neural network classifies any system state as one state of some clustered states. The simulation results using clustered system state information and those of various dispatching rules are compared and the most compatible dispatching rule to the system state is defined. Finally there are made two knowledge bases. The simulation experiments are given to compare the proposed methods with other scheduling methods. The result shows the superiority of the proposed knowledge base.

• Korean Journal of Computational Design and Engineering
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• v.17 no.4
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• pp.274-281
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• 2012

This paper proposed a control simulation method for design and verification of the transport system in an automobile assembly line based on digital manufacturing system. The design of the transport system involves two major activities: mechanical design (device specification) and electrical design (device behavior and system control). Conventionally, the simulation and emulation system of the transport system focuses on the abstract level, which mainly deals with design verification, alternative comparison, and system diagnosis. Although it can provide overall system visibility in monitoring how well it works in the process and view, its simulation models are not sufficiently realistic to be used for a detailed design or for implementation purposes. In this paper, a digital simulation model for a transport system in an automotive assembly line is constructed by adapting a digital manufacturing methodology. We use the concept of the "Virtual Probe", which transport a carrier instead of the belt of the conveyor. In conclusion, the proposed method is valuable in the process of test run in the shop floor. This method would reduce the time and effort for validating the manufacturing system and improve the productivity and integrity of the control program.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.74-84
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• 2015

The core activities of a bicycle manufacturer are design, engineering analysis, and manufacturing. Therefore, it is important to develop a configuration design system for bicycles in order to automate the design process and facilitate the use of design data in engineering analysis and manufacturing. In this paper, we present a method to develop a bicycle configuration design system based on the part-shape information model. The proposed method enables the construction of a CAD library using modeling functions with equations and parameters that are common to most 3D mechanical CAD systems. Furthermore, the part-shape information model ensures the independence between the configuration design system and the library, making it possible to extend the CAD library flexibly without changing the system architecture.