• International Journal of Contents
• /
• v.13 no.2
• /
• pp.57-65
• /
• 2017

Recently, due to the significance of Industry 4.0, the manufacturing industry is developing globally. Conventionally, the manufacturing industry generates a large volume of data that is often related to process, line and products. In this paper, we analyzed causes of defective products in the manufacturing process using the decision tree technique, that is a well-known technique used in data mining. We used data collected from the domestic manufacturing industry that includes Manufacturing Execution System (MES), Point of Production (POP), equipment data accumulated directly in equipment, in-process/external air-conditioning sensors and static electricity. We propose to implement a model using C4.5 decision tree algorithm. Specifically, the proposed decision tree model is modeled based on components of a specific part. We propose to identify the state of products, where the defect occurred and compare it with the generated decision tree model to determine the cause of the defect.

• Journal of Korea Foundry Society
• /
• v.9 no.1
• /
• pp.39-48
• /
• 1989

A basic three dimensional thermal model has been developed to simulate the solidification sequence for gravity die casting process. The finite difference method was used to analyze the solidification process during all the casting cycles. The prediction of die temperature in the quasi-steady state was analyzed by the boundary element method. The influence of die cooling on the heat flow in the cast/mold system was also investigated. Predictions of the computer simulation on temperature profiles and location of shrinkage defects were in good agreement with those observed in experimental die castings. Models of computer simulation which is developed by this work can be useful for the design and process control of die casting.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.3
• /
• pp.91-96
• /
• 2013

Because the r-fold Wiener process is truly infinitely dimensional and a computer can only handle finitely dimensional subspaces, we study in this paper the basic properties of the m-dimensional approximation function of the r-fold Wiener process.

• Journal of the Korea Society for Simulation
• /
• v.8 no.2
• /
• pp.73-85
• /
• 1999

In this paper, the productivity estimation of the painting line in an automobile plant is studied. To improve the bottleneck and the weak point of the process, computer simulations are performed. In determining the system specification, the status of the conveyor lines and the other physical facilities are considered in order not to intervene with each other and to satisfy the painting facility restrictions. As simulation parameters, production performance ratio, number of hanger and dolley, down time, speed of conveyor and the pitch of a painting body are chosen on the basis of exhaustive field evaluation to study their effects on the capacity of the process. The results of the simulation show that we can improve the capability of they system without additional investment to the plant facility. The best condition for the maximum capacity of the process is selected by comparing the alternative computer simulation results. As a simulation language, Promodel is used which is very useful and easy to use in manufacturing oriented simulation.

• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2390-2392
• /
• 1998

In this paper, we discuss the development of monitoring system with data process equipment which transfers data from Remote Terminal Unit(RTU) to monitoring computer. The RTUs sense temperature, pressure and PLC(Programmable Logic Controller) nodes conditions of scrubber in semiconductor manufacture processing. The data Process equipment is connected every RTU and a monitoring computer through serial communication. This equipment receives informations from RTU, process data, and transfers them to monitoring computer. To avoid congestion in data communication, task scheduling algorithm used RT O/S(Real-Time Operating System) is embedded in ROM which is a part of data Process equipment.

• Computers and Concrete
• /
• v.1 no.1
• /
• pp.15-30
• /
• 2004

In this study, a design process for reinforced concrete structures using the nonlinear FEM analysis is developed. Instead of using the nonlinear analysis to evaluate the required performance after design process, the nonlinear analysis is applied before designing the reinforcement arrangement inside the RC structures. An automatic reinforcement generator for computer aided reinforcement agreement is developed for this purpose. Based on a nonlinear FEM program for analyzing the reinforced concrete structure, a smart fictitious material model of steel, is proposed which can self-adjust the reinforcement to the required amount at the cracking location according to the load increment. Using this tool, the reinforcement ratio required at design load level can be decided automatically. In this paper, an example of RC beam with opening is used to verify the proposed process. Finally, a trial design process for a real size underground RC LNG tank is introduced.

• Design & Manufacturing
• /
• v.13 no.2
• /
• pp.49-53
• /
• 2019

The temperature distribution and lifetime of molds were predicted by computer simulation analysis with various spraying and blowing process of high pressure die casting. After varying the spraying angle and time, the mold temperature, heat exchange and mold life were predicted. As the spraying angle increases, the maximum temperature of the mold decreases, which is because the spraying area increases and the heat exchange with the mold increases. Heat exchange occurs more actively in the blowing process than in the spraying process. This is because the cooling is not performed due to the steam generation. When the spraying angle is 50 degree, the minimum life of the mold is analyzed 200 times. After adjusting the blowing time from 5s to 3s, the minimum lifetime of the mold has been increased almost twice.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.14 no.5
• /
• pp.36-41
• /
• 2015

In this paper, research on the mold design of motor housing produced by the HPDC process was conducted using computer simulations and experiments. Recently, automobile parts have been required to be light and have high strength. The die casting process was used to manufacture automotive motor housings. In the die casting process, the control of casting defects is very important. However, it has usually depended on the experience of the foundry engineer. For the analysis of the manufacturing process of motor housing, the finite element method is applied. Through the simulations using commercial software, the filling pattern and product defects could be confirmed. The analysis results obtained from the filling behavior of the casting process agreed with the experimental results. The computer simulation results of filling behavior were reflected in the optimal mold design of motor housing.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.10
• /
• pp.159-166
• /
• 2017

This study is a discussion of business process reengineering for the next generation information system. To be concrete, we analyze and reengineer the current business process in administration of academic, general and research. This reengineering is conformed by 5 steps, as analyzing environmental status that figures out factors of inside or outside (environmental analyzing), analyzing current condition that diagnoses AS-IS process (current situation analysis), establishing information-oriented vision with strategic accomplishing goals accordingly (visioning), deducing detailed improving tasks (defining tasks), and engineering TO-BE process comprehending improving matters (engineering model). This paper shows BPR model for next generation information system.

• Journal of applied mathematics & informatics
• /
• v.20 no.1_2
• /
• pp.603-610
• /
• 2006

In this paper we discuss the complete convergence of the linear process generated by negatively orthant dependent random variables under suitable conditions.