• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.113-117
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• 2003

In the industrial field nowadays the information that needs to be handled arc increasing and requires faster speed in contrast with PLC(Programmable Logic Controller) or DCS(Distributed Control System) based control systems these days. The work environment these days are mostly based on PC, so the control systems are wanted in PC. At Fieldbus used automated systems performing distributed process control by PC performs and combines into one system in order to maximize the increase of productivity, lower the expense, planning constructing and maintaining the reliance of automation. These latest automation systems unites process, makes distributed control process able, and can control and supervise at remote PC.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.723-729
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• 2005

Traditional statistical process control(SPC) applied to discrete part industry in the form of control charts can look for and eliminate assignable causes by process monitoring. On the other hand, engineering process control(EPC) applied to the process industry in the form of feedback control can maintain the process output on the target by continual adjustment of input variable. This study presents controlling and monitoring rules adopted variable sampling interval(VSI) to change sampling intervals in a predetermined fashion on the predicted process levels for integrated EPC and SPC systems. Twelve rules classified by EPC schemes(MMSE, constrained PI, bounded or deadband adjustment policy) and type of sampling interval combined with EWMA chart of SPC are proposed under IMA(1,1) disturbance model and zero-order (responsive) dynamic system. The properties of twelve control rules under three patterns of process change(sudden shift, drift and random shift) are evaluated and discussed through simulation and control rules for integrated VSI EPC and SPC systems are recommended.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.7
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• pp.557-561
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• 2016

Recently, in the manufacturing process of flat panel displays, mass production methods of inline system has been emerged. In particular the next generation OLED display manufacturing process, horizontal inline evaporation process has been tried. It is important for the success of OLED inline evaporation process to develop a magnetic levitation transport system capable of transferring a carrier equipped with a mother glass with high accuracy without any physical contact along the rail under vacuum condition. In the case of existing wheel-based transfer system, it is not suitable for OLED evaporation process requiring high cleanliness. On the other hand, the magnetic levitation transport system has an advantage that it does not generate any dust and it is possible to achieve high-precision control because there are not non-linear factors such as friction force. In this paper, we introduce the high-precision magnetic levitation transport system, which is currently under development, for OLED evaporation process.

• IE interfaces
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• v.21 no.4
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• pp.418-434
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• 2008

This paper studied issues in decision making on the production control policy of a cathode plate manufacturing process in zinc refining plant. The present production system has a long lead time from raw materials (aluminum plate) to products (cathode plate) due to many WIP inventories. Because WIP inventories are stocked at each process and moved from one place to another frequently, they are the main cause of inefficiency in the process. In this paper, to solve this problem, several production control policies have been identified and studied. Several simulation models are used to compare the performances of these production control policies. The output lead time and WIP (Work In Process) of real production system are compared with those of simulation models. PUSH, CONWIP, DBR, KANBAN and CONWIP-DBR models have been used to simulate and review the optimized production control policy that achieves the target output quantities with decreased lead time and WIP. The simulation results of each production control policy show that CONWIP and CONWIP-DBR models are the good production control policy under the present production system. Especially in present production system, CONWIP with one parameter is easier control policy than CONWIP-DBR with two parameters. Therefore CONWIP has been selected as the best optimum production control policy. With CONWIP, lead time has been reduced by 97% (from 6,653 to 187 minute) and WIP has been reduced from 1,488 to 53, compared to the present system.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.179.3-179
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• 2001

This paper describes the dual system technology of PC based control system at steel plant. Because PC is developed to be used in wide area such as Office Automation, Personal, It is cheaper and more portable than the present process control system, but is less stable and less reliable. In this research, We gathered the fault example of a general process control system and steel process control system, analyzed the cause of fault and decided the target fault that took over in our proposed system. The proposed PC based system is the dual system that has a shared RAID system connected by SCSI bus between two systems. In order to assist system reliability, we proposed watchdog manager to monitor ...

• Journal of Korean Institute of Industrial Engineers
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• v.10 no.2
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• pp.51-65
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• 1984

A process quality control system is designed which incorporates run tests, normality test, process capability studies, etc., into control chart scheme, and a software package for microcomputers is developed. The system is interactive and has data base management capabilities. All programs are written in BASIC language.

• Journal of Korean Society for Quality Management
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• v.24 no.2
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• pp.172-178
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• 1996

In this study, we developed a software for statistical process control. This software presents $\bar{x}$, R, CUSUM, EWMA control chart and process capability index. In this system, statistical process control methods are integrated into the automated method on a real time base. It is available in process control of specified type and can be performed on personal computer with network system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.327-327
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• 2000

Derivation of a slab dimension from the desired tolerance degrades the product quality, resulting in significant yield loss by trimming. This necessitates the dimensional control system to be operated in tighter dimensional accuracy. This paper presents an integral approach to a dimensional control system design taking into account the interaction between the edging process and the gap rolling process. To investigate the effects of each process controller, a simple PID controller is adopted as a preliminary study. The control performance is analyzed in detail in terms of the system response accuracy for various operating conditions.

• IE interfaces
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• v.20 no.3
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• pp.257-266
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• 2007

To survive in rapidly changing business environment, the enterprises of all over the world are trying to integrate their IT infra structure and are trying to automate their business process. Service Oriented Architecture (SOA) is being accepted as an IT standard to support efficient system integration and flexible business process automation between enterprises or departments. The material control system is required this software architecture between manufacturing company and materials supply vendors. This paper introduces concept of SOA, relevant technology about SOA such as Web Services and Business Process Execution Language (BPEL) and Enterprise Service Bus (ESB) and describes how to automate materials control process by designing the material control system based on SOA. The analysis of requirements is proceeded by Unified Modeling Language (UML) and SOA delivery strategy is selected the top-down strategy. And this paper describes how to derive services and operations and how to arrange services in three service layers and how to design business process.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.213-231
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• 2005

Assignable causes producing temporary deviation from the underlying system can influence on process adjustment and process monitoring in dynamic feedback control system. In this paper, the influence of assignable causes on EWMA forecasts and compensatory variables are derived for a dynamic feedback control system. An example is presented to confirm the impact numerically through the analysis of a data.