• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.302-307
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• 1989

A pressure tracking control of hydroforming process is considered in this paper. To account for nonlinearities and uncertainties of the process, an iterative learning control scheme is proposed using Cerebellar Model Arithmatic Computer (CMAC). The experimental result shows that the proposed learning control is superior to any fixed gain controller in the sense that it enables the system to do the same work more effectively as the number of operation increases.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.115-123
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• 2012

Material flow control mechanism is a kind of operational policy in manufacturing. It is very important because it varies throughput, throughput time, and work-in-process (WIP) under the same manufacturing resources. Many Researchers have developed various material flow control mechanisms and insisted that their mechanism is superior to others. However the experimental environment used in the performance comparison are different and impractical. In this paper, we set various manufacturing environments to fairly compare five previous material flow control mechanism : Push, Pull, CONWIP, Gated MaxWIP, and Critical WIP Loops. The simulation results show that the Push is superior to others in both of throughput and WIP if required demand is less than 80% of capacity. In addition, the performance of CONWIP and its variants are not different statistically.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.84-89
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• 2003

Fuzzy controller is one of the succeed controller used in the process control in case of model uncertainties. But it my be difficult to fuzzy controller to articulate the accumulated knowledge to encompass all circumstance. Hence, it is essential to provide a tuning capability. There are many parameters in fuzzy controller can be adapted, scale factor tuning of normalized fuzzy controller is one of the adaptation parameter. Two adaptation methods are implemented in this work on an experimental thermal process, which simulate heating process in liquefied petroleum gases (LPG) recovery process in one of petrochemical industries: Gradient decent (GD) adaptation method; supervisory fuzzy controller. A comparison between the two methods is discussed.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2827-2830
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• 2003

Tele manipulator is distingushed from industrial robot by iterating same specified work. Manipulator operator is included in control loop for controlling the telemanipulator because he decide directly during the work and order controllabily reducing the modelling error of telemanipulator which depend on the PID controller. But position-force control method of bidirectional control impose unsafety of vibiration and Analytic Hierachy Method can stabilize for reducing nonlinear modelling error by expert operator because of transformation empirical control rule to linear model.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.560-565
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• 1986

For the control of chemical process, optimal value of the process should be known at first. And process simulation is the previous step of optimal value calculation. However it is not a simple work to analyze chemical process system. Especially for the large scale chemical process system, many difficulties such as non-linearity and complexity caused by recycle streams should be overcome. In this paper, three strategies of large scale chemical process analysis were explained and discussed with case studies.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06a
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• pp.95-101
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• 1998

The steel door inner was manufactured via a new route, tailored blanking process, to remove hinge reinforcement parts, using thicker panels laser welded, instead. It is very important, first of all, in this process, to design optimum configuration of tailored blanks and determine the optimum process control for the stamping. Generally, it was found that the severe deformation reduction behavior during stamping in the thinner panel around weld line caused cracks and the other troubles in formability. It is our purpose of this investigation to introduce how the process control parameters, such as tailored blank configuration, size, location in the die, the position of weld line, BHF, bead configuration, work on the formability. In addition, causes of cracks and movement of weld line after forming were analyzed and compared with computer simulation work.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.401-406
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• 1988

Various types and huge volume of information such as process instructions, work-in process and parametric data are created in a wafer fabrication process and should be provided to personnels inside or outside the facility. This article describes design criteria and functional description on the information system for small-scale wafer fabrication process to accomplish paperless fab and to support efficient fab management.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.810-814
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• 1996

The purpose of this exclusive welding-machine process using the welding Torch-rotation form is to develop a mechanism which can solve the problem of twisted welding wires and cables. The technique was developed by revising the torch position and smooth controlling of both the formal and reverse rotation. Some of the advantages of using the Torch-rotation form over the Work-rotation technique are the practical uses of increased work space and link work with the automation system of the plant. Using this welding machine process, It is possible to design a specific tool in order to solve the implemental problem. And I produced a control plate which can manipulate the progress of the entire process at the work place. Even if another kind of axle casing's welding work is used this process can be utilized if the fixed tip and work is produced and changed. The development if this exclusive welding-machine could reduce the manpower of skilled welding labor and after considerable analysis, this machine was found to increase productivity and better quality product in comparison to the handmade product.

• Journal of Korea Multimedia Society
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• v.3 no.1
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• pp.63-76
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• 2000

Most work done in CSCW (Computer Supported Collaborative Work) system has been targeted toward supporting the exchange of documents or messages among group members, and yet support for cognitive aspects such as group organization, division and merge of work, and work flow control. The objective of the study is to provide CSCW environment for the engineering design process such as CAD (Computer Aided Design) and CASE (Computer Aided Software Engineering). The proposed DCWA (Distributed Collaborative Writing Aid) system suggests a mechanism that unifies the group organization, work division, and work flow control in the CAO, CASE, and software simulation tool. In particular, CAD relates the group and work partition by providing expressing the relation of drawing object (e.g., binding, attachment, and proportional scaling) which is owned by different members of group, and CASE combining with the simulation tool supports the flexibility of the work flow control. Simulating the prototype before manu-facturing a product can reduce time and cost in development.

• International Journal of Control, Automation, and Systems
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• v.3 no.2
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• pp.252-257
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• 2005

In this work, we propose a simple but efficient method to design a target temperature trajectory for pulling speed tracking control of the crystal grower in the Czochralski crystallization process. In the suggested method, the model predictive control strategy is used to incorporate the complex dynamic effect of the heater temperature on the pulling speed into the temperature trajectory design quantitatively. The feedforward trajectories designed by the proposed method were implemented on 200 mm and 300 mm silicon crystal growers in the commercial Czochralski process. The application results have demonstrated its excellent and consistent tracking performance of pulling speed along whole bulk crystal growth.