• Journal of the Korean Institute of Plant Engineering
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• v.23 no.4
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• pp.29-38
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• 2018

Through process quality information, the time required for process quality analysis has been drastically shortened, the process defect rate has been reduced, and the manufacturing lead time has been shortened and the on-time delivery rate has been improved. Therefore, The purpose of this study is to develop a quality information analysis system model that effectively shortens the time required for process quality analysis in automobile safety belt parts manufacturing process. As a result of experiments on communication operation between manufacturing execution system (MES) quality server, injection machine control computer, injection machine programmable logic controller (PLC) and terminal, in analyzing quality information, the conventional handwriting input method took an average of 20 minutes, but the new multi-network method took about 2 minutes on average. In addition, the process defect rate was reduced by 13% and the manufacturing lead time was shortened from 28 hours to 20 hours. The delivery compliance rate improved from 96 to 99%.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1008-1011
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• 1996

Most control systems of power plants are using classical PID controllers for their process control. In order to get the desired control performances, the correct tuning of PID controllers is very important. Sometimes, it is necessary to retune PID controllers after the change of system operating condition and system design change, etc. Commercial auto-tuning controllers such as relay feedback controller can be used for this purpose. However, using these controllers to the safety-critical systems of nuclear power plants may be cause of unsafe operation, because they are using test signals for tuning. A new system identification auto-tuning method without using test signal has been developed in this paper. This method uses process input/output signals for system identification of unknown control process. From the model information of control process which was obtained from system identification approach, the optimal PID parameters can be calculated. The method can be used in the safety-critical systems because it is not using test signals during system modeling process.

• Journal of the Korea Safety Management & Science
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• v.9 no.5
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• pp.49-55
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• 2007

A special cause producing temporary deviation in the underlying process can influence on process adjustment in First-Order System feedback control system. In this paper, the impact of special causes on the forecasts and the process adjustment that is based on the EWMA forecasts are derived for a first-order system. For some special causes with patterned type of contamination, the influence of the causes on the output process are explicitly investigated. A data set, contaminated by a special cause of level shift, is analyzed to confirm the impact numerically.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.11
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• pp.1-7
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• 2020

Recently, hydrogen has gained considerable attention as an eco-friendly fuel, which helps in reducing carbon dioxide content. Specifically, there is a growing interest in vehicles powered by a hydrogen fuel cell, which is spotlighted as an environmental-friendly alternative. A hydrogen transport system, fuel cell system, fuel supply system, power management system, and hydrogen storage system are key parts of a hydrogen fuel cell truck. In this study, a hydrogen storage system is built and analyzed. The expansion length of the storage vessel at maximum operating pressure (87.5 MPa) was calculated with ABAQUS, and then the optimized system was designed and built. The leak and bubble tests were performed on the built storage system. The leakage of the system was measured to be under 5 cc/hr. Hence, it can be used as a research test for the safety evaluation of leading systems of hydrogen fuel-powered commercial vehicles.

• International Journal of Railway
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• v.2 no.3
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• pp.113-117
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• 2009

Risk management is an important part of system assurance and it is widely used in safety-related system. Railway signal system is one kind of safety-related system and its most important goal is to guarantee the safety of railway system. The method based on risk management can find and solve the security issues of railway signal system more effectively. This paper introduces the basic conception of risk management, studies the whole process of risk management and related tools and techniques and discusses some key points qualitatively combining with the particularity of railway signal system.

• Journal of the Korea Safety Management & Science
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• v.14 no.4
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• pp.23-29
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• 2012

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as appurtenant works, temporary works, structural works, equipment work, finishing work and etc based on accident examples and investigation on actual condition in plants construction work. In addition, the safety management system was developed to perform risk assessment of plants construction and use it for effective safety training for labor.

• Proceedings of the Safety Management and Science Conference
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• 2005.11a
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• pp.194-198
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• 2005

Inventory information system is providing the benefits of smoother demand, lower inventories(work in process, safety stock) and reduced costs. This study focused on improvement of safety level inventory efficiency by inventory information system. The results indicated that inventory information system allowed the company to serve its customers more surely and efficiently.

• Journal of the Korean Institute of Gas
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• v.23 no.2
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• pp.55-60
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• 2019

To develop a plant safety training system using virtual reality technology, we constructed a training system for a large scale plant. Compared with safety training for small plants or unit equipment, many system configurations such as virtual plant model, in-process data processing, work instruction, etc. are required and integrated system works have been carried out. The target plant, RDS process, is a high-risk process(high-temperature, high-pressure) that takes into account the training scenarios that can be taken in the event of a leaking fire in the range and refer to the actual shutdown procedure. The proposed safety training integration system can be used in similar situations that can occur in the RDS process and can be a platform for safety training using virtual reality in a large plant.

• Journal of the Korea Safety Management & Science
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• v.7 no.4
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• pp.165-177
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• 2005

Supply Chain Management(SCM) system is a critical investment that can affect future competitiveness and performance of a company. Selection of a right SCM system is one of the critical issues. This paper provides the characteristic factors of SCM system selection and the SCM system evaluation and selection model based on Analytic Hierarchy Process(AHP). The proposed model can systematically construct the objectives of SCM system selection to support the business goals. A empirical example demonstrates the feasibility of the proposed model and the model can help a company to make better decision-making in selecting SCM system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.404-406
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• 2016

Due to the localization process of offshore drilling system, ensuring safety has emerged as an important. Therefore, step by stem safety analysis about each development process of offshore drilling system is becoming compulsory. Hazard and operability analysis is a method that was successfully used for system safety analysis in industries such as chemical plants. Through this hazard and operability analysis study, to conduct step by step safety analysis accorsing to process, the study conducted hazard and operability analysis in Lp mud system, an area of offshore drilling system.