• Journal of the Korean Society of Systems Engineering
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• v.12 no.1
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• pp.113-120
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• 2016

Steel in a continuous reheat furnace is heated to higher temperature to be treated in the rolling steel process. Due to this reason the continuous reheat furnace system requires an optimal control system to adjust the temperature inside the furnace. Level 2 control systems for continuous reheat furnaces generate automatic heating set points for the level 1 system of the furnace based on the mathematical thermal model which can give a good estimation of steel heating inside the furnace and is used to adjust heating requirements to optimize furnace combustion. For the current study the analytic methodology based on the design procedure from the systems engineering to develop new level 2 control system of a continuous reheat furnace was proposed. The system analysis and the requirements of the level 2 control system were derived using the unified modeling language (UML) 2.0, and the design of database and the graphic user interface (GUI) for the level 2 control system were conducted.

• Journal of the Korean Society for Railway
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• v.17 no.5
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• pp.349-354
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• 2014

Other foreign countries already apply ETCS LEVEL 2 in signaling systems. It provides added functions to control a train using wireless communication compared with ETCS LEVEL 1. Nowadays, the ETCS LEVEL 2 system is being applied on revenue services more and more frequently. Therefore, it is necessary to develop ETCS LEVEL 2 to apply in this country. The advanced technology of the ETCS LEVEL 2 system provides continuous control for train protection, and ATP function, by comparing discontinuous controls on ETCS LEVEL 1. ETCS LEVEL 2 is a better system model for improving passenger safety. This paper describes the design of an onboard speed profile for the ETCS LEVEL 2 system and it forecasts the future of ETCS.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1066-1076
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• 2011

The subsystems of HSR train control system in each country has developed and operated till early 2000, however 2001/16/EC ERTMS is issued for inter-operability among European train control systems in 2001. So it is trend that ERTMS/ETCS has been applied to not only low-speed train system but high-speed train system over 300km/h in many countries of Europe. According to the government policies of the Honam HSR, metropolitan HSR and test lines, incoming on-board signal control system has been required caused by speed limit to 160km/h on the ground signal system. As ETCS-Level 1 system has applied in our railways from 2003, so our train control system has depended on foreign technologies. In this paper, we analyzed to localize train control system for being ready to protect foreign policies and obtaining core technologies of HSR train control system for instance ETCS-Level2.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.29-40
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• 2000

In this paper, under JIT kanban system designed by Moeeni, each performance measures (service level, inventory level) identify the robust optimal level at a uncertain environment, and when there are multiple performance characteristics, it propose the optimal design-method and the optimal level decision-method, which consider multiple performance characteristics.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.202-211
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• 2000

The aim of this study was to compare the apical sealing ability of a new thermoplasticized gutta-percha filling technique, the Easy Filling and the Quick Obturation system with lateral condensation technique and Thermafil system to evaluate their clinical acceptabilities. Fifty-two extracted single-rooted teeth were instrumented to #35 using the .04 taper ProFile system. Four groups of 12 teeth were obturated by lateral condensation technique. Thermafil system and two new thermoplasticized gutta-percha techniques, the Easy Filling system and Quick Obturation system (Meta Dental co. Ltd. Korea), respectively. Four teeth served as controls. After the teeth were immersed in 2% methylene blue dye for 48 hours, they were resected horizontally at 1mm to 5mm level from the anatomical apex using a low-speed microtome. Each section was examined under a stereomicroscope at ${\times40}$ magnification and photographed. After each image was scanned, the leakage area was measured at each level using Brain 3 (Nosdia Tech., Korea) software. Leakage ratio was calculated for each group and was analyzed statistically to come up with the following results: 1. At 1mm level, the Quick Obturation system had the largest amount of apical leakage and it was statistically significant when compared with the lateral condensation group and the Thermafil group (p<0.05). 2. At 2mm and 3mm level, there were no significant difference of apical leakage among all four groups (p>0.05), and from 4mm level, no apical dye penetration was observed in all the groups. In conclusion, the apical seal produced by Easy Filling system and the Quick Obturation system was comparable to lateral condensation technique and Thermafil system except for the 1mm level. More improvement of the apical seal can be expected as the operator becomes skillful with the new techniques.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.121-129
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• 2011

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC or EN standard which is commonly applied to railway system for Automatic Train Protection (ATP) system in accordance with ERTMS/ETCS Level 1 system. This also shows approach methods and relative activities for project lifecycle to accomplish and ensure the system requirements of ATP system, RAMS and system quality activities. These kind of activities for quality assurance of ATP system to obtain Safety Certificate could improve the quality of domestic railway system based on On-Board system of ERTMS/ETCS Level 1 and also contribute to the growth of railway business.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.281-283
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• 2013

In this paper, standing water level control system and a comparison of existing methods (anchor, PDD, DM) and economic analysis was conducted. 1) Cost PDD method (6%), DM system (4%), and the SAL standing water level control system (4%), except for the anchor system is similar to the construction of three methods based on the portion of the anchor system was analyzed that. 2) construction and maintenance costs compared with the sum of the partial was, anchor system (100%), PDD method (39%), DM system (37%), the SAL standing water level control system (21%), the SAL standing water level control system was identified as the lowest cost method of.

• Environmental Engineering Research
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• v.14 no.2
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• pp.111-119
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• 2009

A prototype GIS-based decision support system (DSS) was developed by using a database management system (DBMS), a model management system (MMS), a knowledge-based system (KBS), a graphical user interface (GUI), and a geographical information system (GIS). The method of selecting a dispersion model or a modeling scheme, originally devised by Park and Seok, was developed using our GIS-based DSS. The performances of candidate models or modeling schemes were evaluated by using a single index(statistical score) derived by applying fuzzy inference to statistical measures between the measured and predicted concentrations. The fumigation dispersion model performed better than the models such as industrial source complex short term model(ISCST) and atmospheric dispersion model system(ADMS) for the prediction of the ground level $SO_2$ (1 hr) concentration in a coastal area. However, its coincidence level between actual and calculated values was poor. The neural network models were found to improve the accuracy of predicted ground level $SO_2$ concentration significantly, compared to the fumigation models. The GIS-based DSS may serve as a useful tool for selecting the best prediction model, even for complex terrains.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.2
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• pp.111-120
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• 2002

The multi-level inverter system is very promising in ac drives, when both reduced harmonic contents and high power are required. In case of multi-level inverter system, the loss of switch devices cannot be analyzed by conventional methods. The reason is that the loss of each the switch device is different from one another unlike 2-level. In this paper, a simple and accurate method of computing conduction and switching loss is proposed for multi-level inverter system. The validity of the proposed method is proven for 3-level and 4-revel diode clamped inverter system.

• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.7-15
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• 2005

The purpose of this study was to compare the sealing ability of root canal obturation with or without the use of dentin adhesive system. Forty extracted human teeth with one canal were selected and decoronated. The teeth were divided into two Groups. The obturation procedure of Group 1 was the same as that of Group 2 with the exception of dentin adhesive system. Group 2 were obturated with dentin adhesive system, AH-26, and gutta-percha. After obturation, the teeth were immersed in methylene blue solution for 84 hours. The teeth were sectioned horizontally at 1.5 mm (Level 1), 2.0 mm (Level 2) 2.5 mm (Level 3) from the root apex using a low speed microtome. Distance of dye-penetrated surface and total dentinal surface were measured using SigmaScan Pro 5.0, and the ratio of dye-penetrated distance to the total dentinal distance was analyzed statistically by Mann-Whitney U-test. 1. In both groups, the mean leakage ratio was decreased cervically. 2. At level 1, there was no significant difference between group 1 and group 2 (p > 0.05). 3. At level 2 and 3, group 1 showed significantly higher mean leakage ratio than group 2 (p < 0.05). The results suggest that using dentin adhesive system in root canal obturation procedure reduces the apical microleakage.