• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1072-1077
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• 2006

In this paper a novel 3-phase line interactive UPS(Uninterruptible Power Supply) system with parallel-series active power-line conditioning capability using AC line reactor and two four-leg PWM VSCs(Voltage Source Converters) is proposed. And the strategy of voltage control in proposed UPS system is explained. The objective of voltage control in parallel(shunt) and series PWM VSC of proposed UPS system is to guarantee satisfactory characteristics in steady state and transient state.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1915-1919
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• 1991

The efficiency of automated assembly line is increased by realizing the automation of each assembly cell, monitoring the line information and developing the real-time line control system it. which production flow is controllable. In this paper, the several modules which are important factors when constructing automated real-time control system, such as, line control S/W module, real-time model change module, error handling module and line production management S/W module, are developed. For developing these important programming modules, real-time control and multi-tasking techniques are integrated. In this paper, operating method of real-time line control in PCB automated assembly line is proposed and for effective control of production line by using multi-tasking technique, proper operating method for relating real-time line control with multi-tasking is proposed by defining the levels of signals and tasks. CIM-Oriented modular programming method considering expandability and flexibility will be added for further research in the future.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.237-243
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• 2006

Deicing system is to melt frost or ice freezed in catenary line when the temperature is lower than $0^{\circ}C$ in winter. The principle of deicing system is to melt frost or ice by Joule heat of catenary impedance. The performance of deicing is dependant of deicing current determined by the length of deicing section, deicing impedance and current division ratio of catenary line and messenger line. So, we present technique for estimating deicing current and process for determination of deicing section in the conventional line. Deicing impedance is estimated using Carson-Pollaczek equation, and current division ratio of catenary line and messenger line is estimated using voltage drop, and deicing current is estimated using power system data of deicing system. For the determination of the final deicing section, we verified estimated value comparing with experiment value of deicing impedance and current division ratio of catenary line and messenger line using low voltage experiment. Finally, we verified the validity of estimation technique and process using a simulated test data of real deicing system operation in the Chungju Substation, Chungbuk line.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.2
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• pp.148-152
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• 2010

The superconducting fault current limiter (SFCL) applied into the neural line of a power system, which can limit the unsymmetrical fault current from the single-line ground fault or the double-line ground fault, was reported to be the effective application location of the SFCL in a power system. However, the limiting operation for the symmetrical fault current like the triple line-ground fault is not effective because of properties of the balanced three-phase system. In this paper, the limiting method of the symmetrical fault current in a power system with a SFCL applied into neutral line was suggested. Through the short-circuit experiments of the three-phase fault types for the suggested method, the fault current limiting and recovery characteristics of the SFCL in the neutral line were analyzed and the effectiveness of the suggested method was described.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.91-96
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• 2011

The handling ability of containers at the terminal strongly depends on the performance of the cargo handling system such as RTGC(Rubber Tired Gantry Crane) and RMGC(Rail Mounted Gantry Crane). This paper introduces a guide line measurement system on the operating condition, in which two camera are installed to detect the guide line. Because the line tracking is the basic technique for control system design of RTGC, it is necessary to develop a useful and reliable measurement system. If the displacement and angle of the RTGC relative to a guide line as the trajectory to follow is obtained, the position of RTGC is automatically calculated. Therefore, in this paper, a camera-based measurement system is introduced. The proposed measurement system is robust against light fluctuation and cracks of the guide line. This system consists of two camera and a PC which are installed at the lower side of the RTGC. Two edges of the guide line are detected from an input image taken by the cameras in the moving state, and these positions are determined in a Hough parameter space by using the Hough transformation method. From the experimental results, the accuracy and usefulness of the proposed system is evaluated by comparing other instruments.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.36-43
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• 2004

In-line measurement systems are preferred to those in analytical laboratories, since in-line systems provide rapid response to process upsets. If an in-line measurement system exhibits an unstable variation and if this instability in measurement variation goes undetected, it will make the process monitoring procedure invalid. This paper presents a stability evaluation procedure for the in-line measurement system using two independent readings from the in-line measurement system and one reading from the analytical laboratory, which requires less measurement cost and time.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1310-1320
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• 2007

This study investigated the differences in the importance of store characteristics depending on on-line clothing store type and consumer age. The questionnaires were given to female residents in the ages between 20-39 in Seoul and Kyung-gi province during October 2006. The results were summarized as follows: 1. By analyzing the differences in importances of on-line store characteristics factors it was found that buying process service factor and product searching system factor were important in on-line general merchandise store. and buying process service factor and product factor(all the factors, such as store credit, product, screen-displayed design, searching and approaching system, customer management service) were important in on-line specialty store. 2. By analyzing the differences in importances of on-line store characteristics depending on the store type, buying process system such as refund policy, shipping, high-speed payment and rapid searching, screen-displayed design system, approaching and searching system were more important in on-line general merchandise store when comparing to specialty store. It also showed that the consumer considered the reputation of the store and its image more important in on-line general merchandise store. 3. By analyzing the differences in of on-line clothing store importance depending on age, in the case of on-line general merchandise store, it showed that people in their thirties regarded buying process service factor more important than twenties, and when it came to the product and searching system, it was vice versa. Twenties had a tendency to consider the aspect of product important and, relatively, thirties regarded searching and approaching system factor important. in the case of specialty store. It was found that women in their twenties had a tendency to consider product factor more important.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2538-2541
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• 2005

This paper deals one of the methods of system identification, especially on-line system identification in time-domain. The algorithm in this study needs all states of the system as well input to it for system identification. In this reason, Kalman filter is used for state estimation. But in order to implement a state estimator, the fact that a system model must be known is logical contradiction. To overcome this, state estimation and system parameter estimation are performed simultaneously in one sample. And the result of the system parameter estimation is used as basis to state estimation in next sample. On-line system identification comes, in every sample by performing both processes of state estimation and parameter estimation that are related mutually and recursively. This paper demonstrates the validity of proposed algorithm through an example of an unstable inverted pendulum system. This algorithm can be useful for on-line system identification of a system that has fewer number of measurable output than system order or number of states.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.103-106
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• 2002

This paper has studied a remote AMR(Automatic Meter Reading) system using the power line and the telephone line as a communication media and the digital power meter. In the developed system, because we have used the power line and telephone, the facility is very easy and then its cost is not expensive. The system includes following elements: a digital power meter, an indoor communication system using a power line modem and a telephone line interface system for sending data to the utility company.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.281-288
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• 2008

Cake resistance is influenced by floc size deposited on membrane surface. Enlarging floc size can reduce cake resistance. The small particles are enlarged by coagulation and flocculation process in conventional mixing tank at membrane filtration system. Fully-grown flocs for reducing the cake resistance, however, are ruptured while passing through a pump. In light of this fact, this study aims to experimentally look at the reaggregation phenomenon of mixing system. In addition, reaggregation phenomenon of mixing system is compared with first-aggregation of in-line injection system in which coagulant is injected just before a pump. These results suggest that first-aggregation of in-line injection system is better than reaggregation of mixing system for G-value above $3100sec^{-1}$. Since G-value in pipe of actual membrane filtration system are usually larger than $3100sec^{-1}$. The performance of in-line injection system is expected to be better than the conventional mixing tank system.