• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.78-86
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• 2014

Modular system is a construction method which installs factory-manufactured units on site. It enables to reduce the duration and improve the quality of the construction. Nevertheless, the unit modular system is restrictively applied to domestic market such as barracks, education facilities, low-rise housing. To motivate the application of unit modular system, this study figures out important attributes of the unit modular system in a domestic construction market. Finally this study suggest marketing strategies and influential factors by Importance-Performance Analysis(IPA) based on those attributes focusing on the apartment housing. As a result, Unit modular System in the domestic market has strength on constructability, but it show weakness on usability and economic aspects which are more important in apartment housing market. Thus an improved technology in usability and economic aspects are required to activate the market.

• Nuclear Engineering and Technology
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• v.31 no.5
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• pp.506-511
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• 1999

The pilot system for radioactive liquid laundry waste was developed with treatment capacity, 1ton/hr and set up in the Yong Kwang unit #4. The system is composed of tank module, RO systems and a UV/$H_2O$$_2$photo-oxidation unit. The RO system consists of the BW unit (low-pressure RO for brackish water desalination) and the SW unit (high-pressure RO for seawater desalination). The BW unit possesses 4 RO membranes and it can reduce the feed water volume down to 1/10. This concentrated feed water can be reduced again up to 1/10 in its volume in the SW unit composed of 4 RO membranes. The UV/$H_2O$$_2$ photo-oxidation process unit was used for the detergent degradation. The operation of the pilot system was carried out and verified in its capability through the continuous operation and concentration operation using the actual liquid waste from the power plant. The design criteria and data for industrialization were yielded. The efficiency of the UV/$H_2O$$_2$ photo-oxidation process and the optimum operational procedure were evaluated. The decontamination factors for radioactive cobalt and cesium were measured. This on-site test showed the experimental result in the DF$\geq$300 and volume reduction factor$\geq$100.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1113-1120
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• 2022

In this paper, a communication methodology for the digital FRTU(: Feeder Remote Terminal Unit) required by the smart grid distribution system was studied. The digital FRTU consists of a fault handling unit and a communication unit. The fault handling unit transmits fault information to the communication unit in case of a failure, and the communication unit is designed to autonomously determine the fault section through two-way communication between surrounding digital FRTUs. For performance verification, a performance verification system consisting of 3 line sections based on 3 digital FRTUs was constructed to enable fault simulation for various failure scenarios. Various fault cases including one phase ground fault, line-to-line short-circuit fault, and three-phase short-circuit fault were experimentally simulated on the established performance verification system, and the validity of the developed methodology was confirmed by proving the accurate fault section inference results for each fault simulation case.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.34-37
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• 2001

In this paper, we designed and implemented the 60W DC characteristic measurement system for semiconductor devices. The proposed system is composed of 2 SMU(Source and Measure Unit)s, 2 HPU(High power Unit)s, 2VSU(Voltage Source Unit)s, and 2 VMU(Voltage Measurement Unit)s. HPU can source/measure voltage from -200V to 200V and source/measure current from -3A to 3A within 60W. Experimental results show that the implemented system can measure the power devices such as power BJT, regulator IC, and voltage detector.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1046-1050
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• 2003

In this paper, we describe study on the development or multi-path ultrasonic gas flowmeter using a transit time method. This system includes 5 pairs of ultrasonic transducers. ultrasonic signal processing unit using switch matrix method, computation algorithm of gas flow rate, spool piece type multi-path pipe unit. We have developed enhanced type of main ultrasonic signal processing unit using switch matrix method fer multi-path ultrasonic gas flowmeter. Also, we have developed the new transmitting ＆ receiving method of ultrasonic waves and the new signal processing algorithm for the computation of ultrasonic transit time from received ultrasonic waves. In this study, we have designed more compact signal processing unit compared with the conventional hardware system of multi-path ultrasonic gas flowmeter. We have confirmed its reliability for multi-path ultrasonic gas flowmeter through the laboratory test using calibration system. In the future. we will perform the field test for the developed system in the POSCO gas line.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.559-561
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• 2004

In this paper, we design two types of Main Control Unit for Control Rod Control System and Control Element Drive Mechanism Control System, respectively, using a domestic Distributed Control System(DCS) developed to localize the instrumentation and control(I&C) system for nuclear power plant(NPP). There are many parts developed by domestic skills and being operated successfully in NPP, but the development of I&C system as an essential part has been slow in progress. We will show the great possibility of developing peculiar Korean I&C system by applying this domestic DCS to nuclear I&C system and confirming its successful operation.

• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.4
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• pp.18-27
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• 2010

We had designed and constructed floating type photovoltaic energy generation system. In this paper, we present the result of investigations pertaining to the development of links between unit modules of the floating type photovoltaic energy generation system. The link system installed between the unit modules is made of pultruded FRP, tire, and polyethilene synthetic fiber rope. The link system is analized by the finite element method. The floating type photovoltaic energy generation system consisted of unit modules connected by link system is installed successfully at sea site. In addition, we present the modified design of the floating type photovoltaic energy generation system based on the proto type system.

• Journal of the Korean housing association
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• v.13 no.3
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• pp.45-53
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• 2002

The purpose of this study is to examine the characteristics of unit plans in the high-rise mixed-use condominium and to provide the data fur architectural planning and design. The tools of statistical analysis are frequency, percentage, mean, cross-tab, and correlation. The results of this study are as fellows; The most frequently found shape of unit is a deformed polygon. The common rooms in housing units are dressing room, powder room, offset-kitchen, family room, passage, hallway, and foyer. The specially prepared spaces are wash room, home bar, independent porch, and garden. As to room size and area ratio in a dwelling unit, those of living room are biggest and highest irrespective of unit size. As the floor area of unit increases, does the size of each room and space but the area ratio of each room decreases. This research is made to develop an Apartment Information System. This integrated information system is to be designed to provide residents of high-rise mixed-use condominiums with convenient, economical, and safe life.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.34
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• pp.139-146
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• 1995

This study is concerned with cost analysis in periodic maintenance policy. Generally periodic maintenance policy in which item is repaired periodic interval times. And in the article minimal repair is considered. Minimal repair means that if a unit fails, unit is instantaneously restored to same hazard rate curve as before failure. In the paper periodic maintenance policy with minimal repair is as follows; Operating unit is periodically replaced in periodic maintenance time, if a failure occurs between minimal repair and periodic maintenance time, unit is replaced by a spate until the periodic time comes. Also unit undergoes minimal repair at failures in minimal-repair-for-failure interval. Then total expected cost per unit time is calculated according to maintenance period and scale parameter of failure distribution. Total cost factors ate included operating, fixed, minimal repair, periodic maintenance and replacement cost Numerical example is shown in which failure time of system has erlang distribution.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.152-159
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• 1997

This unit - structure of truss stabilized by cable tension is composed of four truss member adding to a central post and eight cables, and is connected by hinge joints and is stabilized by cable tension. As this unit - structures itself is a statically closed and stabilize system individually, it can be employed to assemble a structure with a variety of configuration. In this paper, for determination the shape of the unit - structure of truss stabilized by the cable, characteristics such as the stabilized range of the various geometrical parameter about unit system and the relation of the best governing paramter is demonstrated, and the relation of the results is compared in the range for the stabilization of unit-structure.