• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.140-144
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• 2007

As an electron scanning microscopes has traditionally required a considerably large room equipped with several service and pipe lines due to its inherent size. As an alternative, a small sized SEM, simply called a mini-SEM, is introduced even if the performance in terms of magnification and resolution is a little inferior to a classical thermal SEM. However, the size and fabrication cost is dramatically reduced, dedicating to opening a new market. The optical system in the mini-SEM is redesigned and specimen stage is quitely reduced and vertical axis is excluded. The design tools and calibration techniques to develope the mini-SEM are introduced and its performance is verified through numerical analysis experiments.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.237-246
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• 2009

Digitalization of not only non-safety but also safety-grade I &C systems with full computerized Main Control Room (MCR) is the recent trend of I&C systems of nuclear power plants (NPP) around the world, while plant maintenance has been shifting from traditional time based maintenance to condition based maintenance. In order to cope with the new trend of operation and maintenance in NPP, a concept of online distributed diagnostic system for both plant operation and maintenance has been proposed in order to further improve both the plant efficiency and the work environment of plant operation staff members by organizational learning. In this respect, the research subjects of human machine interface (HMI) for the online distributed diagnostic system are also discussed for supporting the plant personnel at both MCR and local working places in the plant by the application of advanced ICT (Information and Communication Technologies).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1444-1449
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• 2000

This environmental influence of the noise produced by a number of air-conditioner out-door units in a multi-unit housing is predicted and evaluated. The method based on Ray tracing theory and mirror image source theory is utilized. Each ventilation window in a machine room is considered as a sound source which contributes to the overall noise level of the surrounding environment. The adopted method has been found a very efficient tool to assess the environmental noise impact.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.173-176
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• 2002

DAS(Data Acquisition System) as a ground support equipment has played a critical role in proving the status of ready-to-fire of a rocket system before launch. But it is hard to implement and place a real-time measuring system in a control room at a long distance from the vehicle. In this paper DAS is introduced by being located at the LEC(Launch Equipment Container)[1], 50 meters away from the rocket and connected to remote monitoring system via fiber optics with TCP/IP protocol by means of client/server algorithm. Therefore real-time data acquisition and storage are guaranteed and a convenient and useful MMI (Man-Machine Interface) can be developed.

• Journal of the Korean housing association
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• v.9 no.3
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• pp.119-131
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• 1998

This paper is a part of "The Study of the Traditional Korean Ethnic Farmhousing in Yanbian, China". The purpose of this study focuses on Korean farm house and is twofold: 1) to survey the working space and storage space for tools: 2) to investigate the daily use of space according to the different work activities. It is based on a survey of 124 households in the farm villages of Lunching, China. Survey research methods included a field study in Dallajae. A questionnaire was used to conduct this study. the study found that the working space for the koran farm family is divided into an indoor area and outdoor area. The indoor space includes working areas where the families live their daily life, cook, launder, clean, mange the house keeping, usually stare the grain. The outdoor space includes areas to store the grain, farm tools, rice box, shelves and other things such as sewing machine, iron, and tools used for cleaning the house and for farming. The center of life and work for the farm family was the chung-ji-kan (the combined kitchen and major ondol living room) located in the indoor space.oor space.

• Progress in Superconductivity and Cryogenics
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• v.2 no.2
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• pp.37-43
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• 2000

This paper describes the construction and test results of a 10kVA single phase HTS transformer. Double pancake windings with BSCCO-2223 HTS tape and G10-FRP cryostat with room temperature bore are used in the transformer. Two double pancake windings are connected in series to provide 188 turns and other two double pancake windings are connected in parallel to conduct the secondary current of 45.4[A]. Coefficients of the constructed transformer are obtained using the fundamental teats of the transformer. According to the test results, larger leakage reactance than expected is observed due to the bulky core which surrounds the sryostat.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.8-13
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• 2002

In order to obtain the basic informations for the development of high strength and high weldability aluminum alloy sheets, the experimental study was carried out to evaluate resistance spot welding characteristics and welding parameters (welding current, welding time, electrode force) far the aluminum alloy sheets. The mechanical properties of spot weld of aluminum alloy were evaluated by tensile shear test and by peel test at room temperature and also the welding possible zone was established through variation of current electrode force and welding time.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.131-132
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• 2017

As the building is becomes bigger and larger, it can lead to big damage in case of fire. Also, tunnel, machine room and underground joint are spaces that can cause high temperature fire above 1,350℃ in case of fire. Therefore, a refractory material is need that can be withstand in high temperatures for long time. One side, the composition of oyster shell is CaCO₃ of 90% or more. It is expected that it will be possible to use it as a high calcium natural material which is the material of the refractory board. According to, Study on bending, compressive strength of mortar according to temperature and heating time change using oyster shell as aggregate the most commonly occurring particle sizes form 2.5mm to 5mm.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.219-219
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• 2000

A Plate type pipe is used for heat exchange in radiator of a vehicle. The pipe has several rooms through which water flows and heat is dissipated into outside . In the case that there are small holes, cracks or some scratches on the plate, the radiators lost their functions due to Leakage. This may result in overheating of engine in a car. Thus, we need to perform the entire inspection of the plate type pipe in advance before assembling the radiator. In manufacturing process of the plate type pipe, the productive speed is very high and that may be performed continuously. So, there is no room to perform the outlook inspection by typical image processing techniques. This paper proposes a new method to inspect the outlook surface of the plate type pipe automatically with high speed. Especially, the sequential processing technique of an algorithm which detects defects on the surfaces of the plate type pipe is proposed for line scan camera which captures line image. To evaluate the inspection performance, a series of experiments is performed.

• Tribology and Lubricants
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• v.11 no.5
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• pp.144-149
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• 1995

Use of high-quality basestocks is increasing to produce high-performance lubricants. However, their tribological characteristics have not been understood clearly yet. In this study, a newly developed basestock from a fuel hydrocracker and a poly-alpha-olefin are selected and investigated on the properties of lubricants formulated with them. The Lubricants are prepared by blending the basestocks with typical additives such as a zinc dialkyldithiophosphate, a dispersant, a detergent and a dispersant-inhibitor package. Frictional and wear-preventing properties are investigated using an oscillating-type wear-testing machine. The contact is a ball-on-disk mode and the testing temperature is varied from room temperature to 200$^{\circ}$C. The results show that their frictional property is varied significantly and that the non-conventional oils result in lower friction and lower wear compared with conventional lubricants, especially at the higher temperatures.