• Journal of the Korean Society for Precision Engineering
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• v.1 no.2
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• pp.47-57
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• 1984

The porous matterials are used both to control the flow of the compressed gas and to serve as the bearing surface. This porous design offers several advantages over the conventional externally pressurized gas bearings. It can simplify the construction, lower the gas consumption, and make the cleaning of the gas supply less critical. Test apparatus was cinstructed to experi- mentally investigate maximum load capacity of thrust bearing was measured 200 Kg (15Kg/$\mu$m), and radial bearing was 36 Kg/$\mu$m. And a rotation accuracy of face waving was 0.0127$\mu$m, and center waving was measured 0.5 $\mu$m. Finally, the use of this method of design and manufacturing will contribute to many practical application in the field required for precision and high stability.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.786-789
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• 2004

Corrosion of reinforced concrete structures in marine environment is one of the most important mechanism of deterioration. However, conventional rehabilitation techniques in tidal zone, which consist of removing delaminated areas of concrete, cleaning affected steel and patching with portland cements mortar, have proven to be ineffective for marine structures. Also, repairs are often repeated every several years. The purpose of this report is to announce appropriate repair method of highway bridge damaged by chloride attack in marine environment (application of cathodic protection) using FRP and antiwashout underwater mortar.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.142-148
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• 2013

High-power ultrasonic promotes a chemical reaction by its own energy, thus it has been used for sonochemistry applications. For example, it has been mostly used for mixing, reaction catalyst, dispersion and disintegration. High-power ultrasonic transducer is made with structure based on a Bolt-clamped Langevin type Transducer (BLT), But it has difficulty in the development because degradation of piezoelectric ceramic by the heat generation of BLT. In this study, for a development of the transducer of 25 kHz and 1000 W used in sonochemistry and industrial cleaning, BLT with a hole in its center and tubular type waveguide of the transducer were designed based on finite element method (FEM). The transducer was fabricated based on the design parameter, and the impedance characteristics are measured experimentally and compared with the numerical results.

• Journal of computational fluids engineering
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• v.17 no.2
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• pp.58-64
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• 2012

Turbulent flows in a intake part of vacuum cleaner are studied by RANS simulations. The governing equations are solved by the SIMPLE algorithm based on the finite volume method of the unstructured grid system. The predicted results show that the suction performance is closely related to the variation of flow structure in the intake part. In order to investigate for the cleaning of bedclothes and carpet without sticking, several design changes are applied. The introduction of a solid cylinder in the intake part changes vortical structures significantly. Based on this result, a new design with spiral brushes is proposed. The design shows a good behavior for the suction performance and the flow control.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.36-41
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• 2016

A method is proposed for the improvement of deposition reproducibility in the selective electrodeposition process using laser masking and DC voltage. Selective electrodeposition using laser masking and DC voltage can achieve a deposited layer with micro patterns. However, selective electrodeposition using laser masking and DC voltage have a critical problem: the lack of reproducibility in selective deposition. The reproducibility of selective electrodeposition can be improved by a new process that consists of laser masking, two-step electro-deposition, laser scribing, and ultrasonic cleaning. The experiments in this study show that the reproducibility of selective deposition can be successfully improved by the combination of two-step electrodeposition and laser scribing.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.309-318
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• 2010

We introduce a technical approach for reducing three-dimensional infrared (IR) spectroscopic data generated by integral field spectroscopy or slit-scanning observations. The first part of data reduction using IRAF presents a guideline for processing spectral images from long-slit IR spectroscopy. Multichannel image reconstruction, Image Analysis and Display (MIRIAD) is used in the later part to construct and analyze the data cubes which contain spatial and kinematic information of the objects. This technic has been applied to a sample data set of diffuse 2.1218 ${\mu}m$ $H_2$ 1-0 S(1) emission features observed by slit-scanning around Sgr A East in the Galactic center. Details of image processing for the high-dispersion infrared data are described to suggest a sequence of contamination cleaning and distortion correction. Practical solutions for handling data cubes are presented for survey observations with various configurations of slit positioning.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.77-83
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• 2013

In this study, we aimed to determine the optical properties of the plasma used for the dry cleaning method. The optical properties of the atmospheric pressure plasma device were measured through the degree of ionization of hydrogen or nitrogen gas by ionized atmospheric gas. The degree of ionization of hydrogen or nitrogen is closely associated with surface modification. We observed through our experiments that argon gas, an atmospheric gas, caused an increase in the ionization of nitrogen gas, which has similar ionization energy. This type of increase in nitrogen gas ions is believed to affect surface modification. The results of our study show that the pressure of argon gas and the partial pressure of argon and nitrogen gases lead to different results. This important result shows that argon ions can affect the ionization of nitrogen gas.

• Korean Journal of Human Ecology
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• v.9 no.2
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• pp.5-20
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• 2006

This study was a preliminary investigation into improving the environmental and healthy quality of childcare centers. The purpose of this study was to determine the management condition on indoor environment and hygiene of childcare centers in Cheongju. Questionnaire survey was carried out from 11st to 26th of August 2004 by mail. Respondents were consisting of 55 teachers, an executive of each childcare center in Cheongju. From the survey results, there were some problems in 'empty period after remodeling work for preventing sick house syndrome', 'humidity controling', 'glare controling', 'indoor or outdoor noise controling', 'cleaning frequency of each room', 'washing method of toys', 'laundry frequency of rag doll and bedclothes'. So, we need to establish the regulations or give some educations and informations about indoor environment and hygiene to administrators of childcare centers.

• KIEAE Journal
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• v.4 no.3
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• pp.187-194
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• 2004

In many other buildings, hospital is very important because of its function and purpose. A proper building service systems including heating, cooling, ventilation and plumbing systems is required in hospial. Besides, a special systems like medical gas, vacuum cleaning systems are required to prevent contamination as well as cure a patient in hospital. Ventilation is very important method to keep the indoor pressure and clean class. There are some specific rooms to consider clean class and indoor pressure in the general hospital. In this article, specific rooms were set to operating room, laboratory, ICU, isolation unit, and sterilizer room. In this case study, design factors of ventilation system, including air changes of OA and TA, indoor pressure, clean class, filter, and material of system, of specific rooms in hospital were proposed through a literature research and a design examples review.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2465-2467
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• 2004

In this paper we present the guideline to evaluate the easiness of using personal robots and their learning abilities based on the analysis of their built-in commands, user interfaces, and intelligences. Recently, we are breathing with robots that can be able to do lots of roles. cleaning, security, pets and education in real life. They can be classified as home robots, guide robots, service robots, robot pets, and so on. There are, however, no standards to evaluate their ability, so it is not easy to select an appropriate robot when a user wants to buy it. Thus, we present, as a guideline that can be a standard for the evaluation of the personal robots, the standards by means of analyzing existing personal robots and results of the recent research works. We will, also, describe how to apply the evaluation method th the personal robot.