• The Journal of Engineering Geology
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• v.20 no.2
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• pp.121-126
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• 2010

Current technology for radioactive waste disposal facility is operated as part of KURT site characterization in terms of reliability assessment is conducted to expand. In this study, a geological model of KURT surrounding area on the basis of flow characteristics of the site-scale hydrogeological study was about. Distributed in the study area into four boreholes were plotted using the stereo net NS, NW, EW, Low-angle fracture group was able to identify the components of geological models and include top soil layer, belt of weathering, Low-angle fracture zone, fracture zone was divided into. Separated by fracture of the hydraulic test of through the groundwater aquifer that provides the flow hydraulic conductivity and insulation hydraulic affecting the slope of the normal distribution for the size and direction by performing statistical analysis of fracture in the direction of local ns The advantage was confirmed. In addition, Low-angle fracture hydraulic conductivity of the value of 3.61e-07 m/s has a value greater than the major fracture, the fracture zones exist in the base rock and base rock and the hydraulic characteristics of the different methods applied and had to have a different interpretation judged by was.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.114-123
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• 2018

This paper concerns a design and learning method of softmax function neural networks based on K-means clustering. The partial discharge data Information is preliminarily processed through simulation using an Epoxy Mica Coupling sensor and an internal Phase Resolved Partial Discharge Analysis algorithm. The obtained information is processed according to the characteristics of the pattern using a Motor Insulation Monitoring System program. At this time, the processed data are total 4 types that void discharge, corona discharge, surface discharge and slot discharge. The partial discharge data with high dimensional input variables are secondarily processed by principal component analysis method and reduced with keeping the characteristics of pattern as low dimensional input variables. And therefore, the pattern classifier processing speed exhibits improved effects. In addition, in the process of extracting the partial discharge data through the MIMS program, the magnitude of amplitude is divided into the maximum value and the average value, and two pattern characteristics are set and compared and analyzed. In the first half of the proposed partial discharge pattern classifier, the input and hidden layers are classified by using the K-means clustering method and the output of the hidden layer is obtained. In the latter part, the cross entropy error function is used for parameter learning between the hidden layer and the output layer. The final output layer is output as a normalized probability value between 0 and 1 using the softmax function. The advantage of using the softmax function is that it allows access and application of multiple class problems and stochastic interpretation. First of all, there is an advantage that one output value affects the remaining output value and its accompanying learning is accelerated. Also, to solve the overfitting problem, L2-normalization is applied. To prove the superiority of the proposed pattern classifier, we compare and analyze the classification rate with conventional radial basis function neural networks.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.475-482
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• 2002

The experiment was conducted to evaluate a ventilation system, which was devised to encourage farmers to use the enclosed poultry housing system. The study was observed in the National Livestock Research Institute from May 9 to May 30 in 2002. The main results of the experiment are as follows: 1. Although the outside temperature of the enclosed poultry house was 9.6 ${\sim}$ 21.2$^{\circ}C$ with 11.6$^{\circ}C$ variation, the house with an excellent heat insulation was maintained at 32${\sim}$33$^{\circ}C$ in a variation of 2$^{\circ}C$ which is within the range of the optimal temperature for broiler, being aided with two small electric heaters. 2. The average of air flow rates of the upper, middle and low parts of the room in the broiler house were detected at 0.57, 0.22 and 0.04 m/sec, respectively. The air flow in the whole room was distibuted uniformly by a perforated duct. In conclusion, heat and humidity could be controlled without any problem in this enclosed housing system. Especially, air flow in all parts of the room was detected in uniform rates, resulting in the better ventilation performance with air inhalation through the duct and air exhaust through the side walls of the house.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.27.1-27.1
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• 2008

KASI (Korea Astronomy and Space Science Institute) is developing a compact wide-field survey space telescope system, MIRIS (The Multi-purpose IR Imaging System) to be launched in 2010 as the main payload of the Korea Science and Technology Satellite 3. Through recent System Design Review (SDR) and Preliminary Design Review (PDR), most of the system design concept was reviewed and confirmed. The near IR imaging system adopted short F/2 optics for wide field low resolution observation at wavelength band 0.9~2.0 um minimizing the effect of attitude control system. The mechanical system is composed of a cover, baffle, optics, and detector system using a $256\times256$ Teledyne PICNIC FPA providing a $3.67\times3.67$ degree field of view with a pixel scale of 51.6 arcsec. We designed a support system to minimize heat transfer with Muti-Layer Insulation. The electronics of the MIRIS system is composed of 7 boards including DSP, control, SCIF. Particular attention is being paid to develop mission operation scenario for space observation to minimize IR background radiation from the Earth and Sun. The scientific purpose of MIRIS is to survey the Galactic plane in the emission line of Pa$\alpha$ ($1.88{\mu}m$) and to detect the cosmic infrared background (CIB) radiation. The CIB is being suspected to be originated from the first generation stars of the Universe and we will test this hypothesis by comparing the fluctuations in I (0.9~1.2 um) and H (1.2~2.0 um) bands to search the red shifted Lyman cutoff signature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.689-696
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• 2018

System grounding is applied to the neutral point of a power source to secure the from any abnormal voltage and/or grounding fault. System grounding, which is applied mainly in ships is an ungrounded and resistance grounded system. Vessels using the MV power system with 3.3kV, 6.6kV, and 11kV mainly adopt a high resistance grounding system among the resistance grounding systems. The ground fault accounts for 95% of all faults occurring in the electrical system and when a fault occurs, the line-to-ground voltage of the power system is increased excessively, which adversely affects the onboard insulation system. This study analyzed the variation characteristics of the line-to-ground voltage neutral point according to the degree of ground fault in a resistance ground system applied in vessels. For this purpose, the characteristics of the grounding system were first explained, and the modeling of the neutral point potential of the line-to-ground voltage of the resistance grounding system in the vessels was derived. Finally, this study examined how the line-to-ground voltage, line voltage, and neutral point change according to various variable environments through MATLAB simulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.683-688
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• 2018

In this study, we analyzed the heat generation state of a flat heating element by using image processing technology in conjunction with carbon fiber. The flat heating element is manufactured by chopping the carbon fiber to a small size and bonding it again using a dispersing agent. The solution of carbon fiber, bound together using the dispersant, is then filtered onto the nonwoven fabric. The last step is to obtain flat carbon fibers in the form of nonwoven fabrics for the purpose of drying the filtered carbon fibers. In the flat heating element, electricity may be applied to the carbon fiber on the surface produced in this manner. In this study, the flat heating element was analyzed by four methods. The analysis of the heat generation characteristics and heating rate of the flat heating element confirmed that the fabricated sheet heating element corresponds to a normal army. The analysis of the insulation coating and flat heating element module, which can be used for actual product manufacturing, involves two dimensional image analysis using image processing technology. The thermal image analysis of the flat heating element is a programming technique that not only analyzes the heat generation state in both two and three dimensions, but also displays the upper and lower 15 to 20% ranges of temperature corresponding to the heat generation in the image. In the final analysis, it is possible to easily find the erroneous part in the manufacturing process by directly showing the state of the fabricated flat heating element on the screen. By combining this image analysis method of the flat heating element with the existing method, we were able to more accurately analyze the heat generation state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.105-112
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• 2018

This paper proposes a method for fabricating heatable glass using the conduction characteristics of metal thin films deposited on the surface of Low-e(Low emissivity) glass. The heating value of Low-e glass depends on the Joule heat caused by Low-e glass sheet resistance. Hence, its prediction and design are possible by measuring the sheet resistance of the material. In this study, silver electrodes were placed at 50 mm intervals on a soft Low-e glass sample with a low emissivity layer of 11 nm. This study measured the sheet resistance using a 4-point probe, predicted the power consumption and heating value of the Low-e glass, and confirmed the heating performance through fabrication and experience. There are two conventional methods for manufacturing heatable glass. One is a method of inserting nichrome heating wire into normal glass, and the other is a method of depositing a conductive transparent thin film on normal glass. The method of inserting nichrome heating wire is excellent in terms of the heating performance, but it damages the transparency of the glass. The method for depositing a conductive transparent thin film is good in terms of transparency, but its practicality is low because of its complicated process. This paper proposes a method for manufacturing heatable glass with the desired heating performance using Low-e glass, which is used mainly to improve the insulation performance of a building. That is by emitting a laser beam to the conductive metal film coated on the entire surface of the Low-e glass. The proposed method is superior in terms of transparency to the conventional method of inserting nichrome heating wire, and the manufacturing process is simpler than the method of depositing a conductive transparent thin film. In addition, the heat characteristics were compared according to the patterning of the surface thin film of the Low-e glass by an emitting laser and the laser output conditions suitable for Low-e glass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.666-671
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• 2018

A honeycomb panel is a plate made by attaching two surface plateson eitherside of a honeycomb core. The honeycomb plate hasexcellent specific strength and energy absorption and is suitable for use in regions where good impact resistance is required. Recently, with the increasing the need for a lightweight design to facilitate transportation, numerous studies have been conducted using aluminum honeycomb plates as body materials for vehicles such as automobiles and high-speed trains. In addition, honeycomb plates have excellent sound deadening properties, as well as excellent heat insulation and durability. Savings in weight using lightweight materials such as aluminum alloy for honeycomb panel's skin can lead to increase fuel economy and reduction in air pollution. In this study, in order to improve the design technology of the honeycomb plate material, the manufacturing technology of the aluminum honeycomb core and honeycomb plate material and various mechanical properties of the honeycomb plate were evaluated. From the results, it was found that the design of the manufacturing process of the aluminum honeycomb plate, as well as itsproduction and characteristics, were improved. The resulting excellent energy absorption capability of the honeycomb plate was due to the repetitive core buckling, indicating that the higher the compressive strength, the higher the strength per bonded area.

• Asian Journal of Turfgrass Science
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• v.17 no.2_3
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• pp.67-73
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• 2003

A series of studies was conducted during 2 years to investigate the effect of transplanting time and turfgrass species on turf establishment rate of sod for 2002 World Cup Soccer ground construction. The required period of rooting and turf growth for acceptable soccer playing quality on transplanted sod from nursery was tested to collect data for the project authorities of hosting cities and construction companies who were involved in World Cup stadium project. Transplanting time significantly affects on rooting-potential of sod on cool season grass and zoysiagrass, but those effects differently showed by turfgrass species. The enough nursing period for the ground established by Zousiagrass should be secured with proper transplanting time. And the thermal insulation on the turf canopy with other maintenance during Winter should improve the early rooting on zoysiagrass. The sod contained Kentucky bluegrass (85％＋15％ perennial ryegrass, seed wt. basis) showed relatively slow at the early growth and rooting-potential of root, but the potential resulted higher than that of perennial ryegrass turf (85％＋15％ Kentucky) under longer nursing period. Kentucky bluegrass has one of the most strong resistance against environmental stresses, but intensive maintenance practise should be required when the turf transplanted during summer season. Higher mixture rate of perennial ryegrass sod has a rapid root growth compare with other turfgrass species. The rate provided a benefit to an early establishment of turf ground followed by a proper maintenance practise. For the completion of World Cup soccer ground construction for 2002, the most suitable time for sod transplanting in 2001 was March to May or mid Sept. to early Oct. by delayed architect construction schedule.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1585-1593
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• 2015

3D-structured (embossed) aluminum sheets have been used in the heat insulation purpose for automative exhaust parts because of increasing their surface areas and stiffness reinforcement imposed in making the embossing pattern. However, there are many restrictions in press forming of the embossed sheet compared with the flat sheet (non-embossed one) because of its difference in the mechanical properties and the geometrical 3-dimensional shape. In this paper we investigated the deformation characteristic of embossed aluminum sheet in the incremental sheet forming process which has frequently used in the design verification and the trial manufacturing of sheet products. The single point incremental forming (SPIF) experiments for the rectangular cone forming using the CNC machine with a chemical wood-machined die and a circular tool shape showed that the formability of the embossed sheet are better than that of the flat sheet in view of the maximum angle of cone forming. This comes from the fact that the embossed sheet between the tool and the elastic die wall is plastically compressed and the flatted area contributes to increase the plastic deformation. Also the tool path along the outward movement from the center showed a better formability than that of the inward movement from the edge. However the surface quality for the tool path along the outward movement evaluated from the surface deflection is inferior than that of the tool path along the inward movement.