• Fire Science and Engineering
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• v.26 no.6
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• pp.15-23
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• 2012

Indirect Test Method is often used instead of direct test method in test method for extinguishing performance of $CO_2$ extinguishing facility because of high cost, environment problems and difficulties of procedure. But in the danger facilities for a unit of nation, such as a petrochemical plant, a nuclear power plant, or etc. is better to verify the performance of the extinguishment through direct discharge test. In $CO_2$ extinguishing system for total flooding system installed in dangerous facilities in Korea, each protected area in surface fire and deep-seated fire had selected and verified of extinguishing performance of $CO_2$ extinguishing facilities. To get recognized as extinguishing performance, discharged $CO_2$ concentration to protected area should be equivalence with design concentration standards (NFSC and NFPA). The Design Concentration means that $CO_2$ extinguishing agent is considerate of concentration for percentage of allowance (20 %) from extinguishing concentration which available to control of flame. As test result, surface fire and deep seated fire in protected area is obtained $CO_2$ design concentration and maintained design concentration more than 20 minutes as deep-seated fire. Through this study, we introduced direct discharging test method and decision method. And furthermore, especially in the dangerous facilities as a unit of Nation, we suggested necessity about reliability of extinguishing facilities to use direct test method.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.682-691
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• 2020

Careful cleaning and disinfection of pigpens is essential to prevent disease spread and avoid the resultant economic losses. Hygiene in pigpens is generally evaluated by visual monitoring supplemented with bacteriological monitoring, which includes counting the total aerobic bacteria (TAB) and/or fecal indicator bacteria (FIB). However, these methods present drawbacks such as time and labor requirements. As adenosine triphosphate (ATP) is ubiquitous in all living organisms including microorganisms, this study aimed to directly compare the results of microbial assessment and ATP quantification, and to suggest possible detailed application methods of the ATP test for hygiene evaluation in pigpens of a farrowing unit. Before and after standard cleaning procedures, samples were collected from the floor corner, floor center, and feeding trough of four pigpens at different time points. No FIB were detected and both the TAB and ATP levels were significantly decreased in the floor center area after cleaning. FIB were continuously detected after cleaning and disinfection of the floor corners, and there was no significant ATP level reduction. The feeding trough did not show any significant difference in these values before and after cleaning, indicating insufficient cleaning of this area. The levels of TAB and ATP after cleaning were significantly correlated and the average ATP value was significantly lower in the absence of FIB than in their presence. In the absence of standard references, a more thorough hygiene management could be achieved evenly by supplementing cleaning or disinfection based on the lowest ATP results obtained at the cleanest test site, which in the present study was the floor center. Overall, these results indicate that the on-farm ATP test can be used to determine the cleanliness status, in addition to visual inspection, as an alternative to laboratory culture-based testing for the presence of microorganisms.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.193-200
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• 1999

An experimental study is described in which a 305-mm-diameter instrumented drilled shaft was installed in a moderately expansive clay soil during the dry season and monitored over a period of about 18 months. The purpose of the study was In investigate the effects of seasonal moisture changes in the soil on the shear stresses imposed on the sides of the drilled shaft and movements of the shaft head. The soil in the vicinity of the test shaft was instrumented to measure suction and ground surface movement and the relation between suction, total stress and shear strength of the soil at the test site was determined through laboratory triaxial compression testing. Daily rainfall and temperatures were also monitored at the test site, the National Geotechnical Experimentation Site at the University of Houston, where control on surface grading and vegetation existed. Over the course of the study induced unit side shear values of up to 54 kPa were measured in the test shaft. A simple computational model was developed that related observed suction changes to unit side shear induced by the expansion of the soil through the use of the laboratory suction-total stress-shear strength relation.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.761-767
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• 2011

Since the "Low Carbon, Green Growth" as a social requirements is attracted public attention, the policies and investments of the railway which have been less estimated than road is re-considered. Since the starting the commercial service (2004. April), the KTX have been operated successfully while transport passengers over 100million for years. And also the project for development of KHST (Korea High Speed Train ; G7) had been accomplished with a good result, the first trainset of KTX-II which base on G7 project was manufactured and testing now. On the other hand, the world's technology of the high speed train is more faster, and changing to a distributed traction system. To catch up the world's leading technology, the HEMU(High-speed Electric Multiple Unit) project will secure new technology and aims to promote the technology of domestic high-speed train. The authors indicates the result of detail review such as a curve, slope of the track and electrical dead section of the catenary to test at 400kph and also the performance simulation of the developed rolling stock in this paper. As the result, the authors devise the test scenario to perform a maximum speed test (stability at max. speed, acceleration & deceleration etc) with the restricted conditions such as track length, track available time etc by considering above result.

• ETRI Journal
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• v.20 no.1
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• pp.55-73
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• 1998

In this paper we analyze the technological accumulation processes in the Korean semiconductor industry from the institutional approach. Institutional approach, which is closely connected with Neo-Schumpeterian tradition, has emerged as an alternative theoretical framework to neoclassical approach to understand the process of producing technological knowledge. Traditional wisdom of neoclassical approach revealed the limitation to explain the complex nature of knowledge creation and diffusion. US patent data are analyzed in terms of the increasing trend of numbers and its content to measure the rate and direction of technological capability accumulation. This analysis shows that semiconductor technologies are one of the fastest growing fields among Korean technological activities. Moreover, the analysis of patent content suggests that fabrication technologies are the most important area within the technological development of semiconductors, whilst circuit design and testing technologies are beginning to increase in significance. In addition, it is examined how private sectors and public institutions have contributed to generate technological capabilities, and the relationship between them has been changed during the development processes. It is found that Korean firms enhanced their technological capabilities from the learning and assimilation of imported technology to enhanced in-house R&D capabilities in the later stage. The support of public institution and government policy also played significant role to this successful transformation in conjunction with vigorous R&D investment of public sector.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.293-301
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• 2001

This paper is experimental results of investigating the efficiency of horizontal vacuum drainage system. Effects of size and shape of drain on horizontal vacuum drainage were studied. Model tests in the laboratory with soft marine clay were carried out with drain pipe of having three different diameters and PBD (Plastic Board Drain) of strip shape so that consolidation settlement of soft clay due to applied vacuum pressure, amount of discharge, ground settlement and distributions of pore pressure and undrained shear strength were measured during testing. From results of model test, amount of discharge due to vacuum pressure was increased with the diameter of pipe drain whereas the drain efficiency of pipe in per unit area of drain surface was decreased with diameter of pipe. The rate of discharge per unit time was reduced very fast with diameter of pipe. Settlement of ground surface with time was increased with diameter of pipe as a result of increase of discharge to drain pipe.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.5
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• pp.165-170
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• 2003

This paper presents development of solid core suspension disc insulators (cap and cap suspension disc insulator) for replacing cap and pin suspension disc insulators in overhead transmission and distribution lines which expose to lightning discharges. By this means the punctured problem caused by steep front surge voltage created by lightning discharge on the lines can be solved. The solid core suspension insulator was designed and constructed based on the dimensions of conventional suspension disc insulators (cap and pin insulators). The insulators are made of alumina porcelain. The electrical and mechanical characteristics of the solid core suspension insulators were carried out. The puncture test was performed in the air by applying steep front impulse voltage with amplitude about 2.5 per unit of 50% flashover (CFO) of the insulator unit at negative standard lightning impulse $1.2/50\;\mu\textrm{s}$ with steepness up to $9200\;kV/\mu\textrm{s}$. The testing results show that solid core suspension disc insulators are not punctured eventhough the steepness of the steep front impulse voltage was increased up to $9200\;kV/\mu\textrm{s}$.

• Composites Research
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• v.17 no.2
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• pp.34-39
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• 2004

In this paper, a modified and representative unit cell model was employed to study the tensile behaviour of closed-cell metallic foams with varying spatial density distribution as well as material imperfections. The density variation was assumed to follow a statistical probability distribution of the Gaussian type. A multiple cell finite element model, utilising the modified unit cell, was developed. The model exhibits deformation patterns similar to those observed in tensile testing. The nominal stress-strain curve obtained from quasistatic tensile of the foam was compared with experimental findings and was found to be in good agreement in the scheme of maximum strength only if the appropriate density distribution and volume fraction of internal imperfections are taken into account. Moreover, maximum tensile strength of the aluminium foam was found to be more sensitive to the volume fraction of imperfection than standard deviation of the density.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.2
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• pp.164-169
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• 2008

National standard system for calibrating voltage transformer(VT) up to primary voltage of 240 kV have been established in 2005. The system consists of voltage source, regulating unit, VT testing unit, standard VT, VT under test and VT burden. To verify and validate the performance for 240 kV VT calibration system, the comparison with the National Measurement Institute of Australia(NMIA) has been performed using same VTs. The comparison results of the VTs mesured at the Korea Research Institute of Stansdards and Science(KRISS) are consistent with those measured at NMIA within 0.002 % for ratio error and 0.14 min for phase displacement in the primary voltage ranges of Vp = 3300 V - 22000 V with a secondary voltage of Vs = 110 V.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.429-433
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• 2009

Since the "Low Carbon, Green Growth" as a social requirements is attracted public attention, the policies and investments of the railway which have been less estimated than road is re-considered. Since the starting the commercial service (2004. April), the KTX have been operated successfully while transport passengers over 100million for years. And also the project for development of KHST (Korea High Speed Train ; G7) had been accomplished with a good result, the first trainset of KTX-II which base on G7 project was manufactured and testing now. On the other hand, the world's technology of the high speed train is more faster, and changing to a distributed traction system. To catch up the world's leading technology, the HEMU(High-speed Electric Multiple Unit) project will secure new technology and aims to promote the technology of domestic high-speed train. The authors indicates the result of detail review such as a curve, slope of the track and electrical dead section of the catenary to test at 400kph and also the performance simulation of the developed rolling stock in this paper. As the result, the authors devise the test scenario to perform a maximum speed test (stability at max. speed, acceleration & deceleration etc) with the restricted conditions such as track length, track available time etc by considering above result.