• Wind and Structures
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• v.29 no.2
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• pp.87-98
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• 2019

As a regenerated turbulent wind field process, wind tunnel test has proven to be a promising approach for investigating the transmission tower-line system (TTLS) performance in view of experimental scaled models design, simulation techniques of wind field, and wind induced responses subjected to typhoon. However, the challenges still remain in using various wind tunnels to regenerate turbulent wind field with considerable progress having been made in recent years. This review paper provides an overview of the state-of-the-art of the wind tunnel based on active or passive controlled simulation techniques. Specific attention and critical assessment have been given to: (a) the design of experimental scaled models, (b) the simulation techniques of wind field, and (c) the responses of TTLS subjected to typhoon in wind tunnel. This review concludes with the research challenges and recommendations for future research direction.

• Journal of the Korean GEO-environmental Society
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• v.24 no.3
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• pp.15-21
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• 2023

Although standards related to falling stone facilities are established in Korea, the absorption energy of the rockfall prevention net is evaluated from the passage of rockfall and destruction of the rockfall prevention net on field test. The existing PVC coating net does not sufficiently suppress the rockfall load and tears frequently occur, and a high-strength wire rockfall net was developed to prevent. In this study, the performance was analyzed through field tests of the existing PVC coating net and the developed high-strength rockfall net (1,000 MPa, 2,000 MPa).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.7
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• pp.621-627
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• 2013

Field tests of hybrid desiccant cooling systems were conducted from July to August 2011. Data were monitored and transferred in real time over the Internet. The monitored variableswere analyzed to determine the performance characteristics under outdoor conditions. A series of system simulations has been conducted for outdoor conditions of the field tests. The results agree well with the experimental data in general. The system performance has been shown to deteriorate for wetter conditions, as predicted by the simulation.

• ETRI Journal
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• v.34 no.4
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• pp.621-624
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• 2012

A new miniaturized 4-port waveguide generating a transverse electromagnetic wave is proposed. The waveguide presents enhanced performance of higher field uniformity in extended test volume up to an increased test frequency limit compared to that of the conventional 2-port waveguide. The advantageous features of the proposed waveguide have been obtained through a new design scheme based on effective miniaturization maintaining good impedance matching. Consequently, we can provide a more accurate electromagnetic compatibility test method, covering larger devices operating in higher frequencies, which is a marked improvement upon the conventional approaches.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.666-673
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• 2000

This paper describes the full load test results of IGBT VVVF inverter for the railway propulsion system. The 1,650kVA IGBT VVVF inverter has been developed. Therefore, the field test is performed in SMG 6 Line to confirm its the reliability and performance. The train consists of 4M4T(4 Motor car 4 Trailer Car) and the electrical equipment for field test are as follows VVVF inverter 4 sets, 16 traction motors and 2 SIVs. The propulsion system is composed with IC4M(1-Controller 4-Motors). The results of propulsion system which have the excellent acceleration/deceleration and the jerk characteristics as well as starting ability on slope are taken through the field test.

• Journal of Applied Reliability
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• v.17 no.4
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• pp.343-354
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• 2017

Purpose: This paper evaluates the reliability of tapered grid couplings and presents test results through performance and life tests. Methods: The performance and life test method were presented by analyzing the failure modes for the tapered grid coupling. Zero failure test time was calculated to evaluate the reliability of tapered grid couplings and the test was performed under accelerated conditions. The nondestructive test and wear analysis using weighing were also carried out to check the failure modes of the field conditions. Conclusion: This study can be provided to improve the product reliability through failure analysis of a tapered grid coupling. The performance test results of before and after the accelerated life test were presented to confirm the improved reliability of the tapered grid coupling.

• Journal of Drive and Control
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• v.15 no.4
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• pp.23-29
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• 2018

The objective of this paper is to evaluate the reliability of a volute pump and presents test results through performance and life tests. The performance and life test methods were presented by analyzing the failure modes of the volute pump. Zero failure test time was calculated to evaluate the reliability of the volute pump and then, the test was performed under accelerated conditions. The test was also carried out to check the failure modes of the field conditions. This study can be provided to improve the product reliability through failure analysis of the volute pump. And failure cause of typical failure case has been investigated and improvement design has been presented. The performance test results of before and after the accelerated life test were presented to confirm the improved reliability of the volute pump.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.715-723
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• 2018

The energy storage system consists of batteries, power conditioning system and energy management system. If ESS is installed and operated in the field, SAT(Site Acceptance Test) of ESS is being essentially required for the safety and performance of ESS. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W equipments but also performance verification by S/W tool. Therefore, this paper proposes the modeling of portable test equipment in order to evaluate the performance and reliability of ESS by using the PSCAD/EMTDC S/W. And also, the prototype of 30[kW] scaled portable test equipments is implemented based on the S/W modeling. From the results of various simulations and testings such as power quality, LVRT and anti-islanding tests, it is confirmed that 30[kW] scaled portable test equipment is useful for SAT of ESS, because the simulation results of PSCAD/EMTDC are identical to them of 30[kW] test equipment at the same test conditions.

• International Journal of Highway Engineering
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• v.19 no.3
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• pp.1-10
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• 2017

PURPOSES : This paper focuses on strength development according to the mix design with cement type and mineral admixture from laboratory and field tests in cool weather. METHODS : Two methods evaluated the mix design of concrete pavement in cool weather. Firstly, laboratory tests including slump, air contents, setting time, strength, maturity, and freezing-thawing test were conducted. Three alternatives were selected based on the tests. Secondly, a field test was conducted and the optimum mix design in cool weather was suggested. RESULTS : It is an evident from the laboratory test that a mix with type III cement showed better performance than the one with type I cement. There was a delay in strength development of a mix with mineral admixture compared to mix design without any mineral admixture. In the field test, type III cement+flyash 20% mix design proved the best performance. CONCLUSIONS : For concrete pavement in cool weather, mix design using type III cement could overcome the strength delay due to mineral admixture. Moreover, it is possible to make sure of durability of pavement. Therefore, strength and durability problems due to cool weather would decrease.

• Journal of the Korean Society for Advanced Composite Structures
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• v.7 no.1
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• pp.1-8
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• 2016

In this paper, the full-size structural performance test for a lightweight soundproof tunnel composed of partitioned pipe truss members is carried out to investigate the structural performance. In addition, a nonlinear structural analysis of the same finite element model as the full-size testing model is performed to compare the test result. The test and analysis results showed that the lightweight soundproof tunnel ensures the structural safety against wind loads, snow loads and load combinations. As a result, the full-size test and analysis results meet all the design load conditions, hence the proposed lightweight soundproof tunnel is ready for the field application.