• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.155-158
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• 2008

In this study we compared corrosion resistance tests which were carried out according to the national technique standard and the UL standard to ensure the reliability of smoke detectors in foul weather. The sensitivity of smoke detectors became so blunt that the least operational smoke concentration was a maximum change of 13% in the national technique standard, while it was a maximum change of 145% in the UL standard. As a result of this study the test method of corrosion resistance was made an objective evaluation in the national technique standard. Therefore it could be said that a basis of developing the test method of corrosion resistance was prepared for our country.

• 수산해양기술연구
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• 제44권1호
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• pp.68-74
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• 2008

This study is concerned with the development of the basic planing hull form of small fishing boat in 25 knots high speed. A series of model test to determine the optimum performance hull form of actual fishing boat with 10 gross tonnage was carried out for 5 models made available planing hull form in the circulation water channel. Model test was performed with the resistance test to study the hydrodynamic characteristics of model ships and the sinkage and trim measurement to investigate the stability of model ships and also the wave pattern observation to analyze the effectiveness of model ships. As the result, the planing hull form of P-4 with deep V type bow can be derived as the best hull form with good performance especially in ship's resistance efficiency showing less residual resistance and sinkage and trim and the spray effect, etc..

• Journal of Welding and Joining
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• 제10권4호
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• pp.181-189
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• 1992

The purpose of this investigation is to examine the effects of the strengthening treatments on the mechanical properties of the flame-sprayed titania ceramic coating layer. The strengthening treatments for flame sprayed specimens were carried out in 12 different conditions in vaccum furance. The mechanical properties such as microhardness, thermal shock resistance, adhesive strength and erosion resistance were tested for the sprayed specimens after strengthening treatments. And it was clear that the mechanical properties of coating layer were much improved by the strengthening treatments. The results obtained are summarized as follows; 1. It was shown that the metallurgical bond was formed between substrate and coating layer by the strengthening treatments and that thermal shock resistance and adhesive strength were remarkably raised. 2. Microhardness of coating lay was considerably increased by the strengthening treatments. 3. Erosion resistance and porosity of coating layer were slightly improved by the strengthening treatments.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.342-347
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• 2004

Excavation nearby the existing structures is being performed vigorously to get the greatest use of land along with fast economic growth in the downtown area. The application of soil nailing system gradually increases because of an advantage of soil nailing system adjacently constructed in the existing structures. In this study, friction resistance by pull-out is considered as main resistance except resistance formed by flexural rigidity of nail observing that resistance of flexural rigidity is about $0{\sim}15\;%$ of whole safety factor according to degree of flexural rigidity in general soil nail wall and application of geosynthetic fiber soil nailing system is evaluated through laboratory tensile strength test and field pull-out test.

• 한국자동차공학회논문집
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• 제3권2호
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• pp.51-61
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• 1995

A coast down test mothod has been used to determine the resistance forces on running vehicle due to the aerodynamic drag, rolling resistance and driveline resistance. Most of the tests, however, are based on the Velocity-Time measurements, which require a sophisticated velocity measuring device and contain much error by nature. In the present study a coast down test method based on Distance-Time measurements is introduced, which contains the original idea of Russian scientist Prof. Petrushov along with the suggestions for improvement of the accuracy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.426-429
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• 1999

In this paper, we have provided the measurement technique of the grounding mesh resistance by field measurements. The standard of measurement is specified in the IEEE Std 81.2-1991 and JEAC 5001-1988, which is the the fall-of-potential method by test-current injection, but this method is difficult to apply at field, where is small around a electric power substation of domestic. For the convenient measurement method, space of assistant probe and quantity of test-current injection are changed step for step. As the result, ' the proposed measurement technique of grounding mesh resistance is that the space of current and potential probes must be fixed at 150rn from a grounding mesh, the test-current injection has to keep 5A or more.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.187-188
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• 2018

In this study, wind pressure resistance test was carried out among the nine test items of KS F 2622 using five types of water-tight material. After comparing the results with the performance range of the current KS F 2622 wind pressure resistance test, it is recommended to check the adequacy of the addition of the combined series.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.166-167
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• 2019

In this study, to test the performance of concrete used as a concrete admixture as a recycling method of CGS, gypsum was mixed and the chloride ion penetration resistance test of CGS and BFS substituted concrete was conducted. As a result, it was found that without gypsum type test specimen, the CGS sustituted test specimens had lower chloride ion penetration resistance than the BFS substituted specimens. When gypsum was added, it was confirmed that the chloride ion penetration resistance was poor regardless of the type of admixture. In addition, it was confirmed that both admixtures were less resistant to chloride ion penetration than OPC, regardless of the presence of gypsum. However, considering the uneven quality variation of coal, which greatly affects the quality of CGS, further research is needed.

• 전력전자학회논문지
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• 제27권3호
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• pp.206-213
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• 2022

This paper presents setting up a laboratory-scale testbed to estimate the aging of power MOSFET devices and integrated power modules by measuring its on-state voltage and current. Based on the aging mechanisms of the component inside the power module (e.g., bond-wire, solder layer, and semiconductor chip), a system to measure the on-state resistance of device-under-test (DUT) is designed and experimented: a full-bridge circuit applies current stress to DUT, and a temperature chamber controls the ambient temperature of DUT during the aging test. The on-state resistance of SiC MOSFET measured by the proposed testbed was increased by 2.5%-3% after 44-hour of the aging test.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.1181-1190
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• 2023

Hydraulic performance and flow resistance tests were performed to confirm the main parameters of the hydraulic instrumentation that can affect the pump performance of the reactor coolant pump. The flow resistance test offers important experimental data, which are necessary to predict the behavior of the primary coolant when the circulation of the reactor coolant pump is stopped. Moreover, the shape of the hydraulic section of the pump, which was considered in the test, was prepared to compare the mixed-flow- and axial-flow-type models, the difference in the number of blades of the impeller and diffuser, the difference in the shape of the impeller blade and its thickness, and the effect of coating at the suction bell. Additionally, five models of the hydraulic part were manufactured for the experiments. In this study, the differences in performance owing to the design factors were confirmed through the experimental results.