• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.134-135
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• 2003

Abstract in case of the small scale power system separated from large scale power system N-2 contingency, the Over excitation, Under Frequency and Power swing Tripping Relay operate depending on unbalance Of Generation and Load. and then we studied and measured the angle and frequency deviation between generators. moreover, we compared real fault example with simulation results.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.1
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• pp.10-18
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• 2007

In this paper, we extend the multiple time scale control framework to window-based congestion control, in particular, TCP. This is performed by interfacing TCP with a large time scale control module which adjusts the aggressiveness of bandwidth consumption behavior exhibited by TCP as a function of "large time scale" network state. i.e., conformation that exceeds the horizon of the feedback loop as determined by RTT. Performance evaluation of multiple time scale TCP is facilitated by a simulation bench-mark environment which is based on physical modeling of self-similar traffic. If source traffic is not extended exceeding, when RTT is 450ms, in self similar burst environment, performance gain of TCP-SSC is up to 45% for ${\alpha}$=1.05. However, its is acquired only 20% performance gain for ${\alpha}$=1.95 relatively. Therefore we showed that by TCP-MTS at large time scale into a rate-based feedback congestion control, we are able to improve two times performance significantly.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.4
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• pp.14-21
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• 2015

Korean government plans to establish large-scale horticulture facility complexes using reclaimed land in order to improve the national competitiveness of agriculture at the government level. One of the most significant problems arising from the establishment of those large-scale horticulture facilities is that these facilities still largely depend on a fossil fuel and they require 24 h a day heating during the winter season in order to provide the necessary breeding conditions for greenhouse crops. These facilities show large energy consumption due to the use of coverings with large heat transmission coefficients such as vinyl and glass during heating in the winter season. This study investigated the applicability of waste heat from power plant for large-scale horticulture facilities by evaluating the waste heat water temperature, heat loss and energy saving performance as a function of distance between power plant and greenhouse. As a result, utilizing power plant waste heat can reduce the energy consumption by around 85% compared to the conventional gas boiler, regardless of the distance between power plant and greenhouse.

• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.28-32
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• 2007

This study was carried out to investigate the utilization of hemolymph of silkworm, Bombyx mori, as a substitute for fetal bovine serum(FBS) in the insect cell culture. Hemolymph is collected on a small scale by clipping the abdominal leg; however, this method is not appropriate for large scale collection. The hemolymph was collected from 5 th instar larva by centrifugation after cutting of the abdominal legs was more appropriate procedure for large scale collection. The cell growth in the medium supplemented with hemolymph(Baekokjam) collected in large scale was almost same as that in the medium hemolymph supplemented with hemolymph collected in small scale. However, the mutant($wE^b$) hemolymph collected in large scale was still less effective in the cell growth, as compared to the Baekokjam hemolymph collected in large scale. The optimum centrifugation condition for large-scale bleeding was 500 rpm and 15 min.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.169-176
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• 2024

Purpose: In this paper, an experimental study was conducted to analyze the difference in shear strength caused by the problem of excluding coarse particles due to the size of the test specimen in the direct shear test. Method: A large-scale direct shear test was conducted on three weathered soils containing coarse aggregates with a maximum diameter of 50mm. In addition, a small-scale direct shear test was performed using a sample with a maximum diameter of 5 mm, excluding coarse aggregates. Result: In the case of the small-scale direct shear test, compared to the results of the large-scale direct shear test containing large particles, the internal friction angle was about 2.3% smaller, and there was no significant difference. In terms of cohesion, compared to the large-scale direct shear test, the small-scale direct shear test derived about 80.3% smaller value, showing a relatively large difference. Conclusion: In the large-scale direct shear test, it was analyzed that the coarse particles had a greater impact on the cohesion than the internal friction angle. Therefore, granite weathered clay containing coarse particles is judged to have the same shear strength as the cohesive force that is not affected by vertical stress. In this study, it was analyzed that the small-scale direct shear test, which excludes the coarse particles that are commonly used, provides results on the safety side by excluding the effect of coarse particles.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.129-134
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• 2008

Ultrasonic cavitational energy distributions were measured in a large-scale sonoreator. In application of 110 and 170 kHz of ultrasound, the cavitational energy was just detected near the transducer module. However 35 and 72 kHz ultrasound made good distributions from the module to the end of the sonoreactor, Especially, 72 kHz ultrasound application showed most stable and highest cavitational energy value through the whole length. In the comparison between input power and cavitational energy, linear relationships were obtained in 35 and 72 kHz and it was anticipated that these results would be used for the optimization of input power for the design of sonoreactors. And three dimensional energy distribution was depicted through the mapping of cavitaional energy. Average energy in the large-scale sonoreactor was estimated as 62.8 W, which was about 40 % of input power.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1051-1056
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• 2009

Recently, there are many wide road in korea, so The Large scale cut slopes are increasing. Large scale cut slopes are better then small scale in case of construction and maintenance. General, Reinforced Slopes by Shotcrete are difficult to inspect because of stiff Slope and highly Working Area. So the Inspection Techniques are needed by the Non-contact and Non-destructive. On this Study, We are studying the method about efficient valuation and maintenance of Large scale Reinforced slopes by Shotcrete.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.868-877
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• 2011

This paper presents a parallel computing methodology for polymer electrolyte fuel cells (PEFCs) and detailed simulation contours of a real-scale fuel cell. In this work, a three-dimensional two-phase PEFC model is applied to a large-scale 200 $cm^2$ fuel cell geometry that requires roughly 13.5 million grid points based on grid-independence study. For parallel computing, the large-scale computational domain is decomposed into 12 sub-domains and parallel simulations are carried out using 12 processors of 2.53 GHz Intel core i7 and 48GB RECC DDR3-1333. The work represents the first attempt to parallelize a two-phase PEFC code and illustrate two-phase contours in a representative industrial cell.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.295-300
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• 2002

Since the contents of large-scale repair of a condominium were various, a plan document was not prepared. The owners association of the condominium has given priority to decision-making of price priority over quality. Examination is not performed about the contents of the construction supervision business, which checks whether suitable construction is performed, either. On the other hand, the know-how for builders, such as decision of the process plan under which the repair work lessens influence to the safety and life as much as possible since the place where the resident is living turns into a construction site, and selection of a method of construction, is just going to ask. It is an important subject how the structure of the construction contractor selection, which considered quality, is built. Then, this research focuses on large-scale repair construction of the condominium, and arranges the actual condition of a series of processes from plan document creation to construction supervision. The method of research collects the construction documents of the condominium that carried out Barge-scale repair construction. Next, collection arrangement of the data of construction builder selection is carried out. The method of the construction builder selection of those other than a construction price is examined. The method of quality control of large-scale repair construction is examined.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.428-434
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• 2015

The objective of the present study is to analyze the results of the trial-test for the full-scale driving pump, which is arranged in the LCT (Large Cavitation Tunnel). Firstly, the reasons of selecting the final design pump are introduced in terms of the performance analysis in model tests. The trial-test items for the full-scale driving pump are measurements of output current/voltage at the inverter of the main motor and the flow velocity in the LCT test section. The test results show the increase in flow rate of about 10.7% and the decrease in pump head of about 26%, compared with those of final design-pump specification. The motor power has the margin of about 22%. The performance analysis for the full-scale pump is conducted using the commercial code (CFX-10). The delivered power calculated with CFX-10 shows good agreement with that extracted from the full-scale pump test. It is found that CFX-10 is useful to analyze a full-scale pump.