• Journal of computational fluids engineering
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• v.10 no.2
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• pp.60-68
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• 2005

For study on the unsteady wall interference effect, flows around a forced oscillating airfoil in closed test-section wind tunnels have been numerically investigated by solving compressible Navier-Stokes equations. The numerical scheme is based on a node-based finite-volume method with the Roe's flux-difference splitting and an implicit time-integration method coupled with dual time-step sub-iteration. The Spalart-Allmaras one-equation model is employed for the turbulence effect. The computed results of the oscillating airfoil having a thin wake showed that the lift curve slope is increased and the magnitude of hysteresis loop is reduced by the interference effects. Since the vortex around the airfoil is generated and convected downstream faster than the free-air condition, the phase of lift, drag and pitching moment coefficients was shifted. The pressure on the test section wall shows harmonic terms having the oscillating frequency contained in the wail effect.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.870-875
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• 2023

In this paper, we analyzed the revised guidance on electromagnetic (EM) interference qualification of Regulatory Guide 1.180 (Revision 2), which is published by the U.S. Nuclear Regulatory Commission for electromagnetic compatibility qualification for nuclear safety, by comparing it with that of the previous version. We confirmed that the test methods and the acceptance criteria of both CE101 and CE102 tests for conductive emission and RE102 test for radiating emission are changed in the recently revised Regulatory Guide 1.180 (Revision 2). Furthermore, we found that the revised Regulatory Guide 1.180 provides flexibility in the use of alternative methods for EM interference (EMI) qualification, in that a mix of the various base-standards is technically allowed. In addition, the primary revision of the updated Regulatory. Guide 1.180 is that MIL-STD-461G is to be adopted as the latest base-standard, instead of MIL-STD-461E. To evaluate the influence on EMI qualification for nuclear safety due to the endorsement of MIL-STD-461G, we thoroughly analyzed the modifications in the acceptance criteria and test methods for EMI qualification, and then validated the analyzed effect on the EMI qualification, which is caused by the revision of MIL-STD-461, by performing electromagnetic simulation for equipment under RE102 test.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.2
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• pp.117-126
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• 1999

The environmental impact of the KEPCO 765-kV transmission line was studied using a full scale test line in order to develop the design technology. Therefore this paper describes an environmental design summary of the audible noise, hum noise, wind noise, radio interference, TV interference and electric field measurement from the KEPRI 765-kV double circuit transmission test line with a bundle of $6-480mm^2$ conductors per phase. The analysis of the test results shows that 6-Rail and 6-Cardinal conductors bundle satisfy the audible noise criterion & TV interference under the stable rainy weather condition and the radio interference level under the fair weather. And the other items are also agreed with the design level criterion for KEPCO 765-kV transmission line.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.117-122
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• 2020

In this paper, we study the electromagnetic interference in adjacent antenna aperture of multi-function radar for Integrated MAST of naval ship, which is operating plural radars, with test result of two different X-band antennas. Two antennas is placed in the test fixture copying the part of Integrated MAST for the experiment. The test figure is modeled to see the electromagnetic interference when antenna beam is steered by using electromagnetic analysis tool. Also, 6 test scenarios is determined to verify experimentally and each test scenario is run in an anechoic chamber. At the test antenna #1 radiates a pulse signal and the signal from the antenna #2 is stored and analyzed in the optic data format through a receiving device. Based on the result, the effect of electromagnetic interference is suggested when multi-function radars in the Integrated MAST are operating in adjacent distance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.647-652
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• 2001

A noise reduction of noise barrier for high speed train was measured by using scale down model test. A selected types of noise barriers were simple vertical barrier, interference type barrier with plate, interference type barrier with cylindrical pipes. On experiment, in order to make similar present test lane condition, reduced train model and multiple noise sources were considered. As a result. interference type noise barrier with cylindrical pipes is most effective than other barriers. A present height of noise barrier which is established in a test lane is not high enough for reducing patograph noise.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.6
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• pp.485-491
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• 2012

The wall interference effects around the wind-turbine airfoil are experimentally investigated at low Reynolds numbers in a closed test-section wind tunnel. The test is performed at free-stream velocities from 10 to 31 m/s, which correspond to Reynolds numbers ranging from $1.5{\times}10^5$ to $4.6{\times}10^5$ based on chord of the airfoil. The blockage-area ratios, which is the ratio of the chord to the test-section width, are 27.8%, 38.5%, 41.7%, 45.5%, and 55.6%. The test results for the airfoil show that the transition point on the airfoil surface tends to move backward due to wall interference. The wall pressures for an adequate interference correction by a measured-boundary-condition method are desirable more than three times region of the chord before and after around the reference center.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.3
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• pp.71-88
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• 2009

Objectives The purpose of this study is to find out the correlation between Stroop interference and the symptoms of weak children. Methods Questionnaire and performed Stroop interference test were done by 145 patients in OO Oriental Medical Hospital from May to October 2009. 120 patients who were considered as the weak children were divided into two groups: Stroop Interference T score above average group and below average group, and were surveyed again. Results 1. The study showed that age, the highest marked subject and behavior habits correlate to interference score and subjects characteristics. 2. Weak children groups had the highest tendency of having weak heart followed by weak lung spleen, liver, and kidney. Normally, a patient belonged to more than one of the weak children groups. 3. The study showed that a group of children who has weak heart and lung were related to interference score. The group which earned below average interference score had the highest frequency of being children with weak heart group. The group scored above average, however, had the highest chance of being children with weak lung group. 4. The study showed that interference score was related to four out of fifty questions about the weak children symptoms. Plus, related questions were all about the heart weak children symptoms. Conclusions In conclusion, there were significant correlation between interference score and the group consists of children who were weak: more specifically with children with weak heart.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.213-218
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• 2003

Because of the development of digital technology, modern digital instrumentation & control systems are being innovativly developed in industrial plants. Whereas, many analog systems are still being used in nuclear plants, because of the demerits of digital equipment. As known, the demerits of digital equipment are the uncertainty and weaknesses in ambient environments such as smoke & electromagnetic interference In an Integral Reactor, a digital I&C system will be composed of microprocessor, memory and network card. Designers will apply new technique for digital equipment. Thus, it is important for digital I&C systems to operate according to designed functions & performance in the ambient environments during a life cycle. Digital I&C systems should have tolerance in such environments and environment qualification should be concluded To acquire electromagnetic interference qualification of digital equipment, this paper suggests an EMI test requirement. Designers should consider the electromagnetic compatibility and test digital equipment according to each test procedure. This paper involves an EMI test requirement and the results analysis of EUT(Equipment Under Test). Test result analysis will be used as electromagnetic compatibility design guides for Integral Reactor I&C systems.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.2
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• pp.127-134
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• 2017

Vortex Induced Vibration (VIV) is a typical flow-structure interference phenomenon which causes an unsteady flow pattern due to vortex shedding at or near the structure's natural frequency leading to resonant vibrations. VIV may cause premature fatigue failure of marine risers and pipelines. A test model was carried out to investigate the role of a stationary fairing by varying the caudal horn angle to suppress riser VIV taking into account the effect of wake interference. The test results show significant reduction of VIV for risers disposed in tandem and side-by-side. In general, fairing with a caudal horn of $45^{\circ}$ and $60^{\circ}$ are efficient in quelling VIV in risers. The results also reveal fairing can reduce the drag load of risers arranged side-by-side. For the tandem configuration, a fairing can reduce the drag load of an upstream riser, but will enlarge the drag force of the downstream riser.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.694-701
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• 2016

According to revolutionary developments in automobile technologies, eco-friendly advanced vehicles (hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc.) are rapidly increasing. The electromagnetic compatibility is getting more important for development of a vehicle because those advanced vehicles are driven by electric energy and equipped with more electric systems. In general, electromagnetic compatibility tests consist of an electromagnetic interference(EMI) test and an electromagnetic susceptibility(EMS) test. EMI test of the electric vehicles are needed not only in driving mode but also in charging mode because they must be recharged by much electric energy for driving. Depending on vehicle manufacturers, the charging device type and the location of charging device inlet in electric vehicles are various. In this paper, in order to investigate EMI of electric vehicles in charging mode in consideration of the direction of measuring antenna and the location of charging device inlet, a series of electromagnetic emission tests are conducted using three electric vehicles (neighborhood electric vehicle, electric vehicle and electric vehicle-bus). The test results show that electromagnetic emission measurements in charging mode are dependent on the direction of measuring antenna and the location of charging device inlet.