• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.4 s.60
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• pp.48-52
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• 2006

2006 CISPR 총회가 스웨덴 스톡홀름 KISTA에서 개최되었다. CISPR I 회의는 9월 18일부터 20일까지 3일간 WG2 및 WG4를 중심으로 진행되었으며, WG1과 WG3 회의는 9월 20일 오후에 있었다. 우리나라에서는 WG1에 두 가지 제안을 발표하였다. 하나는 2004년 중국 상해 회의에서 처음 제안하여 2005년 남아공 케이프타운 회의에서 Task Force가 구성된 대형 시험품에 대한 CISPR 20의 외부 방사내성 시험레벨에 관한 것이다. 2006년 1월 미국 산타페에서 열린 TF 회의에서 시험결과에 대한 기술적 토론이 있었으며, Round Robin Test(RRT)를 실시하기로 결정되었다. RRT시험은 7월 중순에 실시되었으며, 참여한 시험소는 영국의 SONY, 네덜란드의 Philips, 독일의 SHARP 이었으며, 국내의 여러 EMC 시험소도 추후에 참여하였다. RRT 시험의 결과 및 분석이 이번 스톡홀름 회의에서 발표되었다. 또한, CISPR 13의 방사성 방출(RE)의 측정거리 기준점의 변경에 관한 것이다. 본 고에서는 TV 수신기에 대한 RRT 시험결과 및 분석에 대한 발표 내용을 소개하고자 한다. CISPR 20의 외부 전자기장 내성 시험은 0.8 m인 개방형 스트립라인(Open Strip-line: OSL)내에 시험품을 설치하고 $150kHz{\sim}150MHz$에서 시험하도록 규정하고 있다. OSL에 설치할 수 없는 대형기기는 IEC 61000-4-3에 따라서 주파수 범위 $80MHz{\sim}150MHz$까지 동일한 한계치로 전자파무반사실에서 시험하도록 규정되어 있다. 이에 대해 국내 제조업체 및 EMC 전문가들로 구성된 CISPR I 국내 위원회에서는 IEC 61000-4-3에 의한 전자파무반사실(챔버)에서의 내성시험이 CISPR 20에 의한 OSL에서의 내성시험보다 가혹하다는 문제 제기가 있었다. 이것이 본 안건에 대한 배경이다 지금까지 진행되어 왔던 내용을 요약해 보면 2004년 상해 회의에서, 수치해석 및 측정비교를 통하여 CISPR 20에서 규정하고 있는 OSL 전기장 교정방법의 개선의 필요성과 OSL에서 시험할 수 없는 대형 시험품에 대하여 시험레벨을 조정할 것을 지적하였다. 2005년 케이프타운 회의에서는 실제적으로 TV 방송 수신기 및 관련기기가 두가지 방법으로 시험되었을 때 시험결과에 미치는 영향을 시험품의 전기장 내성 레벨로 비교하였으며, 전자파무반사실에서 시험할 경우 시험레벨이 12 dB 낮추도록 보정되어야 할 것을 제안하였다. 2006년 이번 회의에서는 세계 각국의 시험소와 비교시험을 통하여 나타난 OSL과 전자파무반사실 간의 시험결과의 차이 및 이에 대한 원인을 분석하여 보고하였다. OSL과 전자파무반사실 비교시험에서 나타난 차이는 평균적으로 9 dB의 차이로 나타났으며, 주요 원인은 OSL에서 적용하고 있는 시험품을 OSL내부에 설치한 후 시험품에 의해 변경된 전기장의 세기를 보정해 주는 인자(k2)로 인한 차이(6 dB)와 OSL 내부의 전기장의 세기와 전자파무반사실 균일장 영역의 전기장의 세기의 차이(3 dB)이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.96-102
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• 2003

The thermal design of MGSE(Mechanical Ground Support Equipment) panel is performed for thermal vacum thest of Ka-band EQM(Engineering Qualification Model) payload of communications and broadcasting satellite. The thermal environments are predicted to evaluate the performance of transponder equipments in the thermal vacum chamber. SINDA is used to verify the thermal design of the heat pipe layout. Embedded 16 heat pipes in the EQM payload developed for Ka-band trasponder equipments are designded properly. The heat fluz loaded on the external facesheet is 265W/㎡ for the hot platear function test of the traspinder equipments, and the zero heat flux for the cold plateau case. The maxium predicted heat transport capability is 2723 W-cm.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.511-517
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• 2015

Sound absorption capability of the flame resistant treated sawdust-mandarin peel composite particleboard was were estimated by two microphone transfer function methods. The weight of flame resistant treated board slightly increased by the treatment. The treatment improved fire retardant performance by decreasing the charred area of flame resistant treated board. Sound absorption capabilities of flame resistant treated sawdust-mandarin peel composite particleboard, in the entire estimated frequency range of 500-6,400 Hz was slightly lower than those of the control specimen. Sound absorption capability of both the control and flame resistant treated sawdust-mandarin peel composite particleboards were higher than that of commercial gypsum boards, being widely used as a sound absorber for ceiling at the estimated frequency.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.139-147
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• 2023

The compact tracking radar system is a pulsed radar tracking system that searches, detects, and tracks targets in real time against aircraft targets with a small RCS(Radar Cross Section) maneuvering at high speed. This paper describes the development of comprehensive performance test equipment to verify the performance of the radar system in a anechoic chamber environment. Describes the design and manufacture of comprehensive performance test equipment to meet requirements, including the generation of simulated target signals to simulate aircraft target signals to verify performance in the laboratory environment of radar systems. It also describes a GUI(Graphic User Interface) program to check performance through a test in conjunction with the tracking radar system. Verify the comprehensive performance test equipment implemented through the performance test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.404-407
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• 2018

- A car is a means of transporting passengers or cargo on the ground by transmitting power from the engine to the wheels. In the past, automobiles started from internal combustion engines have recently been introduced with hybrid electric vehicles and pure electric vehicles. As a result, the deployment of high-tech electrical and electronic products is inevitably increased due to the development of technology and stability of various parts, resulting in a more complicated and diversified electromagnetic environment. CISPR 25 is conducting research on the test method for electromagnetic noise. In order to analyze the noise pattern according to the GND condition required in the radiation emission test, various conditions are applied for comparison. 2 Page - General characteristics of EMI chambers, techniques for testing and measuring equipmen 3 Page - RE test : Analysis of Noise due to Ground Strap Change when Sample is in Center, Analysis of Noise due to Ground Strap Changes when the Sample is not in the Center.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.545-550
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• 2016

The main purpose of this study is to analyze and evaluate the feasibility of ligthweight pavement system with pile foundation on soft soil by laboratory small chamber test. In order to verify the stability of lightweight pavement system, the 1/30 scaled downed model system was tested at lab. The soft soil condition was simulated and group piles for skin friction resistance were used. Within the limited lab test, the settlements of pavement system were 0.86 mm for Case A, 0.70 mm for Case B, and 0.50 mm for Case C. The converted maximum settlement differential settlement were 25.8 mm and 10.8 mm. These values meet the inside of specification of Bridge Design Guide in Korea. The use of lightweight pavement systems on soft soils could be an alternative construction method on soft soils to reduce the challenges of conventional design and constructions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.178-183
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• 2012

To simulate space thermal environment in thermal vacuum test, direct or in-direct heater has been applied on the radiator. Both of them, direct heater attached on the radiator and indirect heater with a distance from the radiator, simulate the heat fluxes from the Sun radiation, the Earth IR and Albedo. They also supply the heat fluxes to the radiator of spacecraft to achieve the target temperature according to thermal test conditions. In general, indirect heater is used when the heater is not allowed to attach on the radiator directly due to constraints of coating property or contamination. For in-direct heater design, it is needed to estimate the heat power to make the extreme test conditions and minimize the interference with heat exchange of radiator and shroud. In this study, optimized thermal design of in-direct heater is proposed and investigated by commercial S/W SINDA. The effective values of design factors are also derived.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1160-1164
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• 2017

In this research, a high altitude simulating test facility is designed using vacuum pump system composed of roots pumps and screw pumps. Air flow rate and chamber pressure are 1 kg/s and 2500 Pa, respectively. To design the test facility, experimental tests using certain pump combinations are performed for air injection of the order of hundreds of g/s. From the tests, it is found that 11 roots pumps and 33 screw pumps are required for the considered test facility. Test results are compared with theoretically estimated values. However, intake capacity theoretically estimated is found to be 20 percent larger than test results. This is thought because of higher pressure difference of roots pump for test conditions. Therefore, if more screw pumps are added for the considered pump system, it would be possible to lower the vacuum level of test chamber.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.86-93
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• 2021

In order to remove particulate matter, functional construction materials are developed. However, there is no evaluation method and infrastructure for particulate matter removal rate. Therefore, the purpose of this study was to build a particulate matter removal rate test chamber and to present a method for particulate matter removal rate. As a result, since construction materials have effectiveness in an environment where particulate matter is generated, the particulate matter injection step was proposed as a comparison target. The evaluation of the particulate removal rate was proposed by relative comparison of the slope values obtained by linear regression analysis for all concentration values measured in the particulate matter injection step. In linear regression method, all measured values can be evaluated, and the variability can be evaluated with the coefficient of determination (R-square), so that the reliability of the particulate matter removal rate can be secured.