• The Korean Journal of Air & Space Law and Policy
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• v.19 no.1
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• pp.79-107
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• 2004

Shielding theory is to allow the construction of a structure that would be shielded by existing permanent structures even thought such structure extends above the height limits prescribed for such zones. This theory is mentioned as recommended practices in ICAO Annex, and is adopted, with modification, in the current Military Airbase Law, amended in August 26th 2002. However, the Military Airbase Law adopts shielding standard allowing 45 meters uniformly, which is a unique standard compared to other countries shielding guideline. The basic principle in applying the shielding theory is, after considering the circumstances of location of shielded structure, whether such structure has physical effect on aeronautical operations. Based upon the basic principle of shielding theory, the uniform application of shielding standard in the Military Airbase Law would undermine the safety of aeronautical operations. This article is to review subsection 2 of section 8 of the Military Airbase Law, which adopts modified shielding theory, and is to suggest better guideline. From a comparative analysis perspective, shielding guidelines of ICAO and other countries will be discussed. Based upon this discussion, the general problems of shielding theory and the specific problems in the Military Airbase Law will be examined. Finally, this article suggests the case-by-case application of shielding theory, considering circumstances of location, for the purpose of ensuring aviation safety.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.55-66
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• 2002

In many countries the principle of shielding is employed to permit a more logical approach to restricting new construction and prescribing obstacle marking and lighting. It also reduces the number of cases of new construction requiring review by authorities. Shielding principles are employed when some object, an existing building or natural terrain, already penetrates above one of the obstacle limitation surfaces described in Annex 14. If it is considered that the nature of an object is such that its presence may be permanent, then additional objects within a specified area around it may be permitted to penetrate the surface without being considered as obstacle. The shielding effect of immovable obstacles laterally in final approach and missed approach areas is more uncertain. In certain circumstances, it nay be advantageous to preserve existing unobstructed cross section areas, particularly when the obstacle is close to the runway. This would guard against future changes in either approach or take-off climb area specifications or the adoption of a turned take-off procedure.

• The Korean Journal of Air & Space Law and Policy
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• v.21 no.1
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• pp.97-133
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• 2006

항공기사고는 약 70%가 이 착륙단계에서 일어나는 CFIT사고이다. 그러므로 비행장주위의 장애물 관리는 사고방지에 매우 중요하다. 국내에서도 비행장주위의 장애물제한을 항공법에 규정하고 있고, 최근 개정안으로 제시된 동법 시행규칙에서 ICAO의 차폐기준의 적용을 포함하였으나 이 규정만으로는 비행장 주위의 장애물의 체계적인 관리가 어려우며, 특히 국내 비행장 주위의 차폐이론적용에 필요한 세부기준이 명확하지 않다. 본 연구는 항공장애물과 관련된 ICAO의 규정 및 항공선진국들의 관련 규정을 검토 분석하고 국내 현황과 비교분석한 후 국제기준에 비추어 국내 환경에서도 적용 가능한 비행장 공역에서의 항공장애물관리규정(안)의 방향을 제시하였고 특히 논란의 여지가 많은 차폐이론의 적용의 명확한 기준방안을 제시하였다.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.15-21
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• 2001

전자파 차폐 및 반사방지용으로 사용되는 SiO$_2$/ITO 이층박막의 전기적 특성에 미치는 전이금속이온의 영향에 대해 고찰하고 전자파 차폐이론식으로부터 박막의 전도특성에 모사하여 효과적인 전자파 차폐효과를 얻기 위한 전도막을 설계하고자 하였다. ITO 상층부에 전이금속염을 첨가한 실리카 복합졸을 코팅하여 SiO$_2$/ITO 이층막을 제조한 결과 최저 표면저항치를 나타내는 첨가량은 전이금속의 종류에 따라 차이를 보이지만 Sn 및 Zn이 첨가된 졸로부터 형성된 박막은 $10^{5}$Ω/$\square$ 이하의 낮은 저항치를 보였으며 가장 안정된 표면저하을 나타내었다. 또한 전자파 차폐효과와 전도박막의 표면저항을 차폐이론식으로부터 모사한 결과 Zn과 Sn의 전이금속염이 첨가된 SiO$_2$/ITO 투명전도막은 TCO99에서 정한 전자파 차폐기준에 부합하였다.다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.04a
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• pp.167-171
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• 1994

본 연구에서는 차폐구조 내부에 위치한 소음원의 체적이 비교적 큰 근접 음향 차폐구조로 취급하여, 구조 내부의 공간적 음장분포해석(spatial sound distribution analysis)은 하지 않고 단지 소음원의 표면과 차폐 벽면 간의 공기층에 의한 간섭 영향을 고려하면서, 차폐로 인한 음압의 상승(build up)효과를 고려하여, 직육면체의 형상을 가지는 차폐구조에 부착되는 각각의 벽면들의 음향 삽입손실(Insertion Loss, IL) 특성을 전달매트릭스 기법(Transfer Matrix Analysis, TMA)을 이용하여 해석하였으며, 이러한 벽면들에 대한 이론 해석의 결과로 제작된 벽면들의 음향차폐특성을 시험을 통해 나타내었다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.121-126
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• 2010

Regarding HEMP has been studied as few thousand of paper by major nuclear bomb holding countries with USA for the self protection against nuclear bomb attract. Major HEMP protection facilities are consist of the shielding, filtering, grounding and high voltage protection circuits. Shielding room construction required a highest cost among the key protective facilities. Most of a theoretical formulas listed on the paper and related books has a little correlations in the certain frequency band between the theoretical formulas and field measuring results. For the reasons we proposed the advanced new theoretical formulas and developed the computer simulation S/W as enough as apply to the cost effective shielding room design for HEMP considering the various structural constants.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.21-34
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• 2005

To control the obstacles surrounding aerodrome is significant for preventing air accident and ensuring the long sustaining of aerodromes. On the other hand, within a scope of ensuring safe flight operations, the application of Shielding is one of the issues to be importantly considered to manage efficiently the obstacles limitation around aerodromes, to dissolute the private asset privilege limitation from regulation on aerodrome circumference, and to decrease the pains to manage the obstacles, in terms of not only operating safely but also utilizing efficiently the airspace around aerodromes. The ICAO and other aviation-advanced states mitigate the construction limitation or exempt the obligation of obstacle sign by applying the shielding theory that the obstacles are not regarded as obstacles where are below the shadow surface. The Republic of Korea inserted the new regulation including the applying shielding similar to ICAO on Aviation Act and regulations. It is, however, hard to manage the aviation obstacles around aerodrome efficiently with these new regulation. Particularly, there exists much rooms to dispute because it cannot suggest the specific standard which is necessary to apply shielding theory at airspace of aerodromes. Therefore, in this study, the international standards on aviation obstacles were reviewed, analyzed and compared with those of domestic status. The direction of which guideline for control of aeronautical obstacles applicable within domestic circumstances as well as correspondent with international standard was suggested. Particularly, as far as the disputable application of shielding theory is concerned, the alternatives for aviation safety and efficient airspace operation by suggesting the clear standards alternatives were suggested.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.67.1-67.1
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• 2017

태양의 코로나를 관측하기 위한 코로나그래프의 가장 중요한 부분은 태양 원반으로부터의 빛을 차단하기 위한 차폐기다. 태양 원반 밝기의 1e-6 - 1e-10에 이르는 어두운 외부 코로나(>2Rs)를 관측하기 위해서는 외부차폐기에서 발생하는 회절광을 최소화 하는 것이 중요하다. 우리는 수치실험과 실험실 실험을 통해 원통형 차폐기의 성능을 조사하였다. 수치실험 결과 2.5Rs영역을 가리는 원통형 차폐기의 경우 0.4um의 파장대역에 대해서 그 벽면 각도가 0.39도일 때 차폐기에 의한 회절광이 1e-10Is로 최소가 되었다. 우리는 중국 산동대학교 암터널 실험실에서 시뮬레이션과 일치하는 실험결과를 얻었는데 그 회절광량은 이상적인 경우보다는 조금 더 밝은 1e-9Is 수준이었다. 1e-9Is의 회절광량은 일정 간격으로 배치된9장을 겹쳐놓은 차폐기의 이론적인 성능과 비슷한 값으로 외부차폐기/내부차폐기/리오트 스탑/리오트 스팟 등으로 복잡하고 긴 구조의 코로나그래프가 아닌 외부차폐기만을 이용한 짧은 광학계의 소형 코로나그래프로 외부 코로나 관측이 가능함을 보여준다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.2
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• pp.109-112
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• 2007

The possibility and limitation of one dimensional nano scale electron shielder is briefly discussed. A Nano scale electron shielder will reduce the weight and size of shielding materials. However, practical application still requires further research. In this work, we discuss general problems related to nano scale electron shielder, by taking an arbitrary one dimensional potential barrier as an example.

• Korean Journal of Materials Research
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• v.9 no.9
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• pp.913-918
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• 1999

As an alternative evaluation method of electromagnetic shielding properties, the material parameters are considered in determining the qualitative value of shielding effectiveness. The specimens are metallized nylon fabrics with the thickness of about 0.1 mm and the electrical conductivities in the range from 6.4$\times$10~2.4$\times$10(sup)5 mhos/m. On the basis of shielding theory, the shielding effectiveness (which is a sum of reflection loss and absorption loss) has been determined from the material parameters of the barrier sheets. For the conductive fabrics, the dominant shield mechanism is predicted to be reflection loss, which shows an increasing function of electrical conductivity. Comparing these theoretical value with the directly measured surface impedances, the error range is found to be within 10 dB, which demonstrates that the proposed material-parameters method can be a convenient way to determine the electromagnetic shielding properties.