• Title/Summary/Keyword: ElectroMagnetic Pulse

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An Experimental Study on the Development of Electromagnetic Shielding Concrete Wall for Shielding High-altitude Electromagnetic Pulse (HEMP) (고고도 전자기파(HEMP)차폐를 위한 전자파 차폐 콘크리트 벽체 개발에 관한 실험적 연구)

  • Choi, Hyun-Jun;Kim, Hyung-Chul;Lim, Sang-Woo;Lee, Han-Seung
    • Journal of the Korea Concrete Institute
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    • v.29 no.2
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    • pp.169-177
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    • 2017
  • Rather than causing damage from heat, blast, and radiation of a regular nuclear weapon, recently, it is predicted that North Korea has been inventing high altitude electromagnetic pulse (HEMP) missile in order to incapacitate electronic equipment. HEMP shielding facility is used for military purpose today. Despite the electromagnetic shielding effects from high quality compression plates, problems may include such as the possibility of electromagnetic influx resulting in the welding of the compression plates, and difficulties and high cost of construction. Therefore, in this study, a high electrical conducting material was added to the concrete experimental subject to ensure the shielding effect through electromagnetic waves to for the concrete structure, instead of building a shielding facility separately for the structure. Also, among the experimental subjects, 100 ${\mu}m$ of Iron-Aluminum alloy metal spraying coat was applied to two types with the highest shielding effect, and to two types with the lowest shielding effect. The result of the experiment indicates that experimental subjects added with a high electrical conductivity material did not meet the minimum shielding criteria of MIL-STD-118-125-1 standard, but all the experimental material applied to the metal spraying coating satisfied the minimum shielding criteria. In conclusion, it is considered that 100 µm of Iron-Aluminum alloy metal spraying coat contains high efficiency in the HEMP shielding.

Pulsed-Bias Pulsed-RF Passive Load-Pull Measurement of an X-Band GaN HEMT Bare-chip (X-대역 GaN HEMT Bare-Chip 펄스-전압 펄스-RF 수동 로드-풀 측정)

  • Shin, Suk-Woo;Kim, Hyoung-Jong;Choi, Gil-Wong;Choi, Jin-Joo;Lim, Byeong-Ok;Lee, Bok-Hyung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.1
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    • pp.42-48
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    • 2011
  • In this paper, a passive load-pull using a GaN HEMT (Gallium Nitride High Electron Mobility Transistor) bare-chip in X-band is presented. To obtain operation conditions that characteristic change by self-heating was minimized, pulsed drain bias voltage and pulsed-RF signal is employed. An accuracy impedance matching circuits considered parasitic components such as wire-bonding effect at the boundary of the drain is accomplished through the use of a electro-magnetic simulation and a circuit simulation. The microstrip line length-tunable matching circuit is employed to adjust the impedance. The measured maximum output power and drain efficiency of the pulsed load-pull are 42.46 dBm and 58.7%, respectively, across the 8.5-9.2 GHz band.

An Experimental Study on the Development of Electro Magnetic Pulse Shielding Cement Using Milled Carbon Fiber (저 직경 카본섬유를 사용한 전자기 펄스 차폐 시멘트 개발에 관한 실험적 연구)

  • Min, Tae-Beom
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.4
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    • pp.429-435
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    • 2020
  • In this study, physical properties and EMP shielding performance evaluation of cement paste according to the amount of milled carbon fiber was conducted to develop EMP shielding cement using carbon fiber. The length of the milled carbon fiber used was 100㎛, and it was used as a cement admixture because it showed a powdery form to the naked eye. As a result of the experiment, when 5% of the amount of cement was used, the milled carbon fiber was effective in compressive strength and EMP shielding, and the shielding effect did not increase when used beyond that. As a result of examining the EMP shielding performance according to the thickness of the specimen, the plain without milled carbon fiber had no effect of increasing the shielding rate according to the thickness. The shielding performance of the specimens using the milled carbon fiber increased as the thickness increased. Therefore, in order to increase the EMP shielding rate when comparing and evaluating the performance according to the amount of milled carbon fiber used and the thickness of the specimen, 5% of the milled carbon fiber used is optimal. In addition, the method of increasing the thickness is considered to be effective.

Aspect of the chief of state guard EMP (Electro Magnetic Pulse) protection system for the consideration (국가원수 경호적 측면에서의 EMP(Electro Magnetic Pulse) 방호 시스템에 대한 고찰)

  • Jung, Joo-Sub
    • Korean Security Journal
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    • no.41
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    • pp.37-66
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    • 2014
  • In recent years, with the development of computers and electronics, electronics and communication technology in a growing and each part is dependent on the cross-referencing makes all electronic equipment is obsolete due to direct or indirect damage EMP. Korea and the impending standoff North Korea has a considerable level of technologies related to the EMP, EMP weapons you already have or in a few years, the development of EMP weapons will complete. North Korea launched a long-range missile and conducted a nuclear test on several occasions immediately after, when I saw the high-altitude nuclear blackmail has been strengthening the outright offensive nuclear EMP attacks at any time and practical significance for the EMP will need offensive skills would improve. At this point you can predict the damage situation of Korea's security reality that satisfy the need, more than anything else to build a protective system of the EMP. The scale of the damage that unforeseen but significant military damage and socio-economic damage and fatalities when I looked into the situation which started out as a satellite communications systems and equipment to attack military and security systems and transportation, finance, national emergency system, such as the damage elsewhere. In General, there is no direct casualties reported, but EMP medical devices that rely on lethal damage to people who can show up. In addition, the State power system failure due to a power supply interruption would not have thought the damage would bring State highly dependent on domestic power generation of nuclear plants is a serious nuclear power plant accident in the event of a blackout phenomenon can lead to the plant's internal problems should see a forecast. First of all, a special expert Committee of the EMP, the demand for protective facilities and equipment and conduct an investigation, he takes fits into your budget is under strict criteria by configuring the contractors should be sifting through. He then created the Agency for verification of performance EMP protection after you have verified the performance of maintenance, maintenance, safety and security management, design and construction company organized and systematic process Guard facilities or secret communications equipment and perfect for the EMP, such as protective equipment maneuver system should take.

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Development of the HEMP Generation, Propagation Analysis, and Optimal Shelter Design Tool (고 고도 전자기파(HEMP) 발생과 전파해석 및 방호실 최적 설계 Tool 개발)

  • Kim, Dong Il;Min, Gyeong Chan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.10
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    • pp.2331-2338
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    • 2014
  • The HEMP threat may have acquired new, and urgent, relevance as the proliferation of nuclear weapons and missile technology accelerates of the North Korea, for example, is assessed as already having developed few atomic weapons, and is on the verge of North Korea already has missiles capable of delivering a nuclear warhead against South Korea. ITU K.78, K81 and IEC recommended its counter-measuring for the industrial facilities with navigation and sailing facilities in order to obviate the all of processor equipped system malfunctions from the EMP/HEMP but its simulation must only be done by the computer simulation which had studied on the 1960-1990 years USA/AFWL papers. This result has a significant activities to the South Korea being under the North Korea threat because all of HEMP related products was strongly limited for export. The HEMP cord which was developed newly by the KTI including the HEMP generation & propagation analysis, optimal shelter design tool, essential EM energy attenuation in multi-layered various soils and rocks and HEMP filter design tool. Especially, the least square fitting method was adopted to analysis for the EM energy attenuation in the soils and rocks because it has a various characteristics based on the many times field test reports.

A DC-DC Converter Design for OLED Display Module (OLED Display Module용 DC-DC 변환기 설계)

  • Lee, Tae-Yeong;Park, Jeong-Hun;Kim, Jeong-Hoon;Kim, Tae-Hoon;Vu, Cao Tuan;Kim, Jeong-Ho;Ban, Hyeong-Jin;Yang, Gweon;Kim, Hyoung-Gon;Ha, Pan-Bong;Kim, Young-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.3
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    • pp.517-526
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    • 2008
  • A one-chip DC-DC converter circuit for OLED(Organic Light-Emitting Diode) display module of automotive clusters is newly proposed. OLED panel driving voltage circuit, which is a charge-pump type, has improved characteristics in miniaturization, low cost and EMI(Electro-Magnetic Interference) compared with DC-DC converter of PWM(Pulse Width Modulator) type. By using bulk-potential biasing circuit, charge loss due to parasitic PNP BJT formed in charge pumping, is prevented. In addition, the current dissipation in start-up circuit of band-gap reference voltage generator is reduced by 42% and the layout area of ring oscillator is reduced by using a logic voltage VLP in ring oscillator circuit using VDD supply voltage. The driving current of VDD, OLED driving voltage, is over 40mA, which is required in OLED panels. The test chip is being manufactured using $0.25{\mu}m$ high-voltage process and the layout area is $477{\mu}m{\times}653{\mu}m$.