• Title/Summary/Keyword: High-frequency wave injection

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A Development of the Optimized Shielding Room Design Simulator for HEMP Protection (HEMP 방호용 차폐실 최적설계를 위한 시뮬레이터 개발)

  • Min, Gyung-Chan;Kim, Dong-Il
    • 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.

Behaviors of Impulse Ground Impedances Associated with the Current Injection Point in a Ground Rod (봉상 접지전극에시 전류유입위치에 따른 임펄스 접지임피던스의 특성)

  • Lee, Bok-Hee;Jeong, Dong-Cheol;Lee, Su-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.1
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    • pp.94-100
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    • 2005
  • This paper presents the behaviors of transient and effective impulse impedances of a long ground rod associated with the current injection points. The laboratory test for the time domain performance of actual-sized model ground rod subjected to a lightning stroke current has been carried out The transient ground impedances of long ground rods under impulse currents were higher than the ground resistance. Both of the ground resistance and the effective impulse ground impedance decrease with increasing the length of the ground rods. Also, the effective impulse ground impedances are significantly increased in fast rise time ranges. The reduction of the ground resistance is decisive to improve the impulse impedance characteristics of grounding systems. When the test current is injected at the bottom of ground rod, the oscillating pulses with high frequency are included on the wave front of ground rod potential and the effective impulse impedances are higher than any other cases.

Treatment Effect of Voice Therapy for Sulcus Vocalis and Vocal Bowing -4 Case Reports- (성대구증과 궁형성대의 발성치료의 효과 -증 례 보 고-)

  • Nam, Do-Hyun;Choi, Seong-Hee;Choi, Jae-Nam;Choi, Hong-Shik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.16 no.1
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    • pp.68-75
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    • 2005
  • The treatment of sulcus vocalis and vocal bowing has been commonly used Thyroplasty Type surgery or injection within vocal folds such as Teflon, silicone, collagen. However, and treatment has not been acquired satisfactory treatment effect. This study was conducted to demonstrate voice therapy effect using singer's vocal technique and respiratory training. 4 patients (1 male, 3 females) with sulcus vocalis or bowing, with or without scar were selected for this study and we compared with acoustic, aerodynamic measures and stroboscopy observation before and after voice therapy. The results showed that 1) case 1 (48yr, male) with sulcus vocalis decreased F0 (Fundamental Frequency), increase CQ(Close Quotient) and high degree of satisfaction but not improved voice quality after voice therapy. 2) case 2(19yrs, femal) with mild sulcus vocalis improved as normal voice quality after voice therapy. 3) case 3(38yrs, female) with functional bowing showed abnormalvocal contact before therapy whereas CQ was increased after voice therapy. 4) case 4(27yrs, female) with vocal atrophy and vocal bowing changed normal range of Fo and increased CQ after voice therapy. Even though contact area of both vocal folds was increased and lowered F0 after voice therapy, current outcomes revealed that normal voice quality was not regained. These results might signify that it was difficult that vocal folds couldn't be recovery of symmetry and viscoelastic property of mucosal wave through voice therapy. However, it was difficult for this study to maintain voice therapy so that evaluate effect of voice therapy for long-term. Further study will be needed to long-term follow-up for voice therapy with these patients.

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Development of Jelly-Type Simulating Polymer Based Human Tissue for Research on Hyperthermia by High Frequency Magnetic Field (고주파 자계 온열요법 연구를 위한 젤리형의 고분자계 모의인체)

  • Kim, Oh-Young;Choi, Chang-Young;Ma, Sung-Jae;Lim, Sang-Mung;Seo, Ki-Taek
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.572-575
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    • 2006
  • In this work, a variety of polymer based jelly phantoms suitable for the hyperthermia operations to human organs was synthesized in order to confirm the possibility of auxiliary cancer therapy. Specifically, using an appropriate material composition including polyethylene, Jelly phantoms for brain was prepared and characterized their electrical properties suitable for the monitoring the effect of electromagnetic wave from code division multiple access (CDMA) and personal communication service (PCS) on the human body. In the future, after injection of ferromagnetic nanoparticle into the jelly phantoms, new approach to propose the cancer therapy can be anticipated by monitoring the degree of temperature rise in human body using the photograph of Infrared camera.