• Title/Summary/Keyword: Extremely low power

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Reforming Method for the Technical Regulations of Extremely Low Power Devices (국내 미약 무선국 기술기준 개선방안)

  • Kang, Gun-Hwan;Oh, Se-Jun;Lee, Jae-Chun;Park, Duk-Kyu
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.391-396
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    • 2005
  • In this dissertation, we discuss the trends of policy and analyze the technical regulation for the extremely low power devices in other countries. In addition, this paper proposes a draft revision of technical regulation for new efficient electric field strength of extremely low power devices in accordance with the technical requirement of Electromagnetic Compatibility. Based on these researches, the contents of this study will be useful to contribute a domestic efficient expansion and development of extremely low power devices and strengthen a competitiveness on international communication markets.

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A Study on Configuration of Extremely Low Phase Noise Oscillator Circuit

  • Sakuta, Yukinori;Arai, Yuji;Sekine, Yoshifumi
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1196-1199
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    • 2002
  • The low phase noise frequency source to be used for measurements and so on realizes by oscillator having highly output signal power against output noise power. SAW devices can be used by high power than BAW devices. So we examine on configuration of SAW oscillator circuits with the power gain. In this paper we shall discuss a configuration of oscillator circuit to obtain an extremely low phase noise and an oscillator operating at a non-reactive frequency of SAW resonator.

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New Start-Up Logic for Microturbine by Constant Power Control under an Extremely Low Temperature (극저온 환경에서의 정 출력 제어를 적용한 마이크로터빈의 새로운 시동 로직 개발)

  • Rho, Min-Sik
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.12
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    • pp.1249-1255
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    • 2006
  • This paper presents a constant power control logic for perfect starting a microtubine in vehicle. Under extremely low temperature, performance of the start-up system is severely dropped than that of room temperature because of increasing of load of mechanical parts including engine core and drop of the lead-acid battery capacity. Unfortunately, performance drop of lead-acid battery makes severe problems that cause a malfunction of fuel and lubrication system and power fail of digital devices. So we propose the new start-up logic by constant output power control of lead-acid battery using PWM inverter controller for preventing above problems and keeping good performance of start-up system for microturbine. Also, we prove usefulness of new start-up logic through experimental results under $-32^{\circ}C$ ambient temperature.

Improvement of Fringe Area using ICS Extremely Low Power Repeater (ICS 극소출력 중계기를 이용한 난시청 개선)

  • Choi, Soo-cheol;Cho, Ki-ryang
    • Journal of Broadcast Engineering
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    • v.21 no.1
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    • pp.97-104
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    • 2016
  • In this paper, in order to relieve the area of terrestrial DTV broadcasting, we watch the same channel DTV Repeater output ICS using nano field test and analysis of effect was proven. Interspersed throughout the blanket area(natural) and buildings(artificially) 7 established the field selected as the test area, and each station(KBS1, KBS2, MBC, SBS, EBS) Extremely Low Power ICS Repeater the same channel of the receiving field strength and after install, SNR(Signal to Noise Ratios) verify the equipment to measure the efficacy and minimal output for future ICS type nav should you wish to provide a research-based for the spread.

Study on the Magnetic Shield Effect of Carbon-based Materials at Extremely Low Frequency (탄소계 소재를 이용한 극저주파 영역에서의 자기 차폐효과 연구)

  • Oh, Seong Moon;Kang, Dong Su;Lee, Sang Min;Baek, Un Gyeong;Roh, Jae Seung
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.15-20
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    • 2015
  • To examine the magnetic shielding effect for carbon-based materials at extremely low frequencies (60 Hz), two types of carbon black (Super-P and Denka Black) and a natural graphite (HC-198) were mixed into organic binder at 10 wt.% to produce a coating solution, and a powder coating with varying thickness was applied on an aluminum disk measuring 88 mm in radius. A device was developed to measure the sheielding effect at extremely low frequencies. A closed circuit was achieved by connecting a transformer and a resistor. The applied voltage was fixed at 65 V, and the magnetic field was measured to being the range of 4.95~5.10 mG. Depending on the thickness of the coating layer, the magnetic field showed a decreasing trend. The maximum decrease in the magnetic field of 38.3% was measured when natural graphite was coated with specimens averaging $455{\mu}m$. This study confirmed that carbon-based materials enable magnetic shielding at extremely low frequencies, and that the magnetic shielding effect can be enhanced by varying the coating thickness.

Relationship Between Urinary Melatonin Levels and Extremely Low Frequency Magnetic Fields for the Selected Primary Schoolchildren Living Nearby and Away from Overhead Transmission Power Line (송전선로 주변과 비주변 초등학생을 대상으로 극저주파 자기장 노출과 뇨중 멜라토닌 분비량간의 상관성 연구)

  • Cho, Yong-Sung;Kim, Yoon-Shin;Lee, Jong-Tae;Hong, Seung-Cheol;Jang, Seong-Ki
    • Journal of Environmental Health Sciences
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    • v.30 no.3
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    • pp.191-206
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    • 2004
  • The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

Design of Ultra Low-Voltage NCL Circuits in Nanoscale MOSFET Technology (나노 MOSFET 공정에서의 초저전압 NCL 회로 설계)

  • Hong, Woo-Hun;Kim, Kyung-Ki
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.4
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    • pp.17-23
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    • 2012
  • Ultra low-power design and energy harvesting applications require digital systems to operate under extremely low voltages approaching the point of balance between dynamic and static power consumption which is attained in the sub-threshold operation mode. Delay variations are extremely large in this mode. Therefore, in this paper, a new low-power logic design methodology using asynchronous NCL circuits is proposed to reduce power consumption and not to be affected by various technology variations in nanoscale MOSFET technology. The proposed NCL is evaluated using various benchmark circuits at 0.4V supply voltage, which are designed using 45nm MOSFET predictive technology model. The simulation results are compared to those of conventional synchrouns logic circuits in terms of power consumption and speed.

Study on minimizing Extremely-Low-Frequency magnetic fields around power cables and busbars (송전선과 분전반 모선으로부터 발생하는 극저주파 자기장 저감을 위한 연구)

  • Lou, Ming;Jeung, Gi-Woo;Kim, Dong-Hun
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.88-90
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    • 2009
  • Extremely-Low-Frequency(ELF) magnetic fields are generated around power cables and bus bars in power systems. Such the stray fields may cause disturbances to nearby electronic apparatus and affect even human health. In order to seeking out a proper way to reducing the fields, the first thing to do is to accurately predict field distribution around analysis models of interest. Then, optimization techniques should be applied for finding a more improved design than the initial one. To achieve this goal, commercial electromagnetic software, MagNet, is combined with evolution strategy algorithm. For verification of the proposed method, three-phase power line cables and busbar systems have been tested.

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High-voltage and low power consumption driver for an electronic paper

  • Hattori, Reiji;Wakuda, Satoshi;Asakawa, Michihiro;Masuda, Yoshitomo;Nihei, Norio;Yokoo, Akihiko;amada, Shuhei
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.222-225
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    • 2006
  • A custom-made display driver for an electronic paper is presented, which has high-voltage multilevel output capability and extremely low power consumption. An original level-shifter circuit can effectively reduce the power consumption and the chip area. This driver was implemented to a Quick-Response Liquid Powder Display (QR-LPD) and the image quality and power consumption was estimated.

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A Study on the Exposure Assessment of Extremely Low Frequency Magnetic Fields (극저주파 자계의 노출 평가에 대한 연구)

  • Kim, Eung-Sik;Kim, Myeong-Hun;Min, Suk-Won
    • Journal of the Korean Society of Safety
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    • v.32 no.1
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    • pp.33-40
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    • 2017
  • This paper addresses the assessment methods used to evaluate the magnetic exposure of a human to ELF EMF (Extremely Low Frequency Electromagnetic Field) which is caused by the process of power delivery from 60 Hz commercial power. These days the main concern is primarily focused on the magnetic field. For the exposure assessment, both numerical studies and laboratory experiments were studied and the results of the two compared for methodological suitability. The numerical analyses employ the Impedance Method (IM), Boundary Element Method (BEM), and Finite Element Method (FEM) and the laboratory experiments used various human phantom models made with conductivities congruent to human organs and then exposed to uniform/non-uniform magnetic fields to produce eddy currents. Under these conditions a number of examples have been evaluated and the reliability assessed to present the pros and cons of each methodology.