• 제목/요약/키워드: neutral line

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자유의지에 대한 조작논증과 근원-양립가능주의의 대응 (Compatibilist Replies to Manipulation Arguments)

  • 김성수
    • 논리연구
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    • 제21권3호
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    • pp.373-393
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    • 2018
  • 조작논증은 근원-자유와 결정론이 양립가능하지 않다는 것을 보이고자 한다. 이 논증에 따르면, (1) 일정한 방식으로 조작된 행위는 직관적으로 자유행위가 아니며 (2) 일정한 방식으로 조작된 행위와 결정론적으로 발생한 일상적 행위 사이에 중요한 차이가 없다. 이로부터 결정론적으로 발생한 일상적 행위는, 그것이 양립가능주의자들이 제시한 자유의 조건을 만족하더라도, 자유행위가 아니라는 것이 도출된다. 양립가능주의자들의 대표적인 대응인 '강경한 대응'은 (1)을 부정한다. 그런데 '중립적 입장'에서 볼 때 이 대응은 불충분한 것으로 밝혀진다. 그리고 (1)은 일종의 심리적 오류를 저지른다는 최근의 제안도 이를 극복하지 못한다고 주장한다. 반면 '온건한 대응'은 (2)를 부정한다. 이 대응을 지지하기 위해 먼저 조작적 개입과 단순한 결정 사이의 차이를 밝힌다. 그리고 온건한 대응과 조작논증이 특정한 상황에 대해 서로 다른 예측을 한다는 점에 주목할 때 이 대응을 지지할 이유가 있다고 주장한다.

무선전력전송 전기충전설비용 전원공급장치의 최적운용방안에 관한 연구 (A study on Protection Coordination Method for Electric Vehicle Charging Facility based on the Wireless Power Transmission)

  • 유경상;김병기;김대진;장문석;노대석;고희상
    • 한국산학기술학회논문지
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    • 제18권9호
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    • pp.42-51
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    • 2017
  • 본 논문에서는 전기자동차 배터리의 충전 방안 중 하나로 여겨지는 무선전력전송을 이용할 경우 발생 가능한 보호협조 문제점을 분석한다. 전기충전을 위한 무선전력전송 시스템을 구축하기 위해서는 전원공급장치 개발이 필수적이나, 전원공급장치의 정확한 설치기준이 없기 때문에 운용 시 보호협조 상에 문제점이 발생 할 수 있다. 따라서 본 논문에서는 PSCAD/EMTDC로 무선전력전송 전기충전설비용 전원공급장치를 모델링하여 가능성 있는 사고를 모의해보고, 이를 해결할 수 있는 대안을 제시하고자 한다. 즉, 사고 발생 시, 전원공급장치의 60Hz 대역에서 정격차단용량(12.5kA) 상회 가능성과 20kHz 대역에서의 임피던스 병렬화로 인한 보호기기의 부동작 가능성을 시뮬레이션을 통해 확인하였고, 이에 대한 해결책으로 대칭좌표법을 이용한 사고해석 알고리즘과 사고전류를 저감시킬 수 있는 NGR 산정 알고리즘을 제안하였다. 이를 통해 60Hz 대역에서는 NGR(Neutral Ground Resister)을 도입하여 사고전류를 정격차단용량 이하로 저감시키고, 20kHz 대역에서는 중선선에 CT 설치 및 이에 대한 보호정정을 통해 보호기기 부동작이 방지됨을 확인하였다.

태양광구의 벡터 자기장 구조 (STRUCTURE OF THE PHOTOSPHERIC VECTOR MAGNETIC FIELDS)

  • 조경석;김갑성
    • 천문학논총
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    • 제10권1호
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    • pp.91-108
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    • 1995
  • We have intensively examined the structure of photospheric magnetic fields obtained from the calculation of the polarized radiation transfer for the model atmosphere. To determine more reliable magnetic field in the photospheric region composed of umbra, penumbra and quite area, we have calculated the polarized radiative transfer for a magnetically sensitive spectral line, FeI $6302.5{\AA}$, using our composite model representing three kinds of the atmospheric area distinguished by the pixel value of the Stokes I image over the region. Polarization data of the full Stokes parameters, used in this paper had been obtained from the vector magnetograph on Solar Flare Telescope of National Astronomical Observatory at Mitaka(MTK) in Japan. According to our investigation on the active region in the photosphere, it has been found that the large current density(${\geq}8{\times}10^2A/km^2$) and shear angle(${\geq}85^{\circ}$) should be distributed along the magnetic neutral line. To be compared with the results of MTK, our results in transverse magnetic field strength and direction are similar with those of MTK, however our longitudinal field strength at the center of the spot is somewhat(${\sim}1000$ Gauss) larger than MTK.

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차단기 누적 철분진의 열적특성과 발화위험성 연구 (A Study on the Thermal Characteristics and Fire Hazard of Iron Powder Accumulated on Circuit Break)

  • 김두현;강양현
    • 한국안전학회지
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    • 제27권4호
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    • pp.20-25
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    • 2012
  • The purpose of this study is to analyze the thermal characteristics and to study fire hazard of electric leakage by iron power accumulated on circuit breaker in an iron processing factory. The thermal characteristics were analyzed while current was applied to the powder for ten minutes. Results showed that temperature of iron powder at 100 mA is $160^{\circ}C$ and at 175mA is $240^{\circ}C$. The sparks have occurred as iron powder drops between two(hot line and neutral line) wires and then iron powder explosion occurred while dropping continuously the iron powder on two lines. Those who work in the iron processing industry need to periodically remove and maintain the iron powder. The thermal characteristics in this paper can be used for electrical fire investigation and for basic data of thermal characteristic of leakage current through iron powder at iron processing factories.

Dust-scattered H${\alpha}$ halos around H II regions: On the origins of the diffuse H${\alpha}$ emission

  • 선광일
    • 천문학회보
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    • 제37권1호
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    • pp.74.1-74.1
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    • 2012
  • It is known that the diffuse H${\alpha}$ halos around bright H II regions are more extended than the dust-scattered halos around point sources and the line ratios [S II] ${\lambda}$6716/H${\alpha}$ and [N II] ${\lambda}$6583/H${\alpha}$ observed outside of bright H II regions are generally higher than those in H II regions. These observational facts have been regarded as evidence against the dust-scattering origin of the diffuse H${\alpha}$ emission and the effect of dust-scattering has been neglected in studying the diffuse H${\alpha}$ emission. In this paper, we find, however, that dust-scattered halos of H II regions should be more extended than those of point sources and is in good agreement with the observed H${\alpha}$ profiles around H II regions. We also found that the observed line ratios [S II]/H${\alpha}$, [N II]/H${\alpha}$, and He I ${\lambda}$5876/H${\alpha}$ in the diffuse regions can be well reproduced with the dust-scattered halos around H II regions which are photoionized by late O- and/or early B-type stars in the interstellar medium with the abundances close to those of the warm neutral medium. Therefore, we conclude that the diffuse H${\alpha}$ emission may originate mostly from the dust-scattering.

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접지방식이 상이한 철도배전계통의 연장급전을 위한 전기적 특성분석 (Analysis of electric characteristics for extension power supply between different grounding railway distribution system)

  • 정호성;한문섭;이장무;권삼영;박현준
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.736-741
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    • 2005
  • This paper presents electric characteristics analysis and safe configuration for extension power supply between existent 6.6kV ungrounded distribution system and establishment and improvement 22.9kV direct grounding distribution system. For this, we model 6.6kV ungrounded and 22.9kV direct grounding distribution system of urban underground, ground region. and rural electrical, unelectrical region using PSCAD/EMTDC and analyze voltage drop, charging current, ground and short fault through simulation. To analyze electric characteristics of extension power supply, we simulate extension power supply of overhead line of 6.6kV ungrounded system and underground line of 22.9kV direct grounding system of rural electrical region and propose operation condition for safe extension power supply through result of analysis. Characteristics of voltage drop, charging current, ground and short fault appear almost similarly with electrical characteristic of direct power supply. However, because unbalance of phases may cause relay's malfunction of ungrounded system and ground fault current of direct grounding system may demage facilities of ungrounded system, we propose safe system configuration such as impedance grounding system of neutral point.

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부하변동 시의 고조파제거 및 절전기 개발 (Development of the Harmonics Reduction and Energy Saving Equipment in Variable Loads)

  • 송영복;조용현;최동진
    • 조명전기설비학회논문지
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    • 제20권6호
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    • pp.87-95
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    • 2006
  • 본 연구에서는 부하의 변동 시에 고품질의 전력을 얻기 위하여 중성선과 전력선에 흐르는 각각의 영상 전류 성분과 제3고조파 전류 성분을 감소시킬 수 있는 Zig-Zag 변압기, 그리고 그 변압기의 2차측에 3상 브리지 정류기와 케패시터로 구성된 단상 능동 필터를 제작하였다. 이 단상 능동 필터를 변압기와 비선형 부하에 연결시켜 각 상에 보상 전류를 발생시킴으로써, 비선형 부하로 인하여 발생하는 제3고조파 성분을 감소시킬 수 있었다.

Effect of Phonons on Valley Depolarization in Monolayer WSe2

  • Chellappan, Vijila;Pang, Ai Lin Christina;Sarkar, Soumya;Ooi, Zi En;Goh, Kuan Eng Johnson
    • Electronic Materials Letters
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    • 제14권6호
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    • pp.766-773
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    • 2018
  • In this paper, temperature dependence of the excitonic bands in a mechanically exfoliated tungsten diselenide ($WSe_2$) monolayer is studied using photoluminescence and circular dichroic photoluminescence (PL) in the temperature range between 8 and 300 K. The peak energies associated with the neutral exciton (A), charged exciton (trion) and localized excitons are extracted from the PL spectra revealing a trion binding energy of around 30 meV. The circular dichroic PL measured at 8 K shows about 45% valley polarisation that sharply reduces with increasing temperature to 5% at 300 K with photoexcitation energy of 1.96 eV. A detailed analysis of the emission line-width suggests that the rapid decrease of valley polarisation with the increase of temperature is caused by the strong exciton-phonon interactions which efficiently scatter the excitons into different excitonic states that are easily accessible due to the supply of excess photoexcitation energy. The emission line-width broadening with the increase of temperature indicate residual exciton dephasing lifetime < 100 fs, that correlates with the observed rapid valley depolarisation.

FLASH: The First Large Absorption Survey in HI with the Australian Square Kilometre Array Pathfinder

  • 윤혜인
    • 천문학회보
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    • 제45권1호
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    • pp.63.2-63.2
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    • 2020
  • FLASH is a blind neutral hydrogen (HI) absorption line survey, eventually targeting about 100,000 background radio continuum sources in the entire southern sky using the full 36-antenna of the Australian Square Kilometre Array Pathfinder (ASKAP). Our primary goal is to search for associated and intervening HI absorption lines in the intermediate redshift range 0.4 < z < 1.0. The survey aims to understand the evolution of HI gas in galaxies as well as various physical mechanisms in active galactic nuclei, such as accretion and feedback processes. In this poster, we give an overview of the FLASH survey and present the preliminary results from our first 100-hrs of pilot observations. The latest survey data covers 1,000 square degrees and is ideal for validating observation and data processing in the continuous 300MHz-width low frequency ASKAP band (700-1000MHz). One of the crucial objectives of the pilot survey is to establish the analysis methodology that will be applied to upcoming large absorption surveys in the future. We discuss our data quality validation and present some detections of associated/intervening HI absorption lines. These absorption lines allow us to trace the cold gas properties of active and normal galaxies at higher redshifts where the HI emission line is too weak to be detectable.

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Balmer Wing Formation in Active Galactic Nuclei

  • Chang, Seok-Jun;Lee, Hee-Won
    • 천문학회보
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    • 제40권1호
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    • pp.78.2-78.2
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    • 2015
  • Powered by a supermassive black hole, active galactic nuclei (AGNs) are characterized by prominent emission lines including Blamer lines. The unification scheme of AGNs requires the existence of a thick molecular torus that may hide the broad emission line region. In this configuration, it is expected that the far UV radiation from the central engine can be Raman scattered by neutral hydrogen to reappear around Balmer lines which can be identified observationally with broad Balmer wings. Another mechanism that can form Balmer wings is considered by invoking a fast moving medium around the central engine. In this presentation, we produce Balmer wings that are formed through Raman scattering and also those expected from a fast moving emission flow. It is noted that Raman Balmer wings exhibit stronger red part whereas the opposite behavior is seen in the Balmer wings obtained from a fast moving emission flow.

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