• 제목/요약/키워드: Field measuring

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운방전에 의해 발생한 전계와 자계 파형의 파라미터 분석 (Parametric Analysis of the Electric and Magnetic Field Waveforms Produced by Intracloud Lightning Discharges)

  • 이복희;이우철
    • 조명전기설비학회논문지
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    • 제20권2호
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    • pp.81-88
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    • 2006
  • 본 연구에서는 뇌방전의 전기적 특성에 대해 파악하고자 전계 및 자계 측정시스템을 구축하였다. 주파수 대역 및 응답감도는 전계측정시스템 $40[Hz]{\sim}2.6[MHz]$, 2.1[(V/m)/mV], 자계 측정시스템 $300[Hz]{\sim}1[MHz]$, 28[nT/mV]이다. 구축한 측정시스템을 이용하여 뇌방전에 의해 발생한 전계와 자계 파형을 관측하고, 파형의 여러 가지 파라미터에 대해 통계적으로 분석하였다. 그 결과 전계와 자계 파형은 극성의존성이 미약하였으며, 전계와 자계 파형의 상승시간과 영점교차시간의 평균값은 각각 $5.5[{\mu}s],\;21[{\mu}s]$로 나타났다.

다중 낙뢰에 의해서 발생한 전장 파형의 특성 (Characteristics of the Electric Fields Produced by Multiple Lightning Return Strokes)

  • 이복희;정동철;이동문
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권6호
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    • pp.330-336
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    • 2004
  • In this work, in order to obtain the detailed information about lightning electromagnetic pulses, the electric fields radiated from multiple lightning return strokes were measured and analyzed statistically. The electric field measuring system consists of a hemisphere antenna of 30cm in diameter, integrator and data acquisition device, and its frequency bandwidth ranges from 200Hz to 1.56MHz, and the sensitivity is 0.96㎷/V/m. The electric field signals are digitized every 200ns with the transient signal analyzer having the resolution of 12-bit and the recording length of 5 kilowords and are registered at personal computer. As a result, the electric fields produced by the first return stroke begin with a slow initial part or front, which starts just after or during the last stepped leader. On the average the rise times of the electric fields for the positive first, second and third strokes are 4.21${\mu}\textrm{s}$, 3.94${\mu}\textrm{s}$ and 2.75${\mu}\textrm{s}$, respectively, and those for the negative first, second and third strokes are 3.46${\mu}\textrm{s}$, 3.15${\mu}\textrm{s}$ and 2.79${\mu}\textrm{s}$, respectively. The zero-crossing times of the electric fields for first return strokes range from about 10 to 80${\mu}\textrm{s}$. The mean zero-crossing times for subsequent return strokes are shorter than those for first lightning return strokes.

현장포럼 적용을 위한 농촌주민생활만족도 조사표 개선 연구 (A Study on the Improvement for Survey Table of Rural Residents Satisfaction for the Application of Rural Forum)

  • 이창범;정남수;장우석
    • 농촌계획
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    • 제20권2호
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    • pp.45-56
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    • 2014
  • There are direct and indirect approaches to measure the quality of rural life with comparison of urban. One of the direct approach is to survey living satisfaction of rural residents. Survey result is also important factor for the understanding of local needs in rural development. Rural Development Adminstration(RDA) has developed a survey table with 71 survey items for measuring the satisfaction of rural residents. In rural field forum which have conducted for finding the direction of rural development, the understanding of local needs with measuring the satisfaction of rural residents is important. But developed survey table is difficult to be applied in rural field forum not only many survey items but also overlapping in survey range. The purpose of this study is to suggest a field-applicable survey table in rural field forum based on results of RDA. Survey items were selected based on the importance score of RDA survey table, and weighting values were applied to each survey items. Finally, we suggested 31 items based on results with principle component and reliability analysis.

열역학법에 의한 펌프의 수력효율측정 (Efficiency measuring in pump using Thermodynamic method)

  • 권영준;서창덕;정용채;박장원
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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    • pp.546-551
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    • 2004
  • An applying Thermodynamic method for the purpose of measuring hydraulic efficiency of pump-motor system, based on IEC60041 code, is not easy to adopt at field test. Even though there were splendid development in measuring technic in discharge measuring through the hydraulic machina lots of unsolved problems concerned in flow-rate are still remain in measuring hydraulic efficiency in hydraulic machine. The key point in measuring hydraulic efficiency is to measure exact flow-rate. So, Thermodynamic methode provides a good solution. This methode measures hydraulic efficiency by detecting the difference of temperature and pressure between the hydraulic process of machine, without measuring flow-rate of pump or turbine. By measuring temperature in mk level and absolute pressure in pascal, we can get a difference of thermodynamic specific energy in Moliere chart before and after of hydraulic process, md that difference is equal to hydraulic loses. Following the standard in proceeding Thermodynamic methode, I hope these trial and records make others be familiar to the thermal methode and make it easer to beginner for trial.

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레이저 스페클 간섭법을 이용한 면내 변형 측정 및 해석에 대한 연구 (I) (A Study on Measurement and Analysis of In-Plane Deformations by Using Laser Speckle Interferometry (I))

  • 강영준;노경완;강형수
    • 한국정밀공학회지
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    • 제15권11호
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    • pp.121-129
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    • 1998
  • In-plane ESPI(Electronic Speckle Pattern Interferometry) was devised to measure in-plane deformations and rotation of a specimen with laser in this study. ESPI is a optical measuring method to be able to measure the deformations of engineering components and materials in industrial fields. The conventional measuring methods of surface deformations such as the strain gauge have many demerits because they are contact and point-to-point measuring ones. But that ESPI is noncontact, nondestructive and whole field measuring method can overcome previous disadvantages. We used ESPI which is sensitive to in-plane displacement for measuring in-plane deformations of a disk. And the 4-frame phase shifting method was used for the quantitative analysis. First of all, the system calibration was done due to an in-plane rotation before getting deformations of a disk. Finally we showed good agreement between the experiment results and those of the FEA(Finite Element Analysis).

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지진해일 피해조사 현장지침 작성 (Drawing up the guideline for a field survey of tsunami damages)

  • 김성민;조용식
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.391-394
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    • 2007
  • The field survey of a tsunami damage is carried out to collect and obtain real data. There data can be used to make the countermeasures against possible tsunami attackings. In the survey, many data collecting techniques such as interviewing with local people, taking pictures of the inundated field, recording the location by the GPS, measuring the level and distance of the maximum flood level can be used for practical and effective survey.

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음원의 지향성이 확산음장 형성에 미치는 영향에 관한 실험연구 (Experimental study for characteristics of diffuse sound field formed by sound source directivity)

  • 신일섭;차광석;조창근;이대우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.1002-1006
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    • 2000
  • It is diffuse sound field that measuring condition of absorption ratio and sound transmission loss for material consist of building are measured in reverberartion room and on-site. In this study, for upkeeping diffuse sound field in reverberation room, it is measured and etimated that sound field is effected according to sound source lacation and characteristics of emission directivity for sound source.

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운방전에 의해 발생된 전장과 자장 파형의 파라미터 분석 (Parametric analysis of the electric and magnetic field waveforms produced by intracloud lightning discharges)

  • 이복희;이우철;조성철
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2005년도 학술대회 논문집
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    • pp.281-284
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    • 2005
  • This paper deals with the parametric analysis of electric and magnetic fields generated by lightning discharges. The measuring system consisted of the plate-type electric field and loop-type magnetic field sensor, the voltage follower, the active integrator and LabVIEW software. The parameters of the electric and magnetic field waveforms produced by intracloud lightning strokes were presented.

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Measuring Safety Culture to Promote Aviation Safety Culture

  • Kim, Dae Ho;Choi, Jeong Yeol
    • 대한인간공학회지
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    • 제35권2호
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    • pp.111-123
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    • 2016
  • Objective: The objective of this research is to study preceding literature on safety culture surveying tools and indicators used in aviation organizations to help the further understanding of aviation safety culture by presenting Korea-Safety Culture Survey Indicator (K-SCSI) as a relevant case. Background: The aviation field puts a great deal of effort in preventive safety management through the application of Safety Management System (SMS), which was co-developed by international aviation organizations such as ICAO and FAA. To successfully operate safety management system, safety culture factors such as the organization member's level of consciousness, attitude and faith regarding safety must be put together. However, the aviation field currently lacks programs to promote safety culture and the exact understanding of some safety culture concepts. Method: This research inquired into the definition of safety culture in the aviation field and the surveying tools used to measure it. It then described the development and application process of the Korea-Safety Culture Survey Indicator (K-SCSI) mainly focusing on case studies. Results: In this research are presented safety culture promoting programs that can be applied to subordinate indicators of K-SCSI such as organization commitment, management involvement, rationality of reward system, employee empowerment and reporting system. Conclusion: For a mature safety culture to settle successfully, it is essential that safety culture survey indicators are developed and applied in a way that fits the organization's features. Also, behavior measuring indicators are required to develop a more objective indicator and thus must be standardized. Application: Cases that deal with the development and application of safety culture measuring tools within the aviation field can be studied and applied in other domains to spread safety culture.