• 제목/요약/키워드: Biased report

검색결과 42건 처리시간 0.029초

시공유형에 따른 ACSR 480Rail 가공송전선 접속개소의 기계적 및 열적 특성 연구 (The Study on Mechanical and Thermal Properties of ACSR 480Rail Conductor with Various Defects)

  • 안상현;김병걸;김상수;손홍관;박인표
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1297_1298
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    • 2009
  • According to previous report, aged sleeves for old transmission lines have various defect such as biased installation or corrosion of steel sleeve. These defects occupied almost 50 percent of investigated aged sleeves. These defects can cause serious accidents such as rapid increasing of sag or falling out of overhead conductor from sleeves. Moreover, the defects have been limited power capacity of transmission line. This paper study on thermal behavior of ACSR 480Rail conductor and sleeve with various defect model. The detailed results were presented in the text.

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Statistical Bias and Inflated Variance in the Genehunter Nonparametric Linkage Test Statistic

  • Song, Hae-Hiang;Choi, Eun-Kyeong
    • Communications for Statistical Applications and Methods
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    • 제16권2호
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    • pp.373-381
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    • 2009
  • Evidence of linkage is expressed as a decreasing trend of the squared trait difference of two siblings with increasing identical by descent scores. In contrast to successes in the application of a parametric approach of Haseman-Elston regression, notably low powers are demonstrated in the nonparametric linkage analysis methods for complex traits and diseases with sib-pairs data. We report that the Genehunter nonparametric linkage statistic is biased and furthermore the variance formula that they used is an inflated one, and this is one reason for a low performance. Thus, we propose bias-corrected nonparametric linkage statistics. Simulation studies comparing our proposed nonparametric test statistics versus the existing test statistics suggest that the bias-corrected new nonparametric test statistics are more powerful and attains efficiencies close to that of Haseman-Elston regression.

강 슬리브 파단 직선 슬리브의 장력 및 열적 특성 분석 연구 (The Study on Tension and thermal properties of Corrosive-fractured Steel Sleeve)

  • 안상현;김병걸;김상수;손홍관;박인표;김성규
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.104-105
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    • 2008
  • According to previous report, aged sleeves of old transmission line showed several defaulted installation patterns, which is biased or corrosive-fractured of steel sleeve installed cases. The latter case occupied almost 25 percent of investigated aged sleeves. These defects can cause serious accidents such as rapid increasing of sag or falling out of overhead conductor from sleeves. This paper studies thermal properties and tension for ACSR conductor in case of fractured steel sleeve model. The detailed results were presented in the text.

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Threshold voltage control in dual gate ZnO-based thin film transistors

  • Park, Chan-Ho;Lee, Ki-Moon;Lee, Kwang-H.;Lee, Byoung-H.;Sung, Myung-M.;Im, Seong-Il
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.527-530
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    • 2009
  • We report on the fabrication of ZnO-based dual gate (DG) thin-film transistors (TFTs) with 20 nm-thick $Al_2O_3$ for both top and bottom dielectrics, which were deposited by atomic layer deposition on glass substrates at $200^{\circ}C$. Whether top or bottom gate is biased for sweep, our TFT almost symmetrically operates under a low voltage of 5 V showing a field mobility of ~0.4 $cm^2/V{\cdot}s$ along with the on/off ratio of $5{\times}10^4$. The threshold voltage of our DG TFT was systematically controlled from 0.5 to 2.0 V by varying counter gate input from +5 to -2 V.

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Switchable Uncompensated Antiferromagnetic Spins: Their Role in Exchange Bias

  • Lee, Ki-Suk;Kim, Sang-Koog;Kortright J.B.;Kim, Kwang-Youn;Shin, Sung-Chul
    • Journal of Magnetics
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    • 제10권1호
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    • pp.36-39
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    • 2005
  • We report element-resolved and interface-sensitive magnetization reversals investigated from an oppositely exchange-biased NiFe/FeMn/Co structure by employing soft x-ray resonant Kerr rotation measurements. We have found not only switchable uncompensated antiferromagnetic regions with its sizable thicknesses at both interfaces of the FeMn layer but also their strong coupling to the individual ferromagnetic layers. These experimental results provide a better insight into experimentally observed reductions in exchange-bias field on the basis of an interface-proximity model proposed in this work.

Universal time relaxation behavior of the exchange bias in ferromagnetic/antiferromagnetic bilayers

  • Dho Joonghoe
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2005년도 동계학술연구발표회 및 2차 아시안포럼
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    • pp.80-81
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    • 2005
  • The resilience of the exchange bias ($H_{EX}$) in ferromagnet / antiferromagnet bilayers is generally studied in terms of repeated hysteresis loop cycling or by protracted annealing under reversed field (training and long-term relaxation respectively). The stability of $H_{EX}$ is fundamental for practical application of exchange bias systems. In this paper we report measurements of training and relaxation in FeNi films coupled with the antiferromagnet FeMn. We show that $H_{EX}$ suppressed both by training and relaxation was partially recovered as soon as a field cycling for consecutive hysteresis loop measurement was stopped or the magnetization of the ferromagnet was switched back to the biased direction.

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고령남성의 경제활동참가 결정요인 연구 - 노후빈곤노동가설 및 숙련편향기술진보설을 중심으로 - (Study on Factors Determining Labor Force Participation Rate of Older males : The Elderly Poverty Labor Hypothesis and Skill-Biased Technological Change Hypothesis)

  • 지은정
    • 한국사회복지학
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    • 제60권3호
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    • pp.31-58
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    • 2008
  • 본 연구는 기존에 제기된 고령남성의 경제활동참가를 설명하는 이론(가설)이 우리나라 고령남성의 경제활동참가를 설명하기에는 부족하다는 판단아래, 노후빈곤노동가설과 숙련편향기술진보설을 적용하여 분석하였다. 자료는 통계청의 경제활동인구총괄($1965{\sim}2007$), 추계인구($1965{\sim}2007$), 임금구조기본통계($1993{\sim}2005$), 노동패널 $1{\sim}9$차 원 자료, 2005년 가계조사이며, 회귀분석은 로지스틱 분석을 활용하였다. 분석결과 첫째, 우리나라 고령남성의 경제활동참가율은 산업화가 본격적으로 이루어진 1965년 이후 증가추세를 이어가고 있어, 선진국의 감소추세와는 다르다. 둘째, $1998{\sim}2005$년까지 빈곤 고령남성의 경제활동참가율이 비빈곤 고령남성의 경제활동참가율보다 평균 5.2% 높았다. 셋째, 점점 상위 직종(고위직 및 전문가)은 비고령 계층이 차지하고, 하위 직종(단순노무직)은 고령계층이 주를 이루어가고 있었다. 넷째, 고학력자의 노동공급이 증가한 것보다 그들에 대한 노동수요는 더 크게 증가한 반면, 저학력자의 노동공급은 줄었는데, 이들에 대한 노동수요는 더 큰 폭으로 감소하였다. 그 결과 대학프리미엄이 139%(1993년)에서 157.8%(2005년)로 높아졌다. 다섯째, 고령자의 경제활동 참가율을 설명하는 이론(가설)으로서, 산업화 근대화 가설은 최근 우리나라 상황에도 적용된다. 그러나 노후풍요가설은 고령자의 경제활동참가에 영향을 미치지만, 영향력은 미약하였다. 특히 노후빈곤이 노후경제활동의 주된 메커니즘으로 나타나, 본 연구에서 주장한 노후빈곤노동가설이 지지되었다. 숙련편향기술진보설은 우리나라 고령남성의 경제활동참가율을 부분적으로 설명하지만, 그 외에도 인적자본 특히 고학력보다는 고졸이면서 상대적으로 숙련편향정도가 낮은 직종의 기술 혹은 노후빈곤이 영향을 미친 것으로 판단된다.

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마하-젠더 광 변조기와 EDFA로 구성된 아날로그 광통신 링크에서 변조기 바이어스 조정을 이용한 랜덤 지터의 감소 (Jitter Reduction by Modulator-Bias Control in Analog Fiber-Optic Links Employing a Mach-Zehnder Modulator Followed by an Erbium-Doped Fiber Amplifier)

  • 이민영;윤영민;신종덕
    • 전기전자학회논문지
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    • 제13권4호
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    • pp.103-109
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    • 2009
  • 본 논문에서는 마하-젠더 광 변조기와 EDFA(Erbium-Doped Fiber Amplifier)로 구성된 아날로그 광통신 링크에서 광 변조기에 인가되는 바이어스 전압의 조정을 통해 광통신 링크 출력의 랜덤 지터를 효과적으로 감소시키는 방법에 관하여 연구하였다. 광 변조기의 바이어스를 $0.5\;V_{\pi}$로부터 약 $0.089\;V_{\pi}$로 이동시켰을 때, 10 GHz RF 신호의 이득은 최대 10.65 dB가 증가하였고, 랜덤 지터는 EDFA의 입력 광 파워가 -0.11 dBm일 때 최대 46.5% 감소하였다.

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전기화재원인분류의 문제점 분석 및 개선안 제시 (Improvement and Analysis for an Electrical Fire Cause Classification)

  • 이종호;김두현;김성철
    • 한국화재소방학회논문지
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    • 제23권2호
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    • pp.36-40
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    • 2009
  • 본 논문은 전기화재 통계의 신뢰성을 향상시키고 효율적인 전기화재 자료를 수집하기 위한 전기화재 원인분류의 개발에 관한 연구이다. 전기화재에 대한 잘못되거나 편향된 지식은 전기화재에 대한 형태 분류를 바뀌게 한다. 전기화재 원인분석에 있어 화재조사자들이 올바르게 보고서를 작성할 수 있는 표준화된 형식을 개발하는 것이 필요하다. 본 연구에서는 원인들간의 인과관계를 고려한 계층구조로 새롭게 개발된 전기화재 원인분류체계를 제안하였다. 그리고 제안된 분류체계는 전기화재 조사 및 통계에 사용될 수 있으며, 전기화재 진단의 오류를 최소화할 수 있다.

A New Approach to Statistical Analysis of Electrical Fire and Classification of Electrical Fire Causes

  • Kim, Doo-Hyun;Lee, Jong-Ho;Kim, Sung-Chul
    • International Journal of Safety
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    • 제6권2호
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    • pp.17-21
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    • 2007
  • This paper aims at the statistical analysis of electrical fire and classification of electrical fire causes to collect electrical fires data efficiently. Electrical fire statistics are produced to monitor the number and characteristics of fires attended by fire fighters, including the causes and effects of fire so that action can be taken to reduce the human and financial cost of fire. Electrical fires make up the majority of fires in Korea(including nearly 30% of total fires according to recent figures), The incorrect and biased knowledge for electrical fires changed the classification of certain types of fires, from non-electrical to electrical. It is convenient and required to develop the standardized form that makes, in the assessment of the cause of electrical fires, the fire fighters directly ticking the appropriate box on the fire report form or making an assessment of a text description. Therefore, it is highly recommended to develop electrical fire cause classification and electrical fire assessment on the fire statistics in order to categorize and assess electrical fires exactly. In this paper newly developed electrical fire cause classification structure, which is well-defined hierarchical structure so that there are not any relationship or overlap between cause categories, is suggested. Also fire statistics systems of foreign countries are introduced and compared.