• 제목/요약/키워드: Variation Factor

검색결과 2,277건 처리시간 0.029초

다변량 해석기법을 이용한 인천연안해역의 수질평가 (The Evaluation of Water Quality in Coastal Sea of Incheon Using a Multivariate Analysis)

  • 김종구
    • 한국환경과학회지
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    • 제15권11호
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    • pp.1017-1025
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    • 2006
  • This study was conducted to evaluate characteristic of water duality in coastal sea of Incheon using a multivariate analysis. The analysis data in coastal sea of Incheon was aquired by the NFRDI data which was surveyed from March 1997 to November 2003. Eleven water quality parameters were determined on each survey The results were summarized as follow : Water quality in Incheon coastal sea could be explained up to 64.62% by three factors which were included in loading of fresh water and nutrients by the land(36.98%), seasonal variation(16.19%), and internal metabolism (11.24%). The results of time series analysis by factor score, in case of factor 1, station 1 influenced by Han river was shown to high factor score and station 3 located by outer sea was shown to low factor score. In case of factor 2, station 1 was appeared to high variation and station 3 was appeared to low variation. The result of cluster analysis by station was classified into three group that has different water quality characteristics. Especially, station 1 which affected by Han river and station 4 which affected by sewage treatment plant was appeared to considerable water quality characteristics against other station. In yearly cluster analysis, three group was classified and water quality in 2003 years due to high precipitation was different to another year. It could be suggested from these results that it is important to control discharge of fresh water by Han rivet and sewage treatment plant for water quality management of coastal sea of Incheon.

방사선조사에 의한 R-C 직.병렬회로에서의 손상효과에 관한 연구 (A Study on Irradiation Effect by $Co^{60}$ of the R-C Series-Parallel Circuits)

  • 서국철;조성욱
    • 한국조명전기설비학회지:조명전기설비
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    • 제1권2호
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    • pp.57-61
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    • 1987
  • 원자력 산업에서 사용되고 있는 모든 재료의 특성은 방사선조사에 의한 손상효과로 변하게 된다. 본 연구에서는 저항과 콘덴서의 직.병렬회로에서의 방사선조사에 의한 전기적 특성이 여하히 변화되는가를 연구하였다. 연구결과 얻어진 주요 결론은 다음과 같다. 1. R-C 직렬회로에서 조사선량이 $10^6[r]$까지는 임피던스변화율이 증가되다가 그 이상의 조사선량에서는 포화상태에 이르게 되는데 포화상태에서의 증가율은 1.25[%]정도이었다. 2. R-C 직렬회로에서 조사선량이 $10^6[r]$ 까지는 증가변화율이 감소되다가 그 이상의 조사선량에서는 포화상태에 이르게 되는데 감소율은 0.5[%]정도이었다. 3. R-C 병렬회로에서는 방사선량이 $10^6[r]$까지는 임피던스변화율이 증가되다가 그 이상의 방사선량에서는 포화상태에 이르게 되는데 증가율은 0.5[%]정도이었다. 4. R-C 병렬회로에서는 방사선량이 $10^6[r]$까지는 감소되다가 그 이상의 방사선량에서는 포화상태에 이르게 되는데 감소율은 1.3[%]정도이었다.

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General Linearly Constrained Narrowband Adaptive Arrays in the Eigenvector Space

  • Chang, Byong Kun
    • Journal of information and communication convergence engineering
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    • 제15권3호
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    • pp.137-142
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    • 2017
  • A general linearly constrained narrowband adaptive array is examined in the eigenvector space. The optimum weight vector in the eigenvector space is shown to have the same performance as in the standard coordinate system, except that the input signal correlation matrix and look direction steering vector are replaced with the eigenvalue matrix and transformed steering vector. It is observed that the variation in gain factor results in the variation in the distance between the constraint plane and the origin in the translated weight vector space such that the increase in gain factor decreased the distance from the constraint plane to the origin, thus affecting the nulling performance. Simulation results showed that the general linearly constrained adaptive array performed better at an optimal gain factor compared with the conventional linearly constrained adaptive array in a coherent signal environment and the former showed similar performance as the latter in a noncoherent signal environment.

Three-Phase AC-to-DC Resonant Converter Operating in High Power Factor Mode in High-Voltage Applications

  • Chaudhari, Madhuri A.;Suryawanshi, Hiralal M.;Kulwal, Abhishek;Mishra, Mahesh K.
    • Journal of Power Electronics
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    • 제8권1호
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    • pp.60-73
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    • 2008
  • In this paper a three-phase ac-to-dc resonant converter with high input power factor and isolated output is proposed. To improve the input power factor of the converter, high frequency current is injected into the input of the three-phase diode bridge rectifier. It is injected through an impedance network consisting of a series of L-C branches from the output of the high frequency three-phase inverter. A narrow switching frequency variation is required to regulate the output voltage. A design example with different design curves is illustrated along with the component ratings. Experimental verification of the converter is performed on a prototype of 3 kW, 1000 V output, operating above 300 kHz. Experimental results confirm the concept of the proposed converter. Narrow switching frequency variation is required to regulate the output voltage.

Effects of Fabrication Process Variation on Impedance of Neural Probe Microelectrodes

  • Cho, Il Hwan;Shin, Hyogeun;Lee, Hyunjoo Jenny;Cho, Il-Joo
    • Journal of Electrical Engineering and Technology
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    • 제10권3호
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    • pp.1138-1143
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    • 2015
  • Effects of fabrication process variations on impedance of microelectrodes integrated on a neural probe were examined through equivalent circuit modeling and SPICE simulation. Process variation and the corresponding range were estimated based on experimental data. The modeling results illustrate that the process variation induced by metal etching process was the dominant factor in impedance variation. We also demonstrate that the effect of process variation is frequency dependent. Another process variation that was examined in this work was the thickness variation induced by deposition process. The modeling results indicate that the effect of thickness variation on impedance is negligible. This work provides a means to predict the variations in impedance values of microelectrodes on neural probe due to different process variations.

3축 이동하중을 고려한 충격계수 응답스펙트럼 개발 및 중소규모 RC 슬래브 노후교량 응답계수 분석 (Development of Impact Factor Response Spectrum with Tri-Axle Moving Loads and Investigation of Response Factor of Middle-Small Size-RC Slab Aged Bridges)

  • 김태현;홍상현;박경훈;노화성
    • 한국구조물진단유지관리공학회 논문집
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    • 제23권2호
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    • pp.67-74
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    • 2019
  • 본 논문에서는 노후된 중소규모 RC슬래브 교량에 대한 응답계수를 분석하였다. 이 응답계수는 진동수 기반 교량의 내하력 예측 모델에서 중요한 변수이며, 정적 및 동적 응답계수로 구성되어 있다. 정적 및 동적 응답계수는 교량의 현재와 이전(또는 설계) 상태의 진동수 변화와 충격 계수 변화에 따라 각각 결정된다. 여기서 충격계수 변화는 충격계수 응답스펙트럼에서 교량의 고유진동수에 따라 산출된다. 본 연구에서 고려한 총 4개의 대상교량은 지간길이가 12 m이고 시공 후 30년 이상 된 RC슬래브 노후 교량이다. 진동수 분석을 위해 덤프 트럭을 이용한 현장 동적 재하시험과 설계기반 FE모델을 이용한 고유치 해석을 통해 교량의 현재 및 설계 상태의 고유 진동수를 각각 도출하였다. 충격계수 응답스펙트럼 개발에 있어서 좀 더 현실적인 조건을 반영하기 위해 3축이동하중과 단순지지 및 양단고정 조건을 고려하였다. 분석 결과 응답계수는 0.21에서 0.91까지 광범위하게 분포하였고, 정적 응답계수가 총 응답계수 결과에 크게 기여한 반면 동적 응답계수는 결과에 작은 영향을 미쳤다. 1축 이동하중과 단순지지 조건에서의 응답계수와 비교해 보았을 때 최대 오차는 약 3%미만으로 매우 작게 나타났다.

Hairstyle 변화에 의한 얼굴 이미지 요인과 분석 -Computer Graphic simulation을 이용하여 - (The Factor and Analysis on the Face Image to Hairstyle Variation - using by Computer Graphic Simulation-)

  • 도주연;권영숙
    • 한국의류학회지
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    • 제16권3호
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    • pp.243-250
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    • 1992
  • The purposes of this research were to analyze factor structure and the face image to hairstyles which was made by Computer graphic simulation. To select ten hairstyle, a standard face selected between women of $20\~25$ years, and four factor (straight, curl, hair length, front hair, part hair) which were made of stand of hairstyle were applied. The results were as follows; 1 face image factor by hairstyle variation were found to five factor; negative and pogitive, indivisuality, youthfulness, unbanity, intelligence. 2. The result of analysis to face image by hairstyle factor were (1) In the hair state, straight hair was explained by the youthful, pure, decent image than curl. (2) In the hair length, the longer hair was explained by the more feminine, softness image. The shorter hair was explained by the more vigorous, youthful image. (3) In the presence of front hair, bang hair was explained by the commonness, moderate, classical image than all back hair (4) In the part hair, part hair was explained by the modern and unbanity image than no part hair.

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중복된 멀티캐리어 DS-CDMA 시스템의 서브밴드 중복율 변화에 따른 성능개선에 관한 연구 (A Study on the Performance Improvement with Subband Overlapping Variation for Overlapped Multicarrier DS-CDMA Systems)

  • 오정헌;박광철;김기두
    • 대한전자공학회논문지TC
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    • 제37권9호
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    • pp.11-23
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    • 2000
  • 멀티캐리어 DS-CDMA는 다중경로 페이딩 채널에서 광대역 시스템의 구현에 효과적인 방법이다. 본 논문에서는 콘볼루션 코딩을 적용한 중복된 멀티캐리어 DS-CDMA 시스템을 제안하고, 중복율 변화에 대한 성능을 분석하여 정해진 서브밴드 캐리어 수에 따라 최적의 성능을 제공하는 중복율을 제시한다. 특히 전체 서브캐리어 수에 따라 최적의 성능을 제공하는 중복율을 제시한다. 특히 전체 서브캐리어 수 M*R 값이 같다면 콘볼루션 코딩율 1/M과 반복 코딩율 1/R 값에 관계없이 칩 성형필터의 rolloff인자 β값이 같으면 중복율 변화에 따른 BET의 변화 형태가 거의 동일함을 보인다. 그리고 서브밴드의 중복인자 (0<β≤2) 변화와 rolloff인자(0<β≤1)의 변화에 따른 MUI를 분석하여 기존의 멀티태리어 시스템과 성능을 비교하고, 제안한 시스템의 중복율 변화에 따른 성능 개서 정도를 보인다.

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Factor Analysis of Biometric Traits of Kankrej Cows to Explain Body Conformation

  • Pundir, R.K.;Singh, P.K.;Singh, K.P.;Dangi, P.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권4호
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    • pp.449-456
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    • 2011
  • Eighteen different biometric traits in 407 Kankrej cows from their breeding zone, i.e. Palanpur district of Gujarat, India, were recorded and analyzed by factor analysis to explain body conformation. The averages of body length, height at withers, height at shoulder, height at knee, heart girth, paunch girth, face length, face width, horn length, horn diameter, distance between horns, ear length, ear width, neck length, neck diameter, tail length with switch, tail length without switch and distance between hip bones were $123.44{\pm}0.37$, $124.49{\pm}0.28$, $94.68{\pm}0.30$, $38.2{\pm}0.14$, $162.56{\pm}0.56$, $178.95{\pm}0.70$, $44.09{\pm}0.10$, $15.91{\pm}0.05$, $42.47{\pm}0.53$, $26.07{\pm}0.19$, $13.34{\pm}0.08$, $31.24{\pm}0.12$, $16.10{\pm}0.05$, $50.63{\pm}0.18$, $73.21{\pm}0.32$, $111.62{\pm}0.53$, $89.34{\pm}0.34$ and $17.28{\pm}0.10\;cm$, respectively. The correlation coefficients between different traits ranged from -0.806 (horn diameter and distance between horns) to 0.815 (heart girth and paunch girth). Most of the correlations were positive and significant. Factor analysis with promax rotation with power 3 revealed three factors which explained about 66.02% of the total variation. Factor 1 described the cow body and explained 38.89% of total variation. The second factor described the front view/face of the cow and explained 19.68% of total variation. The third factor described the back of the cow and explained 7.44% of total variation. It was necessary to include some more variables for factor 3 to obtain a reliable estimate of the back view of the cow. The lower communities shown for distance between horns, horn diameter, ear width and neck diameter indicated that these traits did not contribute effectively to explaining body conformation and can be dropped from recording, whereas all other traits are important and needed to explain body conformation in Kankrej cows. The result suggests that principal component analysis (PCA) could be used in breeding programs with a drastic reduction in the number of biometric traits to be recorded to explain body conformation.

Landsat 영상을 이용한 국내 경지면적 변화에 따른 요인분석 및 추정방법에 관한 연구 (A Study of the Primary Factor Analysis and Estimated Methods According to Domestic Agricultural Area Variations Using Landsat Images)

  • 허준;김우선;손홍규;조형식
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2007년도 춘계학술발표회 논문집
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    • pp.459-462
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    • 2007
  • Long time ago, Korea region based on the agriculture society has been changed in terms of a variety of factors, differently a metropolis. Specially the region located nearby urban area generates a number of variations by the environmental, economic and social factors, these variations have appeared with the similar characteristics in other areas. On that score, if we classify variation factors by means of analyzing quantitative or assign the standards or weights to apply as a agent concept, will anticipate mote accurate information of the land-use ratio, squares related of agriculture region in the future. In this study, we estimated applicable possibilities and extract the variation factor between annual surveying images and real values which estimated local products, variation factors related of attributes through Landsat images of Korea for the 5 years.

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