• 제목/요약/키워드: normalizing

검색결과 298건 처리시간 0.026초

피해지역 자동추출을 위한 공간영상 피해 항목별 최적 영상처리 및 임계치 결정에 관한 연구 (Study on optimal image processing and identifying threshold values for automatic extraction of the damaged areas)

  • 서정택;김계현;남기범;김태훈
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2010년도 춘계학술대회
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    • pp.121-127
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    • 2010
  • 본 연구에서는 피해 전 후 고해상도 항공영상을 이용하여 풍수해 피해정보를 자동 추출하는데 있어 결과물의 신뢰성 제고 방안에 대해 연구하였다. 연구 대상지역은 2008년 집중호우로 인해 큰 피해를 입은 경상북도 봉화지역을 선정하였으며, 해당 지역 중 특히 피해가 집중된 서벽리, 애당리 지역에 대하여 피해 전 후 영상을 확보하고 자동탐지를 수행하였다. 피해 지역의 자동탐지 수행 전 Normalizing, 대비강조, Equalizing 등의 영상처리를 수행하고, 자동추출 결과의 정확도를 비교하여 피해항목별 최적의 영상처리를 결정하였다. 최적의 영상처리가 적용된 영상에 대하여 피해 항목별 피해형태를 파악하였으며, 가장 정확한 결과물이 추출되는 최적의 임계치를 결정하였다. 도로 항목의 경우 Normalizing 영상처리를 수행하고 임계치를 120으로 부여하여 자동탐지를 수행한 경우 가장 정확한 추출 결과가 나타났으며, 농경지 항목의 경우 대비강조 영상처리와 임계치가 100으로 부여된 경우 피해 지역의 추출이 가장 정확하게 나타났다. 본 연구결과는 향후 유사한 재해 발생 시 초기 신속한 피해규모 산출이 가능하게 하여 적절한 후속 조치를 취할 수 있도록 한다. 또한, 다중밴드 피해 전 후 영상 확보가 가능할 경우 추가적인 피해 항목의 최적 영상처리와 임계치 결정이 가능해지며, 토지피복 분류를 거쳐 피해지역 자동탐지 수행 시 원하는 피해항목만을 선택적으로 추출하는 것도 가능할 것으로 판단된다.

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선박용 공기압축기 크랭크샤프트의 최적열처리 조건과 경제적 효과에 관한 연구 (Optimal Heat Treatment Condition and Economic Effects of the Crank Shaft for marine Air-Compressor)

  • 김윤해
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권3호
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    • pp.284-291
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    • 1999
  • Recently the ductile cast iron is being used successfully to the parts for processing machinery vessels and gear etc. This study is mainly concerned with the heat treatment for the specimens of crank shaft which are made of ductile cast iron. The results obtained are summarized as follows. Comparing the mechanical properties of the specimens for the normalized ductile cast irons the specimen heat treated at $550^{\circ}C$ was the best for crank shaft of air-compressor. After austenizing at $910^{\circ}C$ it was observed that the higher the reheating temperature is the less tensile strength and the hardness became which was supposedly attributed to the fact that the amount of pearlite. Austenite matrix was reduced by reheating after normalizing and that as the reheating tem-perature went up the pearlite generated was less and the distance between the pearlites were widened at last made pearlite globular. In the comparsison of crank shaft for air compressor made of ductile cast iron with that made by forged steel the crank shaft made of ductile cast iron was superior in economical terms. And ductile cast iron could be practically enough if only the elonga-tion which was inferior mechanical property to forged steel could be reinforced by increasing the diameter of crank pin when designing the crank shaft.

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보일러 배관용 P92 파이프강의 기계적 특성 및 미세조직에 관한 연구 (A Study on the Mechanical Property and Microstructure of SA213 P92 Boiler Pipe Steel)

  • 김범수;손태하;민택기
    • 설비공학논문집
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    • 제24권11호
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    • pp.777-783
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    • 2012
  • The hardness and strength test was performed to make the manufacturing process of SA213 P92 boiler pipe steel. And the microstructure change was studied to find out the cause of room temperature property of P92 steel, ie, low hardness and strength property. The room temperature property of P92 steel depends on the improper normalizing and cooling rate. Especially, Ferrite was formed and the steel had low hardness when the temperature was decreased slowly under the cooling rate $1^{\circ}C$/min after normalizing at the temperature around $A_{c1}$ to $A_{c3}$. The critical heat treatment temperature and cooling rate was over $900^{\circ}C$ and over $10^{\circ}C$/min to satisfy the minimum yield and tensile stress which was laid down by ASME Code.

노멀라이징 열처리한 구상 흑연 주철의 마찰.마모특성 평가에 관한 연구 (A Study on the Evaluation of the Friction and Wear Properties for Normalized Ductile Cast Iron)

  • 김윤해
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권4호
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    • pp.440-446
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    • 1999
  • This study is mainly concerned with the friction and wear properties for the specimens of crank shaft which are made of ductile cast iron. The friction and wear tests were carried out for the nor-malized ductile cast iron specimens and their properties were compared with each other at reheat-ing temperatures(550^{\circC,\; 600^{\circ}C,\; 650^{\circ}$) and in dry condition at different friction velocity(0.94 m/s 1.88m/s 2.83m/s) range. After austenized at $910^{\circ}C$ it is observed that the higher the reheating temperature is the hardness becomes decrease which is supposedly attributed to the fact that the amount of pearlite austenite matrix is rduced by reheating after normalizing and that as the reheating temperature goes up the pearlite generated is less and the interval between the pearlites were widened at last to make pearlite globular. At the low velocity the friction coefficient increase in the beginning and gets stabilized as the sliding distance increases. As the friction velocity grows the friction coefficient decreases suppos-edly since the abrasive wear is heavier at low velocity than at the high velocity as the friction tem-perature at low velocity is lower than at high velocity.

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Trellis-Based Decoding of High-Dimensional Block Turbo Codes

  • Kim, Soo-Young;Yang, Woo-Seok;Lee, Ho-Jin
    • ETRI Journal
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    • 제25권1호
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    • pp.1-8
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    • 2003
  • This paper introduces an efficient iterative decoding method for high-dimensional block turbo codes. To improve the decoding performance, we modified the soft decision Viterbi decoding algorithm, which is a trellis-based method. The iteration number can be significantly reduced in the soft output decoding process by applying multiple usage of extrinsic reliability information from all available axes and appropriately normalizing them. Our simulation results reveal that the proposed decoding process needs only about 30% of the iterations required to obtain the same performance with the conventional method at a bit error rate range of $10^{-5}\;to\;10^{-6}$.

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직접 적응 제어기의강인성 및 성능의 개선에 관한연구 (A Study on the Improvement of Robustness of a Direct Adaptive Controller)

  • 김응석;김홍필;양해원
    • 대한전기학회논문지
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    • 제40권6호
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    • pp.606-614
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    • 1991
  • A robust direct adaptive controller with respect to additive and multiplicative unmodeled dynamics is designed. A new term, proportional to the product of the bounded tracking error and normalizing signal, is added to the conventional control input for improvement of robustness and performances of an adaptive system. It is shown by the mathematical analysis and simulation results that the stability of the closed loop system is guaranteed and the performance of the system is improved.

타블릿 입력(入力)에 의한 동화(動畵)의 생성(生成)과 대응점(代應点)의 자동추출(自動推出)에 관한 연구(硏究) (A Study on the Auto-Detecting of Corresponding Points and the Animation-Generating by Tablet-Input.)

  • 이인동;김태균;권오석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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    • pp.1065-1068
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    • 1987
  • This study is to show the method of corresponding points-detection by sampling and normalizing. And it explains the procedures of the animation package which generate animation through the collation of image codes.

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A note on Box-Cox transformation and application in microarray data

  • Rahman, Mezbahur;Lee, Nam-Yong
    • Journal of the Korean Data and Information Science Society
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    • 제22권5호
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    • pp.967-976
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    • 2011
  • The Box-Cox transformation is a well known family of power transformations that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. Normalization (studentization) of the regressors is a common practice in analyzing microarray data. Here, we implement Box-Cox transformation in normalizing regressors in microarray data. Pridictabilty of the model can be improved using data transformation compared to studentization.

확장된 PID 자기동조기의 설계 (Design of the Extended PID Self-Tuner)

  • 金鍾煥;崔桂根
    • 대한전자공학회논문지
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    • 제23권4호
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    • pp.439-444
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    • 1986
  • In this paper the PID-B self-tuner[1] is extended to allow a less abrupt response to set point or plant parameter changes and to control a nonminimum phase plant. The proposed extended PID/ST derived from the direct pole-placement PID/ST is obtained with the Bezout identity as the underlying design method. And its control gains are normalized by the integral control gain. Although the integral control gain is normalized to 1 in our scheme, the so-called "set point and derivative kick" can be avoided sufficiently by normalizing the measurement vector and set point.

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