• 제목/요약/키워드: correction formula

검색결과 140건 처리시간 0.018초

NASA 모델의 편차보정에 의한 광역지역의 지표온도산출 정확도 향상 (NASA Model Deviation Correction for Accuracy Improvement of Land Surface Temperature Extraction in Broad Region)

  • 엄대용;박준규;김민규;강준묵
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2006년도 춘계학술발표회 논문집
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    • pp.281-286
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    • 2006
  • In this study, acquired time series Landsat TM/ETM+ image to extract land surface temperature for wide-area region and executed geometric correction and radiometric correction. And extracted land surface temperature using NASA Model, and I achieved the first correction by perform land coverage category for study region and applies characteristic emission rate. Land surface temperature that acquire by the first correction analyzed correlation with Meteorological Administration's temperature data by regression analysis, and established correction formula. And I wished to improve accuracy of land surface temperature extraction using satellite image by second correcting deviations between two datas using establishing correction formula. As a result, land surface temperature that acquire by 1,2th correction could correct in mean deviation of about ${\pm}3.0^{\circ}C$ with Meteorological Administration data. Also, could acquire land surface temperature about study region by relative high accuracy by applying to other Landsat image for re-verification of study result.

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Development of stress correction formulae for heat formed steel plates

  • Lim, Hyung Kyun;Lee, Joo-Sung
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제10권2호
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    • pp.141-152
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    • 2018
  • The heating process such as line heating, triangular heating and so on is widely used in plate forming of shell plates found in bow and stern area of outer shell in a ship. Local shrinkage during heating process is main physical phenomenon used in plate forming process. As it is well appreciated, the heated plate undergoes the change in material and mechanical properties around heated area due to the harsh thermal process. It is, therefore, important to investigate the changes of physical and mechanical properties due to heating process in order to use them plate the design stage of shell plates. This study is concerned with the development of formula of plastic hardening constitutive equation for steel plate on which line heating is applied. In this study the stress correction formula for the heated plate has been developed based on the numerical simulation of tension test with varying plate thickness and heating speed through the regression analysis of multiple variable case. It has been seen the developed formula shows very good agreement with results of numerical simulation. This paper ends with usefulness of the present formula in examining the structural characteristic of ship's hull.

GPS와 Echo Sounder를 이용한 하상 모니터링 (Estuary Riverbed Monitoring using GPS and Echo Sounder)

  • 홍정수;이용희;이기부;이동락
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2006년도 춘계학술발표회 논문집
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    • pp.83-88
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    • 2006
  • We intend to increase in efficiency of the topographic monitoring of seabed or riverbed by combined with DGPS, RTK GPS and echo sounder. For this study, we defined the error correction of the echo sounder with the experiment of water tank, which is considered the characteristic of estuary riverbed and then we developed the s/w for 3-dimensional monitoring of estuary riverbed and applied the s/w to field test and improved the various problems. On analyzing topography of estuary riverbed by combined GPS with echo sounder, the draught error which is yielded to change of length from the water surface by the movement of survey vessel to the end of the transducer was eliminated by geometrical rearrangement and we defined the correction formula, z = BM+ SAH- $DBR_{(i)}$ - DRT - ED. The sounding error about the echo sounder and characteristic of estuary riverbed was found by understanding the relation of average diameter and residual error and we defined correction formula, Y= -0.00474*In(X) -0.0045 by the regression analysis. and then we verified applicability of correction formula.

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도로변 공동주택의 층별 소음보정계수 산정에 관한 연구 (A study on the Calculation of Noise Correction Coefficient on each floor for the estimation on the roadside traffic noise around the Apartment Building)

  • 박영민;이지왕;고정용
    • 환경영향평가
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    • 제14권1호
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    • pp.25-36
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    • 2005
  • Actually, prediction formula of road traffic noise for EIA(Environmental Impact Assessment) has been used that proposed by National Institute of Environmental Research in 1999. The prediction formula, however, was calculated predicted noise level according to noise level producing on first floor, then needs to correct noise level at each floor in the case of apartment building. The investigation was carried out to calculate the correction coefficient for commonly using in EIA of large scaled apartment development areas. The noised level at each floor were measured from August 2001 to March 2002 at 31 investigation points of large scaled apartment development area in national wide. Measured data were divided and treated with 4 types as 3th floor, 5th floor, 7th floor and 10th floor and then the correction coefficients of each floor were calculated using by correlation formula according to each floor.

Correction and Experimental Verification of Velocity Circulation in a Double-blade Pump Impeller Outlet

  • Kai, Wang;Qiong, Liu
    • International Journal of Fluid Machinery and Systems
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    • 제8권4호
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    • pp.311-317
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    • 2015
  • It is difficulty to calculate velocity circulation in centrifugal pump impeller outlet accurately. Velocity circulations of a double-blade pump impeller outlet were calculated with Stodola formula, Weisner formula and Stechkin formula. Simultaneously, the internal flow of impeller for the double-blade pump were measured with PIV technology and average velocity circulations at the 0.8, 1.0 and 1.2 times of design flow were obtained. All the experimental values were compared with the above calculation values at the three conditions. The results show that calculation values of velocity circulations with Weisner formula is close to the experimental values. On the basis of the above, velocity circulations of impeller outlet were corrected. The results of experimental verification show that the corrected calculation errors, whose maximum error is 3.65%, are greatly reduced than the uncorrected calculation errors. The research results could provide good references for establishment of theoretical head and multi-condition hydraulic optimization of double-blade pumps.

AN APPROXIMATED EUROPEAN OPTION PRICE UNDER STOCHASTIC ELASTICITY OF VARIANCE USING MELLIN TRANSFORMS

  • Kim, So-Yeun;Yoon, Ji-Hun
    • East Asian mathematical journal
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    • 제34권3호
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    • pp.239-248
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    • 2018
  • In this paper, we derive a closed-form formula of a second-order approximation for a European corrected option price under stochastic elasticity of variance model mentioned in Kim et al. (2014) [1] [J.-H. Kim, J Lee, S.-P. Zhu, S.-H. Yu, A multiscale correction to the Black-Scholes formula, Appl. Stoch. Model. Bus. 30 (2014)]. To find the explicit-form correction to the option price, we use Mellin transform approaches.

신형식 자동차 적용에 따른 연비 보정식 검토에 관한 연구 (Study on new type vehicle fuel economy correction formula review according to the applicable)

  • 임재혁;김성우;이민호;김기호
    • 에너지공학
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    • 제25권4호
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    • pp.198-206
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    • 2016
  • 자동차 표시연비는 국가적으로 에너지관리 지표로서 활용되며, 자동차 제작사의 기술개발을 유도하고, 소비자 차량구매 시 정보제공의 역할을 담당하고 있다. 하지만 정부의 표시연비가 체감연비와 상이하다는 소비자 불만이 지속되어 정부는 보다 정확한 표시연비 측정을 위해 미국의 5-cycle 시험방법을 국내 차량 기준에 맞게 재설정하여 도입하였다. 본래는 다양한 환경조건 및 주행패턴이 반영된 5개의 시험모드를 모두 주행함으로써 측정된 결과 값을 표시연비로 계산하는 방법이지만 소요되는 자원의 급격한 증가에 따른 충격을 완화하기 위하여 2개의 시험모드(도심(FTP-75 mode), 고속도로(HWFET mode))의 결과 값을 5-cycle 시험법으로 계산된 연비 값과 동등한 수준으로 산출하는 5-cycle 보정식을 사용하고 있다. 이 보정식은 2011년에 30대 차량의 5-cycle 시험방법으로 산출되었으나 최근 자동차 기술의 급속한 발전으로 인한 신형식 자동차에 대한 기존 5-cycle 보정식에 대한 검토가 필요할 것으로 판단되었다. 본 연구에서는 최근 기술이 적용된 14대의 신형식 자동차를 대상으로 기존과 동일한 시험 방법을 통해 시험모드별 연비 특성을 확인하고, 기존에 개발된 보정식과 차이를 분석한 결과 기존 시험 차량 결과와 큰 차이를 보이지 않았으며 보정식 또한 최대 1.5% 이내의 오차로써 기존 연비 보정식은 현재의 자동차 기술발전에 따른 개선도에 크게 영향을 받고 있지 않음을 알 수 있었다.

곡선부의 구조 특성을 고려한 선박용 파이프 루프 설계식 개발 (Development of Design Formulas for Pipe Loops Used in Ships Considering the Structural Characteristics of Curved Portions)

  • 박치모;배병일
    • 한국해양공학회지
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    • 제26권5호
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    • pp.87-93
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    • 2012
  • Many longitudinally-arranged pipes in ships are equipped with loops as a measure to reduce stresses caused by displacement loads conveyed from the hull girder bending and/or thermal loads of carried fluid of non-ambient temperature. But as the loops have some negative effects such as causing extra manufacturing cost and occupying extra space, the number and the dimensions of the loops need to be minimized. In the meanwhile, a design formula for pipe loops has been developed by modeling them as a spring element of which stresses and axial stiffness are calculated based on the beam theory. But as the beam theory turns out to be inappropriate to deal with the complex structural behavior in the curved corner portion of the loop, this paper aims at improving the previously developed design formula by adopting correction factors which can allow for the gap between the results of beam theory and a more accurate analysis. This paper adopts a finite element analysis with two-dimensional shell elements with some validation work for it. The paper ends with a sample application of the proposed formulas showing their accuracy and efficiency.

원격탐사 자료에 의한 지표온도추출 정확도 향상에 관한 연구 (A Study on the Accuracy Improvement of Land Surface Temperature Extraction by Remote Sensing Data)

  • 엄대용
    • 한국지리정보학회지
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    • 제9권2호
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    • pp.159-172
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    • 2006
  • 본 연구에서는 광역지역에 대한 지표온도를 추출할 목적으로 대상지역에 대한 시계열 Landsat TM/ETM+영상을 획득하여 기하보정 및 방사보정을 실시하고 NASA모델을 이용하여 지표온도를 추출하였다. 그리고 대상지역에 대한 피복분류를 통하여 이에 따른 고유 방사율을 적용하는 1차 보정을 실시하는 한편, 기상청 기온자료와의 상관관계를 분석하여 보정식을 설정하고 영상으로부터 획득한 지표온도를 2차적으로 보정함으로써 영상을 이용한 지표온도 추출의 정확도를 향상시키고자 하였다. 그 결과, 1,2차 보정에 의해 획득한 지표온도는 기상청자료와 약 ${\pm}3.0^{\circ}C$의 평균편차내에서 보정된 지표온도를 획득할 수 있었다. 연구결과의 재검증을 위하여 다른 시기의 Landsat 영상에 적용함으로써 대상지역에 대한 지표온도를 비교적 높은 정확도로 획득할 수 있었다.

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Correction of CIEDE2000 Color Difference Formula for the Analysis of Low Chroma and Low Lightness Colors

  • Woo Hwa-Lyung;Kim, Sam-Soo;Hudson Samuel M.
    • 한국염색가공학회지
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    • 제18권5호
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    • pp.72-79
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    • 2006
  • There are many discrepancies between visually perceived color-difference and that which is quantified from an instrumental measurement when dark color samples are measured in the textile industry. The samples were prepared to represent these dark shades and the values of the instrumental results from conventional color-difference formulae(CIELAB, CMC, BFD II, CIE94, LCD99 and CIEDE2000). Those of visual assessment were compared. The experimental results show that the CIELAB formula gives the best performance over other formulae, and the CIEDE2000 formula for the color-difference according to chroma presents the worst performance. Therefore, we can say that the problems in color matching of dark shades are caused by imperfect formula, because the results obtained from a color-difference formulae are different and the CMC which is used as a standard color-difference formula in the textile industry is not correct. So, a revised color-difference formula is proposed in this study, to account for these problems.