• Title/Summary/Keyword: Average relative error

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유도결합 플라스마 질량분석기를 이용한 담배 제품의 무기물 반정량 분석 (Semiquantitative Analysis of metal for Cigarette Product by Inductively Coupled Plasma Mass Spectrometry)

  • 조성일;김효근;황건중
    • 한국연초학회지
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    • 제31권2호
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    • pp.95-106
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    • 2009
  • Semiquantitative analysis by ICP-MS has proven to be a powerful tool for fast screening, in addition, it does not require the element of interest to be present in the calibration standard, making it especially useful for the analysis of unknown samples. In this study, seven cigarette samples were analyzed by the rapid semi-quantitative analysis method based on the ICP-MS. For each cigarette sample, cut tobacco, cigarette paper, filter (before and after smoking), and smoke condensate were analyzed. The accuracy of the analysis technique was evaluated by comparing results obtained from Calibration Check Standard(CCS) and calibration method. Relative Percentage Error(RPE) value of all elements measured for three CCS showed a stable result of less than ${\pm}20%$. Compared to full quantitative analysis by calibration method, the results for cigarette samples showed average error within ${\pm}15%$.

관개계획을 위한 일기예보의 신뢰성과 활용성 (Reliability and Applicability of Weather Forecasts for Irrigation Scheduling)

  • 이남호
    • 한국농공학회지
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    • 제41권6호
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    • pp.25-32
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    • 1999
  • The purpose of this study is to analyse the accuracy of weather forecasts of temperature, precipitation probability , and sky condition and to evaluate the applicability of weather forecasts for the estimation of potential evapotranspiration for irrigation scheduling. Five weather station s were selected to compare forecasted and measured climatcal data. The error between forecasted and measured temperature was calculated and discussed. The accuracy of temperature forecast using relative frequency of the error was calculated . The temperature forecasting showed considerably high accuracy. Average sunshine hours for forecasted sky conditions were calculated and showed reasonable quality. From the reliability graphs, the forecasting precipation probabililty was reliable. Potential evapotranspirations were calculated and compared using forecast and measured temperatures. The weather forecast is considered usable for irrigation scheculing.

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A study on Average CN Estimation in River Basin using Satellite Data

  • Kwon, Bong-kyum;Jo, Myung-Hee;Ahn, Seung-Sep;Kiyoshi, Yamada
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.499-499
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    • 2002
  • The goal of this study is to apply and evaluate the precipitation outflow in river basin using satellite data and GIS for proposing the efficient watershed management method. Not only precipitation outflow data but also various spatial data such as digital map, soil map, geologic map and multi-temporal TM images were used. Using landcover classification result and soil map were applied to estimate the average CN. The CN value of 63.37 by SCS method was produced in AMC-2 condition otherwise the result of direct estimation with observation method was 63 CN value. The relative error of two results was 0.59%. It can be possible to apply the satellite data for precipitation outflow analysis. For more accurate and credible analysis of this, the more multi-temporal satellite and real observation data will be needed.

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만성 뇌졸중 환자들의 Step Test의 상대적·절대적 신뢰도와 타당도 (The Relative·Absolute Reliability and Validity of Step Test in Patients with Chronic Stroke)

  • 이병권;최현수;안승헌
    • 대한통합의학회지
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    • 제5권1호
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    • pp.43-53
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    • 2017
  • Purpose : To examine the relative absolute reliability and validity of step test (ST) scores in subjects with chronic stroke. Method : A total of 27 stroke patients, participated in the study. A relative reliability index (intraclass correlation coefficient, ICC) was used to examine the level of agreement of inter-rater test-retest reliability for ST score. Absolute reliability indices, including the standard error of measurement(SEM) and the minimal detectable change (MDC), and limits of agreement by Bland and Altman analysis. The validity was demonstrated by spearman correlation of ST score with 10 m Walk Test (10mWT), Fugl-Meyer Assessment-Lower/Extremity (FMA-L/E)-total score, Berg Balance Scale (BBS)-total score. Result : An excellent inter-rater reliability in ST scores was found (paretic, ICC=0.993~0.996; nonparetic, ICC=0.982~0.991). In addition, excellent test-retest reliability was found (paretic, ICC=0.992; nonparetic, ICC=0.967). It all showed acceptable SEM of the ST score as paretic and nonparetic were 0.22 and 0.46 respectively (average score <10 %), and the MDC of the paretic and nonparetic were 0.61 and 1.27 respectively (possible highest score <20 %). indicating that measures had a small and acceptable measurement error. The ST score of paretic and nonparetic were also found to be significantly associated with 10MWT (r=0.77~0.79), FMA-LE scores (r=0.73~0.81) and BBS scores (r=0.72~0.76). Conclusion : The ST showed highly sufficient Inter-rater test-retest agreement and validity and acceptable measurement errors caused by due to chance variation in measurement. It also can be used by clinicians and researchers to assess the balance and mobility performance and monitor functional change in chronic stroke patients.

스마트폰 카메라와 2차원 바코드를 이용한 실내 주차장 내 측위 방법 (Positioning Method Using a Vehicular Black-Box Camera and a 2D Barcode in an Indoor Parking Lot)

  • 송지현;이재성
    • 한국정보통신학회논문지
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    • 제20권1호
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    • pp.142-152
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    • 2016
  • 실내 측위 분야에서는 사용할 수 없는 GPS 의 한계를 극복하기 위해 대두되고 있는 기술들은 대부분 사설 무선 통신망(Private Wireless Network)를 이용한 방법이다. 그러나 이러한 방법들은 설치 및 유지 보수비용이 많이 들고 측위 오차가 수 미터로 실내 주차장 등 정밀한 측위가 필요한 장소에서 사용하기에 부적합하다. 본 논문에서는 QR 코드 인식 기반 차량용 실내 측위 방법을 제안하였다. QR 코드 스캔을 통해 절대 좌표를 얻고 아핀 변환(affine transform)을 통한 기울기(Tilt) 및 회전(Roll) 보정과 스케일 변환 및 삼각함수를 이용한 카메라의 위치 정보(상대좌표)를 획득하여 정밀한 위치 좌표를 계산한다. 결과적으로 13.79cm 의 평균 오차를 달성해 기존 무선 네트워크 기반 기술의 오차 50cm 대비 단지 27.6% 정도 오차율에 해당함을 확인하였다.

VDT사용자의 시기능 불편과 굴절이상 (Visual Problems and Refractive Error at Video Display Termianls)

  • 서용원;최영준
    • 한국안광학회지
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    • 제3권1호
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    • pp.75-86
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    • 1998
  • 18세에서 27세 사이의 남자 82명 여자 70명 총 152명을 대상으로 2시간 동안 쉬지 않고 VDT작업을 하도록 한 후, 안구 및 전신증상 등을 조사하고 시력, 타각적 굴절이상, 조절력 상위량 등을 측정한 결과, 안구증상으로는 눈의 피로를 느끼는 사항이 45.71%로 가장 많았고, 시기능 이상으로는 물체가 흐려 보이는 경우가 80.39%, 전신증상으로는 어깨가 아픈 사람이 33.33%로 가장 높게 나타났다. 시력변화는 평균나안시력 0.47에서 0.42로 약 10%가 저하했으며 타각적 굴절이상은 0.10D정도 근시도가 증가했다. 조절력은 7.46D에서 6.74D로 약 0.72D 정도 줄었고, 조절용이성은 2.27초에서 2.50초로 0.23초만큼 지연되었다. 실성상대조절량은 4.76D에서 4.16D로 0.50D만큼 감소했고 허성상대조절량은 2.46D에서 2.33D로 0.13D 만큼 줄었다. 사위량은 평균 $1.82{\Delta}$ B.O.에서 $3.24{\Delta}$ B.O.으로 내 사위량이 증가했다.

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수명분포가 지수화-지수분포를 따르는 소프트웨어 신뢰모형 특성에 관한 연구 (A Study on the Characteristics of Software Reliability Model Using Exponential-Exponential Life Distribution)

  • 김희철;문송철
    • Journal of Information Technology Applications and Management
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    • 제27권3호
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    • pp.69-75
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    • 2020
  • In this paper, we applied the shape parameters of the exponentialized exponential life distribution widely used in the field of software reliability, and compared the reliability properties of the software using the non-homogeneous Poisson process in finite failure. In addition, the average value function is also a non-decreasing form. In the case of the larger the shape parameter, the smaller the estimated error in predicting the predicted value in comparison with the true value, so it can be regarded as an efficient model in terms of relative accuracy. Also, in the larger the shape parameter, the larger the estimated value of the coefficient of determination, which can be regarded as an efficient model in terms of suitability. So. the larger the shape parameter model can be regarded as an efficient model in terms of goodness-of-fit. In the form of the reliability function, it gradually appears as a non-increasing pattern and the higher the shape parameter, the lower it is as the mission time elapses. Through this study, software operators can use the pattern of mean square error, mean value, and hazard function as a basic guideline for exploring software failures.

Axial compressive behaviour of circular CFFT: Experimental database and design-oriented model

  • Khan, Qasim S.;Sheikh, M. Neaz;Hadi, Muhammad N.S.
    • Steel and Composite Structures
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    • 제21권4호
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    • pp.921-947
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    • 2016
  • Concrete Filled Fibre Reinforced Polymer Tube (CFFT) for new columns construction has attracted significant research attention in recent years. The CFFT acts as a formwork for new columns and a barrier to corrosion accelerating agents. It significantly increases both the strength capacity (Strength enhancement ratio) and the ductility (Strain enhancement ratio) of reinforced concrete columns. In this study, based on predefined selection criteria, experimental investigation results of 134 circular CFFT columns under axial compression have been compiled and analysed from 599 CFFT specimens available in the literature. It has been observed that actual confinement ratio (expressed as a function of material properties of fibres, diameter of CFFT and compressive strength of concrete) has significant influence on the strength and ductility of circular CFFT columns. Design oriented models have been proposed to compute the strength and strain enhancement ratios of circular CFFT columns. The proposed strength and strain enhancement ratio models have significantly reduced Average Absolute Error (AAE), Mean Square Error (MSE), Relative Standard Error of Estimate (RSEE) and Standard Deviation (SD) as compared to other available strength and strain enhancement ratios of circular CFFT column models. The predictions of the proposed strength and strain enhancement ratio models match well with the experimental strength and strain enhancement ratios investigation results in the compiled database.

회귀모형에 의한 상수도 1일 급수량 예측에 관한 연구 (A Study on the Prediction of Daily Urban Water Demand with Multiple Regression Model)

  • 박성천;문병석;오창주;이병조
    • 한국농공학회지
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    • 제40권1호
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    • pp.68-77
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    • 1998
  • The purpose of this paper is to establish a method estimating the daily urban water demand using statistical analysis that is used for developing the efficient management and operation of the water supply facilities, and accurary of the model is verified by error rate and F-value. The data used in this study were the daily urban water use, the weather conditions such as temperature, precipitation, relative humidity, etc, and the day of The week. The case study was taken placed for the city of Namwon in Korea. The raw data used in this study were rearranged either by month or by season for analysis purpose, and the statistical analysis was applied to the data to obtain the regression model As a result of this study, the linear regression model was developed to estimate the daily urban water use with weather condition. The regression constant and coefficients of the model were determined for each month of a year. The accuracy of the model was within 3% of average error and within 11% of maximum error. The resulting model was found to he useful to the practical operation and management of the water supply facilities.

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돔형 인공천공의 개발 및 CIE표준담천공 구현 검증에 관한 연구 (Development and Validation of Sky Simulator for Reproducing CIE Overcast Sky Model)

  • 신주영;윤근영;김정태
    • KIEAE Journal
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    • 제10권6호
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    • pp.97-103
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    • 2010
  • Sky simulator is a effective daylighting design tool that can evaluate three dimensional performance of lighting. Especially, the dome type sky simulator offer reliable and reproducible daylighting performance with different standard sky models. Recently, K university has developed the dome type sky simulator(sky dome) with the diameter of 6.5m and the height of 3.7m. The sky dome consists of a group of 145 large steel panels with 72 halogen lamps which are arranged in a circular array. The luminance distribution of the sky dome can be calibrated by changing the angle and the brightness of the lamps respectively. To allow more reliable prediction and evaluation of daylighting through the sky dome, It is essential to validate the sky luminance distribution of the sky dome. This study consider the validation of the comparisons between the measured and the calculated luminance values for the CIE standard overcast sky. Also, the error rate between the measured and the calculated luminance values were compared to the previous studies. The results indicated that the K university sky dome can reproduce reliable CIE standard overcast sky with the average relative error rate of 4.4% and root-mean-square error(RMSE) of 5.4%.