• 제목/요약/키워드: L$_2$ error test

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Estimation of Design Rainfall by the Regional Frequency Analysis using Higher Probability Weighted Moments and GIS Techniques (III) - On the Method of LH-moments and GIS Techniques - (고차확률가중모멘트법에 의한 지역화빈도분석과 GIS기법에 의한 설계강우량 추정 (III) - LH-모멘트법과 GIS 기법을 중심으로 -)

  • 이순혁;박종화;류경식;지호근;신용희
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.5
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    • pp.41-53
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    • 2002
  • This study was conducted to derive the regional design rainfall by the regional frequency analysis based on the regionalization of the precipitation suggested by the first report of this project. According to the regions and consecutive durations, optimal design rainfalls were derived by the regional frequency analysis for L-moment in the second report of this project. Using the LH-moment ratios and Kolmogorov-Smirnov test, the optimal regional probability distribution was identified to be the Generalized extreme value (GEV) distribution among applied distributions. regional and at-site parameters of the GEV distribution were estimated by the linear combination of the higher probability weighted moments, LH-moment. Design rainfall using LH-moments following the consecutive duration were derived by the regional and at-site analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE), relative bias (RBIAS) and relative reduction (RR) in RRMSE for the design rainfall were computed and compared in the regional and at-site frequency analysis. Consequently, it was shown that the regional analysis can substantially more reduce the RRMSE, RBIAS and RR in RRMSE than at-site analysis in the prediction of design rainfall. Relative efficiency (RE) for an optimal order of L-moments was also computed by the methods of L, L1, L2, L3 and L4-moments for GEV distribution. It was found that the method of L-moments is more effective than the others for getting optimal design rainfall according to the regions and consecutive durations in the regional frequency analysis. Diagrams for the design rainfall derived by the regional frequency analysis using L-moments were drawn according to the regions and consecutive durations by GIS techniques.

Verification of the Reliability and Validity of the Short Form 36 Scale in Indonesian Middle-aged and Older Adults

  • Arovah, Novita Intan;Heesch, Kristiann C.
    • Journal of Preventive Medicine and Public Health
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    • v.53 no.3
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    • pp.180-188
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    • 2020
  • Objectives: The Short Form 36 (SF-36) questionnaire is increasingly being used to measure health-related quality of life (HRQoL) in Indonesia. However, evidence that it is valid for use in Indonesian adults is lacking. This study assessed the validity and reliability of the SF-36 in Indonesian middle-aged and older adults. Methods: Adults aged 46-81 years (n=206) in Yogyakarta, Indonesia completed the SF-36, another measure of HRQoL (the EuroQoL visual analogue scale [EQ-VAS]), and measures assessing their demographic characteristics. Fifty-four percent (n=121) completed the SF-36 measure again 1 week later. Confirmatory factor analysis was conducted to confirm the factor structure of the SF-36. Internal consistency reliability was estimated using Cronbach's alpha, and test-retest reliability was assessed using intraclass correlations. Convergent and discriminant validity were assessed by computing correlations among SF-36 subscales, between subscales and the 2 component scores, and between component scores and EQ-VAS scores. Results: Most scaling assumptions were met. The hypothetical factor structure fit the data poorly (root mean square error of approximation [RMSEA]=0.108) and modification was required for a good fit (RMSEA=0.060). Scores on all subscales demonstrated acceptable internal consistency (α>0.70) and test-retest reliability (r>0.70). Divergent validity was supported by weak to moderate interscale correlations (r=0.19 to 0.64). As expected, the 2 summary scores were moderately to strongly correlated with the EQ-VAS (r>0.60). Conclusions: The findings adequately support the use of SF-36 in Indonesian middle-aged and older adults, although the optimal algorithm for computing component scores in Indonesia warrants further investigation.

Static strength of collar-plate reinforced tubular T-joints under axial loading

  • Shao, Yong-Bo
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.323-342
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    • 2016
  • To study the effect of collar-plate reinforcement on the static strength of tubular T-joints under axial loading, fundamental research work is carried out from both experimental test and finite element (FE) simulation. Through experimental tests on 7 collar-plate reinforced and 7 corresponding un-reinforced tubular T-joints under axial loading, the reinforcing efficiency is investigated. Thereafter, the static strengths of the above 14 models are analyzed by using FE method, and it is found that the numerical results agree reasonably well with the experimental data to prove the accuracy of the presented FE model. Additionally, a parametric study is conducted to analyze the effect of some geometrical parameters, i.e., the brace-to-chord diameter ratio ${\beta}$, the chord diameter-to-chord wall thickness ratio $2{\gamma}$, collar-plate thickness to chord wall thickness ratio ${\tau}_c$, and collar-plate length to brace diameter ratio $l_c/d_1$, on the static strength of a tubular T-joint. The parametric study shows that the static strength can be greatly improved by increasing the collar-plate thickness to chord wall thickness ratio ${\tau}_c$ and the collar-plate length to brace diameter ratio $l_c/d_1$. Based on the numerical results, parametric equations are obtained from curving fitting technique to estimate the static strength of a tubular T-joint with collar-plate reinforcement under axial loading, and the accuracy of these equations is also evaluated from error analysis.

Consolidation Behavior of Soft Ground by Prefabricated Vertical Drains (연직드레인 공법에 의한 연약지반의 압밀거동)

  • 이달원;강예묵
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.376-381
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    • 1998
  • The large scaled field test by prefabricated vertical drains was performed to evaluate the superiority of vertical discharge capacity for drain materials through compare and analyze the time-settlement behavior with drain spacing and the compression index and consolidation coefficient obtained by laboratory experiments and field monitoring system 1. The relation of measurement settlement( $S_{m}$) versus design settlement( $S_{t}$) and measurement consolidation ratio( $U_{m}$) versus design consolidation ratio( $U_{t}$) were shown $S_{m}$=(1.0~l.1) $S_{t}$, $U_{m}$=(1.13~l.17) $U_{t}$, at 1.0m drain spacing and $S_{m}$=(0.7~0.8) $S_{t}$, $U_{m}$=(0.92~0.99) $U_{t}$ at 1.5m drain spacing, respectively. 2. The relation of field compression index( $C_{cfield}$) and virgin compression index( $V_{cclab}$) was shown $C_{cfield}$=(1.0~1.2) $V_{cclab}$, But it was nearly same value when considered the error with determination method of virgin compression index and prediction method of total settlement. 3. field consolidation coefficient was larger than laboratory consolidation coefficient, and the consolidation coefficient ratio( $C_{h}$/ $C_{v}$) were $C_{h}$=(2.4 ~ 3.0) $C_{v}$. $C_{h}$=(3.5 ~ 4.3) $C_{v}$ at 1.0m and 1.5m drain spacing and increased with increasing of drain spacingngasing of drain spacingng spacingng

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A Study on Compact Network RTK for Land Vehicles and Real-Time Test Results

  • Song, Junesol;Park, Byungwoon;Kee, Changdon
    • Journal of Positioning, Navigation, and Timing
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    • v.7 no.1
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    • pp.43-52
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    • 2018
  • In recent years, the need of high accuracy navigation for vehicles has increased due to the development of autonomous driving vehicles and increase in land transportation convenience. This study is performed for vehicle users to achieve a performance of centimeter-level positioning accuracy by utilizing Compact Network Real-time Kinematic (RTK) that is applicable as a national-level infrastructure. To this end, medium-baseline RTK was implemented in real time to estimate accurate integer ambiguities between reference stations for reliable generation of Network RTK correction using the linear combination of carrier-phase observations and L1/L2 pseudo-range measurements. The residual tropospheric error was estimated in real time to improve the accuracy of double-differenced integer ambiguity resolution between network configuration reference stations that have at least 30 km or longer baseline distance. In addition, C++ based software was developed to enable real-time generation and broadcasting of Compact Network RTK correction information by utilizing an accurately estimated double-differenced integer ambiguity values. As a result, the horizontal and vertical 95% accuracy was 2.5cm and 5.2cm, respectively, without performance degradation due to user's position change within the network.

Determination of Vitamin $B_12$ by Agar Diffusion Method (원통평판법을 이용한 비타민 $B_12$의 정량)

  • Lee, Sung-Ho;Cho, Chin-Sung;Song, Young-Joon
    • Journal of Pharmaceutical Investigation
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    • v.21 no.2
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    • pp.79-84
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    • 1991
  • The agar diffustion method using Escherichia coli was investigated for determination of Vitamin $B_{l2}$ instead of turbidimetric method using Lactobacillus leichannii (USP XXII method). The turbidimetric method is difficult to control the test organism and it has complicated procedure. From this study, it was found that the agar diffusion method on the determination of Vitamin $B_{12}$ in pharamaceutical preparation is simple and convenient as compared with turbidimetric method. Also we found that the coefficient of variation in reproducibility and the standard error in recovery were 2.18% and 1.83%, respectively.

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The Study of Error for Analysis in Dynamic Image from the Error of Count Rates in NaI (Tl) Scintillation Camera (NaI (Tl) 신틸레이션 카메라에서 계수율 오차에 따른 동적 영상 분석치 산출 오류에 관한 연구)

  • Oh, Joo-Young;Kang, Chun-Goo;Kim, Jung-Yul;Park, Hoon-Hee;Oh, Ki-Baek;Kim, Jae-Sam
    • Journal of radiological science and technology
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    • v.36 no.4
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    • pp.291-297
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    • 2013
  • This study is aimed to evaluate the effect of $T_{1/2}$ upon count rates in the analysis of dynamic scan using NaI (Tl) scintillation camera, and suggest a new quality control method with this effects. We producted a point source with $^{99m}TcO_4^-$ of 18.5 to 185 MBq in the 2 mL syringes, and acquired 30 frames of dynamic images with 10 to 60 seconds each using Infinia gamma camera (GE, USA). In the second experiment, 90 frames of dynamic images were acquired from 74 MBq point source by 5 gamma cameras (Infinia 2, Forte 2, Argus 1). There were not significant differences in average count rates of the sources with 18.5 to 92.5 MBq in the analysis of 10 to 60 seconds/frame with 10 seconds interval in the first experiment (p>0.05). But there were significantly low average count rates with the sources over 111 MBq activity at 60 seconds/frame (p<0.01). According to the second analysis results of linear regression by count rates of 5 gamma cameras those were acquired during 90 minutes, counting efficiency of fourth gamma camera was most low as 0.0064%, and gradient and coefficient of variation was high as 0.0042 and 0.229 each. We could not find abnormal fluctuation in $x^2$ test with count rates (p>0.02), and we could find the homogeneity of variance in Levene's F-test among the gamma cameras (p>0.05). At the correlation analysis, there was only correlation between counting efficiency and gradient as significant negative correlation (r=-0.90, p<0.05). Lastly, according to the results of calculation of $T_{1/2}$ error from change of gradient with -0.25% to +0.25%, if $T_{1/2}$ is relatively long, or gradient is high, the error increase relationally. When estimate the value of 4th camera which has highest gradient from the above mentioned result, we could not see $T_{1/2}$ error within 60 minutes at that value. In conclusion, it is necessary for the scintillation gamma camera in medical field to manage hard for the quality of radiation measurement. Especially, we found a tendency that count rate changes over time at this study, and we proved that it can effect $T_{1/2}$. And also, there is need of appropriate phantoms and the method of quality management like this study, because there are not any advice or limitation degrees for domestic medical purpose scintillation camera.

The Effect of Regular Exercise on anxiety Level of Older People (노인들의 규칙적인 체육활동이 노후불안 수준에 미치는 영향)

  • Jeon, Ik-Gi;Lee, Sun Hee
    • 한국노년학
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    • v.28 no.4
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    • pp.953-968
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    • 2008
  • This research was performed to recognize anxiety level of older people, to find out anxiety level after or before regular exercises, and to find out how much anxiety level could be lowered by the sports activities. This research selected a population among the students who enrolled at sport activity classes (e, g., physical exercises, gate ball, volume dance) at L, S, J, Y (a), Y (b), D older people college located in Seoul and Gyoenggi area. 200 of the population were chosen as candidates by convenience sampling, nonprobability sampling. Considering the age of the candidates, total 200 cases were collected by using two methods (survey and interview) simultaneously. The data assessment was made by SPSS 12.0 Version. Error tolerance in statistics is .05. The data was analyzed by using frequency analysis, paired t-test and independent t-test. After analyzing anxiety awareness level after and before regular exercises, anxiety of older people are classified by four factors. First, anxiety for loss is 3.756 (M=3.756) before exercises, while 1.942 (M=1.942) after exercises. Second, fear for aging is 3.443 before exercises and 2.243 after exercises. Third, anxiety for physical appearance is 3.253 before exercises and 2.310 after exercises. Finally, anxiety caused by psychological insecurity is 3.060 before exercises, while 1.666 after exercises. Error of tolerance for all factors falls within .001. Anxiety score after exercises is lower than that of before exercises for every factor as well. As a result, regular physical exercises appeared to reduce anxiety level of older people.

Mistranslation or Adaptation in Medieval Manuscripts: Can One Tell the Difference\ulcorner

  • Burton, Tom.L.
    • Lingua Humanitatis
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    • v.2 no.2
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    • pp.129-141
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    • 2002
  • Editors of medieval texts that are translated from other languages face difficulties when the translation differs significantly from the original. Are the differences unintended, the result of misunderstanding and mistranslation\ulcorner Or do they proceed from a conscious decision on the translator's part to change the meaning of the original\ulcorner Is it possible to be sure one knows the difference\ulcorner This paper discusses three test cases encountered in preparing for the Early English Text Society a critical edition of Sidrak and Bokkus, the fifteenth-century English verse translation of the Old French prose book of knowledge, Le livre de Sidrac.

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MULTIGRID METHOD FOR TOTAL VARIATION IMAGE DENOISING

  • HAN, MUN S.;LEE, JUN S.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.6 no.2
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    • pp.9-24
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    • 2002
  • Total Variation(TV) regularization method is effective for reconstructing "blocky", discontinuous images from contaminated image with noise. But TV is represented by highly nonlinear integro-differential equation that is hard to solve. There have been much effort to obtain stable and fast methods. C. Vogel introduced "the Fixed Point Lagged Diffusivity Iteration", which solves the nonlinear equation by linearizing. In this paper, we apply multigrid(MG) method for cell centered finite difference (CCFD) to solve system arise at each step of this fixed point iteration. In numerical simulation, we test various images varying noises and regularization parameter $\alpha$ and smoothness $\beta$ which appear in TV method. Numerical tests show that the parameter ${\beta}$ does not affect the solution if it is sufficiently small. We compute optimal $\alpha$ that minimizes the error with respect to $L^2$ norm and $H^1$ norm and compare reconstructed images.

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