• Title/Summary/Keyword: statistical error

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Evaluation of Statistical Analysis of Radiologist's Journal: Focus on Journal of Korean Society of Computer Tomographic Technology (방사선사 학술지에 게재된 통계방법 분석: 대한전산화단층기술학회지 중심으로)

  • Kim, Sang-Hyun;Lee, Mi-Hwa
    • Journal of Digital Convergence
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    • v.12 no.9
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    • pp.275-282
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    • 2014
  • The aim of this study was to investigate the statistical trend and errors of articles in the journal of Korean society of computed tomographic technology for contribution to the academic development of the professional society. Preliminary findings indicate that there are various statistical errors in the papers in the journal of Korean society of computed tomographic technology. Results suggest that the statistical education needs to be strengthened from university education to instructional course lecture of academic society. The improvement of the quality of the paper by improving awareness of the statistical error.

Convergence Analysis of the Modified Adaptive Sign (MAS) Algorithm Using a Mixed Norm Error Criterion

  • Lee, Young-Hwan
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.3E
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    • pp.62-68
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    • 1997
  • In this paper, a modified adaptive sign (MAS) algorithm based on a mixed norm error criterion is proposed. The mixed norm error criterion of be minimized is constructed as a combined convex function of the mean-absolute error and the mean-absolute error to the third power. A convergence analysis of the MAS algorithm is also presented. Under a set of mild assumptions, a set of nonlinear evolution equations that characterizes the statistical mean and mean-squared behavior of the algorithm is derived. Computed simulations are carried out to verify the validity of our derivations.

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Statistical Errors of Articles Published in the Journal of Oriental Rehabilitation Medicine(I) (한방재활의학과학회지의 통계적 오류에 관한 고찰(I))

  • Park, Tae-Yong;Heo, Tae-Young;Shin, Byung-Cheul
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.4
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    • pp.105-130
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    • 2010
  • Objectives : The purpose of this study was to assess the statistical methods errors used in the journal of Oriental Rehabilitation Medicine(JORM) and to identify the types of errors in statistical analysis. Methods : We reviewed quantitative articles that were published in the JORM from January 2005 through October 2009. Those were not used by statistical analysis such as literature studies, case study, review articles were not included in this analysis. A total of 296 articles was reviewed. We evaluated the adequacy and the validity of the statistical techniques with our checklist established be modified Lee's checklist, and three statistical evaluators assessed together to minimize bias. Results : Of the 222 articles, 213 were used in inferential and descriptive statistics. Of those 80% of articles adopting descriptive and inferential statistics were detected having statistical errors. One articles used 1.7 statistical method unit generally. Most frequently employed statistics were student t-test, one way ANOVA. pearson correlation analysis, Mann-whitney U test, paired t-test, and chi-square test in their order. However, most frequent statistics having errors were similar in order. The most common statistic errors were as follow: 1. absence of normality test, 2. misuse between paired test and unpaired test, 3. wrong choice of repeated measures analysis without consideration of time variables, 4, increase of Type I error by using inappropriate multiple test, 5. inappropriate application of discrete or categorical data instead of continuous data in correlation analysis, 6. poor consideration of basic consumption in chi-square test, 7. confusion between frequency comparison and average comparison, 8. mentioning the statistical technique without using it. Conclusions : We found various mistake or misuses in the applications of statistical methodologies in the articles published in the JORM. Careful consideration of statistical use and review from the specialist of statistics are warranted for improving the quality of JORM.

Optimization of the construction scheme of the cable-strut tensile structure based on error sensitivity analysis

  • Chen, Lian-meng;Hu, Dong;Deng, Hua;Cui, Yu-hong;Zhou, Yi-yi
    • Steel and Composite Structures
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    • v.21 no.5
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    • pp.1031-1043
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    • 2016
  • Optimization of the construction scheme of the cable-strut tensile structure based on error sensitivity analysis is studied in this paper. First, the element length was extracted as a fundamental variable, and the relationship between element length change and element internal force was established. By setting all pre-stresses in active cables to zero, the equation between the pre-stress deviation in the passive cables and the element length error was obtained to analyze and evaluate the error effects under different construction schemes. Afterwards, based on the probability statistics theory, the mathematical model of element length error is set up. The statistical features of the pre-stress deviation were achieved. Finally, a cable-strut tensile structure model with a diameter of 5.0 m was fabricated. The element length errors are simulated by adjusting the element length, and each member in one symmetrical unit was elongated by 3 mm to explore the error sensitivity of each type of element. The numerical analysis of error sensitivity was also carried out by the FEA model in ANSYS software, where the element length change was simulated by implementing appropriate temperature changes. The theoretical analysis and experimental results both indicated that different elements had different error sensitivities. Likewise, different construction schemes had different construction precisions, and the optimal construction scheme should be chosen for the real construction projects to achieve lower error effects, lower cost and greater convenience.

A Review of Statistical Methods in the Journal of Oriental Obstetrics & Gynecology (대한한방부인과학회지에서 사용된 통계방법에 관한 연구)

  • Kim, Yoon-Sang;Oh, Hyun-Sook;Lim, Eun-Mee
    • The Journal of Korean Obstetrics and Gynecology
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    • v.25 no.1
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    • pp.70-78
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    • 2012
  • Objectives: The purpose of this article is not until to investigate the changes and types of statistical methods and to point out the statistical errors after analyzing the method of articles that improve the quality of the statistical analysis of papers published in the Journal of Oriental Obstetrics and Gynecology. Methods: Papers published in the Journal of Oriental Obstetrics and Gynecology from 2009 to 2011 were reviewed for methodological and statistical validity using a modified version of Ahn's checklist. A statistician reviewed individual papers and evaluated the list items in the checklist for each paper. To avoid the potential assessment error by the statistician who lacks expertise in the field of Oriental Obstetrics and Gynecology. Results: A total of 190 papers including 64 original articles, 40 reviews article, 58 case report and 28 brief communication were reviewed. Statistics methods used in 121 papers were composed of t-test(58.7%), ANOVA test(19.8%) and ${\chi}^2$- test (14.0%) et al. Whereas only 14.9% of papers were free of statistical errors, the number of omission errors was 58 and the number of commission errors was 149 each. Conclusions: A variety of statistical errors were encountered in papers published in the Journal of Oriental Obstetrics and Gynecology. Accordingly, researchers should be more careful when it comes to describing and applying statistical methods.

Analysis of Statistical Methods Currently used in Toxicology Journals

  • Na, Jihye;Yang, Hyeri;Bae, SeungJin;Lim, Kyung-Min
    • Toxicological Research
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    • v.30 no.3
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    • pp.185-191
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    • 2014
  • Statistical methods are frequently used in toxicology, yet it is not clear whether the methods employed by the studies are used consistently and conducted based on sound statistical grounds. The purpose of this paper is to describe statistical methods used in top toxicology journals. More specifically, we sampled 30 papers published in 2014 from Toxicology and Applied Pharmacology, Archives of Toxicology, and Toxicological Science and described methodologies used to provide descriptive and inferential statistics. One hundred thirteen endpoints were observed in those 30 papers, and most studies had sample size less than 10, with the median and the mode being 6 and 3 & 6, respectively. Mean (105/113, 93%) was dominantly used to measure central tendency, and standard error of the mean (64/113, 57%) and standard deviation (39/113, 34%) were used to measure dispersion, while few studies provide justifications regarding why the methods being selected. Inferential statistics were frequently conducted (93/113, 82%), with one-way ANOVA being most popular (52/93, 56%), yet few studies conducted either normality or equal variance test. These results suggest that more consistent and appropriate use of statistical method is necessary which may enhance the role of toxicology in public health.

Data-Adaptive ECOC for Multicategory Classification

  • Seok, Kyung-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.1
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    • pp.25-36
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    • 2008
  • Error Correcting Output Codes (ECOC) can improve generalization performance when applied to multicategory classification problem. In this study we propose a new criterion to select hyperparameters included in ECOC scheme. Instead of margins of a data we propose to use the probability of misclassification error since it makes the criterion simple. Using this we obtain an upper bound of leave-one-out error of OVA(one vs all) method. Our experiments from real and synthetic data indicate that the bound leads to good estimates of parameters.

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Statistical Correction of Numerical Model Forecasts for Typhoon Tracks

  • Sohn, Keon-Tae
    • Communications for Statistical Applications and Methods
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    • v.12 no.2
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    • pp.295-304
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    • 2005
  • This paper concentrates on the prediction of typhoon tracks using the dynamic linear model (DLM) for the statistical correction of the numerical model guidance used in the JMA. The DLM with proposed forecast strategy is applied to reduce their systematic errors using the latest observation. All parameters of the DLM are updated dynamically and backward forecasting is performed to remove the effect of initial values.

Development of a Transfer Function Model to Forecast Ground-level Ozone Concentration in Seoul (서울지역의 지표오존농도 예보를 위한 전이함수모델 개발)

  • 김유근;손건태;문윤섭;오인보
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.6
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    • pp.779-789
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    • 1999
  • To support daily ground-level $O_3$ forecasting in Seoul, a transfer function model(TFM) has been developed by using surface meteorological data and pollutant data(previous-day [$O_3$] and [$NO_2$]) from 1 May to 31 August in 1997. The forecast performance of the TFM was evaluated by statistical comparison with $O_3$ concentration observed during September it is shown that correlation coefficient(R), root mean squared error(RMSE), normalized mean squared error(NMSE) and mean relative error(MRE) were 0.73, 15.64, 0.006 and 0.101, respectively. The TFM appeared to have some difficulty forecasting very high $O_3$ concentrations. To compare with this model, multiple regression model(MRM) was developed for the same period. According to statistical comparison between the TFM and MRM. two models had similar predictive capability but TFM based on $O_3$ concentration higher than 60 ppb provided more accurate forecast than MRM. It was concluded that statistical model based on TFM can be useful for improving the accuracy of local $O_3$ forecast.

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The Utilization of Local Document Information to Improve Statistical Context-Sensitive Spelling Error Correction (통계적 문맥의존 철자오류 교정 기법의 향상을 위한 지역적 문서 정보의 활용)

  • Lee, Jung-Hun;Kim, Minho;Kwon, Hyuk-Chul
    • KIISE Transactions on Computing Practices
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    • v.23 no.7
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    • pp.446-451
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    • 2017
  • The statistical context-sensitive spelling correction technique in this thesis is based upon Shannon's noisy channel model. The interpolation method is used for the improvement of the correction method proposed in the paper, and the general interpolation method is to fill the middle value of the probability by (N-1)-gram and (N-2)-gram. This method is based upon the same statistical corpus. In the proposed method, interpolation is performed using the frequency information between the statistical corpus and the correction document. The advantages of using frequency of correction documents are twofold. First, the probability of the coined word existing only in the correction document can be obtained. Second, even if there are two correction candidates with ambiguous probability values, the ambiguity is solved by correcting them by referring to the correction document. The method proposed in this thesis showed better precision and recall than the existing correction model.