• Title/Summary/Keyword: Non-Parametric Research

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A new approach for content-based video retrieval

  • Kim, Nac-Woo;Lee, Byung-Tak;Koh, Jai-Sang;Song, Ho-Young
    • International Journal of Contents
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    • v.4 no.2
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    • pp.24-28
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    • 2008
  • In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.

Parametric and Non Parametric Measures for Text Similarity (텍스트 유사성을 위한 파라미터 및 비 파라미터 측정)

  • Mlyahilu, John;Kim, Jong-Nam
    • Journal of the Institute of Convergence Signal Processing
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    • v.20 no.4
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    • pp.193-198
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    • 2019
  • The wide spread of genuine and fake information on internet has lead to various studies on text analysis. Copying and pasting others' work without acknowledgement, research results manipulation without proof has been trending for a while in the era of data science. Various tools have been developed to reduce, combat and possibly eradicate plagiarism in various research fields. Text similarity measurements can be manually done by using both parametric and non parametric methods of which this study implements cosine similarity and Pearson correlation as parametric while Spearman correlation as non parametric. Cosine similarity and Pearson correlation metrics have achieved highest coefficients of similarity while Spearman shown low similarity coefficients. We recommend the use of non parametric methods in measuring text similarity due to their non normality assumption as opposed to the parametric methods which relies on normality assumptions and biasness.

Prediction Intervals for Day-Ahead Photovoltaic Power Forecasts with Non-Parametric and Parametric Distributions

  • Fonseca, Joao Gari da Silva Junior;Ohtake, Hideaki;Oozeki, Takashi;Ogimoto, Kazuhiko
    • Journal of Electrical Engineering and Technology
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    • v.13 no.4
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    • pp.1504-1514
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    • 2018
  • The objective of this study is to compare the suitability of a non-parametric and 3 parametric distributions in the characterization of prediction intervals of photovoltaic power forecasts with high confidence levels. The prediction intervals of the forecasts are calculated using a method based on recent past data similar to the target forecast input data, and on a distribution assumption for the forecast error. To compare the suitability of the distributions, prediction intervals were calculated using the proposed method and each of the 4 distributions. The calculations were done for one year of day-ahead forecasts of hourly power generation of 432 PV systems. The systems have different sizes and specifications, and are installed in different locations in Japan. The results show that, in general, the non-parametric distribution assumption for the forecast error yielded the best prediction intervals. For example, with a confidence level of 85% the use of the non-parametric distribution assumption yielded a median annual forecast error coverage of 86.9%. This result was close to the one obtained with the Laplacian distribution assumption (87.8% of coverage for the same confidence level). Contrasting with that, using a Gaussian and Hyperbolic distributions yielded median annual forecast error coverage of 89.5% and 90.5%.

A Non-parametric Analysis of the Tam-Jin River : Data Homogeneity between Monitoring Stations (탐진강 수질측정 지점 간 동질성 검정을 위한 비모수적 자료 분석)

  • Kim, Mi-Ah;Lee, Su-Woong;Lee, Jae-Kwan;Lee, Jung-Sub
    • Journal of Korean Society on Water Environment
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    • v.21 no.6
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    • pp.651-658
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    • 2005
  • The Non-parametric Analysis is powerful in data test especially for the non- normality water quality data. The data at three monitoring stations of the Tam-Jin River were evaluated for their normality using Skewness, Q-Q plot and Shapiro-Willks tests. Various constituent of water quality data including temperature, pH, DO, SS, BOD, COD, TN and TP in the period of January 1994 to December 2004 were used as dataset. Shapiro-Willks normality test was carried out for a test 5% significance level. Most water quality data except DO at monitoring stations 1 and 2 showed that data does not normally distributed. It is indicating that non-parametric method must be used for a water quality data. Therefore, a homogeneity was conducted by Mann-Whitney U test (p<0.05). Two stations were paired in three pairs of such stations. Differences between stations 1, 2 and stations 1, 3 for pH, BOD, COD, TN and TP were meaningful, but Tam-Jin 2 and 3 stations did not meaningful. In addition, a narrow gap of the water quality ranges is not a difference. Categories in which all three pairs of stations (1 and 2, 2 and 3, 1 and 3) in the Tam-Jin River showed difference in water quality were analyzed on TN and TP. The results of in this research suggest a right analysis in the homogeneity test of water quality data and a reasonable management of pollutant sources.

A study comparison of mortality projection using parametric and non-parametric model (모수와 비모수 모형을 활용한 사망률 예측 비교 연구)

  • Kim, Soon-Young;Oh, Jinho
    • The Korean Journal of Applied Statistics
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    • v.30 no.5
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    • pp.701-717
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    • 2017
  • The interest of Korean society and government on future demographic structures is increasing due to rapid aging. Korea's mortality rate is decreasing, but the declined gap is variable. In this study, we compare the Lee-Carter, Lee-Miller, Booth-Maindonald-Smith model and functional data model (FDM) as well as Coherent FDM using non-parametric smoothing technique. We are then examine a reasonable model for projecting on mortality declined rate trend in terms of accuracy of mortality rate by ages and life expectancy. The possibility of using non-parametric techniques for the prediction of mortality in Korea was also examined. Based on the analysis results, FDM and Coherent FDM, which uses the non-parametric technique and reflects the trend of recent data, are excellent. As a result, FDM and Coherent FDM are good fit, and predictability is also excellent assuming no significant future changes.

Copula Approach for the Measurement of Integrated Risk of National Pension Fund (Copula를 이용한 국민연금기금의 통합위험에 관한 연구)

  • Byun, Jin-Ho;Nam, Chae-Woo;Lee, Ho-Sun
    • IE interfaces
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    • v.24 no.1
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    • pp.24-39
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    • 2011
  • In this paper, we study the methodology for the measurement and integration of market risk and credit risk using Copula. We apply the methodology of Rosenberg, and Schuermann(2006) to the assets of pension system. Firstly we estimate dynamics of risk factors and their effects on investment returns, then use the estimated result to simulate future movement of risk factors and distribution of investment returns. Finally we measure integrated risk using integrated return distribution by Copula and simulated future investment return distributions. We found the integrated risk changing with the correlation of risks and investment weights of risks and confirmed the diversification effect of risks. This result is consistent when we use normal Copula and normal marginals, t-Copula and t(3) marginals, and normal Copula and non-parametric marginals. And in the case of non-parametric maginals, larger integrated risk is calculated. It means that use of non-parametric marginals is more conservative.

Bootstrap simulation for quantification of uncertainty in risk assessment

  • Chang, Ki-Yoon;Hong, Ki-Ok;Pak, Son-Il
    • Korean Journal of Veterinary Research
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    • v.47 no.2
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    • pp.259-263
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    • 2007
  • The choice of input distribution in quantitative risk assessments modeling is of great importance to get unbiased overall estimates, although it is difficult to characterize them in situations where data available are too sparse or small. The present study is particularly concerned with accommodation of uncertainties commonly encountered in the practice of modeling. The authors applied parametric and non-parametric bootstrap simulation methods which consist of re-sampling with replacement, in together with the classical Student-t statistics based on the normal distribution. The implications of these methods were demonstrated through an empirical analysis of trade volume from the amount of chicken and pork meat imported to Korea during the period of 1998-2005. The results of bootstrap method were comparable to the classical techniques, indicating that bootstrap can be an alternative approach in a specific context of trade volume. We also illustrated on what extent the bias corrected and accelerated non-parametric bootstrap method produces different estimate of interest, as compared by non-parametric bootstrap method.

A Research of the Reliability Analysis and Application Method Based on Non-parametric Statistics Using Field Data (야전 운용자료를 이용한 비 모수 통계 기반의 신뢰도 분석 기법 및 활용 방안 연구)

  • Na, Il-Yong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.4
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    • pp.594-600
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    • 2010
  • In this paper, we introduced non-parametric statisticals method that could analyse the field data and proposed application ways such as repair-part demand forcasting, MTBF estimation and trend analysis, identity comparison with two populations using the analytical results. In addition, we applied that to real field data which has been collected for about ten years from K series tracked vehicle. After that, we compared the results with those using traditional parametric statistical method, and verified the usability of them.

The Evaluation of Relative Management Efficiency of Automobile Companies Using Non-parametric Approach (비모수 검정을 활용한 자동차 기업의 상대적 경영 효율성 평가)

  • Ha, Gui Ryong;Choi, Suk Bong
    • Knowledge Management Research
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    • v.15 no.2
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    • pp.147-164
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    • 2014
  • This paper investigated the efficiency of automobile firms by using several non-parametric approaches. First, using Data Envelopment Analysis (DEA), the paper has investigated the critical factors that determine the relative efficiency of management performance in automobile companies. Second, we examined how the firm size impact on the difference of this efficiency by using Kruskl-Wallis Test. Third, by using Mann-whitney test, we also investigated the difference of the efficiency accoss existence of technological innovation activity. Finally, the paper explored the relationship between technological innovation and management efficiency by using logistic regression model. The findings of this study provided practical information for inefficient automobile firms to find benchmarking firms and strategic position to improve their efficiency. The result also provided theoretical and methodological implications for those who explore factors affecting management efficiencies. Future research directions with the limitation of the study are discussed.

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Video retrieval method using non-parametric based motion classification (비-파라미터 기반의 움직임 분류를 통한 비디오 검색 기법)

  • Kim Nac-Woo;Choi Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.2 s.308
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    • pp.1-11
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    • 2006
  • In this paper, we propose the novel video retrieval algorithm using non-parametric based motion classification in the shot-based video indexing structure. The proposed system firstly gets the key frame and motion information from each shot segmented by scene change detection method, and then extracts visual features and non-parametric based motion information from them. Finally, we construct real-time retrieval system supporting similarity comparison of these spatio-temporal features. After the normalized motion vector fields is created from MPEG compressed stream, the extraction of non-parametric based motion feature is effectively achieved by discretizing each normalized motion vectors into various angle bins, and considering a mean, a variance, and a direction of these bins. We use the edge-based spatial descriptor to extract the visual feature in key frames. Experimental evidence shows that our algorithm outperforms other video retrieval methods for image indexing and retrieval. To index the feature vectors, we use R*-tree structures.