• 제목/요약/키워드: Mean vector

검색결과 692건 처리시간 0.019초

불균형 데이터 학습을 위한 지지벡터기계 알고리즘 (Support Vector Machine Algorithm for Imbalanced Data Learning)

  • 김광성;황두성
    • 한국컴퓨터정보학회논문지
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    • 제15권7호
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    • pp.11-17
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    • 2010
  • 본 논문에서는 클래스 불균형 학습을 위한 이차 최적화 문제의 해를 구하는 개선된 SMO 학습 알고리즘을 제안한다. 클래스에 서로 다른 정규화 값이 부여되는 지지벡터기계의 최적화 문제의 구현에 SMO 알고리즘이 적합하며, 제안된 알고리즘은 서로 다른 클래스에서 선택된 두 라그랑지 변수의 현재 해를 구하는 학습 단계를 반복한다. 제안된 학습 알고리즘은 UCI 벤치마킹 문제에서 테스트되어 클래스 불균형 분포를 반영하는 g-mean 평가를 이용한 일반화 성능이 SMO 알고리즘과 비교되었다. 실험 결과에서 제안된 알고리즘은 SMO에 비해 적은 클래스 데이터의 예측율을 높이고 학습시간을 단축시킬 수 있다.

등각사상과 평균값좌표계를 이용한 정점 법선벡터 계산법 (Vertex Normal Computation using Conformal Mapping and Mean Value Coordinates)

  • 김형석;김호숙
    • 한국정보통신학회논문지
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    • 제13권3호
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    • pp.451-457
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    • 2009
  • 컴퓨터그래픽스에서 다루어지는 대부분의 물체들은 메쉬 형태로 표현된다. 보다 다양한 형태로의 변형이나 현실감 있는 렌더링을 얻기 위해서는 정점에서의 올바른 법선벡터 계산이 필수적이다. 이에 대한 기존 연구들은 정점의 기하학적 특성을 단순하게 반영하는 가중치를 사용하였다. 본 논문에서는 국지적 기하학 특성을 종합적으로 반영하는 등각사상과 이웃 정점과의 상호관계를 연속적으로 표현할 수 있는 중간값 좌표계를 사용하는 방법을 제안한다. 논문에서 제시된 방법이 기존 다른 방법에 비해서 보다 정확한 법선벡터를 계산할 수 있음을 실험을 통해서 알 수 있다.

A Comparative Study Between Linear Regression and Support Vector Regression Model Based on Environmental Factors of a Smart Bee Farm

  • Rahman, A. B. M. Salman;Lee, MyeongBae;Venkatesan, Saravanakumar;Lim, JongHyun;Shin, ChangSun
    • 스마트미디어저널
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    • 제11권5호
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    • pp.38-47
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    • 2022
  • Honey is one of the most significant ingredients in conventional food production in different regions of the world. Honey is commonly used as an ingredient in ethnic food. Beekeeping is performed in various locations as part of the local food culture and an occupation related to pollinator production. It is important to conduct beekeeping so that it generates food culture and helps regulate the regional environment in an integrated manner in preserving and improving local food culture. This study analyzes different types of environmental factors of a smart bee farm. The major goal of this study is to determine the best prediction model between the linear regression model (LM) and the support vector regression model (SVR) based on the environmental factors of a smart bee farm. The performance of prediction models is measured by R2 value, root mean squared error (RMSE), and mean absolute error (MAE). From all analysis reports, the best prediction model is the support vector regression model (SVR) with a low coefficient of variation, and the R2 values for Farm inside temperature, bee box inside temperature, and Farm inside humidity are 0.97, 0.96, and 0.44.

Application of Response Surface Methodology and Plackett Burman Design assisted with Support Vector Machine for the Optimization of Nitrilase Production by Bacillus subtilis AGAB-2

  • Ashish Bhatt;Darshankumar Prajapati;Akshaya Gupte
    • 한국미생물·생명공학회지
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    • 제51권1호
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    • pp.69-82
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    • 2023
  • Nitrilases are a hydrolase group of enzymes that catalyzes nitrile compounds and produce industrially important organic acids. The current objective is to optimize nitrilase production using statistical methods assisted with artificial intelligence (AI) tool from novel nitrile degrading isolate. A nitrile hydrolyzing bacteria Bacillus subtilis AGAB-2 (GenBank Ascension number- MW857547) was isolated from industrial effluent waste through an enrichment culture technique. The culture conditions were optimized by creating an orthogonal design with 7 variables to investigate the effect of the significant factors on nitrilase activity. On the basis of obtained data, an AI-driven support vector machine was used for the fitted regression, which yielded new sets of predicted responses with zero mean error and reduced root mean square error. The results of the above global optimization were regarded as the theoretical optimal function conditions. Nitrilase activity of 9832 ± 15.3 U/ml was obtained under optimized conditions, which is a 5.3-fold increase in compared to unoptimized (1822 ± 18.42 U/ml). The statistical optimization method involving Plackett Burman Design and Response surface methodology in combination with an AI tool created a better response prediction model with a significant improvement in enzyme production.

A Study on the Comparison of Electricity Forecasting Models: Korea and China

  • Zheng, Xueyan;Kim, Sahm
    • Communications for Statistical Applications and Methods
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    • 제22권6호
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    • pp.675-683
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    • 2015
  • In the 21st century, we now face the serious problems of the enormous consumption of the energy resources. Depending on the power consumption increases, both China and South Korea face a reduction in available resources. This paper considers the regression models and time-series models to compare the performance of the forecasting accuracy based on Mean Absolute Percentage Error (MAPE) in order to forecast the electricity demand accurately on the short-term period (68 months) data in Northeast China and find the relationship with Korea. Among the models the support vector regression (SVR) model shows superior performance than time-series models for the short-term period data and the time-series models show similar results with the SVR model when we use long-term period data.

Evaluating Properties of Variable Sampling Interval EWMA Control Charts for Mean Vector

  • Kwon, Yong-Man;Chang, Duk-Joon
    • Journal of the Korean Data and Information Science Society
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    • 제16권3호
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    • pp.639-650
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    • 2005
  • Theoretical and numerical comparison have shown that variable sampling interval (VSI) charts are substantially more efficient than fixed sampling interval(FSI) charts in term of ATS(average time to signal). But the frequency of switching between different sampling intervals is a complicating factor in VSI procedures. VSI EWMA charts for monitoring mean vector of related qualify characteristics are investigated. To compare the efficiencies of the proposed charts, the performances are evaluated for matched FSI and VSI charts in terms of average time to signal(ATS) and average number of samples to signal(ANSS). For the switching behavior of the proposed VSI charts, average number of switches(ANSW) are also investigated.

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태양광 발전량 예측을 위한 빅데이터 처리 방법 개발 (Development of Solar Power Output Prediction Method using Big Data Processing Technic)

  • 정재천;송치성
    • 시스템엔지니어링학술지
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    • 제16권1호
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    • pp.58-67
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    • 2020
  • A big data processing method to predict solar power generation using systems engineering approach is developed in this work. For developing analytical method, linear model (LM), support vector machine (SVN), and artificial neural network (ANN) technique are chosen. As evaluation indices, the cross-correlation and the mean square root of prediction error (RMSEP) are used. From multi-variable comparison test, it was found that ANN methodology provides the highest correlation and the lowest RMSEP.

소표본 errors-in-vairalbes 모형에서의 통계 추론 (Small-Sample Inference in the Errors-in-Variables Model)

  • 소병수
    • 품질경영학회지
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    • 제25권1호
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    • pp.69-79
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    • 1997
  • We consider the semiparametric linear errors-in-variables model: yi=(${\alpha}+{\beta}ui+{\varepsilon}i$, xi=ui+${\varepsilon}i$ i=1, …, n where (xi, yi) stands for an observation vector, (ui) denotes a set of incidental nuisance parameters, (${\alpha}$ , ${\beta}$) is a vector of regression parameters and (${\varepsilon}i$, ${\delta}i$) are mutually uncorrelated measurement errors with zero mean and finite variances but otherwise unknown distributions. On the basis of a simple small-sample low-noise a, pp.oximation, we propose a new method of comparing the mean squared errors(MSE) of the various competing estimators of the true regression parameters ((${\alpha}$ , ${\beta}$). Then we show that a class of estimators including the classical least squares estimator and the maximum likelihood estimator are consistent and first-order efficient within the class of all regular consistent estimators irrespective of type of measurement errors.

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Comparison of accumulate-combine and combine-accumulate methods in multivariate CUSUM charts for mean vector

  • Chang, Duk-Joon;Heo, Sunyeong
    • Journal of the Korean Data and Information Science Society
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    • 제24권4호
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    • pp.919-929
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    • 2013
  • We compared two basic methods, combine-accumulate method and accumulate-combine method, using the past quality information in multivariate quality control procedure for monitoring mean vector of multivariate normal process. When small or moderate shifts have occurred, accumulate-combine method yields smaller average run length (ARL) and average time to signal (ATS) than combine-accumulate method. On the other hand, we have found from our numerical results that combine-accumulate method has better performances in terms of switching behavior than accumulate-combine method. In industry, a quality engineer could select one of the two method under the comprehensive consideration about the required time to signal, switching behavior, and other physical factors in the production process.

낮은 차원의 벡터 변환을 통한 음성 변환 (Voice conversion using low dimensional vector mapping)

  • 이기승;도원;윤대희
    • 전자공학회논문지S
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    • 제35S권4호
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    • pp.118-127
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    • 1998
  • In this paper, we propose a voice personality transformation method which makes one person's voice sound like another person's voice. In order to transform the voice personality, vocal tract transfer function is used as a transformation parameter. Comparing with previous methods, the proposed method can obtain high-quality transformed speech with low computational complexity. Conversion between the vocal tract transfer functions is implemented by a linear mapping based on soft clustering. In this process, mean LPC cepstrum coefficients and mean removed LPC cepstrum modeled by the low dimensional vector are used as transformation parameters. To evaluate the performance of the proposed method, mapping rules are generated from 61 Korean words uttered by two male and one female speakers. These rules are then applied to 9 sentences uttered by the same persons, and objective evaluation and subjective listening tests for the transformed speech are performed.

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