• Title/Summary/Keyword: Mahalanobis 거리

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SMOTE by Mahalanobis distance using MCD in imbalanced data (불균형 자료에서 MCD를 활용한 마할라노비스 거리에 의한 SMOTE)

  • Jieun Jung;Yong-Seok Choi
    • The Korean Journal of Applied Statistics
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    • v.37 no.4
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    • pp.455 -465
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    • 2024
  • SMOTE (synthetic minority over-sampling technique) has been used the most as a solution to the problem of imbalanced data. SMOTE selects the nearest neighbor based on Euclidean distance. However, Euclidean distance has the disadvantage of not considering the correlation between variables. In particular, the Mahalanobis distance has the advantage of considering the covariance of variables. But if there are outliers, they usually influence calculating the Mahalanobis distance. To solve this problem, we use the Mahalanobis distance by estimating the covariance matrix using MCD (minimum covariance determinant). Then apply Mahalanobis distance based on MCD to SMOTE to create new data. Therefore, we showed that in most cases this method provided high performance indicators for classifying imbalanced data.

Speaker Verification Using SVM Kernel with GMM-Supervector Based on the Mahalanobis Distance (Mahalanobis 거리측정 방법 기반의 GMM-Supervector SVM 커널을 이용한 화자인증 방법)

  • Kim, Hyoung-Gook;Shin, Dong
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.3
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    • pp.216-221
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    • 2010
  • In this paper, we propose speaker verification method using Support Vector Machine (SVM) kernel with Gaussian Mixture Model (GMM)-supervector based on the Mahalanobis distance. The proposed GMM-supervector SVM kernel method is combined GMM with SVM. The GMM-supervectors are generated by GMM parameters of speaker and other speaker utterances. A speaker verification threshold of GMM-supervectors is decided by SVM kernel based on Mahalanobis distance to improve speaker verification accuracy. The experimental results for text-independent speaker verification using 20 speakers demonstrates the performance of the proposed method compared to GMM, SVM, GMM-supervector SVM kernel based on Kullback-Leibler (KL) divergence, and GMM-supervector SVM kernel based on Bhattacharyya distance.

Transformed Augmented Cucker-Smale Model with Mahalanobis Distance and Statistical Degrees of Freedom for Improving Efficiency of Flocking Flight System (시스템의 성능 향상을 위해 마할라노비스 거리와 자유도를 이용하여 변형시킨 쿠커-스메일 모델)

  • Jung, Jae-Hwi
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.8
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    • pp.573-580
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    • 2020
  • One of challengeable problems of multi-agent systems is a positioning control. Augmented Cucker-Smale model is using for controlling position and velocity of the multi-agent system. The original model applies same coefficients to all agents in same group, so that does not consider characteristic of each agent. To enhance performance of the original model, this paper transforms original coefficients to Mahalanobis distance coefficients that reflects an initial distribution of multi-agent systems and applies statistical degrees of freedom. This paper not only confirms tendency of enhanced performance of the suggested model by using monte-carlo simulation, but also additionally compares trajectory of the original model with the suggested model to confirm coefficients of Mahalanobis distance performing correctly.

Development of a Multiobjective Optimization Algorithm Using Data Distribution Characteristics (데이터 분포특성을 이용한 다목적함수 최적화 알고리즘 개발)

  • Hwang, In-Jin;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.12
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    • pp.1793-1803
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    • 2010
  • The weighting method and goal programming require weighting factors or target values to obtain a Pareto optimal solution. However, it is difficult to define these parameters, and a Pareto solution is not guaranteed when the choice of the parameters is incorrect. Recently, the Mahalanobis Taguchi System (MTS) has been introduced to minimize the Mahalanobis distance (MD). However, the MTS method cannot obtain a Pareto optimal solution. We propose a function called the skewed Mahalanobis distance (SMD) to obtain a Pareto optimal solution while retaining the advantages of the MD. The SMD is a new distance scale that multiplies the skewed value of a design point by the MD. The weighting factors are automatically reflected when the SMD is calculated. The SMD always gives a unique Pareto optimal solution. To verify the efficiency of the SMD, we present two numerical examples and show that the SMD can obtain a unique Pareto optimal solution without any additional information.

A Fault Diagnosis on the Rotating Machinery Using Mahalanobis Distance (마할라노비스 거리를 이용한 회전기기의 이상진단)

  • Park, Sang-Gil;Park, Won-Sik;Jung, Jae-Eun;Lee, You-Yub;Oh, Jae-Eung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.7
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    • pp.556-560
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    • 2008
  • As higher reliability and accuracy on production facilities are required to detect incipient faults, a diagnostic system for predictive maintenance of the facility is highly recommended. In this paper, we present a study on the application of vibration signals to diagnose faults for a Rotating Machinery using the Mahalanobis Distance-Taguchi System. RMS, Crest Factor and Kurtosis that is known as the Statistical Methods and the spectrum analysis are used to diagnose faults as parameters of Mahalanobis distance.

Ellipsoid Fuzzy-ART for Pattern Recognition Improvement (패턴인식을 위한 타원형 Fuzzy-ART)

  • 강성호;정성부;임중규;이현관;엄기환
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.305-308
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    • 2003
  • This paper proposed Ellipsoid Fuzzy-ART (Fuzzy-Adaptive Resonance Theory) for recognition performance improvement to use Mahalanobis distance. The suggested method uses Mahalanobis distance to decide pattern boundary region at vector space. In order to confirm the validity of proposed method, comparison of the performance has made between existing method and the proposed method through simulation.

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Optimization of Sheet Metal Forming Process Using Mahalanobis Taguchi System (마하라노비스 다구찌(Mahalanobis Taguchi) 시스템을 이용한 박판 성형 공정의 최적화)

  • Kim, Kyung-Mo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.1
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    • pp.95-102
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    • 2016
  • Wrinkle, spring-back, and fracture are major defects frequently found in the sheet metal forming process, and the reduction of such defects is difficult as they are affected by uncontrollable factors, such as variations in properties of the incoming material and process parameters. Without any countermeasures against these issues, attempts to reduce defects through optimal design methods often lead to failure. In this research, a new multi-attribute robust design methodology, based on the Mahalanobis Taguchi System (MTS), is presented for reducing the possibilities of wrinkle, spring-back, and fracture. MTS performs experimentation, based on the orthogonal array under various noise conditions, uses the SN ratio of the Mahalanobis distance as a performance metric. The proposed method is illustrated through a robust design of the sheet metal forming process of a cross member of automotive body.

Performance Improvement of Microphone Array Speech Recognition Using Features Weighted Mahalanobis Distance (가중특징 Mahalanobis거리를 이용한 마이크 어레이 음석인식의 성능향상)

  • Nguyen, Dinh Cuong;Chung, Hyun-Yeol
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.1E
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    • pp.45-53
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    • 2010
  • In this paper, we present the use of the Features Weighted Mahalanobis Distance (FWMD) in improving the performance of Likelihood Maximizing Beamforming (Limabeam) algorithm in speech recognition for microphone array. The proposed approach is based on the replacement of the traditional distance measure in a Gaussian classifier with adding weight for different features in the Mahalanobis distance according to their distances after the variance normalization. By using Features Weighted Mahalanobis Distance for Limabeam algorithm (FWMD-Limabeam), we obtained correct word recognition rate of 90.26% for calibrate Limabeam and 87.23% for unsupervised Limabeam, resulting in a higher rate of 3% and 6% respectively than those produced by the original Limabearn. By implementing a HM-Net speech recognition strategy alternatively, we could save memory and reduce computation complexity.

Target Identification using the Mahalanobis Distance and Geometric Parameters (마할라노비스 거리와 기하학적 파라메터에 의한 표적의 인식)

  • 이준웅;권인소
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.7
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    • pp.814-820
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    • 1999
  • We propose a target identification algorithm for visual tracking. Target identification is realized by finding out corresponding line segments to the hypothesized model segments of the target. The key idea is the combination of the Mahalanobis distance with the geometrical relationship between model segments and extracted line segments.

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