• Title/Summary/Keyword: 마할라노비스 거리

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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.

A Simplification of Polynomial Representations for the Moments of the Mahalanobis Distances (마할라노비스 거리의 모멘트에 대한 다정식 표현의 간략화)

  • 김수중;홍재근
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.21 no.3
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    • pp.1-5
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    • 1984
  • It is investigated that Mahalanobis distances are invariant under a proper transformation and interest MDs are distributed as non-central chi-square while it is well known that intraset MDs are distributed as central chi-square. And their moments have been expressed as simple polynomials whose coefficients satisfy straightforward recursive relations.

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New Statistical Pattern Recognition Technology for Condition Assessment of Cable-stayed Bridge on Earthquake Load (지진하중을 받는 사장교의 상태평가를 위한 새로운 통계적 패턴 인식 기술)

  • Heo, Gwanghee;Kim, Chunggil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.3
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    • pp.747-754
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    • 2014
  • In spite of its usefulness for health monitoring of structures on steady external load, the statistical pattern recognition technology (SPRT), based on Mahalanobis distance theory (MDT), is not good enough for the health monitoring of structures on large variability external load like earthquake. Damage is usually determined by the difference between the average measured value of undamaged structure and the measure value of damaged one. So when external variability gets larger, the difference gets bigger along, which is thus easily mistaken for a damage. This paper aims to overcome the problem and develop an improved Mahalanobis distance theory (IMDT), that is, a SPRT with revised MDT in order to decrease external variability so that we will be able to continue to monitor the structure on uncertain external variability. This method is experimentally tested to see if it precisely evaluates the health of a cable-stayed bridge on each general random load and earthquake load. As a result, the IMDT is found to be valid in locating structural damage made by damaged cables by means of data from undamaged cables. So it is proved to be effectively applicable to the health monitoring of bridges on external load of variability.

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.

Development Small Size RGB Sensor for Providing Long Detecting Range (원거리 검출범위를 제공하는 소형 RGB 센서 개발)

  • Seo, Jae Yong;Lee, Si Hyun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.12
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    • pp.174-182
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    • 2015
  • In this paper, we developed the small size RGB sensor that recognizes a long distance using a low-cost color sensor. Light receiving portion of the sensor was used as a camera lens for far distance recognition, and illuminating unit was increased the strength of the light by using a high-power white LED and a lens mounted on the reflector. RGB color recognition algorithm consists of the learning process and the realtime recognition process. We obtain a normalized RGB color reference data in the learning process using the specimens painted with target colors, and classifies the three colors using the Mahalanobis distance in recognition process. We apply the developed the RGB color recognition sensor to a prototype of the part classification system and evaluate the performance of its.

Improvement of Face Recognition Speed Using Pose Estimation (얼굴의 자세추정을 이용한 얼굴인식 속도 향상)

  • Choi, Sun-Hyung;Cho, Seong-Won;Chung, Sun-Tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.5
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    • pp.677-682
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    • 2010
  • This paper addresses a method of estimating roughly the human pose by comparing Haar-wavelet value which is learned in face detection technology using AdaBoost algorithm. We also presents its application to face recognition. The learned weak classifier is used to a Haar-wavelet robust to each pose's feature by comparing the coefficients during the process of face detection. The Mahalanobis distance is used to measure the matching degree in Haar-wavelet selection. When a facial image is detected using the selected Haar-wavelet, the pose is estimated. The proposed pose estimation can be used to improve face recognition speed. Experiments are conducted to evaluate the performance of the proposed method for pose estimation.

Development of Predictive Models for Subway Disaster Forecasting (지하철 재난 전조 예측 모델 개발)

  • Park, Mi Yun;Park, Wan Soon;Lee, Jeonghun;Kwon, and Se Gon
    • Journal of Korean Society of Disaster and Security
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    • v.10 no.2
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    • pp.1-6
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    • 2017
  • In the previous research, the research on the development of subway disaster detection system that discovers the disaster early warning of the subway station disaster and the evacuation to the passengers based on the Internet of things. This paper as a follow-up study analyzes the sensor data installed in the station in real time to quickly detect the disaster. In particular, we developed a statistical methodology based on the Mahalanobis distance in consideration of the environment that varies depending on the installation location of the sensor during initial system construction.

Visualizing multidimensional data in multiple groups (다그룹 다차원 데이터의 시각화)

  • Huh, Myung-Hoe
    • The Korean Journal of Applied Statistics
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    • v.30 no.1
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    • pp.83-93
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    • 2017
  • A typical approach to visualizing k (${\geq}2$)-group multidimensional data is to use Fisher's canonical discriminant analysis (CDA). CDA finds the best low-dimensional subspace that accommodates k group centroids in the Mahalanobis space. This paper proposes an alternative visualization procedure functioning in the Euclidean space, which finds the primary dimension with maximum discrimination of k group centroids and the secondary dimension with maximum dispersion of all observational units. This hybrid procedure is especially useful when the number of groups k is two.

A study on early faults detection of pressurizer pressure control system using MTS (MTS를 이용한 가압기 압력 제어 계통의 조기 고장 감지에 대한 연구)

  • Cha, Jae-Min;Kim, Joon-Young;Shin, Junguk;Yeom, Choongseob;Kang, Seong-Ki
    • The Korean Journal of Applied Statistics
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    • v.29 no.7
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    • pp.1385-1398
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    • 2016
  • A pressurizer is a major equipment system in a nuclear power plant (NPP) and controls the reactor cooling system pressure within the allowable range. Faults in the pressurizer can be critical to the NPP; therefore, early fault detection in the pressurizer is significant for NPP safety. This study applies Mahalanobis Taguchi system (MTS), which is one of the promising pattern classification methods, based on the Mahalanobis distance concept and Taguchi quality engineering theory to the early fault detection problem of the pressurizer pressure control system. We conducted experiments using data from full scope NPP simulator based on a pressurizer pressure transmitter faults scenario to validate the faults detection performance of MTS. As a result, MTS can rapidly detect the faults compared to conventional faults detection based on single sensor monitoring.