• Title/Summary/Keyword: Bayes rule

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Separating Signals and Noises Using Mixture Model and Multiple Testing (혼합모델 및 다중 가설 검정을 이용한 신호와 잡음의 분류)

  • Park, Hae-Sang;Yoo, Si-Won;Jun, Chi-Hyuck
    • The Korean Journal of Applied Statistics
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    • v.22 no.4
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    • pp.759-770
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    • 2009
  • A problem of separating signals from noises is considered, when they are randomly mixed in the observation. It is assumed that the noise follows a Gaussian distribution and the signal follows a Gamma distribution, thus the underlying distribution of an observation will be a mixture of Gaussian and Gamma distributions. The parameters of the mixture model will be estimated from the EM algorithm. Then the signals and noises will be classified by a fixed threshold approach based on multiple testing using positive false discovery rate and Bayes error. The proposed method is applied to a real optical emission spectroscopy data for the quantitative analysis of inclusions. A simulation is carried out to compare the performance with the existing method using 3 sigma rule.

Statistical Estimation of Motion Trajectories of Falling Petals Based on Particle Filtering (Particle Filtering에 근거한 낙하하는 꽃잎의 운동궤적의 통계적 추정)

  • Lee, Jae Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.7
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    • pp.629-635
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    • 2016
  • This paper presents a method for predicting and tracking the irregular motion of bio-systems, - such as petals of flowers, butterflies or seeds of dandelion - based on the particle filtering theory. In bio-inspired system design, the ability to predict the dynamic motion of particles through adequate, experimentally verified models is important. The modeling of petal particle systems falling in air was carried out using the Bayesian probability rule. The experimental results show that the suggested method has good predictive power in the case of random disturbances induced by the turbulence of air.

An Analysis on Confidence Level of Domestic Precision Guided Missile(PGM) based on Live-fire Test Results (국내 정밀유도무기 사격시험 결과 기반 신뢰수준 분석)

  • Seo, Bo-Gil;Yoon, Young Ho;Kim, Bo Ram
    • Journal of Korean Society for Quality Management
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    • v.48 no.1
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    • pp.215-225
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    • 2020
  • Purpose: The purpose of this study was to show current states of domestic Precision Guided Missile(PGM) by analyzing Live-fire test results using general methods to get the Confidence Levels. Methods: Live-fire test results were used to get Confidence Levels of PGM. The Confidence Levels were derived by two general methods. The first method was Binomial distribution and second was convergence of Hypergeometric distribution and Bayes' rule. Results: The results of this study are as follows; The more Live-fire tests of PGM are performed, the higher Confidence Level of PGM will be estimated. And the number of Live-fire tests are related to a unit price of PGM. This results means that the increase of live-fire test, which is useful data for preparation and evaluation of Development Tests / Operation Tests for PGMs, is only way to enhance the Confidence Levels of each PGMs. Conclusion: This study shows the relationship between the Live-fire tests and Confidence Levels of PGMs and it will be used on Live-fire Test & Evaluation of PGMs for reference.

Prototype based Classification by Generating Multidimensional Spheres per Class Area (클래스 영역의 다차원 구 생성에 의한 프로토타입 기반 분류)

  • Shim, Seyong;Hwang, Doosung
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.2
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    • pp.21-28
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    • 2015
  • In this paper, we propose a prototype-based classification learning by using the nearest-neighbor rule. The nearest-neighbor is applied to segment the class area of all the training data into spheres within which the data exist from the same class. Prototypes are the center of spheres and their radii are computed by the mid-point of the two distances to the farthest same class point and the nearest another class point. And we transform the prototype selection problem into a set covering problem in order to determine the smallest set of prototypes that include all the training data. The proposed prototype selection method is based on a greedy algorithm that is applicable to the training data per class. The complexity of the proposed method is not complicated and the possibility of its parallel implementation is high. The prototype-based classification learning takes up the set of prototypes and predicts the class of test data by the nearest neighbor rule. In experiments, the generalization performance of our prototype classifier is superior to those of the nearest neighbor, Bayes classifier, and another prototype classifier.

An Efficient Face Region Detection for Content-based Video Summarization (내용기반 비디오 요약을 위한 효율적인 얼굴 객체 검출)

  • Kim Jong-Sung;Lee Sun-Ta;Baek Joong-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.7C
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    • pp.675-686
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    • 2005
  • In this paper, we propose an efficient face region detection technique for the content-based video summarization. To segment video, shot changes are detected from a video sequence and key frames are selected from the shots. We select one frame that has the least difference between neighboring frames in each shot. The proposed face detection algorithm detects face region from selected key frames. And then, we provide user with summarized frames included face region that has an important meaning in dramas or movies. Using Bayes classification rule and statistical characteristic of the skin pixels, face regions are detected in the frames. After skin detection, we adopt the projection method to segment an image(frame) into face region and non-face region. The segmented regions are candidates of the face object and they include many false detected regions. So, we design a classifier to minimize false lesion using CART. From SGLD matrices, we extract the textual feature values such as Inertial, Inverse Difference, and Correlation. As a result of our experiment, proposed face detection algorithm shows a good performance for the key frames with a complex and variant background. And our system provides key frames included the face region for user as video summarized information.

Statistical Life Prediction of Corroded Pipeline Using Bayesian Inference (베이지안 추론법을 이용한 부식된 배관의 통계적 수명예측)

  • Noh, Yoojeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2401-2406
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    • 2015
  • Pipelines are used by large heavy industries to deliver various types of fluids. Since this is important to maintain the performance of large systems, it is necessary to accurately predict remaining life of the corroded pipeline. However, predicting the remaining life is difficult due to uncertainties in the associated variables, such as geometries, material properties, corrosion rate, etc. In this paper, a statistical method for predicting corrosion remaining life is proposed using Bayesian inference. To accomplish this, pipeline failure probability was calculated using prior information about pipeline failure pressure according to elapsed time, and the given experimental data based on Bayes' rule. The corrosion remaining life was calculated as the elapsed time with 10 % failure probability. Using 10 and 50 samples generated from random variables affecting the corrosion of the pipe, the pipeline failure probability was estimated, after which the estimated remaining useful life was compared with the assumed true remaining useful life.

A study of Bayesian inference on auto insurance credibility application (자동차보험 신뢰도 적용에 대한 베이지안 추론 방식 연구)

  • Kim, Myung Joon;Kim, Yeong-Hwa
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.4
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    • pp.689-699
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    • 2013
  • This paper studies the partial credibility application method by assuming the empirical prior or noninformative prior informations in auto insurnace business where intensive rating segmentation is expanded because of premium competition. Expanding of rating factor segmetation brings the increase of pricing cells, as a result, the number of cells for partial credibility application will increase correspondingly. This study is trying to suggest more accurate estimation method by considering the Bayesian framework. By using empirically well-known or noninformative information, inducing the proper posterior distribution and applying the Bayes estimate which is minimizing the error loss into the credibility method, we will show the advantage of Bayesian inference by comparison with current approaches. The comparison is implemented with square root rule which is a widely accepted method in insurance business. The convergence level towarding to the true risk will be compared among various approaches. This study introduces the alternative way of redcuing the error to the auto insurance business fields in need of various methods because of more segmentations.

Improving the Accuracy of Document Classification by Learning Heterogeneity (이질성 학습을 통한 문서 분류의 정확성 향상 기법)

  • Wong, William Xiu Shun;Hyun, Yoonjin;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.24 no.3
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    • pp.21-44
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    • 2018
  • In recent years, the rapid development of internet technology and the popularization of smart devices have resulted in massive amounts of text data. Those text data were produced and distributed through various media platforms such as World Wide Web, Internet news feeds, microblog, and social media. However, this enormous amount of easily obtained information is lack of organization. Therefore, this problem has raised the interest of many researchers in order to manage this huge amount of information. Further, this problem also required professionals that are capable of classifying relevant information and hence text classification is introduced. Text classification is a challenging task in modern data analysis, which it needs to assign a text document into one or more predefined categories or classes. In text classification field, there are different kinds of techniques available such as K-Nearest Neighbor, Naïve Bayes Algorithm, Support Vector Machine, Decision Tree, and Artificial Neural Network. However, while dealing with huge amount of text data, model performance and accuracy becomes a challenge. According to the type of words used in the corpus and type of features created for classification, the performance of a text classification model can be varied. Most of the attempts are been made based on proposing a new algorithm or modifying an existing algorithm. This kind of research can be said already reached their certain limitations for further improvements. In this study, aside from proposing a new algorithm or modifying the algorithm, we focus on searching a way to modify the use of data. It is widely known that classifier performance is influenced by the quality of training data upon which this classifier is built. The real world datasets in most of the time contain noise, or in other words noisy data, these can actually affect the decision made by the classifiers built from these data. In this study, we consider that the data from different domains, which is heterogeneous data might have the characteristics of noise which can be utilized in the classification process. In order to build the classifier, machine learning algorithm is performed based on the assumption that the characteristics of training data and target data are the same or very similar to each other. However, in the case of unstructured data such as text, the features are determined according to the vocabularies included in the document. If the viewpoints of the learning data and target data are different, the features may be appearing different between these two data. In this study, we attempt to improve the classification accuracy by strengthening the robustness of the document classifier through artificially injecting the noise into the process of constructing the document classifier. With data coming from various kind of sources, these data are likely formatted differently. These cause difficulties for traditional machine learning algorithms because they are not developed to recognize different type of data representation at one time and to put them together in same generalization. Therefore, in order to utilize heterogeneous data in the learning process of document classifier, we apply semi-supervised learning in our study. However, unlabeled data might have the possibility to degrade the performance of the document classifier. Therefore, we further proposed a method called Rule Selection-Based Ensemble Semi-Supervised Learning Algorithm (RSESLA) to select only the documents that contributing to the accuracy improvement of the classifier. RSESLA creates multiple views by manipulating the features using different types of classification models and different types of heterogeneous data. The most confident classification rules will be selected and applied for the final decision making. In this paper, three different types of real-world data sources were used, which are news, twitter and blogs.

Robust Maneuvering Target Tracking Applying the Concept of Multiple Model Filter and the Fusion of Multi-Sensor (다중센서 융합 및 다수모델 필터 개념을 적용한 강인한 기동물체 추적)

  • Hyun, Dae-Hwan;Yoon, Hee-Byung
    • Journal of Intelligence and Information Systems
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    • v.15 no.1
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    • pp.51-64
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    • 2009
  • A location tracking sensor such as GPS, INS, Radar, and optical equipments is used in tracking Maneuvering Targets with a multi-sensor, and such systems are used to track, detect, and control UAV, guided missile, and spaceship. Until now, Most of the studies related to tracking Maneuvering Targets are on fusing multiple Radars, or adding a supplementary sensor to INS and GPS. However, A study is required to change the degree of application in fusions since the system property and error property are different from sensors. In this paper, we perform the error analysis of the sensor properties by adding a ground radar to GPS and INS for improving the tracking performance by multi-sensor fusion, and suggest the tracking algorithm that improves the precision and stability by changing the sensor probability of each sensor according to the error. For evaluation, we extract the altitude values in a simulation for the trajectory of UAV and apply the suggested algorithm to carry out the performance analysis. In this study, we change the weight of the evaluated values according to the degree of error between the navigation information of each sensor to improve the precision of navigation information, and made it possible to have a strong tracking which is not affected by external purposed environmental change and disturbance.

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Fault Localization for Self-Managing Based on Bayesian Network (베이지안 네트워크 기반에 자가관리를 위한 결함 지역화)

  • Piao, Shun-Shan;Park, Jeong-Min;Lee, Eun-Seok
    • The KIPS Transactions:PartB
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    • v.15B no.2
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    • pp.137-146
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    • 2008
  • Fault localization plays a significant role in enormous distributed system because it can identify root cause of observed faults automatically, supporting self-managing which remains an open topic in managing and controlling complex distributed systems to improve system reliability. Although many Artificial Intelligent techniques have been introduced in support of fault localization in recent research especially in increasing complex ubiquitous environment, the provided functions such as diagnosis and prediction are limited. In this paper, we propose fault localization for self-managing in performance evaluation in order to improve system reliability via learning and analyzing real-time streams of system performance events. We use probabilistic reasoning functions based on the basic Bayes' rule to provide effective mechanism for managing and evaluating system performance parameters automatically, and hence the system reliability is improved. Moreover, due to large number of considered factors in diverse and complex fault reasoning domains, we develop an efficient method which extracts relevant parameters having high relationships with observing problems and ranks them orderly. The selected node ordering lists will be used in network modeling, and hence improving learning efficiency. Using the approach enables us to diagnose the most probable causal factor with responsibility for the underlying performance problems and predict system situation to avoid potential abnormities via posting treatments or pretreatments respectively. The experimental application of system performance analysis by using the proposed approach and various estimations on efficiency and accuracy show that the availability of the proposed approach in performance evaluation domain is optimistic.