• Title/Summary/Keyword: Bayes theory

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SIMPLE RANKED SAMPLING SCHEME: MODIFICATION AND APPLICATION IN THE THEORY OF ESTIMATION OF ERLANG DISTRIBUTION

  • RAFIA GULZAR;IRSA SAJJAD;M. YOUNUS BHAT;SHAKEEL UL REHMAN
    • Journal of applied mathematics & informatics
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    • v.41 no.2
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    • pp.449-468
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    • 2023
  • This paper deals in the study of the estimation of the parameters of Erlang distribution based on rank set sampling and some of its modifications. Here we considered Maximum Likelihood (ML) and the Bayesian technique to estimate the shape and scale parameter of Erlang distribution based on RSS and its some modifications such as ERSS, MRSS, and MRSSu. The derivation for unknown parameters of Erlang distribution is well presented using normal approximation to the asymptotic distribution of ML estimators. But due to the complexity involves in the integral, the Bayes estimator of unknown parameters is obtained using MCMC method. Further, we compared the MSE of estimation in different sampling schemes with different set sizes and cycle size. A real-life data application is also given to illustrate the efficiency of the proposed scheme.

Image Segmentation Based on Fusion of Range and Intensity Images (거리영상과 밝기영상의 fusion을 이용한 영상분할)

  • Chang, In-Su;Park, Rae-Hong
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.9
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    • pp.95-103
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    • 1998
  • This paper proposes an image segmentation algorithm based on fusion of range and intensity images. Based on Bayesian theory, a priori knowledge is encoded by the Markov random field (MRF). A maximum a posteriori (MAP) estimator is constructed using the features extracted from range and intensity images. Objects are approximated by local planar surfaces in range images, and the parametric space is constructed with the surface parameters estimated pixelwise. In intensity images the ${\alpha}$-trimmed variance constructs the intensity feature. An image is segmented by optimizing the MAP estimator that is constructed using a likelihood function based on edge information. Computer simulation results shw that the proposed fusion algorithm effectively segments the images independentl of shadow, noise, and light-blurring.

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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.

Moving object segmentation using Markov Random Field (마코프 랜덤 필드를 이용한 움직이는 객체의 분할에 관한 연구)

  • 정철곤;김중규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.3A
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    • pp.221-230
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    • 2002
  • This paper presents a new moving object segmentation algorithm using markov random field. The algorithm is based on signal detection theory. That is to say, motion of moving object is decided by binary decision rule, and false decision is corrected by markov random field model. The procedure toward complete segmentation consists of two steps: motion detection and object segmentation. First, motion detection decides the presence of motion on velocity vector by binary decision rule. And velocity vector is generated by optical flow. Second, object segmentation cancels noise by Bayes rule. Experimental results demonstrate the efficiency of the presented method.

Developing and Pre-Processing a Dataset using a Rhetorical Relation to Build a Question-Answering System based on an Unsupervised Learning Approach

  • Dutta, Ashit Kumar;Wahab sait, Abdul Rahaman;Keshta, Ismail Mohamed;Elhalles, Abheer
    • International Journal of Computer Science & Network Security
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    • v.21 no.11
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    • pp.199-206
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    • 2021
  • Rhetorical relations between two text fragments are essential information and support natural language processing applications such as Question - Answering (QA) system and automatic text summarization to produce an effective outcome. Question - Answering (QA) system facilitates users to retrieve a meaningful response. There is a demand for rhetorical relation based datasets to develop such a system to interpret and respond to user requests. There are a limited number of datasets for developing an Arabic QA system. Thus, there is a lack of an effective QA system in the Arabic language. Recent research works reveal that unsupervised learning can support the QA system to reply to users queries. In this study, researchers intend to develop a rhetorical relation based dataset for implementing unsupervised learning applications. A web crawler is developed to crawl Arabic content from the web. A discourse-annotated corpus is generated using the rhetorical structural theory. A Naïve Bayes based QA system is developed to evaluate the performance of datasets. The outcome shows that the performance of the QA system is improved with proposed dataset and able to answer user queries with an appropriate response. In addition, the results on fine-grained and coarse-grained relations reveal that the dataset is highly reliable.

A Study on Fault Classification by EEMD Application of Gear Transmission Error (전달오차의 EEMD적용을 통한 기어 결함분류연구)

  • Park, Sungho;Choi, Joo-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.2
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    • pp.169-177
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    • 2017
  • In this paper, classification of spall and crack faults of gear teeth is studied by applying the ensemble empirical mode decomposition(EEMD) for the gear transmission error(TE). Finite element models of the gears with the two faults are built, and TE is obtained by simulation of the gears under loaded contact. EEMD is applied to the residuals of the TE which are the difference between the normal and faulty signal. From the result, the difference of spall and crack faults are clearly identified by the intrinsic mode functions(IMF). A simple test bed is installed to illustrate the approach, which consists of motor, brake and a pair of spur gears. Two gears are employed to obtain the TE for the normal, spalled, and cracked gears, and the type of the faults are separated by the same EEMD application process. In order to quantify the results, crest factors are applied to each IMF. Characteristics of spall and crack are well represented by the crest factors of the first and the third IMF, which are used as the feature signals. The classification is carried out using the Bayes decision theory using the feature signals acquired through the experiments.

Network based Anomaly Intrusion Detection using Bayesian Network Techniques (네트워크 서비스별 이상 탐지를 위한 베이지안 네트워크 기법의 정상 행위 프로파일링)

  • Cha ByungRae;Park KyoungWoo;Seo JaeHyun
    • Journal of Internet Computing and Services
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    • v.6 no.1
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    • pp.27-38
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    • 2005
  • Recently, the rapidly development of computing environments and the spread of Internet make possible to obtain and use of information easily. Immediately, by opposition function the Hacker's unlawful intrusion and threats rise for network environments as time goes on. Specially, the internet consists of Unix and TCP/IP had many vulnerability. the security techniques of authentication and access controls cannot adequate to solve security problem, thus IDS developed with 2nd defence line. In this paper, intrusion detection method using Bayesian Networks estimated probability values of behavior contexts based on Bayes theory. The contexts of behaviors or events represents Bayesian Networks of graphic types. We profiled concisely normal behaviors using behavior context. And this method be able to detect new intrusions or modificated intrusions. We had simulation using DARPA 2000 Intrusion Data.

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