• Title/Summary/Keyword: bayesian classification

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Region-based Multi-level Thresholding for Color Image Segmentation (영역 기반의 Multi-level Thresholding에 의한 컬러 영상 분할)

  • Oh, Jun-Taek;Kim, Wook-Hyun
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.6 s.312
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    • pp.20-27
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    • 2006
  • Multi-level thresholding is a method that is widely used in image segmentation. However most of the existing methods are not suited to be directly used in applicable fields and moreover expanded until a step of image segmentation. This paper proposes region-based multi-level thresholding as an image segmentation method. At first we classify pixels of each color channel to two clusters by using EWFCM(Entropy-based Weighted Fuzzy C-Means) algorithm that is an improved FCM algorithm with spatial information between pixels. To obtain better segmentation results, a reduction of clusters is then performed by a region-based reclassification step based on a similarity between regions existing in a cluster and the other clusters. The clusters are created using the classification information of pixels according to color channel. We finally perform a region merging by Bayesian algorithm based on Kullback-Leibler distance between a region and the neighboring regions as a post-processing method as many regions still exist in image. Experiments show that region-based multi-level thresholding is superior to cluster-, pixel-based multi-level thresholding, and the existing mettled. And much better segmentation results are obtained by the post-processing method.

Classification of Viruses Based on the Amino Acid Sequences of Viral Polymerases (바이러스 핵산중합효소의 아미노산 서열에 의한 바이러스 분류)

  • Nam, Ji-Hyun;Lee, Dong-Hun;Lee, Keon-Myung;Lee, Chan-Hee
    • Korean Journal of Microbiology
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    • v.43 no.4
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    • pp.285-291
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    • 2007
  • According to the Baltimore Scheme, viruses are classified into 6 main classes based on their replication and coding strategies. Except for some small DNA viruses, most viruses code for their own polymerases: DNA-dependent DNA, RNA-dependent RNA and RNA-dependent DNA polymerases, all of which contain 4 common motifs. We undertook a phylogenetic study to establish the relationship between the Baltimore Scheme and viral polymerases. Amino acid sequence data sets of viral polymerases were taken from NCBI GenBank, and a multiple alignment was performed with CLUSTAL X program. Phylogenetic trees of viral polymerases constructed from the distance matrices were generally consistent with Baltimore Scheme with some minor exceptions. Interestingly, negative RNA viruses (Class V) could be further divided into 2 subgroups with segmented and non-segmented genomes. Thus, Baltimore Scheme for viral taxonomy could be supported by phylogenetic analysis based on the amino acid sequences of viral polymerases.

A CORBA-Based Collaborative Work Supported Medical Image Analysis and Visualization System (코바기반 협업지원 의료영상 분석 및 가시화 시스템)

  • Chun, Jun-Chul;Son, Jae-Gi
    • The KIPS Transactions:PartD
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    • v.10D no.1
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    • pp.109-116
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    • 2003
  • In this paper, a CORBA-based collaborative medical image analysis and visualization system, which provides high accessibility and usability of the system for the users on distributed environment is introduced. The system allows us to manage datasets and manipulates medical images such as segmentation and volume visualization of computed geometry from biomedical images in distributed environments. Using Bayesian classification technique and an active contour model the system provides classification results of medical images or boundary information of specific tissue. Based on such information, the system can create real time 3D volume model from medical imagery. Moreover, the developed system supports collaborative work among multiple users using broadcasting and synchronization mechanisms. Since the system is developed using Java and CORBA, which provide distributed programming, the remote clients can access server objects via method invocation, without knowing where the distributed objects reside or what operating system it executes on.

A Study on Anomalous Propagation Echo Identification using Naive Bayesian Classifier (나이브 베이지안 분류기를 이용한 이상전파에코 식별방법에 대한 연구)

  • Lee, Hansoo;Kim, Sungshin
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.89-90
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    • 2016
  • Anomalous propagation echo is a kind of abnormal radar signal occurred by irregularly refracted radar beam caused by temperature or humidity. The echo frequently appears in ground-based weather radar. In order to improve accuracy of weather forecasting, it is important to analyze radar data precisely. Therefore, there are several ongoing researches about identifying the anomalous propagation echo all over the world. This paper conducts researches about a classification method which can distinguish anomalous propagation echo in the radar data using naive Bayes classifier and unique attributes of the echo such as reflectivity, altitude, and so on. It is confirmed that the fine classification results are derived by verifying the suggested naive Bayes classifier using actual appearance cases of the echo.

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A study on the Filtering of Spam E-mail using n-Gram indexing and Support Vector Machine (n-Gram 색인화와 Support Vector Machine을 사용한 스팸메일 필터링에 대한 연구)

  • 서정우;손태식;서정택;문종섭
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.14 no.2
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    • pp.23-33
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    • 2004
  • Because of a rapid growth of internet environment, it is also fast increasing to exchange message using e-mail. But, despite the convenience of e-mail, it is rising a currently bi9 issue to waste their time and cost due to the spam mail in an individual or enterprise. Many kinds of solutions have been studied to solve harmful effects of spam mail. Such typical methods are as follows; pattern matching using the keyword with representative method and method using the probability like Naive Bayesian. In this paper, we propose a classification method of spam mails from normal mails using Support Vector Machine, which has excellent performance in pattern classification problems, to compensate for the problems of existing research. Especially, the proposed method practices efficiently a teaming procedure with a word dictionary including a generated index by the n-Gram. In the conclusion, we verified the proposed method through the accuracy comparison of spm mail separation between an existing research and proposed scheme.

Malicious Code Detection using the Effective Preprocessing Method Based on Native API (Native API 의 효과적인 전처리 방법을 이용한 악성 코드 탐지 방법에 관한 연구)

  • Bae, Seong-Jae;Cho, Jae-Ik;Shon, Tae-Shik;Moon, Jong-Sub
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.4
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    • pp.785-796
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    • 2012
  • In this paper, we propose an effective Behavior-based detection technique using the frequency of system calls to detect malicious code, when the number of training data is fewer than the number of properties on system calls. In this study, we collect the Native APIs which are Windows kernel data generated by running program code. Then we adopt the normalized freqeuncy of Native APIs as the basic properties. In addition, the basic properties are transformed to new properties by GLDA(Generalized Linear Discriminant Analysis) that is an effective method to discriminate between malicious code and normal code, although the number of training data is fewer than the number of properties. To detect the malicious code, kNN(k-Nearest Neighbor) classification, one of the bayesian classification technique, was used in this paper. We compared the proposed detection method with the other methods on collected Native APIs to verify efficiency of proposed method. It is presented that proposed detection method has a lower false positive rate than other methods on the threshold value when detection rate is 100%.

New genotype classification and molecular characterization of canine and feline parvoviruses

  • Chung, Hee-Chun;Kim, Sung-Jae;Nguyen, Van Giap;Shin, Sook;Kim, Jae Young;Lim, Suk-Kyung;Park, Yong Ho;Park, BongKyun
    • Journal of Veterinary Science
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    • v.21 no.3
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    • pp.43.1-43.13
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    • 2020
  • Background: Canine parvovirus (CPV) and feline panleukopenia (FPV) cause severe intestinal disease and leukopenia. Objectives: In Korea, there have been a few studies on Korean FPV and CPV-2 strains. We attempted to investigate several genetic properties of FPV and CPV-2. Methods: Several FPV and CPV sequences from around world were analyzed by Bayesian phylo-geographical analysis. Results: The parvoviruses strains were newly classified into FPV, CPV 2-I, CPV 2-II, and CPV 2-III genotypes. In the strains isolated in this study, Gigucheon, Rara and Jun belong to the FPV, while Rachi strain belong to CPV 2-III. With respect to CPV type 2, the new genotypes are inconsistent with the previous genotype classifications (CPV-2a, -2b, and -2c). The root of CPV-I strains were inferred to be originated from a USA strain, while the CPV-II and III were derived from Italy strains that originated in the USA. Based on VP2 protein analysis, CPV 2-I included CPV-2a-like isolates only, as differentiated by the change in residue S297A/N. Almost CPV-2a isolates were classified into CPV 2-III, and a large portion of CPV-2c isolates was classified into CPV 2-II. Two residue substitutions F267Y and Y324I of the VP2 protein were characterized in the isolates of CPV 2-III only. Conclusions: We provided an updated insight on FPV and CPV-2 genotypes by molecular-based and our findings demonstrate the genetic characterization according to the new genotypes.

Human Gait-Phase Classification to Control a Lower Extremity Exoskeleton Robot (하지근력증강로봇 제어를 위한 착용자의 보행단계구분)

  • Kim, Hee-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.7
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    • pp.479-490
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    • 2014
  • A lower extremity exoskeleton is a robot device that attaches to the lower limbs of the human body to augment or assist with the walking ability of the wearer. In order to improve the wearer's walking ability, the robot senses the wearer's walking locomotion and classifies it into a gait-phase state, after which it drives the appropriate robot motions for each state using its actuators. This paper presents a method by which the robot senses the wearer's locomotion along with a novel classification algorithm which classifies the sensed data as a gait-phase state. The robot determines its control mode using this gait-phase information. If erroneous information is delivered, the robot will fail to improve the walking ability or will bring some discomfort to the wearer. Therefore, it is necessary for the algorithm constantly to classify the correct gait-phase information. However, our device for sensing a human's locomotion has very sensitive characteristics sufficient for it to detect small movements. With only simple logic like a threshold-based classification, it is difficult to deliver the correct information continually. In order to overcome this and provide correct information in a timely manner, a probabilistic gait-phase classification algorithm is proposed. Experimental results demonstrate that the proposed algorithm offers excellent accuracy.

Bayesian Approach to Users' Perspective on Movie Genres

  • Lenskiy, Artem A.;Makita, Eric
    • Journal of information and communication convergence engineering
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    • v.15 no.1
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    • pp.43-48
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    • 2017
  • Movie ratings are crucial for recommendation engines that track the behavior of all users and utilize the information to suggest items the users might like. It is intuitively appealing that information about the viewing preferences in terms of movie genres is sufficient for predicting a genre of an unlabeled movie. In order to predict movie genres, we treat ratings as a feature vector, apply a Bernoulli event model to estimate the likelihood of a movie being assigned a certain genre, and evaluate the posterior probability of the genre of a given movie by using the Bayes rule. The goal of the proposed technique is to efficiently use movie ratings for the task of predicting movie genres. In our approach, we attempted to answer the question: "Given the set of users who watched a movie, is it possible to predict the genre of a movie on the basis of its ratings?" The simulation results with MovieLens 1M data demonstrated the efficiency and accuracy of the proposed technique, achieving an 83.8% prediction rate for exact prediction and 84.8% when including correlated genres.

Features Reduction using Logistic Regression for Spam Filtering (로지스틱 회귀 분석을 이용한 스펨 필터링의 특징 축소)

  • Jung, Yong-Gyu;Lee, Bum-Joon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.2
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    • pp.13-18
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    • 2010
  • Today, The much amount of spam that occupies the mail server and network storage occurs the lack of negative issues, such as overload, and for users to delete the spam should spend time, resources have a problem. Automatic spam filtering on the incidence to solve the problem is essential. A lot of Spam filters have tried to solve the problem emerged as an essential element automatically. Unlike traditional method such as Naive Bayesian, PCA through the many-dimensional data set of spam with a few spindle-dimensional process that narrowed the operation to reduce the burden on certain groups for classification Logistic regression analysis method was used to filter the spam. Through the speed and performance, it was able to get the positive results.