• 제목/요약/키워드: segmentation analysis

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Independent Component Analysis를 이용한 의료영상의 자동 분할에 관한 연구 (A Study of Automatic Medical Image Segmentation using Independent Component Analysis)

  • 배수현;유선국;김남형
    • 대한전기학회논문지:시스템및제어부문D
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    • 제52권1호
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    • pp.64-75
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    • 2003
  • Medical image segmentation is the process by which an original image is partitioned into some homogeneous regions like bones, soft tissues, etc. This study demonstrates an automatic medical image segmentation technique based on independent component analysis. Independent component analysis is a generalization of principal component analysis which encodes the higher-order dependencies in the input in addition to the correlations. It extracts statistically independent components from input data. Use of automatic medical image segmentation technique using independent component analysis under the assumption that medical image consists of some statistically independent parts leads to a method that allows for more accurate segmentation of bones from CT data. The result of automatic segmentation using independent component analysis with square test data was evaluated using probability of error(PE) and ultimate measurement accuracy(UMA) value. It was also compared to a general segmentation method using threshold based on sensitivity(True Positive Rate), specificity(False Positive Rate) and mislabelling rate. The evaluation result was done statistical Paired-t test. Most of the results show that the automatic segmentation using independent component analysis has better result than general segmentation using threshold.

Segmentation Performance Analysis of the Otsu Algorithm for Spent Nuclear Fuel Cladding Image According to Morphological Operations

  • Jee A Baik;Jun Won Choi;Jung Jin Kim
    • 방사성폐기물학회지
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    • 제22권3호
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    • pp.301-311
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    • 2024
  • Hydride analysis is required to assess the mechanical integrity of spent nuclear fuel cladding. Image segmentation, which is a hydride analysis method, is a technique that can analyze the orientation and distribution of hydrides in cladding images of spent nuclear fuels. However, the segmentation results varied according to the image preprocessing. Inaccurate segmentation results can make hydride difficult to analyze. This study aims to analyze the segmentation performance of the Otsu algorithm according to the morphological operations of cladding images. Morphological operations were applied to four different cladding images, and segmentation performance was quantitatively compared using a histogram, between-class variance, and radial hydride fraction. As a result, this study found that morphological operations can induce errors in cladding images and that appropriate combinations of morphological operations can maximize segmentation performance. This study emphasizes the importance of image preprocessing methods, suggesting that they can enhance the accuracy of hydride analysis. These findings are expected to contribute to the advancements in integrity assessment of spent nuclear fuel cladding.

Automated segmentation of concrete images into microstructures: A comparative study

  • Yazdi, Mehran;Sarafrazi, Katayoon
    • Computers and Concrete
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    • 제14권3호
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    • pp.315-325
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    • 2014
  • Concrete is an important material in most of civil constructions. Many properties of concrete can be determined through analysis of concrete images. Image segmentation is the first step for the most of these analyses. An automated system for segmentation of concrete images into microstructures using texture analysis is proposed. The performance of five different classifiers has been evaluated and the results show that using an Artificial Neural Network classifier is the best choice for an automatic image segmentation of concrete.

이미지 분할(image segmentation) 관련 연구 동향 파악을 위한 과학계량학 기반 연구개발지형도 분석 (Scientometrics-based R&D Topography Analysis to Identify Research Trends Related to Image Segmentation)

  • 김영찬;진병삼;배영철
    • 한국산업융합학회 논문집
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    • 제27권3호
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    • pp.563-572
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    • 2024
  • Image processing and computer vision technologies are becoming increasingly important in a variety of application fields that require techniques and tools for sophisticated image analysis. In particular, image segmentation is a technology that plays an important role in image analysis. In this study, in order to identify recent research trends on image segmentation techniques, we used the Web of Science(WoS) database to analyze the R&D topography based on the network structure of the author's keyword co-occurrence matrix. As a result, from 2015 to 2023, as a result of the analysis of the R&D map of research articles on image segmentation, R&D in this field is largely focused on four areas of research and development: (1) researches on collecting and preprocessing image data to build higher-performance image segmentation models, (2) the researches on image segmentation using statistics-based models or machine learning algorithms, (3) the researches on image segmentation for medical image analysis, and (4) deep learning-based image segmentation-related R&D. The scientometrics-based analysis performed in this study can not only map the trajectory of R&D related to image segmentation, but can also serve as a marker for future exploration in this dynamic field.

통계 정보와 유전자 학습에 의한 최적의 문장 분할 위치 결정 (Determination of an Optimal Sentence Segmentation Position using Statistical Information and Genetic Learning)

  • 김성동;김영택
    • 전자공학회논문지C
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    • 제35C권10호
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    • pp.38-47
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    • 1998
  • 실용적인 기계번역 시스템을 위한 구문 분석은 긴 문장의 분석을 허용하여야 하는데 긴 문장의 분석은 높은 분석의 복잡도 때문에 매우 어려운 문제이다. 본 논문에서는 긴 문장의 효율적인 분석을 위해 문장을 분할하는 방법을 제안하며 통계 정보와 유전자 학습에 의한 최적의 문장 분할 위치 결정 방법을 소개한다. 문장 분할 위치의 결정은 분할 위치가 태그된 훈련 데이타에서 얻어진 어휘 문맥 제한 조건을 이용하여 입력문장의 분할 가능 위치를 결정하는 부분과 여러 개의 분할 가능 위치 중에서 안전한 분할을 보장하고 보다 많은 분석의 효율 향상을 얻을 수 있는 최적의 분할 위치를 학습을 통해 선택하는 부분으로 구성된다. 실험을 통해 제안된 문장 분할 위치 결정 방법이 안전한 분할을 수행하며 문장 분석의 효율을 향상시킴을 보인다.

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Volumetric CT Texture Analysis of Intrahepatic Mass-Forming Cholangiocarcinoma for the Prediction of Postoperative Outcomes: Fully Automatic Tumor Segmentation Versus Semi-Automatic Segmentation

  • Sungeun Park;Jeong Min Lee;Junghoan Park;Jihyuk Lee;Jae Seok Bae;Jae Hyun Kim;Ijin Joo
    • Korean Journal of Radiology
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    • 제22권11호
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    • pp.1797-1808
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    • 2021
  • Objective: To determine whether volumetric CT texture analysis (CTTA) using fully automatic tumor segmentation can help predict recurrence-free survival (RFS) in patients with intrahepatic mass-forming cholangiocarcinomas (IMCCs) after surgical resection. Materials and Methods: This retrospective study analyzed the preoperative CT scans of 89 patients with IMCCs (64 male; 25 female; mean age, 62.1 years; range, 38-78 years) who underwent surgical resection between January 2005 and December 2016. Volumetric CTTA of IMCCs was performed in late arterial phase images using both fully automatic and semi-automatic liver tumor segmentation techniques. The time spent on segmentation and texture analysis was compared, and the first-order and second-order texture parameters and shape features were extracted. The reliability of CTTA parameters between the techniques was evaluated using intraclass correlation coefficients (ICCs). Intra- and interobserver reproducibility of volumetric CTTAs were also obtained using ICCs. Cox proportional hazard regression were used to predict RFS using CTTA parameters and clinicopathological parameters. Results: The time spent on fully automatic tumor segmentation and CTTA was significantly shorter than that for semi-automatic segmentation: mean ± standard deviation of 1 minutes 37 seconds ± 50 seconds vs. 10 minutes 48 seconds ± 13 minutes 44 seconds (p < 0.001). ICCs of the texture features between the two techniques ranged from 0.215 to 0.980. ICCs for the intraobserver and interobserver reproducibility using fully automatic segmentation were 0.601-0.997 and 0.177-0.984, respectively. Multivariable analysis identified lower first-order mean (hazard ratio [HR], 0.982; p = 0.010), larger pathologic tumor size (HR, 1.171; p < 0.001), and positive lymph node involvement (HR, 2.193; p = 0.014) as significant parameters for shorter RFS using fully automatic segmentation. Conclusion: Volumetric CTTA parameters obtained using fully automatic segmentation could be utilized as prognostic markers in patients with IMCC, with comparable reproducibility in significantly less time compared with semi-automatic segmentation.

요인분석과 군집분석을 통한 세분화 및 전략방향 제시: 특수법인 사례를 중심으로 (A Strategy Through Segmentation Using Factor and Cluster Analysis: focusing on corporations having a special status)

  • 조용준;김영화
    • 응용통계연구
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    • 제20권1호
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    • pp.23-38
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    • 2007
  • 세분화는 크게 목적변수의 유무에 따라 분석방법이 달라지게 된다. 본 논문은 특수법인의 경영지표를 바탕으로 목적변수가 존재하지 않을 경우의 세분화를 통해 전략방향을 도출하는 사례 연구를 제안하고자 한다. 군집분석을 통한 세분화의 경우, 많은 변수를 사용하여 분류를 하게 되면 군집별 특성화가 어렵게 된다. 따라서 군집의 특성을 잘 반영할 수 있는 대표적 요인변수를 요인분석을 통해 추출하고 이 대표요인을 바탕으로 2단계 군집분석을 통한 세분화를 고려하였다. 이를 통해 총 6개의 세분화 군집을 도출하고 각 군집 별 강점요인을 강화하고 약점요인을 보완하는 방향으로 전략방향을 설정하여 제안하고자 한다.

영어의 강음절(강세 음절)과 한국어 화자의 단어 분절 (Strong (stressed) syllables in English and lexical segmentation by Koreans)

  • 김선미;남기춘
    • 말소리와 음성과학
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    • 제3권1호
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    • pp.3-14
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    • 2011
  • It has been posited that in English, native listeners use the Metrical Segmentation Strategy (MSS) for the segmentation of continuous speech. Strong syllables tend to be perceived as potential word onsets for English native speakers, which is due to the high proportion of strong syllables word-initially in the English vocabulary. This study investigates whether Koreans employ the same strategy when segmenting speech input in English. Word-spotting experiments were conducted using vowel-initial and consonant-initial bisyllabic targets embedded in nonsense trisyllables in Experiment 1 and 2, respectively. The effect of strong syllable was significant in the RT (reaction times) analysis but not in the error analysis. In both experiments, Korean listeners detected words more slowly when the word-initial syllable is strong (stressed) than when it is weak (unstressed). However, the error analysis showed that there was no effect of initial stress in Experiment 1 and in the item (F2) analysis in Experiment 2. Only the subject (F1) analysis in Experiment 2 showed that the participants made more errors when the word starts with a strong syllable. These findings suggest that Koran listeners do not use the Metrical Segmentation Strategy for segmenting English speech. They do not treat strong syllables as word beginnings, but rather have difficulties recognizing words when the word starts with a strong syllable. These results are discussed in terms of intonational properties of Korean prosodic phrases which are found to serve as lexical segmentation cues in the Korean language.

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잠재계층분석기법(Latent Class Analysis)을 활용한 영화 소비자 세분화에 관한 연구 (Segmentation of Movie Consumption : An Application of Latent Class Analysis to Korean Film Industry)

  • 구교령;이장혁
    • 한국경영과학회지
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    • 제36권4호
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    • pp.161-184
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    • 2011
  • As movie demands become more and more diversified, it is necessary for movie related firms to segment a whole heterogeneous market into a number of small homogeneous markets in order to identify the specific needs of consumer groups. Relevant market segmentation helps them to develop valuable offer to target segments through effective marketing planning. In this article, we introduce various segmentation methods and compare their advantages and disadvantages. In particular, we analyze "2009~2010 consumer survey data of Korean Film Industry" by using Latent Class Analysis(LCA), a statistical segmentation method which identifies exclusive set of latent classes based on consumers' responses to an observed categorical and numerical variables. It is applied PROC LCA, a new SAS procedure for conducting LCA and finally get the result of 11 distinctive clusters showing unique characteristics on their buying behaviors.

분류나무를 활용한 군집분석의 입력특성 선택: 신용카드 고객세분화 사례 (Classification Tree-Based Feature-Selective Clustering Analysis: Case of Credit Card Customer Segmentation)

  • 윤한성
    • 디지털산업정보학회논문지
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    • 제19권4호
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    • pp.1-11
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    • 2023
  • Clustering analysis is used in various fields including customer segmentation and clustering methods such as k-means are actively applied in the credit card customer segmentation. In this paper, we summarized the input features selection method of k-means clustering for the case of the credit card customer segmentation problem, and evaluated its feasibility through the analysis results. By using the label values of k-means clustering results as target features of a decision tree classification, we composed a method for prioritizing input features using the information gain of the branch. It is not easy to determine effectiveness with the clustering effectiveness index, but in the case of the CH index, cluster effectiveness is improved evidently in the method presented in this paper compared to the case of randomly determining priorities. The suggested method can be used for effectiveness of actively used clustering analysis including k-means method.