• Title/Summary/Keyword: K-MEANS

검색결과 17,911건 처리시간 0.055초

Automatic Extraction of Blood Flow Area in Brachial Artery for Suspicious Hypertension Patients from Color Doppler Sonography with Fuzzy C-Means Clustering

  • Kim, Kwang Baek;Song, Doo Heon;Yun, Sang-Seok
    • Journal of information and communication convergence engineering
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    • 제16권4호
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    • pp.258-263
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    • 2018
  • Color Doppler sonography is a useful tool for examining blood flow and related indices. However, it should be done by well-trained operator, that is, operator subjectivity exists. In this paper, we propose an automatic blood flow area extraction method from brachial artery that would be an essential building block of computer aided color Doppler analyzer. Specifically, our concern is to examine hypertension suspicious (prehypertension) patients who might develop their symptoms to established hypertension in the future. The proposed method uses fuzzy C-means clustering as quantization engine with careful seeding of the number of clusters from histogram analysis. The experiment verifies that the proposed method is feasible in that the successful extraction rates are 96% (successful in 48 out of 50 test cases) and demonstrated better performance than K-means based method in specificity and sensitivity analysis but the proposed method should be further refined as the retrospective analysis pointed out.

Colorectal Cancer Staging Using Three Clustering Methods Based on Preoperative Clinical Findings

  • Pourahmad, Saeedeh;Pourhashemi, Soudabeh;Mohammadianpanah, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권2호
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    • pp.823-827
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    • 2016
  • Determination of the colorectal cancer stage is possible only after surgery based on pathology results. However, sometimes this may prove impossible. The aim of the present study was to determine colorectal cancer stage using three clustering methods based on preoperative clinical findings. All patients referred to the Colorectal Research Center of Shiraz University of Medical Sciences for colorectal cancer surgery during 2006 to 2014 were enrolled in the study. Accordingly, 117 cases participated. Three clustering algorithms were utilized including k-means, hierarchical and fuzzy c-means clustering methods. External validity measures such as sensitivity, specificity and accuracy were used for evaluation of the methods. The results revealed maximum accuracy and sensitivity values for the hierarchical and a maximum specificity value for the fuzzy c-means clustering methods. Furthermore, according to the internal validity measures for the present data set, the optimal number of clusters was two (silhouette coefficient) and the fuzzy c-means algorithm was more appropriate than the k-means clustering approach by increasing the number of clusters.

k-means 클러스터링을 이용한 강판의 부식 이미지 모니터링 (Corrosion Image Monitoring of steel plate by using k-means clustering)

  • 김범수;권재성;최성웅;노정필;이경황;양정현
    • 한국표면공학회지
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    • 제54권5호
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    • pp.278-284
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    • 2021
  • Corrosion of steel plate is common phenomenon which results in the gradual destruction caused by a wide variety of environments. Corrosion monitoring is the tracking of the degradation progress for a long period of time. Corrosion on steel plate appears as a discoloration and any irregularities on the surface. In this study, we developed a quantitative evaluation method of the rust formed on steel plate by using k-means clustering from the corroded area in a given image. The k-means clustering for automated corrosion detection was based on the GrabCut segmentation and Gaussian mixture model(GMM). Image color of the corroded surface at cut-edge area was analyzed quantitatively based on HSV(Hue, Saturation, Value) color space.

주파수 분석 기반 RSA 단순 전력 분석 (Simple Power Analysis against RSA Based on Frequency Components)

  • 정지혁;윤지원
    • 정보보호학회논문지
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    • 제31권1호
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    • pp.1-9
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    • 2021
  • 본 논문은 RSA 복호화 과정에서 발생한 전력 신호로부터 암호연산을 예측하는 과정을 주파수 분석과 K-means 알고리즘을 이용하여 자동화하는 것을 제안한다. RSA 복호화 과정은 제곱 연산과 곱셈 연산으로 나뉘며, 시간에 따른 연산의 종류를 예측하게 되면, RSA 암호의 키(key)값을 알 수 있게 된다. 본 논문은 복호화 과정에서 발생한 전력 파형을 2차원 주파수 신호로 변환한 후, K-means algorithm을 이용하여 연산의 종류에 따라 주파수 벡터를 분류하였다. 이후, 이러한 분류된 주파수 벡터를 이용하여 연산의 종류를 예측한다.

K-means 클러스터링과 트랜스포머 기반의 교차 도메인 추천 (Cross-Domain Recommendation based on K-Means Clustering and Transformer)

  • 김태훈;김영곤;박정민
    • 한국인터넷방송통신학회논문지
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    • 제23권5호
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    • pp.1-8
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    • 2023
  • 교차 도메인 추천은 다른 도메인에 있는 관련 사용자 정보 데이터와 아이템 데이터를 공유하는 방법입니다. 주로 사용자 중복이 많은 온라인 쇼핑몰이나 유튜브, 넷플릭스와 같은 멀티미디어 서비스 컨텐츠에서 사용됩니다. K-means 클러스터링을 통해 사용자 데이터와 평점을 기반으로 군집화를 실시하여 임베딩을 생성합니다. 이 결과를 트랜스포머 네트워크를 통해 학습한 후 사용자 만족도를 예측합니다. 그런 다음 트랜스포머 기반 추천 모델을 사용하여 사용자에게 적합한 아이템을 추천합니다. 이 연구를 통해 추천함으로써 더 적은 시간적 비용으로 초기 사용자 문제를 예측하고 사용자들의 만족도를 높일 수 있다는 결과를 실험을 통해 보여주었습니다.

증분형 K-means 클러스터링 기반 방사형 기저함수 신경회로망 모델 설계 (Design of Incremental K-means Clustering-based Radial Basis Function Neural Networks Model)

  • 박상범;이승철;오성권
    • 전기학회논문지
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    • 제66권5호
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    • pp.833-842
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    • 2017
  • In this study, the design methodology of radial basis function neural networks based on incremental K-means clustering is introduced for learning and processing the big data. If there is a lot of dataset to be trained, general clustering may not learn dataset due to the lack of memory capacity. However, the on-line processing of big data could be effectively realized through the parameters operation of recursive least square estimation as well as the sequential operation of incremental clustering algorithm. Radial basis function neural networks consist of condition part, conclusion part and aggregation part. In the condition part, incremental K-means clustering algorithms is used tweights of the conclusion part are given as linear function and parameters are calculated using recursive least squareo get the center points of data and find the fitness using gaussian function as the activation function. Connection s estimation. In the aggregation part, a final output is obtained by center of gravity method. Using machine learning data, performance index are shown and compared with other models. Also, the performance of the incremental K-means clustering based-RBFNNs is carried out by using PSO. This study demonstrates that the proposed model shows the superiority of algorithmic design from the viewpoint of on-line processing for big data.

K-means 클러스터링을 이용한 데이터 분류 (Data classification using K-means clustering)

  • 임선자;윤성대
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2020년도 추계학술발표대회
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    • pp.1087-1088
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    • 2020
  • 본 논문에서는 특징 추출 분석, 관심 영역을 추출하기 위한 몇 가지 종래의 이미지 전처리 방법과 K-means 클러스터링 및 이미지 분할방법을 통해서 얻어진 결과를 정상적인 세포와 비정상 세포를 추출하는 기법을 제안한다. 그 결과 97.8% 분류로 우수한 성능을 보여주었다.

예측을 이용한 효율적인 K-Means 알고리즘 (An Efficient K-means Clustering Algorithm using Prediction)

  • 지태창;이현진;이일병
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2008년도 추계학술발표대회
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    • pp.3-4
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    • 2008
  • 본 논문에서 k-means 군집화 알고리즘을 효율적으로 적용하는 방법을 제안했다. 제안하는 알고리즘의 특징을 속도 향상을 위해 예측 데이터를 이용한 것이다. 군집화 알고리즘의 각 단계에서 군집을 변경할 데이터만 최인접 군집을 계산함으로써 계산 시간을 줄일 수 있었다. 제안하는 알고리즘의 성능 비교를 위해서 KMHybrid 와 비교했다. 제안하는 알고리즘은 데이터의 차원이 큰 경우에 KMHybrid 보다 높은 속도 향상을 보였다.

A k-means++ Algorithm for Internet Shopping Search Engine

  • Jian-Ji Ren;Jae-kee Lee
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2008년도 추계학술발표대회
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    • pp.75-77
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    • 2008
  • Nowadays, as the indices of the major search engines grow to a tremendous proportion, vertical search services can help customers to find what they need. Search Engine is one of the reasons for Internet shopping success in today's world. The import one part of search engine is clustering data. The objective of this paper is to explore a k-means++ algorithm to calculate the clustering data which in the Internet shopping environment. The experiment results shows that the k-means++ algorithm is a faster algorithm to achieved a good clustering.