• 제목/요약/키워드: k-Nearest neighbor

검색결과 641건 처리시간 0.025초

A Low Complexity PTS Technique using Threshold for PAPR Reduction in OFDM Systems

  • Lim, Dai Hwan;Rhee, Byung Ho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권9호
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    • pp.2191-2201
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    • 2012
  • Traffic classification seeks to assign packet flows to an appropriate quality of service (QoS) class based on flow statistics without the need to examine packet payloads. Classification proceeds in two steps. Classification rules are first built by analyzing traffic traces, and then the classification rules are evaluated using test data. In this paper, we use self-organizing map and K-means clustering as unsupervised machine learning methods to identify the inherent classes in traffic traces. Three clusters were discovered, corresponding to transactional, bulk data transfer, and interactive applications. The K-nearest neighbor classifier was found to be highly accurate for the traffic data and significantly better compared to a minimum mean distance classifier.

Classification of Traffic Flows into QoS Classes by Unsupervised Learning and KNN Clustering

  • Zeng, Yi;Chen, Thomas M.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제3권2호
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    • pp.134-146
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    • 2009
  • Traffic classification seeks to assign packet flows to an appropriate quality of service(QoS) class based on flow statistics without the need to examine packet payloads. Classification proceeds in two steps. Classification rules are first built by analyzing traffic traces, and then the classification rules are evaluated using test data. In this paper, we use self-organizing map and K-means clustering as unsupervised machine learning methods to identify the inherent classes in traffic traces. Three clusters were discovered, corresponding to transactional, bulk data transfer, and interactive applications. The K-nearest neighbor classifier was found to be highly accurate for the traffic data and significantly better compared to a minimum mean distance classifier.

An Anomaly Detection Algorithm for Cathode Voltage of Aluminum Electrolytic Cell

  • Cao, Danyang;Ma, Yanhong;Duan, Lina
    • Journal of Information Processing Systems
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    • 제15권6호
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    • pp.1392-1405
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    • 2019
  • The cathode voltage of aluminum electrolytic cell is relatively stable under normal conditions and fluctuates greatly when it has an anomaly. In order to detect the abnormal range of cathode voltage, an anomaly detection algorithm based on sliding window was proposed. The algorithm combines the time series segmentation linear representation method and the k-nearest neighbor local anomaly detection algorithm, which is more efficient than the direct detection of the original sequence. The algorithm first segments the cathode voltage time series, then calculates the length, the slope, and the mean of each line segment pattern, and maps them into a set of spatial objects. And then the local anomaly detection algorithm is used to detect abnormal patterns according to the local anomaly factor and the pattern length. The experimental results showed that the algorithm can effectively detect the abnormal range of cathode voltage.

An Improved Text Classification Method for Sentiment Classification

  • Wang, Guangxing;Shin, Seong Yoon
    • Journal of information and communication convergence engineering
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    • 제17권1호
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    • pp.41-48
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    • 2019
  • In recent years, sentiment analysis research has become popular. The research results of sentiment analysis have achieved remarkable results in practical applications, such as in Amazon's book recommendation system and the North American movie box office evaluation system. Analyzing big data based on user preferences and evaluations and recommending hot-selling books and hot-rated movies to users in a targeted manner greatly improve book sales and attendance rate in movies [1, 2]. However, traditional machine learning-based sentiment analysis methods such as the Classification and Regression Tree (CART), Support Vector Machine (SVM), and k-nearest neighbor classification (kNN) had performed poorly in accuracy. In this paper, an improved kNN classification method is proposed. Through the improved method and normalizing of data, the purpose of improving accuracy is achieved. Subsequently, the three classification algorithms and the improved algorithm were compared based on experimental data. Experiments show that the improved method performs best in the kNN classification method, with an accuracy rate of 11.5% and a precision rate of 20.3%.

Identification of Plastic Wastes by Using Fuzzy Radial Basis Function Neural Networks Classifier with Conditional Fuzzy C-Means Clustering

  • Roh, Seok-Beom;Oh, Sung-Kwun
    • Journal of Electrical Engineering and Technology
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    • 제11권6호
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    • pp.1872-1879
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    • 2016
  • The techniques to recycle and reuse plastics attract public attention. These public attraction and needs result in improving the recycling technique. However, the identification technique for black plastic wastes still have big problem that the spectrum extracted from near infrared radiation spectroscopy is not clear and is contaminated by noise. To overcome this problem, we apply Raman spectroscopy to extract a clear spectrum of plastic material. In addition, to improve the classification ability of fuzzy Radial Basis Function Neural Networks, we apply supervised learning based clustering method instead of unsupervised clustering method. The conditional fuzzy C-Means clustering method, which is a kind of supervised learning based clustering algorithms, is used to determine the location of radial basis functions. The conditional fuzzy C-Means clustering analyzes the data distribution over input space under the supervision of auxiliary information. The auxiliary information is defined by using k Nearest Neighbor approach.

시야각으로 한정된 최근접 질의 (View Field Nearest Neighbor Queries)

  • 이성민;정하림;박준표;정연돈
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(C)
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    • pp.153-156
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    • 2011
  • 최근 많은 관심을 받고 있는 증강현실 위치기반 서비스와 같이 사용자의 한정된 시야각이 존재하는 상황에서 사용자가 원하는 데이터를 효과적으로 제공하기 위하여 본 논문에서는 새로운 위치기반 질의인 시야 최근접 질의 (VFNN: View Field Nearest Neighbor Queries)를 소개한다. VFNN 질의는 사용자의 시야각내에 위치하는 가장 가까운 데이터를 검색한다. 본 논문에서 제안하는 VFNN 질의 처리 알고리즘은 가장 널리 활용되고 있는 공간 데이터 색인 구조인 $R^*$-tree를 사용한다. 특히, 질의 점과 MBR 사이의 최소거리인 MINDIST뿐만 아니라, 질의 점과 MBR 사이의 최대 각, 최소 각을 정의한다. 이를 활용하여 $R^*$-tree 탐색 시 질의 결과 값을 포함하지 않는 노드들을 연산에서 제외함으로써 질의 처리의 효율성을 향상시킨다. 마지막으로 실험을 통하여 VFNN 질의 처리 알고리즘의 성능을 평가한다.

사각형 특징 기반 분류기와 AdaBoost 를 이용한 실시간 얼굴 검출 및 인식 (Real-time Face Detection and Recognition using Classifier Based on Rectangular Feature and AdaBoost)

  • 김종민;이웅기
    • 통합자연과학논문집
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    • 제1권2호
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    • pp.133-139
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    • 2008
  • Face recognition technologies using PCA(principal component analysis) recognize faces by deciding representative features of faces in the model image, extracting feature vectors from faces in a image and measuring the distance between them and face representation. Given frequent recognition problems associated with the use of point-to-point distance approach, this study adopted the K-nearest neighbor technique(class-to-class) in which a group of face models of the same class is used as recognition unit for the images inputted on a continual input image. This paper proposes a new PCA recognition in which database of faces.

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KNN-based Image Annotation by Collectively Mining Visual and Semantic Similarities

  • Ji, Qian;Zhang, Liyan;Li, Zechao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권9호
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    • pp.4476-4490
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    • 2017
  • The aim of image annotation is to determine labels that can accurately describe the semantic information of images. Many approaches have been proposed to automate the image annotation task while achieving good performance. However, in most cases, the semantic similarities of images are ignored. Towards this end, we propose a novel Visual-Semantic Nearest Neighbor (VS-KNN) method by collectively exploring visual and semantic similarities for image annotation. First, for each label, visual nearest neighbors of a given test image are constructed from training images associated with this label. Second, each neighboring subset is determined by mining the semantic similarity and the visual similarity. Finally, the relevance between the images and labels is determined based on maximum a posteriori estimation. Extensive experiments were conducted using three widely used image datasets. The experimental results show the effectiveness of the proposed method in comparison with state-of-the-arts methods.

Detection and Classification of Bearing Flaking Defects by Using Kullback Discrimination Information (KDI)

  • Kim, Tae-Gu;Takabumi Fukuda;Hisaji Shimizu
    • International Journal of Safety
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    • 제1권1호
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    • pp.28-35
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    • 2002
  • Kullback Discrimination Information (KDI) is one of the pattern recognition methods. KDI defined as a measure of the mutual dissimilarity computed between two time series was studied for detection and classification of bearing flaking on outer-race and inner-races. To model the damages, the bearings in normal condition, outer-race flaking condition and inner-races flaking condition were provided. The vibration sensor was attached by the bearing housing. This produced the total 25 pieces of data each condition, and we chose the standard data and measure of distance between standard and tested data. It is difficult to detect the flaking because similar pulses come out when balls pass the defection point. The detection and classification method for inner and outer races are defected by KDI and nearest neighbor classification rule is proposed and its high performance is also shown.