• Title/Summary/Keyword: K-nearest neighbor algorithm

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An Approach of Dimension Reduction in k-Nearest Neighbor Based Short-term Load Forecasting

  • Chu, FaZheng;Jung, Sung-Hwan
    • Journal of Korea Multimedia Society
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    • v.20 no.9
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    • pp.1567-1573
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    • 2017
  • The k-nearest neighbor (k-NN) algorithm is one of the most widely used benchmark algorithm in classification. Nowadays it has been further applied to predict time series. However, one of the main concerns of the algorithm applied on short-term electricity load forecasting is high computational burden. In the paper, we propose an approach of dimension reduction that follows the principles of highlighting the temperature effect on electricity load data series. The results show the proposed approach is able to reduce the dimension of the data around 30%. Moreover, with temperature effect highlighting, the approach will contribute to finding similar days accurately, and then raise forecasting accuracy slightly.

The Method to Process Approximate k-Nearest Neighbor Queries in Spatial Database Systems (공간 데이터베이스 시스템에서 근사 k-최대근접질의의 처리방법)

  • 선휘준;김홍기
    • Journal of the Korea Computer Industry Society
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    • v.4 no.4
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    • pp.443-448
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    • 2003
  • Approximate k-nearest neighbor queries are frequently occurred for finding the k nearest neighbors to a given query point in spatial database systems. The number of searched nodes in an index must be minimized in order to increase the performance of approximate k nearest neighbor queries. In this paper. we suggest the technique of approximate k nearest neighbor queries on R-tree family by improving the existing algorithm and evaluate the performance of the proposed method in dynamic spatial database environments. The simulation results show that a proposed method always has a low number of disk access irrespective of object distribution, size of nearest neighbor queries and approximation rates as compared with an existing method.

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Feature Selection for Multiple K-Nearest Neighbor classifiers using GAVaPS (GAVaPS를 이용한 다수 K-Nearest Neighbor classifier들의 Feature 선택)

  • Lee, Hee-Sung;Lee, Jae-Hun;Kim, Eun-Tai
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.6
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    • pp.871-875
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    • 2008
  • This paper deals with the feature selection for multiple k-nearest neighbor (k-NN) classifiers using Genetic Algorithm with Varying reputation Size (GAVaPS). Because we use multiple k-NN classifiers, the feature selection problem for them is vary hard and has large search region. To solve this problem, we employ the GAVaPS which outperforms comparison with simple genetic algorithm (SGA). Further, we propose the efficient combining method for multiple k-NN classifiers using GAVaPS. Experiments are performed to demonstrate the efficiency of the proposed method.

Semantic Word Categorization using Feature Similarity based K Nearest Neighbor

  • Jo, Taeho
    • Journal of Multimedia Information System
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    • v.5 no.2
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    • pp.67-78
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    • 2018
  • This article proposes the modified KNN (K Nearest Neighbor) algorithm which considers the feature similarity and is applied to the word categorization. The texts which are given as features for encoding words into numerical vectors are semantic related entities, rather than independent ones, and the synergy effect between the word categorization and the text categorization is expected by combining both of them with each other. In this research, we define the similarity metric between two vectors, including the feature similarity, modify the KNN algorithm by replacing the exiting similarity metric by the proposed one, and apply it to the word categorization. The proposed KNN is empirically validated as the better approach in categorizing words in news articles and opinions. The significance of this research is to improve the classification performance by utilizing the feature similarities.

Optimal dwelling time prediction for package tour using K-nearest neighbor classification algorithm

  • Aria Bisma Wahyutama;Mintae Hwang
    • ETRI Journal
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    • v.46 no.3
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    • pp.473-484
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    • 2024
  • We introduce a machine learning-based web application to help travel agents plan a package tour schedule. K-nearest neighbor (KNN) classification predicts the optimal tourists' dwelling time based on a variety of information to automatically generate a convenient tour schedule. A database collected in collaboration with an established travel agency is fed into the KNN algorithm implemented in the Python language, and the predicted dwelling times are sent to the web application via a RESTful application programming interface provided by the Flask framework. The web application displays a page in which the agents can configure the initial data and predict the optimal dwelling time and automatically update the tour schedule. After conducting a performance evaluation by simulating a scenario on a computer running the Windows operating system, the average response time was 1.762 s, and the prediction consistency was 100% over 100 iterations.

Performance Improvement of Nearest-neighbor Classification Learning through Prototype Selections (프로토타입 선택을 이용한 최근접 분류 학습의 성능 개선)

  • Hwang, Doo-Sung
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.2
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    • pp.53-60
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    • 2012
  • Nearest-neighbor classification predicts the class of an input data with the most frequent class among the near training data of the input data. Even though nearest-neighbor classification doesn't have a training stage, all of the training data are necessary in a predictive stage and the generalization performance depends on the quality of training data. Therefore, as the training data size increase, a nearest-neighbor classification requires the large amount of memory and the large computation time in prediction. In this paper, we propose a prototype selection algorithm that predicts the class of test data with the new set of prototypes which are near-boundary training data. Based on Tomek links and distance metric, the proposed algorithm selects boundary data and decides whether the selected data is added to the set of prototypes by considering classes and distance relationships. In the experiments, the number of prototypes is much smaller than the size of original training data and we takes advantages of storage reduction and fast prediction in a nearest-neighbor classification.

Interference Elimination Method of Ultrasonic Sensors Using K-Nearest Neighbor Algorithm (KNN 알고리즘을 활용한 초음파 센서 간 간섭 제거 기법)

  • Im, Hyungchul;Lee, Seongsoo
    • Journal of IKEEE
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    • v.26 no.2
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    • pp.169-175
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    • 2022
  • This paper introduces an interference elimination method using k-nearest neighbor (KNN) algorithm for precise distance estimation by reducing interference between ultrasonic sensors. Conventional methods compare current distance measurement result with previous distance measurement results. If the difference exceeds some thresholds, conventional methods recognize them as interference and exclude them, but they often suffer from imprecise distance prediction. KNN algorithm classifies input values measured by multiple ultrasonic sensors and predicts high accuracy outputs. Experiments of distance measurements are conducted where interference frequently occurs by multiple ultrasound sensors of same type, and the results show that KNN algorithm significantly reduce distance prediction errors. Also the results show that the prediction performance of KNN algorithm is superior to conventional voting methods.

The Design and Implementation of Location Information System using Wireless Fidelity in Indoors (실내에서 Wi-Fi를 이용한 위치 정보 시스템의 설계 및 구현)

  • Kwon, O-Byung;Kim, Kyeong-Su
    • Journal of Digital Convergence
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    • v.11 no.4
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    • pp.243-249
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    • 2013
  • In this paper, GPS(Global Positioning System) that can be used outdoors and GPS(Global Positioning System) is not available for indoor Wi-Fi(Wireless Fidelity) using the Android-based location information system has been designed and implemented. Pedestrians in a room in order to estimate the location of the pedestrian's position, regardless of need to obtain the absolute position and relative position, depending on the movement of pedestrians in a row it is necessary to estimate. In order to estimate the initial position of the pedestrian Wi-Fi Fingerprinting was used. Most existing Wi-Fi Fingerprinting position error small WKNN(Weighted K Nearest Neighbor) algorithm shortcoming EWKNN (Enhanced Weighted K Nearest Neighbor) using the algorithm raised the accuracy of the position. And in order to estimate the relative position of the pedestrian, the smart phone is mounted on the IMUInertial Measurement Unit) because the use did not require additional equipment.

Data Classification Using the Robbins-Monro Stochastic Approximation Algorithm (로빈스-몬로 확률 근사 알고리즘을 이용한 데이터 분류)

  • Lee, Jae-Kook;Ko, Chun-Taek;Choi, Won-Ho
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.624-627
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    • 2005
  • This paper presents a new data classification method using the Robbins Monro stochastic approximation algorithm k-nearest neighbor and distribution analysis. To cluster the data set, we decide the centroid of the test data set using k-nearest neighbor algorithm and the local area of data set. To decide each class of the data, the Robbins Monro stochastic approximation algorithm is applied to the decided local area of the data set. To evaluate the performance, the proposed classification method is compared to the conventional fuzzy c-mean method and k-nn algorithm. The simulation results show that the proposed method is more accurate than fuzzy c-mean method, k-nn algorithm and discriminant analysis algorithm.

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Model-Based Object Recognition using PCA & Improved k-Nearest Neighbor (PCA와 개선된 k-Nearest Neighbor를 이용한 모델 기반형 물체 인식)

  • Jung Byeong-Soo;Kim Byung-Gi
    • The KIPS Transactions:PartB
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    • v.13B no.1 s.104
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    • pp.53-62
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    • 2006
  • Object recognition techniques using principal component analysis are disposed to be decreased recognition rate when lighting change of image happens. The purpose of this thesis is to propose an object recognition technique using new PCA analysis method that discriminates an object in database even in the case that the variation of illumination in training images exists. And the object recognition algorithm proposed here represents more enhanced recognition rate using improved k-Nearest Neighbor. In this thesis, we proposed an object recognition algorithm which creates object space by pre-processing and being learned image using histogram equalization and median filter. By spreading histogram of test image using histogram equalization, the effect to change of illumination is reduced. This method is stronger to change of illumination than basic PCA method and normalization, and almost removes effect of illumination, therefore almost maintains constant good recognition rate. And, it compares ingredient projected test image into object space with distance of representative value and recognizes after representative value of each object in model image is made. Each model images is used in recognition unit about some continual input image using improved k-Nearest Neighbor in this thesis because existing method have many errors about distance calculation.