نتایج جستجو برای: knn

تعداد نتایج: 4566  

Journal: :IEEE transactions on ultrasonics, ferroelectrics, and frequency control 2007
Isaku Kanno Takuya Mino Shuichiro Kuwajima Takaaki Suzuki Hidetoshi Kotera Kiyotaka Wasa

(K(x),Na(1-x))NbO(3) (KNN) thin films were deposited on (001)SrRuO(3)/(001)Pt/(001)MgO substrates by RF-magnetron sputtering, and their piezoelectric properties were investigated. The x-ray diffraction measurements indicated that the KNN thin films were epitaxially grown with the c-axis orientation in the perovskite tetragonal system. The lattice constant of the c-axis increased with increasing...

2005
Liangxiao Jiang Harry Zhang Jiang Su

Accurate probability-based ranking of instances is crucial in many real-world data mining applications. KNN (k-nearest neighbor) [1] has been intensively studied as an effective classification model in decades. However, its performance in ranking is unknown. In this paper, we conduct a systematic study on the ranking performance of KNN. At first, we compare KNN and KNNDW (KNN with distance weig...

2014
Zoltan Geler Vladimir Kurbalija Milos Radovanovic Mirjana Ivanovic

For classification of time series, the simple 1-nearest neighbor (1NN) classifier in combination with an elastic distance measure such as Dynamic Time Warping (DTW) distance is considered superior in terms of classification accuracy to many other more elaborate methods, including k-nearest neighbor (kNN) with neighborhood size k > 1. In this paper we revisit this apparently peculiar relationshi...

2018
Arthur Flexer Jeff Stevens

This paper is concerned with the impact of hubness, a general problem of machine learning in high-dimensional spaces, on a real-world music recommendation system based on visualisation of a k-nearest neighbour (knn) graph. Due to a problem of measuring distances in high dimensions, hub objects are recommended over and over again while anti-hubs are nonexistent in recommendation lists, resulting...

2014
Tao Chu Chao He

Lead-free (K0.5Na0.5)NbO3-LiNbO3 (KNN-LN) and (K0.5Na0.5)NbO3-LiTaO3 (KNN-LT) ferroelectric single crystals, with the dimensions of 11  11  5 mm and 5  5  3 mm, were grown successfully using the top-seeded solution growth (TSSG) method, respectively. The crystal structures were analyzed by means of X-ray diffraction, showing orthorhombic symmetry for KNN-LN single crystals and coexistence o...

2006
Xue-Mei Jiang Wen-Guan Song Wei-Guo Feng

Collaborative filtering has been very successful in both research and E-commence applications. One of the most popular collaborative filtering algorithms is the k-Nearest Neighbor (KNN) method, which finds k nearest neighbors for a given user to predict his interests. Previous research on KNN algorithm usually suffers from the data sparseness problem, because the quantity of items users voted i...

Journal: :Chaos 2018
Warren M. Lord Jie Sun Erik M. Bollt

Nonparametric estimation of mutual information is used in a wide range of scientific problems to quantify dependence between variables. The k-nearest neighbor (knn) methods are consistent, and therefore expected to work well for a large sample size. These methods use geometrically regular local volume elements. This practice allows maximum localization of the volume elements, but can also induc...

2015
Alexander Fargus

Condition monitoring systems for prognostics and diagnostics can enable large and complex systems to be operated more safely, at a lower cost and have a longer lifetime than is possible without them. AURA Alert is a condition monitoring system that uses a fast approximate k Nearest Neighbour (kNN) search of a timeseries database containing known system states to identify anomalous system behavi...

2009
Amal Perera D. G. Niroshini Dayaratne William Perrizo

Data classification attempts to assign a category or a class label to an unknown data object based on an available similar data set with class labels already assigned. K nearest neighbor (KNN) is a widely used classification technique in data mining. KNN assigns the majority class label of its closest neighbours to an unknown object, when classifying an unknown object. The computational efficie...

Journal: :NeuroImage 2011
Jeroen de Bresser Marileen P. Portegies Alexander Leemans Geert Jan Biessels L. Jaap Kappelle Max A. Viergever

Automated brain segmentation methods with a good precision and accuracy are required to detect subtle changes in brain volumes over time in clinical applications. However, the ability of established methods such as SIENA, US and kNN to estimate brain volume change have not been compared on the same data, nor been evaluated with ground-truth manual segmentations. We compared measurements of brai...

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