• Title/Summary/Keyword: k-mean clustering

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Time Management Behavior and Self-Efficacy in Nursing Students (간호대학생의 시간관리 행동유형과 자기효능감)

  • Kim, Hyun-Young;Kim, Se-Young;Seo, Hyang-Won;So, Eun-Hye
    • Journal of Korean Academy of Nursing Administration
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    • v.17 no.3
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    • pp.293-300
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    • 2011
  • Purpose: This study was done to explore time management behavior and self-efficacy in nursing students and to analyze the correlations between time management behavior and self-efficacy. Methods: The data were collected from May 12 to 20 2010 using self-report questionnaires about time management behavior and self-efficacy of nursing students. The data from 508 students were analyzed using descriptive analysis, K-means clustering, and one-way ANOVA. Results: The mean score for time management behavior was 3.03${\pm}$1.11 out of a possible 5, and self-efficacy was 3.65${\pm}$0.42 out of a possible 6. Four groups were identified according to time management behavior. The four groups were significantly different on self-efficacy total (p=<.05) and self-regulatory efficacy (p=.<005). The group with the highest score for time management had the highest score for self-efficacy. Conclusions: The results of the study indicate that time management behavior styles are related to self-efficacy for nursing students. Therefore, time management education programs based on the time management behavior styles are needed to increase self-efficacy in nursing students.

Movie recommendation system using community detection based on label propagation (레이블 전파에 기반한 커뮤니티 탐지를 이용한 영화추천시스템)

  • Xinchang, Khamphaphone;Vilakone, Phonexay;Lee, Han-Hyung;Song, Min-Hyuk;Park, Doo-Soon
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.05a
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    • pp.273-276
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    • 2019
  • There is a lot of information in our world, quick access to the most accurate information or finding the information we need is more difficult and complicated. The recommendation system has become important for users to quickly find the product according to user's preference. A social recommendation system using community detection based on label propagation is proposed. In this paper, we applied community detection based on label propagation and collaborative filtering in the movie recommendation system. We implement with MovieLens dataset, the users will be clustering to the community by using label propagation algorithm, Our proposed algorithm will be recommended movie with finding the most similar community to the new user according to the personal propensity of users. Mean Absolute Error (MAE) is used to shown efficient of our proposed method.

Design of Pedestrian Detection and Tracking System Using HOG-PCA and Object Tracking Algorithm (HOG-PCA와 객체 추적 알고리즘을 이용한 보행자 검출 및 추적 시스템 설계)

  • Jeon, Pil-Han;Park, Chan-Jun;Kim, Jin-Yul;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.4
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    • pp.682-691
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    • 2017
  • In this paper, we propose the fusion design methodology of both pedestrian detection and object tracking system realized with the aid of HOG-PCA based RBFNN pattern classifier. The proposed system includes detection and tracking parts. In the detection part, HOG features are extracted from input images for pedestrian detection. Dimension reduction is also dealt with in order to improve detection performance as well as processing speed by using PCA which is known as a typical dimension reduction method. The reduced features can be used as the input of the FCM-based RBFNNs pattern classifier to carry out the pedestrian detection. FCM-based RBFNNs pattern classifier consists of condition, conclusion, and inference parts. FCM clustering algorithm is used as the activation function of hidden layer. In the conclusion part of network, polynomial functions such as constant, linear, quadratic and modified quadratic are regarded as connection weights and their coefficients of polynomial function are estimated by LSE-based learning. In the tracking part, object tracking algorithms such as mean shift(MS) and cam shift(CS) leads to trace one of the pedestrian candidates nominated in the detection part. Finally, INRIA person database is used in order to evaluate the performance of the pedestrian detection of the proposed system while MIT pedestrian video as well as indoor and outdoor videos obtained from IC&CI laboratory in Suwon University are exploited to evaluate the performance of tracking.

Detection of Multiple Salient Objects by Categorizing Regional Features

  • Oh, Kang-Han;Kim, Soo-Hyung;Kim, Young-Chul;Lee, Yu-Ra
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.1
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    • pp.272-287
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    • 2016
  • Recently, various and effective contrast based salient object detection models to focus on a single target have been proposed. However, there is a lack of research on detection of multiple objects, and also it is a more challenging task than single target process. In the multiple target problem, we are confronted by new difficulties caused by distinct difference between properties of objects. The characteristic of existing models depending on the global maximum distribution of data point would become a drawback for detection of multiple objects. In this paper, by analyzing limitations of the existing methods, we have devised three main processes to detect multiple salient objects. In the first stage, regional features are extracted from over-segmented regions. In the second stage, the regional features are categorized into homogeneous cluster using the mean-shift algorithm with the kernel function having various sizes. In the final stage, we compute saliency scores of the categorized regions using only spatial features without the contrast features, and then all scores are integrated for the final salient regions. In the experimental results, the scheme achieved superior detection accuracy for the SED2 and MSRA-ASD benchmarks with both a higher precision and better recall than state-of-the-art approaches. Especially, given multiple objects having different properties, our model significantly outperforms all existing models.

A Study of using Emotional Features for Information Retrieval Systems (감정요소를 사용한 정보검색에 관한 연구)

  • Kim, Myung-Gwan;Park, Young-Tack
    • The KIPS Transactions:PartB
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    • v.10B no.6
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    • pp.579-586
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    • 2003
  • In this paper, we propose a novel approach to employ emotional features to document retrieval systems. Fine emotional features, such as HAPPY, SAD, ANGRY, FEAR, and DISGUST, have been used to represent Korean document. Users are allowed to use these features for retrieving their documents. Next, retrieved documents are learned by classification methods like cohesion factor, naive Bayesian, and, k-nearest neighbor approaches. In order to combine various approaches, voting method has been used. In addition, k-means clustering has been used for our experimentation. The performance of our approach proved to be better in accuracy than other methods, and be better in short texts rather than large documents.

Image Retrieval Using Color & Spatial Distribution between Pixel Layers (Pixel layer 들 간의 색상 공간 분포에 따른 공간적 분포를 이용한 영상 검색)

  • An, Jaehyun;Ha, Seong Jong;Lee, Sang Hwa;Cho, Nam Ik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.07a
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    • pp.294-297
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    • 2012
  • 본 논문에서는 컬러 영상의 검색을 위하여 영상을 색상 정보에 기반한 pixel layer (cluster)의 집합체로 모델링하고, 두 layer 간의 유사도를 각 layer 를 이루는 pixel 들의 색상 분포에 따른 공간적 분포를 이용하여 측정하는 기법을 제안한다. 먼저 pixel layering 단계에서는 HSV 색 공간에서 mean-shift clustering 알고리즘을 통해 초기 layer 들을 얻고, 비슷한 색상의 layer 들은 합쳐 영상의 soft segmentation 과 유사한 결과를 얻는다. 비교할 두 영상에서 pixel layering 을 한 후, 각 layer 를 이진화된 공간분포 지도로 형성하고 그 차이를 비교함으로써 유사도를 측정한다. 이 때, 사용하는 가중치로서 HSV 색 공간 분포의 비슷한 정도를 정의하는데, 이는 HSV 색 공간을 XYZ 의 3 차원 좌표로 설정하고, overlap 되는 pixel 수로 정의하였다. 본 논문에서 제안한 pixel layer 들 간의 색상 공간 분포에 따른 공간적 분포를 이용한 영상 검색 기법은 MPEG-7 에서 정의한 대표색상 기반의 영상 검색보다 우수한 성능을 보여주었다.

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Implementation of Elbow Method to improve the Gases Classification Performance based on the RBFN-NSG Algorithm

  • Jeon, Jin-Young;Choi, Jang-Sik;Byun, Hyung-Gi
    • Journal of Sensor Science and Technology
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    • v.25 no.6
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    • pp.431-434
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    • 2016
  • Currently, the radial basis function network (RBFN) and various other neural networks are employed to classify gases using chemical sensors arrays, and their performance is steadily improving. In particular, the identification performance of the RBFN algorithm is being improved by optimizing parameters such as the center, width, and weight, and improved algorithms such as the radial basis function network-stochastic gradient (RBFN-SG) and radial basis function network-normalized stochastic gradient (RBFN-NSG) have been announced. In this study, we optimized the number of centers, which is one of the parameters of the RBFN-NSG algorithm, and observed the change in the identification performance. For the experiment, repeated measurement data of 8 samples were used, and the elbow method was applied to determine the optimal number of centers for each sample of input data. The experiment was carried out in two cases(the only one center per sample and the optimal number of centers obtained by elbow method), and the experimental results were compared using the mean square error (MSE). From the results of the experiments, we observed that the case having an optimal number of centers, obtained using the elbow method, showed a better identification performance than that without any optimization.

ESTIMATION OF THE POWER PEAKING FACTOR IN A NUCLEAR REACTOR USING SUPPORT VECTOR MACHINES AND UNCERTAINTY ANALYSIS

  • Bae, In-Ho;Na, Man-Gyun;Lee, Yoon-Joon;Park, Goon-Cherl
    • Nuclear Engineering and Technology
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    • v.41 no.9
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    • pp.1181-1190
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    • 2009
  • Knowing more about the Local Power Density (LPD) at the hottest part of a nuclear reactor core can provide more important information than knowledge of the LPD at any other position. The LPD at the hottest part needs to be estimated accurately in order to prevent the fuel rod from melting in a nuclear reactor. Support Vector Machines (SVMs) have successfully been applied in classification and regression problems. Therefore, in this paper, the power peaking factor, which is defined as the highest LPD to the average power density in a reactor core, was estimated by SVMs which use numerous measured signals of the reactor coolant system. The SVM models were developed by using a training data set and validated by an independent test data set. The SVM models' uncertainty was analyzed by using 100 sampled training data sets and verification data sets. The prediction intervals were very small, which means that the predicted values were very accurate. The predicted values were then applied to the first fuel cycle of the Yonggwang Nuclear Power Plant Unit 3. The root mean squared error was approximately 0.15%, which is accurate enough for use in LPD monitoring and for core protection that uses LPD estimation.

Classification of Terrestrial LiDAR Data Using Factor and Cluster Analysis (요인 및 군집분석을 이용한 지상 라이다 자료의 분류)

  • Choi, Seung-Pil;Cho, Ji-Hyun;Kim, Yeol;Kim, Jun-Seong
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.4
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    • pp.139-144
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    • 2011
  • This study proposed a classification method of LIDAR data by using simultaneously the color information (R, G, B) and reflection intensity information (I) obtained from terrestrial LIDAR and by analyzing the association between these data through the use of statistical classification methods. To this end, first, the factors that maximize variance were calculated using the variables, R, G, B, and I, whereby the factor matrix between the principal factor and each variable was calculated. However, although the factor matrix shows basic data by reducing them, it is difficult to know clearly which variables become highly associated by which factors; therefore, Varimax method from orthogonal rotation was used to obtain the factor matrix and then the factor scores were calculated. And, by using a non-hierarchical clustering method, K-mean method, a cluster analysis was performed on the factor scores obtained via K-mean method as factor analysis, and afterwards the classification accuracy of the terrestrial LiDAR data was evaluated.

Design of Meteorological Radar Echo Classifier Based on RBFNN Using Radial Velocity (시선속도를 고려한 RBFNN 기반 기상레이더 에코 분류기의 설계)

  • Bae, Jong-Soo;Song, Chan-Seok;Oh, Sung-Kwun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.3
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    • pp.242-247
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    • 2015
  • In this study, we propose the design of Radial Basis Function Neural Network(RBFNN) classifier in order to classify between precipitation and non-precipitation echo. The characteristics of meteorological radar data is analyzed for classifying precipitation and non-precipitation echo. Input variables is selected as DZ, SDZ, VGZ, SPN, DZ_FR, VR by performing pre-processing of UF data based on the characteristics analysis and these are composed of training and test data. Finally, QC data being used in Korea Meteorological Administration is applied to compare with the performance results of proposed classifier.