• Title/Summary/Keyword: machine learning

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Learning Multidimensional Sequential Patterns Using Hellinger Entropy Function (Hellinger 엔트로피를 이용한 다차원 연속패턴의 생성방법)

  • Lee, Chang-Hwan
    • The KIPS Transactions:PartB
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    • v.11B no.4
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    • pp.477-484
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    • 2004
  • The technique of sequential pattern mining means generating a set of inter-transaction patterns residing in time-dependent data. This paper proposes a new method for generating sequential patterns with the use of Hellinger measure. While the current methods are generating single dimensional sequential patterns within a single attribute, the proposed method is able to detect multi-dimensional patterns among different attributes. A number of heuristics, based on the characteristics of Hellinger measure, are proposed to reduce the computational complexity of the sequential pattern systems. Some experimental results are presented.

A Study on Training Ensembles of Neural Networks - A Case of Stock Price Prediction (신경망 학습앙상블에 관한 연구 - 주가예측을 중심으로 -)

  • 이영찬;곽수환
    • Journal of Intelligence and Information Systems
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    • v.5 no.1
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    • pp.95-101
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    • 1999
  • In this paper, a comparison between different methods to combine predictions from neural networks will be given. These methods are bagging, bumping, and balancing. Those are based on the analysis of the ensemble generalization error into an ambiguity term and a term incorporating generalization performances of individual networks. Neural Networks and AI machine learning models are prone to overfitting. A strategy to prevent a neural network from overfitting, is to stop training in early stage of the learning process. The complete data set is spilt up into a training set and a validation set. Training is stopped when the error on the validation set starts increasing. The stability of the networks is highly dependent on the division in training and validation set, and also on the random initial weights and the chosen minimization procedure. This causes early stopped networks to be rather unstable: a small change in the data or different initial conditions can produce large changes in the prediction. Therefore, it is advisable to apply the same procedure several times starting from different initial weights. This technique is often referred to as training ensembles of neural networks. In this paper, we presented a comparison of three statistical methods to prevent overfitting of neural network.

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Robust Multi-Layer Hierarchical Model for Digit Character Recognition

  • Yang, Jie;Sun, Yadong;Zhang, Liangjun;Zhang, Qingnian
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.699-707
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    • 2015
  • Although digit character recognition has got a significant improvement in recent years, it is still challenging to achieve satisfied result if the data contains an amount of distracting factors. This paper proposes a novel digit character recognition approach using a multi-layer hierarchical model, Hybrid Restricted Boltzmann Machines (HRBMs), which allows the learning architecture to be robust to background distracting factors. The insight behind the proposed model is that useful high-level features appear more frequently than distracting factors during learning, thus the high-level features can be decompose into hybrid hierarchical structures by using only small label information. In order to extract robust and compact features, a stochastic 0-1 layer is employed, which enables the model's hidden nodes to independently capture the useful character features during training. Experiments on the variations of Mixed National Institute of Standards and Technology (MNIST) dataset show that improvements of the multi-layer hierarchical model can be achieved by the proposed method. Finally, the paper shows the proposed technique which is used in a real-world application, where it is able to identify digit characters under various complex background images.

Wrist and Grasping Forces Estimation using Electromyography for Robotic Prosthesis (근전도 신호를 이용한 손목 힘 및 악력 추정)

  • Kim, Young-Jin;Lee, Dong-Hyuk;Park, Hyeonjun;Park, Jae-Han;Bae, Ji-Hun;Baeg, Moon-Hong
    • The Journal of Korea Robotics Society
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    • v.12 no.2
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    • pp.206-216
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    • 2017
  • This paper proposes a method to simultaneously estimate two degrees of freedom in wrist forces (extension - flexion, adduction - abduction) and one degree of freedom in grasping forces using Electromyography (EMG) signals of the forearms. To correlate the EMG signals with the forces, we applied a multi - layer perceptron(MLP), which is a machine learning method, and used the characteristics of the muscles constituting the forearm to generate learning data. Through the experiments, the similarity between the MLP target value and the estimated value was investigated by applying the coefficient of determination ($R^2$) and root mean square error (RMSE) to evaluate the performance of the proposed method. As a result, the $R^2$ values with respect to the wrist flexion-extension, adduction - abduction and grasping forces were 0.79, 0.73 and 0.78 and RMSE were 0.12, 0.17, 0.13 respectively.

Extraction of Protein-Protein Interactions based on Convolutional Neural Network (CNN) (Convolutional Neural Network (CNN) 기반의 단백질 간 상호 작용 추출)

  • Choi, Sung-Pil
    • KIISE Transactions on Computing Practices
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    • v.23 no.3
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    • pp.194-198
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    • 2017
  • In this paper, we propose a revised Deep Convolutional Neural Network (DCNN) model to extract Protein-Protein Interaction (PPIs) from the scientific literature. The proposed method has the merit of improving performance by applying various global features in addition to the simple lexical features used in conventional relation extraction approaches. In the experiments using AIMed, which is the most famous collection used for PPI extraction, the proposed model shows state-of-the art scores (78.0 F-score) revealing the best performance so far in this domain. Also, the paper shows that, without conducting feature engineering using complicated language processing, convolutional neural networks with embedding can achieve superior PPIE performance.

Analysis of Commute Time Embedding Based on Spectral Graph (스펙트럴 그래프 기반 Commute Time 임베딩 특성 분석)

  • Hahn, Hee-Il
    • Journal of Korea Multimedia Society
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    • v.17 no.1
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    • pp.34-42
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    • 2014
  • In this paper an embedding algorithm based on commute time is implemented by organizing patches according to the graph-based metric, and its performance is analyzed by comparing with the results of principal component analysis embedding. It is usual that the dimensionality reduction be done within some acceptable approximation error. However this paper shows the proposed manifold embedding method generates the intrinsic geometry corresponding to the signal despite severe approximation error, so that it can be applied to the areas such as pattern classification or machine learning.

A Study on the Reclassification of Author Keywords for Automatic Assignment of Descriptors (디스크립터 자동 할당을 위한 저자키워드의 재분류에 관한 실험적 연구)

  • Kim, Pan-Jun;Lee, Jae-Yun
    • Journal of the Korean Society for information Management
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    • v.29 no.2
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    • pp.225-246
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    • 2012
  • This study purported to investigate the possibility of automatic descriptor assignment using the reclassification of author keywords in domestic scholarly databases. In the first stage, we selected optimal classifiers and parameters for the reclassification by comparing the characteristics of machine learning classifiers. In the next stage, learning the author keywords that were assigned to the selected articles on readings, the author keywords were automatically added to another set of relevant articles. We examined whether the author keyword reclassifications had the effect of vocabulary control just as descriptors collocate the documents on the same topic. The results showed the author keyword reclassification had the capability of the automatic descriptor assignment.

K-Means-Based Polynomial-Radial Basis Function Neural Network Using Space Search Algorithm: Design and Comparative Studies (공간 탐색 최적화 알고리즘을 이용한 K-Means 클러스터링 기반 다항식 방사형 기저 함수 신경회로망: 설계 및 비교 해석)

  • Kim, Wook-Dong;Oh, Sung-Kwun
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.8
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    • pp.731-738
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    • 2011
  • In this paper, we introduce an advanced architecture of K-Means clustering-based polynomial Radial Basis Function Neural Networks (p-RBFNNs) designed with the aid of SSOA (Space Search Optimization Algorithm) and develop a comprehensive design methodology supporting their construction. In order to design the optimized p-RBFNNs, a center value of each receptive field is determined by running the K-Means clustering algorithm and then the center value and the width of the corresponding receptive field are optimized through SSOA. The connections (weights) of the proposed p-RBFNNs are of functional character and are realized by considering three types of polynomials. In addition, a WLSE (Weighted Least Square Estimation) is used to estimate the coefficients of polynomials (serving as functional connections of the network) of each node from output node. Therefore, a local learning capability and an interpretability of the proposed model are improved. The proposed model is illustrated with the use of nonlinear function, NOx called Machine Learning dataset. A comparative analysis reveals that the proposed model exhibits higher accuracy and superb predictive capability in comparison to some previous models available in the literature.

A study on semi-supervised kernel ridge regression estimation (준지도 커널능형회귀모형에 관한 연구)

  • Seok, Kyungha
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.2
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    • pp.341-353
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    • 2013
  • In many practical machine learning and data mining applications, unlabeled data are inexpensive and easy to obtain. Semi-supervised learning try to use such data to improve prediction performance. In this paper, a semi-supervised regression method, semi-supervised kernel ridge regression estimation, is proposed on the basis of kernel ridge regression model. The proposed method does not require a pilot estimation of the label of the unlabeled data. This means that the proposed method has good advantages including less number of parameters, easy computing and good generalization ability. Experiments show that the proposed method can effectively utilize unlabeled data to improve regression estimation.

Teachers’Recognition in Food/Nutrition, Textile/Clothing Units in Home Economics Text Book of Middle School (중학교 가정교과서 의생활 및 주생활 단원에 대한 교사의 인식 및 활용)

  • 장현숙;조필교
    • Journal of Korean Home Economics Education Association
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    • v.7 no.2
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    • pp.113-123
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    • 1995
  • The purpose of this study is to investigate teachers’ recognition in Food/Nutrition, Textile/Clothing part in Home Economics Text Book of Middle School and to provide the basic data for the improvement of its curriculum. 147 Home Economics teachers in Taegu city and Kyungsangbukdo area responded to the questionnaire. The results are summarized as follows: 1. Most of Home Economics teachers have graduated Dept. of Home Economics Education and have ever taken teacher training. And even those who ever taken teacher training are not satisfied with training curriculum contents. Therefore, the result of this study shows that teacher training curriculum contents should be improved so as to be helpful for the actual teaching and learning. 2. In terms of the suitability of contents of food & nutrition and contents of textiles & clothing to the student’s learning development levels, the degree of suitability is in the order of nutrition & health, nutrition in adolescence, food selection, kinds and functions of nutrients in food & nutrition curriculum, and in the order of suitable clothing, mixture rate of fabrics, purchase of clothing, clothing in adolescence, clothing selection. The contents of making processed foods and usage of sewing machine of the existing text book have turned out not to be appropriate. 3. Most teachers suggest that dietary guideline for health, misconception about food & nutrition selection of ready-made suit suitable clothing for situation & character as well as the contents of the existing text book should be included in the new text book.

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