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111.
112.
Power Quality (PQ) is becoming more and more important day by day in the electric network. Signal processing, pattern recognition and machine learning are increasingly being studied for the automatic recognition of any disturbances that may occur during the generation, transmission, and distribution of electricity. There are three main steps to identify the PQ disturbances. These include the use of signal processing methods to calculate the features representing the disturbances, the selection of those that are more useful than these feature sets to prevent the creation of a complex classification model, the creating a classification model that recognizes multiple classes using the selected feature subsets. In this study, one-dimensional (1D) PQ disturbances signals are transformed into two-dimensional (2D) signals, 2D discrete wavelet transforms (2D-DWT) are used to extract the features. The features are extracted by using the wavelet families such as Daubechies, Biorthogonal, Symlets, Coiflets and Fejer-Korovkin in 2D-DWT to analyze PQ disturbances. Whale Optimization Algorithm (WOA) and k-nearest neighbor (KNN) classifier determine the feature subsets. Then, WOA and k nearest neighbor (KNN) classifier are used to determine the feature group. By using KNN and Support Vector Machines (SVM) classification methods, Classifier models that distinguish PQ disturbances are formed. The main aim of the study is to determine the features derived from 2D wavelet coefficients for different wavelet families and to determine which of them has a better classification performance to distinguish PQ disturbances signals. At the same time, different classification methods are simulated and a model which can classify PQ disturbances signals with high performance is created. Also, the generated models are analysed for their performance in terms of different noise levels (40 dB, 30 dB, 20 dB). The result of this simulation study shows that the model developed to classify PQ disturbances is superior to conventional models and other 2D signal processing methods in the literature. In addition, it was concluded that the proposed method can cope better with noisy signals by low computational complexity and higher classification rate. 相似文献
113.
114.
This paper presents an optimized cuttlefish algorithm for feature selection based on the traditional cuttlefish algorithm, which can be used for diagnosis of Parkinson’s disease at its early stage. Parkinson is a central nervous system disorder, caused due to the loss of brain cells. Parkinson's disease is incurable and could eventually lead to death but medications can help to control symptoms and elongate the patient's life to some extent. The proposed model uses the traditional cuttlefish algorithm as a search strategy to ascertain the optimal subset of features. The decision tree and k-nearest neighbor classifier as a judgment on the selected features. The Parkinson speech with multiple types of sound recordings and Parkinson Handwriting sample’s datasets are used to evaluate the proposed model. The proposed algorithm can be used in predicting the Parkinson’s disease with an accuracy of approximately 94% and help individual to have proper treatment at early stage. The experimental result reveals that the proposed bio-inspired algorithm finds an optimal subset of features, maximizing the accuracy, minimizing number of features selected and is more stable. 相似文献
115.
聚类分析已成功用于认知诊断评估(CDA)中,使用广泛的聚类分析方法为K-means算法,有研究已证明K-means在CDA中具有较好的聚类效果。而谱聚类算法通常比K-means分类效果更佳,本研究将谱聚类算法引进CDA,探讨了属性层级结构、属性个数、样本量和失误率对该方法的影响。研究发现:(1)谱聚类算法要比K-means提供更好的聚类结果,尤其在实验条件较苛刻时,谱聚类算法更加稳健;(2)线型结构聚类效果最好,收敛型和发散型相近,独立型结构表现较差;(3)属性个数和失误率增加后,聚类效果会下降;(4)样本量增加后,聚类效果有所提升,但K-means方法有时会有反向结果出现。 相似文献
116.
William D. Nietmann 《World Futures: Journal of General Evolution》2013,69(1-2):59-84
In this paper, we present a new approach to improve the performance of a genetic algorithm. This approach sheds a new light on the concept of identity in a biomimetic system. We argue that introducing redundancy at the component level emphasizes the identity of the system. Then we present the Dynamic Logic of Contradiction elaborated by the philosopher Stephane Lupasco and we show how it relates to our proposition. This correlation allows us to give a meaning to the concept of identity. 相似文献
117.
David Maldavsky 《The International journal of psycho-analysis》2003,84(3):607-635
Systematic research on language has a solid starting point in Freudian hypotheses on sexuality. This theory is the semantic ground for categorising narrations and providing a basis for the research method. The author places his research in the frame of the systematisation of the Freudian theory of substitute formations in the preconscious. He affirms that these formations are influenced in a particular way by each variant of sexuality. The author proposes an inventory (in Freudian terms) of those variants of sexuality, and he affirms that they can be detected in the discourse. Five universal scenes having the status of a canon, with specific features for each of the ways in which sexuality is manifested, make up narrations. The author describes the features of each narration and provides some examples. He also examines problems related to the use of the method (the coexistence of different variants of sexuality in a single fragment of a narration and the successive steps in the use of the method). The author briefly considers some other problems: the analysis of defences, the study of words and theoretical research. Finally, he examines the validity and reliability of the method. 相似文献
118.
Motivated by specialization (lateralization) that occurs in corresponding left and right regions of the cerebral cortex, several past computational models have studied conditions under which functional specialization can arise during learning due to underlying asymmetries in paired neural networks. However, these past studies have not addressed the basic issue of how such underlying asymmetries arise in the first place. As an initial step in addressing this issue, we investigated the hypothesis that underlying asymmetries will appear in paired neural networks during a simulated evolutionary process when fitness is based not only on maximizing performance, but also on minimizing various ‘costs’ such as energy consumption, neural connection weights, and response times. Simulated evolution under these conditions consistently produced networks with left–right asymmetries in region size, excitability and plasticity. These underlying asymmetries were often synergistic, leading to subsequent functional lateralization during network training. While our computational models are too simple for these results to be directly extrapolated to real nervous systems, they provide support for the hypothesis that brain asymmetries and lateralization in biological nervous systems may be a consequence of cost minimization present during evolution, and are the first computational demonstration of emergent population lateralization. 相似文献
119.
By means of more than a dozen user friendly packages, structural equation models (SEMs) are widely used in behavioral, education,
social, and psychological research. As the underlying theory and methods in these packages are vulnerable to outliers and
distributions with longer-than-normal tails, a fundamental problem in the field is the development of robust methods to reduce
the influence of outliers and the distributional deviation in the analysis. In this paper we develop a maximum likelihood
(ML) approach that is robust to outliers and symmetrically heavy-tailed distributions for analyzing nonlinear SEMs with ignorable
missing data. The analytic strategy is to incorporate a general class of distributions into the latent variables and the error
measurements in the measurement and structural equations. A Monte Carlo EM (MCEM) algorithm is constructed to obtain the ML
estimates, and a path sampling procedure is implemented to compute the observed-data log-likelihood and then the Bayesian
information criterion for model comparison. The proposed methodologies are illustrated with simulation studies and an example.
The research described herein was fully supported by a grant (CUHK 4243/03H) from the Rearch Grants Council of the Hong Kong
Special Administration Region. The authors are thankful to the Editor, the Associate Editor, and anonymous reviewers for valuable
comments which improve the paper significantly, and are grateful to ICPSR and the relevant funding agency for allowing the
use of their data.
Requests for reprints should be sent to S. Y. Lee, Department of Statistics, The Chinese University of Hong Kong, Shatin,
N. T., Hong Kong. 相似文献
120.
The usage of video content has increased in past ten decades. As a result, increase in usage of commercial video coding standards called High Efficiency Video Coding (HEVC/H.265). A self-Adaptive N-depth Context Tree Weighting algorithm (SANDCTW) is proposed to overcome the limitations of Context tree weighting (CTW) method, which applied in CABAC know as Context Adaptive Binary Arithmetic Coding. This CABAC uses KT estimators and relies on beginning with the Bayesian approach to determine the true distribution of the next symbol to select for data compression. This approach is suitable only if the true distribution is stationary, the proposed SANDCTW that uses discounted KT estimators, which is suitable if the distribution is non-stationary and it reduces the computation and memory cost. Additionally, Block size sustained intra mode detection (BSSIMD) is proposed based on the mass-center and sub-sampling approach. In this approach, all correlation directions about the entire block associated to the intra-prediction mode and DC mode directions determined by using mass-center vector. Then, the modes corresponding to the determined directions selected as the best intra-prediction candidates during the intra-coding process for computing Rate-Distortion Optimization (RDO) with less complexity. The bit rate of 60–70 frames per second (fps) achieved in this technique based on the different block, size. Thus, the bit rate is also reduced significantly compared with the preceding H.265 standard. 相似文献