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Number of results: 7
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Abstract

In this paper, the applications of the multivariate data analysis and optimization on vibration signals from compressors have been tested on the assembly line to identify nonconforming products. The multivariate analysis has wide applicability in the optimization of weather forecasting, agricultural experiments, or, as in this case study, in quality control. The techniques of discriminant analysis and linear program were used to solve the problem. The acceleration and velocity signals used in this work were measured in twenty-five rotating compressors, of which eleven were classified as good baseline compressors and fourteen with manufacturing defects by the specialists in the final acoustic test of the production line. The results obtained with the discriminant analysis separated the conforming and nonconforming groups with a significance level of 0.01, which validated the proposed methodology.
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Abstract

Even though the discrimination against women in science have been studied for at least half of the century and any many actions have been taken to promote careers of female researchers, their chances are still far from equal. Many barriers have disappeared, but increasingly precarious model of academic career makes it more difficult for women. The interviews conducted with laureates of prestigious competitions by the Foundation for Polish Science allowed for analysis of what Polish researchers think about the role of gender and parenthood in academic career. The have also served to identify factors that were crucial – according to the interviewed female scientists – for their success in science. As the interviews indicate, the requirements od academic career are the same in case of both: men and women, which could suggest lack of discrimination. On the other hand, the expectation that women will be able to meet the criteria set up by male experiences does not mean equal playing field. To assess real chances for academic success, other non-academic aspects of researchers’ life need to be taken into consideration, especially their limitations for dedicating time to research and for mobility. Young researchers – men as well as women – experience increasing uncertainty in regard to their academic future. Growing competition for employment and research funding, makes it much more difficult for women to fulfil the expectations of a fast-track, mobile career. The interviews formed the basis for identification of support mechanisms in this respect.
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Abstract

When the distribution of water quality samples is roughly balanced, the Bayesian criterion model of water-inrush source generally can obtain relatively accurate results of water-inrush source identification. However, it is often difficult to achieve desired classification results when training samples are imbalanced. Sample imbalance is common in the source identification of mine water-inrush. Therefore, we propose a three-dimensional (3D) spatial resampling method based on rare water quality samples, which achieves the balance of water quality samples. Based on the virtual water sample points distributed by the 3D grid, the method uses the 3D Inverse Distance Weighting (IDW) method to interpolate the groundwater ion concentration of the virtual water samples to achieve oversampling of rare water samples. Case study in Gubei Coal Mine shows that the method improves overall discriminant accuracy of the Bayesian criterion model by 5.26%, from 85.26% to 90.69%. In particular, the discriminative precision of the rare class is improved from 0% to 83.33%, which indicates that the method can improve the discriminant accuracy of the rare class to large extent. In addition, this method increases the Kappa coefficient of the model by 19.92%, from 52.26% to 72.19%, increasing the degree of consistency from “general” to “significant”. Our research is of significance to enriching and improving the theory of prevention and treatment of mine water damage.
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Abstract

The concept of family reunification is well established in contemporary migration laws, at both the national and international levels. Focusing on international and EU law, in this article I argue that while existing provisions on family reunification are formulated in neutral language, from the gender point of view the enforcement of these substantively neutral rules may, in certain situations, result in discrimination, or at least bring about negative consequences, with respect to women in cases both when they are the sponsors of migration or the bearers of consequences of male migration. Following presentation of the international legal framework on family reunification and the relevant international jurisprudence, I deal with some rather common aspects relating to the personal scope of family reunification regulations, covering only the issues of who can, and who cannot, join their family member(s)/sponsor(s) in a foreign country (i.e. the unmarried minor rule, excluded forms of marriages – polygamous and forced marriages - and age limits). Some procedural aspects of family reunification are then dealt with (waiting periods, delays in proceedings, and end of a relationship as a cause for termination of residence rights.). These issues are examined with respect to concerns that they may cause indirect, or even direct, gender discrimination in some cases, while in others they may affect women more negatively than men.
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Abstract

The paper provides statistical analysis of the photographs of four various granular materials (peas, pellets, triticale, wood chips). For analysis, the (parametric) ANOVA and the (nonparametric) Kruskal-Wallis tests were applied. Additionally, the (parametric) two-sample t-test and (non-parametric) Wilcoxon Rank-Sum Test for pairwise comparisons were performed. In each case, the Bonferroni correction was used. The analysis shows a statistical evidence of the presence of differences between the respective average discrete pixel intensity distributions (PID), induced by the histograms in each group of photos, which cannot be explained only by the existing differences among single granules of different materials. The proposed approach may contribute to the development of a fast inspection method for comparison and discrimination of granular materials differing from the reference material, in the production process.
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Abstract

An application specific integrated design using Quadrature Linear Discriminant Analysis is proposed for automatic detection of normal and epilepsy seizure signals from EEG recordings in epilepsy patients. Five statistical parameters are extracted to form the feature vector for training of the classifier. The statistical parameters are Standardised Moment, Co-efficient of Variance, Range, Root Mean Square Value and Energy. The Intellectual Property Core performs the process of filtering, segmentation, extraction of statistical features and classification of epilepsy seizure and normal signals. The design is implemented in Zynq 7000 Zc706 SoC with average accuracy of 99%, Specificity of 100%, F1 score of 0.99, Sensitivity of 98% and Precision of 100 % with error rate of 0.0013/hr., which is approximately zero false detection.
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Abstract

In Western music culture instruments have been developed according to unique instrument acoustical features based on types of excitation, resonance, and radiation. These include the woodwind, brass, bowed and plucked string, and percussion families of instruments. On the other hand, instrument performance depends on musical training, and music listening depends on perception of instrument output. Since musical signals are easier to understand in the frequency domain than the time domain, much effort has been made to perform spectral analysis and extract salient parameters, such as spectral centroids, in order to create simplified synthesis models for musical instrument sound synthesis. Moreover, perceptual tests have been made to determine the relative importance of various parameters, such as spectral centroid variation, spectral incoherence, and spectral irregularity. It turns out that the importance of particular parameters depends on both their strengths within musical sounds as well as the robustness of their effect on perception. Methods that the author and his colleagues have used to explore timbre perception are: 1) discrimination of parameter reduction or elimination; 2) dissimilarity judgments together with multidimensional scaling; 3) informal listening to sound morphing examples. This paper discusses ramifications of this work for sound synthesis and timbre transposition.
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