6,704 research outputs found

    Provenance of Leon Idzykovsky’s book collection as a source of historical and bibliological research

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    Висвітлено значення провенієнцій як історичного джерела в реконструкції бібліотечних фондів історичних бібліотек. Охарактеризовано різновиди провенієнцій, які розкривають шляхи формування та організацію книгозбірні Леона Ідзіковського та є важливим джерелом при виявленні та реконструкції цього книжкового зібрання.The article deals with provenance as a source of historical and bibliological research. Compiled has been the list of provenance on the books from Leon Idzykovsky’s books collection. The author studies the role of provenance in the reconstruction of library collections

    An Ensemble of Optimal Trees for Classification and Regression (OTE)

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    Predictive performance of a random forest ensemble is highly associated with the strength of individual trees and their diversity. Ensemble of a small number of accurate and diverse trees, if prediction accuracy is not compromised, will also reduce computational burden. We investigate the idea of integrating trees that are accurate and diverse. For this purpose, we utilize out-of-bag observation as validation sample from the training bootstrap samples to choose the best trees based on their individual performance and then assess these trees for diversity using Brier score. Starting from the first best tree, a tree is selected for the final ensemble if its addition to the forest reduces error of the trees that have already been added. A total of 35 bench mark problems on classification and regression are used to assess the performance of the proposed method and compare it with kNN, tree, random forest, node harvest and support vector machine. We compute unexplained variances and classification error rates for all the methods on the corresponding data sets. Our experiments reveal that the size of the ensemble is reduced significantly and better results are obtained in most of the cases. For further verification, a simulation study is also given where four tree style scenarios are considered to generate data sets with several structures

    Variation of electric shielding on virtual Frisch-grid detectors

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    Because of the low mobility of holes, CdZnTe (CZT) detectors operate as electron-transport-only type devices whose particular geometrical parameters and contacts configurations are specially chosen to minimize the contribution of uncollected holes into the output signal amplitudes (induction effect). Several detector configurations have been proposed to address this problem. One of them employs a large geometrical aspect ratio, parallelepiped-shaped crystal with two planar contacts on the top and bottom surfaces (anode and cathode) and an additional shielding electrode placed on a crystal\u27s side to create the virtual Frisch-grid effect. We studied the effect of the shielding electrode length, as well as its location, on the responses of 6 x 6 x 15 mm(3) virtual Frisch-grid detectors. We found that the length of the shielding electrode placed next to the anode can be reduced to 5 mm with no adverse effects on the device performance. Meanwhile, this allows for charge loss correction by reading the cathode signal
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