Wyniki wyszukiwania - BazTech

1

An estimation of large-signal stability for the bilinear DC-DC converters

Liu S., Zhou L., Lu W.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

262--265

EN

An approach to the analysis of large-signal stability of a Boost converter via the small-signal loop gains is presented. The large-signal stable region of the small-signal designed bilinear Boost converter is estimated in light of the Input-output stability concept. By doing so, the effects of small-signals on large-signal stability are revealed. The effectiveness of the presented approach is verified by simulations and good agreement is reported.

PL

Zaprezentowano analizę stabilności przekształtnika DC-DC typu Boost dla dużych sygnałów. Porównano pracę dla małych i dużych sygnałów i porównano stabilność układów.

2

Feature Words Selection for Knowledge-based Word Sense Disambiguation with Syntactic Parsin

Lu W., Huang H., Zhu C.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 1b

82-87

EN

Feature words are crucial clues for word sense disambiguation. There are two methods to select feature words: window-based and dependency-based methods. Both of them have some shortcomings, such as irrelevant noise words or paucity of feature words. In order to solve the problems of the existing methods, this paper proposes two methods to select feature words with syntactic parsing, which are based on phrase structure parsing tree (PTree) and dependency parsing tree (DTree). With the help of syntactic parsing, the proposed methods can select feature words more accurately, which can alleviate the effect of noise words of window-based method and can avoid the paucity of feature words of dependency-based method. Evaluation is performed on a knowledge-based WSD system with a publicly available lexical sample dataset. The results show that both of the proposed methods are superior to window-based and dependency-based methods, and the method based on PTree is better than the method based on DTree. Both of them are preferred strategies to select feature words to disambiguate ambiguous words.

PL

W artykule zaproponowano dwie metody selekcji cech słowa bazujące na analizie składni struktury frazy oraz analizie składni zależności. Badania przeprowadzono przy wykorzystaniu rożnych baz danych. Proponowana metoda ma większą dokładność niż dotychczas stosowane metody: okna i zależności.

3

Solution of some problems of single-scale wavelet transform processor using a magnetostatic surface wave device

Lu W., Kuang L., Lü X., Zhu C., Zhang T., Zhang J.

Metrology and Measurement Systems

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2012

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Vol. 19, nr 4

685-692

EN

In this paper, we investigate the implementation schemes of a single-scale wavelet transform processor using magnetostatic surface wave (MSSW) devices. There are three implementation schemes: the interdigital transducer, the meander line transducer and the grating transducer. Because the interdigital transducer has excellent properties, namely, good frequency characteristic and low insertion loss, we use the interdigital transducer as the implementation scheme of a single-scale wavelet transform processor using MSSW device. In the paper, we also present the solutions to the three key problems: the direct coupling between the input transducer and the output transducer, the insertion loss, and the loss characteristics of the gyromagnetic film having an influence on the wavelet transform processor. There are two methods of reducing the direct coupling between the input transducer and the output transducer: increasing the distance between the input transducer and the output transducer, and placing a metal "wall" between the input transducer and the output transducer. There also are two methods of reducing the insertion loss of a single-scale wavelet transform processor using a MSSW device for scale: the appropriate thickness of the yttrium iron garnet (YIG) film and the uniform magnetic field. The smaller the ferromagnetic resonance linewidth of the gyromagnetic film, the smaller the magnetostatic wave propagation loss.

4

Development of an HPLC fingerprint for quality control and species differentiation of Uncaria rhynchophylla (Miq.) ex Havil

Lu W., Yang F., Wang S.

Acta Chromatographica

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2012

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Vol. 24, no. 4

643--651

EN

The stems of Uncaria rhynchophylla (Miq.) ex Havil have a long history of use in traditional Chinese medicine to treat diseases and improve health. There is evident evidence that alkaloids constituents are mainly responsible for the beneficial effects of this plant medicine. The amounts of the major bioactive alkaloids in this plant vary widely with species, habitat, and as such, and establishment of a high-performance liquid chromatography (HPLC) fingerprint for quality control of this herbal medicine is of particular importance. The most alkaloids are used for medicine treatment and research. On the basis of the chromatographic data, a consistent HPLC fingerprint pattern containing 15 common peaks was obtained. Among these common peaks, four were identified as rhynchophylline, isorhynchophylline, corynoxeine, and isocorynoxeine. On the basis of this HPLC fingerprint and principal-components analysis, the quality of fifteen samples from different producing areas of China was objectively assessed. To summarize, the data described in this study offer valuable information for quality control and proper use of U. rhynchophylla (Miq.) ex Havil.