Wyniki wyszukiwania - Biblioteka Nauki

1

A Fast Classification Method of Faults in Power Electronic Circuits Based on Support Vector Machines

100%

Cui J. , Shi G. , Gong C.

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2017

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tom Vol. 24, nr 4

701--720

EN

Fault detection and location are important and front-end tasks in assuring the reliability of power electronic circuits. In essence, both tasks can be considered as the classification problem. This paper presents a fast fault classification method for power electronic circuits by using the support vector machine (SVM) as a classifier and the wavelet transform as a feature extraction technique. Using one-against-rest SVM and one-against-one SVM are two general approaches to fault classification in power electronic circuits. However, these methods have a high computational complexity, therefore in this design we employ a directed acyclic graph (DAG) SVM to implement the fault classification. The DAG SVM is close to the one-against-one SVM regarding its classification performance, but it is much faster. Moreover, in the presented approach, the DAG SVM is improved by introducing the method of Knearest neighbours to reduce some computations, so that the classification time can be further reduced. A rectifier and an inverter are demonstrated to prove effectiveness of the presented design.

2

Cadmium-induced alterations in morpho-physiology of two peanut cultivars differing in cadmium accumulation

100%

Zhang Z. , Liu C. , Wang X. , Shi G.

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2013

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tom 35

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nr 07

EN

This study examines differences in the morphophysiological responses of low- and high-cadmium (Cd) accumulating peanut (Arachis hypogaea L.) cultivars to Cd stress. The biomass, Cd accumulation, leaf gas exchange, root morphology, root respiration, and hydraulic conductivity of Qishan 208 (low-Cd accumulator) and Haihua 1 (high-Cd accumulator) were determined via a hydroponic experiment. Exposure of peanut plants to 2 and 20 μM Cd considerably decreased their shoot biomass, net photosynthetic rate, transpiration rate, stomatal conductance, total root length, number of root tips, root respiration, and hydraulic conductivity. The root biomass, root surface area, and average diameter were unaffected by Cd exposure. The two cultivars differed in Cd accumulation and morphophysiological responses to Cd stress. Qishan 208 accumulated less Cd in plant tissues but was more sensitive to Cd stress than Haihua 1. The total root length, surface area, average diameter, number of root tips, and root respiration rate of Haihua 1 were significantly higher than those of Qishan 208. The well-developed root system and higher root respiration of Haihua 1 may be responsible for its high Cd accumulation capacity.

3

The regulating function of heterotrimeric G proteins in the immune system

100%

Wang Y. , Li Y. , Shi G.

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nr 4

4

Numerical Study on Thermal Environment in Mine Gob Under Coal Oxidation Condition

100%

Wang Y. , Shi G. , Wang D.

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tom Vol. 20, nr 3

567--578

EN

The most feared of hazards in underground mines are those of fires and explosions. This study focuses on the temperature-rising process of residual coal under spontaneous combustion condition in coal mine gob. A numerical model has been established considering the chemical reaction, heat transfer and components seepage flow. The temperature distributions and maximum values for different positrons at various times have been calculated by using the coupled model. An experimental model has been also developed for model calibration. The validation indicates the numerical model is accurate and suitable for solving the temperature-rising problem in coalmines. The simulation results show that high temperature zone appears at the air intake roadway side in the gob and enlarging the ventilation flux increases the risk of self-ignition of coal. The research results can be used to predict the temperature-rising of coal spontaneous combustion and coal resources prevention.

PL

Pożary i wybuchy stanowią największe zagrożenia w kopalniach. Opisane w pracy badania dotyczą procesów powodujących wzrost temperatury resztkowego węgla, doprowadzający do jego samozapłonu, w odpadach z kopalni. Model numeryczny sformułowano, biorąc pod uwagę reakcje chemiczne, wymianę ciepła i przepływy składników. Rozkłady temperatury i maksymalne wartości w różnych położeniach i w różnych czasach zostały obliczone z użyciem modelu sprzężonego. Do kalibracji został również opracowany model doświadczalny. Walidacja wykazała, że model numeryczny jest dokładny i odpowiedni do rozwiązania problemu wzrostu temperatury w kopalniach węgla. Wyniki symulacji wskazują, że strefa podwyższonej temperatury pojawia się na szlakach wlotu powietrza do materiału i zwiększenie strumienia wentylującego zwiększa ryzyko samozapłonu węgla. Wyniki badań mogą być wykorzystane do przewidywania wzrostu temperatury grożącego samozapłonem węgla oraz do ochrony jego zasobów.

5

Physiological responses of Scirpus validus to nitrate stress

75%

Li X. , Li H. , Shi G. , Xiao M. , Li C. , Xie H.

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nr 1

6

Exceptionally well-preserved Early Cretaceous leaves of Nilssoniopteris from central Mongolia

75%

Herrera F. , Shi G. , Tsolmon G. , Ichinnorov N. , Takahashi M. , Crane P. R. , Herendeen P. S.

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2018

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tom 58

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nr 2

7

The mitochondria mediate the induction of NOX1 gene expression by aldosterone in an ATF-1-dependent manner

63%

Fu Y. , Shi G. , Wu Y. , Kawai Y. , Qing T. , Yue L. , Xia Q. , Miyamori I. , Fan C.

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2011

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tom 16

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nr 2

EN

High aldosterone (Ald) levels can induce hypertrophy of vascular smooth muscle cells (VSMCs), which carries high risks of heart failure. A previous study showed that Ald induces hypertrophy of VSMCs by up-regulating NOX1, a catalytic subunit of NADPH oxidase that produces superoxides. However, the precise mechanism remains unknown. Diphenylene iodonium (DPI) is known as an inhibitor of complex I in the mitochondrial respiratory chain, and it was also found to almost completely suppress the induction of NOX1 mRNA and the phosphorylation of activating transcription factor (ATF-1) by PGF2α or PDGF in a rat VSMC cell line. In this study, we found that the Ald-induced phosphorylation of ATF-1 and NOX1 expression was significantly suppressed by DPI. Silencing of ATF-1 gene expression attenuated the induction of NOX1 mRNA expression, and over-expression of ATF-1 restored Ald-induced NOX1 expression. On the basis of this data, we show that the mitochondria mediate aldosterone-induced NOX1 gene expression in an ATF-1-dependent manner.