1,146 research outputs found
Three-phase four-leg flying-capacitor multi-level inverter-based active power filter for unbalanced current operation.
This study describes a new application of flying capacitor multi-level inverters whereby a three-phase, four-leg three-level inverter is used for harmonic current cancellation and unbalanced current compensation in a four-wire system. A direct three-dimensional-pulse-width modulation (3D-PWM) scheme is developed to deal with the increased state redundancy in the four-leg flying capacitor multi-level inverter. Test results show much superior performance in the four-leg case, which may allow the use of smaller DC supply capacitors. A new modified dead-beat current control algorithm is proposed and combined successfully with the 3D-PWM modulation technique in a hardware demonstrator of a complete active filter
NARROMI: a noise and redundancy reduction technique improves accuracy of gene regulatory network inference.
MOTIVATION: Reconstruction of gene regulatory networks (GRNs) is of utmost interest to biologists and is vital for understanding the complex regulatory mechanisms within the cell. Despite various methods developed for reconstruction of GRNs from gene expression profiles, they are notorious for high false positive rate owing to the noise inherited in the data, especially for the dataset with a large number of genes but a small number of samples.
RESULTS: In this work, we present a novel method, namely NARROMI, to improve the accuracy of GRN inference by combining ordinary differential equation-based recursive optimization (RO) and information theory-based mutual information (MI). In the proposed algorithm, the noisy regulations with low pairwise correlations are first removed by using MI, and the redundant regulations from indirect regulators are further excluded by RO to improve the accuracy of inferred GRNs. In particular, the RO step can help to determine regulatory directions without prior knowledge of regulators. The results on benchmark datasets from Dialogue for Reverse Engineering Assessments and Methods challenge and experimentally determined GRN of Escherichia coli show that NARROMI significantly outperforms other popular methods in terms of false positive rates and accuracy.
AVAILABILITY: All the source data and code are available at: http://csb.shu.edu.cn/narromi.htm
Dynamic and Postdeformation Recrystallization of Nuclear-Grade 316LN Stainless Steel
Nuclear-grade 316LN stainless steel was subjected to single and double compressions at 1173β1473 K and strain rates of 0.01β10 sβ»ΒΉ. The dynamic and postdeformation recrystallization was investigated through analysis of the stressβstrain curves and microstructure evolution. The thermal deformation equation and the quantitative relationships between the critical stress for the initiation of dynamic recrystallization and the ZenerβHollomon parameter, Z, and between the dynamic recrystallization grain size D and Z were derived. Dynamic recrystallization developed through an ordinary mechanism at low Z values and through a necklace mechanism at high Z values, with a critical Z value of about 3.6 10ΒΉβΆ . At 1273β1473 K, softening of 316LN stainless steel after deformation was characterized by an Avrami-type equation, where the Avrami parameter, n, has no appreciable temperature dependence, and an average value of n and the activation energy, Qrex , were 0.68 and 129 kJ/mol, respectively.ΠΠ΅ΡΠΆΠ°Π²Π΅ΡΡΠ°Ρ ΡΡΠ°Π»Ρ 316LN ΡΠ΄Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΊΠ»Π°ΡΡΠ° ΠΏΠΎΠ΄Π²Π΅ΡΠ³Π°Π»Π°ΡΡ ΠΎΠ΄Π½ΠΎ- ΠΈ Π΄Π²ΡΠΊΡΠ°ΡΠ½ΠΎΠΌΡ ΡΠΆΠ°ΡΠΈΡ ΠΏΡΠΈ 1173...1473 Π ΠΈ ΡΠΊΠΎΡΠΎΡΡΠΈ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ 0,01...10 Ρβ»ΒΉ. ΠΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠ°Ρ ΠΈ ΠΏΠΎΡΡΠ΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ΅ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΠ·Π°ΡΠΈΡ ΠΈΠ·ΡΡΠ°Π»Π°ΡΡ Ρ ΠΏΠΎΠΌΠΎΡΡΡ Π°Π½Π°Π»ΠΈΠ·Π° Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΎΡ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΡ ΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΌΠΈΠΊΡΠΎΡΡΡΡΠΊΡΡΡΡ. ΠΡΠ»ΠΈ Π²ΡΠ²Π΅Π΄Π΅Π½Ρ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ ΡΠ΅ΠΏΠ»ΠΎΠ²ΠΎΠΉ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΈ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠ΅ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΈΠΌ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠ΅ΠΌ ΠΈΠ½ΠΈΡΠΈΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΈ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠΌ ΠΠ΅Π½Π΅ΡΠ° Π₯ΠΎΠ»Π»ΠΎΠΌΠΎΠ½Π° Z, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΌΠ΅ΠΆΠ΄Ρ ΡΠ°Π·ΠΌΠ΅ΡΠΎΠΌ Π·Π΅ΡΠ½Π° D ΠΏΡΠΈ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΈ Z. ΠΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΠ΅ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΠ·Π°ΡΠΈΡ ΡΠ°Π·Π²ΠΈΠ²Π°Π»Π°ΡΡ ΠΏΠΎ ΠΎΠ±ΡΡΠ½ΠΎΠΌΡ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΡ ΠΏΡΠΈ Π½ΠΈΠ·ΠΊΠΈΡ
Π·Π½Π°ΡΠ΅Π½ΠΈΡΡ
Z ΠΈ ΠΏΠΎ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΡ ΠΎΠΆΠ΅ΡΠ΅Π»ΡΡ ΠΏΡΠΈ Π²ΡΡΠΎΠΊΠΈΡ
Π·Π½Π°ΡΠ΅Π½ΠΈΡΡ
Z, ΠΏΡΠΈ ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠΌ Π·Π½Π°ΡΠ΅Π½ΠΈΠΈ Z ΠΏΡΠΈΠΌΠ΅ΡΠ½ΠΎ 3 6 10ΒΉβΆ. ΠΡΠΈ 1273...1473 Π ΡΠ°Π·ΡΠΏΡΠΎΡΠ½Π΅Π½ΠΈΠ΅ Π½Π΅ΡΠΆΠ°Π²Π΅ΡΡΠ΅ΠΉ ΡΡΠ°Π»ΠΈ 316LN ΠΏΠΎΡΠ»Π΅ Π΄Π΅ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΠΏΠΈΡΡΠ²Π°Π΅ΡΡΡ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ΠΌ ΠΠ²ΡΠ°ΠΌΠΈ, Π³Π΄Π΅ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡ ΠΠ²ΡΠ°ΠΌΠΈ n Π½Π΅ ΠΏΡΠΎΡΠ²Π»ΡΠ΅Ρ Π²ΡΡΠ°ΠΆΠ΅Π½Π½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½ΠΎΠΉ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ, Π° Π΅Π³ΠΎ ΡΡΠ΅Π΄Π½Π΅Π΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΠΈ ΡΠ½Π΅ΡΠ³ΠΈΡ Π°ΠΊΡΠΈΠ²Π°ΡΠΈΠΈ Qrex ΡΠΎΡΡΠ°Π²Π»ΡΡΡ 0,68 ΠΈ 129 ΠΊΠΠΆ/ΠΌΠΎΠ»Ρ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎ
Kondo spin liquid and magnetically long-range ordered states in the Kondo necklace model
A simplified version of the symmetric Kondo lattice model, the Kondo necklace
model, is studied by using a representation of impurity and conduction electron
spins in terms of local Kondo singlet and triplet operators. Within a mean
field theory, a spin gap always appears in the spin triplet excitation spectrum
in 1D, leading to a Kondo spin liquid state for any finite values of coupling
strength (with as hopping and as exchange); in 2D and 3D cubic
lattices the spin gaps are found to vanish continuously around and , respectively, where quantum phase transitions
occur and the Kondo spin liquid state changes into an antiferromagnetically
long-range ordered state. These results are in agreement with variational Monte
Carlo, higher-order series expansion, and recent quantum Monte Carlo
calculations for the symmetric Kondo lattice modelComment: Revtex, four pages, three figures; to be published in Physical Review
B1, 1 July (2000
Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV
By analyzing the data sets of 17.3 pb taken at GeV
and 6.5 pb taken at GeV with the BESII detector at the
BEPC collider, we have measured the observed cross sections for 12 exclusive
light hadron final states produced in annihilation at the two energy
points. We have also set the upper limits on the observed cross sections and
the branching fractions for decay to these final states at 90%
C.L.Comment: 8 pages, 5 figur
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