Error-voltage-based open-switch fault diagnosis strategy for matrix converters with model predictive control method

This paper proposes an error-voltage based open-switch fault diagnosis strategy for matrix converter (MC). A finite control set model predictive control (FCS-MPC) method is used to operate the MC. The MC system performances under normal operation and under a single open-switch fault operation are analyzed. A fault diagnosis strategy has also been implemented in two steps. First, the faulty phase is detected and identified based on a comparison of the reference and estimated output line-to-line voltages. Then, the faulty switch is located by considering the switching states of the faulty phase. The proposed fault diagnosis method is able to locate the faulty switch accurately and quickly without additional voltage sensors. Simulation and experimental results are presented to demonstrate the feasibility and effectiveness of the proposed strateg

Relationship between neonatal dacryocystitis and cesarean section and the treatment of neonatal dacryocystitis

AIM: To explore the treatment of neonatal dacryocystitis of different ages and the relationship between caesarean section and neonatal dacryocystitis.<p>METHODS: A total of 260 cases(260 eyes)of children with neonatal dacryocystitis were divided into 1-3 months group, 4-6 months group, 7-12 months group and 13-24 months group, Each group was respectively given the lacrimal sac massage, lacrimal passage irrigation and probing of lacrimal passage method. Curative effect of each method was observed in different groups. Analysis was made to determine whether caesarean section was the cause of neonatal dacryocystitis.<p>RESULTS: The comparison between 1-3 months group and 4-6 months group showed significant difference(<i>χ</i>²=19.89, <i>P</i><0.05). Lacrimal sac massage was effective for babies under 6 months, particularly in 1-3 months babies. The curative effect of lacrimal passage irrigation in four groups was compared, and there was statistical significance in the difference between the curative effect of each group(<i>χ</i>²=54.95, <i>P</i><0.05). The difference between the 1-3 months group and 4-6 months group was <i>χ</i>²=0.00003, <i>P</i>>0.05, lacrimal passage irrigation of these two groups showed no significant difference in efficacy. The comparison result between the other two groups showed no significant difference(<i>P</i><0.05), lacrimal passage irrigation effects are different from each group. The comparison result between 7-12 months group and 13-24 months group was <i>χ</i>²=10.29, <i>P</i><0.05. Infants born by cesarean section accounted for 85% of all cases. <p>CONCLUSION:Lacrimal sac massage can exert very good therapeutic effects in infants less than 3 months. The curative effects of irrigation of lacrimal passage are quite good in babies under 12 months. Probing of lacrimal passage has a good curative effect in 7-12 months infants, but a poor curative effect in babies over 12 months. Caesarean section is an important cause for neonatal dacryocystitis

Molecular Cloning and Functional Characterization of the Dehydrin (IpDHN) Gene From Ipomoea pes-caprae

Dehydrin (DHN) genes can be rapidly induced to offset water deficit stresses in plants. Here, we reported on a dehydrin gene (IpDHN) related to salt tolerance isolated from Ipomoea pes-caprae L. (Convolvulaceae). The IpDHN protein shares a relatively high homology with Arabidopsis dehydrin ERD14 (At1g76180). IpDHN was shown to have a cytoplasmic localization pattern. Quantitative RT-PCR analyses indicated that IpDHN was differentially expressed in most organs of I. pes-caprae plants, and its expression level increased after salt, osmotic stress, oxidative stress, cold stress and ABA treatments. Analysis of the 974-bp promoter of IpDHN identified distinct cis-acting regulatory elements, including an MYB binding site (MBS), ABRE (ABA responding)-elements, Skn-1 motif, and TC-rich repeats. The induced expression of IpDHN in Escherichia coli indicated that IpDHN might be involved in salt, drought, osmotic, and oxidative stresses. We also generated transgenic Arabidopsis lines that over-expressed IpDHN. The transgenic Arabidopsis plants showed a significant enhancement in tolerance to salt/drought stresses, as well as less accumulation of hydrogen peroxide (H2O2) and the superoxide radical (O2−), accompanied by increasing activity of the antioxidant enzyme system in vivo. Under osmotic stresses, the overexpression of IpDHN in Arabidopsis can elevate the expression of ROS-related and stress-responsive genes and can improve the ROS-scavenging ability. Our results indicated that IpDHN is involved in cellular responses to salt and drought through a series of pleiotropic effects that are likely involved in ROS scavenging and therefore influence the physiological processes of microorganisms and plants exposed to many abiotic stresses

How to Achieve Efficiency and Accuracy in Discrete Element Simulation of Asphalt Mixture: A DRF-Based Equivalent Model for Asphalt Sand Mortar

The clump-based discrete element model is one of the asphalt mixture simulation methods, which has the potential to not only predict mixture performance but also simulate particle movement during compaction, transporting, and other situations. However, modelling of asphalt sand mortar in this method remains to be a problem due to computing capacity. Larger-sized balls (generally 2.0-2.36 mm) were usually used to model the smaller particles and asphalt binder, but this replacement may result in the mixture\u27s unrealistic volumetric features. More specifically, replacing original elements with equal volume but larger size particles will increase in buck volume and then different particle contacting states. The major objective of this research is to provide a solution to the dilemma situation through an improved equivalent model of the smaller particles and asphalt binders. The key parameter of the equivalent model is the diameter reduction factor (DRF), which was proposed in this research to minimize the effects of asphalt mortar\u27s particle replacement modelling. To determine DRF, the DEM-based analysis was conducted to evaluate several mixture features, including element overlap ratio, ball-wall contact number, and the average wall stress. Through this study, it was observed that when the original glued ball diameters are ranging from 2.00 mm and 2.36 mm, the diameter reduction factor changes from 0.82 to 0.86 for AC mixtures and 0.80 to 0.84 for SMA mixtures. The modelling method presented in this research is suitable not only for asphalt mixtures but also for the other particulate mix with multisize particles

Montage: a grid portal and software toolkit for science-grade astronomical image mosaicking

Montage is a portable software toolkit for constructing custom, science-grade mosaics by composing multiple astronomical images. The mosaics constructed by Montage preserve the astrometry (position) and photometry (intensity) of the sources in the input images. The mosaic to be constructed is specified by the user in terms of a set of parameters, including dataset and wavelength to be used, location and size on the sky, coordinate system and projection, and spatial sampling rate. Many astronomical datasets are massive, and are stored in distributed archives that are, in most cases, remote with respect to the available computational resources. Montage can be run on both single- and multi-processor computers, including clusters and grids. Standard grid tools are used to run Montage in the case where the data or computers used to construct a mosaic are located remotely on the Internet. This paper describes the architecture, algorithms, and usage of Montage as both a software toolkit and as a grid portal. Timing results are provided to show how Montage performance scales with number of processors on a cluster computer. In addition, we compare the performance of two methods of running Montage in parallel on a grid.Comment: 16 pages, 11 figure