Strong Cosmic Censorship in Charged de Sitter spacetime with Scalar Field Non-minimally Coupled to Curvature

We examine the stability and the strong cosmic censorship in the Reissner-Nordstrom-de Sitter (RN-dS) black hole by investigating the evolution of a scalar field non-minimally coupled to the curvature. We find that when the coupling parameter is negative, the RN-dS black hole experiences instability. The instability disappears when the coupling parameter becomes non-negative. With the increase of the coupling parameter, the violation of the strong cosmic censorship occurs at a larger critical charge ratio. But such an increase of the critical charge is suppressed by the increase of the cosmological constant. Different from the minimal coupling situation, it is possible to accommodate $\beta\ge1$ in the near extremal black hole when the scalar field is non-minimally coupled to curvature. The increase of the cosmological constant can allow $\beta\ge1$ to be satisfied for even smaller value of the coupling parameter. The existence of $\beta\ge1$ implies that the resulting curvature can continuously cross the Cauchy horizon.Comment: 14 pages, 4 figures, 5 table

Rotor fault diagnosis based on wavelet packet energy spectrum and adaptive fuzzy weighted support vector machine

In this study, a novel application of a wavelet packet energy-weighted support vector machine (WPE-WSVM) is proposed to perform fault classification of helicopter rotor. Because the helicopter rotor fault signal is weak, it is difficult to extract fault feature. The wavelet package is adopted to decompose the vibration signals on the fuselage into different frequency bands, and to eliminate the noise. And then single signal was reconstructed to extract the energy in each frequency band serving as fault feature vectors. And support vector machine was applied for classifying the failure mode of the helicopter rotor. For classification task support vector machine is used due to its good robustness and generalization performances. But the classification accuracy of standard support vector machine is relative slow when the number of samples of different classes is dramatically different. So a fuzzy weighted support vector machine was proposed, which added weight coefficient to samples of different classes. A comparative analysis of standard support vector machine and proposed fuzzy weighted support vector machine is done. The proposed fuzzy weighted support vector machine improved the classification accuracy of class with fewer samples. The proposed method is sufficiently accurate, fast, and robust, which makes it suitable for use in helicopter rotor fault diagnosis applications

Evaluation of anti-hyperglycemic activities of phloridzin in diabetic mice

Background: The aim of the study was to investigate the hypoglycemic effects of Phloridzin.Methods and Materials: High fat diet induced diabetic KKAy mice were administered with phloridzin at an oral dose (60 mg/kg/day, ig.) for 10 weeks. A range of parameters, including blood glucose and lipid, serum insulin, glucose tolerance, were tested to evaluate its anti-hyperglycemic effects.Results: Phloridzin decreased water-intake, body weight, FBG, FINS, HOME-IR, Serum leptin, and CRP levels, increased serum adiponectin level in diabetic mice. Phloridzin also improved the oral glucose tolerance test (OGTT) to a certain degree. In addition, phloridzin decreased liver index, and epididymal, perirenal white adipose tissue indexs, increased pancreas index in diabetic mice. At last, phloridzin increased hepatic GK activity and hepatic glycogen level, decreased hepatic PEPCK, G-6-Pase activities in diabetic mice.Conclusions: Phloridzin possessed anti-hyperglycemic activities.Keywords: Diabetes, Phloridzin, FBG, Insulin resistance, Area under curv