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Clock synchronization is a very important issue for the applications of wireless sensor networks. The sensors need to keep a strict clock so that users can know exactly what happens in the monitoring area at the same time. This paper proposes a novel internal distributed clock synchronization solution using group neighborhood average. Each sensor node collects the offset and skew rate of the neighbors. Group averaging of offset and skew rate value are calculated instead of conventional point-to-point averaging method. The sensor node then returns compensated value back to the neighbors. The propagation delay is considered and compensated. The analytical analysis of offset and skew compensation is presented. Simulation results validate the effectiveness of the protocol and reveal that the protocol allows sensor networks to quickly establish a consensus clock and maintain a small deviation from the consensus clock. [ABSTRACT FROM AUTHOR]

This paper presents a reference function based 3D FLC design methodology using support vector regression (SVR) learning. The concept of reference function is introduced to 3D FLC for the generation of 3D membership functions (MF), which enhance the capability of the 3D FLC to cope with more kinds of MFs. The nonlinear mathematical expression of the reference function based 3D FLC is derived, and spatial fuzzy basis functions are defined. Via relating spatial fuzzy basis functions of a 3D FLC to kernel functions of an SVR, an equivalence relationship between a 3D FLC and an SVR is established. Therefore, a 3D FLC can be constructed using the learned results of an SVR. Furthermore, the universal approximation capability of the proposed 3D fuzzy system is proven in terms of the finite covering theorem. Finally, the proposed method is applied to a catalytic packed-bed reactor and simulation results have verified its effectiveness. [ABSTRACT FROM AUTHOR]

The article focuses on liquid crystal polymer (LCP) substrates fabricated with microstrip ultra-wideband bandpass filter (UWB BPF) with ultra-fine conductor traces. LCP materials with unique properties between the crystalline and amorphous polymers like minimal and consistent dimensional stability variation, low coefficient of hygroscopic expansion, high heat resistance is considered to be promising substrates for wireless applications. Prior to fabrication, the LCP surfaces were pretreated by oxygen using Vacute Reactive Ion Etcher (RIE). Fabrication of UWB BPF was done by photolithography and wet etching by the use of ammonium persulfate as etching solution. The UWB BPF fabricated LCP surface showed better performance due to adequate adhesion of ultra-fine conductor traces.

A novel and compact millimeter-wave microstrip ultra-wideband bandpass filter working over 22–29-GHz band based on liquid crystal polymer substrates for automotive radar systems is developed for the first time in this article. By using a dual-mode ring resonator and novel parallel-coupled input/output feed structure, an ultra-wideband bandpass filter is realized. After optimization of the design and process, the filter is fabricated on liquid crystal polymer substrates using standard processing technology. Simulations and measurements are compared and discussed. The fabricated filter exhibits a return loss lever better than 20 dB, an insertion loss of 8 dB, and a 3-dB bandwidth of 25%, which agreed well with simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2276–2280, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23634 [ABSTRACT FROM AUTHOR]

In response to the strong coupling between line-of-sight angular rate and attitude error in the output of the strapdown rotating projectile, a method based on adaptive fading volume covariance Kalman filtering (AFCKF) is proposed. To achieve the decoupling of line-of-sight angular rate, the relative motion characteristics of missile and target are considered. A state model is constructed, which includes an estimation model of line-of-sight angular rate in the terminal guidance phase, and a measurement model including line-of-sight angle and attitude angular is established based on geometric relationships. To solve the problem of filter failure caused by the divergence of the line-of-sight angular rate estimation results in traditional CKF for rotating projectile, a fading factor based on residual sequence is introduced to adjust the predicted state covariance for quick convergence of the estimation results. To verify the effectiveness of AFCKF, typical interferences of attitude angle and measurement angle are considered. Simulation results show that the mean estimation errors of line-of-sight elevation rate and azimuth rate of the proposed method are 30.41% and 42.18% of the traditional EKF, respectively, effectively improving the accuracy of line-of-sight angular rate estimation for rotating projectil

The Gangdese belt of the southern Lhasa terrane (southern Tibet) records a Chilean-type accretionary orogeny driven by subduction of Neotethyan oceanic lithosphere, prior to Indo-Asian collision and formation of the Tibetan Plateau. We present detailed structural analysis of outcrops and a drill core in the Jiama copper ore district along with 40Ar-39Ar cooling ages from white mica, plagioclase, and potassium feldspar and zircon U-Pb geochronology of granitoids and sandstone. These data add new constraints to the formation of a major angular unconformity, deformation along and within the footwall of the Gangdese décollement, and the coupling between deformation and magmatism. Structural analysis indicates that top- to- the-south motion along the décollement produced south-vergent folding and thrusting of Upper Jurassic to Cretaceous strata in the Gangdese back-arc basin. A synthesis of new and compiled age data reveals that the décollement and associated south-vergent deformation occurred between ca. 90 and 65 Ma, contemporaneous with the formation of a major ca. 85-69 Ma angular unconformity between the overlying Paleocene-Eocene Linzizong Formation and the underlying Upper Cretaceous Shexing Formation. We posit that this deformation in the Gangdese belt resulted from flat-slab subduction of the Neotethyan oceanic slab beneath the southern margin of the Asian continent. A flat-slab subduction geometry is consistent with previously documented synchronous thrusting in the forearc and back-arc basins as well as the observed arc magmatic lull of the Gangdese belt between ca. 80 and 65 Ma. [ABSTRACT FROM AUTHOR]

A series of new biaryloxazolidinone derivatives has been designed and synthesized using the combination principle and blocking metabolic site to improve their antibacterial activity and stability. Apart from the excellent antibacterial profile against S. aureus (MIC = 0.25 mg mL-1), MRSA (MIC = 0.25 mg mL-1), LREF (MIC = 0.031 mg mL-1), VRE (MIC = 0.031 mg mL-1), GBS (MIC = 0.031 mg mL-1), and Spn (MIC = 0.031 mg mL-1), compound 13b-6 also displayed good stability and safety, excellent rat PK profile with long half-life time (T1/2 = 17.7 h), and moderate plasma exposure (AUC0-t = 74.4 ng mL-1). [ABSTRACT FROM AUTHOR]

This paper proposes a damage detection method based on an improved DAS imaging algorithm by introducing time difference due to anisotropy of composite material. First, the finite element characteristic frequency method is used to obtain the dispersion curve of the composite plate, and the validity of the dispersion curve is verified. Next, the average phase velocity of the Lamb wave at mixed modes in the composite plate is obtained by two-dimensional Fourier transform (2-D FFT). The mixed modal group velocity is calculated according to the corresponding phase velocity, the mean change rate of the phase velocity and the dispersion curve obtained by simulation. The time difference due to anisotropy of composite material is investigated, and the damage location is estimated by the delay-and-sum (DAS) imaging algorithm. Experiments on carbon fiber multilayer composite plates verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

• A baseline-free time reversal probabilistic imaging algorithm is proposed. • The focusing mechanism of wave source is used to eliminate the dispersion Lamb wave. • The relative distance is used to adjust the weight distribution function. • The proposed algorithm can accurately identify and locate multiple damages. Active ultrasonic guided wave is considered to be the most effective and important on-line damage monitoring method for industrial steel plates structure health monitoring. Aiming at the problem of poor practicability of extracting damage scattering signal from baseline signal, a baseline-free time reversal probabilistic imaging algorithm (BFTRPI algorithm) is proposed in this paper based on ultrasound guided waves time reversal theory and probability statistics principle. Firstly, the time reversal of signal and the adaptive focusing mechanism of wave source are used to eliminate the dispersion effect of Lamb wave by the multi-sensor network. Secondly, the energy characteristic difference coefficient between the reconstructed Lamb wave signal and the original excitation signal, is taken as the damage factor. Finally, the relative distance between the damage and the direct path of the sensor-actuator channel is used to adjust the weight distribution function. The weighted probabilistic values of each sensor path in the sensor network are mapped to the discrete coordinates in the detection area, and the probabilistic imaging of the damage appearing on these discrete coordinates is constructed for multiple damages imaging and location. Experiments on aluminium sheets show that the method can clearly separate the damage scattering signals without baseline signals, achieve the focus of the original excitation signal, and obtain the damage probability images of structure. Compared to traditional probability distribution function method, it has better imaging accuracy and imaging quality. The positioning accuracy of the BFTRPI algorithm is obviously higher than that of traditional algorithm. The estimated position by BFTRPI algorithm is more close to the actual damage position. The location area of damage and artifact for traditional algorithm are both higher than that of BFTRPI algorithm. This method can accurately identify and locate multiple damages in aluminium sheet, which verifies the validity of this method and has certain engineering application value. [ABSTRACT FROM AUTHOR]

Imaging for damage in plate structure by Lamb waves is one of the most effective methods in the field of structural health monitoring. In order to improve the accuracy of damage localization, a novel method is proposed to modify damage exponent probability imaging algorithm based on delay-and-sum imaging by using time reversal Lamb waves. A new probability distribution function is introduced to improve the damage index probability method and is combined with delay-and-sum method for damage localization. Experimental results on aluminum plate show that the hybrid algorithm achieves better accuracy of damage location and imaging quality than the conventional delay-and-sum method. [ABSTRACT FROM AUTHOR]

Single nucleotide polymorphisms (SNPs) are widely used in functional genomics and genetics research work. The high-quality sequence of rice genome has provided a genome-wide SNP and proteome resource. However, the impact of SNPs on protein phosphorylation status in rice is not fully understood. In this paper, we firstly updated rice SNP resource based on the new rice genome Ver. 7.0, then systematically analyzed the potential impact of Non-synonymous SNPs (nsSNPs) on the protein phosphorylation status. There were 3,897,312 SNPs in Ver. 7.0 rice genome, among which 9.9% was nsSNPs. Whilst, a total 2,508,261 phosphorylated sites were predicted in rice proteome. Interestingly, we observed that 150,197 (39.1%) nsSNPs could influence protein phosphorylation status, among which 52.2% might induce changes of protein kinase (PK) types for adjacent phosphorylation sites. We constructed a database, SNP_rice, to deposit the updated rice SNP resource and phosSNPs information. It was freely available to academic researchers at http://bioinformatics.fafu.edu.cn. As a case study, we detected five nsSNPs that potentially influenced heterotrimeric G proteins phosphorylation status in rice, indicating that genetic polymorphisms showed impact on the signal transduction by influencing the phosphorylation status of heterotrimeric G proteins. The results in this work could be a useful resource for future experimental identification and provide interesting information for better rice breeding. [ABSTRACT FROM AUTHOR]

The article presents a study that determines how transgenic shRNA pigs offers viable tool for producing animals with enhanced resistance to foot and mouth disease virus (FMDV) infection.