A modified QP-free feasible method

AbstractIn this paper, we presented a modified QP-free filter method based on a new piecewise linear NCP functions. In contrast with the existing QP-free methods, each iteration in this algorithm only needs to solve systems of linear equations which are derived from the equality part in the KKT first order optimality conditions. Its global convergence and local superlinear convergence are obtained under mild conditions

Surface-to-surface calibration of acoustic emission sensors

Acoustic emission (AE) testing is widely employed in robotics technologies due to its non-destructive property. As the major component of AE testing, the AE sensor significantly affects the accuracy and reliability of testing results. To improve the performance of AE testing, it is essential to calibrate the sensitivity of AE sensors in frequency domain. Based on the concept of relative calibration, this paper proposes a surface-to-surface calibration method for AE sensors. This method can obtain the frequency response of AE sensors point by point and the sensitivity in various frequency bandwidths simultaneously. A prototype system is designed and experiments are conducted on the systems with AE sensors. The measurement result is consistent with that obtained with the result from Physical Acoustics Corporation (PAC). To further improve the testing accuracy of the proposed system in frequency domain, the surface-to-surface calibration method is also employed to process and analyze signals in time domain efficiently. Compared with ISO standards, the experimental apparatus structure of the surface-to-surface calibration method is relatively simple, and the operation is more convenient

Reliability estimation of load sharing capacity-c-out-of-n pairs:G Balanced system

In many cases, systems are required to provide a specified capacity such as the case of power distribution system. A system fails when its capacity does not meet the required minimum capacity. In this paper, we investigate reliability estimation of capacity-c-out-of-n pairs:G Balanced systems which consist of units in a balanced spatial configuration. When one of the units fails its load is shared among the remaining units. The load shared by each operating unit affects its reliability and hence the system reliability. We incorporate load sharing effect on reliability of individual units into the estimation of system reliability. Higher load sharing has adverse effect on system reliability as demonstrated using a numerical example.Scopu

Active-Site Dynamics of SpvC Virulence Factor from Salmonella typhimurium and DensityFunctional Theory Study of Phosphothreonine Lyase Catalysis

The newly discovered SpvC effector protein from Salmonella typhimurium interferes with the host immune response by dephosphorylating mitogen-activated protein kinases (MAPKs) with a β-elimination mechanism. To understand this unique phosphothreonine lyase catalysis, the dynamics of the enzyme−substrate complex of the SpvC effector is investigated with a 3.2 ns molecular dynamics simulation, which reveals that the phosphorylated peptide substrate is tightly held in the active site by a hydrogen bond network and the lysine general base is positioned for the abstraction of the alpha hydrogen. The catalysis is further modeled with density functional theory (DFT) in a truncated active-site model at the B3LYP/6-31+G(d,p) level of theory. The DFT calculations indicate the reaction proceeds via a single transition state, featuring a concerted proton abstraction from the α-carbon by Lys136 and β-elimination of the phosphate leaving group. Key kinetic isotopic effects are predicted based on the truncated active-site model

Active-Site Dynamics of SpvC Virulence Factor fromSalmonella typhimuriumand Density Functional Theory Study of Phosphothreonine Lyase Catalysis

Photograph of an Indian Blanket flower, the official State wildflower of Oklahoma, in the Fort Gibson State Park