Fault detection of redundant systems based on B-spline neural network

The fault detection and isolation of redundant sensor systems based on B-spline neural networks is presented in this paper. The network is trained using an algorithm with an adaptive learning rate. To further save computation time, the residual vector is transformed from a multivariate B-spline function to an univariate B-spline function. The detection of abrupt and drifting faults using the proposed method is discusses. The performance of the proposed method is illustrated by an example involving a redundant system consisting of six sensors.published_or_final_versio

Conditional control of the quantum states of remote atomic memories for quantum networking

Quantum networks hold the promise for revolutionary advances in information processing with quantum resources distributed over remote locations via quantum-repeater architectures. Quantum networks are composed of nodes for storing and processing quantum states, and of channels for transmitting states between them. The scalability of such networks relies critically on the ability to perform conditional operations on states stored in separated quantum memories. Here we report the first implementation of such conditional control of two atomic memories, located in distinct apparatuses, which results in a 28-fold increase of the probability of simultaneously obtaining a pair of single photons, relative to the case without conditional control. As a first application, we demonstrate a high degree of indistinguishability for remotely generated single photons by the observation of destructive interference of their wavepackets. Our results demonstrate experimentally a basic principle for enabling scalable quantum networks, with applications as well to linear optics quantum computation.Comment: 10 pages, 8 figures; Minor corrections. References updated. Published at Nature Physics 2, Advanced Online Publication of 10/29 (2006

From time series analysis to a modified ordinary differential equation

In understanding Big Data, people are interested to obtain the trend and dynamics of a given set of temporal data, which in turn can be used to predict possible futures. This paper examines a time series analysis method and an ordinary differential equation approach in modeling the price movements of petroleum price and of three different bank stock prices over a time frame of three years. Computational tests consist of a range of data fitting models in order to understand the advantages and disadvantages of these two approaches. A modified ordinary differential equation model, with different forms of polynomials and periodic functions, is proposed. Numerical tests demonstrated the advantage of the modified ordinary differential equation approach. Computational properties of the modified ordinary differential equation are studied

A Paclitaxel-Eluting Stent for the Prevention of Coronary Restenosis

Background Intimal hyperplasia and resulting restenosis limit the efficacy of coronary stenting. We studied a coronary stent coated with the antiproliferative agent paclitaxel as a means of preventing restenosis. Methods We conducted a multicenter, randomized, controlled, triple-blind study to evaluate the ability of a paclitaxel-eluting stent to inhibit restenosis. At three centers, 177 patients with discrete coronary lesions (<15 mm in length, 2.25 to 3.5 mm in diameter) underwent implantation of paclitaxel-eluting stents (low dose, 1.3 µg per square millimeter, or high dose, 3.1 µg per square millimeter) or control stents. Antiplatelet therapies included aspirin with ticlopidine (120 patients), clopidogrel (18 patients), or cilostazol (37 patients). Clinical follow-up was performed at one month and four to six months, and angiographic follow-up at four to six months. Results Technical success was achieved in 99 percent of the patients (176 of 177). At follow-up, the high-dose group, as compared with the control group, had significantly better results for the degree of stenosis (mean [±SD], 14±21 percent vs. 39±27 percent; P<0.001), late loss of luminal diameter (0.29±0.72 mm vs. 1.04±0.83 mm, P<0.001), and restenosis of more than 50 percent (4 percent vs. 27 percent, P<0.001). Intravascular ultrasound analysis demonstrated a dose-dependent reduction in the volume of intimal hyperplasia (31, 18, and 13 mm3, in the high-dose, low-dose, and control groups, respectively). There was a higher rate of major cardiac events in patients receiving cilostazol than in those receiving ticlopidine or clopidogrel. Among patients receiving ticlopidine or clopidogrel, event-free survival was 98 percent and 100 percent in the high-dose and control groups, respectively, at one month, and 96 percent in both at four to six months. Conclusions Paclitaxel-eluting stents used with conventional antiplatelet therapy effectively inhibit restenosis and neointimal hyperplasia, with a safety profile similar to that of standard stents.published_or_final_versio

Structural reliability analysis of multiple limit state functions using multi-input multi-output support vector machine

Selecting and using an appropriate structural reliability method is critical for the success of structural reliability analysis and reliability-based design optimization. However, most of existing structural reliability methods are developed and designed for a single limit state function and few methods can be used to simultaneously handle multiple limit state functions in a structural system when the failure probability of each limit state function is of interest, for example, in a reliability-based design optimization loop. This article presents a new method for structural reliability analysis with multiple limit state functions using support vector machine technique. A sole support vector machine surrogate model for all limit state functions is constructed by a multi-input multi-output support vector machine algorithm. Furthermore, this multi-input multi-output support vector machine surrogate model for all limit state functions is only trained from one data set with one calculation process, instead of constructing a series of standard support vector machine models which has one output only. Combining the multi-input multi-output support vector machine surrogate model with direct Monte Carlo simulation, the failure probability of the structural system as well as the failure probability of each limit state function corresponding to a failure mode in the structural system can be estimated. Two examples are used to demonstrate the accuracy and efficiency of the presented method

New MACRO results on atmospheric neutrino oscillations

The final results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons in absorbers was used to estimate the neutrino energy of each event. The angular distributions, the L/E_nu distribution, the particle ratios and the absolute fluxes all favour nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A discussion is made on the Monte Carlos used for the atmospheric neutrino flux. Some results on neutrino astrophysics are also briefly discussed.Comment: Invited Paper at the NANP03 Int. Conf., Dubna, 200

Effect of Chronic Alcohol Consumption on Phosphatidylcholine Hydroperoxide Content of Rat Liver and Brain

Purpose: To investigate the correlation between alcohol-induced oxidative stress and tissue phosphatidylcholine hydroperoxide (PC-OOH) content of rat liver and brain.Methods: Ten Wistar rats were divided into two groups: one group was given 20 % ethanol (5 g/kg) and the other the same volume of normal saline, orally once a day for 6 weeks. Catalase activity, malondialdehyde (MDA) content, total antioxidant capacity (TAC) and PC-OOH content of liver and brain were determined.Results: The ethanol-treated group had lower catalase activity and total antioxidant capacity. MDA level in the liver was 0.33 ± 0.07 μM/mg protein which is significantly (p &lt; 0.05) higher than that of the control group (0.17 ± 0.06 μM/mg protein), but in brain, there was no significant difference. PC-OOH level in the ethanol-treated group was 46.91 ± 12.87 pmol/mg in liver and 71.97 ± 26.12 pmol/mg protein in brain while PC-OOH level of control group was 21.40 ± 10.71 pmol/mg protein in liver and that in brain was 25.29 ± 5.67 pmol/mg protein pmol. Thus, PC-OOH levels in both liver and brain were significantly (p &lt; 0.05) higher than that of control group. PC-OOH content in the liver and brain correlated significantly (p &lt; 0.05) with catalase activity and total antioxidant capacity (TAC).Conclusion: The study demonstrates that PC-OOH content in liver and brain tissues may be a marker for alcohol-induced oxidative stress.Keywords: Alcohol Toxicity, Oxidative Stress, Phosphatidylcholine Hydroperoxide, Liver, Brain, Biomarke

A Cellular Pathway Involved in Clara Cell to Alveolar Type II Cell Differentiation after Severe Lung Injury

Regeneration of alveolar epithelia following severe pulmonary damage is critical for lung function. We and others have previously shown that Scgb1a1-expressing cells, most likely Clara cells, can give rise to newly generated alveolar type 2 cells (AT2s) in response to severe lung damage induced by either influenza virus infection or bleomycin treatment. In this study, we have investigated cellular pathway underlying the Clara cell to AT2 differentiation. We show that the initial intermediates are bronchiolar epithelial cells that exhibit Clara cell morphology and express Clara cell marker, Scgb1a1, as well as the AT2 cell marker, pro-surfactant protein C (pro-SPC). These cells, referred to as pro-SPC[superscript +] bronchiolar epithelial cells (or SBECs), gradually lose Scgb1a1 expression and give rise to pro-SPC[superscript +] cells in the ring structures in the damaged parenchyma, which appear to differentiate into AT2s via a process sharing some features with that observed during alveolar epithelial development in the embryonic lung. These findings suggest that SBECs are intermediates of Clara cell to AT2 differentiation during the repair of alveolar epithelia following severe pulmonary injury.Singapore-MIT Alliance for Research and Technology Center. Infectious Disease Research Grou

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

Forced electrostriction by constraining polarization switching enhances the electromechanical strain properties of incipient piezoceramics

Recently developed lead-free incipient piezoceramics are promising candidates for off-resonance actuator applications due to their exceptionally large electromechanical strains. Their commercialization currently faces three critical challenges: the high driving electric field required for delivering the potentially large strains; large strain hysteresis, which is inappropriate for precision devices; and relatively high temperature dependencies. We propose that instead of utilizing incipient piezoelectric strains, harnessing the maximum possible electrostriction would provide a highly effective way to resolve all these challenges. This concept was experimentally demonstrated using textured 0.97Bi(1/2)(Na0.78K0.22) 1/2TiO3-0.03BiAlO(3) as an exemplary incipient piezoceramic, whereby texturing was achieved using a reactive templated grain-growth technique. The manufactured textured ceramic is characterized by S-max/E-max of 995 pm V-1 and an electrostrictive coefficient, Q(33), of 0.049 m(4) C-2. Both these parameters are as large as those of single crystals. The current work presents a significant advancement in the field of lead-free ceramics and can guide future efforts in this direction. In addition, the concept presented here can be easily transferred to other disciplines involving the design of functional properties of various materiaope