Online identification of continuous-time systems with unknown time delay

In this note, we present a recursive algorithm for online identification of systems with unknown time delay. The proposed algorithm can be interpreted as an approximate nonlinear least-squares, corresponding to modified normalized or un-normalized least-squares when the normalizing factor /spl gamma/>0 or /spl gamma/=0, respectively. Both algorithms are essentially extensions to general least-squares methodology. Simulation studies demonstrate the characteristics and performance of these algorithms.     

Defect Tolerance for Nanoscale Crossbar-Based Devices

The need for defect maps and per-chip placement and routing limits the efficiency of test and defect tolerance techniques in nanoscale crossbar-based devices. The authors propose a method using two simulation programs that circumvents these difficulties to find fault-free implementations of logic functions on defective crossbars.     

Electrochemical synthesis and In situ spectroelectrochemistry of conducting NMPy‐TiO2 and ZnO polymer nanocomposites for Li secondary battery applications

Poly(N‐methylpyrrole) (PNMPy), poly(N‐methylpyrrole‐TiO₂) (PNMPy‐TiO₂), and poly (N‐methylpyrrole‐ZnO) (PNMPy‐ZnO) nanocomposites were synthesized by in situ electropolymerization for cathode active material of lithium secondary batteries. The charge–discharging behavior of a Li/LiClO₄/PNMPy battery was studied and compared with Li/LiClO₄/PNMPy‐nanocomposite batteries. The nanocomposites and PNMPy films were characterized by cyclic voltammetry, in situ resistivity measurements, in situ UV–visible, and Fourier transform infra‐red (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The differences between redox couples (ΔE) were obtained for polymer nanocomposites and PNMPy films. During redox scan, a negative shift of potential was observed for polymer nanocomposite films. Significant differences from in situ resistivity of nanocomposites and PNMPy films were obtained. The in situ UV–visible spectra for PNMPy and polymer nanocomposite films show the intermediate spectroscopic behavior between polymer nanocomposites and PNMPy films. The FTIR peaks of polymer nanocomposite films were found to shift to higher wavelengths in PNMPy films. The SEM and TEM micrographs of nanocomposite films show the presence of nanoparticle in PNMPy backbone clearly. The result suggests that the inorganic semiconductor particles were incorporated in organic conducting PNMPy, which consequently modifies the properties and morphology of the film significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41526.     

Optimization of the coercivity-modifying hydrogenation and re-calcination processes for strontium hexaferrite powder synthesized conventionally

Strontium hexaferrite powder, synthesised conventionally in-house from strontium carbonate (SrCO3) and hematite (Fe2O3) without additives, has been treated in a static hydrogen atmosphere and subsequently calcined in static air under different conditions. The optimum time, temperature, and initial pressure of hydrogenation and the optimum temperature of re-calcination for a fixed time of 1 h were determined using a combination of X-ray diffraction, vibrating sample magnetometer, and high-resolution scanning electron microscope techniques.Increasing the temperature, initial pressure, and time of hydrogenation up to the determined optimum values resulted in the decomposition of the strontium hexaferrite into Fe2O3 and Sr7Fe10O22, together with a more marked reduction of the resultant Fe2O3 to Fe. This was accompanied by the conversion of the initial single-crystal particles into very fine sub-grains, which is the reason for the higher coercivities obtained after re-calcination. Increasing the hydrogenation and re-calcination parameters beyond the optimum values, however, generally resulted in grain growth, which decreased the final magnetic properties. Increasing the re-calcination temperature to 1000 °C resulted in completion of the hexaferrite reformation. Beyond this temperature, however, the coercivity decreased due to grain growth.The optimum conditions were as follows: hydrogenation at 700 °C for 1 h under an initial pressure of 1.3 bar and then re-calcination in air at 1000 °C for 1 h. The highest coercivity obtained after re-calcination was around 400 kA/m. The remanence and saturation magnetization values were very similar to their initial values before the hydrogen treatment.     

Sustained delivery of olanzapine from sunflower oil‐based polyol‐urethane nanoparticles synthesised through a cyclic carbonate ring‐opening reaction

The forefront horizon of biomedical investigations in recent decades is parcelling‐up and delivery of drugs to achieve controlled/targeted release. In this regard, developing green‐based delivery systems for a spatiotemporal controlling therapeutic agent have drawn a lot of attention. A facile route based on cyclic carbonate ring‐opening reaction has been utilised to synthesise a bio‐based polyol‐containing urethane bond [polyol‐urethane (POU)] as a nanoparticulate drug delivery system of olanzapine in order to enhance its bioavailability. After characterisation, the nanoparticles were also estimated for in vitro release, toxicity, and pharmacokinetic studies. As olanzapine has shown poor bioavailability and permeability in the brain, the sustained release of olanzapine from the designed carriers could enhance pharmacokinetic effectiveness. POU in the aqueous solution formed micelles with a hydrophobic core and embedded olanzapine under the influence of its hydrophobic nature. Drug release from the nanoparticles (90 ± 0.43 nm in diameter) indicated a specific pattern with initial burst release, and then a sustained release behaviour (82 ± 3% after 168 h), by the Higuchi‐based release mechanism. Pharmacokinetics assessments of POU‐olanzapine nanoparticles were carried in male Wistar rats through intravenous administration. The obtained results paved a way to introduce the POU as an efficient platform to enhance the bioavailability of olanzapine in therapeutic methods.Inspec keywords: hydrophobicity, nanomedicine, nanofabrication, nanoparticles, drug delivery systems, biomedical materials, polymers, brainOther keywords: cyclic carbonate ring‐opening reaction, nanoparticulate drug delivery system, bioavailability, drug release, initial burst release, Higuchi‐based release mechanism, POU‐olanzapine nanoparticles, sunflower oil‐based polyol‐urethane nanoparticles, forefront horizon, biomedical investigations, green‐based delivery systems, spatiotemporal controlling therapeutic agent, bio‐based polyol‐containing urethane bond, polyol‐urethane, toxicity, pharmacokinetic studies, olanzapine, aqueous solution, micelles, hydrophobic core, Pharmacokinetics, male Wistar rats, brain     

Effects of mobile rotational movements in wireless propagation channels

The impact of non-straight movements of a mobile station (MS), for example rotation of the MS, on the statistics of a wireless propagation channel needs to be studied in the modern literature of wireless channel modelling. The authors formulate the effects of MS rotation on a cross-correlation model for a multiple-input multiple-output Rayleigh fading channel in a two-dimensional (2D) multipath propagation medium. The authors consider communication over a non-isotropic wave propagation environment employing directional antenna propagation patterns (APPs) at both transmitter and receiver arrays. The cross-correlation function (CCF) is computed when the MS rotates with a constant angular velocity and moves with a constant linear speed on the 2D plane. It is shown that the angular movement of the MS results in a cyclostationary channel process. In such a situation, the authors analyse the derived CCF using the continuous-time Fourier series in terms of the MS angular velocity, the parameters of the propagation environment and the employed antennas. The numerical evaluation shows that the energy dispersion in different frequencies is significantly influenced by the type of the directional APP, the distribution of scatterers and the angular Doppler shift. Furthermore, the authors establish an approximate relationship between the coherence-time and the MS angular velocity using a numerical curve fitting.     

Testing Exponentiality Based on Kullback-Leibler Information With Progressively Type-II Censored Data

We express the joint entropy of progressively censored order statistics in terms of an incomplete integral of the hazard function, and provide a simple estimate of the joint entropy of progressively Type-II censored data. We then construct a goodness-of-fit test statistic based on Kullback-Leibler information with progressively Type-II censored data. Finally, by using Monte Carlo simulations, the power of the test is estimated, and compared against several alternatives under different progressive censoring schemes     

Fabrication of a PVC membrane samarium(III) sensor based on N,N′,N″-tris(4-pyridyl)trimesic amide as a selectophore

A new ion-selective electrode for Sm^3 + ion is described based on the incorporation of N,N′,N″-tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 ± 0.5 mV decade^? 1 over a wide concentration range of 1.0 × 10^? 2 and 1 × 10^? 6 mol L^? 1, with a lower detection limit of 4.7 × 10^? 7 mol L^? 1 and satisfactor applicable pH range of 3.6–9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm^3 + over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm^3 +. Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures.     

Role of Organizational Project Management Maturity Factors on Project Success

The importance of projects has resulted in increased international standards, academic research, and education and training on project management concepts. However, studies show that the number of successful projects has not changed significantly. As conventional wisdom emphasizes organizational project management maturity, the aim of this research effort is to study the relations between project success and project performance factors, and organizational project management maturity.The results of this study suggest that having a project portfolio management function within the organization improves the likelihood of assigning priority for projects and meeting quality expectations and project objectives. The presence of formalized project management processes may influence the assigning of project priority and the use of project planning tools and techniques. Furthermore, organizations with project policies and procedures in place are more likely to require project managers to have their PMP certification. Results show that customer satisfaction is considered the most important project success factor and more so for organizations with portfolio management in place.