Synthesis of Ni Nanoparticles by Pulsed Laser Ablation Method in Liquid Phase

AbstractLaser ablation in liquids has been intensively studied in recent years, due to present numerous potentials in laser material micro-processing, including nanomaterials and nanostructures synthesize. Compared to others, typically chemical methods, pulsed laser ablation (PLA) in liquid is a simple and “green” technical method that normally operates in water or organic liquids under ambient conditions. Here, pure Ni nanostrutures were synthesized using PLA method in 30mL of acetone. A simple fiber pulsed laser setup has been not only employed to reduce the micron Ni particles to nano-sized by the PLA method, but also with no-induced oxidation at room temperature and free additive in liquid. The particle size, spectral analysis and morphology of the products were characterized by UV-vis spectrometry, energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The TEM image indicates spherical shapes with a narrow size distribution, compared with other methods, with ∼10nm in diameter respectively

Optimum Multi-Dimensional Interval Routing Schemes on Networks with Dynamic Cost Links

One of the fundamental tasks in any distributed computing system is routing messages between pairs of nodes. An Interval Routing Scheme (IRS) is a~space efficient way of routing messages in a network. The problem of characterizing graphs that support an IRS is a well-known problem and has been studied for some variants of IRS. It is natural to assume that the costs of links may vary over time (dynamic cost links) and to try to find an IRS which routes all messages on shortest paths (optimum IRS). In this paper, we study this problem for a~variant of IRS in which the labels assigned to the vertices are $d$-ary integer tuples ($d$-dimensional IRS). The only known results in this case are for specific graphs like hypercubes, $n$-dimensional grids, or for the 1-dimensional case. We give a complete characterization for the class of networks supporting multi-dimensional strict and linear (no cyclic intervals) interval routing schemes with dynamic cost links

Filtering Noise Caused by Sensor Selection for an Ultra-wide Band Position Tracking System

A filter designed to be optimal for alternating multi-sensor tracking systems is presented. This filter can be used on ultra-wide band position tracking systems such as the Ubisense system. In this thesis, a comprehensive evaluation of the accuracy of the Ubisense tracking system in a multi-room building is given. Then the multi-modality of the noise distribution of such a system is shown. A multi-sensor tracking system is then simulated and a Kalman filter is used to filter the measurements. It is shown that the Kalman filter is not optimal for such a system and the need for a filter that addresses the issue of multi-modality is explained. Finally a modified particle filter is designed and is shown to effectively reduce the noise in an alternating multi-sensor position tracking system

Bayesian Analysis of Transition Model for Longitudinal Ordinal Response Data: Application to Insomnia Data

In this paper, we present a Bayesian framework for analyzing longitudinal ordinal response data. In analyzing longitudinal data, the possibility of correlations between responses given by the same individual needs to be taken into account. Various models can be used to handle such correlations such as marginal modeling, random effect modeling and transition (Markov) modeling. Here a transition modeling is used and a Bayesian approach is presented for analyzing longitudinal data. A cumulative logistic regression model and the Bayesian method, using MCMC, are implemented for obtaining the parameters estimates. Our approach is applied on a two-period longitudinal Insomnia data where the Bayesian estimate for measure of association, , between the initial and follow-up ordinal responses is obtained in each level of a treatment variable. Then, the sensitivity of posterior summaries to changes of prior hyperparameters is investigated. We also use Bayes factor criterion for testing some important hypotheses