Transition from ballistic to thermalized transport of the metal sputtered species in DC magnetron

Tunable Diode Laser Induced Fluorescence (TD-LIF) technique has been optimized to accurately measure the titanium (Ti) sputtered Atoms Velocity Distribution Functions (AVDF) in a magnetron discharge operating in Direct Current (DC) mode. The high spatial and spectral resolution achieved unveils some features of the transport of the metal sputtered atoms and their thermalization. The two groups of thermalized and energetic atoms have been very well separated compared to previous works. Hence, the fitting of the energetic atoms group shows dumping from modified Thompson to Gauss distribution when the product pressure-distance from the target increases. In parallel, sputtered metal transport from the target has been simulated using the Monte Carlo collision (MCC) approach. The direct comparison between numerical and experimental results led to an improved cross section for Titanium - Argon momentum transfer, based on the \textit{ab initio} formulae of the interaction potential derived from noble gases interaction. The numerical parametric study of the angular distribution and cut-off energy for the initial distribution of sputtered atoms steered to a precise characterization of the initial conditions, allowed by the accuracy of experimental data. A very good overall agreement is obtained for measured and calculated AVDFs. The confrontation between measured and modeling results emphasized the major role played by the argon ions not only in the sputtering process but also in the neutral metal transport, by the gas rarefaction near the target. The microscopic description provided by the MCC model clearly reveals different transport regimes: ballistic, diffusive, and back-scattering and brings new insights on the thermalization of sputtered species in the intermediate pressure range.

Applying Improve Differential Evolution Algorithm for Solving Gait Generation Problem of Humanoid Robots

This chapter addresses an approach to generate 3D gait for humanoid robots. The proposed method considers gait generation matter as optimization problem with constraints. Firstly, trigonometric function is used to produce trial gait data for conducting simulation. By collecting the result, we build an approximation model to predict final status of the robot in locomotion, and construct optimization problem with constraints. In next step, we apply an improve differential evolution algorithm with Gauss distribution for solving optimization problem and achieve better gait data for the robot. This approach is validated using Kondo robot in a simulated dynamic environment. The 3D gait of the robot is compared to human in walk.

Extension of In-Gap Electronic-State Spectrum Extraction Technique Based on Transient Photo-Voltage Measurement

This article puts forward a novel insight for extraction of trap state density (DOST) based on the transient photo-voltage (TPV) experimental data. Inspired by the method based on the Gauss distribution model, we introduce a universal general distribution model and present a general technique of DOST distribution from the experimental data of TPV measurement. The method based on the exponential (Gauss) distribution model is the one (two) order special case of our method. Compared to the method based on the exponential model (applicable only when the TPV result satisfies linear relation) and Gauss model (applicable only when the TPV result satisfies quadratic function relation), our work is effective for arbitrary TPV result.

Application of Vibration Signals for the Quantitative Analysis of the Optimal Threshold of Bearing Failure

This study established the prognostics and health management system for bearing failure. The vibration signals measured during the bearing operation were used for prognostics. First, the time-domain signal of vibration was calculated through generalized fractal dimensions, and the relationship diagram of generalized fractal dimensions and time was obtained. Then, the trend of bearing failure was compared by the GFDal results. However, the results can only be used for qualitative feature extraction. The bearing failure at the beginning cannot be determined by qualitative methods. Therefore, this study further converted the calculation results of GFDs into a Gauss distribution curve based on the statistical method under normal operation of the bearing. The Gauss distribution curve of the bearing under normal operation and at different time was overlapped. The overlap rate of the bearing area under different times was calculated. The minimum value was taken as the diagnostic standard, which was the optimal threshold of bearing failure defined in this study and was used as the quantitative basis for bearing failure. Therefore, the comparison of the area overlap rate under the Gauss distribution curve between the normal bearing and the bearing under test could provide diagnosis to the bearing failure. Moreover, the time point of the initial failure of the bearing could also be estimated based on the optimal failure threshold.

PECULIARITIES OF THE DIAMETER DISTRIBUTIONS OBTAINED AT SUBMILISECOND DURATION OF DISCHARGE PULSES SPARK-EROSIVE ALUMINUM PARTICLES AND CAVERNS ON THE SURFACE OF ITS GRANULES

The conditions and technique for obtaining single-mode size distributions of spark-erosive aluminum particles are given. The statistical parameters of the size distributions of spark-erosive aluminum particles and caverns on the surface of its granules, obtained at a submilisecond duration of discharge pulses were calculated. A comparative analysis of the volumes of metal of erosion caverns and particles is carried out. The agreement of the diameter distributions of spark-erosive particles and caverns obtained in practice with the following theoretical distributions of a continuous random variable: Gauss, Weibull, the integral of the Rosin-Rammler function, and also log-normal distribution is verified. In this case, the parameters of theoretical distributions were calculated both by the statistical parameters of the distributions obtained in practice, and by the criterion of the smallest value of the average module of the relative deviation of the theoretical and practical distributions. It has been shown that for the values of the parameters of theoretical distributions that correspond to the statistical parameters of practical distributions, the distribution of erosive particles by diameters is in the best agreement with the Gauss distribution, and the caverns – with the distribution of integral of the Rosin-Rammler function. References 27, figures 2, tables 3.

Rekonfiguracija distributivne mreže i otočna kompenzacija uz prisustvo vetro generatora

In this paper, the distribution network reconfiguration with simultaneous capacitor switching, in the presence of wind generators, by Simulated Annealing (SA) is presented. Analysed test network has 69 nodes including the slack one and 73 branches, all of which can commutate. Following assumptions are made: load in nodes is changed according to Gauss distribution and wind generator power with Weibull one, every hour, then there are two wind generators of 200 kW maximum power each (10% of total, nominal active power load) and they can be allocated to any node but the slack one. The same is valid for the capacitor banks regarding allocation. This switching logic is unrealistic. On its basis more realistic one was issued with fixed nodes for allocation of wind generators and capacitor banks (the most frequently visited nodes), by Monte Carlo graphical method. Input power factor is to be greater than 0.85 which is not fulfilled with commencing configuration (from the start) so that allocation of capacitor banks is mandatory. Another constraint is that the network should not be overcompensated. Four realistic scenarios are investigated. In the first one only network with wind generators is analysed and the rest are dedicated to all possible combinations of the regulation. The programme is automated indicating the price of configuration, generated banks, input data (active and reactive load, power and location of wind generators) and savings which change on an hourly basis. The wind generators are uniformly distributed in accordance to nodes (for the less realistic scenario) and generate only active power complying with Weibull distribution. The graphical results are presented for a 1000-hour operation (operation in one thousand hours, every hour different) and the analysis is done for a thousand-hour work. The presented method shows that considerable savings can be achieved by simultaneous application of reconfiguration method and capacitor switching with already allocated wind generators.

Study on pilling performance of polyester-cotton blended woven fabrics

Aiming at the classic problem of pilling of polyester-cotton blended woven fabrics, pilling grades were evaluated by image analysis method to study the effects of yarn twist, spinning method, warp, and weft density, fabric cover factor and fabric singeing on pilling performance. The length and density distribution of fabric hairiness was studied by Nano measurer software. The respective roles of polyester and cotton fibers were studied by using scanning electron microscope and quantitative chemical analysis method. The experimental results showed that the factors for the best anti-pilling fabric are that yarn twist is 950 N/m, the spinning method is siro-compact spinning, warp density is 394 N/10cm, weft density is 265 N/10cm, fabric cover factor is 103.9%, and fabric should be singed. Cotton hairiness is fractured, which is wrapped by polyester hairiness to form pills. The frequency distribution of hairiness is approximately given by Gauss distribution. Mass ratio of polyester and cotton hairiness is nearly 66%/34%.

Advanced Statistical Analysis of Grain Structure in Single-Phase Materials Nanostructured by High-Pressure Torsion

Elaboration of statistical analysis of grain structure in bulk single-phase metal materials, subjected to high-pressure torsion, is proposed. The method includes a combination of logarithmic standard distribution and Gauss distribution, in order to improve fitting of histograms of grain size distribution by the statistical model. The possibility of division of grain structure into different groups, taking into account specific features of distributions in every group, is demonstrated. The use of calculated parameters of grain size distributions is proposed to identify groups of grains by their origin. The grain structure analysis is given by an example of tin bronze nanostructured by high-pressure torsion. The agreement of the analysis results with the experimental data is demonstrated.

Privacy Loss Classes: The Central Limit Theorem in Differential Privacy

Quantifying the privacy loss of a privacy-preserving mechanism on potentially sensitive data is a complex and well-researched topic; the de-facto standard for privacy measures are ε-differential privacy (DP) and its versatile relaxation (ε, δ)-approximate differential privacy (ADP). Recently, novel variants of (A)DP focused on giving tighter privacy bounds under continual observation. In this paper we unify many previous works via the privacy loss distribution (PLD) of a mechanism. We show that for non-adaptive mechanisms, the privacy loss under sequential composition undergoes a convolution and will converge to a Gauss distribution (the central limit theorem for DP). We derive several relevant insights: we can now characterize mechanisms by their privacy loss class, i.e., by the Gauss distribution to which their PLD converges, which allows us to give novel ADP bounds for mechanisms based on their privacy loss class; we derive exact analytical guarantees for the approximate randomized response mechanism and an exact analytical and closed formula for the Gauss mechanism, that, given ε, calculates δ, s.t., the mechanism is (ε, δ)-ADP (not an over-approximating bound).