Propagation of epistemic uncertainty in queueing models with unreliable server using chaos expansions

In this paper, we develop a numerical approach based on Chaos expansions to analyze the sensitivity and the propagation of epistemic uncertainty through a queueing systems with breakdowns. Here, the quantity of interest is the stationary distribution of the model, which is a function of uncertain parameters. Polynomial chaos provide an efficient alternative to more traditional Monte Carlo simulations for modelling the propagation of uncertainty arising from those parameters. Furthermore, Polynomial chaos expansion affords a natural framework for computing Sobol' indices. Such indices give reliable information on the relative importance of each uncertain entry parameters. Numerical results show the benefit of using Polynomial Chaos over standard Monte-Carlo simulations, when considering statistical moments and Sobol' indices as output quantities

Numerical Model for Oxide Scale Growth with Explicit Treatment of Vacancy Fluxes

In the framework of research on behaviour of nuclear waste containers, to evaluate the effects of possible evolution of experimental conditions, as well as evolution of parameters controlling oxidation rate during long-term interim storage, a numerical model has been developed in order to take into account non-stationary states. To anticipate effects like cold working of the metal on the scale growth kinetics and risks of scale detachment by over saturation of vacancies at the metal/oxide interface in the course of scale growth, the model is based on the calculation of chemical species, but also vacancies profiles evolution in the oxide and the metal following a simple time integration. An original numerical treatment is proposed to easily describe elimination of vacancies by introducing sink strength in the metal. The first calculations are presented and discussed

The Effect of Rearrangement of the Most Incompatible Particle on Increase of Convergence Speed of PSO

This article presents a new method for increasing the speed of Particle Swarm Optimization (PSO) method. The particle swarm is an optimization method that was inspired by collective movement of birds and fish looking for food. This method is composed of a group of particles: each particle tries to move in one direction that the best individual and best group of particles occur in that direction. Different articles tried to expand PSO so that global optimization is gained in less time. One of the problems of this model that occurs in most cases is falling of particles in local optimum. By finding the most incompatible particle and its rearrangement in the searching space, we increase convergence speed in some considered methods. Different tests of this method in standard searching space demonstrated that this method takes account of suitable function of increasing the convergece speed of particles.DOI:http://dx.doi.org/10.11591/ijece.v3i2.202

A Method of Steganography – P Message With Q Coefficient (SPMQC)

In this paper, we are going to propose a method for Steganography- which is based on deceiving χ2 algorithm. Since the cover image coefficients and stego image coefficients histograms have significant differences for purposes of statistical properties, statistical analysis of χ2-test reveals the existence of hidden messages inside stego image. We are introducing an idea for hiding messages in the cover image. It causes that DCT (Discrete Cosine Transforms) coefficient histogram not to have remarkable modification before and after embedding message. As a result, identifying the hidden message inside an image is impossible for an eavesdropper through χ2 -test. In this paper, we are proposing a better method with developing this algorithm. In fact, the capacity and the security of embedding messages increase extremely.DOI:http://dx.doi.org/10.11591/ijece.v3i2.201

Robust power series algorithm for epistemic uncertainty propagation in Markov chain models

In this article, we develop a new methodology for integrating epistemic uncertainties into the computation of performance measures of Markov chain models. We developed a power series algorithm that allows for combining perturbation analysis and uncertainty analysis in a joint framework. We characterize statistically several performance measures, given that distribution of the model parameter expressing the uncertainty about the exact parameter value is known. The technical part of the article provides convergence result, bounds for the remainder term of the power series, and bounds for the validity region of the approximation. In the algorithmic part of the article, an efficient implementation of the power series algorithm for propagating epistemic uncertainty in queueing models with breakdowns and repairs is discussed. Several numerical examples are presented to illustrate the performance of the proposed algorithm and are compared with the corresponding Monte Carlo simulations ones

Adaptive Adjustment of PSO Coefficients Taking the Notion from the Bee Behavior in Collecting Nectar

In particle swarm optimization, a set of particles move towards the global optimum point according to their experience and experience of other particles. Parameters such as particle rate, particle best experience, the best experience of all the particles and particle current position are used to determine the next position of each particle. Certain relationships received the input parameters and determined the next position of each particle. In this article, the relationships are accurately assessed and the amount of the effect of input parameters is horizontally set. To set coefficients adaptively, the notion is taken from bee behavior in collecting nectar. This method was implemented on software and examined in the standard search environments. The obtained results indicate the efficiency of this method in increasing the rate of convergence of particles towards the global optimum

INVESTIGATING MANAGEMENT OF WASTE IN GOVERNMENTAL MEDICAL AND HYGIENIC CENTERS OF FARASH BAND'S CITY

Introduction: Growth of urbanization has led to changes in production and components of nosocomial wastes and proper management of repelling solid wastes is an issue that has direct relationship to health and infection's control in society. Although the numbers of these materials are low, but can cause lots of dangers. This study has been done with the aim of determining quantity and quality and also condition of management of wastes at medical and hygienic centers in year 94. Methodology: In this descriptive-sectional study that performed at governmental hygienic and medical centers of Farash Band, productive wastes divided into 3 main groups and the condition of wastes management was also investigated on the basis of prepared check list from management's regulation of nosocomial wastes. By using panel regression, the effect of various variables on rate of infectious wastes and all the productive and nosocomial wastes was analyzed. Results: Findings of study showed that productive wastes are related to the numbers of referred people and are more than other hygienic and medical centers in hospitals. Although a meaningful relation between the rate of productive and infectious wastes and the numbers of referred people has not been observed, but the rate of productive and infectious waste in hospitals was more than other centers and it was statistically meaningful. Conclusion: Daily productions of thousands tons of waste in different areas (of country) and all kinds that they have according to pollution, are an issues that considering population's growth and development of industry and technology should be placed at up to hygiene and environment's plans of the country. According to the importance of this issue, at first items about hygienic dangers, type and the rate of waste and then collection and excretion systems should be noticed

Randomised comparison of oral ofloxacin alone with combination of parenteral antibiotics in neutropenic febrile patients

Prompt treatment with empirical antibiotics in neutropenic febrile patients reduces morbidity and mortality. Most patients have been treated with parenteral combination antibiotics, but newer antibiotics with broad-spectrum bactericidal activity have made monotherapy feasible. Ofloxacin, a broad-spectrum fluoroquinolone, has the additional advantage that bactericidal concentrations can be achieved with oral administration. We have compared ofloxacin as an oral single agent with standard parenteral combination antibiotics for the management of neutropenic febrile patients in a prospective, randomised trial. Patients with severe neutropenia (absolute neutrophil count less than or equal to 0.5 x 10(9)/l), fever above 38 degrees C, and ability to take drugs by mouth were eligible for the study. After initial investigations, 60 patients were randomly assigned to oral ofloxacin 400 mg twice daily and 62 to parenteral combination antibiotic therapy (amikacin 15 mg/kg daily, plus, at various times in the trial, carbenicillin, cloxacillin, or piperacillin). Patients were examined 72 h and 7 days after the start of treatment and when neutropenia resolved. 24 (40%) ofloxacin-treated and 26 (42%) combination-treated patients had pyrexia of unknown origin (PUO). In both treatment groups, the treatment success rate was higher for such patients than for those with clinically or microbiologically documented infections (92% vs 67% [p less than 0.05] for ofloxacin; 85% vs 64% for combination). There were no significant differences in success rates of ofloxacin and combination treatment for these subgroups or overall (77% vs 73%). Patients with neutropenia for less than 1 week had better responses to both treatments than patients with longer-lasting neutropenia. There were 4 (7%) deaths in the ofloxacin group and 6 (10%) in the combination group. Both regimens were well tolerated. We conclude that oral single-agent ofloxacin is as effective as parenteral combination antibiotic therapy in neutropenic febrile patients, especially those expected to have short durations of neutropenia

Effect of Temperature on Demographic Parameters of the Hawthorn Red Midget Moth, Phyllonorycter corylifoliella, on Apple

The hawthorn red midget moth, Phyllonorycter corylifoliella (Hübner) (Lepidoptera: Gracillariidae), is one of the most serious pests of apple and pear orchards in Iran, however little is known about its biology and relationship with environmental factors. The reproduction and population growth parameters of P. corylifoliella were examined at six constant temperatures (15, 20, 25, 30, 33 and 35° C) on apple var. golden delicious. At 35° C, P. corylifoliella failed to develop beyond the first instar. The lowest (13%) and highest (64%) mortality rates of immature stages occurred at 25 and 33° C, respectively. The life expectancies (ex) decreased with increasing of age and the life expectancies of one-day-old larvae were estimated to be 38.68, 33.34, 35.11, 26.28 and 16.11 days at 15, 20, 25, 30 and 33° C, respectively. The highest intrinsic rate of natural increase (rm), net reproductive rate (Ro) and finite rate of increase (λ) at 25° C were 0.100 ± 0.003, 47.66 ± 5.47 and 1.11 ± 0.00, respectively. The mean generation time (T) decreased with increasing temperatures from 86.86 ± 0.53 days at 15° C to 33.48 ± 0.16 days at 30° C. Doubling time (DT) varied significantly with temperature and the shortest doubling time was obtained at 25° C. The results of this study provide direction for future research on evaluating the performance of P. corylifoliella and the efficiency of its natural enemies in apple orchards under variable environmental conditions