Erlang distributed activity times in stochastic activity networks

summary:It is assumed that activity times in stochastic activity networks (SANs) are independent Erlang random variable (r.v.). A recurrence method of determining the $k$th moments of the completion time is presented. Applications are provided for illustration and are used to evaluate the applicability and appropriateness of the Erlang model to represent activity network

Measures of Risk on Variability with Application in Stochastic Activity Networks

We propose a simple measure of variability of some of the more commonly used distribution functions in the class of New-Better-than-Used in Expectation (NBUE). The measure result in a ranking of the distributions, and the methodology used is applicable to other distributions in NBUE class beside the one treated here. An application to stochastic activity networks is given to illustrate the idea and the applicability of the proposed measure. Keywords: Alternative Risk measure, Portfolio, Coefficient of Variation, Skewness, Project management,  Stochastic activity networks

Raman-active modes in defective peapod

International audienceThe vibrational properties of defective single-walled carbon nanotube filled with C60 fullerene is the subject of the current study. For this aim we use the spectral moments method in the framework of the bond-polarization theory to calculate the nonresonant Raman spectra of hexa-vacancy defective C60 peapods. Essentially, the vibrational properties are closely coupled with the atomic structure of the system. The evolution of the Raman spectrum as a function of the spatial arrangement of defects in carbon nanotubes is discussed. This work provides benchmark theoretical results to understand the experimental data of defective C60 peapod

Cyclodextrin enhances corneal tolerability and reduces ocular toxicity caused by diclofenac

With advances in refractive surgery and demand for cataract removal and lens replacement, the ocular use of nonsteroidal anti-inflammatory drugs (NSAIDs) has increased. One of the most commonly used NSAIDs is diclofenac (Diclo). In this study, cyclodextrins (CDs), α-, β-, γ-, and HP-β-CDs, were investigated with in vitro irritation and in vivo ulceration models in rabbits to reduce Diclo toxicity. Diclo-, α-, β-, γ-, and HP-β-CD inclusion complexes were prepared and characterized and Diclo-CD complexes were evaluated for corneal permeation, red blood cell (RBCs) haemolysis, corneal opacity/permeability, and toxicity. Guest- (Diclo-) host (CD) solid inclusion complexes were formed only with β-, γ-, and HP-β-CDs. Amphipathic properties for Diclo were recorded and this surfactant-like functionality might contribute to the unwanted effects of Diclo on the surface of the eye. Contact angle and spreading coefficients were used to assess Diclo-CDs in solution. Reduction of ocular toxicity 3-fold to16-fold and comparable corneal permeability to free Diclo were recorded only with Diclo-γ-CD and Diclo-HP-β-CD complexes. These two complexes showed faster healing rates without scar formation compared with exposure to the Diclo solution and to untreated groups. This study also highlighted that Diclo-γ-CD and Diclo-HP-β-CD demonstrated fast healing without scar formation

VoroCrust: Voronoi Meshing Without Clipping

Polyhedral meshes are increasingly becoming an attractive option with particular advantages over traditional meshes for certain applications. What has been missing is a robust polyhedral meshing algorithm that can handle broad classes of domains exhibiting arbitrarily curved boundaries and sharp features. In addition, the power of primal-dual mesh pairs, exemplified by Voronoi-Delaunay meshes, has been recognized as an important ingredient in numerous formulations. The VoroCrust algorithm is the first provably-correct algorithm for conforming polyhedral Voronoi meshing for non-convex and non-manifold domains with guarantees on the quality of both surface and volume elements. A robust refinement process estimates a suitable sizing field that enables the careful placement of Voronoi seeds across the surface circumventing the need for clipping and avoiding its many drawbacks. The algorithm has the flexibility of filling the interior by either structured or random samples, while preserving all sharp features in the output mesh. We demonstrate the capabilities of the algorithm on a variety of models and compare against state-of-the-art polyhedral meshing methods based on clipped Voronoi cells establishing the clear advantage of VoroCrust output.Comment: 18 pages (including appendix), 18 figures. Version without compressed images available on https://www.dropbox.com/s/qc6sot1gaujundy/VoroCrust.pdf. Supplemental materials available on https://www.dropbox.com/s/6p72h1e2ivw6kj3/VoroCrust_supplemental_materials.pd

Self-learning Kinetic Monte-Carlo method: application to Cu(111)

We present a novel way of performing kinetic Monte Carlo simulations which does not require an {\it a priori} list of diffusion processes and their associated energetics and reaction rates. Rather, at any time during the simulation, energetics for all possible (single or multi-atom) processes, within a specific interaction range, are either computed accurately using a saddle point search procedure, or retrieved from a database in which previously encountered processes are stored. This self-learning procedure enhances the speed of the simulations along with a substantial gain in reliability because of the inclusion of many-particle processes. Accompanying results from the application of the method to the case of two-dimensional Cu adatom-cluster diffusion and coalescence on Cu(111) with detailed statistics of involved atomistic processes and contributing diffusion coefficients attest to the suitability of the method for the purpose.Comment: 18 pages, 9 figure

Life Adaptation Program & Its Effect on Daily Living Skills of Autistic Children and Their Parents Stress

This study aimed to investigate the effect of life adaptation program on daily living skills (DLS) of autistic children and their parent's stress. A quasi -experimental design was utilized in this study. A purposive sample of thirty autistic children and their parents were recruited from Autism Day Care Unit-Beit El-shams- Child Psychiatry Clinic in El-Abbassia Mental Health Hospital. Three tools were used to conduct the current study, sociodemographic and medical data sheet, autistic child skills scale, and parent's stress scale. The results showed that, more than eighty percent of the studied children had low level of daily living skills, and slightly more than half of the studied parents had moderate stress level. Findings revealed that there was a highly statistically significant difference between pre-post program regarding daily living skills & there was a highly statistically significant difference between parents stress pre and post program. In conclusion, early intervention play significant role in the development of DLS of all ages, yet further researches are needed for developing and maintenance of DLS of autistic children. Keywords: autistic disorder, daily living skills, parents stress