Impact of Obstacles on the Degree of Mobile Ad Hoc Connection Graphs

What is the impact of obstacles on the graphs of connections between stations in Mobile Ad hoc Networks? In order to answer, at least partially, this question, the first step is to define both an environment with obstacles and a mobility model for the stations in such an environment. The present paper focuses on a new way of considering the mobility within environments with obstacles, while keeping the core ideas of the well-known Random WayPoint mobility model (a.k.a RWP). Based on a mesh-partitioning of the space, we propose a new model called RSP-O-G for which we compute the spatial distribution of stations and analyse how the presence of obstacles impacts this distribution compared to the distribution when no obstacles are present. Coupled with a simple model of radio propagation, and according to the density of stations in the environment, we study the mean degree of the connection graphs corresponding to such mobile ad hoc networks

Photoelectric Emission from Interstellar Dust: Grain Charging and Gas Heating

We model the photoelectric emission from and charging of interstellar dust and obtain photoelectric gas heating efficiencies as a function of grain size and the relevant ambient conditions. Using realistic grain size distributions, we evaluate the net gas heating rate for various interstellar environments, and find less heating for dense regions characterized by R_V=5.5 than for diffuse regions with R_V=3.1. We provide fitting functions which reproduce our numerical results for photoelectric heating and recombination cooling for a wide range of interstellar conditions. In a separate paper we will examine the implications of these results for the thermal structure of the interstellar medium. Finally, we investigate the potential importance of photoelectric heating in H II regions, including the warm ionized medium. We find that photoelectric heating could be comparable to or exceed heating due to photoionization of H for high ratios of the radiation intensity to the gas density. We also find that photoelectric heating by dust can account for the observed variation of temperature with distance from the galactic midplane in the warm ionized medium.Comment: 50 pages, including 18 figures; corrected title and abstract field

A Survey of Connectivity in Mobile Ad Hoc Networks

Mobile Ad hoc networks are networks without centralized infrastructures in which stations can move permanently in a given environment. One of the main issues in this domain is evaluation of communication algorithms which are used there. An approach to study this problem consists in studying communication graphs induced by mobile ad hoc networks. In these graphs, stations become nodes and when two stations are able to communicate, an edge is automatically created between the two corresponding nodes. Then, the study of the communication of the ad hoc networks is limited to the study of the connectivity of their connection graphs. This paper surveys studies of connectivity properties in such graphs

La mucoviscidose (intérêts des sels de benzo[c]quinolizinium, synthèse de nouvelles molécules, généralités sur les essais cliniques)

POITIERS-BU Médecine pharmacie (861942103) / SudocSudocFranceF

Impact of square environment on the connectivity in finite ad hoc networks

International audienceThis paper aims at studying some connectivity properties for random geometric graphs when they are constrained by the topological space in which they are embedded. More precisely, we focus our attention on limited square and rectangular environments. In order to analyse the impact of such environments on related graphs, we observe the evolution of mean degree. We propose an approach aiming at estimating the impact of the environment borders on the connectivity and we provide an analytical formula for computing the mean degree value depending on borders effects

Optimisation of heat affected zone by partial swarm optimisation in air plasma cutting operation

439-443This paper presents development of mathematical model for prediction of heat affected zone (HAZ) and optimisedparameters for air plasma cutting operation on AISI 6061 aluminium alloy. Experimental and predictive values from RSM arefound of same trend. Partial swarm optimisation (PSO) was employed to optimise cutting parameters. Deviation of HAZobtained by optimised HAZ model is 2.72%. Optimum cutting parameters for minimum HAZ are: output current, 100 A;stand-off gap, 1 mm and pressure, 620.52 kPa

Self-determination theory and individuals’ intention to participate in donation crowdfunding

Abstract Purpose – This study aims to examine the factors that affect individuals’ intention of participating in donation crowdfunding in the context of Oman. Design/methodology/approach – This study used the self-determination theory. A total of 250 respondents from Oman participated. The data is collected by online survey and analyses by using the partial least squares technique. Findings – The results illustrate that sense of self-worth, perceived donor effectiveness and moral obligation positively affect donation intention (DI) towards crowdfunding projects. Furthermore, subjective norms and perceived behavioural control positively impact individuals’ intention to contribute to donation crowdfunding. Originality/value – The results contribute to the literature on donation crowdfunding by identifying the driving forces of individuals’ DI to crowdfunding projects in Oman. Keywords Donation,Crowdfunding,Self-determinationtheory(SDT) Paper type Research pape

Self-determination theory and individuals’ intention to participate in donation crowdfunding

Abstract Purpose – This study aims to examine the factors that affect individuals’ intention of participating in donation crowdfunding in the context of Oman. Design/methodology/approach – This study used the self-determination theory. A total of 250 respondents from Oman participated. The data is collected by online survey and analyses by using the partial least squares technique. Findings – The results illustrate that sense of self-worth, perceived donor effectiveness and moral obligation positively affect donation intention (DI) towards crowdfunding projects. Furthermore, subjective norms and perceived behavioural control positively impact individuals’ intention to contribute to donation crowdfunding. Originality/value – The results contribute to the literature on donation crowdfunding by identifying the driving forces of individuals’ DI to crowdfunding projects in Oman. Keywords Donation,Crowdfunding,Self-determinationtheory(SDT) Paper type Research pape