Preferred Language
Articles
/
XYZ-soYBIXToZYAL3LHN
Connectivity and rendezvous in distributed DSA networks
...Show More Authors

In this paper, we use concepts and results from percolation theory to investigate and characterize the effects of multi-channels on the connectivity of Dynamic Spectrum Access networks. In particular, we focus on the scenario where the secondary nodes have plenty of vacant channels to choose from-a phenomenon which we define as channel abundance. To cope with the existence of multi-channels, we use two types of rendezvous protocols: naive ones which do not guarantee a common channel and advanced ones which do. We show that, with more channel abundance, even with the use of either type of rendezvous protocol, it becomes difficult for two nodes to agree on a common channel, thereby potentially remaining invisible to each other. We model this invisibility as a Poisson thinning process and show that invisibility is even more pronounced with channel abundance. Following the disk graph model, we define and characterize connectivity of the secondary network in terms of the available number of channels, deployment densities, number of transceivers per node, and communication range. When primary users are absent, we derive the critical number of channels which maintains super-criticality of the secondary network. When primary users are present, we characterize and analyze the connectivity for all the regions: channel abundance, optimal, and channel deprivation. Our results can be used to decide on the goodness of any channel rendezvous algorithm by computing the expected resultant connectivity.

Scopus Crossref
Publication Date
Sun Jan 01 2012
Journal Name
Lambert Academic Publishing
Expressions of Gratitude in American English and Iraqi Arabic, Al-Zubaidi Nassier |... | bol
...Show More Authors

Expressions of Gratitude in American English and Iraqi Arabic (). Expressing gratitude is one of the most frequently occurring communicative acts in...

View Publication
Publication Date
Tue Jan 01 2019
Journal Name
Aip Conference Proceedings
Experimental and theoretical study of (PVC) nanoparticles prepared by laser ablation in ethanol
...Show More Authors

In this manuscript divide into two parts the first experimental and the second theoretical. The experimental part of polyvinyl chloride (PVC) can be used with aluminum (30%). Nanomaterials are synthesized by a laser pulse melting solution by ethanol. The effect of laser on the structural, morphological, optical, and electrical properties of nanoparticles (PVC) was examined by UV spectroscopy, x-ray diffraction (XRD), electron microscopy (TEM). The theoretical part of the DFT can be used to approximate the generalized gradient of the Perdew, Burke, and Ernzerhof (PBE) / 6-31G (d) groups, which were created using additional Gaussian 09 software through Gaussian 5.08. To build PVC nanocrystal pure which chemical formula [(C2H3Cl)n] and build (

... Show More
Publication Date
Thu Oct 28 2021
Journal Name
International Journal Of Research In Social Sciences And Humanities
Analysis of the Sustainable Value Chain and its Role in Reducing Quality Costs
...Show More Authors

Contemporary developments in various sciences and the impact of technological changes require an integrated vision of the activities and work of the organization in Iraq in light of the high costs of products and their low quality compared to imported products of high quality and low cost, and the need to use modern cost techniques based on a clear and specific philosophy that contributes to increasing the efficiency and effectiveness of management In the business environment and how it can contribute to reducing product costs and being environmentally friendly at the same time, it is no secret that the main goal of most organizations is to maximize profitability and reduce costs to the minimum, but this matter is not achieved autom

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Impact of empowerment and functional flexibility in evaluating worker performance :an empirical study
...Show More Authors

This study was conducted in the Department of Employment and Loans at the Ministry of Labor and Social Affairs to indicate the importance and impact of both the empowerment and the functional flexibility in evaluating the performance of the employees. To achieve the objectives of the study, the data was collected through a questionnaire form designed for this purpose based on previous studies. Data obtained for a significant evaluation of the relationship between the components of both the empowerment and the functional flexibility with the components of the evaluation and determining the degree of importance of each component of both the empowerment and functional flexibility for the components of the evaluation by the extractio

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jan 27 2019
Journal Name
Journal Of The College Of Education For Women
Historical Paths of the Political Conflict in Iraq and its Development After 3002
...Show More Authors

Following the political development in Iraq Since 7112 exposed kind of political traditions about how to manage the conflicts that have different Iraqi powers .That what was clear since the formation of permanent government since in 7112 .
The case of conflict between political powers in administrating Iraq state and the withdrawal of American Forcesintroduces questions:
0-Is it possible that that the beginning of Iraq state building shall ease this conflict and peacemaking in the post-conflict period?
7- To what extent the Iraqi powerswas to manage their disputes in non-military like elections which was held in 7112?
2- What is the range of the extent of the political operation after the American withdrawal?
The important

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2016
Journal Name
Journal Of The College Of Languages (jcl)
The tragedies of love and death in the tragedy of Federico Garcia Lorca
...Show More Authors

Abstract:

    Federico Garcia Lorca is considered in european and american literary circles as revolutionary symbol of contemporary literature writer through close association with the concerns of his country and the world, and also through the violent propensity to freedom, emancipation and innovation. This personal multi-talent has a significant impact in the spanish literary movement, in particularly, and in world, in general. If Lorca has andalusia blood, is no stranger to contemporary arab man to read to him, and contemplates his experience analyst and literary critic. This research is serious study of this character. There is no doubt the reader will put in front of many facts about personali

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 15 2009
Journal Name
Journal Of Kerbala University
Viscosity and Volumetric studies of some amino acids in solutions at different temperatures
...Show More Authors

Densities ρ and viscosities η for several concentrations of amino acids (Serine, Cysteine and Threonine) at different temperatures (298.15, 303.15 and 308.15K) have been measured. On the basis of these data, the apparent molal volumes v , partial molal volumes at infinite dilution v , slope Sv , Gibbs free energy of activation for viscous flow of solution ∆G1,2 and Jones – Dole Bcoefficients were calculated the nature of solute-solvent and solute-solute interactions have been discussed in terms of the values of v , v , Sv and B-coefficents

Publication Date
Mon Dec 02 2013
Journal Name
Iraqi Medical Journal
Etiology and Antibiotic Sensitivity for Otitis Media in A Central Pediatric Teaching Hospital.
...Show More Authors

Publication Date
Thu Dec 15 2022
Journal Name
Al-adab Journal
The Application of Hirschberg Maxims in Frost’s ‘Mending Wall’ and Darwish’s ‘Scenario Jaahiz’
...Show More Authors

View Publication
Crossref
Publication Date
Mon Mar 15 2021
Journal Name
Al-academy
The effectiveness of media communication and its problems in the contemporary theatrical presentation
...Show More Authors

View Publication
Crossref