Preferred Language
Articles
/
VoZ8soYBIXToZYAL47HT
Multi-Channel Distributed DSA Networks: Connectivity and Rendezvous Tradeoffs
...Show More Authors

In this paper, we investigate and characterize the effects of multi-channel and rendezvous protocols on the connectivity of dynamic spectrum access networks using percolation theory. 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-channel, 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 protocols, 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 represent the multiple channels as parallel edges in a graph and build a multi-layered graph (MLG) in R2. In order to study the connectivity, we show how percolation occurs in the MLG by coupling it with a typical discrete percolation. Using a Boolean model and the MLG, we study both cases of primaries' absence and presence. For both cases, we define and characterize connectivity of the secondary network in terms of the available number of channels, deployment densities, number of simultaneous transmissions per node, and communication range. When primary users are absent, we derive the critical number of channels which maintains supercriticality 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. For each region we show the requirement and the outcome of using either type of rendezvous techniques. Moreover, we find the tradeoff between deployment-density versus rendezvous probability which results in a connected network. Our results can be used to decide on the goodness of any channel rendezvous algorithm by computing the expected resultant connectivity. They also provide a guideline for achieving connectivity using minimal resources.

Scopus Clarivate Crossref
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Some Thoughts on Greetings in English and Arabic
...Show More Authors

The present study examines the main points of differences in the subject of greetings between the English language and the Arabic language. From the review of the related literature on greetings in both languages, it is found that Arabic greeting formulas are more elaborate than the English greetings, because of the differences in the social customs and the Arabic traditions and the Arabic culture. It is also found that Arabic greetings carry a religious meaning basing on the Islamic principle of “the same or more so”, which might lead to untranslatable loopholes when rendered in English.

View Publication Preview PDF
Publication Date
Sun Dec 16 2018
Journal Name
Al-academy
Melodic and Rhythmic Construction of Monologues in Iraq
...Show More Authors

The research studies the melodic and rhythmic characteristics of monologue, in addition to how it was transferred from the Arab homeland to Iraq and   reviewed its most prominent performers, as well as a review     of the monologue types and their propagation in the Arab homeland such as comical, dramatic, and political and guidance monologues. 

The methodological framework included: the problem of the research, the importance of the research and the objective of the research which is to uncover the melodic and rhythmic structure of the monologue in Iraq.   The limits of the research included the objective limit tackling the  art of monologue and the spatial limit which is Baghdad

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Aug 02 2022
Journal Name
Journal Of Legal Sciences
Judicial Precedent and Its Controls – A Comparative Study
...Show More Authors

Judicial jurisprudence is one of the important legal solutions to address the shortcomings of legislation. Throughout its long history, human societies have known many cases in which the judge finds himself facing a legislative vacuum in addition to civil legal texts that are difficult for the judge to implement due to ambiguity or contradiction, which requires diligence. To rule on resolving disputes before him in order not to deny justice, but the judge in his jurisprudence was not absolute, but rather bound by certain controls represented by observing the wisdom of legislation on the one hand and taking into account the nature of the texts on the other side, and from here this research came to shed light on the jurisprudence and its cont

... Show More
View Publication
Publication Date
Mon Apr 03 2023
Journal Name
The Journal Of Physical Chemistry A
Excited-State Aromaticity Reversals in Naphthalene and Anthracene
...Show More Authors

Aromaticity reversals between the electronic ground (S0) and low-lying singlet (S1, S2) and triplet (T1, T2, T3) states of naphthalene and anthracene are investigated by calculating the respective off-nucleus isotropic magnetic shielding distributions using complete-active-space self-consistent field (CASSCF) wavefunctions involving gauge-including atomic orbitals (GIAOs). The shielding distributions around the aromatic S0, antiaromatic S1 (1Lb), and aromatic S2 (1La) states in naphthalene are found to resemble the outcomes of fusing together the respective S0, S1, and S2 shielding distributions of two benzene rings. In anthracene, 1La is lower in energy than 1Lb, and as a result, the S1 state becomes aromatic, and the S2 state becomes anti

... Show More
View Publication
Scopus (18)
Crossref (18)
Scopus Clarivate Crossref
Publication Date
Mon Nov 26 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Serum Zinc and Copper Changes in Male Infertility
...Show More Authors

Objective: The aim of this study to detect the correlation between trace elements such as zinc, copper and
spermatogenesis, sperm viability and motility.
Methodology: Serum and semen samples were collected from one hundred twenty patients with age ranged (20-
50 years) attending the high institute for Embryo Research and Infertility Treatment/ Baghdad University, in
addition to thirty fertile males their age comparable to that of patients. The period of this study was from June
2004 until the end of October 2004.
Results: The result of routine seminal fluid analysis of all infertile males was divided according to WHO, (1999) limit
into four groups: Asthenospermia(A), Asthenoteratospermia(AT), Oligoasthenoteratospermi

... Show More
View Publication Preview PDF
Publication Date
Thu Mar 04 2021
Journal Name
Journal Of Coastal Conservation
Solar system planetary alignment triggers tides and earthquakes
...Show More Authors

View Publication
Scopus (5)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Sun Mar 13 2011
Journal Name
Baghdad Science Journal
Extraction and Purification of albumin from Hunan plasma
...Show More Authors

This study includes adescription of Human serum Albumin by amodified using ion- exchange chromatography with manipulated comparison with cold ethanol precipitation method , It has been nticed that this procedure is superior orer the classical method . The Final yield by the new method 69.32% with purity of 83.42% compared with cohn which yield 60.30 % with purity of 80.7 % . The new method prored that it suitable for the pusi Fication of such material because it yield no precipitation material and it increases the Final yield of albumin solutions . • Human serum Albumin . • Albumin purification . • Ion – exchange chromatography . • Human plasma . • Albumin extraction .

View Publication Preview PDF
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
World Journal Of Dentistry
Facial Fractures in Preschool- and School-aged Children
...Show More Authors

Aim: The purpose of this study was to analyze the patterns of facial fractures in children and to compare them between preschool- and school-aged children. Materials and methods: This retrospective observational study included 57 children with facial fractures. The variables analyzed were the age of the patients—divided into a preschool-aged group (0–5 years) and a school-aged group (6–12 years)—gender, cause of trauma, the facial bones involved, the pattern of fracture, the modality of treatment used, the time between injury and treatment, and the postoperative complications. Results: The incidence of facial fractures in children ≤12 years was 30.2%. The patients consisted of 40 (70.2%) males and 17 (29.8%) females, and most pati

... Show More
View Publication
Scopus (3)
Crossref (3)
Scopus Crossref
Publication Date
Sat Sep 30 2017
Journal Name
College Of Islamic Sciences
Revelation period And suspicions of Orientalists: Critical study
...Show More Authors

With the narratives and sayings in the biography of the Prophet and the science of the Koran, Orientalists used this case as a pretext to distort the biography of the Prophet and his character and patience for his call. Researcher in the folds of his research.

View Publication Preview PDF
Publication Date
Tue Jul 01 2014
Journal Name
Political Sciences Journal
Depleted Uranium And use an American in Iraq
...Show More Authors

اليورانيوم المنضب واستخدامه امريكياً في العراق

View Publication Preview PDF
Crossref