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 Dec 05 2010
Journal Name
Baghdad Science Journal
Study of Humoral Immune Response In Children Infected With Visceral Leishmaniasis
...Show More Authors

40 blood sample were taken from children infected with kala-azar at age less than ten years, who were admitted to El-Eskan child hospital, and central health laboratory in Baghdad. At the same time 15 sample collected from healthy child for comparing. During research estimated immunoglobulins level ( IgG, IgM, IgA) and (IFAT) IFAT test recorded a higher indicate antibodies level witch was synergistic with infected severity, the stander level of antibodies arrange between 1/16, 1/32 and 1/64 that means it graduate from the lowest one 1/16 into the highest one 1/64 within groups. During infectious the IgG ,IgM level recorded the higher level (2012.9 mg/dl) and (154.3 mg/dl) compared to the control group (874.3 mg/dl),

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 20 2019
Journal Name
Baghdad Science Journal
Social Worked-Examples Technique to Enhance Student Engagement in Program Visualization
...Show More Authors

Learning programming is among the top challenges in computer science education. A part of that, program visualization (PV) is used as a tool to overcome the high failure and drop-out rates in an introductory programming course. Nevertheless, there are rising concerns about the effectiveness of the existing PV tools following the mixed results derived from various studies. Student engagement is also considered a vital factor in building a successful PV, while it is also an important part of the learning process in general. Several techniques have been introduced to enhance PV engagement; however, student engagement with PV is still challenging. This paper employed three theories—constructivism, social constructivism and cognitive load t

... Show More
View Publication Preview PDF
Crossref (1)
Clarivate Crossref
Publication Date
Sun Aug 03 2025
Journal Name
Journal Of Physical Education
Studying the Reality of Racket Sports' Administrative Problems In Iraq
...Show More Authors

View Publication
Publication Date
Wed Jul 05 2023
Journal Name
Journal Of Pragmatics Research
Analysis of Impoliteness Strategies Used in Putin's Speech at Annexation Ceremony
...Show More Authors

This study aims to investigate the types of impoliteness strategies used in Putin's speech at the annexation ceremony. All of Putin's speeches were intentionally delivered to cause damage to the hearers' negative and positive faces. Culpeper's (2011) classifications of impoliteness, which consist of five strategies that are the opposite of politeness, were adopted. The data were collected from the President of Russia, providing a rich source for analysis. Qualitative and quantitative analyses were employed to achieve the study objectives. Qualitative analysis allowed for a detailed examination of the impoliteness strategies employed, while quantitative analysis provided a broader understanding of their frequency and distribution. Putin most

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
International Journal Of Research In Social Sciences & Humanities
the ROLE OF ORGANIZATIONAL JUSTICE IN DEVELOPING PSYCHOLOGICAL OWNERSHIP OF WORKERS
...Show More Authors

The research aims to demonstrate the role of organizational justice as an independent variable in influencing the achievement of development of the sense of psychological ownership of workers as a dependent variable. The current research variables were distinguished as being effective variables in terms of the field and affecting the achievement of success for organizations. In order to achieve this goal, it was applied on a sample of employees in the Iraqi Ministry of Transport employees, whose number reached (84) individuals, and the data were collected through the questionnaire as a main tool, to come out with a set of conclusions that contribute to raising the levels of the researched company, and based on the importance of the

... Show More
View Publication
Crossref
Publication Date
Wed Sep 15 2021
Journal Name
Al-academy
Dramatic wonder in children's theater performances: ميادة مجيد امين اسماعيل الباجلان
...Show More Authors

Dramatic wonders at children's theatre shows Search summary The importance of the current study is to present an important concept, from the point of view of those interested in the field of literature and the theater of the child, namely (miraculous) because it represents an innate tendency immersed in the child's mind, and therefore it is easy to impress him when attracting him with a text and a presentation addressed to him, to achieve the aesthetic and intellectual vision, so the problem of research was in the following question: (dramatic wonders in children's theater performances) and the importance of research lies in the importance of the importance of the role of wonder for dramatic discourse in children's theatre performances,

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 01 2013
Journal Name
Journal Of Engineering
The Use of Bracing Dampers in Steel Buildings Under Seismic Loading
...Show More Authors

Publication Date
Sun Dec 29 2019
Journal Name
Iraqi Journal Of Science
Reservoir units of Mishrif Formation in Majnoon Oil field, Southern Iraq
...Show More Authors

The reservoir units of Mishrif Formation in Majnoon oil field were studied by using available wireline logs (gamma ray, porosity and resistivity) and facies that derived from core and cutting samples for three wells including Mj-1, Mj-15, and Mj-20. The reservoir properties were determined and interpreted by using IP software. The results showed that unit D have the best reservoir properties due to high effective porosity, low water saturation and very low volume of shale. Furthermore, a large part of this unit was deposited in shoal environment. The other reservoir units are then graded in reservoir properties including units B, A, F & E respectively, except unit C, which is considered as a cap unit, because it consists of rest

... Show More
Scopus (14)
Crossref (13)
Scopus Crossref
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
A Factorial Study for separation anxiety in students, of Baghdad City
...Show More Authors

A Factorial Study for separation anxiety in students, of Baghdad City

View Publication Preview PDF
Publication Date
Thu May 12 2011
Journal Name
Al-mustansiriyah Journal Of Science
Histological study of optic tectum in Iraqi fish Barbus luteus (Heckel)
...Show More Authors

The ceiling of the midbrain has a couple of optic lobes which are prominent and used as an optic center that reflex what it receives from eye retina fibers. The histology of optic tectum has been studied in Iraqi fish Barbus luteus (Heckel) . It was found that the number of optic tectum were six main strata organized from the outside to the inside as follows : the stratum marginal (SM), the stratum opticum (SO), the stratum fibrosum et griseum superficialis (SFGS), the stratum griseum central (SGC), the stratum album central (SAC), the stratum periventricular (SPV), . the tow last strata consider deep layers on the optic tectum. It was noticed that the superficial strata was the first (SM), while the thickest strata was the four (SGC), whic

... Show More