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.
Abu Al-Ala Al-Ma’arri is a linguist and writer who showed his prowess in poetry, so he had poetry collections, including “The ulna fell,” which is one of the books that attracted the attention of scholars such as (Tabrizi, Al-Khwarizmi, Al-Bateliusi and Al-Zamakhshari) .
To explain his language in it, the investigators’ hands finally revealed an explanation of this book, which was the work of Abu Al-Ala Al-Ma’arri himself. Those who studied the Divan (The Zind) and its explanations or the character and language of Al-Ma’arri did not pay any attention to it. Therefore, I made this research a continuation of those efforts, using semantic research as a means of revealing Al-Maarri's ef
... Show MoreRhythm is considered one of the creative concepts in the recent architectural thought; it has emerged clearly as a mean of creating the highest levels of creativity in architecture, especially in contemporary architectural movements. The importance of rhythm has emerged, especially, when the architecture , its beginnings concentrated on the principle of the links with poetic structures. Many architectural studies deal with concept of rhythm in architecture with different ways various according to the trend of each study, this show the importance of studying the concept of rhythm in the architectural field in general. This study try to focus on the utilization of rhythm as creative system in architecture of heritage and contemporary
... Show MoreObjective: To assess knowledge and skills level regarding oxygen administration methods at p
ediatric teaching hospitals in Mosul City.
Methodology: A descriptive study was applied at pediatric teaching hospitals (Al-Kansaa, and Ibn Al-Atheer) in Mosul City from 8 of October / 2018 till 29 of May / 2019. The selection of the sample was non- probability (Purposive). This sample involved of (52) nurses. The questionnaire was constructed which consists of three parts and provided for nurses. The questionnaire validity was carried out through a panel of experts. To evaluate statistically the reliability of instruments, the pilot study was applied through period from 20– till –31 of January / 2019. Non-randomly (6) nurses from Ibn S
Asmari is the main productive reservoir in Abu Ghirab oilfield in the south-east part of Iraq. It has history production extends from 1976 up to now with several close periods. Recently, the reservoir suffers some problems in production, which are abstracted as water production rising with oil production declining in most wells. The water problem type of the field and wells is identified by using Chan's diagnostic plots (water oil ratio (WOR) and derivative water oil ratio (WOR') against time). The analytical results show that water problem is caused by the channeling due to high permeability zones, high water saturation zones, and faults or fracturing. The numerical approach is also used to study the water movement insi
... Show MoreDiabetes mellitus is a set of metabolic diseases, the most prevalent of which is chronic hyperglycemia. The culprits include insulin synthesis, insulin action, or both. Osteoporosis is a progressive systemic skeletal disorder defined by decreased bone mass and micro architectural degeneration of bone tissue, resulting in increased bone fragility and fracture risk, according to the World Health Organization (WHO). The degree of Nervosa damage determines how much a diabetic patient's body has been compromised. The current study's goal is an estimation: Age, BMI, FBS, HbA1C, D3, ALP, Ca, P, and Osteocalcin in Iraqi T2DM Women's patients with and without Osteoporosis. Three vitamins are required for Osteocalcin biosynthesis: vitamin K for Gla f
... Show MorePaul Auster's City of Glass is here singled out as representative of the writer's The New
York Trilogy. All throughout his novelistic career, Auster has been working on a pseudothesis
that adheres to a certain aesthetic of disappearance. The study engages this Austerian
aesthetic apropos of certain theoretical stretches such as the Emersonian "Not Me", the
Thoreauvian "interval" or "nowhere", the Deleuzian "nomadic trajectory", the Derridian
"grammè" or "specter", and the Baudrillardian "disappearance". The city of the novel's titling
is here seen as the trope of all that which has already disappeared, and hence it is seen as the
space (mise en scène) where the perfect crime of the murder of the real is to be thoro
Pesticide poisoning is a serious global public health issue and is responsible for a sizable number of annual fatalities. This study was designed to examine the potentially harmful effects of adult rats being exposed to imidacloprid (IMD) as a nanoparticle by determining the chronic effect of inhalation of (5,10 and 20) mg/kg/b.w. of nano-imidacloprid for a duration of 60 days. The most important biochemical parameters of the serum liver function parameters were aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase ALP, kidney function [blood urea, creatinine, and urea], and oxidative stress parameters (MDA, GSH, and CAT) in all treated groups when
This study aimed to isolate and identify Cryptococcus species from three distinct sources: sputum samples of pigeon fanciers, dried pigeon droppings, and eucalyptus tree leaves. A total of 150 specimens were collected over a two-month period, comprising 50 samples each from human sputum, pigeon droppings collected across various areas of Baghdad, and eucalyptus leaves obtained from the Baghdad College of Veterinary Medicine. All samples were cultured on Sabouraud dextrose agar supplemented with chloramphenicol and incubated at 25°C for 2–3 days. From the initial cultures, 20 isolates presumptively identified as Cryptococcus spp. were obtained: 6 isolates (12%) from human sputum, 9 isolates (18%) from pigeon droppings, and 5 isol
... Show MoreBackground: Osteoarthritis OA is the most common joint disorder in the world. Injection of high molecular weight hyaluronic acid intra-articular with steroid is a one of the used therapeutic option for patients with (OA)knee.
Objectives: Objective of this study was the evaluation the efficacy, safety, pluse duration of action of viscosupplementation of the HMWHA( high molecular weight hyluranic acid ).
Type of the study: Cross-sectional study.
Methods: From 81 patients with sever knee pain due to OA (grades 3–4) were recruited from Al-Yarmouk teaching hospital & a private clinic during the period from January 2014 till July 2016.
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