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.
Wisdom is the separation and distinction between aim in the word and work and the lack thereof in accordance with the knowledge surrounding the arts of science, which reached a thorough understanding of things and put them in the quorum. In this research, I have tried to discern the characteristics of the wisdom of Imam Hassan al-Askari (peace be upon him) and to explain his methods and actions which are indicative of the various facets of wisdom required by the nature of the actions and behavior that he has to deal with. Or future mother.
The second topic was devoted to the style of Imam (p) and his wisdom in the situations that necessitated the diversity of methods of dealing such as the method of concealment and the method of refer
The problem of housing in Iraq is a long-rooted and rooted problem, and it needs a great effort to find out its causes and thus give essential points that contribute to alleviating and addressing it, and it is worth noting that research into the housing problem and the housing sector in Iraq is not done in isolation from other sectors and studies. As well as the economic policies pursued and the social and political conditions. It is known that the Iraqi economy is a unilateral (rentier) economy, that is, it depends almost entirely on exporting oil and obtaining revenues, and that the economic decision and economic policies followed in Iraq are greatly affected by several factors, including the economic, social and political fact
... Show MoreThe theatre is one of the main pillars of the human aesthetic thinking as it contains logical explanations for the public human life aspects outside time and environment. When we find that the directive philosophical thinking moving away from the stylistic constants and the virtual laws in taboos that control the accomplishment in terms of the traditional shapes, the employment and the theatrical reception. Some directors moved in post-modernism concepts in a perceptive that liberates thought from its natural context in thinking into an innovative perceptive. The aesthetic images are the basic premise in the prohibition of the philosophical thinking interpretation in order to move the directive thinking and this movement depends on the v
... Show Moreالأهداف: تهدف الدراسة إلى التعرف على مستوى نزاع العمل والأسرة لدى الممرضات في المستشفيات التعليمية في مدينة
الناصرية , تحديد العلاقة بين نزاع العمل والاسرة و عمر الممرضات في المستشفيات التعليمية في مدينة الناصرية.
منهجية البحث: تم إجراء دراسة ذات تصميم وصفيي في المستشفيات التعليمية بمدينة الناصرية خلال الفترة من 1 نوفمبر 2020 إلى 1 أبريل 2021 من أجل تحديد ا
... Show MoreAn easy, eclectic, precise high-Performance Liquid Chromatographic (HPLC) procedure was evolved and validated to estimate of Piroxicam and Codeine phosphate. Chromatographic demarcation was accomplished on a C18 column [Use BDS Hypersil C18, 5μ, 150 x 4.6 mm] using a mobile phase of methanol: phosphate buffer (60:40, v/v, pH=2.3), the flow rate was 1.1 mL/min, UV detection was at 214 nm. System Suitability tests (SSTs) are typically performed to assess the suitability and effectiveness of the entire chromatography system. The retention time for Piroxicam was found to be 3.95 minutes and 1.46 minutes for Codeine phosphate. The evolved method has been validated through precision, limit of quantitation, specificity,
... Show MoreMany studies and researches related to the audio and visual medium have shed light on the creative process that has taken place through them as well as the aesthetic and artistic creation and have dealt with many fields of knowledge and creativity in this field of art, which managed to study and follow its intellectual and technical tools for creating achievements through this medium, in its forefront come the elements of the cinematic language, which is characterized by possessing multiple features of aesthetic and semantic employment to reach the recipient as it is a tool of the artistic expression that gives the material it deals with aesthetic and intellectual dimensions from various aspects. "The artistic expression cannot be achiev
... Show MoreVaccine hesitancy poses a significant risk to global recovery from COVID-19. To date however, there is little research exploring the psychological factors associated with vaccine acceptability and hesitancy in Iraq.
To explore attitudes towards COVID-19 vaccination in Iraq. To establish the predictors of vaccine uptake and vaccine hesitancy in an Iraqi population.
Using a cross-sectional design, 7,778 participants completed an online questionnaire exploring their vaccination status, likelihood of infection, perc
A study conducted a laboratory experiment to measure the release of potassium and the dissolution of feldspar minerals in soils from different locations in Karbala Province (Ain Al-tamur, Qasr Al-Akhyar, Fadak Farm). The study involved the addition of organic acids (fulvic and humic) and mineral acids (sulfuric and phosphoric) at concentrations of 5% and 10% to sand-separated soil samples obtained through wet sieving. Feldspar minerals were identified using a polarized light microscope, and the percentage of each type of feldspar mineral was calculated. The results demonstrated that organic acids outperformed mineral acids in releasing potassium at both concentrations. Among the organ
Fourteen morphologically varied Ricinus communis L. seeds were collected from different localities in Egypt, El-Sudan and Saudi Arabia. Seed morphology and ITS barcoding analysis were performed to assess their diversity and phylogenetic relationship. Sequence’s alignment of nrITS region from different accessions display high levels of genetic similarities. Cluster analysis could not group different accessions according to their geographical distribution. Nevertheless, the genetic barcodes are interestingly matched with the morphological features of the Ricinus seeds. In conclusion, seed morphology proved to be a valuable tool in evaluating biodiversity and phylogenetic relationship in plant species with different loca
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