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.
The research current (Comment formal for Hruvijat in contemporary Iraqi porcelain). In an attempt to study the Arab character that inspired the Iraqi artist of all intellectual its terms of reference and stylistic by taking advantage of the cultural heritage and the rebuilding of the character to create a system ride of relationships that focus on structural body ceramic body ideas and multiple implications are invested in the structural fabric of the products of contemporary ceramic .vdila for ways to achieve and processing techniques and transmission of functional specificity (blogging) and cosmetic particularly to semantics derive from the content and expresses itself templates ceramic raw materials and by building works of art in pla
... Show MoreIn this paper, there are two main objectives. The first objective is to study the relationship between the density property and some modules in detail, for instance; semisimple and divisible modules. The Addition complement has a good relationship with the density property of the modules as this importance is highlighted by any submodule N of M has an addition complement with Rad(M)=0. The second objective is to clarify the relationship between the density property and the essential submodules with some examples. As an example of this relationship, we studied the torsion-free module and its relationship with the essential submodules in module M.
This research attempts to investigate narrative structure in oral narrative particularly in Oprah's Show from a sociolinguistic viewpoint. Narrative is said to be universal in the sense that it is found in all times and places. There is no society or culture without narrative. Oral narrative is organized in a specific order. The research aims at studying and analyzing this order. In addition to that, it highlights the importance of narrative in conveying some moral messages to people who are listening to the story. The study is divided into two parts; theoretical and practical. The theoretical part draws on presenting a survey of literature which includes definitions and explanations of some related terms. The practical part is concerned
... Show MoreForm naming system Simiaúaa can not be studied in isolation from the dimensionality of social and psychological , no doubt that names carry data psyche during social interaction , deflagration volunteered her body signifier in formats that meet the margin emotional part of the signified , Vtngams forms functions in coordinated trading to function as semantic double , it operates on coding , as well as carry emotional charge .
The science of semiotics cares Pettmvsal indications and forms of circulation, and is made form the semantic patterns , and pattern of production , and methods of functioning . Stop quite a few specialists and critics and researchers at Dalia ignorant poet and knight known ( Duraid bin embolism Jashmi ) ; it rep
Background: Osteoid osteoma(OO) is a relatively common benign skeletal neoplasm of unknown etiology that is composed of osteoid and woven bone, usually seen in adolescent and young males Although, the clinical, radiological and scintigraphic features of OO have been well described, these features may be misleading or altered in the cases of lesser trochanter of the femur which is relatively uncommon location for OO with a few number of cases reported up to date.Case Presentation: We report a case of a 20-year-old man who presented with painful limpThe pain had begun six months earlier and was made worse by walking and by exercise., with normal initial X-rays .The diagnosis was made after six months when typical Computed tomography, magne
... Show MoreVisceral leishmaniasis (VL) is a parasitic infection caused by an intracellular growth of Leishmania spp. in macrophage cells. The autoimmune disorder is a condition takes place when the immune system produces antibodies which incorrectly attacked its own body tissues. VL has been involved as an effect or on the autoimmune aspect. This study was conducted to identify the auto antibodies profile in patients infected with VL. The presences of auto antibodies in 21 Iraqi children infected with VL were tested for laboratory autoimmune aspect. The highest percentage of seropositive in Leishmania patients was observed for anti-ds DNA, anti-Mi-2, anti-Ku and anti-PCNA antibodies (90.5%, 90.5%, 90.5% and 61.9%) respectively, while the lowest percen
... Show MoreIn petroleum industry, the early knowledge of “pore pressure gradient” is the basis in well design and the extraction of these information is more direct when the pore pressure gradient is equal to normal gradient; however, this matter will be more complex if it deviate from that limit which is called “abnormal pore pressure”, if this variable does not put in consideration, then many drilling problems will occur might lead to entire hole loss. To estimate the pore pressure gradient there are several methods, in this study; Eaton method’s is selected to extract the underground pressure program using drilling data (normalized rate of penetration) and logs data (sonic and density log). The results shows that an abnormal high press
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