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 Civil Rights era has been an era of struggle for the African American in the
Unites states. Thus, many writers devoted their writing to reflect the racism and
discrimination that many have suffered from, among them is Ralph Ellison.
Ralph Ellison is a 20th century African-American writer and scholar best known for
his renowned, award-winning novel Invisible Man. He illustrates the powerful
social and political forces that conspire to keep black Americans in their place,
denying them the right to life, liberty, and the pursuit of happiness guaranteed to all
Americans. Invisible Man is a 1952 novel that addresses many of the social and intellectual
issues facing African-Americans in the twentieth century. It exa
Rheumatoid arthritis (RA) is a systematic autoimmune disorder with chronic inflammation changes of unknown etiology. Various synovial inflammatory and proliferative alterations may contribute to the cartilaginous tissues and invasive bony tissues, leading to destructive joints and malformed bones. This disease is mostly due to infective microorganisms or genetic susceptibility causing immune system disturbances through triggering both T-cells and B-cells. Furthermore, different immune cells may secret cytokines, which are responsible for some RA pathogenesis activity. From ninety individuals, serum sample was collected; thirty of them were normal and sixty cases were patients with RA attended a privet medical clin
... Show MoreThe reason for studying (The secret of Repentance and Confession in Christianity) goes back to the deep roots of repentance in all religions, specially the three revealed religions, and those who adhere to them. The human psych by nature is incessantly demanding sins and the wrong deeds. It is in need of repentance which God has opened for them. Almighty God is happy when his creatures repent and refrain from sinning. This is the reason for success in life and the hereafter and the principle of the happiness. It is also a condition for the good course. Therefore, man should refrain from sinning and feel regret for committing sins forever.
The Islamic religion approach Rabbani urges and seeks to bring happiness to people, as Allah says: ((We sent thee not all people glad tidings and a warner, but most people do not know)) Spa: State 28
Islam looks at the concept of educational values through positive behavior derived emerging through formal and informal education. The Islamic approach works on the basis of a systematic and clear rule in the form of an integrated system includes multiple areas. As the lead actor role as the desired position.
Although
Review of multidrug sensitivity and resistance in enterococcus
اليورانيوم المنضب واستخدامه امريكياً في العراق
Alms (or Zakat) is one of the Pillar of Islam and it was atask imposed on
Muslims. Becomes of the importance of this task and its influence on the human
Psychic in particular and on the Society in general this study aims at Studying the
words that it refers to in the Holy Quran, At the beginning the researcher has
introduced the words it refers to, and the significance of each in the Holy Quran and
the Speciality of each one of such words, then the Structures they donet have been
also introduced, whether such structures are descriptive, adverbial or verbal.This was
introduced in addition to explaining the influence of changing the Shape of such
words in emphasizing the meaning and the influence of Portraiting styl
The research team seeks to study the phenomena of random housing in Iraqi society in general and Baghdad city in particular by standing on the causes behind this phenomena and its relation with security situation in Baghdad. The researchers adopted a theoretical and practical framework. The main objective is to diagnose the risks caused by the escalation of slums in Baghdad city.
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.
Deception is defined as a linguistic and non-linguistic behavior that is used in interaction in order to make the addressees believe what is believed to be false or lack evidence. McCornack (1992) classifies deception into four manipulative strategies (i.e., fabrication, distortion, equivocation and concealment), other scholars argue that deception encompasses the strategies of “fabrication (outright lying), equivocation (being vague and ambiguous), or concealment (with holding relevant information) Thus, the present study investigates the deception strategies and motives that are used by Johnny Depp and Amber Heard during their defamation trials. Qualitative and quantitative methods are employed when analyzing the data in question. Th
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