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.
In his novel entitled Victory. Joseph Conrad asserts himself as a writer for man
as a moral agent in this universe. His characters exhibit the possibilities for isolation
and moral deterioration in modern life. The aim of this research is to investigate some
social issues that touch the core of humanity. In this novel, Conrad's perceptive eyes
has noted so many social issues that need to be tackled. Implicitly and explicitly,
Conrad launches so many controversial issues like : communication and
disengagement or skepticism , conflict between heart and mind ,fate, demonic
identification sense of guilt in man, men , women and homosexuality, the clash
between the civilized and the raw ,the disregarded local people and
Lexicography, the art and craft of dictionary-making, is as old as writing. Since its very early stages several thousands of years ago, it has helped to serve basically the every-day needs of written communication among individuals in communities speaking different languages or different varieties of the same language. Two general approaches are distinguished in the craft of dictionary-making: the semasiological and the onomasiological. The former is represented by usually-alphabetical dictionaries as such, i.e. their being inventories of the lexicon, while the latter is manifested in thesauruses. English and Arabic have made use of both approaches in the preparation of their dictionaries, each having a distinct aim ahead. Wit
... Show MoreAndrogenetic alopecia (AGA) or baldness is a common form of hair loss, affecting men more than women .The exact causes and pathogenesis of baldness are not well understood. A search for new drug is still needed. This study aims to evaluate the role of gonadotropins hormones in hair loss in males and its possibility to be used as treatment target. A total of 78 volunteers 43 with baldness and 35 healthy men were participated in this study. Their age ranged between (20-49) years, the studied groups were divided into two categories: firstly according to age (group1: 20-29 year), (group2: 30-39 year),and (group3: 40-49 year).Secondly according to baldness degree. LH and FSH were measured by using Enzyme Linked Immunosorbent Assay (ELISA) kits.
... Show MoreCrimes are prohibited by law and God Almighty has forbidden them with punishment or punishment.
The punishment is the prescribed punishments that the law has determined in its place and stipulated in the Book of God or the Sunnah of His Prophet, may God bless him and grant him peace.
Ta’zir: These are the punishments that are left to the ruler to assess according to what he sees as preventing corruption on earth and preventing evil. Extrapolation has proven that all the provisions of Islamic Sharia include the interests of the people, and they are based on five matters: what is in it is preserving the religion, what is in it is preserving the soul, and what is in it is preserving the soul. It involves preserving the mind, preserv
Praise be to God, Lord of the Worlds, and prayers and peace be upon our Master Muhammad and upon all his family and companions:
And then: What most concerns rational people and reformers in the modern era is the moral deviation and delinquency that dominates childhood, due to family disintegration and the lack of discipline of most societies according to the religious and moral motives called for by the heavenly messages, especially Islam, which is the final message and guarantees the reform of people in life. Every time and place.
Islam has drawn attention to this issue (childhood) and made it the focus of its consideration, considering that the child is the nucleus of society and the preparation for the future, so it ordered that
Background: Asymptomatic bacteriuria (ASB) is
defined as isolation of a specified quantitative count
of bacteria in an appropriately collected urine
specimen from an individual without symptoms or
signs of urinary tract infection.
Aim of study: To evaluate the frequency of
bacteriuria according to age, pregnancy, and type II
diabetes mellitus in a sample of Iraqi women.
Patients and Methods: A total of 125 female
individuals were involved. The study participants
were classified into the following groups: nonpregnant
women with type II diabetes mellitus,
pregnant women with type II diabetes mellitus,
pregnant women without type II diabetes mellitus, and
apparently healthy non-pregnant women. Urine
This paper is devoted to the discussion the relationships of connectedness between some types of graphs (resp. digraph) and Gm-closure spaces by using graph closure operators.
The research deals with the global ceramic achievement within the international forums in the past decades. As follows، showing and presenting the aesthetic and intellectual values leading to common constants that establish international artistic studies that achieve the purpose of circulation and marketing of artworks. Contemporary global plastic art has witnessed a number of technical and social transformations and changes at the technical and pragmatic levels under the pressure of the changing and accelerating tide towards technical، cognitive، social and cultural concepts.
The second chapter came to the first topic: deliberative and commoditization، and the second topic: the deliberativeness of contemporary global ceramics.