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.
This research deals with the technical configuration of the beautiful visions among Bany Ahmar poets reflected through the incarnation of beautiful artistic images that manifests itself clearly in the combination of two contradictories simultaneously.
The main conclusion is, the Andalusian poets try to use those fictional visions in search of aesthetic pleasure and values, through forming an image from water and fire as two prominent contradicted elements to express the impact of the heat of wine which soon vanishes when it is mixed with water. By this, they show the beautiful side of nature that suggests joy and splendor.
Was and military music still in Iraq whatever tributary of Music, where contributed Brphi Iraqi music musicians, authors and composers of musicians skilled and qualified teachers, was, and still have a big role in the growth and prosperity and progress of contemporary Iraqi music through active and vital role and make a lot of musical tenders excellence in various military and civilian walks of life whether it be in the days of war or peace.As it is the military music schools and the main source of the most important in the education of these machines and training. Therefore occupies the military musicians in Iraq prestigious and important, particularly in the Iraqi National Symphony Orchestra started the forefront of the musical instrum
... 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
1.Chapter I (systematic framework) which includes: the research problem and the importance of the research, the need for it, the goals of the research, the temporal &spatial boundaries, determine the terms and defined procedurally.2.Chapter II - the theoretical framework: It consists of three sections are:•The first topic:- the concept of references and experimentation in the theater. •The second topic:- the director of academic and experimentation in Iraq. Two paragraphs in this section came after the introduction, in first paragraph to talk about the Iraqi theater academic and experimentation, and in the second paragraph the researcher spoke about the academic director of the Iraqi and experimentation. 3.Chapter III - Actions -
... Show Moreلقد تسبب انتشار الإرهاب في العالم وكذلك الحروب الأهلية والصراعات في أوائل القرن الحادي والعشرين في جميع أنحاء العالم في الكثير من الأضرار وخلفت ضحايا جسيمة. أدت الهجمات الإرهابية على النساء، مثل اختطاف بوكو حرام لأكثر من 270 تلميذة في نيجيريا وتقارير عن انتشار الاغتصاب والاعتداء الجنسي في المناطق التي مزقتها الحرب، إلى إنتاج العديد من العروض المسرحية في الولايات المتحدة التي تصور خواص الجناة وكذلك الضحا
... Show MoreThe study of cooperative education is important not only for researchers but also for those interested in studying educational methods, such as university professors, teachers in schools, and all educational institutions. This is because of its effectiveness in teaching students, developing their skills, developing their ideas and employing them in the study and finding appropriate solutions to the questions posed by the teacher. It also helps in instilling a spirit of cooperation among the students by dividing them into groups to achieve the desired goals. The aim of the study is to clarify how important it is for teachers to use cooperative education in addressing the educational, social and psychological aspects when teaching stu
... Show MoreThe modern nation state, by virtue of its institutional nature, is divided into political and non-political institutions according to their respective jurisdictions. It is natural for non-political institutions to perform their functions under the control of the political establishment, for two reasons: first, Second: Ensuring the achievement of cooperation, harmony and integration between these different institutions in serving the stability of the society and its continuity and achieving its supreme objectives. The location of the military establishment is part of the non-political institutions of the state, since it carries out a non-political function that is based on defending the homeland against any threats that may threaten its s
... Show MoreNeurolinguistics is a new science, which studies the close relationship between language and neuroscience, and this new interdisciplinary field confirms the functional integration between language and the nervous system, that is, the movement of linguistic information in the brain in receiving, acquiring and producing to achieve linguistic communication; Because language is in fact a mental process that takes place only through the nervous system, and this research shows the benefit of each of these two fields to the other, and this science includes important topics, including: language acquisition, the linguistic abilities of the two hemispheres of the brain, the linguistic responsibility of the brain centers, and the time limit for langua
... Show MoreAre the actions and rulings of God Almighty justified by intentions and purposes or not? This is a matter of the minutes of the science of theology in which there was a wide difference between the Islamic groups, especially the verbal ones.
This study is an attempt to reach the correct opinion or to avoid it, and to clarify the disagreement that took place in this issue, especially in the Ash'ari school of thought, and it is also an attempt to reconcile opinions as much as possible, and to explain what may appear to be disagreements among some.
Therefore, I divided this research into two topics, and issued it with an introduction in which I defined the terms that are related to the explanation.