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

These researches have shown the magnitude of the influence that culture exerts on all human extensions and spaces. Rather, the conviction of many thinkers, researchers and specialists in the comprehensiveness of this influence is such that it is used as a starting point and perspective to explain the various aspects, manifestations, problems and practices. According to these perceptions, a man carries a cultural mind that is slowly formed throughout the young years of a man’s life and is completed upon reaching the age of maturity. Therefore, it has become evident in the behavioral, social and human sciences to acknowledge the multiplicity of human thought patterns as a natural result of the different cultures of peoples and societies.

This paper aims at presenting a comparison between objective and subjective tests . This paper attemptsto shed light on these two aspects of tests and make do a compression by using suitable techniques for objective and subjective tests .

     The paper compares between the two techniques used by the objective and subjective tests respectively, the time and efforts required by each type, the extent to which each type can be reliable, and the skills each type is suitable to measure.

     The paper shows that objective tests, on the contrary of the subjective ones, encourages guess> Objective tests are used to test specific areas of langua

The research aims to review the concepts of banking efficiency and its relationship to performance, productivity and efficiency, as well as analyze the efficiency of the banking in micro-economic view.
In order to achieve the objectives of the research We have been employed graphic, Econometrics  and Mathematical methods to derive the different concepts of banking efficiency.

We showed that there are two main methods used to measure the bank efficiency, the first called Stochastic Frontier Analysis , this technique depends on the parametric methods, The other method is called Data Envelopment Analysis is based on mathematical programming methods

The aim of the current research is to explore the health, psychological, and social implications of Internet addiction. Internet addiction is a new type of addiction, which negatively affects an individual’s life and creates social problems, psychological and nervous disorders. The research is divided into three sections: The first section is devoted to the definition of the research and includes the research problem, its importance in addition to the objectives, and the search terms were defined in it. The second section included the concept of addiction on the Internet and the causes, symptoms of addiction, forms, and previous studies were reviewed. As for the third topic, it deals with the theories explaining Internet addiction and

تم تقييم المعرفة والوعي تجاه داء الكريبتوسبوريديوس في هذه الدراسة خلال الفترة من أبريل 2009 حتى يونيو 2011 ، من بين 188 شخصًا من كلا الجنسين تم تقسيمهم إلى مجموعات ومجموعات فرعية مختلفة على النحو التالي المجموعة 1: تشمل 48 طبيبًا من مختلف المستشفيات والرعاية الصحية الأولية مراكز في بغداد تم تقسيم هذه المجموعة إلى 30 طبيبًا متخصصًا و 18 طبيبًا ممارسًا عامًا. المجموعة الثانية: تضم 45 عضو هيئة تدريس من قسم الأحياء ، قس

      In this paper, we introduce the concepts of Large-lifting and Large-supplemented modules as a generalization of lifting and supplemented modules.  We also give some results and properties of this new kind of modules.

   Let  be a commutative ring with identity, and  be a unitary left R-module. In this paper we, introduce and study a new class of modules called pure hollow (Pr-hollow) and pure-lifting (Pr-lifting). We give a fundamental, properties of these concept.  also, we, introduce some conditions under which the quotient and direct sum of Pr-lifting modules is Pr-lifting.