Cognitive radio is observed as a new approach, which could be cope with the spectral limitations. This approach is designed to detect whether a particular segment of the radio spectrum is currently in use and to jump into the temporarily unused spectrum rapidly without interfering with the transmissions of other users. CR is the promising radio technology which aims to detect and utilize the temporally unused spectrum bands by sensing its radio environment in order to improve spectrum utilization. To enhance the sensing performance, cooperative spectrum sensing has been proposed. However, when the number of cognitive user tends to be very large, the bandwidth for reporting sensing results to the common receiver will be very huge. In this paper we described interference avoidance in spectrum sensing and then we illustrated the benefits of cooperation in cognitive radio by considering a simple user network and showing improvement in agility , we propose a practical scheme which allows cooperation between cognitive users.
The effect of Al dust particles on glow discharge regions, discharge
voltage, discharge current, plasma potential, floating potential,
electron density and electron temperature in planar magnetron
sputtering device has been studied experimentally. Four cylindrical
Langmuir probes were employed to measure plasma parameters at
different point on the radial axis of plasma column. The results
shows the present of Al dust causes to increase the discharge voltage
and reduce the discharge current. There are two electron groups in
the present and absent of Al dust particles. The radial profiles of
plasma parameters in the present of dust are non- uniform. The
floating potential of probe becomes more negatively while
Some responses to ancient grammarians
And contemporary researchers
In monograms
The Messengers and the Imam of the God-fearing, Muhammad is God, his family, and all of his companions. As for what comes after... Fainting is one of the involuntary symptoms and states that occur to a person when carrying out his life’s tasks suddenly due to his loss of sense and movement, so he loses consciousness for a period of time that is short or may be long, and the person is held accountable and responsible for every moment of his life. He is required to perform duties specified by Sharia law, such as prayer, fasting, and Hajj...and fainting prevents him from performing these actions. We must consider the opinions of jurists and know the legal implications resulting from it. It was said that a person has a capacity that enable
... Show MoreThe graphic privacy feature is one of the most important specifications for the existence of any type of design achievements alike, which is one of the graphic products with its multiple data, and from here the current research investigates the graphic privacy of vector graphics design with all its technical descriptions and concepts associated with it and the possibility of achieving it to the best that it should be from Where its formal structure in children's publications, where the structural structure of the current research came from the first chapter, which contained the research problem, which came according to the following question: What is the graphic privacy in the design of vector graphics in children's publ
... Show MoreTourism is a human phenomenon and economic and social activity. It represents an effective forces in the life of the individuals and state alike. As any other economic and human activity has appositive and negative results.
So there is a necessary to planning and activate this sector to get the most possible advantage.
Tourism has special importance out of its effect on the structure and performance of national economy. It can be regarded a dynamic activity with mutual effect include all the economic activities within and out the state. Tourism is affected and affect the production con summing , joineries , communication , ports ,hotel , restaurants ,internal and
... Show MoreThis research aims to identify the nature effect of some mechanisms governance in the Accounting Conservatism for a sample of the practices of companies (banks) in the Iraq Stock Exchange and identify any of this mechanics most effects in the accounting Conservatism. To achieve this objective the use of all of it (the size of the board of directors, management ownership, ownership concentration, the auditor's report) as independent variables was used model Basu revised to measure the Accounting Conservatism , which was considered a variable follower with taking into account the effect of the control variables represented by the (company size and leverage) of a sample of listed on the Iraq Stock Exchange companies for the pe
... Show MoreDuring recent decades, hundreds of thousands of Iraqis lost their lives as a result of wars, economic blockade, or acts of violence and terrorism. The loss of a family member, especially husband makes women suddenly bears full responsibility for the family. Lost could impose new changes in psychological, social, and economical roles. These changes usually combine with the negative effects aftermath the lost trauma. Some of the reports in Iraq showed there were increased and huge numbers of widows and orphans. This study aimed to identify the aspects of Posttraumatic Growth (PTG) in Iraq women who lost their close relatives (especially husbands). 52 of Iraqi women who lost their husband and 49 women who experienced other traumatic events
... Show MoreThe present research studies numbers and its uses in the Islamic ornament. The study consists of four chapters; the first is dedicated to the problem of the research, the value of the study, and the aim of the study, and its limit. The problem of the study deals with the uses of numbers in Islamic ornament and how these numbers were used for aesthetic purposes. What are the analytical bases that enable us to read the geometrical compositions ornament numerically? The value of the research is the study forms an analytical and visual study of the numbers in the Islamic ornamentation. Additionally, this study is an aesthetic assessment to the philosophy of the number and its uses in Islamic architecture. The study is limited to the ornament
... Show MoreThe main objective of this work is to introduce and investigate fixed point (F. p) theorems for maps that satisfy contractive conditions in weak partial metric spaces (W.P.M.S), and give some new generalization of the fixed point theorems of Mathews and Heckmann. Our results extend, and unify a multitude of (F. p) theorems and generalize some results in (W.P.M.S). An example is given as an illustration of our results.