Cognitive radio technology is used to improve spectrum efficiency by having the cognitive radios act as secondary users to access primary frequency bands when they are not currently being used. In general conditions, cognitive secondary users are mobile nodes powered by battery and consuming power is one of the most important problem that facing cognitive networks; therefore, the power consumption is considered as a main constraint. In this paper, we study the performance of cognitive radio networks considering the sensing parameters as well as power constraint. The power constraint is integrated into the objective function named power efficiency which is a combination of the main system parameters of the cognitive network. We prove the exi

This research set to indicate the role of the opportunity cost in the overall economic development (human and social development) by selecting the most appropriate alternative for the growth of the country in exchange for sacrificing profit limits to achieve this growth and development of the country, especially in the present circumstances of the country and after studying the reality of the economic case for him, as the problem lies with don't selecting the best alternative that enhances the gross domestic product, which extends to promote overall economic development and revive the industrial and agricultural sectors, productivity is more like Impotent, versus sacrifice alternative consumption may bring more financially lucrative than

This study aims at defining the concept of the fragile state, a term that came into existence in 2014, when the states that had internal Problems and external interventions were referred to as the failure states. However, the indicators for their designation and the criteria adopted are 12 indicators that address all aspects of the State’s duties vis-a-vis its citizens. The study examined the reasons that led to the continuation of Iraq within the fragile states, and the selection of the five years within the time limits of the study due to the factors that led to the decline of Iraq and falling back within the most fragile countries. The study dealt with the fragile state challenges to the media reality as a result of the change of it

Abstract:

     The use of economic resources enjoyed Iraq by especially oil resources, which constitute the main source of financial revenue, would the economic surplus outside the oil sector increases by mobilizing and rallying the labor power and turn it into an access capitalism, , was the cause of "the inaction of the productive sectors of the economy, made the investment planning process and even investment in human capital was not rationality with the increasing number of unemployed, particularly certificates and specializations high campaign, direction of the government towards market liberalism after 2003 through the, was focused not follow a clear economic policies, and the absence of planning

China's economic policy and its huge capabilities operate according to an expansion strategy, especially in investing foreign projects, as the past ten years have witnessed a major development in the elements of comprehensive strength, especially in the economic field, in 2014 China launched the largest initiative in the world, represented by the Belt and Road Project (BRI), which links nearly 70 countries, through this project, a very important region has emerged, which is (the port of cadres) in Pakistan, as China has headed towards that region and given the highest importance that is in its interest in the first place regardless of the great Pakistani interest, This is consistent with its future aspirations, especially after breaking

The freedom to promote ideas is one of the freedoms protected by constitutions and laws, and it is exercised by individuals through traditional and electronic media. However, this freedom must be exercised according to certain limits, represented by the necessity of respecting human rights, just as individuals have the freedom to exercise their right to publish and express their opinion in every way. Frankly, in return, she must respect the rights of others . Perhaps the development that has occurred in the various media, including journalism, radio, television, and the emergence of a new medium represented by the Internet, has contributed significantly to harming the security of individuals through the promotion of extremist ideas. This be

The research Reviews the sides of highlight importance of the Nano-Accounting which doing the accounting performance functions fully computerized without the intervention of an accountant, to solve the problem of not keeping up the  rationalization of recording and accounting systems, with the rationalization of production which fully computerized.(be invisible and hidden accounting), resulting by linking or interaction of the accounting, additive production system represented three-dimensional printers, open source and recycling. That which result the rationalizing the facilities of production, organization and self-control which derived nanotechnology idea, which aims to minimize materials and change it properties, then view the a

Adolescence important and sensitive stage in social terms, being a stage where learns teenager bear social responsibilities and composition of their ideas about family life, as well as it is the stage where the teenager looking to himself for an important place in the community to become independent socially people, so it highlights the role of Social Work to do better effort and I believe him in order to prepare for the adolescent stage of adolescence and help him overcome the problems so that makes it adapts to the society in which he lives

The treasury bills one internal government debt instruments in iraq that were used to finance temporary deficits in the government budget, There fore the government resorted to issuing for the purpose of providing liquidity, As well as to invest in productive progects, After that it was financing the budget deficit by the monetary authovity of  the central baalpennek  [the new cash velease] which led to negative effects on the Iraqi econome, Thus we find that the treasury transfers have formed alarge proportion of the gross domestic government debt to finance the deficit ayear ago 2003.                      &nbs