In this paper, we discuss physical layer security techniques in downlink networks, including eavesdroppers. The main objective of using physical layer security is delivering a perfectly secure message from a transmitter to an intended receiver in the presence of passive or active eavesdroppers who are trying to wiretap the information or disturb the network stability. In downlink networks, based on the random feature of channels to terminals, opportunistic user scheduling can be exploited as an additional tool for enhancing physical layer security. We introduce user scheduling strategies and discuss the corresponding performances according to different levels of channel state information (CSI) at the base station (BS). We show that the availability of CSI of eavesdroppers significantly affects not only the beamforming strategy but also the user scheduling. Eventually, we provide intuitive information on the effect of CSI on the secrecy performance by considering three scenarios: perfect, imperfect, and absence of eavesdropper's CSI at the BS.
The habitat type and food availability always influence the population size of many
organisms. Bird’s feeding pattern should be abstracted to complete avian community structure
data. The agronomy main research farm of Orissa University of Agriculture and Technology
is a well-managed multi-crop agro-ecosystem which provides a suitable ground for ecological
research. In a multi-crop farmland, the association of Barn Swallow Hirundo rustica Linnaeus,
1758, with the Indian mustard Brassica juncea (L.) Czernajew, 1859 crops have been
recorded for the first time while hovering only on this field. A flock of Barn swallows was
recorded in 32 field visits while flying continuously over the Indian mustard field after
flow
A study has been performed to compare the beddings in which ductile iron pipes are buried. In water transmission systems, bends are usually used in the pipes. According to the prescribed layout, at these bends, unbalanced thrust forces are generated that must be confronted to prevent the separation of the bend from the pipe. The bed condition is a critical and important factor in providing the opposite force to the thrust forces in the restraint joint system. Due to the interaction between the native soil and the bedding layers in which the pipe is buried and the different characteristics between them. Also, the interaction with the pipe material makes it difficult to calculate the real forces opposite to the thrust forces and the way they
... Show MoreThis study was conducted to determine the ability of water treatment system (Vortisand) to reduce some chemical and physical properties for tigris river raw water, It consisted of turbidity, electrical conductivity, pH, total hardness, calcium Hardness as well as temperature in order to determine the unit`s efficiency for reducing their concentration as compared to those in the water produced by some classical potable water projects (Dora and Wathba) in Baghdad. Samples were collected during the cold months (December 2016 and January 2017) and during the hot months (May and June 2017). The results showed that this system has the ability to reduce some properties such as turbidity, the values were 215NTU in raw water and decreased to NTU
... Show MoreABSTRACT
Metal (II) complexes of Co, Ni, Cu and Zn with cefdinir C14H13N5O5S2 derivative (L) were synthesized and identification by elemental analysis CHNS Uv-Vis, FTIR, TGA, metal analysis AA, magnetic susceptibility and conduct metric measurement. by analysis the ligand behaves as a bidentate. For the cobalt complex, Tetrahedral geometry shape was suggested, while other complexes that have nickel, copper and zinc ions were proposed as octahedral geometry shape. The experimental method was studied for prevention of corrosion carbon steel in 3.5% NaCl by using a novel Cefdinir derivations drugs. The results showed that metal complex was a strong corro
... Show MoreThe research aims to determine the strength of the relationship between time management and work pressure and administrative leadership, where he was taken a sample of (47) of the administrative leadership at the Higher Institute of security and administrative development in the Ministry of Interior was used questionnaire as a key tool in collecting data and information and analyzed the answers to the sample surveyed by using Statistical program (spss) in the arithmetic mean of the calculation and test (t) and the correlation coefficient, the research found the most important results: the existence of significant moral positive relationship between both time management and work pressure and administrative leadership, the leadership of th
... Show MoreFirst: the definition searchEnsure the definition Introduction of research and its importance, as it was addressed to the importance of the importance of training in the development of people and institutions and the importance of diversifying the training vocabulary and a lot of relevant courses for its role to develop work and get away from the routine work, and was put up for the importance of research to identify the problems and obstacles facing the process of providing training as the best in order to access to the ambition sought by workers on training and even the trainees while defined research problem that was observed weak performance and cost-effective training through the study of some of the questionnaires distributed
... Show MoreThe purpose of this paper is to building a comprehensive quality scale for school sports activities from the standpoint of physical education teachers in the directorates of education in the Governorate of Baghdad. The researchers used the descriptive approach with the survey method because it is the most appropriate to the nature of the problem and to achieve the objectives of the research .The good selection of the sample will reduce sampling errors, which enhances the honesty and accuracy of the data, which is representative of the research community and is always linked to its representation of the community and the possibility of generalizing its results to the group from which it was taken, as it represents the research community with
... Show MoreThe research discusses with organizational spirituality and its implications on the organizational performance in the General Company for Food Industries in Abu Ghraib (Baghdad). The aim of the research was to determine the contribution of organizational spirituality in the organizational performance of the surveyed company. In order to achieve the objectives of the research، two main hypotheses were adopted. Several sub-hypotheses centered on the relationship between organizational spirituality and organizational performance in terms of its dimensions (Meaning work، self-esteem، community affiliation،
... Show MoreAim of the Study: The paper aims at identifying the extent of the role of strategic leadership represented by its four dimensions (administrative, transformational, political, moral) in fulfilling the requirements of university governance (Context, message and Goal, Management orientation, Independence, Issue, Sharing)
Methodology: A survey is applied to (107) members of the teaching staff at the college of Administration and Economics/ University of Mosul. To achieve the goals of the study, the researcher makes use of a number of tools such as: questionnaire, statistical tools and methods (repetitions, perce
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