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 structure is considered in its scientific formula one of the concepts which complete the architectural image that seeks to take out an effective and attractive structure in contemporary architectural production, especially that the structure -in general- represents strength in addition to delight and functional benefits according to Vitruvius trinity. So, the role of structure depends on making its aesthetical properties able to give efficiency within architectural product. That has come through adoption of intellectual mechanism of structural means and details –as a whole or parts- and focused on structure with the recipient's needs, aesthetical, and sensory purposes in addition to its fundamental role of stabilit
... Show MoreBackground: Radiation therapy reported to be an effective in palliating pain. Objective: To describe roles of palliative radiotherapy in controlling pain in metastatic cancerous patients, and evaluation of radio-therapy doses in pain management. Methods: A prospective observational study carried out at the Baghdad Radiotherapy and Nuclear Medicine Center/Baghdad Medical City Complex, Baghdad, Iraq, from 1st of December 2018 to 30th of May 2019. 88 Patients, were included. Patients were assessed before applying radiotherapy, and at the end of treatment. Pain scoring used from 0 to 10. Kaplan Meier survival curve used. Result: The mean±SD of age was 55.44±11.1 years, and the most frequent age group was 41-50years as 37(42.1%). Breas
... Show MoreFlexible pavement design and analysis were carried out in the past with semi-experimental methods, using elastic characteristics of pavement layers. Due to the complex interferences between various layers and their time consumption, the traditional pavement analysis, and design methods were replaced with fast and powerful methods including the Finite Element Method (FEM) and the Discrete Element Method (DEM). FEM requires less computational power and is more appropriate for continuous environments. In this study, flexible pavement consisting of 5 layers (surface, binder, base, subbase, and subgrade) had been analyzed using FEM. The ABAQUS (6.14-2) software had been utilized to investigate the influence of the base layer depth on ver
... Show MoreUltrasound is a mechanical energy which can generate altering zones of compression and rarefaction along its path in the tissues. Ultrasound imaging can provide a real time screening for blood and multiple organs to aiding the diagnostic and treatment. However, ultrasound has the potential to deposit energy in the blood and tissues causing bio effects which is depending on ultrasound characteristics that including frequency and the amount of intensity. These bio effects include either a stable cavitation presented non thermal effects or inertial cavitation of harmful effect on the tissues. The non-thermal cavitation can add features in diagnostic imaging and treatment more than the inertial cavitation. Ultrasound Contrast agents are a micro
... Show MoreBackground: There are various secreted proteins affecting the prognosis of oral squamous cell carcinoma (OSCC) and one of them is Angiopoietin-2(Ang-2) which is thought to have an essential role in the development and progression of the tumor. Aim of the study: This study was conducted to determine the expression of (Ang-2) in (OSCC) to assess its correlations with clinicopathological parameters of the tumor. Material and Methods: 36 formalin- fixed, paraffin- embedded tissue blocks histologically diagnosed as OSCC were examined for Ang-2 immunohistochemical expression semi quantitively. Results: The expression of Ang-2 was significantly associated with histopathological grade (P value=0.023), while there is no significant association wi
... Show MoreThe Glass Manegerie is a metaphor, which is one of the greatest plays of great writer Williams. The play talks about the poor people in society and how try to escape this group of people from the real world to get rid of the hardness of this tuff reality and live in a fantasy world that is much like the glass where the world is very weak this world is acting by Laura, she is owner of these animals breakable glass where it's weak and unable to defend itself as well as the mother Amanda is a very selfish never think about her children but only herself.
Background: disturbed physiological rhythm of blood pressure in preeclampsia is a common finding. The role of oxidative stress in pathogenesis of preeclampsia is well accepted. Melatonin is a powerful free radical scavenger so it's rapidly consumed by enhanced reactive oxygen species in preeclampsia causing non-dipping in blood pressure.Objective: To evaluate the change in plasma melatonin levels in patients with preeclampsia and its relationship with blood pressure.Patients and methods: In this prospective case control study a total of 40 primigravidae pregnant women were recruited during the period of 11 months between August 2015 and August 2016 in Baghdad teaching hospital, medical city, Iraq, divided into two groups:First group
... Show MoreEmploying the social personalities (celebrities) in all fields (artistic, sports, media, etc.) is an important media and visual communication means of identification for the companies and institutions in order to convey the advertising idea in accordance with the creative, aesthetic and functional principles aimed at promoting products and gaining the symbolic value for the company. This study investigates the employment of social personalities in the commercial advertising design in order to pinpoint the importance of employing celebrities and their representation in the advertisement to convey the meaning that signifies the advertisement goal. Thus the question of the study is: "What are the mechanisms of employing celebrities in the d
... Show MoreThe best design of subsurface trickle irrigation systems requires knowledge of water and salt distribution patterns around the emitters that match the root extraction and minimize water losses. The transient distribution of water and salt in a two-dimensional homogeneous Iraqi soil domain under subsurface trickle irrigation with different settings of an emitter is investigated numerically using 2D-HYDRUS software. Three types of Iraqi soil were selected. The effect of altering different values of water application rate and initial soil water content was investigated in the developed model. The coefficient of correlation (R2) and the root-mean-square error (RMSE) was used to validate the predicted numerical res
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