Cognitive radios have the potential to greatly improve spectral efficiency in wireless networks. Cognitive radios are considered lower priority or secondary users of spectrum allocated to a primary user. Their fundamental requirement is to avoid interference to potential primary users in their vicinity. Spectrum sensing has been identified as a key enabling functionality to ensure that cognitive radios would not interfere with primary users, by reliably detecting primary user signals. In addition, reliable sensing creates spectrum opportunities for capacity increase of cognitive networks. One of the key challenges in spectrum sensing is the robust detection of primary signals in highly negative signal-to-noise regimes (SNR).In this paper , we present the system design approach to meet this challenge with technique , The design space is diverse as it involves various types of primary user signals, We analysis of signal processing approaches and identify the regimes where these techniques are applicable. The goal of this paper is to present a practical system design view of spectrum sensing functionality.
The most important topic for psychologist generally is factor of education and it's active tools because learning needs active perception for stimulus that recived by the educator and give it avalue and meaning , Need for cognition is
very important in the various daily fields of life , especially in learning and teaching and the academy work , it help with shifting the learning level for people , and icreas the intense and challenge between them
The research endeavored to achieve the following aim :
1- Measuring the level of peripheral perception for the university student .
2- Measuring the level of need for cognition for the university student .
3- Measuring the level of peripheral perception for the university student
We propose a novel strategy to optimize the test suite required for testing both hardware and software in a production line. Here, the strategy is based on two processes: Quality Signing Process and Quality Verification Process, respectively. Unlike earlier work, the proposed strategy is based on integration of black box and white box techniques in order to derive an optimum test suite during the Quality Signing Process. In this case, the generated optimal test suite significantly improves the Quality Verification Process. Considering both processes, the novelty of the proposed strategy is the fact that the optimization and reduction of test suite is performed by selecting only mutant killing test cases from cumulating t-way test ca
... Show MoreProviding Iraqi students with proficiency in English is the ultimate goal of the educational system which is a way of getting knowledge in the fields of arts, sciences, transferring knowledge and sciences to other communities. Therefore, conducting such a type of study is very important because the contents of English textbooks have a huge influence on learning of the students. Once the content of English textbooks contain errors as the correct one, this will effect on his/her learning. The present study is an attempt to evaluate the new course entitled “English for Iraq” for fifth grade students for secondary schools, by Olivia Johnston and Mark Farell. It aims to answer eleven questions relating to the following domains: strength, obj
... Show MoreThis study aims to recognize the most common thinking styles and level of the need for cognitive university students , the relation between thinking styles and the need for cognitive, and there are differences according to gender .The sample consists of (250) males and females university students for the academic year (2013-2014), and the researcher uses two scales;" thinking styles scale (Harison &Bramson, 1986), and the need for cognitive scale" (Cacioppo, Petty & Kao , 1996).
The results show that there is difference in the range of the prevalence of the thinking styles among university students , the scientific thinking style is the most common , the students have got the arrange level of the need for cognitive , and there
In a connected graph , the distance function between each pair of two vertices from a set vertex is the shortest distance between them and the vertex degree denoted by is the number of edges which are incident to the vertex The Schultz and modified Schultz polynomials of are have defined as:
respectively, where the summations are taken over all unordered pairs of distinct vertices in and is the distance between and in The general forms of Schultz and modified Schultz polynomials shall be found and indices of the edge – identification chain and ring – square graphs in the present work.
Hypothesis CO2 geological storage (CGS) involves different mechanisms which can store millions of tonnes of CO2 per year in depleted hydrocarbon reservoirs and deep saline aquifers. But their storage capacity is influenced by the presence of different carboxylic compounds in the reservoir. These molecules strongly affect the water wetness of the rock, which has a dramatic impact on storage capacities and containment security. However, precise understanding of how these carboxylic acids influence the rock’s CO2-wettability is lacking. Experiments We thus systematically analysed these relationships as a function of pressure, temperature, storage depth and organic acid concentrations. A particular focus was on identifying organic acid conce
... Show MoreThe current research aimed to identify the cognitive-behavioral therapy on people with depression, through the following hypothesis (there are no statistically significant differences in the sample before and after cognitive-behavioral therapy). The importance of research is highlighted through the use of cognitive-behavioral therapy, to be used in treating depression, anxiety and fears by health institutions. It is also considered as a reference for psychological studies related to this topic to be added to our libraries that already suffer from a scarcity of this type of resources. The cognitive-behavioral therapy was used in the treatment of five male subjects.
The study revealed the existence of statistically significant diff
... Show MoreRenewal is generally considered an urgent requirement of life, and a section of its continuation, because renewal means that life exists and continues, and just as renewal is in life, renewal is in science, and in this research the issue of renewal in the science of interpretation, and showed through research that renewal in This science was an urgent demand throughout the Islamic ages, as the research showed the necessity of renewal in the material of interpretation, its method and methods, and the researcher presented the opinions of schools about renewal in the interpretation of the Noble Qur’an inferred by living models that refer to their owners.
The master sintering concept is introduced as a unifying sintering model for the initial, intermediate and final stage of sintering. The master sintering curve is independent on the time-temperature trajectory due to account for its integral. The master sintering curve is constructed on a material parameter, which is the activation energy for sintering and other curve shaping parameters, which depends on the initial state of the powder. Literature data of sintering of TiO2 compacts with two initial packing densities of 55% and 69% of theoretical is utilized for the construction of the master sintering curves. The higher initial packing density compact shows higher densification rate, which is reflected by different set of shaping paramet
... Show MoreTriticale is being evaluated as a substitute for corn in animal feed and as a forage crop for Florida. Storage of triticale seed is difficult in Florida's hot and humid climate, and more information about the relationships between equilibrium moisture content (EMC) and equilibrium relative humidity (ERH) at constant temperature (sorption isotherms) of triticale is needed to develop improved storage methods. Therefore, the primary research objective was to measure the EMC for triticale seed at different ERH values at three different constant temperatures (5°C, 23°C, and 35°C) using six desiccation jars containing different saturated salt concentrations. The secondary objective was to determine the best fit equation describing these relati
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