The objective of this study was tointroduce a recursive least squares (RLS) parameter estimatorenhanced by using a neural network (NN) to facilitate the computing of a bit error rate (BER) (error reduction) during channels estimation of a multiple input-multiple output orthogonal frequency division multiplexing (MIMO-OFDM) system over a Rayleigh multipath fading channel.Recursive least square is an efficient approach to neural network training:first, the neural network estimator learns to adapt to the channel variations then it estimates the channel frequency response. Simulation results show that the proposed method has better performance compared to the conventional methods least square (LS) and the original RLS and it is more robust at high speed mobility.
During the last quarter century, many changes have taken place in the tanks industry and also in the materials that used in its production، while concrete is the most suitable material where concrete tanks has the benefits of strength, long service life and cost effectiveness. So, it is necessary improvement the
conventional concrete in order to adapt the severe environment requirements and as a result high
performance concrete (HPC) was used. It is not fundamentally different from the concrete used in the past, although it usually contains fly ash, ground granulated blast furnace slag and silica fume, as well as
superplasticizer. So, the content of cementitious material is high and the water/cement ratio is low. In this
stu
Three different distribution modules of silicon solar cells in a panel are used in this study . Each module consists of five identical circular silicon solar cells of radius (5cm) and then the total panel areas are identical. The five solar cells are arranged in the panel in different shapes: circular, triangular and rectangular .The efficiency for these three panel distribution are measured indoor and outdoor. The results show that the efficiency is a function of the cells distribution.
The thermal performance of indirect expansion solar assisted heat pump, IX-SAHP, was investigated experimentally under Iraqi climate. An Indirect-Solar Assisted Heat Pump system was designed, built, instrumented and tested. Experimental tests were conducted by varying the controlling parameters to investigate their effects on the thermal performance of the IX-SAHP such as cooling water flow rate, heating water flow rate, ambient temperature and solar radiation intensity. The investigation covered values of cooling water flow rate of (2, 3, 4, 5 l/min) and heating water flow rate of (2, 3, 4, 5 l/min) under meteorological condition of Baghdad from November 2014 to January 2015.
The results indicated that the performance of the IX-
... Show MoreIn this work, a flat-plate solar air heater (FSAH) and a tubular solar air heater (TSAH) were designed and tested numerically. The work investigates the effect of increasing the contact area between the flowing air and the absorber surface of each heater and predicts the expected results before the fabrication of the experimental rig. Three-dimensional two models were designed and simulated by the ANSYS-FLUENT 16 Program. The solar irradiation and ambient air temperature were measured experimentally on December 1st 2022, at the weather conditions of Baghdad City- Iraq, at three air mass flow rates, 0.012 kg/s, 0.032 kg/s, and 0.052 kg/s. The numerical results showed the advantage in the thermal performance of
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The teacher is the most able to achieve the goals of education in education because he has the ability to affect the behavior of the disciples testified and its actions and appearance and other actions that convey pupils with it sometimes in a manner unconscious or unconscious , and the importance of the role of the teacher in the educational process , it is necessary to compromise the care and attention to the extent that commensurate with the important role that the rise in the preparation of youth and composition , and as a result is needed to continue efforts to improve the quality of teacher preparation so that it can be more effective and positive in the educational process .
First - Research Goals -<
No-fine concrete (NFC) is cellular concrete and it’s light weight concrete produced with the exclusion of sand from the concrete. This study includes the mechanical properties of lightweight reinforced by steel fiber, containing different proportions of steel fiber. This study was done using number of tests. These tests were density, compressive strength, flexural strength and absorption. These tests of the molds at different curing time. The results of tests that implication of fiber to No. fine concrete did not affect significantly on the compressive strength, While the flexural strength were gets better. Results explained that, the flexural strength of (1%) fiber No- fine concrete molds are four times that of the reference mold
... Show MoreThe main objective and primary concern to every investor not only to achieve a greater return on his or her investments, but also to create the largest possible value of these investments the, researchers and those interested in the field of investment and financial analysis try to develop standards for performance valuation is guided through the  
... Show MoreAbstract:
The research aims to achieve defining the concept of environmental quality and associated costs. Studying the impact of environmental quality costs on the performance of economic units. Measuring the relationship between environmental quality and environmental performance of the units. Where the research problem is represented in the weak awareness of some economic units of the importance of environmental quality costs and their impact on evaluating environmental performance, and this leads to neglecting environmental considerations and not improving environmental performance effectively, which negatively affects the en
... Show MoreIn recent decades, there has been increasing interest in wastewater treatment because of its direct impact on the environment and public health. Over time, other forms of treatment have been developed and modified, including extended aeration. This process is included in the suspended growth system. In this paper, a comparative study was conducted between the efficiency of the extended aeration plant and that of the trickling filter plant in removal of BOD and COD. The method of comparison was done by knowing the value of the pollutant before and after the treatment and then extract the removal ratio of each pollutant within each plant. The results showed that the percentage of removal of BOD in the trickling filte
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