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Hexapod Robot Static Stability Enhancement using Genetic Algorithm
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Abstract

Hexapod robot is a flexible mechanical robot with six legs. It has the ability to walk over terrain. The hexapod robot look likes the insect so it has the same gaits. These gaits are tripod, wave and ripple gaits. Hexapod robot needs to stay statically stable at all the times during each gait in order not to fall with three or more legs continuously contacts with the ground. The safety static stability walking is called (the stability margin). In this paper, the forward and inverse kinematics are derived for each hexapod’s leg in order to simulate the hexapod robot model walking using MATLAB R2010a for all gaits and the geometry in order to derive the equations of the sub-constraint workspaces for each hexapod’s leg. They are defined as the sub-constraint workspaces volumes when the legs are moving without collision with each other and they are useful to keep the legs stable from falling during each gait. A smooth gait was analyzed and enhanced for each hexapod’s leg in two phases, stance phase and swing phase. The proposed work focused on the two approaches first, the modified classical stability margins. In this approach, the range of stability margins is evaluated for all gaits. The second method is called stability margins using Genetic Algorithm (GA) that enhanced the static stability by getting the best stability margins for hexapod robot and these results are useful to get best stable path planning of hexapod robot with smaller error than the first approach and with better new stable coordinates of legs tips than the first method. In addition, the second approach is useful for getting the better new stable center body coordinates than center body coordinates in the first approach of hexapod robot.

Keywords: Kinematics, Stability Margin, Workspace, Genetic Algorithm and Hexapod Robot.

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Publication Date
Tue Apr 24 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Very High Q-Factor Based On G-Shaped Resonator Type Metamaterial Absorber
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High Q-factor based on absorption can be achieved by tuning (the reflection and the transition percentage). In this work, the simple design and simulated in S-band have been investigated. The simulation results of G-shape resonator are shown triple band of absorption peaks 60%, 91.5%, and 70.3%) at resonance frequency 2.7 GHz, 3.26 GHz, and 4.05 GHz respectively. The results exhibited very high of the Q-factor ( 271 ) at resonance frequency ( 3.26 GHz ).  The high Q-factor can be used to enhance the sensor sensing, narrowband band filter and  image sensing.

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Publication Date
Mon Jan 20 2020
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Assessment of the Quality of Drinking Water for Plants in the Al-Karkh, Baghdad, Iraq
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     The study aims to assess some physical, chemical, and bacterial characteristics of two drinking water treatment plants of Al- Dora and Al-Qadisiya in the area of ​​Karkh, Baghdad, Iraq. The areas covered by each plants and these sites of areas selected as the nearest and the farthest point from plants, for winter and summer season. Some physicochemical parameters of water quality were taken in this study and these parameters were temperature water, pH, electrical conductivity, total dissolved solids, free residual chlorine, calcium, magnesium, nitrate, nitrite, sulphate and heavy metals (lead). In addition to four bacterial indicators of drinking water pollution (APC, Total Coliform, Fecal Coliform

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Kinetics of the Saponification of Mixed Fats Consisting of Olein and Stearin
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This research presents the kinetics of the saponification reaction using mixed fats of olein and stearin [in the ratio (3:1)] with NaOH solution. In this reaction, excess solution of NaOH was used to ensure the reaction being irreversible. Three parameters were varied to show their effects on the reaction rate .They are: percentage excess of NaOH solution (10 % - 100 %) , temperature (100-150)oC , and stirring speed (400-1100) rpm. It was noticed that increasing the percentage excess of NaOH solution enhances the rate of reaction while increasing temperature decreases the reaction rate since it is exothermic reaction.    Increasing stirring speed also improves the reaction rate because it is mass transfer controlled .Calcu

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Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Lorenz model and chaos masking /addition technique
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Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Comparison between some of linear classification models with practical application
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Linear discriminant analysis and logistic regression are the most widely used in multivariate statistical methods for analysis of data with categorical outcome variables .Both of them are appropriate for the development of linear  classification models .linear discriminant analysis has been that the data of explanatory variables must be distributed multivariate normal distribution. While logistic regression no assumptions on the distribution of the explanatory data. Hence ,It is assumed that logistic regression is the more flexible and more robust method in case of violations of these assumptions.

In this paper we have been focus for the comparison between three forms for classification data belongs

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Publication Date
Sat Apr 01 2023
Journal Name
Journal Of Engineering
Modeling and Simulating NOMA Performance for Next Generations
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Non-orthogonal Multiple Access (NOMA) is a multiple-access technique allowing multiusers to share the same communication resources, increasing spectral efficiency and throughput. NOMA has been shown to provide significant performance gains over orthogonal multiple access (OMA) regarding spectral efficiency and throughput. In this paper, two scenarios of NOMA are analyzed and simulated, involving two users and multiple users (four users) to evaluate NOMA's performance. The simulated results indicate that the achievable sum rate for the two users’ scenarios is 16.7 (bps/Hz), while for the multi-users scenario is 20.69 (bps/Hz) at transmitted power of 25 dBm. The BER for two users’ scenarios is 0.004202 and 0.001564 for

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Publication Date
Fri Dec 30 2022
Journal Name
Iraqi Journal Of Science
Climate parameters analysis as an indication of climate Changes for Diwaniya, Nasiriya, Kut and Karbala meteorological stations - Central and southern Iraq: Karbala climate condition as a case study
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       The climate parameters (rainfall, number of rainy days and temperature) data for about seventy years from 1941 – 2009 for three Iraqi meteorological stations (Diwaniya, Nasiriya, and Kut) were investigated and gave good evidence of climate change. As well as  the climatic water balance and the climatic conditions were determined at Karbala meteorological station for the years (1982-2015). The annual precipitation for Karbala station-reflect declination from 105 mm for the period 1982-1990 to about 71 mm for the years 2011- 2015 confirms the effect of global climate change. Analyzing Karbala climate parameters reflects that the total annual rainfall is (89 mm), evaporation is (2984 mm), while the mean monthly relative humi

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Publication Date
Sun Apr 26 2020
Journal Name
Iraqi Journal Of Science
The Effect of Cigarette Smoking on Blood and Biochemical Parameters: A Comparative Study Among Male Smokers and Non-Smokers In Baghdad City
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The impact of smoking on human health is remarkable and can lead to death. This research was performed to test the effects of cigarette smoking on some parameters that are considered as signs of critical problems in human body. The study was carried out on fifty Iraqi male smokers in Baghdad city, who smoked at least 10 cigarettes per day for at least 15 years. The group includes 25 male smokers with an age range of 20 -55 years and 25 male non-smokers who were collected with the same range of age for statistical comparison. The results of the study revealed significant increases in blood parameters, including hemoglobin (Hb, 16.0917 (g/dl) , packed cell volume (PCV, 49.2%), red blood cells (RBC, 5.4763 X1012/L), white blood cell (WBC, 1

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Publication Date
Wed Jul 01 2020
Journal Name
Journal Of Engineering
Evaluating the Uses of Concrete Demolishing Waste in improving the Geotechnical Properties of Expansive Soil
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Expansive soil is one of the most serious problems that face engineers during the execution of any infrastructure projects. Soil stabilization using chemical admixture is one of the most traditional and widespread methods of soil improvement. Nevertheless, soil improvement on site is one of the most economical solutions for many engineering applications. Using construction and demolishing waste in soil stabilization is still under research., The aim of this study is to identify the effect of using concrete demolishing waste (CDW) in soil stabilization. Serious tests were conducted to investigate the changes in the geotechnical properties of the natural soil stabilized with CDW. From the results, it is concluded that the

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Publication Date
Wed Jul 29 2020
Journal Name
Iraqi Journal Of Science
Interpolation and Statistical Analysis for Evaluation of Global Earth Gravity Models Based on GPS and Orthometric Heights in the Middle of Iraq
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The regions around the world need to perform their results based on the local geoid. However, each region has different ground topography based on the amount of gravity in this region. Nowadays, the recent global Earth's gravity model of 2008 is successfully used for different purposes in geosciences research. This research presents an overview of the preliminary evaluation results of the new Earth Gravitation Model (EGM08) in the middle of Iraq. For completeness, the evaluation tests were also performed for EGM96 by examining 31 stations distributed over four Iraqi provinces. The national orthometric heights were compared with the GPS /leveling data obtained from these stations. This study illustrated that the GPS /leveling based on EGM

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