Preferred Language
Articles
/
alkej-466
Motion Control of Three Links Robot Manipulator (Open Chain) with Spherical Wrist
...Show More Authors

Robot manipulator is a multi-input multi-output system with high complex nonlinear dynamics, requiring an advanced controller in order to track a specific trajectory. In this work, forward and inverse kinematics are presented based on Denavit Hartenberg notation to convert the end effector planned path from cartesian space to joint space and vice versa where a cubic spline interpolation is used for trajectory segments to ensure the continuity in velocity and acceleration.  Also, the derived mathematical dynamic model is based on Eular Lagrange energy method to contain the effect of friction and disturbance torques beside the inertia and Coriolis effect. Two types of controller are applied ; the nonlinear computed torque control (CTC) and the simpler form of its Proportional Derivative plus Gravity (PD+G)  where they are designed to reduce the tracking trajectory errors which tend to zero where the used Kp and Kv gains are 900,60. Also, the RMS errors for tracking a step input of CTC were equal to  [2.5E-14, 4.4E-14, 5.0E-14, -4.7E-14, -3.9E-14, -4.6E-14] (deg) and of PD+G were equal to [-1.77E-5, -1.22E-6, -4.28E-6, -8.97E-6, -1.32E-5, 1.05E-5] (deg)  for joints one to six, respectively. The results show that CTC is more accurate but requires additional acceleration input and is more computationally extensive and PD+G controller is performed with acceptable tracking errors in manipulator position control applications.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Mar 01 2008
Journal Name
Al-khwarizmi Engineering Journal
The Effects of Vortex Generator Types on Heat Transfer and Flow Structure in a Rectangular Duct Flows
...Show More Authors

    In this numerical study a detailed evaluation of the heat transfer characteristics and flow structure in a laminar and turbulent flow through a rectangular channel containing built-in of different type vortex generator has been a accomplished in a range of Reynolds number between 500 and 100,000.A modified version of ESCEAT code has been used to solve Navier-Stokes and energy equations. The purpose of this paper is to present numerical comparisons in terms of temperature, Nusselt number and flow patterns on several configurations of longitudinal vortex generator including new five cases. The structures of heat and flow were studied, using iso-contours of velocity components, vortices, temperature and Nusselt n

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 30 2022
Journal Name
College Of Islamic Sciences
Judge's Preaching to the Litigants and Witnesses An Applied Doctrinal Study on Judicial Decisions of Saudi Courts
...Show More Authors

Abstract

Praise be to Allah and prayers and peace be upon our Prophet, Muhammad, his family and all of his companions,

This research addresses the issue of judge's preaching to the litigants and witnesses; it is a very significant issue since the judge cannot know the insides and facts, but it issues judgments based on the hearings. Since people are originally wrong-doing and ignorant, they, therefore, commit injustice, oppression, false adversarial, and false testimony. However, some people can possibly retreat and return to the right, after being inattentive or recalcitrant, by preaching. This fact led scholars to talk about the judge's preaching to litigant and witnesses and this research is conducted

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Analytical study on the implications of the GATS Agreement and its implications on the Egyptian banking sector
...Show More Authors

International trade in services is becoming increasingly important as it is an economic activity that deals with invisible trade, which has become increasingly important in the balance of international trade. The establishment of the WTO is a starting point in international trade relations. It is responsible for all aspects of international trade, , And in view of the continued increase in international trade in services, the need for more internationally recognized rules has become more urgent, especially as it has been increasingly proven that the traditional framework of public services is inadequate to operate some of the most dynamic and innovative sectors of the economy. (GATS) to be the regulatory framework for this sector

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 23 2022
Journal Name
Journal Of Educational And Psychological Researches
The level of evaluation of the educational counselors ’performance as a predictor of their level of satisfaction with their evaluation
...Show More Authors

The current research aims to reveal the level of satisfaction of the mentors with the evaluation of their performance according to gender (male - female) and to formulate the predictive equation for the level of performance (dependent variable) from knowing the level of satisfaction with the evaluation (independent variable). (16 paragraphs) contains alternatives to the answer that measures the level of satisfaction (weak, medium, and high) (1,2,3), that is, with a hypothetical average of (32). It consisted of 100 educational counselors consisting of 45 males and 55 females, the results of the research concluded that the level of satisfaction with performance is below the mean when compared with the hypothetical average of the scale of s

... Show More
View Publication Preview PDF
Publication Date
Thu Jun 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Characterization of Delamination Effect on Free Vibration of Composite Laminates Plate Using High Order Shear Deformation Theory
...Show More Authors

 A dynamic analysis method has been developed to investigate and characterize embedded delamination on the dynamic response of composite laminated structures. A nonlinear finite element model for geometrically large amplitude free vibration intact plate and delamination plate analysis is presented using higher order shear deformation theory where the nonlinearity was introduced  in the Green-Lagrange sense. The governing equation of the vibrated plate were derived using the Variational approach. The effect of different orthotropicity ratio, boundary condition and delamination size on the non-dimenational fundamental frequency and frequency ratios of plate for different stacking sequences are studied. Finally th

... Show More
View Publication Preview PDF
Publication Date
Mon Dec 20 2021
Journal Name
Baghdad Science Journal
Impact of Denial-of-Service Attack on Directional Compact Geographic Forwarding Routing Protocol in Wireless Sensor Networks
...Show More Authors

Directional Compact Geographic Forwarding (DCGF) routing protocol promises a minimal overhead generation by utilizing a smart antenna and Quality of Service (QoS) aware aggregation. However, DCGF was tested only in the attack-free scenario without involving the security elements. Therefore, an investigation was conducted to examine the routing protocol algorithm whether it is secure against attack-based networks in the presence of Denial-of-Service (DoS) attack. This analysis on DoS attack was carried out using a single optimal attacker, A1, to investigate the impact of DoS attack on DCGF in a communication link. The study showed that DCGF does not perform efficiently in terms of packet delivery ratio and energy consumption even on a sin

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The impact of organizational learning capabilities on the promotion of knowledge capital Applied research at Wasit University
...Show More Authors

Abstract

      The current research aims at identifying any of the dimensions of organizational learning abilities that are more influential in the knowledge capital of the university and the extent to which they can be applied effectively at Wasit University. The current research dealt with organizational learning abilities as an explanatory variable in four dimensions (Experimentation and openness, sharing and transfer of knowledge, dialogue, interaction with the external environment ), and knowledge capital as a transient variable, with four dimensions (human capital, structural capital, client capital, operational capital). The problem of research is the following questio

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Apr 30 2023
Journal Name
Al-kindy College Medical Journal
The Ameliorating Effect of Ashwagandha (Withania Somnifera) Extract on Hippocampus and Growth Plate Changes Associated With Propylthiouracil Induced Hypothyroidism in Juvenile Rats : Ashwagandha on Hippocampus and Growth Plate Changes Associated With hypothyroid rats
...Show More Authors

Background: Hypothyroidism is a decrease in the production of the thyroid hormones and leads to gland dysfunction. Ashwagandha extract was used as an ayurvedic treatment and supposed to be as antihypothyroidism agent.

Objectives: to investigate the impact of ashwagandha (Ash) extract on propylthiouracil (PTU)-induced hypothyroidism in rats.

Subjects and Methods: The rats were divided into three groups, control group, PTU (hypothyroid) group (6mg/kg/day by oral route), PTU (6mg/kg/day by oral route) +Ash (50mg/kg/day by oral route) treated group. All treatment continued for

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (3)
Scopus Crossref
Publication Date
Thu Feb 24 2022
Journal Name
Journal Of Educational And Psychological Researches
Social Care for the Disabled students and its influence on the Scientific Level (University of Baghdad as example)
...Show More Authors

The enrollment of students in the university represents a new stage in their life that differ from the previous educational stages that student has previously established. It should be noted that students with special needs at the University of Baghdad are not large numbers. It appears that these students have an excel role in their colleges most often, That is, the handicap was not a barrier to their scientific progress, but rather an incentive for them to excel. The most important conclusion reached by the researcher is that the University of Baghdad had no role in caring for people with special needs and caring for them financially, socially, psychologically, healthily and economically, they need to pay attention to them and take care

... Show More
View Publication Preview PDF
Publication Date
Sat Apr 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
The Role of Treasury bills to the most important monetary variables in Iraq for the period 1990 – 2013
...Show More Authors

The treasury bills one internal government debt instruments in iraq that were used to finance temporary deficits in the government budget, There fore the government resorted to issuing for the purpose of providing liquidity, As well as to invest in productive progects, After that it was financing the budget deficit by the monetary authovity of  the central baalpennek  [the new cash velease] which led to negative effects on the Iraqi econome, Thus we find that the treasury transfers have formed alarge proportion of the gross domestic government debt to finance the deficit ayear ago 2003.                      &nbs

... Show More
View Publication Preview PDF
Crossref