Preferred Language
Articles
/
joe-676
Variable Structure Control Design for a Magnetic Levitation System
...Show More Authors

In this paper the variable structure control theory is utilized to derive a discontinuous controller to the magnetic levitation system. The magnetic levitation system model is considered uncertain, which subjected to the uncertainty in system parameters, also it is open-loop unstable and strongly nonlinear. The proposed variable structure control to magnetic levitation system is proved, and the area of attraction is determined. Additionally, the chattering, which induced due to the discontinuity in control law, is attenuated by using a non-smooth approximate. With this approximation the resulted controller is a continuous variable structure controller with a determined steady state error according to the selected control parameters. Finally the ability and the effectiveness of the proposed continuous variable structure controller to the magnetic levitation system are verified via numerical simulations. When state initiated inside the area of attraction, the results show that the ball position can be directed to follow various desired positions, with steady state error not exceeding .  

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Sep 30 2024
Journal Name
Iraqi Journal Of Science
Overlapping Structure Detection in Protein-Protein Interaction Networks Using a Modified Version of Particle Swarm Optimization
...Show More Authors

In today's world, the science of bioinformatics is developing rapidly, especially with regard to the analysis and study of biological networks. Scientists have used various nature-inspired algorithms to find protein complexes in protein-protein interaction (PPI) networks. These networks help scientists guess the molecular function of unknown proteins and show how cells work regularly. It is very common in PPI networks for a protein to participate in multiple functions and belong to many complexes, and as a result, complexes may overlap in the PPI networks. However, developing an efficient and reliable method to address the problem of detecting overlapping protein complexes remains a challenge since it is considered a complex and har

... Show More
View Publication
Scopus Crossref
Publication Date
Sat Jan 21 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Environmental parameters drive the phytoplankton community structure: a case study in Baghdad Tourist Island Lake, Iraq
...Show More Authors

Phytoplankton community is a model for of monitoring  aquatic systems and interpreting the environmental change in aquatic systems. The present study aimed to forecast environmental parameters that drive the change of phytoplankton community structure in the lake. The present study was carried out in Baghdad Tourist Island Lake (BTIL) for the period From October 2021 to May 2022. The study included the quality and quantity of phytoplankton, moreover, the highest and lowest value of the physical and chemical parameters were (Water temperature (13-30 °C), Light penetration (94-275cm), electric conductivity (837-1128 µS/cm), salinity (0.5-0.7 ‰), pH (7-8.2), total alkalinity (126-226 mg CaCO3/L), total Hardness (297-395 mg CaCO3/L

... Show More
Preview PDF
Crossref
Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A study Histological Structure Of The hombencephalon (Cerebellum) In The Pigeon Columba livia gaddi (GmeIin, 1789)
...Show More Authors

   A histological study was conducted to examine the structure of rhombencephalon (Cerebellum) in Columba livia gaddi (Gmeiin, 1789).  The result showed that the cerebellum is aportion of the brain lying behind the cerebrum, the surface of the cerebellum contains deep folds.  The cerebellum consists of two regions a cerebellar cortex that is called gray matter composed of three major layers from the outside to the inside, as follows: molecular layer, Purkinje cells layer and granular layer, the second region of cerebellum called medulla. This is the white matter.
 

View Publication Preview PDF
Publication Date
Wed Dec 01 2021
Journal Name
Open Biology
Structure and in silico simulations of a cold-active esterase reveals its prime cold-adaptation mechanism
...Show More Authors

Here we determined the structure of a cold active family IV esterase (EstN7) cloned from Bacillus cohnii strain N1. EstN7 is a dimer with a classical α/β hydrolase fold. It has an acidic surface that is thought to play a role in cold-adaption by retaining solvation under changed water solvent entropy at lower temperatures. The conformation of the functionally important cap region is significantly different to EstN7's closest relatives, forming a bridge-like structure with reduced helical content providing greater access to the active site through more than one substrate access tunnel. However, dynamics do not appear to play a major role in cold adaption. Molecular dyn

... Show More
View Publication
Scopus (13)
Scopus
Publication Date
Sat Jan 21 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Environmental parameters drive the phytoplankton community structure: a case study in Baghdad Tourist Island Lake, Iraq
...Show More Authors

Phytoplankton community is a model for of monitoring  aquatic systems and interpreting the environmental change in aquatic systems. The present study aimed to forecast environmental parameters that drive the change of phytoplankton community structure in the lake. The present study was carried out in Baghdad Tourist Island Lake (BTIL) for the period From October 2021 to May 2022. The study included the quality and quantity of phytoplankton, moreover, the highest and lowest value of the physical and chemical parameters were (Water temperature (13-30 °C), Light penetration (94-275cm), electric conductivity (837-1128 µS/cm), salinity (0.5-0.7 ‰), pH (7-8.2), total alkalinity (126-226 mg CaCO3/L), total Hardness (297-395 mg CaCO3/L), Ca

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jan 12 2019
Journal Name
Journal Of The College Of Education For Women
The relationship between the economic structure and the development of the spatial structure Abu Ghraib District
...Show More Authors

The phenomenon of spatial variation in the economic, social and urban development levels is considered prevalent in most of the economic and social systems,this relates to the concentration of most of those activities in certain regions and because of their rarity in other regions , that led to the emergence of the problem of the sharp contrast between the most developed areas and least developed areas within the same region or within the regions of the same country,
Reduction of this variables , in addition to the development of areas through following up and relying on an effective regional development enabling to reduce unemployment as well as to stop the migration of the unplanned for population,
And the ideal use of available

... Show More
View Publication Preview PDF
Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Internal control – Internal check
...Show More Authors

Abstract

All the economic  units whether productive or service units , strive to achieve specific objectives , their presence and continuity depend on them and the quality of the performance and service present to the society . This units to be able to achieve their objectives , must own basic assets to perform the activities , and apply laws , systems , and instructions , in addition to legal , managerial , and financial authorities . So this units to endeavor maintain this assets , in addition to sound application of laws ,systems . and procedures to enhance their performance . For this purpose arise the role of internal control and internal check in maintenance of assets and sound application of&n

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jul 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Classical Continuous Optimal Control for Quaternary Nonlinear Parabolic Boundary Value Problems with State Vector Constraints
...Show More Authors

This paper aims to study the quaternary classical continuous optimal control problem consisting of the quaternary nonlinear parabolic boundary value problem, the cost function, and the equality and inequality constraints on the state and the control. Under appropriate hypotheses, it is demonstrated that the quaternary classical continuous optimal control ruling by the quaternary nonlinear parabolic boundary value problem has a quaternary classical continuous optimal control vector that satisfies the equality constraint and inequality state and control constraint. Moreover, mathematical formulation of the quaternary adjoint equations related to the quaternary state equations is discovered, and then the weak form of the quaternary adjoint

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Oct 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Investigating the Structural and Magnetic Properties of Nickel Oxide Nanoparticles Prepared by Precipitation Method
...Show More Authors

This work used the deposition method to synthesize nickel oxide nanoparticles. The materials mainly used in this study were nickel sulfate hexahydrate (as a precursor) and NaOH (as a precipitant). The properties of the nanopowder were characterized by XRD, FE-SEM, EDX, and VSM. The obtained results confirmed the presence of nickel oxide nanoparticles with a face-centered cubic (FCC) structure with a lattice constant (a=4.17834 Å). Scherer and Williamson-Hall equations were used to calculate the crystallite size of about (30.5-35.5) nm. The FE-SEM images showed that the particle shape had a ball-like appearance with a uniform and homogeneous distribution and confirmed that the particles were within the nanoscale. The presence of oxygen a

... Show More
View Publication Preview PDF
Crossref (10)
Crossref
Publication Date
Tue Oct 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Comparison between Process Control Charts and Fuzzy Multinomial Control Charts with Practical Appliance
...Show More Authors

     The control charts are one of the scientific technical statistics tools that will be used to control of production and always contained from three lines  central line and upper, lower lines to control quality of production and represents set of numbers so finally the operating productivity under control or nor than depending on the actual observations. Some times to calculating the control charts are not accurate and not confirming, therefore the Fuzzy Control Charts are using instead of Process Control Charts so this method is more sensitive, accurate and economically for assisting decision maker to control the operation system as early time. In this project will be used set data fr

... Show More
View Publication Preview PDF
Crossref