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
Sat Nov 10 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Impact of Socio-economic Status on Age at Menarche among Secondary School Students at AL-Dora Region in Baghdad Governorate
...Show More Authors

Objective: To assess the Impact of Socio-economic status on age at menarche among secondary school students at
AL-Dora city in Baghdad, Iraq.
Methodology: This is a cross sectional study with multi-stage sampling was carried out during the period from the
3
th of December2013 to 12th of March 2014. The Sample comprised of 1760 girls, 1510 girls from urban area and
250 from rural area was included in the study. In first stage, selection of schools was done, and one class was
selected randomly from each level of Education, The data collection through a special questionnaire which Contain
the age of girl by year, class level, birth order, number of household, number of rooms, residency (urban/rural),
education level

... Show More
View Publication Preview PDF
Publication Date
Wed Aug 16 2023
Journal Name
مجلة الاستاذ للعلوم الانسانية والاجتماعية- كلية التربية ابن رشد – جامعة بغداد،
Using the Theory of Conceptual Metaphor in Two Sonnets by Victorian Female Poets
...Show More Authors

This study has applied the theoretical framework of conceptual metaphor theory to the analysis of the source and target domains of metaphors that are used in two English nineteenth century sonnets, both written by contemporaneous female poets. The quantitative and qualitative results of the textual analysis have clearly revealed that Elizabeth Barrett Browning’s sonnet 23 centres around the conceptual mapping of the journey of love and life with that of possession. In contrast, Christina Rossetti’s sonnet Remember tackles the central conceptual mapping of death as a journey in relation to its further experiential connections. In addition, the application of conceptual metaphor theory in identifying the frequencies and densities of metap

... Show More
Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Study of the imperatives of promoting financial inclusion in Iraq: Opportunities and challenges
...Show More Authors

The aim of the research is to provide an analytical study to promote financial inclusion in Iraq by clarifying the opportunities and challenges of the economic and demographic situation in Iraq, studying the structure of the financial system and introducing non-bank financial institutions operating in Iraq, and using the descriptive approach. Analytical in the study of the phenomenon of research, the research reached a number of conclusions, the most prominent of which were:

  • Iraqi society is a young society.
  • The majority of the population is 70 percent. They live almost in urban areas.
  • The coverage of bank branch networks is concentrated in only four provinces, leaving other provinces outside financial

... Show More
View Publication Preview PDF
Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
The effects of silica addition on the structural, electrical and mechanical characteristics of MgAl2O4 spinel ceramic phase
...Show More Authors

The ceramic compound Mg1-xSixAl2O4 (x= 0, 0.1, 0.2, 0.3, 0.4) was prepared from nano powder of Al2O3 and MgO doped with Nano powder of SiO2 at different molar ratios. The specimens were prepared by standard chemical solid reaction technique and sintered at 1450 oC. Structure of the specimens was analyzed by using X-ray diffraction (XRD). The X-ray patterns of the specimens showed the formation of pure simple cubic spinel structure MgAl2O4 phase with space group of ̅ . The average grain size and surface topology were studied by atomic force microscopy. The results showed that the average grain size was about 73-90 nm. The DC electrical properties of the specimen were measured. The apparent density was found to increase and the porosity a

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Nov 24 2015
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
The Impact of External Environment Factors on the Quality of Educational Services (An Empirical Study): The Impact of External Environment Factors on the Quality of Educational Services (An Empirical Study)
...Show More Authors

This research aims to identify the role of external environment factors on the quality of educational services, from the academic point of view, where the distribution of a questionnaire to a random sample of (100) university professors, and then analyzing a model, and test the validity of this model using structural modeling (SEM) (Structural Equation Modeling).
And then test the relationships between variables using the software of Statistical Package for Social Sciences (SPSS V.18), the research found a number of conclusions, the most important conclusion is: the external environment factors has significant impact on the quality of educational services.

View Publication Preview PDF
Publication Date
Thu Jan 02 2014
Journal Name
Sino Us
“Actual Experience”: Correcting Misconceptions Through Analyzing Harriet Wilson’s Our Nig
...Show More Authors

African-American writers during the 19th century wrote in the shadow of the prominent romance, sentimental, and domestic fiction. Harriet Wilson’s Our Nig (1859) reflects an “alternative social character”, for the female protagonist suffers racism in the free North, because she is a mulatto child. Through depicting the life of free blacks, who supposedly lives a better life than Southern slaves, Wilson exposes how she has actually lived and sensed life in antebellum America. According to Raymond Williams (2011), there are two kinds of literary writings. The first represents the general tendency of the age, and he calls it “dominant social character”; representing the majority content of both the public writing and speaking. But, a

... Show More
View Publication
Publication Date
Fri Apr 28 2017
Journal Name
جامعة بغداد- كلية اللغات- قسم اللغة العبرية
The morphological construction of kitchen terms in Hebrew language
...Show More Authors

This research sheds light on the morphological construction of kitchen terms in Hebrew language, especially methods of derivation, by offering an extensive review of the most important methods of morphological derivation. The field of kitchen terms is a fertile and rich field, where we see daily production of new kitchen tools which require suitable names with specific meanings. Morphologically, the research interested in methods of morphological derivation. So as to know and identify the common and effective methods to derive the kitchen terms in Hebrew language, in addition to put a special glossary of these terms. The research found that most of the kitchen terms were derived according to the methods of derivation prevailing in Hebrew la

... Show More
Preview PDF
Publication Date
Wed May 29 2019
Journal Name
Iraqi Journal Of Physics
The influence of various pH values on the aerogel physical properties by sol-gel technique
...Show More Authors

Hydrophobic silica aerogels were successfully preparation by an ambient pressure drying method from sodium silicate (Na2SiO3) with different pH values (5, 6, 7, 8, 9 and 10). In this study, acidic HCl (1M), a basic NH4OH (1M) were selected as a catalyst to perform the surface modification in a TMCS (trimethylchlorosilane) solution. The surface chemical modification of the aerogels was assured by the Fourier transform infrared (FTIR) spectroscopic studies. Other physical properties, such as pore volume and pore size and specific surface area were determined by Brunauer-Emmett- Teller (BET) method. The effect of pH values on the bulk density of aerogel. The sol–gel parameter pH value in the sol, have marked effects on the physical proper

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jun 02 2019
Journal Name
Baghdad Science Journal
Estimating the Reliability Function of (2+1) Cascade Model
...Show More Authors

This paper discusses reliability R of the (2+1) Cascade model of inverse Weibull distribution. Reliability is to be found when strength-stress distributed is inverse Weibull random variables with unknown scale parameter and known shape parameter. Six estimation methods (Maximum likelihood, Moment, Least Square, Weighted Least Square, Regression and Percentile) are used to estimate reliability. There is a comparison between six different estimation methods by the simulation study by MATLAB 2016, using two statistical criteria Mean square error and Mean Absolute Percentage Error, where it is found that best estimator between the six estimators is Maximum likelihood estimation method.

View Publication Preview PDF
Scopus (6)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Wed Jun 29 2022
Journal Name
Journal Of The College Of Education For Women
Cognitive Motive of the Kindergarten Child
...Show More Authors

Encouraging children towards the cognitive motivation through the discovery and knowledge of the environment around them is essential. Thus, during the two researchers’ supervision of the practical lessons that involved the female students’ application of their experience in the Applied Kindergarten Laboratory, it has been noticed that there was a difference in the cognitive motivation of kindergarten children. In order to reinforce the research problem, the two researchers sent an open questionnaire to a sample of randomly selected kindergarten teachers from Al-Karkh and Al-Rasafa sides. The responses collected accentuated the researchers’ sense of the existing problem. To achieve the aim of the study represented by examining the

... Show More
View Publication Preview PDF
Crossref