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Variable Structure Control Design for a Magnetic Levitation System
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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 .  

 

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Publication Date
Thu Aug 31 2023
Journal Name
Journal Of Tikrit University For Humanities
ثورات الأندلسيين بعد تسليم مدينة غرناطة دراسة تاريخية للأسباب والنتائج
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الكتابة عن الأندلس بعد تسليم مدينة غرناطة يحمل في ثناياه ألم كبير، لأن الأندلسيين عاشوا تجربة إنسانية قاسية سببها الأساس غياب التسامح الديني والعدالة الاجتماعية، الأمر الذي دفعهم للثورة مطالبين بحقوقهم التي نصت عليها معاهدة تسليم المدينة. فقد  عاش أولئك حياة صعبة ، فكانوا صورة  للصراع  بين حضارتين  الإسلامية والغربية ،  ويمكن تلمس ذلك الصراع من خلال دراسة ثوراتهم ضد السلطة الحاكمة التي يبدو من تتبع أح

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Effect of Refractive Index on Photon Natural Mass and Wavelength
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In this article it is proved experimentally that the photon is a particle that has mass and constant wavelength by explaining the effect of refractive index on the wavelength and the natural mass of photon. It is very difficult to measure the mass of photon, a simple and easy process was proposed in this paper to calculate the mass length of photon in vacuum (Y) and in medium (Y*), by measuring the length of laser beam in air (Lair) and in medium (Lmed). A new method was postulated to calculate refractive index by using these relations (n = Y*/Y), and (n = Lmed / Lair) which supposed a new theory of light.

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Publication Date
Mon Jan 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Difficulties in the application of modern trends in physics in middle schools of the province of Baghdad, from the perspective of teachers of physics
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     The goal of current research is to identify the difficulties in the application of modern physics in the middle schools of the province of Baghdad schools from the perspective of teachers of physics trends, sample search of (127) teachers, Karkh Third Directorate, and use Researcher questionnaire data collection tool after applying it to teachers who have experience (5) years and more after confirmation of the validity and reliability of the scale (the tool) researcher has used the averages for the purpose of interpreting the results. the results showed that the difficulties have been in the order following: (difficulties related educational environment of modern trends of teaching, curriculum-related dif

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Publication Date
Wed Oct 11 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Deductive Group Pattern in Developing the Creative Thinking of Second Intermediate Grade Pupils in History Discipline
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The present study aims to identify the effectiveness of deductive group patterns in developing the creative thinking of second-intermediate-grade pupils in history discipline. The current null hypothesis has been investigated: There are no statistically significant differences at (0.05) between the scores mean of the experimental group pupils who were taught according to the deductive group pattern and the scores mean of the control group pupils who were taught according to traditional method in creative thinking testing. the study sample was divided into two groups: an experimental group of (30) female students and a control group of (31) female students. The two groups are equalized based on the variables of age, the scores of the firs

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Publication Date
Sat Dec 30 2023
Journal Name
Journal Of The College Of Education For Women
Civilizational Manifestations in the City of Astrabath in the Sixth Century AH
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The current study is concerned with presenting a descriptive study of the history of the city of Astrabath in the sixth century AH. The problem that the research tried to answer is represented in the investigation of historical news, and the study of the most prominent cultural aspects which characterizing that city. The research also aims to reach the geographical location of that city, its name and its suburbs. The importance of the research lies in the knowledge of everything related to the role of the civilization of Astrabath, as well as tracing the entry of the Arabs to it, so that it became a cultural, economic and scientific center and its historical role in the sixth century AH. The research reminde us with the scientific role o

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Publication Date
Tue Dec 29 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of the activities of the national poverty reduction strategy On achieving the sustainable development goals An applied research in the Ministry of Labor and Social Affairs
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The objective of the research is to shed light on the nature of the impact of the activities of the national strategy for poverty alleviation in achieving the goals of sustainable development, and the research problem was represented by Is there an effect of the activities of the national strategy for poverty reduction in achieving the goals of sustainable development? and represents the field of research in the Ministry of Labor and Social Affairs For the years (2012-2016) and the results of the sustainable development goals indicators for the years (2012-2016), the ready-made statistical program (SPSS ver.10) was used to calculate the percentages, multiple linear regression equation, the F test and the R2 coefficient, and the research

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Publication Date
Sun May 02 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of the auditor in allocating common costs in the gas industry and its reflection on the company's performance: Applied Research in North Gas Company
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The auditor has a role in allocating joint costs in the gas industry, and the auditor's procedures are considered as systematic critical examination, analysis and evaluation of everything related to costs in general and joint costs in the gas industry in particular, with the aim of controlling the joint costs of gas industry products, and knowing the share of the cost of each product from the total industry costs Gas products reflect the reality of the company's performance by discovering weaknesses, defects and any errors, to ensure increased effectiveness and efficiency of the parties concerned with auditing them and imposing control and control over the company's resources, as well as

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Publication Date
Tue Sep 08 2020
Journal Name
Baghdad Science Journal
Evaluation of Different Nitrogen Management on Yield and Some of the Yield Components of Rice (Shiroudi cultivar)
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Nitrogen (N) is a key growth and yield-limiting factor in cultivated rice areas. This study has been conducted to evaluate the effects of different conditions of N application on rice yield and yield components (Shiroudi cultivar) in Babol (Mazandaran, Iran) during the 2015- 2016 season. A factorial experiment executed of a Randomized Complete Block Design (RCBD) used in three iterations. In the first factor, treatments were four N amounts (including 50, 90, 130, and 170 kg N ha-1), while in the second factor, the treatments consisted of four different fertilizer splitting methods, including T1:70 % at the basal stage + 30 % at the maximum tillering stage, T2:1/3 at the basal stage + 1/3 at the maximum ti

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Publication Date
Fri Dec 30 2022
Journal Name
College Of Islamic Sciences
جدلية جدليّة العقل والنّقل وعلاقتهما بالاستدلال مسائل الاعتقاد بين مدرستي أهل الحديث والأشاعرة: - عرض ومناقشة
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This research highlights one of the most important issues that have been controversial between Islamic schools, which is the duality of Intellect  and Revelation and the nature of their relationship, in two core points:

The first point: Could there be a real conflict between Intellect  and revelation? While the school of hadith view that this assumption is a rational assumption that does not real as long as the revelation is correct and the Intellect  is clear, and that what is claimed are due to other Intellect s, we find that the Ash’ari school adopts the saying that the real conflict may occur, but rather confirms its occurrence.

The second point: For whom is the priority, for the Intellect  or th

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Publication Date
Sun Jun 30 2024
Journal Name
حوليات أداب عين شمس
المنظور الزمني وعلاقته بجودة الحياة الاكاديمية لدى طلبة جامعة بغداد
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Abstract The aim of the current research is to identify the time perspective and the quality of academic life of Baghdad University students. The research also aims to identify the relationship between the time perspective and the academic quality of Baghdad University students and the extent to which the time perspective dimension of academic quality contributes to the identification of the difference between the time perspectives in terms of gender. Finally, the research aims to identify if there is a significant difference in the quality of academic life between males and females. The scales were applied to a number of (434) university male and female student. A one-sample t-test, a two-sample t-test, the analysis of the variation, the P

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