New Model Reference Adaptive System Speed Observer for Field-Oriented Control Induction Motor Drives Using Neural Networks

One of the primary advantages of field-oriented controlled induction motor for high performance application is the capability for easy field weakening and the full utilization of voltage and current rating of the inverter to obtain a wide dynamic speed rangeThis paper describes a Model Reference Adaptive System (MRAS) based scheme using Artificial Neural Network (ANN) for online speed estimation of sensorless vector controlled induction motor drive. The proposed MRAS speed observer uses the current model as an adaptive model. The neural network has been then designed and trained online by employing a back propagation network (BPN) algorithm. The estimator was designed and simulated in Matlab/Simulink. Simulation result shows a good performance of speed estimator. The simulation results show good performance in various operating conditions. Also Performance analysis of speed estimator with the change in resistances of stator is presented. Simulation results show this estimator robust to parameter variations especially resistances of stator

New Model Reference Adaptive System Speed Observer for Field-Oriented Control Induction Motor Drives Using Neural Networks

One of the primary advantages of field-oriented controlled induction motor for high performance application is the capability for easy field weakening and the full utilization of voltage and current rating of the inverter to obtain a wide dynamic speed rangeThis paper describes a Model Reference Adaptive System (MRAS) based scheme using Artificial Neural Network (ANN) for online speed estimation of sensorless vector controlled induction motor drive. The proposed MRAS speed observer uses the current model as an adaptive model. The neural network has been then designed and trained online by employing a back propagation network (BPN) algorithm. The estimator was designed and simulated in Matlab/Simulink. Simulation result shows a good performance of speed estimator. The simulation results show good performance in various operating conditions. Also Performance analysis of speed estimator with the change in resistances of stator is presented. Simulation results show this estimator robust to parameter variations especially resistances of stator

Association of IFN-γ and P2X7 Receptor Gene Polymorphisms in Susceptibility to Tuberculosis Among Iranian Patients

Interferon-gamma (IFN-γ) and P2X7 receptor are crucial for host defence against mycobacterial infections. Recent studies have indicated that IFN-γ, IFN-γ receptor 1 (IFN-γR1) andP2X7 gene polymorphisms are associated with susceptibility to pulmonary tuberculosis (TB). However, the relationship between IFN-γ and P2X7 polymorphism and TB susceptibility remains inconclusive in Iranian population. For this reason, single nucleotide polymorphisms (SNPs) in IFN-γ (G+2109A), IFN-γR1 (G-611A) and P2X7 genes (at –762, 1513 position) in patients (n = 100) were assessed using PCR-RFLP. Data were analysed with SPSS version 18. For the 2109 loci of IFN-γ gene, the frequency of mutant alleles between patients and controls were not statistically significant. However, there was a significant difference between the TB patient and controls for –611 alleles of IFN-γR1 (P = 0.01). Additionally, the frequency of P2X7 gene polymorphisms (SNP-762 and 1513) between patients and controls was statistically significant. In conclusions, our study revealed a significant association of IFN-γR1 and P2X7 genes polymorphisms with risk of developing TB in Iranian population

A New Robust Nonlinear Control Strategy for UIPC in Isolated Hybrid Microgrids

This paper focuses on the control of unified interphase power controller (UIPC) in isolated hybrid microgrids (HmGs), where the UIPC is used as the main component for interconnecting of AC and DC sub-grids. The investigated HmG encompasses two AC sub-grids and one purely storage DC sub-grid (PSDC) and multiple adjustable loads. A robust nonlinear model reference adaptive control (NMRC) strategy is offered for controlling the UIPC, keeping an acceptable two-way power exchange control with uncomplicated topology. Further, a novel configuration for the DC link power converter is suggested using the dual-active-bridge topology. Also, a harmonic-based modeling method is used to model the UIPC's power converter. The proposed configuration provides bidirectional power flow, increased power density, straightforward adaptation of zero-voltage switching, and direct access to cascading and parallelism to increase the ratings and reliability of UIPC. The simulation results illustrate the feasibility of the suggested topology for isolated HmGs

A Comparative Study of Realism from the Perspective of Waltz and Ferdowsi

1. Introduction Realism is one of the most important and one of the oldest theories in political sciences and international relations. Attraction, objectivism, and on the other hand, closeness to conventional understanding in the analysis of political phenomena is the factor that has promoted and sustained this theory. The theoretical dominance of realism is such that intellectuals of international relations consider realism as the mainstream theory. (Griffiths, 1992:3). Waltz's theory of realism is based on four basic hypotheses: 1) Pessimism about human nature. 2) War is the final solution for settling the problems. 3) The security of the government and its survival is the most important goal. 4) The only way that is put forward for the governments is to increase power. (Jackson & Sorensen, 2015:chp3). Accordingly, realists emphasize the constraints of agents' corruption and the lack of supreme authority of the international system, which requires increased power and security. In Persian historical and literary texts, Ferdowsi can be considered as the closest intellectual to Waltz's realist approach. Shahnameh is an epic work in which the concepts of war, power and security are the most important words used. In addition the independence movements in the third and fourth centuries AH, that coincided with the rise of Feudalism and chaos caused by weak power structure of the Iranian monarchy, influenced the importance of realism in Ferdowsi's political thoughts. The main question of the research is to what extent is Waltz's theory of political realism compatible with Ferdowsi's political thought? With regard to the main question of the research, it is hypothesized that considering the events and political disorders in Ferdowsi’s era, Hakim Toos has expressed his political-theoretical views on the need to increase power and ensure security in Iran, through using the anecdotes and legends of his predecessors, which is compatible with the main political realistic Hypotheses of Waltz.   2. Methodology This article uses the "Content Analysis" method; Because this method is useful for orderly, objective and quantitative description of communication content. Sampling of sources is purposeful and is done with a theoretical framework that is based on key words such as government, power, hierarchical structure, rationality and war in Kent Waltz’s theoretical realism framework.   3. Discussion In the turbulent internal conditions and the cultural and identity collapse of Iran in the Ferdowsi era, he was able to offer an appropriate answer and a favorable plan for the future of Iranian identity by epic and paying attention to the main elements of the political reality. By dealing with epics and wise advices, he gathered the behavior of the heroes and even their defeats and victories into a system of political thought. In addition, the concepts that can be extracted from the myths mentioned in Shahnameh are to build a desirable society in order to unite the Iranian government and prevent the collapse of this historical-cultural-political system. Iranian mythology represents the mental structures left over from ancient Iran and Ferdowsi's attempts to elevate the value of these structures in his time to create a powerful and free-standing Iran in the framework of a political school that the authors consider close to political realism in international relations theories. The authors believe that Shahnameh is a strong theoretical structure that, in the shade of stories and philosophies, expresses Ferdowsi's desirable political system in order to portray a powerful and famous Iran for future generations.   4. Conclusion Although Waltz's realism can be identified in many schools, the central concepts in his political thought are key concepts such as human nature, power, war, the structure of the international system, and rationality. Although some approaches place more emphasis on each of these concepts and theoretically explain political events from that perspective, they all owe much to his philosophical view of the nature of human existence and nature. Regarding Ferdowsi's political thought, due to the geographical conditions, the unfavorable situation of national and religious culture, the rule of Feudalism and the growing weakening of Iranian power and identity under the rule of Sultan Mahmoud Ghaznavi, Ferdowsi's greatest concern about the political future was a single entity called Iran. Accordingly, in long fictional systems and mythical and historical metaphors, he expresses his political thought, which is closest in meaning to the philosophical approach of political realism. lism

Preservation of the environment in the light of Jurisprudential rules

The environment is a gift from God and has very positive effects on human life; the concern for environmental protection has led to the formulation of a legal system called "Environmental Law", which itself proves the necessity of research on this vital issue. It does not have the cultural and ideological perceptions of human societies, but simply and clearly, the rules and foundations, elements, and goals of such a system can be found in religions, beliefs, and divine and human cultures, especially the comprehensive and universal religion of Islam. From all the verses, hadith, rules, and foundations of Islamic jurisprudence, it is possible to propose the presumption that in this divine religion, the environment is considered one of the values that can be protected, and any action against the environment is limited unless it considered as a nessasery action. This research, which has been done based on descriptive-analytical methods and based on library sources, led to the conclusion that from the point of view of Islamic jurisprudence, to prove the necessity of preserving the environment, in addition to numerous verses and narrations regarding the preservation of some environmental components such as Water, soil, air, animals and plants and the wisdom can be referred to several jurisprudential rules such as the Lazarar, Ehteram, Etlaf, Edalat, and the Zemaneyad. This research is trying to investigate the main issue based on these rules