Aircraft Jet Engine Health Monitoring Through System Identification Using Ensemble Neural Networks

In this thesis a new approach for jet engine Fault Detection and Isolation (FDI) is proposed using ensemble neural networks. Ensemble methods combine various model predictions to reduce the modeling error and increase the prediction accuracy. By combining individual models, more robust and accurate representations are almost always achievable without the need of ad-hoc fine tunings that are required for single model-based solutions. For the purpose of jet engine health monitoring, the model of the jet engine dynamics is represented using three different stand-alone or individual neural network learning algorithms. Specifically, a dynamic multi-layer perceptron (MLP), a dynamic radial-basis function (RBF) neural network, and a dynamic support vector machine (SVM) are trained to individually model the jet engine dynamics. The accuracy of each stand-alone model in identification of the jet engine dynamics is evaluated. Next, three ensemble-based techniques are employed to represent jet engine dynamics. Namely, two heterogenous ensemble models (an ensemble model is heterogeneous when different learning algorithms (neural networks) are used for training its members) and a homogeneous ensemble model (all the models are generated using the same learning algorithm (neural network)). It is concluded that the ensemble models improve the modeling accuracy when compared to stand-alone solutions. The best selected stand-alone model (i.e the dynamic radial-basis function neural network in this application) and the best selected ensemble model (i.e. a heterogenous ensemble) in term of the jet engine modeling accuracy are selected for performing the FDI study. Engine residual signals are generated using both single model-based and ensemble-based solutions under various engine health conditions. The obtained residuals are evaluated in order to detect engine faults. Our simulation results demonstrate that the fault detection task using residuals that are obtained from the ensemble model results in more accurate performance. The fault isolation task is performed by evaluating variations in residual signals (before and after a fault detection flag) using a neural network classifier. As in the fault detection results, it is observed that the ensemble-based fault isolation task results in a more promising performance

Reading and Intellectual Comparison of Siyasat-Nameh and Qaboos-Nameh based on the P4C Theory

The Philosophy Program for Children or Fabak, known worldwide by the acronym (P4C) to improve children's thinking, was presented in 1962 by Lipman, who is a professor at Columbia University. With regard to the components of philosophy for the child and the three literary, intellectual, and psychological competencies, there can be found anecdotes in Persian literature in which at least one or two philosophical themes and concepts appropriate to indigenous culture have been used. Since, according to the objectives of the Philosophy Program for the Child, there must be selected anecdotes that are in line with the standards and principles of Fabak, the two books of Siyasat-Nameh written by Khajeh Nizam al-Molk Tousi and Qaboos-Nameh from Onsor al-Maali Keykavus can be a prominent example of Persian literature in this field. These two books are valuable Persian works, full of ethical concepts and educational teachings expressed in the story. By examining the stories, in line with the features of the Fabak stories, we find that most of the stories in the two books are both engaging and child-friendly in terms of processing as well as themes. In this essay, he has attempted to explain the philosophy program for the child according to the founder of the program, Lipman, and others such as Philip Kam, and to explain the characteristics of intellectual stories. Therefore, content analysis and deductive analysis have been used to do this and to explain the underlying data

Cyber security for smart grid: a human-automation interaction framework

Abstract-- Power grid cyber security is turning into a vital concern, while we are moving from the traditional power grid toward modern Smart Grid (SG). To achieve the smart grid objectives, development of Information Technology (IT) infrastructure and computer based automation is necessary. This development makes the smart grid more prone to the cyber attacks. This paper presents a cyber security strategy for the smart grid based on Human Automation Interaction (HAI) theory and especially Adaptive Autonomy (AA) concept. We scheme an adaptive Level of Automation (LOA) for Supervisory Control and Data Acquisition (SCADA) systems. This level of automation will be adapted to some environmental conditions which are presented in this paper. The paper presents a brief background, methodology (methodology design), implementation and discussions. Index Terms—smart grid, human automation interaction, adaptive autonomy, cyber security, performance shaping facto

The isolation and preliminary characterization of native cyanobacterial and microalgal strains from lagoons contaminated with petroleum oil in Khark Island

Introduction: Algae has many applications in terms of ecology, biodiversity, agriculture, medicine, biotechnology, industry, etc. They are potent organisms in bio-active compound production, bioremediation and primary producer. Therefore, it is important to discover local strains with biotechnological and ecological applications. Materials and methods: Soil and water samples were collected from different sites of Khark Island (Persian Gulf). The samples were cultivated and purified using different techniques. Seven different antibiotics together with other physical methods used to purify the isolates. Results: Throughout the project 7 strains including 2 eukaryotic algae and 5 cyanobacteria have been isolated. Imipenem and cycloheximide were the best antibiotics for purification of cultures. Three of isolates were morphologically similar to Arthronema africanum, Pseudanabaena teremula, Anabaenopsis sp. However, they have some different characteristics which according to the present identification keys it is not possible to identify their identity (they have nominated Kh.C.d2, Kh.T.1 and Kh.T.2). Discussion and conclusion: According to the results, isolated strains were identified at the genus level based on morphology characters; therefore the complementary examinations such as molecular identification, ITS, 18s rRNA, 16s rRNA and sequencing can help to approve the strains identity. Upon approval of the new strains account for morphological traits are necessary for their easy identification. The Imipenem antibiotic is the best for eukaryotic algae purification and Cycloheximide is suitable for prokaryotic algae (cyanobacteria) purification

Studying of Biomineralization on Badab Sourt travertine deposit spring, Kiasar, Mazandaran Province

Introduction: Travertine results in the accumulation of calcium carbonate on karst springs, hot springs, small rivers and marshes. Badab Sourt is the travertine-maker spring that located in Mazandaran province and is the second natural place in Iran. It has two springheads with different characteristics and different colors and different sediments that give unique beauty to spring. Travertine is a good model to study the relationship between environment and microorganisms. This study centered on the influence of microorganisms on precipitation of calcium carbonate and isolation of microorganisms that have precipitation potential. Materials and methods: Here, to assess effects of microorganisms on mineralization were used microscopic and culture methods; from stone samples, photos have gotten with SEM and polarizing microscope and from water sample bacteria were isolated. Mineralization function of bacteria was investigated with culturing them on B4 medium and mineralization potential was approved by polarizing microscope. Results: SEM photos showed microorganisms have effect on mineralization and can act as a nucleus in beginning of crystal production. Finally, five strains Bss-3, Bsw-28d, Bss-11a, Bsw-1c1, and Bsw-39b were isolated, which have ability to precipitate calcium carbonate. In between strain Bss-3 that has 99.6% similarity with taxon Labrenzia aggregate IAM 12614T was the first report that has the ability to precipitate calcium carbonate and among the strains, strain Bsw-28d with precipitation of 45.6 mg / ml CaCO3 was the best strain. Discussion and conclusion: Microorganisms are important in the formation and evolution of their surrounding environments, thereby native microbes must be concerned for conserving and restoring the environments