Numerical investigation of V/STOL jet induced interactions

Direct numerical simulation using the full three dimensional, time dependent Navier-Stokes equations is used to investigate V/STOL jet induced interactions. The objective of this numerical simulation is to compute accurately the details of the flow field and to achieve a better understanding of the physics of the flow, including the role of initial turbulence in the jet, the influence of forward motion on hover aerodynamics, the collision zone and fountain characteristics. Preliminary results are presented

Model Prediction-Based Approach to Fault Tolerant Control with Applications

Abstract— Fault-tolerant control (FTC) is an integral component in industrial processes as it enables the system to continue robust operation under some conditions. In this paper, an FTC scheme is proposed for interconnected systems within an integrated design framework to yield a timely monitoring and detection of fault and reconfiguring the controller according to those faults. The unscented Kalman filter (UKF)-based fault detection and diagnosis system is initially run on the main plant and parameter estimation is being done for the local faults. This critical information\ud is shared through information fusion to the main system where the whole system is being decentralized using the overlapping decomposition technique. Using this parameter estimates of decentralized subsystems, a model predictive control (MPC) adjusts its parameters according to the\ud fault scenarios thereby striving to maintain the stability of the system. Experimental results on interconnected continuous time stirred tank reactors (CSTR) with recycle and quadruple tank system indicate that the proposed method is capable to correctly identify various faults, and then controlling the system under some conditions

Bibliographic Review on Distributed Kalman Filtering

In recent years, a compelling need has arisen to understand the effects of distributed information structures on estimation and filtering. In this paper, a bibliographical review on distributed Kalman filtering (DKF) is provided.\ud The paper contains a classification of different approaches and methods involved to DKF. The applications of DKF are also discussed and explained separately. A comparison of different approaches is briefly carried out. Focuses on the contemporary research are also addressed with emphasis on the practical applications of the techniques. An exhaustive list of publications, linked directly or indirectly to DKF in the open literature, is compiled to provide an overall picture of different developing aspects of this area

Comparison of crisp and fuzzy character networks in handwritten word recognition

Experiments involving handwritten word recognition on words taken from images of handwritten address blocks from the United States Postal Service mailstream are described. The word recognition algorithm relies on the use of neural networks at the character level. The neural networks are trained using crisp and fuzzy desired outputs. The fuzzy outputs were defined using a fuzzy k-nearest neighbor algorithm. The crisp networks slightly outperformed the fuzzy networks at the character level but the fuzzy networks outperformed the crisp networks at the word level

Teachers\u27 metacognitive awareness and metacognitive instructional practice: A mixed method study in Egypt

Metacognition plays a vital role in 21st entury learning as it is found to be avery important predictor of learning. Research shows that metacognition can be taught and promoted inside the classroom. However, a gap was found between theory and practice where instructional practices that are actually done by teachers to promote metacognition are scarce. Litereture suggests that developing teachers\u27 metacognitve skills is a prerequisite for promoting metacognition inside the classroom. In addition, research investigating teachers\u27 metacognition is scarce with methodological concerns about the exisiting studies since they use self report for data collection that are not found to be ecologically valid compared to online measures like observations with several calls for mixed methods to give a holisitic view about teachers metacognition. The current study is a mixed method study that collects data through a quantitative followed by a qualitative method. For the quantitative study, 394 teachers from 31 schools from different socioeconomic levels in Cairo answered the Arabic adapted version of the Metacognitive Awareness inventory (MAI). Statisitcal analysis shows high level of metacognitve awareness by Egyptian teachers. In addition, t test an ANOVA shows no significant differences inteachers metacognitive awareness based on gender, subjects taught, type of schools or grade level. The only signifcant difference found was in experience where teachers with 6 to 15 years of experience show signifcantly higher metacognitive awareness compared to teachers of 16 or more years of experience while there was no siginificant difference between novice teachers (0-5 years of experience) and teachers with 6 to 15 years of experience. For the qualitative study, four female teachers were interviewed and observed through two cycles of pre-observation interview, class observations and post observation interview and several themes emerged of how teachers think and use metacognitive instructional practices to adapt their instructions

Could informality be the solution? An instrumental variable approach on the informality of M/SE in Egypt

The expansion of the informal sector constitutes one of the major issues in Egypt. Yet, micro and small enterprises (M/SEs) proved their important role on the social and economic level, but most of them are running on an informal basis. That's why this paper tries to estimate the impact of informality on the performance of M/SEs. Relying on an instrumental variable approach, the results showed that the higher is the probability of operating in the formal sector, the higher is the productivity of the firm. This effect is subject to the realization of a specific channel, which accounts for the characteristics of the firm, the entrepreneur and all the constraints faced by the firm. These findings highlight the importance of formalization policies to reduce the expansion of the informal sector