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Munteanu E.,Advanced Studies and Research Center | Ursu L.,National Institute for Aerospace Research Elie Carafoli
UPB Scientific Bulletin, Series D: Mechanical Engineering | Year: 2010

The present work continues some recent researches of the authors ([1], [2]) in the vibration active control domain for a composite wing model by using MFC (Macro-Fiber-Composite) piezo actuators. The robustness characteristics of the optimal control LQR (Linear Quadratic Regulator) are recovered by the Kalman filter applying a special construction for the estimator. The obtained control law is called LQG/LTR (Linear Quadratic Gaussian/Loop Transfer Recovery). Moreover, including an internal model in the compensator of the system confers more robustness properties and remarkable performances.

Cucu-Dumitrescu C.,Advanced Studies and Research Center
IEEE Geoscience and Remote Sensing Letters | Year: 2014

This letter presents a technique to derive cloud-and shadow-masks from satellite images. The technique is based on a mutual confirmation algorithm that uses all available solar bands, but no thermal infrared bands. The process of mutual confirmation consists of first searching and then identifying partial geometrical overlap between first-guess (preliminary) bright (cloud candidates) and associated dark (cloud shadow candidates) pixels in the image. The thresholds needed for the algorithm to operate are adjusted dynamically and are scene dependent, but need no additional information about radiometric calibration or solar geometry. The algorithm's success rate (percentage of correct classification compared to a manual/visual mask) when applied on a handful of Landsat-5 scenes is found to exceed 95% for cloud pixels and 90% for shadow pixels. © 2013 IEEE.

Zavalan L.,Polytechnic University of Bucharest | Teleaga D.,Advanced Studies and Research Center | Stoia-Djeska M.,Polytechnic University of Bucharest
AIP Conference Proceedings | Year: 2013

This paper investigates the pseudo-compressibility method for the incompressible Euler equations with a FVPM (Finite-Volume-Particle Method) discretization. The code uses Roe's upwind method with a Linear Data Reconstruction for the convective terms. The study focuses on the verification of the code. The method of manufactured solutions is used to examine the global discretization error and to verify the order of accuracy. © 2013 AIP Publishing LLC.

Munteanu E.,Advanced Studies and Research Center
Control Engineering and Applied Informatics | Year: 2010

The paper presents a possible way to obtain a numerical model for structural vibration active control. Using data and analysis results from different commercial software tools, such as ANSYS, ZAERO and MATLAB, one can find an optimal model to test the system dynamic response and design an active control law. Different algorithms for resolving the eigenvalue problem and different methods for system order reduction are presented here. A wing composite model as a representative aerospace structure is design and numerical tested for flutter.

Poncos V.,Advanced Studies and Research Center | Teleaga D.,Advanced Studies and Research Center | Boukhemacha M.A.,Technical University of Civil Engineering Bucharest | Toma S.A.,Advanced Studies and Research Center | Serban F.,Advanced Studies and Research Center
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2014

This work focuses on monitoring the ground motion and infrastructure stability in an urban environment, namely in the city of Bucharest. Bucharest is a fast developing city with the average construction rate of 8-20% new buildings with respect to the existing ones. Consequently, the civil engineering industry faced new challenges related to the need of having taller buildings with deeper underground levels, a developing network of subway lines and more bridges with large diameter piles' foundations. All these new works have an important impact upon the upper ground stability. The PSI (Persistent Scatterer Interferometry) technique is used to extract the ground deformation in Bucharest from archived C-band ESA data and from more recent TerraSAR-X data. The conducted analysis constitutes historical case studies for Bucharest City covering the intervals 1992-1999, 2003-2009 and 2011-2012. © 2014 IEEE.

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