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Arad, Romania

Aurel Vlaicu University of Arad is a state university founded in 1972/1990 in Arad, Romania. Wikipedia.

Ndban S.,Aurel Vlaicu University
Fuzzy Sets and Systems | Year: 2016

In the present paper we firstly introduce the notion of fuzzy pseudo-norm, then we extend, improve and complete the results obtained by T. Bag and S.K. Samanta for fuzzy norms, in the fuzzy pseudo-norms context. Lastly, we introduce and discuss the notions of fuzzy F-norm and fuzzy F-space. By means of several auxiliary results, we obtain a characterization of metrizable topological linear spaces in terms of fuzzy F-norm. © 2014 Elsevier B.V. Source

Duma V.-F.,Aurel Vlaicu University
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2014

We review some of the most important scanning systems that are competitive in high-end biomedical imaging applications such as Optical Coherence Tomography (OCT), but also Confocal Microscopy (CM) or multiphoton microscopy. Both 1-D (uni-dimensional) and 2-D (bi-dimensional) scanning systems are considered. The paper discusses different scanners, including polygon mirror, galvanometer-based and Risley prisms. Their configurations and characteristics, as well some of our contributions in the domain are presented. The tendency of applying them into special designs such as handheld scanning probes and endoscopes - the latter with MEMS (Micro-Electro-Mechanical Systems) and micro-systems is pointed out. A discussion on further advancements of scanning technology in biomedical applications in general and in OCT in particular concludes the study. © 2014 Copyright SPIE. Source

Duma V.-F.,Aurel Vlaicu University | Duma V.-F.,University of Rochester
Optical Engineering | Year: 2010

We study different possible scanning functions of a galvanometer-based scanner (GS), considered with an optimal profile for the user, i.e., symmetrical, linear on their active portions, and with fast stop-and-turn parts. The scope is to obtain the function that provides the highest theoretical limit of the duty cycle of the device. From the equation of the oscillatory mirror, the active torque is obtained with regard to the scanning function. Several equations are studied for the stop-and-turn parts: polynomials of different orders and sinusoidal. We demonstrate that the choice has to be done between the two most advantageous scanning functions: linear plus parabolic and linear plus sinusoidal. The relationships between the characteristic parameters of the GS, i.e., stop-and-turn time interval, scan frequency and velocity, duty cycle, and maximum inertia torque are deduced and compared for these two functions. We demonstrate that, contrary to what is considered in the literature, the best function, i.e.,the one that provides the highest duty cycle (and to obtain that, the lowest inertia torque, for minimum stop-and-turn time) is the linear plus parabolic function. © 2010 Society of Photo-Optical Instrumentation Engineers. Source

Nadaban S.,Aurel Vlaicu University
International Journal of Computers, Communications and Control | Year: 2015

In this paper we continue the study of fuzzy continuous mappings in fuzzy normed linear spaces initiated by T. Bag and S.K. Samanta, as well as by I. Sadeqi and F.S. Kia, in a more general settings. Firstly, we introduce the notion of uniformly fuzzy continuous mapping and we establish the uniform continuity theorem in fuzzy settings. Furthermore, the concept of fuzzy Lipschitzian mapping is introduced and a fuzzy version for Banach's contraction principle is obtained. Finally, a special attention is given to various characterizations of fuzzy continuous linear operators. Based on our results, classical principles of functional analysis (such as the uniform boundedness principle, the open mapping theorem and the closed graph theorem) can be extended in a more general fuzzy context. © 2006-2015 by CCC Publications. Source

Duma V.-F.,Aurel Vlaicu University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

We present a brief overview of our contributions in the field of laser scanning technologies, applied for a variety of applications, from industrial, dimensional measurements to high-end biomedical imaging, such as Optical Coherence Tomography (OCT). Polygon Mirror (PM) scanners are presented, as applied from optical micrometers to laser sources scanned in frequency for Swept Sources (SSs) OCT. Galvanometer-based scanners (GSs) are approached to determine the optimal scanning function in order to obtain the highest possible duty cycle. We demonstrated that this optimal scanning function is linear plus parabolic, and not linear plus sinusoidal, as it has been previously considered in the literature. Risley prisms (rotational double wedges) scanners are pointed out, with our exact approach to determine and simulate their scan patterns in order to optimize their use in several types of applications, including OCT. A discussion on the perspectives of scanning in biomedical imaging, with a focus on OCT concludes the study. © 2013 SPIE. Source

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