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1. Characterization of Gravitational Waves Signals Using Neural Networks

Author

Caramete, A., Constantinescu, A. I., Caramete, L. I., Popescu, T., Balasov, R. A., Felea, D., Rusu, M. V., Stefanescu, P., and Tintareanu, O. M.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Gravitational wave astronomy has been already a well-established research domain for many years. Moreover, after the detection by LIGO/Virgo collaboration, in 2017, of the first gravitational wave signal emitted during the collision of a binary neutron star system, that was accompanied by the detection of other types of signals coming from the same event, multi-messenger astronomy has claimed its rights more assertively. In this context, it is of great importance in a gravitational wave experiment to have a rapid mechanism of alerting about potential gravitational waves events other observatories capable to detect other types of signals (e.g. in other wavelengths) that are produce by the same event. In this paper, we present the first progress in the development of a neural network algorithm trained to recognize and characterize gravitational wave patterns from signal plus noise data samples. We have implemented two versions of the algorithm, one that classifies the gravitational wave signals into 2 classes, and another one that classifies them into 4 classes, according to the mass ratio of the emitting source. We have obtained promising results, with 100% training and testing accuracy for the 2-class network and approximately 95% for the 4-class network. We conclude that the current version of the neural network algorithm demonstrates the ability of a well-configured and calibrated Bidirectional Long-Short Term Memory software to classify with very high accuracy and in an extremely short time gravitational wave signals, even when they are accompanied by noise. Moreover, the performance obtained with this algorithm qualifies it as a fast method of data analysis and can be used as a low-latency pipeline for gravitational wave observatories like the future LISA Mission., Comment: 51 pages, 29 figures. This work was presented at the 13th International LISA Symposium, 2020

Published
2020

10. The brain-structural correlates of mathematical expertise

Author

Popescu, T, Sader, E, Schaer, M, Thomas, A, Terhune, D, Dowker, A, Mars, R, and Cohen Kadosh, R

Subjects
Adult, Male, Brain Mapping, Grey matter, Action, intention, and motor control, White matter, Brain, Expertise, Neuropsychological Tests, Magnetic Resonance Imaging, Article, Numerical cognition, Young Adult, Cognition, Cross-Sectional Studies, Parietal Lobe, Image Processing, Computer-Assisted, Anisotropy, Humans, Female, Mathematics
Abstract

Contains fulltext : 208139.pdf (Publisher’s version ) (Open Access) Studies in several domains of expertise have established that experience-dependent plasticity brings about both functional and anatomical changes. However, little is known about how such changes come to shape the brain in the case of expertise acquired by professional mathematicians. Here, we aimed to identify cognitive and brain-structural (grey and white matter) characteristics of mathematicians as compared to non-mathematicians. Mathematicians and non-mathematician academics from the University of Oxford underwent structural and diffusion MRI scans, and were tested on a cognitive battery assessing working memory, attention, IQ, numerical and social skills. At the behavioural level, mathematical expertise was associated with better performance in domain-general and domain-specific dimensions. At the grey matter level, in a whole-brain analysis, behavioural performance correlated with grey matter density in left superior frontal gyrus - positively for mathematicians but negatively for non-mathematicians; in a region of interest analysis, we found in mathematicians higher grey matter density in the right superior parietal lobule, but lower grey matter density in the right intraparietal sulcus and in the left inferior frontal gyrus. In terms of white matter, there were no significant group differences in fractional anisotropy or mean diffusivity. These results reveal new insights into the relationship between mathematical expertise and grey matter metrics in brain regions previously implicated in numerical cognition, as well as in regions that have so far received less attention in this field. Further studies, based on longitudinal designs and cognitive training, could examine the conjecture that such cross-sectional findings arise from a bidirectional link between experience and structural brain changes that is itself subject to change across the lifespan. 11 p.

Published
2019
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15. The brain-structural correlates of mathematical expertise

Author

Popescu, T., Sader, E.N., Schaer, M., Thomas, A.G., Terhune, D.B., Dowker, A., Mars, R.B., Cohen Kadosh, R., Popescu, T., Sader, E.N., Schaer, M., Thomas, A.G., Terhune, D.B., Dowker, A., Mars, R.B., and Cohen Kadosh, R.

Abstract

Contains fulltext : 208139.pdf (publisher's version ) (Open Access), Studies in several domains of expertise have established that experience-dependent plasticity brings about both functional and anatomical changes. However, little is known about how such changes come to shape the brain in the case of expertise acquired by professional mathematicians. Here, we aimed to identify cognitive and brain-structural (grey and white matter) characteristics of mathematicians as compared to non-mathematicians. Mathematicians and non-mathematician academics from the University of Oxford underwent structural and diffusion MRI scans, and were tested on a cognitive battery assessing working memory, attention, IQ, numerical and social skills. At the behavioural level, mathematical expertise was associated with better performance in domain-general and domain-specific dimensions. At the grey matter level, in a whole-brain analysis, behavioural performance correlated with grey matter density in left superior frontal gyrus - positively for mathematicians but negatively for non-mathematicians; in a region of interest analysis, we found in mathematicians higher grey matter density in the right superior parietal lobule, but lower grey matter density in the right intraparietal sulcus and in the left inferior frontal gyrus. In terms of white matter, there were no significant group differences in fractional anisotropy or mean diffusivity. These results reveal new insights into the relationship between mathematical expertise and grey matter metrics in brain regions previously implicated in numerical cognition, as well as in regions that have so far received less attention in this field. Further studies, based on longitudinal designs and cognitive training, could examine the conjecture that such cross-sectional findings arise from a bidirectional link between experience and structural brain changes that is itself subject to change across the lifespan.

Published
2019

18. Biological treatments of cadmium contamination continental waters with Nostoc gelatinosum and Spirulina platensis (Nordst.) Geitl. immobilized in Na-alginate

Author

Popescu, T., Ouddane, B., Dobrojan, S., Andruh, N., Salaru, V., Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Published
2016

19. Biological treatments of cadmium contamination continental waters with spirulina platensis (nordst.) geitl. immobilized in na-alginate beads

Author

Popescu, T., Ouddane, B., Dobrojan, S., Andruh, N., Salaru, V., Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Published
2016

20. The structure of the mathematical brain

Author

Popescu, T, Cohen Kadosh, R, and Humphreys, G

Subjects
Cognitive Neuroscience, Experimental psychology
Abstract

Humans have an innate ability to deal with numerosity and other aspects of magnitude. This ability is generally honed through education in and experience with mathematics, which necessarily changes the brain structurally and functionally. These changes can be further manipulated through non-invasive electrical brain stimulation. Studying these processes in the case of maths not only constitutes research of great practical impact – given the importance of numerical skills in today's society – but also makes use of maths as a suitable domain in which to study plasticity. In this thesis, I aimed to explore how expertise with numbers shapes brain and behaviour, and also the degree to which processing numbers is similar to other domains in terms of the necessity of healthy brain regions believed to underlie normal processing within and across these domains. In Study 1, behavioural and structural brain differences were found cross-sectionally between mathematicians and non-mathematicians. A double dissociation between those groups was found between grey matter density in the frontal lobe and behavioural performance: their correlation was positive for mathematicians but negative for controls. These effects may have been caused by years of experience, by congenital predispositions, or, plausibly, by both of these factors, whose disambiguation is non-trivial. Study 2 used transcranial random noise stimulation (tRNS) to assist arithmetic learning. A novel montage was used to enhance brain function during the stage when it is believed to be most involved. Real as compared to sham tRNS enhanced reaction times (RTs) and learning rate on a calculation-based task, but not on a retrieval-based task. The effects were only observed in conditions of high task difficulty. Study 3 examined structural MRI measures before and after arithmetic training to determine how either frontal or parietal tRNS applied with the task changes the structure of the brain longitudinally as compared to sham. Previous results (including those of Study 2) of behavioural facilitation in terms of enhanced RTs to calculation problems were replicated, and further interpreted. Both frontal and parietal tRNS modulated the changes that occurred, pre-to-post training, in terms of cortical volume and gyrification of frontal, parietal and temporal areas. Study 4 investigated the shared neural and cognitive resources used for processing numerical magnitude and musical pitch, by probing how stimulus-response compatibility (SRC) effects for each of the two dimensions compare in a group of mainly temporoparietal lesion patients with numerical impairments versus controls. A double dissociation was found in that numerically impaired patients did not show the number-based SRC effect but did show the pitch-based one, while control subjects demonstrated the opposite trend. Overall, the results of these studies leave us with three main messages. First, expertise in numbers and mathematics, whether acquired through years of experience (Study 1) or through a few days of tRNS-assisted training (Study 3), appears to be associated with complex changes in the morphology of several brain structures. Some – but not all – of these structures are maths-relevant, and, in the case of tRNS-assisted training, they are distal to the site of the stimulating electrodes. Second, tRNS can improve performance in arithmetic (Studies 2 and 3), although the mechanisms by which this occurs are not yet fully understood, neither neurally nor behaviourally. Third, I found (Study 4) that brain lesions leading to impairment in the number domain do not necessarily affect processing in other domains – such as pitch – that are otherwise linked to number via a putative common code in the parietal lobes.

Published
2016

21. Biological treatments of cadmium contamination continental waters with dried Nostoc gelatinosum and living Spirulina platensis (Nordst.) Geitl. immobilized in Na-alginate

Author

Popescu, T., Ouddane, B., Dobrojan, S., Andruh, N., Salaru, V., Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Published
2016

23. Hydrothermal route to (Fe, N) codoped titania photocatalysts with increased visible light activity.

Author

DIAMANDESCU, L., FEDER, M., VASILIU, F., TANASE, L., SOBETKII, ARCADII, DUMITRESCU, I., TEODORESCU, M., and POPESCU, T.

Subjects
PHOTOCATALYSTS, VISIBLE spectra, HYDROTHERMAL synthesis, TITANIUM dioxide nanoparticles, X-ray diffraction
Abstract

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2017
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33. Optimization of Manufacturing Processes by Reducing the Costs of Tools and Equipment on Hydraulically Operated High-Pressure Technological Lines

Author

Popescu Teodor Costinel, Chiriţă Alexandru-Polifron, Popescu Ana-Maria Carla, Vlad Andrei, Trăneci Gheorghe Alexandru, and Popescu Alina Iolanda

Subjects
low pressure, pumping unit, oscillating hydraulic pressure intensifier, high pressure, hydraulic cylinder, Engineering (General). Civil engineering (General), TA1-2040
Abstract

Most technological manufacturing lines include hydraulically operated stationary tools, devices and equipment. During a manufacturing cycle, there are phases, usually short, in which part of the hydraulic cylinders of the drive systems concerned, with small gauges and displacement speeds, have to generate / maintain high clamping or pressing forces, which implies functioning at high working pressures. The solution for such cylinders is to use modular hydraulic pumping units comprising: oil tank; low-pressure electric pump; hydraulic directional valve for starting, stopping and changing the direction of displacement of the cylinder; electric pump pressure control valve; pressure filter; return filter; oscillating hydraulic pressure intensifier (minibooster mounted directly on the cylinder). Such pumping units, which consume low pressure (in the primary side of the minibooster) to generate high pressure (in the secondary side of the minibooster), are cost-effective when it comes to the procurement of components, installing them, the space required for installation, and their maintenance, too. The classic applications of using them are for achieving and maintaining high pressure values, either in volumes of closed spaces (endurance tests on pipes and tanks), or at the active stroke end of hydraulic cylinders (hydraulic presses). The authors demonstrate, on a laboratory test bench, the following: - The range of applications of such pumping units can be extended in a third direction, namely for actuation of hydraulic cylinders with low gauge / speeds and constant high load (high working pressure) over the entire stroke; - The uniformity of displacement of these cylinders with load over the entire stroke, fed and actuated by such pumping units, is weakly affected by the pulsating mode of operation of the hydraulic pressure intensifier.

Published
2022
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40. The Influence of the Au Nanoparticles Dimension on the Photocatalytic Performances of TiO2-Au Porous Composites.

Author

Melinte, G., Baia, M., Georgescu, D., Baia, L., Iancu, V., Diamandescu, L., Popescu, T., Cotet, L. C., Barbu-Tudoran, L., Dancu, V., and Simon, S.

Subjects
NANOPARTICLES, TITANIUM dioxide, TRANSMISSION electron microscopy, X-ray diffraction, SALICYLIC acid, CRYSTALLIZATION, PHOTODEGRADATION, CHEMICAL decomposition
Abstract

The influence of Au nanoparticles dimension on the photocatalytic performances of the TiO2 aerogels-Au composites was evaluated. Structural and morphological peculiarities of the TiO2 aerogel, unloaded and loaded with 5 and 22 nm Au nanoparticles, were studied by transmission electron microscopy technique, X-ray diffraction and N2-sorption measurements. UV-Vis diffuse reflectance measurements were performed to determine the band gap energies. The photocatalytic activity was evaluated by monitoring the salicylic acid photodegradation. It was found that the Au nanoparticles promote the anatase phase crystallization and produce the decrease of the specific surface area and band gap energy values. The porous composite with the smallest Au nanoparticles dimension exhibits the best photocatalytic performances. [ABSTRACT FROM AUTHOR]

Published
2012
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41. Program Package for Process Identification and Control System Design

Author

Popescu, T., Sima, V., Varga, A., and Vasiliu, C.

Abstract

This paper provides a general description of a large suite of FORTRAN programs called SIPAC which allow the identification, design and simulation of linear time-invariant dynamic systems. The programs included in SIPAC can all be used in a conversational mode of working. Wide collection of modern identification and design techniques of control systems is provided. The process model may be given by a transfer function matrix, system matrix or 3tate-space equations. Transformations between these representations are available. Then the optimal control, pole allocation and state estimation problems can be solved. Finally the open or closed loop resultant system may be simulated. SIPAC has already been used to solve several problems from the process control industries.

Published
1979
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42. WCE 2010 - World Congress on Engineering 2010: Preface

Author

Korsunsky, A. M., Hunter, A., Hukins, D. W. L., Gelman, L., Hogger, C. J., Ceglarek, D. J., Payne, S., Ao, S. I., Ahmad, M., Alexandrou, I., Al-Nuaimy, W., Amavasai, B. P., An, Y. -Y, Ariwa, E., Arteche, J., Audrino, F., Ayesh, A., Baber, C., Bailey, C., Balkan, N., Barria, J., Bartosova, J., Benkrid, K., Bleijs, H., Bluck, M., Bose, I., Bouzas, P. R., Braiden, P. M., Brdys, M., Burriesci, G., Cannataro, M., Carvalho, A., Chang, C. -C, Chen, D., Chen, G. G., Chen, Y. -S, Chiclana, F., Cooke, A., Das, D. B., Davis, D. N., Dayoub, I., Raman, S. D. C. V., Demetriou, I. C., Devai, F., Dilmaghani, R. S., Dini, D., Drikakis, D., Durkan, C., Durodola, J., Etebar, K., Fenn, P., Figueiredo, A., Florou, G., Freear, S., Gabrys, B., Galbraith, G. H., Gaskell, P. H., Gaura, E., Ge, Z. -Q, Ghafouri-Shiraz, H., Ghavami, M., Giannopoulos, K., Pruneda Gonzalez, R. E., Gracia, A. M., Grecos, C., Guan, L., Gulpinar, N., Guo, R., Guo, Y., Hardalupas, Y., He, L., Herrero, J. R., Hicks, B. J., Hines, E. L., Hodgson, S., Horsfall, A., Hosein, P., Hu, F., Hu, O., Ijomah, W., Ming, J., James, A., Jancovic, P., Jhumka, A., Kamareddine, F., Kannan, R., Karsligil, M. E., Katircioglu, S. T., Khalid, A., Kokossis, A., Kontis, K., Kulekci, M. O., Laukaitis, A., Leeson, M., Limbachiya, M. C., Li, L., Lin, P., Ling, W. -K, Macias Lopez, E. M., Lovas, T., Luglio, M., Mainardi, S., Mahanti, P. K., Marinos, I., Maropoulos, P., Mativenga, P., Mavrommatis, G., Meintanis, S. G., Meisel, Y. D., Mekid, S., Mias, C., Morin, A., Musliu, N., Nabhani, F., Naguib, R., Olatunbosun, O., Olsen, S., Ozalp, A. A., Pang, A. -C, Pao, W. K. -S, Piera, M. A., Pinciroli, F., Popescu, T. D., Power, H., Prewett, P. D., Putrus, G. A., Railton, C., Raja, V., Resta, M., Ristic, M., Roy, R., Alessandra Russo, Sadri, F., Sahinkaya, M. N., Sakata, T., Salous, S., Sazhin, S., Scepi, G., Seneviratne, L., Seng, Q. T., Shammas, N., Shepherd, D. E. T., Short, T., Siddique, M. N. H., Singh, R., Sirlantzis, K., Solanas, A., Stathaki, T., Todd-Pokropek, A., Velez, F. J., Vicent, A. M. P., Virdee, B., Walters, R. J., Wang, C. H. -T, Wang, J., Wang, W., Wang, X. -Z, Ware, M., Webb, P., Wen, D., Wen, J., Wood, A., Woodhead, R., Woods, J., Wu, Q. H., Utyuzhnikov, S. V., Xu, H., Xu, Y., Yan, Y., Yang, G. -C, Yang, W., Yang, X. -S, Yu, H. -F, Zhao, Y., Zharkova, V., Zhong, Q. -C, and Zopounidis, C.

49. WCE 2010 - World Congress on Engineering 2010: Preface

Author

Ahmad, M., Alexandrou, I., Al-Nuaimy, W., Amavasai, B. P., An, Y. -Y, Ariwa, E., Arteche, J., Audrino, F., Ayesh, A., Baber, C., Bailey, C., Balkan, N., Barria, J., Bartosova, J., Benkrid, K., Bleijs, H., Bluck, M., Bose, I., Bouzas, P. R., Braiden, P. M., Brdys, M., Burriesci, G., Cannataro, M., Carvalho, A., Chang, C. -C, Chen, D., Chen, G. G., Chen, Y. -S, Chiclana, F., Cooke, A., Das, D. B., Davis, D. N., Dayoub, I., Deb, S., Demetriou, I. C., Devai, F., Dilmaghani, R. S., Dini, D., Drikakis, D., Durkan, C., Durodola, J., Etebar, K., Fenn, P., Figueiredo, A., Florou, G., Freear, S., Gabrys, B., Galbraith, G. H., Gaskell, P. H., elena gaura, Ge, Z. -Q, Ghafouri-Shiraz, H., Ghavami, M., Giannopoulos, K., Gonzalez, R. E. P., Gracia, A. M., Grecos, C., Guan, L., Gulpinar, N., Guo, R., Guo, Y., Hardalupas, Y., He, L., Herrero, J. R., Hicks, B. J., Hines, E. L., Hodgson, S., Horsfall, A., Hosein, P., Hu, F., Hu, H., Ijomah, W., Ming, J., James, A., Jancovic, P., Jhumka, A., Kamareddine, F., Kannan, R., Karsligil, M. E., Katircioglu, S. T., Khalid, A., Kokossis, A., Kontis, K., Kulekci, M. O., Laukaitis, A., Leeson, M., Limbachiya, M. C., Li, L., Lin, P., Ling, W. -K, Macias Lopez, E. M., Lovas, T., Luglio, M., Mainardi, S., Mahanti, P. K., Marinos, I., Maropoulos, P., Mativenga, P., Mavrommatis, G., Meintanis, S. G., Meisel, Y. D., Mekid, S., Mias, C., Morin, A., Musliu, N., Nabhani, F., Naguib, R., Olatunbosun, O., Olsen, S., Ozalp, A. A., Pang, A. -C, Pao, W. K. -S, Piera, M. A., Pinciroli, F., Popescu, T. D., Power, H., Prewett, P. D., Putrus, G. A., Railton, C., Raja, V., Resta, M., Ristic, M., Roy, R., Russo, A., Sadri, F., Sahinkaya, M. N., Sakata, T., Salous, S., Sazhin, S., Scepi, G., Seneviratne, L., Seng, Q. T., Shammas, N., Shepherd, D. E. T., Short, T., Siddique, M. N. H., Singh, R., Sirlantzis, K., Solanas, A., Stathaki, T., Todd-Pokropek, A., Velez, F. J., Vicent, A. M. P., Virdee, B., Walters, R. J., Wang, C. H. -T, Wang, J., Wang, W., Wang, X. -Z, Ware, M., Webb, P., Wen, D., Wen, J., Wood, A., Woodhead, R., Woods, J., Wu, Q. H., Utyuzhnikov, S. V., Xu, H., Xu, Y., Yan, Y., Yang, G. -C, Yang, W., Yang, X. -S, Yu, H. -F, Zhao, Y., Zharkova, V., Zhong, Q. -C, and Zopounidis, C.

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