Armeanu C.C.,Romanian National Institute for Optoelectronics
UPB Scientific Bulletin, Series A: Applied Mathematics and Physics | Year: 2016
3D image reconstruction algorithms fall into one of the three major categories of methods: analytical reconstruction-the filtered backprojection (FBT) method, iterative reconstruction-algebraic reconstruction techniques (ART), statistical image reconstruction techniques (SIRT) and hybrid methods. The analytical methods are based on filtered backprojection (FBP) are currently and widely used on radiology scanners because of their computational efficiency and numerical stability. These mathematical models are applied in X-ray imaging, thermograms, multispectral scanning and many more. Presented study is oriented on X-ray image reconstruction applied in the field of Cultural Heritage investigations, field in which it becomes one of the most important source of information.
Chilibon I.,Romanian National Institute for Optoelectronics
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016
This paper reviews concepts and applications in low-power electronics and energy harvesting technologies. Various piezoelectric materials and devices for small power generators useful in renewable electricity are presented. The vibrating piezoelectric device differs from the typical electrical power source in that it has capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. In general, vibration energy could be converted into electrical energy using one of three techniques: electrostatic charge, magnetic fields and piezoelectric. A low power piezoelectric generator, having a PZT element was realised in order to supply small electronic elements, such as optoelectronic small devices, LEDs, electronic watches, small sensors, interferometry with lasers or Micro-electro-mechanical System (MEMS) array with multi-cantilevers. © 2016 SPIE.
Ene D.,Romanian National Institute for Optoelectronics
ACM International Conference Proceeding Series | Year: 2015
Advanced research means in the study of cultural heritage are more and more popular and used at large scale. Either there are Xray installations, nuclear facilities or photonics equipment, these innovations proved to offer enough resources to study the cultural goods, offering perspectives and solutions that traditional ones could not offer, showing in this manner their limitations. In the past years more and more campaigns were reported, one of the outlines being the huge amount of obtained data. In this paper is presented a solution to manage the output data from various methods, solution represented by data base. The platform that will contain these data bases will have to deal with various information, from different domains, and will handle information regarding the history of the objects, location, author, owner and also physicochemical characterization of the objects. Furthermore, an item that should be considered in development of the platform is regarding how the data will be related, since the platform comes in the help of cultural heritage and it will be accessible for different type of users: from the general user to the specialist in the field (restorer, archaeologist, engineer, biologist, physicist etc.). © 2015 ACM.
Zoran M.,Romanian National Institute for Optoelectronics
International Journal of Remote Sensing | Year: 2012
Geospatial data, coupled with ground-based observations where available, enable scientists to survey pre-earthquake signals in areas of strong tectonic activity. On 11 March 2011, at local time 14:46 JST (05:46 UTC), a mega-earthquake of moment magnitude (M w) 9.0 and shallow focus (24 km), known as the Tohoku-Oki earthquake, occurred on the Japan Trench plate boundary off the eastern shore of northern Honshu, followed by a large tsunami on the Pacific coast of Japan. This article is an attempt to analyse the development of thermal anomalies in land surface temperature (LST) preceding the 11 March 2011 Tohoku earthquake. In order to correlate LST variations and the Tohoku earthquake, we analysed time-series Moderate Resolution Imaging Spectroradiometer (MODIS) Terra/Aqua satellite daytime/night-time and National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR) data. A clear rise of LST (1-10°C), which is apparently related to pre-seismic activity, was observed 2 weeks before the major event in all analysed satellite data around the earthquake epicentre. © 2012 Copyright Taylor and Francis Group, LLC.
Chilibon I.,Romanian National Institute for Optoelectronics |
Marat-Mendes J.N.,New University of Lisbon
Journal of Sol-Gel Science and Technology | Year: 2012
New advances in the sol-gel processing of ferroelectric ceramic powders and thin films and recently, scientific and technological interests in ferroelectric ceramics have been focused particularly on thin films. This is mainly due to their great potential applications in integrated electronics as passive components and as non-volatile ferroelectric memories, optoelectronic devices, etc. Special attention has been paid to the effects of the microstructure and composition on the piezoelectric properties of ferroelectric ceramic powders and thin films, and various characterization techniques are reported. This paper introduces the basic principles governing ferroelectricity and lists the various materials which exhibit these properties. The processing of ferroelectric ceramics and thin films in general and sol-gel processing in particular, with some examples are described. Finally, important applications of ferroelectric films and microstructure examination as well as powerful techniques are briefly discussed. © 2012 Springer Science+Business Media New York.
Armeanu C.,Romanian National Institute for Optoelectronics
2015 22nd International Conference on Systems, Signals and Image Processing - Proceedings of IWSSIP 2015 | Year: 2015
Image processing of radiograms is one of the fields that have known a very fast development since the digitalization of the radiological imagery. Depending on the objects that are studied, different approaches have been developed. In Cultural Heritage investigations image processing, the image analysis can go from conversion of image types and classes, morphological filtering, deblurring, and other image enhancement tools, to image transforms or refinement of regions of interest. In the present work, historical aretefacts, that are not to be opened, will be investigated by X-ray, and then the images will be processed and enhanced. Also for the case studied it would be analyzed the possibility of 3D reconstruction of an object of interest, inside the studied object by an alternative method. © 2015 IEEE.
Chelmus A.,Romanian National Institute for Optoelectronics
2015 22nd International Conference on Systems, Signals and Image Processing - Proceedings of IWSSIP 2015 | Year: 2015
The purpose of this paper is to present the data obtained during a GPR investigation taken inside a 300 year old Romanian church. The local legends say that underneath the church there is a buried treasure. The data refuted the existence of any treasure, but the radargrams revealed some disruptions in the electromagnetic waves propagation that identify three zones of interest. A part of this results will be presented using three methods of data processing. © 2015 IEEE.
Carstea E.M.,Romanian National Institute for Optoelectronics |
Baker A.,University of New South Wales |
Bieroza M.,University of Bristol |
Reynolds D.,University of the West of England
Water Research | Year: 2010
Real-time fluorescence monitoring has been mostly performed in marine systems, with little progress being made in the application of fluorescence excitation-emission matrix (EEM) spectroscopy, especially for freshwater monitoring. This paper presents a two weeks experiment where real-time fluorescence EEM data have been obtained for Bourn Brook, Birmingham, UK, using an in-situ fibre-optic probe. Fluorescence EEMs were measured every 3min for two weeks, with control 'grab' samples every hour analyzed for fluorescence EEMs as well as pH, conductivity and dissolved organic carbon. Comparison of real-time and control samples showed an excellent agreement, with no evidence of fibre-optic probe fouling. EEMs of different character were identified using self-organizing maps, which demonstrated seven clusters of fluorescence EEMs which related to the intensity of fluorescence and relative intensities of peak T1 and T2 vs. peak C and peak A fluorescence. Fluorescence intensity of peaks A and C were observed to increase with rainfall, and a diesel pollution event was detected through an increase in T2 fluorescence. © 2010 Elsevier Ltd.
Calin M.A.,Romanian National Institute for Optoelectronics |
Parasca S.V.,Clinical Hospital for Plastic Surgery and Burns
Lasers in Medical Science | Year: 2010
The optical properties of the skin (absorption coefficient, scattering coefficient, refractive index) may serve to characterize the skin and are important for correct light dosimetry in many optical diagnostic procedures and laser treatments especially photodynamic therapy and laser therapy. We determined in vivo the optical properties of tissues near the wrist, elbow and knee in subjects of different ages using diffuse reflectance spectroscopy, having in view the establishment of laser system types for the laser treatment of posttraumatic lesions in subjects of different ages. Diffuse reflection of light from biological tissue is due to the variation in refractive index of tissular and cellular components and the surrounding medium and depends on the wavelength of the incident optical radiation. The diffuse reflectance spectrum of the tissues tested showed two maxima localized at λM1 ≈ 610 nm and λM2 ≈ 675 nm. Laser systems which emit radiation at these wavelengths are not efficient for the treatment of joints, regardless of the subject's age. The deep tissues have a strong absorption in the range 630-700 nm, which indicates that for treating posttraumatic lesions we can use laser systems such as the He-Ne laser, the GaAlAs laser, and the InGaAlAs laser. Using Kramers-Kronig analysis of the diffuse reflectance spectra, the optical parameters n(ω) and k(ω) were determined. The age-dependent changes in these optical parameters of tissue must be taken into consideration and the use of laser treatments or optical diagnosis methods must be based on a knowledge of these properties and of the optical radiation parameters. © Springer-Verlag London Ltd 2009.
Simileanu M.,Romanian National Institute for Optoelectronics
Romanian Reports in Physics | Year: 2016
The present paper reports analyses made on bronze objects using Laser Induced Breakdown Spectroscopy technique. Where Cultural Heritage is concerned, a very important factor consists in obtaining maximum information with minimum invasiveness. Therefore, the irradiation, acquisition and detection parameters of the current LIBS setup (of INOE) were explored in order to assess the current potential of single pulse 1064 nm LIBS quantitative analyses on artefacts that contain copper. Certified standards (copper based alloys) were used for shaping the calibration curves, taking into consideration Cu, Sn and Pb concentrations. Each set of investigations was acquired using three laser energies (above the ablation threshold). After the proper working regime was established, quantitative LIBS analyses were made on an Censer, in order to determine the concentration of the major chemical elements identified. The data processing was made in LabView and MatLAB dedicated applications. © 2016, Editura Academiei Romane. All rights reserved.