Nenad Milosevic - Academia.edu (original) (raw)

Uploads

Papers by Nenad Milosevic

We present a novel real-time stereo smart camera for sparse disparity (depth) map estimation of m... more We present a novel real-time stereo smart camera for sparse disparity (depth) map estimation of moving objects at up to 200 frames/sec. It is based on a 128x128 pixel asynchronous optical transient sensor, using address-event representation (AER) protocol. An address-event based algorithm for stereo depth calculation including calibration, correspondence and reconstruction processing steps is also presented. Due to the onchip data pre-processing the algorithm can be implemented on a single low-power digital signal processor.

Physical Review Letters, 2004

We identify a laser configuration in which attosecond electron wave packets are ionized, accelera... more We identify a laser configuration in which attosecond electron wave packets are ionized, accelerated to multi-MeV energies, and refocused onto their parent ion. Magnetic focusing of the electron wave packet results in return currents comparable with large scale accelerator facilities. This technique opens an avenue towards imaging attosecond dynamics of nuclear processes.

Physical Review Letters, 2002

We present analytic tunnel ionization rates for hydrogenlike ions in ultrahigh intensity laser fi... more We present analytic tunnel ionization rates for hydrogenlike ions in ultrahigh intensity laser fields, as obtained from a semiclassical solution of the three-dimensional Dirac equation. This presents the first quantitative determination of tunneling in atomic ions in the relativistic regime. Our theory opens the possibility to study strong laser field processes with highly charged ions, where relativistic ionization plays a dominant role.

Tehnicki vjesnik - Technical Gazette, 2016

Original scientific paper The behaviour of welded joints in local zones, as well as their mutual ... more Original scientific paper The behaviour of welded joints in local zones, as well as their mutual influence, represents one of the main challenges in welded structure design. Namely, the main issue lies in determining the mechanical properties of materials in a welded joint. These properties are necessary for an accurate calculation of welded structure integrity. The possibility of obtaining local strain/displacement values makes the "Digital Image Correlation" (DIC) technique suitable for welded joint testing and determining of mechanical properties. In this paper a tensile testing machine was used for loading and a two camera system was used for 3D strain analysis. A specimen with parallel sides, obtained by welding of a V joint was used. Calibration was performed prior to testing, in order to ensure dimensional consistency of the system. Application of DIC technique using Aramis software for measuring local displacement/strain in a welded joint is presented in this paper. Due to tension in the V-weld specimen (Base material-S235JRG2, electrode wire-VAC 60), mutual influence of mechanical properties of local zones is present, wherein the root weld had the highest stiffness.

Applications of High Field and Short Wavelength Sources IX, 2001

Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizin... more Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizing gas is presented. Our analysis shows that the harmonics are produced in very intense pulses with unexpectedly good coherence properties, allowing focusing of attosecond pulses.

Proceedings of 2010 IEEE International Symposium on Circuits and Systems, 2010

Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously de... more Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously detect the significant relative light intensity changes in a scene and output them in a form of Address-Event representation. These vision sensors capture dynamical discontinuities on-chip for a reduced data volume compared to that from intensity images. Therefore, they support detection, segmentation and tracking of moving objects in the

Tehnicki vjesnik - Technical Gazette, 2016

Original scientific paper The behaviour of welded joints in local zones, as well as their mutual ... more Original scientific paper The behaviour of welded joints in local zones, as well as their mutual influence, represents one of the main challenges in welded structure design. Namely, the main issue lies in determining the mechanical properties of materials in a welded joint. These properties are necessary for an accurate calculation of welded structure integrity. The possibility of obtaining local strain/displacement values makes the "Digital Image Correlation" (DIC) technique suitable for welded joint testing and determining of mechanical properties. In this paper a tensile testing machine was used for loading and a two camera system was used for 3D strain analysis. A specimen with parallel sides, obtained by welding of a V joint was used. Calibration was performed prior to testing, in order to ensure dimensional consistency of the system. Application of DIC technique using Aramis software for measuring local displacement/strain in a welded joint is presented in this paper. Due to tension in the V-weld specimen (Base material-S235JRG2, electrode wire-VAC 60), mutual influence of mechanical properties of local zones is present, wherein the root weld had the highest stiffness.

Applications of High Field and Short Wavelength Sources IX, 2001

Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizin... more Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizing gas is presented. Our analysis shows that the harmonics are produced in very intense pulses with unexpectedly good coherence properties, allowing focusing of attosecond pulses.

Proceedings of 2010 IEEE International Symposium on Circuits and Systems, 2010

Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously de... more Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously detect the significant relative light intensity changes in a scene and output them in a form of Address-Event representation. These vision sensors capture dynamical discontinuities on-chip for a reduced data volume compared to that from intensity images. Therefore, they support detection, segmentation and tracking of moving objects in the

Physical Review Letters, 2002

The first reported measurements of single attosecond pulses use laser dressed single-photon extre... more The first reported measurements of single attosecond pulses use laser dressed single-photon extreme ultraviolet (XUV) ionization of gas atoms. The determination of XUV pulse duration from the electron spectrum is based on a classical theory. Although classical models are known to give a qualitatively correct description of strong laser atom interaction, the validity must be scrutinized by a quantummechanical analysis. We establish a theoretical framework for the accurate temporal characterization of attosecond XUV pulses. Our analysis reveals an improved scheme that allows for direct experimental discrimination between single and multiple attosecond pulses.

Physical Review Letters, 2002

The first reported measurements of single attosecond pulses use laser dressed single-photon extre... more The first reported measurements of single attosecond pulses use laser dressed single-photon extreme ultraviolet (XUV) ionization of gas atoms. The determination of XUV pulse duration from the electron spectrum is based on a classical theory. Although classical models are known to give a qualitatively correct description of strong laser atom interaction, the validity must be scrutinized by a quantummechanical analysis. We establish a theoretical framework for the accurate temporal characterization of attosecond XUV pulses. Our analysis reveals an improved scheme that allows for direct experimental discrimination between single and multiple attosecond pulses.

Physical Review Letters, 2002

A numerical simulation of attosecond harmonic pulse generation in a three-dimensional fieldionizi... more A numerical simulation of attosecond harmonic pulse generation in a three-dimensional fieldionizing gas is presented. Calculated harmonic efficiencies quantitatively reproduce experimental findings. This allows a quantitative characterization of attosecond pulse generation revealing information currently not accessible by experiment. The rapid phase variation and spatiotemporal distortions of harmonics are smaller than anticipated, allowing focusing of 30-nm, 750-as pulses to intensities in excess of 10 13 W͞cm 2. Feasibility of such pulses brings novel applications such as extreme ultraviolet nonlinear optics and attosecond pump probe spectroscopy within reach.

Journal of the Optical Society of America B, 2003

Recently the initial measurements of single attosecond pulses with laser-dressed single-photon XU... more Recently the initial measurements of single attosecond pulses with laser-dressed single-photon XUV ionization of gas atoms were reported. Determination of the extreme-ultraviolet (XUV) pulse duration from the electron spectrum is based on a classical theory. Although classical models are known to give a qualitatively correct description of strong laser-atom interaction, the validity range for accurate determination of subfemtosecond pulses must be scrutinized by quantum mechanical analysis. We establish a theoretical framework for the accurate temporal characterization of attosecond XUV pulses by using a Fourier-Bessel expansion of the XUV electron spectrum under the strong field approximation and a semiclassical derivation, setting earlier results on a rigorous theoretical footing. Our analysis reveals an improved scheme that is by more than an order of magnitude more efficient than the one used so far and allows for direct experimental discrimination between single and multiple attosecond pulses.

We present a novel real-time stereo smart camera for sparse disparity (depth) map estimation of m... more We present a novel real-time stereo smart camera for sparse disparity (depth) map estimation of moving objects at up to 200 frames/sec. It is based on a 128x128 pixel asynchronous optical transient sensor, using address-event representation (AER) protocol. An address-event based algorithm for stereo depth calculation including calibration, correspondence and reconstruction processing steps is also presented. Due to the onchip data pre-processing the algorithm can be implemented on a single low-power digital signal processor.

Physical Review Letters, 2004

We identify a laser configuration in which attosecond electron wave packets are ionized, accelera... more We identify a laser configuration in which attosecond electron wave packets are ionized, accelerated to multi-MeV energies, and refocused onto their parent ion. Magnetic focusing of the electron wave packet results in return currents comparable with large scale accelerator facilities. This technique opens an avenue towards imaging attosecond dynamics of nuclear processes.

Physical Review Letters, 2002

We present analytic tunnel ionization rates for hydrogenlike ions in ultrahigh intensity laser fi... more We present analytic tunnel ionization rates for hydrogenlike ions in ultrahigh intensity laser fields, as obtained from a semiclassical solution of the three-dimensional Dirac equation. This presents the first quantitative determination of tunneling in atomic ions in the relativistic regime. Our theory opens the possibility to study strong laser field processes with highly charged ions, where relativistic ionization plays a dominant role.

Tehnicki vjesnik - Technical Gazette, 2016

Original scientific paper The behaviour of welded joints in local zones, as well as their mutual ... more Original scientific paper The behaviour of welded joints in local zones, as well as their mutual influence, represents one of the main challenges in welded structure design. Namely, the main issue lies in determining the mechanical properties of materials in a welded joint. These properties are necessary for an accurate calculation of welded structure integrity. The possibility of obtaining local strain/displacement values makes the "Digital Image Correlation" (DIC) technique suitable for welded joint testing and determining of mechanical properties. In this paper a tensile testing machine was used for loading and a two camera system was used for 3D strain analysis. A specimen with parallel sides, obtained by welding of a V joint was used. Calibration was performed prior to testing, in order to ensure dimensional consistency of the system. Application of DIC technique using Aramis software for measuring local displacement/strain in a welded joint is presented in this paper. Due to tension in the V-weld specimen (Base material-S235JRG2, electrode wire-VAC 60), mutual influence of mechanical properties of local zones is present, wherein the root weld had the highest stiffness.

Applications of High Field and Short Wavelength Sources IX, 2001

Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizin... more Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizing gas is presented. Our analysis shows that the harmonics are produced in very intense pulses with unexpectedly good coherence properties, allowing focusing of attosecond pulses.

Proceedings of 2010 IEEE International Symposium on Circuits and Systems, 2010

Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously de... more Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously detect the significant relative light intensity changes in a scene and output them in a form of Address-Event representation. These vision sensors capture dynamical discontinuities on-chip for a reduced data volume compared to that from intensity images. Therefore, they support detection, segmentation and tracking of moving objects in the

Tehnicki vjesnik - Technical Gazette, 2016

Original scientific paper The behaviour of welded joints in local zones, as well as their mutual ... more Original scientific paper The behaviour of welded joints in local zones, as well as their mutual influence, represents one of the main challenges in welded structure design. Namely, the main issue lies in determining the mechanical properties of materials in a welded joint. These properties are necessary for an accurate calculation of welded structure integrity. The possibility of obtaining local strain/displacement values makes the "Digital Image Correlation" (DIC) technique suitable for welded joint testing and determining of mechanical properties. In this paper a tensile testing machine was used for loading and a two camera system was used for 3D strain analysis. A specimen with parallel sides, obtained by welding of a V joint was used. Calibration was performed prior to testing, in order to ensure dimensional consistency of the system. Application of DIC technique using Aramis software for measuring local displacement/strain in a welded joint is presented in this paper. Due to tension in the V-weld specimen (Base material-S235JRG2, electrode wire-VAC 60), mutual influence of mechanical properties of local zones is present, wherein the root weld had the highest stiffness.

Applications of High Field and Short Wavelength Sources IX, 2001

Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizin... more Numerical simulation of attosecond harmonic pulse generation in a three dimensional field-ionizing gas is presented. Our analysis shows that the harmonics are produced in very intense pulses with unexpectedly good coherence properties, allowing focusing of attosecond pulses.

Proceedings of 2010 IEEE International Symposium on Circuits and Systems, 2010

Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously de... more Biologically-inspired dynamic vision sensors have been introduced in 2002 which asynchronously detect the significant relative light intensity changes in a scene and output them in a form of Address-Event representation. These vision sensors capture dynamical discontinuities on-chip for a reduced data volume compared to that from intensity images. Therefore, they support detection, segmentation and tracking of moving objects in the

Physical Review Letters, 2002

The first reported measurements of single attosecond pulses use laser dressed single-photon extre... more The first reported measurements of single attosecond pulses use laser dressed single-photon extreme ultraviolet (XUV) ionization of gas atoms. The determination of XUV pulse duration from the electron spectrum is based on a classical theory. Although classical models are known to give a qualitatively correct description of strong laser atom interaction, the validity must be scrutinized by a quantummechanical analysis. We establish a theoretical framework for the accurate temporal characterization of attosecond XUV pulses. Our analysis reveals an improved scheme that allows for direct experimental discrimination between single and multiple attosecond pulses.

Physical Review Letters, 2002

The first reported measurements of single attosecond pulses use laser dressed single-photon extre... more The first reported measurements of single attosecond pulses use laser dressed single-photon extreme ultraviolet (XUV) ionization of gas atoms. The determination of XUV pulse duration from the electron spectrum is based on a classical theory. Although classical models are known to give a qualitatively correct description of strong laser atom interaction, the validity must be scrutinized by a quantummechanical analysis. We establish a theoretical framework for the accurate temporal characterization of attosecond XUV pulses. Our analysis reveals an improved scheme that allows for direct experimental discrimination between single and multiple attosecond pulses.

Physical Review Letters, 2002

A numerical simulation of attosecond harmonic pulse generation in a three-dimensional fieldionizi... more A numerical simulation of attosecond harmonic pulse generation in a three-dimensional fieldionizing gas is presented. Calculated harmonic efficiencies quantitatively reproduce experimental findings. This allows a quantitative characterization of attosecond pulse generation revealing information currently not accessible by experiment. The rapid phase variation and spatiotemporal distortions of harmonics are smaller than anticipated, allowing focusing of 30-nm, 750-as pulses to intensities in excess of 10 13 W͞cm 2. Feasibility of such pulses brings novel applications such as extreme ultraviolet nonlinear optics and attosecond pump probe spectroscopy within reach.

Journal of the Optical Society of America B, 2003

Recently the initial measurements of single attosecond pulses with laser-dressed single-photon XU... more Recently the initial measurements of single attosecond pulses with laser-dressed single-photon XUV ionization of gas atoms were reported. Determination of the extreme-ultraviolet (XUV) pulse duration from the electron spectrum is based on a classical theory. Although classical models are known to give a qualitatively correct description of strong laser-atom interaction, the validity range for accurate determination of subfemtosecond pulses must be scrutinized by quantum mechanical analysis. We establish a theoretical framework for the accurate temporal characterization of attosecond XUV pulses by using a Fourier-Bessel expansion of the XUV electron spectrum under the strong field approximation and a semiclassical derivation, setting earlier results on a rigorous theoretical footing. Our analysis reveals an improved scheme that is by more than an order of magnitude more efficient than the one used so far and allows for direct experimental discrimination between single and multiple attosecond pulses.