The largest regional earthquakes provide the most significant contribution to the earthquake-rela... more The largest regional earthquakes provide the most significant contribution to the earthquake-related damage, they also responsible for the most of the long-term regional seismic moment release. Thus, in order to develop physically based earthquake hazard assessments, one should be able to connect the moment rate from the observed seismicity to its long-term predictions based on geodetic and geological information. We study here a most detailed spatial distribution of geodesy- and geology-based expected moment rate in California and the Great Basin (see Blewitt et al., "GPS Velocity and Strain Rate Fields in the Great Basin and California", Session G2) and compare it with the observed seismic moment rate on different temporal and spatial scales. The comparison clearly demonstrates a moment deficiency at intermediate and small spatial scales that can be explained, at intermediate scales, by the heavy-tailed Pareto distribution of seismic moment and the typically short time-span of catalogs. On short spatial scales the observed moment deficiency is significantly larger than that predicted by a simple Pareto model. We present a statistical framework for studying these and other related phenomena connected with the seismic moment release.
-phosphate diesters, in this case dibenzyl phos- phate, and internal N-H O-P H-bonding are report... more -phosphate diesters, in this case dibenzyl phos- phate, and internal N-H O-P H-bonding are reported. The design of efficient host molecules for phosphate anion guests has been attracting much current attention because of the many important biological roles of phosphates and poten- tial applications in biotechnology. 1 Organic receptors equipped with acidic hydrogens have been proved to be efficient hosts
Tripodal ligands N(CH2Py)3-n(CH2Py-6-NHR)n(R=H, n=1-3 L1-3, n=0 tpa; R=CH2tBu, n=1-3 L&am... more Tripodal ligands N(CH2Py)3-n(CH2Py-6-NHR)n(R=H, n=1-3 L1-3, n=0 tpa; R=CH2tBu, n=1-3 L'1-3) are used to investigate the effect of different hydrogen bonding microenvironments on structural features of their LZnX complexes (X=Cl-, NO3-, OH-). The X-ray structures of [(L2)Zn(Cl)](BPh4)2.0.5(H2O.CH3CN), [(L3)Zn(Cl)](BPh4)3.CH3CN, [(L'1)Zn(Cl)](BPh4) 1', [(L'2)Zn(Cl)](BPh4)2'.CH3OH, and [(L'3)Zn(Cl)](BPh4)3' have been determined and exhibit trigonal bipyramidal geometries with intramolecular (internal) N-HCl-Zn hydrogen bonds. The structure of [(L'2)Zn(ONO2)]NO3 4'.H2O with two internal N-HO-Zn hydrogen bonds has also been determined. The axial Zn-Cl distance lengthens from 2.275 A in [(tpa)Zn(Cl)](BPh4) to 2.280-2.347 A in 1-3, 1'-3'. Notably, the average Zn-N(py) distance is also progressively lengthened from 2.069 A in [(tpa)Zn(Cl)](BPh4) to 2.159 and 2.182 A in the triply hydrogen bonding cavity of 3 and 3', respectively. Lengthening of the Zn-Cl and Zn-N(py) bonds is accompanied by a progressive shortening of the trans Zn-N bond from 2.271 A in [(tpa)Zn(Cl)](BPh4) to 2.115 A in 3 (2.113 A in 3'). As a result of the triply hydrogen bonding microenvironment the Zn-Cl and Zn-N(py) distances of 3 are at the upper end of the range observed for axial Zn-Cl bonds, whereas the axial Zn-N distance is one of shortest among N4 ligands that induce a trigonal bipyramidal geometry. Despite the…
International Journal of Production Research, 2010
In this paper we present a simple and fast approach for MAT generation in discrete form. It is us... more In this paper we present a simple and fast approach for MAT generation in discrete form. It is used for manufacturability analysis in the part modelling stage of injected parts. The method is a volume thinning method based on straight skeleton computation, modified and applied in 3D on B-rep models in STL. The volume thinning of the B-rep model is based on its boundary surfaces offset towards the model interior. The surfaces’ offset is done with an adequately proposed offset distance which makes some of the non adjacent offset model surfaces overlap (they ‘meet’ in mid-surface or MAT). Offset surfaces are used to reconstruct the topology of a new B-rep model (offset model). Overlapping surfaces in the offset model are detected, separated and aggregated to MAT. For adequate MAT precision and adequate MAT radius function, we propose to treat B-rep model concave edges (vertices) as cylinders (spheres) of zero-radius and offset them in an adequate way. On these bases, we present an iterative algorithm in which MAT is constructed in an incremental way by consecutive volume thinning of the obtained offset models. MAT construction is finished when an empty offset model is obtained. An algorithm has been created and implemented in Visual C++. Some of the obtained results are presented in this paper.
ABSTRACT Both Fresnel diffraction and propagation in second order dispersive transmission lines a... more ABSTRACT Both Fresnel diffraction and propagation in second order dispersive transmission lines are expressed by Fresnel integrals and a unified approach of these domains can be developed on the basis of this formal analogy. Spatial curvatures of spherical emitters and receivers, as used in the metaxial theory of diffraction, and temporal chirp functions are shown to be equivalent. As a consequence, results proved in diffraction theory can be transposed to transmission lines; classical formulae that hold true for Gaussian beams have their exact counterparts that apply to Gaussian wave packet propagation in optical fibers. Applications to dispersion compensation in optical communication systems are explicitely described.
ABSTRACT Periodically shifting replicas of a function is equivalent to sampling its standard Four... more ABSTRACT Periodically shifting replicas of a function is equivalent to sampling its standard Fourier transform, but not its general fractional order Fourier transform. Indeed, sampling in the fractional domain can be achieved after defining fractional shift operators and a fractional convolution product. Standard formulae that hold true for standard operations can be generalized to the fractional calculus. A proof of the fractional sampling theorem is derived by using the former operators and the theorem is applied to computing digital holograms that work in the Fresnel regime. A condition for optimizing the distance between a diffracting object and the diffracted pattern detected by a discrete device is also given: it allows for sampling at an appropriate rate which is in accordance with the detector cell period as well as with the sampling theorem and interpolation formula.
The 13th Ieee International Symposium on Personal Indoor and Mobile Radio Communications, Sep 26, 2002
Page 1. POLARIZATION DIVERSITY IN INDOOR SCENARIOS: AN EXPERIMENTAL STUDY AT 1.8 AND 2.5 GHZ Susa... more Page 1. POLARIZATION DIVERSITY IN INDOOR SCENARIOS: AN EXPERIMENTAL STUDY AT 1.8 AND 2.5 GHZ Susana Loredo', Benito Manteca', Rafael P. Torres' 'University of Oviedo, Campus de Viesques, Edif. dep*ental4,33204 Gijbn, Spain, [email protected] ...
In this paper the authors propose an algorithm oriented to increase the capacity of MIMO systems.... more In this paper the authors propose an algorithm oriented to increase the capacity of MIMO systems. The method, based on LMS algorithm, adapts the radiation pattern of one of the transmitter antennas in such a way that the channel viewed by this antenna becomes as orthogonal as possible to the channel seen by the other transmitter antenna. The adaptive system is based on two possible parameters: the spatial correlation or the lowest eigenvalue. Capacity improvements of up to 1 bit/s/Hz can be obtained by applying the adaptive algorithm to a 2x2 MIMO system.
The 13th Ieee International Symposium on Personal Indoor and Mobile Radio Communications, Sep 26, 2002
In this communication a method is presented for measuring the main parameters required to estimat... more In this communication a method is presented for measuring the main parameters required to estimate the capacity of the radio channel for wideband communications as the root mean square time delay and the coherence bandwith. This method is based on the possibility of estimating the power delay profile from the knowledge of only the module of the transfer function of the channel in conjunction with the Hilbert Transform. The major advantages of the method are first, the possibility to experimentally characterize the wideband channel performance by employing widely used and low cost instrumentation, and second the possibility to extend the technique to outdoor radio channels. The error associated to the approximated method is quantified, so that it can be used from an engineering point of view in the planning and development of wideband wireless communications systems.
Vtc Spring 2009 Ieee 69th Vehicular Technology Conference, 2009
AbstractIn this contribution we analyze the performance of several transmission strategies in a ... more AbstractIn this contribution we analyze the performance of several transmission strategies in a MIMO-OFDM system deployed in a wireless metropolitan area network. With this aim, a measurement campaign has statistically characterized a typical outdoor-indoor scenario for wireless ...
The geography of minimal symplectic 4-manifolds with arbitrary fundamental group and symplectic 6... more The geography of minimal symplectic 4-manifolds with arbitrary fundamental group and symplectic 6-manifolds with abelian fundamental group of small rank, and with arbitrary fundamental group are addressed.
Final Report Ohio State Univ Columbus Electroscience Lab, Oct 1, 1991
In order to provide a set of benchmark flight data for a reusable Aeroassisted Orbit Transfer Veh... more In order to provide a set of benchmark flight data for a reusable Aeroassisted Orbit Transfer Vehicle (AOTV) application, NASA undertook the development of an Aeroassisted Flight Experiment (AFE) which will be launched from the Space Shuttle. A representative aeroassist trajectory will be flown and sensor measurements of aerodynamic performance, thermal protection response, and plasma ionization reentry effects will be obtained. Discussed here is the spacecraft antenna. Estimates of signal transmissions from the AFE to the Tracking and Data Relay Satellites (TDRS) during the reentry period are given. The computer modeling of the antennas is presented with and without the reentry plasma.
Communications in Mathematical Physics, Aug 2, 2012
In this note, four-manifold theory is employed to study generalized complex structures. We drasti... more In this note, four-manifold theory is employed to study generalized complex structures. We drastically enlarge the number of available known examples of generalized complex four-manifolds by building on recent constructions of different smooth structures. Generalized complex structures that have multiple type change loci are constructed.
Le sujet concerne la réalisation d'un phototraceur utilisant un écran à micro-miroirs (DMD : ... more Le sujet concerne la réalisation d'un phototraceur utilisant un écran à micro-miroirs (DMD : Digital Micro-mirror Device) fonctionnant dans l'UV entre 300 et 400 nm. Ce phototraceur permet la photo-inscription directe dans des polymères de fonctions optiques intégrées et/ou d'éléments diffractifs.
Se propone una definición integral para la convolución fraccional(CVF) y la correlación fracciona... more Se propone una definición integral para la convolución fraccional(CVF) y la correlación fraccional(CRF). Se muestra el diseño de los filtros y simulaciones. Se ha hallado que los filtros deben ser curvos (esferas) y dicha curvatura esta relacionada con el orden fraccional. Dada la dificultad técnica para fabricar superficies esféricas se ha optado por el diseño de un filtro complejo. Este filtro se consigue mediante un registro holográfico, en el cual el haz referencia tiene frente de onda esf¿erico.
The largest regional earthquakes provide the most significant contribution to the earthquake-rela... more The largest regional earthquakes provide the most significant contribution to the earthquake-related damage, they also responsible for the most of the long-term regional seismic moment release. Thus, in order to develop physically based earthquake hazard assessments, one should be able to connect the moment rate from the observed seismicity to its long-term predictions based on geodetic and geological information. We study here a most detailed spatial distribution of geodesy- and geology-based expected moment rate in California and the Great Basin (see Blewitt et al., "GPS Velocity and Strain Rate Fields in the Great Basin and California", Session G2) and compare it with the observed seismic moment rate on different temporal and spatial scales. The comparison clearly demonstrates a moment deficiency at intermediate and small spatial scales that can be explained, at intermediate scales, by the heavy-tailed Pareto distribution of seismic moment and the typically short time-span of catalogs. On short spatial scales the observed moment deficiency is significantly larger than that predicted by a simple Pareto model. We present a statistical framework for studying these and other related phenomena connected with the seismic moment release.
-phosphate diesters, in this case dibenzyl phos- phate, and internal N-H O-P H-bonding are report... more -phosphate diesters, in this case dibenzyl phos- phate, and internal N-H O-P H-bonding are reported. The design of efficient host molecules for phosphate anion guests has been attracting much current attention because of the many important biological roles of phosphates and poten- tial applications in biotechnology. 1 Organic receptors equipped with acidic hydrogens have been proved to be efficient hosts
Tripodal ligands N(CH2Py)3-n(CH2Py-6-NHR)n(R=H, n=1-3 L1-3, n=0 tpa; R=CH2tBu, n=1-3 L&am... more Tripodal ligands N(CH2Py)3-n(CH2Py-6-NHR)n(R=H, n=1-3 L1-3, n=0 tpa; R=CH2tBu, n=1-3 L'1-3) are used to investigate the effect of different hydrogen bonding microenvironments on structural features of their LZnX complexes (X=Cl-, NO3-, OH-). The X-ray structures of [(L2)Zn(Cl)](BPh4)2.0.5(H2O.CH3CN), [(L3)Zn(Cl)](BPh4)3.CH3CN, [(L'1)Zn(Cl)](BPh4) 1', [(L'2)Zn(Cl)](BPh4)2'.CH3OH, and [(L'3)Zn(Cl)](BPh4)3' have been determined and exhibit trigonal bipyramidal geometries with intramolecular (internal) N-HCl-Zn hydrogen bonds. The structure of [(L'2)Zn(ONO2)]NO3 4'.H2O with two internal N-HO-Zn hydrogen bonds has also been determined. The axial Zn-Cl distance lengthens from 2.275 A in [(tpa)Zn(Cl)](BPh4) to 2.280-2.347 A in 1-3, 1'-3'. Notably, the average Zn-N(py) distance is also progressively lengthened from 2.069 A in [(tpa)Zn(Cl)](BPh4) to 2.159 and 2.182 A in the triply hydrogen bonding cavity of 3 and 3', respectively. Lengthening of the Zn-Cl and Zn-N(py) bonds is accompanied by a progressive shortening of the trans Zn-N bond from 2.271 A in [(tpa)Zn(Cl)](BPh4) to 2.115 A in 3 (2.113 A in 3'). As a result of the triply hydrogen bonding microenvironment the Zn-Cl and Zn-N(py) distances of 3 are at the upper end of the range observed for axial Zn-Cl bonds, whereas the axial Zn-N distance is one of shortest among N4 ligands that induce a trigonal bipyramidal geometry. Despite the…
International Journal of Production Research, 2010
In this paper we present a simple and fast approach for MAT generation in discrete form. It is us... more In this paper we present a simple and fast approach for MAT generation in discrete form. It is used for manufacturability analysis in the part modelling stage of injected parts. The method is a volume thinning method based on straight skeleton computation, modified and applied in 3D on B-rep models in STL. The volume thinning of the B-rep model is based on its boundary surfaces offset towards the model interior. The surfaces’ offset is done with an adequately proposed offset distance which makes some of the non adjacent offset model surfaces overlap (they ‘meet’ in mid-surface or MAT). Offset surfaces are used to reconstruct the topology of a new B-rep model (offset model). Overlapping surfaces in the offset model are detected, separated and aggregated to MAT. For adequate MAT precision and adequate MAT radius function, we propose to treat B-rep model concave edges (vertices) as cylinders (spheres) of zero-radius and offset them in an adequate way. On these bases, we present an iterative algorithm in which MAT is constructed in an incremental way by consecutive volume thinning of the obtained offset models. MAT construction is finished when an empty offset model is obtained. An algorithm has been created and implemented in Visual C++. Some of the obtained results are presented in this paper.
ABSTRACT Both Fresnel diffraction and propagation in second order dispersive transmission lines a... more ABSTRACT Both Fresnel diffraction and propagation in second order dispersive transmission lines are expressed by Fresnel integrals and a unified approach of these domains can be developed on the basis of this formal analogy. Spatial curvatures of spherical emitters and receivers, as used in the metaxial theory of diffraction, and temporal chirp functions are shown to be equivalent. As a consequence, results proved in diffraction theory can be transposed to transmission lines; classical formulae that hold true for Gaussian beams have their exact counterparts that apply to Gaussian wave packet propagation in optical fibers. Applications to dispersion compensation in optical communication systems are explicitely described.
ABSTRACT Periodically shifting replicas of a function is equivalent to sampling its standard Four... more ABSTRACT Periodically shifting replicas of a function is equivalent to sampling its standard Fourier transform, but not its general fractional order Fourier transform. Indeed, sampling in the fractional domain can be achieved after defining fractional shift operators and a fractional convolution product. Standard formulae that hold true for standard operations can be generalized to the fractional calculus. A proof of the fractional sampling theorem is derived by using the former operators and the theorem is applied to computing digital holograms that work in the Fresnel regime. A condition for optimizing the distance between a diffracting object and the diffracted pattern detected by a discrete device is also given: it allows for sampling at an appropriate rate which is in accordance with the detector cell period as well as with the sampling theorem and interpolation formula.
The 13th Ieee International Symposium on Personal Indoor and Mobile Radio Communications, Sep 26, 2002
Page 1. POLARIZATION DIVERSITY IN INDOOR SCENARIOS: AN EXPERIMENTAL STUDY AT 1.8 AND 2.5 GHZ Susa... more Page 1. POLARIZATION DIVERSITY IN INDOOR SCENARIOS: AN EXPERIMENTAL STUDY AT 1.8 AND 2.5 GHZ Susana Loredo', Benito Manteca', Rafael P. Torres' 'University of Oviedo, Campus de Viesques, Edif. dep*ental4,33204 Gijbn, Spain, [email protected] ...
In this paper the authors propose an algorithm oriented to increase the capacity of MIMO systems.... more In this paper the authors propose an algorithm oriented to increase the capacity of MIMO systems. The method, based on LMS algorithm, adapts the radiation pattern of one of the transmitter antennas in such a way that the channel viewed by this antenna becomes as orthogonal as possible to the channel seen by the other transmitter antenna. The adaptive system is based on two possible parameters: the spatial correlation or the lowest eigenvalue. Capacity improvements of up to 1 bit/s/Hz can be obtained by applying the adaptive algorithm to a 2x2 MIMO system.
The 13th Ieee International Symposium on Personal Indoor and Mobile Radio Communications, Sep 26, 2002
In this communication a method is presented for measuring the main parameters required to estimat... more In this communication a method is presented for measuring the main parameters required to estimate the capacity of the radio channel for wideband communications as the root mean square time delay and the coherence bandwith. This method is based on the possibility of estimating the power delay profile from the knowledge of only the module of the transfer function of the channel in conjunction with the Hilbert Transform. The major advantages of the method are first, the possibility to experimentally characterize the wideband channel performance by employing widely used and low cost instrumentation, and second the possibility to extend the technique to outdoor radio channels. The error associated to the approximated method is quantified, so that it can be used from an engineering point of view in the planning and development of wideband wireless communications systems.
Vtc Spring 2009 Ieee 69th Vehicular Technology Conference, 2009
AbstractIn this contribution we analyze the performance of several transmission strategies in a ... more AbstractIn this contribution we analyze the performance of several transmission strategies in a MIMO-OFDM system deployed in a wireless metropolitan area network. With this aim, a measurement campaign has statistically characterized a typical outdoor-indoor scenario for wireless ...
The geography of minimal symplectic 4-manifolds with arbitrary fundamental group and symplectic 6... more The geography of minimal symplectic 4-manifolds with arbitrary fundamental group and symplectic 6-manifolds with abelian fundamental group of small rank, and with arbitrary fundamental group are addressed.
Final Report Ohio State Univ Columbus Electroscience Lab, Oct 1, 1991
In order to provide a set of benchmark flight data for a reusable Aeroassisted Orbit Transfer Veh... more In order to provide a set of benchmark flight data for a reusable Aeroassisted Orbit Transfer Vehicle (AOTV) application, NASA undertook the development of an Aeroassisted Flight Experiment (AFE) which will be launched from the Space Shuttle. A representative aeroassist trajectory will be flown and sensor measurements of aerodynamic performance, thermal protection response, and plasma ionization reentry effects will be obtained. Discussed here is the spacecraft antenna. Estimates of signal transmissions from the AFE to the Tracking and Data Relay Satellites (TDRS) during the reentry period are given. The computer modeling of the antennas is presented with and without the reentry plasma.
Communications in Mathematical Physics, Aug 2, 2012
In this note, four-manifold theory is employed to study generalized complex structures. We drasti... more In this note, four-manifold theory is employed to study generalized complex structures. We drastically enlarge the number of available known examples of generalized complex four-manifolds by building on recent constructions of different smooth structures. Generalized complex structures that have multiple type change loci are constructed.
Le sujet concerne la réalisation d'un phototraceur utilisant un écran à micro-miroirs (DMD : ... more Le sujet concerne la réalisation d'un phototraceur utilisant un écran à micro-miroirs (DMD : Digital Micro-mirror Device) fonctionnant dans l'UV entre 300 et 400 nm. Ce phototraceur permet la photo-inscription directe dans des polymères de fonctions optiques intégrées et/ou d'éléments diffractifs.
Se propone una definición integral para la convolución fraccional(CVF) y la correlación fracciona... more Se propone una definición integral para la convolución fraccional(CVF) y la correlación fraccional(CRF). Se muestra el diseño de los filtros y simulaciones. Se ha hallado que los filtros deben ser curvos (esferas) y dicha curvatura esta relacionada con el orden fraccional. Dada la dificultad técnica para fabricar superficies esféricas se ha optado por el diseño de un filtro complejo. Este filtro se consigue mediante un registro holográfico, en el cual el haz referencia tiene frente de onda esf¿erico.
EQxposición de técnicas y métodos de trabajo del Taller de Alineación y Balanceo Literario "Leona... more EQxposición de técnicas y métodos de trabajo del Taller de Alineación y Balanceo Literario "Leonardo"
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