cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Towards Accurate Pixel-wise Object Tracking by Attention Retrieval
Creators: name: Zhang, Zhipeng
name: Li, Bing
name: Hu, Weiming
name: Peng, Houwen
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The encoding of the target in object tracking moves from the coarse bounding-box to fine-grained segmentation map recently. Revisiting de facto real-time approaches that are capable of predicting mask during tracking, we observed that they usually fork a light branch from the backbone network for segmentation. Although efficient, directly fusing backbone features without considering the negative influence of background clutter tends to introduce false-negative predictions, lagging the segmentation accuracy. To mitigate this problem, we propose an attention retrieval network (ARN) to perform soft spatial constraints on backbone features. We first build a look-up-table (LUT) with the ground-truth mask in the starting frame, and then retrieves the LUT to obtain an attention map for spatial constraints. Moreover, we introduce a multi-resolution multi-stage segmentation network (MMS) to further weaken the influence of background clutter by reusing the predicted mask to filter backbone features. Our approach set a new state-of-the-art on recent pixel-wise object tracking benchmark VOT2020 while running at 40 fps. Notably, the proposed model surpasses SiamMask by 11.7/4.2/5.5 points on VOT2020, DAVIS2016, and DAVIS2017, respectively. We will release our code at https://github.com/researchmm/TracKit.
description: Some technical errors. We would provide new versions later
A study of advancement in application opportunities of aluminum metal matrix composites
Creators: name: SHARMA, ARUN Kumar
name: Bhandari, Rakesh
name: Aherwar, Amit
name: Pinca-Bretoteand, Camelia
Publisher: name: figshare
Year: 2020
Subjects: subject: Mechanical Engineering
subject: FOS: Mechanical engineering

description: Materials are continuously developed with the time being due to the necessity of human civilization and therefore advancement of each material in its highest classes is the best research necessity. The search for new and advanced materials is always an important subject for contemporary technological requirements and to make a product at optimum cost which is a basic consumer demand. New materials are continually developed and materials properties improved in line with existing technological developments in order to meet safety and operational standards. Composites have developed continuously from its early to the advanced stages. The need and consumption of metal matrix composites (MMCs) continuously increasing worldwide with the time because of its high applications. A continuous need observed in industries which make the path to develop stronger lightweight material which having high efficiency and performance across a wide variety of industries. The product manufacturers are generally in need of lightweight, medium strength and less cost, for them aluminum metal matrix composites (AlMMCs) is an asset. AlMMCs for many engineering applications are seen as new generation potential materials. AlMMCs offer great promise for producing composites with the required properties for certain applications with a wide variety of reinforcing materials. The AlMMCs are evolved to obtain good mechanical and tribological characteristics with lightweight, based on specification and application requirements. In this article, various aspects and analysis of applications fields of AlMMCs discussed in brief.
High polarization, endurance and retention in sub-5 nm Hf$_{0.5}$Zr$_{0.5}$O$_2$ films
Creators: name: Lyu, Jike
name: Song, Tingfeng
name: Fina, Ignasi
name: Sánchez, Florencio
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ferroelectric HfO$_2$ is a promising material for new memory devices, but significant improvement of important properties is necessary to reach applications. However, precedent literature shows that a dilemma between polarization, endurance and retention exists. Since all these properties should be simultaneously high, overcoming this issue is of the highest relevance. Here, we demonstrate that high crystalline quality sub-5 nm Hf0.5Zr0.5O2 capacitors, integrated epitaxially with Si(001), present combined high polarization (2Pr of 27 uC/cm2 in the pristine state), endurance (2Pr > 6 uC/cm2 after E11 cycles) and retention (2Pr > 12 uC/cm2 extrapolated at 10 years) using same poling conditions (2.5 V). This achievement is demonstrated in films thinner than 5 nm, thus opening bright possibilities in ferroelectric tunnel junctions and other devices.
description: Supporting Information available at https://pubs.rsc.org/en/content/articlehtml/2020/nr/d0nr02204g (paper published as open access)
Langevin equation with Coulomb friction
Creators: name: Hayakawa, Hisao
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We propose a Langevin model with Coulomb friction. Through the analysis of the corresponding Fokker-Planck equation, we have obtained the steady velocity distribution function under the influence of the external field.
description: 10 pages, 1 figure. to be published in Physica D
CP violation and the CKM matrix: impact of the asymmetric B Factories
Creators: name: Pivk, Muriel
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: An up-to-date profile of the CKM matrix is presented, with emphasis on the interpretation of recent CP-violation results from the $B$ factories. The apex of the Unitarity Triangle is determined by a global CKM fit. A study is performed to probe the dynamics of B decays into $ππ$, $Kπ$, $ρπ$ and $ρρ$ within two theoretical frameworks. A model-independent investigation of New Physics effects in $\Bz\Bzb$ mixing is given.
description: 4 pages, 8 figures, Contributed to 32nd International Conference on High-Energy Physics (ICHEP 04), Beijing, China, 16-22 Aug 2004
The Color-Magnitude Effect in Early-Type Cluster Galaxies
Creators: name: Lopez-Cruz, Omar
name: Barkhouse, Wayne A.
name: Yee, H. K. C.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the analysis of the color-magnitude relation (CMR) for a sample of 57 X-ray detected Abell clusters within the redshift interval 0.02 <= z <= 0.18. We use the B-R vs R color-magnitude plane to establish that the CMR is present in all our low-redshift clusters and can be parameterized by a single straight line.We find that the CMRs for this large cluster sample of different richness and cluster types are consistent with having universal properties. The k-corrected color of the individual CMRs in the sample at a fixed absolute magnitude have a small intrinsic dispersion of ~0.05 mag. The slope of the CMR is consistent with being the same for all clusters, with the variations entirely accountable by filter band shifting effects. We determine the mean of the dispersion of the 57 CMRs to be 0.074 mag, with a small rms scatter of 0.026 mag. However, a modest amount of the dispersion arises from photometric measurement errors and possible background cluster superpositions; and the derived mean dispersion is an upper limit. Models which explain the CMR in terms of metallicity and passive evolution can naturally reproduce the observed behavior of the CMR in this paper. The observed properties of the CMR are consistent with models in which the last episode of significant star formation in cluster early-type galaxies occurred significantly more than ~3 Gyr ago, and that the core set of early-type galaxies in clusters were formed more than 7 Gyr ago. (abridged)
description: Accepted ApJ, 17 pages, 4 figures (high-res fig 1 available in ApJ version)
title: Rectangular core-collapse supernova remnants : application to Puppis A
Creators: name: Meyer, Dominique M.-A.
name: Velazquez, Pablo F.
name: Petruk, Oleh
name: Chiotellis, Alexandros
name: Pohl, Martin
name: Camps-Farina, Artemi
name: Petrov, Miroslav
name: Reynoso, Estela M.
name: Toledo-Roy, Juan C.
name: Schneiter, E. Matias
name: Castellanos-Ramirez, Antonio
name: Esquivel, Alejandro
Publisher: name: Universität Potsdam
Year: 2025
Subjects: subject: 530 Physik

description: Core-collapse supernova remnants are the gaseous nebulae of galactic interstellar media (ISM) formed after the explosive death of massive stars. Their morphology and emission properties depend both on the surrounding circumstellar structure shaped by the stellar wind-ISM interaction of the progenitor star and on the local conditions of the ambient medium. In the warm phase of the Galactic plane (n approximate to 1 cm(-3), T approximate to 8000 K), an organized magnetic field of strength 7 mu G has profound consequences on the morphology of the wind bubble of massive stars at rest. In this paper, we show through 2.5D magnetohydrodynamical simulations, in the context of a Wolf-Rayet-evolving 35 M 0 star, that it affects the development of its supernova remnant. When the supernova remnant reaches its middle age (15-20 kyr), it adopts a tubular shape that results from the interaction between the isotropic supernova ejecta and the anisotropic, magnetized, shocked stellar progenitor bubble into which the supernova blast wave expands. Our calculations for non-thermal emission, i.e. radio synchrotron and inverse-Compton radiation, reveal that such supernova remnants can, due to projection effects, appear as rectangular objects in certain cases. This mechanism for shaping a supernova remnant is similar to the bipolar and elliptical planetary nebula production by wind-wind interaction in the low-mass regime of stellar evolution. If such a rectangular core-collapse supernova remnant is created, the progenitor star must not have been a runaway star. We propose that such a mechanism is at work in the shaping of the asymmetric core-collapse supernova remnant Puppis A.
description: Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe; 1467
Bioconversion of mountain pine beetle-killed lodgepole pine to ethanol
Creators: name: Ewanick, Shannon Melinda
Publisher: name: University of British Columbia
Year: 2010

description: Global warming is widely acknowledged as being caused by an increase in the production of greenhouse gases, largely CO₂, generated from the burning of fossil fuels such as gasoline. By offsetting a portion of gasoline usage with alternative fuels, such as ethanol, CO₂ emissions could be reduced. Bioethanol can be produced from many types of biomass, including softwoods. For maximal ethanol yield from softwoods, the most effective bioconversion process is considered by many to be SO₂-catalysed steam explosion followed by separate or simultaneous hydrolysis and fermentation. This method has been shown to be effective on both spruce and Radiata pine, although past research at UBC on Douglas-fir showed that additional delignification was necessary in order to obtain satisfactory sugar recovery and hydrolytic conversion. Another promising softwood species for bioconversion in British Columbia is lodgepole pine, which has been severely affected by the mountain pine beetle and its associated fungus and is consequently widely available and relatively inexpensive. Prior to investigating the bioconversion of lodgepole pine, the UBC steam explosion process was evaluated and was found to be comparable to that used at Lund University in Sweden. Following this, optimization of pretreatment conditions of beetle-killed lodgepole pine for maximal ethanol yield revealed that the highest ethanol yield after SSF, 77% of theoretical, was derived from substrates pretreated at 200°C, 5 min, 4% SO₂. When these and other conditions were applied to healthy, and mixed (50/50 healthy/beetle-killed) wood, the beetle-killed substrate provided higher sugar recovery after pretreatment, higher hydrolytic conversion, and higher overall ethanol yield after SSF. This was likely a result of two factors. The first, reduced uptake of SO₂ during the impregnation step effectively reduced the pretreatment severity and increased sugar recovery and fermentability. Secondly, increased fines may have improved the enzymatic digestibility of the substrate. The work in this thesis established the technical feasibility of producing ethanol from lodgepole pine in a two-step process consisting of SO₂-catalyzed steam explosion followed by SSF of the combined liquid and solid fractions. In addition, the short residence time required for SSF as well as the reduced cost of the raw material suggest that the process could be economically attractive as well.
Matrix materials used in composites.pdf
Creators: name: SHARMA, ARUN Kumar
name: Bhandari, Rakesh
name: Aherwar, Amit
name: Rimasauskiene, Ruta
Publisher: name: figshare
Year: 2020
Subjects: subject: 91299 Materials Engineering not elsewhere classified
subject: FOS: Materials engineering
subject: Mechanical Engineering
subject: FOS: Mechanical engineering

description: Composites are very significant materials for a large variety of applications in various engineering areas because of their enhanced mechanical, physical, and machining properties. These materials have been endless of applications because of their behavior, mainly mechanical, compared to other materials since it has demonstrated less density and significantly higher resistance. The composite materials have many benefits and excellent properties in comparison to conventional materials, which make the application of composites in many areas. More research and studies are being carried out to improve the characteristics and manufacturing techniques further, to promote the potential implementation of composites. In recent years, the application and development of MMCs have increased in many engineering fields. With the arrival of innovative technologies, high research activities and the development of different processing techniques, composites with improved properties become attractive materials for engineering applications. A wide array of metals, especially low-density metals or alloys, are generally selected as the matrix material for the composite. This research article provides a brief overview of matrix materials generally used in composites, and types of composites, with their important aspects.
Modelling the adoption of automatic milking systems in Noord-Holland
Creators: name: Floridi, Matteo
name: Bartolini, Fabio
name: Peerlings, Jack
name: Polman, Nico
name: Viaggi, Davide
name: Floridi, Matteo
name: Bartolini, Fabio
name: Peerlings, Jack
name: Polman, Nico
name: Viaggi, Davide
Publisher: name: Unknown
Year: 2013
Subjects: subject: Agricultural and Food Policy
subject: Farm Management
subject: Livestock Production/Industries
subject: real options
subject: dairy livestock
subject: automatic milking systems
subject: investment
subject: uncertainty
subject: Common Agricultural Policy

description: Innovation and new technology adoption represent two central elements for the business and industry development process in agriculture. One of the most relevant innovations in dairy farms is the robotisation of the milking process through the adoption of Automatic Milking Systems (AMS). The purpose of this paper is to assess the impact of selected Common Agricultural Policy measures on the adoption of AMS in dairy farms. The model developed is a dynamic farm-household model that is able to simulate the adoption of AMS taking into account the allocation of productive factors between on-farm and off-farm activities. The model simulates the decision to replace a traditional milking system with AMS using a Real Options approach that allows farmers to choose the optimal timing of investments. Results show that the adoption of AMS, and the timing of such a decision, is strongly affected by policy uncertainty and market conditions. The effect of this uncertainty is to postpone the decision to adopt the new technology until farmers have gathered enough information to reduce the negative effects of the technological lock-in. AMS adoption results in an increase in farm size and herd size due to the reduction in the labour required for milking operations.
A Chandra Snapshot Survey of IR-bright LINERs: A Possible Link Between Star Formation, AGN Fueling, and Mass Accretion
Creators: name: Dudik, R. P.
name: Satyapal, S.
name: Gliozzi, M.
name: Sambruna, R. M.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from a high resolution X-ray imaging study of nearby LINERs observed by Chandra. This study complements and extends previous X-ray studies of LINERs, focusing on the under-explored population of nearby dust-enshrouded infrared-bright LINERs. The sample consists of 15 IR-bright LINERs (L_FIR/L_B > 3), with distances that range from 11 to 26 Mpc. Combining our sample with previous Chandra studies we find that ~ 51% (28/55) of the LINERs display compact hard X-ray cores. The nuclear 2-10 keV luminosities of the galaxies in this expanded sample range from ~ 2 X 10^38 ergs s^-1 to ~ 2 X 10^44 ergs s^-1. We find an intriguing trend in the Eddington ratio vs. L_FIR and L_FIR/L_B for the AGN-LINERs in the expanded sample that extends over seven orders of magnitude in L/L_Edd. This correlation may imply a link between black hole growth, as measured by the Eddington ratio, and the star formation rate (SFR), as measured by the far-IR luminosity and IR-brightness ratio. If the far-IR luminosity is an indicator of the molecular gas content in our sample of LINERs, our results may further indicate that the mass accretion rate scales with the host galaxy's fuel supply. We discuss the potential implications of our results in the framework of black hole growth and AGN fueling in low luminosity AGN. (Abridged)
description: Accepted for publication by ApJ 14 pages, 13 figures
A new mechanism for freezing extra dimensions with higher-order curvature terms
Creators: name: Tahara, Hiroaki W. H.
name: Kobayashi, Tsutomu
name: Yokoyama, Jun'ichi
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We construct a model of higher dimensional cosmology in which extra dimensions are frozen by virtue of the cubic-order Lovelock gravity throughout the cosmic history from inflation to the present with radiation and matter-dominated regimes in between.
description: 6 pages
Charging-driven coarsening and melting of a colloidal nanoparticle monolayer at an ionic liquid-vacuum interface
Creators: name: Bischak, Connor G.
name: Raybin, Jonathan G.
name: Kruppe, Jonathon W.
name: Ginsberg, Naomi S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We induce and investigate the coarsening and melting dynamics of an initially static nanoparticle colloidal monolayer at an ionic liquid-vacuum interface, driven by a focused, scanning electron beam. Coarsening occurs through grain interface migration and larger-scale motions such as grain rotations, often facilitated by sliding dislocations. The progressive decrease in area fraction that drives melting of the monolayer is explained using an electrowetting model whereby particles at the interface are solvated once their accumulating charge recruits sufficient counterions to subsume the particle. Subject to stochastic particle removal from the monolayer, melting is recapitulated in simulations with a Lennard-Jones potential. This new driving mechanism for colloidal systems, whose dynamical timescales we show can be controlled with the accelerating voltage, opens the possibility to manipulate particle interactions dynamically without need to vary particle intrinsic properties or surface treatments. Furthermore, the decrease in particle size availed by electron imaging presents opportunities to observe force and time scales in a lesser-explored regime intermediate between typical colloidal and molecular systems.
description: 14 pages, 6 figures, also see supplementary ancilliary file
Numerical study of resistivity of model disordered three-dimensional metals
Creators: name: Gilman, Yulia
name: Tahir-Kheli, Jamil
name: Allen, Philip B.
name: Goddard, William A.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We calculate the zero-temperature resistivity of model 3-dimensional disordered metals described by tight-binding Hamiltonians. Two different mechanisms of disorder are considered: diagonal and off-diagonal. The non-equilibrium Green function formalism provides a Landauer-type formula for the conductance of arbitrary mesoscopic systems. We use this formula to calculate the resistance of finite-size disordered samples of different lengths. The resistance averaged over disorder configurations is linear in sample length and resistivity is found from the coefficient of proportionality. Two structures are considered: (1) a simple cubic lattice with one s-orbital per site, (2) a simple cubic lattice with two d-orbitals. For small values of the disorder strength, our results agree with those obtained from the Boltzmann equation. Large off-diagonal disorder causes the resistivity to saturate, whereas increasing diagonal disorder causes the resistivity to increase faster than the Boltzmann result. The crossover toward localization starts when the Boltzmann mean free path relative to the lattice constant has a value between 0.5 and 2.0 and is strongly model dependent.
description: 4 pages, 5 figures
Matrix materials used in composites: A comprehensive study
Creators: name: SHARMA, ARUN Kumar
name: Bhandari, Rakesh
name: Aherwar, Amit
name: Rimasauskiene, Ruta
Publisher: name: figshare
Year: 2020
Subjects: subject: 91202 Composite and Hybrid Materials
subject: FOS: Materials engineering
subject: Mechanical Engineering
subject: FOS: Mechanical engineering
subject: 91299 Materials Engineering not elsewhere classified

description: Composites are very significant materials for a large variety of applications in various engineering areas because of their enhanced mechanical, physical, and machining properties. These materials have been endless of applications because of their behavior, mainly mechanical, compared to other materials since it has demonstrated less density and significantly higher resistance. The composite materials have many benefits and excellent properties in comparison to conventional materials, which make the application of composites in many areas. More research and studies are being carried out to improve the characteristics and manufacturing techniques further, to promote the potential implementation of composites. In recent years, the application and development of MMCs have increased in many engineering fields. With the arrival of innovative technologies, high research activities and the development of different processing techniques, composites with improved properties become attractive materials for engineering applications. A wide array of metals, especially low-density metals or alloys, are generally selected as the matrix material for the composite. This research article provides a brief overview of matrix materials generally used in composites, and types of composites, with their important aspects.
title: Simulationsbasierter Vergleich von Human Body Modellen und ATD-Dummys in Komfortsitzpositionen hinsichtlich Kinematik und Verletzungsmechanismen in Frontal-Crashs
Creators: name: Wiegand, Johanna
Publisher: name: UNSPECIFIED
Year: 2025

description: Die Euro NCAP Organisation (europäische Verbraucherschutzorganisation zur Fahrzeugsicherheit) plant zukünftig Simulationsergebnisse im Rahmen des Virtual Testings als festen Bestandteil des Bewertungsverfahrens zu integrieren. Dabei sollen sowohl Menschmodelle, als auch ATD-Dummies, zum Einsatz kommen. Im Rahmen dieser Masterarbeit wird diskutiert, inwieweit sich die Kriterien im bisherigen Testprotokoll des Euro NCAP und die entsprechenden Grenzwerte auf das Menschmodell übertragen lassen. Ebenfalls analysiert wird, welchen Einuss ein vergrößerter Lehnenwinkel (Komfortsitzpositionen) auf die Ergebnisse des Euro NCAP Testprotokolls hat. Im ersten Schritt wird dazu aus den am Markt zur Verfügung stehenden Modellen ein geeignetes Menschmodell ausgewählt. Mit diesem Modell werden in einer Schlittenumgebung (Beschleunigungs-Simulations-Anlage als Fahrzeugersatzumgebung) unterschiedliche Komfortsitzpositionen simuliert. Die Ergebnisse mit Menschmodell werden denen mit Dummy-Modell gegenüber gestellt. Zunächst werden die Unterschiede zwischen Menschmodell und Dummy in ihrem kinematischen Verhalten diskutiert. Daran anschließend erfolgt die Auswertung von ausgewählten Belastungsgrößen sowie die Bewertung nach dem Euro NCAP Testprotokoll. Basierend auf diesen Ergebnissen werden Ideen diskutiert, inwieweit die Modelle zur Beurteilung der Insassensicherheit geeignet sind und warum sich Ergebnisse zwischen den Ersatzmodellen unterscheiden. Dazu werden Ansätze vorgestellt, wie das Euro NCAP Testprotokoll ergänzt und/oder angepasst werden könnte, abhängig davon, ob Menschmodelle oder Dummy-Modelle, beziehungsweise aufrechte Sitzpositionen oder Komfortsitzpositionen bewertet werden sollen.
Design and numerical analysis of metallic Ronchi diffraction gratings acting as reflective beam-splitter
Creators: name: Torcal-Milla, Francisco Jose
name: Sanchez-Brea, Luis Miguel
Publisher: name: arXiv
Year: 2024
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this work, a reflective beam-splitter based on a metallic Ronchi diffraction grating normally illuminated is designed and analysed. This kind of beam-splitter could have potential applications in photonics and optical technologies in which robustness is necessary since it may be manufactured over malleable metallic substrates.
 The main idea under the design is as simple as obligating the zero-th diffraction order to be null. Firstly, scalar approach is performed, showing an approximation to the parameters of the grating necessary to achieve beam-splitting. After that, a more rigorous approach such as Rigorous Coupled Waves Analysis (TE and TM polarization) is used to evaluate the proposed diffraction gratings as reflective beam-splitters.
 Beam-splitting is demonstrated for TE and TM polarization with slightly different dimensional parameters of the diffraction grating. Besides, we show how physical height of the grating grooves that allows cancelling zero-th diffraction order for a certain illumination wavelength depends on the metals used to manufacture the grating and its period. The dependence of the grooves height on the period is exponentially decreasing. To complete the analysis, we demonstrate how for a given grating period, the grooves height also depends on the illumination wavelength. Keywords: Diffraction, Diffraction grating, Beam-splitter
Internal quantum efficiency of AlGaN/AlN quantum dot superlattices for electron-pumped ultraviolet sources
Creators: name: Harikumar, A.
name: Donatini, F.
name: Bougerol, C.
name: Bellet-Amalric, E.
name: Thai, Q. -M.
name: Dujardin, C.
name: Dimkou, I.
name: Purcell, S. T.
name: Monroy, E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this paper, we describe the growth and characterization of 530-nm-thick superlattices (100 periods) of AlxGa1-xN/AlN (x = 0, 0.1) Stranski-Krastanov quantum dots for application as the active region of electron-beam pumped ultraviolet lamps. Highly dense (>10e11 cm-2) quantum dot layers are deposited by molecular beam epitaxy, and we explore the effect of the III/V ratio during the growth process on their optical performance. The study considers structures emitting in the 244-335 nm range at room temperature, with a relative linewidth in the 6-11% range, mainly due to the QD diameter dispersion inherent in self-assembled growth. Under electron pumping, the emission efficiency remains constant for acceleration voltages below 9 kV. The correlation of this threshold with the total thickness of the superlattice and the penetration depth of the electron beam confirms the homogeneity of the nanostructures along the growth axis. Below the threshold, the emission intensity scales linearly with the injected current. The internal quantum efficiency is characterized at low injection, which reveals the material properties in terms of non-radiative processes, and high injection, which emulates carrier injection in operation conditions. In quantum dots synthesized with III/V ratio < 0.75, the internal quantum efficiency remains around 50% from low injection to pumping power densities as high as 200 kW/cm2, being the first kind of nanostructures that present such stable behaviour.
Polyanalytic Reproducing Kernels on the Quantized Annulus
Creators: name: Demni, Nizar
name: Mouayn, Zouhair
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Physics (math-ph)
subject: Complex Variables (math.CV)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: While dealing with the constant-strength magnetic Laplacian on the annulus, we complete J. Peetre's work. In particular, the eigenspaces associated with its discrete spectrum are true-polyanalytic spaces with respect to the invariant Cauchy-Riemann operator, and we write down explicit formulas for their reproducing kernels. The latter are expressed by means of the fourth Jacobi theta function and of its logarithmic derivatives when the magnetic field strength is an integer. Under this quantization condition, we also derive the transformation rule satisfied by the reproducing kernel under the automorphism group of the annulus.
description: normalising constant is corrected, the Bergman kernel of the punctured disc is retrieved
Semiclassical ionization dynamics of the hydrogen molecular ion in an electric field of arbitrary orientation
Creators: name: Bartsch, T.
name: Uzer, T.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Quasi-static models of barrier suppression have played a major role in our understanding of the ionization of atoms and molecules in strong laser fields. Despite their success, in the case of diatomic molecules these studies have so far been restricted to fields aligned with the molecular axis. In this paper we investigate the locations and heights of the potential barriers in the hydrogen molecular ion in an electric field of arbitrary orientation. We find that the barriers undergo bifurcations as the external field strength and direction are varied. This phenomenon represents an unexpected level of intricacy even on this most elementary level of the dynamics. We describe the dynamics of tunnelling ionization through the barriers semiclassically and use our results to shed new light on the success of a recent theory of molecular tunnelling ionization as well as earlier theories that restrict the electric field to be aligned with the molecular axis.
Polaridades y ambivalencias ante el nuevo escenario agrario. Un estudio con estudiantes de Formacion Prodesional Agraria de la COmunidad Valenciana
Creators: name: Llopis Goig, Ramon
name: Vidal Gonzalez, Miguel
name: Llopis Goig, Ramon
name: Vidal Gonzalez, Miguel
Publisher: name: Unknown
Year: 2006
Subjects: subject: Research Methods/ Statistical Methods
subject: Innovaciones
subject: adopcion
subject: modelo logistico
subject: modelo Gompertz
subject: modelo Bass
subject: modelo exponencial
subject: Innovation
subject: adoption and diffusion
subject: logistic model
subject: Gompertz model
subject: Bass model
subject: exponential model

description: Se describe la estructura analitica de los modelos de adopcion de innovaciones tecnologicas mas utilizados en la literatura, haciendo hincapie en las aplicaciones agricolas desde el punto de vista del empresario agrario, y se analiza empiricamente como se ha difundido la tecnologia de riego localizado desde 1975 hasta 2005. Para ello, se han aplicado los modelos Logistico, Gompertz, Esponencial y Bass utilizando datos de campo de una de las comutasa de difusion del conocimiento duplica a la de adopcion, que la adopcion ha llegado a su techo y que la difusion de esta tecnologia viene determindada fundamentalmente por el efecto de imitacion e interacciones personales...This paper is aimed at describing the analytic structure of models for adoption of technology innovations most used in the literature, and at empirically analysing the diffusion of the localised irrigation technology from 1975 to 2005. The emphasis is placed on applications for agriculture from the farm manager's point of view. With this purpose, the following models have been applied: Logistic, Gompertz, Exponential and Bass. Field data from one of the biggest irrigation communities in Spain have been used. when the data from this process is analyzed and estimated, it shows that the knowledge diffusion rate is twice that of adoption, and that adoption has reached its peak. The spread of this technology is fundamentally determined by the imitation effect and personal interactions.
Making waves on CMB power spectrum and inflaton dynamics
Creators: name: Kawasaki, Masahiro
name: Takahashi, Fuminobu
name: Takahashi, Tomo
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss cosmic microwave background anisotropies in models with an unconventional primordial power spectrum. In particular, we consider an initial power spectrum with some ``spiky'' corrections. Interestingly, such a primordial power spectrum generates ``wavy'' structure in the CMB angular power spectrum.
description: 8 pages, 2 figures, version accepted for publication in Physics Letters B; several references are added
BN_Chinook_malathion_Diazinon_yakima_CDD.neta
Creators: name: Mitchell, Chelsea
name: Chu, Valerie
name: Harris, Meagan
name: Landis, Wayne
name: Stackelberg, Katherine Von
name: Stark, John D.
Publisher: name: figshare
Year: 2020
Subjects: subject: 50205 Environmental Management
subject: FOS: Earth and related environmental sciences
subject: Environmental Science

description: These .neta files can be opened using Netica software available as a free limited version here https://www.norsys.com/download.html.
Visualization of the spatial variation of wood density in Western Hemlock
Creators: name: Henze, Kim-Jana
Publisher: name: University of British Columbia
Year: 2010

description: Previous studies of the within tree variation in density of western hemlock have constructed 2 dimensional maps of the variation in wood density from pith to bark and longitudinally within the tree, and have concluded that wood from the outer part of the stem is denser than wood found near the centre of the tree, and wood density decreases with tree height. Based on such information it should be possible to segregate wood from the outer, basal, parts of the tree stem following primary conversion and allocate it to end uses requiring hardness and higher strength. This premise assumes that circumferential variation in wood density in hemlock is insignificant, and such information is not available for western hemlock. This study mapped the density of the lower 5 m of four second-growth western hemlock stems in the x, (radial), y, (longitudinal) and circumferential (Θ) directions to determine their relative contributions to the overall pattern of density variation in hemlock stems. Computational and advanced visualization techniques were used to create 3-dimensional models of the spatial distribution of density in the hemlock stems. Circumferential variation in density was not significant, and previously established wood density trends from pith to bark and with height in the stem were confirmed. 3-dimensional images showed higher density wood in the outer part of the stem but the highest density wood did not form a continuous sheath in this part of the stem. Nevertheless, it should still be possible to utilize denser wood from the outer part of the tree for end uses requiring higher strength and hardness. Two novel and previously unreported features were observed. Firstly it appeared that the shape of the lower density juvenile wood core was cylindrical irrespective of the external shape of the stem. Secondly in one tree there was circumferential, helical variation in wood density with increasing height in the tree. It would be desirable to confirm whether these features are commonly found in western hemlock by examining greater numbers of trees.
New Expansion Rate Estimate of the Scorpius-Centaurus Association Based on T Tauri Stars from the Gaia DR2 Catalog
Creators: name: Bobylev, V. V.
name: Bajkova, A. T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The kinematic properties of the Scorpius-Centaurus association were studied using spatial velocities of approximately 700 young T Tauri stars. Their proper motions and trigonometric parallaxes were selected by Zari et al. from the Gaia DR2 catalog, and radial velocities were taken from various sources. The linear expansion coefficients new estimate of the association $K=39\pm2$ km/s/kpc is obtained by considering the influence of the galactic spiral density wave with an amplitude of radial disturbances $f_R=5$ km/s and solar phase in the wave $-120^\circ$. The proper rotation of the association is shown to be small. The residual velocity ellipsoid of these stars has semimajor axes $σ_{1,2,3}=(7.72,1.87,1.74)\pm(0.56,0.37,0.22)$ km/s and is positioned at an angle $12\pm2^\circ$ to the galactic plane.
description: 14 pages, 2 figures, 2 tables
Modified Mach Zehnder interferometer for spatial coherence measurement
Creators: name: Torcal-Milla, FJ
name: Lobera, J
name: Roche, EM
name: Lopez, AM
name: Palero, V
name: Andres, N
name: Arroyo, P
Publisher: name: arXiv
Year: 2024
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Spatial coherence of light sources is usually obtained by using the classical Youngs interferometer. Despite the original experiment has been improved in successive works, some drawbacks still remain. In addition, several pairs of points must be used to characterize the totally the 2D complex-coherence degree of the source. In this work, an alternative based on a modified Mach-Zehnder interferometer which includes a pair of lenses is presented. With this modified Mach-Zehnder interferometer, we are able to measure the spatial coherence length between any two points of the laser beam section simultaneously. The set-up does not have any movable part, which makes it robust and portable. To test it, the two-dimensional spatial coherence of a high-speed laser with two cavities has been measured for different pulse energy values. We observe from the experimental measurements that the complex degree of coherence changes with the selected output energy. Both laser cavities seem to have similar complex coherence degree for maximum energy although it is not symmetrical. Thus, this analysis will allow us to determine the best configuration of the double cavity laser for interferometric applications. Furthermore, the proposed approach can be applied to any other light sources.
Effects of CP-violating phases in supersymmetry
Creators: name: Hesselbach, S.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recent studies about the impact of the CP-violating complex parameters in supersymmetry on the decays of third generation squarks and about T-odd asymmetries in neutralino and chargino production and decay are reviewed. The CP-even branching ratios of the third generation squarks show a pronounced dependence on the phases of A_t, A_b, mu and M_1 in a large region of the supersymmetric parameter space. This could have important implications for stop and sbottom searches and the MSSM parameter determination in future collider experiments. We have estimated the expected accuracy in the determination of the parameters by global fits of measured masses, decay branching ratios and production cross sections. We have found that the parameter A_t can be determined with an error of 2 - 3%, whereas the error on A_b is likely to be of the order of 50 - 100%. In addition we have studied CP-odd observables, like asymmetries based on triple product correlations, which are necessary to unambiguously establish CP violation. We have analysed these asymmetries in neutralino and chargino production with subsequent three-body decays at the International Linear Collider with longitudinally polarised beams in the MSSM with complex parameters M_1 and mu. The asymmetries, which appear already at tree-level because of spin correlation between production and decay, can be as large as 20% and will therefore be an important tool for the search for CP-violating effects in supersymmetry.
description: 13 pages, LaTeX, 7 eps figures, uses appolb.cls, presented at the final meeting of the European Network ``Physics at Colliders'', Montpellier, September 26 - 27, 2004
3D Object Detection From LiDAR Data Using Distance Dependent Feature Extraction
Creators: name: Engels, Guus
name: Aranjuelo, Nerea
name: Arganda-Carreras, Ignacio
name: Nieto, Marcos
name: Otaegui, Oihana
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper presents a new approach to 3D object detection that leverages the properties of the data obtained by a LiDAR sensor. State-of-the-art detectors use neural network architectures based on assumptions valid for camera images. However, point clouds obtained from LiDAR are fundamentally different. Most detectors use shared filter kernels to extract features which do not take into account the range dependent nature of the point cloud features. To show this, different detectors are trained on two splits of the KITTI dataset: close range (objects up to 25 meters from LiDAR) and long-range. Top view images are generated from point clouds as input for the networks. Combined results outperform the baseline network trained on the full dataset with a single backbone. Additional research compares the effect of using different input features when converting the point cloud to image. The results indicate that the network focuses on the shape and structure of the objects, rather than exact values of the input. This work proposes an improvement for 3D object detectors by taking into account the properties of LiDAR point clouds over distance. Results show that training separate networks for close-range and long-range objects boosts performance for all KITTI benchmark difficulties.
description: 10 pages, 8 figures, 6th International Conference on Vehicle Technology and Intelligent Transport Systems (VEHITS 2020)
Agricultura y trabajo rural en la globalizacion
Creators: name: Delgado Cabeza, Manuel
name: Gavira Alvarez, Lina
name: Delgado Cabeza, Manuel
name: Gavira Alvarez, Lina
Publisher: name: Unknown
Year: 2006
Subjects: subject: Agribusiness
subject: Labor and Human Capital
subject: Agricultura
subject: sistema agroalimentario
subject: trabajo rural
subject: condiciones de trabajo
subject: pobreza
subject: agriculture
subject: agro-alimentary system
subject: rural work
subject: labor conditions
subject: social policy
subject: poverty

description: El presente trabajo consta de dos partes. En la primera se sintetizen las tendencias de la evolucion de la agricultura en los ultimos quinquenios, articulandose esta como el primer eslabon dentro de la dinamica del sistema agroalimentario. En la segunda parte, despues de algunas consideracioens sobre los limites de la categoria de mercado de trabajo rural, se analizan las tendencias dominantes en la actividad y las condiciones laborales en las zonas rurales, para terminar el trabajo con el planteamiento de algunas propuestas politicas...The present work consists of two parts. In the first one the tendencies of the evolution of agriculture in the last few decades are synthesized, articulating this one as the first link within the dynamics of the agro-alimentary system. In the second part, after some considerations on the limits of the rural labour market category, the dominant tendencies in the activity and the working conditions in the rural areas are analysed, ending this work with the exposition of some political proposals.
முனைவர் இரா. இளவரசு படைப்புகளில் மொழித்தூய்மை
Creators: name: Devarkaivalyam, Ashok
Publisher: name: figshare
Year: 2020
Subjects: subject: 200315 Indian Languages
subject: FOS: Languages and literature

description: உலகில் இனக்குழுக்களின் அடிப்படையில் மொழிகள் பல்வேறாக முகிழ்ந்தன. மொழியே சமூகத்தை வழிநடத்துகிறது. இனக்குழுக்களில் ஏற்பட்ட தொடர்பின் விளைவால் மொழிகளில் கலப்பு ஏற்பட்டன. மொழிக்கலப்பு எந்த ஒரு மொழியின் தனித்துவத்தையும் இழக்குச் செய்வதாய் அமைந்து விடுகிறது. மொழிப்பற்றாளர்கள் மொழிக்கலப்பைச் சிறிதும் ஏற்பதில்லை. அந்த வகையில் பேராசிரியர் இளவரசு அவர்களின் படைப்புகளில் மொழித்தூய்மை மிகச்சிறந்த வகையில் காக்கப்பட்டு மொழி உணர்வானது ஊட்டப்படுகிறது. பிறர் அறிந்து கொள்ளமுடியாத தன் வாழ்க்கை குறிப்பிலும் (டைரி) பிறமொழி கலவாத நிலையைக் கையாண்டுள்ளார். கோப உணர்ச்சியையும் தூயத்தமிழையே கைக்கொண்டுள்ளார். பிறமொழிச்சொற்கள் இவர் படைப்புகளில் தவிர்க்கப்பட்டுள்ளன. செவ்வியல் வழக்கை ஆளுதல் சொற்களைத் தமிழ்ப்படுத்துதல் தமிழில் மிளிர்தல் என்று பேராசிரியர; இளவரசு அவர்களின் தமிழ் மொழித்தூய்மை அவர் தம் படைப்புகளில் நன்கு வெளிப்பட்டுள்ளது.