cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Rogers-Szego polynomials and Hall-Littlewood symmetric functions
Creators: name: Warnaar, S. Ole
Publisher: name: arXiv
Year: 2007
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05E05

description: We use Rogers-Szego polynomials to unify some well-known identities for Hall-Littlewood symmetric functions due to Macdonald and Kawanaka.
description: 18 pages
Far field imaging by a planar lens: diffraction versus superresolution
Creators: name: Kuhta, Nicholas A.
name: Podolskiy, Viktor A.
name: Efros, Alexei L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We resolve the long standing controversy regarding the imaging by a planar lens made of left-handed media and demonstrate theoretically that its far field image has a fundamentally different origin depending on the relationship between losses {inside} the lens and the wavelength of the light $λ$. At small enough $λ$ the image is always governed by diffraction theory, and the resolution is independent of the absorption if both Im$ε\ll 1$ and Im$μ\ll 1$. For any finite $λ$, however, a critical absorption exists below which the superresolution regime takes place, though this absorption is extremely low and can hardly be achieved. We demonstrate that the transition between diffraction limited and superresolution regimes is governed by {the} universal parameter combining absorption, wavelength, and lens thickness. Finally, we show that this parameter is related to the resonant excitation of the surface plasma waves.
Characterizing entanglement with geometric entanglement witnesses
Creators: name: Krammer, Philipp
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show how to detect entangled, bound entangled, and separable bipartite quantum states of arbitrary dimension and mixedness using geometric entanglement witnesses. These witnesses are constructed using properties of the Hilbert-Schmidt geometry and can be shifted along parameterized lines. The involved conditions are simplified using Bloch decompositions of operators and states. As an example we determine the three different types of states for a family of two-qutrit states that is part of the "magic simplex", i.e. the set of Bell-state mixtures of arbitrary dimension.
description: 19 pages, 4 figures, some typos and notational errors corrected. To be published in J. Phys. A: Math. Theor
Harmonised Procedures on Photovoltaic Modules Long-Term Energy Yield Measurements and Performance Evaluation under Outdoor Conditions
Creators: name: Craciun, D.
name: Helmbrecht, V.
name: Tselepis, S.
name: Kyritsis, A.
name: Hatziargyriou, N.
name: Latoufis, K.
name: Misara, S.
name: Funtan, P.
name: Strauß, P.
name: Ellis, A.
name: Bründlinger, R.
Publisher: name: WIP
Year: 2012
Subjects: Components for PV Systems
Standardisation

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3074-3081
description: Procedures on photovoltaic (PV) modules long-term tests under outdoor conditions have so far not been
adopted by international standardisation committees. Notwithstanding the current practices applied within different
laboratories with respect to PV outdoor tests, a commonly agreed and harmonised procedure has not been detailed so far.
DERlab’s approach to fill in standardisation activities gaps led to the development of technical guidelines providing
specifications for PV modules energy yield measurement under outdoor conditions, related testing setup and
measurement equipment accuracy requirements. DERlab recommendations offer consistent measurement procedures
allowing direct comparison of PV modules energy yield under varying environmental conditions, as well as guidelines
for module and measurement equipment maintenance. These guidelines complement recommendations contained in
current international standards. This article describes the DERlab guidelines and also discusses options of data processing
and key insights that can be derived from the measurements (e.g. module degradation, efficiency or energy yield).
The Complex Dialogue between Photovoltaics and Pre-Existing: Starting Point for a Discussion
Creators: name: Scognamiglio, A.
name: Berni, A.
name: Frontini, F.
name: Polo López, C.S.
name: Maturi, L.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
PV and Architecture

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 4161-4168
description: The shift from traditional fossil fuels to renewables is implying a diffusion of “visible” PV modules in our buildings and landscapes. In contrast with traditional fossil fuels, which were hidden in the ground somewhere, far from the city life, renewable energy generation systems, and Photovoltaics (PV) in particular, are visible. This change is generally perceived as negative by the public, since the introduction of PV is evaluated as disturbing the pre-existing. Pre-existing can be understood as the landscape whose image the public is used to, at the small scale as well as at the large scale (buildings and natural or built landscapes). Research carried out in the past years has been done to solve the problem by integrating PV into buildings, that is trying to hide PV in shapes that the public already knows, without consuming additional ground surfaces. Nevertheless, the European and national policies are pushing towards an increasing use of PV, so that now its use is not limited at the building scale, but includes the landscape scale. How could landscapes look like to incorporate this energy source? How would these energy needs match the needs related to the preservation of our landscapes?
In order to understand how this problem can be approached and what are the different needs of cultural heritage conservation vs. “planet preservation”, ENEA opened a discussion with the different actors that play a role in the dialogue between PV and pre-existing. This paper will refer about the preliminary results of this discussion.
Aproximation of Si-Based PV Module Output Parameters by Comparison of Different Translation Techniques
Creators: name: Saly, V.
name: Perný, M.
name: Frantik, O.
name: Hladik, J.
name: Hanák, K.
Publisher: name: WIP
Year: 2012
Subjects: Components for PV Systems
PV Modules

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3225-3228
description: The paper deals with diagnostics of PV modules based on Si. This diagnostics is based on
measurement of I-V characteristics at natural outdoor conditions and consequently in prediction of output parameters
of observed modules by translation techniques to “Standard Test Condition”. Translation by STN EN 60904 (EIC
60904) and methods of Anderson, Marion, Bleasser were acquired from three different irradiation and temperature
conditions. The comparison shows an approximation to output power parameters of investigated PV modules.
The optical Stark shift to control the dark exciton occupation of a quantum dot in a tilted magnetic field
Creators: name: Neumann, Miriam
name: Kappe, Florian
name: Bracht, Thomas K.
name: Cosacchi, Michael
name: Seidelmann, Tim
name: Axt, Vollrath Martin
name: Weihs, Gregor
name: Reiter, Doris E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: When a detuned and strong laser pulse acts on an optical transition, a Stark shift of the corresponding energies occurs. We analyze how this optical Stark effect can be used to prepare and control the dark exciton occupation in a semiconductor quantum dot. The coupling between the bright and dark exciton states is facilitated by an external magnetic field. Using sequences of laser pulses, we show how the dark exciton and different superposition states can be prepared. We give simple analytic formulas, which yield a good estimate for optimal preparation parameters. The preparation scheme is quite robust against the influence of acoustic phonons. We further discuss the experimental feasibility of the used Stark pulses. Giving a clear physical picture our results will stimulate the usage of dark excitons in schemes to generate photons from quantum dots.
description: 10 pages, 6 figures
Cohen-Macaulay, Shellable and unmixed clutters with a perfect matching of König type
Creators: name: Morey, Susan
name: Reyes, Enrique
name: Villarreal, Rafael H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Commutative Algebra (math.AC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 13F55, 05C65, 05C75

description: Let $\mathcal{C}$ be a clutter with a perfect matching $e_1,...,e_g$ of König type and let $Δ_\mathcal{C}$ be the Stanley-Reisner complex of the edge ideal of $\mathcal{C}$. If all c-minors of $\mathcal{C}$ have a free vertex and $\mathcal{C}$ is unmixed, we show that $Δ_\mathcal{C}$ is pure shellable. We are able to describe, in combinatorial and algebraic terms, when $Δ_\mathcal{C}$ is pure. If $\mathcal{C}$ has no cycles of length 3 or 4, then it is shown that $Δ_\mathcal{C}$ is pure if and only if $Δ_\mathcal{C}$ is pure shellable (in this case $e_i$ has a free vertex for all $i$), and that $Δ_\mathcal{C}$ is pure if and only if for any two edges $f_1,f_2$ of $\mathcal{C}$ and for any $e_i$, one has that $f_1\cap e_i\subset f_2\cap e_i$ or $f_2\cap e_i\subset f_1\cap e_i$. It is also shown that this ordering condition implies that $Δ_\mathcal{C}$ is pure shellable, without any assumption on the cycles of $\mathcal{C}$. Then we prove that complete admissible uniform clutters and their Alexander duals are unmixed. In addition, the edge ideals of complete admissible uniform clutters are facet ideals of shellable simplicial complexes, they are Cohen-Macaulay, and they have linear resolutions. Furthermore if $ \mathcal{C}$ is admissible and complete, then $\mathcal{C}$ is unmixed. We characterize certain conditions that occur in a Cohen-Macaulay criterion for bipartite graphs of Herzog and Hibi, and extend some results of Faridi--on the structure of unmixed simplicial trees--to clutters with the König property without 3-cycles or 4-cycles.
description: 22 pages
Advances in Solar Radiation Resource Assessment in India
Creators: name: Kumar, A.
name: Giridhar, G.
name: Vashistha, R.
name: Meyer, R.
name: Mitra, I.
name: Schwandt, M.
name: Chattbar, K.
Publisher: name: WIP
Year: 2012
Subjects: PV - a Major Electricity Source
PV Globalisation, Policies and Administrative Barriers

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 4724-4730
description: India launched National Solar Mission in 2010, which aims at to set up 20 000 MW of grid connected
solar power, besides 2 000 MW equivalent of off-grid applications and cumulative growth of solar thermal collector
area to 20 million m2 by 2022. Availability of reliable and accurate solar radiation data is crucial to achieve the
targets. As a result of this initiative, Ministry of New and Renewable Energy (MNRE) of Government of India (GoI)
has awarded a project to Centre for Wind Energy Technology, Chennai in the year 2011 to set up 51 Solar Radiation
Resource Assessment (SRRA) stations using the state-of-the-art equipment in various parts of the country, especially
the sites with high potential for solar power. The GoI project has synergy with SolMap project, which is implemented
by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) in cooperation with the MNRE. SolMap
project is contributing to SRRA project in establishing quality checks on the data obtained as per International
protocols and helping data processing to generate investment grade data. The paper highlights the details of SRRA
stations and an attempt has been made to present some of the important results of quality control and data analysis
with respect to DNI and GHI. While our analysis of the data over one year finds that intensity and profile of the
insolation are not uniform across the geographic regions, the variability in DNI is particularly high. Strong influence
of monsoon is also identified. SRRA infrastructure aims to develop investment grade solar radiation resource
information to assist project activities under the National Solar Mission of India.
High-resolution CARMA Observation of Molecular Gas in the North America and Pelican Nebulae
Creators: name: Kong, Shuo
name: Arce, Héctor G.
name: Carpenter, John M.
name: Bally, John
name: Ossenkopf-Okada, Volker
name: Sánchez-Monge, Álvaro
name: Sargent, Anneila I.
name: Suri, Sümeyye
name: McGehee, Peregrine
name: Lis, Dariusz C.
name: Klessen, Ralf
name: Mairs, Steve
name: Zucker, Catherine
name: Smith, Rowan J.
name: Nakamura, Fumitaka
name: Pillai, Thushara G. S.
name: Kauffmann, Jens
name: Zhang, Shaobo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the first results from a CARMA high-resolution $^{12}$CO(1-0), $^{13}$CO(1-0), and C$^{18}$O(1-0) molecular line survey of the North America and Pelican (NAP) Nebulae. CARMA observations have been combined with single-dish data from the Purple Mountain 13.7m telescope to add short spacings and produce high-dynamic-range images. We find that the molecular gas is predominantly shaped by the W80 HII bubble that is driven by an O star. Several bright rims are probably remnant molecular clouds heated and stripped by the massive star. Matching these rims in molecular lines and optical images, we construct a model of the three-dimensional structure of the NAP complex. Two groups of molecular clumps/filaments are on the near side of the bubble, one being pushed toward us, whereas the other is moving toward the bubble. Another group is on the far side of the bubble and moving away. The young stellar objects in the Gulf region reside in three different clusters, each hosted by a cloud from one of the three molecular clump groups. Although all gas content in the NAP is impacted by feedback from the central O star, some regions show no signs of star formation, while other areas clearly exhibit star formation activity. Other molecular gas being carved by feedback includes the cometary structures in the Pelican Head region and the boomerang features at the boundary of the Gulf region. The results show that the NAP complex is an ideal place for the study of feedback effects on star formation.
description: accepted by AJ
Development of the tolerant wind tunnel for bluff body testing
Creators: name: Hameury, Michel
Publisher: name: University of British Columbia
Year: 2010

description: In conventional wind tunnels the solid-wall or open-jet test section imposes on the flow field around the test model new boundary conditions absent in free air. Unless a small model is used, the solid-wall test section generally increases the loadings on the model while the open-jet boundary decreases the loadings compared to the unconfined case. However, the development of a low wall-interference test section and its successful demonstration would allow the testing of relatively large models without the application of often uncertain correction formulae. The Tolerant wind tunnel, which makes use of the opposite effects of solid and open boundaries, is a transversely slatted-wall test section designed to produce at an optimal wall open-area ratio (OAR) low-correction data for a wide variety of model shapes and sizes. Initially intended for low-speed airfoil testing, its use is theoretically and experimentally investigated here in connection with bluff body testing. A simple mathematical model based on two-dimensional potential flow theory and solved with the help of a vortex surface-singularity technique is used to estimate the best wall configuration. The theory predicts an optimum OAR of about 0.45 at which pressure distributions on flat plate and circular cylinder models of blockage ratios up to 33.3 % would differ from the free-air values by not more than 1 %. On the other hand, experiments performed with flat plate, circular cylinder and circular-cylinder-with-splitter-plate models indicate the existence of an optimum configuration around OAR = 0.6. The experiments also show a maximum allowable blockage in the Tolerant wind tunnel to be equivalent to the blockage created by a 33.3 %-blockage-ratio flat plate model.
Inverter with Multiple MPP Trackers: Requirements and State of the Art Solutions
Creators: name: Staudacher, D.
Publisher: name: WIP
Year: 2012
Subjects: Components for PV Systems
Balance of System Components

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3630-3633
description: For most people inverters with multiple MPP Trackers (MPPT) seem to be more flexible compared to
inverters with a single MPPT. At first glance this assumption appears to be correct, however, the devil is in the detail.
The purpose of this project is to show that not every inverter with multiple MPPT’s is automatically usable for each
application. There are high requirements on such an inverter which must be fulfilled to be as flexible as always
assumed.
The local stellar velocity field via vector spherical harmonics
Creators: name: Makarov, V. V.
name: Murphy, D. W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We analyze the local field of stellar tangential velocities for a sample of $42 339$ non-binary Hipparcos stars with accurate parallaxes, using a vector spherical harmonic formalism. We derive simple relations between the parameters of the classical linear model (Ogorodnikov-Milne) of the local systemic field and low-degree terms of the general vector harmonic decomposition. Taking advantage of these relationships we determine the solar velocity with respect to the local stars of $(V_X,V_Y,V_Z)=(10.5, 18.5, 7.3)\pm 0.1$ \kms. The Oort's parameters determined by a straightforward least-squares adjustment in vector spherical harmonics, are $A=14.0\pm 1.4$, $B=-13.1\pm 1.2$, $K=1.1\pm 1.8$, and $C=-2.9\pm 1.4$ \kmspc. We find a few statistically significant higher degree harmonic terms, which do not correspond to any parameters in the classical linear model. One of them, a third-degree electric harmonic, is tentatively explained as the response to a negative linear gradient of rotation velocity with distance from the Galactic plane, which we estimate at $\sim -20$ \kmspc. The most unexpected and unexplained term within the Ogorodnikov-Milne model is the first-degree magnetic harmonic representing a rigid rotation of the stellar field about the axis $-Y$ pointing opposite to the direction of rotation. This harmonic comes out with a statistically robust coefficient $6.2 \pm 0.9$ \kmspc, and is also present in the velocity field of more distant stars. The ensuing upward vertical motion of stars in the general direction of the Galactic center and the downward motion in the anticenter direction are opposite to the vector field expected from the stationary Galactic warp model.
description: accepted in AJ
AFRETEP: Lessons Learned from Capacity Building Experiences with African Academia
Creators: name: Pinedo Pascua, I.
name: Tromboni, U.
name: Bódis, K.
name: Szabó, S.
Publisher: name: WIP
Year: 2012
Subjects: PV - a Major Electricity Source
PV Globalisation, Policies and Administrative Barriers

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 4348-4351
description: The year 2012 has been designated as the International Year of Sustainable Energy for All by the
United Nations General Assembly, aiming to expand access to modern energy services by 2030. In September 2010,
the Africa-EU Renewable Energy Cooperation Program was launched at the First High Meeting of the Africa-EU
Energy Partnership (AEEP), contributing to the agreed energy targets in Africa by 2020: 10,000MW of hydropower,
5,000MW of wind power capacity, 500MW of solar energy and tripling the capacity of other renewables, providing
new access of energy to 100 million people.
The international community is committed to supporting Africa to address its energy challenges but the definition of
continental priorities and ways of implementation is under national, sub-regional and regional African policy
domains. What is then the role to be played by other stakeholders like academia, private sector and society?
A Thin Electromagnetic Absorber for Wide Incidence Angles and Both Polarizations
Creators: name: Luukkonen, Olli
name: Costa, Filippo
name: Monorchio, Agostino
name: Tretyakov, Sergei A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: In this paper a planar electromagnetic absorber is introduced whose performance is maintained over a wide change of the incidence angle for both TE and TM polarization. The absorber comprises an array of patches over a grounded dielectric slab, with clear advantage in terms of manufacturability. It is shown that a high value of the relative permittivity of the substrate is essential for the operation of the absorber. The main contribution of the paper is to demonstrate and practically use the presence of an additional resonance of high-impedance surfaces when the plasma frequency of the wire medium comprising metallic vias in the dielectric substrate is close to the original resonance of the high-impedance surface. The presence of the vias between FSS and the ground plane is discussed both for the case of a high-permittivity absorber and for a low permittivity one. The radius of the vias influences the oblique incidence TM absorption, and when properly designed, the insertion of the vias result in bandwidth enlargement and higher absorption.
Acoustic plasmons in type-I Weyl semimetals
Creators: name: Afanasiev, A. N.
name: Greshnov, A. A.
name: Svintsov, D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Massless chiral fermions emergent in inversion symmetry-breaking Weyl semimetals (WSMs) reside in the vicinity of multiple low symmetry nodes and thus acquire strongly anisotropic dispersion. We investigate the longitudinal electromagnetic modes of two-component degenerate Weyl plasma relevant to the realistic band structure of type-I WSM. We show that the actual spectrum of three dimensional collective density excitations in TaAs family of WSM is gaples due to emergence of acoustic plasmons corresponding to out-of-phase oscillations of the plasma components. These modes exist around the [001] crystallographic direction and are weakly damped, thanks to large difference in the Weyl velocities of the $W_1$ and $W_2$ quasiparticles when propagating along [001]. We show that acoustic plasmons can manifest themselves as slow beatings of electric potential superimposed on fast plasmonic oscillations upon charge relaxation. The revealed acoustic modes can stimulate purely electronic superconductivity, collisionless plasmon instabilities, and formation of Weyl soundarons.
description: 10 pages, 7 figures
The Nexus of Production Diversity, Market Participation and Dietary Diversity: Insights from Ethiopia
Creators: name: Getahun, Tigabu
name: Fetene, Gebeyehu
name: Getahun, Tigabu
name: Fetene, Gebeyehu
Publisher: name: Unknown
Year: 2021
Subjects: subject: Agricultural and Food Policy
subject: production diversity
subject: consumption (diet) diversity
subject: risk preference
subject: market participation
subject: endogeneity

description: This study examines the nexus among production diversity, market participation, and consumption diversity in smallholder households. It identifies the main factors that influence smallholder farm households’ decision to diversify production and evaluates the effect of production diversity and market participation on consumption diversity. To this end, we use a three-wave panel data of 7110 households in rural Ethiopia. The estimation results from the Mundlak Fixed Effects instrumental method suggest that risk-averse households, households with larger cultivated land, households with larger family size and family labor, and households who participate in community meetings are more likely to diversify their production. The results further reveal that production diversity has a statistically significant and positive effect on the consumption diversity of household members, but not dietary diversity of children and women. We find that market integration is more relevant in improving nutrition than production diversity. These results suggest that policies that merely focus on encouraging smallholder farmers to diversify production would not be that effective unless they are coupled with interventions that aim to integrate smallholder farmers to the market.
Investigation by STEM-EELS of helium density in nanobubbles formed in aged palladium tritides
Creators: name: Evin, B.
name: Leroy, E.
name: Segard, M.
name: Paul-Boncour, V.
name: Challet, S.
name: Fabre, A.
name: Latroche, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: 3He nanobubbles created by radioactive decay of tritium in palladium tritide are investigated after several years of aging. Scanning Transmission Electron Microscopy Electron Energy-Loss Spectroscopy (STEM-EELS) has been used to measure helium density from the helium K-edge around 23 eV. Helium densities were found between 20 and 140 (+/-30) He/nm3 and the corresponding nanobubble pressures range between 0.1 and 3 (+/-0.2) GPa. Measuring helium density and mapping He atoms by STEM-EELS enables to differentiate bubbles from empty cavities in the palladium tritide matrix.
Combination of Angular Selective Photonic Structure and Concentrating Solar Cell System
Creators: name: Höhn, O.
name: Peters, M.
name: Zilk, M.
name: Ulbrich, C.
name: Schwarz, U.T.
name: Bläsi, B.
Publisher: name: WIP
Year: 2012
Subjects: Material Studies, New Concepts and Ultra-High Efficiency
New Materials, Cells and Modules

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 353-357
description: One possibility to achieve higher efficiencies in solar cell systems is to integrate angularly selective
photonic filters in order to decrease radiative losses.
Thermodynamically, the use of an angularly selective filter and a concentrator are equivalent. In both cases the
efficiency of solar cells is increased by a manipulation of the ratio of the solid angles from which light is received
and into which light is emitted. This ratio enters the equation to calculate entropic losses connected to étendue:
The larger this ratio gets, the lower the entropic losses will be and the higher is the potential efficiency of the
solar cell system.
The difference between concentration and angular confinement is the angle which is affected. In concentrating
systems the angle of incidence is increased, whereas in angularly confined systems the angle of emission is
decreased. Maximum efficiency is reached, if both angles are equal. Of course the angle of emission cannot get
smaller than the angle of incidence. To achieve the highest efficiencies, both systems can be combined.
For this reason a solar cell system that combines concentration and angular confinement is investigated and
discussed. For a GaAs solar cell system, as it is assumed for the calculations, the Shockley-Queisser efficiencylimit
with a perfect angular confinement is 41.71%, whereas in a system without any confinement the limit is
32.5%.
Starting with this system, modified Bragg and quasi-Rugate filters are considered to approximate a realistic
efficiency enhancement using real filters in a concentrator solar cell system.
Snapshot Compressive Imaging: Principle, Implementation, Theory, Algorithms and Applications
Creators: name: Yuan, Xin
name: Brady, David J.
name: Katsaggelos, Aggelos K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Capturing high-dimensional (HD) data is a long-term challenge in signal processing and related fields. Snapshot compressive imaging (SCI) uses a two-dimensional (2D) detector to capture HD ($\ge3$D) data in a {\em snapshot} measurement. Via novel optical designs, the 2D detector samples the HD data in a {\em compressive} manner; following this, algorithms are employed to reconstruct the desired HD data-cube. SCI has been used in hyperspectral imaging, video, holography, tomography, focal depth imaging, polarization imaging, microscopy, \etc.~Though the hardware has been investigated for more than a decade, the theoretical guarantees have only recently been derived. Inspired by deep learning, various deep neural networks have also been developed to reconstruct the HD data-cube in spectral SCI and video SCI. This article reviews recent advances in SCI hardware, theory and algorithms, including both optimization-based and deep-learning-based algorithms. Diverse applications and the outlook of SCI are also discussed.
description: Extension of X. Yuan, D. J. Brady and A. K. Katsaggelos, "Snapshot Compressive Imaging: Theory, Algorithms, and Applications," in IEEE Signal Processing Magazine, vol. 38, no. 2, pp. 65-88, March 2021, doi: 10.1109/MSP.2020.3023869
Experimental Studies on the Reaction Temperature of Silicon Production in a Microwave Furnace
Creators: name: Mai, J.-P.
name: Raabe, G.
name: Köhler, J.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Feedstock, Crystallisation and Wafering

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 618-621
description: We present a new developed microwave furnace capable to produce small amounts of metallurgical silicon
[1]. Due to the direct microwave heating of the reaction mixture and a lower over-all temperature compared to
the electric arc furnace, process time and heat losses are reduced. Additionally, the utilization of pure furnace materials
and crucibles, combined with a shorter process time result in lower diffusion of impurities into the produced silicon.
Thus, the microwave process can result in an energy efficient process that is able to produce high quality metallurgical
silicon, which can be easily upgraded to solar silicon. In this work, we present experimental studies on contact
and non-contact temperature measurements during microwave heating of both, the pure compounds and the reaction
mixture.
Cell Performance and Module Reliability for 6 Inch n-Type Silicon Solar Cell with Efficiency of 18.6%
Creators: name: Hu, Y.-C.
name: Chiu, M.-H.
name: Yang, S.-H.
name: Chen, T.-P.
name: Lin, Y.-H.
name: Lu, C.-C.
name: Tung, K.-W.
name: Chen, J.-C.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Improvements

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 908-914
description: Development of n-type silicon solar cell based on full-area Al-rear junction
concepts has been implemented using industrial fabrication techniques. Superior
performance can be reached by using Cz silicon wafer with specific resistivity as
substrate, applying special technology for emitter formation, and optimizing co-firing
process for metallization. Cell efficiency up to 18.6% for 6 inch solar cell was
achieved. Moreover, these high-efficiency n-type solar cells were encapsulated into
module level to evaluate reliability under TC200 conditions.
ET-BERT: A Contextualized Datagram Representation with Pre-training Transformers for Encrypted Traffic Classification
Creators: name: Lin, Xinjie
name: Xiong, Gang
name: Gou, Gaopeng
name: Li, Zhen
name: Shi, Junzheng
name: Yu, Jing
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Encrypted traffic classification requires discriminative and robust traffic representation captured from content-invisible and imbalanced traffic data for accurate classification, which is challenging but indispensable to achieve network security and network management. The major limitation of existing solutions is that they highly rely on the deep features, which are overly dependent on data size and hard to generalize on unseen data. How to leverage the open-domain unlabeled traffic data to learn representation with strong generalization ability remains a key challenge. In this paper,we propose a new traffic representation model called Encrypted Traffic Bidirectional Encoder Representations from Transformer (ET-BERT), which pre-trains deep contextualized datagram-level representation from large-scale unlabeled data. The pre-trained model can be fine-tuned on a small number of task-specific labeled data and achieves state-of-the-art performance across five encrypted traffic classification tasks, remarkably pushing the F1 of ISCX-Tor to 99.2% (4.4% absolute improvement), ISCX-VPN-Service to 98.9% (5.2% absolute improvement), Cross-Platform (Android) to 92.5% (5.4% absolute improvement), CSTNET-TLS 1.3 to 97.4% (10.0% absolute improvement). Notably, we provide explanation of the empirically powerful pre-training model by analyzing the randomness of ciphers. It gives us insights in understanding the boundary of classification ability over encrypted traffic. The code is available at: https://github.com/linwhitehat/ET-BERT.
description: This work has been accepted in Security, Privacy, and Trust track at The Web Conference 2022 (WWW'22)(see https://www2022.thewebconf.org/cfp/research/security/)
The role of carbon segregation on nanocrystallisation of pearlitic steels processed by severe plastic deformation
Creators: name: Sauvage, Xavier
name: Ivanisenko, Yulia
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The nanostructure and the carbon distribution in a pearlitic steel processed by torsion under high pressure was investigated by three-dimensional atom probe. In the early stage of deformation (shear strain of 62), off-stoichiometry cementite was analysed close to interphase boundaries and a strong segregation of carbon atoms along dislocation cell boundaries was observed in the ferrite. At a shear strain of 300, only few nanoscaled off-stoichiometry cementite particles remain and a nanoscaled equiaxed grain structure with a grain size of about 20 nm was revealed. 3D-AP data clearly point out a strong segregation of carbon atoms along grain boundaries. The influence of this carbon atom segregation on the nanostructure formation is discussed and a scenario accounting for the nanocrystallisation during severe plastic deformation is proposed.
Concentration of the ratio between the geometric and arithmetic means
Creators: name: Aldaz, J. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Metric Geometry (math.MG)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 26D15, 60D05

description: We explore the concentration properties of the ratio between the geometric mean and the arithmetic mean, showing that for certain sequences of weights one does obtain concentration, around a value that depends on the sequence.
description: 10 pages
Age constraints in the double pulsar system J0737-3039
Creators: name: Lorimer, D. R.
name: Freire, P. C. C.
name: Stairs, I. H.
name: Kramer, M.
name: McLaughlin, M. A.
name: Burgay, M.
name: Thorsett, S. E.
name: Dewey, R. J.
name: Lyne, A. G.
name: Manchester, R. N.
name: D'Amico, N.
name: Possenti, A.
name: Joshi, B. C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the age constraints that can be placed on the double pulsar system using models for the spin-down of the first-born 22.7-ms pulsar A and the 2.77-s pulsar B with characteristic ages of 210 and 50 Myr respectively. Standard models assuming dipolar spin-down of both pulsars suggest that the time since the formation of B is ~50 Myr, i.e. close to B's characteristic age. However, adopting models which account for the impact of A's relativistic wind on B's spin-down we find that the formation of B took place either 80 or 180 Myr ago, depending the interaction mechanism. Formation 80 Myr ago, closer to B's characteristic age, would result in the contribution from J0737-3039 to the inferred coalescence rates for double neutron star binaries increasing by 40%. The 180 Myr age is closer to A's characteristic age and would be consistent with the most recent estimates of the coalescence rate. The new age constraints do not significantly impact recent estimates of the kick velocity, tilt angle between pre and post-supernova orbital planes or pre-supernova mass of B's progenitor.
description: 5 pages, 2 figures, 1 table, accepted for publication by MNRAS
The $J$-matrix inverse scattering approach for coupled channels with different thresholds
Creators: name: Zaytsev, S. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The inverse scattering method within the $J$-matrix approach to the two coupled-channel problem is discussed. We propose a generalization of the procedure to the case with different thresholds.
description: 20 pages, 3 figures
A new symmetric linearly implicit exponential integrator preserving polynomial invariants or Lyapunov functions for conservative or dissipative systems
Creators: name: Li, Lu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We present a new linearly implicit exponential integrator that preserves the polynomial first integrals or Lyapunov functions for the conservative and dissipative stiff equations, respectively. The method is tested by both oscillated ordinary differential equations and partial differential equations, e.g., an averaged system in wind-induced oscillation, the Fermi-Pasta-Ulam systems, and the polynomial pendulum oscillators. The numerical simulations confirm the conservative properties of the proposed method and demonstrate its good behavior in superior running speed when compared with fully implicit schemes for long-time simulations.
Sol-Ion PV Storage System: Field Trial Results, Spread of Operating Conditions and Performance Evaluation Based on Field Data
Creators: name: Binder, J.
name: Mohring, H.-D.
name: Danzer, M.
name: Schanz, O.
name: Schmiegel, A.U.
name: Linhart, A.
name: Landau, M.
name: Von Appen, J.
name: Niedermeyer, F.
name: Braun, M.
name: Magnor, D.
name: Sauer, D.U.
name: Schuh, H.
name: Thomas, U.
name: Martin, N.
name: Marcel, J.C.
name: Jehoulet, C.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
Large PV Power Plants and Distributed PV: System Aspects and Grid Connection

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3829-3833
description: The French-German Research Project “Sol-ion” has developed a PV storage system based on Li-Ion
batteries. The paper provides an update on the field test results up to August 2012. The data is analyzed with respect
to the parameters critical to the economics of the system and with respect to non-monetary values provided by local
self-sufficiency (autonomy) and back-up capability in case of grid failure. A black-box approach is proposed and
applied to calculate the efficiency of the PV storage system during operation from logged traces of PV energy fed
into the system and energy delivered from the system. Benefit of this approach is to allow collection performance
parameters of PV storage systems from field data, without need for measurements at internal interfaces.
The Zebra Cell Concept - Large Area n-Type Interdigitated Back Contact Solar Cells and One-Cell Modules Fabricated Using Standard Industrial Processing Equipment
Creators: name: Halm, A.
name: Mihailetchi, V.D.
name: Galbiati, G.
name: Koduvelikulathu, L.J.
name: Roescu, R.
name: Comparotto, C.
name: Kopecek, R.
name: Peter, K.
name: Libal, J.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Improvements

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 567-570
description: In this paper we present relevant characteristics of our Zebra cells and one-cell modules. The Zebra cell
is an interdigitated back contact (IBC) solar cell produced at ISC Konstanz using only industrially proven
technologies and standard industrial size 156x156mm² n-type Cz wafers. Wafers of different suppliers have been
evaluated. The best efficiencies achieved so far on a batch of 21 wafers are 21% average (champion cell: 21.3%).
Reverse bias electroluminescence (ReBEL) measurements reveal the unique breakdown behavior of the Zebra cell.
Due to its alternating p+n+ regions on the rear, a homogenous breakdown along the parallel junctions is observed
which does not lead to local shunting. The Zebra cell can be stringed using standard soldering or bonding with
conductive adhesives. Cell to module losses are comparable to standard p-type Al BSF cells. Due to its open rear side
structure, the Zebra cell is bifacial. When testing one-cell modules with transparent and black backsheet outdoors our
measurements show an average rise in power output of 13% relative for the bifacial module compared to its
monofacial reference.
Nanostructure and properties of a Cu-Cr composite processed by severe plastic deformation
Creators: name: Sauvage, Xavier
name: Jessner, Peter
name: Vurpillot, François
name: Pippan, Reinhard
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A Cu-Cr composite was processed by severe plastic deformation to investigate the role of interphase boundaries on the grain size reduction mechanisms. The as-deformed material exhibits a grain size of only 20nm. This gives rise to a dramatic increase of the hardness. Some deformation induced Cu super saturated solid solutions were clearly exhibited and it is shown that they decrease the hardness. The formation of such supersaturated solid solution and their influence on the mechanical properties are discussed.
Investigation of Electrical Properties in Monocast Si Wafer
Creators: name: Liao, Y.-C.
name: Chen, M.-Y.
name: Wu, Y.-C.
name: Huang, H.-H.
name: Huang, P.-S.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Feedstock, Crystallisation and Wafering

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 763-765
description: Wafer quality of multi-crystalline (mc-Si) and mono-crystalline (c-Si) region within the monocast Si
wafer are investigated in this work. C-Si region shows higher internal quantum efficiency in infrared region, which
means better wafer quality. However, it is not easy to predict cell performance by the area of c-Si since c-Si region
might contain crystal defect invisible to naked eyes but could be identified by photoluminescence (PL) technique.
Crystal defect affects the cell efficiency especially on Voc and Jsc whereas wafers from different positions of the
ingot, like multi-Si, also influence the performance of monocast Si wafers. Not only the ratio of c-Si region, but the
positions of the ingot and crystal defect information of monocast wafers are necessary to be realized on cell
performance.
Microscopic processes during ultra-fast laser generation of Frenkel defects in diamond
Creators: name: Griffiths, Benjamin
name: Kirkpatrick, Andrew
name: Nicley, Shannon S.
name: Patel, Rajesh L.
name: Zajac, Joanna M.
name: Morley, Gavin W.
name: Booth, Martin J.
name: Salter, Patrick S.
name: Smith, Jason M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Engineering single atomic defects into wide bandgap materials has become an attractive field in recent years due to emerging applications such as solid-state quantum bits and sensors. The simplest atomic-scale defect is the lattice vacancy which is often a constituent part of more complex defects such as the nitrogen-vacancy (NV) centre in diamond, therefore an understanding of the formation mechanisms and precision engineering of vacancies is desirable. We present a theoretical and experimental study into the ultra-fast laser generation of vacancy-interstitial pairs (Frenkel defects) in diamond. The process is described by a set of coupled rate equations of the pulsed laser interaction with the material and of the non-equilibrium dynamics of charge carriers during and in the wake of the pulse. We find that a model for Frenkel defect generation via the recombination of a bound biexciton as the electron plasma cools provides good agreement with experimental data, reproducing an effective non-linearity of $\sim$ 40 for Frenkel defect generation with respect to laser pulse energy.
description: 17 pages, 11 figures
Increasing PV Self-Consumption, Domestic Energy Autonomy and Grid Compatibility of PV Systems Using Heat-Pumps, Thermal Storage and Battery Storage
Creators: name: Binder, J.
name: Williams, C.O.
name: Kelm, T.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
Large PV Power Plants and Distributed PV: System Aspects and Grid Connection

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 4030-4034
description: Self-consumption of locally generated electricity from domestic PV Systems is limited to 25-35% in
Central Europe due to lack of synchronization between generation and load [1]. Adding heat-pumps and thermal
storage provide efficient means to shift loads in time and thereby increase levels of self-consumption and local
autonomy. The paper analyses these effects for different building standards. The listed self-consumption and
autonomy levels are a result of simulations that involve analysis of the time-series of solar radiation, outside
temperature, hot water demand and electricity demand for a whole year. Battery storage is added to complete the
picture. Finally storage-control algorithms are proposed and simulated, which allow reduction of the peak injection
into the grid to as low as 70% of the nominal peak-output power of the installed domestic PV system.
Cooling a mechanical resonator via coupling to a tunable double quantum dot
Creators: name: Ouyang, Shi-Hua
name: You, J. Q.
name: Nori, Franco
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the cooling of a mechanical resonator (MR) that is capacitively coupled to a double quantum dot (DQD). The MR is cooled by the dynamical backaction induced by the capacitive coupling between the DQD and the MR. The DQD is excited by a microwave field and afterwards a tunneling event results in the decay of the excited state of the DQD. An important advantage of this system is that both the energy level splitting and the decay rate of the DQD can be well tuned by varying the gate voltage. We find that the steady average occupancy, below unity, of the MR can be achieved by changing both the decay rate of the excited state and the detuning between the transition frequency of the DQD and the microwave frequency, in analogy to the laser sideband cooling of an atom or trapped ion in atomic physics. Our results show that the cooling of the MR to the ground state is experimentally implementable.
description: 10 pages, 5 figures