cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spontaneous Electron Emission Versus Dissociation in Internally Hot Silver Dimer Anions
Creators: name: Jasik, Patryk
name: Franz, Jan
name: Kędziera, Dariusz
name: Kilich, Tymon
name: Kozicki, Jan
name: Sienkiewicz, Józef E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Referring to a recent experiment, we theoretically study the process of a two-channel decay of the diatomic silver anion (Ag$_2^-$), namely the spontaneous electron ejection giving Ag$_2$ + e$^-$ and the dissociation leading to Ag$^-$ + Ag. The ground state potential energy curves of the silver molecules of diatomic neutral and negative ion were calculated using proper pseudo-potentials and atomic basis sets. We also estimated the non-adiabatic electronic coupling between the ground state of Ag$_2^-$ and the ground state of Ag$_2$ + e$^-$, which in turn allowed us to estimate the minimal and mean values of the electron autodetachment lifetimes. The relative energies of the rovibrational levels allow the description of the spontaneous electron emission process, while the description of the rotational dissociation is treated with the quantum dynamics method as well as time-independent methods. The results of our calculations are verified by comparison with experimental data.
description: The data that support the findings of this study are openly available in MOST Wiedzy at https://mostwiedzy.pl/en/open-research-data-series/niema,202103311024423091181-0/catalog
Durchdringungswiderstand und Trockenrohdichte
Creators: name: Domsch, Horst
Publisher: name: LANDTECHNIK
Year: 1998

description: Praxis und Wissenschaft sind seit Langem bemüht, den notwendigen Aufwand für die Bodenbearbeitung anhand von Richtwerten für den Gefügezustand abzuleiten. Diesem Vorhaben stehen die Schwierigkeiten einer Bestimmung des Gefügezustandes auf einer Ackerfläche entgegen.
description: LANDTECHNIK, Bd. 53 Nr. 2 (1998)
Do we Live in a "Small Universe"?
Creators: name: Aurich, Ralf
name: Janzer, Holger S.
name: Lustig, Sven
name: Steiner, Frank
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We compute the effects of a compact flat universe on the angular correlation function, the angular power spectrum, the circles-in-the-sky signature, and the covariance matrix of the spherical harmonics coefficients of the cosmic microwave background radiation using the full Boltzmann physics. Our analysis shows that the Wilkinson Microwave Anisotropy Probe (WMAP) three-year data are well compatible with the possibility that we live in a flat 3-torus with volume ~5x10^3 Gpc^3.
Flächenbonitur mit dem Horizontalpenetrometer
Creators: name: Weißbach, Michael
Publisher: name: LANDTECHNIK
Year: 1998

description: Das Horizontalpenetrometer ermöglicht es, Flächen in kurzer Zeit zu bonitieren und anhand der Korrelation von Lagerungsdichte und Bodenfestigkeit die Dichteinhomogenität des Bodens zu erfassen. Messverfahren mit punktartiger diskreter Messwerterfassung schließen eine Bonitur großer Flächen aufgrund des erforderlichen Stichprobenumfanges mit vertretbarem Aufwand aus.
description: LANDTECHNIK, Bd. 53 Nr. 2 (1998)
Controlling Luttinger liquid physics in spin ladders under a magnetic field
Creators: name: Klanjsek, M.
name: Mayaffre, H.
name: Berthier, C.
name: Horvatic, M.
name: Chiari, B.
name: Piovesana, O.
name: Bouillot, P.
name: Kollath, C.
name: Orignac, E.
name: Citro, R.
name: Giamarchi, T.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a 14N nuclear magnetic resonance study of a single crystal of CuBr4(C5H12N)2 (BPCB) consisting of weakly coupled spin-1/2 Heisenberg antiferromagnetic ladders. Treating ladders in the gapless phase as Luttinger liquids, we are able to fully account for (i) the magnetic field dependence of the nuclear spin-lattice relaxation rate 1/T_1 at 250 mK and for (ii) the phase transition to a 3D ordered phase occuring below 110 mK due to weak interladder exchange coupling. BPCB is thus an excellent model system where the possibility to control Luttinger liquid parameters in a continuous manner is demonstrated and Luttinger liquid model tested in detail over the whole fermion band.
description: 4 pages, 3 figures, introduction and conclusion rewritten, published version
Qualitativer Vergleich von NH3- Betriebsmesstechniken
Creators: name: Stegbauer, Barbara
name: Grotz, Stefan Neser Und Walter
name: Gronauer, Andreas
name: Schön, Hans
Publisher: name: LANDTECHNIK
Year: 1998

description: Der Einsatz von NH3-Messgeräten bei Dauermessungen in Ställen und die Vergleichbarkeit der Messergebnisse zu anderen Messungen erfordern die Überprüfung der Messgeräte hinsichtlich wichtiger messtechnischer Parameter. Überprüft wurden am Beispiel eines Legehennenstalles/Bodenhaltung drei verschiedene NH3-Betriebsmessgeräte nach dem Prinzip der Photoakustischen Infrarot-Spektroskopie PAS und des elektrochemischen Sensors ECS auf der Grundlage der VDI 2449, DIN ISO 6879und DIN ISO 8158 in Laborüberprüfungen und Dauermessungen.
description: LANDTECHNIK, Bd. 53 Nr. 2 (1998)
Mulch- und Direktsaat
Creators: name: Papesch, Josef
name: Steinert, Konrad
Publisher: name: LANDTECHNIK
Year: 1998

description: Probleme der Mulch- und Direktsaat, die zu einem verminderten Pflanzenaufgang bei Mais und Zuckerrüben führen, sind vor allem die erhöhte Bodenfestigkeit und damit die Einhaltung der Ablagetiefe, ein unbefriedigendes Räumen oder Schneiden der Mulchauflage, wodurch der Kontakt zwischen Saatgut und feuchteführendem Rillengrund erschwert wird, sowie die ungenügende Bedeckung des Saatgutes. Hohe Schardrücke können zu Schadverdichtungen und damit zur Beeinträchtigung der Pflanzenentwicklung führen.
description: LANDTECHNIK, Bd. 53 Nr. 2 (1998)
Pflugverzicht bei Zuckerrüben
Creators: name: Becker, Clemens
name: Lücke, Wolfgang
Publisher: name: LANDTECHNIK
Year: 1998

description: An neun Standorten Süd- und Ostdeutschlands wurden in einem Feldversuch vier Bodenbearbeitungssysteme mehrjährig auf ihre Eignung für den Zuckerrübenanbau geprüft. Die Ergebnisse zeigten, dass zwischen der Bearbeitung mit Pflug oder ohne Pflug im Mittel kein Unterschied im bereinigten Zuckerertrag bestand. Lediglich bei langjähriger Direktsaat fiel der bereinigte Zuckerertrag deutlich ab. Die Rübenqualität unterschied sich bei differenzierter Bodenbearbeitung nicht. Die variablen Kosten zeigten ebenfalls keine Veränderung. Niedrigere fixe Maschinen- und Arbeitskosten bei pflugloser Bearbeitung und Direktsaat hatten kaum Einfluss auf die Wirtschaftlichkeit.
description: LANDTECHNIK, Bd. 53 Nr. 2 (1998)
Arbeitsbewegungen erkennen und optimieren
Creators: name: Thomas, Jens
Publisher: name: LANDTECHNIK
Year: 1998

description: Zur dreidimensionalen Aufnahme, Darstellung und Auswertung von Arbeitsbewegungen wurde eine bildanalytische Methode weiterentwickelt und angepasst. Das System kombiniert ein digitales Verfahren zur Aufzeichnung von 3D-Bewegungsspuren und -daten in Echtzeit mit herkömmlicher Videotechnik. Verdeckte Mängel an Mensch-Maschine-Schnittstellen und bei der Arbeitsablaufgestaltung können aufgedeckt werden. Vorgestellt werden die systemtechnischen Eigenschaften der Anlage und deren Einsatz am Beispiel der Beschickung einer Porree-Aufbereitungsmaschine.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
Quadrupole radiation and $e^+e^-$ pair production in the collision of nonrelativistic nuclei
Creators: name: Obraztsov, I. V.
name: Milstein, A. I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We analyze the one-photon mechanism of $e^+e^-$ pair production in the collision of nonrelativistic nuclei. The contribution of electric quadrupole radiation of virtual photon to the corresponding cross section is found. The effect of the finite nuclear size is considered in detail. A comparison is made with the contribution of electric dipole radiation of virtual photon and with the contribution of the two-photon pair production mechanism. It is shown that the contribution of electric quadrupole radiation is dominant in a wide range of relative velocities. The cross section for the production of $e^+e^-$ pair with the capture of an electron by one of the nuclei is also analyzed.
description: 7 pages, 2 figues
Di-Higgs and tri-Higgs boson signals of muon $g-2$ at a muon collider
Creators: name: Dermisek, Radovan
name: Hermanek, Keith
name: McGinnis, Navin
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show that new physics explanations of the muon $g-2$ anomaly by the contributions of new leptons mediated by the standard model Higgs boson necessarily lead to large rates for $μ^+ μ^- \to hh$ and $μ^+ μ^- \to hhh$ irrespectively of details of the model or the scale of new physics. For new leptons with the same quantum numbers as the standard model leptons, cross sections are expected to be about 240 ab for $μ^+ μ^- \to hh$ independently of the center of mass energy, $\sqrt{s}$, and about 2.7 ab for $μ^+ μ^- \to hhh$ for $\sqrt{s} = 1$ TeV and growing quadratically with $\sqrt{s}$. Predictions for models featuring new leptons with different quantum numbers and for a type-II two Higgs doublet model, where additional Higgs bosons can contribute to muon $g-2$, are also presented.
description: 4 pages + references, 4 figures. v2: minor additions to text and added appendix to match published version
Mean Field Spin Glass in the Observable Representation
Creators: name: Schulman, L. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The state space for the $N$-spin mean field (SK) spin glass--nominally an $N$-cube--is embedded in a low dimensional continuous space in such a way that metastable and stable phases can easily be discerned, a concept of nearness of configurations defined, and peaks in the Parisi $q$-parameter overlap distribution identified. The dynamical and partly hierarchical interrelation of these phases can be directly imaged.
description: To appear in Phys. Rev. Lett
On the origin of spectral states in accreting black holes
Creators: name: Poutanen, Juri
name: Vurm, Indrek
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The origin of dramatically different electron distributions responsible for Comptonization in black hole X-ray binaries (BHBs) in their various states is discussed. We solve the coupled kinetic equations for photons and electrons without approximations on the relevant cross-sections accounting for Compton scattering, synchrotron radiation, and Coulomb collisions. In the absence of external soft photons, the electrons are efficiently thermalized by synchrotron self-absorption and Coulomb scattering even for pure nonthermal electron injection. The resulting quasi-thermal synchrotron self-Compton spectra have very stable slopes and electron temperatures similar to the hard states of BHBs. The hard spectral slopes observed in the X-rays, the cutoff at 100 keV, and the MeV tail together require low magnetic fields ruling out the magnetic dissipation mechanism. The motion of the accretion disk toward the black hole results in larger Compton cooling and lower equilibrium electron temperature. Our self-consistent simulations show that in this case both electron and photon distributions attain a power-law-dominated shape similar to what is observed in the soft state. The electron distribution in the Cyg X-1 soft state might require a strong magnetic field, being consistent with the magnetically dominated corona.
description: 4 pages, 2 figures; version published in ApJ Letters
Bremsstrahlung emission during $α$-decay of $^{226}{\rm Ra}$
Creators: name: Giardina, Giorgio
name: Fazio, Giovanni
name: Mandaglio, Giuseppe
name: Manganaro, Marina
name: Maydanyuk, Serghei P.
name: Olkhovsky, Vladislav S.
name: Eremin, Nikolay V.
name: Paskhalov, Anton A.
name: Smirnov, Dmitry A.
name: Sacca, Carmelo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We obtained the spectrum of probability of the bremsstrahlung emission accompanying the $α$-decay of $^{226}{\rm Ra}$ (E$_α$=4.8 MeV) by measuring the $α$-$γ$ coincidences and using the model presented in our previous study on the $α-$decay of $^{214}{\rm Po}$ (E$_α$=7.7 MeV). We compare the experimental data with the quantum mechanical calculation and find a good agreement between theory and experiment. We discuss the differences between the photon spectra connected with the $α$-decay of the $^{226}{\rm Ra}$ and $^{214}{\rm Po}$ nuclei. For the two mentioned nuclei we analyze the bremsstrahlung emission contributions from the tunneling and external regions of the nucleus barrier into the total spectrum, and we find the destructive interference between these contributions. We also find that the emission of photons during tunneling of the $α$-particle gives an important contribution to the bremsstrahlung spectrum in the whole E$_γ$ energy range of the studied $^{226}$Ra nucleus.
A fuzzy Multi-Criteria Decision Making approach for Exo-Planetary Habitability
Creators: name: Sánchez-Lozano, Juan Miguel
name: Moya, Andrés
name: Rodríguez-Mozos, José María
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Nowadays, we know thousands of exoplanets, some of them potentially habitable. Next technological facilities (JWST, for example) have exoplanet atmosphere analysis capabilities, but they also have limits in terms of how many targets can be studied. Therefore, there is a need to rank and prioritize these exoplanets with the aim of searching for biomarkers. Some criteria involved, such as the habitability potential of a dry-rock planet versus a water-rich planet, or a potentially-locked planet versus a tidally-locked planet, are often vague and the use of the fuzzy set theory is advisable. We have applied a combination of Multi-Criteria Decision-Making methodologies with fuzzy logic, the Fuzzy Reference Ideal Method (FRIM), to this problem. We have analyzed the habitability potential of 1798 exoplanets from TEPCat database based on a set of criteria (composition, atmosphere, energy, tidal locking, type of planet and liquid water), in terms of their similarity to the only ideal alternative, The Earth. Our results, when compared with the probability index SEPHI, indicate that Kepler-442b, Kepler-062e/f, and LHS_1140b are the best exoplanets for searching for biomarkers, regardless its technical difficulty. If we take into account current technical feasibility, the best candidate is TRAPPIST-1e.
Characteristic Scales of Baryon Acoustic Oscillations from Perturbation Theory: Non-linearity and Redshift-Space Distortion Effects
Creators: name: Nishimichi, Takahiro
name: Ohmuro, Hiroshi
name: Nakamichi, Masashi
name: Taruya, Atsushi
name: Yahata, Kazuhiro
name: Shirata, Akihito
name: Saito, Shun
name: Nomura, Hidenori
name: Yamamoto, Kazuhiro
name: Suto, Yasushi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: An acoustic oscillation of the primeval photon-baryon fluid around the decoupling time imprints a characteristic scale in the galaxy distribution today, known as the baryon acoustic oscillation (BAO) scale. Several on-going and/or future galaxy surveys aim at detecting and precisely determining the BAO scale so as to trace the expansion history of the universe. We consider nonlinear and redshift-space distortion effects on the shifts of the BAO scale in $k$-space using perturbation theory. The resulting shifts are indeed sensitive to different choices of the definition of the BAO scale, which needs to be kept in mind in the data analysis. We present a toy model to explain the physical behavior of the shifts. We find that the BAO scale defined as in Percival et al. (2007) indeed shows very small shifts ($\lesssim$ 1%) relative to the prediction in {\it linear theory} in real space. The shifts can be predicted accurately for scales where the perturbation theory is reliable.
description: 21 pages, 9 figures, references and supplementary sections added, accepted for publication in PASJ
Roles of the quark field in the infrared lattice Coulomb gauge and Landau gauge QCD
Creators: name: Furui, Sadataka
name: Nakajima, Hideo
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The effective coupling of QCD is measured by using the gauge configurations produced by the MILC collaboration in which the Kogut Susskind (KS) fermion is incorporated and by using that produced by the QCDOC collaboration in which the domain wall fermion (DWF) is incorporated. We fix the gauge to the Landau gauge and to the Coulomb gauge. The infrared effective coupling in the Coulomb gauge agrees with the recent extraction at JLab, but that in the Landau gauge shows infrared suppression. The suppression is expected to be due to the color anti-symmetric ghost propagator which in the unquenched configurations has stronger infrared singularity than the color diagonal ghost propagator. The Coulomb form factor in the infrared depends on the kind of the fermion incorporated in the system and the temperature. The quark has the effect of quenching randomness and the fluctuation of the color anti-symmetric ghost propagator is reduced in the unquenched configuration, and the Kugo-Ojima parameter c is closer to 1 in the unquenched configuration than in the quenched configuration.
description: 7 pages, 9 figures, Lattice2007 proceedings (use PoS.cls)
A spectral synthesis method to suppress aliasing and calibrate for delay errors in Fourier transform correlators
Creators: name: Kaneko, Tak
name: Grainge, Keith
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Context: Fourier transform (or lag) correlators in radio interferometers can serve as an efficient means of synthesising spectral channels. However aliasing corrupts the edge channels so they usually have to be excluded from the data set. In systems with around 10 channels, the loss in sensitivity can be significant. In addition, the low level of residual aliasing in the remaining channels may cause systematic errors. Moreover, delay errors have been widely reported in implementations of broadband analogue correlators and simulations have shown that delay errors exasperate the effects of aliasing. Aims: We describe a software-based approach that suppresses aliasing by oversampling the cross-correlation function. This method can be applied to interferometers with individually-tracking antennas equipped with a discrete path compensator system. It is based on the well-known property of interferometers where the drift scan response is the Fourier transform of the source's band-limited spectrum. Methods: In this paper, we simulate a single baseline interferometer, both for a real and a complex correlator. Fringe-rotation usually compensates for the phase of the fringes to bring the phase centre in line with the tracking centre. Instead, a modified fringe-rotation is applied. This enables an oversampled cross-correlation function to be reconstructed by gathering successive time samples. Results: Simulations show that the oversampling method can synthesise the cross-power spectrum while avoiding aliasing and works robustly in the presence of noise. An important side benefit is that it naturally accounts for delay errors in the correlator and the resulting spectral channels are regularly gridded.
description: 10 pages, 8 figures, accepted for publication in A&A
Strong coupling and active cooling in a finite temperature hybrid atom-cavity system
Creators: name: Keary, Lindsey F.
name: Pritchard, Jonathan D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: For a standard two-level atom coupled to the quantized field of a resonant cavity, finite temperature effects lead to thermal occupation of the cavity modes that obfuscates measurement of the quantum nature of the atom-light interaction. In this paper we demonstrate that using a hybrid system of a superconducting cavity coupled to a multi-level Rydberg atom it is possible to observe the quantum nature of strong coupling even at finite temperatures, and to exploit this coupling to permit cooling of the thermal microwave mode towards the ground-state, enabling observation of coherent vacuum Rabi oscillations even at 4~K for realistic experimental parameters. Cooling for multiple atoms is also explored, showing maximal cooling for small samples, making this a viable approach to cavity cooling with potential applications in long-range coupling of superconducting qubits via thermal waveguides.
description: 6 pages, 7 figures
Resistivity peak values at transition between fractional quantum Hall states
Creators: name: Murzin, S. S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Experimental data available in the literature for peak values of the diagonal resistivity in the transitions between fractional quantum Hall states are compared with the theoretical predictions. It is found that the majority of the peak values are close to the theoretical values for two-dimensional systems with moderate mobilities.
description: 3 pages, 1 figure
A $k\cdot p$ effective Hamiltonian generator
Creators: name: Jiang, Yi
name: Fang, Zhong
name: Fang, Chen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: $k\cdot p$ effective Hamiltonian is important for theoretical analysis in condensed matter physics. Based on the 'kdotp-symmetry' package, we develop an upgraded package named 'kdotp-generator'. This generator takes in arbitrary magnetic symmetries with their representations and returns symmetry-allowed $k\cdot p$ Hamiltonians. Using this package, we calculate $k\cdot p$ Hamiltonians for irreducible corepresentations in 1651 magnetic space groups up to the third order, and their linear coupling to external fields including the electromagnetic field and the strain tensor. We hope that the package will facilitate related research in the future.
description: 6 pages, 1 figure
HI Clouds detected towards Virgo with the Arecibo Legacy Fast ALFA Survey
Creators: name: Kent, Brian R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The Arecibo Legacy Fast ALFA survey is in the process of yielding a complete HI dataset of the Virgo Cluster and its environs (Giovanelli et al. 2007, Kent et al., in preparation). Assuming a distance to Virgo of 16.7 Mpc, the minimum detectable HI mass by ALFALFA is of order 2 x 10^7 Msun. A number of the HI detections appear to have interesting properties. Some appear associated with, but offset from, low surface brightness optical counterparts; others, at larger spatial offsets, may be tidally related to optical counterparts. Yet another class includes detections which are not identifiable with any optical counterparts. We present the ALFALFA results on these objects in the Virgo region, as well as followup aperture synthesis observations obtained with the VLA.
description: To appear in Proceedings of IAU Symp #244, "Dark Galaxies and Lost Baryons", June 2007, 10 pages including 7 figures and 1 table
Increase of YBa2Cu3O7 critical currents by Mo substitution and high pressure oxygen annealing
Creators: name: Los, Anton
name: Dabrowski, Bogdan
name: Rogacki, Krzysztof
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We have previously shown for powders that Mo substitution into the CuO chains of YBa2Cu3O7 can create effective pinning centres which significantly increase the critical current density (j_c) in 7 T field by a factor of 4 and 10 at 50 and 60 K, respectively. The present work reports on the influence of the Mo substitution and high-pressure oxygen annealing on the pinning properties and critical currents of YBa_2Cu_{3-x}Mo_xO_{7-d} by comparing pure (x = 0, d > 0) and substituted (x = 0.03, d < 0) single crystals. Pinning properties have been investigated by measurements of magnetization loops and calculations of j_c in the ab-plane, in the temperature range from 2 to 90 K and in fields up to 14 T. Depending on the Mo substitution and the oxygen treatment, several types of pinning centres increasing j_c have been revealed and analysed in the frame of Dew-Hughes' and Kramer's models.
description: 17 pages, 9 figures, 39 references
Path Planning for Manipulation using Experience-driven Random Trees
Creators: name: Pairet, Èric
name: Chamzas, Constantinos
name: Petillot, Yvan
name: Kavraki, Lydia E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Robotic systems may frequently come across similar manipulation planning problems that result in similar motion plans. Instead of planning each problem from scratch, it is preferable to leverage previously computed motion plans, i.e., experiences, to ease the planning. Different approaches have been proposed to exploit prior information on novel task instances. These methods, however, rely on a vast repertoire of experiences and fail when none relates closely to the current problem. Thus, an open challenge is the ability to generalise prior experiences to task instances that do not necessarily resemble the prior. This work tackles the above challenge with the proposition that experiences are "decomposable" and "malleable", i.e., parts of an experience are suitable to relevantly explore the connectivity of the robot-task space even in non-experienced regions. Two new planners result from this insight: experience-driven random trees (ERT) and its bi-directional version ERTConnect. These planners adopt a tree sampling-based strategy that incrementally extracts and modulates parts of a single path experience to compose a valid motion plan. We demonstrate our method on task instances that significantly differ from the prior experiences, and compare with related state-of-the-art experience-based planners. While their repairing strategies fail to generalise priors of tens of experiences, our planner, with a single experience, significantly outperforms them in both success rate and planning time. Our planners are implemented and freely available in the Open Motion Planning Library.
description: IEEE Robotics and Automation Letters
Anpassung des Arbeitsvoranschlages an Klimazonen
Creators: name: Spieß, Barbara
name: Auernhammer, Hermann
Publisher: name: LANDTECHNIK
Year: 1998

description: Zur Optimierung der Auslastung von Maschinen und Arbeitskraft ist in der Außenwirtschaft eine Planung auf Wochenbasis nötig. Dazu wurde das Arbeitszeitkalkulationsprogramm APLAN unter besonderer Berücksichtigung des Wetterrisikos entwickelt. Es berücksichtigt die Klimaregioneinteilung des KTBL für die verfügbaren Zeiten von März bis November. Die Eingabe erfolgt in definierten Masken mit vorgegebenen Ausführungszeitpunkten der benötigten Arbeitsverfahren. Diese wurden für Bayern aus Schlagkarteiaufzeichnungen und aus den Wetterdaten des Bayerischen Agrarmeteorologischen Messnetzes abgeleitet.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
Emissionen von Ammoniak und Lachgas
Creators: name: Schürer, Elke
name: Reitz, Petra
Publisher: name: LANDTECHNIK
Year: 1998

description: Nach der Ausbringung von Flüssigmist kann ein Großteil des Stickstoffes in Form von umweltschädigendem Lachgas und Ammoniak verloren gehen. Zur effizienteren Nutzung des organischen Düngers auf Grünland sowie zur Emissionsminderung wurden Ausbringverfahren wie Schleppschuh und Schlitzdrill entwickelt. Durch eine bandförmige, bodennahe Ausbringung konnten die Ammoniakemissionen um 50 bis 75 % verringert werden. Demgegenüber hat eine vergleichende Untersuchung gezeigt, dass der Schlitzdrill mit bis zu 1170 µg/m2h N20-N die höchsten Lachgasemissionen bewirkt. Ob der Schleppschuh unter Berücksichtigung beider umweltschädigender Gase das geeignete Verfahren darstellt, war eine Fragestellung der Untersuchungen.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
Abdeckmaterialien für Lagerbehälter mit Schweinegülle im Test
Creators: name: Wanka, Ute
name: Köllitsch, Keine
name: Hörnig, Günter
name: Fleischer, Peter
Publisher: name: LANDTECHNIK
Year: 1998

description: Emissionsmindernde Maßnahmen durch Abdeckung von Gülleoberflächen in Lagerbehältern erfordern zusätzliche Kosten. Zu deren Minimierung bieten sich alternative Abdeckmaterialien an, von denen mehrere im Praxis- und Labormaßstab getestet wurden. Die Messung von Schadgas- und Geruchskonzentrationen stand im Mittelpunkt der Untersuchungen. Bei den schwimmenden Abdeckungen aus Stroh, Kunststoffgranulat und Rapsöl spielt aber auch ihre Stabilität nach mechanischen Beanspruchungen (Homogenisierung) eine wichtige Rolle. Es wurden hohe Minderungsraten bei den Schadgas- und Geruchsemissionen erreicht und Erkenntnisse über die zeitlich unterschiedliche Wiederbildung der Abdeckung nach Durchmischung gewonnen.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
Geruchs- und Spurengasemissionen eines Milchviehstalles
Creators: name: Brose, Gregor
name: Hartung, Eberhard
name: Jungbluth, Thomas
Publisher: name: LANDTECHNIK
Year: 1998

description: Die landwirtschaftliche Nutztierhaltung trägt erheblich zur Emission gasförmiger Schadstoffe NHJ, CH4, C02, N20 und Geruch in die Umwelt bei. Zur messtechnischen Quantifizierung der Emissionen aus einem frei belüfteten Milchviehstall wurden Messungen auf einem Praxisbetrieb durchgeführt. Es zeigt sich, dass die starken Schwankungen der Emissionen im tageszeitlichen Verlauf eine kontinuierliche Messung unerlässlich machen.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
Patrimoni destinati, tutela dei creditori ed insolvenza
Creators: name: Acerra, Ilaria
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2006

description: La tesi, dopo un’introduzione del fenomeno della separazione patrimoniale nell’ordinamento giuridico italiano, mira ad esaminarne un’ipotesi specifica data dai patrimoni destinati a specifici affati della riforma societaria (art. 2447-bis c.c. e seguenti) sotto il profilo della tutela dei creditori e dell’insolvenza  sia della società che ha costituito patrimoni destinati, sia dello stesso patrimonio destinato.
AMPPERE: A Universal Abstract Machine for Privacy-Preserving Entity Resolution Evaluation
Creators: name: Yao, Yixiang
name: Ghai, Tanmay
name: Ravi, Srivatsan
name: Szekely, Pedro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences
subject: E.3; F.1.1

description: Entity resolution is the task of identifying records in different datasets that refer to the same entity in the real world. In sensitive domains (e.g. financial accounts, hospital health records), entity resolution must meet privacy requirements to avoid revealing sensitive information such as personal identifiable information to untrusted parties. Existing solutions are either too algorithmically-specific or come with an implicit trade-off between accuracy of the computation, privacy, and run-time efficiency. We propose AMMPERE, an abstract computation model for performing universal privacy-preserving entity resolution. AMPPERE offers abstractions that encapsulate multiple algorithmic and platform-agnostic approaches using variants of Jaccard similarity to perform private data matching and entity resolution. Specifically, we show that two parties can perform entity resolution over their data, without leaking sensitive information. We rigorously compare and analyze the feasibility, performance overhead and privacy-preserving properties of these approaches on the Sharemind multi-party computation (MPC) platform as well as on PALISADE, a lattice-based homomorphic encryption library. The AMPPERE system demonstrates the efficacy of privacy-preserving entity resolution for real-world data while providing a precise characterization of the induced cost of preventing information leakage.
description: 10 pages, 6 figures, Published in CIKM '21; corrected title & fixed abstract formatting
Discovering Dense Correlated Subgraphs in Dynamic Networks
Creators: name: Preti, Giulia
name: Rozenshtein, Polina
name: Gionis, Aristides
name: Velegrakis, Yannis
Publisher: name: arXiv
Year: 2021
Subjects: subject: Social and Information Networks (cs.SI)
subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: Given a dynamic network, where edges appear and disappear over time, we are interested in finding sets of edges that have similar temporal behavior and form a dense subgraph. Formally, we define the problem as the enumeration of the maximal subgraphs that satisfy specific density and similarity thresholds. To measure the similarity of the temporal behavior, we use the correlation between the binary time series that represent the activity of the edges. For the density, we study two variants based on the average degree. For these problem variants we enumerate the maximal subgraphs and compute a compact subset of subgraphs that have limited overlap. We propose an approximate algorithm that scales well with the size of the network, while achieving a high accuracy. We evaluate our framework on both real and synthetic datasets. The results of the synthetic data demonstrate the high accuracy of the approximation and show the scalability of the framework.
description: Full version of the paper included in the proceedings of the PAKDD 2021 conference
Immutable quantized transport in Floquet chains
Creators: name: Höckendorf, Bastian
name: Alvermann, Andreas
name: Fehske, Holger
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show how quantized transport can be realized in Floquet chains through encapsulation of a chiral or helical shift. The resulting transport is immutable rather than topological in the sense that it neither requires a band gap nor is affected by arbitrarily strong perturbations. Transport is still characterized by topological quantities but encapsulation of the shift prevents topological phase transitions. To explore immutable transport we introduce the concept of a shiftbox, explain the relevant topological quantities both for momentum-space dispersions and real-space transport, and study model systems of Floquet chains with strictly quantized chiral and helical transport. Natural platforms for the experimental investigation of these scenarios are photonic Floquet chains constructed in waveguide arrays, as well as topolectrical or mechanical systems.
description: 5 pages plus a bit, 4 figures
title: Identification of Data Structure with Machine Learning: From Fisher to Bayesian networks
Creators: name: Casana Eslava, R
Publisher: name: Liverpool John Moores University
Year: 2019

description: This thesis proposes a theoretical framework to thoroughly analyse the structure of a dataset in terms of a) metric, b) density and c) feature associations. To look into the first aspect, Fisher's metric learning algorithms are the foundations of a novel manifold based on the information and complexity of a classification model. When looking at the density aspect, the Probabilistic Quantum clustering, a Bayesian version of the original Quantum Clustering is proposed. The clustering results will depend on local density variations, which is a desired feature when dealing with heteroscedastic data. To address the third aspect, the constraint-based PC-algorithm is the starting point of many structure learning algorithms, it is focused on finding feature associations by means of conditional independent tests. This is then used to select Bayesian networks, based on a regularized likelihood score. These three topics of data structure analysis were fully tested with synthetic data examples and real cases, which allowed us to unravel and discuss the advantages and limitations of these algorithms. One of the biggest challenges encountered was related to the application of these methods to a Big Data dataset that was analysed within the framework of a collaboration with a large UK retailer, where the interest was in the identification of the data structure underlying customer shopping baskets.
Thermal photon to dilepton ratio in ultra-relativistic heavy ion collisions
Creators: name: Nayak, Jajati K.
name: Alam, Jane
name: Sarkar, Sourav
name: Sinha, Bikash
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The ratio of transverse momentum distribution of thermal photons to dilepton has been evaluated. It is observed that this ratio reaches a plateau beyond a certain value of transverse momentum. We argue that this ratio can be used to estimate the initial temperature of the system by selecting the transverse momentum and invariance mass windows judiciously. It is demonstrated that if the radial flow is large then the plateau disappear and hence a deviation from the plateau can be used as an indicator of large radial flow. The sensitivity of the results on various input parameters has been studied.
description: 9 pages with 11 eps figures
Solare Trocknung von Nassschlämmen
Creators: name: Reuß, Manfred
name: Hainzlmeier, Franz
Publisher: name: LANDTECHNIK
Year: 1998

description: Die direkte solare Trocknung eröffnet physikalisch und ökonomisch interessante Anwendungen im landwirtschaftlichen und industriellen Bereich. Insbesondere bei Nassschlämmen stellt sie eine gute Möglichkeit zur Reduzierung der Masse dar. Das Trockenprodukt bei Gülle oder Klärschlamm weist eine Vielzahl verfahrenstechnischer und umweltrelevanter Vorteile auf. Im durchgeführten Forschungsvorhaben wurden die theoretischen Grundlagen der direkten solaren Trocknung erarbeitet und ein mathematisches Modell entwickelt, das die Simulation des Trocknungsprozesses ermöglicht. Die Modellierung wurde mit Messwerten einer Versuchsanlage überprüft, sie beschreibt den Trocknungsprozess sehr gut. Wegen der großen Effizienz und Vielzahl von Anwendungsmöglichkeiten wäre das Verfahren der direkten Solartrocknung für eine große Verbreitung geeignet.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
p-Symmetric fuzzy measures
Creators: name: Miranda, Pedro
name: Grabisch, Michel
name: Gil, Pedro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: In this paper we propose a generalization of the concept of symmetric fuzzy measure based in a decomposition of the universal set in what we have called subsets of indifference. Some properties of these measures are studied, as well as their Choquet integral. Finally, a degree of interaction between the subsets of indifference is defined.
I comunicatori di impresa. Logiche e poste in gioco di un nuovo campo professionale.
Creators: name: De Feo, Antonietta
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2010

description: Questo lavoro di ricerca, dopo aver richiamato l’importanza che la conoscenza assume nella società contemporanea, si concentra sui processi di professionalizzazione dei comunicatori d’impresa, sul loro percorso di costruzione, distinzione e riconoscimento sociale.
La chiave interpretativa del professionalismo, che riprende il dibattito interno alla sociologia delle professioni, è stata declinata nella ricerca utilizzando l’architettura concettuale di Pierre Bourdieu, che integra l’azione e la situazione nelle sue dimensioni più individuali e interattive con i contesti sociali e istituzionali più ampi.
La ricerca prende avvio da un’analisi della genesi del campo professionale della comunicazione d’impresa, in uno scenario in cui i processi legati alle trasformazioni tecnologiche e gestionali corrono insieme a quelle relazionali. La riflessione prosegue con lo studio della situazione di lavoro dei professionisti della comunicazione, ovvero delle relazioni sociali nelle quali il soggetto è immerso nel momento in cui svolge una specifica attività lavorativa e delle pratiche attraverso cui egli contribuisce a costruire e gestire tali relazioni. La base empirica è costituita da professionisti che operano in tre contesti organizzativi (una multinazionale e due agenzie di comunicazione) e come consulenti. La strategia cognitiva utilizzata per la rilevazione è quella dei racconti di vita e, nel quadro di un’ipotesi connessa al processo di professionalizzazione, le dimensioni indagate sono la base cognitiva, l’autonomia e l’ethos professionale. I risultati emersi sono stati approfonditi in rapporto a una visione d’insieme della professione, che prende in considerazione anche il ruolo svolto delle associazioni professionali nei processi di negoziazione finalizzati al controllo di questo specifico segmento del mercato del lavoro. Ciò che emerge dall’analisi è che le pratiche professionali si fondano su un insieme di competenze di base, di fondamenti conoscitivi interdisciplinari su cui prende origine una segmentazione delle expertise in rapporto al mercato e agli interessi economici organizzati.
Non esiste, pertanto, per i professionisti della comunicazione una giurisdizione già predefinita sull’assegnazione di determinate aree di intervento professionale, sia per la natura variabile e fluida delle conoscenze e sia in rapporto alla morfologia organizzativa dei settori nei quali operano. La relazione tra sapere e condizioni istituzionali della pratica spiegano poi la stessa frammentazione della dimensione associativa e delle strategie collettive di rappresentanza. Lo studio evidenzia che il progetto professionale del comunicatore di impresa è, in definitiva, ancora in via di strutturazione e di crescita.
Thermische Empfindlichkeit von Saatgut
Creators: name: Grothaus, Hans- Peter
Publisher: name: LANDTECHNIK
Year: 1998

description: Eine wirtschaftliche Trocknung von Körnerfrüchten sowie eine thermische Bekämpfung von samenbürtigen Schaderregern an Saatgut verlangt Kenntnisse über bestehende Temperatur, Feuchte Zeit-Wechselwirkungen. Aus empirisch gewonnenen Erkenntnissen lassen sich Schlussfolgerungen über Möglichkeiten und Grenzen einer qualitätserhaltenden thermischen Behandlung von Körnern ableiten.
description: LANDTECHNIK, Bd. 53 Nr. 1 (1998)
Applicazioni criobiologiche in acquacoltura e nella gestione delle risorse idrobiologiche
Creators: name: Vitiello, Valentina
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2010

description: Tra le scienze biotecnologiche riproduttive la crioconservazione, vale a dire lo stoccaggio di materiale biologico (gameti, embrioni, tessuti) a basse temperature (generalmente a –196°C) (Ashwood-Smith, 1980), con il ripristino, allo scongelamento, di tutti i parametri fisiologici caratteristici del materia vivente prima del congelamento, costituisce uno strumento essenziale per contrastare l'impoverimento genetico delle specie allevate, poiché permette programmi di incroci tra popolazioni e scambi internazionali di campioni. Inoltre, consente lo stoccaggio di gameti di organismi geneticamente selezionati, poi utilizzabili per campagne di fecondazione artificiale. Oggi, tecniche di criopreservazione per gameti animali domestici sono ampiamente conosciute ed applicate commercialmente (Fahning & Garcia, 1992).
La crioconservazione costituisce inoltre un importante strumento per la difesa della biodiversità, poiché permette la conservazione di germoplasma di specie rare ed, in tal senso, il suo utilizzo si sta estendendo negli ultimi anni anche al settore vegetale,  con l'istituzione di banche di semi e gemme vegetative (Ozden-Tokatli et al, 2010).
Anche la ricerca di base, infine, può usufruire dei vantaggi della crioconservazione, poiché tale biotecnologia consente il mantenimento in modo sicuro e poco dispendioso di linee genetiche modificate (Glenister & Thornton, 2000) e permette una disponibilità costante di stock qualitativamente omogenei di sistemi biologici modello (Paredes  & Bellas, 2010).
Tale lavoro sperimentale è stato finalizzato alle applicazioni della criopreservazione in ambito acquatico, per la messa a punto di protocolli di criopreservazione per spermatozoi di specie autoctone mediterranee emergenti per il settore acquacolturale, per la validazione delle produzioni in sistemi a ricircuitazione idrica (RAS) mediante l'utilizzo di protocolli già standardizzati, e per l'impiego di sistemi criopreservati in biosaggi innovativi per il monitoraggio ambientale.
Some Challenges in Monitoring Epidemics
Creators: name: Vasiliauskaite, Vaiva
name: Antulov-Fantulin, Nino
name: Helbing, Dirk
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Epidemic models often reflect characteristic features of infectious spreading processes by coupled non-linear differential equations considering different states of health (such as Susceptible, Infected, or Recovered). This compartmental modeling approach, however, delivers an incomplete picture of the dynamics of epidemics, as it neglects stochastic and network effects, and also the role of the measurement process, on which the estimation of epidemiological parameters and incidence values relies. In order to study the related issues, we extend established epidemiological spreading models with a model of the measurement (i.e. testing) process, considering the problems of false positives and false negatives as well as biased sampling. Studying a model-generated ground truth in conjunction with simulated observation processes (virtual measurements) allows one to gain insights into the limitations of purely data-driven methods to assess the epidemic situation. We conclude that epidemic monitoring, simulation, and forecasting are wicked problems, as applying a conventional data-driven approach to a complex system with non-linear dynamics, network effects, and uncertainty can be misleading. Nevertheless, some of the errors can be corrected for, using scientific knowledge of the spreading dynamics and the measurement process. We conclude that such corrections should generally be part of epidemic monitoring, modeling, and forecasting efforts.