cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Constraining mixing processes in stellar cores using asteroseismology. Impact of semiconvection in low-mass stars
Creators: name: Aguirre, V. Silva
name: Ballot, J.
name: Serenelli, A. M.
name: Weiss, A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The overall evolution of low-mass stars is heavily influenced by the processes occurring in the stellar interior. In particular, mixing processes in convectively unstable zones and overshooting regions affect the resulting observables and main sequence lifetime. We study the effects of different convective boundary definitions and mixing prescriptions in convective cores of low-mass stars, to discriminate the existence, size, and evolutionary stage of the central mixed zone by means of asteroseismology. We implemented the Ledoux criterion for convection in our stellar evolution code, together with a time-dependent diffusive approach for mixing of elements when semiconvective zones are present. We compared models with masses ranging from 1 M* to 2 M* computed with two different criteria for convective boundary definition and including different mixing prescriptions within and beyond the formal limits of the convective regions. Using calculations of adiabatic oscillations frequencies for a large set of models, we developed an asteroseismic diagnosis using only l=0 and l=1 modes based on the ratios of small to large separations r01 and r10 defined by Roxburgh & Vorontsov (2003). These variables are almost linear in the expected observable frequency range, and we show that their slope depends simultaneously on the central hydrogen content, the extent of the convective core, and the amplitude of the sound-speed discontinuity at the core boundary. By considering about 25 modes and an accuracy in the frequency determinations as expected from the CoRoT and Kepler missions, the technique we propose allows us to detect the presence of a convective core and to discriminate the different sizes of the homogeneously mixed central region without the need of a strong a priori for the stellar mass.
description: 13 pages, 9 figures, accepted for publication in A&A
Cancer evolution: A multifaceted affair.
Creators: name: Ciriello, Giovanni
name: Magnani, Luca
name: Aitken, Sarah J
name: Akkari, Leila
name: Behjati, Sam
name: Hanahan, Douglas
name: Landau, Dan A
name: Lopez-Bigas, Nuria
name: Lupiáñez, Darío G
name: Marine, Jean-Christophe
name: Martin-Villalba, Ana
name: Natoli, Gioacchino
name: Obenauf, Anna C
name: Oricchio, Elisa
name: Scaffidi, Paola
name: Sottoriva, Andrea
name: Swarbrick, Alexander
name: Tonon, Giovanni
name: Vanharanta, Sakari
name: Zuber, Johannes
Publisher: name: The Francis Crick Institute
Year: 2023
Subjects: classificationCode: Tumour Biology
subject: Tumour Biology
classificationCode: Stem Cells
subject: Stem Cells
classificationCode: Gene Expression
subject: Gene Expression
classificationCode: Genetics & Genomics
subject: Genetics & Genomics
classificationCode: Human Biology & Physiology
subject: Human Biology & Physiology
classificationCode: Cell Cycle & Chromosomes
subject: Cell Cycle & Chromosomes

description: UNLABELLED: Cancer cells adapt and survive through the acquisition and selection of molecular modifications. This process defines cancer evolution. Building on a theoretical framework based on heritable genetic changes has provided insights into the mechanisms supporting cancer evolution. However, cancer hallmarks also emerge via heritable nongenetic mechanisms, including epigenetic and chromatin topological changes, and interactions between tumor cells and the tumor microenvironment. Recent findings on tumor evolutionary mechanisms draw a multifaceted picture where heterogeneous forces interact and influence each other while shaping tumor progression. A comprehensive characterization of the cancer evolutionary toolkit is required to improve personalized medicine and biomarker discovery. SIGNIFICANCE: Tumor evolution is fueled by multiple enabling mechanisms. Importantly, genetic instability, epigenetic reprogramming, and interactions with the tumor microenvironment are neither alternative nor independent evolutionary mechanisms. As demonstrated by findings highlighted in this perspective, experimental and theoretical approaches must account for multiple evolutionary mechanisms and their interactions to ultimately understand, predict, and steer tumor evolution.
Electron-positron bremsstrahlung and pair creation in very high magnetic fields
Creators: name: Jones, P B
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Cross-sections for Rutherford scattering, Coulomb bremsstrahlung and pair creation, have been calculated at very high magnetic fields in order to investigate the photo-production of protons at the polar caps of pulsars whose spin is antiparallel with the polar magnetic flux density. The Landau-Pomeranchuk-Migdal effect at very high magnetic fields is included in a simple electron Green function.
description: 10 pages; to be published in Monthly Notices of the Royal Astronomical Society
Design and analysis of supply-noise-insensitive all-digital phase-locked loops
Creators: name: Yuan, Chen
Publisher: name: University of British Columbia
Year: 2020

description: Phase-locked loops (PLLs) are widely used in communication and digital systems to generate high frequency clocks by multiplying a low-frequency reference clock. Scaling of complementary metal-oxide-semiconductor (CMOS) technology over the last decade has benefitted digital circuits by shrinking their size and reducing their power consumption. On the other hand, it has posed challenges for analog design because of the decreasing power supply voltage and output impedance of transistors. Therefore, an all-digital PLL (ADPLL) becomes increasingly preferable over its conventional analog counterparts in terms of area and design flexibility. PLLs employ an oscillator locked to the phase and frequency of the reference clock. An LC oscillator utilizes an inductor (L) to filter noise, but on-chip inductors require large area and need specific thick metal layers for low loss. Compared to LC oscillators, ring oscillators are more suitable for ADPLL implementation since they occupy smaller area and are compatible to digital CMOS processes without a thick-metal layer option. However, the oscillation frequency of a ring oscillator is determined by the propagation delay of the delay-cells, and thereby very susceptible to power supply noise. In fully-integrated systems, switching of large-scale digital circuits can create large supply ripples and degrade the noise performance of the PLL output. Low dropout (LDO) regulators as well as some cancellation techniques have been adopted in prior-art to mitigate the supply sensitivity of ring-oscillator based ADPLLs. However, these techniques suffer from supply voltage headroom, noise penalty, and design complexity. In this thesis, a low-complexity supply-noise-insensitive ADPLL is proposed that does not degrade the supply voltage headroom, and operates over a wide range of supply-noise amplitude. Fabricated in a 65nm CMOS process, the ADPLL achieves ~ 45 mV of tunable supply-noise-insensitive range where the frequency pushing is less than 10%, operating at 850 mV supply. With the tuning range from 1 GHz to 1.4 GHz, the ADPLL achieves 16 ps integrated jitter at 1.25 GHz output frequency and consumes 2.73 mW of power.
Data Group Anonymity: General Approach
Creators: name: Chertov, Oleg
name: Tavrov, Dan
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: In the recent time, the problem of protecting privacy in statistical data before they are published has become a pressing one. Many reliable studies have been accomplished, and loads of solutions have been proposed. Though, all these researches take into consideration only the problem of protecting individual privacy, i.e., privacy of a single person, household, etc. In our previous articles, we addressed a completely new type of anonymity problems. We introduced a novel kind of anonymity to achieve in statistical data and called it group anonymity. In this paper, we aim at summarizing and generalizing our previous results, propose a complete mathematical description of how to provide group anonymity, and illustrate it with a couple of real-life examples.
description: 8 pages, 2 figures, 1 table. Published in International Journal of Computer Science and Information Security (http://sites.google.com/site/ijcsis/vol-8-no-7-oct-2010)
The efficiency of the noise barrier installed on the acoustically untreated gallery
Creators: name: Shasurin, Aleksandr
Publisher: name: Санкт-Петербургский политехнический университет Петра Великого
Year: 2018
Subjects: subject: noise barrier
subject: gallery
subject: noise in residential development
subject: acoustic efficiency
subject: шумозащитный экран
subject: галерея
subject: шум в жилой застройке
subject: акустическая эффективность

description: The research is targeting at multi-level overpasses which offer one of the solutions for laying the highway in conditions of dense residential development and close proximity to bedroom communities. In terms of acoustics, multi-level overpasses are semi-enclosed structures made of metal and reinforced concrete, where a complex sound field with numerous re-reflections is formed. There is no method of calculating noise from such structures in the literature of our country, therefore forecasting sound levels in the adjacent residential areas while designing noise mitigation measures is extremely challenging. The article proposes the method of calculating the efficiency of the noise barriers installed on the overpass edge based on the statistical theory of acoustics. The main assumption of the proposed model is the allocation of semi-closed volume in an acoustically untreated overpass and generation of a diffuse sound field in it, which is fundamentally different from the currently used methods for calculating the efficiency of the barriers installed in galleries as the barriers located in the open space, similar to motorways on the earth roadbed. When considering the diffuse field, the sound is not diffracted over the upper free edge of the barrier, but radiated outwards through the opening. According to the calculation results using the derived formulas, the efficiency of the barrier installed on the overpass does not exceed 2–6 dBA at its different heights, which corresponds to experimental results.
Transport properties of a shunted surface superlattice in an external magnetic field
Creators: name: Feil, Thomas
name: Gerl, Christian
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik
subject: 73.50.Fq, 75.70.Cn, 72.20.My, 73.50.Jt

description: We study the transport through a shunted surface superlattice system in the presence of an external magnetic field. Such a system consists of a weakly doped, instability free superlattice (shunt) that is overgrown on the edge with a two-dimensional electron system (surface superlattice). A magnetic field parallel to a static applied electric field along the superlattice axis induces current resonances in the shunt characteristics which are explained by Stark-cyclotron resonances. These resonances support the conclusion that the field alignment in the shunted surface superlattice structure is homogeneous. An increasing magnetic field perpendicular to the transport direction leads to characteristic crossings of the current-voltage characteristics of both shunt and surface superlattice. They are explained by a semiclassical model which assumes a competition between the magnetic and electric localization of the miniband electrons. We conclude that our structure indeed presents a domain free high density superlattice and might therefore be a promising candidate for the realization of an active electrically driven Bloch oscillator.
Momentum Resolved Optical Lattice Modulation Spectroscopy for Bose Hubbard Model
Creators: name: Sensarma, Rajdeep
name: Sengupta, K.
name: Sarma, S. Das
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We propose a new method of optical lattice modulation spectroscopy for studying the spectral function of ultracold bosons in an optical lattice. We show that different features of the single particle spectral function in different quantum phases can be obtained by measuring the change in momentum distribution after the modulation. In the Mott phase, this gives information about the momentun dependent gap to particle-hole excitations as well as their spectral weight. In the superfluid phase, one can obtain the spectrum of the gapless Bogoliubov quasiparticles as well as the gapped amplitude fluctuations. The distinct evolution of the response with modulation frequency in the two phases can be used to identify these phases and the quantum phase transition separating them.
description: 5 pages, 2 figures
Generic Conditions for Hydrodynamic Synchronization
Creators: name: Uchida, Nariya
name: Golestanian, Ramin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: Synchronization of actively oscillating organelles such as cilia and flagella facilitates self-propulsion of cells and pumping fluid in low Reynolds number environments. To understand the key mechanism behind synchronization induced by hydrodynamic interaction, we study a model of rigid-body rotors making fixed trajectories of arbitrary shape under driving forces that are arbitrary functions of the phases. For a wide class of geometries, we obtain the necessary and sufficient conditions for synchronization of a pair of rotors. We also find a novel synchronized pattern with a time-dependent phase shift. Our results shed light on the role of hydrodynamic interactions in biological systems, and could help in developing efficient mixing and transport strategies in microfluidic devices.
description: 4 pages, 3 figures
Non-adiabatic spin torque investigated using thermally activated magnetic domain wall dynamics
Creators: name: Eltschka, M.
name: Wötzel, M.
name: Rhensius, J.
name: Krzyk, S.
name: Nowak, U.
name: Kasama, M. Kläui. T.
name: Dunin-Borkowski, R. E.
name: Heyderman, L. J.
name: van Driel, H. J.
name: Duine, R. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Using transmission electron microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions in permalloy (Ni80Fe20) nanowires at room temperature. We show that this purely thermal motion is well described by an Arrhenius law, allowing for a description of the DW as a quasi-particle in a 1D potential landscape. By injecting small currents, the potential is modified, allowing for the determination of the non-adiabatic spin torque: the non-adiabatic coefficient is 0.010 +/- 0.004 for a transverse DW and 0.073 +/- 0.026 for a vortex DW. The larger value is attributed to the higher magnetization gradients present.
Standard GRB, Dirty Fireballs, and the Excluded Middle
Creators: name: Eichler, David
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: It is shown that the contribution of faint gamma-ray bursts (GRB) to the total allsky GRB energy flux is small. The allsky flux of GRB appears to be $5.3 \times 10^{-3}$ erg/$\rm cm^2 y$, with little additional component hidden within weak or otherwise undetectable GRB. This significantly constrains physical models of GRB and dirty fireballs, suggesting a rather sharp dichotomy between them should the latter exist.
description: to appear in The Astrophysical Journal
Composite binders for concrete of protective structures
Creators: name: Fediuk, Roman
name: Lesovik, Valeriy
name: Mochalov, Aleksandr
name: Otsokov, Kamil
name: Lashina, Irina
name: Timokhin, Roman
Publisher: name: Санкт-Петербургский политехнический университет Петра Великого
Year: 2018
Subjects: subject: self-compacting concrete
subject: composite binder
subject: pozzolanic materials
subject: technogenic raw materials
subject: fresh properties
subject: mechanical properties
subject: самоуплотняющийся бетон
subject: композиционное вяжущее
subject: пуццолановые материалы
subject: техногенное сырье
subject: свойства бетонной смеси
subject: механические свойства

description: The composite binders, obtained as a result of joint mechanochemical activation of Portland cement, rice husk ash, quartz sand, screening of limestone crushing and plasticizing additive were considered. The type of binder influence to the rheological and mechanical characteristics of self-compacting concrete mixtures and fiber-reinforced concrete is established. By scanning electron microscopy, it was revealed that the application of the developed binder leads to the compacting of the microstructure, with lamellar and acicular neoplasms filling the isometric and anisometric pores. This leades to the formation of a rigid matrix with a lower porosity, which in turn leads to an increase in the compressive strength of the formed cement stone above 70 MPa. The use of a composite binder increases the physical and mechanical characteristics of fine-grained concrete accordingly (Rcompr over 80 MPa, elastic modulus greater than 40 GPa). The studied rheological characteristics showed that all mixtures with the use of composite binder meet the requirements of fluidity and segregation resistance for self-compacting concrete mixtures. The revealed indexes of shock endurance of fiber-reinforced concrete (30 % higher than for standard reinforced concrete) allow using this material for protective structures.
Cyclotron spin-flip mode as the lowest-energy excitation of unpolarized integer quantum Hall states
Creators: name: Kulik, L. V.
name: Kukushkin, I. V.
name: Dickmann, S.
name: Kirpichev, V. E.
name: Vankov, A. B.
name: Parakhonsky, A. L.
name: Smet, J. H.
name: Klitzing, Klaus von
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik
subject: 73.43.Lp, 75.30.Ds, 71.70.Ej

description: The cyclotron spin-flip modes of spin unpolarized integer quantum Hall states (ν=2,4,6) have been studied with inelastic light scattering. The energy of these modes is significantly smaller compared to the bare cyclotron gap. Second-order exchange corrections are held responsible for a negative energy contribution and render these modes the lowest-energy excitations of unpolarized integer quantum Hall states.
Near-field and far-field dynamics of (Al,In)GaN laser diodes
Creators: name: Schwarz, Ulrich
name: Pindl, Markus
name: Wegscheider, Werner
name: Eichler, Christoph
name: Scholz, Ferdinand
name: Furitsch, Michael
name: Leber, Andreas
name: Miller, Stephan
name: Lell, Alfred
name: Härle, Volker
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: aluminium compounds, indium compounds, gallium compounds, III-V semiconductors, wide band gap semiconductors, semiconductor lasers, beam steering, refractive index, carrier density, waveguide lasers, near-field scanning optical microscopy
subject: 530 Physik
subject: 42.55.Px; 42.60.Jf; 68.37.Uv;

description: Near- and far-field dynamics of edge-emitting (Al,In)GaN laser diodes are measured simultaneously with a 100 nm spatial and a 5 ns temporal resolution using a scanning near-field microscope. We reconstruct the phase distribution at the laser diode facet. Beam steering and near-field mode dynamics are interpreted in terms of thermal and carrier induced change of refractive index in the waveguide.
Dynamics of a Bose-Einstein condensate in a symmetric triple-well trap
Creators: name: Viscondi, T. F.
name: Furuya, K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a complete analysis of the dynamics of a Bose-Einstein condensate trapped in a symmetric triple-well potential. Our classical analogue treatment, based on a time-dependent variational method using SU(3) coherent states, includes the parameter dependence analysis of the equilibrium points and their local stability, which is closely related to the condensate collective behaviour. We also consider the effects of off-site interactions, and how these "cross-collisions" may become relevant for a large number of trapped bosons. Besides, we have shown analytically, by means of a simple basis transformation in the single-particle space, that an integrable sub-regime, known as twin-condensate dynamics, corresponds in the classical phase space to invariant surfaces isomorphic to the unit sphere. However, the quantum dynamics preserves the twin-condensate defining characteristics only partially, thus breaking the invariance of the associated quantum subspace. Moreover, the periodic geometry of the trapping potential allowed us to investigate the dynamics of finite angular momentum collective excitations, which can be suppressed by the emergence of chaos. Finally, using the generalized purity associated to the su(3) algebra, we were able to quantify the dynamical classicality of a quantum evolved system, as compared to the corresponding classical trajectory.
description: 22 pages, 10 figures
Isotropic soft-core potentials with two characteristic length scales and anomalous behaviour
Creators: name: Vilaseca, Pol
name: Franzese, Giancarlo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Isotropic soft-core potentials with two characteristic length scales have been used since 40 years to describe systems with polymorphism. In the recent years intense research is showing that these potentials also display polyamorphism and several anomalies, including structural, diffusion and density anomaly. These anomalies occur in a hierarchy that resembles the anomalies of water. However, the absence of directional bonding in these isotropic potentials makes them different from water. Other systems, such as colloidal suspensions, protein solutions or liquid metals, can be well described by these family of potentials, opening the possibility of studying the mechanism generating the polyamorphism and anomalies in these complex liquids.
In-medium reduction of the η' mass in \sqrt{s_NN} = 200 GeV Au+Au collisions
Creators: name: Vertesi, Robert
name: Csorgo, Tamas
name: Sziklai, Janos
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A reduction of the mass of the η'(958) meson may indicate the restoration of the UA(1) symmetry in a hot and dense hadronic matter, corresponding to the return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a combined PHENIX and STAR data set on the intercept parameter of the two-pion Bose-Einstein correlation functions, as measuremed in \sqrt{s_NN} = 200 GeV Au+Au collisions at RHIC. To describe this combined PHENIX and STAR dataset, an in-medium η' mass reduction of at least 200 MeV is needed, at the 99.9 % confidence level in a broad model class of resonance multiplicities. Energy, system size and centrality dependence of the observed effect is also discussed.
description: Proceedings of an invited talk of Robert Vertesi at the HCBM 2010 workshop, Budapest, Hungary. Proceedings of an invited talk of Tamas Csorgo at the ISMD 2010 conference, Antwerp, Belgium
NMR study of the electron spin polarization in the fractional quantum Hall effect of a single quantum well: Spectroscopic evidence for domain formation
Creators: name: Stern, O.
name: Freytag, N.
name: Fay, A.
name: Dietsche, W.
name: Smet, J. H.
name: Klitzing, Klaus von
name: Schuh, Dieter
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2004
Subjects: subject: 530 Physik
subject: 73.43.−f, 76.60.Cq

description: The authors have developed a technique to determine the electron spin polarization in a single GaAs quantum well by combining resistance-detected (RD) nuclear magnetic resonance (NMR) with conventional NMR. We use this method to study the unpolarized-polarized spin transition at filling factor ν=2∕3 for small and large currents. The formation of domains with these two polarizations at the transition was observed spectroscopically. Domains with full, partial, or no polarization were also uncovered at ν=3∕5 and 4∕7. An anomalous NMR line shape around filling factor ν=1∕3, 1, and 2∕3 was measured. This pecularity of the NMR line is probably not due to skyrmions, as previously reported for ν=1.
Alkali-activated slag binders from rock-wool production wastes
Creators: name: Erofeev, Vladimir
name: Rodin, Alexander
name: Yakunin, Vladislav
name: Bogatov, Andrej
name: Bochkin, Viktor
name: Chegodajkin, Aleksej
Publisher: name: Санкт-Петербургский политехнический университет Петра Великого
Year: 2018
Subjects: subject: alkali-activated slag binder
subject: rock-wool production waste
subject: composite
subject: biological resistance
subject: шлакощелочное вяжущее
subject: отходы производства минеральной ваты
subject: композит
subject: биологическая стойкость

description: The article exposes the results of studies on the production of alkali-activated slag binders from rock-wool production wastes and their composite derivatives, which are resistant to corrosive effects of biological environment. Thermal analysis showed that the structurization in the "rock wool production waste-water-NaOH" system is most efficient with the NaOH/waste ratio of 0.02–0.03, and the main newly-formed phases in the solidified alkali-activated slag composites are low-basic calcium hydrosilicates and analcime. The best values of the physical and mechanical properties of obtained binders are achieved with a waste grinding fineness of 400–450 m2/kg. The compressive strength of the developed composite materials reaches 68 MPa and bending strength is 13.5 MPa with a waste grinding fineness of 300 m2/kg. Composites based on binders made of rock-wool production waste are waterproof and funginert, and individual compounds are fungicidal.
Protein-DNA computation by stochastic assembly cascade
Creators: name: Bar-Ziv, Roy
name: Tlusty, Tsvi
name: Libchaber, Albert
Publisher: name: arXiv
Year: 2010
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Biomolecules (q-bio.BM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The assembly of RecA on single-stranded DNA is measured and interpreted as a stochastic finite-state machine that is able to discriminate fine differences between sequences, a basic computational operation. RecA filaments efficiently scan DNA sequence through a cascade of random nucleation and disassembly events that is mechanistically similar to the dynamic instability of microtubules. This iterative cascade is a multistage kinetic proofreading process that amplifies minute differences, even a single base change. Our measurements suggest that this stochastic Turing-like machine can compute certain integral transforms.
description: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC129313/ http://www.pnas.org/content/99/18/11589.abstract
Numerical modelling of tides and tsunami waves propagation
Creators: name: Klimovich, Vitaly
name: Voronkov, Oleg
name: Davidenko, Vyacheslav
name: Ivanov, Sergey
Publisher: name: Санкт-Петербургский политехнический университет Петра Великого
Year: 2018
Subjects: subject: tide
subject: tsunami wave
subject: long wave
subject: numerical algorithm
subject: hydraulic structure
subject: bay
subject: shallow water model
subject: прилив
subject: волна цунами
subject: длинная волна
subject: численный алгоритм
subject: гидротехническое сооружение
subject: залив
subject: модель мелкой воды

description: Modelling of tides and tsunami waves propagation is important problem for the hydraulic engineering practice since it allows to predict characteristics of these phenomena (load, values of run up and flooding zones, propagation times to structures and so on) and to make reasonable choice of design solution for coastal structures. Numerical modeling is effective way to simulate tides and tsunami waves propagation. Results of simulations of tides and tsunami waves propagation on the basis of shallow water model are presented and analyzed in the article. It was considered explicit and implicit numerical scheme for solution of shallow water model equations, which were verified on the number of experimental results including experimental data on distribution of dam-break wave propagation on a dry and sloping bottom. It is shown that the numerical data of tides in Persian Gulf are well co-ordinated with the data of tidal tables, both on time and on level of tides in various points. Numerical results of tsunami waves propagation in the Krasheninnikov Bay and Kozmino Bay are presented at various angles of tsunami at open boundary of computed area. Numerical results of tide currents for Krasheninnikov Bay are presented for various velocities of a wind. Developed programs may be used, particular, for numerical calculations of impact characteristics of tsunami waves on structures in coastal and offshore zones according requirements of Russian normative documents.
Electronic transport through a quantum dot network
Creators: name: Dorn, August
name: Ihn, Thomas
name: Ensslin, Klaus
name: Wegscheider, Werner
name: Bichler, Max
Publisher: name: Universität Regensburg
Year: 2004
Subjects: subject: 530 Physik
subject: 73.23.Hk, 71.30.+h

description: The conductance through a finite quantum dot network is studied as a function of interdot coupling. As the coupling is reduced, the system undergoes a transition from the antidot regime to the tight binding limit, where Coulomb resonances with on average increasing charging energies are observed. Percolation models are used to describe the conduction in the open and closed regime and contributions from different blockaded regions can be identified. A strong negative average magnetoresistance in the Coulomb blockade regime is in good quantitative agreement with theoretical predictions for magnetotunneling between individual quantum dots.
Screening Embryos for Psychiatric Conditions: Public Perspectives, Ethical and Social Issues
Creators: name: Lázaro-Muñoz, Gabriel
name: Merner, Amanda
Publisher: name: Center for ELSI Resources and Analysis
Year: 2023
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Ethics
subject: Science
subject: ELSI
subject: polygenic risk scores
subject: polygenic embryo screening
subject: psychiatry
subject: reproductive decision making

description: The number of genomic loci identified to be associated with psychiatric disorders have substantially increased over the last decade. Alongside developments in polygenic embryo screening (PES; or PGT-P), the use of polygenic risk scores (PRS) to predict the genetic likelihood of polygenic traits (e.g., height, skin tone) and conditions (e.g., psychiatric disorders), it is now possible to screen embryos intended for invitro fertilization for genetic risk of psychiatric conditions such as schizophrenia or autism spectrum disorders. Private companies have started to offer PES for some psychiatric conditions; however, many ethical issues have been raised in the academic literature. Concerns about the use of PES broadly have included little evidence of clinical utility, limited portability of the PRS used in PES to populations underrepresented in the genome-wide association studies (GWAS) on which they are based, potential for exacerbating healthcare disparities, and impacts on patient autonomy. In addition to these issues, PES for psychiatric disorders may bring forth additional ethical matters that warrant careful consideration given the potential for exacerbating stigma and discrimination related to these conditions. The works below serve as a starting point for examining the ethical, clinical, social issues related to the use of PES for psychiatric conditions, and bring forward the views of clinicians, patients, and the public on the use of this technology for screening and selecting embryos. For more information, we invite you to visit the following website we developed for the community: https://www.polygenicembryo.org. Given the commercial availability of PES, we invite the Federal Trade Commission to evaluate the claims made by companies offering these service, and medical professional organizations to establish guidelines regarding the appropriateness of using PES in reproductive medicine.
The Importance of Scale for Spatial-Confounding Bias and Precision of Spatial Regression Estimators
Creators: name: Paciorek, Christopher J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Residuals in regression models are often spatially correlated. Prominent examples include studies in environmental epidemiology to understand the chronic health effects of pollutants. I consider the effects of residual spatial structure on the bias and precision of regression coefficients, developing a simple framework in which to understand the key issues and derive informative analytic results. When unmeasured confounding introduces spatial structure into the residuals, regression models with spatial random effects and closely-related models such as kriging and penalized splines are biased, even when the residual variance components are known. Analytic and simulation results show how the bias depends on the spatial scales of the covariate and the residual: one can reduce bias by fitting a spatial model only when there is variation in the covariate at a scale smaller than the scale of the unmeasured confounding. I also discuss how the scales of the residual and the covariate affect efficiency and uncertainty estimation when the residuals are independent of the covariate. In an application on the association between black carbon particulate matter air pollution and birth weight, controlling for large-scale spatial variation appears to reduce bias from unmeasured confounders, while increasing uncertainty in the estimated pollution effect.
description: Published in at http://dx.doi.org/10.1214/10-STS326 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)
A model for thread and memory placement on NUMA systems
Creators: name: Funston, Justin
Publisher: name: University of British Columbia
Year: 2018

description: The problem of placement of threads, or virtual cores, on physical cores in a multicore system has been studied for over a decade. Despite this effort, we still do not know how to assign virtual to physical cores on a non-uniform memory access (NUMA) system so as to meet a performance target while minimizing resource consumption. Prior work has made large strides in this area, but these solutions either addressed hardware with specific properties, leaving us unable to generalize the models to other systems, or modeled much simpler effects than the actual performance in different placements. An interdependent problem is how to place memory on NUMA systems. Poor memory placement causes congestion on interconnect links, contention for memory controllers, and ultimately long memory access times and poor performance. Commonly used operating system techniques for NUMA memory placement fail to achieve optimal performance in many cases. Our contribution is a general framework for reasoning about workload placement and memory placement on machines with shared resources. This framework enables us to automatically build an accurate performance model for any machine with a hierarchy of known shared resources. Using our methodology, data center operators can minimize the number of NUMA (CPU+memory) nodes allocated for an application or a service, while ensuring that it meets performance objectives. More broadly, the methodology empowers them to efficiently “pack” virtual containers on the physical hardware. We also present an effective solution for placing memory that avoids congestion on interconnects due to memory traffic and additionally selects the best page size that balances translation lookaside buffer (TLB) effects against more granular memory placement. The solutions proposed can significantly improve performance and work at the operating system level so they do not require changes to applications.
Structure of a Single Sharp Quantum Hall Edge Probed by Momentum-Resolved Tunneling
Creators: name: Huber, Michael
name: Grayson, M.
name: Rother, Martin
name: Biberacher, W.
name: Wegscheider, Werner
name: Abstreiter, Gerhard
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik
subject: 73.43.Jn, 73.43.Qt

description: Momentum-resolved magnetotunneling spectroscopy is performed at a single sharp quantum Hall (QH) edge to probe the structure of integer QH edge modes. An epitaxially overgrown cleaved edge is shown to realize the sharp-edge limit with interchannel distances smaller than both the magnetic length and the Bohr radius where the Chklovskii soft-edge picture is no longer valid. The line shape of principal conductance peaks is explained, and an edge filling factor is determined from the peak position. A step in the dispersion is attributed to fluctuations in the QH ground energy.
Carbon-doped symmetric GaAs/AlGaAs quantum wells with hole mobilities beyond 106 cm2/V s
Creators: name: Gerl, Christian
name: Tranitz, Hans-Peter
name: Wegscheider, Werner
name: Mitzkus, Christian
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: gallium arsenide, aluminium compounds, III-V semiconductors, semiconductor quantum wells, semiconductor doping, hole mobility, two-dimensional hole gas, semiconductor heterojunctions, carbon
subject: 530 Physik
subject: 81.07.St; 73.63.Hs; 73.40.Kp; 61.72.Vv

description: Utilizing a carbon filament doping source, we prepared two-dimensional hole gases in a symmetric quantum-well structure in the GaAs/AlGaAs heterosystem. Low-temperature hole mobilities up to 1.2×106 cm2/V s at a density of 2.3×1011 cm–2 were achieved on GaAs (001) substrates. In contrast to electron systems, the hole mobility sensitively depends on variations of the quantum-well width and the spacer thickness. In particular, an increase of the quantum-well width from an optimal value of 15 nm to 18 nm is accompanied by a 35% reduction of the hole mobility. The quality of ultrahigh-mobility electron systems is not affected by the employed carbon-doping source.
Belastungen der Pflegepersonen in der Akutpsychiatrie der PDAG
Creators: name: Pfister, Tobias
Publisher: name: Hochschule für Angewandte Psychologie FHNW
Year: 2023
Subjects: subject: Belastung
subject: psychiatrische Pflege
subject: transaktionales Stressmodell
subject: Copingstrategien
subject: Salutogenese-Modell
subject: 610 - Medizin und Gesundheit

description: Im Bereich der Pflege sind vielfältige Belastungen im Arbeitsalltag vorhanden, gewisse wie beispielsweise der Personalmangel werden auch häufig in Medien diskutiert. Sind diese Belastungen auch im Akut-Bereich der psychiatrischen Pflege vorhanden und gibt es auch Belastungen, welche speziell im Setting der Psychiatrie auftreten? Diese Frage beschäftigt auch die Psychiatrischen Dienste Aargau AG. Um dies zu untersuchen, wurden 40 Pflegepersonen der Akutpsychiatrie in einem Fragebogen dazu befragt, welche Belastungen in ihrem Arbeitsalltag auftreten und wie sich ihr Umgang mit diesen gestaltet. Die Ergebnisse zeigen, dass die Belastung unter den Pflegepersonen vor allem aufgrund von Personalmangel, Zwangsmassnahmen und verbaler Gewalt entstehen. Dabei konnte anhand von Korrelationen gezeigt werden, dass je häufiger Personalmangel und Zwangsmassnahmen auftreten, desto stärker wird die Belastung durch diese Faktoren wahrgenommen. Die meisten Pflegepersonen wählen als Copingstrategie Gespräche mit Arbeitskolleginnen und -kollegen oder Gespräche mit Personen aus dem privaten Umfeld, um die Belastungen abmildern zu können. Anhand der Ergebnisse wurden Handlungsempfehlungen formuliert, welche das Ziel haben, den Umgang der Pflegepersonen mit Belastungen zu stärken. Die auf Basis der Literatur entwickelten Hypothesen konnten anhand von Tests auf Gruppenunterschiede nicht bestätigt werden.
Topological defects in the edge-state structure in a bilayer electron system
Creators: name: Deviatov, E. V.
name: Dolgopolov, V. T.
name: Würtz, A.
name: Wixforth, A.
name: Wegscheider, Werner
name: Campman, K. L.
name: Gossard, A. C.
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik
subject: 73.40.Qv, 71.30.+h

description: We experimentally demonstrate formation of pointlike topological defects in the edge-state structure in the quantum Hall effect regime. By using of a selective population technique, we investigate equilibration processes between the edge states in bilayer electron structures with a high tunneling rate between layers. Unexpected flattening of the I-V curves in a perpendicular magnetic field at a specific filling factor combination and the recovery of the conventional nonlinear I-V characteristics in tilted fields give a strong evidence for the existence of topological defects.
A self-dual approach to stochastic partial differential equations
Creators: name: Shirin, Boroushaki
Publisher: name: University of British Columbia
Year: 2018

description: In the first part of this thesis, we use the theory of self-duality to provide a variational approach for the resolution of a number of stochastic partial differential equations. We will be able to address the problem of existence of solutions to a class of semilinear stochastic partial differential equations in the form du+A(t,u(t))dt=B(t,u(t)) dW with u(0)=u₀, where for every t∊[0,T], A(t, ‧) is a maximal monotone operator on a reflexive Banach space V, and B is a linear or non-linear operator with values in a Hilbert space H. We use the fact that any maximal monotone operator A can be expressed as a potential of a self-dual Lagrangian L to associate to the equation a (completely) self-dual functional whose minimizer on a suitable path space yields a solution. One particular case of the above equation which already contains a large number of stochastic PDEs is when A is the subdifferential of a convex function φ. More generally, we can deal with equations of the form du(t)= -∂φ(t,u(t))dt + B(t,u(t))dW(t) with u(0)=u₀. We also prove the existence of solutions to SPDEs in divergence form involving a maximal monotone operator β on the n-dimensional Euclidean space which is not necessarily the gradient of a convex function: du= div(β(∇u(t,x)))dt +B(t)dW(t) if u∊[0,T]×D and u(0)=u₀ when u∊∂D where D is a bounded domain in the n-dimensional Euclidean space. In the second part of the thesis, we use methods from optimal transport to address functional inequalities on the n-dimensional sphere. We prove Energy-Entropy duality formulas that yield and improve the celebrated Moser-Onofri inequalities on the 2-dimensional sphere.
Density dependence of microwave induced magnetoresistance oscillations in a two-dimensional electron gas
Creators: name: Simovič, B.
name: Ellenberger, C.
name: Ensslin, Klaus
name: Tranitz, Hans-Peter
name: Wegscheider, Werner
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik
subject: 73.43.Qt, 73.40.−c, 75.47.−m

description: We have measured the magnetoresistance of a two-dimensional electron gas (2DEG) under continuous microwave irradiation as a function of electron density and mobility tuned with a metallic top-gate. In the entire range of density and mobility we have investigated, we observe microwave induced oscillations of large amplitude that are B-periodic. These B-periodic oscillations are reminiscent of the ones reported by Kukushkin et al. [Phys. Rev. Lett. 92, 236803 (2004)] and which were attributed to the presence of edge-magneto-plasmons. We have found that the B-periodicity does not increase linearly with the density in our sample but shows a plateau in the range (2.4–3)×1011 cm−2. In this regime, the phase of the B-periodic oscillations is found to shift continuously by two periods.
Polar distortions in hydrogen bonded organic ferroelectrics
Creators: name: Stroppa, Alessandro
name: Di Sante, Domenico
name: Horiuchi, Sachio
name: Tokura, Yoshinori
name: Vanderbilt, David
name: Picozzi, Silvia
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Although ferroelectric compounds containing hydrogen bonds were among the first to be discovered, organic ferroelectrics are relatively rare. The discovery of high polarization at room temperature in croconic acid [Nature \textbf{463}, 789 (2010)] has led to a renewed interest in organic ferroelectrics. We present an ab-initio study of two ferroelectric organic molecular crystals, 1-cyclobutene-1,2-dicarboxylic acid (CBDC) and 2-phenylmalondialdehyde (PhMDA). By using a distortion-mode analysis we shed light on the microscopic mechanisms contributing to the polarization, which we find to be as large as 14.3 and 7.0\,$μ$C/cm$^{2}$ for CBDC and PhMDA respectively. These results suggest that it may be fruitful to search among known but poorly characterized organic compounds for organic ferroelectrics with enhanced polar properties suitable for device applications.
description: Submitted
Führt eine Verkürzung der Arbeitszeit tatsächlich zu besserer Erholung?
Creators: name: Rey, Lisa
Publisher: name: Hochschule für Angewandte Psychologie FHNW
Year: 2023
Subjects: subject: Arbeitsmodelle
subject: 4-Tage-Woche
subject: Arbeitszeitreduktion
subject: Life Domain Balance
subject: Boundary Management
subject: Erholung
subject: 330 - Wirtschaft

description: Lange Arbeitstage und -wochen können für die Mitarbeitenden gravierende, negative Folgen mit sich bringen. Eine Möglichkeit dieser Gefahr entgegenzuwirken, ist das Arbeitsmodell der 4-Tage-Woche, welches auch von der seerow GmbH eingeführt wurde. Motivation der Umstellung war für das Unternehmen unter anderem ein ausgeglichenes Zusammenspiel von Arbeit und Nicht-Arbeit. Ob diese Effekte eingetroffen sind oder nicht, wird in der vorliegenden Arbeit anhand der folgenden übergeordneten Fragestellung untersucht: „Welche subjektiven Auswirkungen hat die 4-Tage-Woche auf die Life Domain Balance der Mitarbeitenden des Unternehmens seerow GmbH?“. Nebst dem Gleichgewicht der Lebensbereiche wird untergeordnet die individuelle Abgrenzung zwischen den Bereichen und die Erholung der Mitarbeitenden vertieft. Um die Frage zu beantworten, wurden 5 Mitarbeitende der seerow GmbH mit qualitativen Leitfadeninterviews befragt. Die Untersuchung zeigt, dass das Arbeitsmodell der 4-Tage-Woche bei den Mitarbeitenden der seerow GmbH einen positiven Effekt auf den Ausgleich und die Abgrenzung zwischen Lebensbereichen, sowie die Erholung hat. Die grösste Herausforderung liegt bei der gedanklichen und aufgabenorientierten Abgrenzung der Erwerbsarbeit in der Freizeit. Aus dieser Grundlage und unter Berücksichtigung der wissenschaftlichen Literatur wurden dem Unternehmen entsprechende Handlungsempfehlungen abgeleitet.
Large-m_c Asymptotic Behaviour of O(alpha_s^2) Corrections to B -> X_s gamma
Creators: name: Misiak, Mikolaj
name: Steinhauser, Matthias
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present details of our evaluation of the NNLO QCD corrections to BR(B -> X_s gamma) in the heavy charm limit m_c >> m_b/2. Results of this calculation have been essential for estimating O(alpha_s^2) effects in this branching ratio via interpolation in m_c.
description: 13 pages, 2 figures