cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Optimised Informed RRTs for Mobile Robot Path Planning
Creators: name: Maseko, Bongani B.
name: van Daalen, Corné E.
name: Treurnicht, Johann
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: I.2.9

description: Path planners based on basic rapidly-exploring random trees (RRTs) are quick and efficient, and thus favourable for real-time robot path planning, but are almost-surely suboptimal. In contrast, the optimal RRT (RRT*) converges to the optimal solution, but may be expensive in practice. Recent work has focused on accelerating the RRT*'s convergence rate. The most successful strategies are informed sampling, path optimisation, and a combination thereof. However, informed sampling and its combination with path optimisation have not been applied to the basic RRT. Moreover, while a number of path optimisers can be used to accelerate the convergence rate, a comparison of their effectiveness is lacking. This paper investigates the use of informed sampling and path optimisation to accelerate planners based on both the basic RRT and the RRT*, resulting in a family of algorithms known as optimised informed RRTs. We apply different path optimisers and compare their effectiveness. The goal is to ascertain if applying informed sampling and path optimisation can help the quick, though almost-surely suboptimal, path planners based on the basic RRT attain comparable or better performance than RRT*-based planners. Analyses show that RRT-based optimised informed RRTs do attain better performance than their RRT*-based counterparts, both when planning time is limited and when there is more planning time.
description: 6 pages, 3 figures, published in IFAC-PapersOnLine
Exciton-phonon Bound Complex in Single-walled Carbon Nanotubes Revealed by High-field Magneto-optical Spectroscopy
Creators: name: Zhou, Weihang
name: Sasaki, Tatsuya
name: Nakamura, Daisuke
name: Saito, Hiroaki
name: Liu, Huaping
name: Kataura, Hiromichi
name: Takeyama, Shojiro
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: High-field magneto-optical spectroscopy was conducted on highly-selected chiral (6,5) specific single-walled carbon nanotubes. Spectra of phonon sidebands in both 1st and 2nd sub-bands were observed to be unchanged by the application of an external magnetic field up to 52 T. Our analyses led to the conclusion that both phonon sidebands in respective sub-band originate from the dark K-momentum singlet (D-K-S) excitons. Moreover, while the relative ordering between the bandedge bright exciton and its zero-momentum anti-bonding counterpart was found to be opposite for the 1st and 2nd sub-bands, the relative ordering between the D-K-S exciton and the band-edge bright exciton was clarified to be the same for both sub-bands. Energy of these D-K-S excitons was estimated to be ~ 21.5 and ~ 37.3 meV above the band-edge bright exciton for the 1st and 2nd sub-bands, respectively.
description: 5 pages, 4 figures
Formal analogy between the Dirac equation in its Majorana form and the discrete-velocity version of the Boltzmann kinetic equation
Creators: name: Fillion-Gourdeau, F.
name: Herrmann, H. J.
name: Mendoza, M.
name: Palpacelli, S.
name: Succi, S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We point out a formal analogy between the Dirac equation in Majorana form and the discrete-velocity version of the Boltzmann kinetic equation. By a systematic analysis based on the theory of operator splitting, this analogy is shown to turn into a concrete and efficient computational method, providing a unified treatment of relativistic and non-relativistic quantum mechanics. This might have potentially far-reaching implications for both classical and quantum computing, because it shows that, by splitting time along the three spatial directions, quantum information (Dirac-Majorana wavefunction) propagates in space-time as a classical statistical process (Boltzmann distribution).
description: 5 pages, 4 figures
Many-body Non-Hermitian Skin Effect At Finite Temperatures
Creators: name: Cao, Kui
name: Du, Qian
name: Kou, Su-Peng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this study, we investigate the many-body non-Hermitian skin effect at finite temperatures in the thermodynamic limit. Our findings indicate an interesting correspondence between the non-Hermitian skin effect and a linear electric potential effect in this case. This correspondence leads to a unique distribution in non-Hermitian systems; particles in these many-body non-Hermitian systems do not inhabit the energy eigenstates of their single-body counterparts. As a result, the many-body non-Hermitian skin effect is significantly different from the single-body non-Hermitian skin effect. Specifically, for fermionic systems, the non-Hermitian skin effect disrupts the original phase, leading to a real-space Fermi surface. For bosonic systems, it can direct bosons to condense in corners at a decay rate that surpasses exponential, even at high temperatures. It also triggers a remarkable phase transition, resulting in spontaneous U(1) symmetry breaking. Uniquely, this does not generate a Goldstone mode, presenting a deviation from traditional expectations as per the Goldstone theorem.
Reflexive Behaviour: How publication pressure affects research quality in Astronomy
Creators: name: Heuritsch, Julia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Reflexive metrics is a branch of science studies which explores how the demand for accountability and performance measurement in science has shaped the research culture in recent decades. Hypercompetition and publication pressure are part of this neoliberal culture. How do scientists respond to these pressures? Studies on research integrity and organizational culture suggest that people who feel treated unfairly by their institution are more likely to engage in deviant behaviour, such as scientific misconduct. By building up on reflexive metrics, combined with studies on the influence of organisational culture on research integrity, this study reflects on the research behaviour of astronomers: 1) To what extent is research (mis-)behaviour reflexive, i.e. dependent on perceptions of publication pressure and distributive & organisational justice? 2) What impact does scientific misconduct have on research quality? In order to perform this reflection, we conducted a comprehensive survey of academic and non-academic astronomers worldwide and received 3,509 responses. We found that publication pressure explains 19% of the variance in occurrence of misconduct and between 7 and 13% of the variance of the perception of distributive & organisational justice as well as overcommitment to work. Our results on the perceived impact of scientific misconduct on research quality show that the epistemic harm of questionable research practices should not be underestimated. This suggests there is a need for a policy change. In particular, lesser attention to metrics (such as publication rate) in the allocation of grants, telescope time and institutional rewards would foster better scientific conduct and hence research quality.
description: Keywords: Reflexive metrics, publication pressure, research quality, research culture, research integrity, research misconduct
Piezo-orbital backaction force in a rare-earth doped crystal
Creators: name: Louchet-Chauvet, Anne
name: Verlot, Pierre
name: Poizat, Jean-Philippe
name: Chanelière, Thierry
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate a system composed of an ensemble of room temperature rare-earth ions embedded in a bulk crystal, intrinsically coupled to internal strain via their sensitivity to the surrounding crystal field. We evidence the generation of a mechanical response under resonant atomic excitation. We find this motion to be the sum of two fundamental, resonant optomechanical backaction processes: a conservative, piezo-orbital mechanism, resulting from the modification of the crystal field associated with the promotion of the ions to their excited state, and a dissipative, non-radiative photothermal process related to the phonons generated throughout the atomic population relaxation. Our work opens new research avenues in hybrid optomechanics, and highlights new interactions that may be key for understanding the dephasing dynamics of ultra-coherent rare-earth ions.
description: Main text: 6 pages, 4 figures. Supplementary Material: 7 pages, 6 figures
Transformation of stimulus correlations by the retina
Creators: name: Simmons, K. D.
name: Prentice, J. S.
name: Tkacik, G.
name: Homann, J.
name: Yee, H. K.
name: Palmer, S. E.
name: Nelson, P. C.
name: Balasubramanian, V.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: Redundancies and correlations in the responses of sensory neurons seem to waste neural resources but can carry cues about structured stimuli and may help the brain to correct for response errors. To assess how the retina negotiates this tradeoff, we measured simultaneous responses from populations of ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure. We found that pairwise correlations in the retinal output remained similar across stimuli with widely different spatio-temporal correlations including white noise and natural movies. Meanwhile, purely spatial correlations tended to increase correlations in the retinal response. Responding to more correlated stimuli, ganglion cells had faster temporal kernels and tended to have stronger surrounds. These properties of individual cells, along with gain changes that opposed changes in effective contrast at the ganglion cell input, largely explained the similarity of pairwise correlations across stimuli where receptive field measurements were possible.
description: author list corrected in metadata
Scenario generation for market risk models using generative neural networks
Creators: name: Flaig, Solveig
name: Junike, Gero
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Mathematical Finance (q-fin.MF)
subject: Risk Management (q-fin.RM)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business

description: In this research, we show how to expand existing approaches of using generative adversarial networks (GANs) as economic scenario generators (ESG) to a whole internal market risk model - with enough risk factors to model the full band-width of investments for an insurance company and for a one year time horizon as required in Solvency 2. We demonstrate that the results of a GAN-based internal model are similar to regulatory approved internal models in Europe. Therefore, GAN-based models can be seen as a data-driven alternative way of market risk modeling.
Band-selective Holstein polaron in Luttinger liquid material A0.3MoO3 (A = K, Rb)
Creators: name: Kang, L.
name: Du, X.
name: Zhou, J. S.
name: Gu, X.
name: Chen, Y. J.
name: Xu, R. Z.
name: Zhang, Q. Q.
name: Sun, S. C.
name: Yin, Z. X.
name: Li, Y. W.
name: Pei, D.
name: Zhang, J.
name: Gu, R. K.
name: Wang, Z. G.
name: Liu, Z. K.
name: Xiong, R.
name: Shi, J.
name: Zhang, Y.
name: Chen, Y. L.
name: Yang, L. X.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: (Quasi-)one-dimensional systems exhibit various fascinating properties such as Luttinger liquid behavior, Peierls transition, novel topological phases, and the accommodation of unique quasiparticles (e.g., spinon, holon, and soliton, etc.). Here we study molybdenum blue bronze A0.3MoO3 (A = K, Rb), a canonical quasi-one-dimensional charge-density-wave material, using laser-based angle-resolved photoemission spectroscopy. Our experiment suggests that the normal phase of A0.3MoO3 is a prototypical Luttinger liquid, from which the charge-density-wave emerges with decreasing temperature. Prominently, we observe strong renormalizations of band dispersions, which is recognized as the spectral function of Holstein polaron derived from band-selective electron-phonon coupling in the system. We argue that the strong electron-phonon coupling plays a dominant role in electronic properties and the charge-density-wave transition in blue bronzes. Our results not only reconcile the long-standing heavy debates on the electronic properties of blue bronzes but also provide a rare platform to study novel composite quasiparticles in Luttinger liquid materials.
description: 19 pages, 4 figures, accepted by Nature Communications
Collective Human Opinions in Semantic Textual Similarity
Creators: name: Wang, Yuxia
name: Tao, Shimin
name: Xie, Ning
name: Yang, Hao
name: Baldwin, Timothy
name: Verspoor, Karin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Despite the subjective nature of semantic textual similarity (STS) and pervasive disagreements in STS annotation, existing benchmarks have used averaged human ratings as the gold standard. Averaging masks the true distribution of human opinions on examples of low agreement, and prevents models from capturing the semantic vagueness that the individual ratings represent. In this work, we introduce USTS, the first Uncertainty-aware STS dataset with ~15,000 Chinese sentence pairs and 150,000 labels, to study collective human opinions in STS. Analysis reveals that neither a scalar nor a single Gaussian fits a set of observed judgements adequately. We further show that current STS models cannot capture the variance caused by human disagreement on individual instances, but rather reflect the predictive confidence over the aggregate dataset.
description: 16 pages, 7 figures
A new block alternating splitting iteration method for solving a class of two-by-two block complex linear systems
Creators: name: Salkuyeh, Davod Khojasteh
name: Pourbagher, Maeddeh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 49M25, 49K20, 65F10, 65F50

description: A block alternating splitting iteration (BASI) method is presented for solving the system arising from the finite element discretization of the distributed optimal control problem with time-periodic parabolic equations. We prove that the BASI method is unconditionally convergent. We derive the BASI preconditioner and present an estimation formula for the parameter of the BASI preconditioner. Numerical results are presented to verify the efficiency of both the BASI method and the BASI preconditioner. Comparison with some existing methods are also given.
description: 13 pages, submitted
Single Rotating Stars and the Formation of Bipolar Planetary Nebula
Creators: name: Garcia-Segura, G.
name: Villaver, E.
name: Langer, N.
name: Yoon, S. -C.
name: Manchado, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have computed new stellar evolution models that include the effects of rotation and magnetic torques under different hypothesis. The goal is to test if a single star can sustain in the envelope the rotational velocities needed for the magneto hydrodynamical (MHD) simulations to shape bipolar Planetary Nebulae (PNe) when the high mass-loss rates take place. Stellar evolution models with main sequence masses of 2.5 and 5 Mo, and initial rotational velocities of 250 km/s have been followed all the way to the PNe formation phase. We find that stellar cores have to be spun down using magnetic torques in order to reproduce the rotation rates observed for white dwarfs. During the asymptotic giant branch phase and beyond, the magnetic braking of the core has a practically null effect in increasing the rotational velocity of the envelope since the stellar angular momentum is removed efficiently by the wind. We have, as well, tested best possible case scenarios in rather non-physical contexts to give enough angular momentum to the envelope. We find that we cannot get the envelope of a single star rotating at the speeds needed by the MHD simulations to form bipolar PNe. We conclude that single stellar rotators are unlikely to be the progenitors of bipolar PNe under the current MHD model paradigm.
description: 22 pages, 8 figures, accepted by the Astrophysical Journal
The plasma oscillations in a two-dimensional electron-hole liquid under influence Rashba spin-orbit coupling
Creators: name: Dumanov, E. V.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The plasma oscillations of the two-dimensional electron-hole system in the presence of a Rashba spin-orbit coupling are studied. Only the intra-Landau level excitations are taken into account when the electrons and holes are situated on their lowest Landau levels, the filling factor $v^{2}$ being less than 1. The ground state of the two-dimensional electron-hole system is supposed to be the electron-hole liquid. The dispersion relations for the optical and acoustical plasmon modes were obtained. The acoustical plasmon branch has a linear dispersion law in the range of small wave vectors and monotonically increases with saturation at higher values of wave vectors. The optical plasmon branch has a quadratic dependence in the range of long wavelength and a monotonic increasing with saturation as in the case of acoustical branch.
A Taxonomy and Archetypes of Business Analytics in Smart Manufacturing
Creators: name: Wanner, Jonas
name: Wissuchek, Christopher
name: Welsch, Giacomo
name: Janiesch, Christian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Fueled by increasing data availability and the rise of technological advances for data processing and communication, business analytics is a key driver for smart manufacturing. However, due to the multitude of different local advances as well as its multidisciplinary complexity, both researchers and practitioners struggle to keep track of the progress and acquire new knowledge within the field, as there is a lack of a holistic conceptualization. To address this issue, we performed an extensive structured literature review, yielding 904 relevant hits, to develop a quadripartite taxonomy as well as to derive archetypes of business analytics in smart manufacturing. The taxonomy comprises the following meta-characteristics: application domain, orientation as the objective of the analysis, data origins, and analysis techniques. Collectively, they comprise eight dimensions with a total of 52 distinct characteristics. Using a cluster analysis, we found six archetypes that represent a synthesis of existing knowledge on planning, maintenance (reactive, offline, and online predictive), monitoring, and quality management. A temporal analysis highlights the push beyond predictive approaches and confirms that deep learning already dominates novel applications. Our results constitute an entry point to the field but can also serve as a reference work and a guide with which to assess the adequacy of one's own instruments.
Impact of two-level fuzzy cluster head selection model for wireless sensor network: An Energy efficient approach in remote monitoring scenarios
Creators: name: Dutta, P. K.
name: Naskar, M. K.
name: Mishra, O. P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: The robust application of wireless sensor networks has increased during the past decade due to the potential use of wireless nodes in transmission of information by decreasing latency for surveillance and monitoring. The study proposes an Energy Efficient Dynamic Scenario (EEDS) for cluster head allocation for optimum balance in the energy consumption of the whole network that will prolong the lifetime of the network in an efficient manner. In this paper, a two-level fuzzy logic is proposed in choosing cluster head based on node localization and network traffic. In the upper decision making level called global level of qualification leads to better performance of the inference system based on all the above six fuzzy parameters for establishing an energy efficient network model. We develop an algorithm to calculate energy across the network if the source and destination is known. We evaluate the cost and benefit of the data fusion, in order to adaptively adjust whether fusion shall be performed for minimizing the total energy consumption when energy efficient node scheduling migrates from a particular node to another node. Simulation results show that EEDS gives the best performance with respect to network life time density and residual energy of the node.
description: 10 pages,International Journal of Information Processing, 7(2), 69-81, 2013,ISSN : 0973-8215
Screening the Coulomb interaction leads to a prethermal regime in two-dimensional bad conductors
Creators: name: Stanley, L. J.
name: Lin, Ping V.
name: Jaroszyński, J.
name: Popović, Dragana
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The absence of thermalization in certain isolated many-body systems is of great fundamental interest. Many-body localization (MBL) is a widely studied mechanism for thermalization to fail in strongly disordered quantum systems, but it is still not understood precisely how the range of interactions affects the dynamical behavior and the existence of MBL, especially in dimensions $D>1$. By investigating nonequilibrium dynamics in strongly disordered $D=2$ electron systems with power-law interactions $\propto 1/r^α$ and poor coupling to a thermal bath, here we observe MBL-like, prethermal dynamics for $α=3$. In contrast, for $α=1$, the system thermalizes, although the dynamics is glassy. Our results provide important insights for theory, especially since we obtained them on systems that are much closer to the thermodynamic limit than synthetic quantum systems employed in previous studies of MBL. Thus, our work is a key step towards further studies of ergodicity breaking and quantum entanglement in real materials.
description: 27 pages, incl. 4 figs + Supplementary (9 figs, 3 Suppl. Notes, Suppl. References)
Refined Two Weight Estimates for the Bergman Projection
Creators: name: Brocchi, Gianmarco
Publisher: name: arXiv
Year: 2021
Subjects: subject: Complex Variables (math.CV)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 47B38, 30H20, 42B35

description: We prove sufficient conditions for the two-weight boundedness of the Bergman projection on the unit ball. The first condition is in terms of Orlicz averages of the weights, while the second condition is in terms of the mixed $B_{\infty}$-$B_2$ characteristics.
description: 14 pages, 1 figure, to appear in Collectanea Mathematica
Near-infrared studies of glucose and sucrose in aqueous solutions: water displacement effect and red shift in water absorption from water-solute interaction
Creators: name: Jung, Youngeui
name: Hwang, Jungseek
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We use near infrared spectroscopy to obtain concentration dependent glucose absorption spectra in their aqueous solutions in the near-infrared range (3800 - 7500 cm^{-1}). We introduce a new method to obtain reliable glucose absorption bands from aqueous glucose solutions without measuring the water displacement coefficients of glucose separately. Additionally, we are able to extract the water displacement coefficients of glucose, and this may give a new general method using spectroscopy techniques applicable to other water soluble materials. We also observe red shifts in the absorption bands of water in the hydration shell around solute molecules, which comes from contribution of the interacting water molecules around the glucose molecules in solutions. The intensity of the red shift get larger as the concentration increases, which indicates that as the concentration increases more water molecules are involved in the interaction. However, the red shift in frequency does not seem to depend significantly on the concentration up to our highest concentration. We also performed the same measurements and analysis with sucrose instead of glucose as solute and compare.
description: 25 papges, 9 figures
QCD resummation in hadron production
Creators: name: Anderle, Daniele P.
name: Ringer, Felix
name: Vogelsang, Werner
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present calculations of next-to-leading order and resummed QCD corrections for semi-inclusive deep-inelastic scattering and single-inclusive e+e- annihilation. The resummation is performed to next-to-leading logarithmic accuracy. Knowing these QCD corrections is important in order to extract parton distribution functions and fragmentation functions from present and future data for these reactions. We present comparisons of our results to recent data by the COMPASS, HERMES, Belle, and BaBar experiments.
description: Contribution to proceedings of 3rd Workshop on the QCD Structure of the Nucleon (QCD-N'12)
NURTURING GROWTH: PHYSIOTHERAPY'S ESSENTIAL BENEFITS FOR PHYSICALLY IMPAIRED YOUTH
Creators: name: Samuel, J. Adeyemi
name: Amina, T. Olayemi
Publisher: name: AYDEN JOURNAL
Year: 2024
Subjects: physiotherapy, physically and health impaired children (PHIC), Special Education , Rehabilitation Medicine

description: The study sought to investigate into the importance of physiotherapy on the physically and health impaired children (PHIC). The study was carried out at Federal College of Education (Special), Oyo, Oyo State, Nigeria and the population used consisted of PHIC. Twenty (20) PHIC were randomly recruited from 100 – 300 levels of the School of Special Education for the study. 40% were males while 60% were females and their age ranges from 19 – 30 years. A 20 item structured questionnaire was designed and validated was used to collect data from participants. Frequency count of responses was done and simple percentages were used to analyze the data collected. Findings from the study revealed that physiotherapy is very important on the life of PHIC and it was also discovered that physiotherapy plays a major role in improving the life of the PHIC
Low X-Ray Luminosity Galaxy Clusters. II. Optical properties and morphological content at 0.18 < z < 0.70
Creators: name: Castellón, José Luis Nilo
name: Alonso, M. Victoria
name: Lambas, Diego García
name: Mill, Ana Laura O'
name: Valotto, Carlos
name: Carrasco, E. Rodrigo
name: Ramírez, Héctor Cuevas \& Amelia
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: This is the second of a series of papers on low X-ray luminosity galaxy clusters, in which we present the $r^\prime$, $g^\prime$ and $i^\prime$ photometry obtained with GMOS-IMAGE at Gemini North and South telescopes for seven systems in the redshift range of 0.18 to 0.70. Optical magnitudes, colours and morphological parameters, namely, concentration index, ellipticity and visual morphological classification, are also given. At lower redshifts, the presence of a well-defined red cluster sequence extending by more than 4 magnitudes showed that these intermediate-mass clusters had reached a relaxed stage. This was confirmed by the small fraction of blue galaxy members observed in the central regions of $\sim$ 0.75 Mpc. In contrast, galaxy clusters at higher redshifts had a less important red cluster sequence. We also found that the galaxy radial density profiles in these clusters were well fitted by a single power law. At 0.18 $
description: 16 pages, 13 figures, 5 tables. Accepted for publication in MNRAS
On Learning Domain-Invariant Representations for Transfer Learning with Multiple Sources
Creators: name: Phung, Trung
name: Le, Trung
name: Vuong, Long
name: Tran, Toan
name: Tran, Anh
name: Bui, Hung
name: Phung, Dinh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Domain adaptation (DA) benefits from the rigorous theoretical works that study its insightful characteristics and various aspects, e.g., learning domain-invariant representations and its trade-off. However, it seems not the case for the multiple source DA and domain generalization (DG) settings which are remarkably more complicated and sophisticated due to the involvement of multiple source domains and potential unavailability of target domain during training. In this paper, we develop novel upper-bounds for the target general loss which appeal to us to define two kinds of domain-invariant representations. We further study the pros and cons as well as the trade-offs of enforcing learning each domain-invariant representation. Finally, we conduct experiments to inspect the trade-off of these representations for offering practical hints regarding how to use them in practice and explore other interesting properties of our developed theory.
description: NeurIPS 2021
Quantum control and process tomography of a semiconductor quantum dot hybrid qubit
Creators: name: Kim, Dohun
name: Shi, Zhan
name: Simmons, C. B.
name: Ward, D. R.
name: Prance, J. R.
name: Koh, Teck Seng
name: Gamble, John King
name: Savage, D. E.
name: Lagally, M. G.
name: Friesen, Mark
name: Coppersmith, S. N.
name: Eriksson, M. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The similarities between gated quantum dots and the transistors in modern microelectronics - in fabrication methods, physical structure, and voltage scales for manipulation - have led to great interest in the development of quantum bits (qubits) in semiconductor quantum dots. While quantum dot spin qubits have demonstrated long coherence times, their manipulation is often slower than desired for important future applications, such as factoring. Further, scalability and manufacturability are enhanced when qubits are as simple as possible. Previous work has increased the speed of spin qubit rotations by making use of integrated micromagnets, dynamic pumping of nuclear spins, or the addition of a third quantum dot. Here we demonstrate a new qubit that offers both simplicity - it requires no special preparation and lives in a double quantum dot with no added complexity - and is very fast: we demonstrate full control on the Bloch sphere with $π$-rotation times less than 100 ps in two orthogonal directions. We report full process tomography, extracting high fidelities equal to or greater than 85% for X-rotations and 94% for Z-rotations. We discuss a path forward to fidelities better than the threshold for quantum error correction.
description: 6 pages, excluding Appendix
Reflecting on Motivations: How Reasons to Publish affect Research Behaviour in Astronomy
Creators: name: Heuritsch, Julia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Recent research in the field of reflexive metrics have studied the emergence and consequences of evaluation gaps in science. The concept of evaluation gaps captures potential discrepancies between what researchers value about their research, in particular research quality, and what metrics measure. As a result, scientists may experience anomie and adopt innovative ways to cope. These often value quantity over quality and may even compromise research integrity. A consequence of such gaps may therefore be research misconduct and a decrease in research quality. In the language of rational choice theory, an evaluation gap persists if motivational factors arising out of the internal component of an actors situation are incongruent with those arising out of the external components. The aim of this research is therefore to study and compare autonomous and controlled motivations to become an astronomer, to do research in astronomy and to publish scientific papers. Moreover, we study how these different motivational factors affect publication pressure, the experience of organisational justice and the observation of research misconduct. In summary, we find evidence for an evaluation gap and that controlled motivational factors arising from evaluation procedures based on publication record drives up publication pressure, which, in turn, was found to increase the likelihood of perceived frequency of misbehaviour.
description: Keywords: Reflexive Metrics, Research Behaviour, Autonomous Motivation, Controlled Motivation, Evaluation Gap
A minimal model for acoustic forces on Brownian particles
Creators: name: Usabiaga, F. Balboa
name: Delgado-Buscalioni, R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We present a generalization of the inertial coupling (IC) [Usabiaga et al. J. Comp. Phys. 2013] which permits the resolution of radiation forces on small particles with arbitrary acoustic contrast factor. The IC method is based on a Eulerian-Lagrangian approach: particles move in continuum space while the fluid equations are solved in a regular mesh (here we use the finite volume method). Thermal fluctuations in the fluid stress, important below the micron scale, are also taken into account following the Landau-Lifshitz fluid description. Each particle is described by a minimal cost resolution which consists on a single small kernel (bell-shaped function) concomitant to the particle. The main role of the particle kernel is to interpolate fluid properties and spread particle forces. Here, we extend the kernel functionality to allow for an arbitrary particle compressibility. The particle-fluid force is obtained from an imposed no-slip constraint which enforces similar particle and kernel fluid velocities. This coupling is instantaneous and permits to capture the fast, non-linear effects underlying the radiation forces on particles. Acoustic forces arise either because an excess in particle compressibility (monopolar term) or in mass (dipolar contribution) over the fluid values. Comparison with theoretical expressions show that the present generalization of the IC method correctly reproduces both contributions. Due to its low computational cost, the present method allows for simulations with many particles using a standard Graphical Processor Unit (GPU).
Relaxed DP-3-coloring of planar graphs without some cycles
Creators: name: Fang, Huihui
name: Wang, Tao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C15

description: Dvořák and Postle introduced the concept of DP-coloring to overcome some difficulties in list coloring. Sittitrai and Nakprasit combined DP-coloring and defective list coloring to define a new coloring -- relaxed DP-coloring. For relaxed DP-coloring, Sribunhung et al. proved that planar graphs without 4- and 7-cycles are DP-(0, 2, 2)-colorable. Li et al. proved that planar graphs without 4, 8-cycles or 4, 9-cycles are DP-(1, 1, 1)-colorable. Lu and Zhu proved that planar graphs without 4, 5-cycles, or 4, 6-cycles, or 4, 7-cycles are DP-(1, 1, 1)-colorable. In this paper, we show that planar graphs without 4, 6-cycles or 4, 8-cycles are DP-(0, 2, 2)-colorable.
description: 9 pages, 1 figure. A note is added
Throughput Optimal Flow Allocation on Multiple Paths for Random Access Wireless Multi-hop Networks
Creators: name: Ploumidis, Manolis
name: Pappas, Nikolaos
name: Traganitis, Apostolos
Publisher: name: arXiv
Year: 2013
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: In this paper we consider random access wireless multi-hop mesh networks with multi-packet reception capabilities where multiple flows are forwarded to the gateways through node disjoint paths. We address the issue of aggregate throughput-optimal flow rate allocation with bounded delay guarantees. We propose a distributed flow rate allocation scheme that formulates flow rate allocation as an optimization problem and derive the conditions for non-convexity for an illustrative topology. We also employ a simple model for the average aggregate throughput achieved by all flows that captures both intra- and inter-path interference. The proposed scheme is evaluated through NS-2 simulations. Our preliminary results are derived from a grid topology and show that the proposed flow allocation scheme slightly underestimates the average aggregate throughput observed in two simulated scenarios with two and three flows respectively. Moreover it achieves significantly higher average aggregate throughput than single path utilization in two different traffic scenarios examined.
description: Accepted for publication at the 9th IEEE BROADBAND WIRELESS ACCESS WORKSHOP (BWA2013), IEEE Globecom 2013 Workshops
PRÁTICA EXPERIMENTAL EM ELETROMAGNETISMO E ENSINO DE FÍSICA: UM RELATO DE EXPERIÊNCIA NO CURSO DE LICENCIATURA EM CIÊNCIAS DA NATUREZA
Creators: name: Fernando Icaro Jorge Cunha
name: Carla Beatriz Spohr
Publisher: name: Zenodo
Year: 2024

description: O ensino de Física, ao se dissociar dos aspectos sociais e da realidade dos estudantes, enfrenta desafios e pode se tornar abstrato. No contexto do Ensino Superior, a abordagem da Física demanda a integração da Ciência, Tecnologia, Sociedade e Ambiente (CTSA), visando formar educadores embasados tanto em teoria quanto em prática, capazes de promover o pensamento crítico. Este trabalho consiste em um relato de experiência fundamentado em quatro práticas experimentais realizadas na componente curricular de Eletromagnetismo, sob a perspectiva de um discente do Curso de Licenciatura em Ciências da Natureza. Quanto à metodologia, caracteriza-se como qualitativa, integrando revisão narrativa de literatura aos resultados experimentais, estabelecendo conexões entre os fundamentos científicos e os tópicos abordados. Os resultados e conclusões indicam que as práticas proporcionaram uma experiência de aprendizagem significativa em eletrostática e eletrodinâmica, explorando temas como carga elétrica, força elétrica, eletrização, campo elétrico, corrente elétrica, tensão, resistência elétrica, leis de Ohm e propriedades do magnetismo.
A Robust Initialization of Residual Blocks for Effective ResNet Training without Batch Normalization
Creators: name: Civitelli, Enrico
name: Sortino, Alessio
name: Lapucci, Matteo
name: Bagattini, Francesco
name: Galvan, Giulio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Batch Normalization is an essential component of all state-of-the-art neural networks architectures. However, since it introduces many practical issues, much recent research has been devoted to designing normalization-free architectures. In this paper, we show that weights initialization is key to train ResNet-like normalization-free networks. In particular, we propose a slight modification to the summation operation of a block output to the skip-connection branch, so that the whole network is correctly initialized. We show that this modified architecture achieves competitive results on CIFAR-10, CIFAR-100 and ImageNet without further regularization nor algorithmic modifications.
description: 16 pages (4 pages of supplementary material), 9 figures, 2 table
Effects of a temperature dependent viscosity on thermal convection in binary mixtures
Creators: name: Hilt, Markus
name: Glässl, Martin
name: Zimmermann, Walter
Publisher: name: arXiv
Year: 2013
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We investigate the effect of a temperature dependent viscosity on the onset of thermal convection in a horizontal layer of a binary fluid mixture that is heated from below. For an exponential temperature dependence of the viscosity, we find in binary mixtures as a function of a positive separation ratio and beyond a certain viscosity contrast a discontinuous transition between two stationary convection modes having a different wavelength. In the range of negative values of the separation ratio, a (continuous or discontinuous) transition from an oscillatory to a stationary onset of convection occurs beyond a certain viscosity contrast, and for large values of the viscosity ratio, the oscillatory onset of convection is suppressed.
Almost everywhere ergodicity in quantum lattice models
Creators: name: Ampelogiannis, Dimitrios
name: Doyon, Benjamin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We rigorously examine the ergodic properties of quantum lattice models with short range interactions, in the C* algebra formulation of statistical mechanics. Ergodicity results, in the context of group actions on C* algebras, assume that the algebra is asymptotically abelian, which is not the case for time evolution. The Lieb-Robinson bound tells us that the spatial extent of the time evolution of operators is exponentially small outside a light-cone, defined by the Lieb-Robinson velocity. More precisely, this means that the algebra of observables is asymptotically abelian only in a space-like region. This implies a form of ergodicity outside the light-cone, but what happens within it? We show that the long-time average of connected correlation functions of observables, along space-time rays of almost every speed, vanishes. This holds in any state that is invariant under space-time translations and that satisfies weak clustering properties in space. Further, we show that the long-time limit of the n-th moment, with respect to the state, of a ray-averaged observable converges to the n-th power of its ensemble average, which means that there are no fluctuations of ray averages in the long time limit. This is a statement of ergodicity. The ray averages can also be performed in a way that accounts for oscillations, showing that correlations (and moments) of the ray averaged observables cannot sustainably oscillate in the long time limit. Finally, we show that in the GNS representation of the algebra of observables, for any KMS state with the above properties, the long-time limit of the ray averaged commutator converges (in the strong operator topology (SOT)) to 0 and the ray average of any observable converges (in the SOT) to a multiple of the identity. This indicates that observables get "thinner" almost everywhere within the light-cone.
description: v3:Accepted for publication in Commun. Math. Phys. v2:Re-organised results; gave more general statements for some Theorems ( 3.5, 3.6, 3.15 ); added Th 3.10 and proof in Sec. 7, added Th 3.17; added Th 4.4 and proof appendix C; removed trivial corollaries; simplified proofs in Sec. 5, 6.1; re-organised proofs in Sec. 6.1; added Appendix B; added discussion
Lie-Hamilton systems on the plane: properties, classification and applications
Creators: name: Ballesteros, A.
name: Blasco, A.
name: Herranz, F. J.
name: de Lucas, J.
name: Sardón, C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 34A26 (Primary), 17B81, 34A34, 53Z05 (Secondary)

description: We study Lie-Hamilton systems on the plane, i.e. systems of first-order differential equations describing the integral curves of a $t$-dependent vector field taking values in a finite-dimensional real Lie algebra of planar Hamiltonian vector fields with respect to a Poisson structure. We start with the local classification of finite-dimensional real Lie algebras of vector fields on the plane obtained in [A. González-López, N. Kamran and P.J. Olver, Proc. London Math. Soc. 64, 339 (1992)] and we interpret their results as a local classification of Lie systems. Moreover, by determining which of these real Lie algebras consist of Hamiltonian vector fields with respect to a Poisson structure, we provide the complete local classification of Lie-Hamilton systems on the plane. We present and study through our results new Lie-Hamilton systems of interest which are used to investigate relevant non-autonomous differential equations, e.g. we get explicit local diffeomorphisms between such systems. In particular, the Milne-Pinney, second-order Kummer-Schwarz, complex Riccati and Buchdahl equations as well as some Lotka-Volterra and nonlinear biomathematical models are analysed from this Lie-Hamilton approach.
description: 37 pages
Differences in immunogenicity associated with non-product related variability: insights from two pharmacokinetic studies using GP2017, an adalimumab biosimilar
Creators: name: von Richter, Oliver
name: Lemke, Lena
name: Haliduola, Halimuniyazi
name: Balfour, Alison
name: Zehnpfennig, Britta
name: Skerjanec, Andrej
name: Jauch-Lembach, Julia
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Immunology
subject: FOS: Clinical medicine

description: Introduction: Antidrug antibody (ADA) development is known to occur with adalimumab treatment and impacts adalimumab exposure. Here, we compare the impact of immunogenicity on pharmacokinetics (PK) across two randomized PK studies of GP2017, an approved biosimilar adalimumab, in healthy subjects. Methods: Healthy male subjects (N= 107 in study GP17-104; N= 90 in study GP17-103) received a single 40 mg subcutaneous injection of the same GP2017 drug product batch. Cross-study PK comparison was performed for log-transformed Cmax, AUC0–360h, AUC0–last, and AUC0–inf, using an ANCOVA model. Results: The proportion of ADA-positive subjects was higher in GP17-103 (in total 71.1%) vs. GP17-104 (57.9%). Comparison of GP2017 PK between studies showed that the exposure was lower in GP17-103 vs GP17-104, with 90% confidence intervals (CIs) for geometric mean ratios of AUC0–last and AUC0–inf being outside the range of 0.80–1.25. A subgroup analysis showed that in ADA-negative subjects 90% CIs for all PK parameters were within range, with geometric mean ratios close to 1.00. Conclusion: The differences in GP2017 PK between the two groups are not considered to be product-related, but may be due to currently unknown factors related to differences between the two study populations.