cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Hamiltonian Loop Group Actions and T-Duality for group manifolds
Creators: name: Cabrera, A.
name: Montani, H.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We carry out a Hamiltonian analysis of Poisson-Lie T-duality based on the loop geometry of the underlying phases spaces of the dual sigma and WZW models. Duality is fully characterized by the existence of equivariant momentum maps on the phase spaces such that the reduced phase space of the WZW model and a pure central extension coadjoint orbit work as a bridge linking both the sigma models. These momentum maps are associated to Hamiltonian actions of the loop group of the Drinfeld double on both spaces and the duality transformations are explicitly constructed in terms of these actions. Compatible dynamics arise in a general collective form and the resulting Hamiltonian description encodes all known aspects of this duality and its generalizations.
description: 34 pages
HT Camelopardalis: The simplest intermediate polar spin pulse
Creators: name: Evans, P. A.
name: Hellier, Coel
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The intermediate polar HT Cam is unusual in that it shows no evidence for dense absorption in its spectrum. We analyse an XMM-Newton observation of this star, which confirms the absence of absorption and shows that the X-ray spin-pulse is energy independent. The modulation arises solely from occultation effects and can be reproduced by a simple geometrical model in which the lower accretion footprint is fainter than the upper one. We suggest that the lack of opacity in the accretion columns of HT Cam, and also of EX Hya and V1025 Cen, results from a low accretion rate owing to their being below the cataclysmic variable period gap.
description: 5 pages, 6 figures, accepted for publication in MNRAS
The systemic impacts of war : child soldiers and artists in Mozambique, a cultural and structural analysis
Creators: name: Teves, Sandra
Publisher: name: University of British Columbia
Year: 2009

description: Between 1976 and 1992 a vicious armed conflict raged in Mozambique. This history provides essential background for the thesis that explores the impact of armed conflict on individuals who were under 18 at the time. These include former child soldiers and others who have dealt with the experience of war by transforming weapons into art. Eleven years after a peace accord was signed in Mozambique, former child soldiers and artists were interviewed to explore their experiences. Understanding the Mozambican conflict and its impact on young people requires an examination of international frameworks. The thesis examines the United Nations Convention on the Rights of the Child and the limits of a 'rights-based perspective'. The use of children in war requires an understanding of the nature of 'new wars'. The argument is made that conditions created by global institutions and other global factors are as important to understanding the current problems former, child soldiers face, as is their historical experience. The Turning Arms into Ploughshares (TAE) project is a disarmament initiative that exchanges weapons for development tools. Study participants were related to this project. The thesis provides a structural analysis of macro conditions influencing their lives. While attention is paid to global considerations, the role of cultural practices and impacts on healing and reconciliation are noted. The thesis uses a critical cultural studies perspective, based on the work of the Frankfurt School (Adorno, Horkemier, Marcuse and Fromm). Five themes explore the experience and problems confronting former child soldiers and young artists. These are: (1) Education, War and Lost Social Opportunity, (2) Marginalization and Meaning, (3) Exchanging Guns: why bother and for what? (4) Being and Becoming: Healing and Recovery and (5) Art and the Culture o f Hope. The conclusion addresses approaches to social work practice in international settings and the importance of considering global and historical factors when working with children affected by war and living in post-conflict settings The work cautions against overemphasizing the uniqueness of individual experience and failing to pay adequate attention to needs all human beings have in common, and structural realities increasingly affecting all children, worldwide.
Quantum transport theory for nanostructures with Rashba spin-orbital interaction
Creators: name: Sun, Qing-feng
name: Wang, Jian
name: Guo, Hong
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on a general theory for analyzing quantum transport through devices in the Metal-QD-Metal configuration where QD is a quantum dot or the device scattering region which contains Rashba spin-orbital and electron-electron interactions. The metal leads may or may not be ferromagnetic, they are assumed to weakly couple to the QD region. Our theory is formulated by second quantizing the Rashba spin-orbital interaction in spectral space (instead of real space), and quantum transport is then analyzed within the Keldysh nonequilibrium Green's function formalism. The Rashba interaction causes two main effects to the Hamiltonian: (i) it gives rise to an extra spin-dependent phase factor in the coupling matrix elements between the leads and the QD; (ii) it gives rise to an inter-level spin-flip term but forbids any intra-level spin-flips. Our formalism provides a starting point for analyzing many quantum transport issues where spin-orbital effects are important. As an example, we investigate transport properties of a Aharnov-Bohm ring in which a QD having Rashba spin-orbital and e-e interactions is located in one arm of the ring. A substantial spin-polarized conductance or current emerges in this device due to a combined effect of a magnetic flux and the Rashba interaction. The direction and strength of the spin-polarization are shown to be controllable by both the magnetic flux and a gate voltage.
description: 12 pages, 8 figures
Additional file 7 of Digital tools for the recruitment and retention of participants in randomised controlled trials: a systematic map
Creators: name: Frampton, Geoff K.
name: Shepherd, Jonathan
name: Pickett, Karen
name: Griffiths, Gareth
name: Wyatt, Jeremy C.
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 7: Appendix 4. List of map keywords with explanations and comments.
On higher spin Uq(sl_2)-invariant R-matrices
Creators: name: Bytsko, Andrei
Publisher: name: arXiv
Year: 2004
Subjects: subject: Quantum Algebra (math.QA)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 81R50

description: The spectral decomposition of regular Uq(sl_2)-invariant solutions of the Yang-Baxter equation is studied. An algorithm for finding all possible solutions of spin s is developed. It also allows to reconstruct the R-matrix from a given nearest neighbour spin chain Hamiltonian. The algorithm is based on reduction of the Yang-Baxter equation to certain subspaces. As an application, the complete list of inequivalent regular Uq(sl_2)-invariant R-matrices is obtained for generic q and spins up to s=3/2. Some further results about spectral decompositions for higher spins are also obtained. In particular, it is proved that certain types of regular sl_2-invariant R-matrices have no Uq(sl_2)-invariant counterparts.
description: 17 pages, LaTeX 2e
Additional file 4 of Digital tools for the recruitment and retention of participants in randomised controlled trials: a systematic map
Creators: name: Frampton, Geoff K.
name: Shepherd, Jonathan
name: Pickett, Karen
name: Griffiths, Gareth
name: Wyatt, Jeremy C.
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 4: Appendix 1. Systematic map protocol
Canonical Lie-transform method in Hamiltonian gyrokinetics: a new approach
Creators: name: Nicolini, Piero
name: Tessarotto, Massimo
Publisher: name: arXiv
Year: 2004
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The well-known gyrokinetic problem regards the perturbative expansion related to the dynamics of a charged particle subject to fast gyration motion due to the presence of a strong magnetic field. Although a variety of approaches have been formulated in the past to this well known problem, surprisingly a purely canonical approach based on Lie transform methods is still missing. This paper aims to fill in this gap and provide at the same time new insight in Lie-transform approaches.
description: 6 pages, 1 figure. Contributed to the Proceedings of the 24th International Symposium on Rarefied Gas Dynamics, July 10-16, 2004 Porto Giardino Monopoli (Bari), Italy
Possible evidence of ongoing planet formation in AB Aurigae. A showcase of the SPHERE/ALMA synergy
Creators: name: Boccaletti, A.
name: Di Folco, E.
name: Pantin, E.
name: Dutrey, A.
name: Guilloteau, S.
name: Tang, Y. W.
name: Piétu, V.
name: Habart, E.
name: Milli, J.
name: Beck, T. L.
name: Maire, A. -L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Planet formation is expected to take place in the first million years of a planetary system through various processes, which remain to be tested through observations. Aims. With the recent discovery, using ALMA, of two gaseous spiral arms inside the 120 au cavity and connected to dusty spirals, the famous protoplanetary disk around AB Aurigae presents a strong incentive for investigating the mechanisms that lead to giant planet formation. A candidate protoplanet located inside a spiral arm has already been claimed in an earlier study based on the same ALMA data. Methods. We used SPHERE at the Very Large Telescope (VLT) to perform near-infrared (IR) high-contrast imaging of AB Aur in polarized and unpolarized light in order to study the morphology of the disk and search for signs of planet formation. Results. SPHERE has delivered the deepest images ever obtained for AB Aur in scattered light. Among the many structures that are yet to be understood, we identified not only the inner spiral arms, but we also resolved a feature in the form of a twist in the eastern spiral at a separation of about 30 au. The twist of the spiral is perfectly reproduced with a planet-driven density wave model when projection effects are accounted for. We measured an azimuthal displacement with respect to the counterpart of this feature in the ALMA data, which is consistent with Keplerian motion on a 4-yr baseline. Another point sxce is detected near the edge of the inner ring, which is likely the result of scattering as opposed to the direct emission from a planet photosphere. We tentatively derived mass constraints for these two features. Conclusions. The twist and its apparent orbital motion could well be the first direct evidence of a connection between a protoplanet candidate and its manifestation as a spiral imprinted in the gas and dust distributions.
description: accepted in Astronomy and Astrophysics, 8 pages, 5 figures
Agricultural and Food Security Policy Analysis in Central America: Assessing Local Institutional Capacity, Data Availability, and Outcomes
Creators: name: Tschirley, David L.
name: Flores, Luis
name: Mather, David
name: Tschirley, David L.
name: Flores, Luis
name: Mather, David
Publisher: name: Unknown
Year: 2010
Subjects: subject: Agricultural and Food Policy
subject: Community/Rural/Urban Development
subject: Food Security and Poverty
subject: International Development
subject: Food Security
subject: Guatemala
subject: Nicaragua
subject: food policy

description: Performance of the agricultural sector in developing countries is fundamental to ensuring robust and equitable economic growth and broad-based food security. Yet donor support to agricultural development in developing countries has declined continuously for 30 years. This same period saw dramatic deterioration in developing countries’ institutional capacity to provide services to their agricultural sectors. These trends may now be changing, due in part to the global food price crisis of 2007 and 2008 and concerns that it unleashed about the world’s ability to feed its poorest inhabitants. This paper reports on the results of a two week trip to Guatemala and Nicaragua made by Michigan State University’s Food Security Group. The purpose of the trip was to assess two aspects that form the foundation for applied agricultural and food security policy analysis and outreach: (a) the organizations involved in research and outreach on these topics, and (b) existing data sets and processes for continued generation of data sets useful in such analysis and outreach. The team also explored the extent to which policy makers and designers of public programs solicit empirical data and analysis for the design and implementation of local food security programs and policies.
The Space Density of Moderate Luminosity Active Galaxies at z=3
Creators: name: Nandra, K.
name: Laird, E. S.
name: Steidel, C. C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an estimate of the space density of Active Galactic Nuclei (AGN) at z=3. Combining deep X-ray data with Lyman Break Galaxy (LBG) colour-selection in the rest-frame UV makes for highly efficient identification of AGN in a narrow redshift range (z~2.5-3.5). Using Chandra data from the Groth-Westphal Strip and the Hubble Deep Field North, we find a total of 15 X-ray detected LBGs at z~3, the majority of which are unlikely to have been identified in blanket followup surveys of X-ray detected objects. We find the comoving space density of moderate luminosity AGN at z=3 to be a factor ~10 higher than the most powerful objects. The available data are consistent with a roughly constant space density of MLAGN from z=0.5-3, and they are also consistent with a mild decline in the space density above z=1 as predicted by the luminosity-dependent density evolution models of Ueda et al. (2003). This strong AGN activity at z=3 argues against previous suggestions that the majority of black hole accretion occurs at low redshift. A further implication of our investigation is that, as far as can be determined from current data, the majority of the AGN population at z~3 are selected by the LBG dropout technique. Although this is sensitive to AGN with a UV-excess due to an accretion disk, it predominantly identifies star-forming galaxies. A significant fraction of X-ray sources seem likely to be hosted by these more typical LBGs, further strengthening the starburst-AGN connection at high redshift.
description: 6 pages, 1 figures, MNRAS, in press
Measuring and controlling radio-frequency quanta with superconducting circuits
Creators: name: Gely, Mario Florentin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this PhD thesis, we will present the theoretical and experimental work that led to the realization of a radio-frequency circuit quantum electrodynamics system (RFcQED). In chapter 2, we provide a detailed derivation of the Hamiltonian of circuit QED formulated in the context of the Rabi model, and extract expressions for the cross-Kerr interaction. The resulting requirements for the coupling rate in RFcQED are discussed, one of them being the need to dramatically increase the coupling rate compared to typical circuit QED device. In chapter 3 we cover two experimental approaches to increasing the coupling in a circuit QED system, one making use of a high impedance resonator, the second utilizing a large coupling capacitor. In chapter 4, we combine these two approaches to implement RFcQED. Through strong dispersive coupling, we could measure individual photons in a megahertz resonator, demonstrate quantum control by cooling the resonator to the ground state or preparing Fock states, and finally observe with nanosecond resolution the re-thermalization of these states. In chapter 5 we present QuCAT or Quantum Circuit Analyzer Tool in Python, a software package that can be used for the design of circuit QED systems such as the one presented in this thesis. In chapter 6 we discuss how certain interplays between general relativity and quantum mechanics cannot be described using our current laws of physics. In particular, we show how radio-frequency mechanical oscillators are perfect candidates to perform experiments in this regime. In chapter 7 we present the prospects for coupling such mechanical oscillator to weakly anharmonic superconducting circuits such as the transmon qubit or RFcQED systems.
description: PhD thesis, 212 pages, 67 figures. Heavily compressed figures, see DOI for full resolution
Managing Crowded Museums: Visitors Flow Measurement, Analysis, Modeling, and Optimization
Creators: name: Centorrino, Pietro
name: Corbetta, Alessandro
name: Cristiani, Emiliano
name: Onofri, Elia
Publisher: name: arXiv
Year: 2020
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We present an all-around study of the visitors flow in crowded museums: a combination of Lagrangian field measurements and statistical analyses enable us to create stochastic digital-twins of the guests dynamics, unlocking comfort- and safety-driven optimizations. Our case study is the Galleria Borghese museum in Rome (Italy), in which we performed a real-life data acquisition campaign. We specifically employ a Lagrangian IoT-based visitor tracking system based on Raspberry Pi receivers, displaced in fixed positions throughout the museum rooms, and on portable Bluetooth Low Energy beacons handed over to the visitors. Thanks to two algorithms: a sliding window-based statistical analysis and an MLP neural network, we filter the beacons RSSI and accurately reconstruct visitor trajectories at room-scale. Via a clustering analysis, hinged on an original Wasserstein-like trajectory-space metric, we analyze the visitor paths to get behavioral insights, including the most common flow patterns. On these bases, we build the transition matrix describing, in probability, the room-scale visitor flows. Such a matrix is the cornerstone of a stochastic model capable of generating visitor trajectories in silico. We conclude by employing the simulator to increase the number of daily visitors while respecting numerous logistic and safety constraints. This is possible thanks to optimized ticketing and new entrance/exit management.
Utilising and Developing Methods for Routinely Collected Data in Health Research
Creators: name: Garner, Alex
Publisher: name: Lancaster University
Year: 2024

description: The UK’s National Health Service (NHS) is at a turning point, the
 organisation is

 still recovering from the ongoing impact of the COVID-19 pandemic and
 healthcare

 worker strikes have further increased pressures on healthcare delivery.
 Technological advancements and improvements in data usage both provide
 significant opportunities and challenges for the NHS’s near future.

 Data is collected for almost every patient interaction with the NHS, this
 is

 routinely collected data (RCD). There are vast amounts of RCD held within
 NHS

 systems, with massive potential for health research. Enabling large scale
 usage

 of this data requires complex data infrastructure along with streamlining
 of data access procedures, while ensuring patient data remains anonymous
 and confidential. Developing this infrastructure is a technological
 undertaking in itself.

 Presented in this thesis are three projects conducted using RCD
 demonstrating

 opportunities of using this data in research while providing findings to
 impact

 healthcare provision. The first project uses linked NHS data in a State
 Sequence

 Analysis to investigate patterns of healthcare usage of care home
 residents around COVID-19 testing events, demonstrating that vulnerable
 residents received high impact inpatient stays despite known risks. The
 second project evaluates a digital technology intervention in care homes
 using a Generalised Linear Mixed Model framework, finding a reduction in
 unplanned secondary care usage for residents registered on the technology.
 The third project uses administrative emergency department data in a
 survival analysis framework, finding improvements in patient flow on
 strike days are likely due to increased inpatient capacity made available.

 Improved access to NHS routine data is crucial to ensuring that
 researchers can

 undertake responsive analysis to current pressures, such as those
 presented in this thesis, providing evidence to support optimised patient
 care throughout the NHS.
Canted Antiferromagnetism in the Quasi-1D Iron Chalcogenide BaFe$_{2}$Se$_{4}$
Creators: name: Liu, Xiaoyuan
name: Taddei, Keith M.
name: Li, Sheng
name: Liu, Wenhao
name: Dhale, Nikhil
name: Kadado, Rashad
name: Berman, Diana
name: Cruz, Clarina Dela
name: Lv, Bing
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report the synthesis and physical properties studies of quais-1D iron chalcogenide $\rm BaFe_2Se_4$ which shares the $\rm FeSe_4$ tetrahedra building motif commonly seen in the iron chalcogenide superconductors. A high-quality polycrystalline sample was achieved by solid-state reaction method and characterized by X-ray diffraction, electrical resistivity, magnetic susceptibility and neutron diffraction measurements. $\rm BaFe_2Se_4$ is a narrow gap semiconductor that magnetically orders at $\sim$ 310 K. Both neutron powder diffraction results and isothermal M-H loops suggest a canted antiferromagnetic structure where Fe sublattice are antiferromagnetically ordered along the c-axis quasi-1D chain direction, resulting in a net ferromagnetic moment in the perpendicular direction along the a-axis with tilted angle of 18.7$^\circ$ towards the b-axis.
description: 8 pages, 4 figures
Skills, Qualities and Experiences Needed for Future Leaders in Food and Agribusiness Industries of Armenia
Creators: name: Urutyan, Vardan E.
name: Litzenberg, Kerry K.
name: Urutyan, Vardan E.
name: Litzenberg, Kerry K.
Publisher: name: Unknown
Year: 2010
Subjects: subject: Agribusiness
subject: Industrial Organization
subject: Teaching/Communication/Extension/Profession
subject: Armenian agribusiness industry
subject: curriculum
subject: skills
subject: employer
subject: education

description: It is widely recognized that academia should prepare students for the job market as well as provide general education. An important aspect of agribusiness education is that industry leaders expect graduates to have several skills that improve the management capacity of the firm. This responsibility means that curriculum development and implementation must not be conducted by academicians in isolation. Industry must participate and play an active role in curriculum design and curricular reforms. The study quantifies agribusiness industry preferences for agribusiness education and identifies the skills, capabilities and experiences the food and agribusiness companies in Armenia look for in their new employees with the potential to become future leaders in their firms.
description: www.ifama.org
Additional file 3 of Digital tools for the recruitment and retention of participants in randomised controlled trials: a systematic map
Creators: name: Frampton, Geoff K.
name: Shepherd, Jonathan
name: Pickett, Karen
name: Griffiths, Gareth
name: Wyatt, Jeremy C.
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 3: Additional Table 3. List of studies excluded at full-text screening (N = 251) (reference list below table).
BOSHLANGʻICH SINF OʻQUVCHILARINING OʻQISH VA TUSHUNISH KOMPETENSIYASINI TAKOMILLASHTIRISH
Creators: name: Hasanova, Gulbahor
Publisher: name: Zenodo
Year: 2024

description: Ushbu tezis, boshlangʻich sinf oʻquvchilarining oʻqish va tushunish kompetensiyasini takomillashtirish masalalariga qaratilgan bo‘lib, bugungi kunda yurtimizda amalga oshirilayotgan ta’lim tizimidagi islohotlar bilan tahlil qiliingan.
Self-organized synchronization of phonon lasers
Creators: name: Sheng, Jiteng
name: Wei, Xinrui
name: Yang, Cheng
name: Wu, Haibin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: Self-organized synchronization is a ubiquitous collective phenomenon, in which each unit adjusts their rhythms to achieve synchrony through mutual interactions. The optomechanical systems, due to their inherently engineerable nonlinearities, provide an ideal platform to study self-organized synchronization. Here, we demonstrate the self-organized synchronization of phonon lasers in a two-membrane-in-the-middle optomechanical system. The probe of individual membrane enables to monitor the real-time transient dynamics of synchronization, which reveal that the system enters into the synchronization regime via torus birth bifurcation line. The phase-locking phenomenon and the transition between in-phase and anti-phase regimes are directly observed. Moreover, such a system greatly facilitate the controllable synchronous states, and consequently a phononic memory is realized by tuning the system parameters. This result is an important step towards the future studies of many-body collective behaviors in multiresonator optomechanics with long distances, and might find potential applications in quantum information processing and complex networks.
An XMM-Newton view of the cluster of galaxies Abell 85
Creators: name: Durret, F.
name: Neto, G. B. Lima
name: Forman, W.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have observed the cluster of galaxies Abell 85 with XMM-Newton. These data have allowed us to confirm in a previous paper the existence of the extended 4 Mpc filament detected by the ROSAT PSPC in the neighbourhood of this cluster, and to determine an X-ray temperature of about about 2 keV. We now present a thorough analysis of the properties of the X-ray gas in the cluster itself, including temperature and metallicity maps for the entire cluster. These results show that Abell 85 had intense merging activity in the past and is not fully relaxed, even in the central region. We have also determined the individual abundances for some iron-group metals and alpha-elements in various regions; the ratios of these metallicities to the iron abundance show that both supernova types Ia and II must be involved in the intra-cluster gas enrichment. Spectral analysis of the central region suggests a different redshift of the X-ray emitting gas compared to the mean cluster velocity derived from galaxy member redshifts. We discuss the implications of the difference between the cD galaxy redshift, the mean galaxy redshift and the hot gas redshift, as well as the possibility of several groups being accreted on to Abell 85. Finally, we obtain the dynamical mass profile and baryon fraction taking into account the new determined temperature profile. The dynamical mass in Abell 85 has a steep density profile, similar to the ones found in N-body simulations.
description: Accepted for publication in Astronomy & Astrophysics
Low- and high-frequency noise from coherent two-level systems
Creators: name: Shnirman, Alexander
name: Schön, Gerd
name: Martin, Ivar
name: Makhlin, Yuriy
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Recent experiments indicate a connection between the low- and high-frequency noise affecting superconducting quantum systems. We explore the possibilities that both noises can be produced by one ensemble of microscopic modes, made up, e.g., by sufficiently coherent two-level systems (TLS). This implies a relation between the noise power in different frequency domains, which depends on the distribution of the parameters of the TLSs. We show that a distribution, natural for tunneling TLSs, with a log-uniform distribution in the tunnel splitting and linear distribution in the bias, accounts for experimental observations.
description: minor corrections, references added
Experimental measurement of relative path probabilities and stochastic actions
Creators: name: Gladrow, Jannes
name: Keyser, Ulrich F.
name: Adhikari, R.
name: Kappler, Julian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: For diffusive stochastic dynamics, the probability to observe any individual trajectory is vanishingly small, making it unclear how to experimentally validate theoretical results for ratios of path probabilities. We provide the missing link between theory and experiment, by establishing a protocol to extract ratios of path probabilities from measured time series. For experiments on a single colloidal particle in a microchannel, we extract both ratios of path probabilities, and the most probable path for a barrier crossing, and find excellent agreement with independently calculated predictions based on the Onsager-Machlup stochastic action. Our experimental results at room temperature are found to be inconsistent with the low-noise Freidlin-Wentzell stochastic action, and we discuss under which circumstances the latter is expected to describe the most probable path. Furthermore, while the experimentally accessible ratio of path probabilities is uniquely determined, the formal path-integral action is known to depend on the time-discretization scheme used for deriving it; we reconcile these two seemingly contradictory facts by careful analysis of the time-slicing derivation of the path integral. Our experimental protocol enables us to probe probability distributions on path space, and allows us to relate theoretical single-trajectory results to measurement.
description: 24 pages, 12 figures; accepted at Physical Review X
A Characterization of the optimal risk-Sensitive average cost in finite controlled Markov chains
Creators: name: Cavazos-Cadena, Rolando
name: Hernandez-Hernandez, Daniel
Publisher: name: arXiv
Year: 2005
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 93E20, 60F10,, 93C55 (Primary) . (Secondary)

description: This work concerns controlled Markov chains with finite state and action spaces. The transition law satisfies the simultaneous Doeblin condition, and the performance of a control policy is measured by the (long-run) risk-sensitive average cost criterion associated to a positive, but otherwise arbitrary, risk sensitivity coefficient. Within this context, the optimal risk-sensitive average cost is characterized via a minimization problem in a finite-dimensional Euclidean space.
description: Published at http://dx.doi.org/10.1214/105051604000000585 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Statistical modelling and inference for discrete and censored familial data
Creators: name: Zhao, Yinshan
Publisher: name: University of British Columbia
Year: 2009

description: Analysis of familial data with quantitative traits based on the multivariate normal distribution has been well studied. However, little attention has been devoted to traits which do not have a multivariate normal distribution, such as traits with discrete or censored values. In this thesis, we devote our effort to (1) construct models for familial data when the trait value is discrete and/or censored, and (2) study alternative estimation methods when maximum likelihood estimation is infeasible. We discuss two existing classes of models: models with random effects which are multivariate normally distributed, and models constructed from the multivariate normal copula. These two classes include a variety of models which can be applied to familial data. We also propose another class of models which we call conditional independence models. This type of model is based on a conditional independence assumption: for a trait variable, we assume independence of a pair of non-sibling relatives conditional on their parents, so that the dependence structure is built on the Markov property. Maximum likelihood estimates are generally difficult to obtain for random effect models and copula models when there are large families involved. We propose two estimation procedures based on composite likelihoods: the first is a two-stage method in which univariate marginal parameters are estimated based on univariate marginal distributions and the dependence parameters are estimated separately based on bivariate marginal distributions with the marginal parameters treated as known; whereas in the second, all the parameters are estimated using the likelihoods of bivariate marginal distributions. The composite likelihood methods can greatly reduce computation in parameter estimation, but with a price of efficiency loss. In this thesis, extensive investigations based on asymptotic covariance matrices and simulations were carried out to compare the asymptotic efficiency of these two procedures with the maximum likelihood method. In our efficiency comparisons, we investigate the multivariate normal model for a continuous trait, the multivariate probit model for a binary trait, the multivariate Poisson-lognormal mixture model for a count trait and multivariate lognormal model for a censored variable. We found that when the dependence is strong, the first approach is inefficient for the regression parameters; whereas when the dependence is weak, the second approach is inefficient for the dependence parameters. In many familial analyses, quantifying familial association is of great interest. For a binary trait, the odds ratio may be used as a measure of association between a parent-offspring pair or a sibling pair. We develop theories so that the asymptotic variance of an odds ratio can be computed from a 2 x 2 contingency table formed by dependent pairs.
Cyber-Informed Machine Learning
Creators: name: Mellon, Jeffrey
name: Worrell, Clarence
Publisher: name: Carnegie Mellon University
Year: 2025
Subjects: classificationCode: 4612
subject: Software engineering
classificationCode: 4611
subject: Machine learning

description: Consider a security operations center (SOC) that monitors network and endpoint data in real time to identify threats to their enterprise. Depending on the size of its organization, the SOC may receive about 200,000 alerts per day. Only a small portion of these alerts can receive human attention because each investigated alert may require 15-to-20 minutes of analyst attention to answer a critical question for the enterprise: Is this a benign event, or is my organization under attack? This is a challenge for nearly all organizations, since even small enterprises generate far more network, endpoint, and log events than humans can effectively monitor. SOCs therefore must employ security monitoring software to pre-screen and downsample the number of logged events requiring human investigation. Machine learning (ML) for cybersecurity has been researched extensively because SOC activities are data rich, and ML is now increasingly deployed into security software. ML is not yet broadly trusted in SOCs, and a major barrier is that ML methods suffer from a lack of explainability. Without explanations, it is reasonable for SOC analysts not to trust the ML. Outside of cybersecurity, there are broad general demands for ML explainability. The European General Data Protection Regulation (Article 22 and Recital 71) encodes into law the “right to an explanation” when ML is used in a way that significantly affects an individual. The SOC analyst also has a need for explanations because the decisions they must make, often under time pressure and with ambiguous information, can have significant impacts on their organization. We propose cyber-informed machine learning as a conceptual framework for emphasizing three types of explainability when ML is used for cybersecurity:data-to-humanmodel-to-humanhuman-to-modelIn this blog post, we provide an overview of each type of explainability, and we recommend research needed to achieve the level of explainability necessary to encourage use of ML-based systems intended to support cybersecurity operations.
Localization properties of a one-dimensional tight-binding model with non-random long-range inter-site interactions
Creators: name: de Moura, F. A. B. F.
name: Malyshev, A. V.
name: Lyra, M. L.
name: Malyshev, V. A.
name: Dominguez-Adame, F.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We perform both analytical and numerical studies of the one-dimensional tight-binding Hamiltonian with stochastic uncorrelated on-site energies and non-fluctuating long-range hopping integrals . It was argued recently [A. Rodriguez at al., J. Phys. A: Math. Gen. 33, L161 (2000)] that this model reveals a localization-delocalization transition with respect to the disorder magnitude provided . The transition occurs at one of the band edges (the upper one for and the lower one for). The states at the other band edge are always localized, which hints on the existence of a single mobility edge. We analyze the mobility edge and show that, although the number of delocalized states tends to infinity, they form a set of null measure in the thermodynamic limit, i.e. the mobility edge tends to the band edge. The critical magnitude of disorder for the band edge states is computed versus the interaction exponent by making use of the conjecture on the universality of the normalized participation number distribution at transition.
description: 7 pages, 6 postscript figures, uses revtex4
Additional file 2 of Digital tools for the recruitment and retention of participants in randomised controlled trials: a systematic map
Creators: name: Frampton, Geoff K.
name: Shepherd, Jonathan
name: Pickett, Karen
name: Griffiths, Gareth
name: Wyatt, Jeremy C.
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 2: Additional Table 2. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 Checklist.
What is the trouble with Dyson--Schwinger equations?
Creators: name: Kreimer, Dirk
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss similarities and differences between Green Functions in Quantum Field Theory and polylogarithms. Both can be obtained as solutions of fixpoint equations which originate from an underlying Hopf algebra structure. Typically, the equation is linear for the polylog, and non-linear for Green Functions. We argue though that the crucial difference lies not in the non-linearity of the latter, but in the appearance of non-trivial representation theory related to transcendental extensions of the number field which governs the linear solution. An example is studied to illuminate this point.
description: 5 pages contributed to the proceedings "Loops and Legs 2004", April 2004, Zinnowitz, Germany
Product Life Cycles and Innovation in the US Seed Corn Industry
Creators: name: Magnier, Alexandre
name: Kalaitzandonakes, Nicholas G.
name: Miller, Douglas J.
name: Magnier, Alexandre
name: Kalaitzandonakes, Nicholas G.
name: Miller, Douglas J.
Publisher: name: Unknown
Year: 2010
Subjects: subject: Productivity Analysis
subject: Research and Development/Tech Change/Emerging Technologies
subject: Research Methods/ Statistical Methods
subject: Risk and Uncertainty
subject: accelerated failure time
subject: biotechnology
subject: product life cycle
subject: survival analysis

description: The purpose of this study is to evaluate potential changes in the length of product life cycles in the US seed corn industry. We use the observed survival time on the market for hybrids sold during 1997-2009 to conduct a survival analysis. Our empirical results show that the expected lifetimes for corn hybrids with single biotech traits are 5-15% longer than for hybrids with multiple (stacked) traits, and the expected lifetimes for conventional corn are 13-17% longer than stacked hybrids. Also, the product life cycles for all types of hybrids have decreased over the past twelve years (especially after 2004), but the rate of decline is roughly similar across hybrid types. Based on this evidence, we conclude that the shorter product life cycles are closely linked to the accelerated levels of biotech product innovation in the US seed corn industry over the period of analysis.
Additional file 1 of Digital tools for the recruitment and retention of participants in randomised controlled trials: a systematic map
Creators: name: Frampton, Geoff K.
name: Shepherd, Jonathan
name: Pickett, Karen
name: Griffiths, Gareth
name: Wyatt, Jeremy C.
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 1: Additional Table 1. Example systematic reviews of digital approaches for recruitment or retention in clinical and health studies.
Explicit expression for the photon number emission in synchrotron radiation
Creators: name: Manoukian, E. B.
name: Jearnkulprasert, N.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: An explicit and remarkably simple one-dimensional integral expression is derived for the mean number $$ of photons emitted per revolution in synchrotron radiation. The familiar high-energy expression $5πα/\sqrt{3(1-β^2)}$, printed repeatedly in the literature, is found to be inaccurate and only truly asymptotic with relative errors of 160%, 82% for $β=0.8$, 0.9, respectively. A new improved high-energy expression for $$ is given.
description: LaTeX, 3 pages, no figure
Large deviations of the empirical volume fraction for stationary Poisson grain models
Creators: name: Heinrich, Lothar
Publisher: name: arXiv
Year: 2005
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60D05\sep60F10 (Primary) 60G55\sep82B30 (Secondary)

description: We study the existence of the (thermodynamic) limit of the scaled cumulant-generating function L_n(z)=|W_n|^{-1}\logE\exp{z|Ξ\cap W_n|} of the empirical volume fraction |Ξ\cap W_n|/|W_n|, where |\cdot| denotes the d-dimensional Lebesgue measure. Here Ξ=\bigcup_{i\ge1}(Ξ_i+X_i) denotes a d-dimensional Poisson grain model (also known as a Boolean model) defined by a stationary Poisson process Π_λ=\sum_{i\ge1}δ_{X_i} with intensity λ>0 and a sequence of independent copies Ξ_1,Ξ_2,... of a random compact set Ξ_0. For an increasing family of compact convex sets {W_n, n\ge1} which expand unboundedly in all directions, we prove the existence and analyticity of the limit lim_{n\to\infty}L_n(z) on some disk in the complex plane whenever E\exp{a|Ξ_0|}0. Moreover, closely connected with this result, we obtain exponential inequalities and the exact asymptotics for the large deviation probabilities of the empirical volume fraction in the sense of Cramér and Chernoff.
description: Published at http://dx.doi.org/10.1214/105051604000001007 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Microscopic derivation of density functional theory for superfluid systems based on effective action formalism
Creators: name: Yokota, Takeru
name: Kasuya, Haruki
name: Yoshida, Kenichi
name: Kunihiro, Teiji
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: Superconductivity (cond-mat.supr-con)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Density-functional theory for superfluid systems is developed in the framework of the functional renormalization group based on the effective action formalism. We introduce the effective action for the particle-number and nonlocal pairing densities and demonstrate that the Hohenberg-Kohn theorem for superfluid systems is established in terms of the effective action. The flow equation for the effective action is then derived, where the flow parameter runs from $0$ to $1$, corresponding to the non-interacting and interacting systems. From the flow equation and the variational equation that the equilibrium density satisfies, we obtain the exact expression for the Kohn-Sham potential generalized to including the pairing potentials. The resultant Kohn-Sham potential has a nice feature that it expresses the microscopic formulae of the external, Hartree, pairing, and exchange-correlation terms, separately. It is shown that our Kohn-Sham potential gives the ground-state energy of the Hartree-Fock-Bogoliubov theory by neglecting the correlations. An advantage of our exact formalism lies in the fact that it provides ways to systematically improve the correlation part.
description: 26 pages, 1 figure, v2: sentences added to abstract & introduction, symbols unified
Low-cost stereo video design drawings: Handheld system and pelagic BRUVS
Creators: name: Lucas, Sol
name: Berggren, Per
name: Bown, Rosalind MK
name: Johns, Mark
name: Matthews, Sam
name: Nicol, Emma
name: Parton, Kristian
name: Rees, Richard
name: Scotts, Gemma
name: Walker, Victoria
name: Williams, Emma
name: Wright, Nick
name: Araujo, Gonzalo
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 310305
subject: Marine and estuarine ecology (incl. marine ichthyology)
classificationCode: 401501
subject: Marine engineering

description: Engineering drawings and components list for low-cost stereo video systems (handheld systems and pelagic BRUVS)
Measurement of Sugar Cane Chain in Brazil
Creators: name: Neves, Marcos Fava
name: Gustavo Trombin, Vinicius
name: Alberto Consoli, Matheus
name: Neves, Marcos Fava
name: Gustavo Trombin, Vinicius
name: Alberto Consoli, Matheus
Publisher: name: Unknown
Year: 2010
Subjects: subject: Crop Production/Industries
subject: Industrial Organization
subject: chain mapping
subject: chain quantification
subject: agro-industry system
subject: sugar cane sector
subject: ethanol
subject: sugar

description: Despite the historical importance of the sugarcane business in Brazil, which is as old in the country as its colonization, it has never been "photographed in widescreen". This research on the mapping and quantification of business generated in the sugarcane chain in 2008 for the first time gives the scale of the entire sugarcane productive chain in Brazil. The sector now shows the numbers that indicate the industry's role in building the country's GDP, as well as in job creation, tax generation, and the distribution (capillary) of economic activities. By applying the method Strategic Management of Agro-Systems (GESIS), developed by the first author, Professor Marcos Fava Neves, coordinator of the Marketing & Strategic Projects and Research Center, USP (MARKESTRAT), it was found that the sugarcane sector GDP is around $28.1 billion USD, equivalent to almost 2% of the Brazilian GDP or almost all of the income generated in a year in a country like Uruguay. The majority of the industry's inputs are local, explaining its favorable trade balance situation. A series of new products has become increasingly more important and a major transformation is going on in this sector that has one of the oldest and, at the same time, most modern plants with regard to clean energy on the planet.