cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Understanding attitudes towards the biocontrol of African lovegrass: a segmentation approach
Creators: name: Sharp, T. M.
name: Officer, D. I.
name: McConnachie, A. J.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Science Policy
subject: Infectious Diseases
subject: FOS: Health sciences

description: African lovegrass (Eragrostis curvula Schrad. Nees, Poaceae) is an introduced pasture species which provides little grazing or nutritional value for livestock under the prevailing conditions in Australia. Current management options, which include herbicides, strategic grazing of new growth, species replacement and fertiliser application have not been effective at providing sustained reductions in African lovegrass cover. Therefore, biological control (biocontrol) of African lovegrass is now being considered as a potential management tool in Australia. An important initial step in this exploration is to understand community views about African lovegrass and the use of biocontrol agents to manage it. Psychological characteristics including attitudes, knowledge, concern, and environmental values were investigated using an Australia-wide online survey, and respondents were separated into distinct segments using latent profile analysis. This study revealed that, within the sample of stakeholders surveyed, there were two groups that held slightly different views about African lovegrass and the environment, but they did not differ in terms of high levels of support for the potential use of biocontrol agents for African lovegrass. This information provides evidence of strong support for the management of African lovegrass using biocontrol.
Vision Skills Needed to Answer Visual Questions
Creators: name: Zeng, Xiaoyu
name: Wang, Yanan
name: Chiu, Tai-Yin
name: Bhattacharya, Nilavra
name: Gurari, Danna
Publisher: name: arXiv
Year: 2020
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: The task of answering questions about images has garnered attention as a practical service for assisting populations with visual impairments as well as a visual Turing test for the artificial intelligence community. Our first aim is to identify the common vision skills needed for both scenarios. To do so, we analyze the need for four vision skills---object recognition, text recognition, color recognition, and counting---on over 27,000 visual questions from two datasets representing both scenarios. We next quantify the difficulty of these skills for both humans and computers on both datasets. Finally, we propose a novel task of predicting what vision skills are needed to answer a question about an image. Our results reveal (mis)matches between aims of real users of such services and the focus of the AI community. We conclude with a discussion about future directions for addressing the visual question answering task.
description: To be published on Proceedings of the ACM on Human-Computer Interaction, Vol. 4, No. CSCW2, Article 149. Publication date: October 2020
Entomopathogenic nematodes and their symbiotic bacteria from Africa: diversity and use as biological control agents
Creators: name: Abate, Birhan Addisie
name: Mamo, Firew Tafesse
name: Tesfaye, Kassahun
name: Yuankai, Chi
name: Qi, Rende
name: Malan, Antoinette P.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: Ecology
subject: Science Policy
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Computational Biology

description: Extensive surveys of entomopathogenic nematodes (EPNs) have been conducted globally to identify native species. In Africa, EPN-related research has gained much attention over the past two decades, with several surveys having been undertaken in different countries, including Benin, Cameroon, Egypt, Ethiopia, Kenya, Morocco, Nigeria, Rwanda, South Africa and Tanzania. Such surveys have led to the description of 37 EPN species and 16 species of symbiotically associated bacteria being documented from Africa. Whereas South Africa and Egypt have made significant progress in the discovery and identification of EPN, in terms of their symbiotic bacteria and pathogenicity testing against pest insects, in many other African countries, the research is still in its early stages, or is else non-existent. Most research conducted so far has focused on laboratory bioassays, while research on the use of nematodes in more natural environments is scant. The present review provides a comprehensive overview of EPNs and their associated symbiotic bacteria from the African continent. The biological control potential of local EPN isolates against various economically important insect pests in Africa is also discussed.
Why is Random Close Packing Reproducible?
Creators: name: Kamien, Randall D.
name: Liu, Andrea J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We link the thermodynamics of colloidal suspensions to the statistics of regular and random packings. Random close packing has defied a rigorous definition yet, in three dimensions, there is near universal agreement on the volume fraction at which it occurs. We conjecture that the common value of phi_rcp, approximately 0.64, arises from a divergence in the rate at which accessible states disappear. We relate this rate to the equation of state for a hard sphere fluid on a metastable, non-crystalline branch.
description: 4 pages, 1 figure, formerly entitled "Universality of Random Close Packing?"
An explicit formula for free multiplicative Brownian motions via spherical functions
Creators: name: Auer, Martin
name: Voit, Michael
Publisher: name: arXiv
Year: 2024
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 60B20, 60B15, 60F15, 60J65, 60K35, 70F10, 82C22, 43A62, 43A90, 22E46

description: After some normalization, the logarithms of the ordered singular values of Brownian motions on $GL(N,\mathbb F)$ with $\mathbb F=\mathbb R, \mathbb C$ form Weyl-group invariant Heckman-Opdam processes on $\mathbb R^N$ of type $A_{N-1}$. We use classical elementary formulas for the spherical functions of $GL(N,\mathbb C)/SU(N)$ and the associated Euclidean spaces $H(N,\mathbb C)$ of Hermitian matrices, and show that in the $GL(N,\mathbb C)$-case, these processes can be also interpreted as ordered eigenvalues of Brownian motions on $H(N,\mathbb C)$ with particular drifts. This leads to an explicit description for the free limits for the associated empirical processes for $N\to\infty$ where these limits are independent from the parameter $k$ of the Heckman-Opdam processes. In particular we get new formulas for the distributions of the free multiplicative Browniam motion of Biane. We also show how this approach works for the root systems $B_N, C_N, D_N$.
description: Minor corrections and some comments added
Spectral theory of quantum memory and entanglement via Raman scattering of light by an atomic ensemble
Creators: name: Mishina, O. S.
name: Kupriyanov, D. V.
name: Muller, J. H.
name: Polzik, E. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss theoretically quantum interface between light and a spin polarized ensemble of atoms with the spin >= 1 based on an off-resonant Raman scattering. We present the spectral theory of the light-atoms interaction and show how particular spectral modes of quantum light couple to spatial modes of the extended atomic ensemble. We show how this interaction can be used for quantum memory storage and retrieval and for deterministic entanglement protocols. The proposed protocols are attractive due to their simplicity since they involve just a single pass of light through atoms without the need for elaborate pulse shaping or quantum feedback. As a practically relevant example we consider the interaction of a light pulse with hyperfine components of D1 line of 87Rb. The quality of the proposed protocols is verified via analytical and numerical analysis.
description: 15 pages, 7 figures; added references; accepted to PRA
The role of scientific output in public debates in times of crisis: A case study of the reopening of schools during the COVID-19 pandemic
Creators: name: Nane, Gabriela F.
name: van Schalkwyk, François
name: Dudek, Jonathan
name: Torres-Salinas, Daniel
name: Costas, Rodrigo
name: Robinson-Garcia, Nicolas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Digital Libraries (cs.DL)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Situations in which no scientific consensus has been reached due to either insufficient, inconclusive or contradicting findings place strain on governments and public organizations which are forced to take action under circumstances of uncertainty. In this chapter, we focus on the case of COVID-19, its effects on children and the public debate around the reopening of schools. The aim is to better understand the relationship between policy interventions in the face of an uncertain and rapidly changing knowledge landscape and the subsequent use of scientific information in public debates related to the policy interventions. Our approach is to combine scientific information from journal articles and preprints with their appearance in the popular media, including social media. First, we provide a picture of the different scientific areas and approaches, by which the effects of COVID-19 on children are being studied. Second, we identify news media and social media attention around the COVID-19 scientific output related to children and schools. We focus on policies and media responses in three countries: Spain, South Africa and the Netherlands. These countries have followed very different policy actions with regard to the reopening of schools and represent very different policy approaches to the same problem. We analyse the activity in (social) media around the debate between COVID-19, children and school closures by focusing on the use of references to scientific information in the debate. Finally, we analyse the dominant topics that emerge in the news outlets and the online debates. We draw attention to illustrative cases of miscommunication related to scientific output and conclude the chapter by discussing how information from scientific publication, the media and policy actions shape the public discussion in the context of a global health pandemic.
Spin-Current-Induced Charge Accumulation and Electric Current in Semiconductor Nanostructures with Rashba Spin-Orbit Coupling
Creators: name: Li, Jian
name: Shen, Shun-Qing
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate that the flow of a longitudinal spin current with different spin polarization will induce different patterns of charge accumulation in a two-terminal strip, or electric current distribution in a four-terminal Hall-bar structure, of two-dimensional electron gas with Rashba spin-orbit coupling (RSOC). For an in-plane polarized spin current, charges will accumulate either by the two lateral edges or around the center of the strip structure while, for an out-of-plain polarized spin current, charge densities will show opposite signs by the two lateral edges leading to a Hall voltage. Our calculation offers a new route to experimentally detect or differentiate pure spin currents with various spin polarization.
description: 4 pages, 3 figures
Εξόρυξη δεδομένων για κατηγοριοποίηση κειμένων:
Creators: name: Kehayov, Ivaylo Valentinov (Ιβάιλο Κεχαϊόβ )
Publisher: name: Aristotle University of Thessaloniki
Year: 2011
Subjects: Κατηγοριοποίηση
Κείμενα
SVD
Categorization
Text

description: Η κατηγοριοποίηση κειμένων είναι μια διαδικασία στην οποία έγγραφα κατηγοριοποιούνται συνήθως ανάλογα με το θέμα, το μέρος στο οποίο αναφέρονται, την ομάδα ανθρώπων, την εταιρία κλπ. Υπάρχουν τεχνικές που αυτοματοποιούν αυτή την διαδικασία. Μια από αυτές είναι η ευρέως χρησιμοποιούμενη μέθοδος Flesh Reading Ease που υπολογίζει το επίπεδο αναγνωσιμότητας ενός κειμένου και μπορεί να χρησιμοποιηθεί για την κατηγοριοποίηση κειμένων βάση αναγνωσιμότητας. Στην παρούσα διπλωματική εργασία προτείνουμε μια μέθοδο από τον τομέα της εξόρυξης δεδομένων με όνομα Singular Value Decomposition (SVD) για την αυτόματη κατηγοριοποίηση κειμένων βάση αναγνωσιμότητας. Την αξιολογούμε και την συγκρίνουμε με την Flesh Reading Ease καθώς και με άλλες δυο μεθόδους: την ομοιότητα συνημιτόνου και την Aggregated SVD. Για την πειραματική μας αξιολόγηση χρησιμοποιήσαμε το σύνολο δεδομένων Reuters-21578 καθώς και σύνολα δεδομένων που δημιουργήθηκαν με γεννήτρια κειμένων υλοποιημένη από εμάς.
description: Text categorization is a process where documents are categorized usually by topic, place, people, company, etc. There are techniques which automate this process. One of these techniques is a widely used method called Flesh Reading Ease which calculates the readability level of a document and can be used to categorize documents by readability. In this thesis we propose a method from the field of data mining called Singular Value Decomposition (SVD) for automated text categorization by readability. We evaluate it and compare it to Flesh Reading Ease as well as to other two methods: Cosine Similarity and Aggregated SVD. For our experimental evaluation we used the data set Reuters-21578 as well as data sets generated from a text generator implemented by us.
The effect of noise on segmental and prosodic timing in speech production
Creators: name: Bradford, Louise
Publisher: name: University of British Columbia
Year: 2009

description: The present investigation examined the effects of noise on prosodic and segmental timing in speech production, focusing on preboundary lengthening, pausing, speaking rate and trends in segmental duration. Preboundary lengthening was examined using normalized duration measurements. Four subjects participated in this study. Each read syntactically ambiguous sentences to a listener under conditions of quiet and multitalker babble. These sentences were then labeled by listeners according to a seven-point scale of perceived boundary strength (or break index). Each break index corresponded to a level of prosodic phrasing proposed in the literature. In general, speakers were highly individualistic in the ways they altered the segmental components of speech in noise. Three of four subjects decreased their rates of speaking in noise to varying degrees. The greatest changes in segmental durations were observed in vowels and sonorants. Changes in consonant durations were more subject specific. Both the distribution and durations of pauses were characterized by a large degree of intersubject variability. The number of pauses tended to increase with increasing perceptual boundary strength, and pauses at the larger phrase boundaries were significantly longer than those at lower levels of phrasing. Preboundary lengthening was found to increase rapidly across three lower levels of phrasing, while almost no differences were observed between the two highest levels of phrasing across both speaking conditions. This suggests that preboundary lengthening is an important perceptual cue to the lower levels of phrasing, which are marked by few other phonetic cues. The effect of noise on overall timing relationships between prosodic constituents was minimal. The degree of preboundary lengthening remained relatively constant across speaking conditions for all four subjects participating in the experiment. It is proposed that speakers try to maintain prosodic timing relationships in order to preserve speech intelligibility in noise.
Analytic, dust-independent mass-loss rates for red supergiant winds initiated by turbulent pressure
Creators: name: Kee, N. D.
name: Sundqvist, J. O.
name: Decin, L.
name: de Koter, A.
name: Sana, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Red supergiants are observed to undergo vigorous mass-loss. However, to date, no theoretical model has succeeded in explaining the origins of these objects' winds. This strongly limits our understanding of red supergiant evolution and Type II-P and II-L supernova progenitor properties. Aims. We examine the role that vigorous atmospheric turbulence may play in initiating and determining the mass-loss rates of red supergiant stars. Methods. We analytically and numerically solve the equations of conservation of mass and momentum, which we later couple to an atmospheric temperature structure, to obtain theoretically motivated mass-loss rates. We then compare these to state-of-the-art empirical mass-loss rate scaling formulae as well as observationally inferred mass-loss rates of red supergiants. Results. We find that the pressure due to the characteristic turbulent velocities inferred for red supergiants is sufficient to explain the mass-loss rates of these objects in the absence of the normally employed opacity from circumstellar dust. Motivated by this initial success, we provide a first theoretical and fully analytic mass-loss rate prescription for red supergiants. We conclude by highlighting some intriguing possible implications of these rates for future studies of stellar evolution, especially in light of the lack of a direct dependence on metallicity.
description: 14 pages, 9 figures, 2 tables
Estimation of the electron density from spacecraft potential during high frequency electric field fluctuations
Creators: name: Roberts, O. W.
name: Nakamura, R.
name: Torkar, K.
name: Graham, D. B.
name: Gershman, D. J.
name: Holmes, J. C.
name: Varsani, A.
name: Escoubet, C. P.
name: Vörös, Z.
name: Wellenzohn, S.
name: Khotyaintsev, Y.
name: Ergun, R. E.
name: Giles, B. L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Spacecraft potential has often been used to infer electron density with much higher time resolution than is typically possible with plasma instruments. However, recently two studies by Torkar et al. 2017 and Graham et al. 2018 have shown that external electric fields can also have an effect on the spacecraft potential by enhancing photoelectron escape from the surface. Consequently, should the electron density derived from the spacecraft potential be used during an event with a large electric field, the estimation would be contaminated and the user would see the effects of the electric field rather than density perturbations. The goal of this paper is to propose a method to remove the electric field effects to allow the density derived from spacecraft potential to be used even during large amplitude wave events such as Langmuir waves or upper hybrid waves.
description: Published in JGR Space Physics
Accurate, Efficient and Scalable Training of Graph Neural Networks
Creators: name: Zeng, Hanqing
name: Zhou, Hongkuan
name: Srivastava, Ajitesh
name: Kannan, Rajgopal
name: Prasanna, Viktor
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Graph Neural Networks (GNNs) are powerful deep learning models to generate node embeddings on graphs. When applying deep GNNs on large graphs, it is still challenging to perform training in an efficient and scalable way. We propose a novel parallel training framework. Through sampling small subgraphs as minibatches, we reduce training workload by orders of magnitude compared with state-of-the-art minibatch methods. We then parallelize the key computation steps on tightly-coupled shared memory systems. For graph sampling, we exploit parallelism within and across sampler instances, and propose an efficient data structure supporting concurrent accesses from samplers. The parallel sampler theoretically achieves near-linear speedup with respect to number of processing units. For feature propagation within subgraphs, we improve cache utilization and reduce DRAM traffic by data partitioning. Our partitioning is a 2-approximation strategy for minimizing the communication cost compared to the optimal. We further develop a runtime scheduler to reorder the training operations and adjust the minibatch subgraphs to improve parallel performance. Finally, we generalize the above parallelization strategies to support multiple types of GNN models and graph samplers. The proposed training outperforms the state-of-the-art in scalability, efficiency and accuracy simultaneously. On a 40-core Xeon platform, we achieve 60x speedup (with AVX) in the sampling step and 20x speedup in the feature propagation step, compared to the serial implementation. Our algorithm enables fast training of deeper GNNs, as demonstrated by orders of magnitude speedup compared to the Tensorflow implementation. We open-source our code at https://github.com/GraphSAINT/GraphSAINT.
description: 43 pages, 8 figures. arXiv admin note: text overlap with arXiv:1810.11899
Polarization of the fermionic vacuum by a global monopole with finite core
Creators: name: de Mello, E. R. Bezerra
name: Saharian, A. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the vacuum polarization effects associated with a massive fermionic field in a spacetime produced by a global monopole considering a nontrivial inner structure for it. In the general case of the spherically symmetric static core with finite support we evaluate the vacuum expectation values of the energy-momentum tensor and the fermionic condensate in the region outside the core. These quantities are presented as the sum of point-like global monopole and core-induced contributions. The asymptotic behavior of the core-induced vacuum densities are investigated at large distances from the core, near the core and for small values of the solid angle corresponding to strong gravitational fields. As an application of general results the flower-pot model for the monopole's core is considered and the expectation values inside the core are evaluated.
description: 22 pages, 4 figures
Coarse Molecular-Dynamics Determination of the Onset of Structural Transitions: Melting of Crystalline Solids
Creators: name: Amat, Miguel A.
name: Kevrekidis, Ioannis G.
name: Maroudas, Dimitrios
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using a coarse molecular-dynamics (CMD) approach with an appropriate choice of coarse variable (order parameter), we map the underlying effective free-energy landscape for the melting of a crystalline solid. Implementation of this approach provides a means for constructing effective free-energy landscapes of structural transitions in condensed matter. The predictions of the approach for the thermodynamic melting point of a model silicon system are in excellent agreement with those of ''traditional'' techniques for melting-point calculations, as well as with literature values.
Στατιστική ανάλυση Χρονικών Δεδομένων από άρθρα της PubMed σχετικά με φαρμακευτικά Προϊόντα:
Creators: name: Γούσια, Πολυξένη Σωτηρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2011
Subjects: Βιοϊατρικά δεδομένα
Στατιστική ανάλυση
Χρονικά δεδομένα
PubMed
Statistical analysis
Biomedical data

description: Τα τελευταία χρόνια ο αριθμός των βιοϊατρικών άρθρων έχει αυξηθεί σημαντικά γεγονός που καθιστά δύσκολη την αναζήτηση της κατάλληλης πληροφορίας. Οι ερευνητές οφείλουν να είναι ενημερωμένοι σχετικά με όλες τις νέες ανακαλύψεις και θεωρίες και για το λόγο αυτό έχουν αναπτυχθεί πολλοί αλγόριθμοι και εργαλεία που αποσκοπούν στην ανάκτηση και στην ταξινόμηση των βιοϊατρικών δεδομένων. Όσο αφορά το φαρμακευτικό κλάδο, οι τεχνικές της ανάκτησης και εξόρυξης κειμένου αρχίζουν και χρησιμοποιούνται σε μεγάλο βαθμό για την ανακάλυψη νέων φαρμάκων και για την αύξηση του ανταγωνισμού του κλάδου. Ωστόσο, με βάση τη μελέτη που έγινε διαπιστώθηκε ότι δεν υπάρχει κάποια μέθοδος στη βιβλιογραφία, η οποία μετά την ανάκτηση της πληροφορίας, να εξάγει συμπεράσματα με βάση τη χρονική πληροφορία που συνοδεύει τα δεδομένα. Τα εργαλεία εξόρυξης και ανάκτησης κειμένου χρησιμοποιούν την εννοιολογική συνάφεια μεταξύ των δεδομένων και δεν μελετάται πουθενά η χρονική τους εξέλιξη.
description: The volume of the published biomedical research is expanding at an increasing rate. With such explosive growth, it is extremely challenging for the scientists to keep up to date with all of the new discoveries and theories. For this reason there have been developed many tools and algorithms which perform text retrieval and text mining to the biomedical data. Most of the pharmaceutical industries are using the techniques of text retrieval and text mining in order to discover new drugs and to become more competitive. However, based on literature, there isn’t any method which exploits the time information of the data.Basic goal of this project is to propose a new method which ranks the biomedical data and then correlates them based on their behavior through time. Experts will be able to overview the data and with the statistical analysis results will come to important conclusions.
Reducing Urban Speed Limits Decreases Work-Related Traffic Injury Severity: Evidence from Santiago, Chile
Creators: name: Graells-Garrido, Eduardo
name: Toro, Matías
name: Mansilla, Gabriel
name: Nicolai, Matías
name: Mansilla, Santiago
name: Dunstan, Jocelyn
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Work-related transportation incidents significantly impact urban mobility and productivity. These incidents include traffic crashes, collisions between vehicles, and falls that occurred during commuting or work-related transportation (e.g., falling while getting off a bus during the morning commute or while riding a bicycle for work). This study analyzes a decade of work-related transportation incident data (2012--2021) in Santiago, Chile, using records from a major worker's insurance company. Using negative binomial regression, we assess the impact of a 2018 urban speed limit reduction law on incident injury severity. We also explore broader temporal, spatial, and demographic patterns in these incidents in urban and rural areas.
 The urban speed limit reduction is associated with a decrease of 4.26 days in prescribed medical leave for incidents in urban areas, suggesting that lower speed limits contribute to reduced injury severity. Our broader analysis reveals distinct incident patterns across different groups. Workers traveling by motorcycle and bicycle experience more severe injuries when involved in traffic incidents, with marginal effects of 26.94 and 13.06 additional days of medical leave, respectively, compared to motorized vehicles. Women workers tend to have less severe injuries, with an average of 7.57 fewer days of medical leave. Age is also a significant factor, with older workers experiencing more severe injuries -- each additional year of age is associated with 0.57 more days of medical leave. Our results provide insights for urban planning, transportation policy, and workplace safety initiatives.
description: 18 pages, 9 figures. Second version after reviews
Existence of the signal in the signal plus background model
Creators: name: Zhang, Tonglin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62C15 (Primary) 62C10, 62F25, 62F03 (Secondary)

description: Searching for evidence of neutrino oscillations is an important problem in particle physics. Suppose that evidence for neutrino oscillations from an LSND experiment reports a significant positive oscillation probability, but that the LSND result is not confirmed by other experiments. In statistics, such a problem can be proposed as the detection of signal events in the Poisson signal plus background model. Suppose that an observed count $X$ is of the form $X=B+S$, where the background $B$ and the signal $S$ are independent Poisson random variables with parameters $b$ and $θ$ respectively, $b$ is known but $θ$ is not. Some recent articles have suggested conditioning on the observed bound for $B$; that is, if $X=n$ is observed, the suggestion is to base the inference on the conditional distribution of $X$ given $B\le n$. This suggestion is used here to derive an estimator of the probability of the existence of the signal event. The estimator is examined from the view of decision theory and is shown to be admissible.
description: Published at http://dx.doi.org/10.1214/074921706000000653 in the IMS Lecture Notes--Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org)
Development of a modular CdTe detector plane for gamma-ray burst detection below 100 keV
Creators: name: Ehanno, M.
name: Amoros, C.
name: Barret, D.
name: Lacombe, K.
name: Pons, R.
name: Rouaix, G.
name: Gevin, O.
name: Limousin, O.
name: Lugiez, F.
name: Bardoux, A.
name: Penquer, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the development of an innovative CdTe detector plane (DPIX) optimized for the detection and localization of gamma-ray bursts in the X-ray band (below 100 keV). DPIX is part of an R&D program funded by the French Space Agency (CNES). DPIX builds upon the heritage of the ISGRI instrument, currently operating with great success on the ESA INTEGRAL mission. DPIX is an assembly of 200 elementary modules (XRDPIX) equipped with 32 CdTe Schottky detectors (4x4 mm2, 1 mm thickness) produced by ACRORAD Co. LTD. in Japan. These detectors offer good energy response up to 100 keV. Each XRDPIX is readout by the very low noise front-end electronics chip IDeF-X, currently under development at CEA/DSM/DAPNIA. In this paper, we describe the design of XRDPIX, the main features of the IDeF-X chip, and will present preliminary results of the reading out of one CdTe Schottky detector by the IDeF-X V1.0 chip. A low-energy threshold around 2.7 keV has been measured. This is to be compared with the 12-15 keV threshold of the ISGRI-INTEGRAL and BAT-SWIFT instruments, which both use similar detector material.
description: 5 pages, 4 figures in color, Advances in Space Research, COSPAR meeting, Beijing (2006)
Switching the sign of photon induced exchange interactions in semiconductor microcavities with finite quality factors
Creators: name: Chiappe, G.
name: Anda, E. Louis y E. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate coupling of localized spins in a semiconductor quantum dot embedded in a microcavity with a finite quality factor. The lowest cavity mode and the quantum dot exciton are coupled forming a polariton, whereas excitons interact with localized spins via exchange. The finite quality of the cavity Q is incorporated in the model Hamiltonian by adding an imaginary part to the photon frequency. The Hamiltonian, which treats photons, spins and excitons quantum mechanically, is solved exactly. Results for a single polariton clearly demonstrate the existence of a resonance, sharper as the temperature decreases, that shows up as an abrupt change between ferromagnetic and antiferromagnetic indirect anisotropic exchange interaction between localized spins. The origin of this spin-switching finite-quality-factor effect is discussed in detail remarking on its dependence on model parameters, i.e., light-matter coupling, exchange interaction between impurities, detuning and quality factor. For parameters corresponding to the case of a (Cd,Mn)Te quantum dot, the resonance shows up for Q around 70 and detuning around 10 meV. In addition, we show that, for such a quantum dot, and the best cavities actually available (quality factors better than 200) the exchange interaction is scarcely affected.
description: 7 figures, submitted to PRB
On the free energy of a directed polymer in a Brownian environment
Creators: name: Moriarty, John
name: O'Connell, Neil
Publisher: name: arXiv
Year: 2006
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 60K37, 82D30, 60K25, 60J65

description: We prove a formula conjectured in O'Connell and Yor (2001) for the free energy density of a directed polymer in a Brownian environment in 1+1 dimensions.
description: 15 pages. To appear in Markov Processes and Related Filelds (J.T. Lewis special edition)
Dense gas formation in the Musca filament due to the dissipation of a supersonic converging flow
Creators: name: Bonne, L.
name: Schneider, N.
name: Bontemps, S.
name: Clarke, S. D.
name: Gusdorf, A.
name: Lehmann, A.
name: Steinke, M.
name: Csengeri, T.
name: Kabanovic, S.
name: Simon, R.
name: Buchbender, C.
name: Guesten, R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Observations with the Herschel Space Telescope have established that most of the star forming gas is organised in interstellar filaments, a finding that is supported by numerical simulations of the supersonic interstellar medium (ISM) where dense filamentary structures are ubiquitous. We aim to understand the formation of these dense structures by performing observations covering the $^{12}$CO(4-3), $^{12}$CO(3-2), and various CO(2-1) isotopologue lines of the Musca filament, using the APEX telescope. The observed CO intensities and line ratios cannot be explained by PDR (photodissociation region) emission because of the low ambient far-UV field that is strongly constrained by the non-detections of the [C II] line at 158 $μ$m and the [O I] line at 63 $μ$m, observed with the upGREAT receiver on SOFIA, as well as a weak [C I] 609 $μ$m line detected with APEX. We propose that the observations are consistent with a scenario in which shock excitation gives rise to warm and dense gas close to the highest column density regions in the Musca filament. Using shock models, we find that the CO observations can be consistent with excitation by J-type low-velocity shocks. A qualitative comparison of the observed CO spectra with synthetic observations of dynamic filament formation simulations shows a good agreement with the signature of a filament accretion shock that forms a cold and dense filament from a converging flow. The Musca filament is thus found to be dense molecular post-shock gas. Filament accretion shocks that dissipate the supersonic kinetic energy of converging flows in the ISM may thus play a prominent role in the evolution of cold and dense filamentary structures.
description: 16 pages, 17 figures
title: The change in plasma D-dimer does not help to guide the timing of reimplantation in two stage exchange for periprosthetic joint infection
Creators: name: Ackmann, Thomas
name: Schwarze, Jan
name: Gosheger, Georg
name: Schmidt-Bräkling, Tom
name: Schneider, Kristian Nikolaus
name: Dieckmann, Ralf
name: Klingebiel, Sebastian
name: Möllenbeck, Burkhard H. M.
name: Theil, Jan-Christoph
Publisher: name: University of Muenster, Institutional Repository MIAMI
Year: 2022
Subjects: subject: 610 Medicine and health

description: D-dimer has been included in the criteria by the Musculoskeletal Infection Society in 2018 as a novel parameter to diagnose prosthetic joint infection (PJI). However, it is unclear how D-dimer levels change in between stages of a two-stage exchange. We prospectively investigated 30 patients who underwent a two-stage exchange using a spacer for PJI. D-Dimer, CRP and IL-6 were collected before first and second stage surgery and the difference (Δ) in between stages was calculated. The levels of plasma D-Dimer did not change from first to second stage surgery (2770 ng/ml (IQR, 1600–3770 ng/ml) versus 2340 ng/ml (IQR, 1270–4100 ng/ml); p = 0.8) while CRP (4.0 mg/dl (IQR, 1.7–5.5 mg/dl) versus 0.6 mg/dl (IQR, 0.5–0.8 mg/dl); p < 0.001) and IL-6 (21 pg/ml (IQR, 10–29 pg/ml) versus 6 pg/ml (4–9 pg/ml); p < 0.001) decreased. The ΔD-dimer between both stages was 300 ng/ml (range: − 2820 to 4280 ng/ml), the median ΔCRP was − 3.4 mg/dl (IQR, − 1.2 to − 4.8 mg/dl) and ΔIL-6 was − 13 pg/ml (IQR, − 4 to − 20 pg/ml). In 15 of 30 cases (50%) the D-dimer level increased between both stages, whereas the level of CRP (93%; 28/30) and IL-6 (96%; 28/29) decreased in most patients. As the level of serum D-dimers varies greatly, lacks a uniform decrease and does not identify persisting infection, surgeons should be cautious when using it at the timing of reimplantation.
description: Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.
Ανάπτυξη και εφαρμογή συστημάτων επιχειρηματικής ευφυΐας:
Creators: name: Καϊμακάμη, Σοφία Θωμά
Publisher: name: Aristotle University of Thessaloniki
Year: 2011
Subjects: Επιχειρηματική ευφυΐα
Ανάπτυξη
Business intelligence
Development

description: Η παρούσα διπλωματική μεταπτυχιακή εργασία ασχολείται με τα Συστήματα Επιχειρηματικής Ευφυΐας. Πρόκειται για στρατηγικά πληροφοριακά συστήματα, τα οποία στοχεύουν στην υποστήριξη και βελτιστοποίηση της διαδικασίας λήψης αποφάσεων και παράλληλα στην ενίσχυση του ανταγωνιστικού πλεονεκτήματος των επιχειρήσεων. Αρχικά, γίνεται θεωρητική θεμελίωση από την υπάρχουσα βιβλιογραφία και, έπειτα, για τη διεκπεραίωση της εργασίας έχει διεξαχθεί μια έρευνα για την παρούσα κατάσταση στις μεγάλες ελληνικές επιχειρήσεις.
description: This diploma thesis deals with Business Intelligence Systems. This strategic information systems, which aim to support and optimize decision-making process while strengthening the competitive advantage of firms. Initially, there is a theoretical foundation of the existing literature and then to carry out the work was carried out a survey on the current situation in the major Greek companies.
Self-consistent evaluation of quark masses in three flavor crystalline color superconductivity
Creators: name: Ippolito, N. D.
name: Nardulli, G.
name: Ruggieri, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a self-consistent evaluation of the constituent quark masses in the three flavor Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phases of QCD, employing an improved Nambu-Jona Lasinio model. This result allows to determine the window for values of the baryonic chemical potential where the LOFF state is energetically favored.
description: 17 pages, 5 figures, JHEP3 style. A second treatment of the ultraviolet cutoff added. Three figures adapted to the new cutoff. Two references added. Version accepted for publication on JHEP
Time-resolved Stochastic Dynamics of Quantum Thermal Machines
Creators: name: Hegde, Abhaya S.
name: Potts, Patrick P.
name: Landi, Gabriel T.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Steady-state quantum thermal machines are typically characterized by a continuous flow of heat between different reservoirs. However, at the level of discrete stochastic realizations, heat flow is unraveled as a series of abrupt quantum jumps, each representing an exchange of finite quanta with the environment. In this work, we present a framework that resolves the dynamics of quantum thermal machines into cycles classified as engine-like, cooling-like, or idle. We analyze the statistics of individual cycle types and their durations, enabling us to determine both the fraction of cycles useful for thermodynamic tasks and the average waiting time between cycles of a given type. Central to our analysis is the notion of intermittency, which captures the operational consistency of the machine by assessing the frequency and distribution of idle cycles. Our framework offers a novel approach to characterizing thermal machines with significant relevance to experiments involving mesoscopic transport through quantum dots.
description: 6 + 14 pages; 3 + 2 figures
Propagating Air Shower Radio Signals to In-ice Antennas
Creators: name: Latif, Uzair Abdul
name: Huege, Tim
name: Vries, Krijn De
name: Kockere, Simon De
name: Van Den Broeck, Dieder
name: Buitink, Stijn
Publisher: name: Scuola Internazionale Superiore di Studi Avanzati (SISSA)
Year: 2023

description: In-ice Askaryan radio experiments like ARA, RNO-G, and ARIANNA have deployed radio
antennas inside the Greenlandic and Antarctic ice sheets [1–3]. These in-ice radio experiments
are looking to measure the flux of cosmogenic and astrophysical neutrinos at even higher energies
than IceCube (> 1017 eV). The in-ice radio detectors are designed to record and measure coherent
radio Cherenkov emission, known as Askaryan emission, from the particle cascade induced by the
neutrino-ice nuclei collision.
Radio emissions from particle cascades, dubbed extensive air showers, induced by ultra-high
energy cosmic rays interacting in the atmosphere serve as essential backgrounds for Askaryan radio
detectors. Arriving with a relatively high flux, cosmic ray particle cascades produce radio signals
with many similar features compared to neutrino signals. As such, cosmic rays provide the ideal
calibration signal if their signal is understood and can be separated from the neutrino signal. The
effort to fully characterize cosmic-ray signals observed by in-ice radio detectors is underway and
will be the goal of this work. However, it should be noted that this work will be limited to in-air
radio emissions. In contrast, the in-ice emission when the cosmic-ray shower propagates into the
ice sheet will be discussed in another work [4, 5].
In this work, cosmic-ray air shower radio emission will be simulated with CoREAS (CORSIKA-
based Radio Emission from Air Showers) [6]. CoREAS is a sub-module of the CORSIKA (COsmic
Ray SImulations for KAscade) air shower simulation [7]. CoREAS uses the endpoint formalism to
calculate the electric field emission from each shower particle (as simulated by CORSIKA) as the
shower propagates and makes no assumptions regarding the emission mechanism. However, the
CoREAS code has only been designed to work in air using straight-line ray propagation. In reality,
air and ice have density-dependent exponential refractive index profiles that cause radiowave rays
to curve as they propagate toward an observer. The ray-bending effect is much less pronounced for
air than ice since, in polar ice, the refractive index refractive has an exponential profile which has a
large gradient in the first 100 − 200 m. Polar ice refractive index changes from 1.35 at the surface
to 1.78 within 100 − 200 m, and the sharp change in the refractive index causes the rays to bend
significantly near the ice surface.
Global Asymmetry of the Heliosphere
Creators: name: Opher, Merav
name: Stone, Edward C.
name: Liewer, Paulett C.
name: Gombosi, Tamas
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Opher et al. 2006 showed that an interstellar magnetic field parallel to the plane defined by the deflection of interstellar hydrogen atoms can produce a north/south asymmetry in the distortion of the solar wind termination shock. This distortion is consistent with Voyager 1 and Voyager 2 observations of the direction of field-aligned streaming of the termination shock particles upstream the shock. The model also indicates that such a distortion will result in a significant north/south asymmetry in the distance to the shock and the thickness of heliosheath. The two Voyager spacecraft should reveal the nature and degree of the asymmetry in the termination shock and heliosheath.
description: 6 pages, 5 figures, AIP Proceedings of the 5th IGPP "The Physics of the Inner Heliosheath: Voyager Observations, Theory and Future Prospects"
Turning Points in the Evolution of Isolated Neutron Stars' Magnetic Fields
Creators: name: Geppert, U.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: During the life of isolated neutron stars (NSs) their magnetic field passes through a variety of evolutionary phases. Depending on its strength and structure and on the physical state of the NS (e.g. cooling, rotation), the field looks qualitatively and quantitatively different after each of these phases. Three of them, the phase of MHD instabilities immediately after NS's birth, the phase of fallback which may take place hours to months after NS's birth, and the phase when strong temperature gradients may drive thermoelectric instabilities, are concentrated in a period lasting from the end of the proto--NS phase until 100, perhaps 1000 years, when the NS has become almost isothermal. The further evolution of the magnetic field proceeds in general inconspicuous since the star is in isolation. However, as soon as the product of Larmor frequency and electron relaxation time, the so-called magnetization parameter, locally and/or temporally considerably exceeds unity, phases, also unstable ones, of dramatic changes of the field structure and magnitude can appear. An overview is given about that field evolution phases, the outcome of which makes a qualitative decision regarding the further evolution of the magnetic field and its host NS.
description: References updated, typos corrected
Improving entanglement purification through coherent superposition of roles
Creators: name: Miguel-Ramiro, Jorge
name: Pirker, Alexander
name: Dür, Wolfgang
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Entanglement purification and distillation protocols are essential for harnessing the full potential of quantum communication technologies. Multiple strategies have been proposed to approach and optimize such protocols, most however restricted to Clifford operations. In this paper, we introduce a superposed entanglement purification design strategy, leveraging coherent superpositions of the roles of entangled states to enhance purification efficiency, defining a new family of non-Clifford distillation protocols. We demonstrate how this approach can be hierarchically integrated with existing entanglement purification strategies, consistently improving protocols performance.
description: 9 pages, 7 figures
Women who are HIV positive in the Lower Mainland : A survey of social support
Creators: name: Brendle Moczuk, Iris
Publisher: name: University of British Columbia
Year: 2009

description: This study examined whether women who were HIV positive perceived a lack of social support, and in what areas these perceived inadequacies existed. Women who were HIV positive (n=17) and living in the Lower Mainland were recruited by staff at three liaison service-providing organizations to provide a cross-sectional, non-random convenience sample. A survey questionnaire which included the Multidimensional Scale of Perceived Social Support (MSPSS) was either self- administered or conducted via a telephone interview. Statistical significance was found only for support scores crosstabulated with disclosure or non-disclosure of HIV status to friends, but not to family. Women who had HIV- related illnesses did not perceive less support than those who had been asymptomatic. Overall ratings of satisfaction with support were higher than anticipated. The results suggest that more exploratory research is necessary to clarify the meaning of social support for women living with HIV/AIDS.