Miracle-dz/UniFAR-FTUs huggingface dataset:
Frequency responses of streamwise-constant perturbations in channel flows of Oldroyd-B fluids

Non-modal amplification of disturbances in streamwise-constant channel flows of Oldroyd-B fluids is studied from an input–output point of view by analysing the responses of the velocity components to spatio-temporal body forces. These inputs into the governing equations are assumed to be harmonic in the spanwise direction and stochastic in the wall-normal direction and in time. An explicit Reynolds number (Re) scaling of frequency responses from different forcing to different velocity components is developed, showing the same Re dependence as in Newtonian fluids. It is found that some of the frequency response components peak at non-zero temporal frequencies. This is in contrast to Newtonian fluids, where peaks are always observed at zero frequency, suggesting that viscoelastic effects introduce additional time scales and promote development of flow patterns with smaller time constants than in Newtonian fluids. The temporal frequencies, corresponding to the peaks in the components of frequency response, decrease with an increase in viscosity ratio (ratio of solvent viscosity to total viscosity) and show maxima for non-zero elasticity number. Our analysis of the Reynolds–Orr equation demonstrates that the energy-exchange term involving the streamwise/wall-normal polymer stress component τxy and the wall-normal gradient of the streamwise velocity ∂yu becomes increasingly important relative to the Reynolds-stress term as the elasticity number increases and is thus the main driving force for amplification in flows with strong viscoelastic effects.
Model Fusion Experiments for the Cross Language Speech Retrieval Task at CLEF 2007

This paper presents the participation of the University of Ottawa group in the Cross-Language Speech Retrieval (CL-SR) task at CLEF 2007. We present the results of the submitted runs for the English collection. We have used two Information Retrieval systems in our experiments: SMART and Terrier, with two query expansion techniques: one based on a thesaurus and the second one based on blind relevant feedback. We proposed two novel data fusion methods for merging the results of several models (retrieval schemes available in SMART and Terrier). Our experiments showed that the combination of query expansion methods and data fusion methods helps to improve the retrieval performance. We also present cross-language experiments, where the queries are automatically translated by combining the results of several online machine translation tools. Experiments on indexing the manual summaries and keywords gave the best retrieval results.
Creditor Interventions and Firm Innovation : Evidence from Debt Covenant Violations

We examine the effect of creditor interventions on corporate innovation and firm value via the lens of debt covenant violations, where control rights are shifted from equity holders to creditors. Using a difference-in-differences approach and a regression discontinuity design, we find that creditor interventions have a negative, causal effect on innovation output. We further show that the reduction in innovation output is concentrated in innovation activities that are unrelated to the violating firm’s main business, which leads to a more focused scope of innovation investment and ultimately an increase in firm value. Human capital redeployment appears a plausible underlying mechanism through which creditor interventions refocus firm innovation scope and enhance firm value. Our findings are consistent with the argument that creditors help mitigate investment distortions in innovation arising from conflicts of interest between managers and shareholders. Our paper sheds new light on the real effect of creditor interventions. JEL Classification: G21, G32, G34, O31
Swift Observations of GRB 070110: An Extraordinary X-Ray Afterglow Powered by the Central Engine

We present a detailed analysis of Swift multiwavelength observations of GRB 070110 and its remarkable afterglow. The early X-ray light curve, interpreted as the tail of the prompt emission, displays a spectral evolution already seen in other gamma-ray bursts. The optical afterglow shows a shallow decay up to ~2 days after the burst, which is not consistent with standard afterglow models. The most intriguing feature is a very steep decay in the X-ray flux at ~2 × 104 s after the burst, ending an apparent plateau. The abrupt drop of the X-ray light curve rules out an external shock as the origin of the plateau in this burst and implies long-lasting activity of the central engine. The temporal and spectral properties of the plateau phase point toward a continuous central engine emission rather than the episodic emission of X-ray flares. We suggest that the observed X-ray plateau is powered by a spinning-down central engine, possibly a millisecond pulsar, which dissipates energy at an internal radius before depositing energy into the external shock.
THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC SIMULATIONS OF BUOYANT BUBBLES IN GALAXY CLUSTERS

We report results of three-dimensional magnetohydrodynamic simulations of the dynamics of buoyant bubbles in magnetized galaxy cluster media. The simulations are three-dimensional extensions of two-dimensional calculations reported by Jones and De Young. Initially, spherical bubbles and briefly inflated spherical bubbles all with radii a few times smaller than the intracluster medium (ICM) scale height were followed as they rose through several ICM scale heights. Such bubbles quickly evolve into a toroidal form that, in the absence of magnetic influences, is stable against fragmentation in our simulations. This ring formation results from (commonly used) initial conditions that cause ICM material below the bubbles to drive upwards through the bubble, creating a vortex ring; that is, hydrostatic bubbles develop into “smoke rings,” if they are initially not very much smaller or very much larger than the ICM scale height. Even modest ICM magnetic fields with β = Pgas/Pmag ≲ 103 can influence the dynamics of the bubbles, provided the fields are not tangled on scales comparable to or smaller than the size of the bubbles. Quasi-uniform, horizontal fields with initial β ∼ 102 bifurcated our bubbles before they rose more than about a scale height of the ICM, and substantially weaker fields produced clear distortions. These behaviors resulted from stretching and amplification of ICM fields trapped in irregularities along the top surface of the young bubbles. On the other hand, tangled magnetic fields with similar, modest strengths are generally less easily amplified by the bubble motions and are thus less influential in bubble evolution. Inclusion of a comparably strong, tangled magnetic field inside the initial bubbles had little effect on our bubble evolution, since those fields were quickly diminished through expansion of the bubble and reconnection of the initial field.
Preparation of CdO Rhombus-Like Nanostructure and Its Photocatalytic Degradation of Azo Dyes from Aqueous Solution

In this work, a special rhombus-like structure of CdO composed of particles at the nanometre scale was successfully synthesized for the first time. A facile hydrothermal process with a post-reaction calcination was employed to prepare this nanomaterial. Scanning electron microscopy (SEM) images showed that the obtained rhombus-like structure consists of nanoparticles with an average size of 29 nm. The band gap energy of 1.9 eV based on a diffuse reflectance spectroscopy (DRS) showed that the product can be favourable to photoactivity in the visible region of sunlight. The prepared sample was employed to destruct carcinogenic azo dyes, such as Congo Red (CR), Malachite Green (MG) and Crystal Violet (CV). The obtained results showed that the CdO with the special morphology was able to effectively catalyse the degradation of these pollutants. The related decolourization efficiencies were obtained by up to 100% after various lengths of time of light irradiation. It was concluded that the photodegradation of the mentioned organic dyes under visible light irradiation by a CdO rhombus-like nanostructure follows the first-order reaction kinetics. The effect of the initial pH and contact time on the percentage of the decolourization of these organic dyes was also studied.
Low-Luminosity Active Galactic Nuclei at the Highest Resolution: Jets or Accretion Flows?

Six low-luminosity active galactic nuclei (AGNs) have been imaged at multiple frequencies from 1.7 to 43 GHz (2.3-15 GHz for three of the galaxies) using the Very Long Baseline Array. In spite of dynamic ranges of about 100 in several frequency bands, all six galaxies remain unresolved, with size limits at 8.4 GHz of 103-104 times the Schwarzschild radii of the black holes inferred at their galactic centers. The galaxy spectra are roughly flat from 1.7 to 43 GHz, rather than steepening to classical optically thin synchrotron spectra at high frequencies. Although the spectral slopes somewhat resemble predictions for advection-dominated accretion flows, the luminosities are too high for the black hole masses of the galaxies, and the slight spectral steepening at high frequencies cannot be explained by standard simple models of such accretion flows. In contrast, compact jets can accommodate the average spectral index, the relatively high radio luminosity, and the unresolved appearance, but only if the jets in all six galaxies are fairly close to our line of sight. This constraint is in agreement with inclination angle predictions for five of the six AGNs based on the dusty torus unification model.
Monopoles and dyons in non-commutative geometry

Taking advantage of the equivalence between supersymmetric Yang-Mills theory on non-commutative spaces and the field theory limit of D3-branes in the background of NSNS 2-form field, we investigate the static properties of magnetic monopoles and dyons using brane construction techniques. When parallel D3-branes are separated by turning on a Higgs vacuum expectation value, D-strings will stretch between them at an angle which depends on the value of the background 2-form potential. These states preserve half of the supersymmetries and have the same masses as their commutative counterparts in the field theory limit. We also find stable (p,q)-dyons and string junctions.
Enabling Sparse Winograd Convolution by Native Pruning

Sparse methods and the use of Winograd convolutions are two orthogonal approaches, each of which significantly accelerates convolution computations in modern CNNs. Sparse Winograd merges these two and thus has the potential to offer a combined performance benefit. Nevertheless, training convolution layers so that the resulting Winograd kernels are sparse has not hitherto been very successful. By introducing a Winograd layer in place of a standard convolution layer, we can learn and prune Winograd coefficients "natively" and obtain sparsity level beyond 90% with only 0.1% accuracy loss with AlexNet on ImageNet dataset. Furthermore, we present a sparse Winograd convolution algorithm and implementation that exploits the sparsity, achieving up to 31.7 effective TFLOP/s in 32-bit precision on a latest Intel Xeon CPU, which corresponds to a 5.4x speedup over a state-of-the-art dense convolution implementation.
Many-objective virtual machine placement for dynamic environments

This paper presents for the first time a formulation of the Virtual Machine Placement as a Many-Objective problem (MaVMP), considering the simultaneous optimization of the following five objective functions for dynamic environments: (1) power consumption, (2) inter-VM network traffic, (3) economical revenue, (4) number of VM migrations and (5) network traffic overhead for VM migrations. To solve the formulated MaVMP problem, a novel Memetic Algorithm is proposed. As a potentially large number of feasible solutions at any time is one of the challenges of MaVMP, five selection strategies are evaluated in order to automatically select one solution at each time. The proposed algorithm with the considered selection strategies were evaluated in two different scenarios.
Another negotiator's dilemma: Negotiating against a counterpart with a bad reputation

Previous research has pointed to two factors, negotiator characteristics and negotiation situation, to explain when deception occurs in negotiation. In this theoretical development, I argue for the need for an analysis into the way in which a negotiator’s use of deception is impacted by a counterpart’s reputation. I draw on equity theory and prisoner’s dilemma to claim that, when a counterpart has a bad or negative reputation, the primary negotiator is more likely to use deception. I also describe propositions for moderating variables.
Elastic Stream Processing with Latency Guarantees

Many Big Data applications in science and industry have arisen, that require large amounts of streamed or event data to be analyzed with low latency. This paper presents a reactive strategy to enforce latency guarantees in data flows running on scalable Stream Processing Engines (SPEs), while minimizing resource consumption. We introduce a model for estimating the latency of a data flow, when the degrees of parallelism of the tasks within are changed. We describe how to continuously measure the necessary performance metrics for the model, and how it can be used to enforce latency guarantees, by determining appropriate scaling actions at runtime. Therefore, it leverages the elasticity inherent to common cloud technology and cluster resource management systems. We have implemented our strategy as part of the Nephele SPE. To showcase the effectiveness of our approach, we provide an experimental evaluation on a large commodity cluster, using both a synthetic workload as well as an application performing real-time sentiment analysis on real-world social media data.
Vitamin D, vitamin D receptor and tissue barriers

Tissue barriers are critical in the pathogenesis of human diseases, such as atopic dermatitis, inflammatory bowel diseases and various cancers. Preserving or restoring barrier functions of the epithelia cells is a therapeutic strategy to prevent and treat the illness. Mounting evidence indicates that vitamin D and the vitamin D receptor (VDR) play key roles in the pathogenesis of human diseases. In particular, we note an interesting link between vitamin D/VDR signaling and tissue barriers. In the current review, we summarize the recent progress on vitamin D and cell junction complexes. We focus on the functions of VDR and VDR-associated intracellular junction proteins, such as β-catenin and claudins. We also discuss the potential therapeutic functions of vitamin D in treating defective tissue barriers that involve skin, intestine, lung, kidney and other organs. However, the mechanisms for the vitamin D/VDR signaling in tissue barriers remain largely unknown. Further studies on vitamin D/VDR’s multiple functions in physiological models will suggest new therapeutic targets for prevention and treatment diseases with defective barrier functions.
Sensitivity to facial expressions as a function of group experience : holistic theory and nonverbal communication

This research examined nonverbal communication (NVC), namely the decoding of facial affect, in light of a holistic theoretical framework. Primarily a study of communication, this work was aimed at discovering whether or not accuracy in decoding facial affect increased as a function of group/laboratory experience. Twenty-seven subjects (18 experimental and 9 control) took part. All subjects completed a test battery which included the Affect Recognition Scale (ARS), a measure of sensitivity to facial affect. This instrument, based on the work of Ekman and associates (1975), consisted of a series of slides depicting six affect categories--happy, sad, fear, anger, surprise, disgust, each at three intensity levels--slight, moderate and extreme. The Q-Sort, a measure of personal congruence, plus a questionnaire on the nature of group experience were also used as part of the test battery. Each administration of these instruments (pre- and post-) yielded one correlation for the Q-Sort plus a series of scores on the ARS. -- While the mean for both groups changed in a positive direction on the Q-Sort, this change was not statistically significant. There was a statistically significant change on the overall mean of the ARS for the control group on the post-administration. As well on the post, there was a significant difference between groups on one of the ARS subtests. Other non-significant trends were discussed. -- Holistic theory as well as Dabrowski's theory of positive disintegration were used in the discussion of these results. A number of limitations of the study and suggestions for future research were also presented. -- The methodology used in this study may be useful in further attempts to understand the development and theoretical basis of NVC. Much of the value of the work lies in its exploratory heuristic nature and in its attempt to evolve theoretical directions for future NVC research.
Risk stratification for COPD diagnosis through an active search strategy in primary care

Background The aim of this study was to identify the percentage of undiagnosed patients with COPD through the implementation of an active search strategy in a selected subject population. Methods An observational, cross-sectional, multicenter study was conducted in a primary care setting in Spain. General practitioners gave their diagnostic impression of COPD (yes/no) on the basis of clinical criteria of subjects with respiratory symptoms and tobacco exposure. Subsequently, post-bronchodilator spirometry and quality-of-life tests were performed. Multivariate logistic regression techniques using receiver operating characteristic (ROC) curves were used to identify the combination of variables that best discriminates COPD. Results A total of 2,758 patients were screened at 368 primary care centers, of which 1,725 patients were included in the study. Seven hundred and ninety-three patients (46%) were diagnosed with COPD. Clinical judgment resulted in suspected COPD in 1,393 (81%) of the subjects. The best variables to discriminate COPD were a history of lower respiratory tract infections, cough, and dyspnea. This combination identified COPD with a ROCAUC of 0.61 denoting a poor discriminative ability. Conclusion Employing an active search strategy leads to a new COPD diagnosis in almost half of the subjects. Screening of COPD with post-bronchodilator spirometry should be considered mandatory for any high-risk subject visiting the general practitioner clinic for any reason.
Cardiac fibrosis in mice expressing an inducible myocardial-specific Cre driver

SUMMARY Tamoxifen-inducible Cre-mediated manipulation of animal genomes has achieved wide acceptance over the last decade, with numerous important studies heavily relying on this technique. Recently, a number of groups have reported transient complications of using this protocol in the heart. In the present study we observed a previously unreported focal fibrosis and depressed left-ventricular function in tamoxifen-treated αMHC-MerCreMer-positive animals in a Tβ4shRNAflox × αMHC-MerCreMer cross at 6–7 weeks following standard tamoxifen treatment, regardless of the presence of the floxed transgene. The phenotype was reproduced by treating mice from the original αMHC-MerCreMer strain with tamoxifen. In the acute phase after tamoxifen treatment, cell infiltration into the myocardium was accompanied by increased expression of pro-inflammatory cytokines (IL-1β, IL-6, TNFα, IFNγ, Ccl2) and markers of hypertrophy (ANF, BNP, Col3a1). These observations highlight the requirement for including tamoxifen-treated MerCreMer littermate controls to avert misinterpretation of conditional mutant phenotypes. A survey of the field as well as the protocols presented here suggests that controlling the parameters of tamoxifen delivery is important in avoiding the chronic MerCreMer-mediated cardiac phenotype reported here.
A Comparative Exergoeconomic Analysis of Waste Heat Recovery from a Gas Turbine-Modular Helium Reactor via Organic Rankine Cycles

A comparative exergoeconomic analysis is reported for waste heat recovery from a gas turbine-modular helium reactor (GT-MHR) using various configurations of organic Rankine cycles (ORCs) for generating electricity. The ORC configurations studied are: a simple organic Rankine cycle (SORC), an ORC with an internal heat exchanger (HORC) and a regenerative organic Rankine cycle (RORC). Exergoeconomic analyses are performed with the specific exergy costing (SPECO) method. First, energy and exergy analyses are applied to the combined cycles. Then, a cost-balance, as well as auxiliary equations are developed for the components to determine the exergoeconomic parameters for the combined cycles and their components. The three combined cycles are compared considering the same operating conditions for the GT-MHR cycle, and a parametric study is done to reveal the effects on the exergoeconomic performance of the combined cycles of various significant parameters, e.g., turbine inlet and evaporator temperatures and compressor pressure ratio. The results show that the GT-MHR/RORC has the lowest unit cost of electricity generated by the ORC turbine. This value is highest for the GT-MHR/HORC. Furthermore, the GT-MHR/RORC has the highest and the GT-MHR/HORC has the lowest exergy destruction cost rate.
Modular Decomposition and Analysis of Registration Based Trackers

This paper presents a new way to study registration based trackers by decomposing them into three constituent sub modules:appearance model, state space model and search method. It is often the case that when a new tracker is introduced in literature, it only contributes to one or two of these sub modules while using existing methods for the rest. Since these are often selected arbitrarily by the authors, they may not be optimal for the new method. In such cases, this breakdown can help to experimentally find the best combination of methods for these sub modules while also providing a framework within which the contributions of the new tracker can be clearly demarcated and thus studied better. We show how existing trackers can be broken down using the suggested methodology and compare the performance of the default configuration chosen by the authors against other possible combinations to demonstrate the new insights that can be gained by such an approach. We also present an open source system that provides a convenient interface to plug in a new method for any sub module and test it against all possible combinations of methods for the other two sub modules while also serving as a fast and efficient solution for practical tracking requirements.
Self-Focusing in the Damped Nonlinear Schrödinger Equation

We analyze the effect of damping (absorption) on critical self-focusing. We identify a threshold value $\delta_{th}$ for the damping parameter $\delta$ such that when $\delta%gt; \delta_{th}$ damping arrests blowup. When $\delta < \delta_{th}$, the solution blows up at the same asymptotic rate as the undamped nonlinear Schrodinger equation.
Respiration in lakes

This chapter reviews, from a quantitative perspective, estimates and models of planktonic and benthic respiration in lakes, as derived from bottle and core incubations. Using data gleaned from the literature, empiricalmodels of planktonic andbenthic respiration are presented inwhich respiration is shown todepend primarily on lake trophic conditions and, secondarily, on temperature and other factors such as dissolved organic carbon loading and community structure. The possibilities and limits of alternative methods of measuring lake respiration and its components are discussed. Extrapolations of the findings to the globe suggest that about 62–76 Tmol of carbon are respired annually in the world’s lakes, exceeding the estimated gross primary production of these ecosystems. Lakes thus contribute significantly to the oxidation of landderived organic carbon.