pinecone/core-2020-05-10-deduplication huggingface dataset:
Analysis of Boundary-Layer Statistical Properties at Dome C, Antarctica

International audienceThe atmospheric boundary layer over the Antarctic Plateau is unique on account of its isolated location and extreme stability. Here we investigate the characteristics of the boundary layer using wind and temperature measurements from a 45-m high tower located at Dome C. First, spectral analysis reveals that both fields have a scaling behaviour from 30 min to 10 days (spectral slope β≈2 ). Wind and temperature time series also show a multifractal behaviour. Therefore, it is possible to fit the moment-scaling function to the universal multifractal model and obtain multifractal parameters for temperature ( α≈1.51,C1≈0.14 ) and wind speed ( α≈1.34,C1≈0.13 ). The same analysis is repeated separately in winter and summer at six different heights. The β parameter shows a strong stratification with height especially in summer, implying that properties of turbulence change surprisingly rapidly from the ground to the top of the tower
Experimental study of the delayed threshold phenomenon in a Class-A VECSEL

International audienceAn experimental study of the delayed threshold phenomenon in a Vertical Extended Cavity Semiconductor Emitting Laser is carried out. Under modulation of the pump power, the laser intensity exhibits a hysteresis behavior in the vicinity of the threshold. The temporal width of this hysteresis is measured as a function of the modulation frequency, and is proved to follow the predicted scaling law. A model based on the rate equations is derived and used to analyze the experimental observations. A frequency variation of the laser around the delayed threshold and induced by the phase-amplitude coupling is predicted and estimated
Behavioral pricing of energy swing options by stochastic bilevel optimization

Holders of energy swing options are free to specify the amounts of energy to be delivered on short notice, paying a fixed price per unit delivered. Due to the complexity of potential demand patterns, risk elimination by replication of these contract at energy exchange markets is not possible. As a consequence, when selling delivery contracts, the energy producer has to explicitly consider the risk emanating from fluctuations in supply cost. The impact of these risk factors can be mitigated by the contract seller, who is an energy producer, to a certain extent: Supply cost fluctuations can be absorbed by the own generation portfolio whereas demand uncertainties can be influenced by the choice of the strike price, implicitly changing the buyer's behavior. Considering this, the determination of the optimal strike price can be formulated a a stochastic bilevel problem where the optimal decision of upper level player (price setting and production) depends on the optimal decision of a lower level player (demand depending on the price). We present a solution algorithm tailored to the resulting specific stochastic bilevel problem. We illstrate the effects of the behavioral pricing approach by studying behavioral price setting for natural gas swing options, highlighting in particulr the influence of the seller's production and contract portfolio as well as of the market liquidity on optimal exercise prices
Land reforms and population growth

One of the greatest puzzles in demographic history is why in the rich and urbanized England, fertility declined much later than in the poor and rural France. We consider the effects of a land reform on demographic growth by a family-optimization model where relative per capita wealth generates social status and welfare. We show that tenant farming is the major obstacle to escaping the Malthusian trap with high fertility and low productivity. A land reform provides peasants with higher returns for their investments, inducing them to increase their productivity and status rather than their family size. Consequently, the population growth rate slows down, but the productivity of land increases
Technologies to Support Community Flood Disaster Risk Reduction

Floods affect more people globally than any other type of natural hazard. Great potential exists for new technologies to support flood disaster risk reduction. In addition to existing expert-based data collection and analysis, direct input from communities and citizens across the globe may also be used to monitor, validate, and reduce flood risk. New technologies have already been proven to effectively aid in humanitarian response and recovery. However, while ex-ante technologies are increasingly utilized to collect information on exposure, efforts directed towards assessing and monitoring hazards and vulnerability remain limited. Hazard model validation and social vulnerability assessment deserve particular attention. New technologies offer great potential for engaging people and facilitating the coproduction of knowledge
Positional disorder in ammonia borane at ambient conditions

We solve a long-standing experimental discrepancy of NH3BH3, which - as a molecule - has a threefold rotational axis, but in its crystallized form at room temperature shows a fourfold symmetry around the same axis, creating a geometric incompatibility. To explain this peculiar experimental result, we study the dynamics of this system with ab initio Car-Parrinello molecular dynamics and nudged-elastic band simulations. We find that rotations, rather than spatial static disorder, at angular velocities of 2 rev/ps - a time scale too small to be resolved by standard experimental techniques - are responsible for the fourfold symmetry
A Simple Variant of the Merkle-Damg°ard Scheme with a Permutation

We propose a new composition scheme for hash functions.
	It is a variant of the Merkle-Damg°ard construction with a permutation
	applied right before the processing of the last message block. We analyze
	the security of this scheme using the indifferentiability formalism,
	which was first adopted by Coron et al. to the analysis of hash functions.
	And we study the security of simple MAC constructions out of
	this scheme. Finally, we also discuss the random oracle indifferentiability
	of this scheme with a double-block-length compression function or the
	Davies-Meyer compression function composed of a block cipher
Transport Conductivity of Graphene at RF and Microwave Frequencies

We measure graphene coplanar waveguides from direct current (DC) to 13.5GHz and show that the apparent resistance (in the presence of parasitic impedances) has an quadratic frequency dependence, but the intrinsic conductivity (without the influence of parasitic impedances) is frequency-independent. Consequently, in our devices the real part of the complex alternating current conductivity is the same as the DC value and the imaginary part~0. The graphene channel is modelled as a parallel resistive-capacitive network with a frequency dependence identical to that of the Drude conductivity with momentum relaxation time~2.1ps, highlighting the influence of alternating current (AC) electron transport on the electromagnetic properties of graphene. This can lead to optimized design of high-speed analogue field-effect transistors, mixers, frequency doublers, low-noise amplifiers and radiation detectors
Exploring the belief systems of software development professionals

It is commonly accepted that an individual’s beliefs and actions are based on their assessment and perceptions of the world they inhabit. In order to determine what practices an individual is likely to follow at any given time, it is necessary to understand the individual's behavioural intention in a given circumstance. From an Information Technology perspective, software development professional’s belief systems are potentially the basis for the adoption and implementation of new and innovative work practices and processes. In this paper we explore the belief systems of software development professionals to understand the beliefs underlying intention and practice, and seek answers about how they adopt or reject new and innovative software development processes and practices. The results point out a strong influence of past experiences, personality types and repeated behaviour on current software development processes and practices in industrial settings
Effect of annealing in the Sb and In distribution of type II GaAsSb-capped InAs quantum dots

Type II emission optoelectronic devices using GaAsSb strain reduction layers (SRL) over InAs quantum dots (QDs) have aroused great interest. Recent studies have demonstrated an extraordinary increase in photoluminescence (PL) intensity maintaining type II emission after a rapid thermal anneal (RTA), but with an undesirable blueshift. In this work, we have characterized the effect of RTA on InAs/GaAs QDs embedded in a SRL of GaAsSb by transmission electron microscopy (TEM) and finite element simulations. We find that annealing alters both the distribution of Sb in the SRL as well as the exchange of cations (In and Ga) between the QDs and the SRL. First, annealing causes modifications in the capping layer, reducing its thickness but maintaining the maximum Sb content and improving its homogeneity. In addition, the formation of Sb-rich clusters with loop dislocations is noticed, which seems not to be an impediment for an increased PL intensity. Second, RTA produces flatter QDs with larger base diameter and induces a more homogeneous QD height distribution. The Sb is accumulated over the QDs and the RTA enlarges the Sb-rich region, but the Sb contents are very similar. This fact leaves the type II alignment without major changes. Atomic-scale strain analysis of the nanostructures reveal a strong intermixing of In/Ga between the QDs and the capping layer, which is the main responsible mechanism of the PL blueshift. The improvement of the crystalline quality of the capping layer together with higher homogeneity QD sizes could be the origin of the enhancement of the PL emission
Characterization of gas diffusion electrodes for metal-air batteries

Gas diffusion electrodes are commonly used in high energy density metal-air
batteries for the supply of oxygen. Hydrophobic binder materials ensure the
coexistence of gas and liquid phase in the pore network. The phase distribution
has a strong influence on transport processes and electrochemical reactions. In
this article we present 2D and 3D Rothman-Keller type multiphase
Lattice-Boltzmann models which take into account the heterogeneous wetting
behavior of gas diffusion electrodes. The simulations are performed on FIB-SEM
3D reconstructions of an Ag model electrode for predefined saturation of the
pore space with the liquid phase. The resulting pressure-saturation
characteristics and transport correlations are important input parameters for
modeling approaches on the continuum scale and allow for an efficient
development of improved gas diffusion electrodes
TRAP1 downregulation in human ovarian cancer enhances invasion and epithelial-mesenchymal transition

Ovarian cancer (OC) is the second leading cause of gynecological cancer death worldwide. Although the list of biomarkers is still growing, molecular mechanisms involved in OC development and progression remain elusive. We recently demonstrated that lower expression of the molecular chaperone TRAP1 in OC patients correlates with higher tumor grade and stage, and platinum resistance. Herein we show that TRAP1 is often deleted in high-grade serous OC patients (N=579), and that TRAP1 expression is correlated with the copy number, suggesting this could be one of the driving mechanisms for the loss of TRAP1 expression in OC. At molecular level, downregulation of TRAP1 associates with higher expression of p70S6K, a kinase frequently active in OC with emerging roles in cell migration and tumor metastasis. Indeed, TRAP1 silencing in different OC cells induces upregulation of p70S6K expression and activity, enhancement of cell motility and epithelial???mesenchymal transition (EMT). Consistently, in a large cohort of OC patients, TRAP1 expression is reduced in tumor metastases and directly correlates with the epithelial marker E-Cadherin, whereas it inversely correlates with the transcription factor Slug and the matrix metallopeptidases 2 and 9. Strikingly, pharmacological inhibition of p70S6K reverts the high motility phenotype of TRAP1 knock-down cells. However, although p70S6K inhibition or silencing reduces the expression of the transcription factors Snail and Slug, thus inducing upregulation of E-Cadherin expression, it is unable to revert EMT induced by TRAP1 silencing; furthermore, p70S6K did not show any significant correlation with EMT genes in patients, nor with overall survival or tumor stage, suggesting an independent and predominant role for TRAP1 in OC progression. Altogether, these results may provide novel approaches in OC with reduced TRAP1 expression, which could be resistant to therapeutic strategies based on the inhibition of the p70S6K pathway, with potential future intervention in OC invasion and metastasis
Achieving effective visitor orientation in European museums. Innovation versus custodial

Producción CientíficaThe context in which museums operate has evolved considerably over the last few decades, while the challenges they face have increased. The current need for museums to augment their own revenue and improve their performance coupled with the transformation of cultural models towards more experiential services has led many to adopt a consumer orientation in an effort to make museums and their collections increasingly accessible to visitors. This visitor orientation is more than just a wish to bring culture closer to the public, but rather a desire to understand visitors’ demands and thus adapt to their expectations. This paper seeks to explore the relation between visitor orientation and performance in museums. Specifically, the study focuses on technological innovation and tradition as two alternative strategies to respond to visitor expectations. An empirical study was conducted for a sample of 491 European museums. Evidence is found to support the notion that the impact of visitor orientation on economic and market performance depends on how visitors’ needs are perceived and on museums’ commitment to either innovation or tradition and custody. Whereas technological innovation has a positive impact on revenue and economic performance, the impact of custodial orientation is negative. Custodial orientation only proves effective in market terms in large museums but does not prove effective in economic terms, for either small or large museums. This paper offers a guide as to how to deal with visitor orientation in cultural and heritage organizations. Although an orientation to innovate geared towards satisfying visitor needs would seem the logical way for museums to increase visitor numbers, an approach involving too much innovation, often leading museums to becoming shows, has been widely criticized.Ministerio de Economía, Industria y Competitividad (Project ECO2012-38552
Collaborative tools: computer science students' skills versus software industry needs

Software companies encourage and further the use of collaborative tools and skills at the workplace in pursuit of the benefits of their use: they improve communication, productivity and efficiency, and competitiveness. Besides, undergraduate and graduate software engineering computing curricula recommend subjects related to effective cooperative working and group learning. In order to align industry needs and curricula recommendations, universities should provide students with the collaborative knowledge and skills that they will require on the labour market once they finish their degrees. In this scenario, we asked three questions: Are collaborative tools beneficial to software projects? Is it easier for students with knowledge and skills of collaborative tools to find a job? Do enterprises use collaborative tools as a marketing strategy for the recruitment process or are they really empowering their employees to use collaborative tools? This paper explores these questions. We devised a survey addressing the above questions, which was administered to 86 recent computer science graduates. We applied statistical techniques to analyse the responses. From the data gathered during the survey, we conclude that the expected benefits of the use of collaborative tools are in fact corroborated, students skilled in the use of collaborative tools do find it easier to get jobs and companies are not only looking for people with collaborative skills but also use collaborative tools in their routine work processes
Federal Toll Road Concession Program in Brazil: Is It Moving in the Right Direction?

This paper assesses the toll road concession program started by the federal government of Brazil, from its beginning in 1996 until 2012. Brazil has one of the longest road networks, under private concessions, in the entire world. The authors use the case study approach, based on the available information, to analyze the evolution of the program over the course of its history. Specifically, a detailed analysis is conducted from three perspectives: those of the competitiveness of the tender, the impact of toll modifications caused by the rebalancing of the economics of the contract, and the actual evolution of the traffic flows as compared to their estimates, respectively. It is found that the most recent auctions have been very competitive. Moreover, with the original toll roads, bidders relied on early traffic forecasts that turned out to be overly optimistic, and over the years, contract rebalancing has led to large increases in toll rates. Overall, and even though Brazil’s program can be considered successful in many ways, there is still considerable room for improvement
Detection of Ga suboxides and their impact on III-V passivation and fermi-level pinning

The passivation of interface states remains an important problem for III-V based semiconductor devices. The role of the most stable bound native oxides GaOx (0.5 ≤ x ≤ 1.5) is of particular interest. Using monochromatic x-ray photoelectron spectroscopy in conjunction with controlled GaAs(100) and InGaAs(100) surfaces, a stable suboxide (Ga2O) bond is detected at the interface but does not appear to be detrimental to device characteristics. In contrast, the removal of the Ga 3+ oxidation state (Ga2O3) is shown to result in the reduction of frequency dispersion in capacitors and greatly improved performance in III-V based devices
Stability of liquid bridges subject to an eccentric rotation

A cylindrical liquid bridge supported between two circular-shaped disks in isorotation is considered. The effect of an offset between the rotation axis and the axis of the two supporting disks (eccentricity) on the stability of the static liquid bridge is investigated. A numerical method is used to find stable and unstable shapes and to determine the stability limit for different values of eccentricity. The calculated stability limits are compared with analytical results, recovering the same behavior. Numerical results have been also compared with the results of an experiment aboard TEXUS-23, recovering the stability limit and the equilibrium shapes
Stochastic semi-Lagrangian micro–macro calculations of liquid crystalline solutions in complex flows

A general method for the simulation of complex flows of liquid crystalline polymers (LCPs) using a stochastic semi-Lagrangian micro–macro method is introduced. The macroscopic part uses a spatial-temporal second order accurate semi-Lagrangian algorithm, where ideas from the finite element and natural element methods are mixed in order to compute average quantities. The microscopic part employs a stochastic interpretation of the Doi–Hess LCP model, which is discretized with a second order Richardson extrapolated Euler–Maruyama scheme.\ud
The new method is validated and tested using the benchmark problem of flow between rotating eccentric cylinders. In a decoupled analysis, a discussion on the sensibility of the scalar order parameter to the macroscopic flow is offered. For the coupled situation, the proposed method predicts disclinations at certain regions of the geometry, as well as an accentuated abatement of the flow as the strength of the micro–macro interaction increases. Further examples are provided at different Peclet and concentration numbers to gain insight on the behavior of complex flows of LCPs in the eccentric cylinder geometry.\ud
The generality and robustness of the method, as well as its accurate prediction of LCP behavior under complex flows are main features of the implementatio
A user-centric approach to service creation and delivery over next generation networks

Next Generation Networks (NGN) provide Telecommunications operators with the possibility to share their resources and infrastructure, facilitate the interoperability with other networks, and simplify and unify the management, operation and maintenance of service offerings, thus enabling the fast and cost-effective creation of new personal, broadband ubiquitous services. Unfortunately, service creation over NGN is far from the success of service creation in the Web, especially when it comes to Web 2.0. This paper presents a novel approach to service creation and delivery, with a platform that opens to non-technically skilled users the possibility to create, manage and share their own convergent (NGN-based and Web-based) services. To this end, the business approach to user-generated services is analyzed and the technological bases supporting the proposal are explained
Mutual funds performance appraisal using stochastic multicriteria acceptability analysis

Mutual fund investors are concerned with the selection of the best fund in terms of performance among the set of alternative funds. This paper proposes an innovative mutual funds performance evaluation measure in the context of multicriteria decision making. We implement a multicriteria methodology using stochastic multicriteria acceptability analysis, on Greek domestic equity funds for the period 2000–2009. Combining a unique dataset of risk-adjusted returns such as Carhart’s alpha with funds’ cost variables,we obtain a multicriteria performance evaluation and ranking of the mutual funds, by means of an additive value function model. The main conclusion is that among employed variables, the sophisticated Carhart’s alpha plays the most important role in determining fund rankings. On the
other hand, funds’ rankings are affected only marginally by operational attributes. We believe that our results could have serious implications either in terms of a fund rating system or for constructing optimal combinations of portfolios.
Inductions buffer nurses’ job stress, health and organizational commitment

Nurses suffer disproportionate levels of stress and are at risk of sickness-absence and turnover intentions but there is a lack of research clarifying preventions. This study investigated the impact of inductions (job preparation courses) about mental health for nurses’ job stress, general health and organizational commitment. Data from 6,656 nurses were analyzed using structural equation modeling (SEM), showing that mental health inductions increase nurses’ job satisfaction, which reduces their occupational stress and improves their health. SEM showed that these occupational health benefits increase the nurses’ commitment to the organization. Job satisfaction (feeling valued, rewarded) also had a direct effect on nurses’ intentions to continue working for the organization. Mental health inductions are therefore beneficial beyond job performance: they increase occupational health in the nursing profession