HAL-UNICE
Not a member yet
30584 research outputs found
Sort by
Innovation, Credit Constraints and National Banking Systems: A comparison of developing nations
No full textInternational audienceThis chapter extends exiting micro-level studies on the financing decisions of enterprises in developing countries by connecting these decisions both to firms’ innovation activity and to the wider institutional framework formed by the national banking system. The national banking system is recognized as being central to the ability of developing-country firms to acquire the resources and develop the capabilities needed for innovation. We investigate the links between innovation and financial system characteristics for a sample of 36 developing nations spread across 5 regions of the world: Sub-Saharan Africa, the Middle East and North Africa, East Asia and Pacific, South Asia and Central Asia. Our results show that credit constraints have a significant negative impact on innovation performance and that the depth and breadth of the national banking system indirectly affect innovation through their impact on the likelihood that firms face these financing constraints. Moreover, we find that large firms tend to benefit disproportionately from increases in banking system depth while small firms, and to a lesser extent medium-sized firms, reap relative innovation benefits from increases in banking system breadth
Is the Driving Behaviour of Young Novices and Young Experienced Drivers under Alcohol Linked to Their Perceived Effort and Alertness? In: Stanton N. (eds) Advances in Human Aspects of Transportation. AHFE 2017
No full textThe aim is to evaluate effort and alertness perception and objective driving performance of young drivers depending on Blood Alcohol Concentration (BAC) and driving experience. Young novice and young experienced drivers participated in three simulated driving sessions (BACs of 0.0, 0.2 and 0.5 g/L). They had to drive during 45 min. on a simulated highway road. After each driving session, they responded to the Thayer scale and to an adaptation of the NASA-TLX. Results showed that young experienced drivers estimated to make less effort and had better driving performance than young novice drivers. Estimated alertness level was the lowest and speed variation was the highest with BAC 0.5 g/l. It also existed an interaction effect between perceived effort and alcohol and between alertness and alcohol on driving performance. In summary, alcohol degrades driving performance, and especially when the effort is high, alertness is low and drivers lack experience
Audio-visual synchronization in reading while listening to texts: Effects on visual behavior and verbal learning
No full textInternational audienceReading while listening to texts (RWL) is a promising way to improve the learning benefits provided by a reading experience. In an exploratory study, we investigated the effect of synchronizing the highlighting of words (visual) with their auditory (speech) counterpart during a RWL task. Forty French children from 3rd to 5th grade read short stories in their native language while hearing the story spoken by a narrator. In the non-synchronized (S-) condition the text was written in black on a white background, whereas in the synchronized (S+) RWL, the text was written in grey and the words were dynamically written in black when they were aurally displayed, in a karaoke-like fashion. The children were then unexpectedly tested on their memory for the orthographic form and semantic category of pseudowords that were included in the stories. The effect of synchronizing was null in the orthographic task and negative in the semantic task. Children’s preference was mainly for the S- condition, except for the poorest readers who tended to prefer the S+ condition. In addition, the children's eye movements were recorded during reading. Gaze was affected by synchronization, with fewer but longer fixations on words, and fewer regressive saccades in the S+ condition compared to the S- condition. Thus, the S+ condition presumably captured the children's attention toward the currently heard word, which forced the children to be strictly aligned with the oral modality
To be or not to be sick and tired: Managing the visibility of HIV and HIV-related fatigue.
No full textsous pressesInternational audienceThis paper takes a new direction in exploring HIV-related fatigue by adopting a qualitative interactionist approach. We analyse the social meanings attributed to fatigue among people living with HIV in France, the social gains and losses of its visibility and the social frames that condition the discursive and physical expression of fatigue. The two-part methodology combines content analysis of fifty transcribed unstructured interviews conducted across France and participant observations within four HIV-related associations. Results reveal that the visibility of fatigue is associated with the visibility of this stigmatised illness. The expression of fatigue is therefore closely linked with disclosure and concerns about HIV stigma. The degree to which HIV and HIV-related fatigue are rendered (in)visible also depends on structural factors including gender prescriptions, but also context effects such as the type of social or “care” relations involved in a given social frame of interaction
Fully polynomial FPT algorithms for some classes of bounded clique-width graphs
No full textInternational audienceRecently, hardness results for problems in P were achieved using reasonable complexity theoretic assumptions such as the Strong Exponential Time Hypothesis. According to these assumptions, many graph theoretic problems do not admit truly subquadratic algorithms. A central technique used to tackle the difficulty of the above mentioned problems is fixed-parameter algorithms with polynomial dependency in the fixed parameter (P-FPT). Applying this technique to clique-width, an important graph parameter, remained to be done. In this paper we study several graph theoretic problems for which hardness results exist such as cycle problems, distance problems and maximum matching. We give hardness results and P-FPT algorithms, using clique-width and some of its upper-bounds as parameters. We believe that our most important result is an O(k^4 · n + m)-time algorithm for computing a maximum matching where k is either the modular-width or the P4-sparseness. The latter generalizes many algorithms that have been introduced so far for specific subclasses such as cographs. Our algorithms are based on preprocessing methods using modular decomposition and split decomposition. Thus they can also be generalized to some graph classes with unbounded clique-width
Geoarchaeology of the Roman port-city of Ostia: Fluvio-coastal mobility, urban development and resilience
No full textInternational audienceOstia is one of the most extensively excavated cities of the Roman period. The port-city of Rome, which today lies 4 km from the coastline, was established in a very constrained environment at the mouth of the River Tiber. Based on a review of the geoarchaeological and archaeological research at Ostia, 4 new cores analysed through palaeoenvionmental methods, and 21 new radiocarbon dates, we propose a new model of the fluvio-coastal landscape of Ostia from its origin: (1) the coastline shifted rapidly westward between the 8th and the 6th c. BCE followed by a slow progradation and possible erosion phases until the end of the 1st c. CE; (2) the castrum of Ostia (c. late 4th–early 3rd c. BCE) was founded away from the river mouth but close to the River Tiber; (3) between the 4th and the 1st c. BCE, the River Tiber shifted from a position next to the castrum, below the northern Imperial cardo of Ostia, to 150 m to the north; (4) a possible harbour was established to the north of the castrum during the Republican period; (5) the city expanded and a district was built over the harbour and the palaeochannel between the Republican period and the beginning of the 2nd c. CE, showing that Ostia was a dynamic and resilient city during that time. Finally, we suggest the possibility to combine urban fabric analysis (the orientation of the structures) and palaeoenvironmental analysis for reconstructing the evolution of the city in relation to the fluvio-coastal mobility
Linear magneto-viscoelastic model based on magnetic permeability components for anisotropic magnetorheological elastomers
No full textInternational audienceThe storage modulus variation of anisotropic magnetorheological elastomers (MREs) induced by an external magnetic field was modelled in the frequency domain. This involves synthesising five anisotropic MREs with different particle content and measuring its dynamic and magnetic properties. Dynamic properties were measured using a rheometer equipped with a magnetorheological cell and the magnetic permeability of each sample was measured with a vibrating sample magnetometer. Scanning Electron Microscope images were used to determine particle distribution. A four parameter fractional derivative model was used to describe MRE viscoelasticity in the absence of magnetic field and the fitting error was not larger than 1%. Magneto-induced modulus was also studied and two different models were analysed, the one of Jolly et al. (Smart Mater Struct;5:607 (1999)) and the other one of López-López et al. (J Rheol. 56:1209 (2012)). The first model underestimated the influence of the magnetic field for low particle contents while at high ones it overestimated the magnetic field effect, up to 13%. However, in the second model magnetic permeability values were used, and the error between the model prediction and experimental data did not exceed 7%. Hence, a new linear magneto-viscoelastic model was proposed in frequency domain for anisotropic MREs based on López-López et al. model, which predicts the effect of magnetic field on the dynamic shear modulus in function of particle content and frequency
Progenitors of low-luminosity Type II-Plateau supernovae
No full textInternational audienceThe progenitors of low-luminosity Type II-Plateau supernovae (SNe II-P) are believed to be red supergiant (RSG) stars, but there is much disparity in the literature concerning their mass at core collapse and therefore on the main sequence. Here, we model the SN radiation arising from the low-energy explosion of RSG stars of 12, 25, and 27 M on the main sequence and formed through single star evolution. Despite the narrow range in ejecta kinetic energy (2.54.210 erg) in our model set, the SN observables from our three models are significantly distinct, reflecting the differences in progenitor structure (e.g., surface radius, H-rich envelope mass, He-core mass). Our higher mass RSG stars give rise to Type II SNe that tend to have bluer colors at early times, a shorter photospheric phase, and a faster declining -band light curve (LC) more typical of Type II-linear SNe, in conflict with the LC plateau observed for low-luminosity SNe II. The complete fallback of the CO core in the low-energy explosions of our high mass RSG stars prevents the ejection of any Ni (nor any core O or Si), in contrast to low-luminosity SNe II-P, which eject at least 0.001 M of Ni. In contrast to observations, type II SN models from higher mass RSGs tend to show an H absorption that remains broad at late times (due to a larger velocity at the base of the H-rich envelope). In agreement with the analyses of pre-explosion photometry, we conclude that low-luminosity SNe II-P likely arise from low-mass rather than high-mass RSG stars
