Encontrado(s) 2241961 resultado(s)
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The effective two-particle interaction of cold atoms as derived from bragg scattering

  • Sarjonen, R.
  • Saarela, M.
  • Mazzanti Castrillejo, Fernando Pablo
We study the dynamic structure function of ultracold alkali-metal gases for large scattering lengths and momenta where corrections to the mean field approximation become important. We compare our result with the Bragg-scattering measurements in 85Rb by Papp et al. (Phys. Rev. Lett. 101:135301, 2008) and show that these experiments set very strict limits to the shape of the effective two-particle interaction ruling out the contact and hard spheres potentials. Using the Feshbach resonance approximation we derive the effective interaction, which turns out to be very similar to the soft spheres potential in momentum space. At large scattering lengths the interaction becomes universal and could be directly measured by Bragg scattering. We also discuss the experimental conditions needed for the appearance of the maxon-roton structure in the excitation spectrum and finally show that when the scattering length becomes larger than 2000 Bohr radii the uniform gas phase undergoes a phase transition into the density wave state.

On the Induction of New Fuzzy Relations, New Fuzzy Operators and Their Aggregation

  • Carmona Cervelló, Neus
  • Elorza, Jorge
  • Recasens Ferrés, Jorge
  • Bragard, Jean
In this paper we generate fuzzy relations and fuzzy operators using different kind of generators and we study the relationship between them. Firstly, we introduce a new fuzzy preorder induced by a fuzzy operator. We generalize this preorder to a fuzzy relation generated by two fuzzy operators and we analyze its properties. Secondly, we introduce and explore two ways of inducing a fuzzy operator, one from a fuzzy operator and a fuzzy relation and the other one from two fuzzy operators. The first one is an extension of the well-known fuzzy operator induced by a fuzzy relation through Zadeh’s compositional rule. Finally, we aggregate these operators using the quasi-arithmetic mean associated to a continuous Archimedean t-norm. The aim is to compare the operator induced by the quasi-arithmetic mean of the generators with the quasi-arithmetic mean of the generated operators., Peer Reviewed

Grasp analysis and synthesis of 2D articulated objects with 2 and 3 links

  • Alvarado Tovar, Noé
  • Suárez Feijóo, Raúl
This paper proposes a solution to the problem of grasp analysis and synthesis of 2D articulated objects with 2 and 3 links considering frictionless contacts. The boundary of each link of the object is represented with a finite set of points. The grasp analysis is carried out to verify whether a set of contact points on the object boundary allows a force-closure grasp. The grasp synthesis implies the determination of a set of contact points that allows a force-closure grasp. The paper describes how to find the elements of the generalized wrench vector generated by a force applied on any link of the articulated object. The approach have been implemented and some illustrative examples are included in the paper.

Process-oriented analysis for medical devices

  • Sfyrla, Vassiliki
  • Carmona Vargas, Josep
  • Henck, Pascal
Medical Cyber Physical Systems are widely used in modern healthcare environments. Such systems are considered life-critical due to the severity of consequences that faults may cause. Effective methods, techniques and tools for modeling and analyzing medical critical systems are of major importance for ensuring system reliability and patient safety. This work is looking at issues concerning different types of medical industry needs including safety analysis, testing, conformance checking, performance analysis and optimization. We explore the possibility of addressing these issues by exploiting information recorded in logs generated by medical devices during execution. Process-oriented analysis of logs is known as process mining, a novel field that has gained considerable interest in several contexts in the last decade. Process mining techniques will be applied to an industrial use case provided by Fresenius, a manufacturer of medical devices, for analyzing process logs generated by an infusion pump.

To achieve an earlier IFN-¿ response is not sufficient to control mycobacterium tuberculosis infection in mice

  • Vilaplana, Cristina
  • Prats Soler, Clara
  • Marzo, Elena
  • Barril Basil, Carles
  • Vegué Llorente, Marina
  • Díaz, Jorge
  • Valls Ribas, Joaquim
  • López Codina, Daniel
  • Cardona Iglesias, Pere Joan
The temporo-spatial relationship between the three organs (lung, spleen and lymph node) involved during the initial stages of Mycobacterium tuberculosis infection has been poorly studied. As such, we performed an experimental study to evaluate the bacillary load in each organ after aerosol or intravenous infection and developed a mathematical approach using the data obtained in order to extract conclusions. The results showed that higher bacillary doses result in an earlier IFN-c response, that a certain bacillary load (BL) needs to be reached to trigger the IFN-c response, and that control of the BL is not immediate after onset of the IFN-c response, which might be a consequence of the spatial dimension. This study may have an important impact when it comes to designing new vaccine candidates as it suggests that triggering an earlier IFN-c response might not guarantee good infection control, and therefore that additional properties should be considered for these candidates., Peer Reviewed

Effect of filler on the aging potential of asphalt mixtures

  • Miró Recasens, José Rodrigo
  • Martínez Reguero, Adriana Haydée
  • Pérez Jiménez, Félix Edmundo
  • Bianchetto, Hugo Daniel
In this work the effect filler has on the aging of bitumen is analyzed, but incorporating the filler in volume and not in weight. The UCL method is used as the process of accelerated aging and new direct tensile test is used to determine the toughness of the aged mixture and, thus, to assess the effect the filler has. All the tests performed for this paper have shown the protective effect of the fillers used. The new direct tensile test developed by the Road Research Laboratory of the Technical University of Catalonia, allows to observe how an increase of filler produces the increase of the breaking load and the decrease of the maximum deformation, observing that the hydrated lime tends to stiffen the mixture less and make it less brittle than calcium carbonate. In order to minimize the effect of aging on bitumen, the filler content proposed must be 20 or 30% less than the content recommended in conditions when there is no aging, so that when the mixture ages the mastic is able to build up the maximum energy possible., Peer Reviewed

Using MILP to plan holidays and working hours under an annualised hours agreement

  • Corominas Subias, Albert
  • Lusa García, Amaia
  • Pastor Moreno, Rafael
Annualising work hours (AH) is a means of achievement flexibility in the use of human resources to face the seasonal nature of demand. In Corominas et al. (1) two MILP models are used to solve the problem of planning staff working hours with annual horizon. The costs due to overtime and to the employment of temporary workers are minimised, and the distribution of working time over the course of the year for each worker and the distribution of working time provided by temporary workers are regularised. In the aforementioned paper, the following is assumed: (i) the holiday weeks are fixed a priori and (ii) the workers are from different categories who are able to perform specific type of task have se same efficiency; moreover, the values of the binary variables (and others) in the second model are fixed to those in the first model (thus, in the second model these will intervene as constants and not as variables, resulting in an LP model). In the present paper, these assumptions are relaxed and a more general problem is solved. The computational experiment leads to the conclusion that MILP is a technique suited to dealing with the problem.

Aero-thermo-mechanical coupling for flame-wall interaction

  • Baque, B.
  • Errera, M.-P.
  • Roos, A.
  • Feyel, F.
  • Laroche, E.
  • Donjat, D.
This paper investigates a flame-wall interaction consisting of a premixed flame impinging on a metallic plate. This is a coupled problem as the heat transfer from the flame increases the temperature of the plate and bends it, which in turn modifies the shape of the flame. This study aims at designing an aero-thermo-mechanical coupling between both codes CEDRE (Computational Fluid Dynamics) and Z-SeT (computational solid mechanics and heat conduction) to simulate this complex system. Numerical results for aero-thermal coupling are compared with experimental data.

Aging-aware parallel execution

  • Medeiros, Thiarles S.
  • Berned, Gustavo P.
  • Navarro Muñoz, Antoni
  • Rossi, Fábio D.
  • Luizelli, Marcelo C.
  • Brandalero, Marcelo
  • Hübner, Michael
  • Beck, Antonio Carlos S.
  • Lorenzon, Arthur F.
Computation has been pushed to the edge to decrease latency and alleviate the computational burden of the IoT applications in the cloud. However, the increasing processing demands of Edge Applications make necessary the employment of platforms that exploit thread-level parallelism (TLP). Yet, power and heat dissipation rise as TLP inadvertently increases or when parallelism is not cleverly exploited, which may be the result of the non-ideal use of a given PPI (Parallel Program Interface). Besides the common issues, such as the need for more robust power sources and better cooling, heat also adversely affects aging, accelerating phenomenons such as negative bias temperature instability (NBTI) and hot-carrier injection (HCI), which further reduces processor lifetime. Hence, considering that increasing the lifespan of an edge device is key, so the number of times the application set may execute until its end-of-life is maximized, we propose BALDER. It is a learning framework capable of automatically choosing optimal configuration executions (PPI and number of threads) according to the parallel application at hand, aiming to maximize the trade-off between aging and performance. When executing ten well-known applications on two multicore embedded architectures, we show that BALDER can find a nearly-optimal configuration for all our experiments., Peer Reviewed

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