Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
See detailAn equation-free, nested, concurrent multiscale approach without scale-separation
Beex, Lars UL; Kerfriden, Pierre

Scientific Conference (2018, September)

Detailed reference viewed: 48 (0 UL)
Full Text
Peer Reviewed
See detailEquational approach to argumentation networks
Gabbay, Dov M. UL

in Argument and Computation (2012), 3(2-3), 87--142

Detailed reference viewed: 70 (3 UL)
Full Text
Peer Reviewed
See detailThe Equational Approach to CF2 Semantics
Gabbay, Dov M. UL

in Computational Models of Argument - Proceedings of COMMA 2012, Vienna Austria, September 10-12, 2012 (2012)

Detailed reference viewed: 18 (0 UL)
Full Text
Peer Reviewed
See detailAn Equational Approach to Logic Programming
Gabbay, Dov M. UL

in Correct Reasoning - Essays on Logic-Based AI in Honour of Vladimir Lifschitz (2012)

Detailed reference viewed: 53 (0 UL)
Full Text
Peer Reviewed
See detailAn equational approach to the merging of argumentation networks
Gabbay, Dov M. UL; Rodrigues, Odinaldo

in J. Log. Comput. (2014), 24(6), 1253--1277

Detailed reference viewed: 64 (0 UL)
Full Text
Peer Reviewed
See detailEquations of hyperelliptic Shimura curves
Molina Blanco, Santiago UL

in Proceedings of the London Mathematical Society (2012), 105(5), 891--920

Detailed reference viewed: 123 (0 UL)
Full Text
Peer Reviewed
See detailEquations to predict the shear connection capacity of composite beams with slender profiled steel sheeting
Odenbreit, Christoph UL; Vigneri, Valentino UL; Lam, Dennis

Scientific Conference (2019, July)

The rules of EN1994-1-1 for shear connections in composite beams with deep profiled sheeting sometimes lead to an overestimation of the load bearing capacity of the respective shear connection. The ... [more ▼]

The rules of EN1994-1-1 for shear connections in composite beams with deep profiled sheeting sometimes lead to an overestimation of the load bearing capacity of the respective shear connection. The estimation of the impact of the sheeting shape on the calculated connection resistance is based on test results from the late seventies until the early nineties. Meanwhile, new products have appeared on the market with the target to reduce the volume and weight of the concrete in order to maximize the slab efficiency. However, the corresponding effects onto the shear connection have been underestimated because the use of deeper and more narrow deck rib lead to a more slender profile with a changed failure behaviour. Instead of the shearing-off failure of the stud, a combination of concrete cone failure and plastic bending of the stud – with one or two plastic hinges - was identified in laboratory tests. Based on the observed failure mechanisms, a new mechanical model with respective analytical equations for the shear resistance of headed studs in profiled steel sheeting was proposed. The new model extends the yield hinge mechanism, which was developed by Lungershausen [1], to more precisely predict the formation of the number of yield hinges depending on the mechanical and geometrical properties with the support of a finite element model. The complete equations consider the geometry of the stud and the steel decking as well as the material strengths of the stud and concrete. The statistical evaluation shows a good accordance with the developed model and analytical design equations. This contribution presents the new design equations and their background describing the mechanical model, the numerical study and statistical evaluation of push-out test results. [less ▲]

Detailed reference viewed: 60 (10 UL)
Full Text
Peer Reviewed
See detailEquidistribution of signs for modular eigenforms of half integral weight
Inam, Ilker; Wiese, Gabor UL

in Archiv der Mathematik [=ADM] (2013), 101(4), 331--339

Let f be a cusp form of weight k+1/2 and at most quadratic nebentype character whose Fourier coefficients a(n) are all real. We study an equidistribution conjecture of Bruinier and Kohnen for the signs of ... [more ▼]

Let f be a cusp form of weight k+1/2 and at most quadratic nebentype character whose Fourier coefficients a(n) are all real. We study an equidistribution conjecture of Bruinier and Kohnen for the signs of a(n). We prove this conjecture for certain subfamilies of coefficients that are accessible via the Shimura lift by using the Sato-Tate equidistribution theorem for integral weight modular forms. Firstly, an unconditional proof is given for the family {a(tp^2)}_p where t is a squarefree number and p runs through the primes. In this case, the result is in terms of natural density. To prove it for the family {a(tn^2)}_n where t is a squarefree number and n runs through all natural numbers, we assume the existence of a suitable error term for the convergence of the Sato-Tate distribution, which is weaker than one conjectured by Akiyama and Tanigawa. In this case, the results are in terms of Dedekind-Dirichlet density. [less ▲]

Detailed reference viewed: 131 (5 UL)
Full Text
Peer Reviewed
See detailEquihash: asymmetric proof-of-work based on the Generalized Birthday problem
Biryukov, Alex UL; Khovratovich, Dmitry UL

in Proceedings of NDSS 2016 (2016, February)

The proof-of-work is a central concept in modern cryptocurrencies, but the requirement for fast verification so far made it an easy prey for GPU-, ASIC-, and botnet-equipped users. The attempts to rely on ... [more ▼]

The proof-of-work is a central concept in modern cryptocurrencies, but the requirement for fast verification so far made it an easy prey for GPU-, ASIC-, and botnet-equipped users. The attempts to rely on memory-intensive computations in order to remedy the disparity between architectures have resulted in slow or broken schemes. In this paper we solve this open problem and show how to construct an asymmetric proof-of-work (PoW) based on a computationally hard problem, which requires a lot of memory to generate a proof (called "memory-hardness" feature) but is instant to verify. Our primary proposal is a PoW based on the generalized birthday problem and enhanced Wagner's algorithm for it. We introduce the new technique of algorithm binding to prevent cost amortization and demonstrate that possible parallel implementations are constrained by memory bandwidth. Our scheme has tunable and steep time-space tradeoffs, which impose large computational penalties if less memory is used. Our solution is practical and ready to deploy: a reference implementation of a proof-of-work requiring 700 MB of RAM runs in 30 seconds on a 1.8 GHz CPU, increases the computations by the factor of 1000 if memory is halved, and presents a proof of just 148 bytes long. [less ▲]

Detailed reference viewed: 5819 (40 UL)
Full Text
Peer Reviewed
See detailEquilibrated patch recovery for accurate evaluation of upper error bounds in quantities of interest
González-Estrada, O. A.; Ródenas, J. J.; Nadal, E. et al

in ECCOMAS Thematic Conference - ADMOS 2011: International Conference on Adaptive Modeling and Simulation, An IACM Special Interest Conference (2012)

There is an increasing interest on the use of goal-oriented error estimates which help to measure and control the local error on a linear or non-linear quantity of interest (QoI) that might result ... [more ▼]

There is an increasing interest on the use of goal-oriented error estimates which help to measure and control the local error on a linear or non-linear quantity of interest (QoI) that might result relevant for design purposes (e.g. the mean stress value in a particular area, displacements, the stress intensity factor for fracture problems,⋯). In general, residual-based error estimators have been used to obtain upper and lower bounds of the error in quantities of interest for finite element approximations. In this work, we propose a novel a posteriori recovery technique to obtain an upper error bound of the QoI. We use a recovery procedure based on the superconvergent patch recovery (SPR) technique to obtain nearly statically admissible recovered stress fields for the primal and dual problems. This recovery technique was previously used to obtain upper bounds of the error in energy norm and has been used in this paper to obtain a computable version of the upper bound for the quantity of interest. [less ▲]

Detailed reference viewed: 237 (1 UL)
Full Text
Peer Reviewed
See detailEquilibrated patch recovery for accurate evaluation of upper error bounds in quantities of interest
González-Estrada, Octavio Andrés; Ródenas, J J; Nadal, Enrique et al

in Audry, D; Díez, P; Tie, B (Eds.) et al Adaptive Modeling and Simulation. Proceedings of V ADMOS 2011 (2011)

Detailed reference viewed: 70 (0 UL)
Full Text
See detailL'équilibre contractuel dans les pays du Code civil: évolutions croisées
Ancel, Pascal UL

Presentation (2014, March 14)

Detailed reference viewed: 190 (57 UL)
Full Text
Peer Reviewed
See detailEquilibria in social belief removal
Booth, Richard UL; Meyer, Thomas

in Synthese (2010), 177

Detailed reference viewed: 66 (0 UL)
Full Text
See detailEquilibrium and first-best city with endogenous exposure to local air pollution from traffic
Schindler, Mirjam UL; Caruso, Geoffrey UL; Picard, Pierre M UL

E-print/Working paper (2016)

Exposure to urban traffic-induced air pollution is a major health concern of cities. This paper analyzes the urban structure when localized pollution exposure arises from commuting traffic and ... [more ▼]

Exposure to urban traffic-induced air pollution is a major health concern of cities. This paper analyzes the urban structure when localized pollution exposure arises from commuting traffic and investigates the feedback effect of endogenous pollution on residential choices. The presence of stronger traffic-induced air pollution exposure reduces the geographical extent and the population of cities. Land rents fall with distance from the city center while population densities may be non-monotonic. Cleaner vehicle technologies reduce pollution exposure everywhere, increase population and density everywhere and do not affect the spatial extent of the city. The paper compares the urban equilibrium with the first-best. The first-best structure is a less expanded city with higher densities at the center and lower densities at the fringe. [less ▲]

Detailed reference viewed: 214 (18 UL)
Full Text
Peer Reviewed
See detailEquilibrium and first-best city with endogenous exposure to local air pollution from traffic
Schindler, Mirjam UL; Caruso, Geoffrey UL; Picard, Pierre M UL

in Regional Science and Urban Economics (2017), 62

Exposure to urban traffic-induced air pollution is a major health concern of cities. This paper analyzes the urban structure when localized pollution exposure arises from commuting traffic and ... [more ▼]

Exposure to urban traffic-induced air pollution is a major health concern of cities. This paper analyzes the urban structure when localized pollution exposure arises from commuting traffic and investigates the feedback effect of endogenous pollution on residential choices. The presence of stronger traffic-induced air pollution exposure reduces the geographical extent and the population of cities. Land rents fall with distance from the city center while population densities may be non-monotonic. Cleaner vehicle technologies reduce pollution exposure everywhere, increase population and density everywhere and do not affect the spatial extent of the city. The paper compares the urban equilibrium with the first-best. The first-best structure is a less expanded city with higher densities at the center and lower densities at the fringe. [less ▲]

Detailed reference viewed: 224 (10 UL)
Full Text
Peer Reviewed
See detailEquilibrium and sensitivity analysis of dynamic ridesharing
Viti, Francesco UL; Corman, Francesco

Scientific Conference (2013)

Sharing travels is an effective way to increase car occupancy rates and to reduce the number of cars for the same distances traveled. This is a problem involving operations research (how to best match ... [more ▼]

Sharing travels is an effective way to increase car occupancy rates and to reduce the number of cars for the same distances traveled. This is a problem involving operations research (how to best match travels in time and space, what level of similarity for the routes,…) and behavior challenges (on which conditions users choose to share travels, which type of users is willing to share the travel, what is the accepted detour and rescheduling, …). This research aims at filling the gap in the latter aspect by proposing an equilibrium modeling approach for (dynamic) ridesharing. By using a Nested logit model, , greater insight into the impact of different policies, behavioral factors and matching criteria can be presented. We deal with a theoretically interesting basic model structure of a single-link case, in which we study the complex interaction of multiple factors, and the joint sensitivity to the most relevant parameters. This allows us to derive some basic recommendations from the equilibrium states reached. [less ▲]

Detailed reference viewed: 107 (0 UL)
Full Text
Peer Reviewed
See detailEquilibrium in capacitated network models with queueing delays, queue-storage, blocking back and control
Smith, Mike J.; Huang, Wei; Viti, Francesco UL

in Procedia Social and Behavioral Sciences (2013), 80

This paper considers a steady-state, link-based, fixed (or inelastic) demand equilibrium model with explicit link-exit capacities, explicit bottleneck or queuing delays and explicit bounds on queue ... [more ▼]

This paper considers a steady-state, link-based, fixed (or inelastic) demand equilibrium model with explicit link-exit capacities, explicit bottleneck or queuing delays and explicit bounds on queue storage capacities. The (spatial queueing) model at the heart of this equilibrium model takes account of the space taken up by queues both when there is no blocking back and also when there is blocking back. The paper shows in theorem 1 that a feasible traffic assignment model has an equilibrium solution provided prices are used to impose capacity restrictions and utilises this result to show that there is an equilibrium with the spatial queueing model, provided queue-storage capacities are sufficiently large. Other results are obtained by changing the variables and sets in theorem 1 suitably. These results include: (1) existence of equilibrium results (in both a steady state and a dynamic context) which allow signal green-times to respond to prices and (2) an existence of equilibrium result which allow signal green-times to respond to spatial queues; provided this response follows the P0 control policy in Smith (1979, 1987). These results show that under certain conditions the P0 control policy maximises network capacity. The spatial queueing model is illustrated on a simple network. Finally the paper includes elastic demand; this is necessary for long-run evaluations. Each of the steady state models here may be thought of as a stationary solution to the dynamic assignment problem either with or without blocking back. [less ▲]

Detailed reference viewed: 174 (4 UL)
Full Text
Peer Reviewed
See detailEquilibrium Liquid Crystal Phase Diagrams and Detection of Kinetic Arrest in Cellulose Nanocrystal Suspensions
Honorato Rios, Camila UL; Kuhnhold, Anja UL; Bruckner, Johanna et al

in Frontiers in Materials (2016), 3

The cholesteric liquid crystal self-assembly of water-suspended cellulose nanocrystal (CNC) into a helical arrangement was observed already more than 20 years ago, and the phenomenon was used to produce ... [more ▼]

The cholesteric liquid crystal self-assembly of water-suspended cellulose nanocrystal (CNC) into a helical arrangement was observed already more than 20 years ago, and the phenomenon was used to produce iridescent solid films by evaporating the solvent or via sol–gel processing. Yet, it remains challenging to produce optically uniform films and to control the pitch reproducibly, reflecting the complexity of the three-stage drying process that is followed in preparing the films. An equilibrium liquid crystal phase formation stage is followed by a non-equilibrium kinetic arrest, which in turn is followed by structural collapse as the remaining solvent is evaporated. Here, we focus on the first of these stages, combining a set of systematic rheology and polarizing optics experiments with computer simulations to establish a detailed phase diagram of aqueous CNC suspensions with two different values of the surface charge, up to the concentration where kinetic arrest sets in. We also study the effect of varying ionic strength of the solvent. Within the cholesteric phase regime, we measure the equilibrium helical pitch as a function of the same parameters. We report a hitherto unnoticed change in character of the isotropic–cholesteric transition at increasing ionic strength, with a continuous weakening of the first-order character up to the point where phase coexistence is difficult to detect macroscopically due to substantial critical fluctuations. [less ▲]

Detailed reference viewed: 190 (12 UL)
Full Text
Peer Reviewed
See detailEquilibrium models in multimodal container transport systems
Corman, Francesco; Viti, Francesco UL; Negenborn, Rudy

in Flexible Services and Manufacturing Journal (2017), 29

Detailed reference viewed: 197 (6 UL)
Full Text
Peer Reviewed
See detailEquilibrium morphology of misfit particles in elastically stressed solids under chemo-mechanical equilibrium conditions
Zhao, X.; Bordas, Stéphane UL; Qu, J.

in Journal of the Mechanics and Physics of Solids (2015), 81

Detailed reference viewed: 159 (6 UL)