Search results for " stability."
showing 10 items of 1315 documents
Diffusive neural network
2002
Abstract A non-connectionist model of a neuronal network based on passive diffusion of neurotransmitters is presented as an alternative to hard-wired artificial neural networks. Classic thermodynamical approach shows that the diffusive network is capable of exhibiting asymptotic stability and a dynamics resembling that of a chaotic system. Basic computational capabilities of the net are discussed based on the equivalence with a Turing machine. The model offers a way to represent mass-sustained brain functions in terms of recurrent behaviors in the phase space.
Consensus in Noncooperative Dynamic Games: a Multi-Retailer Inventory Application
2008
We focus on Nash equilibria and Pareto optimal Nash equilibria for a finite horizon noncooperative dynamic game with a special structure of the stage cost. We study the existence of these solutions by proving that the game is a potential game. For the single-stage version of the game, we characterize the aforementioned solutions and derive a consensus protocol that makes the players converge to the unique Pareto optimal Nash equilibrium. Such an equilibrium guarantees the interests of the players and is also social optimal in the set of Nash equilibria. For the multistage version of the game, we present an algorithm that converges to Nash equilibria, unfortunately, not necessarily Pareto op…
Existence and Optimality of Nash Equilibria in Inventory Games
2005
Abstract This paper studies the stability and optimality of a distributed consensus protocol for n -player repeated non cooperative games under incomplete information. At each stage, the players choose binary strategies and incur in a payoff monotonically decreasing with the number of active players. The game is specialized to an inventory application, where fixed costs are shared among all retailers, interested in whether reordering or not from a common warehouse. The authors focus on Pareto optimality as a measure of coordination of reordering strategies, proving that there exists a unique Pareto optimal Nash equilibrium that verifies certain stability conditions.
Heterogeneous network games: Conflicting preferences
2013
Proceeding at: 2nd Annual UECE Lisbon Meeting: Game Theory and Applications, took place 2010, November, 4-6, in Lisbon (Portugal). The event Web site http://pascal.iseg.utl.pt/~uece/lisbonmeetings2010/ In many economic situations, a player pursues coordination or anti-coordination with her neighbors on a network, but she also has intrinsic preferences among the available options. We here introduce a model which allows to analyze this issue by means of a simple framework in which players endowed with an idiosyncratic identity interact on a social network through strategic complements or substitutes. We classify the possible types of Nash equilibria under complete information, finding two thr…
Noncooperative dynamic games for inventory applications: A consensus approach
2008
We focus on a finite horizon noncooperative dynamic game where the stage cost of a single player associated to a decision is a monotonically nonincreasing function of the total number of players making the same decision. For the single-stage version of the game, we characterize Nash equilibria and derive a consensus protocol that makes the players converge to the unique Pareto optimal Nash equilibrium. Such an equilibrium guarantees the interests of the players and is also social optimal in the set of Nash equilibria. For the multi-stage version of the game, we present an algorithm that converges to Nash equilibria, unfortunately not necessarily Pareto optimal. The algorithm returns a seque…
Thermoconvective instability and local thermal non-equilibrium in a porous layer with isoflux-isothermal boundary conditions
2014
The effects of lack of local thermal equilibrium between the solid phase and the fluid phase are taken into account for the convective stability analysis of a horizontal porous layer. The layer is bounded by a pair of plane parallel walls which are impermeable and such that the lower wall is subject to a uniform flux heating, while the upper wall is isothermal. The local thermal non-equilibrium is modelled through a two-temperature formulation of the energy exchange between the phases, resulting in a pair of local energy balance equations: one for each phase. Small-amplitude disturbances of the basic rest state are envisaged to test the stability. Then, the standard normal mode procedure is…
Investigation of thermal stability of ethylene copolymers with POSS - Study under static and dynamic conditions
2018
Abstract In the paper there was studied thermal stability of a series of ethylene copolymers with monoalkenylsiloxy- or monoalkenylsilsesquioxanes (POSS) under dynamic and static conditions. The copolymers proved to be more thermally stable than neat polyethylene and neat silsesquioxane comonomers. The kind and the content of the POSS units significantly affected degradation of the copolymers. Thermal oxidation process resulted in structural changes of the (co)polymers as it was evidenced by the variations in the kind and content of carbonyl, as well as by unsaturated end groups. Depending on the structure of the POSS comonomer incorporated into the polymer chain, the silsesquioxane units o…
Fabrication, characterization, thermal stability and nanoassemblies of novel pullulan-aspirin conjugates
2017
Abstract Present study deals with homogeneous and one-pot synthesis of novel macromolecular prodrugs (MPDs) of aspirin onto naturally occurring hydrophilic biopolymer pullulan. Pullulan-aspirin conjugates were synthesized by using green carboxylic acid activating reagent 1,1′-carbonyldiimidazole (CDI). The aspirin was first reacted with CDI to prepare aspirin-imidazolide at RT for 24 h which in situ reacted with pre-dissolved pullulan and the reaction preceded further for 24 h at 80 °C under nitrogen. Degree of substitution (DS 0.32–0.40) of aspirin onto pullulan was calculated from 1H NMR spectroscopy. Spectroscopic techniques confirmed the high covalent drug loading and purity. Thermal an…
Synthesis and mesomorphism of related series of triphilic ionic liquid crystals based on 1,2,4-triazolium cations
2021
Abstract The synthesis, liquid crystal and conductivity properties of a series of 27 salts based on the 5-(4-(alkyloxy)phenyl)-1,2,4-triazol-4-ium cation bearing a perfluoroalkyl chain with triflate, tetrafluoroborate and bistriflimide anion are reported. The cations are regarded as triphilic on account of their three distinct regions – hydrocarbon, fluorocarbon and ionic. The mesophases were characterised by a combination of polarised optical microscopy, calorimetry and small-angle scattering experiments using both X-rays and neutrons, while thermal stability was probed using thermogravimetric analysis. The liquid crystal properties are found to be dependent on the anion and the length of …
Synthesis and thermal behavior of Janus dendrimers, part 1
2010
Abstract Eight Janus-type dendrimers up to the second generation were synthesized, and their thermal properties were evaluated. Compounds consist of the dendritic bisMPA based polyester moieties, and either 3,4-dihexyloxybenzoic acid or 3,4-dihexadecyloxybenzoic acid moieties, attached to opposite sides of the pentaerythritol core. The structures of the molecules were verified with 1 H NMR, 13 C NMR, ESI TOF mass spectrometry and elemental analysis. The thermal stability was evaluated by thermogravimetric analysis, displaying onset decomposition temperatures ( T d ) ranging from 241 to 308 °C. Phase transitions were studied by differential scanning calorimetry. Based on the performed studie…