Search results for "peliteoria"
showing 10 items of 34 documents
Asymptotic Hölder regularity for the ellipsoid process
2020
We obtain an asymptotic Hölder estimate for functions satisfying a dynamic programming principle arising from a so-called ellipsoid process. By the ellipsoid process we mean a generalization of the random walk where the next step in the process is taken inside a given space dependent ellipsoid. This stochastic process is related to elliptic equations in non-divergence form with bounded and measurable coefficients, and the regularity estimate is stable as the step size of the process converges to zero. The proof, which requires certain control on the distortion and the measure of the ellipsoids but not continuity assumption, is based on the coupling method.
Service Provisioning and User Association for Heterogeneous Wireless Railway Networks
2017
In addition to comforting passengers' journey, the modern railway system is responsible to support a variety of on-board Internet services to meet the passenger's demands on seamless service provisioning. In order to provide wireless access to the train, one idea attracting increasing attention is to deploy a series of track-side access points (TAPs) with high-speed data rates along the rail lines dedicated to the broadband mobile service provisioning on board. Due to the heavy data traffic flushing into the base stations (BSs) of the cellular networks, TAPs act as a complement to the BSs in data delivery. In this paper, we focus on the TAP association problem for service provisioning in a …
Service Provisioning with Multiple Service Providers in 5G Ultra-dense Small Cell Networks
2015
In this work, a game theoretical approach for addressing the virtual network service providers (NSPs), small cell provider (SCP) and user interaction in heterogenous small cell networks is presented. In particular, we consider the users can select the services of different NSPs based on their prices. The NSPs have no dedicated hardware and need to rent from the SCP in term of radio resources, e.g., small cell base stations (SBSs) in order to provide satisfied services to the users. Due to the fact that the selfish parties involved aim at maximizing their own profits, a hierarchical dynamic game framework is presented to address interactive decision problem. In the lower-level, a Stackelberg…
Evolutionary game theory of continuous traits from a causal perspective
2023
Modern evolutionary game theory typically deals with the evolution of continuous, quantitative traits under weak selection, allowing the incorporation of rich biological detail and complicated nonlinear interactions. While these models are commonly used to find candidates for evolutionary endpoints and to approximate evolutionary trajectories, a less appreciated property is their potential to expose and clarify the causal structure of evolutionary processes. The mathematical step of differentiation breaks a nonlinear model into additive components which are more intuitive to interpret, and when combined with a proper causal hypothesis, partial derivatives in such models have a causal meanin…
New insights on the role of ecology and life-history in social evolution
2017
Biological altruism, defined as a behaviour that benefits others at an apparent cost to the focal individual, is found abundantly across different levels of biological organization. While kin selection has been useful for explaining both cooperation and conflict in specialized cooperative societies, more theoretical work has to be done to develop models for realistic ecological and life-history contexts. This thesis aims to fill this gap by providing several new insights on the role of ecology and life-history in various social systems. Firstly, I propose a model that incorporates realistic ecological mechanisms of population regulation and study how different population regulation mechanisms affe…
Multistage coalition formation game of a self-enforcing international environmental agreement
2008
Samalla kun ympäristöongelmiin liittyvät uhkat kasvavat, niihin tarvitaan yhä kansainvälisempiä poliittisia ratkaisuja. Viime vuosikymmenellä solmittiin useita monenkeskisiä sopimuksia ympäristön suojelemiseksi, mutta näiden sopimusten vaikuttavuus on heikko ja jatkuvuus uhattuna.Yulia Pavlova perehtyi tutkimuksessaan useisiin näkökulmiin valtiollisista linjauksista tarkoituksenaan tukea sopimuksiin liittyvää päätöksentekoa. Hän ehdottaa muutamia peliteoriaan pohjautuvia sääntelytekniikoita.- Nykyisten monenkeskisten ympäristösopimusten suurimpana heikkoutena on joidenkin maiden sitoutumattomuus, Pavlova huomauttaa.Väitöskirja käsittelee ongelmaa, joka liittyy sekä akateemiseen tutkimukseen…
Regularization in multistage cooperitive games
2004
Maria Dementievan väitöskirja käsittelee yhteistyöpelien teoriaa ja niiden ratkaisemista. Työssä pyritään kuvaamaan peliteorian ongelmien ratkaisujoukon ns. aliytimen ominaisuuksia. Työn päähuomio on kiinnitetty monivaiheisten yhteistyöpelien ratkaisujen aikakonsistenttisyyteen liittyvään problematiikkaan.Tämä problematiikka liittyy läheisesti proseduuriin, joka pyrkii kohdentamaan hyötyä pelaajille pelin jokaisessa vaiheessa. Työssä käsitellään myös ns. supistettua peliominaisuutta ja dynaamista konsistenttisyyttä liittyen erääseen tunnetun Davis-Maschler-pelin muunnelmaan. Tämän muunnelman aikakonsistettisyystarkasteluun esitetään uusi lähestymistapa. This thesis deals with solutions of c…
Local regularity estimates for general discrete dynamic programming equations
2022
We obtain an analytic proof for asymptotic H\"older estimate and Harnack's inequality for solutions to a discrete dynamic programming equation. The results also generalize to functions satisfying Pucci-type inequalities for discrete extremal operators. Thus the results cover a quite general class of equations.
Gradient and Lipschitz Estimates for Tug-of-War Type Games
2021
We define a random step size tug-of-war game and show that the gradient of a value function exists almost everywhere. We also prove that the gradients of value functions are uniformly bounded and converge weakly to the gradient of the corresponding $p$-harmonic function. Moreover, we establish an improved Lipschitz estimate when boundary values are close to a plane. Such estimates are known to play a key role in the higher regularity theory of partial differential equations. The proofs are based on cancellation and coupling methods as well as an improved version of the cylinder walk argument. peerReviewed
On the local and global regularity of tug-of-war games
2018
This thesis studies local and global regularity properties of a stochastic two-player zero-sum game called tug-of-war. In particular, we study value functions of the game locally as well as globally, that is, close to the boundaries of the game domains. Furthermore, we formulate a continuous time stochastic differential game and discuss, among other things, the equicontinuity of the families of value functions. The main motivation is to understand the properties of the games on their own right. As applications, we obtain an existence and a regularity result for a nonlinear elliptic p-Laplace type partial differential equation and a characterization of the solution to a parabolic p-Laplace typ…