16 research outputs found
The Physics of Dissent and the Effects of Movement Momentum
The STATA dataset that supports the findings of this study is publicly available from the Harvard Dataverse at https://doi.org/10.7910/DVN/JYM19E
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Better the devil you know? How fringe terrorism can induce an advantage for moderate nonviolent campaigns
Rebel Financing and Terrorism in Civil Wars
This book investigates the ways in which the lethality of terrorist violence depends on how rebel organizations finance their rebellion.
The leaders of rebel groups make calculated decisions on the intensity of terrorism killings, considering the benefits and costs of targeting non-combatants against the financing needs of their organization. The study specifically focuses on analyzing the effects of different external financing options available to rebel groups and takes into account the role of local populations in making financing available. This comparative approach to external financing reveals new hypotheses that are empirically verified and differ from the expectations and findings of prior research. The book's findings are relevant to policy discussions on counter-insurgency strategies that prioritize protecting populations from human rights abuses. Existing doctrines tend to overlook the potential impact of targeted efforts to isolate insurgents from specific financing sources on the capacity to secure local populations.
This book will be of interest to students of civil wars, terrorism studies, political violence, and security studies
From doctrine to detonation: ideology, competition, and terrorism in campaigns of mass resistance
A fully-distributed proximal-point algorithm for Nash equilibrium seeking with linear convergence rate
We address the Nash equilibrium problem in a partial-decision information scenario, where each agent can only observe the actions of some neighbors, while its cost possibly depends on the strategies of other agents. Our main contribution is the design of a fully-distributed, single-layer, fixed-step algorithm, based on a proximal best-response augmented with consensus terms. To derive our algorithm, we follow an operator-theoretic approach. First, we recast the Nash equilibrium problem as that of finding a zero of a monotone operator. Then, we demonstrate that the resulting inclusion can be solved in a fully-distributed way via a proximal-point method, thanks to the use of a novel preconditioning matrix. Under strong monotonicity and Lipschitz continuity of the game mapping, we prove linear convergence of our algorithm to a Nash equilibrium. Furthermore, we show that our method outperforms the fastest known gradient-based schemes, both in terms of guaranteed convergence rate, via theoretical analysis, and in practice, via numerical simulations.</p
Fast generalized Nash equilibrium seeking under partial-decision information
We address the generalized Nash equilibrium seeking problem in a partial-decision information scenario, where each agent can only exchange information with some neighbors, although its cost function possibly depends on the strategies of all agents. The few existing methods build on projected pseudo-gradient dynamics, and require either double-layer iterations or conservative conditions on the step sizes. To overcome both these flaws and improve efficiency, we design the first fully-distributed single-layer algorithms based on proximal best-response. Our schemes are fixed-step and allow for inexact updates, which is crucial for reducing the computational complexity. Under standard assumptions on the game primitives, we establish convergence to a variational equilibrium (with linear rate for games without coupling constraints) by recasting our algorithms as proximal-point methods, opportunely preconditioned to distribute the computation among the agents. Since our analysis hinges on a restricted monotonicity property, we also provide new general results that significantly extend the domain of applicability of proximal-point methods. Besides, our operator-theoretic approach favors the implementation of provably correct acceleration schemes that can further improve the convergence speed. Finally, the potential of our algorithms is demonstrated numerically, revealing much faster convergence with respect to projected pseudo-gradient methods and validating our theoretical findings.Team Sergio GrammaticoTeam DeSchutte
A fully-distributed proximal-point algorithm for Nash equilibrium seeking with linear convergence rate
We address the Nash equilibrium problem in a partial-decision information scenario, where each agent can only observe the actions of some neighbors, while its cost possibly depends on the strategies of other agents. Our main contribution is the design of a fully-distributed, single-layer, fixed-step algorithm, based on a proximal best-response augmented with consensus terms. To derive our algorithm, we follow an operator-theoretic approach. First, we recast the Nash equilibrium problem as that of finding a zero of a monotone operator. Then, we demonstrate that the resulting inclusion can be solved in a fully-distributed way via a proximal-point method, thanks to the use of a novel preconditioning matrix. Under strong monotonicity and Lipschitz continuity of the game mapping, we prove linear convergence of our algorithm to a Nash equilibrium. Furthermore, we show that our method outperforms the fastest known gradient-based schemes, both in terms of guaranteed convergence rate, via theoretical analysis, and in practice, via numerical simulations.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team DeSchutte