1,721,239 research outputs found
Synthesis of Reward Machines for Multi-Agent Equilibrium Design
No full textMechanism design is a well-established game-theoretic paradigm for designing games to achieve desired outcomes. This paper addresses a closely related but distinct concept, equilibrium design. Unlike mechanism design, the designer’s authority in equilibrium design is more constrained; she can only modify the incentive structures in a given game to achieve certain outcomes without the ability to create the game from scratch. We study the problem of equilibrium design using dynamic incentive structures, known as reward machines. We use weighted concurrent game structures for the game model, with goals (for the players and the designer) defined as mean-payoff objectives. We show how reward machines can be used to represent dynamic incentives that allocate rewards in a manner that optimises the designer’s goal. We also introduce the main decision problem within our framework, the payoff improvement problem. This problem essentially asks whether there exists a dynamic incentive (represented by some reward machine) that can improve the designer’s payoff by more than a given threshold value. We present two variants of the problem: strong and weak. We demonstrate that both can be solved in polynomial time using a Turing machine equipped with an NP oracle. Furthermore, we also establish that these variants are either NP-hard or coNP-hard. Finally, we show how to synthesise the corresponding reward machine if it exists
Automated temporal equilibrium analysis: Verification and synthesis of multi-player games
Full text linkIn the context of multi-agent systems, the rational verification problem is concerned with checking which temporal logic properties will hold in a system when its constituent agents are assumed to behave rationally and strategically in pursuit of individual objectives. Typically, those objectives are expressed as temporal logic formulae which the relevant agent desires to see satisfied. Unfortunately, rational verification is computationally complex, and requires specialised techniques in order to obtain practically useable implementations. In this paper, we present such a technique. This technique relies on a reduction of the rational verification problem to the solution of a collection of parity games. Our approach has been implemented in the Equilibrium Verification Environment (EVE) system. The EVE system takes as input a model of a concurrent/multi-agent system represented using the Simple Reactive Modules Language (SRML), where agent goals are represented as Linear Temporal Logic (LTL) formulae, together with a claim about the equilibrium behaviour of the system, also expressed as an LTL formula. EVE can then check whether the LTL claim holds on some (or every) computation of the system that could arise through agents choosing Nash equilibrium strategies; it can also check whether a system has a Nash equilibrium, and synthesise individual strategies for players in the multi-player game. After presenting our basic framework, we describe our new technique and prove its correctness. We then describe our implementation in the EVE system, and present experimental results which show that EVE performs favourably in comparison to other existing tools that support rational verification
Endogenous Energy Reactive Modules Games: Modelling Side Payments among Resource-Bounded Agents
Full text linkWe introduce Energy Reactive Modules Games (ERMGs), an extension of Reactive Modules Games (RMGs) in which actions incur an energy cost (which may be positive or negative), and the choices that players make are restricted by the energy available to them. In ERMGs, each action is associated with an energy level update, which determines how their energy level is affected by the performance of the action. In addition, agents are provided with an initial energy allowance. This allowance plays a crucial role in shaping an agent’s behaviour, as it must be taken into consideration when one is determining their strategy: agents may only perform actions if they have the requisite energy. We begin by studying rational verification for ERMGs and then introduce Endogenous ERMGs, where agents can choose to transfer their energy to other agents. This exchange may enable equilibria that are impossible to achieve without such transfers. We study the decision problem of whether a stable outcome exists under both the Nash equilibrium and Core solution concepts
Designing Equilibria in Concurrent Games with Social Welfare and Temporal Logic Constraints
Full text linkIn game theory, mechanism design is concerned with the design of incentives so that a desired outcome of the game can be achieved. In this paper, we explore the concept of equilibrium design, where incentives are designed to obtain a desirable equilibrium that satisfies a specific temporal logic property. Our study is based on a framework where system specifications are represented as temporal logic formulae, games as quantitative concurrent game structures, and players\u27 goals as mean-payoff objectives. We consider system specifications given by LTL and GR(1) formulae, and show that designing incentives to ensure that a given temporal logic property is satisfied on some/every Nash equilibrium of the game can be achieved in PSPACE for LTL properties and in NP/ΣP 2 for GR(1) specifications. We also examine the complexity of related decision and optimisation problems, such as optimality and uniqueness of solutions, as well as considering social welfare, and show that the complexities of these problems lie within the polynomial hierarchy. Equilibrium design can be used as an alternative solution to rational synthesis and verification problems for concurrent games with mean-payoff objectives when no solution exists or as a technique to repair concurrent games with undesirable Nash equilibria in an optimal way.arXiv admin note: substantial text overlap with arXiv:2106.1019
On the complexity of rational verification
Full text linkRational verification refers to the problem of checking which temporal logic properties hold of a concurrent/multiagent system, under the assumption that agents in the system choose strategies that form a game theoretic equilibrium. Rational verification can be understood as a counterpart to model checking for multiagent systems, but while classical model checking can be done in polynomial time for some temporal logic specification languages such as CTL, and polynomial space with LTL specifications, rational verification is much harder: the key decision problems for rational verification are 2EXPTIME-complete with LTL specifications, even when using explicit-state system representations. Against this background, our contributions in this paper are threefold. First, we show that the complexity of rational verification can be greatly reduced by restricting specifications to GR(1), a fragment of LTL that can represent a broad and practically useful class of response properties of reactive systems. In particular, we show that for a number of relevant settings, rational verification can be done in polynomial space and even in polynomial time. Second, we provide improved complexity results for rational verification when considering players’ goals given by mean-payoff utility functions—arguably the most widely used approach for quantitative objectives in concurrent and multiagent systems. Finally, we consider the problem of computing outcomes that satisfy social welfare constraints. To this end, we consider both utilitarian and egalitarian social welfare and show that computing such outcomes is either PSPACE-complete or NP-complete
Hubungan Antara Stres Kerja Dengan Burnout Pada Karyawan Perusahaan Daerah Bank Pengkreditan Rakyat (PD BPR) Karimun Provinsi Kepulauan Riau
Full text linkThe relationship Between Work Stres and Burnout in Employees of Regional People’s Credit Bank (PD BPR) Karimun Riau Island Province Najib Muhammad Alim 178110167 ABTRACT Abstract. Burnout is a state of being squeezed out and losing psychic and physical energy. In general, burnout is more likely to occur in individuals who have experienced continuous prolonged work stress as a result of feeling powerless to change work situations. The impact of burnout can cause a person to be disturbed and a decrease in personal achievement at work. The purpose of this study was to determine whether there is a relationship between work stress and burnout in employees at the Regional People's Credit Bank (PD BPR) Karimun, Riau Islands Province. The proposed hypothesis is that there is a relationship between job stress and burnout. This study uses a saturated sampling technique from the population to be used as a sample in terms of the shape of the saturated sample and the form of the special population (Sugiyono, 2017), namely all employees of the Regional People's Credit Bank (PD BPR) Karimun, Riau Islands Province with a sample of 50 people. Data collection carried out using 2 scales, namely the work stress scale, and the burnout scale. data analysis technique using non-parametric analysis. The results of this study indicate that the level of burnout and work stress at the Regional Credit Bank Karimun Company, Riau Islands Province, is in the medium category as many as 29 people out of 50 employees or 58.00% and 33 people out of 50 employees or 66.00%
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
sj-docx-1-ine-10.1177_15910199241233333 - Supplemental material for Utilization and reimbursement of diagnostic cerebral angiograms: A Medicare trends analysis from 2013 to 2020
No full textSupplemental material, sj-docx-1-ine-10.1177_15910199241233333 for Utilization and reimbursement of diagnostic cerebral angiograms: A Medicare trends analysis from 2013 to 2020 by Avi A Gajjar, Michael M Covell, Najib Muhammad, Cathleen Kuo, Georgios S Sioutas, Mohamed M Salem, Sebastian Ivan Fras, Brian T Jankowitz, Jan-Karl Burkhardt and Visish M Srinivasan in Interventional Neuroradiology</p
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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