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Efficiency and fairness trade-offs in two player bargaining games
Get PDFRecent work on the evolution of social contracts and conventions has often used models of bargaining games, with reinforcement learning. A recent innovation is the requirement that every strategy must be invented either through through learning or reinforcement. However, agents frequently get stuck in highly-reinforced “traps” that prevent them from arriving at outcomes that are efficient or fair to the both players. Agents face a trade-off between exploration and exploitation, i.e. between continuing to invent new strategies and reinforcing strategies that have already become highly reinforced by yielding high rewards. In this paper I systematically study the relationship between rates of invention and the efficiency and fairness of outcomes in two-player, repeated bargaining games. I use a basic reinforcement learning model with invention, and five variations of this model, designed introduce various forms of forgetting, to prioritize more recent reinforcement, or to maintain a higher rate of invention. I use computer simulations to investigate the outcomes of each model. Each models shows qualitative similarities in the relationship between the efficiency and fairness of outcomes, and the relative amount of exploration or exploitation that takes place. Surprisingly, there are often trade-offs between the efficiency and the fairness of the outcomes
Insights from exact social contagion dynamics on networks with higher-order structures
Get PDFRecently there has been an increasing interest in studying dynamical processes on networks ex-
hibiting higher-order structures, such as simplicial complexes, where the dynamics acts above and
beyond dyadic interactions. Using simulations or heuristically derived epidemic spreading models it
was shown that new phenomena can emerge, such as bi-stability/multistability. Here, we show that
such new emerging phenomena do not require complex contact patterns, such as community struc-
tures, but naturally result from the higher-order contagion mechanisms. We show this by deriving
an exact higher-order SIS model and its limiting mean-field equivalent for fully connected simplicial
complexes. Going beyond previous results, we also give the global bifurcation picture for networks
with 3- and 4-body interactions, with the latter allowing for two non-trivial stable endemic steady
states. Differently from previous approaches, we are able to study systems featuring interactions
of arbitrary order. In addition, we characterise the contributions from higher-order infections to
the endemic equilibrium as perturbations of the pairwise baseline, finding that these diminish as
the pairwise rate of infection increases. Our approach represents a first step towards a principled
understanding of higher-order contagion processes beyond triads and opens up further directions for
analytical investigations
Unconventional Reservoir Characterization and Formation Evaluation: A Case Study of a Tight Sandstone Reservoir in West Africa
Get PDFUnconventional reservoirs, including gas shales and tight gas sands, have gained prominence in the energy sector due to technological advancements and escalating energy demands. The oil industry is eagerly refining techniques to decipher these reservoirs, aiming to reduce data collection costs and uncertainties in reserve estimations. Characteristically, tight reservoirs exhibit low matrix porosity and ultra-low permeability, necessitating artificial stimulation for enhanced production. The efficacy of the stimulation hinges on the organic material distribution, the rock’s mechanical attributes, and the prevailing stress field. Comprehensive petrophysical analysis, integrating standard and specialized logs, core analyses, and dynamic data, is pivotal for a nuanced understanding of these reservoirs. This ensures a reduction in prediction uncertainties, with parameters like shale volume, porosity, and permeability being vital. This article delves into an intricate petrophysical evaluation of the Nene field, a West African unconventional reservoir. It underscores the geological intricacies of the field, the pivotal role of data acquisition, and introduces avant-garde methodologies for depth matching, rock typing, and the estimation of permeability. This research highlights the significance of unconventional reservoir exploration in today’s energy milieu, offering a granular understanding of the Nene field’s geological challenges and proffering a blueprint for analogous future endeavours in unconventional reservoirs
What Sentence Repetition Tasks Can Reveal about the Processing Effort Associated with Different Types of Code-Switching.
Get PDFIn this study, we explored the linguistic consolidation processes associated with bilingual processing using an experimental paradigm novel in bilingualism research, i.e., sentence repetition. We tested 46 L1-German L2-English bilinguals immersed in the L2 context. Firstly, we compared participants’ sentence repetition accuracy in single-language sentences and in sentences involving code-switches. Secondly, we investigated the processing cost associated with different types of code-switching, i.e., alternation, insertion, and dense code-switching. Finally, we assessed the following potential predictors of repetition accuracy: regular usage of different code-switching types, executive functions (working memory and inhibitory control), as well as relevant bilingualism variables (proficiency, dominance, and immersion). Our first finding was that bilinguals displayed reduced repetition accuracy in sentences involving code-switches compared to single-language sentences, but only when the single-language sentences were in the participants’ L1. This suggests that any processing costs associated with code-switching are modulated by bilinguals’ language background. Moreover, bilinguals’ poor performance in L2 compared to L1 single-language sentences, despite reporting high levels of L2 exposure frequency, highlights the importance of age of acquisition and dominance profiles for language processing. In terms of code-switching, our results revealed that bilinguals’ repetition accuracy differed across different types of code-switching. The processing effort associated with different types of code-switching in the sentence repetition task was primarily driven by the structural depth and the degree of mixing of the involved code-switch, i.e., dense forms of code-switching involving high levels of linguistic co-activation were harder to repeat than alternations involving unintegrated language switching. This effect partially converged with bilinguals’ sociolinguistic practices because bilinguals also reported lower exposure frequency to dense code-switching, but no direct correlations were observed at the level of individual differences. In terms of general cognitive functions, repetition accuracy was modulated by working memory but not by inhibitory control. By investigating this issue, we hope to contribute to our understanding of language processing in the face of cross-linguistic consolidation processes.
Keywords: multilingualism; bilingualism; code-switching; sentence repetition; language processin
Miniature physical sphere-in-contact models of heterogeneous catalysts and metal nanoparticles
Get PDFDigitizing SU(2) gauge fields and what to look out for when doing so
Get PDFWith the long term perspective of using quantum computers and tensor networks for lattice gauge
theory simulations, an efficient method of digitizing gauge group elements is needed. We thus
present our results for a handful of discretization approaches for the non-trivial example of SU(2),
such as its finite subgroups, as well as different classes of finite subsets. We focus our attention
on a freezing transition observed towards weak couplings. A generalized version of the Fibonacci
spiral appears to be particularly efficient and close to optimal
Are you in or not? A study into student intention to use immersive metaverse for learning
Get PDFLearning and teaching have been transformed by technologies in the last few decades. The rise of immersive technologies, such as the metaverse, has started gaining educators’. This phenomenon brings the need for a thorough understanding of how the metaverse could be adopted effectively for learning purposes. This study applied the Technology Acceptance Model (TAM) and Diffusion of Innovation (DoI) to investigate the variables affecting student intention of using immersive metaverse for learning purposes. An online survey was conducted to collect student responses from a US university. A sample of 81 responses was analysed using Structural Equation Modelling (SEM). The results indicate that compatibility and perceived risk influence perceived ease of use and usefulness. Perceived usefulness influences attitudes which consequently influence the intention to use. However, personal innovativeness was not found to influence perceived ease of use and usefulness. The perceived ease of use was not found to impact attitudes
Understanding the Geopolitical and Socio-Economic Factors Affecting the Food Supply Chain in Ukraine: An Exploratory Study
Get PDFThis paper presents an ongoing study that explores the influence of geopolitical and socio-economic factors on the Ukrainian food supply chain and its implications for food security. Focusing on specific sectors within Ukraine, our research aims to provide a comprehensive understanding of the intricate dynamics between geopolitics, socio-economic conditions, and the functioning of the food supply chain. To collect data, we have employed focus groups as the primary methodology, engaging key stakeholders from various sectors, including farmers, distributors, retailers, policymakers, and consumers. These focus group discussions enable us to delve into their perspectives, experiences, and challenges in relation to the influence of geopolitical and socio-economic factors on the Ukrainian food supply chain. Preliminary literature review reveals several noteworthy insights, including the impact of trade policies and regional conflicts on the availability and accessibility of specific food products in targeted regions of Ukraine. Building upon these initial findings, our ongoing study aims to propose strategies to enhance the resilience and efficiency of Ukraine’s food supply chain. By tailoring policies to address the specific needs of different regions and socio-economic groups, we anticipate mitigating the adverse effects of geopolitical dynamics on the food system. Moreover, fostering collaboration among stakeholders will be crucial in navigating the complexities and challenges inherent in managing the Ukrainian food supply chain
Multistability, intermittency, and hybrid transitions in social contagion models on hypergraphs
Get PDFAlthough ubiquitous, interactions in groups of individuals are not yet thoroughly studied. Frequently, single groups are modeled as critical-mass dynamics, which is a widespread concept used not only by academics but also by politicians and the media. However, less explored questions are how a collection of groups will behave and how their intersection might change the dynamics. Here, we formulate this process as binary-state dynamics on hypergraphs. We showed that our model has a rich behavior beyond discontinuous transitions. Notably, we have multistability and intermittency. We demonstrated that this phenomenology could be associated with community structures, where we might have multistability or intermittency by controlling the number or size of bridges between communities. Furthermore, we provided evidence that the observed transitions are hybrid. Our findings open new paths for research, ranging from physics, on the formal calculation of quantities of interest, to social sciences, where new experiments can be designed