scholarly journals Uncertainty Quantification, Model Calibration and Sensitivity

2021 ◽  
pp. 71-92
Author(s):  
Jakub Bijak ◽  
Jason Hilton
Keyword(s):  
Experimental Design ◽  
Uncertainty Quantification ◽  
Computational Models ◽  
Agent Based Models ◽  
Agent Based ◽  
Quantification Model ◽  
High Level ◽  
Comprehensive Framework ◽  
Shed Light

AbstractBetter understanding of the behaviour of agent-based models, aimed at embedding them in the broader, model-based line of scientific enquiry, requires a comprehensive framework for analysing their results. Seeing models as tools for experimenting in silico, this chapter discusses the basic tenets and techniques of uncertainty quantification and experimental design, both of which can help shed light on the workings of complex systems embedded in computational models. In particular, we look at: relationships between model inputs and outputs, various types of experimental design, methods of analysis of simulation results, assessment of model uncertainty and sensitivity, which helps identify the parts of the model that matter in the experiments, as well as statistical tools for calibrating models to the available data. We focus on the role of emulators, or meta-models – high-level statistical models approximating the behaviour of the agent-based models under study – and in particular, on Gaussian processes (GPs). The theoretical discussion is illustrated by applications to the Routes and Rumours model of migrant route formation introduced before.

scholarly journals Agent Based Models of Polymicrobial Biofilms and the Microbiome—A Review

2021 ◽  
Vol 9 (2) ◽  
pp. 417
Author(s):  
Sherli Koshy-Chenthittayil ◽  
Linda Archambault ◽  
Dhananjai Senthilkumar ◽  
Reinhard Laubenbacher ◽  
Pedro Mendes ◽  
...  
Keyword(s):  
Species Interactions ◽  
Computational Models ◽  
Human Microbiome ◽  
Agent Based Modeling ◽  
Autonomous Agent ◽  
Agent Based Models ◽  
Agent Based ◽  
Complex Interactions ◽  
Mucosal Surfaces ◽  
Living Organisms

The human microbiome has been a focus of intense study in recent years. Most of the living organisms comprising the microbiome exist in the form of biofilms on mucosal surfaces lining our digestive, respiratory, and genito-urinary tracts. While health-associated microbiota contribute to digestion, provide essential nutrients, and protect us from pathogens, disturbances due to illness or medical interventions contribute to infections, some that can be fatal. Myriad biological processes influence the make-up of the microbiota, for example: growth, division, death, and production of extracellular polymers (EPS), and metabolites. Inter-species interactions include competition, inhibition, and symbiosis. Computational models are becoming widely used to better understand these interactions. Agent-based modeling is a particularly useful computational approach to implement the various complex interactions in microbial communities when appropriately combined with an experimental approach. In these models, each cell is represented as an autonomous agent with its own set of rules, with different rules for each species. In this review, we will discuss innovations in agent-based modeling of biofilms and the microbiota in the past five years from the biological and mathematical perspectives and discuss how agent-based models can be further utilized to enhance our comprehension of the complex world of polymicrobial biofilms and the microbiome.

Religiously permissible consumption

2019 ◽  
Vol 10 (3) ◽  
pp. 948-960 ◽  
Author(s):  
Dominika Maison ◽  
Marta Marchlewska ◽  
Rizqy Amelia Zein ◽  
Dewi Syarifah ◽  
Herison Purba
Keyword(s):  
Experimental Design ◽  
Similar Pattern ◽  
Design Methodology ◽  
Energy Drink ◽  
Moderator Variable ◽  
Content Type ◽  
Shed Light

Purpose The purpose of this paper is to investigate the influence of the halal label on product perceptions among Muslims high (vs low) in the centrality of their religion. Design/methodology/approach It was hypothesized that a halal label would predict positive product perceptions, especially among those Muslims who scored high in the Centrality of Religiosity Scale (CRS). The study was conducted among 187 Muslims in Indonesia, a country in which Islam is the dominant religion. We used an experimental design where two products (cake and energy drink), with (n = 85) or without (n = 102) the halal label (depending on the experimental condition), were displayed. The participants were randomly assigned to the research conditions. Following product exposure, the participants evaluated products on perception scales (e.g. tasty, healthy). Finally, the centrality of religiosity (moderator variable) was measured. Findings The results of the analysis showed that the halal label increased positive product perceptions among those Muslims who scored high in the CRS. A similar pattern of results was obtained for both products (cake and energy drink), though the described effect was even more pronounced in the case of the energy drink. Originality/value Results shed light on the role of religiosity in consumption, especially in consumers’ responses to the halal label.

Monetary and Fiscal Policy Analysis With an Agent-Based Macroeconomic Model

2008 ◽  
Vol 228 (2-3) ◽  
Author(s):  
Gottfried Haber
Keyword(s):  
Public Sector ◽  
Fiscal Policy ◽  
Policy Analysis ◽  
Macroeconomic Policy ◽  
Formation Mechanisms ◽  
Agent Based Models ◽  
Agent Based ◽  
Expectation Formation ◽  
The Public ◽  
High Level

SummaryMacroeconomic policy analysis is a challenge for agent-based models because these types of model are generally much elaborated on the specific market levels for partial (micro) markets, but have been of limited use for macroeconomic policy issues due to calibration and “model closure” issues.Moreover, macroeconomic policy measures at a high level of aggregation, such as general fiscal policy and monetary policy, tend to include several microeconomic aspects determined by the macroeconomic policy makers (i.e. the specific process of money transmission, budget constraints within/for the public sector, etc.), which are not usually captured by agent-based models with an emphasis on microfoundation. Thus, a fully-specified macroeconomic agent-based model, AS1, is applied in this paper. Specifically, the monetary sector is modeled in detail, and both the central bank and the public sector are set up as separate agents with their own expectations and behavior. The paper has two aims: (a) to show that economic policy may be analyzed in this context with more elaborate expectation formation mechanisms than in traditional models, and (b) to demonstrate that this might change the assessment of policy effectiveness. Two illustrative examples for monetary and fiscal policies are presented with different levels of rationality and differences in the expectation formation process.

AI-Driven Agent-Based Models to Study the Role of Vaccine Acceptance in Controlling COVID-19 Spread in the US

2021 ◽  
Author(s):  
Parantapa Bhattacharya ◽  
Dustin Machi ◽  
Jiangzhuo Chen ◽  
Stefan Hoops ◽  
Bryan Lewis ◽  
...  
Keyword(s):  
Agent Based Models ◽  
Vaccine Acceptance ◽  
Agent Based ◽  
The Us

Agent‐Based Modeling

2009 ◽  
Author(s):  
Scott de Marchi ◽  
Scott E. Page
Keyword(s):  
Mathematical Models ◽  
Computational Methods ◽  
Computational Models ◽  
Agent Based Modeling ◽  
Agent Based Models ◽  
Agent Based ◽  
Agent Interactions ◽  
Game Theoretic ◽  
Mathematical Analyses ◽  
The Stability

This article provides a discussion on agent-based modeling. Two examples that show the ability of computational methods to extend game-theoretic results are presented. It then discusses modeling agents, modeling agent interactions, and system behaviour. In addition, it describes how agent-based models differ from and complement mathematical models and concludes with some suggestions for how one might best leverage the strengths of agent-based models to advance political science. Most mathematical analyses of game-theoretic models do not look into the stability and attainability of their equilibria and would be made richer by complementing them with agent-based models that explored those properties. The ability of computational models to test the robustness of formal results would be reason alone to add them to tool kits. As a methodology, agent-based modeling should be considered as in its infancy, its enormous potential limited only by the scientific and creative talents of its practitioners.

scholarly journals Leveraging social influence to address overweight and obesity using agent-based models: The role of adolescent social networks

2015 ◽  
Vol 125 ◽  
pp. 203-213 ◽  
Author(s):  
J. Zhang ◽  
L. Tong ◽  
P.J. Lamberson ◽  
R.A. Durazo-Arvizu ◽  
A. Luke ◽  
...  
Keyword(s):  
Social Networks ◽  
Social Influence ◽  
Overweight And Obesity ◽  
Agent Based Models ◽  
Agent Based

Domestic-Level Factors and Negotiation (In)Flexibility in the WTO

2012 ◽  
Vol 17 (1) ◽  
pp. 115-138 ◽  
Author(s):  
Jannie Lilja
Keyword(s):  
Information Exchange ◽  
Policy Making ◽  
Market Access ◽  
Public Outreach ◽  
High Level ◽  
The Empirical Analysis ◽  
Domestic Level ◽  
Shed Light ◽  
Preliminary Support

Abstract Some suggest that the fault lines of the WTO’s perceived failures actually lie in failures at the domestic level. This study examines the factors that can explain flexibility (and inflexibility) in multilateral trade negotiations within WTO member states. To shed light on the role of domestic factors in influencing WTO positions, we examine one member state in connection with a high-level meeting. India at the July 2008 Ministerial is selected primarily for methodological reasons. The empirical analysis provides preliminary support for the proposition that domestic policy-making structures marked by continuous information exchange and coordination are more likely to yield negotiation flexibility in multilateral talks. More specifically, the intense interaction that marks the relationships between actors involved in policy making on Non-Agricultural Market Access (NAMA) and services, where the Indian negotiation position was flexible overall, stands in contrast to what took place in the area of agriculture, where India took a manifestly inflexible stand. Competing explanations fail to fully account for the variation in these negotiating postures. A key insight from the analysis is that organized and regularized consultations, involving the same actors over time, are important. There is also a need for public outreach strategies in connection with high-level WTO meetings.

scholarly journals Multiscale Agent-Based and Hybrid Modeling of the Tumor Immune Microenvironment

Processes ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 37 ◽  
Author(s):  
Kerri-Ann Norton ◽  
Chang Gong ◽  
Samira Jamalian ◽  
Aleksander Popel
Keyword(s):  
Immune Response ◽  
Tumor Heterogeneity ◽  
Computational Models ◽  
Digital Pathology ◽  
Hybrid Modeling ◽  
Immune Microenvironment ◽  
Agent Based ◽  
Tumor Immune Microenvironment ◽  
Cancer Tumor

Multiscale systems biology and systems pharmacology are powerful methodologies that are playing increasingly important roles in understanding the fundamental mechanisms of biological phenomena and in clinical applications. In this review, we summarize the state of the art in the applications of agent-based models (ABM) and hybrid modeling to the tumor immune microenvironment and cancer immune response, including immunotherapy. Heterogeneity is a hallmark of cancer; tumor heterogeneity at the molecular, cellular, and tissue scales is a major determinant of metastasis, drug resistance, and low response rate to molecular targeted therapies and immunotherapies. Agent-based modeling is an effective methodology to obtain and understand quantitative characteristics of these processes and to propose clinical solutions aimed at overcoming the current obstacles in cancer treatment. We review models focusing on intra-tumor heterogeneity, particularly on interactions between cancer cells and stromal cells, including immune cells, the role of tumor-associated vasculature in the immune response, immune-related tumor mechanobiology, and cancer immunotherapy. We discuss the role of digital pathology in parameterizing and validating spatial computational models and potential applications to therapeutics.

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