Get information about air quality using 'Airly' <https://airly.eu/> API through R.

Utilities for working with hourly air quality monitoring data
    with a focus on small particulates (PM2.5). A compact data model is 
    structured as a list with two dataframes. A 'meta' dataframe contains 
    spatial and measuring device metadata associated with deployments at known 
    locations. A 'data' dataframe contains a 'datetime' column followed by 
    columns of measurements associated with each "device-deployment".
    Algorithms to calculate NowCast and the associated Air Quality Index (AQI)
    are defined at the US Environmental Projection Agency AirNow program:
    <https://document.airnow.gov/technical-assistance-document-for-the-reporting-of-daily-air-quailty.pdf>.

Retrieve air quality data via the 'AirNow'
    <https://www.airnow.gov/> API.

Airport problems, introduced by Littlechild and Owen (1973)
    <https://www.jstor.org/stable/2629727>, are cost allocation 
    problems where agents share the cost of a facility (or service) based on 
    their ordered needs. Valid allocations must satisfy no-subsidy constraints, 
    meaning that no group of agents contributes more than the highest cost of 
    its members (i.e., no agent is allowed to subsidize another). A rule is a 
    mechanism that selects an allocation vector for a given problem. This 
    package computes several rules proposed in the literature, including both 
    standard rules and their variants, such as weighted versions, rules for 
    clones, and rules based on the agents’ hierarchy order. These rules can be 
    applied to various problems of interest, including the allocation of 
    liabilities and the maintenance of irrigation systems, among others.  
    Moreover, the package provides functions for graphical representation, 
    enabling users to visually compare the outcomes produced by each rule, 
    or to display the no-subsidy set. In addition, it includes four datasets 
    illustrating different applications and examples of airport problems. For a 
    more detailed explanation of all concepts, see Thomson (2024)
    <doi:10.1016/j.mathsocsci.2024.03.007>.