Bartering integer commodities with exogenous prices

The analysis of markets with indivisible goods and fixed exogenous prices has played an important role in economic models, especially in relation to wage rigidity and unemployment. This research report provides a mathematical and computational details associated to the mathematical programming based approaches proposed by Nasini et al. (accepted 2014) to study pure exchange economies where discrete amounts of commodities are exchanged at fixed prices. Barter processes, consisting in sequences of elementary reallocations of couple of commodities among couples of agents, are formalized as local searches converging to equilibrium allocations. A direct application of the analyzed processes in the context of computational economics is provided, along with a Java implementation of the approaches described in this research report.Comment: 30 pages, 5 sections, 10 figures, 3 table

SDL - The IoT Language

Interconnected smart devices constitute a large and rapidly growing element of the contemporary Internet. A smart thing can be as simple as a web-enabled device that collects and transmits sensor data to a repository for analysis, or as complex as a web-enabled system to monitor and manage a smart home. Smart things present marvellous opportunities, but when they participate in complex systems, they challenge our ability to manage risk and ensure reliability. SDL, the ITU Standard Specification and Description Language, provides many advantages for modelling and simulating communicating agents – such as smart things – before they are deployed. The potential for SDL to enhance reliability and safety is explored with respect to existing smart things below. But SDL must advance if it is to become the language of choice for developing the next generation of smart things. In particular, it must target emerging IoT platforms, it must support simulation of interactions between pre-existing smart things and new smart things, and it must facilitate deployment of large numbers of similar things. Moreover, awareness of the potential benefits of SDL must be raised if those benefits are to be realized in the current and future Internet of Things.Peer ReviewedPostprint (published version

Optimal buildings’ energy consumption calculus through a distributed experiment execution

The calculus of building energy consumption is a demanding task because multiple factors must be considered during experimentation. Additionally, the definition of the model and the experiments is complex because the problem is multidisciplinary. When we face complex models and experiments that require a considerable amount of computational resources, the application of solutions is imperative to reduce the amount of time needed to define the model and the experiments and to obtain the answers. In this paper, we first address the definition and the implementation of an environmental model that describes the behavior of a building from a sustainability point of view and enables the use of several simulations and calculus engines in a cosimulation scenario. Second, we define a distributed experimental framework that enables us to obtain results in an accurate amount of time. This methodology has been applied to the energy consumption calculation, but it can also be applied to other modeling problems that usually require a considerable amount of resources by reducing the amount of time needed to perform modeling, implementation, verification, and experimentation.Peer ReviewedPostprint (published version

Covid-19: la malinterpretación de los datos de la pandemia daña la confianza del público

Dos cartas publicadas en The Lancet y The Lancet Public Health en los últimos meses defienden la necesidad de evaluar de forma independiente la respuesta española ante la covid-19. Estamos de acuerdo, pero nos gustaría complementarlas con tres puntos que nos acercan a la ciencia abierta. Nos referimos a la confusión terminológica, la calidad de los datos y su disponibilidad

SARS-CoV-2 Spread Forecast Dynamic Model Validation through Digital Twin Approach, Catalonia Case Study

The spread of the SARS-CoV-2 modeling is a challenging problem because of its complex nature and lack of information regarding certain aspects. In this paper, we explore a Digital Twin approach to model the pandemic situation in Catalonia. The Digital Twin is composed of three different dynamic models used to perform the validations by a Model Comparison approach. We detail how we use this approach to obtain knowledge regarding the effects of the nonpharmaceutical interventions and the problems we faced during the modeling process. We use Specification and Description Language (SDL) to represent the compartmental forecasting model for the SARS-CoV-2. Its graphical notation simplifies the different specialists’ understanding of the model hypotheses, which must be validated continuously following a Solution Validation approach. This model allows the successful forecasting of different scenarios for Catalonia. We present some formalization details, discuss the validation process and present some results obtained from the validation model discussion, which becomes a digital twin of the pandemic in Catalonia

Using Specification and Description Language for Life Cycle Assesment in Buildings

The definition of a Life Cycle Assesment (LCA) for a building or an urban area is a complex task due to the inherent complexity of all the elements that must be considered. Furthermore, a multidisciplinary approach is required due to the different sources of knowledge involved in this project. This multidisciplinary approach makes it necessary to use formal language to fully represent the complexity of the used models. In this paper, we explore the use of Specification and Description Language (SDL) to represent the LCA of a building and residential area. We also introduce a tool that uses this idea to implement an optimization and simulation mechanism to define the optimal solution for the sustainability of a specific building or residential

SDL Cellular Automaton COVID-19 conceptualization

The digitalization of a phenomenon allows us to understand, discuss, and predict its behavior. In environmental areas, and specifically in a pandemic situation this is not an exception. The language selected to perform this conceptualization must help in the understanding of the phenomenon and must be capable to be executed, if possible, automatically, to simplify the verification process. Also, the language must be an agreement between the different parties involved in the model definition; all the specialist must feel confident with the language to be able to collaborate in a transdisciplinary approach in the model definition. In this paper, we present a conceptualization of the COVID-19 pandemic situation. The model represented in Specification and Description Language allows a detailed parametrization of the pandemic situation and a further expansion of an initial model defined using the System Dynamics approach to Cellular Automaton approach. This expansion of the conceptualization done in SDL simplifies the validation of the different models obtained. Also, the use of SDL simplifies the integration in the model of real-time data to perform the system validations. We detail the conceptualization done using SDL for the Cellular Automaton model