Towards a unified conceptual model representation

A good documentation or representation is important for communicating simulation conceptual models between stakeholders effectively. A good conceptual model representation may be used as a legal document in a simulation project contract; it may be used as a model description, which is crucial in a distributed simulation environment for model reusability and interoperability and, finally, it can improve the credibility of the model. This paper proposes a unified representation of simulation conceptual models. A conceptual model comprises a number of components, which can be grouped into the problem domain and the model domain. A number of diagrams and textual representations are proposed to represent each of the conceptual model components. Our intention is to initiate the discussion and development of a unified conceptual model representation that will benefit stakeholders involved in a simulation project. A case study in health-care is used to show how the proposed unified conceptual modelling can be applied in practice

Effect of Weathering on Functional Group and Mechanical Properties of Polypropylene-kenaf Composites

The functional group and the mechanical properties of unweathered and weathered polypropylen (PP)-kenaf composites have been analyzed by Forier-Transformed Infrared Spectroscopy (FT-IR) and Universal Testing Machine. The composites have been prepared from PP(60 %w) + kenaf (40 %w) and PP(60 %w) + kenaf (40 %w) + maleic anhydride grafted polypropylene (MAPP) (1 %w) by blending method using laboplastomill mixer at 175 oC for 8 minutes then the blend was pressed by using hotpress at 175 oC, for 8 minutes with pressure of 50 kgf. Weathering sampling periods is 5.5 months. Surface chemical analysis of PP-kenaf and PP-kenaf-MAPP composites using FT-IR showed that lignin content decreased and surface oxidation (carbonyl content) increased during exposure. PP-kenaf and PP-kenaf-MAPP composites weathering result in reduced strength properties

Approaching simulation to modelers: a user interface for large-scale demographic simulation

Extended version / Versió extesaAgent-based modeling is one of the promising modeling tools that can be used in the study of population dynamics. Two of the main obstacles hindering the use of agent-based simulation in practice are its scalability when the analysis requires large-scale models such as policy studies, and its ease-of-use especially for users with no programming experience. While there has been a significant work on the scalability issue, ease-of-use aspect has not been addressed in the same intensity. This paper presents a graphical user interface designed for a simulation tool which allows modelers with no programming background to specify agent-based demographic models and run them on parallel environments. The interface eases the definition of models to describe individual and group dynamics processes with both qualitative and quantitative data. The main advantage is to allow users to transparently run the models on high performance computing infrastructures.Postprint (author's final draft

A Case of Primary Ileocecal Lymphoma

Primary lymphoma in gastrointestinal tract is not very common. Ileocecal region is the commonest site for primary lymphoma and diffuse large B cell lymphoma (DLBCL) is the most prevalent subtype. The clinical presentation in this condition is pain in right lower quadrant region and this can very confusing since many diseases can also cause this problem like infection and inflammatory disease. In this paper, we report a case of primary lymphoma subtype DLBCL in ileocecal region that come to emergency department with ileus obstruction. Abdominal computerized tomography (CT) scan and colonoscopy revealed tumour in ileocecal region ascendens colon. Hemicolectomy was performed and the specimen was sent to pathology which revealed non-Hodgkin lymphoma with subtype DLBCL CD20 (+). The patient had undergone of Rituximab, Cyclophosphamide, Doxorubicine, Vincristin, and Prednison (RCHOP) chemotherapy regimen and had complete remission

Simulation, optimization, and machine learning in sustainable transportation systems: Models and applications

[EN] The need for effective freight and human transportation systems has consistently increased during the last decades, mainly due to factors such as globalization, e-commerce activities, and mobility requirements. Traditionally, transportation systems have been designed with the main goal of reducing their monetary cost while offering a specified quality of service. During the last decade, however, sustainability concepts are also being considered as a critical component of transportation systems, i.e., the environmental and social impact of transportation activities have to be taken into account when managers and policy makers design and operate modern transportation systems, whether these refer to long-distance carriers or to metropolitan areas. This paper reviews the existing work on different scientific methodologies that are being used to promote Sustainable Transportation Systems (STS), including simulation, optimization, machine learning, and fuzzy sets. This paper discusses how each of these methodologies have been employed to design and efficiently operate STS. In addition, the paper also provides a classification of common challenges, best practices, future trends, and open research lines that might be useful for both researchers and practitioners.This work has been partially supported by the Spanish Ministry of Science, Innovation, and Universities (PID2019-111100RB-C21-C22/AEI/10.13039/501100011033, RED2018-102642-T) and the SEPIE Erasmus+ Program (2019-I-ES01-KA103-062602), and the IoF2020-H2020 (731884) project.Torre-Martínez, MRDL.; Corlu, CG.; Faulin, J.; Onggo, BS.; Juan-Pérez, ÁA. (2021). Simulation, optimization, and machine learning in sustainable transportation systems: Models and applications. Sustainability. 13(3):1-21. https://doi.org/10.3390/su1303155112113

The role of simulation and serious games in teaching concepts on circular economy and sustainable energy

[EN] The prevailing need for a more sustainable management of natural resources depends not only on the decisions made by governments and the will of the population, but also on the knowledge of the role of energy in our society and the relevance of preserving natural resources. In this sense, critical work is being done to instill key concepts-such as the circular economy and sustainable energy-in higher education institutions. In this way, it is expected that future professionals and managers will be aware of the importance of energy optimization, and will learn a series of computational methods that can support the decision-making process. In the context of higher education, this paper reviews the main trends and challenges related to the concepts of circular economy and sustainable energy. Besides, we analyze the role of simulation and serious games as a learning tool for the aforementioned concepts. Finally, the paper provides insights and discusses open research opportunities regarding the use of these computational tools to incorporate circular economy concepts in higher education degrees. Our findings show that, while efforts are being made to include these concepts in current programs, there is still much work to be done, especially from the point of view of university management. In addition, the analysis of the teaching methodologies analyzed shows that, although their implementation has been successful in favoring the active learning of students, their use (especially that of serious games) is not yet widespread.This work has been partially supported by the Spanish Ministry of Science (PID2019-111100RB-C21-C22/AEI/10.13039/501100011033, RED2018-102642-T) and the SEPIE Erasmus+ Program (2019-I-ES01-KA103-062602).Torre-Martínez, MRDL.; Onggo, BS.; Corlu, CG.; Nogal, M.; Juan-Pérez, ÁA. (2021). The role of simulation and serious games in teaching concepts on circular economy and sustainable energy. Energies. 14(4):1-21. https://doi.org/10.3390/en1404113812114

Eliciting Agents’ Behaviour using Scenario-Based Questionnaire in Agent-Based Dairy Supply Chain Simulation

A scenario-based questionnaire is a survey method that aims to identify the respondents’ decision rules using their responses to a series of scenarios. It is rarely used in agent-based modelling and simulation (ABMS) with most researchers preferring a survey with closed questions as the data collection method. This is particularly true for ABMS studies in agri-food supply chains. In our paper, we design a scenario-based questionnaire to elicit the behaviour of agents in ABMS and apply it in a dairy supply chain case. Our findings suggest that respondents respond well to a scenario-based questionnaire as it relates more closely to their actual decision-making process. Furthermore, our experiment shows that the decision rules extracted using a scenario-based questionnaire improve ABMS validity

Hybrid simulation: Historical lessons, present challenges and futures

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A BPMN extension to support discrete-event simulation for healthcare applications:an explicit representation of queues, attributes and data-driven decision points

Stakeholder engagement in simulation projects is important, especially in healthcare where there is a plurality of stakeholder opinions, objectives and power. One promising approach for increasing engagement is facilitated modelling. Currently, the complexity of producing a simulation model means that the ‘model coding’ stage is performed without the involvement of stakeholders, interrupting the possibility of a fully-facilitated project. Early work demonstrated that with currently-available software tools we can represent a simple healthcare process using Business Process Model and Notation (BPMN) and generate a simulation model automatically. However, for more complex processes, BPMN currently has a number of limitations, namely the ability to represent queues and data-driven decision points. To address these limitations, we propose a conceptual design for an extension to BPMN (BPMN4SIM) using Model Driven Architecture. Application to an elderly emergency care pathway in a UK hospital shows that BPMN4SIM is able to represent a more-complex business process

Improving police control rooms using simulation

Police command and control centres are the main point of contact for the public who require help. Like other areas of UK public services, police forces are set targets for their performance. Some of these targets relate to the speed at which they respond to calls for assistance from the public. In this paper we share our experience in improving the performance of command and control centres of a UK Police Force; a project which started as a classical simulation exercise and ended up with a significant reorganization in a UK Police Force