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Publications

Publications by SEM

2023

Playing hide and seek: tackling in-store picking operations while improving customer experience

Authors
Moreira, FN; Amorim, P;

Publication
CoRR

Abstract

2022

A Novel Discrete Particle Swarm Optimization Algorithm for the Travelling Salesman Problems

Authors
Sequeiros, JA; Silva, R; Santos, AS; Bastos, J; Varela, MLR; Madureira, AM;

Publication
INNOVATIONS IN INDUSTRIAL ENGINEERING

Abstract
There are Optimization Problems that are too complex to be solved efficiently by deterministic methods. For these problems, where deterministic methods have proven to be inefficient, if not completely unusable, it is common to use approximate methods, that is, optimization methods that solve the problems quickly, regardless of their size or complexity, even if they do not guarantee optimal solutions. In other words, methods that find acceptable solutions, efficiently. One particular type of approximate method, which is particularly effective in complex problems, are metaheuristics. Particle Swarm Optimization is a population-based metaheuristic, which has been particularly successful. In order to broaden the application and overcome the limitation of Particle Swarm Optimization, a discrete version of the metaheuristics is proposed. The Discrete Particle Swarm Optimization, DPSO, will change the PSO algorithm so it can be applied to discrete optimization problems. This alteration will focus on the velocity update equation. The DPSO was tested in an instance of the Traveling Salesman Problem, att48, 48 points problems proposed by Padberg and Rinaldi, which showed some promising results.

2022

Business models for the digital transformation of audiovisual archives

Authors
Rodrigues, JC;

Publication
INTERNATIONAL JOURNAL OF ENTREPRENEURIAL BEHAVIOR & RESEARCH

Abstract
Purpose This study contributes to the understanding of how cultural organizations are using digital technologies to redesign their business models and enable sustainable and impactful audiovisual digital archives. Design/methodology/approach An inductive multiple case research design was used. Five cases of audiovisual digital archives of independent films were selected. Data collected was based on desk research, onsite visits, interviews with top managers responsible for the digitalization of some of the archives and experimentation with the services provided. Data was collected and analyzed based on a theoretical framework defined from the literature for business models of cultural organizations. Findings The archives analyzed faced the challenge of aligning the commercial viability with a mission of making content available to increase cultural knowledge. A sustainable business model may be achieved by using different revenue models, while guaranteeing to offer a value proposition carefully aligned with stakeholders' expectations. Moreover, an impactful business model, i.e. a business model that enhances the creation of cultural value for customers and reaches wider audiences, requires careful audience management and the use of data analysis about audience behavior to adjust the offering. Finally, the business model must consider the resources, activities and infrastructure that ensure critical capabilities for the business and must be designed to ensure financial resilience of the organization. Originality/value This study contributes with a holistic analysis of business models for the digital transformation of cultural organizations, detailing alternative configurations for the most relevant components of a digital business model for audiovisual archives.

2022

Adaptability and Procedural Content Generation for Educational Escape Rooms

Authors
Sousa D.; Coelho A.; Torres M.F.; Garcia A.R.; Rossini T.;

Publication
Proceedings of the European Conference on Games-based Learning

Abstract
We present a literature review that aims to understand the role of the Educational Escape Room (EER) in improving the teaching, learning, and assessment processes through an EER design framework. The main subject is to identify the recent interventions in this field in the last five years. Our study focuses on understanding how it is possible to create an EER available to all students, namely visually challenged users. As a result of the implementation of new learning strategies that promote autonomous learning, a concern arose in adapting educational activities to each student's individual needs. To study the adaptability of each EER, we found the EER design framework essential to increase the student experience by promoting the consolidation of knowledge through narrative and level design. The results of our study show evidence of progress in students' performance while playing an EER, revealing that students' learning can be effective. Research on Procedural Content Generation (PCG) highlighted how important it is to implement adaptability in future studies of EERs. However, we found some limitations regarding the process of evaluating learning through the EERs, showing how important it is to study and implement learning analytics in future studies in this field.

2022

Performance benchmarking of power-to-gas plants using Composite Indicators

Authors
Heymann, F; Rudisuli, M; Scheidt, FV; Camanho, AS;

Publication
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

Abstract
Driven by the need for decarbonizing energy carriers across sectors, and the increasing availability of low-cost renewable electricity generation future energy systems will see a rise of power-to-gas technology. For example, hydrogen and its derivates can make enable the usage of carbon-neutral electricity for hard-to abate industry sectors and serve as long-term seasonal storage. Given recent drafts of ambitious political hydrogen strategies around the world, the question arises which power-to-gas configurations provide the highest value for money from a power system perspective. This work provides a flexible framework to compare the performance of current power-to-gas sites all over the world. Power-to-gas technologies are assessed with a benchmarking framework based on Composite Indicators to compare the system value of existing conversion technologies, plant sizes, cost structures, and configurations. Our analysis confirms recent research that suggests that plant performance is higher for larger projects and improves as projects move from research stage over pilot stage to commercial stage. Our findings inform policy makers and electricity system planners who aim to identify the economically and technically most promising solutions for investment.

2022

A C plus plus application programming interface for co-evolutionary biased random-key genetic algorithms for solution and scenario generation

Authors
Oliveira, BB; Carravilla, MA; Oliveira, JF; Resende, MGC;

Publication
OPTIMIZATION METHODS & SOFTWARE

Abstract
This paper presents a C++ application programming interface for a co-evolutionary algorithm for solution and scenario generation in stochastic problems. Based on a two-space biased random-key genetic algorithm, it involves two types of populations that are mutually impacted by the fitness calculations. In the solution population, high-quality solutions evolve, representing first-stage decisions evaluated by their performance in the face of the scenario population. The scenario population ultimately generates a diverse set of scenarios regarding their impact on the solutions. This application allows the straightforward implementation of this algorithm, where the user needs only to define the problem-dependent decoding procedure and may adjust the risk profile of the decision-maker. This paper presents the co-evolutionary algorithm and structures the interface. We also present some experiments that validate the impact of relevant features of the application.

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