Browsing by Author "Moura, Ana"
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- E-local pseudovarietiesPublication . Moura, AnaGeneralizingapropertyofthepseudovarietyofallaperiodicsemi- groups observed by Tilson, we call E-local a pseudovariety V which satisfies the following property: for a finite semigroup, the subsemigroup generated by its idempotents belongs to V if and only if so do the subsemigroups generated by the idempotents in each of its regular D-classes. In this paper, we present sev- eral sufficient or necessary conditions for a pseudovariety to be E-local or for a pseudoidentity to define an E-local pseudovariety. We also determine several examples of the smallest E-local pseudovariety containing a given pseudovariety.
- Idempotent-generated semigroups and pseudovarietiesPublication . Almeida, Jorge; Moura, AnaThe operator which constructs the pseudovariety generated by the idempotent-generated semigroups of a given pseudovariety is investigated. Several relevant examples of pseudovarieties generated by their idempotent- generated elements are given as well as some properties of this operator. Particular attention is paid to the pseudovarieties in {J, R, L, DA} concerning this operator and their generator ranks and idempotent-generator ranks.
- Impact of COVID-19 pandemic to EDUCON: a bibliometric analysisPublication . Silva, Mariana Miguel; Costa, Alexandra R.; Moura, Ana; Alves, Gustavo R.In recent years, bibliometrics has been widely used as a methodology for the analysis of scientific production, proving to be an excellent instrument for supporting scientific policy decisions. In this paper, we present a bibliometric analysis of the 12 editions of the Global Engineering Education Conference (EDUCON). Several indicators were used, namely number of submitted articles, the rate of accepted submissions, number of article citations, and the number of references per article, among other indicators. We also intend to add the comparison of the results obtained in the ten first editions held in-site and the last two editions, which have the particularity of having been carried out fully online, evaluating, by this way, the impact of the COVID-19 pandemic crisis to EDUCON. The results show an increase in the number of papers submitted and published over the years, evidencing a growing notoriety of the conference. The same growth tendency is visible regarding the number of authors involved in the conference. Regarding the impact of the online editions, data from the next edition is still required to establish better comparisons and conclusions.
- Internacionalização do ensino superior: para além da mobilidade internacionalPublication . Sousa, Marina; Nogueira, Teresa; Barata, Ana; Moura, Ana; Félix, Carlos; Escudeiro, Nuno; Costa, VítorA internacionalização não pode ser implementada na ausência do entendimento sobre as mudanças permanentes a que o mundo global está hoje sujeito e o seu propósito deve ser a melhoria da qualidade e dar um contributo significativo para a sociedade. Mesmo na presença de um número considerável de estratégias internacionais, nacionais, regionais e locais que dinamizam a internacionalização através da mobilidade, o número de estudantes em mobilidade internacional na área da OCDE em 2015 representa cerca de 5,6% das matrículas a nível mundial, valor que demonstra que a maioria dos estudantes são-no no seu país de origem. O padrão de mobilidade concentra-se num pequeno conjunto de países, moldado por fatores de proximidade, e os maiores países anfitriões são as economias avançadas de língua inglesa. Proporcionar excelentes oportunidades de mobilidade é fundamental, mas além de oferecer oportunidades para a pequena proporção de estudantes que pode estudar fora, a instituição deve esforçar-se para oferecer, a todos, as competências necessárias para obter sucesso no mundo global. O objetivo desta comunicação é discutir o conceito de internacionalização at-home e a criação de uma cultura promotora da compreensão internacional ou intercultural que não implique necessariamente o envolvimento em programas de mobilidade ou outras atividades além-fronteiras.
- A Mathematical Model for Supermarket Order PickingPublication . Costa e Silva, Eliana; Cruz, Manuel; Lopes, Isabel Cristina; Moura, AnaOrder picking consists in retrieving products from storage locations to sat- isfy independent orders from multiple customers. It is generally recognized as one of the most significant activities in a warehouse (Koster et al, 2007). In fact, order picking accounts up to 50% (Frazelle, 2001) or even 80% (Van den Berg, 1999) of the total warehouse operating costs. The critical issue in today’s business environ- ment is to simultaneously reduce the cost and increase the speed of order picking. In this paper, we address the order picking process in one of the Portuguese largest companies in the grocery business. This problem was proposed at the 92nd European Study Group with Industry (ESGI92). In this setting, each operator steers a trolley on the shop floor in order to select items for multiple customers. The objective is to improve their grocery e-commerce and bring it up to the level of the best inter- national practices. In particular, the company wants to improve the routing tasks in order to decrease distances. For this purpose, a mathematical model for a faster open shop picking was developed. In this paper, we describe the problem, our proposed solution as well as some preliminary results and conclusions.
- A mathematical model for supermarket order pickingPublication . Silva, Eliana Costa e; Cruz, Manuel; Lopes, Isabel Cristina; Moura, AnaOrder picking consists in retrieving products from storage locations to satisfy independent orders from multiple customers. It is generally recognized as one of the most significant activities in a warehouse (Koster et al, 2007). In fact, order picking accounts up to 50% (Frazelle, 2001) or even 80% (Van den Berg, 1999) of the total warehouse operating costs. The critical issue in today’s business environment is to simultaneously reduce the cost and increase the speed of order picking. In this paper, we address the order picking process in one of the Portuguese largest companies in the grocery business. This problem was proposed at the 92nd European Study Group with Industry (ESGI92). In this setting, each operator steers a trolley on the shop floor in order to select items for multiple customers. The objective is to improve their grocery e-commerce and bring it up to the level of the best international practices. In particular, the company wants to improve the routing tasks in order to decrease distances. For this purpose, a mathematical model for a faster open shop picking was developed. In this paper, we describe the problem, our proposed solution as well as some preliminary results and conclusions.
- Representations of the free profinite object over DAPublication . Moura, AnaIn this paper, we extend to DA some techniques developed by Almeida and Weil, and Almeida and Zeitoun for the pseudovariety R to obtain representations of the implicit operations on DA: by labeled trees of finite height, by quasi-ternary labeled trees, and by labeled linear orderings. We prove that two implicit operations are equal over DA if and only if they have the same representation, for any of the three representations. We end the paper by relating these representations.
- Revenue management prlcing in Douro Hotels [Study Group Report]Publication . Correia, Elisete; Dias, Sónia; Ferreira, Fernanda A.; Moura, Ana; Nunes, Paula; Pereira, Maria Teresa Ribeiro; Santos, Jorge; Pereira, Carla Santos; Soares, Filomena Baptista; Soares, JoãoThe Douro Palace Hotel management wants to develop a software that helps them with the dynamic pricing of the hotel rooms. Revenue Management software is widely used for data analysis of demand and prices. However the hotel barely follows the software recommendations for pricing decisions, mainly due to the lack of understanding of the rationale and the inherent difficulty in validating pricing decisions. The hotel would like to have a reliable model in order to give to the manager an overview of the business and how to act to improve the sales. The questions raised at the study group are related to this. In this report, we present two distinct methodologies to address the hotel request. The first approach is excel based and more practically oriented towards to be an immediate help of the current pricing decisions. A second approach is more formal, mathematically speaking, but requires a more time consuming implementation. It is based on a recent operations management/operations research paper. On short term plan, we propose the implementation of an automatic generation of excel files that will enable Douro Palace Hotel react more often/finely to the competition pricing. A thorough statistical analysis of the Demand function and the corresponding segmentation is also required - for simulation purposes or decision support. We think that Douro Palace Hotel should differentiate prices more often and promptly (both upwardly and downwardly) depending on the perception of the demand and the competitors prices. On a long term plan, we propose the implementation of more sophisticated approaches, mathematically speaking, such as the one described in this report.
- The word problem for omega-terms over DAPublication . Moura, AnaIn this paper, we solve the word problem for ω-terms over DA. We extend to DA the ideas used by Almeida and Zeitoun to solve the analogous problem for the pseudovariety R applying also a representation by automata of implicit operations on DA, which was recently obtained by the author. Considering certain types of factors of an implicit operation on DA, we can prove that a pseudoword on DA is an ω-term if and only if the associated minimal DA- automaton is finite. Finally, we complete the result by effectively computing in polynomial time the minimal DA-automaton associated to an ω-term.