Abordagens de otimização para o planeamento e escalonamento integrado de operações

Dissertação de mestrado em Engenharia de SistemasNeste projeto consideramos o problema integrado de planeamento e escalonamento de operações em máquinas paralelas e idênticas, descrito em Kis e Kovács (2012). O problema é composto por duas partes que são resolvidas, simultaneamente, de uma forma integrada. A primeira parte consiste em determinar as tarefas que serão processadas em cada período de tempo. Esta é a parte de planeamento do problema que tem de ser resolvido para o horizonte de tempo determinado. A segunda parte consiste em atribuir as tarefas às máquinas disponíveis em cada período de tempo, de acordo com as suas datas de lançamento correspondentes e de modo a que todas as tarefas sejam processadas até ao final do horizonte de planeamento. Sempre que uma tarefa é realizada antes ou após a sua data esperada, incorre numa penalização. O objetivo global do problema consiste em determinar o planeamento e o escalonamento associados que minimizem os custos totais dessas penalizações. Tendo em conta as caraterísticas particulares do problema em estudo, foi feita uma breve análise a problemas de escalonamento de operações existentes na literatura e onde se percebe a forte ligação entre os problemas de máquinas paralelas idênticas e os problemas de corte e empacotamento de 1-dimensão, mais especificamente, de bin-packing. Pelo que foram seguidas técnicas associadas a este tipo de problemas. Esta dissertação apresenta novas abordagens de otimização com base em métodos heurísticos de pesquisa local e meta-heurísticos, baseados na pesquisa de vizinhança variável (VNS – Variable Neighborhood Search) usando duas estruturas de vizinhança. Foram implementados dois algoritmos diferentes na construção das soluções inicias conjugados com quinze variantes da sequência inicial das tarefas, alcançando, naturalmente, resultados distintos. Para a obtenção de resultados e de modo a avaliar o desempenho dos mesmos, foram realizadas experiências computacionais com instâncias de referência descritas na literatura. Assim, para além da comparação entre os diferentes resultados obtidos neste projeto foi também possível comparar os resultados conseguidos com outros já existentes para as mesmas instâncias.In this project, we consider the integrated planning and scheduling problem on parallel identical machines as in Kis and Kovács (2012). The problem is composed by two parts that are solved simultaneous in an integrated form. The first part consists in assessing which should be processed in each period of time. This is the part of the problem planning that has to be solved in a certain planning horizon. The second part consists in allocating jobs to the available machines in each time period according to their corresponding release date in a way that every job is processed until the end of the time space. Every time a job is allocated before or after its due date it incurs in a penalty. The overall objective of the problem consists in establishing the integrated planning and scheduling that minimizes the total costs of these penalties. Taking into consideration the specifics of the problem under study a brief analysis to the scheduling operation problems in literature was made in which a strong connection can be correlated between the problems of identical parallel machine and the problems of cutting and packing 1-dimension, more specifically bin-packing. Therefore, techniques associated with this type of problem were followed. This dissertation introduces new approaches of optimization based in heuristics methods of local search and metaheuristics based on Variable Neighborhood Search (VNS) using two neighborhood structures. Two different algorithms were implemented in the construction of initial solutions combining with fifteen different initial sequence of jobs, reaching distinct results. To achieve results and in order to evaluate their performance, computational experiences were performed with reference instances described in the literature. Thus, in addition to the comparison between different obtained results in this project was also possible to compare with the results achieved in other already existing projects for the same instances

Smart and parallel general variable neighborhood search for the pollution-routing problem

This work addresses a new approach to the Pollution-Routing Problem (PRP), a variant of the Vehicle Routing Problem (VRP) under environmental concerns, which includes costs associated with fuel, drivers, and greenhouse gas emissions. The many factors impacting the environment and, simultaneously, the real cost of the routes are usually ignored in the approaches defined to solve routing problems since the total distance traveled remains the standard objective. However, in pollution-routing problems, these elements play an essential role and each one is significantly influenced by the vehicle load and/or speed over the pathways which are followed. To contribute with methods that can provide solutions within an acceptable computational time, we explore local search and meta-heuristic based approaches, with emphasis on a Smart and Parallel General Variable Neighborhood Search algorithm for the PRP. Innovative neighborhood structures allowing continuous speed values in the arcs were a implemented. Additionally, we incorporate parallel programming strategies. To evaluate the effectiveness of these strategies, we report on the computational experiments conducted on benchmark instances, and we compare the results obtained with other studies from the literature.The first author has been supported by FCT – Fundac¸ao para a Ciência e Tecnologia, through national funds from MCTES – Ministerio da Ciência, Tecnologia e Ensino Superior, and by European Social Fund through NORTE2020 – Programa Operacional Regional Norte, within the research grant SFRH/BD/146217/2019. This work has been supported by FCT – Fundação para a Ciencia e a Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

A Fertilização em "Marthasterias glacialis" (Echinodermata, Asteroidea)

Dissertação de Doutoramento em Biologia Celular apresentada ao Instituto de Ciências Biomédicas de Abel Salazar da Universidade do Port

Investigating the role of symptom valorisation in tuberculosis patient delay in urban areas in Portugal

URBANTB group: Patrícia Soares (Representative of the consortium), Mário Carreira, Sofia Pereira, Catarina Alves, Filipe Alves, Ana Rodrigues, Ana Moreira, Márcia Cardoso, Sandra Mota, Ana Gomes, Liliana Ferreira, Marta Lopes, Isabel Correia, Juan Rachadell, Maria Gameiro, Ângela Dias, Manuel Pereira, Jorge Gonçalves, Maria Gonçalves, Adriana Taveira, Celene Neves, Lucinda Silva, Maria Mendes, Maria Teixeira, Maria Pereira, Milena Piedade, Antónia Teixeira & Carlos Carvalho.Background: Diagnosis delay contributes to increased tuberculosis (TB) transmission and morbimortality. TB incidence has been decreasing in Portugal, but median patient delay (PD) has risen. Symptom valorisation may determine PD by influencing help-seeking behaviour. We aimed to analyse the association between symptom valorisation and PD, while characterising individuals who disregarded their symptoms. Methods: A cross-sectional study was conducted among TB patients in Lisbon and Oporto in 2019 - 2021. Subjects who delayed seeking care because they did not value their symptoms or thought these would go away on their own were considered to have disregarded their symptoms. PD was categorised using a 21-day cut-off, and a 30-day cut-off for sensitivity analysis. We estimated the effect of symptom valorisation on PD through a directed acyclic graph. Then, a multivariable regression analysis characterised patients that disregarded their symptoms, adjusting for relevant variables. We fitted Poisson regression models to estimate crude and adjusted prevalence ratios (PR). Results: The study included 75 patients. Median PD was 25 days (IQR 11.5-63.5), and 56.0% of participants had PD exceeding 21 days. Symptom disregard was reported by 38.7% of patients. Patients who did not value their symptoms had higher prevalence of PD exceeding 21 days compared to those who valued their symptoms [PR 1.59 (95% CI 1.05-2.42)]. The sensitivity analysis showed consistent point estimates but wider confidence intervals [PR 1.39 (95% CI 0.77-2.55)]. Being a smoker was a risk factor for symptom disregard [PR 2.35 (95% CI 1.14-4.82)], while living in Oporto [PR 0.35 (95% CI 0.16-0.75)] and having higher household incomes [PR 0.39 (95% CI 0.17-0.94)] were protective factors. Conclusions: These findings emphasise the importance of symptom valorisation in timely TB diagnosis. Patients who did not value their symptoms had longer PD, indicating a need for interventions to improve symptom recognition. Our findings also corroborate the importance of the socioeconomic determinants of health, highlighting tobacco as a risk factor both for TB and for PD.This work was supported by the Fundação para a Ciência e Tecnologia (FCT, Portugal) [Grant: PTDC/SAU-PUB/31346/2017]. The present publication was funded by Fundação para a Ciência e Tecnologia (FCT, Portugal) national support through Comprehensive Health Research Centre (CHRC) [UIDP/04923/2020].info:eu-repo/semantics/publishedVersio

A real-time optimization algorithm for the integrated planning and scheduling problem towards the context of industry 4.0

In this paper, we analyze the integration of two different problems in the supply chain, concerning the tactical and operational levels, and how the integration of two complex problems can be profitable towards the context of industry 4.0. More precisely, we address the integrated planning and scheduling problem on parallel and identical machines, seeking fast solutions that are globally optimal and flexible.In the planning phase, a set of jobs is assigned to their processing periods of time. On the other hand, in the scheduling phase, jobs are assigned to a machine in a given order.We propose a new metaheuristic approach through a variable neighborhood descent algorithm which iteratively explores four neighborhood structures with a first improvement strategy.The suggested algorithm was extensively tested using a large set of benchmark instances. The obtained results are discussed and compared with other approaches from literature.- This work has been supported by FCT - Fundacao para a Ciencia e a Tecnologia within the Project Scope: UID/CEC/00319/2019

IMPACT OF MICROCREDIT ON SUSTAINABLE DEVELOPMENT OF BUSINESS

Microcredit emerged in the 1970s, in Bangladesh, as a tool for sustainable development. However, in Portugal, it only took its first steps in the late 1980’s and emerged as a response to unemployment. This paper provides an overview of micro credit system in Portugal and aims to identify the profile of the successful microentrepreneur and point out the reasons that most contribute to the sustainability of microcredit business initiatives. Although the paper is mainly exploratory, we combined different methodologic approaches. First, we conducted interviews with key informants, then, we applied a questionnaire to microentrepreneurs. The survey contained three sections, namely, socio-demographic characteristics; characteristics of project; attitude as an entrepreneur. A sample group consisting of 96 participants of microfinance programme participated in the research. The findings indicate that the profile of the successful microentrepreneur is an individual with a superior degree, already have been employed, with positive or very positive level for the innovation of the product/service, for the adjustment of the business to the environment, for prior planning and for the accompaniment by public/non-profit institution. In a less degree, a positive level for training/professional experience in the project area and a positive level for self-esteem/self-confidence have also some influence. The results point out that the attitude as a microentrepreneur is less important than the characteristics of the project to the outcome of the microenterprise

Acetabular Coverage Area Occupied by the Femoral Head as an Indicator of Hip Congruency

Accurate radiographic screening evaluation is essential in the genetic control of canine HD, however, the qualitative assessment of hip congruency introduces some subjectivity, leading to excessive variability in scoring. The main objective of this work was to validate a method-Hip Congruency Index (HCI)-capable of objectively measuring the relationship between the acetabulum and the femoral head and associating it with the level of congruency proposed by the Fédération Cynologique Internationale (FCI), with the aim of incorporating it into a computer vision model that classifies HD autonomously. A total of 200 dogs (400 hips) were randomly selected for the study. All radiographs were scored in five categories by an experienced examiner according to FCI criteria. Two examiners performed HCI measurements on 25 hip radiographs to study intra- and inter-examiner reliability and agreement. Additionally, each examiner measured HCI on their half of the study sample (100 dogs), and the results were compared between FCI categories. The paired t-test and the intraclass correlation coefficient (ICC) showed no evidence of a systematic bias, and there was excellent reliability between the measurements of the two examiners and examiners’ sessions. Hips that were assigned an FCI grade of A (n = 120), B (n = 157), C (n = 68), D (n = 38) and E (n = 17) had a mean HCI of 0.739 ± 0.044, 0.666 ± 0.052, 0.605 ± 0.055, 0.494 ± 0.070 and 0.374 ± 0.122, respectively (ANOVA, p < 0.01). Therefore, these results show that HCI is a parameter capable of estimating hip congruency and has the potential to enrich conventional HD scoring criteria if incorporated into an artificial intelligence algorithm competent in diagnosing HD