https://repositorio.ufpb.br/jspui/handle/123456789/30089 PPGEPS Mon, 13 Apr 2026 03:21:38 GMT 2026-04-13T03:21:38Z http://repositorio.ufpb.br:443/jspui/retrieve/138265/PPGEPS.png https://repositorio.ufpb.br/jspui/handle/123456789/30089 https://repositorio.ufpb.br/jspui/handle/123456789/37513 Título: Barreiras à implementação da economia circular nas compras públicas: estudo de caso em instituição pública de ensino superior Autor(es): Oliveira, Augusto César Temóteo de Orientador: Morioka, Sandra Naomi Abstract: Circular Economy aims to manage finite resources responsibly by promoting product regeneration to mitigate environmental impacts. Within this context, public procurement emerges as a highly relevant approach, exerting significant influence on prices and the availability of goods and services, thus being crucial for promoting circularity. The transition to a circular economy in public procurement is a strategic imperative for sustainability, with relevance for Public Higher Education Institutions, given their potential to align administrative practices with academic missions. This study analyses the obstacles to adopting circular criteria in the tendering processes of a federal university in Northeast Brazil, combining documentary analysis with insights from managers. The results indicate that institutional barriers—such as lack of inter-departmental coordination and the absence of clear government guidelines— overshadow operational limitations. It was further identified that insufficient technical training and a fragmented, risk-averse organisational culture hinder the systematic incorporation of circular principles into procurement processes. The analysis also revealed catalytic effects amongst barriers, whereby specific combinations (e.g., insufficient policies, excessive bureaucracy, and rigid tender criteria) mutually reinforce each other, leading to institutional paralysis and directly impacting the low achievement of strategic circularity targets. As its contribution, the study provides a comprehensive diagnosis of these challenges, demonstrating their interdependence and proposing pathways for their mitigation. The practical implications point to the need for ongoing training, revision of regulations, and the development of specific indicators. It is recommended that future research investigates governance models tailored to the reality of Brazilian public institutions, with emphasis on coordination between different levels of administration. It is concluded that the effective implementation of a circular economy in government procurement demands transformations that transcend procedural adjustments, requiring profound cultural changes and institutional commitment. Editor: Universidade Federal da Paraíba Tipo: Dissertação Mon, 25 Aug 2025 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/37513 2025-08-25T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/37438 Título: Heurísticas de programação matemática para o problema de dimensionamento de lotes de múltiplos itens com restrições de capacidade e máquinas paralelas distintas Autor(es): França, Ricardo Lukas de Medeiros Orientador: Kramer, Hugo Harry Frederico Ribeiro Abstract: Lot-sizing problems are among the most relevant in the production planning literature. This work addresses the Multi-Item Capacitated Lot-Sizing Problem with Unrelated Parallel Machines (CLSP-PM), classified as NP-hard and aiming to determine an optimal production plan that meets periodic demands without exceeding machine capacities while minimizing total costs. The problem is tackled through heuristic methods combined in three different ways: (i) Relax-and-Fix is applied to generate an initial solution, followed by Fix-and-Optimize as a local search procedure, in both static and dynamic versions. (ii) A Column Generation-Based Heuristic (HCG) is then used as a constructive method, combined with Fix-and-Optimize, comparing the resolution of the pricing problem via Dynamic Programming (DP) and Mixed Integer Programming (MIP). (iii) The HCG is further extended with a production transfer heuristic (TH) to ensure solution feasibility, maintaining the comparisons between DP and MIP, and using both static and dynamic versions of Fix-and-Optimize for each case. Experiments on 2,880 benchmark instances show that, in particular, the combination of HCG with DP, TH, and dynamic Fix-and-Optimize achieved near-zero gaps in several instance classes. These results outperform literature methods in solution quality, reaching average gaps of 0.51% for the static version and 0.42% for the dynamic version, with competitive computing times. Editor: Universidade Federal da Paraíba Tipo: Dissertação Thu, 28 Aug 2025 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/37438 2025-08-28T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/36855 Título: Uma abordagem pragmática para avaliação de risco ergonômico: um modelo curto e abrangente para avaliar riscos psicossociais no local de trabalho Autor(es): Torres, Carlos Rodrigo de Souza Orientador: Bolis, Ivan Abstract: Psychosocial risks are recognized as significant contributors to occupational health problems. Preventing and managing these risks requires adequate workload management, promoting a positive work culture, and providing mental health support services. However, a shortcoming in psychosocial risk management is the lack of rapid and comprehensive tools for assessing and recognizing these risks in the workplace. The aim of this study was to verify the usefulness of the PRD-PRQ (Participatory, Rapid and Detailed Questionnaire of Psychosocial Risks) tool as an ergonomic demand analysis instrument. The study was conducted in a hospital in the state of Alagoas. Initially, a literature review on psychosocial risks and ergonomics was carried out. Subsequently, the PRD-PRQ tool was applied to the target audience of the research. Concomitantly, an ergonomic demand analysis was carried out through interviews with managers and team leaders in eight sectors of the evaluated hospital. The questionnaire was answered by 251 workers, and interviews were conducted with eight managers or team leaders, covering administrative and care sectors of the hospital. The results show that high workload, intense pace, lack of balance between personal and professional life and the perception of organizational injustice are the main factors that affect the mental and physical health of workers. In addition, relationship problems between colleagues and superiors and inadequate working conditions, such as lack of thermal comfort, were identified. The results indicate that the PRD-PRQ tool has the potential to be used as a useful and effective instrument for ergonomic demand analysis, contributing to the identification and assessment of psychosocial risks, providing a comprehensive understanding of working conditions and workers' needs. Further studies are needed to validate its effectiveness and scope in different work contexts. Editor: Universidade Federal da Paraíba Tipo: Dissertação Thu, 27 Feb 2025 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/36855 2025-02-27T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/34902 Título: Modelagem e otimização simultânea de processos de medição e fabricação por filamento fundido Autor(es): Barbosa, Francisco Tiago Araújo Orientador: Peruchi, Rogério Santana Abstract: Additive manufacturing using fused filament fabrication (FFF) is transforming the production of three-dimensional parts. However, the quality of printed parts can vary and may not meet customer specifications, raising questions about performance, precision, and the evaluation of the measurement system. Therefore, there is a need for research to address these issues related to the quality of 3D-printed products. This dissertation presents a set of studies on modeling and multi-response optimization for the additive manufacturing process. The main objective of this research is to propose an optimization method capable of adjusting the effects of printing parameters, such as layer width, layer height, infill density, and printing speed, on the responses of dimensional accuracy and measurement system precision. To achieve these goals, the following specific objectives were set: analyze the state-of-the-art in fused deposition modeling; simultaneously optimize the manufacturing process and the measurement system; improve operational performance, dimensional accuracy, and the measurement system; and optimize printing parameters with respect to energy consumption. A central composite design (CCD) experimental plan was used in conjunction with response surface methodology to assess the effects of factors on response variables. Quadratic regression models were estimated using the Ordinary Least Squares (OLS) method. For multi-objective optimization, the desirability method and the normalized global criterion (NGC) method were employed. The optimal configurations proposed by the desirability method were a layer width of 0.6 mm, a layer height of 0.28 mm, an infill density of 90%, and a speed of 50 mm/s. The expected results are: dimensional accuracy (Y̅w = 10.00, Y̅t = 4.02, Ca;w = 1.00, Ca;t = 0.99) and measurement system precision (Cgk;w = 2.387 and Cgk;t = 1.846). In the second proposal, parameters were added to the dimensional precision responses (E and Ct). After optimization using the normalized global criterion (NGC) method, the results were: LW = 0.59, LH = 0.12, ID = 10.00, and S = 50.00. Thus, this research aims to enhance fused filament fabrication by providing practical solutions to improve the quality and efficiency of three-dimensional part production Editor: Universidade Federal da Paraíba Tipo: Dissertação Wed, 28 Aug 2024 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/34902 2024-08-28T00:00:00Z