Departamento de Engenharia Electromecânica
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Browsing Departamento de Engenharia Electromecânica by Sustainable Development Goals (SDG) "11:Cidades e Comunidades Sustentáveis"
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- Coopetition Technology-Enabled Service Ecosystems: A Framework to Improve the Portuguese Ornamental Stone SectorPublication . Silva, Agostinho Manuel Antunes da; Cardoso, António João MarquesThis doctoral thesis critically examines the design, implementation, and effectiveness of coopetition networks among small and medium-sized enterprises (SMEs) within the dynamic and complex realms of digital and global supply chains. The study addresses the challenges that SMEs face, including financial constraints, operational inefficiencies, scalability issues, customer satisfaction demands, and pressures related to ecological sustainability. To address these challenges, the research introduces and empirically tests the Coopetition Network for Value Cocreation (CN-VCC) framework, subsequently operationalized through the Industrial Internet of Things (IIoT) as the Coopetition Technology-enabled Service Ecosystem (CNEcoTech). The Design Science Research (DSR) methodology, integrated with Service-Dominant (S-D) Logic, underpins the framework's development and validation, with a specific focus on the Portuguese ornamental stone sector (OS-PT), an industry of significant economic importance that is yet to be fully challenged by digital transformation and global market integration. Following the DSR stages of designing and developing an artefact, implementing a Proof-ofConcept (PoC), and an Experimental Pilot Project, the thesis assesses the CN-EcoTech artefacts's impact across multiple dimensions: operational efficiency, scale, customer satisfaction, and ecological sustainability. The findings reveal that engagement levels within the CN-EcoTech framework correlate with significant improvements in OS.PT SMEs. Specifically, SMEs fully engaged in the framework demonstrated enhanced deal closures, robust customer relationships, and superior operational outcomes compared to their less-engaged counterparts. This differential highlights the potential of deep integration into technology-based coopetition frameworks to overcome traditional and emerging market challenges. The thesis confirms that the CN-EcoTech framework facilitates long-term collaboration among SMEs and effectively addresses the challenges of digital and global supply chains. It extends beyond the immediate empirical setting of the OS-PT sector, suggesting broader applicability to similar SME-dominated industries facing digital integration challenges. Academically, this research augments the understanding of coopetition dynamics and provides a structured approach to evaluating and implementing technology-enabled service ecosystems. However, more importantly, it offers actionable insights for industry stakeholders and policymakers, empowering them with strategies to enhance SME competitiveness and sustainability in line with the United Nations Sustainable Development Goals (SDGs). This thesis lays a foundation for future research to explore the scalability of the CN-EcoTech framework across diverse sectors. It offers a robust model for enhancing SME resilience and innovation capacity in a globally interconnected economy.
- Driving Healthcare Monitoring with IoT and Wearable Devices: A Systematic ReviewPublication . João Pedro da Silva Baiense; Zdravevski, Eftim; Coelho, Paulo Jorge Simões; Serrano Pires, Ivan Miguel; Velez, Fernando J.Wearable technologies have become a significant part of the healthcare industry, collecting personal health data and extracting valuable information for real-time assistance. This review article analyzes 35 scientific publications on driving healthcare monitoring with IoT and wearable device applications. These articles were considered in a quantitative and qualitative analysis using the Natural Language Processing framework and the PRISMA methodology to filter the search results. The selected articles were published between January 2010 and May 2024 in one of the following scientific databases: IEEE Xplore, Springer, ScienceDirect (i.e., El- sevier), Association for Computing Machinery (ACM), Multidisciplinary Digital Publishing Institute (MDPI), or PubMed Central. The analysis considers population, methods, hardware, features, and communications. The research highlights that data collected from one or numerous sensors is processed and accessible in a database server for various uses, such as informing professional careers or assisting users. The review sug- gests that robust and efficient driving healthcare monitoring with IoT and wearable devices applications can be designed considering the valuable principles presented in this review.
- Fractal Patch Antenna based on Photonic Crystal for Enhanced Millimeter-Wave Communication in Intelligent Transportation SystemsPublication . Bagheri, Nila; Peha, Jon; Velez, Fernando J.; VelezThis paper introduces a Fractal Patch Antenna (FPA) integrated with Photonic Crystals (PhC) designed for Intelligent Transportation Systems (ITS) in the Millimeter-wave bands (mmWaves) given the importance of the application of mmWaves in Vehicle-to-Everything (V2X) networks, we assumed, as examples, that the antenna is designed to resonate at three frequency bands: 31.42 GHz, 37.76 GHz, and 38.92 GHz. With a gain of 10.88 dBi, at 38.92GHz, the antenna demonstrates promising signal reception and transmission capabilities, which are anticipated to be important for ITS operations. The antenna bandwidth covers multiple frequency bands, enabling versatile communication in mmWaves V2X applications. To evaluate the performance of the antenna, we conducted a detailed analysis of its configuration. This included a comparison of the antenna with and without the PhC integration, as well as an exploration of rectangular lattice structure. In addition, variations in hole sizes and spacing were examined to assess their impact on key parameters such as the gain and reflection coefficient. The integration of fractal geometry and PhC structures results in a compact, high-performance antenna suitable for mmWave communication. The integration of fractal geometry and PhC structure results in compactness and high performance in mmWaves communication applications. Through simulation and analysis, including radiation pattern, gain, and reflection coefficient plot assessment, the antenna performance is thoroughly evaluated. The study highlights the potential of the proposed FPA-PhC antenna configuration to enhance communication networks within the ITS, significantly advancing the ITS system with support from the mmWave bands.
- Radio Coverage Assessment and Indoor Communication Enhancement in Hospitals: A Case Study at CHUCBPublication . da Silva, Óscar; Teixeira, Emanuel; Corceiro, Ana; Reis, António; Velez, Fernando J.The adoption of wireless medical technologies in hospital environments is often limited by cellular coverage issues, especially in indoor areas with complex structures. This study presents a detailed radio spectrum measurement campaign conducted at the Cova da Beira University Hospital Center (CHUCB), using the NARDA SRM-3006 and R&S®TSME6 equipment. The signal strength and quality of 5G NR, LTE, UMTS, and NB-IoT technologies were evaluated. Critical coverage gaps were identified, particularly at points 17, 19, and 21. Results revealed that operators MEO and NOS dominate coverage, with MEO providing better 5G NR coverage and NOS excelling in LTE signal quality. Based on the results, the localized installation of femtocells is proposed to improve coverage in these areas. The approach was designed to be scalable and replicable, with a planned application at Cumura Hospital (Guinea-Bissau), reinforcing the applicability of the solution in contexts with limited infrastructure. This work provides both technical and clinical contributions to achieving ubiquitous cellular coverage in healthcare settings.