Sapientia
Repositório Científico da UAlg
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Alterações de estrutura nos mercados: o exemplo do petróleo
Publication . Agostinho, Luís; Viegas, Cristina; Morais, Henrique
A importância dos combustíveis fósseis na oferta mundial de energia e a relação entre as suas flutuações e os fenómenos geoeconómicos e geopolíticos, tornam aliciante analisar as forças maiores por detrás do comportamento, amiúde inesperado, do preço do petróleo. É objetivo deste trabalho estudar os acontecimentos socioeconómicos contemporâneos a alterações de estrutura no preço do petróleo, que com elas possam indiciar relações de causalidade. Neste estudo é utilizada a metodologia de Bai & Perron para a deteção de alterações de estrutura. A amostra consiste em observações dos preços de fecho de contratos de futuros negociados nos EUA, West Texas Intermediate, correspondentes a várias maturidades. Três pontos são por nós identificados como essenciais sobre a formação do preço do petróleo. Em primeiro lugar, observa-se o impacto significativo de fatores macroeconómicos, especialmente os mais relacionados com a procura, como principais impulsionadores de alterações de estrutura nos mercados de petróleo. Também é assinalada a influência da OPEP na determinação dos preços, realçando o seu papel proeminente no panorama global do petróleo, embora com menor impacto nas alterações de estrutura identificadas. Por fim, a pesquisa sugere que, num contexto mais amplo, eventos geopolíticos tendem, por norma, a não desencadear alterações estruturais significativas no mercado do petróleo.
From print to pixels: prototyping a virtual exhibition for the Faro museum poster collection
Publication . Martins, Alexandre; Carrega, Jorge; d'Orey, Rui; Mendes da Silva, Bruno
In 2022, CIAC - Research Center in Arts and Communication and the Faro Municipal Museum began a cooperation to study, enrich and disseminate a unique poster collection that belonged to the Portuguese scenographer Joaquim António Viegas. It comprises 330 illustrated posters from the cinema, circus and advertising industries. This partnership entails the coproduction of multiple exhibitions about the collection, but also future research of the materials that form this important heritage. One of the objectives/aims of this work is to develop a website which will collect and present the information about the poster collection, while also serving as a platform to show virtual exhibitions of the same collection. In this paper we present the initial stages of the development of a 3D real time exhibition which is intended to open simultaneously with a physical exhibit of the posters dedicated to early Italian cinema - scheduled to be inaugurated in March of 2024. We will describe some of the first steps we have taken so far which covers the exploration of tools devoted to building 3D environments, the tasks we already achieved and lay down a couple ideas for the future of this project. We hope the prototype we present here might function as a model and a proof of concept for digital representations and reinterpretations of future exhibits of this singular legacy.
Human branding in political marketing: a systematic literature review and agenda for future research
Publication . Soares, Vitor Reis; Rodriguez y Rodriguez, Martius Vicente; Montalvão, Sérgio de Sousa; Martins Rodrigues, Maria Carolina; Oliveira, Antonio Batista da Silva
When Speed, Butler, and Collins introduced the theory of human brands into the field of political marketing, the topic garnered increasing interest from researchers. As a result of this growing academic attention, it became essential to update key concepts and clarify emerging terminologies in order to advance the conceptual and theoretical understanding of this evolving literature. To address this need, we conducted a systematic literature review (SLR) to identify the theories, research contexts, characteristics, and methodological approaches explored within the domain. Through this review, we modernized fundamental concepts such as authority, authenticity, humanization, and positioning. Furthermore, building on the theory of political brands and contributions related to human brands, we propose a basic definition of the human brand in politics. As the first SLR in this area, this paper serves as both a guide for marketing professionals developing human brands and a resource for researchers. It provides guidance on conducting an SLR and highlights future research directions, presenting a forward-looking agenda with 16 potential avenues for addressing existing gaps in the field.
Exploring the use of data envelopment analysis for formative evaluation of senior high schools in ghana
Publication . Aikins, Emmanuel; Pereira dos Santos, Sérgio; Amado, Carla
This study explores the use of data envelopment analysis (DEA) for the formative evaluation of senior high schools (SHS) in Ghana and investigates how the DEA results can help improve their performance. By assessing the relative performance of 215 public SHS across five regions (Greater Accra Region, Ashanti Region, Central Region, Upper West Region, and Upper East Region), the study contributes to the broader discourse on knowledge-based economies by demonstrating how data-driven insights can optimize resource allocation and improve human capital development. The schools are classified into groups A, B, and C based on students’ entrance examination scores, and a hierarchical categorization DEA procedure is applied to assess them across three dimensions: resource efficiency, resource effectiveness, and effectiveness. This study highlights the crucial role of knowledge creation, diffusion, and application in education management by fostering deep engagement with decision-makers, ensuring the acceptance of DEA results, and promoting continuous improvement in institutional performance. The findings reveal significant disparities in school efficiency and effectiveness, underscoring the need for structured knowledge-sharing mechanisms. To support sustained performance improvement and better resource utilization, we propose the establishment of an educational performance observatory. This initiative would function as a platform for knowledge diffusion, enabling underperforming schools to benchmark against high-performing institutions, thus reinforcing the foundational role of knowledge exchange in strengthening educational systems and, by extension, the knowledge economy.
A demographic model to forecast Dinophysis acuminata harmful algal blooms
Publication . Vieira, Vasco Manuel Nobre de Carvalho da Silva; Leal Rosa, Teresa; Sobrinho-Gonçalves, Luís; Mateus, Marcos Duarte; Mota, Bernardo
Harmful algal blooms (HABs) in marine environments have significant adverse effects on public health, aquaculture and recreational activities. Surges of certain phytoplanktonic toxin-producing microalgae (mostly dinoflagellates or diatoms species) can induce Amnesic, Diarrhetic or Paralytic Shellfish Poisoning (ASP, DSP and PSP). Among HAB species, the genus Dinophysis leads to DSP in human consumers; this being the most recurrent problem in the Iberian Peninsula with the biggest economic impact on clam production and harvesting. While complete elimination of HABs is not feasible, timely implementation of appropriate measures can prevent their negative consequences. This is critical for aquaculture. Research on D. acuminata (dominant Dinophysis species in the North Atlantic) has been focused on ecophysiology and population dynamics, although with few modelling attempts. Weekly monitoring along the Portuguese coast since 2006 has revealed that D. acuminata thrives under spring/summer photosynthetically active radiation (PAR) coupled with water temperatures below 20°C, which typically coincide with the local upwelling regime. In order to advance this knowledge numerically, we developed a demographic model linking D. acuminata growth rate to PAR and sea surface temperature (SST). The 13-year (1-Jan-2006 to 31-Dec-2018) time-series of observations was closely fit by model forecasts. However, the model demonstrated limitations in issuing timely warnings of harmful proliferation of D. acuminata, failing to do so in 50% of cases, and issuing incorrect warnings in 5% of the cases. Furthermore, improving the odds of emitting timely warnings always worsened the odds of emitting false warnings, and vice-versa. To simultaneously improve both aspects, the modelling results clearly indicated the need of implementing both census/ projection intervals smaller than 7 days and a laboratory detection limit below 20 cell/L. The time resolution of the census and of the model proved to be the most limiting factor that must be addressed in order to improve numerical forecasting of HABs.