Percorrer por autor "Cruz, Luís"
A mostrar 1 - 9 de 9
Resultados por página
Opções de ordenação
- Affect and the adoption of pro-environmental behaviour: A structural modelPublication . Coelho, Filipe; Pereira, Maria C.; Cruz, Luís; Simões, Paula; Barata, EduardoPro-environmental behaviour (PEB) is an essential part of changing societies towards a more sustainable future. The literature on PEB has provided significant insights into how the anticipated emotions arising from specific ecological actions contribute to environmentally friendly conduct. Our research departs from these studies by focusing on general affect as a determinant of PEB. Moreover, we specify mechanisms for the transmission effects of trait (rather than state) affect into PEB. We use structural equation modelling to test the hypotheses, with a sample of 925 individuals. The results show that the influence of positive affect on (reported) PEB is partially mediated by environmental concern and perceived consumer effectiveness. As to negative affect, the findings suggest only a direct effect on PEB. We also found differences between males and females. These are novel results that help to illuminate the complex issue of what shapes PEB, thereby supporting relevant theoretical and practical implications.
- Assessing an agri-food development strategy : a bi-regional input–output model with resource-constrained sectorsPublication . Cruz, Luís; Ramos, Pedro N.; Barata, Eduardo; Sargento, AnaUneven regional development is widely recognised. This paper explores the effectiveness of a regional development strategy based on the agri-food sector expansion in a laggard agriculture dependent region. We use a bi-regional rectangular Input– Output model, explicitly taking into account the methodological and policy implications of resource-constrained products. Results confirm that local transformation of agricultural products has a positive but limited effect, due to land restrictions and impact leaks to the more complex and developed region. The regional development strategy would be more effective if it focuses instead on non-tradable products or not so dependent on natural resources.
- Cluster Engineering & Tooling: da importância na Região Centro à inserção na cadeia de valor globalPublication . Ferreira, João Pedro; Rebolho, Jose Miguel; Cruz, Luís; Raposo, Vitor; Sargento, AnaEste trabalho centra-se no cluster Engineering & Tooling (E&T), apresentando três análises complementares: (i) a concentração geográfica e avaliação da sua importância económica, do ponto de vista regional e nacional, suportada nos quocientes de localização baseados no volume de negócios e análise shift-share para compreender a evolução do emprego; (ii) as interdependências intersetoriais, analisando a evolução dos indicadores das Contas Nacionais do INE; e (iii) a integração do cluster no contexto do comércio internacional e das cadeias de valor global através da análise multirregional Input-Output com base na World Input-Output Database. Conclui-se que o E&T apresenta relevância especial na Região Centro, mas também no contexto da economia nacional e respetiva integração internacional, devido à elevada especialização da Região (destacando-se as NUTS-III Regiões de Leiria e de Aveiro) e à componente diferencial ou regional, que estimulou um aumento do emprego nestes setores na Região Centro mais significativo do que no resto do país. Ao nível nacional, os setores associados ao cluster revelaram resiliência e capacidade de ligeiro crescimento (assentando também nas exportações), mesmo num contexto particularmente adverso à economia. O comércio internacional mostrou igualmente ser um fator determinante para a evolução do cluster, demonstrando a existência de dependências internas e externas.
- H.264/SVC ROI encoding with spatial scalabilityPublication . Ferreira, Lino; Cruz, Luís; Assunção, Pedro A. AmadoThis paper proposes two H.264/AVC compliant methods for encoding Regions-of-Interest (ROI) with spatial scalability and evaluates their respective rate-distortion-complexity performance. The base layer is kept unchanged and provides lower resolution images with roughly constant quality, without identification of the ROI. In the proposed methods there is no need to encode contour information because the ROI is implicitly defined in the upper layer of the spatial resolution in a transparent way by using different encoding parameters for the ROI and its complementary region. It is shown, that spatial scalability in ROI can be efficiently used to enhance specific regions of an image sequence in both spatial resolution and quality with low coding complexity. The proposed encoding scheme is suitable for remote surveillance, medical applications and entertainment, where higher resolution and higher quality ROI is a useful functionality for object/face recognition, selective encryption, detail analysis, etc.
- Non-market Valuation of Environmental Goods in PortugalPublication . Barata, Eduardo; Simões, Paula; Cruz, LuísThis paper reviews the empirical research of the non-market environmental valuation methodologies in Portugal and identifies opportunities for linking results to policy. Four research questions are addressed: what has been done; what common features can be observed; what do we know about the validity of the values; and which trends have been found in the recent research. We conclude that environmental valuation in Portugal has a noticeable regional application, e.g., natural parks and traditional landscapes. Contingent valuation is the leading method. Price, income and the use of the resource for recreational purposes are among the most important explanatory variables. The results confirm the theoretical validity of the methods and their potential for local/regional policy purposes.
- Objective quality prediction model for lost frames in 3D video over TSPublication . Feitor, Bruno; Assunção, Pedro; Soares, João; Cruz, Luís; Marinheiro, RuiThis paper proposes an objective model to predict the quality of lost frames in 3D video streams. The model is based only on header information from three different packet-layer levels: Network Abstraction Layer (NAL), Packetised Elementary Streams (PES) and Transport Stream (TS). Transmission errors leading to undecodable TS packets are assumed to result in frame loss. The proposed method estimates the size of the lost frames, which is used as a model parameter to predict their objective quality measured as the Structural Similarity Index Metric (SSIM). The results show that SSIM of missing stereoscopic frames in 3D coded video can be predicted with Root Mean Square Error (RMSE) accuracy of about 0.1 and Pearson correlation coefficient of 0.8, taking the SSIM of uncorrupted frames as reference. It is concluded that the proposed model is capable of estimating the SSIM quite accurately using only the lost frames estimated sizes.
- Regional planning insights from a portuguese bi-regional input-output model – the potential impact of agri food industryPublication . Sargento, Ana; Ramos, Pedro; Barata, Eduardo; Cruz, LuísIn Portugal, the public debate at regional level is typically engaged in the discussion of asymmetries amongst the ‘interior’ and the ‘coast’. What is often discussed, with political and social relevance, is the extent of the interior’s delay (in terms of development) comparatively to the coastal region, and into what extent the dynamics of the economy, or eventually the ‘bias’ introduced by public policies, contributes to this drawback. Interestingly, however, the Portuguese regional science has miscarried this debate, largely on the grounds that the official statistics do not include this cleavage. Indeed, the design of the NUTS II in Portugal splits the country horizontally, forgetting the vertical gap that splits the interior regions from the coastal ones. The first objective of this paper is therefore to refocus the debate - in scientific terms – on the actual territorial disparity in Portugal: the contrast Coast-Interior. Accordingly, this paper starts by presenting the structure of a bi-regional Input-Output (IO) model for the Portuguese Economy. We consider a rectangular IO model (431 products by 125 industries), decomposing the Portuguese economy into two regions with comparable territorial sizes (the Coastal Region, comprising 44% of the Portuguese continental area, and the Interior Region). the model is ‘closed’ for the private consumption of households below 65 (which is supposed to be endogenous, as it depends on regional employment and therefore on households’ earnings. Multi-regional IO models describe the inter-sectoral dependencies both within the region and between the regions. The main aim is then to assess how the effects of a shock that hits only one of the regions are ‘distributed’ among the two regions. In particular, we intend to analyse at a greater detail the role of the agri-food sector in the Interior Region. Overall results illustrate the dependence of the Interior on the Coastal region, and that the (positive or negative) effects of a shock that hits the Interior Region tend to leak significantly to the Coastal Region, while an exogenous event in the Coastal Region tends to see its effects relatively more contained within the region.Thus, this analysis can be particularly relevant to policy-makers in dealing with regional and territorial planning, as they are better informed about the root causes of some outcomes. Accordingly, a summary of the key lessons learned and a discussion of their policy relevance, both at regional and national levels, will be offered.
- Role of distinct export strategies in regional growth. A multi-regional input-output approach (PReMMIA)Publication . Ferreira, João-Pedro; Cruz, Luís; Raposo, Vitor; Rebolho, José Miguel; Lopes, Luís; Teotónio, Carla; Barata, Eduardo; Sargento, AnaThe relationship between exports and economic growth is a critical aspect of contemporary economic policy at both national and regional levels. However, until recently, the lack of regional data has hindered comprehensive empirical analysis of trade at the regional level, limiting our understanding of why different strategies yield varying national and regional economic outcomes in terms of growth, income distribution, labor versus capital gains, and balance of payments. This paper offers both a methodological contribution and a policy-focused analysis. First, it introduces the Portuguese Regions Model for Multi-Impact Analysis (PReMMIA) by providing a detailed account of its development, including the preparation of national-level data, the regionalization of input-output tables, the specification of structural forms, and the assumptions underlying the model’s closure. Then, PReMMIA is applied to evaluate how diverse export specialization strategies lead to distinct socio-economic impacts. The results highlight the potential for spillover effects across various scenarios and emphasize the need for decision-makers to understand the economic complexities and trade-offs in their decisions.
- Video summary generation and coding using temporal scalabilityPublication . Ferreira, Lino; Cruz, Luís; Assunção, Pedro A. AmadoIn this paper two algorithms for video summary generation and coding are proposed. Two distortion metrics used in the video summary generation algorithm are compared and an algorithm with reduced computational complexity is presented. The paper also proposes two frame structures in the temporal domain suitable for coding using temporal scalability of the H.264/SVC.