On universal central extensions of Hom-Leibniz algebras

In the category of Hom-Leibniz algebras we introduce the notion of Hom-corepresentation as adequate coefficients to construct the chain complex from which we compute the Leibniz homology of Hom-Leibniz algebras. We study universal central extensions of Hom-Leibniz algebras and generalize some classical results, nevertheless it is necessary to introduce new notions of α-central extension, universal α-central extension and α-perfect Hom-Leibniz algebra due to the fact that the composition of two central extensions of Hom-Leibniz algebras is not central. We also provide the recognition criteria for these kind of universal central extensions. We prove that an α-perfect Hom-Lie algebra admits a universal α-central extension in the categories of Hom-Lie and Hom-Leibniz algebras and we obtain the relationships between both of them. In case α = Id we recover the corresponding results on universal central extensions of Leibniz algebras.

Determining factors of environmental management practices in portuguese local entities

Purpose: The aim of this paper is to analyse the development of environmental management practices by Portuguese local entities and their determining factors. Design/methodology/approach: The data were collected by sending a postal questionnaire. In order to measure the degree of development of environmental management practices an index of environmental management practices (EMPI) was developed, which reflects the extent to which a set of 16 environmental management practices have been implemented by the entities included in the sample. Four variables are considered in this study as possible factors that drive the development of environmental management practices by local entities, namely type of entity, size, proactive environmental strategy and Local Agenda 21 Findings: Results indicate the degree of development of environmental management practices in Portuguese local entities is low. Additionally, entity size, the adoption of proactive environmental strategies and the implementation of Local Agenda 21 are explaining factors of the degree of development of such practices. Originality/value: This study adds to the international research on environmental management in public sector by providing empirical data from a country, Portugal, where empirical evidence is still relatively limited.

Determining factors of environmental management practices in portuguese local entities

Purpose – The purpose of this paper is to analyse the development of environmental management practices by Portuguese local entities and their determining factors. Design/methodology/approach – The data were collected by sending a postal questionnaire. In order to measure the degree of development of environmental management practices, an index of environmental management practices (EMPI) was developed, which reflects the extent to which a set of 16 environmental management practices have been implemented by the entities included in the sample. In total, four variables are considered in this study as possible factors that drive the development of environmental management practices by local entities: type of entity; size; proactive environmental strategy; and Local Agenda 21. Findings – Results indicate the degree of development of environmental management practices in Portuguese local entities is low. Additionally, entity size, the adoption of proactive environmental strategies and the implementation of Local Agenda 21 are explaining factors of the degree of development of such practices. Originality/value – The paper adds to the international research on environmental management in the public sector by providing empirical data from a country, Portugal, where empirical evidence is still relatively limited.

Improving FEM crash simulation accuracy through local thickness estimation based on CAD data

In this paper, we present a method for estimating local thickness distribution in nite element models, applied to injection molded and cast engineering parts. This method features considerable improved performance compared to two previously proposed approaches, and has been validated against thickness measured by di erent human operators. We also demonstrate that the use of this method for assigning a distribution of local thickness in FEM crash simulations results in a much more accurate prediction of the real part performance, thus increasing the bene ts of computer simulations in engineering design by enabling zero-prototyping and thus reducing product development costs. The simulation results have been compared to experimental tests, evidencing the advantage of the proposed method. Thus, the proposed approach to consider local thickness distribution in FEM crash simulations has high potential on the product development process of complex and highly demanding injection molded and casted parts and is currently being used by Ford Motor Company.

Tourism impacts of a portuguese world heritage historic center: residents’ perspectives

The aim of this study is twofold. First, the study analyzes local community perspectives of the importance of the WHS classification of the historic center of Évora. Second, the study analyzes local residents’ perceived tourism impacts on the municipality of Évora. The methodology comprises quantitative research based on a self-administered survey applied to convenience samples of local residents of Évora in the beginning of 2014. The main results reveal that local residents have a strongly positive perception of the WHS designation. With regard to the perceived tourism impacts, a principal component factor analysis delineated three positive and three negative tourism impacts. The comparison of the mean scores of these factors across residents that live near and far from the historic center reveals that the most valued and least valued factors are common to all groups of residents. Nevertheless, in terms of positive impacts, the residents that live near the historic center revealed higher means than the residents that live far from it, whereas in terms of negative impacts, the latter group revealed higher means than former group.

Residents’ perspectives on tourism impacts of portuguese world heritage historic centers: Angra do Heroísmo and Évora

The aim of this study is twofold. First, the study analyzes local community perspectives of the importance of the World Heritage Site (WHS) classification of the historic centers of Angra do Heroísmo and Évora. Second, the study analyzes local residents’ perceived tourism impacts on the municipalities of Angra do Heroísmo and Évora. The methodology comprises quantitative research based on a self-administered survey applied to convenience samples of local residents of the two Portuguese municipalities in 2014. The main results reveal that local residents have a strongly positive perception of the WHS designation in both municipalities. With regard to the perceived tourism impacts, residents from Angra do Heroísmo have a stronger agreement about the impacts of tourism on their city than the residents of Évora, except for the negative social and cultural impacts. The comparison of the mean scores of these impacts across residents that live near and far from the historic centers reveals that the most valued and least valued impacts in the three categories of impacts (economic, social and cultural, and environmental) are common to all groups of residents. Nevertheless, residents living in or near the historic center of Angra do Heroísmo have higher means in the majority of tourism impacts (in all categories), with only one negative impact to concern the majority of respondents. Among the residents from Évora, residents living in or near the historic center have higher means in the majority of economic impacts but lower means in almost social and cultural impacts. With regard to the environmental impacts, residents living in or near the historic center have higher means scores in the positive impacts and lower means scores in the negative environmental impacts.