5,169 research outputs found
Overview of energy storage technologies for PV systems
Tese de mestrado integrado, Engenharia da Energia e do Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2015Devido ao desenvolvimento tecnológico e às exigências da sociedade, o consumo de energia elétrica tem vindo a aumentar. Com esta procura, foi necessário desenvolver novas formas de produzir energia limpa, promovendo a diminuição de emissões de gases promotores de efeito de estufa e da utilização de combustíveis fósseis. Uma vez que as energias renováveis são variáveis no tempo e não despacháveis, é impossível ter-se apenas produção de energia a partir de fontes renováveis. Para suprimir este problema, pode-se recorrer ao armazenamento de energia. Esta dissertação teve como objetivo identificar e analisar as várias tecnologias de armazenamento de energia existentes. Foi feita uma comparação entre elas e identificada qual a tecnologia que se adapta melhor a um sistema fotovoltaico. Posteriormente foi feito um enquadramento das várias tecnologias em vários tipos de aplicações, tais como, em aplicações comerciais e residenciais, aplicações em transportes, em aplicações off-grid e na aplicação para integração com energias renováveis. Foi feita também uma análise do mercado existente e onde estão presentes as oportunidades de mercado (autoconsumo, retificação da rede e off-grid). Por fim foi feito um estudo para três casos distintos, incluindo o dimensionamento de um banco de baterias. A escolha das baterias foi feita através da análise das suas características e custos.Due to a development in technology and society’s requirements, the consumption of electrical energy has been increasing. With this demand, it was necessary to develop new forms of producing cleaner energy. This would consequently help promote a decrease in gas emissions, related to the greenhouse effect and to the utilization of fossil fuels. Renewable energy is known to be variable in time and not dispatchable. For these reasons, it is impossible to obtain production of energy only from renewable sources. To suppress this problem, storing energy can be a resolution. The purpose of this dissertation was to identify and analyze various existent technologies used in storing energy. They were also compared with each other. With the obtained information, one technology was identified as the most suitable for a photovoltaic system. An outline of various technologies in various types of applications was elaborated. This includes commercial and residential applications, applications in transports, off-grid applications and applications to integrate in renewable energies. An analysis of the existing market and the location of market opportunities was also done (auto-consumption, grid rectification and off-grid). Finally, a case study for three different cases was developed including the sizing of a battery bank. The choice of the batteries was done taking into account its characteristics and costs
Business Intelligence Applied to Sentiment Analysis in a Higher Education Institution
Social media allows institutions to not only publicize their work and get feedback from
the community about it, but also to keep in touch with their alumni network and foster
conversations between the academic community. While sentiment analysis allows a better
understanding of what is being said about a brand and how to improve the use of this
communication platform. The main goal of the current work is to build a Business
Intelligence System for a Higher Education Institution (HEI) based on content extracted
from social media. So, Posts, likes, dislikes, shares, comments and number of visits were
extracted from Facebook, Google Maps Reviews, Instagram, LinkedIn, Student Forums,
Twitter and YouTube. With this data and the ETL process a Data Warehouse (DW) in
SQL Server and 17 Dashboards in Power BI were developed. Posts that had the most likes
were about reporting a death of someone from the school, the school mascot, the
pandemic or welcoming new students. Overall, the weekends were the days with more
interactions. Students are concerned about accommodation, transport, and the school
academic offer. This analysis allows a better understanding of what is being said about
this HEI and how to improve the communication strateg
Evolving Cellular Automata Schemes for Protein Folding Modeling Using the Rosetta Atomic Representation
Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG [Abstract] Protein folding is the dynamic process by which a protein folds into its final native structure. This is different to the traditional problem of the prediction of the final protein structure, since it requires a modeling of how protein components interact over time to obtain the final folded structure. In this study we test whether a model of the folding process can be obtained exclusively through machine learning. To this end, protein folding is considered as an emergent process and the cellular automata tool is used to model the folding process. A neural cellular automaton is defined, using a connectionist model that acts as a cellular automaton through the protein chain to define the dynamic folding. Differential evolution is used to automatically obtain the optimized neural cellular automata that provide protein folding. We tested the methods with the Rosetta coarse-grained atomic model of protein representation, using different proteins to analyze the modeling of folding and the structure refinement that the modeling can provide, showing the potential advantages that such methods offer, but also difficulties that arise.This study was funded by the Xunta de Galicia and the European Union (European Regional Development Fund - Galicia 2014-2020 Program), with grants CITIC (ED431G 2019/01), GPC ED431B 2019/03 and IN845D-02 (funded by the “Agencia Gallega de Innovación”, co-financed by Feder funds), and by the Spanish Ministry of Science and Innovation (project PID2020-116201GB-I00). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer NatureXunta de Galicia; ED431G 2019/01Xunta de Galicia; ED431B 2019/03Xunta de Galicia; IN845D-0
National vs. European mandate: a rational choice model of interest rate decisions by the European Central Bank
Paper prepared for the 33rd annual conference and 8th research conference of UACES, Newcastle, 2-4 September 2003.The aim of this paper is to investigate to what extent the members of the Governing Council of the European Central Bank (ECB) act as if they had a national mandate, instead of acting in the interests of price stability in the euro area as a whole. The paper develops a simple rational choice model of interest rate decisions inside the Governing Council of the ECB based on national mandates, and tests it against a model based on a European mandate, using monthly data from January 1999 to July 2003. The paper concludes that the model assuming national mandates explains the data better, and derives some implications for the reform of the ECB and other pseudo-independent institutions such as the European Commission, especially in the eve of the next enlargement
Who are the professionals at the interface of science working at research funding, science policy making, and similar organisations?
The scientific endeavour involves not only those working in research performing organisations-but also those in science funding, policy making, and think tank organisations, among others. The workforce in all these entities is composed of researchers, policy decision makers, managers, administrators, technicians, and other supporting staff. Within this community, professionals working at the interface of science (PIoSs) can be defined as those working in the research management and administration (RMA) domain, including varied areas such as science strategy and policy support, research funding procurement, project management, facilities management, communication and dissemination, knowledge and technology transfer, valorisation and impact, and related areas. Researchers have been often studied, namely regarding their job satisfaction, entrepreneurial spirit, and migration patterns. However, the PIoS community has seldom been studied, with only a few reports existing, for example on their profile and roles. Specifically, the PIoS community working at non-research performing organisations has not been explicitly addressed in the literature. This paper reports on the results of an ongoing project aimed at studying the profiles, roles, and functions of PIoSs working at organisations such as research funders, policy makers, and think tanks. The corresponding specificities of these professionals are highlighted and their involvement in professional associations is addressed. It is argued that they are intrinsically part of the wider PIoS (often called RMA) profession and that their full engagement in this community would benefit these individuals and the research and innovation ecosystem at large.José Santos is grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio
Informació negativa en copiar l'elecció de parella
Triar parella és una de les decisions més importants per a qualsevol organisme viu, especialment per a les femelles, per a les quals els costos reproductius són generalment més elevats. Per tant, s'espera que aquesta selecció sexual actuarà sobre el comportament de les femelles a l'hora d'escollir parella, afavorint els comportaments que són capaços de prendre les millors decisions. Els models clàssics de l'evolució de l'elecció femenina de parella assumeixen que les seves preferències són genèticament innates. Això vol dir que les femelles amb un, per exemple, al·lel que les faci tenir una "preferència pel verd" preferiran aparellar-se amb mascles que presentin ornaments d'aquest color, i que aquesta preferència no canviarà al llarg de la vida de les femelles, amb independència de l'actuació dels mascles amb ornaments verds. Són les preferències de les femelles exclusivament genètiques i, per tant, immutables? L'evidència empírica suggereix que no és així.Elegir pareja es una de las decisiones más importantes para cualquier organismo vivo, especialmente para las hembras, para las cuales los costes reproductivos son generalmente más elevados. Por lo tanto, se espera que esta selección sexual actuará sobre el comportamiento de las hembras a la hora de escoger pareja, favoreciendo los comportamientos que son capaces de tomar las mejores decisiones. Los modelos clásicos de la evolución de la elección femenina de pareja asumen que sus preferencias son genéticamente innatas. Esto quiere decir que las hembras con un, por ejemplo, alelo que las haga tener una "preferencia por el verde" preferirán aparearse con machos que presenten ornamentos de ese color, y que esta preferencia no cambiará a lo largo de la vida de las hembras, con independencia de la actuación de los machos con ornamentos verdes. ¿Son las preferencias de las hembras exclusivamente genéticas y, por tanto, inmutables? La evidencia empírica sugiere que no es así.Choosing whom to mate with is one of the most important decisions for any living organism, especially for females, for whom the costs of reproduction are generally higher. It is, therefore, expected that sexual selection will act on female mate choice behaviour, favouring the ones capable of making the better decisions. The classical models of female mate choice evolution assume that their preferences are genetically innate. This means that females with an (e.g.) allele for "green preference" would prefer mating with males displaying green ornaments, and that this preference will never change throughout females' lives, independently of the performance of green males. Are females' preference exclusively genetic and, therefore, immutable? Empirical evidence suggests it is not
Editorial statement: The first year of the European Journal of Government and Economics
<p>In this editorial statement we present a balance of the first year of life of the <em>European Journal of Government and Economics</em>. We discuss the main developments that concern the journal’s indexation by academic databases. We also comment on the approval of a code of publication ethics and malpractice. Finally, we emphasise the dangers of excessive technical sophistication and the need to keep an integrated approach between the fields of political science and economics, according to the spirit of the journal.</p
A framework for the management of research and innovation projects in academic settings
The contemporary complex settings under which research and innovation
(R&I) activities are executed in academic institutions calls for the definition of suitable
management and administration approaches. To this end, (1) the existing literature on the
management of R&I projects in the academia is reviewed; (2) major specificities of R&I
projects are discussed; (3) recent trends in project management are addressed; and (4) a
specific framework for the management of R&I projects in higher education is proposed. The
proposed management framework is defined in eight pillars, namely: (i) clarification of scope
and goals; (ii) use of standards; (iii) scalability and flexibility; (iv) workflow modelling;
(v) use of tools, techniques and templates; (vi) existence of a “project board” or similar; (vii)
adequate risk management; and (viii) organizational learning. The authors argue that
it should be seen as a practical tool for university managers and administrators to apply a
structured and comprehensive overview of key action areas that will increase the effectiveness,
efficiency and impact of R&I project management and administration in academic contexts.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial
support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020
and UIDP/00690/2020) and SusTEC (LA/P/0007/2021). This article is a result of the
project “ValorNatural – Valorização de Recursos Naturais através da Extração de Ingredientes
de Elevado Valor Acrescentado para Aplicações na Indústria Alimentar” (NORTE-01-0247-
FEDER-024479), supported by Norte Portugal Regional Operational Programme (NORTE
2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional
Development Fund (ERDF).info:eu-repo/semantics/publishedVersio
Editorial statement: The first two years of EJGE
In this editorial statement we explain the developments in the European Journal of Government and Economics in its second year of existence. In this period, the journal has continued its international expansion, entered some new indices and started to experience its impact, as measured by the number of citations in other journals. After two years of publication, we have also learned some lessons that should help us redefine the role of EJGE
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