Browsing by Issue Date, starting with "2015-07"
Now showing 1 - 10 of 41
Results Per Page
Sort Options
- Abordagem conceitual às estratégias de Internacionalização sob pressões institucionais duais para legitimidade e conformidadePublication . Ferreira, Manuel Portugal; Serra, Fernando RibeiroInternacionalizar as operações requer que as empresas multinacionais (EMNs) desenvolvam estratégias capazes de lidar, simultaneamente, com as pressões institucionais externas, para a legitimidade, e as pressões institucionais internas, para a conformidade. Neste artigo conceitual e baseado na literatura de teoria institucional em negócios internacionais, desenvolve-se um conjunto de proposições teóricas sobre quais as estratégias de entrada nos mercados externos seguidas pelas EMNs face aos ambientes institucionais. Com foco predominante no ambiente institucional externo e nas diferenças de desenvolvimento institucional, também aborda a relevância de considerar o ambiente interno. As estratégias de entrada tendem a ser baseadas em modos de baixo envolvimento e em parcerias, como joint ventures, para entrar em países institucionalmente imaturos ou institucionalmente mais distantes. As aquisições e as parcerias podem ser usadas se as pressões institucionais forem menores. Conclui-se com uma discussão geral e o apontamento de questões para pesquisas futuras.
- Intra Predictive Depth Map Coding Using Flexible Block PartitioningPublication . Lucas, Luis F. R.; Wegner, Krzysztof; M. M. Rodrigues, Nuno; Pagliari, Carla L.; Silva, Eduardo A. B. da; Faria, SergioA complete encoding solution for efficient intra-based depth map compression is proposed in this paper. The algorithm, denominated predictive depth coding (PDC), was specifically developed to efficiently represent the characteristics of depth maps, mostly composed by smooth areas delimited by sharp edges. At its core, PDC involves a directional intra prediction framework and a straightforward residue coding method, combined with an optimized flexible block partitioning scheme. In order to improve the algorithm in the presence of depth edges that cannot be efficiently predicted by the directional modes, a constrained depth modeling mode, based on explicit edge representation, was developed. For residue coding, a simple and low complexity approach was investigated, using constant and linear residue modeling, depending on the prediction mode. The performance of the proposed intra depth map coding approach was evaluated based on the quality of the synthesized views using the encoded depth maps and original texture views. The experimental tests based on all intra configuration demonstrated the superior rate-distortion performance of PDC, with average bitrate savings of 6%, when compared with the current state-of-the-art intra depth map coding solution present in the 3D extension of a high-efficiency video coding (3D-HEVC) standard. By using view synthesis optimization in both PDC and 3D-HEVC encoders, the average bitrate savings increase to 14.3%. This suggests that the proposed method, without using transform-based residue coding, is an efficient alternative to the current 3D-HEVC algorithm for intra depth map coding.
- Known Mean, Unknown Maxima? Testing the Maximum Knowing Only the MeanPublication . Santos, Rui; Oliveira Martins, João Paulo; Felgueiras, MiguelIn the quantitative group testing problem, the use of the group mean to identify if the group maximum is greater than a prefixed threshold (infected group) is analyzed, using n independent and identically distributed individuals. Under these conditions, it is shown that the information of the mean is sufficient to classify each group as infected or healthy with low probability of misclassification when the underline distribution is a unilateral heavy-tailed distribution.
- Improving Organizational Effectiveness with Enterprise Information SystemsPublication . Varajão, João Eduardo; Cruz-Cunha, Maria Manuela; Martinho, Ricardo; Varajão, João Eduardo; Cruz-Cunha, Maria Manuela; Martinho, RicardoInformation and communication technologies are widely used to improve organizational efficiency and ensure effective workflows. Technology and software systems provide the opportunity to improve productivity and efficiency when used correctly; however, professionals continue to encounter challenges in a variety of settings.Improving Organizational Effectiveness with Enterprise Information Systems analyzes the challenges and solutions associated with integrating new technologies in organizations, including key topics in cloud computing, project management, and operational procedure development and implementation. This publication is an essential reference source for senior managers, CIOs, ICT professionals, project managers, researchers, academicians, and upper level students interested in the applications and advances in ICTs and IS.
- Semantic Integration Framework for Resources IdentificationPublication . Pragosa, Miguel; Basto-Fernandes, Vitor; Luísa OliveiraThe global adoption of information technology systems throughout all activity domains lead to the existence of a huge amount of information systems unable to interoperate, first of all, because of different ways of identifying resources. Different transport and application level protocols for data exchange also raise some interoperability difficulties. Common interoperability scenarios rely on tightly controlled, specific communities of information technology islands. In this chapter we present and discuss the usage of lexical, syntactic and semantic lexical technologies to address interoperability problems at the product identification level, in the context of food consumption analysis.
- The efficacy of MS-222 as anaesthetic agent in four freshwater aquarium fish speciesPublication . Chambel, João; Pinho, Rúben; Sousa, Rita; Ferreira, Tânia; Baptista, Teresa; Severiano, Vera; MENDES, SUSANA; Pedrosa, RuiThe efficacy of anaesthetic tricaine methanesulfonate (MS-222) was evaluated in four freshwater aquarium fish species, Zebrafish (Danio rerio), Guppy (Poecilia reticulata), Discu (Symphysodon discus) and Green swordtail (Xiphophorus helleri). The correct dose of anaesthetic should induce the plane 4 of anaesthesia in less than 180 s, recovery in less than 300 s and must survive when exposed during 30 min to anaesthetic. Fishes were exposed to six concentrations of anaesthetic (75, 100, 125, 150, 200 and 250 mg L-1) and the time of fish reaching plane 4 of anaesthesia, post exposure recovery, and the percentage of survival when fish were subject to 30 min in the anaesthetic were recorded. The optimal doses varied according to the species: D. rerio - 75, 100 and 125 mg L-1, P. reticulata - 125, 150 and 200 mg L-1, S. discus - 75 and 100 mg L-1 and X. helleri - 125 and 150 mg L-1. The induction time generally decreased significantly with increasing concentration of MS-222 for all of the species evaluated. The recovery time had a tendency to increase with the increase of the MS-222 concentration for D. rerio, P. reticulata and S. discus. On the other hand, X. helleri recovery time decreased with the increase of MS-222 concentration. MS-222 proved to be effective in anaesthesia for all the freshwater ornamental species studied. The main results clearly show that the optimal dose to anesthetize is fish species dependent and it is completely wrong to extrapolate optimal anaesthetic concentrations between different species.
- Corporate social disclosure in the health sector : an overall analysis using GRI inputsPublication . Gomes, Bernardo; Eugénio, Teresa Cristina PereiraCorporations' activities and market dynamics are changing realities from the North to The South. Growing awareness among stakeholders is leading to an increasing demand for corporate’ responsibility while an implicit financial benefit is accelerating the debate among managers. Although this has been thoroughly discussed, there is little consensus regarding the concept of corporate responsibility and its influence on business. Industry has been found to be an important predictor of corporations’ social disclosure, yet research on some industries remains scarce or inexistent. This document aims to analyse corporate social disclosure (CSD) in the health sector according to GRI’ performance indicators. The sample consists of all listed companies offering health services and/or health products, present in GRI world database in 2012. Results suggest the existence of significant differences in CSD across the continents, an important valorisation of External Assurance adoption and a possible relation between CSD and CFP. This study is expected to be a valid contribution to the literature by facilitating a better understanding of the CSR phenomenon as a whole.
- Análise comparativa do uso de tecnologias de fabrico rápido no processo produtivo de elementos moldantes para moldes de injeção de plásticosPublication . Domingues, Liliana Cristina Ferreira; Martinho, Pedro Miguel Gonçalves; Alves, Maria Leopoldina Mendes Ribeiro de SousaCom a evolução da indústria e da exigência do mercado, existe cada vez mais a necessidade de dar resposta a essas mesmas exigências, criando uma constante evolução e procura de processos/produtos novos. Uma dessas indústrias é a indústria de injeção de plástico. Inicialmente, as ferramentas utilizadas na injeção plástica eram exclusivamente fabricadas por processos convencionais, contudo, devido ao custo e tempo de entrega das mesmas, tornou-se necessário encontrar alternativas. Estas alternativas têm por base os princípios da prototipagem e fabrico rápido. O uso de moldes híbridos pressupõe a utilização de processos convencionais e de processos alternativos na mesma ferramenta. Este projeto aborda o uso dos processos alternativos para o fabrico de ferramentas para a moldação por injeção e a influência que esses processos alternativos têm nas peças injetadas. Foram projetados blocos moldantes em resina epóxi, carregadas com diferentes percentagens de alumínio, com o intuito de serem utilizadas num molde existente no Laboratório de Tecnologia Mecânica, da Escola Superior de Tecnologia e Gestão de Leiria. Para tal, a chapa da bucha foi substituída por uma chapa projetada para alojar os blocos moldantes, tendo em conta as dimensões da chapa original. A injeção plástica foi realizada com dois polímeros diferentes, polipropileno e poliestireno. As amostras obtidas foram submetidas a três análises: dimensional, visual e mecânica. A análise dimensional teve como objetivo perceber se existe influência do material do bloco moldante na estabilidade dimensional da peça injetada; a análise visual permitiu identificar os problemas geométricos ocorridos nos provetes; e por fim, a análise mecânica permitiu identificar a influência nos parâmetros mecânicos dos provetes, que cada bloco moldante provocou. As conclusões obtidas neste projeto mostram que apesar dos processo alternativos serem uma alternativa, ainda continuam a ter algumas limitações, as quais foram identificadas neste projeto, tais como, permitir um sistema de refrigeração adequado e proporcionar boas características mecânicas nos componentes, quando comparados com processos convencionais.
- RuleSIM: a toolkit for simulating the operation and improving throughput of rule-based spam filtersPublication . Ruano-Ordás, David; Fdez-Glez, Jorge; Fdez-Riverola, Florentino; Basto-Fernandes, Vitor; Méndez, José RamónThis paper introduces RuleSIM, a toolkit comprising different simulation tools specifically designed to aid researchers concerned about spam-filtering throughput. RuleSIM allows easily designing, developing, simulating and comparing new scheduling heuristics using different filters and sets of e-mails. Simulation results can be both graphically analysed, by using different complementary views, and quantitatively compared through several measures. Moreover, the underlying RuleSIM API can be easily integrated with third-party Java optimization platforms to facilitate debugging and achieve better configurations for rule scheduling. RuleSIM is free software distributed under the terms of GNU Lesser General Public License, and both source code and documentation are publicly available at https://github.com/rulesim/v2.0. Copyright © 2015 John Wiley & Sons, Ltd.
- Camelina oil as a source of polyunsaturated fatty acids for the production of human milk fat substitutes catalyzed by a heterologous Rhizopus oryzae lipasePublication . Faustino, Ana Rita; Osório, Natália M.; Tecelão, Carla; Canet, Albert; Valero, Francisco; Ferreira‐Dias, SuzanaThis study aims to produce human milk fat substitutes (HMFS) rich in polyunsaturated fatty acids (PUFA),mainly the essential omega-3 linolenic acid, by acidolysis reaction between tripalmitin (PPP) and free fattyacids (FFA) from camelina oil, in stirred batch reactor and solvent-free media. The non-commercialheterologous Rhizopus oryzae lipase (rROL), immobilized on Lewatit VP OC 1600 or on Relizyme OD403/S, and the immobilized commercial lipase from Rhizomucor miehei (Lipozyme RM IM) were tested asbiocatalysts. Both lipases are sn-1,3 selective. After 24 h reaction at 60°C, using biocatalyst loads of 5 wt%(in relation to tripalmitin), 48.9, 43.6, and 18.3 mol% of fatty acid incorporation in triacylglycerols (TAG)were obtained with Lipozyme RM IM and rROL immobilized on Lewatit or on Relizyme, respectively.rROL immobilized on Lewatit was selected as biocatalyst for the acidolysis, as alternative to the commercialimmobilized lipases. With this biocatalyst, the molar incorporation increased with its initial water activity(0.55–0.95). Modeling acidolysis catalyzed by rROL immobilized on Lewatit was performed by responsesurface methodology, as a function of temperature (58–72°C) and molar ratio FFA:PPP (1.2:1–6.8:1). Thehighest PPP consumption was achieved at 60°C with a molar ratio of 2:1. The yield of HMFS (new TAG)increased from 42.6 wt% (5% biocatalyst load) to 52% with 8% load, after 24 h acidolysis.Practical applications: Camelina oil showed to be a good source of PUFA, mainly essential fatty acids,to incorporate in HMFS. After 24 h acidolysis under optimized conditions, catalyzed by the non-commercial sn-1,3 regioselective rROL immobilized on Lewatit VP OC 1600, the TAG fraction contains67.7 mol% of palmitic acid at position 2. These structured lipids rich in PUFA can be used in blends with1,3-dioleoyl-2-palmitoyl-glycerol (OPO) in order to mimic the human milk fat. The performance of thisbiocatalyst was comparable to that observed with Lipozyme RM IM. The replacement of high-costcommercial immobilized lipases by rROL immobilized on Lewatit may reduce the biocatalyst cost. Inaddition, since the best molar ratio FFA:PPP for rROL is 2:1, i.e., the stoichiometric value for theacidolysis catalyzed by sn-1,3 regioselective lipases, the use of this biocatalyst will reduce downstreamcosts related with unconverted FFA recovery.