ESTiG - Resumos em Proceedings Não Indexados à WoS/Scopus
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- À descoberta de software para explorar a programação linear no ensino secundárioPublication . Barros, Paula Maria; Pereira, Ana I.; Teixeira, Ana P.Na sociedade actual, no quotidiano ou profissionalmente, somos várias vezes confrontados com situações em que temos de tomar decisões de planeamento ou de gestão de forma a rentabilizar os recursos disponíveis e minimizar os custos ou consumos, ou seja, temos de resolver problemas de optimização. Se neste tipo de problemas todas as funções envolvidas (função objectivo e restrições) são lineares estamos perante um problema de Programação Linear (PL). Como uma das finalidades da disciplina de Matemática no Ensino Secundário é desenvolver a capacidade de usar a Matemática como instrumento de interpretação e intervenção no real, torna-se imprescindível que esses alunos explorem também problemas de PL. De realçar, que nos programas em vigor a Programação Linear é um dos temas obrigatórios das disciplinas de Matemática A do 11.º ano e Matemática B do 12.º ano do Ensino Secundário e do módulo A10 (designado por Optimização) do Ensino Profissional. Porém, os problemas reais de PL, e mesmo as suas adaptações, nem sempre são fáceis e rápidos de resolver, pois podem envolver um considerável número de variáveis, pelo que se torna imprescindível o recurso a ferramentas tecnológicas. Estas, para além de constituírem um objecto de motivação e predisposição para a aprendizagem, permitem que os alunos resolvam uma maior diversidade de problemas e se centrem mais na análise e interpretação de resultados. Existem diversos programas de computador como o Solver do Excel, o WinQSB, o Programación Lineal e o Winplot, de acesso livre (na generalidade) e facilmente utilizáveis pelos alunos, que possibilitam a exploração gráfica, no caso bidimensional, ou analítica dos problemas de PL. Nesta comunicação, pretende-se dar uma ideia de como se podem resolver problemas concretos de Programação Linear com esses programas, discutindo, simultaneamente, as suas potencialidades e limitações.
- Abordagem contingencial à relação entre inovação, autonomia, desempenho e resultados organizacionaisPublication . Fontes, Carla; Leite, Joaquim; Fernandes, Paula OdeteO principal objetivo deste estudo é validar as relações de interdependência entre estratégia de inovação nos serviços, autonomia estrutural, sistemas de avaliação de desempenho e resultados organizacionais de eficácia e eficiência, tendo como suporte a teoria da contingência. A pesquisa foi baseada em dados recolhidos através de inquéritos por questionário enviados aos diretores de escolas do ensino secundário do setor público de Portugal continental. Recorreu-se ao uso de estatísticas descritivas, ao coeficiente de correlação de Spearman e Análise de Equações Estruturais, no tratamento dos dados. A evidência demonstrou que existem algumas relações entre as variáveis estudadas, reforçando proposições da teoria da contingência organizacional.
- Abordagem contingencial dos fatores contextuais em relação ao uso das práticas de contabilidade de gestãoPublication . Leite, Akaísa; Leite, JoaquimO presente trabalho de investigação científica procurou atingir dois objetivos: (i) avaliar o uso das práticas de Contabilidade de Gestão e (ii) verificar hipóteses de relação entre cinco contingências (o nível da concorrência, a dimensão da organização, a diversidade de produtos, a importância de informação de custos para a tomada de decisões e a tecnologia avançada de produção) e o uso das práticas de Contabilidade de Gestão. As hipóteses de investigação do modelo de análise foram suportadas na teoria da contingência organizacional. O estudo incidiu sobre uma população de 512 empresas da indústria têxtil e vestuário que fazem parte da Associação Têxtil e Vestuário de Portugal (ATP). Os dados foram recolhidos em meados do ano 2014 através de um inquérito por questionário online enviado às empresas por correio eletrónico.
- Uma abordagem metaheurística para um problema integrado de dimensionamento de lotes e de sequenciamentoPublication . Pimentel, Carina; Alvelos, Filipe; Duarte, António; Carvalho, J.M. Valério deNesta comunicação apresenta-se um problema integrado de dimensionamento de lotes e de sequenciamento desses lotes, baseado num problema real de uma indústria Têxtil. Numa solução para o problema as quantidades a produzir por artigo/componente/tamanho são divididas em vários lotes de dimensão variável, determinam-se as máquinas onde os lotes definidos serão produzidos, assim como a ordem segundo a qual esses lotes devem ser produzidos em cada máquina. Os objectivos a atingir são: (1) a minimização do atraso total e (2) a minimização do desvio entre os instantes de conclusão dos vários componentes que pertencem ao mesmo artigo final. Este segundo objectivo tem particular importância no contexto do problema real, de forma a garantir um fluxo regular da produção, embora tenha tido um tratamento muito limitado, senão inexistente, na literatura. Para modelar correctamente este segundo objectivo, o tempo é considerado numa escala contínua. O problema caracteriza-se pela existência de vários conjuntos de máquinas paralelas idênticas; de procuras arbitrárias e datas de entrega associadas a artigos finais; de uma matriz de compatibilidade entre máquinas e artigos/componentes/tamanhos; de datas de disponibilidade de máquinas e pela possibilidade de divisão da procura em várias procuras menores (lot Splitting). Para resolver o problema propõe-se uma metaheurística baseada em pesquisa local (variable neighborhood search). Serão apresentados resultados para um conjunto de instâncias geradas com base no problema real.
- Abordagens da matemática no ensino superior com o geogebra e sua relação com os estilos de aprendizagemPublication . Cordeiro, Edite; Miranda, Luísa; Morais, Carlos; Alves, PauloNa perspetiva de inovar e de ir ao encontro das formas de aprender dos estudantes do ensino superior, avaliou-se a conjugação da utilização de abordagens suportadas por recursos digitais no contexto de ensino e aprendizagem de Matemática com as suas formas de aprender. Neste sentido, desenvolveu-se um estudo apoiado pelo software GeoGebra. Os objetivos que orientaram esta investigação foram: identificar os estilos de aprendizagem dos sujeitos participantes no estudo; averiguar a importância atribuída pelos sujeitos à utilização do GeoGebra em competências a adquirir; relacionar as perceções com os estilos de aprendizagem dos estudantes. Em termos de metodologia, a investigação pode ser considerada exploratória seguindo uma abordagem de natureza mista. A recolha de dados relativa à avaliação da utilização do GeoGebra foi efetuada por questionário construído pelos autores do estudo e pelo questionário Honey-Alonso de estilos de aprendizagem. No desenvolvimento do artigo são apresentados os resultados em função dos objetivos definidos.
- Accounting for business combinations: (Un)desirable uniformity?Publication . Ribeiro, Humberto; Crowther, DavidFor many years, two methods existed alongside each other in the USA to account for business combinations: the pooling of interests method, applied to operations, such as mergers, that met all the conditions as stated at APB Opinion No. 16; and the purchase method for all other combinations. This dual accounting status was also widespread through many other countries, although some included substantial GAAP differences (e.g. USA versus UK) or applied restrictions to the application of those methods. The 1998 G4+1 Position Paper concerning business combinations recognized the inconvenience of this diversity in accounting and recommended the use of a single method, preferably the purchase method. Following a long period of discussion and controversy, as is usual when the business combinations topic is on the table, FASB published in 2001 the SFAS No. 141, which confirmed the purchase as the unique method for business combinations accounting. Simultaneously FASB also issued SFAS No. 142, which replaced goodwill amortization for impairment tests. In the meantime, IASB also started a business combinations project scheduled in two phases. The first has produced already IFRS 3, issued in March 2004, which also determined the purchase method as the single way for business combinations. The second phase is still in course and will provide guidance about the purchase method application (or ‘acquisition method’, as the board meanwhile decided to rename it). Once again, this topic has proved to be a very fertile ground for discussions, as IASB apparently dropped the ‘fresh start’ application and issued an ED with proposed amendments for the recently published IFRS 3. In the UK, business combinations accounting is still ruled by FRS 6 and FRS 7, which are not aligned with IFRS 3 and further IASB proposals. ASB is monitoring the IASB project and it is very likely to adopt its GAAPs, which means that business combinations accounting in the UK will change very soon. The accounting trend for business combinations seems now clear, but many questions remain, such as, was the pooling of interests method ban a major loss? Which challenges arise from replacement of goodwill amortization for impairment tests? With this paper the authors intend to discuss how and if business combinations accounting uniformity is indeed desirable, highlighting advantages and disadvantages, benefits and eventual problems for professionals and stakeholders. A final note to stress is that this paper deals with uniformity of business combinations accounting and not with international accounting harmonisation, to which we are required to refer since it is inherent to recent developments within this topic.
- Accounting for business combinations: lessons from the U.S.A.?Publication . Ribeiro, Humberto; Crowther, DavidThe number of different accounting practices at national level is considerable in Europe. The adoption of IAS/IFRS is a relevant step towards accounting harmonization in Europe, but also results in a dual accounting system for European companies. The accounting for business combinations provides a good example of profusion of different possible methods used by companies in different European countries, with implications on the comparability of financial statements. From the twenty-one European countries surveyed by FEE in 2002, only three did not allow the pooling of interests in any circumstance. In terms of purchased goodwill accounting, amortization was the default treatment. Fifteen countries had refutable amortization period limits, but ten countries had no absolute limits. Moreover, eight countries allowed write off to equity. If the accounting for business combinations in Europe was already a Tower of Babel, another level has been then added to it following IAS/IFRS adoption by EU. Within this dual accounting system, since 2005 listed companies ruled by the law of a Member State are required to prepare their consolidated accounts according IASB’s standards (EC, 2002). The matrix of possibilities has increased. Listed companies with consolidated accounts can only use purchase method, but pooling is still allowed for the remaining, except in few countries. Purchased goodwill is to be amortized by every company, using arbitrary ceilings; or is to be written off; or, finally, is to be subject to impairment tests by companies who adopted IFRS. The discrepancy among the different national GAAP is significant, and between these and IASB’s is huge. To mitigate these differences, some European countries are preparing changes in their national sets of accounting standards. Regarding business combination accounting, countries such as the U.K. (FRED 36 – 39, 2005), and Portugal (NCRF 14, 2007), have produced exposure drafts intended to align their national GAAP with IFRS 3. However, when does such changes will be enforced is unclear. The number of countries to follow these steps is also something to be known in the next years. On the other side of the Atlantic, from 2001 the purchased method is the single accounting method accepted, and purchased goodwill is to be tested using impairment tests. A major change that included every company in the U.S.A., regardless the company status, this is, being listed or reporting consolidated statements. The adoption of the new business combinations was controversial, as many argued it would produce significant economical effects. Several managers from high tech companies even argued that M&A activity would suffer if pooling were to be abolished. To verify whether the FASB new pronouncements have had impact on the M&A activity, we have carried out a study with the purpose to capture any possible effects from the adoption of the new accounting standards. We have found that the new accounting standards did not have any significant impact on the M&A activity in the U.S.A.. Accordingly, we argue that national European accounting boards should also follow IASB GAAP to enhance comparability among European companies involved in M&A deals.
- Accuracy of Jitter and Shimmer MeasurementsPublication . Teixeira, João Paulo; Gonçalves, André AmorimA synthesized speech signal was used to measure the accuracy of the Jitter and Shimmer parameters calculated by a previously presented algorithm. The formant model of speech synthesis was used to produce speech signals with a controlled glottal periods and magnitudes according to previously determined Jitter and Shimmer parameters values. The Jitter parameters (jitta, jitter, rap and ppq5) and the Shimmer parameters (ShdB, Shim, apq3 and apq5) were calculated with a previously developed algorithm and compared with the analytic determined values and also with measures made with Praat software. Experiments with different type of jitter and shimmer perturbations and with different F0 values were conducted. Also the influence of F0 variations on Shimmer and Jitter measures was experimented.
- Acoustic analysis of vocal dysphoniaPublication . Teixeira, João Paulo; Fernandes, Paula OdeteVoice acoustic analysis is becoming more and more usefúl in diagnosis of voice disorders or laryngological pathologies. The facility to record a voice sigiial is an advantage over other invasive techniques. This paper presents the statistical analyzes ofa set of voice parameters like jitter, shimmer and HNR over a 4 groups of subjects vvith dysphonia, fünctional dysphonia, hyperfünctional dysphonia, and psychogenic dysphonia and a control group. No statistical signifícance differences over pathologic groups were found but clear tendencies can be seen between pathologic and control group. The tendencies indicates this parameters as a good features to be used in an intelligent diagnosis system, moreover the jitter and shimmer parameters measured over different tones and vowels.
- Active methodology in mechanical technologyPublication . Ribeiro, J.E.; Barros, Paula Maria; Silva, FloraThe course unit of Mechanical Technology II, which is taught in the 1st semester of the 3rd year, is integrated in the course structure of the Degree in Mechanical Engineering from the School of Technology and Management of the Polytechnic Institute of Bragança. The course contents are organized in fifteen themes that cover different manufacturing processes and which can be classified into two main groups: machining processes and metal joint processes (welding and structural adhesives). The classes of the course unit are divided into theoretical and practical (2 hours each). Usually in the theoretical classes prevail the exposition of contents by the teacher, while the practical classes have an experimental component of design and experimental work that is implemented in laboratory where the students conceive and manufacture real metal components. Considering the analysis of students' performance based on the approval of the course unit, it can be observed that in the academic years prior to 2016/2017 the approval rate was relatively high, for example in the three previous years this rate varied between 78% and 90%. However, if the theoretical component is separated from the practical component is verified that the students in theoretical part have a much lower classification, the percentage of approved classifications ranged from 19% to 42% for the same period. Thus, it is the practical component that essentially contributes to the observed approval rate, and there is doubt if the difficulties of theoretical concepts are overcome at the end of the whole process. In this context, there was a need to rethink new ways of approaching the theoretical component of the course unit that contribute to a greater involvement of the students in the classes and, consequently, to a more meaningful learning of the contents. To reach this objective, in the academic years 2016/2017 and 2017/2018, in the theoretical classes of the course unit the exposition of the themes was carried out by the students instead of traditional mode. In this way, the students were in charge of presenting the theoretical subjects. At the end of each presentation there was a large group discussion in the class, involved the discussion about the application of theoretical contents to practical cases. In order to encourage the student involvement in the debate and the previous study of content, at the end of each class, was proposed a "lesson question", which consisted of a written answer to one or two questions on the topic presented. The main goal of this work is to compare the results of this methodology for two different conditions. In academic year 2016/2017 the class has 15 students while the academic year 2017/2018 the class has 50 students. The analysis of the impact of the described methodology was carried out by the teacher, reflecting on the practice and confronting his experience of teaching the course unit in previous years, based on the students' performance. Was purposed a questionnaire to analyse the student’ opinion about the contribution of the applied methodology to their learning.