Browsing by Issue Date, starting with "2015-12-21"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Catchment influences on the hydrological flows to lake terra alta (Linhares, ES, Brazil) and ecohydrology perspectivesPublication . Gago González, Mónica; Moreira da Silva, M.; Barroso, Gilberto FonsecaLake Terra Alta (LTA) (A= 3.9 km2; Zmax= 22.1.m) is a tropical natural lake located in the State of Espírito Santo (Southeast Brazil) being one of the 90 lakes which form the Lake District of Lower Doce Rover Valley (LDRV). LTA catchment area is 144.7 km2 and is composed by 8 subbasins and 7 tributaries streams. Its predominant land use is pasturage and smaller dimension cropping and Eucalyptus forestry, with no urban areas or industrial activities. Catchments morphometry and land uses and land cover have implications on the catchments hydromorphological processes, thus influencing hydrological flows to downstream lake. Therefore, hydrological knowledge is necessary to subsidize basin management plans. LTA is under pressure of direct water withdraw for irrigation, as well as water withdraws from the tributary rivers and fluvial damming. Nutrient inputs from catchment natural loads and anthropogenic activities (i.e., agriculture, livestock, forestry). Those pressures may compromise lake ecosystem services that are provided by water quantity and quality. In this regard, an echohydrological approach provide a more concise support for Integrated Lake Basin Management (ILBM), considering the relationships of lake catchment, stakeholders and governance systems. The main goal of this study is to evaluate the hydrological flows to LTA under an ecohydrological approach, integrating catchment morphometry, hydrography, hydrology, and land use and land cover. Based on a georeferenced database, river discharge measurements and modeling, and hydrochemistry analysis of the tributary streams, loads of nutrients are obtained. Subbasins data are analyzed through multivariate statistical analysis (i.e., PCA) in relation to mentioned catchments features. The obtained results provide sound information of the influence and relationships of land use and morphometry on the different subbasins. Thus, providing valuable information for the sustainable management of the basin and propose ecohydrologycal responses for inflow nutrient abatement and improve freshwater inputs to lake ecosystem to ensure ecosystem services provided by LTA.
- Interfaces humano-computador com reconhecimento de gestos e representação holográficaPublication . Sousa, Luís Carlos Rodrigues de; Monteiro, J. M.; Rodrigues, J. M .F.Hoje em dia, várias tecnologias estão em desenvolvimento com o intuito de permitir uma melhoria da interatividade humano-computador. No domínio do reconhecimento de instruções por exemplo, diversos dispositivos permitem determinar os gestos das mãos de utilizadores. Esta capacidade pode ser utilizada vantajosamente num grande número de aplicações, em especial naquelas em que os teclados e ecrãs táteis não são as melhores soluções. Há ainda outros dispositivos que são capazes de detetar todo o corpo do utilizador, permitindo entre outros, o reconhecimento dos gestos efetuados com o braço ou o corpo completo. Em todo o caso, a melhoria da interatividade humano-computador não se restringe ao reconhecimento de gestos. Um dos domínios que tem ganho grande relevância nos últimos anos é o da representação holográfica. Os hologramas permitem uma visualização de personagens e objetos mais próxima daquela a que estamos habituados, e por essa via, a mais natural. Nesta dissertação desenvolvem-se e combinam-se estes dois domínios. Começa-se por apresentar o estudo e desenvolvimento de vários sistemas de reconhecimento de gestos corporais, permitindo a construção de novas aplicações capazes de maximizar a interatividade com o computador. Em seguida o reconhecimento de gestos é combinado com a representação holográfica, suportando a criação e o desenvolvimento de uma rececionista, ou de uma relações públicas de uma empresa, produto ou evento. Ao combinar hologramas com reconhecimento de gestos, o sistema desenvolvido permite uma interação dinâmica com os utilizadores, em resposta ao que lhes for solicitado, servindo de guia orientador e de fonte de informação útil. O resultado é uma instalação inovadora, capaz de produzir hologramas a partir de objetos virtuais ou de vídeos de pessoas reais que podem ser observados em toda a sua volta (360o).
- Sistema de visão inteligente de baixo custo para parque de estacionamentoPublication . Saraiva, David Vaz de; Rodrigues, J. M .F.Sistemas inteligentes para parque de estacionamento contribuem para a redução de tráfego, facilitando aos utilizadores a procura de um lugar de estacionamento, o que permite poupar tempo e dinheiro. No entanto, tais sistemas requerem, geralmente, instalações dispendiosas. Na presente dissertação, é proposto um sistema de visão computacional de baixo custo baseado no Raspberry Pi 2 e numa HD webcam para a deteção de lugares livres. O algoritmo de visão é baseado num detetor de arestas e num limite dinâmico atribuído a cada lugar para inferir sobre o estado do lugar. O sistema foi testado em ambiente real com diferentes condições atmosféricas e oclusões parciais entre os veículos. O algoritmo corre em tempo real e tem uma taxa de sucesso de 99.6%.
- Monitoring of urban transportation networks using wireless sensor networksPublication . Carvalho, Nuno Miguel G. M; Correia, NoéliaWith today’s technologies, constant growth of people in major cities and the permanent concern with our natural resources, such as energy, it is inevitable that we look for ways to improve our urban transportation networks. One way of improving transportation networks is to make an efficient vehicle routing. In this thesis vehicle routing with backup provisioning, using wireless sensor technologies, is proposed. We start by collecting the entry and exit of people inside urban transportations, which will give us a view of fleet load over time, using wireless sensor technologies. For this purpose a monitoring software was developed. Such data gathering and monitoring tool will allow data analysis in real time and, according to information extracted, to propose solutions for service improvements. In this thesis the possibility of using such data to plan vehicle routes with backup provisioning is discussed. That is, a variant of the open vehicle routing problem is proposed, called vehicle routing with backup provisioning, where the possibility of reacting to overloading/overcrowding of vehicles in certain stops is considered. After mathematically formalizing the problem a heuristic algorithm to plan routes is proposed. Results show that vehicle routing with backup provisioning can be a way of providing sustainable urban mobility with efficient use of resources, while increasing quality of service perceived by users. We expect this tool to be useful for the improvement of Urban Transportation Networks.
- The intra-industry effects of going concern withdrawn audit reportsPublication . Sorocovici, Cristina; Coelho, Luís; Peixinho, RúbenThe market reaction to the disclosure of corporate news and the intra-industry effect of such announcements are two important topics in the accounting and finance domain. For instance, Taffler, Lu and Kausar (2004) shows that the market underreacts to the announcement of a going concern opinion (GCO), but completely anticipates the announcement of a going concern withdrawal (GCW) (Kausar, Taffler and Tan, 2006). In addition, Coelho, Peixinho and Terjesen (2014) shows that the GCO disclosure generates an intra-industry competitive effect in the industry rival firms. However, little is known about the intra-industry effect of a GCW. This master thesis investigates investors’ reaction to the withdrawal of a going concern audit opinion. In particular, this research clarifies if this good news impacts in the industry rivals of GCW firms and contributes to understand if investors process immediately the implications of such news. The sample consists of 95 US companies that had their going concern audit opinion withdrawn between 1995 and 2008. It particularly investigates whether industry rivals of GCW firms experience abnormal returns in the surrounding days to the announcement of such good news by the announcing firms. The results show that, contrary to the GCW firms, rival firms are associated to negative abnormal returns of approximately -1,5% for the (-5, 5), (-6, 6) and (-10, 10) windows surrounding the GCW announcement. In addition, there is some evidence that this competitive effect is due to investor’s reaction immediately after the announcement day and not by an anticipation of the information. The robustness tests indicate that the competitive effect is likely to be influenced by the first GCW cases per industry and is not driven by the most representative industries in the GCW sample.