996 resultados para scenario work
Resumo:
Outsourcing is a management strategy through which an organization transfers work, responsibilities and decision power to an external source. In the present scenario of global competitiveness, where firms have to react more quickly to changes in markets, outsourcing stands out as a strategy that, if adequately used by the organizations, can leverage the differentiation between one firm and its competitors. The growing use of outsourcing as a management strategy by organizations, results from the maturity reached in their use by organizations and an increase of the offer by service providers. With the increasing use of outsourcing, the complexity and the risk associated have also risen. Understanding the perspective of the customer and of the service provider and the outsourcing processes framework should contribute to a success of the customer / service provider relationship and enhance the benefits and reduce their risks. In this work, there is a contextualization of outsourcing, different methods for managing the outsourcing process from the customer's and the service provider perspective are discussed, and a methodology for managing the outsourcing process from the perspective of the service provider is proposed. The methodological approach used in this work was the case study. The case study discusses an initiative to outsource a process of bottling and packaging in the Port Wine industry. In this study it was concluded that the methodology proposed is suitable for the management of the outsourcing process by the service provider.
Resumo:
Ergonomic interventions such as increased scheduled breaks or job rotation have been proposed to reduce upper limb muscle fatigue in repetitive low-load work. This review was performed to summarize and analyze the studies investigating the effect of job rotation and work-rest schemes, as well as, work pace, cycle time and duty cycle, on upper limb muscle fatigue. The effects of these work organization factors on subjective fatigue or discomfort were also analyzed. This review was based on relevant articles published in PubMed, Scopus and Web of Science. The studies included in this review were performed in humans and assessed muscle fatigue in upper limbs. 14 articles were included in the systematic review. Few studies were performed in a real work environment and the most common methods used to assess muscle fatigue were surface electromyography (EMG). No consistent results were found related to the effects of job rotation on muscle activity and subjective measurements of fatigue. Rest breaks had some positive effects, particularly in perceived discomfort. The increase in work pace reveals a higher muscular load in specific muscles. The duration of experiments and characteristics of participants appear to be the factors that most have influenced the results. Future research should be focused on the improvement of the experimental protocols and instrumentation, in order to the outcomes represent adequately the actual working conditions. Relevance to industry: Introducing more physical workload variation in low-load repetitive work is considered an effective ergonomic intervention against muscle fatigue and musculoskeletal disorders in industry. Results will be useful to identify the need of future research, which will eventually lead to the adoption of best industrial work practices according to the workers capabilities.
Resumo:
The last decade has witnessed a major shift towards the deployment of embedded applications on multi-core platforms. However, real-time applications have not been able to fully benefit from this transition, as the computational gains offered by multi-cores are often offset by performance degradation due to shared resources, such as main memory. To efficiently use multi-core platforms for real-time systems, it is hence essential to tightly bound the interference when accessing shared resources. Although there has been much recent work in this area, a remaining key problem is to address the diversity of memory arbiters in the analysis to make it applicable to a wide range of systems. This work handles diverse arbiters by proposing a general framework to compute the maximum interference caused by the shared memory bus and its impact on the execution time of the tasks running on the cores, considering different bus arbiters. Our novel approach clearly demarcates the arbiter-dependent and independent stages in the analysis of these upper bounds. The arbiter-dependent phase takes the arbiter and the task memory-traffic pattern as inputs and produces a model of the availability of the bus to a given task. Then, based on the availability of the bus, the arbiter-independent phase determines the worst-case request-release scenario that maximizes the interference experienced by the tasks due to the contention for the bus. We show that the framework addresses the diversity problem by applying it to a memory bus shared by a fixed-priority arbiter, a time-division multiplexing (TDM) arbiter, and an unspecified work-conserving arbiter using applications from the MediaBench test suite. We also experimentally evaluate the quality of the analysis by comparison with a state-of-the-art TDM analysis approach and consistently showing a considerable reduction in maximum interference.
Resumo:
In this work a forest fire detection solution using small autonomous aerial vehicles is proposed. The FALCOS unmanned aerial vehicle developed for remote-monitoring purposes is described. This is a small size UAV with onboard vision processing and autonomous flight capabilities. A set of custom developed navigation sensors was developed for the vehicle. Fire detection is performed through the use of low cost digital cameras and near-infrared sensors. Test results for navigation and ignition detection in real scenario are presented.
Resumo:
This work presents a hybrid coordinated manoeuvre for docking an autonomous surface vehicle with an autonomous underwater vehicle. The control manoeuvre uses visual information to estimate the AUV relative position and attitude in relation to the ASV and steers the ASV in order to dock with the AUV. The AUV is assumed to be at surface with only a small fraction of its volume visible. The system implemented in the autonomous surface vehicle ROAZ, developed by LSA-ISEP to perform missions in river environment, test autonomous AUV docking capabilities and multiple AUV/ASV coordinated missions is presented. Information from a low cost embedded robotics vision system (LSAVision), along with inertial navigation sensors is fused in an extended Kalman filter and used to determine AUV relative position and orientation to the surface vehicle The real time vision processing system is described and results are presented in operational scenario.
Resumo:
13th IEEE/IFIP International Conference on Embedded and Ubiquitous Computing (EUC 2015). 21 to 23, Oct, 2015, Session W1-A: Multiprocessing and Multicore Architectures. Porto, Portugal.
Resumo:
Paper/Poster presented in Work in Progress Session, 28th GI/ITG International Conference on Architecture of Computing Systems (ARCS 2015). 24 to 26, Mar, 2015. Porto, Portugal.
Resumo:
Poster presented in Work in Progress Session, 28th GI/ITG International Conference on Architecture of Computing Systems (ARCS 2015). 24 to 26, Mar, 2015. Porto, Portugal.
Resumo:
This work presents a low cost RTK-GPS system for localization of unmanned surface vehicles. The system is based on the use of standard low cost L1 band receivers and in the RTKlib open source software library. Mission scenarios with multiple robotic vehicles are addressed as the ones envisioned in the ICARUS search and rescue case where the possibility of having a moving RTK base on a large USV and multiple smaller vehicles acting as rovers in a local communication network allows for local relative localization with high quality. The approach is validated in operational conditions with results presented for moving base scenario. The system was implemented in the SWIFT USV with the ROAZ autonomous surface vehicle acting as a moving base. This setup allows for the performing of a missions in a wider range of environments and applications such as precise 3D environment modeling in contained areas and multiple robot operations.
Resumo:
Os primeiros trabalhos sobre Computer-Supported Cooperative Work surgiram na segunda metade da década de 80, estabelecendo-se um campo de investigação interdisciplinar com enfoque no papel do computador e das tecnologias da comunicação no apoio do trabalho em grupo (Ishii et al., 1994). Ao abordar esta área de investigação torna-se claro que é necessário ter em conta a diversidade dos grupos e das tarefas que estes devem de utilizar, entre outros factores importantes. As implicações desta diversidade são discutidas ao nível concepção de interfaces de groupware, em que um maior envolvimento dos utilizadores nas fases iniciais parece ser necessário, e ao nível dos Sistemas de Apoio à Decisão em Grupo.
Resumo:
The Azores archipelago is a zone with a vast cultural heritage, presenting a building stock mainly constructed in traditional stone masonry. It is known that this type of construction exhibits poor behaviour under seismic excitations; however it is extensively used in seismic prone areas, such as this case. The 9th of July of 1998 earthquake was the last seismic event in the islands, leaving many traditional stone constructions severely damaged or totally destroyed. This scenario led to an effort by the local government of improving the seismic resistance of these constructions, with the application of several reinforcement techniques. This work aims to study some of the most used reinforcement schemes after the 1998 earthquake, and to assess their effectiveness in the mitigation of the construction’s seismic vulnerability. A brief evaluation of the cost versus benefit of these retrofitting techniques is also made, seeking to identify those that are most suitable for each building typology. Thus, it was sought to analyze the case of real structures with different geometrical and physical characteristics, by establishing a comparison between the seismic performance of reinforced and non-reinforced structures. The first section contains the analysis of a total of six reinforcement scenarios for each building chosen. Using the recorded 1998 earthquake accelerograms, a linear time-history analysis was performed for each reinforcement scenario. A comparison was then established between the maximum displacements, inter-storey drift and maximum stress obtained, in order to evaluate the global seismic response of each reinforced structure. In the second part of the work, the examination of the performance obtained in the previous section, in relation to the cost of implementing each reinforcement technique, allowed to draw conclusions concerning the viability of implementing each reinforcement method, based on the book value of the buildings in study.
Resumo:
The integration of wind power in eletricity generation brings new challenges to unit commitment due to the random nature of wind speed. For this particular optimisation problem, wind uncertainty has been handled in practice by means of conservative stochastic scenario-based optimisation models, or through additional operating reserve settings. However, generation companies may have different attitudes towards operating costs, load curtailment, or waste of wind energy, when considering the risk caused by wind power variability. Therefore, alternative and possibly more adequate approaches should be explored. This work is divided in two main parts. Firstly we survey the main formulations presented in the literature for the integration of wind power in the unit commitment problem (UCP) and present an alternative model for the wind-thermal unit commitment. We make use of the utility theory concepts to develop a multi-criteria stochastic model. The objectives considered are the minimisation of costs, load curtailment and waste of wind energy. Those are represented by individual utility functions and aggregated in a single additive utility function. This last function is adequately linearised leading to a mixed-integer linear program (MILP) model that can be tackled by general-purpose solvers in order to find the most preferred solution. In the second part we discuss the integration of pumped-storage hydro (PSH) units in the UCP with large wind penetration. Those units can provide extra flexibility by using wind energy to pump and store water in the form of potential energy that can be generated after during peak load periods. PSH units are added to the first model, yielding a MILP model with wind-hydro-thermal coordination. Results showed that the proposed methodology is able to reflect the risk profiles of decision makers for both models. By including PSH units, the results are significantly improved.
Resumo:
Temos vindo a assistir nos últimos anos a uma evolução no que respeita à avaliação do risco de crédito. As constantes alterações de regulamentação bancária, que resultam dos Acordos de Basileia, têm vindo a impor novas normas que condicionam a quantidade e a qualidade do risco de crédito que as Instituições de Crédito podem assumir nos seus balanços. É de grande importância as Instituições de Crédito avaliarem o risco de crédito, as garantias e o custo de capital, pois têm um impacto direto na sua gestão nomeadamente quanto à afetação de recursos e proteção contra perdas. Desta forma, pretende-se com o presente trabalho elaborar e estruturar um modelo de rating interno através de técnicas estatísticas, assim como identificar as variáveis estatisticamente relevantes no modelo considerado. Foi delineada uma metodologia de investigação mista, considerando na primeira parte do trabalho uma pesquisa qualitativa e na segunda parte uma abordagem quantitativa. Através da análise documental, fez-se uma abordagem dos conceitos teóricos e da regulamentação que serve de base ao presente trabalho. No estudo de caso, o modelo de rating interno foi desenvolvido utilizando a técnica estatística designada de regressão linear múltipla. A amostra considerada foi obtida através da base de dados SABI e é constituída por cem empresas solventes, situadas na zona de Paredes, num horizonte temporal de 2011-2013. A nossa análise baseou-se em três cenários, correspondendo cada cenário aos dados de cada ano (2011, 2012 e 2013). Para validar os pressupostos do modelo foram efetuados testes estatísticos de Durbin Watson e o teste de significância - F (ANOVA). Por fim, para obtermos a classificação de rating de cada variável foi aplicada a técnica dos percentis. Pela análise dos três cenários considerados, verificou-se que o cenário dois foi o que obteve maior coeficiente de determinação. Verificou-se ainda que as variáveis independentes, rácio de liquidez geral, grau de cobertura do ativo total pelo fundo de maneio e rácio de endividamento global são estatisticamente relevantes.
Resumo:
A crescente necessidade de meios de inspecção e recolha de informação de infraestruturas e do meio ambiente natural, origina o recurso a meios tecnológicos cada vez mais evoluídos. Neste contexto, os robôs móveis autónomos aéreos surgem como uma ferramenta importante. Em particular, os veículos aéreos de asa móvel, pela sua manobrabilidade e controlo podem-se utilizar eficazmente em meios complexos como cenários interiores onde o ambiente é parcialmente controlado. A sua utilização em coordenação com outros veículos robóticos móveis e em particular com a crescente autonomia de decisão, permitem uma eficiência elevada, por exemplo, em tarefas de recolha automática de informação, vigilância, apoio a comunicações, etc. A inexistência de um veículo autónomo de asa móvel no cenário multi-robótico desenvolvido pelo Laboratório de Sistemas Autónomos do Instituto Superior de Engenharia do Porto, aliada às suas aplicações referidas, criou a necessidade do desenvolvimento de um veículo desta gama. Identificou-se, pois, o desenvolvimento de um veículo autónomo aéreo do tipo quadrotor com capacidade de vôo base estabilizado como o problema a resolver. Foi efectuado um levantamento de requisitos do sistema, a caracterização de um veículo autónomo aéreo Vertical Take-off and Landing - VTOL, e efectuado um trabalho de pesquisa a fim de possibilitar o conhecimento das técnicas e tecnologias envolvidas. Tendo em vista o objectivo de controlo e estabilização do veículo, foi efectuada a modelização do sistema que serviu não só para a melhor compreensão da sua dinâmica mas também para o desenvolvimento de um simulador que possibilitou a validação de estratégias de controlo e avaliação de comportamentos do veículo para diferentes cenários. A inexistência de controladores de motores brushless adequada (frequência de controlo), originou o desenvolvimento de um controlador dedicado para motores brushless, motores esses utilizados para a propulsão do veículo. Este controlador permite uma taxa de controlo a uma frequência de 20KHz, possui múltiplas interfaces de comunicação (CAN, RS232, Ethernet, SPI e JTAG), é de reduzido peso e dimensões e modular, visto ter sido implementado em dois módulos, i.e., permite a sua utilização com diferentes interfaces de potência. Projectou-se um veículo autónomo aéreo em termos físicos com a definição da sua arquitectura de hardware e software bem como o sistema de controlo de vôo. O sistema de estabilização de vôo compreende o processamento de informação fornecida por um sistema de navegação inercial, um sonar e o envio de referências de velocidade para cada um dos nós de controlo ligados a um barramento CAN instalado no veículo. A implementação do veículo foi alcançada nas suas vertentes mecânica, de hardware e software. O UAV foi equipado com um sistema computacional dotando-o de capacidades para o desempenho de tarefas previamente analisadas. No presente trabalho, são também tiradas algumas conclusões sobre o desenvolvimento do sistema e sua implementação bem como perspectivada a sua evolução futura no contexto de missões coordenadas de múltiplos veículos robóticos.
Resumo:
Dissertação de Mestrado apresentada ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Contabilidade e Finanças, sob orientação do Doutor José Amorim