O Sistema uniforme de contas para a indústria hoteleira

Dissertação de Mestrado apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Contabilidade e Finanças, sob orientação de Professor Doutor Filipe Ambrósio e co-orientação do Mestre António Melo

A satisfação dos colaboradores com o sistema de recompensas: um estudo empírico em cooperativas agrícolas da Região Norte de Portugal

Esta dissertação tem como objetivo central o estudo da satisfação dos colaboradores com o sistema de recompensas de que beneficiam nas organizações onde trabalham. A lógica subjacente ao seu desenvolvimento privilegia, primeiramente, uma abordagem sobre os conceitos de sistema de recompensas e de satisfação e, consequentemente, as teorias que relacionam ambos os conceitos. Foi aplicado um inquérito por questionário a uma amostra de 94 colaboradores de duas cooperativas agrícolas localizadas na região Norte de Portugal. Foram testadas algumas hipóteses de estudo capazes de permitir caracterizar os sistemas de recompensas desenvolvidos nas cooperativas agrícolas objeto de estudo. A análise dos resultados permite concluir que: 1) é menor a satisfação com o sistema de recompensas entre os colaboradores do sexo feminino; 2) é maior a valorização atribuída à componente monetária do que à componente não monetária do sistema de recompensas; 3) a antiguidade na organização não influencia a satisfação dos colaboradores com o sistema de recompensas de que beneficiam; 4) predomina a componente monetária fixa no sistema de recompensas de ambas as cooperativas; 5) a maior satisfação com o sistema de recompensas de que beneficiam é encontrada entre os colaboradores com habilitações de nível superior e; 6) não foram encontradas diferenças na satisfação com o sistema de recompensas entre os colaboradores acima versus abaixo dos 45 anos. Baseado nestes resultados, na parte final desta dissertação são discutidas as principais implicações teóricas e práticas. Algumas limitações bem como sugestões para futura pesquisa são também apresentadas.

A distributed system for learning programming on-line

Several Web-based on-line judges or on-line programming trainers have been developed in order to allow students to train their programming skills. However, their pedagogical functionalities in the learning of programming have not been clearly defined. EduJudge is a project which aims to integrate the “UVA On-line Judge”, an existing on-line programming trainer with an important number of problems and users, into an effective educational environment consisting of the e-learning platform Moodle and the competitive learning tool QUESTOURnament. The result is the EduJudge system which allows teachers to apply different pedagogical approaches using a proven e-learning platform, makes problems easy to search through an effective search engine, and provides an automated evaluation of the solutions submitted to these problems. The final objective is to provide new learning strategies to motivate students and present programming as an easy and attractive challenge. EduJudge has been tried and tested in three algorithms and programming courses in three different Engineering degrees. The students’ motivation and satisfaction levels were analysed alongside the effects of the EduJudge system on students’ academic outcomes. Results indicate that both students and teachers found that among other multiple benefits the EduJudge system facilitates the learning process. Furthermore, the experi- ment also showed an improvement in students’ academic outcomes. It must be noted that the students’ level of satisfaction did not depend on their computer skills or their gender.

CIDER - envisaging a COTS communication infrastructure for evolutionary dependable real-time systems

It is foreseen that future dependable real-time systems will also have to meet flexibility, adaptability and reconfigurability requirements. Considering the distributed nature of these computing systems, a communication infrastructure that permits to fulfil all those requirements is thus of major importance. Although Ethernet has been used primarily as an information network, there is a strong belief that some very recent technological advances will enable its use in dependable applications with real-time requirements. Indeed, several recently standardised mechanisms associated with Switched-Ethernet seem to be promising to enable communication infrastructures to support hard real-time, reliability and flexible distributed applications. This paper describes the motivation and the work being developed within the CIDER (Communication Infrastructure for Dependable Evolvable Real-Time Systems) project, which envisages the use of COTS Ethernet as an enabling technology for future dependable real-time systems. It is foreseen that the CIDER approach will constitute a relevant stream of research since it will bring together cutting edge research in the field of real-time and dependable distributed systems and the industrial eagerness to expand Ethernet responsabilities to support dependable real-time applications.

Plano de negócios para a criação de empresa de produção hortícola

Trabalho de projeto apresentado ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Gestão das Organizações, Ramo de Gestão de Empresas Orientador: Professor Doutor Orlando Manuel Martins Marques de Lima Rua

A simulation model for the IEEE 802.15.4 protocol: delay/throughput evaluation of the GTS mechanism

The IEEE 802.15.4 protocol has the ability to support time-sensitive Wireless Sensor Network (WSN) applications due to the Guaranteed Time Slot (GTS) Medium Access Control mechanism. Recently, several analytical and simulation models of the IEEE 802.15.4 protocol have been proposed. Nevertheless, currently available simulation models for this protocol are both inaccurate and incomplete, and in particular they do not support the GTS mechanism. In this paper, we propose an accurate OPNET simulation model, with focus on the implementation of the GTS mechanism. The motivation that has driven this work is the validation of the Network Calculus based analytical model of the GTS mechanism that has been previously proposed and to compare the performance evaluation of the protocol as given by the two alternative approaches. Therefore, in this paper we contribute an accurate OPNET model for the IEEE 802.15.4 protocol. Additionally, and probably more importantly, based on the simulation model we propose a novel methodology to tune the protocol parameters such that a better performance of the protocol can be guaranteed, both concerning maximizing the throughput of the allocated GTS as well as concerning minimizing frame delay.

A comprehensive simulation study of slotted CSMA/CA for IEEE 802.15.4 wireless sensor networks

In this paper, we analyze the performance limits of the slotted CSMA/CA mechanism of IEEE 802.15.4 in the beacon-enabled mode for broadcast transmissions in WSNs. The motivation for evaluating the beacon-enabled mode is due to its flexibility for WSN applications as compared to the non-beacon enabled mode. Our analysis is based on an accurate simulation model of the slotted CSMA/CA mechanism on top of a realistic physical layer, with respect to the IEEE 802.15.4 standard specification. The performance of the slotted CSMA/CA is evaluated and analyzed for different network settings to understand the impact of the protocol attributes (superframe order, beacon order and backoff exponent) on the network performance, namely in terms of throughput (S), average delay (D) and probability of success (Ps). We introduce the concept of utility (U) as a combination of two or more metrics, to determine the best offered load range for an optimal behavior of the network. We show that the optimal network performance using slotted CSMA/CA occurs in the range of 35% to 60% with respect to an utility function proportional to the network throughput (S) divided by the average delay (D).

On the performance limits of slotted CSMA/CA in IEEE 802.15.4 for broadcast transmissions in wireless sensor networks

The IEEE 802.15.4 has been adopted as a communication protocol standard for Low-Rate Wireless Private Area Networks (LRWPANs). While it appears as a promising candidate solution for Wireless Sensor Networks (WSNs), its adequacy must be carefully evaluated. In this paper, we analyze the performance limits of the slotted CSMA/CA medium access control (MAC) mechanism in the beacon-enabled mode for broadcast transmissions in WSNs. The motivation for evaluating the beacon-enabled mode is due to its flexibility and potential for WSN applications as compared to the non-beacon enabled mode. Our analysis is based on an accurate simulation model of the slotted CSMA/CA mechanism on top of a realistic physical layer, with respect to the IEEE 802.15.4 standard specification. The performance of the slotted CSMA/CA is evaluated and analyzed for different network settings to understand the impact of the protocol attributes (superframe order, beacon order and backoff exponent), the number of nodes and the data frame size on the network performance, namely in terms of throughput (S), average delay (D) and probability of success (Ps). We also analytically evaluate the impact of the slotted CSMA/CA overheads on the saturation throughput. We introduce the concept of utility (U) as a combination of two or more metrics, to determine the best offered load range for an optimal behavior of the network. We show that the optimal network performance using slotted CSMA/CA occurs in the range of 35% to 60% with respect to an utility function proportional to the network throughput (S) divided by the average delay (D).

Digital serious games and simulation games - comparison of two approaches to lean training

In an increasingly competitive and globalized world, companies need effective training methodologies and tools for their employees. However, selecting the most suitable ones is not an easy task. It depends on the requirements of the target group (namely time restrictions), on the specificities of the contents, etc. This is typically the case for training in Lean, the waste elimination manufacturing philosophy. This paper presents and compares two different approaches to lean training methodologies and tools: a simulation game based on a single realistic manufacturing platform, involving production and assembly operations that allows learning by playing; and a digital game that helps understand lean tools. This paper shows that both tools have advantages in terms of trainee motivation and knowledge acquisition. Furthermore, they can be used in a complementary way, reinforcing the acquired knowledge.

Using the TRAILER tool for managing informal learning in academic and professional contexts: the learner perspective

Informal Learning plays an important role in everyone's life and yet we often are unaware of it. The need to keep track of the knowledge acquired through informal learning is increasing as its sources become increasingly diverse. This paper presents a study on a tool developed to help keeping track of learners' informal learning, both within academic and professional contexts, This tool, developed within the European Commission funded TRAILER project, will further integrate the improvements suggested by users during the piloting phase. The two studied contexts were similar regarding the importance and perception of Informal Learning, but differed concerning tool usage. The overall idea of managing one's informal learning was well accepted and welcomed, which validated the emerging need for a tool with this purpose.

Managing Informal Learning in professional contexts: the learner’s perspective

Informal Learning is present in everyone's life but its awareness only recently has been reported. The need to keep track of the knowledge acquired this way is increasing as its sources diversity also increases. This work presents the pilots trials on the use of a tool developed to help keeping track of the learners’ informal learning, within a number of companies spread out in three countries. This tool developed through the European Commission funded project TRAILER, is still under development, which will allow integrating the set of improving suggestions obtained from users during the piloting phase. The overall idea of managing one’s informal learning was well accepted and welcomed, which validated the emerging need for a tool with this purpose.

Aplicação de metodologias Lean ao fabrico de elevadores

Num mercado cada vez mais competitivo, torna-se fundamental para as empresas produzirem mais com menos recursos, aumentando a eficiência interna, através da otimização dos seus processos. Neste contexto aparece o Lean Manufacturing, metodologia que tem como objetivo criar valor para os stakeholders, através da eliminação de desperdício na cadeia de valor. Este projeto descreve a análise e a formulação de soluções do processo de produção de um Módulo de Serviço, produto que faz parte do sistema elétrico de um elevador. Para análise do problema utilizamos técnicas e ferramentas lean, tais como, o value stream mapping (VSM), o diagrama de processo e o diagrama de spaghetti. Para formulação do problema usamos o value stream design (VSD), a metodologia 5S, o sistema Kanban e a criação de fluxo contínuo, através do conceito takt time, do sistema Pull, da definição do processo pacemaker, da programação nivelada (Heijunka), do conceito pitch time e da caixa de nivelamento (Heijunka Box). Com este projeto pretendemos demonstrar que a implementação de um fluxo unitário de peças através da filosofia Lean Manufacturing, acrescenta qualidade ao produto, cria flexibilidade, aumenta a produtividade, liberta áreas de produção, aumenta a segurança, reduz o custo com o stock e aumenta a motivação organizacional.

Modelização de equivalente eléctrico para rede de nervuras de folhas vegetais

A tese tem como objectivo principal a criação de um modelo equivalente eléctrico da rede de nervuras de algumas folhas vegetais e analisar o seu comportamento a estímulos eléctricos, analisando-se também a respectiva resposta em frequência. A motivação desta tese passa pela observação dos sistemas existentes na natureza. Neste caso, as folhas vegetais e analisar se são sistemas de ordem fraccionária ou não. Para a sua elaboração, fez-se uma breve abordagem à estrutura das plantas, sob o ponto de vista da botânica e elaborou-se um método de fotografia das amostras, mapeamento da rede de nervuras e medição dos segmentos que compõem essa mesma rede. A tese termina com um capítulo de resultados experimentais.

Validação do questionário de desenvolvimento emocional em adultos – QDE_A

O tema da inteligência emocional tem vindo a ganhar protagonismo no plano pessoal, organizacional e societário. A emocionalidade e a racionalidade devem ser ambas consideradas e valorizadas de forma equilibrada. Este estudo teve como amostra 507 enfermeiros a trabalhar em organizações do ramo da saúde. Estes profissionais têm uma tarefa complexa, uma vez que lidam diariamente com pessoas, que devido à sua situação de saúde fragilizada, estão mais vulneráveis e com o seu estado emocional mais alterado, o que remete para a necessidade de avaliar o desenvolvimento emocional dos mesmos. Definimos como objetivo geral contribuir para um maior conhecimento empírico sobre o desenvolvimento emocional em adultos. Os objetivos específicos são: a tradução e validação do questionário de desenvolvimento emocional em adultos (QDE_A) de Pérez-Escoda, Bisquerra, Filella e Soldevila (2010), adaptado à situação portuguesa, em enfermeiros; e a avaliação do desenvolvimento emocional dos mesmos. No que respeita à metodologia, o estudo é de carácter quantitativo, descritivo, exploratório e inferencial. Numa amostra de 507 enfermeiros, de duas regiões com caraterísticas socioeconómicas distintas, foi aplicado o QDE_A.A validação do mesmo foi concretizada através de uma análise fatorial exploratória e de uma análise fatorial confirmatória (CFA). Como objetivado foi conseguida a validação do QDE_A, tendo sido obtido um modelo constituído por cinco dimensões do desenvolvimento emocional, muito aproximado ao modelo proposto por Goleman (1995), sendo, assim, possível a sua utilização em investigações futuras e em intervenções na área da gestão dos recursos humanos e coaching. Relativamente ao objetivo de estudo, sobre o desenvolvimento emocional dos enfermeiros, verificámos que estes possuem níveis médios a elevados de desenvolvimento emocional global e que, dentro das dimensões, a auto motivação e a gestão das emoções são as mais evidenciadas, tendo em vista o incremento do desenvolvimento da inteligência emocional destes profissionais.

Integration of e-learning systems with repositories of learning objects

This paper describes a communication model to integrate repositories of programming problems with other e-Learning software components. The motivation for this work comes from the EduJudge project that aims to connect an existing repository of programming problems to learning management systems. When trying to use the existing repositories of learning objects we realized that they are mainly specialized search engines and lack features for integration with other e-Learning systems. With this model we intend to clarify the main features of a programming problem repository, in order to enable the design and development of software components that use it. The two main points of this model are the definition of programming problems as learning objects and the definition of the core functions exposed by the repository. In both cases, this model follows the existing specifications of the IMS standard and proposes extensions to deal with the special requirements of automatic evaluation and grading of programming exercises. In the definition of programming problems as learning objects we introduced a new schema for meta-data. This schema is used to represent meta-data related to automatic evaluation that cannot be conveniently represented using the standard: the type of automatic evaluation; the requirements of the evaluation engine; or the roles of different assets - tests cases, program solutions, etc. In the definition of the core functions we used two different web services flavours - SOAP and REST - and described each function as an operation for each type of interface. We describe also the data types of the arguments of each operation. These data types consist mainly on learning objects and their identifications, but include also usage reports and queries using XQuery.