Abstract

Abstract
Students today lack the real experiences needed to make sense of complex technical concepts although industry is one of the primary customers that constantly challenges academia to make curricula more relevant to professional practice. Our response to these influences was to create and test idea of Distributed and Remote Lab dedicated to active learning. In this survey, the experiments on representational fidelity measures are erformed on two types of "client" user interface (Wall and Window) in two modes of presentation (Desktop and Video beam) of the distributed manufacturing system. The proposed remote system has allowed students from Belgrade, Serbia to dynamically interact with a real manufacturing process held in Minho's Lab, Portugal, to carry out a remote experimental practice. This survey gives advantage to Wall interface, in the fields of smooth display of view changes and object motion and consistency of object behaviour. There are also weaker correlations between representational fidelity measures when Wall interface is used and certain advantage on desktop presentation mode. © Faculty of Mechanical Engineering, Belgrade.

Abstract
This paper studies the dynamic price competition between two firms that sell horizontally differentiated durable goods and, subsequently, provide exclusive complementary goods and services to their customers. The paper analyzes how optimal pricing strategies are affected by the existence of network effects associated with the size of firms' consumer base. The interaction is thoroughly analyzed as a continuous time linear-quadratic differential game. We provide a necessary and sufficient condition for the existence of a unique duopoly equilibrium in affine strategies. When this condition holds, we show that optimal pricing strategies crucially depend on the nature of the network effects.

Abstract
Purpose: The paper aims to analyse the engagement in sustainability reporting assurance (SRA) by a sample of Portuguese firms between 2008 and 2011. Design/methodology/approach: Bivariate and multivariate non-parametric statistics is used to analyse some factors that influence the decision to have sustainability reports assured. Findings: Results indicate that size, leverage, profitability, listing status and industrial affiliation are determinants of SRA, whereas type of ownership is not. A downward trend in sustainability reporting and its assurance was also detected. Research limitations/implications: The sample is small. Originality/value: It adds to the scarce research on SRA by providing new empirical data in a context of crisis and extends prior research by analysing the effects of listing status and type of ownership. © Emerald Group Publishing Limited.

Abstract
Underwater wireless communication systems are becoming a priority in terms of research and technological development due to the increasing demand for exploring the oceans in areas such as pharmaceutical, oil, minerals, environmental and biodiversity. This demand is increasing exponentially with the need for high data rate and near-real-time communications. In this work an underwater low power acoustic modem to operate over tens of meters, achieving a maximum data rate of 1 Mbps, is presented. This solution allows for reprogramming the digital signal processing block enabling the use of different types of digital modulations in order to improve the modem's performance. The system is based on a poly(vinylidene fluoride) PVDF ultrasonic emitter transducer which is capable of sending high quality signals needed for digital modulations with high symbol rates per carrier period. BPSK, BFSK and OOK modulations have been tested. The results registered were 3x10(-3) BER with 1 Mbps OOK, 2.3x10-5 with 512 kbps and 1x10-8 with 256 kbps.

Abstract
In the Smart Grid environment, it is expected that Home Energy Management Systems (HEMS) should be capable of managing appliances inside the house, in order to provide reserve services. This paper aims at estimating the flexibility of a Portuguese typical residential load diagram. For this purpose, a bottom-up approach is used, i.e., the aggregated flexible load demand is determined taking into account the availability of each appliance to be controlled by the HEMS. The comfort requirements of the consumers are also incorporated in the flexibility calculations by integrating realistic load models into HEMS.