Online intra-task device scheduling for hard real-time systems

A large part of power dissipation in a system is generated by I/O devices. Increasingly these devices provide power saving mechanisms, inter alia to enhance battery life. While I/O device scheduling has been studied in the past for realtime systems, the use of energy resources by these scheduling algorithms may be improved. These approaches are crafted considering a very large overhead of device transitions. Technology enhancements have allowed the hardware vendors to reduce the device transition overhead and energy consumption. We propose an intra-task device scheduling algorithm for real time systems that allows to shut-down devices while ensuring system schedulability. Our results show an energy gain of up to 90% when compared to the techniques proposed in the state-of-the-art.

A preliminary idea for an 8-competitive, log2 DMAX + log2 log2 1/U asymptotic-space, interface generation algorithm for two-level hierarchical scheduling of constrained-deadline sporadic tasks on a uniprocessor

Consider a single processor and a software system. The software system comprises components and interfaces where each component has an associated interface and each component comprises a set of constrained-deadline sporadic tasks. A scheduling algorithm (called global scheduler) determines at each instant which component is active. The active component uses another scheduling algorithm (called local scheduler) to determine which task is selected for execution on the processor. The interface of a component makes certain information about a component visible to other components; the interfaces of all components are used for schedulability analysis. We address the problem of generating an interface for a component based on the tasks inside the component. We desire to (i) incur only a small loss in schedulability analysis due to the interface and (ii) ensure that the amount of space (counted in bits) of the interface is small; this is because such an interface hides as much details of the component as possible. We present an algorithm for generating such an interface.

JamLab: augmenting sensornet testbeds with realistic and controlled interference generation

Radio interference drastically affects the performance of sensor-net communications, leading to packet loss and reduced energy-efficiency. As an increasing number of wireless devices operates on the same ISM frequencies, there is a strong need for understanding and debugging the performance of existing sensornet protocols under interference. Doing so requires a low-cost flexible testbed infrastructure that allows the repeatable generation of a wide range of interference patterns. Unfortunately, to date, existing sensornet testbeds lack such capabilities, and do not permit to study easily the coexistence problems between devices sharing the same frequencies. This paper addresses the current lack of such an infrastructure by using off-the-shelf sensor motes to record and playback interference patterns as well as to generate customizable and repeat-able interference in real-time. We propose and develop JamLab: a low-cost infrastructure to augment existing sensornet testbeds with accurate interference generation while limiting the overhead to a simple upload of the appropriate software. We explain how we tackle the hardware limitations and get an accurate measurement and regeneration of interference, and we experimentally evaluate the accuracy of JamLab with respect to time, space, and intensity. We further use JamLab to characterize the impact of interference on sensornet MAC protocols.

Online robust optimization framework for QoS guarantees in distributed soft real-time systems

In distributed soft real-time systems, maximizing the aggregate quality-of-service (QoS) is a typical system-wide goal, and addressing the problem through distributed optimization is challenging. Subtasks are subject to unpredictable failures in many practical environments, and this makes the problem much harder. In this paper, we present a robust optimization framework for maximizing the aggregate QoS in the presence of random failures. We introduce the notion of K-failure to bound the effect of random failures on schedulability. Using this notion we define the concept of K-robustness that quantifies the degree of robustness on QoS guarantee in a probabilistic sense. The parameter K helps to tradeoff achievable QoS versus robustness. The proposed robust framework produces optimal solutions through distributed computations on the basis of Lagrangian duality, and we present some implementation techniques. Our simulation results show that the proposed framework can probabilistically guarantee sub-optimal QoS which remains feasible even in the presence of random failures.

REXIB: Remote Experiments Interface Builder

Remote Experimentation is an educational resource that allows teachers to strengthen the practical contents of science & engineering courses. However, building up the interfaces to remote experiments is not a trivial task. Although teachers normally master the practical contents addressed by a particular remote experiment they usually lack the programming skills required to quickly build up the corresponding web interface. This paper describes the automatic generation of experiment interfaces through a web-accessible Java application. The application displays a list of existent modules and once the requested modules have been selected, it generates the code that enables the browser to display the experiment interface. The tools? main advantage is enabling non-tech teachers to create their own remote experiments.

Using test infrastructures for (remote) online evaluation of the sensitivity to SEUs of FPGAs

This paper proposes an online mechanism that can evaluate the sensitivity of single event upsets (SEUs) of field programmable gate arrays (FPGAs). The online detection mechanism cyclically reads and compares the values form the external and internal configuration memories, taking into account the mask information. This remote detection method also signals any mismatch as a result of a SEU that affects both used and not-used FPGA parts, which maximizes the monitored area. By utilizing an external, Web-accessible controller that is connected to the test infrastructure, the possibility of running the same operation in a remote manner is enabled. Moreover, the need for a local memory to store the mask values is also eliminated.

Quantity-setting competition with differentiated goods under uncertain demand

We consider a quantity-setting duopoly model, and we study the decision to move first or second, by assuming that the firms produce differentiated goods and that there is some demand uncertainty. The competitive phase consists of two periods, and in either period, the firms can make a production decision that is irreversible. As far as the firms are allowed to choose (non-cooperatively) the period they make the decision, we study the circumstances that favour sequential rather than simultaneous decisions.

Privatization and entry of a foreign firm with demand uncertainty

We investigate the effects of trade with a foreign firm and privatization of the domestic pubUc firm on an incentive for the domestic firm to reduce costs by undertaking R&D investment, under demand uncertainty. We suppose that the domestic firm is less efficient than the foreign firm. However, the domestic firm can lower its marginal costs by conducting cost-reducing R&D investment. We examine the impacts of entry of a foreign firm, and the effects of demand uncertainty, on decisions upon cost-reducing R&D investment by the domestic firm and how these affect the domestic welfare.

A flexible online apparatus for projectile launch experiments

In order to provide a more flexible learning environment in physics, the developed projectile launch apparatus enables students to determine the acceleration of gravity and the dependence of a set of parameters in the projectile movement. This apparatus is remotely operated and accessed via web, by first scheduling an access time slot. This machine has a number of configuration parameters that support different learning scenarios with different complexities.

A new horizon for online teaching and learning

The Polytechnic Institute of Oporto (IPP), which has a solid history of online education and innovation through the use of technology, has been particularly interested and focused on Massive Open Online Courses (MOOC) developments. The aim of this paper is to present the whole process from initial discussions to completion of the “Mathematics Without Limits” MOOC Project that exists in IPP and also to contribute for a change in the way as teaching and learning Mathematics is seen and practiced nowadays. In 2013, IPP developed its own platform, which gave us the opportunity to explore new educational techniques as a pedagogical resource as well as to enhance students’ motivation, through a set of interactive materials at their disposal, totally adapted to their needs. Students lack of motivation is mainly justified by their weak Math preparation, poor consolidated basis on the subject and different backgrounds of the students. To tackle this issue and based on our Math online courses teaching experience, we decided to create short duration MOOC, expecting to aid retention of students and also to reverse the path of students giving up on Math by giving them a friendly way of managing their own learning commitment. We also think that this MOOC will be a good approach to level out some math skills among freshmen.

A new horizon for online teaching and learning

The Polytechnic Institute of Oporto (IPP), which has a solid history of online education and innovation through the use of technology, has been particularly interested and focused on Massive Open Online Courses (MOOC) developments. The aim of this paper is to present the whole process from initial discussions to completion of the “Mathematics Without Limits” MOOC Project that exists in IPP and also to contribute for a change in the way as teaching and learning Mathematics is seen and practiced nowadays. In 2013, IPP developed its own platform, which gave us the opportunity to explore new educational techniques as a pedagogical resource as well as to enhance students’ motivation, through a set of interactive materials at their disposal, totally adapted to their needs. Students lack of motivation is mainly justified by their weak Math preparation, poor consolidated basis on the subject and different backgrounds of the students. To tackle this issue and based on our Math online courses teaching experience, we decided to create short duration MOOC, expecting to aid retention of students and also to reverse the path of students giving up on Math by giving them a friendly way of managing their own learning commitment. We also think that this MOOC will be a good approach to level out some math skills among freshmen.

A New horizon for online teaching and learning

The Polytechnic Institute of Oporto (IPP), which has a solid history of online education and innovation through the use of technology, has been particularly interested and focused on Massive Open Online Courses (MOOC) developments. The aim of this paper is to present the whole process from initial discussions to completion of the “Mathematics Without Limits” MOOC Project that exists in IPP and also to contribute for a change in the way as teaching and learning Mathematics is seen and practiced nowadays. In 2013, IPP developed its own platform, which gave us the opportunity to explore new educational techniques as a pedagogical resource as well as to enhance students’ motivation, through a set of interactive materials at their disposal, totally adapted to their needs. Students lack of motivation is mainly justified by their weak Math preparation, poor consolidated basis on the subject and different backgrounds of the students. To tackle this issue and based on our Math online courses teaching experience, we decided to create short duration MOOC, expecting to aid retention of students and also to reverse the path of students giving up on Math by giving them a friendly way of managing their own learning commitment. We also think that this MOOC will be a good approach to level out some math skills among freshmen.

Web marketing: desenvolvimento de uma presença online para uma unidade hoteleira – Projeto Oporto Invictus Hostel

O hotel, para muitos autores, tem como função oferecer abrigo para quem está distante da sua casa e atender às suas necessidades básicas. A hotelaria tem como função básica alojar as pessoas que estão longe da sua residência e que precisam de um quarto com uma cama para dormir e uma casa de banho (Duarte, 1996). Para Beni (2003), um hotel, além de ter a função básica de alojar, tem uma característica que nenhum outro estabelecimento comercial possui, que é o facto de o consumidor se deslocar até ao hotel para poder utilizar os serviços disponíveis. Outra característica muito especifica da atividade hoteleira, é o facto de o atendimento ser o mais importante na hora da prestação do serviço. O Hostel é uma designação muito usada atualmente como sinónimo de albergue. É um tipo de unidade hoteleira que se caracteriza pelos preços convidativos e pela possibilidade de socialização dos hóspedes, onde cada hóspede pode arrendar uma cama ou beliche, num dormitório partilhado, com casa de banho, lavandaria e, por vezes, cozinha, também em regime partilhado. Os Hostels são geralmente económicos praticando preços intitulados low-­‐cost. Definir uma estratégia para a Internet é hoje um imperativo para qualquer organização que pretenda utilizar este canal de comunicação para promover a sua atividade. As unidades hoteleiras também não são exceção; a necessidade de comunicar com os públicos alvo no sentido de aumentarem a captação de turistas exige uma presença na Internet que consiga simultaneamente informar e motivar à escolha pelos serviços prestados. A Internet evidencia um incontornável potencial informativo e comunicativo em questões de rapidez de circulação: número de pessoas que atinge e áreas geográficas que abarca; e devido às suas características de imaterialidade, instantaneidade e multimédia, democratiza o acesso à informação e a determinados tipos de bens, facilita a comunicação entre pessoas e instituições e universaliza as oportunidades, eliminando as barreiras espaciais, geográficas e temporais (Balsa, 2007). Rapidamente as unidades hoteleiras se aperceberam das vantagens e potencialidades da Internet: rápida, imediata, económica, integrada no dia-­‐a-­‐dia de trabalho e lazer e acessível a um cada vez maior número de pessoas. A nível geral, mas com especial incidência no caso das unidades hoteleiras, a Internet apresenta inúmeras vantagens ao nível da estruturação da informação em bases de dados e da sua apresentação dinâmica, tirando partido da inclusão de objetos multimédia em páginas HTML. Os objetos multimédia podem incluir áudio, vídeo,animações em tecnologia Flash e mesmo animações 3D tornando a visita a um sítio Web com este tipo de conteúdos, uma experiência muito gratificante. Por sua vez, a interatividade, característica do próprio funcionamento das páginas Web, facilita a interação entre a unidade hoteleira e o visitante. A interatividade permite ou facilita uma relação ativa entre o utilizador e o hotel. O utilizador passa de espectador passivo a interveniente ativo no processo de consulta da informação. Na web, os avanços tecnológicos têm sido constantes. Em 1980, Alvin Toffler’s no seu bestseller ‘The Third Wave’ previu um novo tipo de consumidor a quem chamou de ‘prosumer’ e que seria um misto de DIY (do-­it-­yourself) produtor e consumidor em mercados offline (Toffler, 1980). Foi sem dúvida de uma grande visão, mas sem os recentes avanços na web e nas tecnologias digitais, a maioria dos utilizadores não poderia ter dado o salto de espectador passivo para ator que participa ativamente na construção da web (Shuen, 2008). O aparecimento das redes sociais que permitem criar comunidades com interesses afins, o desenvolvimento de plataformas como o Youtube.com para a partilha de vídeos, a vulgarização de plataformas como o flickr.com para a partilha de imagens constituíram marcos determinantes para aquilo a que se designa por WEB 2.0 (tecnologia do século XXI). Enquanto no tempo da WEB 1.0 (tecnologia dos anos 90) os sites eram essencialmente estáticos e a interatividade não era levada aos limites, agora com a WEB 2.0 é possível construir modelos de negócio com conteúdos mais ricos simulando, com muito maior realismo, em ambientes virtuais, o que se passa em ambientes reais. Os sítios Web das unidades hoteleiras estão a evoluir rapidamente para um modelo que contemple as potencialidades da WEB 2.0 Tendo em consideração a importância das unidades hoteleiras no panorama do turismo, a relevância da Internet como meio de comunicação entre as instituições e os cidadãos e a necessidade das unidades hoteleiras disporem de uma estratégia de comunicação digital para difundir as suas valências e atividades, entendemos justificar-­se fazer uma revisão da literatura onde: procuraremos compreender a importância do turismo na sociedade atual assim como, o impacto das novas tecnologias da informação em atividades relacionadas com o turismo e ainda, procuraremos perceber quais os canais de comunicação digital que estão ao dispor dos profissionais de turismo, nomeadamente os gestores de unidades hoteleiras, para promover os seus serviços. O objetivo principal deste trabalho consiste em mostrar como foi desenvolvido uma estratégia de comunicação digital para promover online uma unidade hoteleira low cost, no caso presente o Oporto Invictus Hostel. Trata­‐se de um projeto integrado em que não só se criaram as diferentes peças de comunicação como se definiu e aplicou uma estratégia promocional com vista à divulgação do Hostel. O projeto apresentado evidencia como é possível, com recursos limitados, criar um sistema integrado de comunicação digital online que promova uma pequena unidade hoteleira, de forma a dar-­‐lhe visibilidade tanto a nível nacional como internacional. O projeto está dividido em cinco partes. Numa primeira parte é feita a apresentação do briefing que resultou de uma primeira reunião com o cliente. Numa segunda parte apresenta­‐se a fase de planeamento relativa ao desenvolvimento do projeto. Numa terceira parte descreve-­se o processo de implementação do projeto. Na quarta fase abordam-se os testes funcionais e na quinta e última fase faz-­se referencia a aspetos relacionados com a conclusão do projeto.

Personalisation of Networked Video

Following targeted advertising and product placement, TV and online media needs more personalised methods of engaging viewers by integrating advertising and informational messages into playout content, whether real-time broadcast or on-demand. Future advertising solutions need adaptivity to individuals or on-line groups to respond to the commercial requirements of clients and agencies.

Personalised placement in networked video

Personalised video can be achieved by inserting objects into a video play-out according to the viewer's profile. Content which has been authored and produced for general broadcast can take on additional commercial service features when personalised either for individual viewers or for groups of viewers participating in entertainment, training, gaming or informational activities. Although several scenarios and use-cases can be envisaged, we are focussed on the application of personalised product placement. Targeted advertising and product placement are currently garnering intense interest in the commercial networked media industries. Personalisation of product placement is a relevant and timely service for next generation online marketing and advertising and for many other revenue generating interactive services. This paper discusses the acquisition and insertion of media objects into a TV video play-out stream where the objects are determined by the profile of the viewer. The technology is based on MPEG-4 standards using object based video and MPEG-7 for metadata. No proprietary technology or protocol is proposed. To trade the objects into the video play-out, a Software-as-a-Service brokerage platform based on intelligent agent technology is adopted. Agencies, libraries and service providers are represented in a commercial negotiation to facilitate the contractual selection and usage of objects to be inserted into the video play-out.