Demsi - a demand response simulator in the context of intensive use of distributed generation

Demand response can play a very relevant role in future power systems in which distributed generation can help to assure service continuity in some fault situations. This paper deals with the demand response concept and discusses its use in the context of competitive electricity markets and intensive use of distributed generation. The paper presents DemSi, a demand response simulator that allows studying demand response actions and schemes using a realistic network simulation based on PSCAD. Demand response opportunities are used in an optimized way considering flexible contracts between consumers and suppliers. A case study evidences the advantages of using flexible contracts and optimizing the available generation when there is a lack of supply.

A probabilistic methodology for distributed generation location in isolated electrical service area

Distributed generation unlike centralized electrical generation aims to generate electrical energy on small scale as near as possible to load centers, interchanging electric power with the network. This work presents a probabilistic methodology conceived to assist the electric system planning engineers in the selection of the distributed generation location, taking into account the hourly load changes or the daily load cycle. The hourly load centers, for each of the different hourly load scenarios, are calculated deterministically. These location points, properly weighted according to their load magnitude, are used to calculate the best fit probability distribution. This distribution is used to determine the maximum likelihood perimeter of the area where each source distributed generation point should preferably be located by the planning engineers. This takes into account, for example, the availability and the cost of the land lots, which are factors of special relevance in urban areas, as well as several obstacles important for the final selection of the candidates of the distributed generation points. The proposed methodology has been applied to a real case, assuming three different bivariate probability distributions: the Gaussian distribution, a bivariate version of Freund’s exponential distribution and the Weibull probability distribution. The methodology algorithm has been programmed in MATLAB. Results are presented and discussed for the application of the methodology to a realistic case and demonstrate the ability of the proposed methodology for efficiently handling the determination of the best location of the distributed generation and their corresponding distribution networks.

Self-optimizing through CBR learning

In this paper, we foresee the use of Multi-Agent Systems for supporting dynamic and distributed scheduling in Manufacturing Systems. We also envisage the use of Autonomic properties in order to reduce the complexity of managing systems and human interference. By combining Multi-Agent Systems, Autonomic Computing, and Nature Inspired Techniques we propose an approach for the resolution of dynamic scheduling problem, with Case-based Reasoning Learning capabilities. The objective is to permit a system to be able to automatically adopt/select a Meta-heuristic and respective parameterization considering scheduling characteristics. From the comparison of the obtained results with previous results, we conclude about the benefits of its use.

Self-managing agents for dynamic scheduling in manufacturing

The main purpose of this paper is to propose a Multi-Agent Autonomic and Bio-Inspired based framework with selfmanaging capabilities to solve complex scheduling problems using cooperative negotiation. Scheduling resolution requires the intervention of highly skilled human problem-solvers. This is a very hard and challenging domain because current systems are becoming more and more complex, distributed, interconnected and subject to rapidly changing. A natural Autonomic Computing (AC) evolution in relation to Current Computing is to provide systems with Self-Managing ability with a minimum human interference.

Computação em nuvem: avaliação do retorno do investimento: o caso do Ensino Superior Português

Em Portugal, as instituições de ensino superior dispõem de plataformas de e-learning que reflectem uma mais-valia para o processo de ensino-aprendizagem. No entanto, estas plataformas caracterizam-se por serem de âmbito privado expondo, desta forma, a tímida abertura das instituições na partilha do seu conhecimento, como também dos seus recursos. O paradigma Cloud Computing surge como uma solução, por exemplo, para a criação de uma federação de nuvens capaz de contemplar soluções heterogéneas, garantindo a interoperabilidade entre as plataformas das várias instituições de ensino, e promovendo os objectivos propostos pelo Processo de Bolonha, nomeadamente no que se refere à partilha de informação, de plataformas e serviços e promoção de projectos comuns. Neste âmbito, é necessário desenvolver ferramentas que permitam aos decisores ponderar as mais-valias deste novo paradigma. Assim, é conveniente quantificar o retorno esperado para o investimento, em recursos humanos e tecnológicos, exigido pelo modelo Cloud Computing. Este trabalho contribui para o estudo da avaliação do retorno do investimento (ROI) em infra-estruturas e serviços TIC (Tecnologias de Informação e Comunicação), resultante da análise de diferentes cenários relativos à introdução do paradigma Cloud Computing. Para tal, foi proposta uma metodologia de análise baseada num questionário, distribuído por diversas instituições de ensino superior portuguesas, contendo um conjunto de questões que permitiram identificar indicadores, e respectivas métricas, a usar na elaboração de modelos de estimação do ROI.

Private cloud computing platforms. Analysis and implementation in a Higher Education Institution

The constant evolution of the Internet and its increasing use and subsequent entailing to private and public activities, resulting in a strong impact on their survival, originates an emerging technology. Through cloud computing, it is possible to abstract users from the lower layers to the business, focusing only on what is most important to manage and with the advantage of being able to grow (or degrades) resources as needed. The paradigm of cloud arises from the necessity of optimization of IT resources evolving in an emergent and rapidly expanding and technology. In this regard, after a study of the most common cloud platforms and the tactic of the current implementation of the technologies applied at the Institute of Biomedical Sciences of Abel Salazar and Faculty of Pharmacy of Oporto University a proposed evolution is suggested in order adorn certain requirements in the context of cloud computing.

Suporte à computação paralela e distribuída em Java: API e comunicação entre nós cooperantes

Este trabalho é uma parte do tema global “Suporte à Computação Paralela e Distribuída em Java”, também tema da tese de Daniel Barciela no mestrado de Engenharia Informática do Instituto Superior de Engenharia do Porto. O seu objetivo principal consiste na definição/criação da interface com o programador, assim como também abrange a forma como os nós comunicam e cooperam entre si para a execução de determinadas tarefas, de modo a atingirem um único objetivo global. No âmbito desta dissertação foi realizado um estudo prévio relativamente aos modelos teóricos referentes à computação paralela, assim como também foram analisadas linguagens e frameworks que fornecem suporte a este mesmo tipo de computação. Este estudo teve como principal objetivo a análise da forma como estes modelos e linguagens permitem ao programador expressar o processamento paralelo no desenvolvimento das aplicações. Como resultado desta dissertação surgiu a framework denominada Distributed Parallel Framework for Java (DPF4j), cujo objetivo principal é fornecer aos programadores o suporte para o desenvolvimento de aplicações paralelas e distribuídas. Esta framework foi desenvolvida na linguagem Java. Esta dissertação contempla a parte referente à interface de programação e a toda a comunicação entre nós cooperantes da framework DPF4j. Por fim, foi demonstrado através dos testes realizados que a DPF4j, apesar de ser ainda um protótipo, já demonstra ter uma performance superior a outras frameworks e linguagens que possuem os mesmos objetivos.

Cloud computing sobre a plataforma Windows Azure

A utilização massiva da internet e dos serviços que oferece por parte do utilizador final potencia a evolução dos mesmos, motivando as empresas a apostarem no desenvolvimento deste tipo de soluções. Requisitos como o poder de computação, flexibilidade e escalabilidade tornam-se cada vez mais indissociáveis do desenvolvimento aplicacional, o que leva ao surgimento de paradigmas como o de Cloud Computing. É neste âmbito que surge o presente trabalho. Com o objetivo de estudar o paradigma de Cloud Computing inicia-se um estudo sobre esta temática, onde é detalhado o seu conceito, a sua evolução histórica e comparados os diferentes tipos de implementações que suporta. O estudo detalha posteriormente a plataforma Azure, sendo analisada a sua topologia e arquitetura, detalhando-se os seus componentes e a forma como esta mitiga alguns dos problemas mencionados. Com o conhecimento teórico é desenvolvido um protótipo prático sobre esta plataforma, em que se exploram algumas das particularidades da topologia e se interage com as principais redes sociais. O estudo culmina com uma análise sobre os benefícios e desvantagens do Azure e através de um levantamento das necessidades da empresa, determinam-se as oportunidades que a utilização da plataforma poderá proporcionar.

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.

A study on security grade assignment model for mobile users in urban computing

The relation between the information/knowledge expression and the physical expression can be involved as one of items for an ambient intelligent computing [2],[3]. Moreover, because there are so many contexts around user/spaces during a user movement, all appplcation which are using AmI for users are based on the relation between user devices and environments. In these situations, it is possible that the AmI may output the wrong result from unreliable contexts by attackers. Recently, establishing a server have been utilizes, so finding secure contexts and make contexts of higher security level for save communication have been given importance. Attackers try to put their devices on the expected path of all users in order to obtain users informationillegally or they may try to broadcast their SPAMS to users. This paper is an extensionof [11] which studies the Security Grade Assignment Model (SGAM) to set Cyber-Society Organization (CSO).

Application-specific modified particle swarm optimization for energy resource scheduling considering vehicle-to-grid

This paper presents a modified Particle Swarm Optimization (PSO) methodology to solve the problem of energy resources management with high penetration of distributed generation and Electric Vehicles (EVs) with gridable capability (V2G). The objective of the day-ahead scheduling problem in this work is to minimize operation costs, namely energy costs, regarding he management of these resources in the smart grid context. The modifications applied to the PSO aimed to improve its adequacy to solve the mentioned problem. The proposed Application Specific Modified Particle Swarm Optimization (ASMPSO) includes an intelligent mechanism to adjust velocity limits during the search process, as well as self-parameterization of PSO parameters making it more user-independent. It presents better robustness and convergence characteristics compared with the tested PSO variants as well as better constraint handling. This enables its use for addressing real world large-scale problems in much shorter times than the deterministic methods, providing system operators with adequate decision support and achieving efficient resource scheduling, even when a significant number of alternative scenarios should be considered. The paper includes two realistic case studies with different penetration of gridable vehicles (1000 and 2000). The proposed methodology is about 2600 times faster than Mixed-Integer Non-Linear Programming (MINLP) reference technique, reducing the time required from 25 h to 36 s for the scenario with 2000 vehicles, with about one percent of difference in the objective function cost value.

Distributed active traction control system applied to the RoboCup middle size league

This work addresses the problem of traction control in mobile wheeled robots in the particular case of the RoboCup Middle Size League (MSL). The slip control problem is formulated using simple friction models for ISePorto Team robots with a differential wheel configuration. Traction was also characterized experimentally in the MSL scenario for relevant game events. This work proposes a hierarchical traction control architecture which relies in local slip detection and control at each wheel, with relevant information being relayed to a higher level responsible for global robot motion control. A dedicated one axis control embedded hardware subsystem allowing complex local control, high frequency current sensing and odometric information procession was developed. This local axis control board is integrated in a distributed system using CAN bus communications. The slipping observer was implemented in the axis control hardware nodes integrated in the ISePorto robots and was used to control and detect loss of for traction. %and to detect the ball in the kicking device. An external vision system was used to perform a qualitative analysis of the slip detection and observer performance results are presented.

A framework for realistic real-time walkthroughs in a VR distributed environment

Virtual and augmented reality (VR/AR) are increasingly being used in various business scenarios and are important driving forces in technology development. However the usage of these technologies in the home environment is restricted due to several factors including lack of low-cost (from the client point of view) highperformance solutions. In this paper we present a general client/server rendering architecture based on Real-Time concepts, including support for a wide range of client platforms and applications. The idea of focusing on the real-time behaviour of all components involved in distributed IP-based VR scenarios is new and has not been addressed before, except for simple sub-solutions. This is considered as “the most significant problem with the IP environment” [1]. Thus, the most important contribution of this research will be the holistic approach, in which networking, end-systems and rendering aspects are integrated into a cost-effective infrastructure for building distributed real-time VR applications on IP-based networks.

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.

Setting target rotation time in PROFIBUS based real-time distributed applications

In this paper, we analyse the ability of Profibus fieldbus to cope with the real-time requirements of a Distributed Computer Control System (DCCS), where messages associated to discrete events must be made available within a maximum bound time. Our methodology is based on the knowledge of real-time traffic characteristics, setting the network parameters in order to cope with timing requirements. Since non-real-time traffic characteristics are usually unknown at the design stage, we consider an operational profile where, constraining non-real-time traffic at the application level, we assure that realtime requirements are met.