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Publications

2017

2D computational modeling of optical trapping effects on malaria-infected red blood cells

Authors
Paiva, JS; Ribeiro, RSR; Jorge, PAS; Rosa, CC; Guerreiro, A; Cunha, JPS;

Publication
Optics InfoBase Conference Papers

Abstract
A computational method for optical fiber trapping of healthy and Malariainfected blood cells characterization is proposed. A trapping force relation with the infection stage was found, which could trigger the development of a diagnostic sensor. © OSA 2017.

2017

Towards Decentralized Conformance Checking in Model-Based Testing of Distributed Systems

Authors
Lima, BMC; Faria, JCP;

Publication
Proceedings - 10th IEEE International Conference on Software Testing, Verification and Validation Workshops, ICSTW 2017

Abstract
In a growing number of domains, the provisioning of end-to-end services to the users depends on the proper interoperation of multiple products, forming a new distributed system. To ensure interoperability and the integrity of this new distributed system, it is important to conduct integration tests that verify not only the interactions with the environment but also the interactions between the system components. Integration test scenarios for that purpose may be conveniently specified by means of UML sequence diagrams, possibly allowing multiple execution paths. The automation of such integration tests requires that test components are also distributed, with a local tester deployed close to each system component, and a central tester coordinating the local testers. In such a test architecture, it is important to minimize the communication overhead during test execution. Hence, in this paper we investigate conditions upon which conformance errors can be detected locally (local observability) and test inputs can be decided locally (local controllability) by the local testers, without the need for exchanging coordination messages between the test components during test execution. The conditions are specified in a formal specification language that allows executing and validating the specification. Examples of test scenarios are also presented, illustrating local observability and controllability problems associated with optional messages without corresponding acknowledgment messages, races and non-local choices. © 2017 IEEE.

2017

Two alternative robust optimization models for flexible power management of electric vehicles in distribution networks

Authors
Pirouzi, S; Aghaei, J; Niknam, T; Shafie Khah, M; Vahidinasab, V; Catalao, JPS;

Publication
ENERGY

Abstract
This paper presents a robust optimization problem of the flexible bidirectional power management of a smart distribution network and harmonic compensation of nonlinear loads using electric vehicles (EVs) equipped with bidirectional chargers. The base deterministic model of the proposed problem is as mixed-integer nonlinear programming (MINLP), having the objective function to minimize the economic and technical indices subject to harmonic load flow equations, EVs constraints, system operation and harmonic indices limits. This model is converted to a mixed-integer linear programming (MILP) model in the next step. In the proposed MILP model, the active, reactive and apparent loads, electrical energy, reactive power and harmonic current prices, as well as EVs characteristics, are considered uncertain parameters. Accordingly, two alternative robust optimization approaches have been implemented for the conditions of having both the probability distribution function or the bounded uncertainty in the proposed MILP problem model. The proposed model is tested on distribution networks to demonstrate its efficiency and performance. The results show that the MINLP model can be substituted by the proposed high-speed MILP model. In addition, the capacity of the injecting power of EVs is reduced in the worst case scenario with respect to the scenario that is used in the deterministic model, while the consumed power of loads and EVs and energy price increases in this scenario. Finally, the payment of EV owners is reduced by considering EVs power and harmonic control.

2017

Networks of Universities as a Tool for GCIO Education

Authors
Barbosa, LS; Santos, LP;

Publication
EGOV

Abstract
Networking and collaboration, at different levels and through differentiated mechanisms, have become increasingly relevant and popular as an effective means for delivering public policy over the past two decades. The variety of forms of collaboration that emerge in educational scenarios makes it hard to reach general conclusions about the effectiveness of collaboration in general and of inter-institutional networks in particular. The university environment is particularly challenging in this respect as typically different agendas for collaboration and competition co-exist and are often promoted by very same entities. Although no ‘one-fits-all’ model exists for the establishment of a network of universities, the prime result of the research reported in this paper is that the concept of such a network is a most promising instrument for delivering specific services within the high education universe. In this context, the paper discusses the potential of these networks for the design of educational programmes for the GCIO (Government Chief Information Officer) function and proposes a set of guidelines to successfully establish such networks.

2017

Estratégia, inovação e mudança: casos de estudo sobre competitividade

Authors
Oliveira, Manuel Au-Yong; Gonçalves, Ramiro;

Publication

Abstract
Este livro sobre estratégia, inovação e mudança aborda diversas áreas – áreas tais como a simulação, a tecnologia, a internacionalização, o outsourcing, a integração vertical, a liderança, a gestão de recursos humanos, a educação, as aquisições, a cultura (nacional e corporativa), o marketing, a responsabilidade social corporativa, a inovação, o empreendedorismo e os modelos de negócio. A estratégia, quer da perspetiva da formulação, quer da perspetiva da implementação (figura 1), torna-se um imperativo em tempos de grande evolução tecnológica e mudança. Em que mercados devo competir? Qual a abordagem melhor para o mercado? Quem serão os meus competidores? Como deverei organizar a minha empresa? Quais são as minhas forças e quais são as minhas fraquezas, a nível interno? Quais são as oportunidades e quais são as ameaças presentes no ambiente externo? Quem serão os melhores clientes para os meus produtos e serviços? Como deverei organizar-me para maximizar a minha reputação entre os meus stakeholders? Que tipo de ferramentas de conceção estratégica poderei usar para ajudar o meu negócio a crescer de forma sustentada? Os capítulos deste livro, cada um retratando uma realidade diferente, procuram fornecer soluções para estas e outras questões pertinentes, para estrategas nacionais e também internacionais. (...)

2017

First light for GRAVITY: Phase referencing optical interferometry for the Very Large Telescope Interferometer

Authors
Abuter, R; Accardo, M; Amorim, A; Anugu, N; Avila, G; Azouaoui, N; Benisty, M; Berger, JP; Blind, N; Bonnet, H; Bourget, P; Brandner, W; Brast, R; Buron, A; Burtscher, L; Cassaing, F; Chapron, F; Choquet, E; Clenet, Y; Collin, C; du Foresto, VC; de Wit, W; de Zeeuw, PT; Deen, C; Delplancke Stroebele, F; Dembet, R; Derie, F; Dexter, J; Duvert, G; Ebert, M; Eckart, A; Eisenhauer, F; Esselborn, M; Fedou, P; Finger, G; Garcia, P; Dabo, CEG; Lopez, RG; Gendron, E; Genzel, R; Gillessen, S; Gonte, F; Gordo, P; Grould, M; Groezinger, U; Guieu, S; Haguenauer, P; Hans, O; Haubois, X; Haug, M; Haussmann, F; Henning, T; Hippler, S; Horrobin, M; Huber, A; Hubert, Z; Hubin, N; Hummel, CA; Jakob, G; Janssen, A; Jochum, L; Jocou, L; Kaufer, A; Kellner, S; Kendrew, S; Kern, L; Kervella, P; Kiekebusch, M; Klein, R; Kok, Y; Kolb, J; Kulas, M; Lacour, S; Lapeyrere, V; Lazareff, B; Le Bouquin, JB; Lena, P; Lenzen, R; Leveque, S; Lippa, M; Magnard, Y; Mehrgan, L; Mellein, M; Merand, A; Moreno Ventas, J; Moulin, T; Mueller, E; Mueller, F; Neumann, U; Oberti, S; Ott, T; Pallanca, L; Panduro, J; Pasquini, L; Paumard, T; Percheron, I; Perraut, K; Perrin, G; Pflueger, A; Pfuhl, O; Duc, TP; Plewa, PM; Popovic, D; Rabien, S; Ramirez, A; Ramos, J; Rau, C; Riquelme, M; Rohloff, RR; Rousset, G; Sanchez Bermudez, J; Scheithauer, S; Schoeller, M; Schuhler, N; Spyromilio, J; Straubmeier, C; Sturm, E; Suarez, M; Tristram, KRW; Ventura, N; Vincent, F; Waisberg, I; Wank, I; Weber, J; Wieprecht, E; Wiest, M; Wiezorrek, E; Wittkowski, M; Woillez, J; Wolff, B; Yazici, S; Ziegler, D; Zins, G;

Publication
ASTRONOMY & ASTROPHYSICS

Abstract
GRAVITY is a new instrument to coherently combine the light of the European Southern Observatory Very Large Telescope Interferometer to form a telescope with an equivalent 130m diameter angular resolution and a collecting area of 200 m(2). The instrument comprises fiber fed integrated optics beam combination, high resolution spectroscopy, built-in beam analysis and control, near-infrared wavefront sensing, phase-tracking, dual-beam operation, and laser metrology. GRAVITY opens up to optical/infrared interferometry the techniques of phase referenced imaging and narrow angle astrometry, in many aspects following the concepts of radio interferometry. This article gives an overview of GRAVITY and reports on the performance and the first astronomical observations during commissioning in 2015/16. We demonstrate phase-tracking on stars as faint as m(K) approximate to 10 mag, phase-referenced interferometry of objects fainter than m(K) approximate to 15 mag with a limiting magnitude of m(K) approximate to 17 mag, minute long coherent integrations, a visibility accuracy of better than 0.25%, and spectro-differential phase and closure phase accuracy better than 0.5 degrees, corresponding to a differential astrometric precision of better than ten microarcseconds (as). The dual-beam astrometry, measuring the phase difference of two objects with laser metrology, is still under commissioning. First observations show residuals as low as 50 mu as when following objects over several months. We illustrate the instrument performance with the observations of archetypical objects for the different instrument modes. Examples include the Galactic center supermassive black hole and its fast orbiting star S2 for phase referenced dual-beam observations and infrared wavefront sensing, the high mass X-ray binary BP Cru and the active galactic nucleus of PDS 456 for a few mu as spectro-differential astrometry, the T Tauri star S CrA for a spectro-differential visibility analysis, xi Tel and 24 Cap for high accuracy visibility observations, and eta Car for interferometric imaging with GRAVITY.

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