3,603 research outputs found

    Constraining the Location of Microlensing Objects by using the Finite Source Effect in EAGLE events

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    We propose a new method to constrain the location of microlensing objects using EAGLE (Extremely Amplified Gravitational LEnsing) events. We have estimated the rate of EAGLE events by taking the finite-source effect in to account. We found that the EAGLE event rate for using a 1-m class telescope w hose limiting magnitude is V∼21V \sim 21 is the same as or higher than that of the ordinary microlensing events which have been found to date. We have also found that the fraction of transit EAGLE events is large enough to detect: between 4∼804 \sim 80 % depending on the lens location. Since the lens proper motion can be measured for a transit event, one can distinguish whether the lens is a MACHO (MAssive Compact Halo Object) in our hal o or one of the known stars in the Large Magellanic Cloud (LMC) from the proper motion measurement for each transit EAGLE event. Moreover, we show that the fraction of transit EAGLEs in all EAGLE events signif icantly depends on the lensing locations: the transit EAGLE fraction for the sel f-lensing case is 2∼152 \sim 15 times larger than that for halo MACHOs. Thus, one can constrain the location of lens objects by the statistics of the tr ansit events fraction. We show that we can reasonably expect 0∼60 \sim 6 transit events out of 21 EAGLE events in 3 years. We can also constrain the lens population properties at a gre ater than 99% confidence level depending on the number of transit events de tected. We also present the duration of EAGLE events, and show how an hourly ob servational mode is more suitable for an EAGLE event search program.Comment: 18 pages, 4 figures, accepted for publication in Ap

    Microjansky sources at 1.4 GHz

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    We present a deep 1.4 GHz survey made with the Australia Telescope Compact Array (ATCA), having a background RMS of 9 microJy near the image phase centre, up to 25 microJy at the edge of a 50' field of view. Over 770 radio sources brighter than 45 microJy have been catalogued in the field. The differential source counts in the deep field provide tentative support for the growing evidence that the microjansky radio population exhibits significantly higher clustering than found at higher flux density cutoffs. The optical identification rate on CCD images is approximately 50% to R=22.5, and the optical counterparts of the faintest radio sources appear to be mainly single galaxies close to this optical magnitude limit.Comment: 6 pages, 4 figures, accepted by ApJ Letters 4 May 199

    Towards a collective knowledge for a smart electric vehicle charging strategy

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    In this work is proposed the design of a system to create and handle Electric Vehicles (EV) charging procedures, based on intelligent process. Due to the electrical power distribution network limitation and absence of smart meter devices, Electric Vehicles charging should be performed in a balanced way, taking into account past experience (spread in a social network). In order to allow information exchange and to help user mobility, it was also created a mobile application to assist the EV driver on these processes. This proposed Smart Electric Vehicle Charging System uses Vehicle-to-Grid (V2G) technology, in order to connect Electric Vehicles and also renewable energy sources to Smart Grids (SG). This system also explores the new paradigm of Electrical Markets (EM), with deregulation of electricity production and use, in order to obtain the best conditions for commercializing electrical energy.The authors are grateful to the FCT (Fundação para a Ciência e a Tecnologia) and to the MIT-Portugal Program, for funding the Project MIT-PTIEDAM-SMS/00301200

    Mobi_system : a personal travel assistance for electrical vehicles in smart cities

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    In this work it is proposed the design of a mobile system to assist car drivers in a smart city environment oriented to the upcoming reality of Electric Vehicles (EV). Taking into account the new reality of smart cites, EV introduction, Smart Grids (SG), Electrical Markets (EM), with deregulation of electricity production and use, drivers will need more information for decision and mobility purposes. A mobile application to recommend useful related information will help drivers to deal with this new reality, giving guidance towards traffic, batteries charging process, and city mobility infrastructures (e.g. public transportation information, parking places availability and car & bike sharing systems). Since this is an upcoming reality with possible process changes, development must be based on agile process approaches (Web services).Fundação para a Ciência e a Tecnologia (FCT)MIT-Portugal Progra

    Development and test of an intra-vehicular network based on bluetooth low energy

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    This paper presents the development and test of an intra-vehicular system, based on Bluetooth Low Energy (BLE), designed to present to the driver, in real-time, information collected from multiple sensors distributed inside of the car, using an Android smartphone. The architecture of the implemented BLE network is composed by the smartphone, which has the role of central station, and two BLE modules (peripheral stations) based on the CC2540 system-on-chip, which collect relevant sensor information from the battery system and the traction system of an electric car. Results based on an experimental performance evaluation of the wireless network show that the network is able to satisfy the application requirements, as long as the network parameters are properly configured taking into account the peculiarities of the BLE data transfer modes and the limitations of the BLE platform.This work is supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

    A conceptual V2G aggregation platform

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    In this work is proposed the design of a system to create and handle an Electric Vehicle (EV) community, based on social networks collaborative approach and a credit mechanism to incentive participation and divide profits. This system is part of a V2G (Vehicle-to-Grid) module that allows EV owners to be aggregated in communities and participate in the electricity market. With this system it is possible for the EV owners to win money while the EVs are parked and plugged, delivering back to the electrical grid part of the energy stored in the batteries, increasing the attractiveness of EVs.Fundação para a Ciência e a Tecnologia (FCT) - Project MIT-Pt/EDAM-SMS/0030/2008.MIT-Portugal Progra

    Fused Filament Fabrication over fabrics: experiments and applications

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    The focus of this paper is to explore the use of Fused Filament Fabrication technology, a material extrusion additive manufacturing technology, by depositing melted Polilactic Acid (PLA) over a substrate – fabric - instead of on an empty building tray. The textile’s composition, nozzle and building plate temperature, printed PLA thickness and printed geometry have been considered as variables that could influence the structural and adhesion properties on this study so, therefor, were took into consideration and tested throughout the printing process through specimens printed with different combined parameters. The aim of this exploration process was developing an experimental procedure to study the limitations and capabilities of this printing technology over textiles, and which different variables’ combination would contribute to a better overall result in the development of a self-supporting textile based structural model, that could be apply in different contexts without the need of any extra external support. Results showed that PLA adherence to the fabric is correlated with nozzle/building plate temperature and printing thickness: higher temperature and thickness provide higher adherence. The weave of the textile didn´t reflect on better results but the polyester felt fabric exhibit maximum adherence with printed PLA in all sets of temperatures. In addition, geometries with reinforcement lines along the fabric stress direction provided better structural results. These results enable new application possibilities for the FFF technology combined in fabrics such as in interior, fashion and shoe ware design.publishe

    Context aware advisor for public transportation

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    This paper presents an Android-based mobile app designed to provide real time context aware public transportation information and advice to its users through the combination of the user's preferences and geographic context with data retrieved from a public transportation information system called XTraN Passenger. Thus, this mobile app contributes to fulfill the necessities of the passengers, and also provides an incentive for people to use the public transportation infrastructure more frequently. The proposed mobile app allows the users to benefit from the access to real time public transportation data in a simple and intuitive way. The validation of the features and operation of the developed app was assessed with results from use cases and real-world experimental tests using public transportation data from a Brazilian bus fleet operator.This work is supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 –Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941

    An energy management platform for public buildings

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    This paper describes the development and implementation of an electronic platform for energy management in public buildings. The developed platform prototype is based on the installation of a network of wireless sensors using the emerging Long Range (LoRa) low power long-range wireless network technology. This network is used to collect sensor data, which is stored online and manipulated to extract knowledge and generate actions toward energy saving solutions. In this process, gamification approaches were used to motivate changes in the users' behavior towards more sustainable actions in public buildings. These actions and the associated processes can be implemented as public services, and they can be replicated to different public buildings, contributing to a more energy-sustainable world. The developed platform allows the monitoring and management of the heating/cooling, electric power consumption, and lighting levels. In order to validate the proposed electronic platform, sensor information was collected in the context of a university campus, which was used as an application scenario in public buildings.info:eu-repo/semantics/publishedVersio

    An Android-based personalized public transportation advisor

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    This work presents the development of a mobile application which allows the user to access real time data related with public transportation information. This application combines the geographic user context and preferences with the data provided by a public transportation information system, fulfilling the necessities of today’s passengers and providing an incentive for the population to use the public transportation infrastructure. The proposed application, still in prototype stage, allows the user to benefit from real time access to public transportation data in a simple and intuitive form. Results from use cases and real world tests using data from a Brazilian bus fleet operator were employed to validate the operability and features of the developed prototype.info:eu-repo/semantics/acceptedVersio
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