Browsing by Author "Rosado, José"
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- Comparison of Electric Vehicle Charging Efficiency with IEVCC and a typical EVSEPublication . Cardoso, Filipe; Rosado, José; Silva, MarcoMore than a fashion trend, EVs (Electric Vehicles) are here to stay and present themselves as a solution for combating climate change. In addition to the TCO (Total Cost Ownership) reductions, these vehicles are much more efficient than their equivalent ICE (Internal Combustion Engine) counter parts. Even if all the energy used to charge an EV comes from renewable sources, one of the points in the energy transfer chain, where efficiency can be optimized is in the charging process, whose efficiency depends on the charging power. This results from the fact that the EV internal charger has a fixed minimum power consumption to operate. Charging with a higher power results in less time charging, so less time is spent wasting energy on the EV internal charger. EVs come equipped with an internal charger whose charging power can be controlled by an external charge controller, commonly known as an EVSE (Electric Vehicle Supply Equipment). Manufacturers typically supply EVSEs with a fixed charging power setting, so they can be used on a household plug without any safety issues concerns. Usually, this power is set to around 2.3 kW for 230 V, but it is not uncommon to find values around 1.84 kW and very rarely 2.76 kW (which cor- responds to currents of 8∼12A). Often these EVSEs, due to the low charging power, do not always allow the users to restore the total charge used on a common day. In addition, the use of energy in a house is conditioned by the contracted power, which, if exceeded, triggers the main switchboard of the house. This requires some scheduling to manage an EV chargng session in conjunction with other house appliances usage. The use of an EVSE that considers the instantaneous house consumption and adjusts the EV charging to the maximum available power, allows to maximize the charging efficiency. A new EVSE that implements these functionalities has been developed and is addressed in this work. This EVSE, which is called IEVCC (Intelligent Electric Vehicle Charger Controller) is compared with a fixed EVSE, and the results show greater efficiency in the charging process.
- Torrent Poisoning Protection with a Reverse Proxy ServerPublication . Godinho, António; Cardoso, Filipe; Rosado, José; Sá, Filipe; Caldeira, FilipeA Distributed Denial-of-Service attack uses multiple sources operating in concert to attack a network or site. A typical DDoS flood attack on a website targets a web server with multiple valid requests, exhausting the server’s resources. The participants in this attack are usually compromised/infected computers controlled by the attackers. There are several variations of this kind of attack, and torrent index poisoning is one. A Distributed Denial-of-Service (DDoS) attack using torrent poisoning, more specifically using index poisoning, is one of the most effective and disruptive types of attacks. These web flooding attacks originate from BitTorrent-based file-sharing communities, where the participants using the BitTorrent applications cannot detect their involvement. The antivirus and other tools cannot detect the altered torrent file, making the BitTorrent client target the webserver. The use of reverse proxy servers can block this type of request from reaching the web server, preventing the severity and impact on the service of the DDoS. In this paper, we analyze a torrent index poisoning DDoS to a higher education institution, the impact on the network systems and servers, and the mitigation measures implemented.