2014
Autores
Pereira, R; Moreira, AHJ; Leite, M; Rodrigues, PL; Queirós, S; Rodrigues, NF; Leão, P; Vilaça, JL;
Publicação
SeGAH 2014 - IEEE 3rd International Conference on Serious Games and Applications for Health, Books of Proceedings
Abstract
Laparoscopic surgery (LS) has revolutionized traditional surgical techniques introducing minimally invasive procedures for diagnosis and local therapies. LSs have undeniable advantages, such as small patient incisions, reduced postoperative pain and faster recovery. On the other hand, restricted vision of the anatomical target, difficult handling of the surgical instruments, restricted mobility inside the human body, need of dexterity to hand-eye coordination and inadequate and non-ergonomic surgical instruments may restrict LS only to more specialized surgeons. To overcome the referred limitations, this work presents a new robotic surgical handheld system - the EndoRobot. The EndoRobot was designed to be used in clinical practice or even as a surgical simulator. It integrates an electromechanical system with 3 degrees of freedom. Each degree can be manipulated independently and combined with different levels of sensitivity allowing fast and slow movements. As other features, the EndoRobot has battery power or external power supply, enables the use of bipolar radiofrequency to prevent bleeding while cutting and allows plug-and-play of the laparoscopic forceps for rapid exchange. As a surgical simulator, the system was also instrumented to measure and transmit, in real time, its position and orientation for a training software able to monitor and assist the trainee's surgical movements.
2014
Autores
Rodrigues, H; Jose, R; Coelho, A; Melro, A; Ferreira, MC; Falcao e Cunha, JFE; Monteiro, MP; Ribeiro, C;
Publicação
SENSORS
Abstract
Mobile payments still remain essentially an emerging technology, seeking to fill the gap between the envisioned potential and widespread usage. In this paper, we present an integrated mobile service solution based on the near field communication (NFC) protocol that was developed under a research project called MobiPag. The most distinctive characteristic of Mobipag is its open architectural model that allows multiple partners to become part of the payment value-chain and create solutions that complement payments in many unexpected ways. We describe the Mobipag architecture and how it has been used to support a mobile payment trial. We identify a set of design lessons resulting from usage experiences associated with real-world payment situations with NFC-enabled mobile phones. Based on results from this trial, we identify a number of challenges and guidelines that may help to shape future versions of NFC-based payment systems. In particular, we highlight key challenges for the initial phases of payment deployments, where it is essential to focus on scenarios that can be identified as more feasible for early adoption. We also have identified a fundamental trade-off between the flexibility supported by the Mobipag solution and the respective implications for the payment process, particularly on the users' mental model.
2014
Autores
Renna, F; Laurcnti, N; Tomasin, S;
Publicação
2014 4TH INTERNATIONAL CONFERENCE ON WIRELESS COMMUNICATIONS, VEHICULAR TECHNOLOGY, INFORMATION THEORY AND AEROSPACE & ELECTRONIC SYSTEMS (VITAE)
Abstract
We consider a wiretap multiple-input multiple-output multiple-eavesdropper (MIMOME) channel, where agent Alice aims at transmitting a secret message to agent Bob, while leaking no information on it to an eavesdropper agent Eve. We assume that Alice has more antennas than both Bob and Eve, and that she has only statistical knowledge of the channel towards Eve. We focus on the low-noise regime, and assess the secrecy rates that are achievable when the secret message determines the distribution of a multivariate Gaussian mixture model (GMM) from which a realization is generated and transmitted over the channel. In particular, we show that if Eve has fewer antennas than Bob, secret transmission is always possible at low-noise. Moreover, we show that in the low-noise limit the secrecy capacity of our scheme coincides with its unconstrained capacity, by providing a class of covariance matrices that allow to attain such limit without the need of wiretap coding.
2014
Autores
Soares, FJ; Barbeiro, PN; Gouveia, C; Lopes, JAP;
Publicação
Power Systems
Abstract
The uncertainties related to when and where Plug-in Electric Vehicles (PEVs) will charge in the future requires the development of stochastic based approaches to identify the corresponding load scenarios. Such tools can be used to enhance existing system operators planning techniques, allowing them to obtain additional knowledge on the impacts of a new type of load, so far unknown or negligible to the power systems, the PEVs battery charging. This chapter presents a tool developed to evaluate the steady state impacts of integrating PEVs in distribution networks. It incorporates several PEV models, allowing estimating their charging impacts in a given network, during a predefined period, when different charging strategies are adopted (non-controlled charging, multiple tariff policies and controlled charging). It uses a stochastic model to simulate PEVs movement in a geographic region and a Monte Carlo method to create different scenarios of PEVs charging. It allows calculating the maximum number of PEVs that can be safely integrated in a given network and the changes provoked by PEVs in the load diagrams, voltage profiles, lines loading and energy losses. Additionally, the tool can also be used to quantify the critical mass (percentage) of PEV owners that need to adhere to controlled charging schemes in order to enable the safe operation of distribution networks. © Springer Science+Business Media Singapore 2015.
2014
Autores
Antunes, MJ; Afonso, A; Pinto, FM;
Publicação
NEW PERSPECTIVES IN INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 2
Abstract
USB dongles have been used by a wide range of software manufacturers to store a copy-protected of their application's license. The licenses validation procedure through USB dongles faces several concerns, as the risks of theft or losing dongle. Also, in scenarios where the number of dongles is reduced, users may have to wait for dongle access, which may lead to loss of productivity. In this paper we propose a client/server distributed architecture for remote software licenses validation, through USB/IP protocol. The proposed approach aims to take advantage of USB/IP for distributed access to a set of USB dongles physically connected to a remote USB server, over a TCP/IP network. We describe the deployment and enhancements made to an existing open source USB/ IP implementation and also present the results obtained with this architecture in a real world scenario, for validation of computer forensics applications licenses that uses USB dongles.
2014
Autores
Fangaia, S; Almeida, M; Carvalho, L; Nicolau, P;
Publicação
Biodental Engineering II - Proceedings of the 2nd International Conference on Biodental Engineering, BIODENTAL 2012
Abstract
Introduction: The atraumatic preparation of the implant bed and the presence of healthy bone factors have been considered essential for osseointegration of an implant. Heat generation during bone drilling has been related with the pressure applied by the operator, characteristics of the drill bit, the drilling depth, the type of irrigation, the rotational speed of the drilling time and the density of the bone tissue. Although bone drilling practice has been performed under irrigation, recent studies in the literature propose the use of a clinical protocol without irrigation. The primary objective of this study was to use an optical fibber Bragg grating sensor to measure thermal variations during implant bed preparation using surgical drills with a new surface coating. Materials and Methods:A literature review was performed and a pilot study designed using a fresh pig's jaw at room temperature, and three drilling groups were performed: Group I - Straumann® Drill without irrigation Group II - Straumann® Drill coated Titanium Nitride and Aluminum (NiTiAl) without irrigation. Group III (Control) - Straumann®) Drill with irrigation. The perforationswere made sequentially, using drills of 2.2, 2.8 and 3.5 mm, to a depth of 10 mm, at a speed of 800 rpmand 0.2 mm/s under a constant force of 4N. Changes in temperaturewere recorded using an optical fibber Bragg grating sensor, placed in an intra-osseous location.Results:Implant bed preparation procedure produced a temperature rise of: 0.39°C to 0.53°C, 1.28°C to 2.70°C, and 1.57°C to 4.39°C in group I, II and III respectively. The drills coated with NiTiAl and without irrigation have a lower temperature increase when compared with the uncoated drills, maintaining the procedure without irrigation. Discussion and Conclusions: The optical fibber Bragg gratings sensors have the ability to register changes in temperature that occur during the preparation of the implant bed. The coating of surgical drills with NiTiAl caused a minor increase of temperature in comparison with drills without coating. Perforations without irrigation performed at a speed of 800 rpm with a force of 4N do not seem to significantly increase the temperature in bone. © 2014 Taylor & Francis Group, London.
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