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Search Results: 1 - 10 of 581419 matches for " Joel J. P. C. Rodrigues "
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A Novel Intra-body Sensor for Vaginal Temperature Monitoring
Joel J. P. C. Rodrigues,Jo?o Caldeira,Binod Vaidya
Sensors , 2009, DOI: 10.3390/s90402797
Abstract: Over the years some medical studies have tried to better understand the internal behavior of human beings. Many researchers in this domain have been striving to find relationships between intra-vaginal temperature and certain female health conditions, such as ovulation and fertile period since woman’s intra-vaginal temperature is one of the body parameters most preferred in such studies. However, due to lack of a appropriate technology, medical research devoted to studying correlations of such body parameters with certain womans’ body phenomena could not obtain better results. This article presents the design and implementation of a novel intra-body sensor for acquisition and monitoring of intra-vaginal temperatures. This novel intra-body sensor provides data collection that is used for studying the relation between temperature variations and female health conditions, such as anticipation and monitoring of the ovulation period, detection of pregnancy contractions, preterm labor prevention, etc.. The motivation for this work focuses on the development of this new intra-body sensor that will represent a major step in medical technology. The novel sensor was tested and validated on hospitalized women as well as normal healthy women. Finally our medical team has attested to the accuracy, usability and performance of this novel intra-body sensor.
Detecting Intra-Fraction Motion in Patients Undergoing Radiation Treatment Using a Low-Cost Wireless Accelerometer
Farid Farahmand,Kevin O. Khadivi,Joel J. P. C. Rodrigues
Sensors , 2009, DOI: 10.3390/s90906715
Abstract: The utility of a novel, high-precision, non-intrusive, wireless, accelerometerbased patient orientation monitoring system (APOMS) in determining orientation change in patients undergoing radiation treatment is reported here. Using this system a small wireless accelerometer sensor is placed on a patient’s skin, broadcasting its orientation to the receiving station connected to a PC in the control area. A threshold-based algorithm is developed to identify the exact amount of the patient’s head orientation change. Through real-time measurements, an audible alarm can alert the radiation therapist if the user-defined orientation threshold is violated. Our results indicate that, in spite of its low-cost and simplicity, the APOMS is highly sensitive and offers accurate measurements. Furthermore, the APOMS is patient friendly, vendor neutral, and requires minimal user training. The versatile architecture of the APOMS makes it potentially suitable for variety of applications, including study of correlation between external and internal markers during Image-Guided Radiation Therapy (IGRT), with no major changes in hardware setup or algorithm.
New Trends on Ubiquitous Mobile Multimedia Applications
Joel J. P. C. Rodrigues,Marco Oliveira,Binod Vaidya
EURASIP Journal on Wireless Communications and Networking , 2010, DOI: 10.1155/2010/689517
Abstract:
Underwater Wireless Sensor Communications in the 2.4 GHz ISM Frequency Band
Jaime Lloret,Sandra Sendra,Miguel Ardid,Joel J. P. C. Rodrigues
Sensors , 2012, DOI: 10.3390/s120404237
Abstract: One of the main problems in underwater communications is the low data rate available due to the use of low frequencies. Moreover, there are many problems inherent to the medium such as reflections, refraction, energy dispersion, etc., that greatly degrade communication between devices. In some cases, wireless sensors must be placed quite close to each other in order to take more accurate measurements from the water while having high communication bandwidth. In these cases, while most researchers focus their efforts on increasing the data rate for low frequencies, we propose the use of the 2.4 GHz ISM frequency band in these special cases. In this paper, we show our wireless sensor node deployment and its performance obtained from a real scenario and measures taken for different frequencies, modulations and data transfer rates. The performed tests show the maximum distance between sensors, the number of lost packets and the average round trip time. Based on our measurements, we provide some experimental models of underwater communication in fresh water using EM waves in the 2.4 GHz ISM frequency band. Finally, we compare our communication system proposal with the existing systems. Although our proposal provides short communication distances, it provides high data transfer rates. It can be used for precision monitoring in applications such as contaminated ecosystems or for device communicate at high depth.
A Network Access Control Framework for 6LoWPAN Networks
Luís M. L. Oliveira,Joel J. P. C. Rodrigues,Amaro F. de Sousa,Jaime Lloret
Sensors , 2013, DOI: 10.3390/s130101210
Abstract: Low power over wireless personal area networks (LoWPAN), in particular wireless sensor networks, represent an emerging technology with high potential to be employed in critical situations like security surveillance, battlefields, smart-grids, and in e-health applications. The support of security services in LoWPAN is considered a challenge. First, this type of networks is usually deployed in unattended environments, making them vulnerable to security attacks. Second, the constraints inherent to LoWPAN, such as scarce resources and limited battery capacity, impose a careful planning on how and where the security services should be deployed. Besides protecting the network from some well-known threats, it is important that security mechanisms be able to withstand attacks that have not been identified before. One way of reaching this goal is to control, at the network access level, which nodes can be attached to the network and to enforce their security compliance. This paper presents a network access security framework that can be used to control the nodes that have access to the network, based on administrative approval, and to enforce security compliance to the authorized nodes.
A Low Energy Consumption DOA Estimation Approach for Conformal Array in Ultra-Wideband
Liangtian Wan,Lutao Liu,Guangjie Han,Joel J. P. C. Rodrigues
Future Internet , 2013, DOI: 10.3390/fi5040611
Abstract: Most direction-of-arrival (DOA) estimation approaches for conformal array suffer from high computational complexity, which cause high energy loss for the direction finding system. Thus, a low energy consumption DOA estimation algorithm for conformal array antenna is proposed in this paper. The arbitrary baseline direction finding algorithm is extended to estimate DOA for a conformal array in ultra-wideband. The rotation comparison method is adopted to solve the ambiguity of direction finding. The virtual baseline approach is used to construct the virtual elements. Theoretically, the virtual elements can be extended in the space flexibility. Four elements (both actual and virtual elements) can be used to obtain a group of solutions. The space angle estimation can be obtained by using sub-array divided technique and matrix inversion method. The stability of the proposed algorithm can be guaranteed by averaging the angles obtained by different sub-arrays. Finally, the simulation results verify the effectiveness of the proposed method with high DOA estimation accuracy and relatively low computational complexity.
Socially-Aware Venue Recommendation for Conference Participants
Feng Xia,Nana Yaw Asabere,Joel J. P. C. Rodrigues,Filippo Basso,Nakema Deonauth,Wei Wang
Computer Science , 2013,
Abstract: Current research environments are witnessing high enormities of presentations occurring in different sessions at academic conferences. This situation makes it difficult for researchers (especially juniors) to attend the right presentation session(s) for effective collaboration. In this paper, we propose an innovative venue recommendation algorithm to enhance smart conference participation. Our proposed algorithm, Social Aware Recommendation of Venues and Environments (SARVE), computes the Pearson Correlation and social characteristic information of conference participants. SARVE further incorporates the current context of both the smart conference community and participants in order to model a recommendation process using distributed community detection. Through the integration of the above computations and techniques, we are able to recommend presentation sessions of active participant presenters that may be of high interest to a particular participant. We evaluate SARVE using a real world dataset. Our experimental results demonstrate that SARVE outperforms other state-of-the-art methods.
A New Wireless Biosensor for Intra-Vaginal Temperature Monitoring
Jo?o M. L. P. Caldeira,Joel J. P. C. Rodrigues,Jo?o F. R. Garcia,Isabel de la Torre
Sensors , 2010, DOI: 10.3390/s101110314
Abstract: Wireless Body Sensors for medical purposes offer valuable contributions to improve patients’ healthcare, including diagnosis and/or therapeutics monitoring. Body temperature is a crucial parameter in healthcare diagnosis. In gynecology and obstetrics it is measured at the skin’s surface, which is very influenced by the environment. This paper proposes a new intra-body sensor for long-term intra-vaginal temperature collection. The embedded IEEE 802.15.4 communication module allows the integration of this sensor in a Wireless Sensor Network (WSN) for remote data access and monitoring. We present the sensor architecture, the construction of the corresponding testbed, and its performance evaluation. This sensor may be used in different medical applications, including preterm labor prevention and fertility and ovulation period detection. The features of the constructed testbed were validated in laboratory tests verifying its accuracy and performance.
On the Impact of Localization and Density Control Algorithms in Target Tracking Applications for Wireless Sensor Networks
Andre N. Campos,Efren L. Souza,Fabiola G. Nakamura,Eduardo F. Nakamura,Joel J. P. C. Rodrigues
Sensors , 2012, DOI: 10.3390/s120606930
Abstract: Target tracking is an important application of wireless sensor networks. The networks’ ability to locate and track an object is directed linked to the nodes’ ability to locate themselves. Consequently, localization systems are essential for target tracking applications. In addition, sensor networks are often deployed in remote or hostile environments. Therefore, density control algorithms are used to increase network lifetime while maintaining its sensing capabilities. In this work, we analyze the impact of localization algorithms (RPE and DPE) and density control algorithms (GAF, A3 and OGDC) on target tracking applications. We adapt the density control algorithms to address the k-coverage problem. In addition, we analyze the impact of network density, residual integration with density control, and k-coverage on both target tracking accuracy and network lifetime. Our results show that DPE is a better choice for target tracking applications than RPE. Moreover, among the evaluated density control algorithms, OGDC is the best option among the three. Although the choice of the density control algorithm has little impact on the tracking precision, OGDC outperforms GAF and A3 in terms of tracking time.
Situa??o epidemiológica da leucose bovina enzoótica em Portugal entre os anos de 1995 e 2005
Poeta, P.;Coelho, A.C.;Rodrigues, J.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2008, DOI: 10.1590/S0102-09352008000500030
Abstract: this paper evaluated the epidemiological situation of the enzootic bovine leucosis from 1995 to 2005, in portugal. with exception of the south region, algarve, the disease was distributed throughout the country, being more prevalent in the north, between douro and minho and trás-os-montes, than in the centre. a decrease in prevalence and incidence of the infection throughout the studied period was also observed.
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