A random access MAC protocol for MPR satellite networks

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Líneas de actuación educativa en torno a la igualdad y la diversidad : el punto de vista de los MPR.

Resumen basado en el que aporta la revista

Heating requirements, minimum property requirements for properties of one or two living units applicable in all insuring office areas except Honolulu and San Juan. MPR rev. no. 1.

"Supersedes MPR revision no. 44."

Comparison between cone-beam and multislice computed tomography for identification of simulated bone lesions

There are many studies that compare the accuracy of multislice (MSCT) and cone beam (CBCT) computed tomography for evaluations in the maxillofacial region. However, further studies comparing both acquisition techniques for the evaluation of simulated mandibular bone lesions are needed. The aim of this study was to compare the accuracy of MSCT and CBCT in the diagnosis of simulated mandibular bone lesions by means of cross sectional images and axial/MPR slices. Lesions with different dimensions, shape and locularity were produced in 15 dry mandibles. The images were obtained following the cross sectional and axial/MPR (Multiplanar Reconstruction) imaging protocols and were interpreted independently. CBCT and MSCT showed similar results in depicting the percentage of cortical bone involvement, with great sensitivity and specificity (p < 0.005). There were no significant intra- or inter-examiner differences between axial/MPR images and cross sectional images with regard to sensitivity and specificity. CBCT showed results similar to those of MSCT for the identification of the number of simulated bone lesions. Cross sectional slices and axial/MPR images presented high accuracy, proving useful for bone lesion diagnosis.

Assessment of simulated mandibular condyle bone lesions by cone beam computed tomography

There are many limitations to image acquisition, using conventional radiography, of the temporomandibular joint (TMJ) region. The Computed Tomography (CT) scan is a better option, due to its higher accuracy, for purposes of diagnosis, surgical planning and treatment of bone injuries. The aim of the present study was to analyze two protocols of cone beam computed tomography for the evaluation of simulated mandibular condyle bone lesions. Spherical lesions were simulated in 30 dry mandibular condyles, using dentist drills and drill bits sizes 1, 3 and 6. Each of the mandibular condyles was submitted to cone beam computed tomography (CBCT) using two protocols: 1) axial, coronal and sagittal multiplanar reconstruction (MPR); and 2) sagittal plus coronal slices throughout the longitudinal axis of the mandibular condyles. For these protocols, 2 observers analyzed the CBCT images independently, regarding the presence or not of injuries. Only one of the observers, however, performed on 2 different occasions. The results were compared to the gold standard, evaluating the percentage of agreement, degree of accuracy of CBCT protocols and observers' examination. The z test was used for the statistical analysis. The results showed there were no statistically significant differences between the 2 protocols. There was greater difficulty in the assessment of small-size simulated lesions (drill # 1). From the results of this study, it can be concluded that CBCT is an accurate tool for analyzing mandibular condyle bone lesions, with the MPR protocol showing slightly better results than the sagittal plus coronal slices throughout the longitudinal axis.

ADHD in a representative sample of the Brazilian population: estimated prevalence and comparative adequacy of criteria between adolescents and adults according to the item response theory

Background: Attention deficit hyperactivity disorder (ADHD) is a clinically significant disorder in adulthood, but current diagnostic criteria and instruments do not seem to adequately capture the complexity of the disorder in this developmental phase. Accordingly, there are limited data on the proportion of adults affected by the disorder, specially in developing countries. Method: We assessed a representative household sample of the Brazilian population for ADHD with the Adult ADHD Self-report Scale (ASRS) Screener, and evaluated the instrument according to the Rasch model of item response theory. Results: The sample was comprised by 3007 individuals, and the overal prevalence of positive screeners for ADHD was 5.8% [95% confidence interval (CI), 4.8-7.0]. Rasch analyses revealed the misfitt of the overall sample to expectations of the model. The evaluation of the sample stratified by age revealed that data for adolescents showed a signficant fittnes to the model expectations, while items completed by adults were not adequated. Conclusions: The lack of fitness to the model for adult respondents challenges the possibility of a linear transformation of the ordinal data into interval measures and the utilization of parametric analyses of data. This result suggests that diagnostic criteria and instruments for adult ADHD must take into account a developmental perspective. Moreover, it calls for further evaluation of currently employed research methods in light of modern theories of psychometrics. Copyright (C) 2010 John Wiley & Sons, Ltd.

Malformations of Cortical Development in Patients With Mid line Facial Defects and Ocular Hypertelorism

Objectives: We studied the neuroimaging and neurophysiological aspects of 17 patients with midline facial defects with ocular hypertelorism (MFDH). Methods: The investigation protocol included a previous semistructured questionnaire about family history; gestational, neonatal, and postnatal development; and dysmorphologic and neurologic evaluation. Recognized monogenic disorders and individuals with other well-known conditions were excluded. All patients had high resolution magnetic resonance imaging (MRI) with multiplanar reconstruction (MPR) and routine electroencephalograms (EEGs). Results: We detected abnormalities in five patients whose MRIs had been previously reported as normal. MRI showed central nervous system (CNS) structural abnormalities in all patients, which included commissural alterations in 16/17 (94%), malformations of cortical development in 10/17 (58%), disturbances of neural tube closure in 7/17(42%), and posterior fossa anomalies in 6/17 (35%). Some patients had more than one type of malformation occurring at different stages of the embryonary process. EEGs showed epileptiform activity in 4/17 (24%) and background abnormalities in 5/17 (29%) of patients. Conclusion: This study clearly demonstrated the presence of structural and functional neurologic alterations related to MFDH. Therefore, the CNS anomalies cannot be considered incidental findings but an intrinsic part of this condition, which could be related to environmental effects and/or genetic mutations. These findings would provide a basis for future investigations on MFDH and should also be considered when planning rehabilitation.

Screening for serious mental illness in the general population with the K6 screening scale: results from the WHO World Mental Health (WMH) survey initiative

Data are reported on the background and performance of the K6 screening scale for serious mental illness (SMI) in the World Health Organization (WHO) World Mental Health (WMH) surveys. The K6 is a six-item scale developed to provide a brief valid screen for Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) SMI based on the criteria in the US ADAMHA Reorganization Act. Although methodological studies have documented good K6 validity in a number of countries, optimal scoring rules have never been proposed. Such rules are presented here based on analysis of K6 data in nationally or regionally representative WMH surveys in 14 countries (combined N = 41,770 respondents). Twelve-month prevalence of DSM-IV SMI was assessed with the fully-structured WHO Composite International Diagnostic Interview. Nested logistic regression analysis was used to generate estimates of the predicted probability of SMI for each respondent from K6 scores, taking into consideration the possibility of variable concordance as a function of respondent age, gender, education, and country. Concordance, assessed by calculating the area under the receiver operating characteristic curve, was generally substantial (median 0.83; range 0.76-0.89; inter-quartile range 0.81-0.85). Based on this result, optimal scaling rules are presented for use by investigators working with the K6 scale in the countries studied. Copyright (c) 2010 John Wiley & Sons, Ltd.

The generalized multiprocessor periodic resource interface model for hierarchical multiprocessor scheduling

Composition is a practice of key importance in software engineering. When real-time applications are composed it is necessary that their timing properties (such as meeting the deadlines) are guaranteed. The composition is performed by establishing an interface between the application and the physical platform. Such an interface does typically contain information about the amount of computing capacity needed by the application. In multiprocessor platforms, the interface should also present information about the degree of parallelism. Recently there have been quite a few interface proposals. However, they are either too complex to be handled or too pessimistic.In this paper we propose the Generalized Multiprocessor Periodic Resource model (GMPR) that is strictly superior to the MPR model without requiring a too detailed description. We describe a method to generate the interface from the application specification. All these methods have been implemented in Matlab routines that are publicly available.

Variation in response of Schistosoma mansoni strains to schistosomicides

The BH strain of Schistosoma mansoni was found to be highly susceptible, to hy cant hone (1 x 80 mg/kg), oxamniquine (1 x 100 mg/kg) niridazole (5 x 100 mg/kg), praziquantel (1 x 100 mg/kg), oltipraz (5 x 125 mg/kg) and amoscanate (1 x 300 mg/kg) and is therefore a good reference strain for chemotherapeutic trials. By contrast, the MPR-1 strain was shown to have developed resistance to oxamniquine without ever having been dosed with oxamniquine. Other oxamniquine/hycanthone resistant strains were shown to have maintained their resistance and a strain believed to be partially resistant to oltipraz was evaluated.

Compositional multiprocessor scheduling: the GMPR interface

Composition is a practice of key importance in software engineering. When real-time applications are composed, it is necessary that their timing properties (such as meeting the deadlines) are guaranteed. The composition is performed by establishing an interface between the application and the physical platform. Such an interface typically contains information about the amount of computing capacity needed by the application. For multiprocessor platforms, the interface should also present information about the degree of parallelism. Several interface proposals have recently been put forward in various research works. However, those interfaces are either too complex to be handled or too pessimistic. In this paper we propose the generalized multiprocessor periodic resource model (GMPR) that is strictly superior to the MPR model without requiring a too detailed description. We then derive a method to compute the interface from the application specification. This method has been implemented in Matlab routines that are publicly available.

A Random Access Protocol incorporating Multi-Packet Reception, Retransmission Diversity and Successive Interference Cancellation

8th International Workshop on Multiple Access Communications (MACOM2015), Helsinki, Finland.

Multipacket reception in LTE femtocell networks

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

QoS in LEO satellite networks with multipacket reception

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Redes de acesso aleatório com capacidade de receção de múltiplos pacotes

Com o aumento do número de dispositivos móveis, os sistemas de comunicação sem fios têm evoluído de forma a aumentar os débitos de transferência de dados. Nos sistemas de comunicação sem fios tradicionais, um nó recetor apenas permite a receção de um sinal de cada vez (Single Packet Reception - SPR). Com o aparecimento de técnicas de receção múltipla (ex. CDMA, UWB, MU-MIMO), tornou-se possível a receção de múltiplos pacotes em simultâneo (Multipacket Reception - MPR). Porém, os protocolos de controlo de acesso ao meio (MAC) não foram adaptados de forma a tirar partido da capacidade de MPR no recetor. Esta dissertação aborda a condição de receção de múltiplos pacotes em simultâneo, caracterizando o número médio de pacotes recebidos, tendo em conta o número total de transmissões. A partir desta caracterização, é estudado o desempenho de três protocolos MAC. Os protocolos são baseados numa fase de negociação seguida de uma fase de transmissão. A caracterização do número médio de pacotes recebidos permite avaliar de uma forma integrada (nível físico e MAC) o desempenho dos diferentes protocolos MAC. Finalmente, a avaliação de desempenho evidencia o aumento de débito quando é utilizado MPR nas duas fases (negociação e transmissão), o que constitui um bom ponto de partida para o desenho de futuros protocolos MAC para sistemas MPR.