Image upsampling algorithms applied on Nuclear Medicine: comparision of hqnx and nxSaI algorithms families with two interpolation algorithms - nearest neighbour and bicubic interpolation

Introduction: Image resizing is a normal feature incorporated into the Nuclear Medicine digital imaging. Upsampling is done by manufacturers to adequately fit more the acquired images on the display screen and it is applied when there is a need to increase - or decrease - the total number of pixels. This paper pretends to compare the “hqnx” and the “nxSaI” magnification algorithms with two interpolation algorithms – “nearest neighbor” and “bicubic interpolation” – in the image upsampling operations. Material and Methods: Three distinct Nuclear Medicine images were enlarged 2 and 4 times with the different digital image resizing algorithms (nearest neighbor, bicubic interpolation nxSaI and hqnx). To evaluate the pixel’s changes between the different output images, 3D whole image plot profiles and surface plots were used as an addition to the visual approach in the 4x upsampled images. Results: In the 2x enlarged images the visual differences were not so noteworthy. Although, it was clearly noticed that bicubic interpolation presented the best results. In the 4x enlarged images the differences were significant, with the bicubic interpolated images presenting the best results. Hqnx resized images presented better quality than 4xSaI and nearest neighbor interpolated images, however, its intense “halo effect” affects greatly the definition and boundaries of the image contents. Conclusion: The hqnx and the nxSaI algorithms were designed for images with clear edges and so its use in Nuclear Medicine images is obviously inadequate. Bicubic interpolation seems, from the algorithms studied, the most suitable and its each day wider applications seem to show it, being assumed as a multi-image type efficient algorithm.

Using a prioritized medium access control protocol for incrementally obtaining an interpolation of sensor readings

This paper addresses sensor network applications which need to obtain an accurate image of physical phenomena and do so with a high sampling rate in both time and space. We present a fast and scalable approach for obtaining an approximate representation of all sensor readings at high sampling rate for quickly reacting to critical events in a physical environment. This approach is an improvement on previous work in that after the new approach has undergone a startup phase then the new approach can use a very small sampling period.

A influência dos parâmetros nas estimativas VAR: caso prático

Dissertação de Mestrado em Finanças Empresariais

O risco do custo e do tempo no escanamento de projetos

Dissertação apresentada ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Logística Orientada por: Prof. Dr. Pedro Godinho

The immediate effects of atlanto-occipital joint manipulation and suboccipital muscle inhibition technique on active mouth opening and pressure pain sensitivity over latent myofascial trigger points in the masticatory muscles

DESIGN: A randomized controlled trial.OB JECTIVE: To investigate the immediate effects on pressure pain thresholds over latent trigger points (TrPs) in the masseter and temporalis muscles and active mouth opening following atlanto-occipital joint thrust manipulation or a soft tissue manual intervention targeted to the suboccipital muscles. BACKGROUND : Previous studies have described hypoalgesic effects of neck manipulative interventions over TrPs in the cervical musculature. There is a lack of studies analyzing these mechanisms over TrPs of muscles innervated by the trigeminal nerve. METHODS: One hundred twenty-two volunteers, 31 men and 91 women, between the ages of 18 and 30 years, with latent TrPs in the masseter muscle, were randomly divided into 3 groups: a manipulative group who received an atlanto-occipital joint thrust, a soft tissue group who received an inhibition technique over the suboccipital muscles, and a control group who did not receive an intervention. Pressure pain thresholds over latent TrPs in the masseter and temporalis muscles, and active mouth opening were assessed pretreatment and 2 minutes posttreatment by a blinded assessor. Mixed-model analyses of variance (ANOVA) were used to examine the effects of interventions on each outcome, with group as the between-subjects variable and time as the within-subjects variable. The primary analysis was the group-by-time interaction. RESULTS: The 2-by-3 mixed-model ANOVA revealed a significant group-by-time interaction for changes in pressure pain thresholds over masseter (P<.01) and temporalis (P =.003) muscle latent TrPs and also for active mouth opening (P<.001) in favor of the manipulative and soft tissue groups. Between-group effect sizes were small. CONCLUSIONS: The application of an atlanto-occipital thrust manipulation or soft tissue technique targeted to the suboccipital muscles led to an immediate increase in pressure pain thresholds over latent TrPs in the masseter and temporalis muscles and an increase in maximum active mouth opening. Nevertheless, the effects of both interventions were small and future studies are required to elucidate the clinical relevance of these changes. LEVEL OF EVIDENCE : Therapy, level 1b. J Orthop Sports Phys Ther 2010;40(5):310-317. doi:10.2519/jospt.2010.3257. KEYWORDSDS: cervical manipulation, muscle trigger points, neck, TMJ, upper cervical.

A decision-support system based on particle swarm optimization for multiperiod hedging in electricity markets

This paper proposes a particle swarm optimization (PSO) approach to support electricity producers for multiperiod optimal contract allocation. The producer risk preference is stated by a utility function (U) expressing the tradeoff between the expectation and variance of the return. Variance estimation and expected return are based on a forecasted scenario interval determined by a price range forecasting model developed by the authors. A certain confidence level is associated to each forecasted scenario interval. The proposed model makes use of contracts with physical (spot and forward) and financial (options) settlement. PSO performance was evaluated by comparing it with a genetic algorithm-based approach. This model can be used by producers in deregulated electricity markets but can easily be adapted to load serving entities and retailers. Moreover, it can easily be adapted to the use of other type of contracts.

Validade e fiabilidade da versão portuguesa do Stroke Aphasic Depression Questionnaire-21

O objectivo deste estudo é determinar as propriedades psicométricas da versão portuguesa do Stroke Aphasic Depression Questionnaire-21 (SADQ-21). Envolveu 120 sujeitos, 33 dos quais com afasia. Os resultados demonstraram que o SADQ-21 revela uma consistência interna muito elevada (α=0,87). A validade de construção identificou cinco domínios. A variância total explicada pelos factores foi elevada (65,85%). A correlação entre a medida de ouro e o SADQ-21 é estatisticamente significativa (p<0,05). Os indivíduos com afasia estão significativamente mais deprimidos que os sem afasia (p=0,0001). Conclui-se que o SADQ-21 é um instrumento adequado para a avaliação da sintomatologia depressiva em pessoas com afasia.

A long-term swarm intelligence hedging tool applied to electricity markets

This paper proposes a swarm intelligence long-term hedging tool to support electricity producers in competitive electricity markets. This tool investigates the long-term hedging opportunities available to electric power producers through the use of contracts with physical (spot and forward) and financial (options) settlement. To find the optimal portfolio the producer risk preference is stated by a utility function (U) expressing the trade-off between the expectation and the variance of the return. Variance estimation and the expected return are based on a forecasted scenario interval determined by a long-term price range forecast model, developed by the authors, whose explanation is outside the scope of this paper. The proposed tool makes use of Particle Swarm Optimization (PSO) and its performance has been evaluated by comparing it with a Genetic Algorithm (GA) based approach. To validate the risk management tool a case study, using real price historical data for mainland Spanish market, is presented to demonstrate the effectiveness of the proposed methodology.

A long-term risk management tool for electricity markets using swarm intelligence

This paper addresses the optimal involvement in derivatives electricity markets of a power producer to hedge against the pool price volatility. To achieve this aim, a swarm intelligence meta-heuristic optimization technique for long-term risk management tool is proposed. This tool investigates the long-term opportunities for risk hedging available for electric power producers through the use of contracts with physical (spot and forward contracts) and financial (options contracts) settlement. The producer risk preference is formulated as a utility function (U) expressing the trade-off between the expectation and the variance of the return. Variance of return and the expectation are based on a forecasted scenario interval determined by a long-term price range forecasting model. This model also makes use of particle swarm optimization (PSO) to find the best parameters allow to achieve better forecasting results. On the other hand, the price estimation depends on load forecasting. This work also presents a regressive long-term load forecast model that make use of PSO to find the best parameters as well as in price estimation. The PSO technique performance has been evaluated by comparison with a Genetic Algorithm (GA) based approach. A case study is presented and the results are discussed taking into account the real price and load historical data from mainland Spanish electricity market demonstrating the effectiveness of the methodology handling this type of problems. Finally, conclusions are dully drawn.

Qualidade de vida do doente com insuficiência cardíaca do Centro Hospitalar Tâmega e Sousa

A Insuficiência Cardíaca (IC), como uma doença crónica, tem vindo a ser alvo de análise devido ao seu impacto, não só a nível económico, mas também a nível da qualidade de vida (QV). Vários estudos demonstram que os doentes com IC apresentam um comprometimento da QV, em várias dimensões. OBJETIVO: Descrever a QV dos doentes com IC do Centro Hospitalar Tâmega e Sousa (CHTS). METODOLOGIA: O estudo é quantitativo, transversal, prospetivo e descritivo. Foi aplicado, entre janeiro a junho de 2012, o Euro Quality of Life Instrument-5D (EQ-5D) para avaliar o estado de saúde (ES) e o Kansas City Cardiomyopathy Questionnaire (KCCQ) para avaliar a QV de 326 doentes com IC, dos quais 226 seguidos na Consulta Externa (77,9% masculinos, idade média 67,5 ±11,6 anos, desvio padrão) e 100 na Clínica de IC (CIC) (73,0% masculinos, idade média 59,0 anos, desvio padrão ±12,7). Foi usada a estatística descritiva, teste t, qui quadrado e a análise da variância. RESULTADOS: Os doentes do género feminino, do grupo etário 75-100 anos, solteiros, divorciados, separados ou viúvos, que não sabem ler nem escrever, sem apoio dos amigos e sem condições económicas mínimas para o tratamento da IC apresentaram pior ES e QV. Os doentes submetidos à terapia de ressincronização cardíaca e às cirurgias valvular e de revascularização tiveram melhor QV. Os doentes com IC de etiologia isquémica e em classe III-IV da New York Heart Association apresentaram pior ES. Nestas classes e com fração de ejeção ≤35% os doentes tiveram pior QV. Os doentes da CIC evidenciaram melhor ES e QV. CONCLUSÕES: A QV dos doentes com IC do CHTS é influenciada pelos fatores pessoais, clínicos e pelo local de intervenção. É fundamental mensurar a QV, na prática clínica, para evidenciar a perceção do ES dos doentes e o impacto da IC na QV.

Capacidade antioxidante de cervejas comerciais

Mestrado em Engenharia Química

Qualidade do chocolate: estudo de alguns parâmetros

O chocolate é considerado uma emulsão complexa e um alimento de luxo, que durante o seu consumo provoca estímulos que activam os centros de prazer do cérebro Humano. Tendo em conta a importância deste alimento torna-se necessário estudar e avaliar a melhor forma de melhorar a qualidade do chocolate. Este trabalho teve como objectivo verificar e analisar a qualidade do processo de fabrico da massa de chocolate, no que respeita (i) a rastreabilidade das matérias-primas e do produto acabado e, por outro lado, (ii) determinar e estudar o efeito de alguns parâmetros do processo nas características da massa, através das variáveis viscosidade, tensão de corte, tensão de corte crítica (“yield value”) e granulometria. Estas variáveis foram medidas em massas de chocolate de leite com o nome de formulação CAI e provenientes das duas unidades fabris da empresa (UF1 e UF2). Os parâmetros estudados na UF1 foram a influência das conchas e dos ingredientes. Na UF2 estudou-se a influência dos inutilizados de fabrico e a influência dos inutilizados de fabrico juntamente com o efeito de um ingrediente que foi o açúcar. Os resultados da viscosidade, tensão de corte e tensão de corte crítica (“yield value”) foram analisados estatisticamente por análise de variância (ANOVA), recorrendo aos testes de Komolgorov-Smirnov, Shapiro-Wilk e de Levene para verificar as condições de aplicabilidade desta análise. Os resultados da granulometria como não aderiram a uma distribuição normal foram analisados pelo método não paramétrico de Kruskal-Wallis. Estas análises foram executadas no programa “Statistical Package for the Social Sciences” (SPSS). Pelos resultados obtidos, conclui-se que, para a UF1, a concha afecta a tensão de corte, viscosidade e a tensão de corte crítica do chocolate produzido, na medida em que existem diferenças entre as conchas estudadas. Para esta unidade conclui-se que os ingredientes também influenciam a granulometria da massa. No caso da UF2, conclui-se que a tensão de corte é afectada apenas pelo lote de açúcar, a viscosidade é afectada tanto pelo lote de açúcar como pela presença de inutilizados de fabrico e a tensão de corte crítica não é afectada por nenhum destes efeitos. A granulometria, nesta unidade é afectada pelos lotes de açúcar estudados.

Short- and medium-term effects of manual therapy on cervical active range of motion and pressure pain sensitivity in latent myofascial pain of the upper trapezius muscle: a randomized controlled trial

Objective: The purpose of this study was to investigate effects of different manual techniques on cervical ranges of 17 motion and pressure pain sensitivity in subjects with latent trigger point of the upper trapezius muscle. 18 Methods: One hundred seventeen volunteers, with a unilateral latent trigger point on upper trapezius due to computer 19 work, were randomly divided into 5 groups: ischemic compression (IC) group (n = 24); passive stretching group (n = 20 23); muscle energy technique group (n = 23); and 2 control groups, wait-and-see group (n = 25) and placebo group 21 (n = 22). Cervical spine range of movement was measured using a cervical range of motion instrument as well as 22 pressure pain sensitivity by means of an algometer and a visual analog scale. Outcomes were assessed pretreatment, 23 immediately, and 24 hours after the intervention and 1 week later by a blind researcher. A 4 × 5 mixed repeated- 24 measures analysis of variance was used to examine the effects of the intervention and Cohen d coefficient was used. 25 Results: A group-by-time interaction was detected in all variables (P b .01), except contralateral rotation. The 26 immediate effect sizes of the contralateral flexion, ipsilateral rotation, and pressure pain threshold were large for 3 27 experimental groups. Nevertheless, after 24 hours and 1 week, only IC group maintained the effect size. 28 Conclusions: Manual techniques on upper trapezius with latent trigger point seemed to improve the cervical range of 29 motion and the pressure pain sensitivity. These effects persist after 1 week in the IC group. (J Manipulative Physiol 301 Ther 2013;xx:1-10)

Association between birth weight and neuromotor performance: a twin study

The development of neonatal intensive care has led to an increase in the prevalence of children with low birth weight and associated morbidity. The objectives of this study are to verify (1) The association between birth weight (BW) and neuromotor performance? (2) Is the neuromotor performance of twins within the normal range? (3) Are intra-pair similarities in neuromotor development of Monozygotic (MZ) and Disygotic (DZ) twins of unequal magnitude? The sample consisted of 191 children (78 MZ and 113 DZ), 8.9+3.1 years of age and with an average BW of 2246.3+485.4g. In addition to gestational characteristics, sports participation and Zurich Neuromotor Assessment (ZNA) were observed at childhood age. The statistical analysis was carried out with software SPSS 18.0, the STATA 10 and the ZNA performance scores. The level of significance was 0.05. For the neuromotor items high intra and inter-investigator reliabilities were obtained (0.793variance. Twins showed elevated percentages of subjects (32.7%<76.9%) with low performance

Capacity sharing and stealing in serverbased real-time systems

A dynamic scheduler that supports the coexistence of guaranteed and non-guaranteed bandwidth servers is proposed. Overloads are handled by an efficient reclaiming of residual capacities originated by early completions as well as by allowing reserved capacity stealing of non-guaranteed bandwidth servers. The proposed dynamic budget accounting mechanism ensures that at a particular time the currently executing server is using a residual capacity, its own capacity or is stealing some reserved capacity, eliminating the need of additional server states or unbounded queues. The server to which the budget accounting is going to be performed is dynamically determined at the time instant when a capacity is needed. This paper describes and evaluates the proposed scheduling algorithm, showing that it can efficiently reduce the mean tardiness of periodic jobs. The achieved results become even more significant when tasks’ computation times have a large variance.