83 research outputs found

    Simulation of digital phase-locked loops

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    Simulation equations are developed for first and second order digital phase locked loops. Examples of loop simulation are given to determine loop performance with respect to several loop parameters

    Analysis of a first order phase locked loop in the presence of Gaussian noise

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    A first-order digital phase locked loop is analyzed by application of a Markov chain model. Steady state loop error probabilities, phase standard deviation, and mean loop transient times are determined for various input signal to noise ratios. Results for direct loop simulation are presented for comparison

    Analysis of first and second order binary quantized digital phase-locked loops for ideal and white Gaussian noise inputs

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    Specific configurations of first and second order all digital phase locked loops are analyzed for both ideal and additive white gaussian noise inputs. In addition, a design for a hardware digital phase locked loop capable of either first or second order operation is presented along with appropriate experimental data obtained from testing of the hardware loop. All parameters chosen for the analysis and the design of the digital phase locked loop are consistent with an application to an Omega navigation receiver although neither the analysis nor the design are limited to this application

    Analysis and design of a second-order digital phase-locked loop

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    A specific second-order digital phase-locked loop (DPLL) was modeled as a first-order Markov chain with alternatives. From the matrix of transition probabilities of the Markov chain, the steady-state phase error of the DPLL was determined. In a similar manner the loop's response was calculated for a fading input. Additionally, a hardware DPLL was constructed and tested to provide a comparison to the results obtained from the Markov chain model. In all cases tested, good agreement was found between the theoretical predictions and the experimental data

    Draft genome sequences of five fungal strains isolated from Kefir

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    We present the annotated draft genome sequences of five fungal strains isolated from kefir grains. These isolates included three ascomycetous (Candida californica, Kazachstania exigua, and Kazachstania unispora) and one basidiomycetous (Rhodotorula mucilaginosa) species. The results revealed a detailed overview of the metabolic features of kefir fungi that will be potentially useful in biotechnological applications

    Information system for monitoring and assessing stress among medical students

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    Author ProofThe severe or prolonged exposure to stress-inducing factors in occupational and academic settings is a growing concern. The literature describes several potentially stressful moments experienced by medical students throughout the course, affecting cognitive functioning and learning. In this paper, we introduce the EUSTRESS Solution, that aims to create an Information System to monitor and assess, continuously and in real-time, the stress levels of the individuals in order to predict chronic stress. The Information System will use a measuring instrument based on wearable devices and machine learning techniques to collect and process stress-related data from the individual without his/her explicit interaction. A big database has been built through physiological, psychological, and behavioral assessments of medical students. In this paper, we focus on heart rate and heart rate variability indices, by comparing baseline and stress condition. In order to develop a predictive model of stress, we performed different statistical tests. Preliminary results showed the neural network had the better model fit. As future work, we will integrate salivary samples and self-report questionnaires in order to develop a more complex and intelligent model.QVida+ project (Estimação Contínua de Qualidade de Vida para Auxílio Eficaz à Decisão Clínica), funded by European Structural funds (FEDER-003446), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement

    Income differences in food consumption in the 1995 Australian national nutrition survey

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    Objective: To assess the relationships between an index of per capita income and the intake of a variety of individual foods as well as groups of food for men and women in different age groups. Design: Cross-sectional national survey of free-living men and women. Subjects: A sample of 5053 males and 5701 females aged 18 y and over who completed the Australian National Nutrition Survey 1995. Methods: Information about the frequency of consumption of 88 food items was obtained. On the basis of scores on the Food Frequency Questionnaire, regular and irregular consumers of single foods were identified. The relationships between regularity of consumption of individual foods and per capita income were analysed via contingency tables. Food variety scores were derived by assigning individual foods to conventional food group taxonomies, and then summing up the dichotomised intake scores for individual foods within each food group. Two-way ANOVA (income age group) were performed on the food variety scores for males and females, respectively. Results: Per capita income was extensively related to the reported consumption of individual foods and to total and food group variety indices. Generally, both men and women in low income households had less varied diets than those in higher-income households. However, several traditional foods were consumed less often by young high-income respondents, especially young women. Conclusions: Major income differentials in food variety occur in Australia but they are moderated by age and gender. Younger high-income women, in particular, appear to have rejected a number of traditional foods, possibly on the basis of health beliefs. The findings also suggest that data aggregation has marked effects on income and food consumption relationships.<br /

    Happiness Through Vacationing: Just a Temporary Boost or Long-Term Benefits?

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    Does vacationing add to our happiness in the long run? This question was addressed in a study of 3,650 Dutch citizens who reported their leisure travel every 3 months during 2 years and rated their happiness at the end of each year. Participants who had been on vacation appeared to be marginally happier, in terms of hedonic level of affect, than those who had not. This difference in Affect balance between vacationers and non-vacationers is probably due to a very minor causal effect of vacationing on hedonic level of affect. Possibly, vacationing is positively reminisced and these memories allow for the prevalence of more positive affect in people's lives. Happiness did not predict vacationing. The effect of holiday trips on vacationers' happiness is mostly short-lived; among vacationers, happiness was unrelated to the number of trips and days spent on vacation. A separate analysis of vacationers, who value vacationing most, yielded the same results. Implications for future research are discussed
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