30 resultados para frequency scaling factors

em Deakin Research Online - Australia


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With the increasing trends of mobile interactions, voice authentication applications are in a higher demand, giving rise to new rounds of research activities. Authentication is an important security mechanism that requires the intended communication parties to present valid credentials to the communication network. In a stronger sense, all the involved parties are required to be authenticated to one another (mutual authentication). In the voice authentication technique described in this paper, the voice characteristics of an intended individual wishing to take part in a communication channel will be classified and processed. This involves a low overhead voice authentication scheme, which features equalization and scaling of the voice frequency harmonics. The performance of this system is discussed in a Labview 8.5 visual development environment, following a complete security analysis. © 2013 Elsevier Ltd. All rights reserved.

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 With the rising demands on cloud services, the electricity consumption has been increasing drastically as the main operational expenditure (OPEX) to data center providers. The geographical heterogeneity of electricity prices motivates us to study the task placement problem over geo-distributed data centers. We exploit the dynamic frequency scaling technique and formulate an optimization problem that minimizes OPEX while guaranteeing the quality-of-service, i.e., the expected response time of tasks. Furthermore, an optimal solution is discovered for this formulated problem. The experimental results show that our proposal achieves much higher cost-efficiency than the traditional resizing scheme, i.e., by activating/deactivating certain servers in data centers.

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The expected pervasive use of mobile cloud computing and the growing number of Internet data centers have brought forth many concerns, such as, energy costs and energy saving management of both data centers and mobile connections. Therefore, the need for adaptive and distributed resource allocation schedulers for minimizing the communication-plus-computing energy consumption has become increasingly important. In this paper, we propose and test an efficient dynamic resource provisioning scheduler that jointly minimizes computation and communication energy consumption, while guaranteeing user Quality of Service (QoS) constraints. We evaluate the performance of the proposed dynamic resource provisioning algorithm with respect to the execution time, goodput and bandwidth usage and compare the performance of the proposed scheduler against the exiting approaches. The attained experimental results show that the proposed dynamic resource provisioning algorithm achieves much higher energy-saving than the traditional schemes.

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Eating frequency may be important in the development of overweight and obesity and other cardiometabolic risk factors; however, the evidence is inconsistent. The aim of the present study was to examine the associations between the number of eating occasions and cardiometabolic risk factors in a national population-based sample of young adults. A cohort of 1273 men and 1502 women, aged 26–36 years, completed a meal pattern chart to record when they had eaten during the previous day (in hourly intervals). The total number of eating occasions was calculated. Diet quality was assessed, waist circumference was measured and a fasting blood sample was taken. Dietary intake was compared with the Australian Guide to Healthy Eating. The associations between the number of eating occasions and cardiometabolic risk factors were calculated using linear regression. Analyses were adjusted for age, education and physical activity. Most men ate three to five times per d and most women ate four to six times. The proportion of participants meeting dietary recommendations increased with the number of eating occasions. For men, an additional eating occasion was associated with reductions in mean values for waist circumference ( − 0·75 cm), fasting glucose ( − 0·02 mmol/l), fasting insulin ( − 0·34 mU/l; 2·04 pmol/l), TAG ( − 0·03 mmol/l), total cholesterol ( − 0·08 mmol/l) and LDL-cholesterol ( − 0·06 mmol/l). Adjustment for waist circumference attenuated the results. Significant trends were not observed for women. In conclusion, a higher number of eating occasions were associated with reduced cardiometabolic risk factors in men. Many associations were mediated by waist circumference.

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Objective: To investigate: (i) how lunch frequency of adolescents varies between schools and between classes within schools; (ii) the associations between frequency of lunch and individual sociodemographic factors and school characteristics; and (iii) if any observed associations between lunch frequency and school characteristics vary by gender and age groups. Design: Cross-sectional study in which students and school headmasters completed self-administered questionnaires. Associations were estimated by multilevel multivariate logistic regression. Setting: The Danish arm of the Health Behaviour in School-Aged Children study 2010. Subjects: Students (n 4922) aged 11, 13 and 15 years attending a random sample of seventy-three schools. Results: The school-level and class-level variations in low lunch frequency were small (intraclass correlation coefficient <2·1 %). At the individual level, low lunch frequency was most common among students who were boys, 13- and 15-year-olds, from medium and low family social class, descendants of immigrants, living in a single-parent family and in a reconstructed family. School-level analyses suggested that having access to a canteen at school was associated with low lunch frequency (OR=1·47; 95% CI 1·14, 1·89). Likewise not having an adult present during lunch breaks was associated with low lunch frequency (OR=1·44; 95% CI 1·18, 1·75). Cross-level interactions suggested that these associations differed by age group. Conclusions: Lunch frequency among Danish students appears to be largely influenced by sociodemographic factors. Additionally, the presence of an adult during lunch breaks promotes frequent lunch consumption while availability of a canteen may discourage frequent lunch consumption. These findings vary between older and younger students.

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TATA box is one of the most important transcription factor binding sites. But the exact sequences of TATA box are still not very clear yet. In this study, we conducted a dedicated analysis on the frequency distribution of TATA Box and its extension sequences on human promoters. Sixteen TATA elements derived from TATA Box motif, TATAWAWN, were classified into three distribution patterns: peak, bottom-peak and bottom. Fourteen TATA extension sequences (up to two base extensions) were predicted to be the new TATA Box elements because of their high motif factors, which indicate their statistical significance. Statistical analysis on the promoters of mouse, zebrafish and drosophila melanogaster verified seven of these elements. It was also observed that the distribution of TATA elements on the promoters of housekeeping genes are very similar with their distribution on the promoters of tissue specific genes in human.

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Consumption of some dietary fibres may benefit bowel health; however, the effect of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre) is unknown. The present study examined the effect of a high-fibre diet containing LKFibre on bowel function and faecal putative risk factors for colon cancer compared to a control diet without LKFibre. Thirty-eight free-living, healthy men consumed an LKFibre and a control diet for 1 month each in a single-blind, randomized, crossover study. Depending on subject energy intake, the LKFibre diet was designed to provide 17–30 g/d fibre (in experimental foods) above that of the control diet. Bowel function self-perception, frequency of defecation, transit time, faecal output, pH and moisture, faecal levels of SCFA and ammonia, and faecal bacterial [ß]-glucuronidase activity were assessed. In comparison to the control diet, the LKFibre diet increased frequency of defecation by 0·13 events/d (P = 0·047), increased faecal output by 21 % (P = 0·020) and increased faecal moisture content by 1·6 % units (P = 0·027), whilst decreasing transit time by 17 % (P = 0·012) and decreasing faecal pH by 0·26 units (P < 0·001). Faecal butyrate concentration was increased by 16 % (P = 0·006), butyrate output was increased by 40 % (P = 0·002) and [ß]-glucuronidase activity was lowered by 1·4 µmol/h per g wet faeces compared to the control diet (P < 0·001). Addition of LKFibre to the diet incorporated into food products improved some markers of healthy bowel function and colon cancer risk in men.

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Background: Reliability or validity studies are important for the evaluation of measurement error in dietary assessment methods. An approach to validation known as the method of triads uses triangulation techniques to calculate the validity coefficient of a food-frequency questionnaire (FFQ).

Objective:
To assess the validity of an FFQ estimates of carotenoid and vitamin E intake against serum biomarker measurements and weighed food records (WFRs), by applying the method of triads. Design: The study population was a sub-sample of adult participants in a randomised controlled trial of b-carotene and sunscreen in the prevention of skin cancer. Dietary intake was assessed by a self-administered FFQ and a WFR. Nonfasting blood samples were collected and plasma analysed for five carotenoids (a-carotene, b-carotene, b-cryptoxanthin, lutein, lycopene) and vitamin E. Correlation coefficients were calculated between each of the dietary methods and the validity coefficient was calculated using
the method of triads. The 95% confidence intervals for the validity coefficients were estimated using bootstrap sampling.

Results: The validity coefficients of the FFQ were highest for a-carotene (0.85) and lycopene (0.62), followed by b-carotene (0.55) and total carotenoids (0.55), while the lowest validity coefficient was for lutein (0.19). The method of triads could not be used for b-cryptoxanthin and vitamin E, as one of the three underlying correlations was negative.

Conclusions:
Results were similar to other studies of validity using biomarkers and the method of triads. For many dietary factors, the upper limit of the validity coefficients was less than 0.5 and therefore only strong relationships between dietary exposure and disease will be detected.

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The aim of this study was to determine the presentation and risk factors for depression in adults with mild/moderate intellectual disability (ID). A sample of 151 adults (83 males and 68 females) participated in a semi-structured interview. According to results on the Beck Depression Inventory II, 39.1% of participants evinced symptoms of depression (2 severe, 14 moderate, and 43 mild). Sadness, self-criticism, loss of energy, crying, and tiredness appeared to be the most frequent indicators of depression or risk for depression. A significant difference was found between individuals with and without symptoms of depression on levels of automatic negative thoughts, downward social comparison and self-esteem. Automatic negative thoughts, quality and frequency of social support, self-esteem, and disruptive life events significantly predicted depression scores in people with mild/moderate ID, accounting for 58.1% of the variance.

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Objectives : To determine entry antibody seroprevalence and seroconversion to hepatitis C virus (HCV) and associated risk factors in newly incarcerated prisoners.

Methods : Males and females entering South Australian prisons completed risk factor surveys and were offered HCV-antibody testing. Participants completed additional surveys and, if HCV-negative at last test, underwent further antibody tests at 3-monthly intervals for up to 15 months. Data were analyzed using univariate and multivariate techniques.

Results : HCV seroprevalence among 662 prison entrants was estimated at 42%. Previous injecting history was highly prevalent at entry (64%) and both community and prison injecting independently predicted entry HCV status. Tattooing was not an important risk factor. While community exposure could not be ruled out, three seroconversions were noted in 148 initially HCV-seronegative individuals occurring in a median 121 days – 4.6 per 100 person-years. Prison injecting was infrequently reported, but HCV-seropositive participants were significantly more likely to commence IDU in prison than seronegative participants (p = 0.035).

Conclusions : Entry HCV seroprevalence in South Australian prisoners is extremely high and may have contributed to a ‘ceiling effect’, minimizing the observable seroconversion rate. Greater frequency of injecting among those already infected with HCV represents a significant threat to other prisoners and prison staff.

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This study aimed to: 1) describe the number, frequency, severity of discomfort and effect of symptoms on life of 29 physical symptoms women experienced at 15 to 25 weeks of gestation; 2) explore whether experiencing this group of physical symptoms more frequently and intensely was associated with a higher score of depressive symptoms and lower self-esteem; (3) examine whether discomfort and effect ratings aided prediction of well being over and above symptom frequency; and (4) investigate which individual physical symptoms contributed most to predicting depressive symptoms and self-esteem. Pregnant women (n = 215) completed the Beck Depression Inventory, Rosenberg Self-Esteem Scale, and a physical symptoms questionnaire. Frequency, discomfort, and the effect of physical symptoms all consistently correlated with higher scores for depressive symptoms, but less consistently with lower self-esteem. Discomfort and the effect of symptoms predicted variance in depressive symptoms after accounting for symptom frequency. Higher frequency, more discomfort, and the effect of fatigue and effect of flatulence were related to depressive symptoms. Relationships between pregnancy-related physical symptoms, depressive symptoms, and low self-esteem suggest that when women report any of these constellation of factors, further screening is indicated. A comprehensive assessment of physical symptoms includes frequency, discomfort, and effect on life.

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Factors which may account for the high frequency of macrovascular disease in diabetics are age, sex, cigarette smoking, hypertension, obesity, lack of exercise, diet, hyperglycaemia, hyperinsulinaeroia, hypercholesterolaemia, hypertriglyceridaemia, low HDL-cholesterol concentration, elevated free fatty acid concentration and enhanced platelet aggregation. Twenty seven (13 men and 14 women) non-insulin-dependent diabetics and thirty eight age, height and weight matched healthy subjects (10 men and 28 women) were studied. None of the subjects were smokers, or hypertensive. No subject had any clinical evidence of peripheral arterial disease, coronary heart disease or cerebrovascular disease. All had apparently normal peripheral pulses and normal ankle/arm blood pressure indices. Methods for determining arterial compliance in the segment between the left subclavian artery and each common femoral artery, and proximal resistance at the common femoral artery and posterior tibial artery, have been reviewed and developed. An appropriate food intake methodology for deriving food indices from food records was developed. Biochemical determinants have been made of glucose tolerance, glycosylated haemoglobin, serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, plasma free fatty acid and insulin. A significant decrease in the arterial compliance, and a significant increase in the arterial proximal resistance at the common femoral artery and posterior tibial artery in non-insulin-dependent diabetics, compared with their healthy controls, have been found. Significant negative correlation between arterial compliance and proximal resistance and, a significant positive correlation between the arterial proximal resistance of common femoral artery and posterior tibial artery were found. Differences between control (healthy subjects) and non-insulin-dependent diabetic groups indicate that preclinical peripheral arterial disease can be recognised even in mild diabetics by non-invasive measurement of arterial compliance or proximal resistance. There were significant and negative correlations between arterial compliance and each of blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid and plasma insulin concentration. There were significant and positive correlations between arterial proximal resistance of common femoral artery and posterior tibial artery and each of blood glucose, glycosylated haemoglobin and plasma free fatty acid concentration. Multivariate analysis to examine each of the biochemical factors Including blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid, plasma Insulin and lipids, showed that the factor which most influenced the arterial compliance and the proximal resistance of posterior tibial artery was the glucose level in the fasting state or the glucose response after a glucose load. In addition, the factors which most influenced proximal resistance of the common femoral artery were free fatty acid -level in the fasting state or glucose response after a glucose load. The factors which most influenced arterial compliance were glucose level in men, and the insulin level in the fasting state or the plasma free fatty acid response after a glucose load in women. These findings indicate that blood glucose, plasma free fatty acid and plasma insulin are risk factors for changes in arterial wall characteristic at a stage when no clinical evidence of macrovascular disease is apparent. Arterial compliance was decreased and the proximal resistance of posterior tibial artery was increased in those with a low intake of protective foods compared with those with a high intake whether healthy subjects or non-insulin-dependent diabetics. Arterial compliance was decreased in non-fish eaters compared with the fish eaters whether healthy subjects or non-insulin-dependent diabetics. Proximal resistance of the posterior tibia! artery in non-fish eaters was increased compared with fish eaters in healthy subjects. Overall, food variety, a protective food score consumption and fish consumption emerge as importance determinants of arterial wall characteristics at a stage when no clinical evidence of macrovascular disease is apparent.

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A study was conducted to investigate the possible influence of body size and composition, errors in portion size estimation, level of satisfaction with body size and degree of dietary restraint on the level of reported food intake obtained using both a food frequency questionnaire and weighed food record. The findings suggest that in dietary studies based on weighed food records, 'weight consciousness', as determined using a measure of dietary restraint, could be more important than influence of body size in determining the level of reported intake.

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This longitudinal research found that women reported significant decreases in sexual desire, frequency of intercourse, and sexual satisfaction during pregnancy and at three and six months after childbirth. The psychological factors examined (role quality, relationship satisfaction, fatigue, life satisfaction, and depression) influenced women's changing sexuality over the perinatal period.

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Background: The long-term effects of skipping breakfast on cardiometabolic health are not well understood.

Objective: The objective was to examine longitudinal associations of breakfast skipping in childhood and adulthood with cardiometabolic risk factors in adulthood.

Design:
In 1985, a national sample of 9–15-y-old Australian children reported whether they usually ate breakfast before school. During follow-up in 2004–2006, 2184 participants (26–36 y of age) completed a meal-frequency chart for the previous day. Skipping breakfast was defined as not eating between 0600 and 0900. Participants were classified into 4 groups: skipped breakfast in neither childhood nor adulthood (n = 1359), skipped breakfast only in childhood (n = 224), skipped breakfast only in adulthood (n = 515), and skipped breakfast in both childhood and adulthood (n = 86). Diet quality was assessed, waist circumference was measured, and blood samples were taken after a 12-h fast (n = 1730). Differences in mean waist circumference and blood glucose, insulin, and lipid concentrations were calculated by linear regression.

Results: After adjustment for age, sex, and sociodemographic and lifestyle factors, participants who skipped breakfast in both childhood and adulthood had a larger waist circumference (mean difference: 4.63 cm; 95% CI: 1.72, 7.53 cm) and higher fasting insulin (mean difference: 2.02 mU/L; 95% CI: 0.75, 3.29 mU/L), total cholesterol (mean difference: 0.40 mmol/L; 95% CI: 0.13, 0.68 mmol/L), and LDL cholesterol (mean difference: 0.40 mmol/L; 95% CI: 0.16, 0.64 mmol/L) concentrations than did those who ate breakfast at both time points. Additional adjustments for diet quality and waist circumference attenuated the associations with cardiometabolic variables, but the differences remained significant.

Conclusions: Skipping breakfast over a long period may have detrimental effects on cardiometabolic health. Promoting the benefits of eating breakfast could be a simple and important public health message.