21,636,075 research outputs found
IST Austria Technical Report
We consider the problem of expected cost analysis over nondeterministic probabilistic programs, which aims at automated methods for analyzing the resource-usage of such programs. Previous approaches for this problem could only handle nonnegative bounded costs. However, in many scenarios, such as queuing networks or analysis of cryptocurrency protocols, both positive and negative costs are necessary and the costs are unbounded as well.
In this work, we present a sound and efficient approach to obtain polynomial bounds on the expected accumulated cost of nondeterministic probabilistic programs. Our approach can handle (a) general positive and negative costs with bounded updates in variables; and (b) nonnegative costs with general updates to variables. We show that several natural examples which could not be handled by previous approaches are captured in our framework.
Moreover, our approach leads to an efficient polynomial-time algorithm, while no previous approach for cost analysis of probabilistic programs could guarantee polynomial runtime. Finally, we show the effectiveness of our approach by presenting experimental results on a variety of programs, motivated by real-world applications, for which we efficiently synthesize tight resource-usage bounds
Association Between Objectively Sleep Pattern and Obesity in the Elderly
Background: Previous studies on the relationship between sleep patterns and obesity in the elderly are limited and have conflicting results. Moreover, few studies have measured sleep patterns objectively. In this study, we investigated objective sleep patterns and their relationship with obesity in the elderly in Tehran, Iran.Methods: In this cross-sectional study, 88 elderly (≥60 years old) who were members of health homes of zone 5 in Tehran, Iran, were included by simple random sampling method in 2014. Sleep patterns were objectively assessed using waist actigraphy for a mean of 4.3 ± 1.7 days). Height, weight, and waist circumference (WC) were measured by standard methods and body mass index (BMI) was calculated. Data entry and statistical analyses were performed using SPSS version 21.Results: Mean actigraphy-assessed sleep duration, sleep efficiency (percentage of time in bed spent sleeping), and sleep latency (time required to fall asleep) were 427 ± 62 min, 71.3 ± 18%, and 14.2 ± 3.8 min, respectively. A negative relationship was found between BMI and sleep duration (r = −0.2, p = 0.03), BMI and sleep efficiency (r = −0.3, p=0.01), and WC and sleep efficiency (r = −0.2, p = 0.04). Also, a positive association was observed between BMI and sleep latency (r = 0.4, p = 0.006).Conclusions: In the elderly, actigraphy-assessed sleep duration was associated with obesity and the sleep efficiency was poor in obese participants. It seems that sleep patterns and BMI are correlated with each other. However, there is a need for prospective studies to affirm causal relationships between these constructs
Association Between Objectively Sleep Pattern and Obesity in the Elderly
Background: Previous studies on the relationship between sleep patterns and obesity in the elderly are limited and have conflicting results. Moreover, few studies have measured sleep patterns objectively. In this study, we investigated objective sleep patterns and their relationship with obesity in the elderly in Tehran, Iran.Methods: In this cross-sectional study, 88 elderly (≥60 years old) who were members of health homes of zone 5 in Tehran, Iran, were included by simple random sampling method in 2014. Sleep patterns were objectively assessed using waist actigraphy for a mean of 4.3 ± 1.7 days). Height, weight, and waist circumference (WC) were measured by standard methods and body mass index (BMI) was calculated. Data entry and statistical analyses were performed using SPSS version 21.Results: Mean actigraphy-assessed sleep duration, sleep efficiency (percentage of time in bed spent sleeping), and sleep latency (time required to fall asleep) were 427 ± 62 min, 71.3 ± 18%, and 14.2 ± 3.8 min, respectively. A negative relationship was found between BMI and sleep duration (r = −0.2, p = 0.03), BMI and sleep efficiency (r = −0.3, p=0.01), and WC and sleep efficiency (r = −0.2, p = 0.04). Also, a positive association was observed between BMI and sleep latency (r = 0.4, p = 0.006).Conclusions: In the elderly, actigraphy-assessed sleep duration was associated with obesity and the sleep efficiency was poor in obese participants. It seems that sleep patterns and BMI are correlated with each other. However, there is a need for prospective studies to affirm causal relationships between these constructs
Ariel - Volume 6 Number 4
Editors
Mark Dembert
J.D. Kanofsky
Frank Chervenak
John Lammie
Curt Cummings
Entertainment
Robert Breckenridge
Joe Conti
Gary Kaskey
Photographer
Larry Glazerman
Overseas Editor
Mike Sinason
Humorist
Jim McCann
Staff
Ken Jaffe
Bob Sklaroff
Halley Faust
Jim Burk
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