Frequency Domain Goodness of Fit Test Based Spectrum Sensing Method with Dynamically Varying Noise

In cognitive radio networks,spectrum sensing under circumstances of dynamically varying noise and lacking prior information is a key challenge to the conventional spectrum sensing algorithms.Since the necessary information is rather difficult to obtain practically,most existing spectrum sensing methods are fettered in applications.Motivated by these,in this paper,a Frequency domain Goodness of Fit Test(FGoF)based spectrum sensing method is proposed.The FGoF makes full use of underlying information in Guard-Bands and the advantages of GoF test works for any distribution.Analytical and simulated results show that the FGoF is a robust spectrum sensing method in cognitive radio with the inherent advantages of invulnerability to dynamically varying noise.

Temporal trends in 6-minute walking distance for older Japanese adults between 1998 and 2017

Background:The 6-minute walking distance(6MWD)is an excellent measure of both functional endurance and health.The primary aim of this study was to estimate temporal trends in 6MWD for older Japanese adults between 1998 and 2017;the secondary aim was to estimate concurrent trends in body size(i.e.,height and mass)and self-reported participation in exercise/sport.Methods:Adults aged 65-79 years were included.Annual nationally representative 6MWD data(n=103,505)for the entire period were obtained from the Japanese Ministry of Education,Culture,Sports,Science and Technology.Temporal trends in means(and relative frequencies)were estimated at the gender-age level by best-fitting sample-weighted linear/polynomial regression models,with national trends estimated by a post-stratified population-weighting procedure.Temporal trends in distributional variability were estimated as the ratio of coefficients of variation.Results:Between 1998 and 2017 there was a steady,moderate improvement in mean 6MWD(absolute=45 m(95%confidence interval(95%CI):43-47);percent=8.0%(95%CI:7.6%-8.4%);effect size=0.51(95%CI:0.48-0.54)).Gender-and age-related temporal differences in means were negligible.Variability in 6MWD declined substantially(ratio of coefficients of variation=0.89,95%CI:0.87-0.92),with declines larger for women compared to men,and for 75-79-year-olds compared to 65-74-year-olds.Correspondingly,there were moderate and negligible increases in mean height and mass,respectively,and negligible increases in the percentage who participated in exercise/sport at least 3 days per week and at least 30 min per session.Conclusion:There has been a steady,moderate improvement in mean 6MWD for older Japanese adults since 1998,which is suggestive of corresponding improvements in both functional endurance and health.The substantial decline in variability indicates that the temporal improvement in mean 6MWD was not uniform across the distribution.Trends in 6MWD are probably influenced by corresponding trends in body size and/or participation in exercise/sport.

Inverse Length Biased Maxwell Distribution:Statistical Inference with an Application

In this paper,we suggested and studied the inverse length biased Maxell distribution(ILBMD)as a new continuous distribution of one parameter.The ILBMD is obtained by considering the inverse transformation technique of the Maxwell length biased distribution.Statistical characteristics of the ILBMD such as the moments,moment generating function,mode,quantile function,the coefficient of variation,coefficient of skewness,Moors and Bowley measures of kurtosis and skewness,stochastic ordering,stress-strength reliability,and mean deviations are obtained.In addition,the Bonferroni and Lorenz curves,Gini index,the reliability function,the hazard rate function,the reverse hazard rate function,the odds function,and the distributions of order statistics for the ILBMD,are presented.The ILBMD parameter is estimated using the maximum likelihood method,the method of moments,the maximum product of spacing technique,the ordinary and weight least square procedures,and the Cramer-Von-Mises methods.The Fishers information,as well as the Rényi and q-entropies,are derived.To investigate the usefulness of the proposed lifetime distribution and to illustrate the purpose of the study,a real dataset of the relief times of 20 patients receiving an analgesic is used.

Risk Factors Associated with Non-Compliance with Respiratory Protection Programs among Firefighters

Non-compliance with respiratory protection programs among firefighters may put them at increased risk of injury and illness from occupational exposures during fire extinguishing activities. This research aims to characterize respiratory protection practices among Florida firefighters. This information will allow better understanding of factors that are associated with non-compliance with respiratory protection guidelines. A survey questionnaire was used to characterize Florida fire departments in this cross-sectional study. Four hundred and seventy-seven surveys were administered to Florida firefighters both in person and electronically to collect information regarding firefighter knowledge and participation in their respective respiratory protection programs during the past twelve months. Survey questions were developed from the model set by the National Fire Protection Association (NFPA) which provides standards and regulations regarding firefighter protections. Summary statistics regarding firefighter department size, coverage area, and firefighter employment type were produced. Multinomial logistic regression analysis was performed to evaluate factors that impact respiratory protection programs. The 477 respondents were 91% male with a mean age of 39 years old (range 21 - 65 years). The majority of respondents, 76%, were non-smokers, 21% former smokers, and 3% current smokers. In regard to ethnicity, respondents were 77% Caucasian, 13% Hispanic, 3% African American, and 4% other. Most respondents were career firefighters, 97%, with less than ten years of experience, 44%, working in a fire department with at least 21 firefighters, 98%. Most respondents, 80%, had a written respiratory program in place. The most cited reason for not having implemented a written respiratory protection program was lack of knowledge related to the program. Multinomial logistic regression analysis of departments with response areas of at least 250,000 square miles produced a statistically significant 0.444 (0.219 - 0.901 CI) odds ratio for having a written respiratory program as compared to those with a less than 10,000 square miles response area. Additional resources need to be given to Florida fire departments to ensure that all firefighters receive adequate respiratory protection in accordance with NFPA guidelines. There is an association between fire departments with large response areas and non-compliance with respiratory protection guidelines in regard to: having a written respiratory program, the frequency of respiratory fit testing, and the frequency of medical fitness testing. This suggests that rural fire departments need additional resources to ensure firefighters are adequately protected. Additional research should focus on why these differences exist in the rural fire departments. Respondents stating a lack of knowledge or no requirement for a written respiratory program suggest that future efforts should focus on respiratory protection education and training.

A method for threshold selection in load extrapolation based on multiple criteria decision-making technology

In order to establish an accurate peak over threshold(POT)model for reasonable load extrapolation,a new threshold selection method based on multiple criteria decision making(MCDM)technology is proposed.The fitting test criterion is taken into consideration in the method.For each candidate threshold,the fitting values of several fitting test criteria are integrated into a comprehensive evaluation value through entropy method and MCDM technology.The threshold corresponding to the minimum comprehensive evaluation value is assumed as the optimal threshold.A random simulation study is carried out to evaluate the performance of the method and to compare them with other literature methods.Genuine load data are applied the proposed method.Both the results shown that the proposed method could be seen as an additional method that complements existing threshold selection methods.

Speed of Thought and Speed of Feet:Examining Perceptual-Cognitive Expertise and Physical Performance in an English Football Academy

The world's greatest professional football players are able to execute effective tactical decisions as well as fulfil various physical demands.However,the degree to which both are associated with greater potential in a football academy is unknown.Therefore,the aim of this study was to investigate decision-making skill and physical performance as contributing factors to coach potential rankings in an English football academy.Ninety-eight outfield academy players(Foundation Development Phase[FDP]under-9 to under-11 n=40;Youth Development Phase[YDP]under-12 to under-16 n=58)participated in the study.They engaged in 45 film-based simulations at two occlusion phases(e.g.,the visual display is cut-off at a precise time during an action),firstly"during"and secondly"post"execution,to examine decision-making skill.Participants also completed four fitness tests to examine physical performance.A classification of"higher-potentials"(top third)and"lower-potentials"(bottom third)were applied through coach rankings.Independent t-tests compared the decision-making and physical performance tests.Higher-potentials made significantly more accurate decisions within the"post"phase within the FDP(P<0.05)and the"during"phase within the YDP(P<0.05).Additionally,higher-potentials were significantly faster for the 0-30 m sprint in both the FDP and YDP(P<0.05),with higher-potentials within the YDP also significantly faster in the 0-10 m sprint(P<0.05)and jumped significantly higher in the countermovement jump(P<0.05).These findings indicated that greater football potential may be associated with superior perceptual-cognitive expertise and quicker sprint ability in both academy age phases,with a greater discriminatory function within the older cohort.

Associations Between Two Measures of Trunk Muscular Endurance Among Male Law Enforcement Officers

Purpose The purpose of this study was to explore the relationship between two measures of trunk muscular endurance.Methods Retrospective data for 520 male law enforcement officers(age 40.16±7.71 years;height=1.81±0.07 m;body mass=94.4±15.01 kg)belonging to a single US based law enforcement agency were used for this analysis.The data provided included:age,height,body mass,sit-up repetitions completed in 1-min(SU)and time to completion for the isometric prone plank(IPP).A Pearson’s product correlation coefficient was used to determine the relationships between the SU and IPP.Results Significant(P<0.001)moderate(r=0.594,R^(2)=0.352)relationships were discovered between the SU and IPP.Conclusion Based on the results of this study it appears that both the SU and IPP tests are appropriate for evaluating trunk muscular endurance,but measure separate qualities(i.e.,dynamic and static muscular endurance).