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.

Prediction Model for Dendrolimus punctatus Walker in Coastal Shelterbelt in Zhejiang Province of China

[Objective] The paper was to establish prediction model for Dendrolimus punctatus Walker in coastal shelterbeh in Zhejiang Province of China. [ Method] Using the principles and methods of SAS software, and according to the correlation analysis and stepwise regression analysis, we selected the relevant meteorological factors from April 1982 to March 2006 as the variables and the population density of D. punctatus from 1983 to 2006 as the dependent variables, to establish the prediction model between insect population density and meteorological factors for D. punctatas in coastal shelterbelt. [ Result] By fitting test, the his- torical compliance rate of the equation was above 85%. When the related data from 2007 to 2011 were used for prediction test, the occurrence condition had small relative error with prediction results except the years seriously affected by natural disasters. [ Conclusion] The paper provides certain reference for pest control against D. punctatus in coastal shelterbelt.

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.

Probability density function and estimation for error of digitized map coordinates in GIS

Traditionally, it is widely accepted that measurement error usually obeys the normal distribution. However, in this paper a new idea is proposed that the error in digitized data which is a major derived data source in GIS does not obey the normal distribution but the p-norm distribution with a determinate parameter. Assuming that the error is random and has the same statistical properties, the probability density function of the normal distribution, Laplace distribution and p-norm distribution are derived based on the arithmetic mean axiom, median axiom and p-median axiom, which means that the normal distribution is only one of these distributions but not the least one. Based on this ideal distribution fitness tests such as Skewness and Kurtosis coefficient test, Pearson chi-square chi(2) test and Kolmogorov test for digitized data are conducted. The results show that the error in map digitization obeys the p-norm distribution whose parameter is close to 1.60. A least p-norm estimation and the least square estimation of digitized data are further analyzed, showing that the least p-norm adjustment is better than the least square adjustment for digitized data processing in GIS.

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.

Nonlinear Fitting Method of Long-Term Distributions for Statistical Analysis of Extreme Negative Surge Elevations

Hydrologic frequency analysis plays an important role in coastal and ocean engineering for structural design and disaster prevention in coastal areas. This paper proposes a Nonlinear Least Squares Method (NLSM), which estimates the three unknown parameters of the Weibull distribution simultaneously by an iteration method. Statistical test shows that the NLSM fits each data sample well. The effects of different parameter-fitting methods, distribution models, and threshold values are also discussed in the statistical analysis of storm set-down elevation. The best-fitting probability distribution is given and the corresponding return values are estimated for engineering design.

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.

Field-based Simplified Approach of Evaluating Knee Extensor Muscle Strength and Size in Male University Freshmen

The purpose of this study was to examine the relationship between field-based simplified approaches and knee extensor muscle strength/size in young men. Knee extensor muscle thickness （MT） of 104 healthy university freshmen was measured at the anterior half of thigh length; maximal voluntary isometric contraction （MVIC） was measured when subjects performed knee extension. Field-based simplified approaches [sit-to-stand, standing long jump （SLJ）, handgrip and upper-leg-50% （thigh） girth] were also measured. MVIC was correlated with SLJ （r = 0.361, P 〈 0.001）, handgrip （r = 0.523, P 〈 0.001） and thigh girth （r = 0.401, P 〈 0.001）, but not with the sit-to-stand test （r = 0.126, P 〉 0.05）. MT was correlated with handgrip （r = 0.317, P 〈 0.001） and thigh girth （r = 0.632, P 〈 0.001）, but not with SLJ （r = 0.038, P 〉 0.05） or the sit-to-stand test （r = 0.145, P 〉 0.05）. A stepwise multiple-regression analysis was applied to the predictor thigh girth to predict knee extensor MT （R2 = 0.399）. To predict knee extensor MVIC, the predictor handgrip, thigh girth and SLJ were applied （R2 = 0.381）. In conclusion, knee extensor muscle strength/size could be evaluated by the field-based simplified approaches, in particular by the thigh girth measurement, which may be major determinant to maintain activities of daily living for healthy young men. However, the 4 field-based simplified approaches appear to be still not of high impact.

Comparative study of probable maximum precipitation and isohyetal maps for mountainous regions, Pakistan

Probable maximum precipitation(PMP) is widely used by hydrologists for appraisal of probable maximum flood(PMF)used for soil and water conservation structures, and design of dam spillways. A number of methods such as empirical, statistical and dynamic are used to estimate PMP, the most favored being statistical and hydro-meteorological. In this paper,PMP estimation in mountainous regions of Pakistan is studied using statistical as well as physically based hydro-meteorological approaches. Daily precipitation, dew point, wind speed and temperature data is processed to estimate PMP for a one-day duration. Maximum precipitation for different return periods is estimated by using statistical approaches such as Gumble and Log-Pearson type-III(LP-III) distribution. Goodness of fit(GOF) test, chi-square test, correlation coefficient and coefficient of determination were applied to Gumble and LP-III distributions. Results reveal that among statistical approaches, Gumble distribution performed the best result compared to LP-III distribution. Isohyetal maps of the study area at different return periods are produced by using the GIS tool, and PMP in mountainous regions varies from 150 to 320 mm at an average value of 230.83 mm. The ratio of PMP for one-day duration to highest observed rainfall(HOR) varied from 1.08 to 1.29 with an average value of 1.18. An appropriate frequency factor(K_m) is very important which is a function of mean for observed precipitation and PMP for 1-day duration, and K_m values varies from 2.54 to 4.68. The coefficient of variability(C_v) varies from minimum value of 28% to maximum value of 43.35%. It was concluded that the statistical approach gives higher results compared to moisture maximization(MM) approach. In the hydro-meteorological approach, moisture maximization(MM) and wind moisture maximization(WMM) techniques were applied and it was concluded that wind moisture maximization approach gives higher results of PMP as compared to moisture maximization approach as well as for Hershfield technique. Therefore, it is suggested that MM approach is the most favored in the study area for PMP estimation, which leads to acceptable results, compared to WMM and statistical approaches.

Correlations of Handgrip Strength with Selected Anthropometric Variables and Flexibility Measure in Indian Inter-university Handball Players

The purpose of this study was of two-fold： firstly to estimate the handgfip strength oflndian inter-university handball players and, secondly to search the correlations of it with selected anthropometric variables and flexibility measure. To serve this purpose, a total of eight anthropometric variables, such as height, weight, body mass index, upper arm length, forearm length, total arm length, hand length and hand breadth, flexibility measure such as, sit and reach test, and right and left handgrip strength were measured on purposely selected 150 Indian inter-university handball players aged 18-25 years collected from the inter-university competition held in Guru Nanak Dev University, Amritsar, India during September, 2013. An adequate number of controls （n = 102） were also taken from the same place for comparisons. The results showed statistically significant between-group differences （P 〈 0.006-0.001） among the male and female handball players and controls in all the variables studied. Statistically significant positive correlations （P _〈 0.023-0.001） of both right and left handgrip strength were found with all the variables studied, except BMI, in Indian inter-university handball players. In conclusion, it may be stated that handgrip strength may be used as one of the indicating factors for physical strength as well as the flexibility measure of the handball players.

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).

Blind spectrum sensing based on the ratio of mean square to variance

Anderson-Darling （AD） sensing, characteristic function （CF） sensing and order statistic （OS） sensing are three common spectrum sensing （SS） methods based on goodness of fit （GOF） testing. However, AD and OS sensing needs the prior information of noise variance; CF and OS sensing have high computation complexity. To circumvent those difficulties, in this paper, the ratio of the mean square to variance （RM2V） of the samples, after deriving its probability density function （PDF）, is employed as a test statistic to detect the availability of the vacant spectrum in the cognitive radio （CR） system. Then a blind SS method based on RM2V is proposed, which is dubbed as RM2V sensing, and its exact theoretical threshold is obtained via the derived PDF of RM2V. The performance of RM2V sensing is evaluated by theoretical analysis and Monte Carlo simulations. Comparing with the conventional energy detection （ED）, AD, CF and OS sensing, RM2V sensing, with no need of noise variance, has advantages from the aspect of computation complexity and detection performance.

Consistency of Chi-Squared Test with Varying Number of Classes

The classical chi-squared goodness of fit test assumes the number of classes is fixed,meanwhile the test statistic has a limiting chi-square distribution under the null hypothesis.It is well known that the number of classes varying with sample size in the test has attached more and more attention.However,in this situation,there is not theoretical results for the asymptotic property of such chi-squared test statistic.This paper proves the consistency of chi-squared test with varying number of classes under some conditions.Meanwhile,the authors also give a convergence rate of KolmogorovSimirnov distance between the test statistic and corresponding chi-square distributed random variable.In addition,a real example and simulation results validate the reasonability of theoretical result and the superiority of chi-squared test with varying number of classes.

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.