To control movement,the brain has to integrate proprioceptive information from a variety of mechanoreceptors.The role of proprioception in daily activities,exercise,and sports has been extensively investigated,using d...To control movement,the brain has to integrate proprioceptive information from a variety of mechanoreceptors.The role of proprioception in daily activities,exercise,and sports has been extensively investigated,using different techniques,yet the proprioceptive mechanisms underlying human movement control are still unclear.In the current work we have reviewed understanding of proprioception and the three testing methods:threshold to detection of passive motion,joint position reproduction,and active movement extent discrimination,all of which have been used for assessing proprioception.The origin of the methods,the different testing apparatus,and the procedures and protocols used in each approach are compared and discussed.Recommendations are made for choosing an appropriate technique when assessing proprioceptive mechanisms in different contexts.展开更多
Purpose： Acute exercise has been linked to the facilitation of executive function, but little is known regarding executive function assessed by the Wisconsin Card Sorting Test （WCST）. The present research consisted...Purpose： Acute exercise has been linked to the facilitation of executive function, but little is known regarding executive function assessed by the Wisconsin Card Sorting Test （WCST）. The present research consisted of two experiments aimed to determine whether acute aerobic exercise influences successive WCST performance. Methods： In Study 1, 27 young adults were randomly assigned to the exercise or reading control group and then instiucted to perform the WCST before and after assigned treatment. In exercise group, participants completed a single bout aerobic exercise with moderate intensity for 20 min on a stationary bike. A similar experimental protocol was replicated in Study 2 with 24 late middle-aged adults to look for age differences during adulthood and control for a potential ceiling effect at young adult age. Results： Although a significant time effect was observed in young adults, both studies revealed that there was no main effect for treatment or an interaction between treatment and time on any of the WCST indices. Conclusion： Acute aerobic exercise failed to influence executive function as assessed by the WCST, revealing that this classical neuropsy- chological test tapping executive function may not be sensitive to acute exercise. Our findings suggest that acute exercise does not broadly affect the entire family of executive functions, or its effect on a specific aspect of executive function may be task-dependent, as proposed by Etnier and Chanj~ （2009）.展开更多
Aiming at the higher bit-rate occupation of motion vector encoding and more time load of full-searching strategies, a multi-resolution motion estimation and compensation algorithm based on adjacent prediction of frame...Aiming at the higher bit-rate occupation of motion vector encoding and more time load of full-searching strategies, a multi-resolution motion estimation and compensation algorithm based on adjacent prediction of frame difference was proposed.Differential motion detection was employed to image sequences and proper threshold was adopted to identify the connected region.Then the motion region was extracted to carry out motion estimation and motion compensation on it.The experiment results show that the encoding efficiency of motion vector is promoted, the complexity of motion estimation is reduced and the quality of the reconstruction image at the same bit-rate as Multi-Resolution Motion Estimation(MRME) is improved.展开更多
This paper presents a vision-based obstacle avoidance method for blind pedestrians in an outdoor sidewalk environ- ment. Unlike many existing travel-aid systems using stereo-vi- sion based methods, the proposed method...This paper presents a vision-based obstacle avoidance method for blind pedestrians in an outdoor sidewalk environ- ment. Unlike many existing travel-aid systems using stereo-vi- sion based methods, the proposed method is able to get obstacle position as well as user motion information by just one monocu- lar camera fixed at the belly of the user. To achieve this goal, a top-view transformation of the road image is used for obstacle detection and user motion estimation, based on which a grid map is generated for navigation. For detection part, the bottom points of erect obstacles are detected by extracting local-maxima and minima on the top-view image while user motion is estimat- ed by analysing the optical flow vector field in the user sur- rounding area. For the obstacle avoidance part, a step score is calculated on the grid map for evaluating the safety of next moving step. Experiments with several sidewalk video-clips show that the proposed obstacle avoidance method is able to provide useful guidance instructions under certain sidewalk environments.展开更多
With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract d...With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract developers' interests to transfer video encoding from specialized hardware to more flexible software. In this paper, the encoding structure is set up first to support complexity scalability; then a lot of high performance algorithms are used on the key time-consuming modules in coding process; finally, at programming level, processor characteristics are considered to improve data access efficiency and processing parallelism. Other programming methods such as lookup table are adopted to reduce the computational complexity. Simulation results showed that these ideas could not only improve the global performance of video coding, but also provide great flexibility in complexity regulation.展开更多
Objective To assess the influence of age on the error of estimate （EE） of maximal oxygen uptake （VO2max） using sex and population specific-equations in cycle ergometer exercise testing, since estimated VO2 max is ...Objective To assess the influence of age on the error of estimate （EE） of maximal oxygen uptake （VO2max） using sex and population specific-equations in cycle ergometer exercise testing, since estimated VO2 max is associated with a substantial EE, often exceeding 20%, possibly due to intrinsic variability of mechanical efficiency. Methods 1850 adults （68% men）, aged 18 to 91 years, underwent maximal cycle ergometer cardiopulmonary exercise testing. Cardiorespiratory fitness （CRF） was assessed relative to sex and age [younger （18 to 35 years）, middle-aged （36 to 60 years） and older （〉 60 years）]. VO2max [mL.（kg.min）-1] was directly measured by assessment of gas exchange and estimated using sex and population specific-equations. Measured and estimated values of VO2max and related EE were compared among the three age- and sex-specific groups. Results Directly measured VO2max of men and women were 29.5 ± 10.5 mL.（kg.min）-1 and 24.2 ± 9.0 mL.（kg·min） -1 （P 〈 0.01）. EE [mL·（kg·min）-1] and percent errors （%E） for men and women had similar values, 0.5 ± 3.2 and 0.4 ± 2.9 mL·（kg·min）-1, and -0.8 ± 13.1% and -1.7 ± 15.4% （P 〉 0.05）, respectively. EE and %E for each age-group were, respectively, for men： younger = 1.9 ± 4.1 mL·（kg·min）-1 and 3.8 ± 10.5%, middle-aged = 0.6 ± 3.1 mL.（kg·min）-1 and 0.4 ± 10.3%, older = -0.2 ± 2.7 mL·（kg·min） -1 and -4.2 ± 16.6% （P 〈 0.01）; and for women： younger = 1.2 ± 3.1 mL.（kg.min）-1 and 2.7 ±10.0%, middle-aged = 0.7 ± 2.8 mL·（kg·min）-1 and 0.5 ± 11.1%, older = -0.8 ± 2.3 mL-（kg·min）-1 and -9.5 ± 22.4% （P 〈 0.01）. Conclusion VO2max were underestimated in younger age-groups and were overestimated in older age groups. Age significantly influences the magnitude of the EE of VO2max in both men and women and should be considered when CRF is estimated using population specific equations, rather than directly measured.展开更多
Background： Prevalence of eating disorders （EDs） among college-aged athletes has risen in recent years. Although measures exist for assessing EDs, these measures have not been thoroughly reviewed in athletes. This ...Background： Prevalence of eating disorders （EDs） among college-aged athletes has risen in recent years. Although measures exist for assessing EDs, these measures have not been thoroughly reviewed in athletes. This study reviewed the validity and reliability evidence of the commonly used measures for assessing EDs in athlete populations aged 18--26 years. Methods： Databases were searched for studies of regarding ED on male and/or female athletes. Inclusion criteria stated the study （a） assessed EDs in an athlete population 18--26 years of age and （b） investigated EDs using a psychometric measure found valid and/or reliable in a non- athlete population and/or athlete population. Results： Fifty studies met the inclusion criteria. Seven and 22 articles, respectively, studied EDs behaviors in male and female athletes whereas 21 articles studied EDs in combined-gender samples. The five most commonly used measures were the Eating Attitudes Test （EAT）, Eating Disorder Inventory （EDI）, Bulimia Test-Revised （BULIT-R）, Questionnaire for Eating Disorder Diagnosis （QEDD）, and the Eating Disorder Examination Questionnaire （EDE-Q）. Conclusion： Only seven studies calculated validity coefficients within the study whereas 47 cited the validity coefficient. Twenty-six calculated a reliability coefficient whereas 47 cited the reliability of the ED measures. Four studies found validity evidence for the EAT, EDI, BULIT-R, QEDD, and EDE-Q in an athlete population. Few studies reviewed calculated validity and reliability coefficients of ED measures. Cross- validation of these measures in athlete populations is clearly needed.展开更多
基金the University of Canberra,Key Laboratory of Exercise and Health Sciences of Ministry of Education,Shanghai University of Sport and Shanghai Municipal Science and Technology Commission (No.13490503800)supported by Shanghai Pujiang Program (No.15PJ1407600)
文摘To control movement,the brain has to integrate proprioceptive information from a variety of mechanoreceptors.The role of proprioception in daily activities,exercise,and sports has been extensively investigated,using different techniques,yet the proprioceptive mechanisms underlying human movement control are still unclear.In the current work we have reviewed understanding of proprioception and the three testing methods:threshold to detection of passive motion,joint position reproduction,and active movement extent discrimination,all of which have been used for assessing proprioception.The origin of the methods,the different testing apparatus,and the procedures and protocols used in each approach are compared and discussed.Recommendations are made for choosing an appropriate technique when assessing proprioceptive mechanisms in different contexts.
基金partially supported by a grant from Ministry of Science and Technology to Yu-Kai Chang (NSC 102-2918-1-179-001102-2420-H-179-001-MY3)
文摘Purpose： Acute exercise has been linked to the facilitation of executive function, but little is known regarding executive function assessed by the Wisconsin Card Sorting Test （WCST）. The present research consisted of two experiments aimed to determine whether acute aerobic exercise influences successive WCST performance. Methods： In Study 1, 27 young adults were randomly assigned to the exercise or reading control group and then instiucted to perform the WCST before and after assigned treatment. In exercise group, participants completed a single bout aerobic exercise with moderate intensity for 20 min on a stationary bike. A similar experimental protocol was replicated in Study 2 with 24 late middle-aged adults to look for age differences during adulthood and control for a potential ceiling effect at young adult age. Results： Although a significant time effect was observed in young adults, both studies revealed that there was no main effect for treatment or an interaction between treatment and time on any of the WCST indices. Conclusion： Acute aerobic exercise failed to influence executive function as assessed by the WCST, revealing that this classical neuropsy- chological test tapping executive function may not be sensitive to acute exercise. Our findings suggest that acute exercise does not broadly affect the entire family of executive functions, or its effect on a specific aspect of executive function may be task-dependent, as proposed by Etnier and Chanj~ （2009）.
基金Supported by the National Natural Science Foundation of China (No. 60803036)the Scientific Research Fund of Heilongjiang Provincial Education Department (No.11531013)
文摘Aiming at the higher bit-rate occupation of motion vector encoding and more time load of full-searching strategies, a multi-resolution motion estimation and compensation algorithm based on adjacent prediction of frame difference was proposed.Differential motion detection was employed to image sequences and proper threshold was adopted to identify the connected region.Then the motion region was extracted to carry out motion estimation and motion compensation on it.The experiment results show that the encoding efficiency of motion vector is promoted, the complexity of motion estimation is reduced and the quality of the reconstruction image at the same bit-rate as Multi-Resolution Motion Estimation(MRME) is improved.
基金supported by the Brain Korea 21 Project in2010the ITRC support program supervised by the NIPA(National IT Industry Promotion Agency)(NIPA-2010-(C1090-1021-0010))
文摘This paper presents a vision-based obstacle avoidance method for blind pedestrians in an outdoor sidewalk environ- ment. Unlike many existing travel-aid systems using stereo-vi- sion based methods, the proposed method is able to get obstacle position as well as user motion information by just one monocu- lar camera fixed at the belly of the user. To achieve this goal, a top-view transformation of the road image is used for obstacle detection and user motion estimation, based on which a grid map is generated for navigation. For detection part, the bottom points of erect obstacles are detected by extracting local-maxima and minima on the top-view image while user motion is estimat- ed by analysing the optical flow vector field in the user sur- rounding area. For the obstacle avoidance part, a step score is calculated on the grid map for evaluating the safety of next moving step. Experiments with several sidewalk video-clips show that the proposed obstacle avoidance method is able to provide useful guidance instructions under certain sidewalk environments.
文摘With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract developers' interests to transfer video encoding from specialized hardware to more flexible software. In this paper, the encoding structure is set up first to support complexity scalability; then a lot of high performance algorithms are used on the key time-consuming modules in coding process; finally, at programming level, processor characteristics are considered to improve data access efficiency and processing parallelism. Other programming methods such as lookup table are adopted to reduce the computational complexity. Simulation results showed that these ideas could not only improve the global performance of video coding, but also provide great flexibility in complexity regulation.
文摘Objective To assess the influence of age on the error of estimate （EE） of maximal oxygen uptake （VO2max） using sex and population specific-equations in cycle ergometer exercise testing, since estimated VO2 max is associated with a substantial EE, often exceeding 20%, possibly due to intrinsic variability of mechanical efficiency. Methods 1850 adults （68% men）, aged 18 to 91 years, underwent maximal cycle ergometer cardiopulmonary exercise testing. Cardiorespiratory fitness （CRF） was assessed relative to sex and age [younger （18 to 35 years）, middle-aged （36 to 60 years） and older （〉 60 years）]. VO2max [mL.（kg.min）-1] was directly measured by assessment of gas exchange and estimated using sex and population specific-equations. Measured and estimated values of VO2max and related EE were compared among the three age- and sex-specific groups. Results Directly measured VO2max of men and women were 29.5 ± 10.5 mL.（kg.min）-1 and 24.2 ± 9.0 mL.（kg·min） -1 （P 〈 0.01）. EE [mL·（kg·min）-1] and percent errors （%E） for men and women had similar values, 0.5 ± 3.2 and 0.4 ± 2.9 mL·（kg·min）-1, and -0.8 ± 13.1% and -1.7 ± 15.4% （P 〉 0.05）, respectively. EE and %E for each age-group were, respectively, for men： younger = 1.9 ± 4.1 mL·（kg·min）-1 and 3.8 ± 10.5%, middle-aged = 0.6 ± 3.1 mL.（kg·min）-1 and 0.4 ± 10.3%, older = -0.2 ± 2.7 mL·（kg·min） -1 and -4.2 ± 16.6% （P 〈 0.01）; and for women： younger = 1.2 ± 3.1 mL.（kg.min）-1 and 2.7 ±10.0%, middle-aged = 0.7 ± 2.8 mL·（kg·min）-1 and 0.5 ± 11.1%, older = -0.8 ± 2.3 mL-（kg·min）-1 and -9.5 ± 22.4% （P 〈 0.01）. Conclusion VO2max were underestimated in younger age-groups and were overestimated in older age groups. Age significantly influences the magnitude of the EE of VO2max in both men and women and should be considered when CRF is estimated using population specific equations, rather than directly measured.
文摘Background： Prevalence of eating disorders （EDs） among college-aged athletes has risen in recent years. Although measures exist for assessing EDs, these measures have not been thoroughly reviewed in athletes. This study reviewed the validity and reliability evidence of the commonly used measures for assessing EDs in athlete populations aged 18--26 years. Methods： Databases were searched for studies of regarding ED on male and/or female athletes. Inclusion criteria stated the study （a） assessed EDs in an athlete population 18--26 years of age and （b） investigated EDs using a psychometric measure found valid and/or reliable in a non- athlete population and/or athlete population. Results： Fifty studies met the inclusion criteria. Seven and 22 articles, respectively, studied EDs behaviors in male and female athletes whereas 21 articles studied EDs in combined-gender samples. The five most commonly used measures were the Eating Attitudes Test （EAT）, Eating Disorder Inventory （EDI）, Bulimia Test-Revised （BULIT-R）, Questionnaire for Eating Disorder Diagnosis （QEDD）, and the Eating Disorder Examination Questionnaire （EDE-Q）. Conclusion： Only seven studies calculated validity coefficients within the study whereas 47 cited the validity coefficient. Twenty-six calculated a reliability coefficient whereas 47 cited the reliability of the ED measures. Four studies found validity evidence for the EAT, EDI, BULIT-R, QEDD, and EDE-Q in an athlete population. Few studies reviewed calculated validity and reliability coefficients of ED measures. Cross- validation of these measures in athlete populations is clearly needed.
