Initiated by Chinese Red Cross Foundation and sponsored by American .General Business Association, Chinese Nuwa (a goddess-creator of the Chinese nation) Culture Large-scale Activities for Public Interests undertake...Initiated by Chinese Red Cross Foundation and sponsored by American .General Business Association, Chinese Nuwa (a goddess-creator of the Chinese nation) Culture Large-scale Activities for Public Interests undertaken by Beijing Absolute Challenge International Advertising Co., Ltd. has recently commenced in an all-round way. A grand ceremony will be held at Nuwa Plaza in Shexian County, Hebei Province on Septemper 24, 2007.展开更多
Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambi...Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambiguity(IBA) increases as the directional difference between beams becomes smaller.An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA.In the district near the base station(BS),all antenna elements(AEs) were activated to generate two beams.As the distance from the train to the BS increased,only the minimum number of AEs satisfying the resolution criterion would be activated.At the cell edge,one beam was switched off due to intolerable IBA.The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival(DOA) estimation error.展开更多
Public parks provide many benefits to the community as the representatives of green area. The allocation of public places plays an extremely important role in the daily lives of inhabitants especially for recreational...Public parks provide many benefits to the community as the representatives of green area. The allocation of public places plays an extremely important role in the daily lives of inhabitants especially for recreational use that could enhance the quality of life of residents in the vicinity. To understand park users’ behavior is one of the most important prerequisites for as-sessing the participation in public service from the park users’ point of view. The pattern of park utilization on location and activity selection are important elements in behavioral study, while the public parks topograph may also influence the typical user’s be-havior. Questionnaire survey on park utilization was used to investigate the interaction between activity involvement and recrea-tional location with the use of linear discriminant analysis (LDA) model. The study found that public park users’ behavior is influenced not only by social characteristics but also by the recreational activities and their specific location characteristics. We found that about 45 percent of park visitors are local residents living within a radius of 3 km preferred travel to parks near their residential area. This implies that location selection behavior is correlated with travel distance, travel time and travel cost. Visit frequencies and on site expenditures reflect the recreation behavior for different type of activities. The overall information can be usefully applied by decision makers to launch appropriate public policy in consistence with the useful results of this study.展开更多
The objective of this study was to clarify the effectiveness of expressing activities in a virtual reality(VR)system for public space planning to support consensus building with citizens,based on the idea that it is i...The objective of this study was to clarify the effectiveness of expressing activities in a virtual reality(VR)system for public space planning to support consensus building with citizens,based on the idea that it is important to consider people’s activities when creating attractive public spaces.We constructed a VR system comprising a background expressed in 3D computer graphics(3DCG)and activities expressed in real video image.As a result of the evaluation experiment,it became easier to visualize the utilization of space by expressing an activity.Although its effectiveness was clarified,some problems regarding the functioning of the system were highlighted.展开更多
Large-scale space membrane antennas have significant potential in satellite communication,space-based early warning,and Earth observation.Because of their large size and high flexibility,the dynamic analysis and contr...Large-scale space membrane antennas have significant potential in satellite communication,space-based early warning,and Earth observation.Because of their large size and high flexibility,the dynamic analysis and control of membrane antenna are challenging.To maintain the working performance of the antenna,the pointing and surface accuracies must be strictly maintained.Therefore,the accurate dynamic modeling and effective active control of large-scale space membrane antennas have great theoretical significance and practical value,and have attracted considerable interest in recent years.This paper reviews the dynamics and active control of large-scale space membrane antennas.First,the development and status of large-scale space membrane antennas are summarized.Subsequently,the key problems in the dynamics and active control of large membrane antennas,including the dynamics of wrinkled membranes,large-amplitude nonlinear vibration,nonlinear model reduction,rigid-flexible-thermal coupling dynamic modeling,on-orbit modal parameter identification,active vibration control,and wave-based vibration control,are discussed in detail.Finally,the research outlook and future trends are presented.展开更多
With an increase in rural-to-urban migration, a rapidly aging population, and the rising risk of developing noncommunicable diseases in China,it is important to understand the epidemiology of physical activity(PA) and...With an increase in rural-to-urban migration, a rapidly aging population, and the rising risk of developing noncommunicable diseases in China,it is important to understand the epidemiology of physical activity(PA) and health in the context of disease prevention and population health.Despite its public health importance, there is a significant lack of knowledge about PA in older Chinese adults that may hamper primary prevention efforts of health promotion in an increasingly aging population. To fill this gap, this article presents a narrative review of PA in the older Chinese adult population with a special focus on residential settings(i.e., urban and rural). Using existing studies, the review examines overall PA patterns and their correlates and discusses public health implications and future research. Although there are some preliminary indications of urban and rural differences in PA in the aging population in China, continued research efforts are needed to facilitate primary prevention efforts aimed at reducing noncommunicable diseases and promoting an active lifestyle among the largest population of older people in the world.展开更多
In late July and early August 2018,Northeast China suffered from extremely high temperatures,with the maxium temperature anomaly exceeding 6°C.In this study,the large-scale circulation features associated with th...In late July and early August 2018,Northeast China suffered from extremely high temperatures,with the maxium temperature anomaly exceeding 6°C.In this study,the large-scale circulation features associated with this heat wave over Northeast China are analyzed using station temperature data and NCEP–NCAR reanalysis data.The results indicate that strong anomalous positive geopotential height centers existed from the lower to upper levels over Northeast China,and the related downward motions were directly responsible for the extreme high-temperature anomalies.The northwestward shift of the western Pacific subtropical high(WPSH)and the northeastward shift of the South Asian high concurrently reinforced the geopotential height anomalies and descending flow over Northeast China.In addition,an anomalous Pacific–Japan pattern in the lower troposphere led to the northwestward shift of the WPSH,jointly favoring the anomalous geopotential height over Northeast China.Two wave trains emanating from the Atlantic region propagated eastwards along high latitudes and midlatitudes,respectively,and converged over Northeast China,leading to the enhancement of the geopotential height anomalies.展开更多
Background: Based on the transtheoretical model, the current study investigated whether awareness of physical activity(PA) recommendations had an impact on the stages of PA behavior change and levels of PA among Chine...Background: Based on the transtheoretical model, the current study investigated whether awareness of physical activity(PA) recommendations had an impact on the stages of PA behavior change and levels of PA among Chinese college students.Methods: In Study 1, with a cross-sectional study design, 9826 students were recruited, and their knowledge of international PA recommendations,PA stage distribution, and self-reported PA level were surveyed. Pearson's χ2 test was used to test whether those participants who were aware and not aware of PA guidelines were equally distributed across the stages of PA behavior, and independent t test was conducted to test the group difference in the actual levels of PA. In Study 2, 279 students who were not aware of the PA recommendations were randomly allocated to either an intervention group or a control group, and only those in the intervention group were presented with international PA guidelines. In both groups,students' PA stages and PA level were examined before the test and then 4 months post-test. Mc Nemar's test for correlated proportions and repeated-measures analysis of variance were conducted to examine the changes in PA stage membership and PA level after the intervention.Results: Study 1 results revealed that only 4.4% of the surveyed students had correct knowledge of PA recommendations. Those who were aware of the recommendations were in later stages of PA behavior(χ~2(4) = 167.19, p < 0.001). They were also significantly more physically active than those who were not aware of the recommendations(t(443.71) = 9.00, p < 0.001, Cohen's d = 0.53). Study 2 results demonstrated that the intervention group participants who were at the precontemplation and contemplation stages at the pre-test each progressed further in the PA stages in the post-test(χ~2(1) = 112.06, p < 0.001; χ~2(1) = 118.76, p = 0.03, respectively), although no significant change in PA level was observed(t(139) < 1, p = 0.89).Conclusion: The results showed that awareness of the PA recommendations was associated with higher stages and levels of PA behavior, and a brief educational exposure to PA recommendations led to improved stages of PA behavior but no change in the levels of PA among Chinese college students. More effective public health campaign strategies are needed to promote the dissemination of the PA recommendations and to raise the awareness of the Chinese student population.展开更多
Background: Preliminary evidence among adults suggests that the ways in which individuals think about their physical activity(PA) behavior is more closely associated with their well-being than self-reported PA. This s...Background: Preliminary evidence among adults suggests that the ways in which individuals think about their physical activity(PA) behavior is more closely associated with their well-being than self-reported PA. This study therefore aimed to examine whether and how self-reported PA and personal beliefs about suffbcient PA are associated with sleep and psychological functioning in a sample of Swiss adolescents, using both cross-sectional and prospective data.Methods: An overall sample of 864 vocational students(368 girls, 17.98± 1.36 years, mean ± SD) was followed prospectively over a 10-month period. At each measurement occasion, participants filled in a series of self-report questiocnaires to assess their PA levels, their personal beliefs about whether or not they engage in sufficient PA, sleep(insomnia symptoms, sleep quality, sleep-onset latency, and number of awakenings),and psychological functioning(depressive symptoms, quality of life, perceived stress, and mental toughness).Results: Adolescents who believe that they are sufficiently physically active to maintain good health reported more restoring sleep. No differen?ces in sleep were found between adolescents who meet PA recommendationsvs. those who do not. Additionally, adolescents who believe that they were sufficiently physically active also reported better psychological functioning. This close relationship between adolescents5 beliefs about their PA involvement and their sleep and psychological functioning was corroborated in the prospective analyses.Conclusion: Cognitive factors should be studied more intensively when elucidating the relationship among PA, sleep, and psychological functioning in young people, particularly when aiming to develop new exercise interventions targeting psychological outcomes.展开更多
Background: Physical inactivity is identified as the fourth leading risk factor for global mortality and associated with increased breast cancer diagnosis and risks of recurrence. Objectives: To investigate the level ...Background: Physical inactivity is identified as the fourth leading risk factor for global mortality and associated with increased breast cancer diagnosis and risks of recurrence. Objectives: To investigate the level of physical activity engagement after breast cancer in survivors and healthy controls. Design: A descriptive casecontrol study on survivors and matched (ethnic, gender, age) healthy controls was surveyed using a pre-post questionnaire and a 1-minute cancer control media. The socio- and medical demographic data, physical activity status information were obtained from self report questionnaires. Results: Breast cancer survivors (n = 51) were found to participate in low-moderate level of physical activity while healthy controls (n = 45) participated in moderate-vigorous level of physical activity. Healthy adults reported more barriers and excuses but all participants (90% survivors and control) were unaware of the strong inverse relationship between level of physical activity and risks of cancer recurrence. The post test on video showed an increased awareness and intention to re-engagement in physical activity for cancer control (M = 7.1 ± 1.53, p < 0.01). Conclusion: The finding suggests that simple public health message within the Model of cancer survivorship care must be disseminated. The “teachable moments” after a cancer diagnosis should be optimised to promote rehabilitation for physically active lifestyle.展开更多
Background:Physical activity is favorable for health,and vigorous sports activity is particularly beneficial.This study investigates the association between changes in sports participation patterns over time and cardi...Background:Physical activity is favorable for health,and vigorous sports activity is particularly beneficial.This study investigates the association between changes in sports participation patterns over time and cardio-metabolic and self-perceived health outcomes.Methods:Data from 3752 adults(18-79 years of age)who participated in 2 national health interview and examination surveys in 1997-1999 and 2008-2011 were included,with a mean follow-up time of about 12 years.A change in self-reported sports activity was analyzed with respect to the incidence of type 2 diabetes,coronary heart disease(CHD),hypertension,obesity,dyslipidemia,metabolic syndrome,and poor self-perceived health.Participants with pre-existing disease or risk factor of interest at baseline were excluded from the analysis.Being sufficiently active in sports was specified as doing sports for at least 1-2 h per week,and 4 activity categories were defined:1)inactive at both time points(inactive-inactive),2)inactive at baseline and active at follow-up(inactive-active),3)active at baseline and inactive at follow-up(active-inactive),and 4)active at both time points(active-active).Associations between sports activity engagement and health outcomes were estimated by logistic regression models with different stages of adjustments.Results:Not engaging in any regular sports activity at both time points(inactive-inactive)was associated with higher rates of type 2 diabetes(odds ratio(OR)=1.82,95%confidence interval(95%CI):1.08-3.08),CHD(OR=1.82,95%CI:1.16-2.84),hypertension(OR=1.36,95%CI:1.03-1.81),metabolic syndrome(OR=1.58,95%CI:1.08-2.32),and poor self-perceived health(OR=2.54,95%CI:1.83-3.53)compared to doing regular sports for a minimum of 1-2 h per week over time(active-active).In case of change from inactivity to any regular sports activity(inactive-active),the rate of risk factor occurrence was not statistically different from the active-active reference group except for poor self-perceived health,but it was higher for type 2 diabetes(OR=2.15,95%CI:1.12-4.14)and CHD(OR=1.77,95%CI:1.03-3.03).Being active at baseline but inactive at follow-up(active-inactive)was not associated with higher disease incidence of type 2 diabetes(OR=0.70,95%CI:0.25-1.97)or CHD(OR=1.20,95%CI:0.49-2.99),but was associated with higher rates of hypertension(OR=1.61,95%CI:1.11-2.34),obesity(OR=2.34,95%CI:1.53-3.57),metabolic syndrome(OR=1.70,95%CI:1.11-2.63),and poor self-perceived health(OR=2.16,95%CI:1.53-3.07)at follow-up.Conclusion:Even a low weekly quantity(1-2 h)of regular sports activity is partly associated with health benefits.Being formerly but not currently active was not associated with an increased disease incidence,but was associated with a higher risk-factor development compared to the reference group(active-active).Becoming active was preventive for risk-factor development but was not preventive for disease incidence,which probably means that the health benefits from sports activity are not sustainable and disease incidence is only shifted to a later period in life.For this reason,the promotion of and commitment to regular sports activity should be addressed as early as possible over the lifespan to achieve the best health benefits.展开更多
Background: Identifying correlates of physical activity that can be targeted as potential mediators is important for developing interventions to promote physical activity in adolescent girls. However, the mediated eff...Background: Identifying correlates of physical activity that can be targeted as potential mediators is important for developing interventions to promote physical activity in adolescent girls. However, the mediated effects of multilevel correlates of physical activity remain poorly understood. Therefore, the present study aimed to examine direct and mediated effects of personal, social and perceived school physical environmental factors on school-based physical activity of Japanese adolescent girls. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 344 junior high school girls were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), perceived school physical environment (equipment, facilities and safety) and physical activity at school (min per week during lunch time and after- school hours). Structural equation modeling analysis controlling for age was performed to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-hours physical activity. Results: The final structural model demonstrated an acceptable fit for each context-specific physical activity. During lunch recess, perceived equipment and friend support exhibited direct effects on physical activity;perceived facilities, safety, and self-efficacy were indirectly associated with physical activity through friend support. During after-school hours, both family and friend support directly affected physical activity at school;perceived safety, facilities and self-efficacy exhibited indirect effects on physical activity through family or friend support. However, there were no significant associations between equipment and after-school-hours physical activity. Regardless of contexts, BMI had neither direct nor indirect effects on physical activity. Conclusion: Social support from family and friends was identified as factors mediating the effects of perceived environment and self-efficacy on school-based physical activity among Japanese adolescent girls. This finding encourages the future development of effective interventions to promote physical activity through family and friend support in the future.展开更多
Purpose: Background: Physical activity is a complex behavior which involves the interaction of multilevel factors at the individual, social and environmental level. However, previous studies have largely focused on ps...Purpose: Background: Physical activity is a complex behavior which involves the interaction of multilevel factors at the individual, social and environmental level. However, previous studies have largely focused on psychological and/or social environmental factors and the direct impact of such factors on physical activity. There are few studies having examined how multilevel factors may interact to influence activity level. Therefore, the purpose of the present study was to examine both direct and indirect effects of multilevel factors on school-based physical activity in Japanese adolescent boys. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 379 junior high school boys were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), school physical environment (equipment, facilities and safety) and average minutes per week of physical activity during lunch time and after-school hours occurring at school. Structural equation modeling analyses controlling for age were utilized to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-school physical activity. Results: During lunch time, self-efficacy exhibited direct positive effects on physical activity. BMI, facilities, and safety were indirectly associated with lunchtime physical activity through self-efficacy. However, there were no significant relationships of equipment and social support with lunchtime physical activity. During after-school hours, family support and facilities directly affected physical activity. Self-efficacy was indirectly related with physical activity through family support. BMI, equipment, and safety indirectly affected physical activity through self-efficacy and/or family support. Conclusion: Effects of multilevel factor on physical activity among adolescent boys differed according to context, which implies that interventions to promote physical activity should be context-specific. Findings encourage the development of future effective interventions to promote physical activity through self-efficacy during lunch time as well as family support during after-school hours.展开更多
Background:There has been an increasing focus on the importance of national policy to address population levels of physical inactivity.It has been suggested that the 4 cornerstones of policy comprise(1)national guidel...Background:There has been an increasing focus on the importance of national policy to address population levels of physical inactivity.It has been suggested that the 4 cornerstones of policy comprise(1)national guidelines on physical activity(PA),(2)setting population goals and targets,(3)surveillance or health-monitoring systems,and(4)public education.The current study aimed to review the policy actions that have addressed each of these elements for children and youth in England and to identify areas of progress and remaining challenges.Methods:A literature search was undertaken to identify past and present documents relevant to PA policy for children and youth in England.Each document was analyzed to identify content relevant to the 4 cornerstones of policy.Results:Physical activity guidelines(Cornerstone 1)for children and youth have been in place since 1998 and reviewed periodically.Physical activity targets(Cornerstone 2)have focussed on the provision of opportunities for PA,mainly through physical education in schools rather than in relation to the proportion of children meeting recommended PA levels.There has been much surveillance(Cornerstone 3)of children’s PA,but this has been undertaken infrequently over time and with varying inclusions of differing domains of activity.There has been only 1 campaign(Cornerstone 4)that targeted children and their intermediaries,Change4Life,which was an obesity campaign focussing on dietary behavior in combination with PA.Most recently,a government infographic supporting the PA guidelines for children and young people was developed,but details of its dissemination and usage are unknown.Conclusion:There have been many developments in national PA policy in England targeted to children and young people.The area of most significant progress is national PA guidelines.Establishing prevalence targets,streamlining surveillance systems,and investing in public education with supportive policies,environments,and opportunities would strengthen national policy efforts to increase PA and reduce sedentary behavior.展开更多
Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations i...Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations in Turkey. The role of the social environment and social factors on PAP is being increasingly recognized. Although social capital(SC) indicators have been examined in high-income countries, there are few studies on developing countries. The aim of this study was to examine the relationship between SC indicators and PAP among Turkish adolescents.Methods: A survey was conducted among 19 high schools in 4 different cities in Turkey in 2016. A total of 506 female and 729 male high school students participated in this study. The dependent variable was overall PAP, which was measured using the short form of the International Physical Activity Questionnaire. The independent variables included self-perceived family, neighborhood, and school SC. Self-rated health and obesity status, measured by body mass index, were other study covariates in multiple binary logistic regression models. Chi-square tests were used to assess the differences between genders.Results: PAP levels were significantly different between males and females. A higher percentage of males reported PAP(77.4%) compared to females(51.0%). Among males, teacher–student interpersonal trust and informal social control were inversely associated with PAP, while high students interpersonal trust was positively associated with increased odds of PAP. For females, students interpersonal trust was inversely associated with PAP.Conclusion: Various SC indicators are associated with PAP for males and females. These associations are different from findings of studies conducted in developed countries. Therefore, health-promotion interventions and policies should consider gender and different social agents on the social and cultural background to improve PAP among Turkish adolescents.展开更多
The activities of all 1513 individuals who visited a public hunting and fishing area near Spearfish, South Dakota, USA, were recorded from May 16 to August 16, 2006. Over the entire period, slightly less than 60% of t...The activities of all 1513 individuals who visited a public hunting and fishing area near Spearfish, South Dakota, USA, were recorded from May 16 to August 16, 2006. Over the entire period, slightly less than 60% of the visitors were engaged in fishing, and they accounted for nearly 80% of the total visitation time. Over 40% of the visitors were primarily there for non-consumptive (not hunting or fishing) reasons, including touring (sight-seeing), dog training and exercising, and swimming. Less than 1% of the visitors were there for photography. The percentage of visitors fishing decreased from a high of over 65% in the first 31-day period to less than 50% in the third 31-day period, with nearly all of the non-consumptive activities showing a reverse trend. The percentage of visitors swimming or conducting dog activities doubled from the first to third periods. The percentage of time that visitors spent fishing decreased over time, while the time spent on non-consumptive activities increased. However, the increase in non-consumptive activity time was not necessarily in proportion to the increase in the number of visitors involved with non-consumptive activities. By the final period, more visitors were at the area for touring, dogs, and swimming, than for fishing, but fishing still accounted for most of the visitation time. These results indicate an abundance of non-consumptive activities on a public area purchased and maintained with revenue from consumptive hunting and fishing activities, creating the opportunity for user conflicts and potentially threatening the user-pay model of natural resource conservation.展开更多
This study was conducted to determine the value added by Income-Generating Activities (IGAs) on the financial performance of public secondary schools, in terms of assets, liability portfolio, and net worth. Secondar...This study was conducted to determine the value added by Income-Generating Activities (IGAs) on the financial performance of public secondary schools, in terms of assets, liability portfolio, and net worth. Secondary school managers have the gigantic task of balancing meager resources between subsistence and development needs as well as good performance in national examinations. However, macro-economic shocks such as inflation, fuel shortage, and crop failure, among others, often militate against the success of public schools. School-based IGAs enable public schools to cope with external economic shocks, without necessarily passing down budgetary adjustments to parents. However, the country lacks a clear policy guideline to facilitate the initiation, management, accounting, reviewing, and financial reporting of IGA projects. Besides, there is no documented information regarding the value added by IGA initiatives to the financial performance of public secondary schools. The study found that IGA and non-IGA schools were significantly different in terms of category, student population, age, annual income, and number of paid workers. Schools having IGAs were 1.9 times more likely to own as many assets as schools not having IGAs. Besides, IGA schools were about 2.2 times less likely to have their liability in excess of the median threshold. Regarding net worth, the study found that schools having IGAs were about 2.1 times more likely to be operating above the median threshold; suggesting that schools having IGAs were wealthier than non-IGA schools. Based on the findings, this study concludes that IGA projects were beneficial to schools by improving the ability of schools to accumulate assets and manage their liabilities. The study recommends the need to: formulate an appropriate policy framework to guide and standardize IGA activities; initiate suitable training programs for school IGA managers; as well as engage business development managers to advice schools on IGA matters.展开更多
This paper generalizes the definition and its scope of large scale activity based on its current practice and supervision system in China, makes risk analysis during activities, and puts forward proposals on carrying ...This paper generalizes the definition and its scope of large scale activity based on its current practice and supervision system in China, makes risk analysis during activities, and puts forward proposals on carrying out relevant standardization works after discussions about the actuality and prospect of social security on large scale activities in China.展开更多
文摘Initiated by Chinese Red Cross Foundation and sponsored by American .General Business Association, Chinese Nuwa (a goddess-creator of the Chinese nation) Culture Large-scale Activities for Public Interests undertaken by Beijing Absolute Challenge International Advertising Co., Ltd. has recently commenced in an all-round way. A grand ceremony will be held at Nuwa Plaza in Shexian County, Hebei Province on Septemper 24, 2007.
基金supported partially by the 973 Program under the Grant 2012CB316100
文摘Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambiguity(IBA) increases as the directional difference between beams becomes smaller.An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA.In the district near the base station(BS),all antenna elements(AEs) were activated to generate two beams.As the distance from the train to the BS increased,only the minimum number of AEs satisfying the resolution criterion would be activated.At the cell edge,one beam was switched off due to intolerable IBA.The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival(DOA) estimation error.
文摘Public parks provide many benefits to the community as the representatives of green area. The allocation of public places plays an extremely important role in the daily lives of inhabitants especially for recreational use that could enhance the quality of life of residents in the vicinity. To understand park users’ behavior is one of the most important prerequisites for as-sessing the participation in public service from the park users’ point of view. The pattern of park utilization on location and activity selection are important elements in behavioral study, while the public parks topograph may also influence the typical user’s be-havior. Questionnaire survey on park utilization was used to investigate the interaction between activity involvement and recrea-tional location with the use of linear discriminant analysis (LDA) model. The study found that public park users’ behavior is influenced not only by social characteristics but also by the recreational activities and their specific location characteristics. We found that about 45 percent of park visitors are local residents living within a radius of 3 km preferred travel to parks near their residential area. This implies that location selection behavior is correlated with travel distance, travel time and travel cost. Visit frequencies and on site expenditures reflect the recreation behavior for different type of activities. The overall information can be usefully applied by decision makers to launch appropriate public policy in consistence with the useful results of this study.
文摘The objective of this study was to clarify the effectiveness of expressing activities in a virtual reality(VR)system for public space planning to support consensus building with citizens,based on the idea that it is important to consider people’s activities when creating attractive public spaces.We constructed a VR system comprising a background expressed in 3D computer graphics(3DCG)and activities expressed in real video image.As a result of the evaluation experiment,it became easier to visualize the utilization of space by expressing an activity.Although its effectiveness was clarified,some problems regarding the functioning of the system were highlighted.
基金the National Natural Science Foundation of China(Grant Nos.12102252 and 12172214)Natural Science Foundation of Chongqing(Grant No.CSTB2023NSCQ-MSX0761).
文摘Large-scale space membrane antennas have significant potential in satellite communication,space-based early warning,and Earth observation.Because of their large size and high flexibility,the dynamic analysis and control of membrane antenna are challenging.To maintain the working performance of the antenna,the pointing and surface accuracies must be strictly maintained.Therefore,the accurate dynamic modeling and effective active control of large-scale space membrane antennas have great theoretical significance and practical value,and have attracted considerable interest in recent years.This paper reviews the dynamics and active control of large-scale space membrane antennas.First,the development and status of large-scale space membrane antennas are summarized.Subsequently,the key problems in the dynamics and active control of large membrane antennas,including the dynamics of wrinkled membranes,large-amplitude nonlinear vibration,nonlinear model reduction,rigid-flexible-thermal coupling dynamic modeling,on-orbit modal parameter identification,active vibration control,and wave-based vibration control,are discussed in detail.Finally,the research outlook and future trends are presented.
基金supported by the Fundamental Research Funds for the Central Universities (GK201603122, GK201603128, and GK201603129)
文摘With an increase in rural-to-urban migration, a rapidly aging population, and the rising risk of developing noncommunicable diseases in China,it is important to understand the epidemiology of physical activity(PA) and health in the context of disease prevention and population health.Despite its public health importance, there is a significant lack of knowledge about PA in older Chinese adults that may hamper primary prevention efforts of health promotion in an increasingly aging population. To fill this gap, this article presents a narrative review of PA in the older Chinese adult population with a special focus on residential settings(i.e., urban and rural). Using existing studies, the review examines overall PA patterns and their correlates and discusses public health implications and future research. Although there are some preliminary indications of urban and rural differences in PA in the aging population in China, continued research efforts are needed to facilitate primary prevention efforts aimed at reducing noncommunicable diseases and promoting an active lifestyle among the largest population of older people in the world.
基金supported by the National Natural Science Foundation of China under Grant 41775073
文摘In late July and early August 2018,Northeast China suffered from extremely high temperatures,with the maxium temperature anomaly exceeding 6°C.In this study,the large-scale circulation features associated with this heat wave over Northeast China are analyzed using station temperature data and NCEP–NCAR reanalysis data.The results indicate that strong anomalous positive geopotential height centers existed from the lower to upper levels over Northeast China,and the related downward motions were directly responsible for the extreme high-temperature anomalies.The northwestward shift of the western Pacific subtropical high(WPSH)and the northeastward shift of the South Asian high concurrently reinforced the geopotential height anomalies and descending flow over Northeast China.In addition,an anomalous Pacific–Japan pattern in the lower troposphere led to the northwestward shift of the WPSH,jointly favoring the anomalous geopotential height over Northeast China.Two wave trains emanating from the Atlantic region propagated eastwards along high latitudes and midlatitudes,respectively,and converged over Northeast China,leading to the enhancement of the geopotential height anomalies.
基金partly supported by the China Scholarship Council (No. 201406010330)
文摘Background: Based on the transtheoretical model, the current study investigated whether awareness of physical activity(PA) recommendations had an impact on the stages of PA behavior change and levels of PA among Chinese college students.Methods: In Study 1, with a cross-sectional study design, 9826 students were recruited, and their knowledge of international PA recommendations,PA stage distribution, and self-reported PA level were surveyed. Pearson's χ2 test was used to test whether those participants who were aware and not aware of PA guidelines were equally distributed across the stages of PA behavior, and independent t test was conducted to test the group difference in the actual levels of PA. In Study 2, 279 students who were not aware of the PA recommendations were randomly allocated to either an intervention group or a control group, and only those in the intervention group were presented with international PA guidelines. In both groups,students' PA stages and PA level were examined before the test and then 4 months post-test. Mc Nemar's test for correlated proportions and repeated-measures analysis of variance were conducted to examine the changes in PA stage membership and PA level after the intervention.Results: Study 1 results revealed that only 4.4% of the surveyed students had correct knowledge of PA recommendations. Those who were aware of the recommendations were in later stages of PA behavior(χ~2(4) = 167.19, p < 0.001). They were also significantly more physically active than those who were not aware of the recommendations(t(443.71) = 9.00, p < 0.001, Cohen's d = 0.53). Study 2 results demonstrated that the intervention group participants who were at the precontemplation and contemplation stages at the pre-test each progressed further in the PA stages in the post-test(χ~2(1) = 112.06, p < 0.001; χ~2(1) = 118.76, p = 0.03, respectively), although no significant change in PA level was observed(t(139) < 1, p = 0.89).Conclusion: The results showed that awareness of the PA recommendations was associated with higher stages and levels of PA behavior, and a brief educational exposure to PA recommendations led to improved stages of PA behavior but no change in the levels of PA among Chinese college students. More effective public health campaign strategies are needed to promote the dissemination of the PA recommendations and to raise the awareness of the Chinese student population.
基金supported by a grant from the Swiss Federal Office for Sports (BASPO)
文摘Background: Preliminary evidence among adults suggests that the ways in which individuals think about their physical activity(PA) behavior is more closely associated with their well-being than self-reported PA. This study therefore aimed to examine whether and how self-reported PA and personal beliefs about suffbcient PA are associated with sleep and psychological functioning in a sample of Swiss adolescents, using both cross-sectional and prospective data.Methods: An overall sample of 864 vocational students(368 girls, 17.98± 1.36 years, mean ± SD) was followed prospectively over a 10-month period. At each measurement occasion, participants filled in a series of self-report questiocnaires to assess their PA levels, their personal beliefs about whether or not they engage in sufficient PA, sleep(insomnia symptoms, sleep quality, sleep-onset latency, and number of awakenings),and psychological functioning(depressive symptoms, quality of life, perceived stress, and mental toughness).Results: Adolescents who believe that they are sufficiently physically active to maintain good health reported more restoring sleep. No differen?ces in sleep were found between adolescents who meet PA recommendationsvs. those who do not. Additionally, adolescents who believe that they were sufficiently physically active also reported better psychological functioning. This close relationship between adolescents5 beliefs about their PA involvement and their sleep and psychological functioning was corroborated in the prospective analyses.Conclusion: Cognitive factors should be studied more intensively when elucidating the relationship among PA, sleep, and psychological functioning in young people, particularly when aiming to develop new exercise interventions targeting psychological outcomes.
文摘Background: Physical inactivity is identified as the fourth leading risk factor for global mortality and associated with increased breast cancer diagnosis and risks of recurrence. Objectives: To investigate the level of physical activity engagement after breast cancer in survivors and healthy controls. Design: A descriptive casecontrol study on survivors and matched (ethnic, gender, age) healthy controls was surveyed using a pre-post questionnaire and a 1-minute cancer control media. The socio- and medical demographic data, physical activity status information were obtained from self report questionnaires. Results: Breast cancer survivors (n = 51) were found to participate in low-moderate level of physical activity while healthy controls (n = 45) participated in moderate-vigorous level of physical activity. Healthy adults reported more barriers and excuses but all participants (90% survivors and control) were unaware of the strong inverse relationship between level of physical activity and risks of cancer recurrence. The post test on video showed an increased awareness and intention to re-engagement in physical activity for cancer control (M = 7.1 ± 1.53, p < 0.01). Conclusion: The finding suggests that simple public health message within the Model of cancer survivorship care must be disseminated. The “teachable moments” after a cancer diagnosis should be optimised to promote rehabilitation for physically active lifestyle.
基金Both surveys (GNHIES98 and DEGS1) are part of the ongoing health-monitoring system conducted the Robert Koch Institute and funded by the German Federal Ministry of Health
文摘Background:Physical activity is favorable for health,and vigorous sports activity is particularly beneficial.This study investigates the association between changes in sports participation patterns over time and cardio-metabolic and self-perceived health outcomes.Methods:Data from 3752 adults(18-79 years of age)who participated in 2 national health interview and examination surveys in 1997-1999 and 2008-2011 were included,with a mean follow-up time of about 12 years.A change in self-reported sports activity was analyzed with respect to the incidence of type 2 diabetes,coronary heart disease(CHD),hypertension,obesity,dyslipidemia,metabolic syndrome,and poor self-perceived health.Participants with pre-existing disease or risk factor of interest at baseline were excluded from the analysis.Being sufficiently active in sports was specified as doing sports for at least 1-2 h per week,and 4 activity categories were defined:1)inactive at both time points(inactive-inactive),2)inactive at baseline and active at follow-up(inactive-active),3)active at baseline and inactive at follow-up(active-inactive),and 4)active at both time points(active-active).Associations between sports activity engagement and health outcomes were estimated by logistic regression models with different stages of adjustments.Results:Not engaging in any regular sports activity at both time points(inactive-inactive)was associated with higher rates of type 2 diabetes(odds ratio(OR)=1.82,95%confidence interval(95%CI):1.08-3.08),CHD(OR=1.82,95%CI:1.16-2.84),hypertension(OR=1.36,95%CI:1.03-1.81),metabolic syndrome(OR=1.58,95%CI:1.08-2.32),and poor self-perceived health(OR=2.54,95%CI:1.83-3.53)compared to doing regular sports for a minimum of 1-2 h per week over time(active-active).In case of change from inactivity to any regular sports activity(inactive-active),the rate of risk factor occurrence was not statistically different from the active-active reference group except for poor self-perceived health,but it was higher for type 2 diabetes(OR=2.15,95%CI:1.12-4.14)and CHD(OR=1.77,95%CI:1.03-3.03).Being active at baseline but inactive at follow-up(active-inactive)was not associated with higher disease incidence of type 2 diabetes(OR=0.70,95%CI:0.25-1.97)or CHD(OR=1.20,95%CI:0.49-2.99),but was associated with higher rates of hypertension(OR=1.61,95%CI:1.11-2.34),obesity(OR=2.34,95%CI:1.53-3.57),metabolic syndrome(OR=1.70,95%CI:1.11-2.63),and poor self-perceived health(OR=2.16,95%CI:1.53-3.07)at follow-up.Conclusion:Even a low weekly quantity(1-2 h)of regular sports activity is partly associated with health benefits.Being formerly but not currently active was not associated with an increased disease incidence,but was associated with a higher risk-factor development compared to the reference group(active-active).Becoming active was preventive for risk-factor development but was not preventive for disease incidence,which probably means that the health benefits from sports activity are not sustainable and disease incidence is only shifted to a later period in life.For this reason,the promotion of and commitment to regular sports activity should be addressed as early as possible over the lifespan to achieve the best health benefits.
文摘Background: Identifying correlates of physical activity that can be targeted as potential mediators is important for developing interventions to promote physical activity in adolescent girls. However, the mediated effects of multilevel correlates of physical activity remain poorly understood. Therefore, the present study aimed to examine direct and mediated effects of personal, social and perceived school physical environmental factors on school-based physical activity of Japanese adolescent girls. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 344 junior high school girls were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), perceived school physical environment (equipment, facilities and safety) and physical activity at school (min per week during lunch time and after- school hours). Structural equation modeling analysis controlling for age was performed to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-hours physical activity. Results: The final structural model demonstrated an acceptable fit for each context-specific physical activity. During lunch recess, perceived equipment and friend support exhibited direct effects on physical activity;perceived facilities, safety, and self-efficacy were indirectly associated with physical activity through friend support. During after-school hours, both family and friend support directly affected physical activity at school;perceived safety, facilities and self-efficacy exhibited indirect effects on physical activity through family or friend support. However, there were no significant associations between equipment and after-school-hours physical activity. Regardless of contexts, BMI had neither direct nor indirect effects on physical activity. Conclusion: Social support from family and friends was identified as factors mediating the effects of perceived environment and self-efficacy on school-based physical activity among Japanese adolescent girls. This finding encourages the future development of effective interventions to promote physical activity through family and friend support in the future.
文摘Purpose: Background: Physical activity is a complex behavior which involves the interaction of multilevel factors at the individual, social and environmental level. However, previous studies have largely focused on psychological and/or social environmental factors and the direct impact of such factors on physical activity. There are few studies having examined how multilevel factors may interact to influence activity level. Therefore, the purpose of the present study was to examine both direct and indirect effects of multilevel factors on school-based physical activity in Japanese adolescent boys. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 379 junior high school boys were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), school physical environment (equipment, facilities and safety) and average minutes per week of physical activity during lunch time and after-school hours occurring at school. Structural equation modeling analyses controlling for age were utilized to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-school physical activity. Results: During lunch time, self-efficacy exhibited direct positive effects on physical activity. BMI, facilities, and safety were indirectly associated with lunchtime physical activity through self-efficacy. However, there were no significant relationships of equipment and social support with lunchtime physical activity. During after-school hours, family support and facilities directly affected physical activity. Self-efficacy was indirectly related with physical activity through family support. BMI, equipment, and safety indirectly affected physical activity through self-efficacy and/or family support. Conclusion: Effects of multilevel factor on physical activity among adolescent boys differed according to context, which implies that interventions to promote physical activity should be context-specific. Findings encourage the development of future effective interventions to promote physical activity through self-efficacy during lunch time as well as family support during after-school hours.
文摘Background:There has been an increasing focus on the importance of national policy to address population levels of physical inactivity.It has been suggested that the 4 cornerstones of policy comprise(1)national guidelines on physical activity(PA),(2)setting population goals and targets,(3)surveillance or health-monitoring systems,and(4)public education.The current study aimed to review the policy actions that have addressed each of these elements for children and youth in England and to identify areas of progress and remaining challenges.Methods:A literature search was undertaken to identify past and present documents relevant to PA policy for children and youth in England.Each document was analyzed to identify content relevant to the 4 cornerstones of policy.Results:Physical activity guidelines(Cornerstone 1)for children and youth have been in place since 1998 and reviewed periodically.Physical activity targets(Cornerstone 2)have focussed on the provision of opportunities for PA,mainly through physical education in schools rather than in relation to the proportion of children meeting recommended PA levels.There has been much surveillance(Cornerstone 3)of children’s PA,but this has been undertaken infrequently over time and with varying inclusions of differing domains of activity.There has been only 1 campaign(Cornerstone 4)that targeted children and their intermediaries,Change4Life,which was an obesity campaign focussing on dietary behavior in combination with PA.Most recently,a government infographic supporting the PA guidelines for children and young people was developed,but details of its dissemination and usage are unknown.Conclusion:There have been many developments in national PA policy in England targeted to children and young people.The area of most significant progress is national PA guidelines.Establishing prevalence targets,streamlining surveillance systems,and investing in public education with supportive policies,environments,and opportunities would strengthen national policy efforts to increase PA and reduce sedentary behavior.
文摘Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations in Turkey. The role of the social environment and social factors on PAP is being increasingly recognized. Although social capital(SC) indicators have been examined in high-income countries, there are few studies on developing countries. The aim of this study was to examine the relationship between SC indicators and PAP among Turkish adolescents.Methods: A survey was conducted among 19 high schools in 4 different cities in Turkey in 2016. A total of 506 female and 729 male high school students participated in this study. The dependent variable was overall PAP, which was measured using the short form of the International Physical Activity Questionnaire. The independent variables included self-perceived family, neighborhood, and school SC. Self-rated health and obesity status, measured by body mass index, were other study covariates in multiple binary logistic regression models. Chi-square tests were used to assess the differences between genders.Results: PAP levels were significantly different between males and females. A higher percentage of males reported PAP(77.4%) compared to females(51.0%). Among males, teacher–student interpersonal trust and informal social control were inversely associated with PAP, while high students interpersonal trust was positively associated with increased odds of PAP. For females, students interpersonal trust was inversely associated with PAP.Conclusion: Various SC indicators are associated with PAP for males and females. These associations are different from findings of studies conducted in developed countries. Therefore, health-promotion interventions and policies should consider gender and different social agents on the social and cultural background to improve PAP among Turkish adolescents.
文摘The activities of all 1513 individuals who visited a public hunting and fishing area near Spearfish, South Dakota, USA, were recorded from May 16 to August 16, 2006. Over the entire period, slightly less than 60% of the visitors were engaged in fishing, and they accounted for nearly 80% of the total visitation time. Over 40% of the visitors were primarily there for non-consumptive (not hunting or fishing) reasons, including touring (sight-seeing), dog training and exercising, and swimming. Less than 1% of the visitors were there for photography. The percentage of visitors fishing decreased from a high of over 65% in the first 31-day period to less than 50% in the third 31-day period, with nearly all of the non-consumptive activities showing a reverse trend. The percentage of visitors swimming or conducting dog activities doubled from the first to third periods. The percentage of time that visitors spent fishing decreased over time, while the time spent on non-consumptive activities increased. However, the increase in non-consumptive activity time was not necessarily in proportion to the increase in the number of visitors involved with non-consumptive activities. By the final period, more visitors were at the area for touring, dogs, and swimming, than for fishing, but fishing still accounted for most of the visitation time. These results indicate an abundance of non-consumptive activities on a public area purchased and maintained with revenue from consumptive hunting and fishing activities, creating the opportunity for user conflicts and potentially threatening the user-pay model of natural resource conservation.
文摘This study was conducted to determine the value added by Income-Generating Activities (IGAs) on the financial performance of public secondary schools, in terms of assets, liability portfolio, and net worth. Secondary school managers have the gigantic task of balancing meager resources between subsistence and development needs as well as good performance in national examinations. However, macro-economic shocks such as inflation, fuel shortage, and crop failure, among others, often militate against the success of public schools. School-based IGAs enable public schools to cope with external economic shocks, without necessarily passing down budgetary adjustments to parents. However, the country lacks a clear policy guideline to facilitate the initiation, management, accounting, reviewing, and financial reporting of IGA projects. Besides, there is no documented information regarding the value added by IGA initiatives to the financial performance of public secondary schools. The study found that IGA and non-IGA schools were significantly different in terms of category, student population, age, annual income, and number of paid workers. Schools having IGAs were 1.9 times more likely to own as many assets as schools not having IGAs. Besides, IGA schools were about 2.2 times less likely to have their liability in excess of the median threshold. Regarding net worth, the study found that schools having IGAs were about 2.1 times more likely to be operating above the median threshold; suggesting that schools having IGAs were wealthier than non-IGA schools. Based on the findings, this study concludes that IGA projects were beneficial to schools by improving the ability of schools to accumulate assets and manage their liabilities. The study recommends the need to: formulate an appropriate policy framework to guide and standardize IGA activities; initiate suitable training programs for school IGA managers; as well as engage business development managers to advice schools on IGA matters.
文摘This paper generalizes the definition and its scope of large scale activity based on its current practice and supervision system in China, makes risk analysis during activities, and puts forward proposals on carrying out relevant standardization works after discussions about the actuality and prospect of social security on large scale activities in China.