充换电站具有电源与负荷的双重性质,分布式电源与储能的联合装置可作为稳定的电网备用电源。当配电网中发生故障时,充换电站和分布式电源的选址定容将直接影响配电网运行的可靠性。该文以带时间函数负荷权重的全网电量中断损失费为目标...充换电站具有电源与负荷的双重性质,分布式电源与储能的联合装置可作为稳定的电网备用电源。当配电网中发生故障时,充换电站和分布式电源的选址定容将直接影响配电网运行的可靠性。该文以带时间函数负荷权重的全网电量中断损失费为目标函数,考虑配电网及交通网联合约束,建立分布式电源与充换电站的协同规划模型,同时采用矩阵方法对变量进行归一化处理,最后采用Matlab进行求解。在结合交通网的IEEE-RBTS Bus 6系统主馈线F4上进行仿真,仿真结果表明,协同规划分布式电源与充换电站能够提高配电网的可靠性指标,规划方案合理。展开更多
Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation method...Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV（whole body vibration） test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.展开更多
Introduction: Living and working conditions are increasingly conducive to a sedentary lifestyle. Many administrative workers are exposed daily to long hours of work in a prolonged sitting position, which can favour th...Introduction: Living and working conditions are increasingly conducive to a sedentary lifestyle. Many administrative workers are exposed daily to long hours of work in a prolonged sitting position, which can favour the onset of diabetes. The aim of the study was to determine the prevalence and factors associated with diabetes among workers at a town hall in Benin in 2019. Methods: This was a descriptive cross-sectional study conducted from December 2018 to January 2019. Exhaustive recruitment was carried out. Data were collected during a face-to-face interview, using a standardized questionnaire including socio-professional factors, behavioral factors, anthropometric measurements, and blood glucose. Frequencies were calculated. Frequencies were compared using the chi-square and Fisher tests. The significance threshold was 5%. Results: A total of 85 workers were included. Their mean age was 41.55 ± 9.82 years, with a sex ratio of 6.1. = The prevalence of diabetes was estimated at 8.2% [95% CI: 3.38 - 16.23%] and 3 of the workers knew they had diabetes. A family history of diabetes was associated with diabetes (p = 0.032). Occupationally, 10.77% of permanent employees had diabetes, compared with 0.0% of non-permanent employees;12.50% of employees with at least 10 years’ seniority had diabetes, compared with 7.25% of those with less seniority;19.05% of employees who spent at least 6 hours a day sitting at work had diabetes, compared with 4.69% of those who spent less time sitting. Conclusion: Preventing chronic disease in the workplace is part of promoting workers’ health, and must take into account occupational factors such as prolonged sitting.展开更多
This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously a...This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration.展开更多
Objective：To investigate the influence of lumbar disc degeneration on the efficacy of lumbar fixed-point rotation manipulation in sitting position in treating lumbar intervertebral disc herniation（LIDH）.Methods：We...Objective：To investigate the influence of lumbar disc degeneration on the efficacy of lumbar fixed-point rotation manipulation in sitting position in treating lumbar intervertebral disc herniation（LIDH）.Methods：We simulated lumbar fixed-point rotation manipulation of sitting position using three finite element models including a normal model,a mild degeneration model and a moderate degeneration model of L3-5,in which the herniated disc was assumed at the left rear of L4 disc and the rotation manipulation was carried out on the right side.The displacement and stress at the left rear of L4 disc of the three models were analyzed.Results：When lumbar fixed-point rotation manipulation in sitting position was carried out,a displacement and stress were generated at the left rear of L4 intervertebral disc of the three models directing forward.The displacement and stress in degeneration models were less than those in the normal model,and the smallest values were found in the moderate degeneration model.From normal model to mild and then to the moderate degeneration model,the displacement decreased by 36% and 59%,and the stress decreased by 22.3% and 45.2%,respectively.Conclusion：The lumbar disc degeneration affects adversely the effectiveness of lumbar fixed-point rotation manipulation in sitting position in the treatment of LIDH.The severer the lumbar degeneration,the greater the influence.展开更多
Background:Prolonged sitting and reduced physical activity lead to low energy expenditures.However,little is known about the joint impact of daily sitting time and physical activity on body fat distribution.We investi...Background:Prolonged sitting and reduced physical activity lead to low energy expenditures.However,little is known about the joint impact of daily sitting time and physical activity on body fat distribution.We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.Methods:This was a cross-sectional analysis of U.S.nationally representative data from the National Health and Nutrition Examination Survey2011-2018 among adults aged 20 years or older.Daily sitting time and leisure-time physical activity(LTPA)were self-reported using the Global Physical Activity Questionnaire.Body fat(total and trunk fat percentage)was determined via dual X-ray absorptiometry.Results:Among 10,808 adults,about 54.6%spent 6 h/day or more sitting;more than one-half reported no LTPA(inactive)or less than 150 min/week LTPA(insufficiently active)with only 43.3%reported 150 min/week or more LTPA(active)in the past week.After fully adjusting for sociodemographic data,lifestyle behaviors,and chronic conditions,prolonged sitting time and low levels of LTPA were associated with higher total and trunk fat percentages in both sexes.When stratifying by LTPA,the association between daily sitting time and body fat appeared to be stronger in those who were inactive/insuufficiently active.In the joint analyses,inactive/insuufficiently active adults who reported sitting more than 8 h/day had the highest total(female:3.99%(95%confidence interval(95%CI):3.09%-4.88%);male:3.79%(95%CI:2.75%-4.82%))and trunk body fat percentages(female:4.21%(95%CI:3.09%-5.32%);male:4.07%(95%CI:2.95%-5.19%))when compared with those who were active and sitting less than 4 h/day.Conclusion:Prolonged daily sitting time was associated with increased body fat among U.S.adults.The higher body fat associated with 6 h/day sitting may not be offset by achieving recommended levels of physical activity.展开更多
Objective: To observe the effect of lumbar spinal point injection on sitting function in children with cerebral palsy. Method: Sixty-two children with post-confirmed cerebral palsy were randomly divided into control g...Objective: To observe the effect of lumbar spinal point injection on sitting function in children with cerebral palsy. Method: Sixty-two children with post-confirmed cerebral palsy were randomly divided into control group and treatment group, 31 each. The control group was given conventional rehabilitation treatment, and the treatment group was given lumbar chiropspinal acupoint injection on the basis of the treatment method of the control group. After 3 consecutive courses of treatment, the sitting score of the two groups before and after treatment (GMFM88) was used to evaluate the sitting score before and after treatment. Outcome: Before treatment, the two groups were evaluated and the differences were not statistically significant (p > 0.05), which was comparable. The two groups (GMFM88) after treatment had significantly increased the differential values, and the difference was statistically significant compared with the same group before treatment (p Conclusion: Conventional rehabilitation combined with lumbar spinal point injection can effectively improve the sitting motor function of children with cerebral palsy.展开更多
The classification of sitting issues is investigated since detailed state classification for humanoid robots plays a key role in the practical application of humanoid robots, particularly for the humanoid robots doing...The classification of sitting issues is investigated since detailed state classification for humanoid robots plays a key role in the practical application of humanoid robots, particularly for the humanoid robots doing complicated tasks. This paper presents the concept, the characteristics tree, and the prototype of the humanoid robot SJTU-HR1. The basic states lbr humanoid robots are proposed, including lying, sitting, standing, and handstanding. Moreover, the sitting states are classified into several states from the viewpoint of topology. The Gy （generalized function） set theory is applied to achieve the kinematic characteristics of the interested end-effectors of the humanoid robot SJTU-HR1. Finally, the results indicate that a large number of the sitting states can be represented by the meaningful notations systematically. Furthermore, the one-to-one correspondence between the state and kinematic characteristics of the interested end-effectors of the SJTU-HR 1 leads to deeper insight into the capabilities of the humanoid robot SJTU-HR1.展开更多
文摘充换电站具有电源与负荷的双重性质,分布式电源与储能的联合装置可作为稳定的电网备用电源。当配电网中发生故障时,充换电站和分布式电源的选址定容将直接影响配电网运行的可靠性。该文以带时间函数负荷权重的全网电量中断损失费为目标函数,考虑配电网及交通网联合约束,建立分布式电源与充换电站的协同规划模型,同时采用矩阵方法对变量进行归一化处理,最后采用Matlab进行求解。在结合交通网的IEEE-RBTS Bus 6系统主馈线F4上进行仿真,仿真结果表明,协同规划分布式电源与充换电站能够提高配电网的可靠性指标,规划方案合理。
基金Supported by National Natural Science Foundation of China(Grant No.51465056)Xinjiang Provincial Natural Science Foundation of China(Grant No.2015211C265)Xinjiang University Ph D Start-up Funds,China
文摘Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV（whole body vibration） test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.
文摘Introduction: Living and working conditions are increasingly conducive to a sedentary lifestyle. Many administrative workers are exposed daily to long hours of work in a prolonged sitting position, which can favour the onset of diabetes. The aim of the study was to determine the prevalence and factors associated with diabetes among workers at a town hall in Benin in 2019. Methods: This was a descriptive cross-sectional study conducted from December 2018 to January 2019. Exhaustive recruitment was carried out. Data were collected during a face-to-face interview, using a standardized questionnaire including socio-professional factors, behavioral factors, anthropometric measurements, and blood glucose. Frequencies were calculated. Frequencies were compared using the chi-square and Fisher tests. The significance threshold was 5%. Results: A total of 85 workers were included. Their mean age was 41.55 ± 9.82 years, with a sex ratio of 6.1. = The prevalence of diabetes was estimated at 8.2% [95% CI: 3.38 - 16.23%] and 3 of the workers knew they had diabetes. A family history of diabetes was associated with diabetes (p = 0.032). Occupationally, 10.77% of permanent employees had diabetes, compared with 0.0% of non-permanent employees;12.50% of employees with at least 10 years’ seniority had diabetes, compared with 7.25% of those with less seniority;19.05% of employees who spent at least 6 hours a day sitting at work had diabetes, compared with 4.69% of those who spent less time sitting. Conclusion: Preventing chronic disease in the workplace is part of promoting workers’ health, and must take into account occupational factors such as prolonged sitting.
文摘This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration.
基金supported by Scientific Research Project for the Construction of Chinese Medicine Province of Administration of Traditional Chinese Medicine of Guangdong(No.20141063)~~
文摘Objective：To investigate the influence of lumbar disc degeneration on the efficacy of lumbar fixed-point rotation manipulation in sitting position in treating lumbar intervertebral disc herniation（LIDH）.Methods：We simulated lumbar fixed-point rotation manipulation of sitting position using three finite element models including a normal model,a mild degeneration model and a moderate degeneration model of L3-5,in which the herniated disc was assumed at the left rear of L4 disc and the rotation manipulation was carried out on the right side.The displacement and stress at the left rear of L4 disc of the three models were analyzed.Results：When lumbar fixed-point rotation manipulation in sitting position was carried out,a displacement and stress were generated at the left rear of L4 intervertebral disc of the three models directing forward.The displacement and stress in degeneration models were less than those in the normal model,and the smallest values were found in the moderate degeneration model.From normal model to mild and then to the moderate degeneration model,the displacement decreased by 36% and 59%,and the stress decreased by 22.3% and 45.2%,respectively.Conclusion：The lumbar disc degeneration affects adversely the effectiveness of lumbar fixed-point rotation manipulation in sitting position in the treatment of LIDH.The severer the lumbar degeneration,the greater the influence.
文摘Background:Prolonged sitting and reduced physical activity lead to low energy expenditures.However,little is known about the joint impact of daily sitting time and physical activity on body fat distribution.We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.Methods:This was a cross-sectional analysis of U.S.nationally representative data from the National Health and Nutrition Examination Survey2011-2018 among adults aged 20 years or older.Daily sitting time and leisure-time physical activity(LTPA)were self-reported using the Global Physical Activity Questionnaire.Body fat(total and trunk fat percentage)was determined via dual X-ray absorptiometry.Results:Among 10,808 adults,about 54.6%spent 6 h/day or more sitting;more than one-half reported no LTPA(inactive)or less than 150 min/week LTPA(insufficiently active)with only 43.3%reported 150 min/week or more LTPA(active)in the past week.After fully adjusting for sociodemographic data,lifestyle behaviors,and chronic conditions,prolonged sitting time and low levels of LTPA were associated with higher total and trunk fat percentages in both sexes.When stratifying by LTPA,the association between daily sitting time and body fat appeared to be stronger in those who were inactive/insuufficiently active.In the joint analyses,inactive/insuufficiently active adults who reported sitting more than 8 h/day had the highest total(female:3.99%(95%confidence interval(95%CI):3.09%-4.88%);male:3.79%(95%CI:2.75%-4.82%))and trunk body fat percentages(female:4.21%(95%CI:3.09%-5.32%);male:4.07%(95%CI:2.95%-5.19%))when compared with those who were active and sitting less than 4 h/day.Conclusion:Prolonged daily sitting time was associated with increased body fat among U.S.adults.The higher body fat associated with 6 h/day sitting may not be offset by achieving recommended levels of physical activity.
文摘Objective: To observe the effect of lumbar spinal point injection on sitting function in children with cerebral palsy. Method: Sixty-two children with post-confirmed cerebral palsy were randomly divided into control group and treatment group, 31 each. The control group was given conventional rehabilitation treatment, and the treatment group was given lumbar chiropspinal acupoint injection on the basis of the treatment method of the control group. After 3 consecutive courses of treatment, the sitting score of the two groups before and after treatment (GMFM88) was used to evaluate the sitting score before and after treatment. Outcome: Before treatment, the two groups were evaluated and the differences were not statistically significant (p > 0.05), which was comparable. The two groups (GMFM88) after treatment had significantly increased the differential values, and the difference was statistically significant compared with the same group before treatment (p Conclusion: Conventional rehabilitation combined with lumbar spinal point injection can effectively improve the sitting motor function of children with cerebral palsy.
基金Acknowledgement This work was supported by the National Basic Research Program of China （2006CB705402）, the Na- tional Natural Science Foundation of China （30770538, 50821003）, and the Joint Research Fund for Overseas Natural Science of China.
文摘The classification of sitting issues is investigated since detailed state classification for humanoid robots plays a key role in the practical application of humanoid robots, particularly for the humanoid robots doing complicated tasks. This paper presents the concept, the characteristics tree, and the prototype of the humanoid robot SJTU-HR1. The basic states lbr humanoid robots are proposed, including lying, sitting, standing, and handstanding. Moreover, the sitting states are classified into several states from the viewpoint of topology. The Gy （generalized function） set theory is applied to achieve the kinematic characteristics of the interested end-effectors of the humanoid robot SJTU-HR1. Finally, the results indicate that a large number of the sitting states can be represented by the meaningful notations systematically. Furthermore, the one-to-one correspondence between the state and kinematic characteristics of the interested end-effectors of the SJTU-HR 1 leads to deeper insight into the capabilities of the humanoid robot SJTU-HR1.
