Prestress enables the Glulam beam could make full use of the compression strength,and then increase the span,but it still could not reduce all drawbacks,such as cross-section weakening and small force arm.To avoid slo...Prestress enables the Glulam beam could make full use of the compression strength,and then increase the span,but it still could not reduce all drawbacks,such as cross-section weakening and small force arm.To avoid slotting and ensure suitable tension and compression couple,one kind of novel anchor has been proposed,which could meet the bearing capacity requirement.And then the bending test of prestressed Glulam beams with a geometric scale ratio of 1:2 was simulated,to investigate the effect of the force arm on bending capacities,failure modes,and deformation performance.Results show that increasing the force arm could improve the ultimate bending per-formance of the beam significantly,and the anchor arm length has a certain effect on the performance,but it is not obvious.Finally,based on Finite element method analysis,the practice design suggestions have been offered.展开更多
AIM To investigate the association between cardiorespiratory fitness and hospitalization events in a cohort of large voluntary arm forces in Taiwan. METHODS The cardiorespiratory fitness and hospitalization events in ...AIM To investigate the association between cardiorespiratory fitness and hospitalization events in a cohort of large voluntary arm forces in Taiwan. METHODS The cardiorespiratory fitness and hospitalization events in armed forces(CHIEF) is a retrospective cohort consisting of more than 4000 professional military members aged 18-50 years in Eastern Taiwan. All participants received history taking, physical examination, chest radiography, 12-lead electrocardiography, blood tests for cell counts and fasting glucose, lipid profiles, uric acid, renal function and liver function in the Hualien Armed Forces General Hospital during 2014. In addition, participants were required to undergo two indoor resistant exercise tests including 2-min push-up and 2-min sit-up, both scored by infrared sensing, and one outdoor endurance 3000-m none weight-bearing running test, the main indicator of cardiorespiratory fitness in the Military Physical Training and Testing Center in Eastern Taiwan in 2014. RESULTS Hospitalization events for cardiovascular disease, acute kidney injury, rhabdomyolysis, severe infectious disease, acute psychiatric illness, diabetes, orthopedic surgery and mortality will be identified in the National Insurance Research Database for 10 years. CONCLUSION CHIEF will be among the largest Eastern Asian armed forces cohort, in which physical status was strictly evaluated to follow up the hospitalization events for severe illness.展开更多
Background: Military families who have a family member with a mental illness see themselves confronted with many demands. Stigmatization is one of these challenges. Stigmatization affects not only the individual who s...Background: Military families who have a family member with a mental illness see themselves confronted with many demands. Stigmatization is one of these challenges. Stigmatization affects not only the individual who suffers from a mental illness but also other family members via stigma by association and vicarious stigma. Stigma by association occurs when mental illness stigma spills over to individuals associated with an individual with a mental illness. Vicarious stigma describes the suffering of family members when they note the impact of stigma on their relative with mental illness. As a societal phenomenon, stigma plays out in social interactions and might therefore influence the social networks of families. It is also associated with healthcare utilization.Methods: Narrative interviews were conducted with 15 family members(partners, spouses, parents and children) of former soldiers of the German Armed Forces with a service-induced mental illness. The transcribed interview data were analyzed using a thematic analysis approach, in which codes were formed and emerging themes were systemized. Relationships between stigma, the families’ reactions to it, its effects on their social relationships and its interference with their healthcare utilization were analyzed.Results: This study provides a detailed description of how relatives of former German soldiers with mental health problems experience stigma by association and vicarious stigma. Their perceptions are shown in a model that describes stigma-related attitudes, reactions to them and their effects on the social relationships of former soldiers’ families. These families felt stigmatized because of the former soldiers’ mental illness(mental illness stigma) and the military context in which it occurred(former soldier stigma). They reacted with nondisclosure, anger, acceptance and self-blame. Stigma was associated with smaller and weaker social networks that were characterized by social exclusion, self-segregation and conflicts with extended family, friends and colleagues. Stigma also affected the families’ healthcare utilization.Conclusions: Urgently needed anti-stigma campaigns, particularly in the civilian context, should address the stigmatization of both mental illness and the military participation of the families affected. They should consider the needs of both former soldiers with a mental illness and their families.展开更多
After the Cold War, all European armed forces have transformed to be prepared for the new geopolitical environment and have taken new tasks. Since then, the European armed forces are more active in international confl...After the Cold War, all European armed forces have transformed to be prepared for the new geopolitical environment and have taken new tasks. Since then, the European armed forces are more active in international conflict management. Whereas most of the European states have suspended the conscription, the Swiss Armed Forces still hold on conscription. However, the Swiss Armed Forces have changed also. The reform "Armee 95" in 1995 and the reform "Armee XXI" in 2004 have transformed the Swiss Armed Forces and extended their range of tasks. Which of these tasks are legitimated by the Swiss population? To answer this question, the Swiss population had been interviewed about the tasks of the Swiss Armed Forces as part of the study "Sicherheit 2016". The tasks which the Swiss population mentioned are displayed in this paper with regard to the transformation process classified and discussed. The evaluation shows that 93% of the interviewees have named one of Switzerland's constitutional duties (defense, support of the civilian authorities, and promotion of peace within an international context) as the most important task of the Swiss Armed Forces. Mainly the national defense order and the subsidiary support of the civilian authorities are approved by the Swiss population.展开更多
Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The ...Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1)the volume and strength of the neck and shoulder muscles and 2)muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel.Methods:Eighteen participants underwent 12 weeks of functional strength training(n=12)or the control protocol(n=6)without additional strength training.Pre-and post-intervention tests included evaluations of isometric strength of the head extensor muscles,flexion,and lateral flexion and rotation,as well as magnetic resonance imaging(MRI)to measure the volume of the m.sternocleidomastoideus,m.trapezius,and deep neck muscles.Furthermore,during a long-arm centrifuge(+1.4 and+3Gz)protocol,the muscular activity levels of the m.sternocleidomastoideus,m.trapezius and m.erector spinae muscles were assessed without a flight helmet,with a helmet,and with a helmet and night vision goggles.Each participant’s perception of muscular strain was noted immediately after the long-arm centrifuge protocol.Results:The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group(P<0.05).Relative muscle activity(%MVC)with a helmet decreased after the intervention in the training but not the control group(P=0.01).Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group(P<0.01).The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups.Conclusions:Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge.展开更多
Due to their relative abundance,stable biological properties and excellent reproductive activity,umbilical cord mesenchymal stem cells have previously been utilized for the treatment of Duchenne muscular dystrophy,whi...Due to their relative abundance,stable biological properties and excellent reproductive activity,umbilical cord mesenchymal stem cells have previously been utilized for the treatment of Duchenne muscular dystrophy,which is a muscular atrophy disease.Three patients who were clinically and pathologically diagnosed with Duchenne muscular dystrophy were transplanted with umbilical cord mesenchymal stem cells by intravenous infusion,in combination with multi-point intramuscular injection.They were followed up for 12 months after cell transplantation.Results showed that clinical symptoms significantly improved,daily living activity and muscle strength were enhanced,the sero-enzyme,electromyogram,and MRI scans showed improvement,and dystrophin was expressed in the muscle cell membrane.Hematoxylin-eosin staining of a muscle biopsy revealed that muscle fibers were well arranged,fibrous degeneration was alleviated,and fat infiltration was improved.These pieces of evidence suggest that umbilical cord mesenchymal stem cell transplantation can be considered as a new regimen for Duchenne muscular dystrophy.展开更多
The objective of this study is to investigate the biomechanical functions of the human ankle-toot complex during the stancephase of walking. The three-dimensional (3D) gait measurement was conducted by using a 3D infr...The objective of this study is to investigate the biomechanical functions of the human ankle-toot complex during the stancephase of walking. The three-dimensional (3D) gait measurement was conducted by using a 3D infrared multi-camera system anda force plate array to record the Ground Reaction Forces (GRF) and segmental motions simultaneously. The ankle-foot complexwas modelled as a four-segment system, connected by three joints: talocrural joint, sub-talar joint and metatarsophalangeal joint.The subject-specific joint orientations and locations were determined using a functional joint method based on the particleswarm optimisation algorithm. The GRF moment arms and joint moments acting around the talocrural and sub-talar joints werecalculated over the entire stance phase. The estimated talocrural and sub-talar joint locations show noticeable obliquity. Thekinematic and kinetic results strongly suggest that the human ankle-foot complex works as a mechanical mechanism with twodifferent configurations in stance phase of walking. These lead to a significant decrease in the GRF moment arms therebyincreasing the effective mechanical advantages of the ankle plantarflexor muscles. This reconfigurable mechanism enhancesmuscle effectiveness during locomotion by modulating the gear ratio of the ankle plantarflexor muscles in stance. This studyalso reveals many factors may contribute to the locomotor function of the human ankle-foot complex, which include not only itsre-configurable structure, but also its obliquely arranged joints, the characteristic heel-to-toe Centre of Pressure (COP) motionand also the medially acting GRF pattern. Although the human ankle-foot structure is immensely complex, it seems that itsconfiguration and each constitutive component are well tuned to maximise locomotor efficiency and also to minimise risk ofinjury. This result would advance our understanding of the locomotor function of the ankle-foot complex, and also the intrinsicdesign of the ankle-foot musculoskeletal structure. Moreover, this may also provide implications for the design of bionicprosthetic devices and the development of humanoid robots.展开更多
A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external struc...A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external structure mechanism, the 3-revolution-prismatic-spherical (3RPS) parallel mechanism is devised from the concept of the human upper-limb anatomy and applied for the shoulder 3-DOF joint. Meanwhile, the orthogonal experiment design method is introduced for its optimal design. Aiming at enhancing the performance of teleoperation, the force feedback is employed by the pneumatic system on ZJUESA to produce the vivid feeling in addition to the soft control interface. Due to the compressibility and nonlinearity of the pneumatic force feedback system, a novel hybrid fuzzy controller for the precise force control is proposed and realized based on the Mega8 microcontroller units as the units of the distributed control system on ZJUESA. With the results of several experiments for master-slave control with force feedback, the feasibility of ZJUESA system and the effect of its hybrid fuzzy controller are verified.展开更多
This paper discusses a force control problem for a flexible Timoshenko arm. The effect of shear deformation and the effect of rotary inertia are considered in Timoshenko beam theory. Most of the research about force c...This paper discusses a force control problem for a flexible Timoshenko arm. The effect of shear deformation and the effect of rotary inertia are considered in Timoshenko beam theory. Most of the research about force control of the flexible arm is based on Euler Bernoulli beam theory. There are a few researches about force control of the flexible arm using Timoshenko beam theory. The aim of the force control is to control the contact force at the contact point. To solve this problem, we propose a simple controller using Timoshenko beam theory. Finally, we describe simulation results using a numerical inversion of Laplace transform carried out to investigate the validity of the proposed controller for the force control problem. The results of the time response show the transverse displacement, the angle of deflection, the slider position, the rotational angle and the contact force toward the desired their values.展开更多
Based on some former studies of Chinese rural society, this paper summerizes the achievements and limitations of general Chinese rural studies and then proposes a social operation model in rural areas which is dominat...Based on some former studies of Chinese rural society, this paper summerizes the achievements and limitations of general Chinese rural studies and then proposes a social operation model in rural areas which is dominated by the squires. It uses some specific historical data and discoveries of feild sduty to further examine the profound influence of the squires on rural politcal construction in three different aspects: the model of clan and religion, the role as inter-mediator and the growth of basic armed forces. The study found that this special social group played a center role in Chinese rural political system from ancient to modem times, particularly, the research considers the decline of the squire society since the establishment of the new government in 1949. In the end, this paper points out the cultural guiding significance of this social model in the study to the rural construction in contemporay China by predicting the possiblity of renaissance展开更多
A kind of new obstacle space expression is proposed in this paper, in which a virtual force field (VFF) is built. Using the torque and joint optimization acted by the virtual force field on the anthropomorphic weld ar...A kind of new obstacle space expression is proposed in this paper, in which a virtual force field (VFF) is built. Using the torque and joint optimization acted by the virtual force field on the anthropomorphic weld arm, the real-time selection of a redundant join (R-joint) is done and its equivalent virtual torque is obtained, thus the redundant joint can be controlled with whose force feedback. An inverse kinematics solution of a 6-DOF robot is applied to other six joints of the arm. Simulation experiments indicate the new inverse kinematics solution has perfect collision avoidance effect, and it is well simplified. Therefore, it can be applied to a welding task in complex operation space.展开更多
基金supported by the Resources Industry Science and Technology Innovation Joint Funding Project of Nanping(N2021Z003)the Special Project of Service Industry Research of Wuyi University under Grant(2021XJFWCY03)+2 种基金the Research Launch Fund of Wuyi University’s Introduct Talent(YJ202309)the Fujian Training Program of Innovation and Entrepreneurship for Undergraduates(S202210397076)Research on the Stress Performance of Reinforced Bamboo Highway Guardrail with Embedded Channel Steel(LS202304).
文摘Prestress enables the Glulam beam could make full use of the compression strength,and then increase the span,but it still could not reduce all drawbacks,such as cross-section weakening and small force arm.To avoid slotting and ensure suitable tension and compression couple,one kind of novel anchor has been proposed,which could meet the bearing capacity requirement.And then the bending test of prestressed Glulam beams with a geometric scale ratio of 1:2 was simulated,to investigate the effect of the force arm on bending capacities,failure modes,and deformation performance.Results show that increasing the force arm could improve the ultimate bending per-formance of the beam significantly,and the anchor arm length has a certain effect on the performance,but it is not obvious.Finally,based on Finite element method analysis,the practice design suggestions have been offered.
基金Supported by The Research Grants from the Hualien-Armed Forces General Hospital,No.805-C105-10the Ministry of National Defense-Medical Affairs Bureau,No.MAB-106-124
文摘AIM To investigate the association between cardiorespiratory fitness and hospitalization events in a cohort of large voluntary arm forces in Taiwan. METHODS The cardiorespiratory fitness and hospitalization events in armed forces(CHIEF) is a retrospective cohort consisting of more than 4000 professional military members aged 18-50 years in Eastern Taiwan. All participants received history taking, physical examination, chest radiography, 12-lead electrocardiography, blood tests for cell counts and fasting glucose, lipid profiles, uric acid, renal function and liver function in the Hualien Armed Forces General Hospital during 2014. In addition, participants were required to undergo two indoor resistant exercise tests including 2-min push-up and 2-min sit-up, both scored by infrared sensing, and one outdoor endurance 3000-m none weight-bearing running test, the main indicator of cardiorespiratory fitness in the Military Physical Training and Testing Center in Eastern Taiwan in 2014. RESULTS Hospitalization events for cardiovascular disease, acute kidney injury, rhabdomyolysis, severe infectious disease, acute psychiatric illness, diabetes, orthopedic surgery and mortality will be identified in the National Insurance Research Database for 10 years. CONCLUSION CHIEF will be among the largest Eastern Asian armed forces cohort, in which physical status was strictly evaluated to follow up the hospitalization events for severe illness.
基金provided by the Federal Ministry of Defence.Funding number:E/U2 AD/FD004/FF551
文摘Background: Military families who have a family member with a mental illness see themselves confronted with many demands. Stigmatization is one of these challenges. Stigmatization affects not only the individual who suffers from a mental illness but also other family members via stigma by association and vicarious stigma. Stigma by association occurs when mental illness stigma spills over to individuals associated with an individual with a mental illness. Vicarious stigma describes the suffering of family members when they note the impact of stigma on their relative with mental illness. As a societal phenomenon, stigma plays out in social interactions and might therefore influence the social networks of families. It is also associated with healthcare utilization.Methods: Narrative interviews were conducted with 15 family members(partners, spouses, parents and children) of former soldiers of the German Armed Forces with a service-induced mental illness. The transcribed interview data were analyzed using a thematic analysis approach, in which codes were formed and emerging themes were systemized. Relationships between stigma, the families’ reactions to it, its effects on their social relationships and its interference with their healthcare utilization were analyzed.Results: This study provides a detailed description of how relatives of former German soldiers with mental health problems experience stigma by association and vicarious stigma. Their perceptions are shown in a model that describes stigma-related attitudes, reactions to them and their effects on the social relationships of former soldiers’ families. These families felt stigmatized because of the former soldiers’ mental illness(mental illness stigma) and the military context in which it occurred(former soldier stigma). They reacted with nondisclosure, anger, acceptance and self-blame. Stigma was associated with smaller and weaker social networks that were characterized by social exclusion, self-segregation and conflicts with extended family, friends and colleagues. Stigma also affected the families’ healthcare utilization.Conclusions: Urgently needed anti-stigma campaigns, particularly in the civilian context, should address the stigmatization of both mental illness and the military participation of the families affected. They should consider the needs of both former soldiers with a mental illness and their families.
文摘After the Cold War, all European armed forces have transformed to be prepared for the new geopolitical environment and have taken new tasks. Since then, the European armed forces are more active in international conflict management. Whereas most of the European states have suspended the conscription, the Swiss Armed Forces still hold on conscription. However, the Swiss Armed Forces have changed also. The reform "Armee 95" in 1995 and the reform "Armee XXI" in 2004 have transformed the Swiss Armed Forces and extended their range of tasks. Which of these tasks are legitimated by the Swiss population? To answer this question, the Swiss population had been interviewed about the tasks of the Swiss Armed Forces as part of the study "Sicherheit 2016". The tasks which the Swiss population mentioned are displayed in this paper with regard to the transformation process classified and discussed. The evaluation shows that 93% of the interviewees have named one of Switzerland's constitutional duties (defense, support of the civilian authorities, and promotion of peace within an international context) as the most important task of the Swiss Armed Forces. Mainly the national defense order and the subsidiary support of the civilian authorities are approved by the Swiss population.
文摘Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1)the volume and strength of the neck and shoulder muscles and 2)muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel.Methods:Eighteen participants underwent 12 weeks of functional strength training(n=12)or the control protocol(n=6)without additional strength training.Pre-and post-intervention tests included evaluations of isometric strength of the head extensor muscles,flexion,and lateral flexion and rotation,as well as magnetic resonance imaging(MRI)to measure the volume of the m.sternocleidomastoideus,m.trapezius,and deep neck muscles.Furthermore,during a long-arm centrifuge(+1.4 and+3Gz)protocol,the muscular activity levels of the m.sternocleidomastoideus,m.trapezius and m.erector spinae muscles were assessed without a flight helmet,with a helmet,and with a helmet and night vision goggles.Each participant’s perception of muscular strain was noted immediately after the long-arm centrifuge protocol.Results:The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group(P<0.05).Relative muscle activity(%MVC)with a helmet decreased after the intervention in the training but not the control group(P=0.01).Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group(P<0.01).The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups.Conclusions:Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge.
基金a grant by Key Projects of Liaoning Province, No. 2008225009
文摘Due to their relative abundance,stable biological properties and excellent reproductive activity,umbilical cord mesenchymal stem cells have previously been utilized for the treatment of Duchenne muscular dystrophy,which is a muscular atrophy disease.Three patients who were clinically and pathologically diagnosed with Duchenne muscular dystrophy were transplanted with umbilical cord mesenchymal stem cells by intravenous infusion,in combination with multi-point intramuscular injection.They were followed up for 12 months after cell transplantation.Results showed that clinical symptoms significantly improved,daily living activity and muscle strength were enhanced,the sero-enzyme,electromyogram,and MRI scans showed improvement,and dystrophin was expressed in the muscle cell membrane.Hematoxylin-eosin staining of a muscle biopsy revealed that muscle fibers were well arranged,fibrous degeneration was alleviated,and fat infiltration was improved.These pieces of evidence suggest that umbilical cord mesenchymal stem cell transplantation can be considered as a new regimen for Duchenne muscular dystrophy.
基金the Structure and Motion Lab,University of LondonCentre for Robotics Research at King's College London+1 种基金BBSRC for their support from grant number BB/H003142/1supported by the Royal Thailand Government
文摘The objective of this study is to investigate the biomechanical functions of the human ankle-toot complex during the stancephase of walking. The three-dimensional (3D) gait measurement was conducted by using a 3D infrared multi-camera system anda force plate array to record the Ground Reaction Forces (GRF) and segmental motions simultaneously. The ankle-foot complexwas modelled as a four-segment system, connected by three joints: talocrural joint, sub-talar joint and metatarsophalangeal joint.The subject-specific joint orientations and locations were determined using a functional joint method based on the particleswarm optimisation algorithm. The GRF moment arms and joint moments acting around the talocrural and sub-talar joints werecalculated over the entire stance phase. The estimated talocrural and sub-talar joint locations show noticeable obliquity. Thekinematic and kinetic results strongly suggest that the human ankle-foot complex works as a mechanical mechanism with twodifferent configurations in stance phase of walking. These lead to a significant decrease in the GRF moment arms therebyincreasing the effective mechanical advantages of the ankle plantarflexor muscles. This reconfigurable mechanism enhancesmuscle effectiveness during locomotion by modulating the gear ratio of the ankle plantarflexor muscles in stance. This studyalso reveals many factors may contribute to the locomotor function of the human ankle-foot complex, which include not only itsre-configurable structure, but also its obliquely arranged joints, the characteristic heel-to-toe Centre of Pressure (COP) motionand also the medially acting GRF pattern. Although the human ankle-foot structure is immensely complex, it seems that itsconfiguration and each constitutive component are well tuned to maximise locomotor efficiency and also to minimise risk ofinjury. This result would advance our understanding of the locomotor function of the ankle-foot complex, and also the intrinsicdesign of the ankle-foot musculoskeletal structure. Moreover, this may also provide implications for the design of bionicprosthetic devices and the development of humanoid robots.
基金National Natural Science Foundation of China(No.50305035)
文摘A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external structure mechanism, the 3-revolution-prismatic-spherical (3RPS) parallel mechanism is devised from the concept of the human upper-limb anatomy and applied for the shoulder 3-DOF joint. Meanwhile, the orthogonal experiment design method is introduced for its optimal design. Aiming at enhancing the performance of teleoperation, the force feedback is employed by the pneumatic system on ZJUESA to produce the vivid feeling in addition to the soft control interface. Due to the compressibility and nonlinearity of the pneumatic force feedback system, a novel hybrid fuzzy controller for the precise force control is proposed and realized based on the Mega8 microcontroller units as the units of the distributed control system on ZJUESA. With the results of several experiments for master-slave control with force feedback, the feasibility of ZJUESA system and the effect of its hybrid fuzzy controller are verified.
文摘This paper discusses a force control problem for a flexible Timoshenko arm. The effect of shear deformation and the effect of rotary inertia are considered in Timoshenko beam theory. Most of the research about force control of the flexible arm is based on Euler Bernoulli beam theory. There are a few researches about force control of the flexible arm using Timoshenko beam theory. The aim of the force control is to control the contact force at the contact point. To solve this problem, we propose a simple controller using Timoshenko beam theory. Finally, we describe simulation results using a numerical inversion of Laplace transform carried out to investigate the validity of the proposed controller for the force control problem. The results of the time response show the transverse displacement, the angle of deflection, the slider position, the rotational angle and the contact force toward the desired their values.
文摘Based on some former studies of Chinese rural society, this paper summerizes the achievements and limitations of general Chinese rural studies and then proposes a social operation model in rural areas which is dominated by the squires. It uses some specific historical data and discoveries of feild sduty to further examine the profound influence of the squires on rural politcal construction in three different aspects: the model of clan and religion, the role as inter-mediator and the growth of basic armed forces. The study found that this special social group played a center role in Chinese rural political system from ancient to modem times, particularly, the research considers the decline of the squire society since the establishment of the new government in 1949. In the end, this paper points out the cultural guiding significance of this social model in the study to the rural construction in contemporay China by predicting the possiblity of renaissance
文摘A kind of new obstacle space expression is proposed in this paper, in which a virtual force field (VFF) is built. Using the torque and joint optimization acted by the virtual force field on the anthropomorphic weld arm, the real-time selection of a redundant join (R-joint) is done and its equivalent virtual torque is obtained, thus the redundant joint can be controlled with whose force feedback. An inverse kinematics solution of a 6-DOF robot is applied to other six joints of the arm. Simulation experiments indicate the new inverse kinematics solution has perfect collision avoidance effect, and it is well simplified. Therefore, it can be applied to a welding task in complex operation space.