Fast walking and jogging are two common exercises for people to maintain health in daily life.But the differences in loading patterns of fast walking and jogging are still unclear.The purpose of this study was to comp...Fast walking and jogging are two common exercises for people to maintain health in daily life.But the differences in loading patterns of fast walking and jogging are still unclear.The purpose of this study was to compare loading patterns in fast walking and jogging at the same speed,and to identify how differences in foot mechanics influence plantar pressure distribution between the two modes of gait.Totally,49 healthy males participated in this study.Data of pressure parameters,including maximum force(MF),peak pressure(PP),contact area(CA),force-time integral(FTI),were recorded by Pedar-X insole plantar pressure measurement system in participants’fast walking and jogging process at 7 km/h.A Load transfer analysis method was used to quantify the plantar load transference from fast walking to jogging.The results showed that MF,PP and CA increased in metatarsal regions and midfoot regions while decreased in toes regions and heel during jogging when compared with fast walking.FTI decreased in all foot regions during jogging compared to fast walking.Under the effects of spring mechanics and the varus of rearfoot during jogging,fast walking and jogging reveal different loading patterns.Compared jogging to fast walking,load transferred as follow:1)in transverse direction,load transferred from lateral foot to medial foot in metatarsal regions and midfoot regions,2)in longitudinal direction,load transferred from toes to the metatarsal,and from heel to the metatarsal and midfoot.These results also provide suggestions for footwear designs.展开更多
The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time...The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time history analy- sis.Based on the numerical results obtained a two-phase load pattern:an inverted triangle(first mode)load pattern until the base shear force reaches β times its maximum value,V_(max)followed by a(x/H)~α form,here β and α being some coeffi- cients depending on the type of the structures considered,is proposed in the paper,which can provide excellent approxima- tion of the seismic capacity curve for low-to-mid-rise shear type buildings.Furthermore,it is shown both the two-phase load pattern proposed and the invariant uniform pattern can be used for low-to-mid-rise shear-bending type and low-rise bending type of buildings.No suitable load patterns have been found for high-rise buildings.展开更多
Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young's modulus of monolayer-...Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young's modulus of monolayer-thick graphyne is almost half of that of graphene, which is estimated to be 0.50 TPa. The mechanical properties of graphene and graphyne are different in the presence of strain. A pre-tension has an important effect on the mechanical properties of a membrane. Both the pre-tension and Young's modulus plots demonstrate index behavior. The toughness of graphyne is stronger than that of graphene due to Young's modulus magnitude. Young's moduli of graphene and graphyne are almost independent of the size ratio of indenter to membrane.展开更多
Distribution system planners usually provide dedicated feeders to its different class of customers,each of whom has its own characteristic load pattern which varies hourly and seasonally.A more realistic modeling shou...Distribution system planners usually provide dedicated feeders to its different class of customers,each of whom has its own characteristic load pattern which varies hourly and seasonally.A more realistic modeling should be devised by considering the daily and seasonal variations in the aggregate load patterns of different class of customers.This paper addresses a new methodology to provide integrated solution for the optimal allocation of distributed generations and network reconfiguration considering load patterns of customers.The objectives considered are to maximize annual energy loss reduction and to maintain a better node voltage profile.Bat algorithm(BA)is a new bio-inspired search algorithm which has shown an advance capability to reach into the promising region,but its exploration is inadequate.The problem is solved by proposing the improved BA(IBA).The proposed method is investigated on the benchmark IEEE 33-bus test distribution system and the results are very promising.展开更多
This paper presents the results of an ongoing investigation into transient pressure pulses using Shan- non entropy. Pressure fluctuations (produced by gas-solid two-phase flow during fluidized dense-phase conveying)...This paper presents the results of an ongoing investigation into transient pressure pulses using Shan- non entropy. Pressure fluctuations (produced by gas-solid two-phase flow during fluidized dense-phase conveying) are recorded by pressure transducers installed at strategic locations along a pipeline. This work validates previous work on identifying the flow mode from pressure signals (Mittal, Mallick, & Wypych, 2014). Two different powders, namely fly ash (median particle diameter 45 μm, particle den- sity 1950 kg/m3. loosely poured bulk density 950 kg/m3) and cement (median particle diameter 15 p,m, particle density 3060 kg/m3, loosely poured bulk density 1070 kg/m3), are conveyed through different pipelines (51 mm I.D. × 70 m length and 63 mm I.D. × 24 m length). The transient nature of pressure fluc- tuations (instead of steady-state behavior) is considered in investigating flow characteristics. Shannon entropy is found to increase along straight pipe sections for both solids and both pipelines. However, Shannon entropy decreases after a bend. A comparison of Shannon entropy among different ranges of superficial air velocity reveals that high Shannon entropy corresponds to very low velocities (i.e. 3-5 m/s) and very high velocities (i.e. 11-14 m/s) while low Shannon entropy corresponds to mid-range velocities (i.e. 6-8 m/s).展开更多
基金supported by National Natural Science Foundation of China,grant number:11502154.
文摘Fast walking and jogging are two common exercises for people to maintain health in daily life.But the differences in loading patterns of fast walking and jogging are still unclear.The purpose of this study was to compare loading patterns in fast walking and jogging at the same speed,and to identify how differences in foot mechanics influence plantar pressure distribution between the two modes of gait.Totally,49 healthy males participated in this study.Data of pressure parameters,including maximum force(MF),peak pressure(PP),contact area(CA),force-time integral(FTI),were recorded by Pedar-X insole plantar pressure measurement system in participants’fast walking and jogging process at 7 km/h.A Load transfer analysis method was used to quantify the plantar load transference from fast walking to jogging.The results showed that MF,PP and CA increased in metatarsal regions and midfoot regions while decreased in toes regions and heel during jogging when compared with fast walking.FTI decreased in all foot regions during jogging compared to fast walking.Under the effects of spring mechanics and the varus of rearfoot during jogging,fast walking and jogging reveal different loading patterns.Compared jogging to fast walking,load transferred as follow:1)in transverse direction,load transferred from lateral foot to medial foot in metatarsal regions and midfoot regions,2)in longitudinal direction,load transferred from toes to the metatarsal,and from heel to the metatarsal and midfoot.These results also provide suggestions for footwear designs.
文摘The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time history analy- sis.Based on the numerical results obtained a two-phase load pattern:an inverted triangle(first mode)load pattern until the base shear force reaches β times its maximum value,V_(max)followed by a(x/H)~α form,here β and α being some coeffi- cients depending on the type of the structures considered,is proposed in the paper,which can provide excellent approxima- tion of the seismic capacity curve for low-to-mid-rise shear type buildings.Furthermore,it is shown both the two-phase load pattern proposed and the invariant uniform pattern can be used for low-to-mid-rise shear-bending type and low-rise bending type of buildings.No suitable load patterns have been found for high-rise buildings.
基金Supported by the National Natural Science Foundation of China under Grant No 11274262the Natural Science Foundation of Hunan Province under Grand No 14JJ2046the Program for Changjiang Scholars and Innovative Research Team in Universities under Grant No IRT13093
文摘Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young's modulus of monolayer-thick graphyne is almost half of that of graphene, which is estimated to be 0.50 TPa. The mechanical properties of graphene and graphyne are different in the presence of strain. A pre-tension has an important effect on the mechanical properties of a membrane. Both the pre-tension and Young's modulus plots demonstrate index behavior. The toughness of graphyne is stronger than that of graphene due to Young's modulus magnitude. Young's moduli of graphene and graphyne are almost independent of the size ratio of indenter to membrane.
文摘Distribution system planners usually provide dedicated feeders to its different class of customers,each of whom has its own characteristic load pattern which varies hourly and seasonally.A more realistic modeling should be devised by considering the daily and seasonal variations in the aggregate load patterns of different class of customers.This paper addresses a new methodology to provide integrated solution for the optimal allocation of distributed generations and network reconfiguration considering load patterns of customers.The objectives considered are to maximize annual energy loss reduction and to maintain a better node voltage profile.Bat algorithm(BA)is a new bio-inspired search algorithm which has shown an advance capability to reach into the promising region,but its exploration is inadequate.The problem is solved by proposing the improved BA(IBA).The proposed method is investigated on the benchmark IEEE 33-bus test distribution system and the results are very promising.
文摘This paper presents the results of an ongoing investigation into transient pressure pulses using Shan- non entropy. Pressure fluctuations (produced by gas-solid two-phase flow during fluidized dense-phase conveying) are recorded by pressure transducers installed at strategic locations along a pipeline. This work validates previous work on identifying the flow mode from pressure signals (Mittal, Mallick, & Wypych, 2014). Two different powders, namely fly ash (median particle diameter 45 μm, particle den- sity 1950 kg/m3. loosely poured bulk density 950 kg/m3) and cement (median particle diameter 15 p,m, particle density 3060 kg/m3, loosely poured bulk density 1070 kg/m3), are conveyed through different pipelines (51 mm I.D. × 70 m length and 63 mm I.D. × 24 m length). The transient nature of pressure fluc- tuations (instead of steady-state behavior) is considered in investigating flow characteristics. Shannon entropy is found to increase along straight pipe sections for both solids and both pipelines. However, Shannon entropy decreases after a bend. A comparison of Shannon entropy among different ranges of superficial air velocity reveals that high Shannon entropy corresponds to very low velocities (i.e. 3-5 m/s) and very high velocities (i.e. 11-14 m/s) while low Shannon entropy corresponds to mid-range velocities (i.e. 6-8 m/s).