The quest for energy efficiency has growing importance in high performance many-core systems. However, in current practices, the power slacks, which are the differences observed between the input power budget and the ...The quest for energy efficiency has growing importance in high performance many-core systems. However, in current practices, the power slacks, which are the differences observed between the input power budget and the actual power consumed in the many-core systems, are typically ignored, thus leading to poor energy efficiency. In this paper, we propose a scheme to effectively power the on-chip communications by exploiting the available power slack that is totally wasted in current many-core systems. As so, the demand for extra energy from external power sources （e.g., batteries） is minimized, which helps improve the overall energy efficiency. In essence, the power slack is stored at each node and the proposed routing algorithm uses a dynamic programming network to find the globally optimal path, along which the total energy stored on the nodes is the maximum. Experimental results have confirmed that the proposed scheme, with low hardware overhead, can reduce latency and extra energy consumption by 44% and 48%, respectively, compared with the two competing routing methods.展开更多
Purpose-Association of American railroads(AAR)standard automatic couplers are designed for much higher capacity than the normal operating loads.However,failure of knuckles and coupler bodies is still a common occurren...Purpose-Association of American railroads(AAR)standard automatic couplers are designed for much higher capacity than the normal operating loads.However,failure of knuckles and coupler bodies is still a common occurrence.Recent studies have shown that fatigue is the main reason behind such failures below the expected load.Moreover,knuckle failures occur more frequently than coupler body failures,which cause operational disruptions and also influence overall coupler life because of nonconforming contact between a new knuckle and an old coupler.In addition to new and old counterparts,undesired contact conditions are often the case with the new assembly due to casting-based manufacturing inaccuracies.Design/methodology/approach-A study is thus carried out in this paper to understand the variation of load transfer paths and its consequences caused by dimensional variability.A finite element model of an E-type coupler’s knuckle is developed and different possible contact conditions of the knuckle with the coupler head are simulated.Knuckles generally fail in pulling mode,during which the possible contacting elements of knuckle are pulling lugs,pin protector regions and pinholes.Due to dimensional variability,contact conditions may exist where an individual or a combination of these elements are in contact.Findings-Simulation results indicate that under regular operational conditions,having only the pulling lugs in contact reduces the risk of knuckle failure and maintains assembly integrity even if the knuckle fails.However,under extreme loading conditions,the safest scenario is when both pulling lugs and pin protector regions are in contact.Originality/value-These findings are believed to assist in defining the dimensional variability limits to ensure the desired contacts between the mating surfaces of the knuckle and coupler body of railway couplers of AAR type.This work contributes to understanding implications of dimensional variability in the railway couplers.The insight presented are useful in design,manufacturing and maintenance of railway coupler’s knuckle.展开更多
Remifentanil is widely used to control intraoperative pain. However, its analgesic effect is limited by the generation of postoperative hyperalgesia. In this study, we investigated whether the impairment of transmembr...Remifentanil is widely used to control intraoperative pain. However, its analgesic effect is limited by the generation of postoperative hyperalgesia. In this study, we investigated whether the impairment of transmembrane protein 16C(TMEM16C)/Slack is required for a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic receptor(AMPAR) activation in remifentanil-induced postoperative hyperalgesia. Remifentanil anesthesia reduced the paw withdrawal threshold from 2 h to 48 h postoperatively,with a decrease in the expression of TMEM16C and Slack in the dorsal root ganglia(DRG) and spinal cord.Knockdown of TMEM16C in the DRG reduced the expression of Slack and elevated the basal peripheral sensitivity and AMPAR expression and function. Overexpression of TMEM16C in the DRG impaired remifentanilinduced ERK1/2 phosphorylation and behavioral hyperalgesia. AMPAR-mediated current and neuronal excitability were downregulated by TMEM16C overexpression in the spinal cord. Taken together, these findings suggest that TMEM16C/Slack regulation of excitatory synaptic plasticity via GluA1-containing AMPARs is critical in the pathogenesis of remifentanil-induced postoperative hyperalgesia in rats.展开更多
The key to studying urban sustainable development depends on quantifying stores, efficiencies of urban metabolisms and capturing urban metabolisms′ mechanisms. This paper builds up the metabolic emergy account and qu...The key to studying urban sustainable development depends on quantifying stores, efficiencies of urban metabolisms and capturing urban metabolisms′ mechanisms. This paper builds up the metabolic emergy account and quantifies some important concepts of emergy stores. Emphasis is placed on the urban metabolic model based on the slack based model(SBM) method to measure urban metabolic efficiencies. Urban metabolic mechanisms are discussed by using the regression method. By integrating these models, this paper analyzes the urban metabolic development in Beijing from 2001 to 2010. We conclude that the metabolic emergy stores of Beijing increased significantly from 2001 to 2010, with the emergy imported accounting for most of the increase. The metabolic efficiencies in Beijing have improved since the 2008 Olympic Games. The population, economic growth, industrial structures, and environmental governance positively affect the overall urban metabolism, while the land expansion, urbanization and environmentally technical levels hinder the improving of urban metabolic efficiencies. The SBM metabolic method and the regression model based on the emergy analysis provide insights into the urban metabolic efficiencies and the mechanism. They can promote to integrate such concepts into their sustainability analyses and policy decisions.展开更多
The slack-taut state of tether is a particular adverse circumstance, which may influence the normal operation state of tension leg platform （TLP）. The dynamic responses of TLP with slack-taut tether are studied with...The slack-taut state of tether is a particular adverse circumstance, which may influence the normal operation state of tension leg platform （TLP）. The dynamic responses of TLP with slack-taut tether are studied with consideration of several nonlinear factors introduced by large amplitude motions. The time histories of stresses of tethers of a typical TLP in slack- taut state are given. In addition, the sensitivities of slack to stiffness and mass are investigated by varying the stiffness of tether and mass of TLP. It is found that slack is sensitive to the mass of TLP. The critical curved surfaces （ over which indicates the slack） for the increase of mass are obtained.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61376024 and No.61306024Natural Science Foundation of Guangdong Province under Grant No.S2013040014366Basic Research Program of Shenzhen under Grant No.JCYJ20140417113430642 and No.JCYJ 20140901003939020
文摘The quest for energy efficiency has growing importance in high performance many-core systems. However, in current practices, the power slacks, which are the differences observed between the input power budget and the actual power consumed in the many-core systems, are typically ignored, thus leading to poor energy efficiency. In this paper, we propose a scheme to effectively power the on-chip communications by exploiting the available power slack that is totally wasted in current many-core systems. As so, the demand for extra energy from external power sources （e.g., batteries） is minimized, which helps improve the overall energy efficiency. In essence, the power slack is stored at each node and the proposed routing algorithm uses a dynamic programming network to find the globally optimal path, along which the total energy stored on the nodes is the maximum. Experimental results have confirmed that the proposed scheme, with low hardware overhead, can reduce latency and extra energy consumption by 44% and 48%, respectively, compared with the two competing routing methods.
文摘Purpose-Association of American railroads(AAR)standard automatic couplers are designed for much higher capacity than the normal operating loads.However,failure of knuckles and coupler bodies is still a common occurrence.Recent studies have shown that fatigue is the main reason behind such failures below the expected load.Moreover,knuckle failures occur more frequently than coupler body failures,which cause operational disruptions and also influence overall coupler life because of nonconforming contact between a new knuckle and an old coupler.In addition to new and old counterparts,undesired contact conditions are often the case with the new assembly due to casting-based manufacturing inaccuracies.Design/methodology/approach-A study is thus carried out in this paper to understand the variation of load transfer paths and its consequences caused by dimensional variability.A finite element model of an E-type coupler’s knuckle is developed and different possible contact conditions of the knuckle with the coupler head are simulated.Knuckles generally fail in pulling mode,during which the possible contacting elements of knuckle are pulling lugs,pin protector regions and pinholes.Due to dimensional variability,contact conditions may exist where an individual or a combination of these elements are in contact.Findings-Simulation results indicate that under regular operational conditions,having only the pulling lugs in contact reduces the risk of knuckle failure and maintains assembly integrity even if the knuckle fails.However,under extreme loading conditions,the safest scenario is when both pulling lugs and pin protector regions are in contact.Originality/value-These findings are believed to assist in defining the dimensional variability limits to ensure the desired contacts between the mating surfaces of the knuckle and coupler body of railway couplers of AAR type.This work contributes to understanding implications of dimensional variability in the railway couplers.The insight presented are useful in design,manufacturing and maintenance of railway coupler’s knuckle.
基金supported by the National Natural Science Foundation of China (82071243, 81801107, 81772043, and 81400908)Tianjin Natural Science Foundation (20JCYBJC00460)Young Elite Scientists Sponsorship Program by Tianjin Municipality, China (TJSQNTJ-2020-10)。
文摘Remifentanil is widely used to control intraoperative pain. However, its analgesic effect is limited by the generation of postoperative hyperalgesia. In this study, we investigated whether the impairment of transmembrane protein 16C(TMEM16C)/Slack is required for a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic receptor(AMPAR) activation in remifentanil-induced postoperative hyperalgesia. Remifentanil anesthesia reduced the paw withdrawal threshold from 2 h to 48 h postoperatively,with a decrease in the expression of TMEM16C and Slack in the dorsal root ganglia(DRG) and spinal cord.Knockdown of TMEM16C in the DRG reduced the expression of Slack and elevated the basal peripheral sensitivity and AMPAR expression and function. Overexpression of TMEM16C in the DRG impaired remifentanilinduced ERK1/2 phosphorylation and behavioral hyperalgesia. AMPAR-mediated current and neuronal excitability were downregulated by TMEM16C overexpression in the spinal cord. Taken together, these findings suggest that TMEM16C/Slack regulation of excitatory synaptic plasticity via GluA1-containing AMPARs is critical in the pathogenesis of remifentanil-induced postoperative hyperalgesia in rats.
基金Under the auspices of National Natural Science Foundation of China(No.41371008,41101119)New Start Academic Research Projects of Beijing Union University(No.ZK201201)
文摘The key to studying urban sustainable development depends on quantifying stores, efficiencies of urban metabolisms and capturing urban metabolisms′ mechanisms. This paper builds up the metabolic emergy account and quantifies some important concepts of emergy stores. Emphasis is placed on the urban metabolic model based on the slack based model(SBM) method to measure urban metabolic efficiencies. Urban metabolic mechanisms are discussed by using the regression method. By integrating these models, this paper analyzes the urban metabolic development in Beijing from 2001 to 2010. We conclude that the metabolic emergy stores of Beijing increased significantly from 2001 to 2010, with the emergy imported accounting for most of the increase. The metabolic efficiencies in Beijing have improved since the 2008 Olympic Games. The population, economic growth, industrial structures, and environmental governance positively affect the overall urban metabolism, while the land expansion, urbanization and environmentally technical levels hinder the improving of urban metabolic efficiencies. The SBM metabolic method and the regression model based on the emergy analysis provide insights into the urban metabolic efficiencies and the mechanism. They can promote to integrate such concepts into their sustainability analyses and policy decisions.
基金supported by the National High-Tech Research and Development Program of China(863 Program,Grant No.2006AA09Z350)the National Natural Science Foundation of China(Grant No.10702073)the"Knowledge Innovation Program"of Chinese Academy of Sciences(Grant No.KJCX2-YW-L02)
文摘The slack-taut state of tether is a particular adverse circumstance, which may influence the normal operation state of tension leg platform （TLP）. The dynamic responses of TLP with slack-taut tether are studied with consideration of several nonlinear factors introduced by large amplitude motions. The time histories of stresses of tethers of a typical TLP in slack- taut state are given. In addition, the sensitivities of slack to stiffness and mass are investigated by varying the stiffness of tether and mass of TLP. It is found that slack is sensitive to the mass of TLP. The critical curved surfaces （ over which indicates the slack） for the increase of mass are obtained.
