Associated dynamic performance of the clamping force control valve used in continuously variable transmission (CVT) is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dy...Associated dynamic performance of the clamping force control valve used in continuously variable transmission (CVT) is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm (GA) with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.展开更多
The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain function...The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain functions,the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal.Recent studies utilized one single long run for task trials of the same condition,the so-called continuous design,to investigate functional connectivity based on task functional magnetic resonance imaging.Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment,which has been examined for working memory,sensory,motor,and semantic task experiments in previous research.But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks.This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks,by using repeated-measures analysis of variance.Across 50 young healthy adults,behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load.Imaging results revealed that the cingulo-opercular,fronto-parietal,and default model networks were associated with not only task activation,but significant main effects of design and load as well as their interaction on intra-and inter-network functional connectivity and global network topology.Moreover,a significant behavior-brain association was identified for the continuous design.This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.展开更多
Well developed continuous speech recognition and synthesis systems demand a high quality continuous speech database which is compact and valid, and whose scientific design would benefit from incorporating linguistic a...Well developed continuous speech recognition and synthesis systems demand a high quality continuous speech database which is compact and valid, and whose scientific design would benefit from incorporating linguistic and phonetic knowledge. It is argued that at the present stage the database should be limited to read speech. To describe those very complex variabilities in continuous speech, the following speech units are proposed: (1) 401syllables without tone; (2) 415 inter-syllabic diphones, (3) 3035 inter-syllabic triphones, (4) 781 inter-syllabic final-initial structures. The 17 basic sefltence patterns in standard Chinese are summarized to cover the most important prosodic phenomena. By using the automatic method,2393 sentences and 388 phrases are selected by above phonetic rules from a large corpus, which includes People's Daily in recent years, TV play scripts and dictionary entries, as the reading text of continuous speech recognition database in standard Chinese. This set of sentences and pbrases covers 99.8% syllables without counting tones, 100% inter-syllable diphones, 99.6% inter-syllable triphones and 100% sentence patterns.展开更多
基金Key Science-Technology Foundation of Hunan Province, China (No. 05GK2007).
文摘Associated dynamic performance of the clamping force control valve used in continuously variable transmission (CVT) is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm (GA) with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.
基金supported by the National Natural Science Foundation of China(62071109 and 61871420)the Provincial Natural Science Foundation of Sichuan(2022NSFSC0504).
文摘The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain functions,the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal.Recent studies utilized one single long run for task trials of the same condition,the so-called continuous design,to investigate functional connectivity based on task functional magnetic resonance imaging.Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment,which has been examined for working memory,sensory,motor,and semantic task experiments in previous research.But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks.This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks,by using repeated-measures analysis of variance.Across 50 young healthy adults,behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load.Imaging results revealed that the cingulo-opercular,fronto-parietal,and default model networks were associated with not only task activation,but significant main effects of design and load as well as their interaction on intra-and inter-network functional connectivity and global network topology.Moreover,a significant behavior-brain association was identified for the continuous design.This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.
文摘Well developed continuous speech recognition and synthesis systems demand a high quality continuous speech database which is compact and valid, and whose scientific design would benefit from incorporating linguistic and phonetic knowledge. It is argued that at the present stage the database should be limited to read speech. To describe those very complex variabilities in continuous speech, the following speech units are proposed: (1) 401syllables without tone; (2) 415 inter-syllabic diphones, (3) 3035 inter-syllabic triphones, (4) 781 inter-syllabic final-initial structures. The 17 basic sefltence patterns in standard Chinese are summarized to cover the most important prosodic phenomena. By using the automatic method,2393 sentences and 388 phrases are selected by above phonetic rules from a large corpus, which includes People's Daily in recent years, TV play scripts and dictionary entries, as the reading text of continuous speech recognition database in standard Chinese. This set of sentences and pbrases covers 99.8% syllables without counting tones, 100% inter-syllable diphones, 99.6% inter-syllable triphones and 100% sentence patterns.