The new three-phase 5-level current-source inverter (CSI) proposed in this paper was developed by connecting three separate single-phase 5-level CSIs in series, and its operational principle was analyzed. There are tw...The new three-phase 5-level current-source inverter (CSI) proposed in this paper was developed by connecting three separate single-phase 5-level CSIs in series, and its operational principle was analyzed. There are two major problems existing in current-source multilevel inverters, one is the complex PWM control method (2-logic to 3-logic conversion), and the other is the problem of current-unbalance between different levels. A simple current-balance control method via DC current feedback is applied in each single-phase 5-level CSI cell to implement the current-balance control between different levels. And to reduce the output current harmonics, POD PWM control technique was used. Simulation and experimental results showed that this new three-phase 5-level CSI topology operates correctly.展开更多
This paper reported an acoustic experiment examining the effect of topic structure and syntax on boundary pitch parameters. Simple discourses containing three sentences were constructed and the boundary between the fi...This paper reported an acoustic experiment examining the effect of topic structure and syntax on boundary pitch parameters. Simple discourses containing three sentences were constructed and the boundary between the first sentence and the second sentence of each discourse varied along the following parameters： （1） topic internal, clause; （2） topic shift, clause; （3） topic internal, sentence; and （4） topic shift, sentence. Seven native speakers of Standard Chinese read the short discourses aloud. The offset f0, f0 Max, and f0 Min of the first sentence and the onset f0, f0 Max, and f0 Min of the second sentence were measured. It was found that relative to topic internal condition, topic shift condition induced higher onset f0 following the boundary. Moreover, this higher onset f0 was caused by the raising of both f0 max and f0 min, suggesting pitch register raising rather than pitch range expansion following the boundary. Syntactic structure as index by clause or sentence was found to have no effect on boundary pitch parameters. These results provide strong evidence for a role of topic strucutre in speech production展开更多
基金Project (No. 50477033) supported by the National Natural Science Foundation of China
文摘The new three-phase 5-level current-source inverter (CSI) proposed in this paper was developed by connecting three separate single-phase 5-level CSIs in series, and its operational principle was analyzed. There are two major problems existing in current-source multilevel inverters, one is the complex PWM control method (2-logic to 3-logic conversion), and the other is the problem of current-unbalance between different levels. A simple current-balance control method via DC current feedback is applied in each single-phase 5-level CSI cell to implement the current-balance control between different levels. And to reduce the output current harmonics, POD PWM control technique was used. Simulation and experimental results showed that this new three-phase 5-level CSI topology operates correctly.
文摘This paper reported an acoustic experiment examining the effect of topic structure and syntax on boundary pitch parameters. Simple discourses containing three sentences were constructed and the boundary between the first sentence and the second sentence of each discourse varied along the following parameters： （1） topic internal, clause; （2） topic shift, clause; （3） topic internal, sentence; and （4） topic shift, sentence. Seven native speakers of Standard Chinese read the short discourses aloud. The offset f0, f0 Max, and f0 Min of the first sentence and the onset f0, f0 Max, and f0 Min of the second sentence were measured. It was found that relative to topic internal condition, topic shift condition induced higher onset f0 following the boundary. Moreover, this higher onset f0 was caused by the raising of both f0 max and f0 min, suggesting pitch register raising rather than pitch range expansion following the boundary. Syntactic structure as index by clause or sentence was found to have no effect on boundary pitch parameters. These results provide strong evidence for a role of topic strucutre in speech production
