By using transfer matrix,the lower-order natural frequencies of the Watt type planar six-barlinkage are calculated in this paper.The experiment of the modal analysis is done with the SignalProcessor 7T17S,and the expe...By using transfer matrix,the lower-order natural frequencies of the Watt type planar six-barlinkage are calculated in this paper.The experiment of the modal analysis is done with the SignalProcessor 7T17S,and the experiment results agree with the calculated ones.This method only re-quires calculation of lower-order transfer matrix and determinant values,so that, it can be done ona minicomputer such as IBM/PC.The method adopted in this paper is also suitable for vibrationanalysis of other types of linkages.展开更多
Short circuit due to the brushes over the commutator segments of DC machines causes reduction in the armature resistance and flux linkage, which is especially meaningful when the electric machine is running at zero or...Short circuit due to the brushes over the commutator segments of DC machines causes reduction in the armature resistance and flux linkage, which is especially meaningful when the electric machine is running at zero or extremely low speed. In design computation of DC machines, usually the average values of the coefficients are used in consideration of the effects of the short circuit. How-ever, the average values have complicated relationships with the parameters of electric machines, therefore, no usable mathematical model has been established yet for precise computation. In this paper, a relatively simple and generalized method for precise computation of the average values of the short-circuit coefficients is proposed. This method decouples some of the machine parameters and, therefore establishes a highly parameterized mathematical model and is convenient in formulation for computation. In addition, the computation data for one and two brush pairs, which are the most common cases, is provided.展开更多
This paper proposed a method to incorporate syntax-based language models in phrase-based statistical machine translation (SMT) systems. The syntax-based language model used in this paper is based on link grammar,which...This paper proposed a method to incorporate syntax-based language models in phrase-based statistical machine translation (SMT) systems. The syntax-based language model used in this paper is based on link grammar,which is a high lexical formalism. In order to apply language models based on link grammar in phrase-based models,the concept of linked phrases,an extension of the concept of traditional phrases in phrase-based models was brought out. Experiments were conducted and the results showed that the use of syntax-based language models could improve the performance of the phrase-based models greatly.展开更多
文摘By using transfer matrix,the lower-order natural frequencies of the Watt type planar six-barlinkage are calculated in this paper.The experiment of the modal analysis is done with the SignalProcessor 7T17S,and the experiment results agree with the calculated ones.This method only re-quires calculation of lower-order transfer matrix and determinant values,so that, it can be done ona minicomputer such as IBM/PC.The method adopted in this paper is also suitable for vibrationanalysis of other types of linkages.
文摘Short circuit due to the brushes over the commutator segments of DC machines causes reduction in the armature resistance and flux linkage, which is especially meaningful when the electric machine is running at zero or extremely low speed. In design computation of DC machines, usually the average values of the coefficients are used in consideration of the effects of the short circuit. How-ever, the average values have complicated relationships with the parameters of electric machines, therefore, no usable mathematical model has been established yet for precise computation. In this paper, a relatively simple and generalized method for precise computation of the average values of the short-circuit coefficients is proposed. This method decouples some of the machine parameters and, therefore establishes a highly parameterized mathematical model and is convenient in formulation for computation. In addition, the computation data for one and two brush pairs, which are the most common cases, is provided.
基金National Natural Science Foundation of China ( No.60803078)National High Technology Research and Development Programs of China (No.2006AA010107, No.2006AA010108)
文摘This paper proposed a method to incorporate syntax-based language models in phrase-based statistical machine translation (SMT) systems. The syntax-based language model used in this paper is based on link grammar,which is a high lexical formalism. In order to apply language models based on link grammar in phrase-based models,the concept of linked phrases,an extension of the concept of traditional phrases in phrase-based models was brought out. Experiments were conducted and the results showed that the use of syntax-based language models could improve the performance of the phrase-based models greatly.
