中文摘要：

字符串识别通过最优路径搜索得到字符切分和字符识别结果．本文将字符同步和时间同步两种搜索模式应用于手写字符串识别系统，比较两种模式下使用不同准则函数和搜索算法的系统性能．同时，提出一种改进的路径评价准则，在此准则下可用动态规划算法进行最优路径的搜索．在联机手写日文字符串识别中的实验结果表明，对于无词典驱动的字符串识别系统，时间同步搜索的效率高于字符同步搜索．利用本文所提出的路径评价准则，可得到与归一化准则相当的切分和识别准确率，但搜索时间大为减少．

英文摘要：

The optimal path search is usually used to obtain the results of character segmentation and character recognition in character string recognition . In this paper, two search fashions are applied to handwritten character string recognition ： character-synchronous and time-synchronous. Their performance is compared by combining different path evaluation criteria and search strategies. Moreover, a modified path evaluation criterion is proposed. The dynamic programming （DP） algorithm can find the optimal path by the proposed criterion. Experimental results of online handwritten Japanese character string recognition show that time-synchronous search is more efficient than character-synchronous search for lexicon-free character string recognition. Under the proposed path evaluation criterion, the equivalent accuracies of the segmentation and recognition to the normalized path evaluation criterion are obtained with greatly reduced search time.