In this paper, we propose an answer seeking algorithm for question answering that integrates structural matching and paraphrasing, and report the results of our empirical evaluation conducted with the aim of examining effects of incorporating those two components. According to the results, the contribution of structural matching and paraphrasing was not so large as expected. Based on error analysis, we conclude that structural matching-based approaches to answer seeking require technologies for (a) coreference resolution, (b) processing of parse forests instead of parse trees, and (c) large-scale acquisition of paraphrase patterns.

We have found a low frequency current oscillation in the n+-AlxGa1-xAs/GaAs (x0.4) modulation-doped electron systems under high electric field applied at low temperatures (77 K or lower). This paper gives a possible explanation for this on the basis of an enhanced Real-Space-Transfer (RST) of two-dimensional carriers caused by the field crowding at the local region along the heterointerface. This model explained the observed low frequency current oscillation semi-quantitatively.