The paper evaluates the e ectiveness of learning for speeding up the solution of constraint satisfaction problems. It extends previous work (Dechter 1990) by introducing a new and powerful variant of learning and by presenting an extensive empirical study on much larger and more di cult problem instances. Our results show that learning can speed up backjumping when using either a xed or dynamic...

The impact of corpora is easily observable in Linguistics: it has changed the way we understand language use. However, despite their potential for impact in society, the use of corpora inside and outside the university settings in Northeast Brazil is still restricted. Rather than compiling another research corpus, the present project aims at engaging several educational communities in the use o...

implicit in the user’s choice of training examples); and they address the question of how to learn by applying a single, fixed learning method. Although such systems provide a useful test bed for examining individual learning mechanisms, they are inadequate for use as real-world learners. The problem is that realworld situations offer countless opportunities for learning, and each of these oppo...

Dedifferentiated liposarcoma (DDL) with divergent dedifferentiation is uncommonly reported variable incidences. Liposarcomas, particularly those manifesting dedifferentiation, occur in the retroperitoneum. They grow into large size, present at very late stages, and can have a poor clinical outcome. Here we rare case of recurrent dedifferentiated dual heterologous differentiation osteosarcoma Ch...

Undergeneration is a problem that undermines successful parsing of unrestricted texts. A popular solution to this problem is automatic grammar correction (or machine learning of grammar). Broadly speaking, grammar correction approaches can be classiied as being either data-driven, or model-based. Data-driven learners use data-intensive methods to acquire grammar. They typically use grammar form...