Typed feature structures are used extensively for the specification of linguistic information in many formalisms. The subsumption relation orders TFSs by their information content. We prove that subsumption of acyclic TFSs is well founded, whereas in the presence of cycles general TFS subsumption is not well founded. We show an application of this result for parsing, where the well-foundedness of subsumption is used to guarantee termination for grammars that are off-line parsable. We define a new version of off-line parsability that (...) is less strict than the existing one; thus termination is guaranteed for parsing with a larger set of grammars. (shrink)

Unification grammars are widely accepted as an expressive means for describing the structure of natural languages. In general, the recognition problem is undecidable for unification grammars. Even with restricted variants of the formalism, off-line parsable grammars, the problem is computationally hard. We present two natural constraints on unification grammars which limit their expressivity and allow for efficient processing. We first show that non-reentrant unification grammars generate exactly the class of context-free languages. We then relax the constraint and show that one-reentrant (...) unification grammars generate exactly the class of mildly context-sensitive languages. We thus relate the commonly used and linguistically motivated formalism of unification grammars to more restricted, computationally tractable classes of languages. (shrink)

Polarized unification grammar (PUG) is a linguistic formalism which uses polarities to better control the way grammar fragments interact. The grammar combination operation of PUG was conjectured to be associative. We show that PUG grammar combination is not associative, and even attaching polarities to objects does not make it order-independent. Moreover, we prove that no non-trivial polarity system exists for which grammar combination is associative. We then redefine the grammar combination operator, moving to the powerset domain, in a way that (...) guarantees associativity. The method we propose is general and is applicable to a variety of tree-based grammar formalisms. (shrink)

Unification grammars are known to be Turing-equivalent; given a grammar G and a word w, it is undecidable whether w L(G). In order to ensure decidability, several constraints on grammars, commonly known as off-line parsability (OLP), were suggested, such that the recognition problem is decidable for grammars which satisfy OLP. An open question is whether it is decidable if a given grammar satisfies OLP. In this paper we investigate various definitions of OLP and discuss their interrelations, proving that some of (...) the OLP variants are indeed undecidable. We then present a novel, decidable OLP constraint which is more liberal than the existing decidable ones. (shrink)

The impact of entrepreneurial passion on business model innovation has become a research focus in the field of entrepreneurship. This study aimed to examine the effect of entrepreneurial passion on entrepreneurial learning and business model innovation. The study used partial least square-structural equation modeling to test the hypotheses on a sample of 389 manufacturing and technology enterprises in the South region of Henan province China. The results of this study revealed that entrepreneurial passion has a positive and significant influence on (...) entrepreneurial learning and business model innovation. The findings of this study showed that entrepreneurial learning positively and significantly mediates the relationship between entrepreneurial passion and business model innovation. Furthermore, the results of this study indicated that curiosity positively and significantly moderates the relationship between entrepreneurial passion and entrepreneurial learning. Lastly, the results are discussed with implications and limitations, which open up future research perspectives. (shrink)

Quantum probability (QP) provides a new perspective for cognitive science. However, one must be clear about the outcome the QP model is predicting. We discuss this concern in reference to modeling the subjective probabilities given by people as opposed to modeling the choice proportions of people. These two models would appear to have different cognitive assumptions.

Contrary to astronomy, the early modern Chinese State did not systematically sponsor mathematics. However, early in his reign, the Kangxi Emperor studied this subject with the Jesuit missionaries in charge of the calendar. His first teacher, Ferdinand Verbiest relied on textbooks based on Christoph Clavius'. Those who succeeded Verbiest as imperial tutors in the 1690s produced lecture notes in Manchu and Chinese. Newly discovered manuscripts show Antoine Thomas wrote substantial treatises on arithmetic and algebra while teaching those subjects. In 1713, (...) the emperor commissioned a group of scholars and officials to compile a standard survey of mathematics. This work opened with the claim that mathematics had its roots in Chinese Antiquity. However, it can be shown that the Jesuits' lecture notes were the main source of the Shuli jingyun. The reconstruction of mathematics under Kangxi's patronage is thus best characterised as the imperial appropriation of Western learning. (shrink)