In this paper, a new bidirectional buck-boost dc-dc converter with capability of soft switching and zero input current ripple is proposed. The coupled inductor is used in the proposed converter to eliminate the input current ripple. In the proposed converter, zero voltage switching (ZVS) and zero current switching (ZCS) can be obtained for the main and auxiliary switches, respectively. In addit...

Many “semiring-like” structures are used in Soft Constraint Satisfaction Problems (SCSPs). We review a few properties of semirings that are useful for dealing with soft constraints, highlighting the differences between alternative proposals in the literature. We then extend the semiring structure by adding the notion of division as a weak inverse operation of product. In particular, division is...

We describe the WordsEye Linguistics tool (WELT), a novel tool for the documentation and preservation of endangered languages. WELT is based on WordsEye (Coyne and Sproat, 2001), a text-toscene tool that automatically generates 3D scenes from written input. WELT has two modes of operation. In the first mode, English input automatically generates a picture which can be used to elicit a descripti...

A soft-switching topology for high power buck converter is proposed. Zero-current turn-on and zero-voltage turn-off is achieved without auxiliary switches. All active switches in the converter transmit power to the load equally. Converter control is simple despite four active switches. Converter operation is described and DC analysis is carried out. All operation modes are identified. The condi...

Many writers have claimed that research and development (R&D) has two faces. In addition to the conventional role of stimulating innovation, R&D enhances technology transfer (absorptive capacity). We explore this idea empirically using a panel of industries across twelve OECD countries. We find R&D to be statistically and economically important in both technological catch-up and innovation. Hum...

The increase in equity prices over the 1990s has to a large degree been attributed to permanently higher productivity growth that is derived from the ‘new economy’ and related research and development (R&D) expenditures. This paper establishes a rational expectations model of technology innovations and equity prices, which shows that under plausible assumptions, productivity advances can only h...