The introduction of affordable, consumer-oriented 3-D printers is a milestone in the current "maker movement," which has been heralded as the next industrial revolution. Combined with free and open sharing of detailed design blueprints and accessible development tools, rapid prototypes of complex products can now be assembled in one's own garage--a game-changer reminiscent of the early days of ...

In this article we study cocycles of discrete countable groups with values in 2G and the ring of affiliated operators UG. We clarify properties of the first cohomology of a group G with coefficients in 2G and answer several questions from De Cornulier et al. (Transform. Groups 13(1):125–147, 2008). Moreover, we obtain strong results about the existence of free subgroups and the subgroup structu...

In his well-known paper \How computer should think" ((Be77b]) Belnap argues that four valued semantics is a very suitable setting for computerized reasoning. In this paper we vindicate this thesis by showing that the logical role that the four-valued structure has among Ginsberg's well-known bilattices is similar to the role that the two-valued algebra has among Boolean algebras. Speciically, w...

We show that three-dimensional incoherent primary sources can be reconstructed from finite-aperture Fresnel-zone mutual intensity measurements by means of coordinate and Fourier transformation. The spatial bandpass and impulse response for three-dimensional imaging that result from use of this approach are derived. The transverse and longitudinal resolutions are evaluated as functions of apertu...

This work investigates first-language (L1) influence on second-language (L2) acquisition of embedded aspect, comparing participants with homogeneous L1 background (Russian) in Greece (L2 Standard Modern Greek) and Cyprus (L2 Cypriot Greek), where verb complementation takes a finite form instead of an infinitival as in Russian. The focus of the experimental study is on those embedded sentential ...

Axiomatic bases of admissible rules are obtained for fragments of the substructural logic R-mingle. In particular, it is shown that a “modus-ponens-like” rule introduced by Arnon Avron forms a basis for the admissible rules of its implication and implication-fusion fragments, while a basis for the admissible rules of the full multiplicative fragment requires an additional countably infinite set...

This symposium explores the role of health as an 'economic engine' in the lower Mississippi River Delta region of the United States. The health as an economic engine model proposes that health is an important and perhaps critical determinant of economic growth and development. This model is the reverse of the more commonly considered paradigm in which economic conditions are major determinants ...

The EOQ and EPQ models with linear and fixed backorder costs are newly analyzed and all formulae are proven using only algebra. Two cases are identified, where backorders should and should not be allowed. The results are shown to include several known special cases. r 2004 Elsevier B.V. All rights reserved.