For nested or heterogeneous datatypes, terminating recursion schemes considered so far have been instances of iteration, excluding efficient definitions of fixed-point unfolding. Two solutions of this problem are proposed: The first one is a system with equi-recursive nonstrictly positive type constructors of arbitrary finite kinds, where fixedpoint unfolding is computationally invisible due to...

At PEPM’91 Sahlin presented a determinacy analysis for Prolog with cut. The analysis was, however, not justified in any kind of semantics for Prolog, so correctness was argued with respect to an intuitive idea of the behaviour of Prolog programs. We now start with a denotational semantics of Prolog and derive a variant of Sahlins analysis as an abstraction of this. We observe that we avoid some...

cobalt is one of the most important constituent present in ceramic industries. glazers are the relevant workers when they are producing blue colored ceramic, causing occupational exposure to such metal. through this study, urinary cobalt was determined in glazers in a ceramic industry when they were producing blue-colored ceramic glazes.in this case-control study, spot urine samples were collec...

The X-ray telescope on board the Swift satellite for gamma-ray burst astronomy has been exposed to the radiation of the space environment since launch in November 2004. Radiation causes damage to the detector, with the generation of dark current and charge trapping sites that result in the degradation of the spectral resolution and an increase of the instrumental background. The Swift team has ...

We describe the design, implementation and performance of a novel airborne system, which integrates commercial waveform LiDAR, CCD (Charge-Coupled Device) camera and hyperspectral sensors into a common platform system. CAF’s (The Chinese Academy of Forestry) LiCHy (LiDAR, CCD and Hyperspectral) Airborne Observation System is a unique system that permits simultaneous measurements of vegetation v...

Complex tensor contraction expressions arise in accurate electronic structure models in quantum chemistry, such as the coupled cluster method. Transformations using algebraic properties of commutativity and associativity can be used to significantly decrease the number of arithmetic operations required for evaluation of these expressions. Operation minimization is an important optimization step...

The purpose of this note is to strengthen the results of [3 ] and to indicate a very brief derivation of some theorems announced without proof in [ l ; 3 ] . We begin by indicating a correction to [3]. Let Si and S2 be Riemann surfaces, ƒ an orientation preserving (orientation reversing) homeomorphism of bounded eccentricity of Si onto 52 and [ƒ] the homotopy class of/; then (Si, [ƒ], S2) is ca...

Continuous CCD photometry of the classical nova DN Gem during 52 nights in the years 1992-98 reveals a modulation with a period 0.127844 d. The semi-amplitude is about 0.03 mag. The stability of the variation suggests that it is the orbital period of the binary system. This interpretation makes DN Gem the fourth nova inside the cataclysmic variable (CV) period gap, as defined by Diaz & Bruch (1...