Most seismic codes specify empirical formulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the formulas specified in present US codes using the available data on the fundamental period of buildings “measured” from their motions recorded during eight California earthquakes, starting from the 1971 San Fernando earthquake and ending with the 1994 Nor...

PURPOSE To describe a new formula, BESSt, to estimate true corneal power after keratorefractive surgery in eyes requiring cataract surgery. SETTING Moorfields Eye Hospital, London, United Kingdom. METHODS The BESSt formula, based on the Gaussian optics formula, was developed using data from 143 eyes that had keratorefractive surgery. The formula takes into account anterior and posterior cor...

In this paper we first define a reduction Æ that transforms an instance of Regular-SAT into a satisfiability equivalent instance Æ of SAT. The reduction Æ has interesting properties: (i) the size of Æ is linear in the size of , (ii) Æ transforms regular Horn formulas into Horn formulas, and (iii) Æ transforms regular 2-CNF formulas into 2-CNF formulas. Second, we describe a new satisfiability t...

1778 CLINICALCHEMISTRY, Vol. 28, No. 8, 1982 evaluation of diabetic control. Gun. Chim. Acta 104, 319-328 (1980). 12. Hankins, W. D., and Holladay, L., A temperature conversion nomogram for glycosylated hemoglobin analysis. Gun. Chim. Acta 104, 251-257 (1980). 13. Worth, R. C., Ashworth, L. A., Burrin, J. M., eta!., Column assay of haemoglobin Ai: Critical effect of temperature. Clin. Chim. Act...

We obtain upper and lower bounds for running times of exponential time algorithms for the detection of weak backdoor sets of 3CNF formulas, considering various base classes. These results include (omitting polynomial factors), (i) a 4.54 algorithm to detect whether there is a weak backdoor set of at most k variables into the class of Horn formulas; (ii) a 2.27 algorithm to detect whether there ...

We introduce the branching transitive closure operator on weighted monadic second-order logic formulas where the branching corresponds in a natural way to the branching inherent in trees. For arbitrary commutative semirings, we prove that weighted monadic second order logics on trees is equivalent to the definability by formulas which start with one of the following operators: (i) a branching t...

The classical Schläfli formula, and its “higher” analogs given in [SS03], are relations between the variations of the volumes and “curvatures” of faces of different dimensions of a polyhedra (which can be Euclidean, spherical or hyperbolic) under a first-order deformation. We describe here analogs of those formulas which are vector-valued rather than scalar. Some consequences follow, for instan...