In this paper we study the complexity of STRIPS planning when operators have a single effect. In particular, we show how the structure of the domain’s causal graph influences the complexity of planning. Causal graphs relate between preconditions and effects of domain operators. They were introduced by Williams and Nayak, who studied unary operator domains because of their direct applicability t...

Discrete element simulation solves Newton's dynamic equilibrium equations for a large set of constantly moving objects. In order to simulate the interaction of these objects, it is necessary, at every timestep, to find and resolve their spatial relationships. For large simulations this process is very computationally intensive, and dominates the cost of the whole simulation. It is desirable, th...

We present numerical calculations of spherically symmetric radiative transport using a two-moment (P-1) method with a two-dimensional non-linear closure on the Eddington factor. The stationary state solutions contain a critical point. We demonstrate that the two-moment equations with a non-linear closure are well behaved. The solutions are physically acceptable , regular and accurate.

Azouz, W. M., Parke, D. V. & Williams, R. T. (1952). Biochem. J. 50, 702. Carpenter, C. C., Shaffer, C. B., Weil, C. S. & Smyth, H. F. (1944). J. industr. Hyg. 26, 69. Danishefsky, I. & Wiilhite, M. (1954). J. biol. 'Chem. 211, 549. Eimhjellen, K. E. (1956). Biochem. J. 64, 4P. El Masri, A. M., Smith, J. N. & Williams, R. T. (1956). Biochem. J. 64, 50. Kamil, I. A., Smith, J. N. & Williams, R. ...

There has been much effort to improve the runtime of matrix multiplication. The trivial algorithm multiplies n×n matrices in O(n) time. Strassen (’69) surprised everyone by giving an O(n) time algorithm. This began a long line of improvements until in 1986, Coppersmith and Winograd achieved O(n). After 24 years of no progress, in 2010 Andrew Stothers, a graduate student in Edinburgh, improved t...

Soybean (Glycine max) is a self-pollinating species that has relatively low nucleotide polymorphism rates compared with other crop species. Despite the low rate of nucleotide polymorphisms, a wide range of heritable phenotypic variation exists. There is even evidence for heritable phenotypic variation among individuals within some cultivars. Williams 82, the soybean cultivar used to produce the...

We present a new algorithm, sie, for designing lumped parameter models from rst principles. Like the ibis system of Williams [1989, 1990], sie uses a qualitative representation of parameter interactions to guide its search and speed the test for working designs. But sie's interaction set representation is considerably simpler than ibis's space of potential and existing interactions. Furthermore...

Copyright © 2010 Massachusetts Medical Society. Williams–Beuren syndrome (also known as Williams’ syndrome; Online Mendelian Inheritance in Man [OMIM] number, 194050), a multi­ system disorder, is caused by deletion of the Williams–Beuren syndrome chromosome region, spanning 1.5 million to 1.8 million base pairs and containing 26 to 28 genes. Exactly how gene loss leads to the characteristic ph...