We propose a conceptually novel method of reconstructing the topology of dynamical networks. By examining the correlation between the variable of one node and the derivative of another node’s variable, we derive a simple matrix equation yielding the network adjacency matrix. Our assumptions are the possession of time series describing the network dynamics, and the precise knowledge of the inter...

Quadratic Bézier curves are important geometric entities in many applications. However, it was often ignored by the literature the fact that a single segment of a quadratic Bézier curve may fail to fit arbitrary endpoint unit tangent vectors. The purpose of this paper is to provide a solution to this problem, i.e., constructing G quadratic Bézier curves satisfying given endpoint (positions and ...

This work addresses the issue of prioritized reasoning in the context of logic programming. The case of preference conditions involving atoms is considered and a refinement of the comparison method of the ASO semantics is presented. The paper introduces the concept of “choice”, as a set of preference rules describing common choice options in different contexts and proposes a new semantics that ...

We give a method for approximating any n-dimensional lattice with a lattice Λ whose factor group Z/Λ has n− 1 cycles of equal length with arbitrary precision. We also show that a direct consequence of this is that the Shortest Vector Problem and the Closest Vector Problem cannot be easier for this type of lattices than for general lattices.

Estimating the independent effect of ‘‘place’’ on health outcomes has proven quite difficult. In this issue of the Journal, Auchincloss and Diez Roux contribute a lucid introduction to agent-based simulation models and argue that they may be a fruitful alternative to current approaches to the problem. Insofar as conceptual understanding must precede empirical investigation, this author agrees. ...

An association between air pollution and hospital admission for heart failure was first noted in the literature in 1995 (1). The association was confirmed in subsequent studies (2, 3), along with many studies showing an association with a more general increase in cardiovascular admissions (4–6). The most consistent associations have been with carbon monoxide and particulate matter, and both Poi...

A new precision vectorization method has been developed for building centerlines of plain shapes. First a dense skeleton is computed. Centerlines are obtained as a subset of branches of the dense skeleton. The dense skeleton can also be used for obtaining medial axes of shapes. To obtain high precision, the distance transformation 12-17-38 was developed, which gives a good approximation of the ...

An experimenter seeks to learn a subject’s preference relation. The experimenter produces pairs of alternatives. For each pair, the subject is asked to choose. We argue that, in general, large but finite data do not give close approximations of the subject’s preference, even when countably infinite many data points are enough to infer the preference perfectly. We then provide sufficient conditi...