Self-Assembly of Infinite Structures

We review some recent results related to the self-assembly of infinite structures in the Tile Assembly Model. These results include impossibility results, as well as novel tile assembly systems in which shapes and patterns that represent various notions of computation self-assemble. Several open questions are also presented and motivated

Self-Assembly of 4-sided Fractals in the Two-handed Tile Assembly Model

We consider the self-assembly of fractals in one of the most well-studied models of tile based self-assembling systems known as the Two-handed Tile Assembly Model (2HAM). In particular, we focus our attention on a class of fractals called discrete self-similar fractals (a class of fractals that includes the discrete Sierpi\'nski carpet). We present a 2HAM system that finitely self-assembles the discrete Sierpi\'nski carpet with scale factor 1. Moreover, the 2HAM system that we give lends itself to being generalized and we describe how this system can be modified to obtain a 2HAM system that finitely self-assembles one of any fractal from an infinite set of fractals which we call 4-sided fractals. The 2HAM systems we give in this paper are the first examples of systems that finitely self-assemble discrete self-similar fractals at scale factor 1 in a purely growth model of self-assembly. Finally, we show that there exists a 3-sided fractal (which is not a tree fractal) that cannot be finitely self-assembled by any 2HAM system

Central Florida Future, Vol. 42 No. 17, March 18, 2010

Demand for travel funds up; Uncover Thursdays; Orlando\u27s finest places to eat; SGA races come with big price tag; Guests gain new admission options at RWC; Campus crime statistics open for analysis.https://stars.library.ucf.edu/centralfloridafuture/3290/thumbnail.jp

Cross-Document Pattern Matching

We study a new variant of the string matching problem called cross-document string matching, which is the problem of indexing a collection of documents to support an efficient search for a pattern in a selected document, where the pattern itself is a substring of another document. Several variants of this problem are considered, and efficient linear-space solutions are proposed with query time bounds that either do not depend at all on the pattern size or depend on it in a very limited way (doubly logarithmic). As a side result, we propose an improved solution to the weighted level ancestor problem

DNA Staged Self-Assembly at Temperature 1

We introduce alternate temperature 1 self-assembly constructions of an n x n square by efficiently utilizing bins and stages to achieve desirable results. These bins are able to contain a variety of tiles or supertiles, which are then mixed together in a pre-determined sequence of distinct stages. The basic 2D tile assembly model at temperature 1 uses 2n-1 tile types to construct a square. The model only utilizes one bin and occurs all in one stage. We will demonstrate how the use of bins and stages will allow for the construction of these squares more efficiently

The Elemental Analysis of Glass Beads

Ancient glass beads as a window to the ancient world Glass beads, both beautiful and portable, have been produced and traded globally for thousands of years. Modern archaeologists study these artifacts through sophisticated methods that analyze the glass composition, a process which can be utilized to trace bead usage through time and across regions. This book publishes open-access compositional data obtained from laser ablation – inductively coupled plasma – mass spectrometry, from a single analytical laboratory, providing a uniquely comparative data set. The geographic range includes studies of beads produced in Europe and traded widely across North America and beads from South and Southeast Asia traded around the Indian Ocean and beyond. The contributors provide new insight on the timing of interregional interactions, technologies of bead production and patterns of trade and exchange, using glass beads as a window to the past. This volume will be a key reference for glass researchers, archaeologists, and any scholars interested in material culture and exchange; it provides a wide range of case studies in the investigation and interpretation of glass bead composition, production and exchange since ancient times. Contributors: Bernard Gratuze (Institut de Recherche sur les ArchéoMATériaux, Centre Ernest-Babelon, UMR 5060 CNRS/Université d'Orléans), Alicia L. Hawkins (University of Toronto Mississauga), Elliot H. Blair (University of Alabama), Jessica Dalton-Carriger (Roane State Community College), Lee M. Panich (Santa Clara University), Thomas R. Fenn (The University of Oklahoma), Alison K. Carter (University of Oregon), Jennifer Craig (McGill University), Mark Aldenderfer (University of California, Merced), Mudit Trivedi (Stanford University), Lindsey Trombetta (The University of Texas at Austin), Jonathan R. Walz (The Field Museum / SIT-Graduate Institute), Akshay Sarathi (Florida Atlantic University), Carla Klehm (University of Arkansas), Marilee Wood (University of the Witwatersrand), Katherine A. Larson (Corning Museum of Glass), Heather Walder (The Field Museum / University of Wisconsin – La Crosse), Laure Dussubieux (The Field Museum) Supplementary Material 'The Elemental Analysis of Glass Beads' Ebook available in Open Access. This publication is GPRC-labeled (Guaranteed Peer-Reviewed Content)

The Niceness of Unique Sink Orientations

Random Edge is the most natural randomized pivot rule for the simplex algorithm. Considerable progress has been made recently towards fully understanding its behavior. Back in 2001, Welzl introduced the concepts of reachmaps and niceness of Unique Sink Orientations (USO), in an effort to better understand the behavior of Random Edge. In this paper, we initiate the systematic study of these concepts. We settle the questions that were asked by Welzl about the niceness of (acyclic) USO. Niceness implies natural upper bounds for Random Edge and we provide evidence that these are tight or almost tight in many interesting cases. Moreover, we show that Random Edge is polynomial on at least n^{Omega(2^n)} many (possibly cyclic) USO. As a bonus, we describe a derandomization of Random Edge which achieves the same asymptotic upper bounds with respect to niceness