Automatic Detection of Egg Shell Cracks

The challenge was to find a reliable, non-intrusive means of detecting cracks in eggs. Intensity data from eggs were collected by VisionSmart for the group to analyse. Given the short time period three main questions were addressed. 1) Is there a feature of the intensity data which detects, and discriminates between pinholes, cage marks and cracks? 2) Are there ways to improve the current data collection process? 3) Are there other data collection methods which should be tried? A partial positive response to 1) is presented and describes the many problems that arose. Some answers to 2) and 3) are also presented

Asymptotics of polygons in restricted geometries subject to a force

International audienceWe consider self-avoiding polygons in a restricted geometry, namely an infinite L × M tube in Z3. These polygons are subjected to a force f, parallel to the infinite axis of the tube. When f > 0 the force stretches the polygons, while when f < 0 the force is compressive. In this extended abstract we obtain and prove the asymptotic form of the free energy in the limit f → −∞. We conjecture that the f → −∞ asymptote is the same as the free energy of Hamiltonian polygons, which visit every vertex in a L × M × N box

Measuring The Effect of Trade Barriers on Exchange Rates Using Data Envelopment Analysis

The presentation slides are from a conference in Vancouver, WA on May 5, 2016.This paper analyzes the implementation of the World Trade Organization’s Uruguay Round policy package and its influence on the US Dollar to Chinese Yuan exchange rate parity. The Farrell Measure of Productive Efficiency associated with the change in the exchange rate parity between time periods before and after implementation provides a method with which to measure the effect. The resulting figures indicate a stabilization of the parity after implementation correlating with the policy change from a floating to a pegged exchange rate. This prompted the hypothesis that the Farrell Measure of Productive Efficiency could have a potential use as a measure of volatility. Further exploration through an additional parity case study offers supplementary support for its potential utilization. Key Words: Data Envelopment Analysis (DEA), Farrell Measure of Productive Efficiency, volatility, floating exchange rate, pegged exchange rat

Crossing-sign discrimination and knot-reduction for a lattice model of strand passage

By performing strand-passages on DNA, type II topoisomerases are known to resolve topological constraints that impede normal cellular functions. The full details of this enzyme-DNA interaction mechanism are, however, not completely understood. To better understand this mechanism, researchers have proposed and studied a variety of random polygon models of enzyme-induced strand-passage. In the present article, we review results from one such model having the feature that it is amenable to combinatorial and asymptotic analysis (as polygon length goes to infinity). The polygons studied, called -SAPs, are on the simple-cubic lattice and contain a specific strand-passage structure, called , at a fixed site. Another feature of this model is the availability of Monte Carlo methods that facilitate the estimation of crossing-sign-dependent knot-transition probabilities. From such estimates, it has been possible to investigate how knot-reduction depends on the crossing-sign and the local juxtaposition geometry at the strand-passage site. A strong relationship between knot-reduction and a crossing-sign-dependent crossing-angle has been observed for this model. In the present article, we review these results and present heuristic geometrical arguments to explain this crossing-sign and angle-dependence. Finally, we discuss potential implications for other models of type II topoisomerase action on DNA

Asymptotics of polygons in restricted geometries subject to a force

We consider self-avoiding polygons in a restricted geometry, namely an infinite L × M tube in Z3. These polygons are subjected to a force f, parallel to the infinite axis of the tube. When f > 0 the force stretches the polygons, while when f < 0 the force is compressive. In this extended abstract we obtain and prove the asymptotic form of the free energy in the limit f → −∞. We conjecture that the f → −∞ asymptote is the same as the free energy of Hamiltonian polygons, which visit every vertex in a L × M × N box

Lattice Models of RNA-DNA R-loop Complexes

NSERC (RGPIN-2020-06339), NSERC USRATwo models are combined to explore the formation and stability of DNA-RNA structures called R-loops. The first is a formal grammar model (FGM) developed by Ferrari and coworkers. The second is a simplified lattice model developed for studying R-loop formation and geometry by Soteros and coworkers for a PIMS VXML project. We combine these into one model and explore the model both theoretically and via computer simulation using Markov chains. The general goals are to explore the probability of R-loop formation and geometric properties of the R-loops