An Accelerated Multiboson Algorithm for Coulomb Gases with Dynamical Dielectric Effects

A recent reformulation [1] of the problem of Coulomb gases in the presence of a dynamical dielectric medium showed that finite temperature simulations of such systems can be accomplished on the basis of completely local Hamiltonians on a spatial lattice by including additional bosonic fields. For large systems, the Monte Carlo algorithm proposed in Ref. [1] becomes inefficient due to a low acceptance rate for particle moves in a fixed background multiboson field. We show here how this problem can be circumvented by use of a coupled particle-multiboson update procedure that improves acceptance rates on large lattices by orders of magnitude. The method is tested on a one-component plasma with neutral dielectric particles for a variety of system sizes.Comment: 13 pages, 2 figures, fixed typos, added reference

Local Simulation Algorithms for Coulomb Gases with Dynamical Dielectric Effects

We discuss the application of the local lattice technique of Maggs and Rossetto to problems that involve the motion of objects with different dielectric constants than the background. In these systems the simulation method produces a spurious interaction force which causes the particles to move in an unphysical manner. We show that this term can be removed using a variant of a method known from high-energy physics simulations, the multiboson method, and demonstrate the effectiveness of this corrective method on a system of neutral particles. We then apply our method to a one-component plasma to show the effect of the spurious interaction term on a charged system.Comment: 13 pages, 4 figure

SEALED WITH A KISS: HEAD-TURNING ASYMMETRIES DURING KISSING ARE MODULATED BY CONTEXT AND INFLUENCE PERCEPTUAL JUDGEMENTS

When leaning forward to kiss a romantic partner, individuals tend to direct their kiss to the right more often than to the left. The theoretical mechanism guiding this asymmetry is that it originates from a right head-turning preference observed within early stages of human development. By contrast, other lateral turning biases are theorized to stem from differences of hemispheric specialization of emotion rather than from an innate influence, to which the lateral direction of these biases are dependent on their situational context. My first two studies examine if the context for non-romantic conventions of lip-kissing convey a comparable right-turn bias, as the existing literature has focused on romantic-kissing gestures. If kissing laterality is caused from an innately guided right head-turning bias, this directionality should transcend different forms of kissing. Study 1 analysed the turning directions of kisses from videos from the First Kiss social media trend, featuring strangers performing a lip-to-lip kiss. The predominant right-turn bias was not supported; rather, no significant directional bias was observed. To further explore the role of a non-romantic kissing context, study 2 introduced the type of kiss shared between a parent and child. Images of parent-parent kissing (romantic context) and parent-child kissing (parental context) couples were collected for an archival analysis. A right-turn kissing bias was revealed, but only for the romantic kissing couples; for parental kisses, a leftward bias was found. Collectively, the first two studies do not coincide with the congenital account of kissing laterality, as attenuated and reversed turning biases were found. For study 3, romantic and parental kissing were further investigated while also exploring if perceptual input of kissing biases corresponds to the direction of motor output. Studies 3a and 3b employed a forced-choice task in which image-pairs of romantic and parental kissing couples were presented and asked which image was perceived as more “passionate” and “loving”, respectively. Kisses between romantic couples were perceived to be more passionate when displaying a right turn in comparison to a left turn, whereas images with neither left nor right turns were perceived to be more loving for parent-child kissing couples. The final study examines how cognitive evaluations unrelated to the kiss are influenced in the field of advertising. Original and mirror-reversed versions of advertisements with models kissing were displayed in a forced-choice preference task and consumer-judgement task. Models illustrating a right turn (vs left turn) when kissing were preferred when identical images were presented. When ads were presented individually, right-turn (vs left-turn) kisses resulted in higher consumer attitudes and purchase intention. This body of research challenges the previous rationale that kissing laterality persists from the right head-turning preference observed in infancy, as contexts with parental and strangers kissing reveal a leftward preference or no directional bias. Our findings also contribute to our understanding of how kissing biases are exhibited within earlier stages of cognitive processing, such that perceptions of passion and consumer preferences for visual stimuli displaying romantic kissing corresponds to the direction of authentic turning behaviour: the right. Further discussion speculates on how cerebral lateralization of emotions may contribute to kissing laterality, to which a variety of future directions are suggested to test these predictions

Convex Hull of Planar H-Polyhedra

Suppose are planar (convex) H-polyhedra, that is, $A_i \in \mathbb{R}^{n_i \times 2}$ and $\vec{c}_i \in \mathbb{R}^{n_i}$. Let $P_i = \{\vec{x} \in \mathbb{R}^2 \mid A_i\vec{x} \leq \vec{c}_i \}$ and $n = n_1 + n_2$. We present an $O(n \log n)$ algorithm for calculating an H-polyhedron with the smallest $P = \{\vec{x} \in \mathbb{R}^2 \mid A\vec{x} \leq \vec{c} \}$ such that $P_1 \cup P_2 \subseteq P$

High-precision Monte Carlo study of directed percolation in (d+1) dimensions

We present a Monte Carlo study of the bond and site directed (oriented) percolation models in $(d+1)$ dimensions on simple-cubic and body-centered-cubic lattices, with $2 \leq d \leq 7$. A dimensionless ratio is defined, and an analysis of its finite-size scaling produces improved estimates of percolation thresholds. We also report improved estimates for the standard critical exponents. In addition, we study the probability distributions of the number of wet sites and radius of gyration, for $1 \leq d \leq 7$.Comment: 11 pages, 21 figure

Average Case Analysis of Java 7's Dual Pivot Quicksort

Abstract. Recently, a new Quicksort variant due to Yaroslavskiy was chosen as standard sorting method for Oracle’s Java 7 runtime library. The decision for the change was based on empirical studies showing that on average, the new algorithm is faster than the formerly used classic Quicksort. Surprisingly, the improvement was achieved by using a dual pivot approach, an idea that was considered not promising by several theoretical studies in the past. In this paper, we identify the reason for this unexpected success. Moreover, we present the first precise average case analysis of the new algorithm showing e. g. that a random permutation of length n is sorted using 1.9n lnn − 2.46n+O(lnn) key comparisons and 0.6n lnn+ 0.08n+O(lnn) swaps. 1