There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Statistical physics has proven to be a fruitful framework to describe phenomena outside the realm of traditional physics. Recent years have witnessed an attempt by physicists to study collective phenomena emerging from the interactions of individuals as elementary units in social structures. A wide list of topics are reviewed ranging from opinion and cultural and language dynamics to crowd behavior, hierarchy formation, human dynamics, and social spreading. The connections between these problems and other, more traditional, topics of statistical physics are highlighted. Comparison of model results with empirical data from social systems are also emphasized.

Statistical physics of social dynamics

N G van Kampen 1981 Amsterdam: North-Holland xiv + 419 pp price Dfl 180 This is a book which, at a lower price, could be expected to become an essential part of the library of every physical scientist concerned with problems involving fluctuations and stochastic processes, as well as those who just enjoy a beautifully written book. It provides an extensive graduate-level introduction which is clear, cautious, interesting and readable.

https://iopscience.iop.org/article/10.1088/0031-9112/34/4/040/pdf

Stochastic Processes in Physics and Chemistry

From the Publisher: 
The accessible presentation of this book gives both a general view of the entire computer vision enterprise and also offers sufficient detail to be able to build useful applications. Users learn techniques that have proven to be useful by first-hand experience and a wide range of mathematical methods. A CD-ROM with every copy of the text contains source code for programming practice, color images, and illustrative movies. Comprehensive and up-to-date, this book includes essential topics that either reflect practical significance or are of theoretical importance. Topics are discussed in substantial and increasing depth. Application surveys describe numerous important application areas such as image based rendering and digital libraries. Many important algorithms broken down and illustrated in pseudo code. Appropriate for use by engineers as a comprehensive reference to the computer vision enterprise.

Computer vision : a modern approach = 计算机视觉 : 一种现代的方法

The occurrence of phase separation is a common feature observed in vehicular traffic. Experiments have shown a similar behavior for pedestrians, though the situation in pedestrian dynamics is more complicated. The two separate phases in one-dimensional “single-file” pedestrian movement are a jammed high-density phase and a phase of medium to high density with slowly moving pedestrians. Both phases consist of interacting particles (pedestrians). To understand the emergence of this kind of phase separation, we develop a simple cellular automaton model. The transition probabilities of the modeled pedestrians in general depend on their current velocities and on the occupancy of the next two cells in front of them. For inhomogeneous initial conditions the simulated pedestrian trajectories clearly feature two distinct phases analogous to the experiment. The lifetime of the decaying jammed phase is consistent with experimental results.

A Simple Model for Phase Separation in Pedestrian Dynamics

The Asymmetric Simple Exclusion Process (ASEP) can be regarded as the simplest possible stochastic transport model or the “mother of all traffic models”. It is a genuine non-equilibrium model which belongs to the class of driven diffusive systems. One of the advantages of this simple model is that many exact results can be derived analytically. In this chapter we sketch how these results can be derived. At the same time, this exercise allows us to demonstrate the application of several theoretical methods, which have already been introduced in Chapter 2 , to the specific case of the ASEP. Moreover, the ASEP is a paradigm for the occurrence of boundary-induced phase transitions. We discuss a general theory based on the dynamics of domain walls or shocks as well as various generalizations of the ASEP, e.g. multispecies models.

Asymmetric Simple Exclusion Process – Exact Results

Zusammenfassung
Strasenverkehr ist eine ideale Spielwiese fur die Physik. Auf der Basis von empirischen Beobachtungen und Experimenten ist die Struktur der verschiedenen Verkehrszustande mittlerweile recht gut verstanden. Verschiedene Modelle aus der Physik wie Zellularautomaten liefern realitatsnahe Simulationsergebnisse von Staus. Dies hat zu interessanten Anwendungen wie Stauprognose-Systemen gefuhrt.

Der Stau als Forschungsobjekt

We introduce a two-species exclusion model to describe the key features of the conflict between the RNA polymerase (RNAP) motor traffic, engaged in the transcription of a segment of DNA, concomitant with the progress of two DNA replication forks on the same DNA segment. One of the species of particles (P) represents RNAP motors while the other (R) represents the replication forks. Motivated by the biological phenomena that this model is intended to capture, a maximum of two R particles only are allowed to enter the lattice from two opposite ends whereas the unrestricted number of P particles constitutes a totally asymmetric simple exclusion process (TASEP) in a segment in the middle of the lattice. The model captures three distinct pathways for resolving the co-directional as well as head-on collision between the P and R particles. Using Monte Carlo simulations and heuristic analytical arguments that combine exact results for the TASEP with mean-field approximations, we predict the possible outcomes of the conflict between the traffic of RNAP motors (P particles engaged in transcription) and the replication forks (R particles). In principle, the model can be adapted to experimental conditions to account for the data quantitatively.

A biologically inspired two-species exclusion model: effects of RNA polymerase motor traffic on simultaneous DNA replication

We extend the Bethe Ansatz solution of a onedimensional integrable fermionic model with correlated hopping to the parameter regime Δt > 1. It is found that the model is equivalent to one with interaction 2 − Δt, but with twisted boundary conditions. Apart from the ground state energy we investigate the low-lying excitations and the asymptotic behaviour of the correlation functions. As in the ease of Δt < 1 we find dominating superconducting correlations for small doping. The behaviour in this regime therefore differs from that of the non-integrable model with symmetric bond-charge interaction (Hirsch model).

Andreas Schadschneider

Papers

A Simple Model for Phase Separation in Pedestrian Dynamics

Asymmetric Simple Exclusion Process – Exact Results

Der Stau als Forschungsobjekt

A biologically inspired two-species exclusion model: effects of RNA polymerase motor traffic on simultaneous DNA replication

Exact solution of the one-dimensional fermionic model with correlated hopping