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 floor field CA model for studying evacuation dynamics is extended in this paper. A method for calculating the static floor field, which describes the shortest distance to an exit door, in an arbitrary geometry of rooms is presented. The wall potential and contraction effect at a wide exit are also proposed in order to obtain realistic behavior near corners and bottlenecks.

Simulations of Evacuation by an Extended Floor Field CA Model

Publisher Summary
This chapter provides an introduction to the modeling of pedestrian dynamics. It is different from most of the other systems since the motion is genuinely two dimensional. Vehicular traffic is mostly one-dimensional or quasi-one-dimensional through the existence of lanes that allow only unidirectional motion. Therefore, one usually deals with a well-defined ordering of vehicles, which is rarely changed through overtaking manoeuvres. Interactions with nearest neighbors are most important, which simplifies modeling considerably. In pedestrian dynamics, however, the situation is more complex, and interactions with other individuals in a certain range have to be taken into account. The most important interactions are not necessarily with the nearest individuals, but might also depend on the relative direction of the velocities. This makes the modeling more challenging theoretically and gives rise to new phenomena related to the spatiotemporal evolution and organization. This complex nature of the mutual interactions between pedestrians gives rise to several self-organization phenomena, which are not observed in vehicular traffic. Therefore, only very few models exist, which can reproduce the empirically observed behavior accurately. A comprehensive theory of pedestrian dynamics has to take into account three different levels of behavior, which are discussed. A brief glimpse is provided into different applications in the area of evacuations and safety analysis.

Chapter Eleven – Pedestrian Dynamics

Cellular automata modelling of traffic flow, as describes in the preceeding chapters, became popular in the nineteen nineties. In this chapter we discuss some of the “classical” approaches to traffic modelling, like fluid-dynamical theories and and car-following approaches, which were originally introduced in the nineteen fifties and revived again in the nineteen nineties. In this chapter we discuss both the older models and their recent extensions. We also compare these approaches, whereever possible, with the corresponding CA approaches.

Vehicular Traffic IV: Non-CA Approaches

This paper introduces a space-continuous force-based model for simulating pedestrian dynamics. The main interest of this work is the quantitative description of pedestrian movement through a bottleneck. Measurements of flow and density will be presented and compared with empirical data. The results of the proposed model show a good agreement with empirical data. Furthermore, we emphasize the importance of volume exclusion in force-based models.

Quantitative Description of Pedestrian Dynamics with a Force-Based Model

The Asymmetric Simple Exclusion Process (ASEP) is the simplest cellular automaton which captures the essential aspects of most transport and traffic phenomena. It describes the directed motion of particles obeying an exclusion principle. For specific applications, however, various generalizations of the ASEP are necessary. These are discussed for the case of highway traffic, ant trails, pedestrian dynamics and intracellular transport.

Andreas Schadschneider

Papers

Simulations of Evacuation by an Extended Floor Field CA Model

Chapter Eleven – Pedestrian Dynamics

Vehicular Traffic IV: Non-CA Approaches

Quantitative Description of Pedestrian Dynamics with a Force-Based Model

Modelling of Transport and Traffic Problems