The Inflection Point of the Speed-Density Relation and the Social Force Model

It has been argued that the speed-density digram of pedestrian movement has an inflection point. This inflection point was found empirically in investigations of closed-loop single-file pedestrian movement. The reduced complexity of single-file movement does not only allow a higher precision for the evaluation of empirical data, but it occasionally also allows analytical considerations for micosimulation models. In this way it will be shown that certain (common) variants of the Social Force Model (SFM) do not produce an inflection point in the speed-density diagram if infinitely many pedestrians contribute to the force computed for one pedestrian. We propose a modified Social Force Model that produces the inflection point.Comment: accepted for presentation at conference Traffic and Granular Flow 201

Chemical reactivity of the compressed noble gas atoms and their reactivity dynamics during collisions with protons

Attempts are made to gain insights into the effect of confinement of noble gas atoms on their various reactivity indices. Systems become harder, less polarizable and difficult to excite as the compression increases. Ionization also causes similar effects. A quantum fluid density functional technique is adopted in order to study the dynamics of reactivity parameters during a collision between protons and He atoms in different electronic states for various projectile velocities and impact parameters. Dynamical variants of the principles of maximum hardness, minimum polarizability and maximum entropy are found to be operative

Quantum analogue of the Kolmogorov-Arnold-Moser transition in the field induced barrier penetration in a quartic potential

Quantum signatures of the Kolmogorov-Arnold-Moser (KAM) transition from the regular to chaotic classical dynamics of a double-well oscillator in the presence of an external monochromatic field of different amplitudes are analysed in terms of the corresponding Bohmian trajectories. It is observed that the classical chaos generally enhances the quantum fluctuations, while the quantum nonclassical effects try to suppress classical stochasticity

Effects of Boundary Conditions on Single-File Pedestrian Flow

In this paper we investigate effects of boundary conditions on one dimensional pedestrian flow which involves purely longitudinal interactions. Qualitatively, stop-and-go waves are observed under closed boundary condition and dissolve when the boundary is open. To get more detailed information the fundamental diagrams of the open and closed systems are compared using Voronoi-based measurement method. Higher maximal specific flow is observed from the pedestrian movement at open boundary condition

Relationship between electrophilicity index, Hammett constant and nucleus-independent chemical shift

Inter-relationships between the electrophilicity index (Ω), Hammett constant (óp @#@) and nucleusindependent chemical shift (NICS (1) - NICS value one ångstrom above the ring centre) have been investigated for a series of meta- and para-substituted benzoic acids. Good linear relationships between Hammett constant vs electrophilicity and Hammett constant vs NICS (1) values have been observed. However, the variation of NICS (1) against CO shows only a low correlation coefficient

Automated Quality Assessment of Space-Continuous Models for Pedestrian Dynamics

In this work we propose a methodology for assessment of pedestrian models continuous in space. With respect to the Kolmogorov-Smirnov distance between two data clouds, representing for instance simulated and the corresponding empirical data, we calculate an evaluation factor between zero and one. Based on the value of the herein developed factor, we make a statement about the goodness of the model under evaluation. Moreover this process can be repeated in an automatic way in order to maximize the above mentioned factor and hence determine the optimal set of model parameters.Comment: 8 pages, 3 figures, accepted at the Proceedings of Traffic and Granular Flow '1

Effect of spherical confinement on chemical reactivity

Numerical Hartree-Fock calculations have been performed with Dirichlet boundary conditions to calculate various global reactivity descriptors such as softness, electronegativity, polarizability, electrophilicity index, and mean excitation energy for several atoms (He, Li, Be, B, C, N, O, F, Ne) and ions (C<SUP>+</SUP>, C<SUP>2+</SUP>, C<SUP>3+</SUP>, C<SUP>4+</SUP>) confined in a spherical box. All of the systems become harder and less polarizable with a decrease in confinement volume. Electronegativity and electrophilicity are not very sensitive, except for very small cutoff radius at which they change abruptly. Mean excitation energy decreases with an increase in the box size. Linear relationship between softness and the cube-root of polarizability is observed for all of the confined atoms and ions. Scaled hardness shows opposite trends of softness, except for Li. Expected behavior is observed for the energy, virial, and various moments. With ionization, systems become more electronegative, harder, and less polarizable at all sizes