Stratified horizontal flow in vertically vibrated granular layers

A layer of granular material on a vertically vibrating sawtooth-shaped base exhibits horizontal flow whose speed and direction depend on the parameters specifying the system in a complex manner. Discrete-particle simulations reveal that the induced flow rate varies with height within the granular layer and oppositely directed flows can occur at different levels. The behavior of the overall flow is readily understood once this novel feature is taken into account.Comment: 4 pages, 6 figures, submitte

Equilibration of quasi-isolated quantum systems

The evolution of a quasi-isolated finite quantum system from a nonequilibrium initial state is considered. The condition of quasi-isolation allows for the description of the system dynamics on the general basis, without specifying the system details and for arbitrary initial conditions. The influence of surrounding results in (at least partial) equilibration and decoherence. The resulting equilibrium state bears information on initial conditions and is characterized by a representative ensemble. It is shown that the system average information with time does not increase. The partial equilibration and non-increase of average information explain the irreversibility of time.Comment: Latex file, 12 page

IDDAP -- Interactive computer assistance for creative digital design

A new computer-aided design program to assist in the initial phases of logical design is described. The program, intended for use via an on-line remote terminal, will allow the designer to study and experiment with design alternatives during the initial creative design phases. An ALGOL-like language is used for specifying the system being designed. In addition to simulating the design, the program allows the user to perform on-line design changes, reorganize data and generate timing diagram information --Abstract, page ii

Bayesian exponential random graph modelling of interhospital patient referral networks

Using original data that we have collected on referral relations between 110 hospitals serving a large regional community, we show how recently derived Bayesian exponential random graph models may be adopted to illuminate core empirical issues in research on relational coordination among health care organisations. We show how a rigorous Bayesian computation approach supports a fully probabilistic analytical framework that alleviates well-known problems in the estimation of model parameters of exponential random graph models. We also show how the main structural features of interhospital patient referral networks that prior studies have described, can be reproduced with accuracy by specifying the system of local dependencies that produce – but at the same time are induced by – decentralised collaborative arrangements between hospitals

Measurable entanglement

Amount of entanglement carried by a quantum bipartite state is usually evaluated in terms of concurrence (see Ref. 1). We give a physical interpretation of concurrence that reveals a way of its direct measurement and discuss possible generalizations.Comment: 3 pages, submitted to Applied Physics Letter

A software system for teaching and commanding the industrial robots

Design features of a system for programming the industrial robots with dynamic control are described. When specifying the system, special attention was given to achieving hardware transportability, simplicity of communication between the user and the system, possibility of active user participation in generation of control algorithms, and possibility of implementing the software on a computer with relatively modest characteristics. The software is intended for implementation on a microprocessor-based system and should enable the user to control a robot via specialized programming language RL which incorporates structures for defining the positions and orientations of working points, motion specification, and synchronization of the robot with its environment. The paper contains descriptions of the RL language and of the system structure. The main characteristics and advantages of the system as well as questions concerning its realization on existing microprocessors are also discussed

The center-of-mass response of confined systems

For confined systems of identical particles, either bosons or fermions, we argue that the parabolic nature of the confinement potential is a prerequisite for the non-dissipative character of the center of mass response to a uniform probe. For an excitation in a parabolic confining potential, the half width of the density response function depends nevertheless quantitatively on properties of the internal degrees of freedom, as is illustrated here for an ideal confined gas of identical particles with harmonic interparticle interactions.Comment: 4 pages REVTEX; accepted as Brief Communication in Phys. Rev.

Exact Quantum Monte Carlo Process for the Statistics of Discrete Systems

We introduce an exact Monte Carlo approach to the statistics of discrete quantum systems which does not rely on the standard fragmentation of the imaginary time, or any small parameter. The method deals with discrete objects, kinks, representing virtual transitions at different moments of time. The global statistics of kinks is reproduced by explicit local procedures, the key one being based on the exact solution for the biased two-level system.Comment: 4 pages, latex, no figures, English translation of the paper