Sommerfeld effect concerns the non-linear jump phenomena induced due to the influence of the unbalance response on a non-ideal drive around the critical speed of the excited structure. In this work, we study the influence of external and internal dampings and gyroscopic forces on the Sommerfeld effect in rotationally symmetric planar dynamical systems. The rotational symmetry assumption allows ...

In metapopulations, the maintenance of local populations can depend on source–sink dynamics, where populations with positive growth rate seed populations with negative growth rate. The pattern and probability of successful dispersal among habitats can therefore be crucial in determining whether local populations will become rare or increase in abundance. We present here data on the dispersal st...

In this paper, we have proposed a study on controllability and optimal harvestingof a prey predator model and mathematical non linear formation of the equation equilibriumpoint of Routh harvest stability analysis. The problem of determining the optimal harvestpolicy is solved by invoking Pontryagin0s maximum principle dynamic optimization of theharvest policy is studied by taking the combined h...

Wordom is a versatile program for manipulation of molecular dynamics trajectories and efficient analysis of simulations. Original tools in Wordom include a procedure to evaluate significance of sampling for principal component analysis as well as modules for clustering multiple conformations and evaluation of order parameters for folding and aggregation. The program was developed with special e...

[naeini1]  housing is the third top factor in human life, after food and clothing in all communities. many variables are involved in determining housing prices and it is impossible to ignore housing feedback. one of the powerful tools to determine the impact of policies in this field is using system dynamics approach. according to this approach, the cause-and- effect diagram of factors affectin...

tehran the capital city of iran, with a population of about 8 million and an area of over 700 km2 is one of the most polluted metropolises in the world. tehran is suffering from a tremendous reduction in its sink capacity for absorption and assimilation of pollution which is generally due to uncontrolled urban sprawl and failure in consideration of ecological aspects into regional land use plan...

Based on the fact the manipulation of fine nanoclusters calls for more precise modeling, the aim of this paper is to conduct an atomistic investigation for interaction analysis of particle-substrate system for pushing and positioning purposes. In the present research, 2D molecular dynamics simulations have been used to investigate such behaviors. Performing the planar simulations can provide a ...

normal 0 false false false en-us x-none ar-sa background: reforms in inpatient care are critical for the enhancement of the efficiency of health systems. it still remains the main costly sector of the health system, accounting for more than 60% of all expenditures. inappropriate and ineffective use of the hospital infrastructure is also a big issue. we aimed to analyze statistical data on healt...