Vol. 5, No. 1 (2016): Regular Issue

The dynamics of a continuum rotor system excited by nonlinear oilfilm force and electromagnetic force is investigated through the Generalized Harmonic Balance Method. The governing differential equation of the continuum rotor system is reduced through the Galerkin’s approximation method. Firstly, the motion in Y-direction is considered as the response of a planar continuum rotor. The analytical periodic motion is obtained and the bifurcation and stability is determined. Secondly, the dynamical model of a spatial continuum rotor is studied. The stability and bifurcation of the analytical periodic motion is obtained and compared to numerical results to show the accuracy of the Generalized Harmonic Balance Method.

In this paper we present a free-oscillation method for acoustic detection of defects in metal rods. For detection of normal rods from rods with defects we use a treatment procedure based on the statistics of the fractional moments. This procedure allows to extract the quanti-tative information from the acoustic signals that are propagated in cylindrical slugs after mechanical strike and having different defects. This information allows separating normal rods (without defects) from the rods having different cuts and differentiating the saw-cut defects with different depth from each other. The analysis of data obtained from this research shows that the proposed method of the fractional moments can be applied for quantitative "reading" of envelopes of different acoustic signals that are obtained by means of free-oscillation method and propagated in dense medium having local defects.

This paper proposes a generalized combination-combination synchronization scheme (GCCS) for identical order chaotic systems. Using the active backstepping technique. Based on active backstepping technique, suitable controllers are designed to achieve GCCS for any desired scaling factor among four chaotic Josephson junctions (JJs) evolving from different initial conditions. Numerical simulations are carried out to verify the feasibility and effectiveness of the proposed GCCS via active backstepping technique. The result shows that the proposed GCCS could be used to vary the JJ signal to any desired level and provide higher security in information transmission due its complex dynamical formulation.

Peptide toxins offer new avenues for development of novel drugs. α- Conotoxin SI, which binds to neuromuscular Nicotinic Acetylcholine Receptor, is such an analgesic drug candidate. Understanding the mechanism of action is crucial for improving the properties of drug candidates. Here, we use docking and molecular dynamics simulations to propose a model for binding of α-Conotoxin SI to Nicotinic Acetylcholine Receptor and discuss its paralysis effect.

In this paper, analysis for a mathematical model of an equivalent circuit to provide solutions of electrical energy power transmission lines (ETL) with Adomian Decomposition Method (ADM) has been proposed. By using Mathematica program, partial differential equations as a function of voltage (current) forming the model are solved and compared with the finite difference method (FDM). The results of some special examples obtained from ADM and FDM illustrate very good synchronism and show the simplicity and the efficiency of the method.

In this study, a delayed ratio dependent predator-prey model with both discrete and distributed delays is investigated. First, the local stability of a positive equilibrium is studied and then the existence of Hopf bifurcations is established. By using the normal form theory and center manifold theorem, the explicit algorithm determining the stability, direction of the bifurcating periodic solutions are derived. Finally, we perform the numerical simulations for justifying the theoretical results.

This paper is devoted to the study of a three species ecosystem model consisting of a prey, a predator and a top predator. This model is given by a reaction diffusion system defined on a circular spatial domain and incorporates the Holling type II and a modified Leslie- Gower functional response. The aim of this paper is to investigate theoretically and numerically the asymptotic behavior of the interior equilibrium of the model. The conditions of boundedness, existence of a positively invariant and attracting set are proved. Sufficient conditions of local/global stability of the positive steady state are established. In the end, we present a numerical evidence of time evolution of the pattern formation.

Analyzing longitudinal observations with an appropriate methodology is important for detecting significant single nucleotide polymorphisms (SNPs) for complex traits in genome wide association studies (GWAS). Here we assumed that genomic signal over time could be traced by a Bayesian random walk- Kalman filter model in state space form to obtain longitudinal residuals. The Kalman filter removes the requirement for collecting the whole data set before making estimations, thus estimates are immediately available. For example, with the functional mapping approach, whole sets of observations must to be collected in advance. This may include months (if not years) of waiting time depending on the nature of the phenotypes and the experimental design. Whereas, because of the longitudinal residuals used in association mapping, biological reasoning can be easily applied given that the signal is genuine. The advantages of our method are demonstrated by both simulated and real datasets.

Biomedical optical imaging has a possibility of a comprehensive diagnosis of thyroid cancer in conjunction with ultrasound imaging. For improvement of the optical imaging, this study develops a higher order scheme for solving the time-dependent radiative transport equation (RTE) by use of the finite-difference and discrete-ordinate methods. The accuracy and efficiency of the developed scheme are examined by comparison with the analytical solutions of the RTE in homogeneous media. Then, the developed scheme is applied to describing photon migration in the human neck model. The numerical simulations show complex behaviors of photon migration in the human neck model due to multiple diffusive reflection near the trachea.