Search results for " Simulation"

NUMERICAL SIMULATION OF MAGNETIC DROPLET DYNAMICS IN A ROTATING FIELD

2013

Dynamics and hysteresis of an elongated droplet under the action of a rotating magnetic field is considered for mathematical modelling. The shape of droplet is found by regularization of the ill-posed initial–boundary value problem for nonlinear partial differential equation (PDE). It is shown that two methods of the regularization – introduction of small viscous bending torques and construction of monotonous continuous functions are equivalent. Their connection with the regularization of the ill-posed reverse problems for the parabolic equation of heat conduction is remarked. Spatial discretization is carried out by the finite difference scheme (FDS). Time evolution of numerical solutions …

Mathematical modelling of an elongated magnetic droplet in a rotating magnetic field

2012

Dynamics of an elongated droplet under the action of a rotating magnetic field is considered by mathematical modelling. The actual shape of a droplet is obtained by solving the initial-boundary value problem of a nonlinear singularly perturbed partial differential equation (PDE). For the discretization in space the finite difference scheme (FDS) is applied. Time evolution of numerical solutions is obtained with MATLAB by solving a large system of ordinary differential equations (ODE).

Rotation-Invariant Texture Retrieval via Signature Alignment Based on Steerable Sub-Gaussian Modeling

2008

This paper addresses the construction of a novel efficient rotation-invariant texture retrieval method that is based on the alignment in angle of signatures obtained via a steerable sub-Gaussian model. In our proposed scheme, we first construct a steerable multivariate sub-Gaussian model, where the fractional lower-order moments of a given image are associated with those of its rotated versions. The feature extraction step consists of estimating the so-called covariations between the orientation subbands of the corresponding steerable pyramid at the same or at adjacent decomposition levels and building an appropriate signature that can be rotated directly without the need of rotating the im…

INFLUENZA DELLA PENDENZA MEDIA DELLE CORRUGAZIONI DI UNA PARETE SCABRA SUL CAMPO DI MOTO TURBOLENTO

2008

A Discrete Model for a Network Having Broken Packages

2009

Broken packages are packages with not enough information regarding the destination address and they have a negative impact on a computer network. Broken packages stay in the router too much time and overload it. This is a real problem which appears in the computer network of Sofia University. We know only the time when a broken package arrives in the router. The problem is to find the computer which send broken packages. The aim of this article is to propose a model for defining the data transmission stability and correctness in a computer network. Our theoretical model is temporal dependent and captures the transmission properties of a computer network.

Securing AODV routing protocol against black hole attack in MANET using outlier detection scheme

2017

Imposing security in MANET is very challenging and hot topic of research science last two decades because of its wide applicability in applications like defense. Number of efforts has been made in this direction. But available security algorithms, methods, models and framework may not completely solve this problem. Motivated from various existing security methods and outlier detection, in this paper novel simple but efficient outlier detection scheme based security algorithm is proposed to protect the Ad hoc on demand distance vector (AODV) reactive routing protocol from Black hole attack in mobile ad hoc environment. Simulation results obtained from network simulator tool evident the simpl…

NICE-MRP: a Near-Optimal Radio-Interference Aware Multi-path Routing Protocol for MANETs

2013

International audience; Nowadays, with the miniaturization of communication devices, dense and highly mobile ad-hoc networks are very common. Besides, more and more devices have several radio interfaces. In such an environment, multi-path routing should be considered. Yet, only few multi-path ad-hoc routing protocols take into account the radio-interferences which might arise between two geographically close routes. Moreover, they generally only forbid the addition of interfering paths rather than looking for a different, more optimized, solution. This paper presents NICE-MRP, a novel multi-path routing protocol for mobile ad-hoc networks giving efficient solutions with respect to physical …

QoS Based Routing Protocol for Intra-Mesh Infrastructure Communications

2015

International audience; Mesh Networks (WMNs) have been considered as a promising alternative to conventional wired networks, thanks to its flexibility and easy deployment. Thus, to ensure a satisfying level of QoS guarantees for real-time and streaming applications such as Voice over IP (VoIP) and Video on Demand (VoD), we propose a novel QoS based routing protocol for wireless mesh environments, called Hybrid QoS Mesh Routing (HQMR), jointly with a clustering algorithm to enhance scalability issues within the mesh infrastructure. HQMR is composed of two routing sub-protocols: a reactive routing sub-protocol for intra-infrastructure communications and a proactive QoS based multi-tree routin…

IMRR and IMPR Routing Protocols For Inter and Intra Wireless Mesh Communications

2015

Given the evolution of wireless technologies, Wireless Mesh Networks (WMN) have appeared as an emerging low-cost solution to ensure last-mile connectivity to the Internet network. However, providing real-time and streaming applications, such as VoIP (Voice over IP) and VoD (Video on Demand), with a satisfying QoS level is considered as an important challenge within these networks. In this paper, we propose a QoS based routing protocol, called Hybrid QoS Mesh Routing (HQMR), jointly with a clustering algorithm to improve the scalability of mesh networks. HQMR is composed of two routing sub- protocols: a reactive QoS based routing protocol for intra-mesh infrastructure communications and a pr…

Comparing Beerkan infiltration tests with rainfall simulation experiments for hydraulic characterization of a sandy-loam soil

2017

[EN] Saturated soil hydraulic conductivity, K-s, data collected by ponding infiltrometer methods and usual experimental procedures could be unusable for interpreting field hydrological processes and particularly rainfall infiltration. The K-s values determined by an infiltrometer experiment carried out by applying water at a relatively large distance from the soil surface could however be more appropriate to explain surface runoff generation phenomena during intense rainfall events. In this study, a link between rainfall simulation and ponding infiltrometer experiments was established for a sandy-loam soil. The height of water pouring for the infiltrometer run was chosen, establishing a sim…