Determination of Mechanical Properties of Compressible Soil in Littoral's Region of Cameroon: Depths Study of Soils Bordering the Wouri River in Douala.

This work deals to the determination of the expansion ratio ( ) and compression index ( ) of soil samples taken at several points around the Wouri coast river of Cameroon. These parameters are the most important soil parameters, necessary to be known before each building project. The undisturbed soils samples are taken at nine different points labeled as P1, P2... P9 at the depths varying from 5m to 9.5 m and distanced around 10 to 15 meters. These studies are motivated by the fact that in this region, mechanical properties of soil have huge effects on buildings. By plotting the void ratio as a function of the logarithm of the pressure, these mechanical parameters are found and compared to that obtained from the inner land of Cameroon, Yaoundé town chosen as an example. As a result, this comparison has allowed us to classify the soil and give some practical advantages when carrying out civil engineering works such as buildings, bridges in coastal area

Fractional-order two-component oscillator: stability and network synchronization using a reduced number of control signals

In this paper, a fractional-order version of a chaotic circuit made simply of two non-idealized components operating at high frequency is presented. The fractional-order version of the Hopf bifurcation is found when the bias voltage source and the fractional-order of the system increase. Using Adams–Bashforth–Moulton predictor–corrector scheme, dynamic behaviors are displayed in two complementary types of stability diagrams, namely the two-parameter Lyapunov exponents and the isospike diagrams. The latest being a more fruitful type of stability diagrams based on counting the number of spikes contained in one period of the periodic oscillations. These two complementary types of stability diagrams are reported for the first time in the fractional-order dynamical systems. Furthermore, a new fractional-order adaptive sliding mode controller using a reduced number of control signals was built for the stabilization of a fractional-order complex dynamical network. Two examples are shown on a fractional-order complex dynamical network where the nodes are made of fractional-order two-component circuits. Firstly, we consider an ideal channel, and secondly, a non ideal one. In each case, increasing of the coupling strength leads to the phase transition in the fractional-order complex network

Multistability Analysis and Function Projective Synchronization in Relay Coupled Oscillators

Regions of stability phases discovered in a general class of Genesio−Tesi chaotic oscillators are proposed. In a relatively large region of two-parameter space, the system has coexisting point attractors and limit cycles. The variation of two parameters is used to characterize the multistability by plotting the isospike diagrams for two nonsymmetric initial conditions. The parameters window in which the jerk system exhibits the unusual and striking feature of multiple attractors (e.g., coexistence of six disconnected periodic chaotic attractors and three-point attraction) is investigated. The second aspect of this study presents the synchronization of systems that act as mediators between two dynamical units that, in turn, show function projective synchronization (FPS) with each other. These are the so-called relay systems. In a wide range of operating parameters; this setup leads to synchronization between the outer circuits, while the relaying element remains unsynchronized. The results show that the coupled systems can achieve function projective synchronization in a determined time despite the unpredictability of the scaling function. In the coupling path, the outer dynamical systems show finite-time synchronization of their outputs, that is, displaying the same dynamics at exactly the same moment. Further, this effect is rather general and it has a wide range of applications where sustained oscillations should be retained for proper functioning of the systems