Transactions on Networks and Communications

Prediction of Travel Time Using Fuzzy Logic Paradigm

2019-07-02T01:55:16+00:00

Predicting travel time is an important aspect of human life. It helps to effectively manage and successfully make the most of time. So much time is usually spent on the road when travelling from one place to another, particularly in developing countries and in a mega city like Lagos for example, a little time wasted is a lot of money lost, hence the need to envisage the likely time to reach destinations.

This research work explores the robustness of fuzzy logic to predict travel time on all major routes out of the town where the Engineering faculty of Lagos State University is situated. This paper takes into consideration important factors that can lead to delay in travel time; period of day, weather, car density, and construction, as the fuzzy inputs and based on experience, fuzzy rules are generated to give an estimated time of arrival.

To prove the validity of this work, data were collected from frequent road users and co-efficient of determination was calculated for all three routes. The co-efficient of determination ranked above 90% for all three routes, two of which are discussed.

Decision Matrix Equation and Block Diagram of Multilayer Electromagnetoelastic Actuator Micro and Nanodisplacement for Communications Systems

2019-07-02T01:55:16+00:00

For the communications systems the parametric block diagram of the multilayer electromagnetoelastic actuator micro and nanodisplacement or the multilayer piezoactuator is determined in contrast to Cady and Mason’s electrical equivalent circuits for the calculation of the piezoelectric transmitter and receiver, the vibration piezomotor. The decision matrix equation of the multilayer electromagnetoelastic actuator is used. The parametric block diagram of multilayer electromagnetoelastic actuator is obtained with the mechanical parameters the displacement and the force. The transfer functions of the multilayer electroelastic actuator are determined. The the generalized parametric block diagram, the generalized matrix equation for the multilayer electromagnetoelastic actuator micro and nanodisplacement are obtained. The deformations of the multilayer electroelastic actuator for the nanotechnology are described by the matrix equation. Block diagram and structural-parametric model of multilayer electromagnetoelastic actuator micro and nanodisplacement of the communications systems are obtained, its transfer functions are bult. Effects of geometric and physical parameters of multilayer electromagnetoelastic actuators and external load on its dynamic characteristics are determined. For calculations the communications systems with the multilayer piezoactuator for micro and nanodisplacement the parametric block diagram and the transfer functions of the multilayer piezoactuator are obtained.

Scalable Multicast Using MPLS in Software Defined Network

2019-07-02T01:55:16+00:00

Multicast helps to deliver data to multiple receivers efficiently. One scalability challenge faced by multicast is the per-channel forwarding states being maintained in the network layer, which increases linearly with the number of established multicast channels. MPLS helps to alleviate this problem by removing forwarding states from non-branch routers on the multicast tree and label switch packets in non-branch routers. To reduce the number of forwarding states in branch routers, many solutions were proposed to merge multicast trees/subtrees from different channels. Software Defined Network (SDN) decouples the control plane from the data plane, which enables low cost commodity design in routers and flexible network feature deployments through software implementation in centralized controllers. Equipped with SDN’s flexible policy and packet processing action installation, multicast tree/subtree merging becomes more convenient in SDN. This paper proposes a new scalable multicast solution in SDN to further reduce the number of forwarding states in routers. In the new solution, first a 2 level MPLS label switching scheme is used to reduce the extra point to point LSPs needed when multicast trees are merged. Secondly, a new multicast tree construction algorithm is designed to pursue more aggressive subtree matching between channels by taking advantage of per channel packet dropping actions in SDN. Simulation results show that the new solution can achieve 10-20 percent reduction in the number of forwarding entries needed for multicast traffic’s forwarding.

Free running VCO based on an unstable transistor circuit system stability optimization under delayed electromagnetic interferences and parasitic effects and engineering applications

2019-07-02T01:55:16+00:00

IN this article, Very Crucial subject discussed in free running VCO based on an unstable transistor circuit system stability optimization under delayed electromagnetic interferences and parasitic effects. Additionally we discuss Free running VCO integrated circuit applications (PLLs, DLL, clock generation, etc.). There are many techniques to generate a Wideband Frequency Modulation (WBFM) signal: analog based, digitally based and hybrid based techniques. The VCO is a very low cost method of generating WBFM signals, such as chirp signals. The VCO has some important properties that are common to all frequency sources. These properties are frequency range, settling time, post-tuning drift, sensitivity and Maximum Sensitivity Ratio (MSR), frequency total accuracy, frequency modulation span, and modulation frequency bandwidth. The VCO frequency of oscillation depends on the resonance frequency set by its equivalent capacitance and inductance. By applying variable bias voltage to a Varactor diode, the capacitance is changed and the oscillation frequency is changed accordingly. The first delay line in our circuit (1) represents the electromagnetic interference in the Varactor diode (D1). We neglect the voltage on the first delay line (V1→ε) and the delay is on the current which flows through Varactor diode. The second and third delay lines (2 and 3) represent the circuit microstrip line's parasitic effects before and after the matching circuit. We neglect the voltages on the second and third delay lines (Vk→ε ; k=2, 3) and the delays are only on the current which flow through the microstrip lines. The free running VCO circuit can represent as delayed differential equations which, depending on variable parameters and delays. There is a practical guideline which combines graphical information with analytical work to effectively study the local stability of models involving delay dependent parameters. The stability of a given steady state is determined by the graphs of some function of τ1, τ2, τ3.