Fuzzy gain scheduling control apply to an RC Hovercraft

The Fuzzy Gain Scheduling (FGS) methodology for tuning the Proportional – Integral – Derivative (PID) traditional controller parameters by scheduling controlled gains in different phases, is a simple and effective application both in industries and real-time complex models while assuring the high achievements over pass decades, is proposed in this article. The Fuzzy logic rules of the triangular membership functions are exploited on-line to verify the Gain Scheduling of the Proportional – Integral – Derivative controller gains in different stages because it can minimize the tracking control error and utilize the Integral of Time Absolute Error (ITAE) minima criterion of the controller design process. For that reason, the controller design could tune the system model in the whole operation time to display the efficiency in tracking error. It is then implemented in a novel Remote Controlled (RC) Hovercraft motion models to demonstrate better control performance in comparison with the PID conventional controller

Xcast6 Treemap Islands - Revisiting Multicast Model

International audienceDue to the complexity and poor scalability, IP Multicast has not been used on the Internet. Recently, Xcast6 - a complementary protocol of IP Multicast has been proposed. However, the key limitation of Xcast6 is that it only supports small multicast sessions. To overcome this, we propose Xcast6 Treemap islands (X6Ti) - a hybrid model of Overlay Multicast and Xcast6. In summary, X6Ti has many advantages: support large multicast groups, simple and easy to deploy on the Internet, no router configuration, no restriction on the number of groups, no multicast routing protocol and no group management protocol. Based on simulation, we compare X6Ti with IP Multicast and NICE protocols to show the benefits of our new model

Xcast6 Treemap Islands - A Mixed Model of Application and Network Layer Multicast

IP multicast is a protocol that deals with group communications with the aim of reducing traffic redundancy in the network. However, due to difficulty in deployment and poor scalability with a large number of multicast groups, IP multicast is still not widely deployed and used on the Internet. Recently, Xcast6 and Xcast6 Treemap, the two network layer multicast protocols, have been proposed with complementary scaling properties to IP multicast: they support a very large number of active multicast sessions. However, the key limitation of these protocols is that they only support small multicast group. In this paper, we propose Xcast6 Treemap island - a hybrid model of Application Layer Multicast (ALM) and Xcast6 that can work for large multicast group. Our model has several key advantages: ease of deployment, efficiency in bandwidth savings, no control message between end-host and router, zero multicast forwarding state at router and no need for a multicast address allocation protocol. In addition, this model is a potential service from which an ISP can get new revenue. Finally, in simulation section, we have made a comparison with IP multicast and NICE protocol to show the feasibility of our new model.Le multicast a été inventé pour gérer les communications de groupes tout en réduisant la charge de trafic redondant sur le réseau. Actuellement, le multicast n'est pas largement déployé et utilisé sur l'Internet, principalement en raison des problèmes de passage à l'échelle avec un grand nombre de groupes. Récemment, Xcast6 et Xcast6 Treemap, ont été proposés pour pallier à ce problème: ces deux protocoles peuvent gérer un très grand nombre de groupes actifs. Toutefois, la principale restriction de ces protocoles est qu'ils ne fonctionnent qu'avec des groupes de très petite taille (avec peu de membres). Dans ce papier, nous proposons Xcast6 Treemap Island- un modèle hybride entre Application Layer Multicast (ALM) et Xcast6 qui peuvent gérer des groupes de grande taille. Les avantages principaux de noetr modèles sont les suivants : facilité de déploiement, utilisation efficace de la bande-passante, suppression des messages de contrôle et aucune nécessité d'un protocole d'allocation d'adresses multicast. Nous montrons la faisabilité et l'efficacité de notre proposition par des simulations où nous comparons notre proposition, un protocole IP multicast traditionnel, et le protocole NICE pour ALM

MaxNet and TCP Reno/RED on Mice Traffic

International audienceCongestion control is a distributed algorithm to share network bandwidth among competing users on the Internet. In the common case, quick response time for mice traffic (HTTP traffic) is desired when mixed with elephant traffic (FTP traffic). The current approach using loss-based with Additive Increase, Multiplicative Decrease (AIMD) is too greedy and eventually, most of the network bandwidth would be consumed by elephant traffic. As a result, it causes longer response time for mice traffic because there is no room left at the routers. MaxNet is a new TCP congestion control architecture using an explicit signal to control transmission rate at the source node. In this paper, we show that MaxNet can control well the queue length at routers and therefore the response time to HTTP traffic is several times faster than with TCP Reno/RED

Carbon nanotube four-terminal devices for pressure sensing applications

Carbon nanotubes (CNTs) are of high interest for sensing applications, owing to their superior mechanical strength, high Young’s modulus and low density. In this work, we report on a facile approach for the fabrication of carbon nanotube devices using a four terminal configuration. Oriented carbon nanotube films were pulled out from a CNT forest wafer and then twisted into a yarn. Both the CNT film and yarn were arranged on elastomer membranes/diaphragms which were ar-ranged on a laser cut acrylic frame to form pressure sensors. The sensors were calibrated using a precisely controlled pressure system, showing a large change of the output voltage of approximately 50 mV at a constant supply current of 100µA and under a low applied pressure of 15 mbar. The results indicate the high potential of using CNT films and yarns for pressure sensing applications

A Wearable, Bending-Insensitive Respiration Sensor Using Highly Oriented Carbon Nanotube Film

Recently, wearable electronics for health monitoring have been demonstrated with considerable benefits for early-stage disease detection. This article reports a flexible, bending-insensitive, bio-compatible and lightweight respiration sensor. The sensor consists of highly oriented carbon nanotube (HO-CNT) films embedded between electro-spun polyacrylonitrile (PAN) layers. By aligning carbon nanotubes between the PAN layers, the sensor exhibits a high sensitivity towards airflow (340 mV/(m/s)) and excellent flexibility and robustness. In addition, the HO-CNT sensor is insensitive to mechanical bending, making it suitable for wearable applications. We successfully demonstrated the attachment of the sensor to the human philtrum for real-time monitoring of the respiration quality. These results indicate the potential of HO-CNT flow sensor for ubiquitous personal health care applications

Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998–2009

Dengue is the most common vector-borne viral disease of humans, causing an estimated 50 million cases per year. The number of countries affected by dengue has increased dramatically in the last 50 years and dengue is now a major public health problem in large parts of the tropical and subtropical world. It is of considerable importance to understand the factors that determine how dengue becomes newly established in areas where the risk of dengue was previously small. Hanoi in North Vietnam is a large city where dengue appears to be emerging. We analyzed 12 years of dengue surveillance data in order to characterize the temporal and spatial epidemiology of dengue in Hanoi and to establish if dengue incidence has been increasing. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure over time, we found there was a significant annual increase in the incidence of notified dengue cases over the period 1999–2008. Dengue cases were concentrated in young adults in the highly urban central areas of Hanoi. This study indicates that dengue transmission is increasing in Hanoi and provides a platform for further studies of the underlying drivers of this emergence

A Cartesian grid technique based on one-dimensional integrated radial basis function networks for natural convection in concentric annuli

This paper reports a radial-basis-function (RBF)-based Cartesian grid technique for the simulation of two-dimensional buoyancy-driven flow in concentric annuli. The continuity and momentum equations are represented in the equivalent stream function formulation that reduces the number of equations from three to one, but involves higher-order derivatives. The present technique uses a Cartesian grid to discretize the problem domain. Along a grid line, one-dimensional integrated RBF networks (1D-IRBFNs) are employed to represent the field variables. The capability of 1D-IRBFNs to handle unstructured points with accuracy is exploited to describe non-rectangular boundaries in a Cartesian grid, while the method's ability to avoid the reduction of convergence rate caused by differentiation is instrumental in improving the quality of the approximation of high-order derivatives. The method is applied to simulate thermally-driven flows in annuli between two circular cylinders and between an outer square cylinder and an inner circular cylinder. High Rayleigh-number solutions are achieved and they are in good agreement with previously published numerical data

Radial-basis-function calculations of buoyancy-driven flow in concentric and eccentric annuli

[Abstract]: This paper is concerned with the application of integrated radial-basis-function networks (IRBFNs) for the simulation of natural convection in concentric and eccentric annuli. Important features of the present technique include: (i) Taking a stream function - temperature formulation as the governing equations; (ii) Employing a Cartesian grid to discretize the problem domain;(iii) Using one-dimensional RBF approximations to represent the approximate solution; and (iv) Constructing the approximations through integration. These features result in an efficient numerical scheme as (i) the number of the governing differential equations is reduced from 4 to 2, (ii) the preprocessing is simple, (iii) the associated matrices have condition numbers in 2-norm that are much lower than those yielded through conventional RBF techniques, and (iv) the reduction of convergence rate caused by differentiation is avoided. A wide range of the Rayleigh number is considered. Results obtained are compared well with available numerical data in literature

Design and Implementation of a VoIP PBX Integrated Vietnamese Virtual Assistant: A Case Study

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