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In this work we tackle the bus stop selection step for the School Bus Routing Problem (SBRP). Our goal is to minimize the number of bus stops in order to assign all students to a bus stop respecting a home-to-bus-stop walking distance constraint. Our strategy creates a large number of possible bus stops points in a road network and uses a pseudo-random constructive heuristic algorithm to assign students...
In this work the allocation of Roadside Units (RSUs) in a V2I network is modeled as a Maximum Coverage Problem. The main objective is to maximize the number of distinct vehicles contacting the infrastructure. Two different approaches are presented to solve the problem. The first one is an ILP model that can found optimal solutions or give sharp upper and lower bounds for the problem. The second one...
In this work we investigate the benefits of an hybrid architecture integrating both mobile roadside units, and stationary roadside units supporting the operation of vehicular networks. Since traffic fluctuates, an architecture employing just stationary roadside units might not be able to properly support the network operation all the time. Similarly, an architecture composed just of mobile roadside...
In this work we propose Delta-r, a new greedy heuristic for solving the allocation of roadside units in order to meet a Δρ1ρ2-Deployment. The Δρ1ρ2-Deployment is a metric for specifying minimal levels of performance from the infrastructure supporting vehicular networks. As far as we are concerned, this is the first QoS-bounded deployment strategy considering both the contact probability, and the contact...
This work presents and discusses the creation of an application to the Voxar Puzzle, an AR platform that has been built in order to promote children's education in a fun and lively way. The application was conceived using a well-structured methodology named Create Innovation Pack that is based on the design thinking theory. This method aims at helping to exploit the potential of a technology to deliver...
In vivo experiments to detect the neuronal magnetic field require high-sensitivity magnetoresistive sensors incorporated in micromachined silicon probes that do not damage the organic tissues and enhance the sensors proximity to the signal sources. When in touch with the tissues, the probe experiences a mechanical stress induced by an unavoidable bending moment. To evaluate its impact on sensor performance,...
This paper presents a low-power and a low output voltage CMOS Bandgap Reference Generator topology with high PSRR and a novel temperature curvature compensation method. The proposed design was implemented in a standard 0.13 µm CMOS process. The main circuit is based in an opamp based β-multiplier bandgap circuit with resistive division. The compensation method cancels out up to 2nd order non-linear...
This article proposes the analysis of the quality of the power provided by two commercial photovoltaic inverters. Initially the inverters are analyzed based on the recent regulations, afterwards the equipment is compared based in the measurement of the distortion rates and power factor during the analyzing period.
Many applications based on variable speed drives require motors to be installed in remote locations, sometimes even inaccessible. This is the case, for example, in oil extraction on subsea environment and underground mining. This paper aims the proposition of an analysis of the applicability of Power Line Communication, when used for data transmission between the supervisory system and remote systems,...
The thyristor crowbar plays an important role in series connected power converters, as dynamic voltage restorers and active filters, since it allows the bypass of the converter and a direct connection between utility and load in case of failures. In general, the crowbar is specified taking into account the energy that it will be subjected to during a short-circuit downstream the converter, leading...
This paper brings the PV model of a real PV farm installation with a total power of 917 kW. All the elements of the PV farm (panels and inverter) are described. Simulation on PSCAD and experimental results at the installation are reported. The PV model is submitted to voltage sags originated in the grid as well as their impact on the photovoltaic power plant.
Resumo - The usage of electrical energy generation with alternative sources is increasing significantly, due to the general concern about the environment and generation with nonrenewable sources. This fact encourages the development of technologies and new researches, to come up with solutions to allow the connection the new systems to the grid in a safe and trustable way. This work presents the project...
Voltage sag is one of the most frequent power quality problems found in industries and power system. Its effects can be numerous such as control equipment trips, process shutdown, production losses. This paper reports three year of voltage sag measurements collected in a research lab. This site is located near to many metal industries which lead to a correlation between the obtained results and possible...
Utility-Accessible External Disconnect Switch (EDS) is an AC switch used in electric power systems to disconnect Distributed Energy Resources (DER) from the main grid during maintenance. The EDS utilization is intended for line worker safety, since it is currently the only mechanism to ensure galvanic disconnection between DER and distribution network. Frequency inverters used in DER has a built-in...
This work presents a novel algorithm for the deployment of roadside units based on partial mobility information. Instead of relying on the individual vehicles trajectories, our proposal relies on the migration ratios between urban regions in order to infer the better locations for the deployment of the roadside units. Our goal is to identify those α locations maximizing the number of distinct vehicles...
The number of dispersed energy resources is growing every day, such as the use of more distributed generators. This paper deals with energy resource scheduling model in future smart grids. The methodology can be used by virtual power players (VPPs) considering day-ahead time horizon. This method considers that energy resources are managed by a VPP which establishes contracts with their owners. The...
Nowadays there has been an important increase of electric equipment in modern aircraft which leads to a rising demand of electrical power. This highlights the necessity of efficient, reliable and high energy density power converters which rectify three-phase 115V ac to 270V dc for power distribution. This paper presents an isolated single-stage PWM rectifier with the integration of a current injection...
This paper proposes a observer-based state feedback controller for the PWM inverter output LCL filter used in PV applications. The controller is comprised of an inner pole-placement loop and its poles are placed following the state-apace control theory. An additional outer current loop is responsible for making sure the grid inductor output current is as clean as possible of harmonic components. Its...
Network interfaces are components largely employed in battery powered mobile devices. Considering the need to save energy on these devices, power management policies were developed taking advantage of idle components, including network interfaces. To increase the efficiency of power management policies for network interfaces, the detection of idle periods with a high hit rate is relevant. In this...
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