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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
401

Aplikace evolučního algoritmu na optimalizační úlohu vibračního generátoru

Nguyen, Manh Thanh January 2018 (has links)
This thesis will deal with the use of artificial intelligence methods for solving optimization problems with multiple variables. A theorethical part presents problems of global optimization and overview of solution methods. For practical reasons, special attention is paid to evolutionary algorithms. The subject of optimization itself is energy harvester based on a piezoelectric effect. Its nature and modeling is devoted to one chapter. A part of the thesis is the implementation of the SOMA algorithm for finding the optimal parameters of the generator for maximum performance.
402

Elektromagnetický rezonátor jako zdroj elektrické energie na železniční trati / Electromagnetic energy harvesting resonator for train trackside

Rusková, Miroslava January 2018 (has links)
The aim of the diploma thesis was to design an electromagnetic generator to the purpose of supplying signalling and safety devices on the rail tracks. The electromagnetic generator is a separate electrical source, which is mainly needed for safety in the case of not covered tracks by electrical installation. The thesis proposes two types of electromagnetic generator and one with non-linear stiffness, which are designed for the passage of trains with low frequency.
403

Systém přizpůsobení zátěže převodníku energie / The system of load matching to the energy converter

Halama, Petr January 2012 (has links)
This master’s thesis deals with energy harvesting from the mechanical energy sources. The mechanical energy may be converted into the electrical by means of a vibrational microgenerator. The thesis deals also with the production of energy from different renewable sources. There have been identified conditions for effective transformation of the remaining energy. In order to satisfy these conditions a circuit for load matching to energy harvester has to be used. Four variants of matching circuit have been designed and analyzed in PSpice or LTspice. It has been designed a system of power factor correction controlled by circuit with discrete components and also by microcontroller. For one of these variants a specific integrated circuit has been used. The designed circuits have been built and their parameters haven been determined by measurement.
404

Nízkoenergetický GSM/GPRS modul pro senzorické aplikace / Low Energy GSM/GPRS Module for Sensoric Applications

Pál, Tamás January 2014 (has links)
This project deals with the problematics of self-powered universal GSM/GPRS module which is used for sensorical applications. The first part analyzes features of mobile networks and applying energy from the environment. The second section expalins the various parts and characteristic of their associated components together with some fundamental functions of the technology for possible realization of sensoric module. The third part describes plan for system realisation and fourth parth illustrates achiaved results.
405

Estudo da colheita de energia para medição de vazão em aplicações de internet das coisas /

Machado Junior, Ireno Gonçalves January 2020 (has links)
Orientador: Eduardo Paciência Godoy / Resumo: A colheita de energia emerge como uma das soluções para a alimentação sustentável de sensores e dispositivos de monitoramento em redes sem fio nas aplicações da Internet das Coisas (IoT), permitindo até mesmo prescindir do uso de baterias. Este trabalho descreve o desenvolvimento de uma plataforma de colheita de energia e monitoramento de vazão a partir de redes de distribuição hidráulicas. O sistema experimental montado apresenta um circuito fechado de fluxo variável de água, criado a partir de uma bomba pressurizadora controlável eletronicamente, com sensor de vazão e um micro hidrogerador. A energia elétrica recuperada através do micro hidrogerador é utilizada para alimentar diferentes dispositivos de IoT com comunicação via Wi-Fi dos dados de monitoramento da vazão e volume, assim como, fornece energia para baterias. Os testes operacionais tiveram como objetivo dimensionar a quantidade de energia recuperada, em comparação com a energia consumida pelos dispositivos e bateria conectadas, em função dos valores de vazão obtidos pela plataforma. Nos testes realizados foi possível demonstrar a capacidade da colheita de energia pelo micro hidrogerador, com geração de aproximadamente 1W de energia e sua utilização para a operação contínua de dispositivos em aplicações de IoT. O estudo e implantação de diferentes modos de operação para os dispositivos medidores de vazão possibilitaram a redução do consumo de energia em até 54,4% e maximizaram a eficiência energética da solução, co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Energy harvesting emerges as one of the solutions for sustainable power supply of sensors and monitoring devices in wireless networks in the Internet of Things (IoT) applications, even allowing to dispense with the use of batteries. This work describes the development of an energy harvesting and flow monitoring platform from hydraulic distribution networks. The assembled experimental system features a variable water flow closed loop, created from an electronically controllable pressurizing pump with flow sensor and a micro hydrogenerator. The electrical energy recovered through the micro-generator supplies different IoT device models with Wi-Fi communication of the flow and volume monitoring data and also provides power for storage batteries. The operational tests aimed to measure the amount of energy recovered, compared to the energy consumed by the connected devices and battery, according to the flow values obtained by the platform. In the tests carried out it was possible to demonstrate the capacity to harvest energy by the micro-generator, generating approximately 1W of energy and its use for the continuous operation of devices in IoT applications. The study and implementation of different modes of operation for flow meter devices make it possible to reduce energy consumption by up to 54.4% and maximize the energy efficiency of the solution, proving the potential of energy recovery as a viable alternative to guarantee the operation of self-sustaining meters for IoT applic... (Complete abstract click electronic access below) / Mestre
406

Vertical beam modal response in a broadband energy harvester

Litak, Grzegorz, Rysak, Andrzej, Borowiec, Marek, Scheffler, Michael, Gier, Joachim 17 September 2019 (has links)
We examined energy harvesting using a vertical composite laminate beam with an additional moving mass subjected to kinematic harmonic excitation. The gravity effect and the moving tip mass applied to the system cause considerable changes in effective spring-mass characteristics of the bending beam. Simultaneously, we observed dynamical beam damping by an additional degree of freedom and non-linear effects including friction between the moving mass and the beam structure. The experiments were performed on the beam excited kinematically by a shaker, while beam velocity measurements were made by a scanning laser vibrometer. We applied modal analysis in the limit of a fairly low excitation level. The selected modal vibrations are illustrated by corresponding output time series.
407

Ionic Electroactive Polymers and Liquid Crystal Elastomers for Applications in Soft Robotics, Energy Harvesting, Sensing and Organic Electrochemical Transistors

Rajapaksha, Chathuranga Prageeth Hemantha 25 April 2022 (has links)
No description available.
408

A Scheduling Scheme for Efficient Wireless Charging of Sensor Nodes in WBAN

Rabby, Md Khurram M., Alam, Mohammad Shah, Shawkat, Shamim Ara, Hoque, Mohammad A. 14 August 2017 (has links)
This paper presents a scheduling algorithm for point to point wireless power transfer system (WPTS) to sensor nodes of wireless body area networks (WBAN). Since the sensors of wireless body area networks are continuously monitoring and sending data to remote central unit, power crisis for these sensor nodes degrades the data transfer of patient monitoring system. Although energy harvesting from ambient sources using electromagnetic induction enhances the longevity of sensor performance, continuous operation in the primary side decreases the overall efficiency. With such paradigm in sight, a framework is proposed for increasing the primary battery longevity and reducing the transmission loss, inductive power is transmitted from primary to secondary unit using medium access control (MAC) protocols for underlying the centralized scheduling opportunity in a collision free scheme for channel access of rare yet critical emergency situation. In a preliminary study, the proposed scheduling for charging sensor nodes in a wireless body area network (WBAN) is evaluated in a case consideration.
409

Electrical Equivalent Modeling of the Reverse Electrowetting-on-Dielectric (REWOD) Based Transducer along with Highly Efficient Energy Harvesting Circuit Design towards Self-Powered Motion Sensor

Gunti, Avinash 08 1900 (has links)
Among various energy harvesting technologies reverse electrowetting-on-dielectric energy harvesting (REWOD) has been proved to harvest energy from low frequency motion such as many human motion activities (e.g. walking, running, jogging etc.). Voltage rectification and DC-DC boosting of low magnitude AC voltage from REWOD can be used to reliably self-power the wearable sensors. In this work, a commercial component-based rectifier and DC-DC converter is designed and experimentally verified, for further miniaturization standard 180 nm CMOS process is used to design the rectifier and the DC-DC boost converter.This work also includes the MATLAB based model for REWOD energy harvester for various REWOD models. In REWOD energy harvesting, a mechanical input during the motion causes the electrolyte placed in between two dissimilar electrodes to squeeze back and forth thereby periodically changing the effective interfacial area, hence generating alternating current. The alternating current is given to the rectifier design. There is no realistic model that has been developed yet for this technique. Thereby, a MATLAB based REWOD model is developed for the realistic simulation of the REWOD phenomenon. In the work, a comparison of different REWOD models such as planar surface, rough surface and porous models are performed demonstrating the variations in capacitance, current and voltage.
410

Conception d'une solution RFID UHF pour l'optimisation de la logistique de bouteilles métalliques / Design of an UHF RFID solution for optimisation of metal cylinder logistics

Safraou, Ahcine 04 April 2018 (has links)
Dans le contexte actuel de transformation numérique, Air Liquide souhaite moderniser le suivi logistique de ses bouteilles de gaz à l'aide de la technologie d'identification radio (RFID) à ultra haute fréquence (UHF) qui remplacerait la solution code-barres actuelle et permettrait de dépasser certaines de ses limites. La numérisation de la traçabilité aura pour conséquence en outre d'enrichir l'interaction entre les actifs industriels et le système de gestion et de production pour ainsi créer l'écosystème IOT (Internet Of Things) spécifique à l'entreprise. Le recours à la RFID UHF est de nos jours largement répandu pour la logistique et la gestion de stocks. Cependant, les environnements métalliques, comme celui que l'on trouve avec les bouteilles de gaz, induisent des perturbations qui dégradent fortement la qualité de la communication radio fréquence (RF). Cela constitue un frein au déploiement de cette technologie dans un tel cadre. Il est nécessaire de comprendre les perturbations induites par les milieux conducteurs afin de s'en affranchir et ainsi proposer une solution efficiente. En plus de cela, les faibles niveaux d'énergie mis en jeu impliquent qu'une étude de l'ensemble des points d'amélioration des dispositifs RFID UHF tant au niveau matériel que logiciel soit réalisée. De cette étude théorique, nous avons fait le choix de concentrer nos efforts sur la conception d'un tag RFID UHF pour objets métalliques répondant au cahier des charges spécifique de l'industriel. Pour aller plus loin dans l'optimisation de la logistique et de la gestion des stocks, nous nous sommes également penchés sur l'étude et la réalisation d'un circuit de récupération d'énergie RFID UHF pour tag augmenté passif équipé d'un capteur. L'objectif est d'apporter une information sur l'état de l'actif en plus de son identité tout en évitant les contraintes liées à la présence d'une batterie ou d'une pile. / In the current context of digital transformation, Air Liquide explores the use of Ultra High Frequency (UHF) Radio Frequency IDentification (RFID) in the gas cylinders supply chain, as a replacement for the current, barcode-based, tracking and inventory solution. Digitalization will also provide the company an opportunity to develop its IOT ecosystem through enriched interaction between assets and their management system. UHF RFID is nowadays commonplace in logistics. However, metal surroundings as found in the gas cylinder's case, yield disturbances in the RF communication, and decreased inventory performances. Therefore, it is necessary to understand the adverse effects of metal surroundings to propose an ad-hoc solution. In addition, dealing with low levels of energy in the RF communication suggests leveraging both hardware and software aspects of RFID devices for potential performance improvements. On the basis of our theoretical study, we focus on the design and testing of an industrial UHF RFID tag suitable for the gas cylinder use case. To enable an even richer, more interactive supply chain, we also design and test an energy harvesting device for the UHF band, to power a tag enriched with an active sensor, without the logistic burden of a battery of limited durability.

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