• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 219
  • 80
  • 36
  • 26
  • 26
  • 10
  • 9
  • 9
  • 7
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 513
  • 160
  • 150
  • 70
  • 57
  • 52
  • 44
  • 43
  • 40
  • 37
  • 37
  • 36
  • 35
  • 35
  • 34
  • 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.
351

Transceiver a TNC pro datovou komunikaci na UHF s obvodem CC1020 / Transceiver and TNC for Data Communication in UHF Band with CC1020 Chip

Hlavica, Petr January 2008 (has links)
The aim of Master’s thesis Transceiver and TNC for Data Communication in UHF Band with CC1020 Chip is design of unit, which provides a data transfer by the packet radio net. It is an experiment, whether CC1020 chip is possible to use for TNC design. The thesis consists of study AX25 a KISS protocols, study of CC1020 features, design of PA and LNA and programming control software for Atmel AVR microcontroller.
352

Simulace přenosu DVB-T v prostředí MATLAB / Simulation of DVB-T transmission chain in the MATLAB environment

Obruča, Martin January 2009 (has links)
This thesis deals with Matlab application developed for simulation of the DVB-T channel coder and decoder. The first part of this thesis includes description of terrestrial digital video broadcasting system and comparison with analogue television. Channel coding and OFDM modulation, used in the DVB-T standard, is described in detail. Application developed in the Matlab environment is described in the second part. The application simulates data transfer of the DVB-T system. Results of the simulated transmission, using developed application are presented in the last part. Namely dependence of the BER on the S/N ratio, using various coder settings, was examined. Maximal possible data rate was determined for these various setting. All obtained values are graphically represented.
353

Modelování PLC komunikačního systému pro zajištění spolehlivosti komunikace / Modelling of PLC system to ensure the reliability of communication

Procházka, Vít January 2010 (has links)
The master´s thesis is focussed on principles and characteristics of Powerline Communications (PLC), practical usage possibilities and advantages and disadvantage of it. There are described mudulations and a channel encoding which are in PLC used. The main part of the thesis deals with a design of a channel as transfer function through the use of two methods, an echo model and the ABCD matrix. After finishing of the design of transfer function the model of communication was created in the Matlab-Simulink program. There were used the narrowband modulations in the model and analyzed the bit error rate of the tranfer data. In the end all results were treated graphically and evaluated.
354

Model distribuční energetické sítě / Power distribution network model

Bradáč, Lubomír January 2012 (has links)
The thesis is focused on PLC technology issues and thus the data transmission over a power-line. This work describes characteristics of the PLC technology, its usage, functional principles and used modulation techniques. The main part of the work describes individual kinds of interferences in the network. The method of necessary steps against these interferences by using the right modulation and relevant coding is also described in the thesis. On the basis of theoretical knowledge, the models of interferences are realized in Matlab/Simulink. The simulative model of power-lines with random parameters is designed and realized for each elected techniques of modulation (BPSK, QPSK, ASK, FSK). The method of PLC channels modeling is chose as a multipath signal spreading for topology with one and two branching and the dependence of their transmission functions are inquired too. The analysis of interference influence on the data transmission is performed via the created models. All acquired results are compared and evaluated in the conclusion of this thesis.
355

Bezdrátový pager / Wireless Messaging System

Machatý, Jiří January 2012 (has links)
This project proposal describes the involvement of a wireless pager. It describes the possibility of realization, block diagrams of the receiver and transmitter controlprogram for their individual and flowcharts. In the theoretical design are taken intoaccount the ease of use, durability and endurance of the battery function. Was chosenfor the realization of a suitable wireless module, with a sufficient range. The goal is todesign a suitable wireless pager with sufficient range, durability and reasonable price that could be used within a department or a house to call for help.
356

Metoda merenja harmonika u realnoj distributivnoj mreži primenom A/D konvertora dvobitne rezolucije / Real power grid harmonic measurement method using 2-bit A/D converters

Beljić Željko 29 December 2016 (has links)
<p>U disertaciji je prikazano teorijsko i praktično istraživanje koje se<br />odnosi na utvrđivanje potrebnih i dovoljnih uslova za merenje<br />harmonika u realnoj elektrodistributivnoj mreži. Cilj istraživanja<br />doktorske disertacije je formulisanje merne metode i na metodi<br />baziranom hardveru - po mogućnosti minimalne rezolucije<br />primenjenih A/D konvertora - praktično dvobitnih za merenje<br />harmonika u realnoj elektrodistributivnoj mreži. Jednostavan<br />hardver omogućuje jednostavna paralelna merenja, kao i mali broj<br />izvora sistematske greške merenja, što je vrlo primenljivo u<br />merenjima u realnoj distributivnoj mreži.Simulacionom analizom, a<br />potom i eksperimentom potvrđena je hipoteza istraživanja.</p> / <p>The dissertation shows the theoretical and practical research related to the<br />determination of necessary and sufficient conditions for the measurement of<br />harmonics in a real power grid. The aim of the PhD research is to formulate<br />method and hardware based on the measurement method - preferably with<br />minimal resolution of applied A/D converter - practically 2-bit, for harmonics<br />measurement in a real power grid. Simple hardware allows simple parallel<br />measurements, as well as a small number of systematic measurement error,<br />which is applicable for measurement in the real power grid. Simulation<br />analysis, followed by the experiment, confirmed the hypothesis of this<br />research.</p>
357

VÄDDNÄTFJÄRILEN I EN FÖRÄNDERLIG VÄRLD : EN STUDIE OM SOLINSTRÅLNINGENS EFFEKT PÅ DESS LARVKOLONIER / The marsh fritillary in a changing world : A study about the solar radiations impacts on its larvae colonies

Hamréus, Moa-Märta January 2022 (has links)
The purpose of the study was to provide further knowledge about if the total amount of solar radiation during the marsh fritillary’s (Euphydryas aurinia) period for larvae development (April 15th – May 15th) and/or flying period (June 1st – June 30th) influenced the average of larvae colonies in the autumn at 12 sites in Dalarna County. Among increased temperatures, global climate models also predict an increased amount of solar radiation and a decrease in cloudiness in northern Europe, as a result of the climate changes. The marsh fritillary has declined rapidly, especially in the Northern of Europe and are in Sweden red-listed as vulnerable (VU). The marsh fritillary is a univoltine species who are dependent on open, sunny, and moist semi-natural grasslands with the hostplant devil’s bit (Succisa pratensis). The data over solar radiation was received from SMHI and had been measured in Borlänge over the last 14 years. The data over the number of larvae colonies was received from Länsstyrelsen Dalarna and had been measured over the last 15 years. The linear regression analysis for both the period of larvae development (p=0,58) and the whole period (p=0,07) indicates that during those periods the solar radiation did not influence the average of larvae colonies. However, the total amount of solar radiation during the flying period (p=0,02) influence the average of larvae colonies during the autumn.
358

Application of NOMA for Mobile High Definition Images

Danda, Aishwarya Reddy, Chama, Naga Manikanta January 2021 (has links)
The telecommunications technology has been developed tremendously as there has been an ever-increasing demand for more speed and reliability. The enormous increase in the number of smart phones and other data consuming devices, combined with the development of enhanced multimedia applications has resulted in a dramatic increase in the volume of mobile data traffic. In order to accommodate the growing needs, it is required to utilise the spectrum efficiently. The design of radio access technology plays an important role in the aspect of system performance. These radio access technologies are typically characterised by the multiple-access techniques used. Non-Orthogonal Multiple Access (NOMA) is a multiple access scheme proposed for 5G and it utilises the power domain which was not sufficiently utilised in the previous systems.        This thesis work is mainly focused on the performance analysis of the NOMA technique in mobile media (images). This analysis is achieved by transmitting a high definition image at various power levels to two users who are located at two different distances from the base station. The images are transmitted through suitable noise channels. An analysis is done on how NOMA copes with the users having poor channel conditions. The performance is analysed by comparing the output images at both the receivers based on the structural similarity index and bit error rate parameters.
359

Design of a 16 GSps RF Sampling Resistive DAC with on-chip Voltage Regulator / Konstruktion av en 16 GSps resistiv digital-analogomvandlare med integrerad spänningsregulator

Thomsson, Pontus, Seyed Aghamiri, Cyrus January 2021 (has links)
Wireless communication technologies continue to evolve to meet the demand for increased data throughput. To achieve higher data throughput one approach is to increase the bandwidth. One problem related to very large bandwidths is the implementation of digital-to-analog converters with sampling rates roughly in the 5 to 20 GHz range. Traditionally, current-steering data converters have been the go-to choice but their linearity suffers at higher frequencies. An alternative to the current-steering digital-to-analog converter is the voltage-mode digital-to-analog converter, which is an attractive option for integration into digital intensive application-specific integrated circuits due to its digital-in-nature architecture. In this thesis, a resistive voltage-mode digital-to-analog converter with an integrated low-dropout voltage regulator is proposed for a sampling rate of 16 GSps. The proposed resistive voltage-mode digital-to-analog converter with an output impedance matched to a 100 Ω load, achieves a spurious-free dynamic range of 64 dBc and intermodulation distortion of 66 dBc for output frequencies up to 5.5 GHz in the worst process corner.
360

Probabilistic Computing: From Devices to Systems

Jan Kaiser (8346969) 22 April 2022 (has links)
<p>Conventional computing is based on the concept of bits which are classical entities that are either 0 or 1 and can be represented by stable magnets. The field of quantum computing relies on qubits which are a complex linear combination of 0 and 1. Recently, the concept of probabilistic computing with probabilistic (<em>p-</em>)bits was introduced where <em>p-</em>bits are robust classical entities that fluctuate between 0 and 1. <em>P-</em>bits can be naturally represented by low-barrier nanomagnets. Probabilistic computers (<em>p-</em>computers) based on <em>p-</em>bits are domain-based hardware accelerators for Monte Carlo algorithms that can efficiently address probabilistic tasks like sampling, optimization and machine learning. </p> <p>In this dissertation, starting from the intrinsic physics of nanomagnets, we show that a compact hardware implementation of a <em>p-</em>bit based on stochastic magnetic tunnel junctions (s-MTJs) can operate at high-speeds in the order of nanoseconds, a prediction that has recently received experimental support.</p> <p>We then move to the system level and illustrate by simulation and by experiment how multiple interconnected <em>p-</em>bits can be utilized to train a Boltzmann machine built with hardware <em>p-</em>bits. We observe that even non-ideal s-MTJs can be utilized for probabilistic computing when combined with hardware-aware learning.</p> <p>Finally, we show how to build a <em>p-</em>computer to accelerate a wide variety of problems ranging from optimization and sampling to quantum computing and machine learning. The common theme for all these applications is the underlying Monte Carlo and Markov chain Monte Carlo algorithms and their parallelism enabled by a unique <em>p-</em>computer architecture.</p>

Page generated in 0.0413 seconds