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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.
121

penalized: A MATLAB toolbox for fitting generalized linear models with penalties

McIlhagga, William H. 07 August 2015 (has links)
Yes / penalized is a exible, extensible, and e cient MATLAB toolbox for penalized maximum likelihood. penalized allows you to t a generalized linear model (gaussian, logistic, poisson, or multinomial) using any of ten provided penalties, or none. The toolbox can be extended by creating new maximum likelihood models or new penalties. The toolbox also includes routines for cross-validation and plotting.
122

The Effect of Icing on the Dispatch Reliability of Small Aircraft

Gates, Melinda M. 08 December 2004 (has links)
In 2000, the National Aeronautics and Space Administration (NASA) initiated a program to promote the use of small aircraft as an additional option for national public transportation. The Small Aircraft Transportation System (SATS) asserted the idea of everyday individuals piloting themselves on trips, within a specified distance range, using a small (4 person), piston powered, un-pressurized aircraft and small airports in close proximity to their origin and destination. This thesis investigates how one weather phenomenon, in-flight icing, affects the dispatch reliability of this transportation system. Specifically, this research presumes that a route is considered a "no-go" for low time pilots in a small, piston powered aircraft if any icing conditions are forecast along the route at the altitude of the flight during the time the traveler desires to make the trip. This thesis evaluates direct flights between Cleveland and Boston; Boston and Washington, D.C.; and Washington, D.C. and Cleveland during the months of November through May for the years 2001 to 2003 at maximum cruising altitudes of 6,000 feet, 8,000 feet, 10,000 feet, and 12,000 feet above mean sea level (MSL). It was found that the overall probability of a "no-go" for all three flight paths at the normal cruising altitude of 12,000 feet is 56.8%. When the cruising altitude is reduced to 10,000 feet, 8,000 feet, and 6,000 feet the probability of a "no-go" for all three flight paths reduces to 54.6%, 48.5%, and 43.7% respectively. / Master of Science
123

Investigation of the Growth of Particles Produced in a Laval Nozzle

Zhalehrajabi, E., Rahmanian, Nejat, Zarrinpashne, S., Balasubramanian, P. 24 June 2014 (has links)
Yes / This study focuses on numerical modeling of condensation of water vapor in a Laval nozzle, using the liquid drop nucleation theory. Influence of nozzle geometry, pressure, and temperature on the average drop size is reported. A computer program written in MATLAB was used used to calculate the nucleation and condensation of water vapor in the nozzle. The simulation results are validated with the available experimental data in the literature for steam condensation. The model reveals that the average drop size is reduced by increasing the divergent angle of the nozzle. The results also confirm that increasing the inlet pressure has a direct effect on the average drop size while temperature rise has an inverse effect on the drop size.
124

FPGA-based real-time simulation model of a rotating missile for hardware verification

Bengtsson, Richard January 2024 (has links)
During the development of complex embedded systems like controllers, conducting real-world testing can often be impractical due to factors such as cost, safety concerns, or unavailability during certain stages of development. In such scenarios, hardware-in-the-loop testing is a practical alternative. Hardware-in-the-loop testing involves interfacing the device under test with a simulation environment that mimics real-world inputs, enabling comprehensive testing without the associated risks or constraints. This thesis focuses on the transformation of a Matlab model depicting the behavior of a falling missile into VHDL. The purpose of this model is to integrate with an FPGA to facilitate real-time testing of control algorithm and associated hardware. The conversion successfully translated the Matlab model into VHDL, enabling execution within the constraints of the real-time system.  While the VHDL model closely mirrors the original Matlab model, minor deviations exist due to the discretisation process, resulting in slight discrepancies. However, suggestions on how to overcome these are proposed.
125

Determinação das freqüências naturais e modos de vibrar de um veículo de dois eixos através de um programa computacional em Matlab-Simulink / Determination of the natural frequencies and ways to vibrate of a vehicle of two axles through a computational program in MatLab-Simulink

Ferreira, Hudson Tadeu 10 December 2003 (has links)
Este trabalho obtém as frequências naturais e seus respectivos modos de vibrar da massa suspensa e não suspensa de um veículo comercial através de um programa computacional desenvolvido em MatLab Simulink. As rodas do veículo são excitadas no modelo teórico com sinais harmônicos de frequência continuamente variável de 0 a 40 Hz e de 0 a 4 Hz, faixas que contém as frequências naturais da massa suspensa e não suspensa. As frequências naturais foram obtidas analisando-se a amplitude máxima das forças normais nos pneus, ângulo de arfagem e rolamento da massa suspensa e outras variáveis (respostas do veículo à excitação imposta na roda dianteira esquerda). A roda esquerda dianteira do veículo foi excitada em laboratório com movimento harmônico aleatório cujo power spectral density mostra uma faixa relativamente plana na faixa de 0 a 22 Hz. As frequências naturais foram obtidas analisando-se o PSD da resposta do veículo medida nos eixos e na massa suspensa. As frequências naturais da massa suspensa e não suspensa obtidas teoricamente foram comparadas com as obtidas no ensaio em laboratório. O conhecimento das frequências naturais da massa suspensa e não suspensa é o primeiro passo para a análise do ride do veículo. Os resultados práticos e teóricos mostraram-se próximos mostrando que o programa computacional desenvolvido em MatLab Simulink é uma opção para o projeto e otimização da suspensão de veículos comerciais. / This study has the natural frequencies and its respective ways of vibration the lifted mass and not lifted of a commercial vehicle through a computerized program developed at MatLab Simulink. The wheels of this vehicle are excited on the theoretic model with harmonic frequency signals continuously variable from 0 to 40 Hz and from 0 to 4 Hz, ranges that have the natural frequencies of the lifted mass and not lifted. These natural frequencies were obtained by analyses of the maximum amplitude of the normal strength on the tires, pitch angle, riding of the lifted mass and variables (reaction of the vehicle to the excitement stressed on the front left wheel). The front left wheel was excited in lab in harmonic random motion of which the power spectral density shows a range reasonable steady at the range of 0 to 22 Hz. The natural frequencies were obtained by the analyses of the PSD the reaction of the vehicle measured on the axels and the lifted mass. The natural frequencies of the lifted and not lifted mass theoretically obtained were compared with the ones obtained at the lab. The data on the natural frequencies of the lifted and not lifted mass is the first step to the analyses of the ride of the vehicle. The practical and theoretical results appear to close showing that the computerized program developed at the MatLab Simulink is an option for the project and suspension upgrades on commercial vehicles.
126

Monitoramento do acesso de veículos de carga em vias urbanas / Monitoring of freight vehicles access on urban roads

Tancredi, Pamela Rosa 04 May 2012 (has links)
O monitoramento do trânsito de veículos rodoviários de carga em vias urbanas é dependente do trabalho de profissionais que precisam estar integralmente atentos ao tráfego de uma determinada via, e assim, identificar a presença desses veículos em meio a cenas complexas. Sistemas automáticos de identificação de veículos em quadros de vídeos podem agregar valor na qualidade de vida das cidades, pois tendem a diminuir os congestionamentos e incrementam segurança ao trânsito. Nesta pesquisa, propõe-se um modelo capaz de identificar e segregar veículos rodoviários de carga em vias urbanas, por meio de técnicas de processamento e análise de vídeos, gravados por câmeras posicionadas em diversos ângulos em dispositivos de acessos a vias urbanas. O sistema foi desenvolvido em linguagem MATLAB® e foram abordadas técnicas referentes às etapas de detecção, segmentação e processamento de objetos em fundos complexos. Ao final do trabalho, o sistema é aplicado em cenários de filmagem na cidade de São Carlos - SP e os resultados obtidos são discutidos. / The monitoring of the road freight vehicles traffic on urban roads relies on the work of professionals who need to be fully aware of the traffic on a specific road, and thereby identify the presence of these vehicles in complex scenes. Automatic vehicle identification in video shots may add value to the city life quality, due to congestion diminishment and traffic security improvement. In this research, a model able to identify and segregate road freight vehicles on urban roads is proposed, by means of video analysis and processing, that were recorded by cameras positioned at different angles on highways accesses on urban roads. The system was developed using MATLAB®. Techniques related to detecting, targeting and processing steps have been used to identify objects in complex backgrounds. At the end of the work, the system is applied to several scenarios that have been filmed in the city of São Carlos - SP and the results are discussed.
127

Utveckling av styrsystem för EMC-kammare

Glans, Mikael January 2009 (has links)
<p>This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type.</p> / <p>Detta examensarbete syftar till att utveckla ett styrsystem för mätning av elektromagnetisk kompabilitet (EMC). Detta har inneburit att ett styrkort uppbyggt kring en ATmega8 mikrokontroller har tillverkats och programmerats. Det har även inneburet utveckling av en övergripande kontrollmjukvara i programmet MATLAB. Styrsystemet har testats med tillfredsställande resultat och kan nu, övervaka och kontrollera mätningar av EMC-typ.</p>
128

Utveckling av styrsystem för EMC-kammare

Glans, Mikael January 2009 (has links)
This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type. / Detta examensarbete syftar till att utveckla ett styrsystem för mätning av elektromagnetisk kompabilitet (EMC). Detta har inneburit att ett styrkort uppbyggt kring en ATmega8 mikrokontroller har tillverkats och programmerats. Det har även inneburet utveckling av en övergripande kontrollmjukvara i programmet MATLAB. Styrsystemet har testats med tillfredsställande resultat och kan nu, övervaka och kontrollera mätningar av EMC-typ.
129

Επεξεργασία σημάτων σε υποβρύχιες επικοινωνίες

Νικολακάκης, Κωνσταντίνος 09 October 2014 (has links)
Στις υποθαλάσσιες επικοινωνίες χρησιμοποιούνται ακουστικά κύματα για τη μεταφορά της πληροφορίας. Κατά τη διαδικασία της μετάδοσης εμφανίζονται προβλήματα που σχετίζον- ται με τη καθυστέρηση διάδοσης, την εξασθένηση του σήματος, τις πολλαπλές οδεύσεις λόγω ανάκλασης καθώς και άλλα προβλήματα που παρουσιάζονται στις ασύρματες επι- κοινωνίες. Στην παρούσα εργασία αναλύεται και εξετάζεται η πλειονότητα αυτών. Στο πρώτο κεφάλαιο γίνεται μία συνοπτική περιγραφή του φαινομένου των διαλείψεων καθώς και η ανάλυση βασικών εννοιών, τις οποίες συναντάμε σε επόμενα κεφάλαια. Στο δεύτερο κεφάλαιο περιγράφεται η πολύπλεξη OFDM, η οποία χρησιμοποιείται στις περισσότερες εφαρμογές των υποθαλάσσιων επικοινωνιών. Στο τρίτο κεφάλαιο αναλύεται μαθηματικά η τυφλή εκτίμηση για συστήματα OFDM και αναφέρονται επίσης προσαρμοστικοί αλγόριθ- μοι για την εκτίμηση του καναλιού με βάση την θεωρία η οποία παρουσιάζεται. Τέλος στο τέταρτο κεφάλαιο παρατίθεται κώδικας matlab, στον οποίο γίνεται χρήση των αλγορίθμων των τρίτου κεφαλαίου με σκοπό την εκτίμηση της κρουστικής απόκρισης του καναλιού, ενώ πέραν της γενικής περίπτωσης εξετάζονται επιπλέον λύσεις sparse μορφής. / --
130

Εξαγωγή κινούμενου αντικειμένου σε βίντεο

Σταμούλη, Μαριάνα 08 December 2008 (has links)
Στην παρούσα διπλωματική μελετήσαμε και αναπτύξαμε αλγορίθμους ανίχνευσης και κατάτμησης κινούμενου αντικειμένου σε βίντεο. Ασχοληθήκαμε με μία σειρά αλγορίθμων που διέφεραν τόσο στην πολυπλοκότητα όσο και στην ποιότητα των αποτελεσμάτων που παρήγαγαν. Σκοπός μας ήταν η ανάλυση αυτών των αλγορίθμων σε βάθος, έτσι ώστε να εντοπίσουμε τις αδυναμίες τους, προσπαθώντας κατά το δυνατόν να τις αντιμετωπίσουμε αλλά και η εφαρμογή τους στην πράξη, ώστε να διαπιστώσουμε την αποτελεσματικότητά τους αλλά και την ευελιξία τους στις ιδιαίτερες απαιτήσεις του κάθε προβλήματος. Στην πρώτη φάση της παρούσας εργασίας μελετήσαμε και αναλύσαμε τη μαθηματική αναπαράσταση των υπό εξέταση αλγορίθμων. Σκοπός μας ήταν να κατανοήσουμε πλήρως τον αλγόριθμο, ώστε να μπορέσουμε στην συνέχεια να τον εφαρμόσουμε, αλλά και να επιφέρουμε κάποιες βελτιστοποιήσεις και απλοποιήσεις στον ίδιο τον αλγόριθμο έτσι ώστε να προσαρμοστεί, όταν χρειαζόταν, στις απαιτήσεις των δικών μας προβλημάτων και να γίνει πιο εύκολα υλοποιήσιμος. Στην συνέχεια υλοποιήσαμε τους αλγορίθμους στο μαθηματικό εργαλείο Matlab και εξομοιώσαμε την λειτουργία τους. Στο στάδιο αυτό, είχαμε την δυνατότητα να μελετήσουμε στην πράξη την αποτελεσματικότητα των αλγορίθμων και να παρατηρήσουμε την ποιότητα των αποτελεσμάτων της εφαρμογής τους για διαφορετικές εισόδους. Τα αποτελέσματα των εξομοιώσεων μας καθοδηγούσαν έτσι ώστε να κάνουμε τις απαραίτητες αλλαγές τόσο στους ίδιους τους αλγορίθμους αλλά κυρίως, στον τρόπο με τον οποίο είχαμε επιλέξει να υλοποιήσουμε καθένα από τους αυτούς στο Matlab. Στο τελευταίο στάδιο, συγκεντρώσαμε τα αποτελέσματα της εξομοίωσης λειτουργίας καθενός από τους αλγορίθμους που μελετήσαμε και αξιολογήσαμε την συμπεριφορά τους. Κάνοντας τις απαραίτητες συγκρίσεις των αποτελεσμάτων, σε συνδυασμό με την πολυπλοκότητα των αλγορίθμων, εξάγαμε τα τελικά συμπεράσματα για τις δυνατότητες και την αποτελεσματικότητα τους αλλά και την τελική μας εκτίμηση για την περαιτέρω βελτιστοποίηση που είναι δυνατό να πραγματοποιηθεί σε κάποιους από αυτούς. / -

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