This diploma thesis deals with system for visible light communication (VLC). There are described basic optical elements like a electroluminescence diode and photodiode. In next chapter is described design of transmitter, optical channel and receiver. Attention is also devoted to modulation suitable for optical communication. The last chapter is devoted to program in Matlab language, which's name is Program for calculation of optical intensity distribution. That program was created in this diploma theses.

O καρκίνος του μαστού είναι μια από τις κυρίες αιτίες θανάτου στις γυναίκες. Καθώς η επιτυχής αντιμετώπιση του συνδέεται με τη φάση της νόσου η έγκαιρη διάγνωση του είναι πολύ σημαντική για τους ασθενείς. Ως τεχνική έγκαιρης διάγνωσης αλλά και πληθυσμιακού έλεγχου χρησιμοποιείται η μαστογραφία με χρήση ακτινών-Χ. Η αποτελεσματικότητα της μαστογραφίας στηρίζεται στην υψηλή ποιότητα απεικόνισης του μαστού αλλά και στο όσο το δυνατόν μικρότερη δόση που εναποτίθεται στον μαστό. Ένα από τα βασικότερα χαρακτηριστικά ποιότητας ενός μαστογραφικου συστήματος που επηρεάζει την ικανότητα απεικόνισης ανομοιογενειών μικρών διαστάσεων (π.χ. αποτιτανώσεων) είναι η χωρική διακριτική ικανότητα. Το κατώτερο αποδεκτό όριο είναι 12 lp/mm για μαστογραφία επαφής. H εστία και ο βαθμός φθοράς της σχετίζεται άμεσα με την χωρική διακριτική ικανότητα και την ποιότητα εικόνας. Σκοπός αυτής της μελέτης ήταν να εξετάσουμε την επίδραση της φθοράς της μαστογραφικής ανόδου, στην χωρική ικανότητα υπό συμβατική και μεγεθυντική γεωμετρία. Μια τέτοια μελέτη δεν ήταν δυνατόν να γίνει πειραματικά σε κλινικές συνθήκες. Για αυτό τον λόγο έγινε χρήση ενός προγράμματος προσομοίωσης σε υπολογιστικό περιβάλλον που στηρίζεται στην τεχνική τυχαίας δειγματοληψίας και στην μέθοδο Monte Carlo (MASTOS Code). Η σημαντική παράμετρος η οποία επιλέχτηκε να εκφράζει τον βαθμό φθοράς της ανόδου είναι η κατανομή της έντασης των φωτονίων της εστίας. Τυπικά υπάρχουν τρεις αντιπροσωπευτικές κατανομές φωτονίων της εστίας, η ομοιόμορφη, η απλή κανονική κατανομή (Gaussian), και η διπλή κανονική ή κανονική κατανομή δύο κορυφών(Double Gaussian). Μια άνοδος χωρίς φθορά αρχικά θεωρήθηκε να έχειμια σχεδόν κανονική κατανομή ένταση φωτονίων και μόλις η καταστροφή αρχίζει η απλή κανονική κατανομή μετατρέπεται σε διπλή κανονική. Αυτή η φθορά της ανόδου οφείλεται κυρίως στην υπερβολική χρήση της και στα υψηλά θερμικά φορτία . Για τη μελέτη της χωρικής διακριτικής ικανότητας χρησιμοποιήθηκε απότομη αιχμή(edge) πάχους 4 cm αποτελούμενη από μόλυβδο, μη διαπερατή από ακτίνες-χ, τοποθετημένη στο κέντρο του πεδίου με την κεντρική ακτίνα της δέσμης κάθετη στην αιχμή και την επιφάνεια του ακτινοβολούμενου αντικειμένου. Έπειτα για τον υπολογισμό της χωρικής διακριτικής ικανότητας υπολογίστηκε αρχικά μία συνάρτηση διασποράς ορίου (ESF) για κάθε εικόνα. Για το σκοπό αυτό μία ορθογώνια περιοχή ενδιαφέροντος επελέγη περιλαμβάνοντας 2 mm από κάθε πλευρά της αιχμής. Το προφίλ του κάθετα υπολογισμένου μέσου όρου των τιμών του grey level κατά μήκος αυτής της απόστασης αντιστοιχεί στη συνάρτηση διασποράς ορίου. Από μαθηματική παραγώγηση της συνάρτησης αυτής προέκυψε η συνάρτηση διασποράς γραμμής (LSF) και με εφαρμογή σε αυτή μετασχηματισμού Fourier καταλήγουμε στη συνάρτηση μεταφοράς διαμόρφωσης (MTF). Οι προκύπτουσες συναρτήσεις μεταφοράς διαμόρφωσης προσαρμόστηκαν με τμήμα κανονικής καμπύλης και η χωρική διακριτική ικανότητα σε lp/mm εξήχθη από αυτές, θεωρώντας ότι αντιστοιχεί στο 5% της MTF. Η συγκεκριμένη μέθοδος μέτρησης της συνάρτησης μεταφοράς διαμόρφωσης είναι πολύ δημοφιλής τελευταία λόγω της απλότητάς της και της καταλληλότητάς της, ειδικά στην ψηφιακή απεικόνιση. Μελετήσαμε την επίδραση της φθοράς της ανόδου στην χωρική διακριτική ικανότητα για δυο μεγέθη εστίας, μια 0.1mm η οποία χρησιμοποιείται στα περισσότερα μαστογραφικά μηχανήματα σήμερα και μια με μεγάλες διαστάσεις όπως 0.5mm. Η μελέτη αυτή έγινε μεταβάλλοντας κάθε φορά τα χαρακτηριστικά της απλής και διπλής κανονικής κατανομής έντασης φωτονίων της εστίας. Ουσιαστικά μεταβάλλαμε την απόσταση μεταξύ των δυο κορυφών (δμ) και την τυπική απόκλιση (σ).Με τον τρόπο αυτό πήραμε εικόνες που αντιστοιχούν κάθε φορά σε διαφορετική κατανομή των φωτονίων στην εστία και επομένως σε διαφορετικό βαθμό φθοράς της ανόδου. Όταν η απόσταση των δυο κορυφών της διπλής κανονικής κατανομής ήταν μηδέν τότε είχαμε κανονική κατανομή η οποία αντιστοιχούσε σε μια άνοδο χωρίς φθορά ενώ όταν η απόσταση των δυο κορυφών της διπλής κατανομής αυξανόταν τότε αντιστοιχούσε σε άνοδο με μεγαλύτερο βαθμό φθοράς. Τέλος διατηρώντας σταθερή την απόσταση τον δυο κορυφών μεταβάλαμε την τυπική απόκλιση της κατανομής (σ) με αποτέλεσμα και σε αυτή την περίπτωση να έχουμε ασυμπτωτική προσέγγιση τηςδιπλής κανονικής κατανομής στην απλή κανονική κατανομή της έντασης των φωτονίων της εστίας. Όταν η εστία είναι καινούργια ακόμα και με διαστάσεις 0.5 mm x 0.5 mm (οι οποίες είναι πάνω από τις τυπικές μαστογραφικές τιμές) τότε η χωρική ικανότητα είναι υψηλή και πάνω από το αποδεκτό όριο των 12 lp/mm για την συμβατική μαστογραφία και καθώς αρχίζει η φθορά της η χωρική διακριτική ικανότητα μειώνεται σε ποσοστό 4% με 8%. Αντίθετα για μεγεθυντικές λήψεις όταν αρχίζει η φθορά της ανόδου λόγο της χρήσης της η χωρική διακριτική ικανότητα γίνετε πολύ μικρή με τιμές που κυμαίνονται γύρω στο 5 lp/mm . Επομένως εστίες με μεγάλες διαστάσεις όπως 0.5 mm δεν είναι κατά κανόνα κατάλληλες για μεγεθυντική λήψη καθώς η χωρική διακριτική ικανότητα είναι πολύ μικρή ειδικά όταν αρχίζει η φθορά τους. Για την ονομαστική εστία 0.1 mm x 0.1 mm. τα αποτελέσματα καθορίζουν ότι μια φθαρμένη άνοδος δεν επηρεάζει σημαντικά την ποιότητα εικόνας στην συμβατική μαστογραφία. Η χωρική διακριτική ικανότητα διατηρείται σε υψηλές τιμές(21 lp/mm) με ασήμαντη διακύμανση (περίπου 2% με 5%) μεταξύ των αποτελεσμάτων κατά τη διάρκεια της φθοράς της. Παρόλα αυτά μια φθαρμένη άνοδος έχει σημαντικό αντίκτυπο στη χωρική διακριτική ικανότητα υπό μεγεθυντικές συνθήκες. Όταν η απόσταση των δυο κορυφών της διπλής κατανομής αυξάνει (που αντιστοιχεί σε μεγαλύτερο βαθμό φθοράς ), η χωρική διακριτική ικανότητα μειώνεται σημαντικά ακόμα και κάτω από το αποδεκτό όριο των 12 lp/mm που συνήθως χρησιμοποιείται σε κλινική πρακτική. Για τον μέγιστο βαθμό μεγέθυνσης (m=2) η σχετική υποβάθμιση ης χωρικής διακριτικής ικανότητας φτάνει το 66%. Όταν η τυπική απόκλιση (σ) των δυο κορυφών αυξάνει σε μια διπλή κατανομή με σταθερή απόσταση (δμ) μεταξύ των δυο κορυφών, τότε το αποτέλεσμα είναι η υποβάθμιση της χωρικής διακριτικής ικανότητας σχεδόν 40% (για m= 1.6 κ εστία 0.1 mm). Η επίδραση της φθοράς της ανόδου στην χωρική διακριτική ικανότητα είναι σημαντική ειδικά για μεγάλους βαθμούς μεγέθυνσης (1.6, 1.8, 2.0). Χαρακτηριστικό είναι το γεγονός ότι μια καινούργια άνοδος προκαλεί μείωση της χωρικής διακριτικής ικανότητας κατά 27%, ενώ μια φθαρμένη άνοδος προκαλεί μείωση που φτάνει το 75% καθώς αυξάνουμε την μεγέθυνση από 1 έως 2 με βήμα 0.2. Επομένως η χωρική διακριτική ικανότητα επηρεάζεται ευθέως από την μορφή την κατανομή της έντασης των φωτονίων στην εστία, η οποία προσδιορίζει και την κατάσταση που βρίσκεται η άνοδος , το μέγεθος της εστίας και την μεγέθυνση. Σανσυμπέρασμα μπορούμε να πούμε ότι μόνο εστίες με μικρές διαστάσεις όπως 0.1 mm είναι κατάλληλες για μεγεθυντική μαστογραφία. Μια φθαρμένη άνοδος με εστία 0.1 mm δεν επηρεάζει σημαντικά την χωρική διακριτική ικανότητα στην μαστογραφία επαφής, ενώ αντίθετα για την μεγεθυντική μαστογραφία(κυρίως μεγάλους βαθμούς μεγέθυνσης) η υποβάθμιση της χωρικής διακριτικής ικανότητας είναι σημαντική. Αυτό το γεγονός είναι σημαντικό για υψηλούς βαθμούς μεγέθυνσης και έτσι η αντικατάσταση της λυχνίας ακτινών–x όταν η εστία αρχίζει να φθείρεται είναι πολύ κρίσιμη καθώς μπορεί να οδηγήσει στον υποβιβασμό της χωρικής διακριτικής ικανότητας. / The aim of this study was to examine the influence of mammographic anode aging, from the construction of a perfect anode up to total damage, on spatial resolution under contact and magnification geometries. The crucial parameter that was selected to reflect the degree of damaging of the anode is the type of the x-ray intensity distribution of the focal spot. Typically, there are three representative focal spot distributions, the uniform, the Gaussian and double-peaked Gaussian. A new anode is initially considered to have an almost Gaussian intensity distribution and when the destruction starts the Gaussian distribution turns to double Gaussian distribution. This damage of anode is owed to its extended use and high thermal loads (melting), which is more apparent in the central area of the focal spot. In order to study this aging effect, the Edge Spread Function (ESF) method was utilized, with a thick sharp edge consisting of lead, no transparent to x-rays imaged under various conditions, and following the corresponding spatial resolution was calculated through the modulation transfer function (MTF). In this study we used two focal spot sizes, a 0.1mm which is using in most mammographic units today and a focal spot with big dimensions such 0.5mm. When the focal spot with dimensions 0.5mm by 0.5mm is new then the resolution is high for contact mammography, but when the anode starts damaged, the 0.5mm focal spot is unsuitably because the resolution is maintained under 10 lp/mm, especially for magnification views. Therefore focal spots with big dimensions such 0.5mm are not suitable for clinical practise and magnifications views. Results for nominal focal spot sizes of 0.1mm by 0.1mm demonstrate that a damaged anode does not significantly affect the spatial resolution in contact mammography, since even in this case the spatial resolution is maintained in high degrees with insignificant variation between the results. Nevertheless, a damage anode has important repercussions on the spatial resolution under magnification conditions. When the distance of the two peaks of double Gaussian is increased (corresponding to higher degrees of destruction) the spatial resolution is significantly decreased even under the acceptable limit of 12 lp/mm that is usually utilized in clinical practice. Furthermore, when for a double Gaussian with fixed distance (δμ) between the two peaks, the standard deviation (σ) of two peaks is increasing then it leads to the reduction of spatial resolution of almost 40% for magnification equal 1.6 and focal spot 0.1mm. Accordingly, the resolution is directly affected by the form of the intensity distribution of the anode and the magnification. This effect is dominant for high magnification degrees, and thus the replacement of the x-ray tube when the focal spot starts being destroyed is very crucial, as the tube aging can potentially lead to the degradation of spatial resolution.

The optical design of a LED illuminator and camera imaging system were studied for potential use in a small medical "robotic type" probe to be used for minimally invasive abdominal surgery. Beam shaping optical reflectors were studied to increase the intensity distribution of the LED beam directed toward a close-by target surface. A CMOS/CCD camera and lens was used to image the targeted area. In addition, extensive optical ray tracing simulations were made to predict the intensity patterns. The experimental measurements and ray tracing simulations were in good agreement, and indicated that 20 degree cone reflectors for the LED sources and appropriate micro-lens/CCD chip imaging optics should provide a useful image at a working distance of about 5 cm.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-08-23T11:35:35Z No. of bitstreams: 1 guilhermegarciamatta.pdf: 1719369 bytes, checksum: 42139fc58efd2d5ccff0c46d5eb98c7b (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-08-28T12:32:23Z (GMT) No. of bitstreams: 1 guilhermegarciamatta.pdf: 1719369 bytes, checksum: 42139fc58efd2d5ccff0c46d5eb98c7b (MD5) / Made available in DSpace on 2018-08-28T12:32:23Z (GMT). No. of bitstreams: 1 guilhermegarciamatta.pdf: 1719369 bytes, checksum: 42139fc58efd2d5ccff0c46d5eb98c7b (MD5) Previous issue date: 2018-07-27 / O objetivo deste estudo foi descrever a estratégia de pacing adotada por corredores durante uma ultramaratona de 6 horas e investigar o efeito de uma velocidade inicial lenta no desempenho, percepção subjetiva de esforço (PSE), fadiga (ROF) e alterações mecânicas. Dezesseis ultramaratonistas foram recrutados e incluídos na parte descritiva (parte 1) deste estudo. Durante a parte experimental (parte 2), 10 atletas realizaram uma terceira sessão subsequente. O estudo contou com 3 sessões de teste: 1) teste de velocidade crítica; 2) ultramaratona de 6 horas self-paced (primeira prova); e 3) ultramaratona de 6 horas com manipulação da velocidade inicial (segunda prova). Durante a primeira prova, os atletas foram instruídos a completarem uma ultramaratona de 6 horas em pista de atletismo, a fim de atingir a maior distância possível. Quatro semanas depois, os participantes foram submetidos a uma segunda ultramaratona de 6 horas, na mesma pista de atletismo e no mesmo horário do dia, na qual eles foram solicitados a correr os primeiros 36 minutos da prova (i.e. primeiros 10%) em velocidades ~18% mais baixas do que a média da velocidade inicial da primeira prova. Em ambas corridas, a PSE, ROF e mecânica de corrida foram coletadas em intervalos de tempo constantes. Os resultados mostraram que de forma geral, os atletas adotam uma estratégia de pacing com perfil sigmoide (F = 32,90; P < 0,001; ηp2 = 0,69), demonstrando um aumento linear na PSE (F = 30,27; P < 0,001; ηp2 = 0,67) e ROF (F = 56,04; P < 0,001; ηp2 = 0,79). O tempo de contato aumentou (F = 9,43; P < 0,001; ηp2 = 0,39) e o tempo de fase aérea diminuiu (F = 9,77; P < 0,001; ηp2 = 0,39) a partir de 1 hora de prova, enquanto que a amplitude de passada diminuiu (F = 9,92; P < 0,001; ηp2 = 0,40) após 2 horas e a frequência não se alterou (F = 0,90; P = 0,45; ηp2 = 0,06) durante a primeira prova. Apesar de uma velocidade média normalizada menor durante 10% de prova (P < 0,001), e maiores durante 50% (P < 0,001) e 90% (P = 0,034), o desempenho não foi diferente entre as provas (57,5 ± 10,2 vs. 56,3 ± 8,5 km; P = 0.298). No entanto, os corredores diminuíram consistentemente a PSE (F = 3,46; P < 0,001; ηp2 = 0,28) e ROF (F = 2,30; P = 0,010; ηp2 = 0,20) durante toda segunda prova. Além disso, o tempo de contato foi menor e o tempo de fase aérea maior na segunda prova, na primeira volta (P < 0,001) e 30 minutos (P < 0,004). A amplitude de passada foi menor na primeira volta (P < 0,001), com 30 minutos (P < 0,001) e 1 hora (P = 0,047), enquanto que frequência foi significativamente menor apenas com 30 minutos (P < 0,001). Diminuir a velocidade inicial de prova em ~18% pode não afetar diretamente o desempenho, mas é capaz de diminuir o desenvolvimento da PSE e ROF. Finalmente, as mecânicas de corrida parecem ser influenciadas principalmente por mudanças na velocidade. / The aim of this study was to describe the pacing strategy adopted by runners during a 6-hour ultramarathon running race and investigate whether a slow-start affect overall performance, ratings of perceived exertion (RPE), ratings of fatigue (ROF) and running mechanics. Sixteen ultrarunners were recruited and took part of the first part of this study (descriptive). During the second part (experimental), 10 participants performed a third additional testing session. The study consisted of three sessions: 1) critical speed test; 2) self-paced 6-hour ultramarathon running race; and 3) 6-hour ultramarathon with initial speed manipulation. During the first race, the athletes were instructed to achieve the greatest possible distance in a 6-hour run in an athletics track. Four weeks later, they performed a second 6-hour ultramarathon, in which they were requested to run the initial 36 minutes (i.e. first 10% of the race) at speeds ~18% below their mean speed of the initial 36 min of the first race (self-paced). During both races, RPE, ROF and running mechanics were measured in consistent time-intervals. Our results showed that, in general, athletes adopted a sigmoid pacing strategy (F = 32.90; P < 0.001; ηp2 = 0.69), increasing linearly their RPE (F = 30.27; P < 0.001; ηp2 = 0.67) and ROF (F = 56.04; P < 0.001; ηp2 = 0.79). The contact times increased (F = 9.43; P < 0.001; ηp2 = 0.39) and aerial times decreased (F = 9.77; P < 0.001; ηp2 = 0.39) after 1 hour of the race, whereas the stride length was lower (F = 9.92; P < 0.001; ηp2 = 0.40) after 2 hours and stride frequency did not change (F = 0.90; P = 0.45; ηp2 = 0.06) during the first race. Despite lower normalised mean speeds during the first 10%-time interval (P < 0.001), and greater speeds at 50% (P < 0.001) and 90% (P = 0.034) of the second race, overall performance was not different between races (57.5 ± 10.2 vs. 56.3 ± 8.5 km; P = 0,298). However, runners decreased their RPE (F = 3.46; P < 0.001; ηp2 = 0.28) and ROF consistently throughout the second race (F = 2.30; P = 0.010; ηp2 = 0.20). Moreover, contact times were higher and aerial times shorter during the second race, during the first lap (P < 0.001) and at 30 minutes (P < 0.004). The stride length was lower during the first lap (P < 0.001), 30 minutes (P < 0.001) and 1 hour (P = 0.047), whereas stride frequency was lower only at 30 minutes (P < 0.001). Decreasing initial speed by ∼18% might not affect 6-hour ultramarathon performances, but it lowers the development of RPE and ROF. Finally, running mechanics seem to be affected mainly by changes in running speed.

This dissertation thesis deals with a long range free space optical links for communication over the distance of few tens of kilometers in the atmosphere. The problematic of the beam propagation and atmospheric effects influencing the beam and the quality of the communication protocol are discussed. The measuring link is also designed to study the parameters of the communication link work conditions. The measuring link consists of two heads. The transmitter head is designed to use two optical beams with laser diodes at the wavelength of the atmospheric windows 850 or 1550 nm and the overall power of hundredths of mW. The receiver head includes the Fressnel lens. For the detection of very weak signal, the avalanche photodiode is used. In the end of this work, due to the high power of the transmitting optical beam, the laser safety conditions are also discussed, including the deduced optical transmitters construction recommendations.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-07-07T14:49:40Z No. of bitstreams: 1 Alexsander Canaparro da Silva.pdf: 655420 bytes, checksum: 0a4a34fe1ed98642d0c0e012c1799fcd (MD5) / Made available in DSpace on 2015-07-07T14:49:40Z (GMT). No. of bitstreams: 1 Alexsander Canaparro da Silva.pdf: 655420 bytes, checksum: 0a4a34fe1ed98642d0c0e012c1799fcd (MD5) Previous issue date: 2012-01-31 / Nenhuma / A indústria brasileira de calçados é parte de um cenário onde a maioria das empresas pertencentes ainda tem suas estratégias fundamentadas na incerteza do sucesso de novos produtos, uma vez que está intimamente relacionada à moda implicando assim mudanças constantes nas coleções. Entretanto, observa-se que algumas empresas buscam desenvolver estratégias que visam uma maior perenidade e, ao mesmo tempo, impõem maior dificuldade em ser seguidas pelos concorrentes, por exemplo, as relacionadas aos canais de distribuição. A intensidade de distribuição é um elemento chave nas estratégias de canal, na medida em que determina como as empresas alcançam e servem seus mercados alvo. Diante disso, fundamentado nos modelos teóricos encontrados na literatura sobre canais de distribuição, busca-se investigar, através de estudo de caso na empresa Grendene S.A., Quais são os fatores que influenciaram a intensidade da distribuição. O estudo tem por objetivos específicos analisar o nível de diversificação dos canais de marketing, bem como as estratégias e fatores que impactaram na intensidade da distribuição; e analisar quais os tipos de conflito no canal e suas implicações. Para tanto, foi desenvolvida uma pesquisa exploratória, cuja coleta de dados primários ocorreu através de entrevistas semiestruturadas em profundidade e através de observação participante, como técnica auxiliar. Os resultados encontrados mostram que diferentes estratégias foram implementadas pela empresa com o intuito de intensificar a distribuição dos produtos por ela comercializados e destacam a forma como ocorre esse processo - na medida em que a empresa está presente em diversos canais, mas não necessariamente através da sua equipe de representantes. Em relação aos antecedentes da intensidade da distribuição, as análises apontam para seis elementos: concorrência, marca, produto, estrutura, cultura e porte da empresa. Por fim, foram identificados os conflitos existentes no canal de distribuição, bem como suas implicações. / The Brazilian shoes industry is part of a scenario where most of the companies from this industry still has its strategies based on the (uncertainty of) success of new products, since it is a sector closely related to fashion, implying on constant changes in collections. However, it seems that some companies try to develop strategies aiming to achieve greater continuity while imposing greater difficulty for being followed by competitors – such as those related to distribution channels. The distribution intensity is a key element in the channel strategies, since it determines the extent to which these companies reach and serve their target markets. Therefore, based on the theoretical models existing in literature on distribution channels, we seek to investigate – through a case study at Grendene SA – what are the factors that influenced the distribution intensity. The study aims to analyze the diversification levels of marketing channels, as well as the strategies and factors that have impacted on the intensity of distribution. Moreover, it analyses what kind of conflicts that are found in the channel, as well as its implications. To that end, an exploratory research was developed based on primary data collection through semi-structured in depth interviews and through a complementary round of participant observation. The results show that different strategies were implemented by the company in order to enhance its products distribution. It also highlights how this process takes place – to the extent that the company is present in several channels, but not necessarily through its own team of representatives. Regarding the factors that influenced the distribution intensity, the analysis points to six elements: competition, brand, product, structure, culture and company size. Finally, the channel conflicts were identified, as well as its implications.

Exercise intensity and its distribution is probably the most important and most heavily debated variable of endurance training. Training induces adaptation but also induces stress responses. Controlling the training-intensity distribution may provide a mechanism for balancing these two effects. It has been reported that elite endurance athletes train with a high volume and load, relative to the sport. These athletes spend the vast majority (>80%) of training time at relatively low intensities (lower than the lactate threshold, zone one), and therefore <20% of training time above the lactate threshold (zones two and three). Experimental studies support the beneficial effects of a high training volume in zone one, and show detrimental effects of replacing zone one training with training in zone two. This is likely due to enhanced recovery from training in zone one compared with training in zone two. The acute recovery following training sessions in zones two and three has been reported to not be different, but the recovery following training in zone one has been reported to be faster. Improvements in physiological adaptation and endurance performance have been reported to be greater following training programmes with higher exercise intensities. Therefore, it has been suggested that a polarised training model, which includes ~80% of training in zone one with ~20% of training in zone three is more beneficial than a threshold training model, with the majority of training in zone two. However, research into an optimal training-intensity distribution is limited. Therefore, the aims of this thesis were to assess the effectiveness of training-intensity distribution on the improvements in physiological adaptation, endurance performance and assess if manipulating training-intensity distribution had an effect on immune function. Study one revealed that the lactate threshold, the lactate turnpoint and maximal performance measures in swimming, cycling and running, assessed using the methods outlined in the study, are reproducible in trained endurance athletes. These tests can therefore be used by trained endurance athletes as part of a physiological testing programme to assess not only endurance performance, but also to demarcate training intensity zones for exercise intensity prescription and monitor moderate to large adaptations to training. Practitioners should take care when deciding on the duration between tests to test for adaptations from training, as adaptations need to be greater than these detected test-retest variations to be considered physiologically meaningful. To the best of the author’s knowledge, study two was the first study to have assessed training-intensity distribution in a group of multisport athletes. Training was monitored over a 6-month period, and testing took place every two months to assess the effect of the training on physiological adaptation. Although speculative due to the number of variables involved, the results suggest that a greater proportion of training time spent in zone one and a lower proportion of training time spent in zone two is beneficial to physiological adaptation. However, given the number of variables associated with assessing the training-intensity distribution in multisport athletes, it is not easy to draw conclusions as to the effectiveness of the training in the different disciplines on the key measures of adaptation in the different disciplines. Study two highlighted the need for future research to focus on experimental manipulation of training-intensity distribution and thus improve our understanding of its impact on the training-induced adaptations in endurance athletes. Study three manipulated the training-intensity distribution in trained endurance athletes in just one discipline, to reduce the number of variables involved. A polarised training model was compared to a threshold training model on the effectiveness to improve physiological adaptation and endurance performance. Results revealed that a polarised training model is recommended for trained cyclists wishing to maximally improve performance and physiological adaptation over a short-term (six week) training period. The first part of study four assessed the effect of a polarised and a threshold training model on immune function markers in trained cyclists. Both endurance training programmes had similar volume, and were sufficient to induce improvements in performance and physiological adaptation. However, despite likely differences in recovery, both training programmes had no effect on the proportion of low or high differentiated or senescent CD8+ or CD4+ T-cells in blood. Therefore, training adaptation was achieved at no cost to this particular aspect of immune function. From these results and evidence from previous studies, it seems likely that athletes need to be overreached to induce any change in immune function following a period of intensified training. The second part of study four assessed the impact of an ironman triathlon race on Epstein-Barr virus (EBV) and Varicella-Zoster virus (VZV) antibody titres and the frequency of low and high differentiated and senescent blood T-cells in trained endurance athletes. Previous work has revealed that an ironman triathlon race increases the proportion of senescent CD4+ T cells and decreases the proportion of naive CD4+ T cells, and thus induces changes the immune space which could leave an individual at a greater risk of infection. This study however, did not find any changes in the proportions of these T cell subsets following an ironman triathlon race. The mean results of this study suggest that there is no relationship between EBV and VZV-specific antibody concentrations and the proportion of senescent, low and highly differientiated T cells. However, on analysis of individual subject data, it seems possible that subjects with a high antibody titre for EBV or VZV 3 wks before a competition might be more at risk of infection post race. A greater subject number would be needed in order to make a more conclusive statement about this relationship. The results of this thesis suggest that future research is required in the area of training-intensity distribution. Firstly, our understanding of the physiological mechanisms responsible for the effectiveness of a polarised training model in trained endurance athletes is limited, and thus studies should attempt to address this issue. Our current knowledge on the mechanisms underlying a blunted T cell response following strenous exercise is also limited. A change in the immune space to a greater proportion of senescent T cells and a lower proportion of naive T cells might contribute to this blunted response. In the current thesis however, the proportions of these T cell markers were unchanged following the training/racing interventions. It is possible that with a higher training load, there could be changes in these markers, and thus this is an exciting area that could have potential implications on athlete health. Finally, testing for antibody titres in endurance athletes is possibly an avenue to detect individuals at the greatest risk of infection if subjected to a large physical and/or mental stress. This could have implications on maintaining athlete health and therefore, allowing athletes to train consistently.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-22T14:27:00Z No. of bitstreams: 1 arthurhenriquesouzanetobossi.pdf: 861040 bytes, checksum: c3c1cec3feee16cacb22f14eb9d27f1c (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: on 2017-06-22T14:35:05Z (GMT) / Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-22T14:39:20Z No. of bitstreams: 1 arthurhenriquesouzanetobossi.pdf: 861040 bytes, checksum: c3c1cec3feee16cacb22f14eb9d27f1c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-07T19:21:44Z (GMT) No. of bitstreams: 1 arthurhenriquesouzanetobossi.pdf: 861040 bytes, checksum: c3c1cec3feee16cacb22f14eb9d27f1c (MD5) / Made available in DSpace on 2017-08-07T19:21:44Z (GMT). No. of bitstreams: 1 arthurhenriquesouzanetobossi.pdf: 861040 bytes, checksum: c3c1cec3feee16cacb22f14eb9d27f1c (MD5) Previous issue date: 2014-08-22 / Para maior empregabilidade do protocolo de teste contra-relógio (CR) de 20 min em campo, é necessária a compreensão (1) de como o desempenho em percurso de subida se relaciona com as medidas laboratoriais típicas e (2) do perfil de pacing adotado. Separados por pelo menos 48 horas, 15 ciclistas moderadamente treinados, incluindo 1 do sexo feminino (30,8±4,8 anos; 176,5±8,0 cm; 78,9±14,5 kg; 56,1±7,7 ml.kg-1.min-1; média ± desvio padrão), realizaram inicialmente um teste anaeróbio Wingate, um teste de esforço incremental até a exaustão e um contrarelógio de campo por 20 min em percurso de subida com 2,7% de inclinação média. Após 5 semanas de treinamento não supervisionado, 10 dos 15 voluntários realizaram um segundo CR para comparação do pacing adotado. As regressões lineares múltiplas stepwise demonstraram que 91% da variação na potência média produzida no CR (W.kg-1) pode ser explicada pelo pico do consumo de oxigênio (ml.kg-1.min-1) e pelo ponto de compensação respiratória (W.kg-1), com coeficientes beta padronizados de 0,64 e 0,39 respectivamente. A realização do CR em aclive pressupõe um ajuste de 94,6% da potência média, de modo a aperfeiçoar a concordância com a potência referente ao ponto de compensação respiratória, em que o diagrama de Bland-Altman demonstrou um viés ± erro aleatório de 0,4±49,7 W ou -0,1±19,7 %. A ANOVA two-way (CR X tempo) para medidas repetidas revelou efeito principal dos intervalos de tempo (p < 0,001) na potência média produzida em cada trecho (122,2±10,0; 97,8±1,2 e 95,1±7,1% para os trechos 0-2, 2-18 e 18-20 min, respectivamente) caracterizando perfil de pacing positivo, tanto no primeiro, quanto no segundo teste (p = 0,116). Em conjunto, estas informações indicam que o protocolo de teste CR de 20 min realizado em subida, aparentemente, seja robusto para monitorar o desempenho de ciclistas de diferentes níveis competitivos. Entretanto, novos estudos mais específicos são importantes para confirmar a reprodutibilidade do desempenho e para verificar a influência do feedback instantâneo da potência produzida. / For a wider applicability of the 20-min time trial (TT) testing protocol in field, it is necessary to understand (1) how performance in an uphill course relates with typical laboratory measures and (2) the pacing profile adopted. Separated by at least 48 hours, 15 moderately trained cyclists, including 1 female (30.8±4.8 years; 176.5±8.0 cm; 78.9±14.5 kg; 56.1±7.7 ml.kg-1.min-1; mean ± standard deviation), initially performed a Wingate anaerobic test, a graded exercise test to exhaustion and a 20-min field time trial in a 2.7% gradient uphill course. After 5 weeks of nonsupervised training, 10 from 15 volunteers performed a second TT for comparison of the pacing adopted. Stepwise multiple linear regressions demonstrated that 91% of TT mean power output variation (W.kg-1) can be explained by peak oxygen consumption (ml.kg-1.min-1) and respiratory compensation point (W.kg-1), with standardized beta coefficients of 0.64 and 0.39 respectively. Performing TT on ascents premises a 94.6% mean power output adjustment in order to improve the agreement with respiratory compensation point power output, which Bland-Altman plot showed a bias ± random error of 0.4±49.7 W or -0.1±19.7 %. Repeated measures two-way ANOVA (TT X time) revealed a main effect of the time intervals (p < 0.001) on the power output of each portion (122.2±10.0; 97.8±1.2 e 95.1±7.1% for the portions 0-2, 2-18 e 18-20 min, respectively) characterizing a positive pacing profile, either in the first and in the second test (p = 0.116). Together, this information indicates that the 20-min TT testing protocol performed on ascent is apparently robust for performance monitoring of different competitive level cyclists. However, more specific new studies are important to confirm performance reproducibility and to verify the influence of power output instant feedback.

This Master’s thesis solves a design and construction of device for gathering and transfer of data into computer. The device should replace graph plotter, by which is measured the optical intensity of a laser beam. From this characteristic it is possible to determine other parameters of the laser beam, such as halfwidth of the beam, angle of divergence and Rayleigh length. The described device - “data gatherer” - measures two voltage values – voltage detected on photodiode and voltage detected on distance moved by photodiode. Measured values of voltage are processed and sent through a serial line into the computer. A pre-amplifier is connected to the control part for both channels of measured values with possibility of amplification. Computer application, which performs graphic interpretation of the measured values, serves as user control peripheral. The product of this project is compact device operating under OS Windows with graphic output.