Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: G. Tong Zhou; Committee Co-Chair: Xiaoli Ma; Committee Member: David V. Anderson; Committee Member: James Stevenson Kenney; Committee Member: Liang Peng; Committee Member: William D. Hunt. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references.

Thesis (Ph.D.) - University of St Andrews, September 2008. / Electronic version restricted until 16th September 2009.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 116-117). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 116-117). Also available on the Internet.

Στην παρούσα Διπλωματική Εργασία εξετάζεται η ακουστική ποιότητα της κεντρικής αίθουσας (Ι1) του Συνεδριακού και Πολιτιστικού Κέντρου του Πανεπιστημίου Πατρών1. Η ακουστική παρά- μετρος που ερευνάται είναι η ”Ενόχληση από ηχώ”. Για τον σκοπό αυτό αναπτύχθηκε αλγόριθμος στο περιβάλλον MATLAB που υλο- ποιεί το Κριτήριο Ενόχλησης από Ηχώ που διατύπωσαν οι Dietsch and Kraak[1] γνωστό και ως Echo Disturbance Criterion ή δείκτης EK. Για τις ανάγκες της διπλωματικής εργασίας πραγματοποιήθηκαν μετρήσεις κρουστικών αποκρίσεων σε διάφορες θέσεις στην πλατεία της αίθουσας με παντοκατευθυντικό μικρόφωνο και με την αμφιωτική διάταξη της κούκλας KEMAR. Επίσης χρησιμοποιήθηκαν κρουστικές αποκρίσεις από προσομοίωση στο πρόγραμμα ακουστικής προσομοίωσης CATT-Acoustic, για τις διάφορες θέσεις. Στη συνέχεια οι κρουστικές αναλύονται από τον αλγόριθμο και εξάγονται τα διαγράμματα με τα κρίσιμα όρια εφαρμογής του κριτηρίου. Τέλος γίνεται η σύγκριση ανάμεσα στις κρουστικές που λάβαμε από το μοντέλο και από τις μετρήσεις. Όπως φαίνεται υπάρχουν σχετικές διαφορές ανάμεσά τους. Οι μετρήσεις τονίζουν κάποια προβλήματα που στην πράξη δεν υφίστανται. / -

Magnetic resonance imaging is a routine and powerful diagnostic technique capable of providing detailed information about the structure and composition of the tissues. This diploma thesis is concerned with the mechanisms of contrast origin and contrast modifications by molecular and nanoparticle contrast agents. First sections of the thesis summarize basic knowledge about pulse sequences and it aims to provide an overview on MRI contrast agent with a special emphasis on paramagnetic gadolinium contrast agents and superparamagnetic nanoparticles. The main purpose of this study is to develop the software called MRICalc, which is able to optimize contrast in MRI images. Based on analysis of signal formula of typical pulse sequences, MRICalc is able to propose the parameters of the pulse sequence for compartment-specific enhancement of the contrast. User chooses from the list of the samples and after calculation he obtains the values of echo time, repetition time and flip angle, all of which simultaneously seem to create the appropriate setting to enhance the contrast. MRICalc also allows to plot contrast function with respect to the chosen parameter. Software, including its graphical user interface, is designed in Python. The sample consists from solution of CuSO4 and distilled water was designed to verify the correct function of MRICalc. Sulphate represents a contrast agent. Preclinical MR system Bruker BioSpec 94/30 USR located at Institute of Scientific Instruments of the ASCR, v.v.i was used to measure contrast curve of FLASH pulse sequence, which is a typical representative of gradient echo. Results of the measurement were compared to the theoretical model provided by MRICalc.

The aim of my work is to comment on the issue of narcissism, which is marked as an epidemic of our time. Narcissism is mostly psychological phenomenon and its generalization to society is difficult. In my preparatory studies on this topic within sociology, I could not find any solution, that would offer a change of position. In my attempt to achieve this, I went back to the original myth.

The task of this thesis is to study the subject of perfusion analysis based on dynamic imaging with T2/T2* contrast. The focus was on the acquisition commonly used for DSC-MRI and especially in the acquisition pulse sequences that use images with different echo time, so called Multi-echo sequence. Principles of dynamic measurement by magnetic resonance imaging, the role of contrast agents and their influence on the relaxation times are described. It also describes the problems perfusion analysis, measurement and mathematical modeling parameters entering to the convolution dependency for getting perfusion parametersIn the experimental part is developed automatic algorithm to gain curves relaxation time T2 *. Next, the synthetic data are created and tested robustness estimate perfusion parameters against noise. In the next phase of work there are compared real scanned objects with using a conversion with T2 * and free of T2*. In the last phase of work is compared influence of length of used echo times on concentration curves and after perfusion analysis influence on resulting perfusion parameters.

Dub reggae is widely regarded as an early form of the remix. Dub artists modify previously recorded reggae songs by manipulating a song's individual tracks with a mixing board and layering them in aural effects such as reverb and echo. These effects are fundamentally spatial in quality, giving the listener an impression of vast open space. This paper is an analysis of the techniques utilized in dub's construction of sonic space as well as an investigation of the cultural meaning of those spaces. My analysis utilizes Josh Kun's theories about "audiotopias" (temporary aural spaces created through music) in order to study how sonic spaces create "new maps" that allow an individual to analyze their current social predicament. These "new maps," therefore, engender a "remapping" of reality, a reconstitutive process that parallels dub's emphasis on modification and alteration. This paper also argues that dub's audiotopias are implicitly natural, although they are constructed through modern recording technologies such as the echo chamber and the reverb unit. A final chapter applies these analytical techniques to one of dub's most popular musical offspring, hip hop.