The technique of cooperative communications is finding its way in the next generations of many wireless communication applications. Due to the distributed nature of cooperative networks, acquiring fading channels information for coherent detection is more challenging than in the traditional point-to-point communications. To bypass the requirement of channel information, differential modulation together with non-coherent detection can be deployed. This thesis is concerned with various issues related to differential modulation and non-coherent detection in cooperative networks. Specifically, the thesis examines the behavior and robustness of non-coherent detection in mobile environments (i.e., time-varying channels). The amount of channel variation is related to the normalized Doppler shift which is a function of user’s mobility. The Doppler shift is used to distinguish between slow time-varying (slow-fading) and rapid time-varying (fast-fading) channels. The performance of several important relay topologies, including single-branch and multi-branch dual-hop relaying with/without a direct link that employ amplify-and-forward relaying and two-symbol non-coherent detection, is analyzed. For this purpose, a time-series model is developed for characterizing the time-varying nature of the cascaded channel encountered in amplify-and-forward relaying. Also, for single-branch and multi-branch dual-hop relaying without a direct link, multiple-symbol differential detection is developed. First, for a single-branch dual-hop relaying without a direct link, the performance of two-symbol differential detection in time-varying Rayleigh fading channels is evaluated. It is seen that the performance degrades in rapid time-varying channels. Then, a multiple-symbol differential detection is developed and analyzed to improve the system performance in fast-fading channels. Next, a multi-branch dual-hop relaying with a direct link is considered. The performance of this relay topology using a linear combining method and two-symbol differential detection is examined in time-varying Rayleigh fading channels. New combining weights are proposed and shown to improve the system performance in fast-fading channels. The performance of the simpler selection combining at the destination is also investigated in general time-varying channels. It is illustrated that the selection combining method performs very close to that of the linear combining method. Finally, differential distributed space-time coding is studied for a multi-branch dual-hop relaying network without a direct link. The performance of this network using two-symbol differential detection in terms of diversity over time-varying channels is evaluated. It is seen that the achieved diversity is severely affected by the channel variation. Moreover, a multiple-symbol differential detection is designed to improve the performance of the differential distributed space-time coding in fast-fading channels.

The search for the closest lattice point arises in many communication problems, and is known to be NP-hard. The Maximum Likelihood (ML) Detector is the optimal detector which yields an optimal solution to this problem, but at the expense of high computational complexity. Existing near-optimal methods used to solve the problem are based on the Sphere Decoder (SD), which searches for lattice points confined in a hyper-sphere around the received point. The SD has emerged as a powerful means of finding the solution to the ML detection problem for MIMO systems. However the bottleneck lies in the determination of the initial radius. This thesis is concerned with the detection of transmitted wireless signals in Multiple-Input Multiple-Output (MIMO) digital communication systems as efficiently and effectively as possible. The main objective of this thesis is to design efficient ML detection algorithms for MIMO systems based on the depth-first search (DFS) algorithms whilst taking into account complexity and bit error rate performance requirements for advanced digital communication systems. The increased capacity and improved link reliability of MIMO systems without sacrificing bandwidth efficiency and transmit power will serve as the key motivation behind the study of MIMO detection schemes. The fundamental principles behind MIMO systems are explored in Chapter 2. A generic framework for linear and non-linear tree search based detection schemes is then presented Chapter 3. This paves way for different methods of improving the achievable performance-complexity trade-off for all SD-based detection algorithms. The suboptimal detection schemes, in particular the Minimum Mean Squared Error-Successive Interference Cancellation (MMSE-SIC), will also serve as pre-processing as well as comparison techniques whilst channel capacity approaching Low Density Parity Check (LDPC) codes will be employed to evaluate the performance of the proposed SD. Numerical and simulation results show that non-linear detection schemes yield better performance compared to linear detection schemes, however, at the expense of a slight increase in complexity. The first contribution in this thesis is the design of a near ML-achieving SD algorithm for MIMO digital communication systems that reduces the number of search operations within the sphere-constrained search space at reduced detection complexity in Chapter 4. In this design, the distance between the ML estimate and the received signal is used to control the lower and upper bound radii of the proposed SD to prevent NP-complete problems. The detection method is based on the DFS algorithm and the Successive Interference Cancellation (SIC). The SIC ensures that the effects of dominant signals are effectively removed. Simulation results presented in this thesis show that by employing pre-processing detection schemes, the complexity of the proposed SD can be significantly reduced, though at marginal performance penalty. The second contribution is the determination of the initial sphere radius in Chapter 5. The new initial radius proposed in this thesis is based on the variable parameter α which is commonly based on experience and is chosen to ensure that at least a lattice point exists inside the sphere with high probability. Using the variable parameter α, a new noise covariance matrix which incorporates the number of transmit antennas, the energy of the transmitted symbols and the channel matrix is defined. The new covariance matrix is then incorporated into the EMMSE model to generate an improved EMMSE estimate. The EMMSE radius is finally found by computing the distance between the sphere centre and the improved EMMSE estimate. This distance can be fine-tuned by varying the variable parameter α. The beauty of the proposed method is that it reduces the complexity of the preprocessing step of the EMMSE to that of the Zero-Forcing (ZF) detector without significant performance degradation of the SD, particularly at low Signal-to-Noise Ratios (SNR). More specifically, it will be shown through simulation results that using the EMMSE preprocessing step will substantially improve performance whenever the complexity of the tree search is fixed or upper bounded. The final contribution is the design of the LRAD-MMSE-SIC based SD detection scheme which introduces a trade-off between performance and increased computational complexity in Chapter 6. The Lenstra-Lenstra-Lovasz (LLL) algorithm will be utilised to orthogonalise the channel matrix H to a new near orthogonal channel matrix H ̅.The increased computational complexity introduced by the LLL algorithm will be significantly decreased by employing sorted QR decomposition of the transformed channel H ̅ into a unitary matrix and an upper triangular matrix which retains the property of the channel matrix. The SIC algorithm will ensure that the interference due to dominant signals will be minimised while the LDPC will effectively stop the propagation of errors within the entire system. Through simulations, it will be demonstrated that the proposed detector still approaches the ML performance while requiring much lower complexity compared to the conventional SD.

Τα συστήματα πολλαπλών κεραιών στον πομπό και στο δέκτη (MIMO) αποτελούν βασικά μέτωπα ανάπτυξης των ασύρματων επικοινωνιών. Ωστόσο, η εφαρμογή της τεχνολογίας MIMO στα κινητά δίκτυα επικοινωνιών αντιμετωπίζει το πρακτικό πρόβλημα της ενσωμάτωσης πολλαπλών κεραιών σε μικρά κινητά τερματικά. Με σκοπό την αντιμετώπιση του εμποδίου αυτού, δημιουργήθηκε ένα άλλο σημαντικό μέτωπο έρευνας, αυτό των συνεργατικών επικοινωνιών. Στο πλαίσιο της παρούσας διδακτορικής διατριβής ασχοληθήκαμε με την ανάπτυξη και μελέτη αλγορίθμων επεξεργασίας σήματος για τα δύο παραπάνω συστήματα. Σχετικά με τα συστήματα MIMO η πρωτοποριακή έρευνα που πραγματοποιήθηκε στα Bell labs στα μέσα της δεκαετίας του ΄90, απέδειξε ότι η χρήση πολλαπλών κεραιών μπορεί να οδηγήσει σε σημαντική αύξηση της χωρητικότητας των ασύρματων συστημάτων βελτιώνοντας την αξιοπιστία της μετάδοσης. Προκειμένου να αξιοποιηθούν οι παραπάνω δυνατότητες απαιτείται η σχεδίαση σύνθετων δεκτών MIMO. Προς αυτήν την κατεύθυνση έχει στραφεί ένας μεγάλος αριθμός μεθόδων ισοστάθμισης του καναλιού και πιο συγκεκριμένα δεκτών ανατροφοδότησης αποφάσεων. Δεδομένου ότι σε ευρυζωνικά συστήματα επικοινωνιών το ασύρματο κανάλι είναι άγνωστο στο δέκτη και μεταβάλλεται χρονικά, στραφήκαμε προς τις προσαρμοστικές μεθόδους ισοστάθμισης. Στα πλαίσια της διαριβής αναζήτησαμε προσαρμοστικούς αλγόριθμους κατάλληλους για τη σχεδίαση προσαρμοστικών ισοσταθμιστών MIMO DFE με τα εξής χαρακτηριστικά: 1) να παρουσιάζουν απόδοση (ταχύτητα σύγκλισης) συγκρίσιμη με αυτή του RLS, 2) η υπολογιστική τους πολυπλοκότητα να είναι μικρότερη από αυτή του RLS και 3) να είναι αριθμητικά ευσταθείς. ΄Εχει αποδειχθεί ότι προσαρμοστικοί αλγόριθμοι που βασίζονται στη μέθοδο των συζυγών κλίσεων (conjugate gradient (CG)) πληρούν τις παραπάνω προϋποθέσεις. Αρχικά αναζητήσαμε τεχνικές που βασίζονται στη μέθοδο αυτή και χρησιμοποιούνται σε προβλήματα προσαρμοστικού φιλτραρίσματος και πιο ειδικά, στο πρόβλημα προσαρμοστικής ισοστάθμισης διαύλου στη περίπτωση SISO. Πιο συγκεκριμένα, υλοποιήσαμε έναν προσαρμοστικό αλγόριθμο στο πεδίο των συχνοτήτων που επεξεργάζεται τα δεδομένα κάθε φορά που λαμβάνεται ένα νέο εισερχόμενο πακέτο δεδομένων. Ο προτεινόμενος ισοσταθμιστής πετυχαίνει μια πολύ καλή απόδοση, ενώ οι υπολογιστικές του απαιτήσεις είναι πολύ χαμηλές. Στη συνέχεια αναπτύξαμε τρεις νέους αλγορίθμους προσαρμοστικής ισοστάθμισης συχνοτικά επιλεκτικών συστημάτων MIMO, που βασίζονται στη μέθοδο CG και στις προβολές Galerkin. Το πρόβλημα σχεδιασμού προσαρμοστικών MIMO DFE αντιμετωπίζεται ως ένα πρόβλημα επίλυσης γραμμικών εξισώσεων, με πολλαπλά δεξιά μέλη, που εξελίσσεται στο χρόνο. Επισημαίνουμε ότι τα σχήματα που προτείνουμε θα μπορούσαν να αποτελέσουν ένα γενικότερο πλαίσιο σχεδίασης προσαρμοστικών δεκτών για συχνοτικά επιλεκτικά συστήματα MIMO, με ιδιότητες σύγκλισης παρόμοιες με αυτές του RLS, έχοντας, ωστόσο, μικρότερες υπολογιστικές απαιτήσεις. Στα πλαίσια της παρούσας διδακτορικής διατριβής αναπτύξαμε τεχνικές εκτίμησης καναλιού για συνεργατικά δίκτυα με N αναμεταδότες που είτε ενισχύουν και αναμεταδίδουν ή αποκωδικοποιούν και αναμεταδίδουν το λαμβανόμενο σήμα. ΄Ολες οι τεχνικές εκτίμησης που προτείναμε υλοποιούνται εξ΄ ολοκλήρου στο πεδίο των συχνοτήτων. Αρχικά παρουσιάσαμε τεχνικές που βασίζονται στη μετάδοση πιλοτικών συμβόλων σε συγκεκριμένες συχνοτικές συνιστώσες. Στη συνέχεια αποδείξαμε ότι όλα τα κανάλια από την πηγή μέσω των αναμεταδοτών προς τον προορισμό μπορούν να εκτιμηθούν τυφλά εάν γνωρίζουμε τις φάσεις της απόκρισης συχνότητας του ασύρματου καναλιού μεταξύ πηγής και προορισμού.. Επιπρόσθετα, πραγματοποιήθηκε ϑεωρητική ανάλυση της απόδοσης των προτεινόμενων σχημάτων η οποία επαληθεύτηκε μέσω προσομοιώσεων σε υπολογιστή. Τέλος, αξιολογήσαμε πειραματικά διάφορα πρωτόκολλα συνεργατικής επικοινωνίας (AF, DF, SF) και τεχνικές κατανεμημένης χωροχρονικής επεξεργασίας DSTC για συνεργατικά δίκτυα σε μια πλατφόρμα υλοποίησης πραγματικού χρόνου που χρησιμοποιεί επεξεργαστές ψηφιακής επεξεργασίας σήματος. Διαπιστώσαμε ότι τα πειραματικά αποτελέσματα συμφωνούν πλήρως με τα θεωρητικά. / Systems employing multiple antennas at the transmitter and the receiver, known as MIMO (multiinput multioutput) systems, as well as space time coding techniques developed for such systems, are two of the main technologies employed for the evolution of wireless communications. However, the application of MIMO technology to mobile networks, often faces the practical implementation problem of having too many antennas on a small mobile terminal. In an attempt to overcome such a severe limitation, cooperative communication schemes have been proposed. This PhD dissertation, described our work on the design and analysis of signal processing algorithms for the two aforementioned systems, as is described in detail next. Concerning MIMO systems, the pioneering work performed at Bell Labs in the middle of the nineties, proved that the use of multiple antennas can lead to a significant increase in wireless systems capacity. To exploit this potential, sophisticated MIMO receivers should be designed. To this end, a large amount of channel equalizers and, more specifically, decision feedback equalizers has been proposed. Because these assumptions are difficult to meet in high rate single carrier systems, we have focused our attention on decision feedback equalizers. . Our main goal is to derive algorithms for updating the MIMO DFE filters with the following characteristics: 1) convergence properties similar to these of the RLS 2) more computationally efficient than RLS and 3) numerically stable. It is known that adaptive algorithms based on the CG (conjugate gradient) have the above characteristics We initially studied this method as an iterative method for solving linear equations and we pointed out the main differences with the steepest descent method, on which the LMS algorithm is based. An extended search of adaptive DFE algorithms, based on the CG method was carried out. More specifically, a new block adaptive CG algorithm was developed. In the resulting algorithm, one CG iteration per block update is executed. In order to reduce even more the complexity, the algorithm was implemented in the Frequency Domain. The proposed equalizer offers a good performance - complexity trade off. Three new adaptive equalization algorithms for wireless systems operating over frequency selective MIMO channels, based on the CG method and the Galerkin projection method, are proposed. The problem of MIMO decision feedback equalizer (DFE) design is formulated as a set of linear equations with multiple righthand sides (RHSs) evolving in time. These schemes provide a flexible framework in MIMO adaptive equalization design to implement schemes with convergence properties comparable to the RLS, but of lower computational cost. Furthermore, we worked on channel estimation for cooperative communication networks, where the nodes either simply amplify and forward the received signal, or they decode and transmit the signal (DF). We first propose efficient channel estimation techniques for relay networks with N relays. The new methods are implemented in the frequency domain (FD). Initially, training based techniques are presented, where the training pilots are multiplexed with the data in the frequency domain. It is then shown that all the channels in the network can be estimated blindly provided that we know the phases of the frequency response of the (Source → Destination) channel. Thus, by making use of a small number of pilots in only one link (the sourcetodestination link) we can estimate all the other channels (Source→Relay i→Destination) in the network. A theoretical performance study of the proposed algorithms is presented and closed form expressions for the mean squared channel estimation error are provided. The presented theoretical analysis is verified by extensive Monte Carlo simulations. The application of the derived schemes to the DF case, and the impact of erroneous detection to their performance are also studied. Finally, we investigated experimentally four cooperative relaying schemes: amplify and forward (AF), detect and forward (DF), cooperative maximum ratio combining (CMRC) and distributed spacetime coding (DSTC), and one novel selection relaying (SR) scheme on a realtime DSP based testbed. The experimental results are fairly close to the ones predicted by theory

Στο πλαίσιο αυτής της διατριβής μελετάται η επίδοση συστημάτων διαφορισμού MIMO σε γενικευμένα κανάλια διαλείψεων. Αρχικά, εξετάζεται η επίδοση των OSTBC σε περιβάλλοντα διαλείψεων Hoyt. Αποδεικνύεται ότι, στην περίπτωση τέτοιων συστημάτων, ο σηματοθορυβικός λόγος (signal to noise ratio, SNR) εκφράζεται ως μία τετραγωνική μορφή κανονικών τυχαίων μεταβλητών και γίνεται χρήση της συνάρτησης πυκνότητας πιθανότητας και της αθροιστικής συνάρτησης κατανομής αυτής της μορφής για τον υπολογισμό των μετρικών επίδοσης. Επιπλέον, μελετάται η σύγκλιση των σειρών που χρησιμοποιούνται για τον υπολογισμό των δύο αυτών συναρτήσεων και κατασκευάζονται νέα άνω φράγματα για το σφάλμα αποκοπής των σειρών. Τα φράγματα αυτά είναι σαφώς πιο αυστηρά από τα ήδη γνωστά από τη βιβλιογραφία. Στη συνέχεια, εισάγεται ένα γενικευμένο μοντέλο διαλείψεων για την ανάλυση επίδοσης των OSTBC και των δεκτών MRC και υπολογίζονται όλες οι μετρικές επίδοσης των δύο συστημάτων για το συγκεκριμένο μοντέλο διαλείψεων. Το μοντέλο αυτό περιλαμβάνει ως ειδικές περιπτώσεις τα πλέον διαδεδομένα μοντέλα καναλιών διαλείψεων, ενώ επιπλέον, επιτρέπει την ανάλυση επίδοσης σε μικτά περιβάλλοντα διαλείψεων όπου τα πολλαπλά κανάλια μπορούν να ακολουθούν διαφορετικές κατανομές. Στη συνέχεια, μελετάται η επίδοση συστημάτων συνεργατικού διαφορισμού με χρήση αναμεταδοτών ανίχνευσης και προώθησης (Detect and Forward, DaF) σε περιβάλλοντα διαλείψεων Rayleigh. Εξετάζονται τρεις διαφορετικοί δέκτες και υπολογίζεται η πιθανότητα σφάλματος ανά bit γι' αυτούς. Τέλος προτείνεται ένας νέος δέκτης για συνεργατικά συστήματα DaF και αποδεικνύεται η ανωτερότητά του σε σύγκριση με τους υπόλοιπους μελετώμενους δέκτες. Όλα τα θεωρητικά αποτελέσματα που παρουσιάζονται στο πλαίσιο της διατριβής συγκρίνονται με αποτελέσματα προσομοιώσεων Monte Carlo που αποδεικνύουν την ορθότητα της ανάλυσης. / This thesis studies the performance of MIMO diversity systems in generalized fading channels. First, we examine the performance of OSTBC in Hoyt fading channels. It is proven that, for this fading model, and when an OSTBC is employed, the signal-to-noise ratio (SNR) of the OSTBC can be expressed as a quadratic form in normal random variables. Therefore, the performance analysis for OSTBC over Hoyt fading channels is performed using the PDF and the CDF of such quadratic forms. In the statistical literature, these functions are expressed in terms of infinite series. The convergence of the series is thoroughly studied and new expressions for the truncation error bound of these series are proposed. The proposed bounds are much tighter than the bounds that can be found in the literature. The expressions for the PDF and the CDF are then used for the performance analysis of OSTBC over Hoyt fading and several performance metrics are calculated. Then, a generalized fading model for the performance analysis of OSTBC and MRC is proposed and the theoretical performance analysis of both MRC and OSTBC is carried out. The main advantage of this model is the fact that it includes as special cases most of the widely used fading models. Furthermore, the performance of cooperative diversity systems employing Detect and Forward (DaF) relays is studied for Rayleigh fading channels. More specifically, three low complexity detection algorithms for these channels are examined and closed-form expressions of the bit error probability (BEP) for these receivers are derived. Finally, a new low complexity receiver for cooperative systems with DaF relays is proposed. Using Monte Carlo Simulations it is shown that this receiver outperforms the three receivers that have been studied. For the systems studied in the thesis, the performance analysis results that have been derived theoretically are compared with Monte Carlo simulations that prove the validity of the analysis.

Le travail présenté dans cette thèse concerne la mise en oeuvre numérique de techniques temporelles pour des applications en compatibilité électromagnétique (CEM) impulsionnelle, essentiellement pour des études en chambre réverbérante à brassage de modes (CRBM). Prenant le contre-pied des approches fréquentielles, adaptées par nature aux études de cavités résonantes, l’idée directrice de ce mémoire a été d’étudier des moyens temporels originaux d’investigation de CRBM en vue de proposer de nouveaux paradigmes pour la caractérisation d’équipements. Originellement développé en acoustique, le processus de retournement temporel (RT) récemment appliqué aux ondes électromagnétiques permet une focalisation spatiale et temporelle de ces dernières d’autant meilleur que le milieu de propagation est réverbérant. Les chambres réverbérantes (CR) sont ainsi des endroits idéaux pour l’application du processus de RT. Après une nécessaire étude des nombreux paramètres qui gouvernent ce dernier couplée à la définition de méthodologies numériques spécifiques, les applications du RT en CRBM sont exposées. En particulier, l’intérêt d’une focalisation sélective pour des tests en susceptibilité rayonnée est démontré. L’importance des coefficients d’absorption et de diffraction des équipements en CRBM justifie leur caractérisation précise et efficace. À cette fin, la mise en oeuvre d’un calcul temporel de section efficace totale de diffraction (TSCS en anglais) est détaillée. L’application de cette nouvelle technique à différentes formes de brasseurs de modes permet au final de confronter ces résultats avec ceux obtenus à l’aide de tests normatifs CEM. / The work presented in this thesis concerns the use of time techniques for impulsive ElectroMagnetic Compatibility (EMC) applications, mainly for Modes Stirred Reverberation Chamber (MSRC) studies. Contrary to approaches from frequency domain, obviously well-fitted for studies in resonant cavities, the main idea of this thesis was to study an original time method for MSRC investigation to propose new paradigms for equipment characterization. Originally developed in acoustics, the Time Reversal (TR) process recently applied to electromagnetic waves allows focusing it both in time and space. The process quality is even higher if the propagation environment is reverberant. Thus, the Reverberation Chambers (RC) are an ideal locations for TR implementation. After a study of parameters involved in the TR process coupled with the definition of specific numerical methods, the applications of TR in MSRC are exposed. In particular, the interest of selective focusing for radiated susceptibility tests is demonstrated. The importance of absorption and diffraction coefficients for MSRC equipment justifies their accurate and efficient characterization. To this end, the implementation of a temporal calculation of the Total Scattering Cross Section (TSCS) in RC is detailed. The application of this new technique to different forms of stirrers allows finally to face these results with those obtained from standard EMC test.

Title: Fluid-structure interaction of compressible flow Author: RNDr. Jaroslava Hasnedlová Department: Department of Numerical Mathematics, Institute of Applied Mathematics Supervisors: Prof. RNDr. Miloslav Feistauer, DrSc., Dr. h. c., Prof. Dr. Dr. h. c. Rolf Rannacher Supervisors' e-mail addresses: feist@karlin.mff.cuni.cz, rannacher@iwr.uni-heidelberg.de Abstract: The presented work is split into two parts. The first part is devoted to the theory of the discontinuous Galerkin finite element (DGFE) method for the space-time discretization of a nonstationary convection-diffusion initial-boundary value problem with nonlinear convection and linear diffusion. The DGFE method is applied sep- arately in space and time using, in general, different space grids on different time levels and different polynomial degrees p and q in space and time discretization. The main result is the proof of error estimates in L2 (L2 )-norm and in DG-norm formed by the L2 (H1 )-seminorm and penalty terms. The second part of the thesis deals with the realization of fluid-structure interaction problem of the compressible viscous flow with the elastic structure. The time-dependence of the domain occupied by the fluid is treated by the ALE (Arbitrary Lagrangian-Eulerian) method, when the compress- ible Navier-Stokes equations are formulated in...

Parental monitoring of settings is not always relevant for the prevention of adolescent crime because adolescents with strong personal moral rules and the ability to exercise self control are unlikely to offend even when they are unsupervised and know that their parents have little knowledge about their activities. Parental monitoring, commonly operationalised as parental supervision or parental knowledge, is often shown to have a negative relationship with crime involvement. However, research often ignores both the mechanism by which these relationships occur and the conditions under which they might (and might not) be found. This thesis uses specialist Space-Time Budget data (from the Peterborough Adolescent and Young Adult Development Study) to allow the comparison of adolescent crime rates in settings characterised by the of convergence of i) the physical presence or absence of parents and other guardians, ii) the psychological presence or absence of parents (represented by adolescent-perceived generalised parental knowledge of the circumstances of unsupervised activity) and iii) personal crime propensity (moral rules and ability to exercise self control). The conclusion derived from the results is that the physical presence of parents and other guardians in settings reduces the rate of adolescent crime committed in those settings; and the psychological presence of parents reduces the criminogenic impact of unsupervised time. Crucially however, these effects of parental monitoring are almost irrelevant for adolescents with a lower personal crime propensity, who are not likely to offend in settings irrespective of the physical or psychological absence of parents and other guardians. These findings provide support for person-environment interactions inherent in the causal model of Situational Action Theory, and provide a novel addition to evidence that could be used in future to inform policy-relevant recommendations concerning parenting behaviour and adolescent offending. Although this thesis provides new evidence about the relationship between parental monitoring and crime, the bulk of its contribution is relevant to a much wider audience. It contributes to the debate on approaches to the study of crime and crime prevention, adds clarity to key concepts and develops theoretical arguments in the field of parental monitoring and crime, develops a novel application of Situational Action Theory, extends theoretical and methodological discussions surrounding situational analysis, applies novel data and analytical methods to the study of the psychological and physical presence of guardians, generates and situates unique findings about the situational role of aspects of parental monitoring and crime, and makes some policy recommendations and suggestions about the nature and direction of future research.

Made available in DSpace on 2011-05-04T12:42:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2009 / (...) O objetivo desta tese foi modelar os fatores de risco associados à ocorrência de leptospirose urbana em diferentes contextos, com especial atenção para aspectos espaciais e temporais. Foram utilizadas técnicas de modelagem tais como, modelos generalizados aditivos e mistos. Também explorou-se técnicas de detecção de aglomerados espaço-temporais. (...) / Leptospirosis, a disease caused by pathogenic spirochete of the genus Leptospira, is one of the most widespread zoonoses in the world, considered a major public health problem associated with the lack of sanitation and poverty. It is endemic in Brazil, data from surveillance show that outbreaks of leptospirosis occur as cyclical annual epidemics during rainfalls. The aim of this thesis was modeling the risk factors associated with the occurrence of leptospirosis in di erent urban contexts, with particular attention to spatial and temporal aspects. We used some modeling techniques such as generalized additive and mixed models. Techniques for detection space-time clusters were also explored. This thesis has prioritized the use of free softwares - R, ubuntu linux operating system, LATEX , SatScan (this is not open source but free). This thesis was prepared in the form of three articles. In the rst article is presented a spatio-temporal analysis of leptospirosis cases occurrence in Rio de Janeiro between 1997 and 2002. Using the detection of space-time clusters - \outbreaks" method - were statistically signi cant only cluster ocorred in 1997 and 1998. Generalized Linear Mixed Models were used to evaluate the risk factors associated with the occurrence of cases that belonged to outbreaks in endemic cases. The cases belonging to the outbreaks are associated with the occurrence of rainfall over 4 mm (OR, 3.71; 95% CI, 1.83 - 7.51). There were no signi cant associations with socioeconomic covariates, in other words, being endemic or epidemic leptospirosis occurs in the same population. The second and third articles examined a seroprevalence survey and seroconversion cohort conducted in Pau da Lima community, Salvador, Bahia. In both Generalized Additive Models were used to t the exposure variables both in individuals and peridomicile context, as well as to estimate the spatial area of leptospirosis risk. The signi cant variables were: gender, age, presence of rats in the peridomicile, domicile near a trash collectin or an open sewer and domicile altitude above sea level. Studies show that individual and contextual variables explain much of the spatial variability of leptospirosis, but there are still factors that were not measured in the studies but which should be investigated. The maps of risk of seroprevalence and seroconversion show distinct regions where the spatial e ect is signi cantly di erent from the global average. It is still lack for a more robust integration between the professionals who develop and operate the GIS, epidemiologists and biostatistics. This integration represents an important advance enabling the development and use of these techniques in Public Health support. The study of prevalence and incidence of endemic areas, in the leptospirosis context, it is very complex and still grow up. The reunion of professional specialists from several areas of human knowledge (eg, clinicians, epidemiologists, geographers, biologists, statisticians, engineers, etc.), it is essential to advance the knowledge about the disease and their relationship to social inequality and environmental well to contribute to the creation of efficient and e ective measures to control endemic diseases.

A presente pesquisa tem como objetivo compreender como se constituem as práticas musicais realizadas fora da aula de música, nos espaços/tempos do/no Conservatório Estadual de Música "Dr. José Zóccoli de Andrade” de Ituiutaba-MG. O aluno desse Conservatório é visto como um ser social, tecido por inúmeras características ligadas ao seu contexto sociocultural, e que têm relação direta com suas práticas musicais nessa escola de música. A partir de um olhar ligado às teorias do cotidiano, pretendeu-se também compreender quais eram essas práticas musicais, como aconteciam e se organizavam nos espaços/tempos em que os alunos estavam no Conservatório, mas, fora da aula de música, em espaços/tempos como corredores, pátio, hall e, até mesmo, na própria sala de aula, horários vagos, recreios, horários burlados, entre outros. O olhar teórico dirigido para essas práticas está fundamentado em alguns conceitos das teorias do cotidiano, sobretudo na perspectiva de Pais (2003); da música e da educação musical como prática social, na visão de Souza (2000, 2004, 2009); nas ideias de Brougère (2012) sobre aprendizagem no cotidiano; e nos conceitos de espaços/tempos, de Lindón (2000). Em uma abordagem qualitativa, o estudo de caso foi o método adotado nesta pesquisa, e os procedimentos de coleta de dados foram observações e entrevistas com alunos. Como conclusão, os alunos se organizam de diferentes formas para realizarem essas práticas musicais, algumas delas de forma prevista e outras não previstas, de formas individuais e/ou compartilhadas, e subsidiadas pela execução e escuta musical. As práticas musicais realizadas nos espaços/tempos livres da aula de música são ações importantes no contexto diversificado dessa escola de música, e que contribui para o entendimento dos processos de ensino/aprendizagem musical nesse Conservatório. / The present research aims at understanding how the musical practices are carried out outside music classes in the space/time in the State Conservatory of Music "Dr. José Zôccoli de Andrade" of Ituiutaba-MG. The student of this Conservatory are seen as social beings made of numerous characteristics due to their socio-cultural context, which is directly related to their musical practices in the school of music. From the point of view related everyday life theories, it was intended to also understand what those musical practices were and how they used to happen and to be organized in space/time when students are at the Conservatory but out of music class in space/time like hallways, patio, hall and even the classroom itself, free time between classes, at the unofficial break time, among others. The theoretical view directed to these practices is based on some concepts of theories of everyday life from the perspective of Pais (2003), of music education as social practice in the vision of Souza (2000, 2004, 2009), the ideas of Brougère (2012) about learning in daily life, and in the concepts of space/time of Lindôn (2000). In a qualitative approach, the case study was the method adopted in this research, and data collection procedures were observations and interviews with students. It is concluded that the students are organized in different ways to perform these musical practices, some of them expected and not expected, individual or/and shared ways and grounded on performances and musical listening. The musical practices carried out in the space/free time music class are important actions in the context of this diversified School of music, and that contributes to the understanding of the teaching/learning processes in the musical Conservatory. / Dissertação (Mestrado)

This thesis presents the development of a Sensor Tower Platform (STP) comprised of an array of Passive Infra-Red (PIR) sensors along with a classification algorithm that enables the STP to distinguish between human intrusion, animal intrusion and clutter arising from wind-blown vegetative movement in an outdoor environment. The research was motivated by the aim of exploring the potential use of wireless sensor networks (WSNs) as an early-warning system to help mitigate human-wildlife conflicts occurring at the edge of a forest. While PIR sensors are in commonplace use in indoor settings, their use in an outdoor environment is hampered by the fact that they are prone to false alarms arising from wind-blown vegetation. Every PIR sensor is made up of one or more pairs of pyroelectric pixels arranged in a plane, and the orientation of interest in this thesis is one in which this plane is a vertical plane, i.e., a plane perpendicular to the ground plane. The intersection of the Field Of View (FOV) of the PIR sensor with a second vertical plane that lies within the FOV of the PIR sensor, is called the virtual pixel array (VPA). The structure of the VPA corresponding to the plane along which intruder motion takes place determines the form of the signal generated by the PIR sensor. The STP developed in this thesis employs an array of PIR sensors designed so as to result in a VPA that makes it easier to discriminate between human and animal intrusion while keeping to a small level false alarms arising from vegetative motion. The design was carried out in iterative fashion, with each successive iteration separated by a lengthy testing phase. There were a total of 5 design iterations spanning a total period of 14 months. Given the inherent challenges involved in gathering data corresponding to animal intrusion, the testing of the SP was carried out both using real-world data and through simulation. Simulation was carried out by developing a tool that employed animation software to simulate intruder and animal motion as well as some limited models of wind-blown vegetation. More specifically, the simulation tool employed 3-dimensional models of intruder and shrub motion that were developed using the popular animation software Blender. The simulated output signal of the PIR sensor was then generated by calculating the area of the 3-dimensional intruder when projected onto the VPA of the STP. An algorithm for efficiently calculating this to a good degree of approximation was implemented in Open Graphics Library (OpenGL). The simulation tool was useful both for evaluating various competing design alternatives as well as for developing an intuition for the kind of signals the SP would generate without the need for time-consuming and challenging animal-motion data collection. Real-world data corresponding to human motion was gathered on the campus of the Indian Institute of Science (IISc), while animal data was recorded at a dog-trainer facility in Kengeri as well as the Bannerghatta Biological Park, both located in the outskirts of Bengaluru. The array of PIR sensors was designed so as to result in a VPA that had good spatial resolution. The spatial resolution capabilities of the STP permitted distinguishing between human and animal motion with good accuracy based on low-complexity, signal-energy computations. Rejecting false alarms arising from vegetative movement proved to be more challenging. While the inherent spatial resolution of the STP was very helpful, an alternative approach turned out to have much higher accuracy, although it is computationally more intensive. Under this approach, the intruder signal, either human or animal, was modelled as a chirp waveform. When the intruder moves along a circular arc surrounding the STP, the resulting signal is periodic with constant frequency. However, when the intruder moves along a more likely straight-line path, the resultant signal has a strong chirp component. Clutter signals arising from vegetative motion does not exhibit this chirp behavior and an algorithm that exploited this difference turned in a classification accuracy in excess of 97%.