In order to provide the means to set up a control theory lab experiment involving position control of a brushed DC motor with current feedback, a pulse-width modulated motor controller was designed. The output voltage is controlled by an analog reference signal and the magnitude of the output current and voltage are measured and output. These inputs and outputs are connected to a DAQ I/O-unit such that the lab experiment can be implemented digitally. In addition, defining equations for the whole system were derived. Comparison between measurements and model showed it possible to use the current as feedback if low-pass filtered and the angular displacement controlled over a small angular interval.

The increase in the consumption of energy year after year emphasizes the importance of power production by photovoltaic (PV) systems. Despite an increase in the use of PV systems, accurate solar power [kWh] daily harvest predicting data are not readily available. Accurate predicted solar power data is necessary because the data is helpful to designers who need to optimally size a PV panel before installation. Moreover, accurately predicted max dc power can indicate whether the PV panel is operating efficiently and economically or not. This thesis develops an approach to predict max solar power based on a Linear Regression model. The approach, which ia a simple regression was implemented using measured data on a response variable, a max solar power (Pmax), and predictor variables such as Global Horizontal (GH), Plane of Array (PA), Short Circuit Current (Isc), Open Circuit Voltage (Voc), and Panel Temperature (Temp). The statistical results of the linear regression model produced reasonable values which agreed with those of the measured data from the solar panel. / text

This thesis explores ceremonial entries in Renaissance France from the perspective of the townspeople who designed and produced them. Existing studies of French entries have tended to see them as expressions of monarchical power, with townspeople coming in submission before the majesty of the king. In contrast, this thesis demonstrates that ceremonial entries were nuanced civic ceremonies which demonstated urban pride and power. Chapter 1 details the weeks of preparations that went into staging a civic reception and the townspeople’s numerous efforts to ensure that the entry was a success. Chapter 2 examines the extramural greeting, where the civic council and other notables came out of the town in procession to greet the visitor and make the formal welcoming speech. The extramural greeting was an important part of the ceremony, as it was the first point of personal contact between the urban elite and the dignitary. The intramural procession is discussed in chapter three. During this part of the ceremony, the dignitary entered through the town gate and processed through the streets until they reached the town’s principal church, where a short service was held. The urban fabric was decorated with flowers, linens, triumphal arches and other decorative structures, while theatrical performances were staged along the length of the processional route. The streets were thronged with ordinary townspeople who had come to both watch and participate in the ceremony. Chapter 4 is concerned with the post-entry festivities, which included banquets, further processions and jousting. The exchange of gifts between the royal guest and the town council was an important element of the post-entry ceremonies, as it was the occasion when the civic councillors could win significant new economic grants for the crown in return for providing a valuable item of silverware.

Τα κινητήρια συστήματα των χαρτοποιητικών μηχανών που παράγουν τα λεπτά χαρτιά (tissue), σύμφωνα με τα εμπειρικά στοιχεία, παρουσιάζουν διάφορα ηλεκτρικά και μηχανικά προβλήματα, τα οποία μπορούν να αποδοθούν στις μεθόδους που χρησιμοποιούνται για το μέχρι τώρα σχεδιασμό τους. Η παρούσα διατριβή στοχεύει στην επίλυση των προβλημάτων αυτών. Τα προβλήματα αυτά είναι η άνιση κατανομή του μηχανικού φορτίου μεταξύ των δύο κινητήρων του ιδίου τμήματος, η υπερφόρτωση του ενός εκ των δύο κυρίων τμημάτων της χαρτοποιητικής μηχανής και η πλήρης διακοπή της λειτουργίας της, και η εμφάνιση φαινομένων μηχανικού συντονισμού ή ενίσχυσης των ροπών των αξόνων που οδηγούν στην καταστροφή του πολυκινητηρίου συστήματος. Για την επίτευξη του στόχου γίνεται ανάλυση των σημερινών δομών των πολυκινητηρίων συστημάτων των χαρτοποιητικών μηχανών λεπτών χαρτιών και αναδεικνύονται τα προβλήματα των. Προτείνεται η αλλαγή της δομής και νέος σχεδιασμός του πολυκινητήριου συστήματος των χαρτοποιητικών μηχανών λεπτών. Γίνεται ανάλυση του κινητηρίου συστήματος του στεγνωτικού τυμπάνου με δύο κινητήρες συνεχούς ρεύματος με κοινό μηχανικό φορτίο και εξομοίωση με MATLAB/SIMULINK χωρίς ελαστικούς άξονες. Εξετάζεται η συμπεριφορά του συστήματος αυτού με ελαστικούς άξονες μέσω εξομοίωσης. Προτείνεται μία μέθοδος ελέγχου για την κατανομή του συνολικού φορτίου στο πολυκινητήριο σύστημα και γίνεται ανάλυση της στατικής και της δυναμικής συμπεριφοράς μέσω εξομοίωσης. Επίσης εξετάζεται η ορθότητα της μεθόδου ελέγχου στην περίπτωση σφαλμάτων σε μία γέφυρα τροφοδοσίας. Για την αντιμετώπιση των μηχανικών προβλημάτων που ανακύπτουν γίνεται διεξοδική ανάλυση ταλαντώσεων. Χρησιμοποιώντας τον προτεινόμενο σχεδιασμό και τις προτεινόμενες μεθόδους ελέγχου επιτυγχάνεται κατανομή του μηχανικού φορτίου σύμφωνα με την ονομαστική ισχύ των κινητήρων μέσα στο ίδιο τμήμα και αντιμετωπίζεται πλήρως η υπερφόρτιση του ενός από τα δύο κύρια τμήματα της μηχανής και έτσι αποφεύγεται η πλήρης διακοπή της λειτουργίας της. Από την ανάλυση των ταλαντώσεων προκύπτει η δυνατότητα να δίνονται κατευθυντήριες γραμμές για την επιλογή των καταλλήλων κινητήρων και των καταλλήλων αξόνων, δηλ. τη σωστή διαστασιολόγιση του συστήματος. / The drive systems of tissue paper machines present various electrical and mechanical problems according to empirical data, which can be attributed to the used design methods. The present thesis aims at solving of such problems. The problems are: the partial treatment of the load sharing in sections, where two motors drive the same mechanical load, the overloading of one of the two main sections of the machine and the interruption of its operation when these sections are mechanically engaged. Concerning the mechanical part of the drive, problems arise due to torsional oscillations created by the resonance phenomena or the shafts torque amplification. In order to achieve the aim, an analysis is carried out of the current structure of the drive systems and the problems due to this structure are brought out. A modified structure and a new design of the drive system are proposed. A control method is proposed to share the load between the two DC motors of the same section and investigation, analysis and simulation of a drive are carried out. The behavior of the drive with elastic shafts is examined. In order to face the overloading of one of the two main sections of the paper machine, a control method is proposed to share the total load to the two main sections of the machine and an analysis of the steady state and dynamic behavior through simulation is carried out. The correctness of this control method is examined in the case of typical faults in one of the power converters. In order to face the mechanical problems an exhaustive analysis is carried out concerning torsional oscillations. Using the proposed design and control methods, the load sharing, according to the nominal power of the motors, is assured for the sections where two motors drive the same mechanical load. The overloading of one of the two sections is completely faced and the interruption of the machine operation is avoided. Torsional oscillations analysis emerges that guidelines can be given for the selection of suitable shafts and motors, namely the correct dimensioning of the system.

The objective of the research is to develop a cost-effective high-power bi-directional dc/dc converter with low total-device ratings, reduced system parasitic effects, and a wide input/output range. Additional objectives of the research are to develop a small-signal model and control methods, and to present performance characterizations. Device stresses in the proposed topology are controlled to maintain minimal levels by varying the duty ratio and phase-shift angle between the primary and the secondary bridges, which results in a low total-device rating, when compared to conventional bi-directional dc/dc topologies. In the proposed topology, soft switching, which reduces power loss, can be realized under specific operating conditions. When the condition that causes minimal device stress is satisfied, zero-voltage switching (ZVS) can be obtained. In the research, ZVS capability is explored for a wide range of voltage conditions as well as for the minimal device-stress condition. The performance characterization includes verifying the soft-switching regions and power-loss estimation. Another part of the thesis is the controller design of the converter. Small-signal models and feedback controllers are developed, and the controllers are experimentally validated. Because in the isolated high-frequency converters, transformer saturation is an important issue, a method to prevent transformer saturation is proposed and experimentally validated.

No description available.

Based on the form-invariant of Maxwell’s equations under coordinate transformations, we extend the theoryof transformation optics to transformation magneto-statics, which can design magnets through coordinatetransformations. Some novel DC magnetic field illusions created by magnets (e.g. rescaling magnets,cancelling magnets and overlapping magnets) are designed and verified by numerical simulations. Ourresearch will open a new door to designing magnets and controlling DC magnetic fields. / <p>QC 20141105</p>

No description available.

This study analyses the evolution of France's relations with Iraq since 1958. It seeks to understand the motivations behind French government, state and private sector interests in Iraq. This is done in the dual context of France's economic rivalry with other western powers in the Middle East, and the Iraqi state's attempts to follow an independent foreign policy while using its oil revenues to rapidly industrialise and arm itself. The text first charts France's rivalry with Britain in the ex-Ottoman empire and its fears of Anglo-American domination of oil supplies. It then demonstrates that while France's early links with Israel continued under President De Gaulle, by the mid sixties they had been eclipsed by the commercial importance of trade with Arab states. The core text then focuses on France's relationship with Iraq since 1958, the year in which new governments came to power in both states. Despite the 1972 nationalisation of the Iraq Petroleum company, in which France had a 25% stake, French politicians and businessmen nevertheless gained favourable access to oil supplies, greatly increasing their exports of defence and high technology products, including a nuclear reactor, to Iraq during the seventies. The Iran-Iraq war (1980-88) intensified both bilateral trade links and the indebtedness of Iraq to France. By the mid-eighties what become a de-facto alliance generated severe problems for France's middle eastern policies, particularly towards Iran. The central themes of the study are the processes of foreign policy formation in France, and the extent and impact of economic interests underlying policy making. The thesis argues that substantial state ownership in France's oil, defence and aeronautical industries, coupled with the common interests and interpretations of a relatively homogeneous and interconnected corps of businessmen, politicians and civil servants, helps explain the continuity of French policy in the region. This is seen to be true despite the change of government (from Gaullist to Socialist) in France in May 1981.

Although historians have acknowledged the importance of gender as a factor in the social and political life of post-revolutionary France, and bibliographical studies have revealed that vast quantities of memoirs were composed during the half century after the outbreak of the Revolution, the lives of women between the late 1790s and the 1830s, and the works in which they wrote about their lives and about the age in which they lived, have hitherto attracted relatively little attention from literary critics and historians. Previous research, moreover, has concentrated on women as writers of poetry and fiction, on the portrayal of women in novels, and on their position in society as it was defined by legislators, doctors, philosophers and the authors of manuals on female education and conduct. As a result, the diversity of women's writing and the complexity of their lives as historical subjects during this period have often been obscured. It is this diversity and complexity which are revealed by studying memoirs. This thesis examines women's memoirs from both a literary and a historical perspective, focusing on the relationship between gender, genre and historical circumstances. It argues that women wrote memoirs and wrote them in the way they did because of the political and social conditions of the age in which they lived. A short introduction outlines the reasons why the memoirs written by women in the first decades of the nineteenth century have been neglected: the preoccupation of literary scholars with memoirs of the ancien regime; the memoir's apparent lack of depth compared to 'true' or 'literary' autobiography; the weakness of most women's memoirs as sources of information on political and military affairs for the Revolution and Empire; and the narrow focus of recent women-centred histories. The rest of the thesis is an attempt to fill in some of these gaps.