565 research outputs found

    Paula Dronen Receives Michigan Advising Award

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    Euroamericanism. Subject & Chaos

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    Philosophy always unites the divided: the finite and the infinite, the fathomable and the unfathomable, created and creator, Man and God. Whenever I think, my thought unites what must remain divided: immanence and transcendence, consistency and inconsistency, European originality and American horizontality. Art and philosophy indicate the contingent nature of reality. They generate resistance against established realities and the dispositives that organize them. Their aim is not to flee from reality but rather to intensify contact with reality by maintaining a distance from it.This work was published in a book funded by national funds through FCT - Fundação para a CiĂȘncia e a Tecnologia, I.P., within the project UIDB/04041/2020 (Centro de Estudos Arnaldo AraĂșjo)info:eu-repo/semantics/publishedVersio

    Euroamericanism

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    Philosophy always unites the divided: the finite and infinite, fathomable and unfathomable, created and creator, Man and God. Whenever I think, my thought unites what must remain divided: immanence and transcendence, consistency and inconsistency, European originality and American horizontality. Art and philosophy indicate the contingent nature of reality. They generate resistance against established realities and the dispositives that organize them. Their aim is not to flee from reality but rather to intensify contact with reality by maintaining a distance to it.info:eu-repo/semantics/publishedVersio

    A Phenomological Study: The Adventist Musician Experience

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    What is the experience of a Seventh-day Adventist professional classical musician? Both Seventh-day Adventists and classical musicians have been the subjects of numerous studies in past decades; however, few to none of those studies have focused on individuals who identify as both. The current study seeks to better understand the experiences of Adventist musicians within their church and within the wider classical music community. Interviews were conducted with five musicians using an initial and a follow-up set of questions. Themes were identified from interview transcripts by a content analysis. Several predicted themes were confirmed such as the experience of one’s career as a ‘calling’, as well as Adventist musicians’ value of excellence and service. Contrary to expectations, Sabbath observance was not seen as a major obstacle. The discovered primary themes included a tension of values, identity realization, caution towards the broader Adventist Church, and a suppressed vision of connection and collaboration. Some limitations on the results and conclusions of this study were the small sample of subjects and the large number of different topic categories addressed. Further research is suggested to explore if the current study’s findings remain consistent when more subjects’ interviews are added to the data pool, and if further understanding can be gained by refining or modifying the interview questions

    Analysis and Design of a Sub-THz Ultra-Wideband Phased-Array Transmitter

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    This thesis investigates circuits and systems for broadband high datarate transmitter systems in the millimeter-wave (mm-wave) spectrum. During the course of this dissertation, the design process and characterization of a power efficient and wideband binary phase-shift keying (BPSK) transmitter integrated circuit (IC) with local oscillator (LO) frequency multiplication and 360° phase control for beam steering is studied. All required circuit blocks are designed based on the theoretical analysis of the underlying principles, optimized, fabricated and characterized in the research laboratory targeting low power consumption, high efficiency and broadband operation. The phase-controlled push-push (PCPP) architecture enabling frequency multiplication by four in a single stage is analytically studied and characterized finding an optimum between output power and second harmonic suppression depending on the input amplitude. A PCPP based LO chain is designed. A circuit is fabricated establishing the feasibility of this architecture for operation at more than 200 GHz. Building on this, a second circuit is designed, which produces among the highest saturated output powers at 2 dBm. At less than 100 mW of direct current (DC) power consumption, this results in a power-added efficiency (PAE) of 1.6 % improving the state of the art by almost 30 %. Phase-delayed and time-delayed approaches to beam steering are analyzed, identifying and discussing design challenges like area consumption, signal attenuation and beam squint. A 60 GHz active vector-sum phase-shifter with high gain of 11.3 dB and output power of 5 dBm, improving the PAE of the state of the art by a factor of 30 achieving 6.29 %, is designed. The high gain is possible due to an optimization of the orthogonal signal creation stage enabled by studying and comparing different architectures leading to a trade off of lower signal attenuation for higher area consumption in the chosen electromagnetic coupler. By combining this with a frequency quadrupler, a phase steering enabled LO chain for operation at 220 GHz is created and characterized, confirming the preceding analysis of the phase-frequency relation during multiplication. It achieves a power gain of 21 dB, outperforming comparable designs by 25 dB. This allows the combination of phase control, frequency multiplication and pre-amplification. The radio frequency (RF) efficiency is increased 40-fold to 0.99 %, with a total power consumption of 105 mW. Motivated by the distorting effect of beam squint in phase-delayed broadband array systems, a novel analog hybrid beam steering architecture is devised, combining phase-delayed and time-delayed steering with the goal of reducing the beam squint of phase-delayed systems and large area consumption of time-delayed circuits. An analytical design procedure is presented leading to the research finding of a beam squint reduction potential of more than 83 % in an ideal system. Here, the increase in area consumption is outweighed by the reduction in beam squint. An IC with a low power consumption of 4.3 mW has been fabricated and characterized featuring the first time delay circuit operating at above 200 GHz. By producing most of the beam direction by means of time delay the beam squinting can be reduced by more than 75 % in measurements while the subsequent phase shifter ensures continuous beam direction control. Together, the required silicon area can be reduced to 43 % compared to timedelayed systems in the same frequency range. Based on studies of the optimum signal feeding and input matching of a Gilbert cell, an ultra-wideband, low-power mixer was designed. A bandwidth of more than 100 GHz was achieved exceeding the state of the art by 23 %. With a conversion gain of –13 dB, this enables datarates of more than 100 Gbps in BPSK operation. The findings are consolidated in an integrated transmitter operating around 246 GHz doubling the highest published measured datarates of transmitters with LO chain and power amplifier in BPSK operation to 56 Gbps. The resulting transmitter efficiency of 7.4 pJ/bit improves the state of the art by 70 % and 50 % over BPSK and quadrature phaseshift keying (QPSK) systems, respectively. Together, the results of this work form the basis for low-power and efficient next-generation wireless applications operating at many times the datarates available today.:Abstract 3 Zusammenfassung 5 List of Symbols 11 List of Acronyms 17 Prior Publications 19 1. Introduction 21 1.1. Motivation........................... 21 1.2. Objective of this Thesis ................... 25 1.3. Structure of this Thesis ................... 27 2. Overview of Employed Technologies and Techniques 29 2.1. IntegratedCircuitTechnology................ 29 2.2. Transmission Lines and Passive Structures . . . . . . . . 35 2.3. DigitalModulation ...................... 41 3. Frequency Quadrupler 45 3.1. Theoretical Analysis of Frequency Multiplication Circuits 45 3.2. Phase-Controlled Push-Push Principle for Frequency Quadrupling.......................... 49 3.3. Stand-alone Phase-Controlled Push-Push Quadrupler . 60 3.4. Phase-Controlled Push-Push Quadrupler based LO-chain with High Output Power ............... 72 9 4. Array Systems and Dynamic Beam Steering 91 4.1. Theoretical Analysis of BeamSteering. . . . . . . . . . . 95 4.2. Local Oscillator Phase Shifting with Vector-Modulator PhaseShifters......................... 107 4.3. Hybrid True-Time and Phase-Delayed Beam Steering . 131 5. Ultra-Wide Band Modulator for BPSK Operation 155 6. Broadband BPSK Transmitter System for Datarates up to 56 Gbps 167 6.1. System Architecture ..................... 168 6.2. Measurement Technique and Results . . . . . . . . . . . 171 6.3. Summary and performance comparison . . . . . . . . . 185 7. Conclusion and Outlook 189 A. Appendix 195 Bibliography 199 List of Figures 227 Note of Thanks 239 Curriculum Vitae 241Diese Dissertation untersucht Schaltungen und Systeme fĂŒr breitbandige Transmittersysteme mit hoher Datenrate im Millimeterwellen (mm-wave) Spektrum. Im Rahmen dieser Arbeit werden der Entwurfsprozess und die Charakterisierung eines leistungseffizienten und breitbandigen integrierten Senders basierend auf binĂ€rer Phasenumtastung (BPSK) mit Frequenzvervielfachung des Lokaloszillatorsignals und 360°-Phasenkontrolle zur Strahlsteuerung untersucht. Alle erforderlichen Schaltungsblöcke werden auf Grundlage von theoretischen Analysen der zugrundeliegenden Prinzipien entworfen, optimiert, hergestellt und im Forschungslabor charakterisiert, mit den Zielen einer niedrigen Leistungsaufnahme, eines hohen Wirkungsgrades und einer möglichst großen Bandbreite. Die phasengesteuerte Push-Push (PCPP)-Architektur, welche eine Frequenzvervierfachung in einer einzigen Stufe ermöglicht, wird analytisch untersucht und charakterisiert. Dabei wird ein Optimum zwischen Ausgangsleistung und UnterdrĂŒckung der zweiten Harmonischen des Eingangssignals in AbhĂ€ngigkeit von der Eingangsamplitude gefunden. Es wird eine LO-Kette auf PCPP-Basis entworfen. Eine Schaltung wird prĂ€sentiert, die die Machbarkeit dieser Architektur fĂŒr den Betrieb bei mehr als 200 GHz nachweist. Darauf aufbauend wird eine zweite Schaltung entworfen, die mit 2 dBm eine der höchsten publizierten gesĂ€ttigten Ausgangsleistungen erzeugt. Mit einer Leistungsaufnahme von weniger als 100mW ergibt sich ein Leistungswirkungsgrad (PAE) von 1.6 %, was den Stand der Technik um fast 30 % verbessert. Es werden phasenverzögerte und zeitverzögerte AnsĂ€tze zur Steuerung der Strahlrichtung analysiert, wobei Entwicklungsherausforderungen wie FlĂ€chenverbrauch, SignaldĂ€mpfung und Strahlschielen identifiziert und diskutiert werden. Ein aktiver Vektorsummen-Phasenschieber mit hoher VerstĂ€rkung von 11.3 dB und einer Ausgangsleistung von 5 dBm, der mit einer PAE von 6.29 % den Stand der Technik um den Faktor 30 verbessert, wird entworfen. Die hohe VerstĂ€rkung ist zum Teil auf eine Optimierung der orthogonalen Signalerzeugungsstufe zurĂŒckzufĂŒhren, die durch die Untersuchung und den Vergleich verschiedener Architekturen ermöglicht wird. Bei der Entscheidung fĂŒr einen elektromagnetischen Koppler rechtfertigt die geringere SignaldĂ€mpfung einen höheren FlĂ€chenverbrauch. Durch die Kombination mit einem Frequenzvervierfacher wird eine LO-Kette mit Phasensteuerung fĂŒr den Betrieb bei 220 GHz geschaffen und charakterisiert, was die vorangegangene Analyse der Phasen-FrequenzBeziehung wĂ€hrend der Multiplikation bestĂ€tigt. Sie erreicht einen Leistungsgewinn von 21 dB und ĂŒbertrifft damit vergleichbare Designs um 25dB. Dies ermöglicht die Kombination von Phasensteuerung, Frequenzvervielfachung und VorverstĂ€rkung. Der HochfrequenzWirkungsgrad wird um das 40-fache auf 0.99 % bei einer Gesamtleistungsaufnahme von 105 mW gesteigert. Motiviert durch den verzerrenden Effekt des Strahlenschielens in phasengesteuerten Breitbandarraysystemen, wird eine neuartige analoge hybride Strahlsteuerungsarchitektur untersucht, die phasenverzögerte und zeitverzögerte Steuerung kombiniert. Damit wird sowohl das Strahlenschielen phasenverzögerter Systeme als auch der große FlĂ€chenverbrauch zeitverzögerter Schaltungen reduziert. Es wird ein analytisches Entwurfsverfahren vorgestellt, das zu dem Forschungsergebnis fĂŒhrt, dass in einem idealen System ein Potenzial zur Reduktion des Strahlenschielens von mehr als 83 % besteht. Dabei wird die Zunahme des FlĂ€chenverbrauchs durch die Verringerung des Strahlenschielens aufgewogen. Es wird ein IC mit einer geringen Leistungsaufnahme von 4.3mW hergestellt und charakterisiert. Dabei wird die erste Zeitverzögerungsschaltung entworfen, die bei ĂŒber 200 GHz arbeitet. Durch die Erzeugung eines Großteils der Strahlrichtung mittels Zeitverzögerung kann das Schielen des Strahls bei Messungen um mehr als 75% reduziert werden, wĂ€hrend der nachfolgende Phasenschieber eine kontinuierliche Steuerung der Strahlrichtung gewĂ€hrleistet. Insgesamt kann die benötigte SiliziumflĂ€che im Vergleich zu zeitverzögerten Systemen im gleichen Frequenzbereich auf 43 % reduziert werden. Auf der Grundlage von Studien zur optimalen Signaleinspeisung und Eingangsanpassung einer Gilbert-Zelle wird ein Ultrabreitband-Mischer mit geringem Stromverbrauch entworfen. Dieser erreicht eine Ausgangsbandbreite von mehr als 100 GHz, die den Stand der Technik um 23% ĂŒbertrifft. Bei einer WandlungsverstĂ€rkung von –13dB ermöglicht dies Datenraten von mehr als 100 Gbps im BPSK-Betrieb. Die Erkenntnisse werden in einem integrierten, breitbandigen Sender konsolidiert, der um 246 GHz arbeitet und die höchsten veröffentlichten gemessenen Datenraten fĂŒr Sender mit LO-Signalkette und LeistungsverstĂ€rker im BPSK-Betrieb auf 56 Gbps verdoppelt. Die daraus resultierende Transmitter-Effizienz von 7.4 pJ/bit verbessert den Stand der Technik um 70 % bzw. 50 % gegenĂŒber BPSKund Quadratur Phasenumtastung (QPSK)-Systemen. Zusammen bilden die Ergebnisse dieser Arbeit die Grundlage fĂŒr stromsparende, effiziente, mobile Funkanwendungen der nĂ€chsten Generation mit einem Vielfachen der heute verfĂŒgbaren Datenraten.:Abstract 3 Zusammenfassung 5 List of Symbols 11 List of Acronyms 17 Prior Publications 19 1. Introduction 21 1.1. Motivation........................... 21 1.2. Objective of this Thesis ................... 25 1.3. Structure of this Thesis ................... 27 2. Overview of Employed Technologies and Techniques 29 2.1. IntegratedCircuitTechnology................ 29 2.2. Transmission Lines and Passive Structures . . . . . . . . 35 2.3. DigitalModulation ...................... 41 3. Frequency Quadrupler 45 3.1. Theoretical Analysis of Frequency Multiplication Circuits 45 3.2. Phase-Controlled Push-Push Principle for Frequency Quadrupling.......................... 49 3.3. Stand-alone Phase-Controlled Push-Push Quadrupler . 60 3.4. Phase-Controlled Push-Push Quadrupler based LO-chain with High Output Power ............... 72 9 4. Array Systems and Dynamic Beam Steering 91 4.1. Theoretical Analysis of BeamSteering. . . . . . . . . . . 95 4.2. Local Oscillator Phase Shifting with Vector-Modulator PhaseShifters......................... 107 4.3. Hybrid True-Time and Phase-Delayed Beam Steering . 131 5. Ultra-Wide Band Modulator for BPSK Operation 155 6. Broadband BPSK Transmitter System for Datarates up to 56 Gbps 167 6.1. System Architecture ..................... 168 6.2. Measurement Technique and Results . . . . . . . . . . . 171 6.3. Summary and performance comparison . . . . . . . . . 185 7. Conclusion and Outlook 189 A. Appendix 195 Bibliography 199 List of Figures 227 Note of Thanks 239 Curriculum Vitae 24

    Dialectic of Restlessness

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    In the section of Aktive PassivitĂ€t (2014) entitled “Ästhetik des Nichtwissens” (The Aesthetic of Unknowing) Martin Seel follows Adorno’s formulation of “determinate indeterminateness” in order to proclaim the “celebration of unknowing” as the “telos of all aesthetic perception” (Seel 2014, 102ff). He’s undoubtedly right that uncertainty and unknowing are part of experiencing a work of art as well as aesthetic reflection. Adorno’s formulation restricts the dimensions of the certain and the uncertain, the known and the unknown, the determinate and the indeterminate. Everything depends upon grasping the character of this restriction. You can speak of dialectic insofar as it remains a negative dialectic that denies itself a final synthesis—a dialectic of restlessness

    Sensitivity of microbial community physiology to soil moisture and temperature in an old field ecosystem

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    2011 Summer.Includes bibliographical references.To view the abstract, please see the full text of the document

    Grundideen algebraischen Denkens in der Grundschule

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    A non-cooperative approach to meta-bargaining theory

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    In meta-bargaining theory we consider (two-person) bargaining games and we assume that the agents want to apply two different bargaining situations. A mechanism is a function which assigns to every meta-bargaining game an allocation depending on the two bargaining solutions supported by the agents. In the literature van Damme (cf. [16]) and Chun (cf. [2]) propose two mechanisms. Under both mechanisms there is only one bargaining solution which constitutes a Nash-equilibrium in every non-cooperative game in which agents can choose bargaining solutions as strategies and the outcome is determined by the mechanism. We point out some undesirable properties of the mechanisms. By modifying each mechanism we propose new mechanisms yielding the same conclusions as the original mechanisms but avoiding these properties. Furthermore, we offer another modification of Chun's mechanisms for which only the Egalitarian solution constitutes a Nash-equilibrium in every non-cooperative game.Meta bargaining, Nash bargaining solution, non-cooperative approach
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