Дисертації з теми "Active and passive circuits"
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Cho, Seong-Ho 1966. "Laser micromachining of active and passive photonic integrated circuits." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/30086.
Повний текст джерелаIncludes bibliographical references (leaves 149-158).
This thesis describes the development of advanced laser resonators and applications of laser-induced micromachining for photonic circuit fabrication. Two major advantages of laser-induced micromachining are direct patterning and writing on large areas of substrates at high speed following the exposure of laser light, without using complicated photomask steps. For passive photonic devices fabrication, a novel femtosecond laser with unprecedented low repetition rates of 4 MHz is demonstrated to generate high intensity pulses, as high as 1.25 MW with 100 nJ pulse energies and 80 fs pulse durations directly from this laser resonator, without using any active devices or amplifiers. These high intensity pulses are applied to transparent glass materials to demonstrate micromachining of waveguides, gratings, couplers, and three dimensional waveguides and their beam couplings. Active and passive semiconductor devices can be monolithically integrated by employing high energy laser pulses to locally disorder quantum well regions. The 45 nm bandgap shifts at 1.55 ptm with a standard Q-switched Nd:YAG laser at 535 nm are realized. Finally, unidirectional semiconductor ring lasers for high-density integration are developed as a potential application to photonic integrated circuits. Hybrid semiconductor S-crossover and retro-reflected ring lasers, as prototypes for unidirectional operation, are built and result in up to 21.5 dB and 24.5 dB of counter-mode suppression ratio, respectively, which is in good agreement with theoretical predictions.
by Seong-Ho Cho.
Ph.D.
McCullough, Denis. "Active and passive filters in the control of industrial harmonics." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334582.
Повний текст джерелаTee, Chyng Wen. "Vertically-coupled microring architecture for large-scale active-passive integration of photonic circuits." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612543.
Повний текст джерелаChirala, Mohan Krishna. "Passive and active circuits in cmos technology for rf, microwave and millimeter wave applications." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2069.
Повний текст джерелаSarmiento, Leon Mayra Susana. "Testing platform implementation and system integration for an active/passive imager system including readout circuit design." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 5.32 Mb., 170 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3220740.
Повний текст джерелаZanzi, Andrea. "Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects." Doctoral thesis, Universitat Politècnica de València, 2020. http://hdl.handle.net/10251/149377.
Повний текст джерела[ES] Las tecnologías ópticas son el eje vertebrador de los sistemas de comunicación mod- ernos que proporcionan acceso de alta velocidad a la Internet, interconexiones efi- cientes entre centros de datos y dentro de ellos. Además, se están expandiendo hacia campos de investigación crecientes y nuevos mercados como son las aplicaciones de comunicaciones por satélite, los LIDAR (Laser Imaging Detection and Ranging), la computación neuromórfica y los circuitos fotónicos programables, por nombrar algunos. La fotónica de silicio está considerada y aceptada ampliamente como una de las tecnologías clave para que dichas aplicaciones puedan desarrollarse. Como resultado, hay una fuerte necesidad de estructuras fotónicas básicas integradas que sean innovadoras, que soporten altas velocidades de transmisión y que sean más eficientes en términos de consumo de potencia, a fin de aumentar la capacidad de los circuitos integrados fotónicos de silicio. El trabajo desarrollado y presentado en esta tesis se centra en el diseño y la car- acterización de dispositivos avanzados pasivos y activos, para circuitos fotónicos integrados. La tesis consta de tres capítulos principales, así como de sendas sec- ciones de motivación y conclusiones que exponen los fundamentos y los logros de este trabajo. El capítulo uno describe el diseño y la caracterización de un modulador electro-óptico Mach-Zehnder incorporado en una unión pn vertical altamente eficien- ciente que explota el efecto de dispersión de plasma en banda O. El capítulo dos está dedicado al diseño y caracterización de una nueva geometría de dispositivo de interferencia multimodo asimétrico y su aplicación en un modulador Mach-Zehnder. El capítulo tres está dedicado al diseño y caracterización de innovadores cristales fotónicos unidimensionales para aplicaciones de modulación con luz lenta. Se pre- senta un amplio análisis de los principales retos derivados del uso de la misma.
[CA] Les tecnologies òptiques són l'eix vertebrador d'aquells sistemes de comunicació moderns que proporcionen accés d'alta velocitat a la Internet, així com intercon- nexions eficients inter i entre centres de dades. A més a més, s'estan expandint cap a camps d'investigació creixents i nous mercats com són les aplicacions de co- municacions per satèl·lit, els LIDAR (Laser Imaging Detection and Ranging), la computació neuromòrfica i els circuits fotònics programables, entre d'altres. La fotònica de silici és considerada i acceptada àmpliament com una de les tecnologies clau i necessàries perquè aquestes aplicacions puguen desenvolupar-se. Per aquest motiu, es fa necessària l'existència d'estructures fotòniques bàsiques integrades que siguen innovadores, que suporten altes velocitats de transmissió i que siguen més eficients en termes de consum de potència, a fi d'augmentar la capacitat dels cir- cuits integrats fotònics de silici. El treball desenvolupat i presentat en aquesta tesi se centra en el disseny i la caracterització de dispositius avançats passius i actius, per a circuits fotònics integrats. La tesi consta de tres capítols principals, així com d'una secció de motivació i una altra de conclusions que exposen els fonaments i els assoliments d'aquest treball. El capítol u descriu el disseny i la caracterització d'un modulador electro-òptic Mach-Zehnder incorporat en una unió pn vertical d'alta efi- ciència que explota l'efecte de dispersió de plasma en la banda O. El capítol dos està dedicat al disseny i caracterització d'una nova geometria de dispositiu d'interferència multimode asimètric així com a la seua aplicació en un modulador Mach-Zehnder. El capítol tres està dedicat al disseny i caracterització d'innovadors cristalls fotònics unidimensionals per a aplicacions de modulació amb llum lenta. S'inclou també una anàlisi detallada dels principals reptes derivats de l'ús d'aquest tipus de llum.
I want to thank you the Generelitat Valenciana and the European Project L3MATRIX for the funding, without them my doctorate would not taken place.
Zanzi, A. (2020). Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149377
TESIS
Al-Bayaty, Hussein Kamal Anwer. "Novel methods of utilization, elimination, and description of the distortion power in electrical circuits." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/10646.
Повний текст джерелаOliver, John Marcus. "3D Micromachined Passive Components and Active Circuit Integration for Millimeter-wave Radar Applications." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77049.
Повний текст джерелаPh. D.
Viellard, Juliette. "Etudes des circuits neuronaux organisant l'évitement actif instrumental et l'évitement contextuel non instrumental." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0456.
Повний текст джерелаMammals, including rodents show a broad range of defensive behaviors as a mean of coping actively, such as avoidance behaviors, or passively such as freezing behavior. The avoidance response is a learned response in which an individual takes control in dangerous situations to deal with threats. One form of avoidance that has been investigated is the signaled active avoidance, where individuals are trained to avoid an environment, and escape in response to a cue previously associated with an aversive stimulus. It has been emphasized that the dmPFC plays an important role in encoding freezing acquisition and expression as well as active avoidance responses. However the neural circuits of the dmPFC processing the expression and acquisition of both active and passive coping strategies are yet to be discovered. To adress this question, we developed a novel behavioral paradigm in which a mouse has the possibility to either passively freeze to an aversive stimulus or to actively avoid it as a function of contextual contingencies. We first investigated the role of the pathway between the dmPFC and PAG in signaled active avoidance, and its relation with freezing. Our results indicate that (i) dmPFC and dl/lPAG sub-regions are activated during avoidance behavior, (ii) and that the optogenetic inhibition of this pathway blocked the acquisition of active avoidance. A non-instrumental form of avoidance is also investigated where the individual learns to avoid the aversive environment using contextual clues only, and displaying risk assessment behaviors toward the fearful environment. It has been previously shown that in this situation, a circuit involving the septohippocampal-hypothalamic-brainstem pathway is involved. It also revealed that the dorsal premammillary nucleus (PMD) must be critically involved in contextual passive avoidance. We analysed how the manipulation of the PMD and its projections to its main targets influences the expression and reconsolidation processes of contextual passive avoidance. Our results showed that (i) a specific septohippocampal-hypothalamic-braintem pathway is involved in our passive avoidance paradigm. (ii) Silencing the PMD during context exposure impairs both avoidance expression and memory reconsolidation and that (iii) the inhibition at terminal level impairs the expression and memory reconsolidation in both dlPAG and AMv. Both parts of the project assessed these questions using Fos immunochemistry analysis, manipulations of neural circuits using optogenetic, and pharmacogenetic techniques
Santos, Heinsten Frederich Leal dos. "Controle de vibrações estruturais usando cerâmica piezoelétricas em extensão e cisalhamento conectadas a circuitos híbridos ativo-passivos." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-28082009-170649/.
Повний текст джерелаThis work presents a numerical analysis of the structural vibration control using piezoelectric materials in extension and shear mode connected to active-passive electric circuits composed of the resistance, inductance and voltage source. For that, a finite element model for sandwich beams with three elastic or piezoelectric layers was developed. A modeling of the electric circuit dynamics and its coupling to the structure with piezoelectric elements was also done. A harmonic analysis of the resulting equations was performed to yield a preliminary evaluation of the effects caused by the electric circuit components on the structure. It was observed that the passive circuit components not only lead to a dynamic vibration absorber effect but also to an amplification of the control authority in case of actuation using the voltage source. Using the standard methodology for the design of dynamic vibration absorbers, expressions were derived for the resistance and inductance values that optimize the passive vibration control performance of the system. A numerical analysis of the passive vibration control was performed for cantilever beams with extension and shear piezoelectric ceramics showing satisfactory results. Then, an analysis of the control authority was carried out for the same structures aiming at an active-passive vibration control. The active control was achieved using a linear quadratic regulator optimal feedback strategy to evaluate the voltage applied to the circuit. A comparison between the obtained results show that hybrid active-passive control is always superior to the purely active or purely passive control for both cases studied, with extension and shear piezoelectric ceramics.
Eleyele, Abidemi Oluremilekun. "Isolated Single-Stage Interleave Resonant PFC Rectifier with Active and Novel Passive Output Ripple Cancellation Circuit." Thesis, Uppsala universitet, Institutionen för elektroteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-423117.
Повний текст джерелаZhu, Ning. "Electrically Small, Near-Field Resonant Parasitic (NFRP) Antennas Augmented with Passive and Active Circuit Elements to Enhance their Functionality." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/297013.
Повний текст джерелаPascal, Yoann. "Étude multicritère pour l'enfouissement partiel ou total de convertisseurs d'électronique de puissance dans un circuit imprimé." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN038/document.
Повний текст джерелаThis thesis deals with Printed-Circuit Board (PCB) embedding of power converters, paradigm according to which electronic components are placed within the substrate itself.First, a simple and economical structure of inductive component, which can be used either as an inductor, a coupler, or a monolithic resonator, is described. A comprehensive analytical model is developed. Prototypes are manufactured, validating the analytical model and highlighting the value of the topology.The arrangement of the power components of a switching cell is then studied. In particular, an analytical model offering an intuitive understanding of the oscillation mechanisms in cells using fast transistors is proposed.A simple and economical top-side connection technic for PCB-embedded power dies using a pressed piece of metal foam is described. A preliminary study, with strong experimental component, is proposed. It shows that the embedded prototypes have electrical performances and a reliability close to that of wire-bonded dies.Finally, the results from the study on the arrangement of the components of a switching cell are used to design and manufacture a chopper based on SiC transistors connected using a piece of pressed metal foam. This chopper proved to be able to continuously deliver 3 kW under 600 V to a load, thereby validating the proposed top-side connection technic
Santos, Heinsten Frederich Leal dos. "Controle ativo-passivo de vibrações estruturais usando materiais piezelétricos: otimização e quanticação de incertezas." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-11052015-100332/.
Повний текст джерелаThis work presents a numerical analysis of the structural vibration control using piezoelectric materials in extension mode connected to active-passive electric circuits composed of resistance, inductance and voltage source. For that, a finite element model for sandwich beams with three elastic or piezoelectric layers was developed. A modeling of the electric circuit dynamics and its coupling to the structure with piezoelectric elements was also done. A harmonic analysis of the resulting equations was performed to yield a preliminary evaluation of the effects caused by the electric circuit components on the structure. It was observed that the passive circuit components not only lead to a dynamic vibration absorber effect but also to an amplification of the control authority in case of actuation using the voltage source. Using the standard methodology for the design of dynamic vibration absorbers, expressions were derived for the resistance and inductance values that optimize the passive vibration control performance of the system. An analysis of the effect of uncertainties of piezoelectric and dielectric constants of piezoelectric ceramic and resistance and inductance components of the shunt circuit on the passive and active-passive control performance for a cantilever beam structure was performed. The objective of this analysis was to quantify robustness and sensitivity of the proposed control. Then, an optimization study of the values of resistance and inductance of the shunt circuit as a function of the maximum control voltage to be applied on a plate with several piezoelectric actuators was performed. Finally and also for the plate structure, an analysis of uncertainties in the stiffness of the adhesive interface between structure and piezoelectric actuators and their effects on the performance of passive control and active-passive was performed.
Settaf, Zakaria. "Étude et réalisation d'un duplexeur SOI accordable multibande pour les futures générations de systèmes de téléphonie mobile." Thesis, Poitiers, 2016. http://www.theses.fr/2016POIT2327/document.
Повний текст джерелаSeveral standards have been defined and are currently used on mobile phones. With the high request for the broadband, several new standards are developed and introduced in 5G. This results in the use of many circuits, dedicated to one standard and thus one frequency band, which increase the difficulty of integrating these dedicated circuits and therefore costly. It hasbecome necessary for designers to propose tunable integrated circuit that can address several frequency ranges with different operating modes.The duplexer allows the establishment of simultaneous communications, using a single antenna for sending and receiving data, without any interferences. It is a vital component, especially for receiver. In fact, the quality of the received signal depends greatly on the duplexer characteristics. This device is designed on the piezoelectric material, which does not allow to achieve a tunable filter according to the frequency. In this context, it seems interesting to study a new architecture of duplexer. Therefore, it is necessary to define the duplexer function based on studies and system simulations, thus identify the constraints and technology limitations. Several duplexer architectures were selected based on recent studies in different research teams.A classification of these architectures was proposed and also improvements to make them integrated and tunable. Among all the solutions studied, the duplexer using hybrid 3dB coupler shown the most attractive performance. Simulations for different frequency bands showed that it's difficult to achieve Tx/Rx isolation requirements. Different solutions have been presented and LNA structure have been changed and thus evaluated by simulations. Thanks to that, the Tx/Rx isolation can be improved through active cancellation structures.The final chapter presents the design, implementation and testing of hybrid 3dB coupler and duplexer. It has been implemented using SOI 0.13 micrometer from ST Microelectronics and tested on BT-resin substrat. The RF performance of the duplexer can be corrected according to the desired frequency band through the switched capacitor. The RF performance of the hybrid 3dB coupler is in the line with expectations and allows to consider its integration in future system developments
Do, Minh-Nhut. "Co-conception et caractérisation de circuits actifs et passifs tri-dimensionnels en bande K pour l'intégration de mycrosystèmes sur silicium aux fréquences milimétriques." Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00196619.
Повний текст джерелаPourabdollah, Nezhad Maziar. "Active and passive plasmonic devices." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3284224.
Повний текст джерелаTitle from first page of PDF file (viewed January 14, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 93-102).
Zuo, Fei. "Passive and active currency portfolio optimisation." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/22612.
Повний текст джерелаMaldonado-Mercado, Julio Cesar. "Passive and active control of structures." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36654.
Повний текст джерелаIncludes bibliographical references (leaves 94-98).
by Julio Cesar Maldonado-Mercado.
M.S.
Scheitrum, Raquel. "Smoking passive addiction or active coping? /." Instructions for remote access. Click here to access this electronic resource. Access available to Kutztown University faculty, staff, and students only, 1999. http://www.kutztown.edu/library/services/remote_access.asp.
Повний текст джерелаSource: Masters Abstracts International, Volume: 45-06, page: 2778. Typescript. Abstract included as two unpaged leaves at back of volume. Includes bibliographical references (leaves 30-35).
Kartha, Satish Chandrashekhar. "Active, Passive and Active/Passive Control Techniques For Reduction of Vibrational Power Flow in Fluid Filled Pipes." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31156.
Повний текст джерелаMaster of Science
Hassan, Samy Aly. "Fundamental studies of passive, active and semi-active automotive suspension systems." Thesis, University of Leeds, 1986. http://etheses.whiterose.ac.uk/2691/.
Повний текст джерелаKim, Sangcheol. "Fabrication of active and passive terahertz structures." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 60 p, 2006. http://proquest.umi.com/pqdweb?did=1203570961&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Повний текст джерелаGarcia, Nil. "Optimization Methods for Active and Passive Localization." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14192/1/garcia.pdf.
Повний текст джерелаOh, Yim-Taek. "Passive and active drag of paralympic swimmers." Thesis, Manchester Metropolitan University, 2015. http://e-space.mmu.ac.uk/615953/.
Повний текст джерелаAl-Mahmoud, Abdulrazzak M. "Microwave passive tunable and active bandpass filters." Thesis, Cranfield University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309711.
Повний текст джерелаCampillo, Javier. "From Passive to Active Electric Distribution Networks." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-31592.
Повний текст джерелаZhou, Shaoyi. "Advances in passive and active damping techniques." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI066.
Повний текст джерелаMechanical systems (e.g. flexible structures) are usually lightly damped so that they vibrate severally in response to dynamic loads. Therefore, vibration control strategies should be adopted in order to reduce the undesired vibration of mechanical systems. The objective of this thesis is to develop multiple vibration control techniques, which are either passive or active. The first part focuses on the application of inerter to enhance the vibration control performance of two existing control devices, the tuned mass damper (TMD) and the series double TMD (SDTMD). The inerter is employed to relate the tuned mass to the ground. In the case of TMD, a mechanical system under stiffness uncertainty is considered and the worst-case H-infinity optimization is addressed by means of an entirely algebraic approach. In the case of SDTMD, the vibration of a deterministic mechanical system is to be controlled and the H-infinity optimal design is carried out via an extended version of fixed points theory (FPT). Instead of using the inerter, the second part consists in improving the control effect by incorporating a linear negative stiffness between the ground and the tuned mass. Two case studies are conducted based on the non-traditional TMD and inerter-based dynamic vibration absorber (IDVA), whose tuned mass is related to the ground by a viscous damper or an inerter-based mechanical network, respectively. Later, the exact electrical realization of non-traditional configurations with or without negative stiffness is proposed, which is based on the piezoelectric transducer enclosed by a particular shunt circuit. This electromechanical analogy enables to extend the applicability of mechanical control devices and to facilitate the precise tuning. In the last part, active and semi-active vibration control techniques are developed. The first strategy consists in enhancing the control capability of passive TMD and IDVA by feeding back the displacement signal of mechanical system to the electromagnetic actuator. The proposed controller can be regarded as one or multiple basic units arranged in series, which is featured by one pole at the origin and two coalesced zeros on the real axis. Distinguished from the previous strategy, the semi-active control technique is based on electromagnetic shunt damping (EMSD), therefore, no additional sensor is required to measure the information of mechanical system. In order to artificially increase the shunt damping performance, the employment of negative inductance (NI) in the shunt circuit is considered. Three possible layouts of NI in the EMSD are assessed in terms of the electromechanical coupling factor, which quantifies the energy conversion efficiency between mechanical and electrical domains. Finally, six types of shunt circuits are optimally tuned according to the FPT and the beneficial effect of NI and the influence of its layout can be underlined
Molander, Jonathan, and Loo Lennart van. "Active Versus Passive Investing : A Comparative Analysis." Thesis, Internationella Handelshögskolan, Jönköping University, IHH, Företagsekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-49153.
Повний текст джерелаSAXBY, DYANI J. "ACTIVE AND PASSIVE FATIGUE IN SIMULATED DRIVING." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1195507547.
Повний текст джерелаWatson, Rose E. (Rose Elliott). "Active or Passive Voice: Does It Matter?" Thesis, University of North Texas, 1993. https://digital.library.unt.edu/ark:/67531/metadc501082/.
Повний текст джерелаPoon, Joyce Kai See Yariv Amnon. "Active and passive coupled-resonator optical waveguides /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-05242007-105741.
Повний текст джерелаMoore, Garrett Lee. "A Hybrid (Active-Passive) VANET Clustering Technique." Diss., NSUWorks, 2019. https://nsuworks.nova.edu/gscis_etd/1077.
Повний текст джерелаDussopt, Laurent. "Technologies et concepts nouveaux d'antennes planaires pour systèmes de communication : structures passives et actives." Nice, 2000. http://www.theses.fr/2000NICE5425.
Повний текст джерелаLiu, Yanzhen. "Active supply harmonic filtering." Thesis, University of Sussex, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266446.
Повний текст джерелаEmonin, Stéphanie. "Analyse de circuits optiques passifs et actifs en microscopie a sonde locale." Dijon, 1998. http://www.theses.fr/1998DIJOS038.
Повний текст джерелаHan, Yehui Ph D. Massachusetts Institute of Technology. "Circuits and passive components for radio-frequency power conversion." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/57983.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 141-149).
This thesis focuses on developing technology for high efficiency power converters operating at very high frequencies. The work in the thesis involves two aspects of such converters: rf (radio-frequency) power circuit design techniques and magnetic material characterization and application. In the aspect of circuit design techniques, the thesis investigates a new class of matching networks that overcomes a major limitation of rf converter circuits - their high sensitivity to loading condition. These networks, which are termed resistance compression networks, serve to substantially decrease the variation in effective resistance seen by a tuned rf inverter as loading conditions change. The thesis explores the operation, performance characteristics, and design of these networks, and present experimental results demonstrating their performance. The thesis also presents analysis and design considerations for lumped (inductor and capacitor) matching networks operating at high efficiency (> 95%). Formulas for calculating matching network efficiency are given and used to evaluate the optimum number of matching stages as a function of conversion ratio. Both simulation and experimental results are presented that validate the analytical formulation. In the aspect of magnetic materials and applications, the thesis investigates the loss characteristics of several commercial rf magnetic materials for power conversion applications in the 10 MHz to 100 MHz range.
(cont.) A measurement method is proposed to identify loss characteristics of different commercial rf magnetic core materials. The loss characteristics of these materials, which have not previously been available, are illustrated and compared in tables and figures. Based on results in characterization of magnetic materials, the thesis describes a procedure for magnetic components design with low permeability magnetic materials that is for very high frequency power conversion applications. This procedure provides a method to compare and evaluate different magnetic materials for given specifications of a magnetic-core inductor. Some important information, e.g. quality factor and size of the inductor can be predicted before the final design. The thesis also investigates some problems such as optimization of a magnetic-core inductor.
by Yehui Han.
Ph.D.
Svanberg, Mikaela, and Emilia Karlsson. "Active or Passive Fund Management : A comparison between active and passive Swedish funds before, during and after the financial crisis." Thesis, Linnéuniversitetet, Institutionen för ekonomistyrning och logistik (ELO), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-75394.
Повний текст джерелаHuo, Xiao. "High performance passive components modeling and integration in RF/microwave systems /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20HUO.
Повний текст джерелаKazemi, Alireza. "Mutual Fund Performance : Active- and Passive Fund Management." Thesis, Jönköping University, JIBS, Economics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-1226.
Повний текст джерелаIn this thesis I will examine active equity mutual fund managers’ ability to outperform an index, which is done by utilizing a sample of four equity mutual funds that mainly invest in large Swedish quoted companies. In order to measure the risk-adjusted performance of the funds, a model created by Michael Jensen will be used. Furthermore, I will investigate whether the managers of the mutual funds increase/decrease the risk level, or rather the beta, when the stock market is bullish/bearish. Hence, two time spans have been chosen, 2001-2003 and 2004-2006, where the previous represents a bearish stock market and the later represents a bullish stock market.
The empirical evidence indicates that one fund in each period was significantly outper-formed by the comparable index. Furthermore, the result also suggests that two significant funds were talking more risk than the index in the bearish time period while three signifi-cant funds decreased the risk level during the bullish time period.
Denna kandidatuppsats undersöker aktiva fondförvaltares förmåga att upptäcka och inve-stera i fonder som presterar bättre än deras jämförekse index. Undersökningen är baserad på fyra aktiefonder som huvudsakligen investerats i Svenska börsnoterade företag. Fonder-nas riskjusterade prestation kommer att mätas med hjälp av en modell som är utformad av Michael Jensen.
Vidare kommer uppsatsen att undersöka om fondförvaltarna ökar eller minskar risk nivån, eller betavärdet, baserat på börsens utveckling under åren 2001-2003 och 2004-2006. Det förgående intervallet representerar en sjunkande börsperiod och det senare en stigande börsperiod.
Det empiriska resultatet indikerar att en signifikant fond i varje tidsintervall presterade säm-re än index. Utöver detta visade även resultatet att två signifikanta fonder ökade risk nivån, jämfört med index, i den sjunkande börsperioden medan tre signifikanta fonder minskade risk nivån i den stigande börsperioden.
Karam, Philippe Chucri. "Modeling passive and active mechanisms in motoneuron dendrites." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/13713.
Повний текст джерелаSherwani, Hashir. "Resource management in active-passive multifunction radar networks." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10056926/.
Повний текст джерелаSousa, Júnior Gabriel Faria de. "Active versus passive management : the case of BOVESPA." Master's thesis, Instituto Superior de Economia e Gestão, 2016. http://hdl.handle.net/10400.5/11647.
Повний текст джерелаO principal objetivo deste trabalho é analisar alguns modelos subjacente à gestão de carteiras ativa e passiva e qual seria seu impacto sobre a escolha de uma determinada carteira constituída por ações que estão integrados no índice BOVESPA, maior mercado bolsista do Brasil. A gestão passiva é baseada numa carteira que visa replicar o comportamento do Índice BOVESPA, tendo como base os preços históricos do índice e no método naïve (1/N), no qual composição da carteira inclui todos os ativos do índice com as mesmas proporções. A gestão ativa baseia-se no método de Markowitz, conhecido como modelo de média variância, que visa maximizar o retorno tendo definido um determinado nível de risco, ou minimizar o risco tendo em conta um nível de retorno esperado. Também é usado o método da variância mínima que consiste em minimizar o risco independentemente do retorno. Nesta abordagem as proporções a investir em cada ativo são revistas mensalmente tendo em conta a evolução do mercado. Outro modelo utilizado será um método ajustado da média variância em que serão mantidos os pesos ótimos do primeiro período para as restantes janelas de dados. Para as determinar são consideradas "janelas" de dados de 1 e 2 anos. É considerado um horizonte de investimento de 10 anos, a partir de Janeiro de 2005 a Dezembro de 2014. Com base nos resultados é possível afirmar que a carteira de média variância deve ser a escolhida, uma vez que apresenta os melhores resultados.
The main purpose of this paper is to analyze some models underlying the active and passive portfolio management and what would be its impact on the choice of a portfolio composed by stocks which are integrated in BOVESPA Index, Brazilian biggest stock market. The passive management approach is based on the historical prices of BOVESPA Index which replicates the behavior of the market and on the naïve method (1/N), in which the portfolio includes all the stocks on the index with the same proportions. Active management is based on the Markowitz model, also known as mean variance model, whose objective is to maximize the return give a set risk level or, minimize the risk given an expected return. The minimum variance model is also used, whose goal is to minimize the risk independent of the return. On these approach the weights of each asset in the portfolio are revised monthly, based on the market evolution. Another model used is a Mean Variance adjusted method in which the first period optimal weights will be maintained for the remaining data windows. In order for these to be determined, "windows" of 1 and 2 years were used. We are considering a 10 year investment horizon, from January 2005 to December 2014. Based on the results, we can affirm that the mean variance portfolio should be chosen, as performed better both in terms of returns and, especially, in terms of Sharpe ratio when compared with the other two portfolios.
Zhang, Zhaowei. "Passive and active Bragg gratings for optical networks." Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/47760/.
Повний текст джерелаGoldstein, Andre L. "Control of Sound Transmission with Active-Passive Tiles." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/27913.
Повний текст джерелаPh. D.
Lam, Margaretha Johanna. "Hybrid Active/Passive Models with Frequency Dependent Damping." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30770.
Повний текст джерелаPh. D.
Ziolkowski, Richard W. "Passive and active metamaterial-inspired nano-scale antennas." IEEE, 2016. http://hdl.handle.net/10150/623141.
Повний текст джерелаHuang, Caijin. "Optical nano-antennas : passive properties and active control." Thesis, Dijon, 2010. http://www.theses.fr/2010DIJOS011/document.
Повний текст джерелаOptical nanoantennas are a new class of optical devices, generally constituted of metal nanoparticles, used for enhancing the interaction between an electromagnetic wave and a nano-scale object. These components are operating in the visible to near infra-red part of the spectrum and are offering solutions for the inherent limitations of optics at the nanometer scale. In particular, the properties of optical antennas are governed by the surface plasmon resonances of the underlying structure. These resonances are associated with a large field confinement, beyond the diffraction limit, and an enhancement of the local electromagnetic response that is used to amplify weak optical processes. The objective of this doctoral thesis is to understand by an experimental approach what are the key parameters characterizing an optical antenna with the aim to control its operation. Through the development of an original microscopy based on a low numerical aperture diascopic illumination and a subsequent spatial filtering, the scattering characteristics of a single optical nano-antenna were successfully measured. Our approach was first tested with simple model antennas (nanoparticles) before investigating multi-element coupled antennas (dimers). In analogy to radiofrequency theory, we have defined and measured important antenna characteristics: operating frequency, detuning factor, gain and emission diagram. We have studied the influence of the morphology of the antenna on these characteristics. Continuing the comparison with microwave antennas, we have introduced the concept of an optical tuner. The operating principle is to modify the medium in which the antenna is emitting its radiation i.e. the load of the device. To this aim, we have employed anisotropic liquid crystal molecules. With this load medium, the orientation of the anisotropy can be controlled by a static electric field. The operation of the optical tuner, i.e. tuning of the antenna to a broadcasting frequency, is demonstrated for electromagnetically coupled antennas
Meade, S. A. "The rapid and rigorous mathematical modelling of passive planar microwave circuits." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238860.
Повний текст джерелаBalik, Hasan Huseyin. "Passive open planar microwave circuit analysis by enhanced spectral domain method." Thesis, University of Bristol, 1997. http://hdl.handle.net/1983/3b619722-649b-483b-a806-6a3494f942ce.
Повний текст джерела