Global ETD Search

1	Defining the genetics of systemic autoimmunity in mouse models of lupus Haraldsson, Katarina January 2008 (has links) Systemic Lupus Erythematosus (SLE) is a chronic multi-organ autoimmune disease considered a prototype for autoantibody and immune complex-mediated tissue injury. Although autoantibodies against a wide diversity of self-antigens are characteristically found in this disease, an important hallmark is the presence of autoantibodies to nuclear antigens. Despite this common clinical feature, individual patients vary widely in the organ systems afflicted, disease severity, disease course, and response to treatment. These characteristics make clinical management of SLE challenging and highlight the need for effective and less toxic therapeutic interventions. Susceptibility to lupus has been shown in both human studies and mouse models to be dependent on genetic predisposition. Therefore, it is likely that knowledge of the genetic basis of SLE will be required before full understanding of SLE pathogenesis can be achieved. In this thesis, studies to define the genetic basis of lupus in an induced and two spontaneous models of the disease are presented. These studies encompass mapping, characterization of interval congenic mice, and cloning of the Lmb3 locus gene. In the first study, a genomewide mapping study was performed to define the genetic basis for resistance of the DBA/2 mice to mercury-induced autoimmunity. On chromosome 1, a single quantitative trait was linked with resistance to HgIA. These results linked the locus Hmr1 to a late stage of lupus with GN. Interval congenic mice are important tools to define and characterize the roles of different loci in lupus-like diseases. The second paper identifies the effect of NZB and NZW Lbw2 alleles on lupus susceptibility by using BWF1 mice with none, one or two copies of the lupus-predisposing NZB.Lbw2 locus. The lack of the NZB locus significantly reduced mortality, GN and B cell activation. IgM anti-chromatin levels in genome-wide mapping was linked only to Lmb2 and none of the known B cell hyperactivity-promoting genes were present in this location, which might indicate a novel B cell activation gene. The third study used reciprocal single locus interval-specific congenic mice to characterize the contribution of Lmb1-4 on the MRL-Faslpr and B6-Faslpr backgrounds. The Lmb3 locus on chromosome 7 was found to have the most prominent phenotype with clear effects on lymphoproliferation, GN and mortality. In the fourth paper the Lmb3 was cloned and shown to be a spontaneous nonsense mutation in the Coro1a gene that encodes an actin-binding and -regulatory protein. Upon further characterization, this genetic alteration was discovered to be a new lupus suppressing mutation that reduced T cell migration, activation, and survival. Our findings highlight the complexity of the genetics of lupus, and further suggest that genes involved in controlling the actin cytoskeleton might be potential targets for autoimmune therapeutics. SLE susceptibility HgIA genome-wide mapping Lbw2 Lmb1-4 suppressing gene Immunology Immunologi
2	Multiuser Receivers For Cdma Downlink Duran, Omer Agah 01 August 2008 (has links) (PDF) In this thesis, multiuser receivers for code division multiple-access (CDMA) downlink are studied under frequency selective fading channel conditions. The receivers investigated in this thesis attempt to estimate desired symbol as a linear combination of chip-rate sampled received signal sequence. A common matrix-vector representation of signals, which is similar to the model given by Paulraj et. al. is constructed in order to analyze the receivers studied in this thesis. Two receivers already well known in the literature are introduced and derived by using the common signal model. One of the receivers uses traditional matched filter and the other uses symbol-level linear minimum mean square error (MMSE) estimation. The receiver that uses traditional matched filter, also known as the conventional RAKE receiver, benefits from time diversity by combining the signal energy from multiple paths. The conventional RAKE receiver is optimal when multiple-access interference (MAI) is absent. Linear MMSE based receivers are known to suppress MAI and to be more robust to noise enhancement. The optimal symbol-level linear MMSE based receiver requires inversion of large matrices whose size is determined by either number of active users or spreading factor. These two parameters can be quite large in many practical systems and hence the computational load of this receiver can be a problem. In this thesis, two alternative low-complexity receivers, which are chip-level linear MMSE equalizer proposed by Krauss et. al. and interference-suppressing RAKE receiver proposed by Paulraj et. al., are compared with the linear full-rank MMSE based receiver and with the conventional RAKE receiver in terms of bit-error-rate performance. Various simulations are performed to evaluate the performance of the receivers and the parameters affecting the receiver performance are investigated.
3	Modeling, Control and Design Considerations for Modular Multilevel Converters Najmi, Vahid 25 June 2015 (has links) This thesis provides insight into state-of-the-art Modular Multilevel Converters (MMC) for medium and high voltage applications. Modular Multilevel Converters have increased in interest in many industrial applications, as they offer the following advantages: modularity, scalability, reliability, distributed location of capacitors, etc. In this study, the modeling, control and design considerations of modular based multilevel converters, with an emphasis on the reliability of the converter, is carried out. Both modular multilevel converters with half-bridge and full-bridge sub-modules are evaluated in order to provide a complete analysis of the converter. From among the family of modular based hybrid multilevel converters, the newly released Alternate Arm Converter (AAC) is considered for further assessment in this study. Thus, the modular multilevel converter with half-bridge and full-bridge power cells and the Alternate Arm Converter as a commercialized hybrid structure of this family are the main areas of study in this thesis. Finally, the DC fault analysis as one of the main issues related to conventional VSC converters is assessed for Modular Multilevel Converters (MMC) and the DC fault ride-through capability and DC fault current blocking ability is illustrated in both the Modular Multilevel Converter with Full-Bridge (FB) power cells and in the Alternate Arm Converter (AAC). Accordingly, the DC fault control scheme employed in the converter and the operation of the converter under the fault control scheme are explained. The main contributions of this study are as follows: The new D-Q model for the MMC is proposed for use in the design of the inner and outer loop control. The extended control scheme from the modular multilevel converter is employed to control the Alternate Arm Converters. A practical reliability-oriented sub-module capacitor bank design is described based on different reliability modeling tools. A Zero Current Switching (ZCS) scheme of the Alternate Arm Converter is presented in order to reduce the switching losses of the Director Switches (DS) and, accordingly, to implement the ZCS, a design procedure for the Arm inductor in the AAC is proposed. The capacitor voltage waveform is extracted analytically in different load power factors and the waveforms are verified by simulation results. A reliability-oriented switching frequency analysis for the modular multilevel converters is carried out to evaluate the effect of the switching frequency on the MMC's operation. For the latter, a DC fault analysis for the MMC with Full-Bridge (FB) power cells and the AAC is performed and a DC fault control scheme is employed to provide the capacitor voltage control and DC fault current limit, and is illustrated herein. / Master of Science Modular Multilevel Converter (MMC) Alternate Arm Converter (AAC) DC Fault ride-through Reliability-Oriented Design Capacitor Voltage Balance Three- Phase Average Modeling DQ axis Modeling
4	HANDSFREE-ENHET FÖR MOBIL TRYGGHETSTELEFON / HANDS-FREE UNIT FOR SAFETY MOBILE TELEPHONE Sundberg, Daniel January 2009 (has links) <p>Cnior Mobile AB i Lindesberg utvecklar en mobil trygghetstelefon för äldre. Detta examensarbete går ut på att utforma en handsfree-enhet för denna. Handsfree-enheten ska integreras i larmknappen, som bärs av användaren runt handleden, och har kontakt med telefonen via blåtandsradio. I examensarbetet ingår att välja ut lämplig högtalare och mikrofon, hitta lösningar för smuts- och vattentålighet samt att lösa problem med ekon och bakgrundsstörningar.</p><p>En högtalare hittades som uppfyllde kraven för smuts- och vattentålighet samtidigt som den hade utmärkt frekvensgång för återgivning av tydligt tal. Vattenavrinning från högtalaren löstes genom att ett sinussvep sänds ut från högtalaren varje gång ett samtal ska kopplas upp. På så sätt pressar ljudtrycket ut vattnet från handledsknappens kavitet. Olika utformningar av ljudhålen i handledsknappens skal provades. Den bästa lösningen för vattenavrinningen var att använda sju stycken runda hål med 1,3 mm i diameter. En ljudtrycksmätning säkerställde att ljudtrycket inte blev lidande av denna utformning av ljudhålen.</p><p>Ekosläckning och bakgrundsstörningsundertryckning sköts av GSM-modulen i trygghetsmobilen. I ekosläckningens manual finns beskrivet hur ekosläckningens 24 parametrar kan justeras för att passa olika applikationer. Endast en mindre ändring av de rekommenderade parametervärdena behövdes för att ekosläckning och bakgrundsstörningsundertryckning skulle fungera tillfredställande.</p><p>Eftersom mikrofonernas datablad visade på så snarlika egenskaper överlämnades mikrofonvalet till företaget, då det kan vara klokt att låta priset avgöra.</p> electro acoustic sound audio hands-free hands free cellphone telephone mobilephone phone safety telefon bluetooth speaker speakerphone senior older waterproof water-proof resistant water-resistant dust GSM GPS IP presbyacusis hearing loss hearing-loss echo echo-cancelling echo-canceller background background-noise suppressing suppressor elektroteknik elektronik akustik ljud hands-free mobiltelefon trygghetstelefon telefon blåtand bluetooth högtalare högtalartelefonfunktion högtalartelefon äldre vattentät vattenavrinning avrinning vattentålig smuts damm GSM GPS IP presbyacusis hörsel hörselnedsättning eko ekosläckning bakgrundsstörning bakgundsstörningsundertryckning undertryckning Electrical engineering Elektroteknik Acoustics Akustik Signal processing Signalbehandling
5	HANDSFREE-ENHET FÖR MOBIL TRYGGHETSTELEFON / HANDS-FREE UNIT FOR SAFETY MOBILE TELEPHONE Sundberg, Daniel January 2009 (has links) Cnior Mobile AB i Lindesberg utvecklar en mobil trygghetstelefon för äldre. Detta examensarbete går ut på att utforma en handsfree-enhet för denna. Handsfree-enheten ska integreras i larmknappen, som bärs av användaren runt handleden, och har kontakt med telefonen via blåtandsradio. I examensarbetet ingår att välja ut lämplig högtalare och mikrofon, hitta lösningar för smuts- och vattentålighet samt att lösa problem med ekon och bakgrundsstörningar. En högtalare hittades som uppfyllde kraven för smuts- och vattentålighet samtidigt som den hade utmärkt frekvensgång för återgivning av tydligt tal. Vattenavrinning från högtalaren löstes genom att ett sinussvep sänds ut från högtalaren varje gång ett samtal ska kopplas upp. På så sätt pressar ljudtrycket ut vattnet från handledsknappens kavitet. Olika utformningar av ljudhålen i handledsknappens skal provades. Den bästa lösningen för vattenavrinningen var att använda sju stycken runda hål med 1,3 mm i diameter. En ljudtrycksmätning säkerställde att ljudtrycket inte blev lidande av denna utformning av ljudhålen. Ekosläckning och bakgrundsstörningsundertryckning sköts av GSM-modulen i trygghetsmobilen. I ekosläckningens manual finns beskrivet hur ekosläckningens 24 parametrar kan justeras för att passa olika applikationer. Endast en mindre ändring av de rekommenderade parametervärdena behövdes för att ekosläckning och bakgrundsstörningsundertryckning skulle fungera tillfredställande. Eftersom mikrofonernas datablad visade på så snarlika egenskaper överlämnades mikrofonvalet till företaget, då det kan vara klokt att låta priset avgöra. electro acoustic sound audio hands-free hands free cellphone telephone mobilephone phone safety telefon bluetooth speaker speakerphone senior older waterproof water-proof resistant water-resistant dust GSM GPS IP presbyacusis hearing loss hearing-loss echo echo-cancelling echo-canceller background background-noise suppressing suppressor elektroteknik elektronik akustik ljud hands-free mobiltelefon trygghetstelefon telefon blåtand bluetooth högtalare högtalartelefonfunktion högtalartelefon äldre vattentät vattenavrinning avrinning vattentålig smuts damm GSM GPS IP presbyacusis hörsel hörselnedsättning eko ekosläckning bakgrundsstörning bakgundsstörningsundertryckning undertryckning Annan elektroteknik och elektronik Fluid Mechanics and Acoustics Strömningsmekanik och akustik Signal Processing Signalbehandling
6	Low Intensity Conflict: Contemporary Approaches and Strategic Thinking Searle, Deane January 2007 (has links) Low Intensity Conflict (LIC) is a significant feature of the contemporary world and it is a particular challenge to the armed forces of many states which are involved is such conflict, or are likely to become so. This thesis is not concerned with how such difficult conflict situations arise. Rather it is concerned with how, from the point of view of the state, they may be contained and ultimately brought to a satisfactory resolution. The work is thus concerned with the practicalities of ending LIC. More specifically, the purpose of this research is to establish a framework of doctrinal and military principles applicable to the prevention and resolution of LIC. The principles of this thesis are based in numerous historical examples of LIC and six in depth case studies. These distilled principles are analysed in two central chapters, and are then applied in two latter defence force chapters so as to ensure there practicality and resilience. Numerous defence academics and military practitioners have been consulted in the production of this thesis; their contribution has further reinforced the functionality of the principles examined in this research. The research illustrates the criticality of a holistic approach to LIC. The function of this approach is to guarantee the stability of the sovereign state, by unifying civil, police, intelligence and military services. The effectiveness of the military elements must also be ensured, as military force is central to the suppression of LIC. Consequently, the research makes strategic and operational prescriptions, so as to improve the capability of defence forces that are concerned with preventing or resolving LIC. low intensity conflict counterinsurgent counterinsurgency insurgent insurgency guerrilla small wars conflict combat urban conflict new zealand defence force australian defence force afghanistan iraq somalia chechnya east timor bougainville bosnia defence policy doctrine soviet russia red army airpower combined arms intelligence command control communications surveillance intervention peacekeeping peacebuilding peace enforcement strategy tactics infantry armour aviation non-urban terrain psychological war small scale operations combat service support civil military affairs urban dominance rapid dominance manoeuvre warfare nationalism restraint civil resolve operation enduring freedom operation anaconda suppressing fire joint warfare synergy strike target acquisition civil affairs public affairs operation iraqi freedom operation telic professionalism asymmetric warfare power projection sea power precision strike C4ISTAR C4ISR HUMINT logistics coalition post war environment internal security population security civil support unitary command expeditionary civil service personnel techniques standard operating procedures artillery protection manoeuvrability firepower visibility helicopters aircraft friendly fire initiative policy training light armoured vehicle light operational vehicle aviation navy air force army counter communications sea control maritime power projection rules of engagement engineers

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