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1
Elliot, Janet Irene, and n/a. "Reading recovery : do children maintain their place in the average band of reading performance in their classrooms in subsequent years?" University of Canberra. Education, 1994. http://erl.canberra.edu.au./public/adt-AUC20060707.132302.
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Compulsory schooling, such as exists in Australia, does not
guarantee literacy in the nation. The literature has established
that a minority of children do fail to learn to read and write
effectively. Failure to learn to read presents a serious disability
to those concerned. Programs such as Reading Recovery are used in
schools to try and identify at risk children and work with them to
reduce illiteracy.
Traditional methods of addressing the literacy problem have not
proven to be effective. Studies in New Zealand, the U.S.A. and in
Australia have established that Reading Recovery is an effective
program. However, there is no longitudinal evidence to establish
whether it is effective in the long run in the A.C.T. This study
sought to establish the long term effectiveness of the program in
the A.C.T. It has compared discontinued Reading Recovery children
three and five years after they had been discontinued from the
program with two 'average ' children from their current class. The
discontinued Reading Recovery sample was drawn by random. The
two classmate control children were selected by the teachers as
performing in the average band of class achievement in reading.
Four research instruments were chosen to collect the data. These
were, interviews with class teachers and the children themselves,
running records, a modified standardized test and an oral retell.
The study confirmed that Reading Recovery is effective in the
A.C.T. and that gains made whilst on the program were sustained in
subsequent years. This being the case, every child who is being
diagnosed as 'at risk' should have access to Reading Recovery .
2
Goudie, Stuart Thomas. "Distal radius fracture : relationships between psychological factors and recovery." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33253.
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Distal radius fracture is a common injury. The majority of people recover well but a proportion have ongoing pain, stiffness, deformity and functional limitation. Associations between these outcomes, injury characteristics and treatment methods are inconsistent, for example a deformed wrist is not always painful, stiff and functionally limiting. The psychological response to fracture and the role that psychological factors play in recovery are complex and poorly understood. Identification and treatment of those psychological factors that might influence disability and symptom intensity could improve outcomes in this large group of patients. The aim of this thesis is to explore the influence of psychological factors on outcome following fracture of the distal radius. To investigate these relationships further a literature review was carried out looking at the association between psychological factors and outcomes in distal radius fracture patients. Prospective studies were then performed in order to identify associations between demographic factors, injury severity, treatment and psychosocial factors and symptom intensity and disability after fracture and to identify predictors of psychological response to injury. A prospective randomised controlled trail (RCT) was then carried out to compare the impact of an additional psychological workbook intervention versus an information workbook in the otherwise routine management of distal radius fracture. The literature review identified evidence to support the association between psychological factors and outcome after acute injury in general but limited evidence specifically pertaining to distal radius fracture. The first prospective study of 216 patients found psychosocial factors to be more strongly associated with disability (Disability of Arm Shoulder and Hand score, DASH) and pain intensity after distal radius fracture than any injury or treatment factor. The second prospective study of 153 patients found that psychological traits are relatively stable in this cohort and that no demographic, injury or treatment factors were associated with the small changes in psychological scores up to 10 weeks following injury. The RCT demonstrated that use of a psychological workbook did not significantly improve disability six weeks after injury compared to an information workbook in a cohort of patients with distal radius fracture (DASH 38 vs 35, p = 0.949). The importance of psychosocial factors in recovery from distal radius fracture has been demonstrated. Following this injury, psychological factors remain stable over time or fluctuate to a small degree with distinct trends. In cohorts with stable psychological responses to fracture, the individual psychological response cannot be reliably predicted by demographic, injury or treatment factors. Use of a psychological workbook intervention does not improve outcomes in patients with a good initial psychological response to injury. Future work should investigate less psychologically stable and well adapted cohorts, establish how best to identify patients at risk of poor outcome and whether, indeed, these specific groups are amenable to treatment and if so what form this intervention should take. It should address limitations identified in this work, primarily, reduce questionnaire fatigue with more focused psychological questionnaires. Ultimately, it should work towards creating a structure where patients can be screened with a recognised psychological scoring system at initial presentation to fracture clinic and allow a sub-group of psychologically mal-adpted patients to be referred on to a dedicated psychology service, that would work to optimise the psychological conditions for recovery.
3
Lee, Jeong Eun. "Sensing Building Structure Using UWB Radios for Disaster Recovery." Thesis, Portland State University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10812182.
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This thesis studies the problem of estimating the interior structure of a collapsed building using embedded Ultra-Wideband (UWB) radios as sensors. The two major sensing problems needed to build the mapping system are determining wall type and wall orientation. We develop sensing algorithms that determine (1) load-bearing wall composition, thickness, and location and (2) wall position within the indoor cavity. We use extensive experimentation and measurement to develop those algorithms.
In order to identify wall types and locations, our research approach uses Received Signal Strength (RSS) measurement between pairs of UWB radios. We create an extensive database of UWB signal propagation data through various wall types and thicknesses. Once the database is built, fingerprinting algorithms are developed which determine the best match between measurement data and database information. For wall mapping, we use measurement of Time of Arrival (ToA) and Angle of Arrival (AoA) between pairs of radios in the same cavity. Using this data and a novel algorithm, we demonstrate how to determine wall material type, thickness, location, and the topology of the wall.
Our research methodology utilizes experimental measurements to create the database of signal propagation through different wall materials. The work also performs measurements to determine wall position in simulated scenarios. We ran the developed algorithms over the measurement data and characterized the error behavior of the solutions.
The experimental test bed uses Time Domain UWB radios with a center frequency of 4.7 GHz and bandwidth of over 3.2 GHz. The software was provided by Time Domain as well, including Performance Analysis Tool, Ranging application, and AoA application. For wall type identification, we use the P200 radio. And for wall mapping, we built a special UWB radio with both angle and distance measurement capability using one P200 radio and one P210 radio.
In our experimental design for wall identification, we varied wall type and distance between the radios, while fixing the number of radios, transmit power and the number of antennas per radio. For wall mapping, we varied the locations of reference node sensors and receiver sensors on adjoining and opposite walls, while fixing cavity size, transmit power, and the number of antennas per radio.
As we present in following chapters, our algorithms have very small estimation errors and can precisely identify wall types and wall positions.
4
Gao, Ruhou. "Area-schedule based design of high pressure recovery radial diffusion systems." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/103447.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, February 2016.Cataloged from PDF version of thesis. "September 2015."
Includes bibliographical references (pages 111-112).
To address the shortcomings of the commonly used channel diffuser and cascade design perspectives, a streamtube perspective is adopted by carefully scheduling the streamtube area with special attention to the diffuser entry region. A design framework for radial diffusion systems is developed based on area scheduling the vaned diffuser. The vaned diffuser and volute designs are assessed numerically through RANS calculations and validated by full-scale compressor experiments. The investigations revel that it is mainly the diffuser area ratio and effective non-dimensional diffusion length that set diffuser performance. A careful balance between these two parameters is shown to enable high diffuser pressure recovery. The diffusion in the semi-vaneless-space, controlled chiefly by the vane suction side geometry, plays a key role in improving diffuser performance. Removing excess thickness from the suction side eliminates flow overspeed, increases effective diffusion length, and leads to higher pressure recovery at reduced stagnation pressure loss. The pressure side thickness distribution controls the channel area schedule. Thin leading edges ensure smooth flow area transition into the channel, and reduce the vane upstream influence and therefore pressure fluctuations as perceived by the impeller. A diffuser design based on the area schedule approach is tested experimentally. A 1.8 fold improvement in diffuser performance parameter CP/Cp,t, where Cp and Cp,t are the diffuser static pressure recovery and the diffuser stagnation pressure loss coefficients respectively, is achieved. In addition, a 0.8% point increase in impeller isentropic efficiency due to reduced vane upstream influence and a 0.74% point increase in impeller-diffuser efficiency are demonstrated. The impact of the volute on diffuser and overall diffusion system performance is also assessed. High diffuser exit Mach numbers and a low volute inlet swirl parameter are shown to reduce volute performance.
by Ruhou Gao.
S.M.
5
Alshammari, Fuhaid. "Radial turbine expander design, modelling and testing for automotive organic Rankine cycle waste heat recovery." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16007.
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Since the late 19th century, the average temperature on Earth has risen by approximately 1.1 °C because of the increased carbon dioxide (CO2) and other man-made emissions to the atmosphere. The transportation sector is responsible for approximately 33% of the global CO2 emissions and 14% of the overall greenhouse gas emissions. Therefore, increasingly stringent regulations in the European Union require CO2 emissions to be lower than 95 gCO₂/km by 2020. In this regard, improvements in internal combustion engines (ICEs)must be achieved in terms of fuel consumption and CO2 emissions. Given that only up to 35% of fuel energy is converted into mechanical power, the wasted energy can be reused through waste heat recovery (WHR) technologies. Consequently, organic Rankine cycle (ORC) has received significant attention as a WHR technology because of its ability to recover wasted heat in low- to medium-heat sources. The Expansion machine is the key component in ORC systems, and its performance has a direct and significant impact on overall cycle efficiency. However, the thermal efficiencies of ORC systems are typically low due to low working temperatures. Moreover, supersonic conditions at the high pressure ratios are usually encountered in the expander due to the thermal properties of the working fluids selected which are different to water. Therefore, this thesis aims to design an efficient radial-inflow turbine to avoid further efficiency reductions in the overall system. To fulfil this aim, a novel design and optimisation methodology was developed. A design of experiments technique was incorporated in the methodology toexplorethe effects of input parameters on turbine performance and overall size. Importantly, performance prediction modelling by means of 1D mean-line modelling was employed in the proposed methodology to examine the performance of ORC turbines at constant geometries. The proposed methodology was validated by three methods: computational fluid dynamics analysis, experimental work available in the literature, and experimental work in the current project. Owing to the lack of actual experimental works in ORC-ICE applications, a test rig was built around a heavy-duty diesel engine at Brunel University London and tested at partial load conditions due to the requirement for a realistic off-high representation of the performance of the system rather than its best (design) point, while taking into account the limitation of the engine dynamometer employed. Results of the design methodology developed for this projectpresented an efficient single-stage high-pressure ratio radial-inflow turbine with a total to static efficiency of 74.4% and an output power of 13.6 kW.Experimental results showed that the ORC system had a thermal efficiency of 4.3%, and the brake-specific fuel consumption of the engine was reduced by 3%. The novel meanlineoff designcode (MOC) was validated with the experimental works from three turbines. In comparison with the experimental results conducted at Brunel University London, the predicted and measured results were in good agreement with a maximum deviation of 2.8%.
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Wu, Yik-chung, and 胡奕聰. "Demodulation and symbol timing recovery in software radio." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B2975785X.
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Guevara, Mauricio, and Boris Flyash. "SOFT RECOVERY RECORDING SYSTEM FOR INTERIOR AND EXTERIOR BALLISTICS CHARACTERIZATION." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604266.
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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, NevadaThe US ARMY, ARDEC; in cooperation with AMCOM AMRDEC, Missile Guidance and Engineering Directorates; the Office of Naval Research; Naval Surface Fire Support; and the Naval Surface Weapon Center, requires multiphase development of a common, low-cost, high G survivable, high accuracy, Micro Electro-Mechanical Systems (MEMS) Inertial Measurement Unit (IMU) and Common, Deeply Integrated, Guidance and Navigation Unit (DI-GNU) for DoD gun launched guided munition and missile applications. The challenge for the Precision Munition Instrumentation Division (PMID) was to develop a Telemetry System to record the interior and exterior ballistics of a M831 TP-T projectile, which will be used as a carrier for soft recovery testing of IMUs and GNUs. This valuable data that would help The Government and contractors develop and validate multiple MEMS IMU design efforts, culminating with live fire verification performance test of pre-production in the Army’s 155-mm Soft Recovery Vehicle (SRVs) and missiles airframes.
8
Rahbar, Kiyarash. "Development and optimization of small-scale radial inflow turbine for waste heat recovery with organic rankine cycle." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6523/.
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This thesis is an investigation of different strategies for efficient development and optimization of radial-inflow turbines (RIT) for small-scale ORC systems. A novel methodology based on mean-line modelling, multi-level optimization and experimental study was proposed and validated for a small-scale compressed air RIT. Extending the proposed approach to organic fluids necessitated the use of real-gas equations. Deficiencies of constant turbine efficiency assumption that was commonly used in the literature were highlighted. A novel approach for integrated modelling of organic RIT with ORC coupled with genetic algorithm optimization technique was developed to alleviate the errors during fluid selection and cycle analysis and also optimize the ORC performance. A novel dual-stage transonic RIT was developed to further improve the ORC performance. The efficiency of such turbine was improved further using 3-D CFD optimization technique. Such optimization proved to be very efficient as it substantially improved the turbine efficiency of both stages by about 10%. CFD results for the optimized dual-stage turbine at design point showed the turbine efficiency of 87.12% and ORC thermal efficiency of 13.19%. Such results were considerably higher than the reported values in the literature and highlighted the effectiveness of the combined mean-line and CFD optimizations developed in thesis.
9
Ekholm, Radford. "Humeral shaft fractures : epidemiology and outcome /." Stockholm : Karolinska institutet, 2007. http://diss.kib.ki.se/2007/978-91-7140-724-5/.
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Kippenberger, Roger Miles. "On Real Time Digital Phase Locked Loop Implementation with Application to Timing Recovery." Thesis, University of Canterbury. Electrical and Computer Engineering, 2006. http://hdl.handle.net/10092/1146.
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In digital communication systems symbol timing recovery is of fundamental importance. The accuracy in estimation of symbol timing has a direct effect on received data error rates. The primary objective of this thesis is to implement a practical Digital Phase Locked Loop capable of accurate synchronisation of symbols suffering channel corruption typical of modern mobile communications. This thesis describes an all-software implementation of a Digital Phase Locked in a real-time system. A timing error detection (TED) algorithms optimally implemented into a Digital Signal Processor. A real-time transmitter and receiver system is implemented in order to measure performance when the received signal is corrupted by both Additive White Gaussian Noise and Flat Fading. The Timing Error Detection algorithm implemented is a discrete time maximum likelihood one known as FFML1, developed at Canterbury University. FFML1 along with other components of the Digital Phase Locked loop are implemented entirely in software, using Motorola 56321 assembly language.
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Robin, Valentin. "Effet de la cristallochimie des minéraux argileux gonflants sur les propriétés d'échange cationique et de dissolution. Implications dans un contexte de réhabilitation de sites miniers acidifiés." Thesis, Poitiers, 2015. http://www.theses.fr/2015POIT2296/document.
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Les smectites sont présentent dans de nombreux environnements de surface et sub-surface au sein desquels elles jouent un rôle prépondérant dans la mobilité des cations majeurs et traces de part leurs capacités d’adsorption. En contexte de réhabilitation de sites miniers exploités par lixiviation acide, ces smectites jouent un rôle dans la remontée du pH des eaux ainsi que dans l’immobilisation des éléments solubilisés. La nature des argiles présentent dans les sables non consolidés d’un aquifère exploité a donc été étudié. La présence de smectites du type beidellite (charge tétraédrique) a été mise en évidence. Cependant, il existe peu d’études sur les propriétés de la beidellite, la majorité portant sur la montmorillonite (charge octaédrique). Un modèle d’échange pour 5 cations majeurs des eaux naturelles (Na, K, Ca, Mg, H) et un élément trace (226Ra) a donc été réalisé sur une beidellite de référence. Les vitesses de dissolution et les mécanismes à l’interface solide/solution en milieu acide ont ensuite été étudiés, validant l’application du modèle d’échange à bas pH. Des effets dus à l’organisation des particules en suspension (texture/agrégation) ont aussi été mis en évidence sur les propriétés d’échange et de dissolution. Lors de ces travaux, l’accent a été mis sur l’impact de la cristallochimie sur la réactivité des smectites par comparaison entre les propriétés de la beidellite et de la montmorillonite. Les résultats indiquent que la cristallochimie des smectites a un impact significatif sur leur comportement, ce paramètre pourrait ainsi être utilisé afin d’alimenter les modèles de transport réactif prenant en compte les propriétés des smectitesSwelling clay minerals, in particular smectites, are present in many surface and subsurface environments in which they have a major impact on the mobility of major cations and trace elements due to their adsorption capacity. In context of remediation of mining environments operated by acid leaching, these smectites can act as pH buffer and play a role in the immobilization of soluble elements. The type of clay minerals present in the poorly consolidated sands of an aquifer leached by acid solutions was studied. The presence of beidellite type smectites (di-octahedral, tetrahedral charge) was evidenced. However, few studies exist on the ion exchange properties or the dissolution of beidellite, as most of them deal with montmorillonite properties (di-octahedral, octahedral charge). Then, an ion-exchange model involving 5 major cations of natural waters (Na, K, Ca, Mg, H) and one trace element (226Ra) was proposed for a reference beidellite. Dissolution rates and interfacial mechanisms in acidic solutions were investigated in order to check for the validity the ion-exchange model at low pH. Moreover, effects due to the texture/aggregation of particles in suspension were evidenced on the ion-exchange and dissolution properties. This study was focused on the impact of the crystal chemistry on reactive property of the smectites, by comparison of the properties of beidellite with those of montmorillonitic minerals. Results indicate that smectites crystal chemistry has a significant impact on their properties, and such parameter could be considered in reactive transport models when they take into account cation exchange and dissolution properties of smectites
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Baserdem, Ciler. "Symbol Timing Recovery For Cpm Signals Based On Matched Filtering." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12608072/index.pdf.
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In this thesis, symbol timing recovery based on matched filtering in Gaussian Minimum Shift Keying (GMSK) with bandwidth-bit period product (BT) of 0.3 is investigated. GMSK is the standard modulation type for GSM. Although GMSK modulation is non-linear, it is approximated to Offset Quadrature Amplitude Modulation (OQAM), which is a linear modulation, so that Maximum Likelihood Sequence Estimation (MLSE) method is possible in the receiver part. In this study Typical Urban (TU) channel model developed in COST 207 is used. Two methods are developed on the construction of the matched filter. In order to obtain timing recovery for GMSK signals, these methods are investigated. The fractional time delays are acquired by using interpolation and an iterative maximum search process. The performance of the proposed symbol timing recovery (STR) scheme is assessed by using computer simulations. It is observed that the STR tracks the variations of the frequency selective multipath fading channels almost the same as the Mazo criterion.
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Olivarez, Nathan. "Mitigating the Effects of Ionospheric Scintillation on GPS Carrier Recovery." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-theses/245.
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Ionospheric scintillation is a phenomenon caused by varying concentrations of charged particles in the upper atmosphere that induces deep fades and rapid phase rotations in satellite signals, including GPS. During periods of scintillation, carrier tracking loops often lose lock on the signal because the rapid phase rotations generate cycle slips in the PLL. One solution to mitigating this problem is by employing decision-directed carrier recovery algorithms that achieve data wipe-off using differential bit detection techniques. Other techniques involve PLLs with variable bandwidth and variable integration times. Since nearly 60% of the GPS signal repeats between frames, this thesis explores PLLs utilizing variable integration times and decision-directed algorithms that exploit the repeating data as a training sequence to aid in phase error estimation. Experiments conducted using a GPS signal generator, software radio, and MATLAB scintillation testbed compare the bit error rate of each of the receiver models. Training-based methods utilizing variable integration times show significant reductions in the likelihood of total loss of lock.
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Yamada, Randy Matthew. "Identification of Interfering Signals in Software Defined Radio Applications Using Sparse Signal Reconstruction Techniques." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/50609.
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Software-defined radios have the agility and flexibility to tune performance parameters, allowing them to adapt to environmental changes, adapt to desired modes of operation, and provide varied functionality as needed. Traditional software-defined radios use a combination of conditional processing and software-tuned hardware to enable these features and will critically sample the spectrum to ensure that only the required bandwidth is digitized. While flexible, these systems are still constrained to perform only a single function at a time and digitize a single frequency sub-band at time, possibly limiting the radio\'s effectiveness. Radio systems commonly tune hardware manually or use software controls to digitize sub-bands as needed, critically sampling those sub-bands according to the Nyquist criterion. Recent technology advancements have enabled efficient and cost-effective over-sampling of the spectrum, allowing all bandwidths of interest to be captured for processing simultaneously, a process known as band-sampling. Simultaneous access to measurements from all of the frequency sub-bands enables both awareness of the spectrum and seamless operation between radio applications, which is critical to many applications. Further, more information may be obtained for the spectral content of each sub-band from measurements of other sub-bands that could improve performance in applications such as detecting the presence of interference in weak signal measurements.
This thesis presents a new method for confirming the source of detected energy in weak signal measurements by sampling them directly, then estimating their expected effects. First, we assume that the detected signal is located within the frequency band as measured, and then we assume that the detected signal is, in fact, interference perceived as a result of signal aliasing. By comparing the expected effects to the entire measurement and assuming the power spectral density of the digitized bandwidth is sparse, we demonstrate the capability to identify the true source of the detected energy. We also demonstrate the ability of the method to identify interfering signals not by explicitly sampling them, but rather by measuring the signal aliases that they produce. Finally, we demonstrate that by leveraging techniques developed in the field of Compressed Sensing, the method can recover signal aliases by analyzing less than 25 percent of the total spectrum.
Master of Science
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Barale, Francesco. "Design of integrated frequency synthesizers and clock-data recovery for 60 GHz wireless communications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37216.
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In this dissertation, the development of the first 60 GHz-standard compatible fully integrated 4-channel phase-locked loop (PLL) frequency synthesizer has been presented. The frequency synthesizer features third-order single loop architecture with completely integrated passive loop filter that does not require any additional external passive component. Two possible realizations of fully integrated clock and data recovery (CDR) circuits suitable for 60 GHz-standard compliant base band signal processing have been presented for the first time as well. The two CDRs have been optimized for either high data rate (3.456 Gb/s) or very low power consumption (5 mW) and they both work with a single 1 V supply.
The frequency synthesizer is intended to generate a variable LO frequency in a fixed-IF heterodyne transceiver architecture. In such configuration the channel selection is implemented by changing the LO frequency by the required frequency step. This method avoids quadrature 50 GHz up/down-conversion thereby lowering the LO mixer design complexity and simplifying the LO distribution network. The measurement results show the PLL locking correctly on each of the four channels while consuming 60 mW from a 1 V power supply. The worst case phase noise is measured to be -80.1 dBc/Hz at 1 MHz offset from the highest frequency carrier (56.16 GHz). The output spectrum shows a reference spur attenuation of -32 dBc. The high data rate CDR features a maximum operating data rate in excess of 3.456 Gb/s while consuming 30 mW of power. The low power CDR consumes only 5 mW and operates at a maximum data rate of 1.728 Gb/s. Over a 1.5 m 60 GHz wireless link, both CDRs allow 95% reduction of the pulse shaping generated input peak-to-peak jitter from 450 ps down to 50 ps.
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Aljanaby, Usama Merry Salih [Verfasser], Rudolf [Akademischer Betreuer] Schilling, and Thomas [Akademischer Betreuer] Sattelmayer. "Numerical Simulation, Design and Optimization a Radial-Inflow Turbine for Energy Recovery Usage of Automobiles / Usama Merry Salih Aljanaby. Betreuer: Rudolf Schilling. Gutachter: Thomas Sattelmayer ; Rudolf Schilling." München : Universitätsbibliothek der TU München, 2015. http://d-nb.info/107997461X/34.
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Orndorff, Aaron. "Transceiver Design for Ultra-Wideband Communications." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/33179.
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Despite the fact ultra-wideband (UWB) technology has been around for over 30 years, there is a newfound excitement about its potential for communications. With the advantageous qualities of multipath immunity and low power spectral density, researchers are examining fundamental questions about UWB communication systems. In this work, we examine UWB communication systems paying particular attention to transmitter and receiver design.
This thesis is specifically focused on a software radio transceiver design for impulse-based UWB with the ability to transmit a raw data rate of 100 Mbps yet encompasses the adaptability of a reconfigurable digital receiver. A 500 ps wide Gaussian pulse is generated at the transmitter utilizing the fast-switching characteristics of a step recovery diode. Pulse modulation is accomplished via several stages of RF switches, filters, and amplifiers on a fully designed printed circuit board specifically manufactured for this project. Critical hardware components at the receiver consist of a bank of ADCs performing parallel sampling and an FPGA employed for data processing. Using a software radio design, various modulation schemes and digital receiver topologies are accommodated along with a vast number of algorithms for acquisition, synchronization, and data demodulation methods. Verification for the design is accomplished through transmitter hardware testing and receiver design simulation. The latter includes bit error rate testing for a variety of modulation schemes and wireless channels using a pilot-based matched filter estimation technique. Ultimately, the transceiver design demonstrates the advantages and challenges of UWB technology while boasting high data rate communication capability and providing the flexibility of a research testbed.
Master of Science
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Garcia-Romeu, Maria Luisa. "Contribución al estudio del proceso de doblado al aire de chapa. Modelo de predicción del ángulo de recuperación y del radio de doblado final." Doctoral thesis, Universitat de Girona, 2005. http://hdl.handle.net/10803/7763.
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Modelo de predicción de la geometría final de una pieza de chapa, radio y ángulo de doblado final, producida mediante un proceso de doblado al aire.Prediction model of final geometry of sheet metal part, radius and final bending angle, manufactured by air free -V bending process.
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D'Addato, Matteo. "Progetto di un PLL analogico a bassissimo consumo per sistemi wake-up radio." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17477/.
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Nei nodi wireless per applicazioni IoT, i ricetrasmettitori (transceiver) a radio-frequenza (RF) sono responsabili della maggior parte del consumo di potenza. Inoltre, se da un lato il picco di potenza assorbita avviene in corrispondenza degli istanti di trasmissione, dall’altro il ricevitore, che deve essere mantenuto sempre attivo anche quando il resto del sistema è in stato di “idle”, consuma una buona frazione dell’energia totale. Al fine di ridurre questo consumo, una particolare tipologia di ricevitori detti di “wake-up” sono tra i principali oggetti di ricerca nell’ambito dell’IoT. Essi hanno prestazioni ridotte e consumo molto basso, poiché devono restare sempre attivi mentre il resto del nodo è in stato di “idle”. Tale Wake-Up Radio (WUR) ha il compito di “ascoltare” il canale e attivare il ricevitore principale ed il microcontrollore solo quando c’è qualche richiesta in arrivo. Una parte integrante del ricevitore Wake-Up è il circuito per la decodifica dei byte trasmessi, che di solito comprendono almeno un codice d’indirizzo, che deve essere estratto e confrontato con l’indirizzo memorizzato nel ricevitore. Soltanto se questo confronto ha esito positivo viene attivato il resto del sistema.
L’obiettivo di questo lavoro di tesi è il progetto di un sistema di clock recovery basato su PLL analogico a bassissimo consumo per sistemi Wake-Up Radio di tipo short-range caratterizzati da una bit rate di 1 kbps. Tale sistema deve fornire alla rete di controllo un clock allineato in fase e frequenza con i dati ricevuti. Rispetto ad altri sistemi in cui si deve semplicemente decodificare un indirizzo, la soluzione basata su PLL oggetto di questo studio (poiché implica consumi e tempi di aggancio non trascurabili) è particolarmente adatta per lunghe trasmissioni. Nel progetto di un PLL a basso consumo l’obiettivo consiste nell’ottimizzare il trade-off tra consumo (con correnti nell’ordine del nanowatt) e tempo di aggancio.
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Yoon, Youngchang. "Reconfigurable CMOS RF power amplifiers for advanced mobile terminals." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/48987.
Full textAbstract:
In recent years, tremendous growth of the wireless market can be defined through the following words: smartphone and high-data rate wireless communication. This situation gives new challenges to RF power amplifier design, which includes high-efficiency, multi-band operation, and robustness to antenna mismatch conditions. In addition to these issues, the industry and consumers demand a low-cost small-sized wireless device. A fully integrated single-chip CMOS transceiver is the best solution in terms of cost and level of integration with other functional blocks. Therefore, the effective approaches in a CMOS process for the abovementioned hurdles are highly desirable. In this dissertation, the new challenges are overcome by introducing adaptability to a CMOS power amplifier. Meaningful achievements are summarized as follows. First, a new CMOS switched capacitor structure for high power applications is proposed. Second, a dual-mode CMOS PA with an integrated tunable matching network is proposed to extend battery lifetime. Third, a switchless dual-band matching structure is proposed, and the effectiveness of dual-band matching is demonstrated with a fully-integrated CMOS PA. Lastly, a reconfigurable CMOS PA with an automatic antenna mismatch recovery system is presented, which can maintain its original designed performance even under various antenna mismatch conditions. Conclusively, the research in this dissertation provides various solutions for new challenges of advanced mobile terminals.
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Roghair, Craig N. "Recovery From and Effects of a Catastrophic Flood and Debris Flow on the Brook Trout (Salvelinus fontinalis) Population and Instream Habitat of the Staunton River, Shenandoah National Park, VA." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/34286.
Full textAbstract:
The Staunton River is a high gradient, second order stream approximately 6 km in length located on the eastern slope of the Blue Ridge Mountains in Shenandoah National Park, VA. In June 1995, a catastrophic flood and debris flow altered the instream habitat and Salvelinus fontinalis population of the Staunton River. The debris flow scoured the streambed, deposited new substrate materials, removed trees from the riparian zone, and eliminated fish from a 1.9km section of the stream. By June 1998, both young-of-year (YOY) and age 1+ S. fontinalis had recolonized the debris flow affected area. The event provided a rare opportunity to examine recovery of the S. fontinalis population and instream habitat in addition to addressing potential effects of the debris flow on movement, activity, and growth of fish in the debris flow affected and unaffected areas of the stream.
Post-recolonization movement and activity were monitored using two-way fish traps (weirs), mark-recapture techniques, and radio telemetry. The weirs failed to produce any movement data. Most fish (91%) in the mark-recapture study had range sizes less than 100m, however biases common to mark-recapture study designs (low recapture rate, flawed logic, etc.) hampered interpretation of results. For example, subsequent recapture of individually marked fish indicated that as many as 54% of marked fish confirmed to have been alive at the time of a recapture session were not recaptured.
Radio telemetry provided information on S. fontinalis movement and activity at seasonal and diel scales during summer and fall. Differences in movement and activity between the debris flow affected and unaffected areas were minimal when compared to seasonal variations. During summer, range sizes were near 0m and crepuscular activity patterns were observed. During the fall range size increased and diel activity was concentrated in the mid-afternoon with a much higher peak than during summer.
Basin-wide visual estimation technique (BVET) fish population surveys performed each spring and fall from 1993 = 1999 provided pre- and post-event fish population abundance and density estimates. Post-event fish growth in the debris flow affected and unaffected areas was monitored using mark-recapture techniques. Abundance and density of both YOY and age 1+ S. fontinalis exceeded pre-event levels within 2-3 years. Growth of YOY and age 1+ fish was significantly greater in the debris flow affected area until spring 1999. Population density appeared to have a strong negative influence on growth. The observed changes in fish growth and differences in fish size associated with population density would be of minimal importance to the typical angler but may suggest a mechanism by which S. fontinalis populations can quickly recover from catastrophic events.
BVET habitat surveys provided information on total stream area, number of pools and riffles, pool and riffle surface area and depth, substrate composition, and large woody debris (LWD) before (1993), immediately following (1995), and four years post-event (1999). Immediately following the debris flow, the stream channel was highly disordered which resulted in an increase in the total number of habitat units and a decrease in average habitat unit surface area, total stream area, and average depth when compared with pre-event conditions. In addition, substrate composition had shifted from small to large diameter particles and LWD loading had increased in both debris flow affected and unaffected areas. Four years after the event, the total number of habitat units, average habitat unit surface area, total stream area, and average depth had all returned to near pre-debris flow levels and substrate composition had begun to shift towards smaller particle sizes. Changes in LWD loading from 1995-1999 reflected changes in the riparian zone following the debris flow. In the unaffected area, where riparian trees remained intact, LWD loading increased, whereas in the debris flow affected area, where riparian trees were eliminated, LWD loading decreased.
For the most part the effects of the debris flow, although immediately dramatic, were in the long term minimal. The debris flow affected area was recolonized rapidly and abundance and density quickly rebounded past pre-event levels. Differences in fish growth between the affected and unaffected area were short lived. Any effect the debris flow affected area may have had on movement or activity was minimal when compared with seasonal variations. Most habitat characteristics reverted to near pre-event levels just four years after the flood and debris flow. Although a number of factors will influence recovery time from such events, these results indicate that immediate management action, such as stocking or habitat modifications, are not necessary in all cases.Master of Science
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Šrámek, Petr. "Implementace softwarového rádia do FPGA." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217786.
Full textAbstract:
The common objective of this project is implementation of software defined radio (SDR) into FPGA. The text contains review and comparison of several hardware concepts intended for SDRs implementation then the methods for digital implementation of various components of radios as the filters, mixers and others are mentioned. Part of the text introduces used hardware platform and describes software support for designing, simulations and implementation into hardware. Significant part of project describes complex of external hardware components as filter, amplifier and control panel designed and built within the project realization. But the main part of project demonstrates design of the software solution of radio receiver. There is specified architecture of radio for FM broadcast receiving, next the more complex systems with carrier recovery algorithm are presented. These systems are able to work with AM, BPSK and QPSK modulations. It is possible to implement all these receivers into hardware and verify their operation. The practical laboratory theme has been outlined within the project run.
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Tall, Ndiogou. "Etude et réalisation de circuits de récupération d'horloge et de données analogiques et numériques pour des applications bas débit et très faible consommation." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4717.
Full textAbstract:
Les circuits de récupération d'horloge et de données sont nécessaires au bon fonctionnement de plusieurs systèmes de communication sans fil. Les travaux effectués dans le cadre de cette thèse concernent le développement de ces circuits avec d'une part la réalisation, en technologie HCMOS9 0,13 μm de STMICROELECTRONICS, de circuits CDR analogiques à 1 et 54 Mbit/s, et d'autre part, la mise en œuvre de fonctions CDR numériques programmables à bas débit. Un circuit CDR fonctionnant à plus bas débit (1 Mbit/s) a été conçu dans le cadre de la gestion d'énergie d'un récepteur ULB impulsionnel non cohérent. Ces deux structures ont été réalisées à l'aide de PLL analogiques du 3ème ordre. Un comparateur de phase adapté aux impulsions issues du détecteur d'énergie a été proposé dans cette étude. Les circuits ont ensuite été dimensionnés dans le but d'obtenir de très bonnes performances en termes de jitter et de consommation. En particulier, les performances mesurées (sous pointes) du circuit CDR à 1 Mbit/s permettent d'envisager une gestion d'énergie efficace (réduction de plus de 97% de la consommation du récepteur). Dans le cadre d'une chaîne de télémesure avion vers sol, deux circuits CDR numériques ont également été réalisés durant cette thèse. Une PLL numérique du second degré a été implémentée en vue de fournir des données et une horloge synchrone de celles-ci afin de piloter une chaîne SOQPSK entièrement numérique. Un circuit ELGS a également mis au point pour fonctionner au sein d'un récepteur PCM/FMClock and data recovery circuits are required in many wireless communication systems. This thesis is about development of such circuits with: firstly, the realization, in HCMOS9 0.13 μm of STMICROELECTRONICS technology, of 1 and 54 Mb/s analog CDR circuits, and secondly, the implementation of programmable digital circuits at low rates. In the aim of an impulse UWB transceiver dealing with video transmission, a CDR circuit at 54 Mb/s rate has been realized to provide clock signal synchronously with narrow pulses (their duration is about a few nanoseconds) from the energy detector. Another CDR circuit has been built at 1 Mb/s rate in a non-coherent IR- UWB receiver power management context. Both circuits have been implemented as 3rd order analog PLL. In this work, a phase comparator suitable for “RZ low duty cycle” data from the energy detector has been proposed. Circuits have been sized to obtain very good performances in terms of jitter and power consumption. Particularly, measured performances of the 1 Mb/s CDR circuit allow to plan an efficient power management (a decrease of more than 97% of the receiver total power consumption). In the context of a telemetry system from aircraft to ground, two digital CDR circuits have also been implemented. A second order digital PLL has been adopted in order to provide synchronous clock and data to an SOQPSK digital transmitter. Also, a digital ELGS circuit has been proposed to work in a PCM/FM receiver. For both CDR structures, the input signal rate is programmable and varies globally from 1 to 30 Mb/s
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Wang, Szu-po, and 王嗣伯. "An FPGA Implementation of Carrier and Symbol-Timing Recovery Techniques for Software Radios." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64548148873097000761.
Full text
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Chen, Chun-Chin, and 陳俊欽. "Effect of Early Occupational Therapy Home-based Exercise Intervention on Hand Functional Recovery for Casting of Distal Radius Fracture." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/65683594129709618250.
Full textAbstract:
碩士高雄醫學大學
職能治療學系碩士在職專班
104
Background and Purpose： The distal radius fracture is one of the common fractures in hand injury. Its occurrence might be related with age and gender, especially, the menopausal women (over 50 years of age), car accident and sport accident. After fracture, orthopedic management would apply plaster to fix the unstable site frequently. But, there are some sequelae complications after removing the plaster, including hand edema, upper extremity joints stiffness or contracture, less strength, pain and deformity. Occupatuonal performance, even activity of daily livings and psychological accommodation might be affected by such complication, if not appropriate treatment. There was few evidence-based study to investigate the effect of early therapeutic treatment after hand fracture. This study was designed to analyze the effect of early occupational therapy for distal radius fracture on hand functional recovery. Method： We recruited 30 participants who had distal radius fracture, from southern Taiwan Local-Teaching Hospital. Subjects were randomized assign into early intervention and controlled groups. In early intervention group, we introduced participants to home exercised programs after early injury two weeks, and the controlled group we conducted oral health care introduction. After removing the plaster (about four weeks), both groups would receive occupational therapy for 12 weeks. We evaluated participants’ joint range of motion, muscle strength, endurance, pain, edema, hand function and quality of live during the 2nd week, 4th week and 12th week after onset. Descriptive data and mixed type repeated measure analysis of covariance were utilized for data analysis. Participants first evaluation results was treated as covariant to control the group differences. Results： We found the early intervention group had better improvement than controlled group among joint range of motion, muscle strength, edema, pain, activity of daily living and hand function. Although, there were not significant statistic difference between two groups in active R.O.M., Purdue hand function test and Quick DASH. But if we consider the 2nd and 3rd evaluation results that there was better improvement in experiment group by mean difference among each parameter. Conclusion： Findings in this study show that the early intervention occupational therapy home program would actually improve in hand functional performance with the effects on decreased R.O.M. limitation in affected side of shoulder, elbow, wrist and fingers, released pain, decreased edema, improved circulation, prevention of tendon adhesion. Moreover, early intervention would benefit the unaffected joints in preventing joint stiffness and contracture, encouraging patients to use their affected limb early. That would promote patients’ quality of live and improved affected side hand function, decreased the unsuitable and inconvenient, consequently helped ADL independence and return to work early.
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Chen, Hui Ting, and 陳惠婷. "The Comparison of Internal Locking Plates and Non-locking Plates Fixation in Wrist Functional Recover for Distal Radius Fractures." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/5wwz3n.
Full textAbstract:
碩士亞洲大學
健康產業管理學系健康管理組碩士在職專班
102
Purpose: The purpose of this study is to investigate the comparison of locking plates and non-locking plates fixation in wrist functional recover for distal radius fractures. To provide surgeons and patients with distal radial fracture fixation bone plate reference is selected. Method: This study was a retrospective study, the first inspection by the case, the investigation of the distal radial fracture patients in January 2008 - June 2013 in a particular hospital .Selection of the bone plate internal fixation patients as research subjects. After the screening of the total number of 164.107 people use of fixed locking plates; fixed non-locking plates of 57 people in November 2013 - January 2014, in order to design their own questionnaires and DISABILITIES OF THE ARM, SHOULDER AND HAND QUESTIONNAIRE(DASH) conducted telephone interviews, DASH scores higher the higher the severity of disability. According to the DASH scores, with two-sample t-test, ANOVA analysis between different variables, recovery of function after wrist surgery differences, using locking and non-locking plates , variable distribution among the differences. To analyze the relevant factors affecting the distal radial fracture after wrist surgery recovery function with Multiple Linear Regression. Result: Distal radial fracture of female patients than men 22%, of which postmenopausal women for the majority(48.2%), based on bivariate analysis, postmenopausal women, 70 years or older, lower levels of education, post-operative DASH scores highest, showing its recovery after surgery the worst case, under the control of other variables, the use of locking plate wrist functional recover for distal radius fractures (DASH score) than non-locking bone plates good 1.37 times, in addition to the type of plates are significantly different than on postoperative wrist function, this study found that surgery age and educational level, factors that also affect functional recovery after wrist surgery, especially in the age at surgery exceed 60 years old , patients with low qualifications in higher education of patients after surgery, wrist functional recovery situation worse. Conclusion and Recommendation: Conclusions: The patients with distal fractures in postmenopausal women, aged 70 years and older, lower levels of education for the functional recovery after wrist worst case. Recommended: (1) More than 60 years and postmenopausal women, advocacy and encouragement should be conducted annually in bone density, enhance the prevention and treatment of osteoporosis and fall prevention knowledge, reducing the risk of fractures caused by falls. (2) Hospitals should focus on lower levels of education for senior citizens, and enhance self-care abilities after their surgery within six months, in order to increase their recovery wrist function. (3) The complexity of patients with osteoporosis or fractures in the economic conditions permit, consider using locking bone plate Distal radius fracture surgery.
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Arabi, Tamim. "Pulse Synchronization and Timing Recovery in Differential Code-Shifted Reference Impulse-Radio Ultra-Wideband (DCSR IR-UWB) System." 2013. http://hdl.handle.net/10222/21853.
Full textAbstract:
Ultra-wideband (UWB) is a revolutionary radio communication system that utilizes a large portion of the frequency spectrum while maintaining low power levels and high data rates. UWB systems can be used both indoors and outdoors within the power-level masks regulated by the Federal Communications Commission, thus making the technology very versatile. One of the main advantages of UWB is its robustness to multi-path diversity. The technology has attracted the interests of research and industry alike, owing to the possibility of implementing low-power, low-complexity, and low-cost devices.
A widely recognized method of transmitting UWB signals is the use of Impulse Radio technology to transmit information. Impulse Radio Ultra-Wideband (IR-UWB) uses repetitive pulses of very short duration, low duty cycle, and low power levels within FCC regulations. One implementation of IR-UWB pulses in non-coherent transmission is the use of Differential Code-Shifted Reference (DCSR) pulses. In this technique, one of the main challenges at the receiver is pulse-level synchronization that times the received pulses at the right moments for accurate pulse detection.
This thesis will introduce two design proposals in attempt to achieve the pulse synchronization. The first proposal is based on a fast-switch-controlled integrator circuit, while the second focuses on the use of an active low pass filter and phase-locked loop circuits to achieve proper clock timing. Both proposals will be presented, together with schematics, computer-aided simulations, and lab tests results.
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"A low power signal front-end for passive UHF RFID transponders with a new clock recovery circuit." 2009. http://library.cuhk.edu.hk/record=b5894042.
Full textAbstract:
Chan, Chi Fat.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references.
Abstracts in English and Chinese.
Abstract --- p.2
摘要 --- p.5
Acknowledgement --- p.7
Table of Contents --- p.9
List of Figures --- p.11
List of Tables --- p.14
Chapter 1. --- Introduction --- p.15
Chapter 1.2. --- Research Objectives --- p.16
Chapter 1.3. --- Thesis Organization --- p.18
Chapter 1.4. --- References --- p.19
Chapter 2. --- Overview of Passive UHF RFID Transponders --- p.20
Chapter 2.1. --- Types of RFID Transponders and Design Challenges of Passive RFID Transponder --- p.20
Chapter 2.2. --- Selection of Carrier Frequency --- p.22
Chapter 2.3. --- Description of Transponder Construction --- p.22
Chapter 2.3.1. --- Power-Generating Circuits --- p.23
Chapter 2.3.2. --- Base Band Processor --- p.28
Chapter 2.3.3. --- Signal Front-End --- p.29
Chapter 2.4. --- Summary --- p.30
Chapter 2.5. --- References --- p.31
Chapter 3. --- ASK Demodulator for EPC C-l G-2 Transponder --- p.32
Chapter 3.1. --- ASK Demodulator Design Considerations --- p.32
Chapter 3.1.1. --- Recovered Envelope Distortion --- p.32
Chapter 3.1.2. --- Input Power Level Considerations --- p.34
Chapter 3.1.3. --- Input RF power Intercepted by ASK Demodulator --- p.36
Chapter 3.2. --- ASK Demodulator Design From [3-4] --- p.36
Chapter 3.2.1. --- Envelope Waveform Recovery Design --- p.37
Chapter 3.2.1.1. --- Voltage Multiplier Branch for Generating Venv --- p.39
Chapter 3.2.1.2. --- Voltage Multiplier Branch for Generating Vref --- p.41
Chapter 3.2.2. --- Design Considerations for Sensitivity of ASK Demodulator --- p.41
Chapter 3.2.3. --- RF Input Power Sharing with Voltage Multiplier --- p.44
Chapter 3.2.4. --- ASK Demodulator and Voltage Multiplier Integrated Estimations for Maximum RF Power Input --- p.47
Chapter 3.2.5. --- Measurement result and Discussion --- p.49
Chapter 3.3. --- Proposed Envelope Detector Circuit --- p.52
Chapter 3.3.1. --- Sensitivity Estimation --- p.52
Chapter 3.3.2. --- Maximum Tolerable Input Power Estimation --- p.53
Chapter 3.3.3. --- Envelope Waveform Recovery of the Proposed Envelope Detector --- p.54
Chapter 3.4. --- Summary --- p.57
Chapter 3.5. --- References --- p.58
Chapter 4. --- Clock Generator for EPC C-l G-2 Transponder --- p.59
Chapter 4.1. --- Design Challenges Overview of Clock Generator --- p.59
Chapter 4.2. --- Brief Review of PIE Symbols in EPC C1G2 Standard --- p.62
Chapter 4.3. --- Proposed Clock Recovery Circuit Based on PIE Symbols for Clock Frequency Calibration --- p.64
Chapter 4.3.1. --- Illustration on PIE Symbols for Clock Frequency Calibration --- p.64
Chapter 4.3.2. --- Symbol time-length counter --- p.72
Chapter 4.3.3. --- The M2.56MHZ Reference Generator and Sampling Frequency Requirement --- p.75
Chapter 4.3.4. --- Symbol Length Reconfiguration for Different Tari and FLL Stability --- p.80
Chapter 4.3.5. --- Frequency Detector and Loop Filter --- p.83
Chapter 4.3.6. --- Proposed DCO Design --- p.84
Chapter 4.3.7. --- Measurement Results and Discussions --- p.88
Chapter 4.3.7.1. --- Frequency Calibration Measurement Results --- p.89
Chapter 4.3.7.2. --- Number x and Tari Variation --- p.92
Chapter 4.3.7.3. --- Temperature and Supply Variation --- p.93
Chapter 4.3.7.4. --- Transient Supply Variation --- p.94
Chapter 4.3.8. --- Works Comparison --- p.95
Chapter 4.4. --- Clock Generator with Embedded PIE Decoder --- p.96
Chapter 4.4.1. --- Clock Generator for Transponder Review --- p.96
Chapter 4.4.2. --- PIE Decoder Review --- p.97
Chapter 4.4.3. --- Proposed Clock Generator with Embedded PIE Decoder --- p.97
Chapter 4.4.4. --- Measurement Results and Discussions --- p.100
Chapter 4.5. --- Summary --- p.103
Chapter 4.6. --- References --- p.105
Chapter 5. --- ASK Modulator --- p.107
Chapter 5.1. --- Introduction to ASK Modulator in RFD Transponder --- p.107
Chapter 5.2. --- ASK Modulator Design --- p.109
Chapter 5.3. --- ASK Modulator Measurement --- p.110
Chapter 5.4. --- Summary --- p.113
Chapter 5.5. --- References --- p.113
Chapter 6. --- Conclusions --- p.114
Chapter 6.1. --- Contribution --- p.114
Chapter 6.2. --- Future Development --- p.116
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Aldubaikhy, Khalid. "Differential Code-Shifted Reference Impulse-Radio Ultra-Wideband Receiver: Timing Recovery and Digital Implementation." 2012. http://hdl.handle.net/10222/15244.
Full textAbstract:
Ultra-wideband (UWB) is a wireless system which transmits signals across a much wider frequency spectrum than traditional wireless systems. The impulse radio (IR) UWB technique uses ultra-short duration pulses of nanoseconds or less. The objective of this thesis is to provide the design, implementation and testing of the timing recovery between the transmitter and receiver of the recently emerging differential code-shifted reference (DCSR) Impulse radio (IR) ultra-wideband (UWB) system. A new non-coherent energy detection based technique and its algorithm are proposed for timing recovery by means of a phase-locked loop (PLL) circuit. Simulations are presented first to verify the proposed algorithm. Then, it is implemented and tested in the Lattice ECP2 field-programmable gate array (FPGA) evaluation board with VHDL codes (a VHSIC hardware description language). The simulation and implementation results show that the proposed timing recovery scheme can be effectively achieved without much error.
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Παπαδήμα, Ελισσάβετ. "Πειραματική αξιολόγηση μηχανισμού ανάκτησης ρυθμού συμβόλων για δορυφορικούς δέκτες." Thesis, 2011. http://nemertes.lis.upatras.gr/jspui/handle/10889/4664.
Full textAbstract:
Η παρούσα διπλωματική εργασία αφορά στην πειραματική αξιολόγηση του μηχανισμού ανάκτησης ρυθμού συμβόλου για ψηφιακούς δέκτες τεχνολογίας SDR που λαμβάνουν δεδομένα μέσω δορυφόρου. Η ορολογία SDR/SR (Software Defined Radio/Software Radio) χρησιμοποιείται για να χαρακτηρίσει τους πομποδέκτες που μπορούν να καθορίζουν σημαντικές παραμέτρους τους και βασικές αρχές της λειτουργίας τους μέσω αναβάθμισης ή ενημέρωσης του λογισμικού τους. Ο μηχανισμός ανάκτησης του ρυθμού συμβόλου (Symbol Timing Recovery, STR) αναπτύχθηκε στα πλαίσια της διδακτορικής διατριβής του διδάκτορος Παναγιώτη Σαββόπουλου. Η παρούσα εργασία μελετά τη σύγκλιση του βρόχου υπό συνθήκες παραμένοντος σφάλματος συχνότητας καθώς επίσης και τον προσδιορισμό του λόγου σήματος προς θόρυβο στην έξοδο του βρόχου κάνοντας χρήση ενός νέου μεγέθους, metric, το οποίο έχει εισαχθεί στα πλαίσια της προαναφερθείσας διδακτορικής διατριβής, υπό συνθήκες λευκού Gaussian θορύβου. Το μέγεθος αυτό είναι σε θέση να δώσει αξιόπιστα αποτελέσματα στις ενδιάμεσες υπομονάδες του δέκτη υπό συνθήκες παραμένοντος σφάλματος συχνότητας. Στην παρούσα εργασία μελετώνται οι QPSK, 8PSK, 16-APSK και 32-APSK διαμορφώσεις διότι αυτές οι διαμορφώσεις χρησιμοποιούνται από το πρότυπο DVB-S2.The purpose of this project is the experimental evaluation of a mechanism for the symbol timing recovery which is used in digital Software Defined Radio receivers. SDR/SR (Software Defined Radio/Software Radio) technology is used to characterise the transmitters and the receivers which are able to determine important parameters and basic primciples for their function through upgrade or briefing of their software. The symbol timing recovery mechanism (STR) was developped in terms of the doctora of dr Panagiotis Savopoylos. The precent project examines the loop’s convergence when there is frequency error as well as the signal to noise ratio in the output of STR with the use of a new size, metric, which was also developped in terms of the doctora which was mentioned before, when there is white Gaussian noise. The metric is able to give reliable results in the intermediate stages of the receiver when there is frequency error. In the precent project are examined the QPSK, 8PSK,16-APSK, 32-APSK modulations because these modulations are used in DVB-S2 standard.
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Wischerhoff, Marius. "Reconstruction of Structured Functions From Sparse Fourier Data." Doctoral thesis, 2015. http://hdl.handle.net/11858/00-1735-0000-001C-7131-B.
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Wang, Xiaoqing. "Real-time MRI and Model-based Reconstruction Techniques for Parameter Mapping of Spin-lattice Relaxation." Doctoral thesis, 2016. http://hdl.handle.net/11858/00-1735-0000-0023-3EEC-E.
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Sharma, Abhay. "Finding A Subset Of Non-defective Items From A Large Population : Fundamental Limits And Efficient Algorithms." Thesis, 2015. http://etd.iisc.ernet.in/handle/2005/2645.
Full textAbstract:
Consider a large population containing a small number of defective items. A commonly
encountered goal is to identify the defective items, for example, to isolate them. In the classical non-adaptive group testing (NAGT) approach, one groups the items into subsets, or pools, and runs tests for the presence of a defective itemon each pool. Using the outcomes the tests, a fundamental goal of group testing is to reliably identify the complete set of defective items with as few tests as possible. In contrast, this thesis studies a non-defective subset identification problem, where the primary goal is to identify a “subset” of “non-defective” items given the test outcomes. The main contributions of this thesis are:
We derive upper and lower bounds on the number of nonadaptive group tests
required to identify a given number of non-defective items with arbitrarily small
probability of incorrect identification as the population size goes to infinity. We
show that an impressive reduction in the number of tests is achievable compared
to the approach of first identifying all the defective items and then picking the
required number of non-defective items from the complement set. For example, in the asymptotic regime with the population size N → ∞, to identify L nondefective items out of a population containing K defective items, when the tests are reliable, our results show that O _ K logK L N _ measurements are sufficient when L ≪ N − K and K is fixed. In contrast, the necessary number of tests using the conventional approach grows with N as O _ K logK log N K_ measurements. Our
results are derived using a general sparse signal model, by virtue of which, they
are also applicable to other important sparse signal based applications such as
compressive sensing.
We present a bouquet of computationally efficient and analytically tractable nondefective subset recovery algorithms. By analyzing the probability of error of the
algorithms, we obtain bounds on the number of tests required for non-defective subset recovery with arbitrarily small probability of error. By comparing with the information theoretic lower bounds, we show that the upper bounds bounds on the number of tests are order-wise tight up to a log(K) factor, where K is the number of defective items. Our analysis accounts for the impact of both the additive noise (false positives) and dilution noise (false negatives). We also provide extensive simulation results that compare the relative performance of the
different algorithms and provide further insights into their practical utility. The
proposed algorithms significantly outperform the straightforward approaches of testing items one-by-one, and of first identifying the defective set and then choosing the non-defective items from the complement set, in terms of the number of measurements required to ensure a given success rate.
We investigate the use of adaptive group testing in the application of finding a
spectrum hole of a specified bandwidth in a given wideband of interest. We propose
a group testing based spectrum hole search algorithm that exploits sparsity in the primary spectral occupancy by testing a group of adjacent sub-bands in a single test. This is enabled by a simple and easily implementable sub-Nyquist sampling scheme for signal acquisition by the cognitive radios. Energy-based hypothesis tests are used to provide an occupancy decision over the group of sub-bands, and this forms the basis of the proposed algorithm to find contiguous spectrum holes of a specified bandwidth. We extend this framework to a multistage sensing algorithm that can be employed in a variety of spectrum sensing scenarios, including non-contiguous spectrum hole search. Our analysis allows one to identify the sparsity and SNR regimes where group testing can lead to significantly lower detection delays compared to a conventional bin-by-bin energy detection scheme. We illustrate the performance of the proposed algorithms via Monte Carlo simulations.
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Καρνέζης, Ιωάννης. "Μελέτη μιας μεθόδου ελάχιστα επεμβατικής οστεοσύνθεσης καταγμάτων του περιφερικού άκρου της κερκίδας." 2006. http://nemertes.lis.upatras.gr/jspui/handle/10889/349.
Full textAbstract:
Παρά τον μεγάλο όγκο της βιβλιογραφίας σχετικά με τα αποτελέσματα της αντιμετώπισης των ασταθών καταγμάτων του περιφερικού άκρου της κερκίδας με κλειστή ανάταξη και ελάχιστα επεμβατική οστεοσύνθεση υπάρχουν ακόμα σημαντικά αναπάντητα ερωτήματα. Πιό συγκεκριμένα, δεν υπάρχουν επαρκή στοιχεία γιά τον ρυθμό αποκατάστασης των κλινικών παραμέτρων κατά τη διάρκεια της μετατραυματικής περιόδου, γιά το τελικό αποτέλεσμα όπως εκφράζεται από τους ασθενείς με τη χρήση κλιμάκων αυτο-αξιολόγησης, καθώς και γιά τον βαθμό επίδρασης συγκεκριμένων ακτινολογικών παραμέτρων στο τελικό λειτουργικό αποτέλεσμα. Επίσης, δεν έχει διερευνηθεί ο συσχετισμός μεταξύ της ακτινολογικής παραμέτρου της παλαμιαίας γωνίας του περιφερικού άκρου της κερκίδας και των φορτίων που αναπτύσσονται στην φυσιολογική κερκιδοκαρπική άρθρωση. Η εργασία αυτή αποτελεί μία προοπτική μελέτη ασταθών καταγμάτων του περιφερικού άκρου της κερκίδας που αντιμετωπίστηκαν με κλειστή ανάταξη και ελάχιστα επεμβατική (διαδερμική) οστεοσύνθεση. Έγινε ανάλυση ακτινολογικών και κλινικών παραμέτρων καθώς και χρησιμοποίηση κλίμακας αυτο-αξιολόγησης της δυσλειτουργίας της πηχεοκαρπικής άρθρωσης γιά συνολικό διάστημα ενός έτους μετά τον τραυματισμό. Τα αποτελέσματα έδειξαν ότι ο ‘τυπικός’ ρυθμός μετατραυματικής αποκατάστασης αντιστοιχεί σε ταχεία κλινική βελτίωση κατά τη διάρκεια των τριών πρώτων μηνών ακολουθούμενη από ήπιου βαθμού δυσλειτουργία. Ωστόσο σημαντική δυσλειτουργία παραμένει σε 10% των ασθενών ένα έτος μετά τον τραυματισμό. Επίσης, τα αποτελέσματα δείχνουν σημαντικές διαφορές στο βαθμό κατά τον οποίο ο περιορισμός συγκεκριμένων αντικειμενικών κλινικών παραμέτρων αντανακλά το επίπεδο δυσλειτουργίας της πηχεοκαρπικής άρθρωσης. Ακτινολογικά, η μόνιμη απώλεια της παλαμιαίας γωνίας, η κερκιδική βράχυνση και η παρουσία ανωμαλίας της αρθρικής επιφάνειας της πηχεοκαρπικής με αρθρικό ‘βήμα’ τουλάχιστον ενός χιλιοστού σχετίζονται με επιμένοντα συμπτώματα πόνου και δυσλειτουργίας, ενώ δεν υπάρχει εμφανής συσχέτιση μεταξύ του τύπου του κατάγματος και του τελικού λειτουργικού αποτελέσματος. Επιπλέον, ανάλυση δυνάμεων της φυσιολογικής πηχεοκαρπικής άρθρωσης έδειξε φορτίσεις που μπορεί να φθάνουν έως 4,2 φορές το ανυψούμενο βάρος, αντίστροφο συσχετισμό μεταξύ της παλαμιαίας γωνίας του περιφερικού άκρου της κερκίδας και του μέγιστου φορτίου στην κερκιδοκαρπική άρθρωση καθώς και μη σημαντική διαφορά μεταξύ της γωνίας διεύθυνσης του μέγιστου φορτίου της κερκιδοκαρπικής και της παλαμιαίας γωνίας του περιφερικού άκρου της κερκίδας.Despite the large volume of published literature on the results of management of unstable fractures of the distal radius using closed reduction and minimally invasive fixation there are still significant unanswered questions. More specifically, there is no sufficient evidence about the rate of recovery of the clinical parameters over the post-traumatic period, the final outcome as expressed by the patients using self-assessment scores and the degree that specific radiographic parameters influence the final functional outcome. Furthermore, the correlation between the radiographic parameter of volar tilt of the distal radius and the normal loads in the radiocarpal joint has not been investigated. The present thesis is a prospective study of unstable fractures of the distal radius managed with closed reduction and minimally invasive (percutaneous) fixation. Analysis of radiographic and clinical parameters as well as of patient-rated wrist dysfunction score for one year following injury was carried out. The results showed that a ‘typical’ rate of post-traumatic recovery corresponds to an initial rapid clinical improvement for the first three months followed by mild wrist dysfunction. However, significant dysfunction persists in 10% of patients one year following injury. Furthermore, the results showed significant differences in the degree to which the restriction of specific objective clinical parameters reflected the level of wrist dysfunction. Regarding the radiographic parameters, permanent loss of palmar tilt of the distal radius, radial shortening and the presence of articular incongruency with an articular ‘step off’ of at least 1 mm correlate with persisting pain and dysfunction while there is no obvious correlation between the fracture type and the final functional outcome. Moreover, force analysis in the normal wrist showed loads as high as 4.2 times the lifted weight, a reverse relationship between the angle of palmar tilt of the distal radius and the maximum radiocarpal load as well as a nonsignificant difference between the angle of the maximum radiocarpal force and the angle of palmar tilt of the distal radius.
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Hamza, Syed Muhammad Farrukh. "Shear-enhanced permeability and poroelastic deformation in unconsolidated sands." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-08-6353.
Full textAbstract:
Heavy oil production depends on the understanding of mechanical and flow properties of unconsolidated or weakly consolidated sands under different loading paths and boundary conditions. Reconstituted bitumen-free Athabasca oil-sands samples were used to investigate the geomechanics of a steam injection process such as the Steam Assisted Gravity Drainage (SAGD). Four stress paths have been studied in this work: triaxial compression, radial extension, pore pressure increase and isotropic compression. Absolute permeability, end-point relative permeability to oil & water (kro and krw), initial water saturation and residual oil saturation were measured while the samples deformed.
Triaxial compression is a stress path of increasing mean stress while radial extension and pore pressure increase lead to decreasing mean stress. Pore pressure increase experiments were carried out for three initial states: equal axial and confining stresses, axial stress greater than confining stress and confining stress greater than axial stress. Pore pressure was increased under four boundary conditions: 1) constant axial and confining stress; 2) constant axial stress and zero radial strain; 3) zero axial strain and constant confining stress; and 4) zero axial and radial strain. These experiments were designed to mimic geologic conditions where vertical stress was either S1 or S3, the lateral boundary conditions were either zero strain or constant stress, and the vertical boundary conditions were either zero strain or constant stress.
Triaxial compression caused a decrease in permeability as the sample compacted, followed by appreciable permeability enhancement during sample dilation. Radial extension led to sample dilation, shear failure and permeability increase from the beginning. The krw and kro increased by 40% and 15% post-compaction respectively for the samples corresponding to lower depths during triaxial compression. For these samples, residual oil saturation decreased by as much as 40%. For radial extension, the permeability enhancement decreased with depth and ranged from 20% to 50% while the residual oil saturation decreased by up to 55%. For both stress paths, more shear-enhanced permeability was observed for samples tested at lower pressures, implying that permeability enhancement is higher for shallower sands. The pore pressure increase experiments showed an increase of only 0-10% in absolute permeability except when the effective stress became close to zero. This could possibly have occurred due to steady state flow not being reached during absolute permeability measurement. The krw curves generally increased as the pore pressure was increased from 0 psi. The increase ranged from 5% to 44% for the different boundary conditions and differential stresses. The kro curves also showed an increasing trend for most of the cases. The residual oil saturation decreased by 40-60% for samples corresponding to shallow depths while it increased by 0-10% for samples corresponding to greater depths. The reservoirs with high differential stress are more conducive to favorable changes in permeability and residual oil saturation. These results suggested that a decreasing mean stress path is more beneficial for production increase than an increasing mean stress path. The unconsolidated sands are over-consolidated because of previous ice loading which makes the sand matrix stiffer. In this work, it was found that over-consolidation, as expected, decreased the porosity and permeability (40-50%) and increased the Young’s and bulk moduli of the sand. The result is sand which failed at higher than expected stress during triaxial compression.
Overall, results show that lab experiments support increased permeability due to steam injection operations in heavy oil, and more importantly, the observed reduction in residual oil saturation implies SAGD induced deformation should improve recovery factors.text