Design and implementation of generalized topologies of time-interleaved variable bandpass Σ−Δ modulators

In this thesis, novel analog-to-digital and digital-to-analog generalized time-interleaved variable bandpass sigma-delta modulators are designed, analysed, evaluated and implemented that are suitable for high performance data conversion for a broad-spectrum of applications. These generalized time-interleaved variable bandpass sigma-delta modulators can perform noise-shaping for any centre frequency from DC to Nyquist. The proposed topologies are well-suited for Butterworth, Chebyshev, inverse-Chebyshev and elliptical filters, where designers have the flexibility of specifying the centre frequency, bandwidth as well as the passband and stopband attenuation parameters. The application of the time-interleaving approach, in combination with these bandpass loop-filters, not only overcomes the limitations that are associated with conventional and mid-band resonator-based bandpass sigma-delta modulators, but also offers an elegant means to increase the conversion bandwidth, thereby relaxing the need to use faster or higher-order sigma-delta modulators. A step-by-step design technique has been developed for the design of time-interleaved variable bandpass sigma-delta modulators. Using this technique, an assortment of lower- and higher-order single- and multi-path generalized A/D variable bandpass sigma-delta modulators were designed, evaluated and compared in terms of their signal-to-noise ratios, hardware complexity, stability, tonality and sensitivity for ideal and non-ideal topologies. Extensive behavioural-level simulations verified that one of the proposed topologies not only used fewer coefficients but also exhibited greater robustness to non-idealties. Furthermore, second-, fourth- and sixth-order single- and multi-path digital variable bandpass digital sigma-delta modulators are designed using this technique. The mathematical modelling and evaluation of tones caused by the finite wordlengths of these digital multi-path sigmadelta modulators, when excited by sinusoidal input signals, are also derived from first principles and verified using simulation and experimental results. The fourth-order digital variable-band sigma-delta modulator topologies are implemented in VHDL and synthesized on Xilinx® SpartanTM-3 Development Kit using fixed-point arithmetic. Circuit outputs were taken via RS232 connection provided on the FPGA board and evaluated using MATLAB routines developed by the author. These routines included the decimation process as well. The experiments undertaken by the author further validated the design methodology presented in the work. In addition, a novel tunable and reconfigurable second-order variable bandpass sigma-delta modulator has been designed and evaluated at the behavioural-level. This topology offers a flexible set of choices for designers and can operate either in single- or dual-mode enabling multi-band implementations on a single digital variable bandpass sigma-delta modulator. This work is also supported by a novel user-friendly design and evaluation tool that has been developed in MATLAB/Simulink that can speed-up the design, evaluation and comparison of analog and digital single-stage and time-interleaved variable bandpass sigma-delta modulators. This tool enables the user to specify the conversion type, topology, loop-filter type, path number and oversampling ratio.

Design and Development of Cooperative caching Framework for improving Data Accessibility in Wireless AD HOC Networks

Cochin University of Science & Technology

Design and development of a diagonal-airflow batch dryer for spatial drying homogeneity

Das Verfahren der Lebensmitteltrocknung wird häufig angewendet, um ein Produkt für längere Zeit haltbar zu machen. Obst und Gemüse sind aufgrund ihres hohen Wassergehalts leicht verderblich durch biochemische Vorgänge innerhalb des Produktes, nicht sachgemäße Lagerung und unzureichende Transportmöglichkeiten. Um solche Verluste zu vermeiden wird die direkte Trocknung eingesetzt, welche die älteste Methode zum langfristigen haltbarmachen ist. Diese Methode ist jedoch veraltet und kann den heutigen Herausforderungen nicht gerecht werden. In der vorliegenden Arbeit wurde ein neuer Chargentrockner, mit diagonalem Luftstömungskanal entlang der Länge des Trocknungsraumes und ohne Leitbleche entwickelt. Neben dem unbestreitbaren Nutzen der Verwendung von Leitblechen, erhöhen diese jedoch die Konstruktionskosten und führen auch zu einer Erhöhung des Druckverlustes. Dadurch wird im Trocknungsprozess mehr Energie verbraucht. Um eine räumlich gleichmäßige Trocknung ohne Leitbleche zu erreichen, wurden die Lebensmittelbehälter diagonal entlang der Länge des Trockners platziert. Das vorrangige Ziel des diagonalen Kanals war, die einströmende, warme Luft gleichmäßig auf das gesamte Produkt auszurichten. Die Simulation des Luftstroms wurde mit ANSYS-Fluent in der ANSYS Workbench Plattform durchgeführt. Zwei verschiedene Geometrien der Trocknungskammer, diagonal und nicht diagonal, wurden modelliert und die Ergebnisse für eine gleichmäßige Luftverteilung aus dem diagonalen Luftströmungsdesign erhalten. Es wurde eine Reihe von Experimenten durchgeführt, um das Design zu bewerten. Kartoffelscheiben dienten als Trocknungsgut. Die statistischen Ergebnisse zeigen einen guten Korrelationskoeffizienten für die Luftstromverteilung (87,09%) zwischen dem durchschnittlich vorhergesagten und der durchschnittlichen gemessenen Strömungsgeschwindigkeit. Um den Effekt der gleichmäßigen Luftverteilung auf die Veränderung der Qualität zu bewerten, wurde die Farbe des Produktes, entlang der gesamten Länge der Trocknungskammer kontaktfrei im on-line-Verfahren bestimmt. Zu diesem Zweck wurde eine Imaging-Box, bestehend aus Kamera und Beleuchtung entwickelt. Räumliche Unterschiede dieses Qualitätsparameters wurden als Kriterium gewählt, um die gleichmäßige Trocknungsqualität in der Trocknungskammer zu bewerten. Entscheidend beim Lebensmittel-Chargentrockner ist sein Energieverbrauch. Dafür wurden thermodynamische Analysen des Trockners durchgeführt. Die Energieeffizienz des Systems wurde unter den gewählten Trocknungsbedingungen mit 50,16% kalkuliert. Die durchschnittlich genutzten Energie in Form von Elektrizität zur Herstellung von 1kg getrockneter Kartoffeln wurde mit weniger als 16,24 MJ/kg und weniger als 4,78 MJ/kg Wasser zum verdampfen bei einer sehr hohen Temperatur von jeweils 65°C und Scheibendicken von 5mm kalkuliert. Die Energie- und Exergieanalysen für diagonale Chargentrockner wurden zudem mit denen anderer Chargentrockner verglichen. Die Auswahl von Trocknungstemperatur, Massenflussrate der Trocknungsluft, Trocknerkapazität und Heiztyp sind die wichtigen Parameter zur Bewertung der genutzten Energie von Chargentrocknern. Die Entwicklung des diagonalen Chargentrockners ist eine nützliche und effektive Möglichkeit um dei Trocknungshomogenität zu erhöhen. Das Design erlaubt es, das gesamte Produkt in der Trocknungskammer gleichmäßigen Luftverhältnissen auszusetzen, statt die Luft von einer Horde zur nächsten zu leiten.

Laboratory performance evaluation of CIR-emulsion and its comparison against CIR-foam test results from Phase III, TR-578

Currently, no standard mix design procedure is available for CIR-emulsion in Iowa. The CIR-foam mix design process developed during the previous phase is applied for CIR-emulsion mixtures with varying emulsified asphalt contents. Dynamic modulus test, dynamic creep test, static creep test and raveling test were conducted to evaluate the short- and long-term performance of CIR-emulsion mixtures at various testing temperatures and loading conditions. A potential benefit of this research is a better understanding of CIR-emulsion material properties in comparison with those of CIR-foam material that would allow for the selection of the most appropriate CIR technology and the type and amount of the optimum stabilization material. Dynamic modulus, flow number and flow time of CIR-emulsion mixtures using CSS-1h were generally higher than those of HFMS-2p. Flow number and flow time of CIR-emulsion using RAP materials from Story County was higher than those from Clayton County. Flow number and flow time of CIR-emulsion with 0.5% emulsified asphalt was higher than CIR-emulsion with 1.0% or 1.5%. Raveling loss of CIR-emulsion with 1.5% emulsified was significantly less than those with 0.5% and 1.0%. Test results in terms of dynamic modulus, flow number, flow time and raveling loss of CIR-foam mixtures are generally better than those of CIR-emulsion mixtures. Given the limited RAP sources used for this study, it is recommended that the CIR-emulsion mix design procedure should be validated against several RAP sources and emulsion types.

Design and implementation of BIRDY satellite data and Radiation Payload simulators

Numerical modelling and simulations are needed to develop and test specific analysis methods by providing test data before BIRDY would be launched. This document describes the "satellite data simulator" which is a multi-sensor, multi-spectral satellite simulator produced especially for the BIRDY mission which could be used as well to analyse data from other satellite missions providing energetic particles data in the Solar system.

Polymer Concrete Overlay Evaluation, 2016

The objectives of this work were to document the state-of-the-practice with respect to polymer concrete overlays, document the placement of two overlays in Iowa, monitor the field performance of the overlays over a two-year period, and relate their performance to material usage and/or workmanship. The two bridges - a Johnson County, Iowa bridge over I-80 on 12th Avenue in Coralville, and the Keg Creek Bridge on Hwy 6 in western Iowa, 10 miles east of Council Bluffs - were overlaid during the summer/fall of 2013. The process by which each bridge was overlaid was similar in many ways, although a few slight differences existed. Over time, each overlay has generally performed quite well with only a few areas of exception. It is believed that these localized areas likely underperformed due to poor deck preparation, improper polymer mixing, snowplow impact, or a combination thereof.

Design and modeling of optical fibers for spatial division multiplexing using the orbital angular momentum of light

Les besoins toujours croissants en terme de transfert de données numériques poussent au développement de nouvelles technologies pour accroître la capacité des réseaux, notamment en ce qui concerne les réseaux de fibre optique. Parmi ces nouvelles technologies, le multiplexage spatial permet de multiplier la capacité des liens optiques actuels. Nous nous intéressons particulièrement à une forme de multiplexage spatial utilisant le moment cinétique orbital de la lumière comme base orthogonale pour séparer un certain nombre de canaux. Nous présentons d’abord les notions d’électromagnétisme et de physique nécessaires à la compréhension des développements ultérieurs. Les équations de Maxwell sont dérivées afin d’expliquer les modes scalaires et vectoriels de la fibre optique. Nous présentons également d’autres propriétés modales, soit la coupure des modes, et les indices de groupe et de dispersion. La notion de moment cinétique orbital est ensuite introduite, avec plus particulièrement ses applications dans le domaine des télécommunications. Dans une seconde partie, nous proposons la carte modale comme un outil pour aider au design des fibres optiques à quelques modes. Nous développons la solution vectorielle des équations de coupure des modes pour les fibres en anneau, puis nous généralisons ces équations pour tous les profils de fibres à trois couches. Enfin, nous donnons quelques exemples d’application de la carte modale. Dans la troisième partie, nous présentons des designs de fibres pour la transmission des modes avec un moment cinétique orbital. Les outils développés dans la seconde partie sont utilisés pour effectuer ces designs. Un premier design de fibre, caractérisé par un centre creux, est étudié et démontré. Puis un second design, une famille de fibres avec un profil en anneau, est étudié. Des mesures d’indice effectif et d’indice de groupe sont effectuées sur ces fibres. Les outils et les fibres développés auront permis une meilleure compréhension de la transmission dans la fibre optique des modes ayant un moment cinétique orbital. Nous espérons que ces avancements aideront à développer prochainement des systèmes de communications performants utilisant le multiplexage spatial.

The Design and Development of Educational Immersive Environments: From Theory to Classroom Deployment

Computer game technology is poised to make a significant impact on the way our youngsters will learn. Our youngsters are ‘Digital Natives’, immersed in digital technologies, especially computer games. They expect to utilize these technologies in learning contexts. This expectation, and our response as educators, may change classroom practice and inform curriculum developments. This chapter approaches these issues ‘head on’. Starting from a review of the current educational issues, an evaluation of educational theory and instructional design principles, a new theoretical approach to the construction of “Educational Immersive Environments” (EIEs) is proposed. Elements of this approach are applied to development of an EIE to support Literacy Education in UK Primary Schools. An evaluation of a trial within a UK Primary School is discussed. Conclusions from both the theoretical development and the evaluation suggest how future teacher-practitioners may embrace both the technology and our approach to develop their own learning resources.

Iowa Scenic/Heritage Byway Evaluation, 2000

This report documents the results of the field inventory and evaluation of the nominated routes. Data is provided describing the visual and heritage character of the nominated routes and locations important to this character. Graphs, displays and maps were produced using the rating system described in the Iowa Scenic Byway Designation Guide. Discussions of specific inventory procedures and evaluation techniques can be found in two reports, Iowa Scenic Byway Evaluation, December 1992, and Iowa Scenic Byway Evaluation, November 1995.

Iowa Scenic/Heritage Byway Evaluation, 2001

This report documents the results of the field inventory and evaluation of the nominated routes. Data is provided describing the visual and heritage character of the nominated routes and locations important to this character. Graphs, displays and maps were produced using the rating system described in the Iowa Scenic Byway Designation Guide. Discussions of specific inventory procedures and evaluation techniques can be found in two reports, Iowa Scenic Byway Evaluation, December 1992, and Iowa Scenic Byway Evaluation, November 1995.

“It’s the People That Drive It”: Motivating and Supporting Collaborative Data Use Practices in Three Teacher Education Programs

Thesis (Ph.D.)--University of Washington, 2016-08

The design and Evaluation of 'CAP Tools' - A computer aided parallelisation tool-kit

Abstract not available

PICTOAPRENDE: Design and evaluation of a tool that contributes to the personal autonomy of children and youth diagnosed with autism spectrum disorder in Ecuador

This paper presents the development and evaluation of PICTOAPRENDE, which is an interactive software designed to improve oral communication. Additionally, it contributes to the development of children and youth who are diagnosed with autism spectrum disorder (ASD) in Ecuador. To fulfill this purpose initially analyzes the intervention area where the general characteristics of people with ASD and their status in Ecuador is described. Statistical techniques used for this evaluation constitutes the basis of this study. A section that presents the development of research-based cognitive and social parameters of the area of intervention is also shown. Finally, the algorithms to obtain the measurements and experimental results along with the analysis of them are presented.

Using interaction data for improving the offline and online evaluation of search engines

This thesis investigates how web search evaluation can be improved using historical interaction data. Modern search engines combine offline and online evaluation approaches in a sequence of steps that a tested change needs to pass through to be accepted as an improvement and subsequently deployed. We refer to such a sequence of steps as an evaluation pipeline. In this thesis, we consider the evaluation pipeline to contain three sequential steps: an offline evaluation step, an online evaluation scheduling step, and an online evaluation step. In this thesis we show that historical user interaction data can aid in improving the accuracy or efficiency of each of the steps of the web search evaluation pipeline. As a result of these improvements, the overall efficiency of the entire evaluation pipeline is increased. Firstly, we investigate how user interaction data can be used to build accurate offline evaluation methods for query auto-completion mechanisms. We propose a family of offline evaluation metrics for query auto-completion that represents the effort the user has to spend in order to submit their query. The parameters of our proposed metrics are trained against a set of user interactions recorded in the search engine’s query logs. From our experimental study, we observe that our proposed metrics are significantly more correlated with an online user satisfaction indicator than the metrics proposed in the existing literature. Hence, fewer changes will pass the offline evaluation step to be rejected after the online evaluation step. As a result, this would allow us to achieve a higher efficiency of the entire evaluation pipeline. Secondly, we state the problem of the optimised scheduling of online experiments. We tackle this problem by considering a greedy scheduler that prioritises the evaluation queue according to the predicted likelihood of success of a particular experiment. This predictor is trained on a set of online experiments, and uses a diverse set of features to represent an online experiment. Our study demonstrates that a higher number of successful experiments per unit of time can be achieved by deploying such a scheduler on the second step of the evaluation pipeline. Consequently, we argue that the efficiency of the evaluation pipeline can be increased. Next, to improve the efficiency of the online evaluation step, we propose the Generalised Team Draft interleaving framework. Generalised Team Draft considers both the interleaving policy (how often a particular combination of results is shown) and click scoring (how important each click is) as parameters in a data-driven optimisation of the interleaving sensitivity. Further, Generalised Team Draft is applicable beyond domains with a list-based representation of results, i.e. in domains with a grid-based representation, such as image search. Our study using datasets of interleaving experiments performed both in document and image search domains demonstrates that Generalised Team Draft achieves the highest sensitivity. A higher sensitivity indicates that the interleaving experiments can be deployed for a shorter period of time or use a smaller sample of users. Importantly, Generalised Team Draft optimises the interleaving parameters w.r.t. historical interaction data recorded in the interleaving experiments. Finally, we propose to apply the sequential testing methods to reduce the mean deployment time for the interleaving experiments. We adapt two sequential tests for the interleaving experimentation. We demonstrate that one can achieve a significant decrease in experiment duration by using such sequential testing methods. The highest efficiency is achieved by the sequential tests that adjust their stopping thresholds using historical interaction data recorded in diagnostic experiments. Our further experimental study demonstrates that cumulative gains in the online experimentation efficiency can be achieved by combining the interleaving sensitivity optimisation approaches, including Generalised Team Draft, and the sequential testing approaches. Overall, the central contributions of this thesis are the proposed approaches to improve the accuracy or efficiency of the steps of the evaluation pipeline: the offline evaluation frameworks for the query auto-completion, an approach for the optimised scheduling of online experiments, a general framework for the efficient online interleaving evaluation, and a sequential testing approach for the online search evaluation. The experiments in this thesis are based on massive real-life datasets obtained from Yandex, a leading commercial search engine. These experiments demonstrate the potential of the proposed approaches to improve the efficiency of the evaluation pipeline.

DESIGN OF EFFICIENT IN-NETWORK DATA PROCESSING AND DISSEMINATION FOR VANETS

By providing vehicle-to-vehicle and vehicle-to-infrastructure wireless communications, vehicular ad hoc networks (VANETs), also known as the “networks on wheels”, can greatly enhance traffic safety, traffic efficiency and driving experience for intelligent transportation system (ITS). However, the unique features of VANETs, such as high mobility and uneven distribution of vehicular nodes, impose critical challenges of high efficiency and reliability for the implementation of VANETs. This dissertation is motivated by the great application potentials of VANETs in the design of efficient in-network data processing and dissemination. Considering the significance of message aggregation, data dissemination and data collection, this dissertation research targets at enhancing the traffic safety and traffic efficiency, as well as developing novel commercial applications, based on VANETs, following four aspects: 1) accurate and efficient message aggregation to detect on-road safety relevant events, 2) reliable data dissemination to reliably notify remote vehicles, 3) efficient and reliable spatial data collection from vehicular sensors, and 4) novel promising applications to exploit the commercial potentials of VANETs. Specifically, to enable cooperative detection of safety relevant events on the roads, the structure-less message aggregation (SLMA) scheme is proposed to improve communication efficiency and message accuracy. The scheme of relative position based message dissemination (RPB-MD) is proposed to reliably and efficiently disseminate messages to all intended vehicles in the zone-of-relevance in varying traffic density. Due to numerous vehicular sensor data available based on VANETs, the scheme of compressive sampling based data collection (CS-DC) is proposed to efficiently collect the spatial relevance data in a large scale, especially in the dense traffic. In addition, with novel and efficient solutions proposed for the application specific issues of data dissemination and data collection, several appealing value-added applications for VANETs are developed to exploit the commercial potentials of VANETs, namely general purpose automatic survey (GPAS), VANET-based ambient ad dissemination (VAAD) and VANET based vehicle performance monitoring and analysis (VehicleView). Thus, by improving the efficiency and reliability in in-network data processing and dissemination, including message aggregation, data dissemination and data collection, together with the development of novel promising applications, this dissertation will help push VANETs further to the stage of massive deployment.