Dissertations / Theses: 'Digital systems'

1

Cereceda, Francisco, Sharif Chacoff, Ignacio Montiglio, Giordana Saavedra, and Sergio Sariego. "Digital systems." Tesis, Universidad de Chile, 2009. http://www.repositorio.uchile.cl/handle/2250/111669.

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Tesis para optar al grado de Magíster en Administración (MBA)
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La promulgación y entrada en vigencia en abril de 2009 de la Ley 20285 de transparencia y acceso a la información pública obliga a los órganos del Estado a disponer de herramientas y formas expeditas y rápidas, que atiendan y respondan los requerimientos que cualquier ciudadano u organización realice acerca de información que el organismo posea y administre. La aplicación de esta normativa encuentra a los órganos del Estado en una situación de precariedad estructural compleja de resolver en cuanto a la capacidad de responder a los requerimientos de información, sobre todo con aquella dimensión que se denomina Transparencia Pasiva y que se refiere a la información histórica acumulada por años en forma física, comúnmente sin respaldo y sin posibilidad de acceso rápido y expedito a ella. En las primeras 32 semanas de vigencia de la ley, según el informe n°8 de la Comisión de Probidad y Transparencia1 de noviembre de 2009, se han registrado 22073 solicitudes de información realizadas por ciudadanos y organizaciones a los diversos órganos del ejecutivo a los que se les aplica la norma, excluyendo a los municipios. De la investigación realizada (ver anexo 3) se desprende que no han tenido mayor dificultad para responder en tiempo y oportunidad cuando la información requerida corresponde a una antigüedad no mayor a 3 años. Esta situación se revierte cuando la información tiene una antigüedad superior a los 3 años. Y mientras más antigua es la información solicitada, más dificultoso es responder al requerimiento en forma rápida, eficiente y confiable. Para abordar esta necesidad Digital Systems, empresa orientada al desarrollo de tecnologías de la información y al diseño de sistemas de administración y procesamiento de datos para las empresas y organizaciones en general, ha diseñado una solución tecnológica para responder a la obligación que genera la 1 Informe n°8: http://www.leydetransparencia.cl/index.php?option=com_content&view=article&id=17&Itemid=7 Diciembre 30, 2009 Digital Systems Plan de Negocios MBA -ICCI 3 Ley de Transparencia a los órganos del Estado, específicamente las obligaciones que están asociadas a Transparencia Pasiva. El servicio consiste en el desarrollo de una Biblioteca Digital en la que se almacena la información documental, la que se organiza según una estructura y se le implanta un motor de búsqueda que permite realizar búsquedas exactas y rápidas. El mercado lo constituyen inicialmente los cerca de 620 órganos del Estado definidos por la normativa (ver anexo 2). Posteriormente ampliaremos la operación a las demás organizaciones públicas que no están sujetas a esta obligación (empresas públicas, poder judicial, poder legislativo y órganos contralores) y a las organizaciones privadas que operan en Chile y en países de Latino América para las que una solución como la planteada puede representar una solución que agrega valor a sus operaciones. La propuesta de valor se basa en que genera ahorros de dinero por la eliminación del almacenamiento de documentos físicos que implica; permite ahorros de espacio por el que se libera generando usos alternativos; y de tiempo por la posibilidad de encontrar rápidamente lo que se requiere. Esto redundará en no sólo cumplir con la ley y disminuir costos, sino que cumplir con calidad, promoviendo el uso de tecnología para el servicio más eficiente y expedito de los usuarios. Requiere de baja inversión; tiene buen retorno, proyectándose utilidades desde el año 2 de operación por más de $30 millones, superando el año 4 los $100 millones. Se ha transformado en una necesidad creciente para los órganos del Estado por la obligatoriedad de la norma y la inexistencia de diseño y sistemas para gestionar dicha información. Diciembre 30, 2009 Digital Systems Plan de Negocios MBA -ICCI 4 El equipo gestor cuenta con experiencia en el diseño y desarrollo de sistemas documentales digitales y bases de datos electrónicas, además del conocimiento de los clientes y de su estado de necesidad.

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2

Fransson, Andreas, and Sebastian Frisk. "DIGITALA SÄLJPROCESSER : Digital innovation som en drivkraft för digital transformation." Thesis, Umeå universitet, Institutionen för informatik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171897.

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In today’s highly digital world a great undertaking for organizations is the transformation of value processes from the classical analog to the modern digital. How and when does this transformation unfold and could digital innovations within sales processes be a driving force for this transformation. For companies striving to achieve such change how and when transformation is possible is an important question to answer. Drawing on extent research through Vial (2019) and Skog (2019) on digital transformation, we aim to answer this question with a multiple case study design covering five different organizations with ties to a consulting firm that provides digital innovation in the form of Search Engine Optimization, web-site development and sales process development. Using the assumption that the disruption has already happened and that companies need to be ambidextrous we analyze our empirical material through key constructs in Vial’s (2019) process model of digital transformation to get a broader understanding of how and when these innovation processes facilitates responses to environmental change by resulting in digital transformation. We find that within some of these organizations a digital transformation has happened through the innovation process, but we also find that some companies are hindered in the transformation by external variables

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3

Brower, Alfred N. "DIGITAL WIDEBAND RECORDING SYSTEMS." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/606438.

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International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada
Historically, those interested in recording one or more channels with analog content of greater than or equal to 2 MHz, must use an analog recorder. In the last few years, advancements in analog-to-digital converter technology, performance enhancement in Digital Signal Processors (DSPs), and digital recording devices have made cost-effective, wideband recording applications possible through the use of all-digital techniques. This paper has three objectives: 1. It attempts to explain the benefits of a wideband digital recorder over the traditional analog variety. 2. It discusses the key elements of a wideband digital recorder. 3. It presents a realizable 10-channel, 30 Mbit PCM digital recorder solution. 4. It presents a realizable 14-channel, 2 MHz (bandwidth) digital recorder solution.

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4

Saleh, Majd. "Digital ecosystem : towards a system of information systems." Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2413.

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Récemment, avec les progrès technologiques rapides que nous observons dans le domaine des Technologies de l'Information et de la Communication (TIC), de nombreux Systèmes d'Information (SI) sont introduits dans nos vies à la maison ou au travail. Cela entraînera des défis croissants pour les utilisateurs, tels que la nécessité de gérer d'énormes quantités de ressources et la difficulté de collaborer avec les autres. Afin de trouver la bonne information au bon moment pour prendre des décisions éclairées, les utilisateurs doivent rechercher des ressources réparties dans de nombreux SI (courriels, réseaux sociaux, pages wiki, notes électroniques, etc.). Le processus de recherche de ressources dans différents SI est coûteux et prend du temps; il doit donc être optimisé. L'émergence des Écosystèmes Numériques (DE) offre aux utilisateurs le potentiel d'améliorer l'accessibilité et la coordination des différents systèmes.D'autre part comparable à un DE, un système de systèmes d'information (SoIS) est composé de SI intégrés qui sont hétérogènes et fonctionnent indépendamment de manière autonome, mais qui sont mis en réseau pour un objectif commun.L'objectif mentionné précédemment, pourrait être l'organisation et le partage de ressources hétérogènes. Cette thèse se concentre sur le passage des Écosystèmes Numériques à un système de systèmes d'information en tant que solution aux défis émergents auxquels sont confrontés les utilisateurs de différents SI dans un contexte de collaboration. Le SoIS donne l'occasion d'explorer comment la collaboration peut être améliorée grâce à une combinaison de différents SI dans l'environnement numérique des organisations. Dans ce contexte, nous avons défini un modèle sémantique et un modèle architectural de SoIS. Nous avons ensuite développé un prototype, appelé MEMORAeSoIS, basé sur ces modèles comme support de collaboration. Ce prototype peut offrir la possibilité d'indexer, de partager, d'annoter et de recommander des ressources importantes provenant de différents SI
Recently, with the rapid technological advancement that we are witnessing in the domain of Information and Communication Technology (ICT), many Information Systems (ISs) are introduced into our lives either at home or at work. That will cause growing challenges for the users, such as the need for managing huge amounts of resources and the difficulty to collaborate with others. In order to find the right information at the right time to make educated decisions, users have to look for resources distributed in many ISs (emails, social networks, wiki pages, electronic notes etc.). The process of searching for resources in different ISs is costly and time-consuming; therefore it needs to be optimized. The emergence of Digital Ecosystems (DE) presents the users with the potential for improving the accessibility and coordination of different systems. On the other hand, comparable to DE, a System of Information Systems (SoIS) is comprised of integrated ISs which are heterogeneous and independently operable on their own but are networked together for a common goal. The goal, as mentioned before, might be organizing and sharing of heterogeneous resources.This thesis focuses on moving from Digital Ecosystems towards a System of Information Systems as a solution to the emergent challenges facing users of different ISs in a collaboration context. The SoIS gives the opportunity to explore how collaboration can be enhanced through a combination of different ISs in the digital environment of organizations. In this context, we defined a semantic model and an architectural model of SoIS. We then developed a prototype, called MEMORAeSoIS, based on these models as collaboration support. This prototype can provide the ability to index, share, annotate, and recommend important resources coming from different ISs.Recently, with the rapid technological advancement that we are witnessing in the domain of Information and Communication Technology (ICT), many Information Systems (ISs) are introduced into our lives either at home or at work. That will cause growing challenges for the users, such as the need for managing huge amounts of resources and the difficulty to collaborate with others. In order to find the right information at the right time to make educated decisions, users have to look for resources distributed in many ISs (emails, social networks, wiki pages, electronic notes etc.). The process of searching for resources in different ISs is costly and time-consuming; therefore it needs to be optimized. The emergence of Digital Ecosystems (DE) presents the users with the potential for improving the accessibility and coordination of different systems. On the other hand, comparable to DE, a System of Information Systems (SoIS) is comprised of integrated ISs which are heterogeneous and independently operable on their own but are networked together for a common goal. The goal, as mentioned before, might be organizing and sharing of heterogeneous resources.This thesis focuses on moving from Digital Ecosystems towards a System of Information Systems as a solution to the emergent challenges facing users of different ISs in a collaboration context. The SoIS gives the opportunity to explore how collaboration can be enhanced through a combination of different ISs in the digital environment of organizations. In this context, we defined a semantic model and an architectural model of SoIS. We then developed a prototype, called MEMORAeSoIS, based on these models as collaboration support. This prototype can provide the ability to index, share, annotate, and recommend important resources coming from different ISs

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5

Spiniak, Juan (Spiniak Irarrazaval). "Digital help service opportunities for communication service providers in the convergent digital home." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/67570.

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Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, February 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 97-100).
Homes are becoming increasingly connected as new technologies allow users to access media and information from any-device at anytime. Notebooks, HDTVs, smartphones, media servers, photo cameras, and video cameras, all form part of this new digital ecosystem where - the vision says - information and content will flow easily across devices, enabled by simple and intuitive user interfaces. These new home technologies are, however, often too complex for most users. Only "digital-natives" or technology savvy groups have the necessary skills, knowledge or confidence to adopt them and to use them effectively. For the rest, trying them becomes painful and frustrating. Moreover, the ecosystem itself adds confusion, given the large number of players involved and the many different kinds of relationships. Unless a dominant player gains enough power to establish a dominant digital home architecture, or this happens in some other way, most companies will continue to innovate around device-specific features that don't address the overall complexity of the complete systems that users have to work with. Digital help services can assist users by simplifying the selection, installation, learning and troubleshooting of new services and devices; facilitating the adoption of new convergent technologies. There is a broad range of potential services, including, for example, 'over the top' (OTT) television integration, smartphone mentoring services, WiFi network configuration and desktop support services. Communication service providers should pay close attention to digital help services as an opportunity to differentiate their offer, strengthen their relationship with end-customers, reduce customer support costs and simplify the adoption of bandwidth-intensive technologies. Moreover, digital help services can speed up the adoption of OTT television services, and companies can use them strategically. The technology help space is evolving and communication service providers need to figure out how they want to participate: offer help services themselves; partner or acquire a existing technology support company; and/or create an open marketplace for technology help services.
by Juan Spiniak.
S.M.in Engineering and Management

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6

Grimes, Todd S. "Adaptive Power Analog-to-Digital Interface for Digital Systems." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1483366560887816.

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7

Åberg, Andreas, and Viktor Åström. "DIGITAL VISARAVLÄSNING." Thesis, Uppsala universitet, Institutionen för elektroteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-446367.

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I modern industrimiljö finns fortfarande en stor mängd analoga visarinstrument. Det är önskvärt att övervaka dessa instrument digitalt vilket medför att kontroll av mätdata kan göras utan att personal behöver vara på plats. På marknaden finns idag ingen aplikation som är utvecklad för att uppfylla denna funktion. Detta examensarbete har undersökt metoder för hur en analog visares värde ska läsas av digitalt och utvecklat en prototyp som kan utföra uppgiften. Prototypen utvecklades med hjälp av datorseende algoritmer för att läsa av den analoga visarens värde. Algoritmerna för datorseende implementerades på en Raspberry Pi4 Model B och en kamera, Rasperry Pi Kameramodul V2. Prototypen som utvecklades uppfyller de funktioner som efterfrågades, och uppnåde en noggranhet på 0.97% +- 0.75 av det procentuella uppmätta värdet hos en analog visares fulla mätspann med en upplösning på 2.5%

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8

Petridis, Panagiotis. "Interacting with Digital Heritage Systems." Thesis, University of Sussex, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487090.

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9

Caldwell, Niall James. "Digital Displacement hydrostatic transmission systems." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/27735.

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Digital Displacement pumps and motors are a new type of hydraulic machine, in which fluid commutation and displacement control are achieved by solenoid actuated valves under the command of a microprocessor, rather than mechanical means. The thesis is that radial piston machines, built according to this principle, offer energy efficiency and control advantages over variable stroke axial piston pumps, when applied to hydrostatic vehicle transmissions. Experimental results on the efficiency of prototypes are analysed and compared to published results from swashplate machines, showing an improvement in energy efficiency. Loss models are proposed and compared with experiment. A Digital Displacement motor suitable for propelling a vehicle is described and the design and development of the mechanics, electro-magnetics and embedded software are described. Experimental results are also presented, illustrating the performance of a demonstrator vehicle driven by the motor, in particular demonstrating the closed-loop regulation of vehicle speed using motor displacement control. A demonstrator vehicle is described which features a hydrostatic transmission using both a Digital Displacement pump and an axial piston motor. Experimental results of pump performance are presented with specific focus on vehicle propel. A control technique is described which increases the sensitivity of the pump at low speeds. Results are presented of tests on the prototype transmission system, focussing on the time-domain system dynamics. A computer simulation model of the vehicle is presented and results compared to experiment.

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10

Harman, Neal Andrew. "Formal specifications for digital systems." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235627.

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11

Bekheit, Mahmoud A. M. "Digital testing of analogue systems." Thesis, University of Strathclyde, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275164.

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12

Chen, Tsorng-Ming. "Design validation of digital systems." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264452.

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13

Engler, Richard, and Dwight Tiqui. "DIGITAL DISTRIBUTION SYSTEMS - GET CONNECTED." International Foundation for Telemetering, 2006. http://hdl.handle.net/10150/603928.

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ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California

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14

Cheung, Si-Wai. "Digital modems for mobile systems." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/33233.

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Michaels, Alan Jason. "Digital chaotic communications." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/34849.

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This dissertation provides the conceptual development, modeling and simulation, physical implementation, and measured hardware results for a practicable digital coherent chaotic communication system. Such systems are highly desirable for robust communications due to the maximal entropy signal characteristics that satisfy Shannon's ideal noise-like waveform and provide optimal data transmission across a flat communications channel. At the core of the coherent chaotic communications system is a fully digital chaotic circuit, providing an efficiently controllable mechanism that overcomes the traditional bottleneck of chaotic circuit state synchronization. The analytical, simulation, and hardware results yield a generalization of direct sequence spread spectrum waveforms, that can be further extended to create a new class of maximal entropy waveforms suitable for optimized channel performance, maximal entropy transmission of chaotically spread amplitude modulated data constellations, and permission-based multiple access systems.

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16

Eberhardson, Karlsson André. "Från digitalt utanförskap till digital gemenskap : En hypotetisk väg till digital gemenskap." Thesis, Umeå University, Department of Informatics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-34955.

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We are in an emerging digital society where we are increasingly dependent on the mastery of IT and digital technologies to better carry out our everyday tasks. They cover everything from keeping in touch with family and friends to pay bills and declare. At the same time there are those who have not learned how to use the new technology and live their lives outside of the digital society. What happens to these people, in a society that is becoming increasingly digitized? Do they take harm by being in digital exclusion? It looks like this are issues that will not become less important as digital technology constantly changes. Technology of the future will be equally undesirable for tomorrow's elderly as today's technology is undesirable for today’s elderly.

This research report looks at how to find a way to get those who involuntary find themselves in digital isolation to get an entry to digital use and become part of the digital society. The report makes use of the Technology Acceptance Model (TAM) and Senior Technology Acceptance & Adoption Model (STAM), models developed to predict whether users will accept or reject a system, to find out how you may be able to get users to want to use and learn a system.

In a study reminiscent of an experiment in which four participants with low experience in IT use has been testing a simple Content Management System (CMS), and started to use IT in their work, this report concludes that there are tendencies showing that workplace could be an interesting entrance when you are trying to create an interest in IT and digital technology in those who are in the digital exclusion.

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Stanton, Christian J. "Material feedback in digital design tools." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/62983.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture; and, (S.M. in System Design and Management)--Massachusetts Institute of Technology, Engineering Systems Division, September 2009.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 67-69).
How do design tools feedback material behavior to the designer? Digital design tools in use by designers today provide a rich environment for design of form but offer little feedback of the material that ultimately realize that form. This lack of materialism limits the value of the design tool and the exploration of the design space where material behavior provides important feedback to the designer. This study examines the modes and value of material feedback in design, illustrates the challenge with current tools and suggests enhancements to design tools to support material feedback.
by Christian J. Stanton.
S.M.in System Design and Management
S.M.

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18

Wassell, Ian J. "Digital mobile radio." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277683.

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19

Wu, Kuang-Tsan. "On spectrally efficient digital transmission systems." Thesis, University of Ottawa (Canada), 1986. http://hdl.handle.net/10393/5408.

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20

Söderquist, Ingemar. "CMOS circuits for digital RF systems /." Linköping : Univ, 2002. http://www.bibl.liu.se/liupubl/disp/disp2002/tek775s.pdf.

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21

Behzadi, M. A. "True digital control of greenhouse systems." Thesis, Lancaster University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236319.

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22

Gould, Lee. "Digital signal conditioning on multiprocessor systems." Thesis, Durham University, 1992. http://etheses.dur.ac.uk/5965/.

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An important application area of modem computer systems is that of digital signal processing. This discipline is concerned with the analysis or modification of digitally represented signals, through the use of simple mathematical operations. A primary need of such systems is that of high data throughput. Although optimised programmable processors are available, system designers are now looking towards parallel processing to gain further performance increases. Such parallel systems may be easily constructed using the transputer family of processors. However, although these devices are comparatively easy to program, they possess a general von Neumann core and so are relatively inefficient at implementing digital signal processing algorithms. The power of the transputer lies in its ability to communicate effectively, not in its computational capability. The converse is true of specialised digital signal processors. These devices have been designed specifically to implement the type of small data intensive operations required by digital signal processing algorithms, but have not been designed to operate efficiently in a multiprocessor environment. This thesis examines the performance of both types of processors with reference to a common signal processing application, multichannel filtering. The transputer is examined in both uniprocessor and multiprocessor configurations, and its performance analysed. A theoretical model of program behaviour is developed, in order to assess the performance benefits of particular code structures and the effects of such parameters as data block size. The transputer implementation is contrasted with that of the Motorola DSP56001 digital signal processor. This device is found to be much more efficient at implementing such algorithms on a single device, but provides limited multiprocessor support. Using the conclusions of this assessment, a hybrid multiprocessor has been designed. This consists of a transputer controlling a number of signal processors, communicating through shared memory, separating tiie tasks of computation and communication. Forcing the transputer to communicate through shared memory causes problems, and these have been addressed. A theoretical performance model of the system has been produced. A small system has been constructed, and is currently running performance test software.

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Qian, Xinben Garrison. "Adaptive systems in digital communication designs." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38821.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.
Includes bibliographical references (leaves 98-100).
by Xinben Garrison Qian.
M.S.

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24

Lamprinos, Christos [Verfasser], Susanne [Sonstige] Stampf, Wael [Akademischer Betreuer] Att, and Sebastian Berthold Maximilian [Sammler] Patzelt. "Time efficiency of digital impression systems." Freiburg : Universität, 2017. http://d-nb.info/1241042926/34.

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25

Uhlán, Christian. "Security in Digital Home Visits." Thesis, Luleå tekniska universitet, Datavetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-74989.

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The purpose of this thesis is to study security for digital home visits, where traditional home visits are replaced by digital home visits using digital technology. The report examines the safety aspects for welfare technology solutions where data is collected from sensor systems and digital platforms and examines di↵erent Swedish laws that implies on a digital home visit. The study proposes an implementation of a prototype application to support users, relatives, and healthcare professionals to conduct digital home visits in a safe manner. The chosen scenario of the digital home visit was to check whether the person has eaten food during the day or not. This was done in a lab kitchen at Lule°a University of Technology with help of Z-wave sensors and a implemented systems. The result is displayed on a secure website. The solution is discussed and compared to other technical solutions of this problem and also to several Swedish laws. This paper finishes with a section aimed to provide a variety of recommendations when implementing a similar system.

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Wittwer, Christian. "Fundamentals of digital imaging /." Online version of thesis, 1995. http://hdl.handle.net/1850/12257.

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Li, Shuo. "System-Level Architectural Hardware Synthesis for Digital Signal Processing Sub-Systems." Doctoral thesis, KTH, Elektronik och Inbyggda System, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180441.

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This thesis presents a novel system-level synthesis framework called System-Level Architectural Synthesis Framework (SYLVA), which synthesizes DigitalSignal Processing (DSP) sub-systems modeled by synchronous data ?ow intohardware implementations in Application-Specific Integrated Circuit (ASIC),Field-Programmable Gate Array (FPGA) or Coarse-Grained ReconfigurableArchitecture (CGRA) style. SYLVA synthesizes in terms of pre-characterizedFunction Implementations (FIMPs). It explores the design space in threedimensions, number of FIMPs, type of FIMPs, and pipeline parallelism be-tween the producing and consuming FIMPs. SYLVA also introduces timingand interface model of FIMPs to enable reuse and automatic generation ofGlobal Interconnect and Control (GLIC) to glue the FIMPs together into aworking system. SYLVA has been evaluated by applying it to several realand synthetic DSP applications and the experimental results are analyzedfor the design space exploration, the GLIC synthesis, the code generation,and the CGRA floorplanning features. The conclusion from the experimentalresults is that by exploring the multi-dimensional design space in terms ofpre-characterized FIMPs, SYLVA explores a richer design space and does itmore effectively compared to the existing High-Level Synthesis (HLS) toolsto improve both engineering and computational efficiency.

QC 20160125

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Vernacotola, Mark J. "Characterization of digital film scanner systems for use with digital scene algorithms /." Online version of thesis, 1995. http://hdl.handle.net/1850/11967.

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Li, Yan Ph D. Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science. "Digital assistance design for analog systems : digital baseband for outphasing power amplifiers." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82353.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 145-150).
Digital assistance is among many aspects that can be leveraged to help analog/mixed-signal designers keep up with the technology scaling. It usually takes the form of predistorter or compensator in an analog/mixed-signal system and helps compensate the nonidealities in the system. Digital assistance takes advantage of the process scaling with faster speed and a higher level of integration. When a digital system is co-optimized with system modeling techniques, digital assistance usually becomes a key enabling block for the high performance of the overall system. This thesis presents the design of digital assistances through the digital baseband design for outphasing power amplifiers. In the digital baseband design, this thesis conveys two major points: the importance of the use of the reduced-complexity system modeling techniques, and the communications between hardware design and system modeling. These points greatly help the success in the design of the energy-efficient baseband. The first part of the baseband design is to realize the nonlinear signal processing unit required by the modulation scheme. Conventional approaches of implementing this functionality do not scale well to meet the throughput, area and energy-efficiency targets. We propose a novel fixed-point piece-wise linear approximation technique for the nonlinear function computations involved in the signal processing unit. The new technique allows us to achieve an energy and area-efficient design with a throughput of 3.4Gsamples/s. Compared to the projected previous designs, our design shows 2x improvement in energy-efficiency and 25x in area-efficiency. The second part of the baseband design devotes to the nonlinear compensator design, aiming to improve the linearity performance of the outphasing power amplifier. We first explore the feasibility of a working compensator by use of an off-line iterative solving scheme. With the confirmation that a compensator does exist, we analyze the structure of the nonlinear baseband-equivalent PA system and create a dynamical real-time compensator model. The resulting compensator provides the overall PA system with around 10dB improvement in ACPR and up to 2.5% in EVM.
by Yan Li.
Ph.D.

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Whiting, Ian Martin. "Closed loop digital control of electrohydraulic systems." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375516.

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Lam, Lawrence G. "Digital Health-Data platforms : biometric data aggregation and their potential impact to centralize Digital Health-Data." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/106235.

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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, School of Engineering, System Design and Management Program, Engineering and Management Program, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 81).
Digital Health-Data is being collected at unprecedented rates today as biometric micro sensors continue to diffuse into our lives in the form of smart devices, wearables, and even clothing. From this data, we hope to learn more about preventative health so that we can spend less money on the doctor. To help users aggregate this perpetual growth of biometric "big" data, Apple HealthKit, Google Fit, and Samsung SAMI were each created with the hope of becoming the dominant design platform for Digital Health-Data. The research for this paper consists of citings from technology strategy literature and relevant journalism articles regarding recent and past developments that pertain to the wearables market and the digitization movement of electronic health records (EHR) and protected health information (PHI) along with their rules and regulations. The culmination of these citations will contribute to my hypothesis where the analysis will attempt to support my recommendations for Apple, Google, and Samsung. The ending chapters will encompass discussions around network effects and costs associated with multi-homing user data across multiple platforms and finally ending with my conclusion based on my hypothesis.
by Lawrence G. Lam.
S.M. in Engineering and Management

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32

Agiorgitis, Georgios, Mohamed Bennani, Mixalis Drakoularakos, and Paul John McConnon. "Digital Wall : The University’s learning and information space." Thesis, Linnéuniversitetet, Institutionen för informatik (IK), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-62472.

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A North American university is engaged in a large transformation project involving the wholeorganisation. Students, Lecturers, departments and additional questions from the shared leadership team are engaging in defining the services offered, in particular from the university library and its associated sub-services. It is an exciting time for the University as it seeks to not only define its services but also how these can be created and consumed.There are many aspects to this re-organisation and many items to be addressed. In this report,we look at the current situation at the University, as well as taking into account the aspirations of the stakeholders. We start by drawing out a Rich Picture, part of Soft System Methodology (SSM) (Checkland, 1981) which we use in order to spot opportunities that are available for further exploration. Much of the information that we use comes from material supplied by the University itself as well as interviews with the Head of Library services and Head of Library IT. We look indepth at how SSM assists in this process of evaluation through its focus on participation and how it may assist us to understand the many different perspectives collected in our research. SSM consequently assists in defining problems with solutions to any areas that have drawn our attention. Following the evaluation of collected data, discussions and our own observations, we identify that a digital wall that is being proposed for the redesigned library presents an opportunity to explore possibilities for exploitation of this technology. Further research on other digital walls such as Brisbane’s Cube (Abdi et al, 2014), and Auraria Library’s Discovery Wall(Burch, 2016) shows some of the uses that these walls have been put to and how the Institutions use them. We then use a number of models to evaluate the data that we collected on digital walls and from the North American University and analyse it in order to inform our thinking. These models can be used independently or collectively to evaluate data from different perspectives. As such we were able to look at problems and solutions from the perspective of many of the actors involved in shaping the future library services. These models and results are discussed in the report. Finally, we take our results and make a number of proposals for the North American University digital wall along with the relevant justifications at the end of this report.

This is a report in the Informatics course 5IK501 during the school year of 2016/2017.

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Gilkeson, John T. "DIGITAL SIGNALING PROCESSOR RESOURCE MANAGEMENT FOR SMALL OFFICE PHONE SYSTEMS." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/318.

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Contemporary small office phone systems are specialized computers that connect a variety of phones within the office and to the local phone company. These systems use digital signaling processors (DSPs) to convert signals from analog to digital and vice-versa. Many different types of applications run on the DSPs and different businesses have varying application needs. Given the systems have limited amounts of DSP resources and growing numbers of applications for a phone system, an administrator needs a way to configure the uses of resources based on their individual business needs. This thesis provides an overview of a system for configuring resources on various types of DSP hardware some of which are removable and have differing tradeoffs between application uses. The system has to be able to change resource allocations while the phone system is running with minimal interruptions to calls. The configuration system needs to be designed to be flexible enough that new applications or DSP hardware could be supported without major changes to code. This thesis presents a system that uses a database-driven model along with algorithms that optimize configuration of DSP hardware given the administrator’s individual application needs.

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Bryars, John, and Gregory S. Smith. "DIGITAL RECORDING SYSTEMS FOR UNDERGROUND NUCLEAR TEST DATA." International Foundation for Telemetering, 1992. http://hdl.handle.net/10150/608934.

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International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California
A Digital Output Recorder (DOR) system was developed by JAYCOR under contract to Defense Nuclear Agency (DNA) for the recording of high-speed digital data from test hardware exposed to radiation during an Underground Nuclear Test conducted at the Nevada Test Site (NTS) in 1991. Electronics hardware for the system is based on the well-supported Versa Module Europe (VME) bus which has become an industry standard for digital process and control systems. The system collects, identifies, and telemeters the data from several interfaces using the VME bus to a common data collection point above ground. The system was designed with built-in flexibility and expandability to meet digital data recording requirements on future underground tests (UGTs).

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Pous, Solà Marc. "Radiated transient interferences in digital communication systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/299210.

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In the Electromagnetic Compatibility research area, an unsolved interference problem is the measurement and evaluation of the distortion produced by radiated transient disturbances on digital communication systems. This impulsive noise, which is generated by switching devices or by sparks, is a broadband interference that covers the spectrum from DC to several hundreds of megahertz or some gigahertz. Additionally, this man-made noise is characterized by its short and random burst parameters, which make really challenging to measure it correctly. During the thesis, we have explained that impulsive noise is not properly measured and evaluated to prevent interference scenarios, when the EMC standard methodologies are applied. Detectors, such as the quasi-peak, frequency sweep measurements or signal-to-noise limiting evaluation described in the harmonized standards of the electromagnetic compatibility do not enable to determine beforehand the influence of transient interferences. Our strategy to overcome the non-profit measurement has been to perform novel measurement and evaluation techniques beyond EMC standards. The measurement technique developed joins the capabilities of EMI receivers and oscilloscope instrumentations to capture accurately the radiated transient interference. To carry out the measurement, the input stage of the EMI receiver is used for filtering and pre-amplifying purposes, conducting the IF output towards the oscilloscope, which is used for triggering and storage. Furthermore, a final post-processing stage is needed to obtain in time-domain the in-phase and quadrature components of the transient interference. Once the radiated transient interference has been measured properly, an accurate evaluation of the distortion produced to a digital communication system can be estimated. To evaluate the impact of the transient interference, a combination of the time-domain measurement with base-band simulation has been proposed to fulfil the thesis goal. The IQ time-domain measurement enables us to characterize the impulsive-noise present at the communication channel and determine the distortion produced to the digital communication system by means of base-band simulation. The procedure to determine the BER using the base-band simulation has been validated with experimental results, comparing the results reached with the developed methodology with the ones obtained when a communication system device is placed under radiated transient. Excellent results have been obtained employing the developed methodology, considering the interference produced by radiated transient to RFID or GSM communication systems Additionally, a new measurement methodology to obtain the amplitude probability diagram (APD) has been developed, offering the possibility to determine the bit-error-rate including limit lines at the APD diagram. This measurement method, based on captures obtained from a general purpose oscilloscope, makes it possible to obtain the APD measurement at any frequency band with the same accuracy provided by an EMI receiver. Furthermore, the post-processing tools using mathematical software produce the APD results rapidly at any bandwidth, and this makes it more powerful than employing an EMI receiver. The successful APD measurement system created is able to obtain the full-spectrum statistical measurement, employing several time-domain captures which can be acquired in practice immediately. In the final chapter of this thesis, the GSM system is interfered by radiated transients produced by sparks. The results provided by the APD diagram including the limit dots have been especially useful due to its fast capacity to interpret and quantify the degradation produced to the GSM system.
En el camp de recerca de la compatibilitat electromagnètica, una de les problemàtiques no resoltes és la mesura i avaluació de les interferències produïdes per transitoris radiats sobre els equips de comunicació digitals. Aquest tipus de soroll impulsiu, que es genera per la commutació d' equips electrònics o guspires, és una interferència de banda ampla que ocupa l' espectre radioelèctric fins a diversos centenars de megahertz o algun gigahertz. A més, aquest soroll es caracteritza per la seva curta durada i l'aleatorietat dels seus paràmetres, i això fa que sigui molt complicat mesurar correctament la interferència. Al llarg de la tesi, hem explicat que el soroll impulsiu no es mesura ni s'avalua adequadament per evitar escenaris d'interferències si s'utilitzen les metodologies definides als estàndards d' EMC. Els detectors, com el de quasi-pic, l'escombratge en freqüència o l'avaluació basada en els límits relacionats amb la relació senyal a soroll no són vàlids per anticipar la influència de les interferències transitòries. La nostra estratègia per solucionar els problemes de les mesures normatives ha estat desenvolupar noves tècniques de mesura i avaluació fora dels estàndards d'EMC. La tècnica de mesura desenvolupada combina les capacitats dels receptors EMI i els oscil·loscopis per capturar la interferència transitòria radiada. Per realitzar les mesures, l'etapa d'entrada del receptor EMI s¿utilitza amb la finalitat de filtrar i preamplificar, enviant la sortida IF cap a l'oscil·loscopi, que es fa servir per detectar i emmagatzemar els transitoris. Per últim, en l'etapa de postprocessament, s'obtenen en el domini del temps els components en fase i en quadratura de la interferència transitòria. Una vegada s'ha mesurat adequadament la interferència radiada, es pot estimar correctament la distorsió produïda sobre els sistemes de comunicació digitals. Per avaluar l'impacte de la interferència transitòria i així complir amb l'objectiu de la tesi, s'ha proposat combinar les mesures en el domini del temps amb la simulació en banda base. La mesura IQ en el domini del temps ens permet caracteritzar el soroll impulsiu present al canal de comunicació i així determinar la distorsió produïda al sistema de comunicació digital mitjançant la simulació en banda base. El procediment per determinar el BER fent servir la simulació en banda base ha estat validat amb resultats experimentals, i s'han comparat els resultats obtinguts utilitzant la metodologia desenvolupada amb els resultats proporcionats directament col·locant un dispositiu sota la influència de transitoris radiats. Els excel¿lents resultats obtinguts considerant interferències produïdes sobre sistemes RFID i GSM han estat publicats. D'altra banda, també s'ha desenvolupat un nou mètode de mesura per adquirir el diagrama de probabilitat d¿amplitud (APD), oferint la possibilitat de determinar la probabilitat d'error en el bit incloent límits en el diagrama APD. Aquest mètode de mesura, basat en captures obtingudes mitjançant un oscil·loscopi de propòsit general, fa possible obtenir la mesura APD en qualsevol banda freqüencial amb la mateixa exactitud que proporciona un receptor EMI. A més, amb les eines de postprocessament desenvolupades és possible produir els resultats APD ràpidament i amb qualsevol amplada de banda, i això fa que sigui un mètode de mesura més potent que no pas utilitzar un receptor EMI. L'exitós sistema de mesura creat per obtenir l'APD és capaç d'obtenir la mesura estadística en tot l'espectre radiolèctric utilitzant poques captures en el domini del temps, les quals a la pràctica soón adquirides de forma inmediata. Al capítol final de la tesi, el sistema GMS és interferit per transistors radiats produïts per guspires. El resultat proporcionat pel diagrama APD, incloent-hi els límits, és especialment útil gràcies a la seva rapidesa per interpretar i quantificar la degradació produïda sobre el sistema GSM.

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Burström, Anders, and Jonas Callander. "Digital Rights Management, Evaluation of existing systems." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2021.

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The aim of this report is to examine if existing Digital Rights Management systems are useful and satisfying to the consumer, copyright owner and distributor. If not, is it possible to design a useful and satisfying Digital Rights Management system?

During the past few years, copyright owners of music, movies and other media have seen how piracy has increased with the introduction of affordable broadband technology. Record and movie corporations have pushed for a solution to piracy and one of them is Digital Rights Management. They want their customers to pay for and then enjoy the digital media but at the same time protect the rights of the copyright owner. That is what Digital Rights Management is all about; protect the copyright owner while allowing the consumer to enjoy their digital media. Digital Rights Management can restrict the users rights to copy and transfer the contents to other devices as well as restrict the number of times a user is allowed to use the media.

The present DRM systems are focusing on preventing digital media from being freely distributed by limiting the ability to copy or move the media. This puts limitations on fair use such as making personal copies of music. Copyright owners and distributors want more consumers to discover DRM, but so far, the consumers have shown little interest.

This report is based on various resources on the Internet such as white papers on Digital Rights Management, our own experimentation and on Microsoft Media Rights Management SDK documentation.

We do not believe it is possible to design a DRM system that consumers, copyright owners and distributors are satisfied with. It is not possible to combine the demands of copyright owners and the consumers’ claims of fair use.

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Bengtsson, Fredrik, and Rikard Berglund. "Digital compensation of distortion in audio systems." Thesis, Linköping University, Department of Electrical Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56392.

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The advancements of computational power in low cost FPGAs are giving the opportunityto implement real-time compensation of loudspeakers and audio systems. The need for expensive commercial audio systems is reduced when the fidelity ofmuch cheaper audio systems easily can be improved by real-time compensation. The topic of this thesis is to investigate and evaluate methods for digital compensationof distortion in audio systems. More specifically, a VHDL module isimplemented to, when necessary, alleviate the problem of drastically deterioratingfidelity of the bass appearing when the input power is too high.

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Protheroe, D. W. "Systematic methods for designing large digital systems." Thesis, London South Bank University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618625.

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Han, Yu. "Optimization of Modulation Constrained Digital Transmission Systems." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37097.

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The regular waterfilling(WF) policy maximizes the mutual information of parallel channels, when the inputs are Gaussian. However, Gaussian input is ideal, which does not exist in reality. Discrete constellations are usually used instead, such as $ M $-PAM and $ M $-QAM. As a result, the mercury/waterfilling (MWF) policy is introduced, which is a generalization of the regular WF. The MWF applies to inputs with arbitrary distributions, while the regular WF only applies to Gaussian inputs. The MWF-based optimal power allocation (OPA) is presented, for which an algorithm called the internal/external bisection method is introduced. The constellation-constrained capacity is discussed in the thesis, where explicit expressions are presented. The expression contains an integral, which does not have a closed-form solution. However, it can be evaluated via the Monte Carlo method. An approximation of the constellation-constrained capacity based on the sphere packing method is introduced, whose OPA is a convex optimization problem. The CVX was used initially, but it did not generate satisfactory results. Therefore, the bisection method is used instead. Capacities of the MWF and its sphere packing approximation are evaluated for various cases, and compared with each other. It turns out the sphere packing approximation has similar performances to the MWF, which validates the approximation. Unlike the MWF, the sphere packing approximation does not suffer from the loss of precision due to the structure of MMSE functions, which demonstrates its robustness.

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Li, Tao. "Digital assembly process design for aircraft systems." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7421.

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The research described in this thesis concentrates on the development of an integrated assembly process design for aircraft systems. Assembly process design is one of the most important and complicated activities in aircraft manufacturing. Many solutions are suggested in previous research to develop process design method. But gaps are found in assembly process design of aircraft system in following studies. In this research, an integration approach which combined with product development philosophy, design for assembly method and digital assembly technology is proposed to solve the issues in the whole product development lifecycle. Three case studies from different design phase are used to examine the integrated process design method. The research results demonstrate that the proposed digital process design method can be used to develop manufacturing strategies of system assembly in early design phase, and improve the accuracy and operability of assembly instructions according to 3-D assembly process plans in detailed design phase. The product design also benefits from this method in terms of correcting design errors in the concurrent engineering process. A proposed process planning system framework based on lightweight CAD is developed in this research. The customized assembly representation of 3DVIA system illustrates the advantages of lightweight CAD when applying in shop floor.

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Weliwitegoda, Dhineth Chamara. "Equaliser performance optimisation for digital communications systems." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417191.

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Yip, Mary. "Image simulation framework for digital mammography systems." Thesis, University of Surrey, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531394.

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Weir, Lindsay Brian. "Digital video for time based analysis systems." Thesis, University of Canterbury. Computer Science, 1994. http://hdl.handle.net/10092/9406.

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Research students within the Psychology Department at the University of Canterbury are involved in exploring emotional responses of human behaviour. Experiments of subjects are video taped and the tapes are subsequently analysed using pen and paper. This approach is time consuming and provides a relatively crude interface for analysis. In this thesis techniques to assist in the analysis of time dependent information are examined in general, although the emphasis is on human behaviour experiments. Digital video analysis methods are examined to evaluate their strengths and weaknesses in comparison to video tape methods. A working prototype system, Video Transcriptor, has been developed on a Macintosh computer in order to evaluate how digital video can assist in analysing human behaviour. This prototype system uses the facilities of QuickTime, Apple's solution to handling time based digital video information. There is a lack of standards for controlling digital video information, so an analysis of various Human-Computer Interface metaphors has been explored. For transcription purposes, an adaptive note-taking facility has been implemented to assist in the analysis of human behaviour. This thesis shows the benefits that digital video provides for the analysis and note-taking of human behaviours compared to video tape methods. The random access capabilities of digital video offer increased control of the video information, which provides faster note-taking and more accurate results compared to video tape based methods of analysis.

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鄧國瀚 and Kwok-hon Tang. "Digital control enhancement of triac cycloconverter systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31231354.

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Jalali, Sammuel. "Wireless Channel Equalization in Digital Communication Systems." Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/cgu_etd/42.

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Our modern society has transformed to an information-demanding system, seeking voice, video, and data in quantities that could not be imagined even a decade ago. The mobility of communicators has added more challenges. One of the new challenges is to conceive highly reliable and fast communication system unaffected by the problems caused in the multipath fading wireless channels. Our quest is to remove one of the obstacles in the way of achieving ultimately fast and reliable wireless digital communication, namely Inter-Symbol Interference (ISI), the intensity of which makes the channel noise inconsequential. The theoretical background for wireless channels modeling and adaptive signal processing are covered in first two chapters of dissertation. The approach of this thesis is not based on one methodology but several algorithms and configurations that are proposed and examined to fight the ISI problem. There are two main categories of channel equalization techniques, supervised (training) and blind unsupervised (blind) modes. We have studied the application of a new and specially modified neural network requiring very short training period for the proper channel equalization in supervised mode. The promising performance in the graphs for this network is presented in chapter 4. For blind modes two distinctive methodologies are presented and studied. Chapter 3 covers the concept of multiple "cooperative" algorithms for the cases of two and three cooperative algorithms. The "select absolutely larger equalized signal" and "majority vote" methods have been used in 2-and 3-algoirithm systems respectively. Many of the demonstrated results are encouraging for further research. Chapter 5 involves the application of general concept of simulated annealing in blind mode equalization. A limited strategy of constant annealing noise is experimented for testing the simple algorithms used in multiple systems. Convergence to local stationary points of the cost function in parameter space is clearly demonstrated and that justifies the use of additional noise. The capability of the adding the random noise to release the algorithm from the local traps is established in several cases.

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Studer, Ahren M. "Verifying Physical Endpoints to Secure Digital Systems." Research Showcase @ CMU, 2011. http://repository.cmu.edu/dissertations/77.

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The proliferation of electronic devices supporting sensing, actuation, and wireless communication enables the monitoring and/or control of a variety of physical systems with digital communication. Such “cyber physical systems” blur the boundaries of the digital and physical worlds, where correct information about the physical world is needed for the correct operation of the digital system. Often in these systems the physical source or destination of information is as important as the information itself. However, the omni-directional and invisible nature of wireless communication makes it difficult to determine communication endpoints. This allows a malicious party to intercept wireless messages or pose as other entities in the system. As such, these systems require new protocols to associate the endpoints of digital communication with physical entities. Traditional security approaches that associate cryptographic keys with names can help verify endpoints in static systems where a string accurately describes the role of a device. In other systems, the role of a device depends on its physical properties, such as location, which change over time. This dynamic nature implies that identification of an endpoint based on a static name is insufficient. Instead, we can leverage devices’ sensing and actuation capabilities to verify the physical properties and determine the physical endpoints of communication. We investigate three different scenarios where the physical source and/or destination is important and propose endpoint verification techniques: verifying the physical endpoints during an exchange between two smartphones, verifying the receiver of information is in a physical space to enable location-based access control, and verifying the source of information to protect Vehicle-to-Vehicle (V2V) applications. We evaluate our proposals in these systems and show that our solutions fulfill the security requirements while utilizing existing hardware. Exchanging Information Between Smartphones Shake on it (SHOT) allows users to verify the endpoints during an exchange of information between two smartphones. In our protocol, the phones use their vibrators and accelerometers to establish a human-observable communication channel. The users hold the phones together while the phones use this channel to bootstrap and verify the authenticity of an exchange that occurs over the higher-bandwidth wireless channel. Users can detect the injection of information from other devices as additional vibrations, and prevent such attacks. Our implementation of SHOT for the DROID smartphone is able to support sender and receiver verification during an exchange between two smartphones in 15 seconds on average. Location-Based Access Control We propose using location-based access control to protect sensitive files on laptops, without requiring any effort from the user to provide security. With a purely wireless electronic system, verifying that a given device is in a physical space is a challenge; either the definition of the physical space is vague (radio waves can travel beyond walls) or the solution requires expensive hardware to measure a message’s time of flight. Instead, we use infrared as a signal that walls can contain. We develop key derivation protocols that ensure only a receiver in the physical room with access to the signal can derive the key. We implement a system that uses the laptop’s webcam to record the infrared signal, derive a key, and decrypt sensitive files in less than 5 seconds. Source Verification for V2V Networks A number of V2V applications use information about nearby vehicles to prevent accidents or reduce fuel consumption. However, false information about the positioning of vehicles can cause erroneous behavior, including accidents that would not occur in the absence of V2V. As such, we need a way to verify which vehicle sent a message and that the message accurately describes the physical state of that vehicle. We propose using LED lights on vehicles to broadcast the certificate a vehicle is currently using. Receivers can use onboard cameras to film the encoding of the certificate and estimate the relative location of the vehicle. This visual channel allows a receiver to associate a physical vehicle at a known location with the cryptographic credentials used to sign a location claim. Our simulations indicate that even with a pessimistic visual channel, visual verification of V2V senders provides sufficient verification capabilities to support the relevant applications.

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Prince, Simon M. "Free-space interconnection of digital optical systems." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/1327.

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Hicks, Dawn L. "Optimal design of digital model-following systems." Thesis, University of Salford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284423.

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Meacham, Richard J. "High-level design routes for digital systems." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298949.

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Bews, R. "Digital crossover networks for active loudspeaker systems." Thesis, University of Essex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383428.

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Dissertations / Theses on the topic 'Digital systems'

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