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Dissertations / Theses on the topic 'Electrical engineer'
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Mulligan, Jennifer Joyce 1978. "Detection and recovery from the obvious engineer attack." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87344.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (leaves 65-66).
by Jennifer Joyce Mulligan.
S.M.
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Cheng, Hoi Wai Thomas 1977. "Identifying customers' unmet needs using a virtual advisor and engineer." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86651.
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Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (leaf 73).
by Hoi Wai Thomas Cheng.
M.Eng.and S.B.
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Recht, Daniel. "Energetic Beam Processing of Silicon to Engineer Optoelectronically Active Defects." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10305.
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This thesis explores ways to use ion implantation and nanosecond pulsed laser melting, both energetic beam techniques, to engineer defects in silicon. These defects are chosen to facilitate the use of silicon in optoelectronic applications for which its indirect bandgap is not ideal. Chapter 2 develops a kinetic model for the use of point defects as luminescence centers for light-emitting diodes and demonstrates an experimental procedure capable of high-throughput screening of the electroluminescent properties of such defects. Chapter 3 discusses the dramatic change in optical absorption observed in silicon highly supersaturated (i.e., hyperdoped) with the chalcogens sulfur, selenium, and tellurium and reports the first measurements of the optical absorption of such materials for photon energies greater than the bandgap of silicon. Chapter 3 examines the use of silicon hyperdoped with chalcogens in light detectors and concludes that while these devices display strong internal gain that is coupled to a particular type of surface defect, hyperdoping with chalcogens does not lead directly to measurable sub-bandgap photoconductivity. Chapter 4 considers the potential for Silicon to serve as the active material in an intermediate-band solar cell and reports experimental progress on two proposed approaches for hyperdoping silicon for this application. The main results of this chapter are the use of native-oxide etching to control the surface evaporation rate of sulfur from silicon and the first synthesis of monocrystalline silicon hyperdoped with gold.Engineering and Applied Sciences
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Bowman, David C. "Image Stitching and Matching Tool in the Automated Iterative Reverse Engineer (AIRE) Integrated Circuit Analysis Suite." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1533766175549951.
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Gerada, David. "High speed electrical machines for the more-electric engine." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659206.
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With the increasingly stringent emissions legislation as well as the hiking fuel prices, engine electrification is currently a prime path for automotive companies to meet the environmental and efficiency targets, thus placing the need for high-performance automotive electrical machines. This research looks at developing high-speed electrical machines for an electrically-assisted turbocharger to be used within Cummins' heavy duty diesel engines. While the potential benefits of such a system are high, integrating a high speed, high power-density electrical machine within the aggressive turbocharger environment is challenging. In this work detailed system multi-domain models which include the electromagnetic, thermal and mechanical aspects are developed. Using these models, together with knowledge of electrical machine material properties, the capabilities and limitations of different types of electrical machines for use in electrically-assisted turbo-charging are determined. The field weakening properties, robustness and relatively low-cost make the Induction Machine the preferred technology for the application. This work provides a set of design guidelines for maximising the power density of high speed Induction Machines. In particular moving away from the conventionally used round rotor-bar and tailoring the split-ratio together with tailoring the machine IS electrical and magnetic loadings are shown to be important aspects in increasing the power density. An algorithm for increasing the power-density of high-speed induction machines is presented. Design recommendations are also presented for PM machines where tailoring the air-gap length is identified and shown to be important in optimising the distribution of losses. A computationally-efficient PEA-based technique is developed for the analysis of closed rotor-slot IMs. The optimized 9.5kW, 50000rpm IM design is prototyped and experimental results compared to those predicted from analysis.
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Silvén, Daniel, and Patrik Karlssson. "Sensorfinger." Thesis, Karlstad University, Faculty of Technology and Science, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-4596.
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Målet med detta examensarbete är att ersätta den tidigare lösningen av sensorfingret med andra komponenter, eller hitta en annan sensor med motsvarande funktion.
Arbetet har begränsats av att ESAB vill ha ett mekaniskt finger för användarvänlighetens skull. Efter en förundersökning av olika typer av sensorer har vi valt att använda oss av trådtöjningsgivare som sensorer till det mekaniska sensorfingret. I och med detta val behövde vi även komma med ett teoretiskt förslag på en mekanisk upphängning av sensorfingret.
Vi har byggt upp två separata Wheatstonebryggor med varsin instrumentförstärkare (INA125). Utsignalen från bryggorna är relativt liten och behövde förstärkas cirka 2000 gånger.
Nollbalansering av bryggorna har skett manuellt med potentiometrar men vi har även gett ett förslag på en lösning där nollbalansering kan ske med ett enkelt knapptryck. Knappen är placerad på upphängningen på ett sådant sätt att man inte kan trycka oavsiktligt på knappen.
Resultatet av arbetet är en uppkoppling på en experimentplatta samt förslag på hur upphängningen och sensorfingret designmässigt kan se ut.
För vidare arbetsgång behövs en prototyp för att testa livslängden och ta reda på vilken känslighet som är mest optimal.
The goal with this degree project was to find a solution with different components to the existing design, or find a sensor with similar function that could replace the previous design of the sensor finger.
Our work has been limited by ESAB due to the user friendly mechanical design of the previous sensor finger. After examining different sensors we choose to use strain gages as sensors for the mechanical sensor finger. With this choice we also needed to suggest a theoretical design for a mechanical attachment of the sensor finger.
We have designed two separate Wheatstone bridges with separate instrumental amplifiers (INA125). The output signals from the bridges are relatively small and need to be amplified around 2000 times.
The zero balancing of the bridges has been done manually with potentiometers but we have also suggested a solution where the zero balancing can be performed by a push-button. The button is placed where you cannot push it unintentionally.
The result of this degree project is a circuit on a veroboard, a designing proposal for the attachment and the sensor finger.
In order to further develop this design it would be necessary to build a prototype to evaluate its life span and find the optimal sensitivity.
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De, Bellis John J. "Optimization procedure for electric propulsion engines." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA374329.
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Thesis (M.S. in Applied Physics) Naval Postgraduate School, December 1999."December 1999". Thesis advisor(s):Oscar Biblarz, James Luscombe. Includes bibliographical references (p. 71-73). Also available online.
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Muller, Jan. "Electrical engineering professionals’ continuing professional development needs within one South African company." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96694.
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Thesis (MPhil)--Stellenbosch University, 2015.ENGLISH ABSTRACT: The aim of the study performed in 2014 was to identify what the Continuing Professional Development (CPD) needs are of a selected group of electrical engineering professionals from one company in South Africa. The interpretivist research paradigm formed the basis for the “Interactive Qualitative Analysis” methodology used in the study. Due to limitations research was focused on only one constituency, a selected group of electrical engineering professionals in one organisation, which is close to, but have very little power over the specific phenomenon of CPD. Research activities included conducting focus group and individual interviews with participants to gain a better understanding of identified problem through the analysis and interpretation of the collected data. The phenomenon of CPD was found to lie within the spectrum of lifelong learning. Due to increasingly fast changing technological and work environments, practicing professionals take part in professional development, if it is compulsory or not, in order to stay competitive in the global arena. Research has shown that compulsory CPD for registered engineering professionals may further their professional development. From the “Possible Implications for CPD Provision for Engineering Professionals” document several issues and concerns were identified, which influence engineering professionals’ perception of the professional body. The CPD system and CPD provision facilitated by the Engineering Council of South Africa (ECSA) may be one of the key reasons why many practicing engineers choose not to register professionally. Through this study the perceived and proposed CPD needs for the selected group of electrical engineering professionals have been identified, but to identify the actual needs of practicing engineering professionals in South Africa, a more detailed study will need to be done that should include all the constituencies that practice within the engineering environment or have any influence on the CPD phenomenon. The study also identified aspects that could help to improve the CPD system and the available CPD initiatives, and enhance the leadership from the professional body. This may positively influence the perception of practicing engineering professionals. Such positive perceptions could result in more practicing engineering professionals registering with ECSA and maintaining their professional registration.
AFRIKAANSE OPSOMMING: Die doel van die studie uitgevoer in 2014 was om die Voortgesette Professionele Ontwikkeling (VPO) behoeftes van ‘n geselekteerde groep elektriese ingenieurs van een maatskappy in Suid-Afrika te bepaal. Die interpretatiewe navorsingsparadigma het die “Interaktiewe Kwalitatiewe Analise” metodologie wat gebruik is in die studie onderlê. Binne die studie beperkinge is gefokus op slegs een konstituensie, ‘n geselekteerde groep professionele elektriese ingenieurs binne een organisasie, wie digby die spesifieke fenomeen van VPO funksioneer, maar baie beperkte mag daaroor het. Navorsingsaktiwiteite het fokusgroeponderhoude en individuele onderhoude met deelnemers ingesluit om ‘n beter begrip van die geïdentifiseerde probleem te verkry deur analise en interpretasie van die ingesamelde data. Die fenomeen van VPO lê binne die spektrum van lewenslange leer. As gevolg van ‘n toenemend snel veranderende tegnologiese en werksomgewing, neem professionele praktisyns deel aan professionele ontwikkeling, of dit verpligtend is of nie, en bly sodoende kompeterend in die globale arena. Maar navorsing het ook bewys dat verpligte VPO vir geregistreerde ingenieurspraktisyns hul professionele ontwikkeling tot voordeel kan strek. Vanuit die “Possible Implications for CPD Provision for Engineering Professionals” dokument is verskeie kwessies en knelpunte geïdentifiseer wat professionele ingenieurs se persepsies van die professionele liggaam mag beïnvloed. Die VPO sisteem en VPO verskaffing wat deur die Suid-Afrikaanse Raad vir Ingenieurswese (SARI) gefasiliteer word, mag een van die kernredes wees waarom vele ingenieurspraktisyns kies om nie professioneel te registreer nie. Die perseptuele en voorgestelde VPO behoeftes van ‘n geselekteerde groep professionele elektriese ingenieurspraktisyns is geïdentifiseer in hierdie studie, maar om die werklike behoeftes van professionele ingenieurspraktisyns in die breër Suid-Afrikaanse konteks te bepaal is ‘n meer gedetailleerde studie nodig wat al die konstituensies insluit wat praktiseer binne die ingenieursomgewing of die VPO fenomeen in dié konteks beïnvloed. Die studie het ook aspekte identifiseer wat kan help om die huidige VPO sisteem en insiatiewe te verbeter, en die leierskap van die professionele liggaam tot voordeel kan strek. Dit mag ‘n positiewe invloed hê op die persepsies van professionele ingenieurspraktisyns. Diesulke positiewe persepsies kan lei tot meer professionele ingenieurspraktisyns wat registreer by SARI en hul professionele registrasie byhou.
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Ambaripeta, Hari Prasad. "Range Extender Development for Electric Vehicle Using Engine Generator Set." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1424202532.
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Pheng, Bobby B. "3D Electromagnetic Simulation Tool Exposure for Undergraduate Electrical Engineers: Incorporation into an Analog Filters Course." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/819.
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With the growth of wireless communications, comes the need for engineers knowledgeable in 3D electromagnetic (EM) simulation of high-frequency circuits. To give electrical engineering students a better understanding of the behavior of electromagnetic fields, experiments including the use of 3D EM simulation software were proposed. Most students get lost in differential equations, curls, and divergences; this thesis aims to remedy that by exposing them to 3D EM simulation, which may motivate them toward further study in electromagnetics. Also, experience using EMPro is very beneficial for future RF/microwave/antenna engineers, as use of 3D EM simulation is becoming a requirement for this field. 3D EM simulators solve problems where using classical analysis techniques is impractical. Classical EM solutions to simple objects such as boxes, cylinders, and spheres, are widely known; but when the object is more complex, numerical approaches are preferred for their speed.
Currently, Cal Poly does not use 3D electromagnetic simulation in any of its courses. Targeted relevant courses include EE 335/375: EM Fields & Transmission Lines, EE 402: EM Waves, EE 405/445: High-Frequency Amplifier Design, EE 425/455: Analog Filter Design, EE 502: Microwave Engineering, and EE 533: Antennas. As a starting point, EE 425/455 was targeted.
In choosing which filters to investigate, simplicity and cost were the most important factors. For simplicity, transverse electromagnetic (TEM) mode filters were chosen; also, using a trough design for these filters would allow for simple construction and access. Also, a circular waveguide filter was chosen as an alternative to the TEM filters, as the modes are either transverse electric or transverse magnetic. To lower costs, printed circuit board was used to construct the filters, along with brass tubing, semi-rigid coaxial cable, and copper plumbing caps.
From these guidelines, three electronic bandpass filter experiments were investigated: a 1 GHz half-wave coaxial resonator filter, a 2 GHz copper end cap filter, and a tunable 1 GHz quarter-wave coaxial resonator filter. Electric and magnetic field coupling was used to excite the filters. They were then simulated using finite difference time domain (FDTD) simulations in Agilent EMPro. From the simulations, tradeoffs between insertion loss and bandwidth were observed. After, the filters were built and measured using a network analyzer. The quarter-wave filter was incorporated in Cal Poly’s EE 455 course during spring 2012. Students completed an EMPro tutorial, simulated the filters, and measured them using network analyzers. Student feedback was mixed, and modifications were made for future implementations.
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GAMA, SINVAL ZAIDAN. "NEW PROFILE FOR AN ELECTRIC ENGINEER IN THE BEGINING OF THE 21ST CENTURY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2002. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=3852@1.
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ELETROBRAS - CENTRAIS ELÉTRICAS BRASILEIRAS S. A.Este trabalho contempla o estudo das propostas REENGE para o perfil de formação do engenheiro, analisando sua fundamentação diante das mudanças estruturais do setor elétrico brasileiro; e pesquisa as necessidades de formação do engenheiro eletricista na visão do mercado de trabalho do mesmo setor, através de pesquisa de campo. Baseado no confronto das opiniões assim levantadas, o trabalho estabelece um perfil de formação do engenheiro eletricista, informado pela visão de futuro da academia e pelas necessidades dos integrantes do mercado de trabalho, fornecendo subsídios para que as diversas instituições de ensino superior estabeleçam seus perfis de formação particulares, conforme estabelecem as Diretrizes Curriculares Nacionais do Curso de Engenharia. O perfil de formação indicado não se restringe a uma lista de conteúdos, e sim a uma abordagem diferente de transmissão de Saberes, onde um conjunto de conhecimentos, habilidades e atitudes necessários para as competências desejáveis é indicados.
This work covers the studies of the REENGE proposals for knowledge background of an engineer background, analyzing its statements on the electric sector structural changes; and it focus the background needs for an electric engineer using the market view of the same sector, throughout field research. Based on the opinions check that came up, the work establishes a background profile for the electric engineer, formed by the academy future vision and the needs of the integrants of the labor market, giving support for many higher education institutions to establish its particular profile background, as the national Curriculum directions for the electric engineer course are established. The background profile indicated is not limited to a list of content, it is a different knowledge transference approach, in which knowledge, skills and attitudes for the necessary desired competence are indicated.
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Strauss, Johannes Matthias. "Direct piston displacement control of free-piston Stirling engines." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85604.
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Thesis (PhD)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: Control of beta-type free-piston Stirling engines has been the topic of research and development for many years. In this dissertation, an alternative approach to free-piston Stirling engine control, namely direct piston displacement control, is proposed. Direct piston displacement control entails the instantaneous and direct control of the piston displacement to control the engine according to preferred criteria, e.g. maximum power conversion or efficiency. To control free-piston engines in this manner, it is necessary to independently control both the displacement of the displacer and the power piston in real time. The primary arrangement by which to achieve this is through external control of the instantaneous forces exerted by the linear electrical machines fixed to the pistons. The challenge of displacement control is whether suitable linear machine technology exists or whether technology could be established that would adhere to the requirements of real time direct control. To answer the question whether direct piston displacement control is at all possible, a process was followed to set specifications that linear machines should adhere to and to set design guidelines for linear machines and free-piston Stirling engines. The first step was to establish the ability to simulate free-piston Stirling engine dynamics accurately. This was done by adapting a second order formulation and to verify and improve the accuracy thereof by comparing simulated results with experimental results of one of the best documented Stirling engines, namely the GPU-3 engine. It was found that this second order formulation could simulate the GPU-3 engine to a fair degree of accuracy. Key indicators were defined and later refined with the view of setting specifications. A case study of the influence of a range of variations, including operational, dimensional and other variations, on the dynamics of the GPU-3 was then undertaken. From the findings of this case study, specifications of the key indicators and design guidelines were established. A design optimisation approach was proposed to evaluate linear machine topologies. This approach makes specific provision for the specifications that linear machines need to adhere to, as well as for representative dynamic responses of the forces exerted on the linear machine by the displacer or the power piston. These representative responses and the associated piston displacement were determined for the displacer, the power piston and the combination of the two from the study conducted to set specifications. An air-core, longitudinal flux linear machine with surface mounted permanent magnets (LFPM) was then evaluated to determine its suitability for direct piston displacement control. This linear machine topology was optimised for the traditional approach to establish a benchmark with which to compare subsequent optimisations. The LFPM linear machine not only compared well with other topologies for the traditional application in resonant free-piston Stirling engines, but it was found also to be able to perform displacement control for both the displacer and the power piston. For both pistons, displacement should however be limited to sinusoidal displacement, and in the case of the displacer, an important qualification is that the linear machine should be assisted by spring forces to reach practical design optimisations. Direct piston displacement control is shown to be possible. Future work should concentrate on the practical implementation thereof in free-piston Stirling engines.
AFRIKAANSE OPSOMMING: Die beheer van beta-tipe vrysuier Stirling enjins is al vir baie jare die onderwerp van navorsing en ontwikkeling. In hierdie proefskrif word ’n alternatiewe benadering tot vrysuier Stirlingenjins voorgestel, naamlik direkte suierverplasingsbeheer. Direkte suierverplasingsbeheer behels die oombliklike en direkte beheer van die suierverplasing om die enjin volgens voorkeur kriteria, soos maksimum drywingsomsetting of benuttingsgraad, te beheer. Om vrysuier enjins op hierdie wyse te beheer, is dit noodsaaklik om intyds die verplasing van beide die verplaser en die werksuier onafhanklik te beheer. Die primêre wyse om dit te bereik is deur eksterne beheer van die oomblikskragte wat uitgevoer word deur die lineêre masjiene wat vas is aan die suiers. Die uitdaging van verplasingsbeheer is of toepaslike lineêre masjien tegnologie bestaan en of tegnologie gevestig kan word wat sal voldoen aan die vereistes van intydse direkte beheer. Om die vraag te beantwoord of direkte suierverplasingsbeheer hoegenaamd moontlik is, is ’n proses gevolg om spesifikasies daar te stel waaraan lineêre masjiene moet voldoen en om ontwerpsriglyne vir lineêre masjiene en vrysuier Stirling enjins te stel. Die eerste stap was om die vermoë daar te stel om vrysuier Stirling enjin dinamika akkuraat te simuleer. Dit is gedoen deur ’n tweede orde formulering aan te pas en om die akkuraatheid daarvan te kontroleer en te verbeter deur gesimuleerde resultate met eksperimentele resultate van een van die bes gedokumenteerde Stirling enjins, naamlik die GPU-3 enjin, te vergelyk. Daar is bevind dat die tweede orde formulering die GPU-3 tot ’n redelike mate akkuraat kon simuleer. Sleutel aanwysers is gedefinieer en later verfyn met die oog op die daarstelling van spesifikasies. ’n Gevallestudie van die invloed van ’n reeks variasies, insluitende operasionele, dimensionele en ander variasies, op die dinamika van die GPU-3 is onderneem. Gegrond op die bevindinge van hierdie gevallestudie kon spesifikasies en ontwerpsriglyne vasgestel word. ’n Ontwerpsoptimeringsbenadering is voorgestel om lineêre masjiene te evalueer. Hierdie benadering maak spesifiek voorsiening vir die spesifikasies waaraan lineêre masjiene moet voldoen, sowel as verteenwoordigende dinamiese response van die kragte wat op die lineêre masjien van die verplaser en die werksuier uitgeoefen word. Vanaf die bevindinge van die studie wat uitgevoer is om spesifikasies daar te stel, is verteenwoordigende response en gepaardgaande suierverplasing bepaal vir die verplaser, die werksuier en die kombinasie van die twee. ’n Lugkern, longitudinale vloed lineêre masjien met oppervlak-gemonteerde permanente magnete (LVPM) is toe geëvalueer om die geskiktheid daarvan te bepaal vir direkte suierverplasingsbeheer. Hierdie lineêre masjien topologie is geoptimeer vir die tradisionele benadering om ’n maatstaf te vestig waarteen daaropvolgende optimerings vergelyk kan word. Die LVPM lineêre masjien vergelyk nie net goed met ander topologieë vir die tradisionele toepassing in resonante vrysuier Stirling enjins nie, maar daar is ook bevind dat dit in staat is om verplasingsbeheer te doen vir beide die verplaser en die werksuier. Vir beide suiers moet die verplasing egter tot sinusvormige verplasing beperk word en in die geval van die verplaser, is ’n belangrike kwalifikasie dat die lineêre masjien ondersteun moet word deur veerkragte om praktiese ontwerpsoptimerings te bereik. Daar is aangetoon dat direkte suierverplasingsbeheer moontlik is. Toekomstige werk moet konsentreer op die praktiese implementering daarvan in vrysuier Stirling enjins.
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Shah, Hemang J. Fontecchio Adam. "Engineered interfaces for liquid crystal technology /." Philadelphia, Pa. : Drexel University, 2007. http://hdl.handle.net/1860/1788.
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Punwaney, Nikhil Narendra. "Building a similarity engine." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119723.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 53).
In the seventeenth century, Philosophers such as Leibniz and Descartes put forward proposal for codes to relate words between languages. The first patents for "translating machines" were applied for in the mid-1930s. Up to the 1980s, most Natural Language Processing (NLP) systems were based on complex sets of hand-written rules. At that time however, the introduction of machine learning algorithms for language processing revolutionized NLP.[5] In 2008, Collobert and Weston exhibited the power of pre-trained word embed- dings in a paper called A unified architecture for natural language processing. Here, word embeddings is highlight for its ability in downstream tasks. They also discuss a neural network architecture that many of todays approaches are built upon. In 2013, Mikolov created word2vec, a toolkit that enabled the training and use of pre-trained embeddings. In 2014, Pennington introduced GloVe, a competitive set of pre-trained embeddings. Starting off, a single word or group of words can be converted into a vector. This vector can be created using the Skip gram method, which predicts the possible words nearby, the LSTM-RNN method, which forms semantic representations of sentences by learning more about the sentence as it iterates through a sentence, using single convolution neural networks, and several other methods. Using these theories, we are trying to build a Similarity Engine which provides machine learning based content search and classification of data.
by Nikhil Narendra Punwaney.
M. Eng.
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Ko, Theodore Jerry. "Teleconferencing session management engine." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36569.
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Hu, Yuanming S. M. Massachusetts Institute of Technology. "The ChainQueen differentiable physics engine." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/121656.
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This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 47-49).
Physical simulators have been widely used in robot planning and control. Among them, differentiable simulators are particularly favored, as they can be incorporated into gradient-based optimization algorithms that are efficient in solving inverse problems such as optimal control and motion planning. Simulating deformable objects is, however, more challenging compared to rigid body dynamics. The underlying physical laws of deformable objects are more complex, and the resulting systems have orders of magnitude more degrees of freedom and therefore they are significantly more computationally expensive to simulate. Computing gradients with respect to physical design or controller parameters is typically even more computationally challenging. In this paper, we propose a real-time, differentiable hybrid Lagrangian-Eulerian physical simulator for deformable objects, ChainQueen, based on the Moving Least Squares Material Point Method (MLS-MPM). MLS-MPM can simulate deformable objects including contact and can be seamlessly incorporated into inference, control and co-design systems. We demonstrate that our simulator achieves high precision in both forward simulation and backward gradient computation. We have successfully employed it in a diverse set of control tasks for soft robots, including problems with nearly 3, 000 decision variables.
by Yuanming Hu.
S.M.
S.M. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
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Arapostathis, Efstathios. "Consulting engineers in the British electric light and power industry, c. 1880-1914." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433399.
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Tang, Chee Meng. "Control Channel Vulnerability Analysis of the Institute of Electrical and Electronics Engineers 802.16m-2011 and 802.16- 2009 Standards." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17466.
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Approved for public release; distribution is unlimitedThe Institute of Electrical and Electronics Engineers (IEEE) 802.16 set of standards, known as Worldwide Interoperability for Microwave Access (WiMAX), is a family of standards widely deployed for wireless network access. Though WiMAX security vulnerabilities have been extensively analyzed, the IEEE 802.16m-2011 standard incorporates the new advanced air interface (AAI), which is substantially different from legacy standards and justifies reexamination on a clean slate. In this research, the vulnerabilities of IEEE 802.16m-2011 control channels are examined at the medium-access (MAC) and the physical (PHY) layers with proposed attack vectors. Methodologies are proposed to overcome challenges in terms of the timing and power associated with manipulating control channels. Attacks that manipulate the transmission power of mobile stations are examined in detail, while other attacks on IEEE 802.16m-2011, including multiple-input multiple-output (MIMO) disruption, network-entry disruption, and water-torture are also discussed. Out of fifteen vulnerabilities presented, thirteen were not previously identified for IEEE 802.16m-2011. Existing and new proposed vulnerabilities within legacy standards (specifically IEEE 802.16-2009) are also discussed, including transmission power manipulation, entry procedure attacks, water-torture attacks, and automatic repeat request attacks. Twelve of eighteen vulnerabilities presented were not previously discussed.
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Weiss, Ron 1970. "Cellular computation and communications using engineered genetic regulatory networks." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8228.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (p. 130-138).
In this thesis, I present an engineering discipline for obtaining complex, predictable, and reliable cell behaviors by embedding biochemical logic circuits and programmed intercellular communications into cells. To accomplish this goal, I provide a well-characterized component library, a biocircuit design methodology, and software design tools. I have built and characterized an initial cellular gate library with biochemical gates that implement the NOT, IMPLIES, and AND logic functions in E. coli cells. The logic gates perform computation using DNA-binding proteins, small molecules that interact with these proteins, and segments of DNA that regulate the expression of the proteins. I introduce genetic process engineering, a methodology for modifying the DNA encoding of existing genetic elements to achieve the desired input/output behavior for constructing reliable circuits of significant complexity. I demonstrate the feasibility of digital computation in cells by building several operational in-vivo digital logic circuits, each composed of three gates that have been optimized by genetic process engineering.
(cont.) I also demonstrate engineered intercellular communications with programmed enzymatic activity and chemical diffusions to carry messages, using DNA from the Vibrio fischeri lux operon. The programmed communications is essential for obtaining coordinated behavior from cell aggregates. In addition to the above experimental contributions, I have developed BioSPICE, a prototype software tool for biocircuit design. It supports both static and dynamic simulations and analysis of single cell environments and small cell aggregates. Finally, I present the Microbial Colony Language (MCL), a model for programming cell aggregates. The language is expressive enough for interesting applications, yet relies on simple primitives that can be mapped to the engineered biological processes described above.
by Ron Weiss.
Ph.D.
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Ormsson, Kristinn Arnar, and Henrik Persson. "A commercial vehicle’s electrical startability." Thesis, KTH, Hälsoinformatik och logistik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230226.
Full textAbstract:
In commercial vehicles, where the driver overnights with the engine turned off whilestill consuming electricity, it is important to know how much the battery can bedischarged before reliable engine starting is at risk. The vehicle’s ability to crank theengine, i.e. startability, changes with the vehicle’s ambient temperature and thebatteries state of charge. The aim of this project is therefore to test the startability ofa commercial vehicle and its cranking system’s behaviour at different ambienttemperatures and battery state of charge. Physical startability tests were planned andperformed on a commercial vehicle at different temperatures inside a climatechamber. The results of these tests show the torque of the vehicle’s powertrainincreasing with lowering temperature while the cranking system’s performancedecreases. This decrease in the cranking system’s performance is a result of thebattery’s lowering ability to supply power at lower temperatures.I tunga fordon, där chauffören spenderar natten med avstängd motor men fortsätteratt förbruka el, är det viktigt att veta hur mycket batterierna kan urladdas innanmotorn inte kan startas. Fordonets förmåga att starta motorn, det vill säga dessstartbarhet, ändras med omgivningstemperaturen och batteriernas laddnivå. Syftetmed projektet var därför att undersöka startbarheten på ett tungt fordon samt dessstartsystems beteende vid olika omgivningstemperaturer och laddningsnivåer påbatterierna. Under projektets gång planerades samt genomfördes provstarter meddet tunga fordonet vid olika omgivningstemperaturer i en klimatkammare.Provstarterna påvisade att släpmomentet på fordonets drivlina ökade med enfallande temperatur medan startsystemets prestanda försämrades. Startsystemetsförsämrade prestanda beror huvudsakligen på batteriernas försämrade förmåga attavge effekt vid lägre temperaturer.
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XING, YASHAN, and WEILONG XU. "Signal Analysis of Fretting Damages on Electrial Connector Systems." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-14540.
Full textAbstract:
Electrical connectors are widely utilized for signal communications in automotive electronic systems whose performance is related to the reliability of the entire system. Electrical connectors are frequently affected by the engine vibration, resulting in fretting damages on electrical connector. In this thesis, the main propose is to find a signal analysis method to predict the fretting damages on fuel pump connector induced by engine vibration. The data of the fuel pump connector is studied from a vibration test of the four-cylinder engine and the dominating frequencies are used in the fretting test to verify the analysis method. The fretting damage is identified through visual inspection by microscope. The model of the connector is built in COMSOL to explain the fretting on the contact surfaces. The results present the signal analysis method can be directly used to predict the risk of fretting damages during the engine vibration. Some significant frequencies are pointed out as guidelines for future tests and optimization.
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Gohary, Mohamed Morsy Abdel Meguid Salama el. "Diesel engines and solar energy for electric and cooling applications." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973168242.
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Willerström, Jakob, Adam Linde, and Johannes Fagrell. "Electrifying the construction process : Replacing diesel engines with electric motors." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-254206.
Full textAbstract:
Diesel engines are commonly used in construction machines, for example excavators. In a diesel engine, the combustion of diesel is a process with a considerable environmental impact, with high amounts of emitted greenhouse gases. The bachelor thesis creates a model that investigates the potential of decreasing the environmental impact when replacing diesel engines with electric motors in the construction phase of the construction process of buildings. The model was made in three steps. In the first step the electric motors’ energy consumption were compared with the diesel engines’ energy consumption. Secondly, the results of the comparison were contrasted against the results of an implemented example as to determine the relevancy of the model. Finally, the carbon dioxide equivalent values of the diesel engines and the electric motors were calculated and compared. The result shows that there is a big potential of decreasing the environmental impact. The reduction is in the order of 63%-99% and it is shown that the share of renewable energy sources in the electricity mix is vital as to make the potential as large as possible.
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Ambrose, Ricardo S. (Ricardo Sean) 1974. "A lightweight multi-database execution engine." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/46220.
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Chung, Jack V. (Jack Vinh) 1978. "Search engine for online physiologic databases." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86654.
Full textAbstract:
Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2001.Includes bibliographical references (leaf 40).
by Jack V. Chung.
M.Eng.and S.B.
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Wong, Brian Wai Fung. "Deep-web search engine ranking algorithms." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61246.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 79-80).
The deep web refers to content that is hidden behind HTML forms. The deep web contains a large collection of data that are unreachable by link-based search engines. A study conducted at University of California, Berkeley estimated that the deep web consists of around 91,000 terabytes of data, whereas the surface web is only about 167 terabytes. To access this content, one must submit valid input values to the HTML form. Several researchers have studied methods for crawling deep web content. One of the most promising methods uses unique wrappers for HTML forms. User inputs are first filtered through the wrappers before being submitted to the forms. However, this method requires a new algorithm for ranking search results generated by the wrappers. In this paper, I explore methods for ranking search results returned from a wrapped-based deep web search engine.
by Brian Wai Fung Wong.
M.Eng.
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Wang, Edward M. 1976. "Supreme Court audio file search engine." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17997.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (leaves 73-74).
Search engines have evolved from simple text indexing to indexing other forms of media, such as audio and video. I have designed and implemented a web-based system that permits people to search the transcripts of selected Supreme Court cases, and retrieve audio file clips relevant to the search terms. The system development compared two implementation approaches, one based on transcript aligning technologies developed by Hewlett-Packard, the other is a servlet-based search system designed to return pre-parsed audio file clips. While the first approach has the potential to revolutionize audio content search, it could not consistently deliver successively parsed audio file clips with the same user friendly content and speed as the simpler second approach. This web service, implemented with the second approach, is currently deployed and publicly available at www.supremecourtaudio.net .
by Edward M. Wang.
M.Eng.
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Ocholi, Eleojo E. "Web engine for investigating consumer consideration." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53176.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Includes bibliographical references (p. 37-38).
Today consumers are presented with a plethora of products each time they want to make a purchase. Sometimes they have up to thousands of options and configurations to pick from and yet many consumers are shown to initially screen this size to create a more manageable set to truly consider in an in-depth way. Companies today are looking for ways to ensure that their products make it into the smaller consideration sets of consumers in order to increase the probability of sales. This thesis documents the design of a web engine that provides a survey framework for investigating algorithms that aim to predict which products a user will place in their consideration set as well as to aid in investigating the factors that can lead to the modification of rules that govern a consumer's consideration set. Firstly I evaluated and documented the improvements required from older systems created by the research group. Then over the course of two studies I designed a highly modular system that is a new iteration of the older versions. Finally, more than 3500 participants used the system during field tests and the system was successful in mitigating the previous issues and delivering a better user experience as well as collecting the necessary data. This project lays the groundwork for a platform that can be used for generally investigation and testing consideration predictive algorithms in various retail spaces.
by Eleojo E. Ocholi.
M.Eng.
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McGinnis, Sean W. (Sean William) 1975. "DAVE : the distributed algorithm visualization engine." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47588.
Full textAbstract:
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 73).
by Sean W. McGinnis.
S.B.and M.Eng.
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Telichevesky, Ricardo. "A numerical engine for distributed sparse matrices." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12217.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (p. 169-173).
by Ricardo Telichevesky.
Ph.D.
31
Parlikar, Tushar Anil 1978. "Experimental implementation of an electromagnetic engine valve." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/87332.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 195-196).
by Tushar Anil Parlikar.
S.M.
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Morris, Richard James Horatio. "Optimisation studies on strain-engineered Germanium heterostructures." Thesis, University of Warwick, 2003. http://wrap.warwick.ac.uk/52780/.
Full textAbstract:
The physical gate lengths of state-of-the-art CMOS devices are 45 nm and are anticipated to reach just 20 nm by 2007. Due to the prohibitive capital expenditure required for next-generation CMOS technologies, leading device manufacturers are now exploring exotic device architectures and novel substrates in which significant device performance enhancements may by obtained using the existing device fabrication infrastructure. This thesis reports studies made on an initial evaluation of hole transport properties in strained Ge channels and comprises physical and electrical characterisation of these heterostructures as well as the analysis of SiGe layers using secondary ion mass spectrometry. The initial work of thesis describes the growth, characterisation and optimisation of a novel strained Ge substrate. The substrate technology was developed using a hybrid-epitaxy technique in which a SiGe strain-relaxed buffer layer, so called "virtual substrate", was grown using a ultra-high vacuum chemical-vapour deposition growth technique and the active strained Ge layer was grown using a solid-source molecular-beam epitaxy growth technology. An advanced chemical cleaning procedure has been developed which includes a modified Piranha etch. The novel cleaning procedure enables the successful integration of the two growth techniques. Significant hole carrier transport enhancements were observed for holes contained within the strained Ge channel. Optimisation of the hole mobility was achieved by the reduction of carrier scattering such as interface roughness scattering and point defect scattering. The optimisation methods employed included growth temperature iterations to reduce Ge channel roughening via elastic relaxation and, channel thickness iterations were also employed in order to minimize channel roughening and defect nucleation. Post-growth annealing procedures were used to combat defects arising from low temperature growth. The Ge heterostructures were grown on strain relaxed buffer layers, terminating with a Ge content of 60%. The optimised strained Ge channel thickness was found to be 20 nm and the growth temperature of the active layers was reduced to 350°C so as to minimise surface roughening. As grown point defects were eliminated at an optimised post-growth anneal temperature of 650°C for 30 minutes under dry N2• Hall mobilities reached 1910 cm2Ns at room temperature rising to 26,900 cm2Ns at 10K. A magneto-conductivity transfonnation measurement and maximum entropy mobility spectrum analysis revealed a room temperature drift mobility of 2700 cm2Ns at a carrier density of l.Ox1012 cm-2 . This result represents a 15-fo1d increase in hole mobility compared to conventional Si substrates at comparable effective fields. The second and important part of this thesis addresses charging effects observed when profiling undoped SiGe layers and the quantification of Ge fraction within SiGe layers using secondary ion mass spectrometry. Due to the highly resistive spreading resistance found for undoped SiGe layers when profiled using an O2+ incident beam, charging effects were found to mask the true layer profile. In order to overcome this problem a new approach is discussed for the first time. By illuminating the sample with a red laser light (wavelength 635mn) electron-hole pairs were created via photon absorption. The excess charge carriers were sufficient to overcome localised charging effects induced by the primary ion beam during SIMS analysis. In this manner, total charge suppression was achieved, thereby enabling a true determination of the SiGe sample profile to be obtained via SIMS. Finally, an analytical method enabling the accurate determination of Ge content of SiGe layers is discussed. The method employs a comparative ion yield methodology and enables both the spatial distribution and Ge concentration of SiGe layers to be accurately determined from a single SIMS measurement.
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Ng, Man Cheuk 1980. "Rapid designs for cache coherence protocol engines in Bluespec." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30166.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 91-92).
In this thesis, we present the framework for Rapid Protocol Engine Development (RaPED). We implemented the framework in Bluespec, which is a high level hardware language based on Term Rewriting Systems (TRSs). The framework is highly parameterized and general, thus allowing designers to design any protocol engine in a short period. Since protocol engines can be developed rapidly, designers can compare different designs instead of freezing the design prematurely in the development process. We used the RaPED to implement a cache coherence protocol for Shen and Arvind's Commit-Reconcile and Fences (CRF) memory model [1]. The CRF allows scalable implementations of shared memory systems by decomposing memory access operations into simpler instructions. However, the focus for Shen's Cachet protocol for the CRF was adaptivity and correctness, it ignored some important implementation issues such as cache-line replacement, efficient buffer management and compatibility with multiword cache lines. In this thesis, we present a protocol called the Multiword Base protocol, which avoids these limitations. We defined the Multi-word CRF (MCRF) memory model to help us to prove the correctness of Multiword Base. The MCRF is a specialization of the CRF with modifications that summarizes the properties of multiword cache lines. We show that Multiword Base is a correct implementation of the CRF by using the MCRF to simulate Multiword Base. Apart from using multiword cache lines, many cache coherence protocols allow a cache to get data directly from another cache. The caches having this property is calling the snoopy caches. In this thesis, we present a CRF variant called the Snoopy CRF (SCRF) memory model, which gives hints to incorporate snoopy caches to the implementations of the CRF.
by Man Cheuk Ng.
S.M.
34
Roy, Tapashree. "Control and localisation of light with engineered nano-structures." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/369991/.
Full textAbstract:
In this thesis I present my research on nano-scale light control using several novel approaches. I have demonstrated a planar metal nano-structure with cylindrical symmetry that is designed to create a super-oscillation of electromagnetic waves to focus light down to sizes smaller than the Abbe diffraction limit. For the first time this super-oscillatory lens was experimentally used for imaging of nano-structures. A pair of 0:3λ diameter nano-holes with 0:16λ edge-to-edge separation were resolved. I have demonstrated a novel type of super-oscillatory lens which produces a continuous distribution of sub-wavelength light localisations extending over several wavelengths along the optical axis. This `optical needle' is also characterised by a large field of view. I have experimentally demonstrated a optical-needle-lens with 7µm depth of focus and 16% narrower than a diffraction-limited focal spot. I have characterised the point spread function of the above-mentioned super-oscillatory lenses, i.e., their ability to accurately image a point source. The images of the point source generated by these super-oscillatory lenses are at least 24% smaller than that produced by an ideal glass lens restrained by the Abbe diffraction limit. I have experimentally verified the imaging characteristics of the optical-needle-lens and demonstrated its ability to detect the off-axis placement of a point-like source. I have developed the nano-fabrication processes for manufacturing the super-oscillatory lenses on thin films of metals (Au, Al, Ti) using gallium focused-ion-beam milling technology. The focusing characteristics of the fabricated structures showed very good agreement with computational predictions. I have computationally shown that objects placed within the field of viewfocfocus of the optical-needle-lens can be imaged with super-resolution quality. This is a significant improvement over the sub-wavelength-step scanning imaging technique reported in this thesis for the other kind of super-oscillatory lens. For example, a super-oscillatory lens can resolve a `random' cluster of 0:15λ diameter nano-holes with the smallest edge-to-edge separation of 0.28λ. I have experimentally demonstrated the first prototype of a solid-immersion superoscillatory lens that promises to achieve a 50 nm hotspot with 405 nm illumination for applications in heat-assisted magnetic recording technology. I have demonstrated for the first time a planar diffraction grating for visible light designed by arranging meta-molecules to produce a periodic phase ramp. I have also demonstrated the first ever metamaterial-based planar lens-array that produced a 2D array of sub-wavelength foci. Finally, I have provided the first experimental evidence that photoluminescence of gold can be substantially enhanced by patterning the film with designed 2D nano-structured array (or, metamaterials). When resonant two-photon excitation is used the metamaterial enhances the photoluminescence by more than 76 times. I have also observed that the photoluminescence emission peaks are linked to the frequencies of absorption resonances in the metamaterials.
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Perjanik, Nicholas Steven. "Tacit Knowledge Capture and the Brain-Drain at Electrical Utilities." Thesis, Walden University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10118978.
Full textAbstract:
As a consequence of an aging workforce, electric utilities are at risk of losing their most experienced and knowledgeable electrical engineers. In this research, the problem was a lack of understanding of what electric utilities were doing to capture the tacit knowledge or know-how of these engineers. The purpose of this qualitative research study was to explore the tacit knowledge capture strategies currently used in the industry by conducting a case study of 7 U.S. electrical utilities that have demonstrated an industry commitment to improving operational standards. The research question addressed the implemented strategies to capture the tacit knowledge of retiring electrical engineers and technical personnel. The research methodology involved a qualitative embedded case study. The theories used in this study included knowledge creation theory, resource-based theory, and organizational learning theory. Data were collected through one time interviews of a senior electrical engineer or technician within each utility and a workforce planning or training professional within 2 of the 7 utilities. The analysis included the use of triangulation and content analysis strategies. Ten tacit knowledge capture strategies were identified: (a) formal and informal on-boarding mentorship and apprenticeship programs, (b) formal and informal off-boarding mentorship programs, (c) formal and informal training programs, (d) using lessons learned during training sessions, (e) communities of practice, (f) technology enabled tools, (g) storytelling, (h) exit interviews, (i) rehiring of retirees as consultants, and (j) knowledge risk assessments. This research contributes to social change by offering strategies to capture the know-how needed to ensure operational continuity in the delivery of safe, reliable, and sustainable power.
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Gupta, Ankush M. "Cross-engine query execution in federated database systems." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106013.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 47-48).
Duggan et al.have created a reference implementation of the BigDAWG system: a new architecture for future Big Data applications, guided by the philosophy that "one size does not fit all." Such applications not only call for large-scale analytics, but also for real-time streaming support, smaller analytics at interactive speeds, data visualization, and cross-storage-system queries. The importance and effectiveness of such a system has been demonstrated in a hospital application using data from an intensive care unit (ICU). In this report, we implement and evaluate a concrete version of a cross-system Query Executor and its interface with a cross-system Query Planner. In particular, we focus on cross-engine shuffle joins within the BigDAWG system.
by Ankush M. Gupta.
M. Eng.
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Chung, Hye Won. "An energy efficient AES engine with DPA-resistance." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/55146.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 73-75).
The advent of portable electronics which transmit and receive sensitive data via wireless communication have led to interest in the design of energy-efficient security engines. The hardware implementation of cryptographic algorithms, however, leaks side-channel information about the operations they process. Differential Power Analysis (DPA) is one of the most powerful attacks to disclose secret key of the engine. This thesis proposes an energy efficient AES-128 engine which is resilient to DPA attacks. A proposed design adopts extensive parallelism and voltage scaling to simultaneously achieve energy efficiency and throughput requirement. Optimized 128-bit architecture and 16 S-boxes placed in the encryption datapath allow the parallel operation of 16 bytes of encryption data at supply voltages in the subthreshold region while maintaining more than tens of Mbps throughput rate. The energy efficient AES core, which does not incorporate techniques to mitigate DPA attack, can operate at 0.35V with 54.12pJ/encrypt. and 64.6Mbps. Before developing countermeasures against DPA, a previously suggested DPA attack methodology in [1] is studied and modified to disclose secret key of our system. The transition power of register is estimated by using the byte-oriented reverse algorithm of AES with the knowledge of a ciphertext and a guess of a secret key. Correlation between the power estimate and the power measurement discloses 12 key bytes (among 16) within 20K encryption runs. A newly proposed AES architecture which balances the Hamming weight of register input can protect the system from DPA attacks.
(cont.) The secured core has been subjected to 100K encryptions, 33x more than the number of runs at which attack can disclose a secret key of the unprotected core, but none of its secret key have yet been disclosed. When running the encryption core at 0.4V and 10IMHz, power increases by 2x compared to the unprotected core. Maximum throughput at 1.OV is reduced by 2/3 for protected core compared with the unprotected core. This IC performance overhead comes at the cost of the increased security.
by Hye Won Chung.
S.M.
38
Pan, Jin M. Eng Massachusetts Institute of Technology. "Performance engineering of the StarLogo Nova Execution Engine." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/113161.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 117).
StarLogo Nova is an online blocks-based programming environment designed for pre-college students to explore the collective behavior of decentralized agents. Users can drag and drop blocks to construct graphical scripts that control how individual agents respond to stimuli. These scripts are run by the Execution Engine and rendered in real-time. By investigating hypotheses about how small tweaks to individual behavior impact the entire system, students learn to think beyond the centralized mindset where all actions are dictated by a singular leader. This thesis migrates the Execution Engine from the aging Adobe ActionScript 3 language to TypeScript, a weakly typed language that transpiles to JavaScript. To promote code health, this thesis introduces code formatters, linters, test cases, and a build process. Finally, this thesis optimizes the StarLogo Nova Execution Engine for performance, consistently beating the previous engine and bringing the execution time per cycle for key benchmarks under 10 milliseconds.
by Jin Pan.
M. Eng.
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Lee, Hsu-Yi. "Ultrastructure and nanomechanical properties of aggrecan from native cartilage and engineered tissue." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60099.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 147-159).
Electrostatic interactions associated with aggrecan, one of the major components of the cartilage extracellular matrix, are responsible for ~50% of the equilibrium compressive elastic modulus of the tissue. The bottle-brush-shaped aggrecan consists of a core protein to which ~100 sulfated glycosaminoglycan (sGAG) chains are attached. Loss of sGAG is one early events in the pathogenesis of osteoarthritis and the resulting degradation of cartilage is irreversible due to its limited capacity for self-repair. Tissue engineering is one of the techniques which holds great potential for cartilage repair. In order to achieve successful repair, a clear understanding of native and engineered cartilage aggrecan is essential. With atomic force microscopy and high resolution force microscopy, the structure of aggrecan single molecules and the nanomechanical properties of an end-grafted aggrecan monolayer were quantified. Adult human aggrecan showed significantly shorter GAG chains and core proteins as well as lower molecular stiffness compared to that of newborn aggrecan. After enzymatic digestion of chondroitin sulfate (CS) GAGs, keratan sulfate GAG chains were visualized near the N-terminal domain of a less extended core protein. Direct visualization of aggrecan aggregates confirmed the structure of the constituent hyaluronic acid, aggrecan G1 domain, and link protein. Increased flexibility of the core protein was found near the G1 domain, which may facilitate the aggregate self-assembly process. Aggregated and non-aggregated aggrecan both showed remarked flexibility (i.e., decreased extension ratio) when the aggrecan areal density increased. These findings on intra- and inter-molecular structure provide insights into the structure-property relationships of aggrecan in vivo. Aggrecan produced by animal-matched bone marrow stromal cells (BMSCs) and chondrocytes seeded in peptide hydrogel were evaluated for their age-associated structure and nanomechanical properties. Independent of age, BMSCs produced longer core proteins and GAG chains than the chondrocytes, suggesting that the BMSC-produced aggrecan was characteristic of that from young cartilage. Comparison of the adult BMSC-produced aggrecan with adult cartilage-extracted aggrecan revealed that adult BMSC-aggrecan has a phenotype characteristic of young growth cartilage: primarily full-length aggrecan core, longer GAG chains and a higher content of chondroitin-4-sulfate in the CS-GAG chains, the latter identified via fluorescence assisted carbohydrate electrophoresis. The nanomechanical stiffness of BMSC-aggrecan was demonstrably greater than that of cartilage-aggrecan at the same total sGAG (fixed charge) density. These results support the use of adult BMSCs for cell-based cartilage repair.
by Hsu-Yi Lee.
Ph.D.
40
Guled, Mohamed. "Optical Network Processor Design For Just-In-Time Signaling Protocol Message Engine Design." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-11072002-132924/.
Full textAbstract:
The purpose of this research has been the development of signaling protocol and associated architecture for Wave Division Multiplexing burst-switching network. The basic premise of this architecture is simple ? data, aggregated in bursts can be transferred from one end point to the other by setting up light path ahead of the arrival of the data. Optical Burst switched network is viewed as one pioneering effort to bring the most bandwidth available from the emerging dWDM technologies to end applications with minimum overhead and latency.
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Dasgupta, Sukrit De Oliveira Jaudelice Cavalcante. "Improving resource management in multi-protocol label switched traffic engineered networks /." Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2821.
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Fatemi, Omid. "Fractal engine, an affine video processor core for multimedia applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/NQ57040.pdf.
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Yuan, Jeffrey W. (Jeffrey Weijie). "Automating website profiling for a deep web search engine." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53187.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 53-55).
The deep web consists of information on the internet that resides in databases or is dynamically generated. It is believed that the deep web represents a large percentage of the total contents on the web, but is currently not indexed by traditional search engines. The Morpheus project is designed to solve this problem by making information in the deep web searchable. This requires a large repository of content sources to be built up, where each source is represented in Morpheus by a profile or wrapper. This research proposes an approach to automating the creation of wrappers by relying on the average internet user to identify relevant sites. A wrapper generation system was created based on this approach. It comprises two components: the clickstream recorder saves characteristic data for websites identified by users, and the wrapper constructor converts these data into wrappers for the Morpheus system. After completing the implementation of this system, user tests were conducted, which verified that the system is effective and has good usability.
by Jeffrey W. Yuan.
M.Eng.
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Chiang, Kenneth H. "Fuzzy logic mode selection for a recuperative turboshaft engine." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/74846.
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Chan, Sau-ha. "Tradeoff between internal combustion engined vehicles and electric vehicles in Hong Kong /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17092267.
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Chan, Sau-ha, and 陳秀霞. "Tradeoff between internal combustion engined vehicles and electric vehicles in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31253064.
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Ramunno, Michael Angelo. "Control Optimization of Turboshaft Engines for a Turbo-electric Distributed Propulsion Aircraft." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587657623577243.
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Varma, Sarvesh. "Cell-based sensors for quantifying cell health and disease progression in engineered systems." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112031.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 180-200).
Healthy cells create healthy beings, while dysfunctional cells cause disease. Studying disease requires an understanding of how cells become dysfunctional from physiological states. Gaining this insight in vitro involves subjecting cells to relevant microenvironments and utilizing methodologies for assaying cells. Critically, to obtain accurate and unbiased insight, it is important to ensure that the cellular microenvironment remains representative, and that the assay methodology itself does not adversely perturb cell state. This thesis presents an approach where cells 'report' upon their healthy or stressed states, which could be assessed to either learn disease mechanisms, or quantified to design 'cell-friendly' methodologies. We engineered cell-based sensors that emit stress-regulated fluorescence, and applied them to characterize how distinct microenvironments regulate cell health. Here, we describe two endeavors that highlight the utility of this approach. We first developed cell stress sensors for a diverse bioinstrumentation community to quantify the impact of engineered systems and methodologies upon cell health. Using NIH3T3 cells, we engineered sensors that report on stresses induced by DNA damage, heat shock, or fluid shear stresses. Each sensor provides sensitive and specific responses to stress-induced pathways (relevant to several cell types), and can be used for a multiplexed stress-readout. The sensors do not require additional reagents and can be conveniently quantified with flow cytometry and real-time imaging. Successful distribution and adoption of the sensors by external users enabled quantitative characterization of flow sorting systems in the context of cell health, which was not explored before. Hence, the cell-sensor methodology designed as an 'open source' tool, could potentially serve as a novel standard for quantifying cell stress, and broadly for designing 'cell-friendly' methodologies. We further utilized cell-based sensors to gain biological insight into stress-regulated diseases. We focused on atherosclerosis, a flow-regulated cardiovascular disease that remains a major cause of morbidity and mortality worldwide. We engineered a novel microfluidic platform to study atherogenesis in vitro that overcomes several limitations of existing models. This device emulates in vivo microenvironments by applying programmable spatiotemporal flow profiles observed from human patients directly upon cultured human cells. Utilizing an endothelial cell-based sensor (that reports on vascular health), device flows were validated with known biomarkers and endothelial signatures. Subsequently, these sensors were used to gain novel insight upon atherogenesis through the impact of hemodynamic flows upon endothelial function. Overall, this thesis presents a facile and quantitative approach to investigate complex cell-stress emergent from diverse bioinstrumentation or within a disease microenvironment, which can be utilized to discover how environmental conditions regulate cell physiology, and human health.
by Sarvesh Varma.
Ph. D.
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Zinnecker, Alicia M. "Modeling for Control Design of an Axisymmetric Scramjet Engine Isolator." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354215841.
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Van, Horn Charles. "Steady State and Transient Efficiencies of a Four Cylinder Direct Injection Diesel Engine For Implementation in a Hybrid Electric Vehicle." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1154354134.
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