74 research outputs found

    Diseño de circuito de protección contra extracción de información secreta en tarjetas inteligentes

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    En el presente trabajo de tesis se realizó el diseño de un circuito de protección contra ataques del tipo Differential Power Analysis (DPA) aplicado a tarjetas inteligentes. Este tipo de tarjetas presenta la misma apariencia física de una tarjeta de crédito pero en su estructura cuenta con un circuito integrado. Se utilizó la tecnología AMS 0.35m de la compañía Austriamicrosystem, y se aplicó la técnica denominada Atenuación de Corriente. Esta se basa en la implementación de un circuito ubicado entre la fuente de alimentación y el procesador criptográfico de la tarjeta inteligente, el cual logra disminuir las variaciones de consumo de corriente presentes durante una operación criptográfica. El circuito de protección se dividió en tres bloques: Sensor de Corriente, Amplificador de Transimpedancia e Inyector de Corriente. Cada uno de estos bloques fue diseñado tomando criterios del diseño de circuitos integrados analógicos, tales como consumo de potencia, área ocupada y ganancia. Para esta etapa de diseño se utilizó el modelo Level 1 del transistor MOSFET. Posteriormente, se realizaron simulaciones a cada uno de los bloques del circuito de protección usando el software Cadence. Finalmente, una vez alcanzados los requerimientos establecidos, se procedió al desarrollo del layout físico del circuito diseñado. El circuito diseñado logra una atenuación de las variaciones de consumo de corriente del 86%. Entre sus principales características se puede mencionar que consume 35.5mW , ocupa 2 60000m y presenta 96MHz de ancho de banda.Tesi

    A Class-E Inductive Powering Link with Backward Data Communications for Implantable Sensor Systems

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    The design and implementation of a wireless power and data transfer system based on inductive coupling, having the potential to be used in numerous implantable bio-medical sensors and systems, is presented. The system consists of an external (primary) unit and an internal (secondary) unit. The external unit incorporates a high-efficiency switch-mode Class-E amplifier operating at ~200 kHz for driving the primary coil. The secondary unit consists of a parallel resonant coil followed by the power recovery circuitry. Means for backward data communication from the internal to the external unit over the same pair of coils has been realized using a simple FSK-based modulation scheme incorporated into the internal unit. FSK demodulation and associated filtering are integrated with the base inductive powering system. Prototype system test results indicate the inductive link efficiency can exceed 80% under optimum operating conditions with the overall power transfer efficiency of approximately 30%. The communication system is capable of transmitting up to 10kbps of data with the FSK carrier frequency (i.e., middle-frequency) being only 120kHz. The complete system functions reliably over an inter-coil distances exceeding 2.5cm with a 5V dc supply

    Wide Bandwidth - High Accuracy Control Loops in the presence of Slow Varying Signals and Applications in Active Matrix Organic Light Emitting Displays and Sensor Arrays

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    This dissertation deals with the problems of modern active matrix organic light-emitting diode AMOLED display back-plane drivers and sensor arrays. The research described here, aims to classify recently utilized compensation techniques into distinct groups and further pinpoint their advantages and shortcomings. Additionally, a way of describing the loops as mathematical constructs is utilized to derive new circuits from the analog design perspective. A novel principle on display driving is derived by observing those mathematical control loop models and it is analyzed and evaluated as a novel way of pixel driving. Specifically, a new feedback current programming architecture and method is described and validated through experiments, which is compatible with AMOLED displays having the two transistor one capacitor (2T1C) pixel structure. The new pixel programming approach is compatible with all TFT technologies and can compensate for non-uniformities in both threshold voltage and carrier mobility of the pixel OLED drive TFT. Data gathered show that a pixel drive current of 20 nA can be programmed in less than 10usec. This new approach can be implemented within an AMOLED external or integrated display data driver. The method to achieve robustness in the operation of the loop is also presented here, observed through a series of measurements. All the peripheral blocks implementing the design are presented and analyzed through simulations and verified experimentally. Sources of noise are identified and eliminated, while new techniques for better isolation from digital noise are described and tested on a newly fabricated driver. Multiple versions of the new proposed circuit are outlined, simulated, fabricated and measured to evaluate their performance.A novel active matrix array approach suitable for a compact multi-channel gas sensor platform is also described. The proposed active matrix sensor array utilizes an array of P-i-N diodes each connected in series with an Inter-Digitated Electrode (IDE). The functionality of 8x8 and 16x16 sensor arrays measured through external current feedback loops is also presented for the 8x8 arrays and the detection of ammonia (NH3) and chlorine (Cl2) vapor sources is demonstrated

    Mu2e Technical Design Report

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    The Mu2e experiment at Fermilab will search for charged lepton flavor violation via the coherent conversion process mu- N --> e- N with a sensitivity approximately four orders of magnitude better than the current world's best limits for this process. The experiment's sensitivity offers discovery potential over a wide array of new physics models and probes mass scales well beyond the reach of the LHC. We describe herein the preliminary design of the proposed Mu2e experiment. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2 approval.Comment: compressed file, 888 pages, 621 figures, 126 tables; full resolution available at http://mu2e.fnal.gov; corrected typo in background summary, Table 3.

    Feasibility of high frequency alternating current power distribution for the automobile auxiliary electrical system

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    This study investigates the feasibility and potential benefits of high frequency alternating current (HFAC) for vehicle auxiliary electrical systems. A 100Vrms, 50kHz sinusoidal AC bus is compared with 14V DC and 42V DC electrical systems in terms of mass and energy efficiency. The investigation is focused on the four main sub-systems of an on-board electrical network, namely: the power generation, power distribution, power conversion and the electrical loads. In addition, a systemlevel inquiry is conducted for the HFAC bus and a comparable 42V DC system. A combination of computer simulation, analytical analysis and experimental work has highlighted benefits for the HFAC power distribution sub-system and for low-torque motor actuators. Specifically, the HFAC conductor mass is potentially 70% and 30% lighter than comparable 14V DC and 42V DC cables, respectively. Also, the proposed cable is expected to be at least 80% more energy efficient than the current DC conductor technology. In addition, it was found that 400Hz AC machines can successfully replace DC motor actuators with a rated torque of up to 2Nm. The former are up to 100% more efficient and approximately 60% lighter and more compact than the existing DC motors in vehicles. However, it is argued that the HFAC supply is not feasible for high-torque motor actuators. This is because of the high energy losses and increased machine torque ripple associated with the use of HFAC power. The HFAC power conversion sub-system offers benefits in terms of simple power converter structure and efficient HFAC/DC converters. However, a significant limitation is the high power loss within HFAC/AC modules, which can be as high as 900W for a 2.4kW load with continuous operation. Similar restrictions are highlighted for the HFAC power generation sub-system, where up to 400W is lost in a 4kW DC/HFAC power module. The conclusion of the present work is that the HFAC system offers mass and energy efficiency benefits for the conventional vehicle by leveraging the use of compact lowtorque motor actuators and lightweight wiring technology

    Feasibility of high frequency alternating current power distribution for the automobile auxiliary electrical system

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    This study investigates the feasibility and potential benefits of high frequency alternating current (HFAC) for vehicle auxiliary electrical systems. A 100Vrms, 50kHz sinusoidal AC bus is compared with 14V DC and 42V DC electrical systems in terms of mass and energy efficiency. The investigation is focused on the four main sub-systems of an on-board electrical network, namely: the power generation, power distribution, power conversion and the electrical loads. In addition, a systemlevel inquiry is conducted for the HFAC bus and a comparable 42V DC system. A combination of computer simulation, analytical analysis and experimental work has highlighted benefits for the HFAC power distribution sub-system and for low-torque motor actuators. Specifically, the HFAC conductor mass is potentially 70% and 30% lighter than comparable 14V DC and 42V DC cables, respectively. Also, the proposed cable is expected to be at least 80% more energy efficient than the current DC conductor technology. In addition, it was found that 400Hz AC machines can successfully replace DC motor actuators with a rated torque of up to 2Nm. The former are up to 100% more efficient and approximately 60% lighter and more compact than the existing DC motors in vehicles. However, it is argued that the HFAC supply is not feasible for high-torque motor actuators. This is because of the high energy losses and increased machine torque ripple associated with the use of HFAC power. The HFAC power conversion sub-system offers benefits in terms of simple power converter structure and efficient HFAC/DC converters. However, a significant limitation is the high power loss within HFAC/AC modules, which can be as high as 900W for a 2.4kW load with continuous operation. Similar restrictions are highlighted for the HFAC power generation sub-system, where up to 400W is lost in a 4kW DC/HFAC power module. The conclusion of the present work is that the HFAC system offers mass and energy efficiency benefits for the conventional vehicle by leveraging the use of compact lowtorque motor actuators and lightweight wiring technology.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Skin Stories: Charting and Mapping the Skin. Research using analogies of human skin tissue in relation to my textile practice.

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    The practice based research SKIN STORIES:: CHARTING AND MAPPING THE SKIN deals with issues across the fields of art, design, technology, biology and material science. In an attempt to bridge the gap between aesthetics and technology by investigating the potential of new and industrial materials, the epidermis is used as a metaphor for creating innovative textile surfaces which behave, look or feel like skin. As a result of theoretical enquiry and practical experiments, interactive design solutions have been developed to a prototype stage for possible application in domestic environments and public spaces as well as for integration into body related design concepts. The development of such functional and interactive textile membranes will hopefully enable individuals to experience a polysensual and responsive environment and it is this aspect which is considered to be an original contribution to knowledge in the textiles field. The aim of this written thesis is not only to illustrate the journeys and investigations made along the way and to demonstrate the outcome of the research, but also to situate the practical work in its cultural, critical and technological context. This thesis is accompanied by an interactive CD-ROM which is a visual representation of my 'research map' and holds a record of the practical work carried out during the research project. The ideas of the project SKIN STORIES:: CHARTING AND MAPPING THE SKIN have been developed and tested during a 3-year research programme towards a Ph. D. at The London College of Fashion, University of the Arts London

    Laboratory Directed Research and Development FY-10 Annual Report

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    The FY 2010 Laboratory Directed Research and Development (LDRD) Annual Report is a compendium of the diverse research performed to develop and ensure the INL's technical capabilities can support the future DOE missions and national research priorities. LDRD is essential to the INL -- it provides a means for the laboratory to pursue novel scientific and engineering research in areas that are deemed too basic or risky for programmatic investments. This research enhances technical capabilities at the laboratory, providing scientific and engineering staff with opportunities for skill building and partnership development

    Advanced Diagnostics, Control and Testing of Diesel Low Temperature Combustion

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    The conventional high temperature diesel combustion is constrained by the classical NOx-soot trade-off, so that any technique to reduce one emission generally increases the other. The simultaneous low NOx and soot can be achieved by lowering the combustion temperature and by preparing a cylinder charge of high homogeneity. However, the lowered combustion temperature may significantly reduce the fuel efficiency of such combustion cycles. Therefore, the overall objective of this work was to conduct a detailed analysis of the diesel LTC cycles that result in simultaneous low NOx and low soot, and to improve the LTC performance through advanced diagnostics and combustion control strategies. The empirical and analytical analyses in this dissertation provide an in-depth understanding of diesel LTC and present an effective strategy for navigating the narrow LTC corridors. The in-cylinder gas sampling tests culminated with the identification of an LTC NOx mechanism whereby the NOx reduction in the presence of combustibles was quantified on a crank angle-resolved basis. The intake gas treatment through catalytic oxidation and fuel reforming of EGR stabilized the LTC cycles. Novel flow management strategies were applied to improve the thermal response and the energy efficiency of the reforming operation. Adaptive combustion control techniques were developed to improve the fuel efficiency of the LTC cycles and to enable navigation within the narrow LTC corridors. A computationally efficient `Pressure Departure Ratio\u27 algorithm for estimating the combustion phasing in real-time was proposed along with a methodology for engine load management within-the-same-cycle, and were shown to improve the LTC operational stability. The detailed EGR analysis helped to develop a systematic LTC control strategy by quantifying the effects of intake charge dilution and boost pressure on the LTC performance metrics. Based on the empirical and analytical analyses, the load management and efficiency improvements of the LTC cycles were demonstrated with three different fuelling strategies as follows: (1) Single-injection LTC with heavy EGR at low loads, (2) Multi-shot LTC (early HCCI) with moderate EGR for mid-load operation, and (3) Split burning LTC for higher engine loads with DPF-tolerant soot

    Prospects for Electric Mobility: Systemic, Economic and Environmental Issues

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    The transport sector, which is currently almost completely based on fossil fuels, is one of the major contributors to greenhouse gas emissions. Heading towards a more sustainable development of mobility could be possible with more energy efficient automotive technologies such as battery electric vehicles. The number of electric vehicles has been increasing over the last decade, but there are still many challenges that have to be solved in the future. This Special Issue “Prospects for Electric Mobility: Systemic, Economic and Environmental Issues” contributes to the better understanding of the current situation as well as the future prospects and impediments for electro mobility. The published papers range from historical development of electricity use in different transport modes and the recent challenges up to future perspectives
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