Search

Organic field‐effect transistors (OFETs) are of great significance in next‐generation optoelectronics and have made remarkable advances during the last decade. For the commercialization of OFETs, power consumption is one of the main issues needed to be addressed. To this end, OFETs with low‐voltage operation are constructed, and several strategies have been successively developed, which have attracted intensive attention for researchers to achieve this goal. In this review, we summarized the recent progress of various approaches for realizing low‐voltage OFETs, including adopting high‐k dielectrics, ultra‐thin dielectric, electrolyte dielectric, and interface engineering. Besides, the potential applications of low‐voltage OFETs in organic electronics are introduced. Finally, we give a brief outlook of this area for the future direction.

The aim of the study is to reduce electricity consumption in rural milk collection points from the popu-lation. The paper presented a study on milk cooling refrigeration installations used at milk collection points in the Republic of Moldova. The design of the installation and the ratio of its electricity consumption nodes were analyzed. In order to reduce energy consumption, solutions have been proposed to improve the constructive-technological parameters of the electric motors in the refrigeration installations for milk cooling. It was proposed to modernize the asynchronous motors by placing permanent magnets on the rotors, which will increase the efficiency and the power factor of the motor, therefore reducing the consumption of active and reactive energy in the electrical network.

[CATALÀ] Amb el present treball pretenc, simular un entorn industrial on es treballi amb diferents tecnologies actuals de l'àmbit de sistemes de la informació. Centrat en la gestió de dades destinades a Bussiness Intelligence, des de la integració dels sensors fins al tractament de dades a gran escala, mitjançant el software d'OSISoft PI. El desenvolupament del projecte consta de tres parts clarament definides. Inicialment es posa en context sobre el sector en el qual es treballa, amb la finalitat de poder veure el gran potencial que ofereix aquest projecte. Seguidament es fa un estudi de les diferents tecnologies de comunicació IoT sense fils de baix consum, els sensors encarregats de la captació de dades, els equips de processament i el software utilitzat. Per últim, es farà el desenvolupament complet del projecte utilitzant els dispositius i equips anteriorment esmentats, a partir dels quals, s'espera obtenir i tractar valors físics en temps real. Finalment, es pot dir que seria un projecte totalment aplicable a qualsevol classe d'indústria on es volguessin extreure dades d'humitat, temperatura i presència, i tindre un registre i control d'aquestes. [ANGLÈS] This project aims to simulate an industrial environment where it works with different actual technologies in the information systems field. Focused on the data management destined to Business Intelligence, from the sensors integration until large-scale data treatment, through the Osisoft Pi software. The development of this project consists of three parts, clearly defined. Initially, talk about the sector in which one works, in order to see the great potential that this project offers. Next, a study is made of the different low-consumption wireless IoT communication technologies, the sensors in charge of capturing data, the processing equipment and software used. Lastly, the complete development of the project will be done using the devices and equipment mentioned above, from which, it is expected to obtain and process physical values in real time. Finally, it can be said that it would be a project fully applicable to any type of industry where they wanted to extract data on humidity, temperature and presence, and have a record and control of these.

���� ������������������ ������ ������������������������ (IoT) ���������� ���� ������������ ������������������������ ����������������, ������������ �������������� ���� ����������������� �������������������, �������������������������� �������������������� ���� ����������������������, ������������������, ��������������������, ������ �������������������� �������� �������������� IoT �������������� ���� ���������� ������ ������������������ ������������������. ���� IoT ������������������ �������� ���������������� ���� ������������������������ �� ���� �������������������� ������ ���������������� ���� ���������������� ���� ������������, �������������������������� ������������������ ������ ���������������� �������������������� ������ �������������� ������������ ���� ������������������, ������ �������������������� ���� ��������������������, ���� ���������� ������ �������������������������� ������������ ���� �������������������� ���������������� ������ ��������������������������, ���������� ������ ������ �������������������� ������ �������������� ������ ������������������ ������������������. ���������� ���� ���������������� IoT ������������������ �������������� ���������������� ���� ���� �������������� ���������������� ���������������������� ������ ������ ���������������� �������������������� ���������������� ���� ���������������� ���� ���������� ����������������. ���� ������������ ������������ ���������� ������ ������ ���� ������ ������������ ������������������������ ���������������� IoT, ������ �������������������������������� ������������ �������� ����������. �������� ���� ������������ ������������������ ������������������������ ������������ ���������������� ���������������� �������� ������ ������������ ������ ����������, ������ ����������������������, �������� �������������� ��������������������, ������ ��������������������, ������ �������������������� ���������������������� ������ ������ ����������������, �������� ������������������, ����������������������, ���������������� �������������������� ��������, ��������������, �������������� ������ ��������������������, ������ �������������������������� Wi-Fi ������ �������������������������� ��������������������������. ������ ������ �������������������� ������������������, ���� ������������������ ������ ������������������ ������������������ ���� ������������������������ �������������� ���� ������ ������ ����������. ���������� ������������������������������ ���� �������������� �������������� ������ ����������������������, �������� ���������� ������ ������������, �������� ����������������������������������������, �������� ������������������ ������ ����������. ���� ������������������ ������ ������������������������ ���������������������� �������������� ���������������������� �������������������� IoT. ������������ ������ �������� ���������� ���� Lora, Bluetooth, MQTT, NFC, ZigBee, Wifi, Cellural (2G/3G/4G/Gsm/Gprs). �������������� ���� ������ ���������������� ������ ������ ������������������ ������������, �������������������� ���� �������������������������� �������������������� ������������������������. �������� �������������� ���������������������� �������������� ���������������������� �������� ������������ IoT, ������ ��������������� ����������������� ������ ������ �������������� ������������������ ��������������������������. �� �������������� ���������������������� ���� ���������� ���� �������������� ���� ������������������ �������� ������ ���������������� �������������������� ������ �������������� ������������������, �������� �������������������� ������������������������, ����������������, ������������������ ������ ���������������������� ��������, ���� �������������������������� ���������������� ���� ���� ���������� ������ IoT ���������������������� ������������������������ LoRa, ���� ������������ ���������������������� �������������� ������ �������� ���� ������������ server, ������ ���������������������� ������ ��������������������. �� �������������� ���������������������� ���� ���������� ������ ������������ �������������������� ������������, ���������� ������ ������������������ ������ ���� �������������� ���� 10 ������������ �������� ���� ���������������� ���������������������� ������ ������ ��������������., The Internet of Things (IoT) is a network of connected devices, also known as 'smart devices', embedded circuits with electronics, software, sensors, connected via an IoT network for the purpose of data exchange. IoT enables devices to be detected or remotely controlled across the network, creating opportunities for better integration of the physical world into computer-connected systems for remote control with improved accuracy and efficiency, as well as reducing the need for human intervention. These IoT devices collect useful data with the help of various technologies and then autonomously transmit the data to other devices. Smart homes are one of the best known examples of IoT devices on the market today. These intelligent automation systems perform a variety of tasks such as controlling lights, heaters, a smart thermostat, ventilation, air conditioning systems and devices such as washing machines, dryers, air purifiers, ovens, refrigerators and freezers that use Wi-Fi for remote monitoring. For the past two decades, the Internet of Things has continued to expand rapidly around the world. It is now used in many industries, in the health sector, in the automotive industry, in transport and elsewhere. The Internet of Things supports dozens of different IoT protocols. Some of them are Lora, Bluetooth, MQTT, NFC, ZigBee, Wifi, Cellural (2G / 3G / 4G / Gsm / Gprs). Depending on the application and the case of use, the most appropriate communication protocol is selected. In this dissertation, an IoT node was developed, a ���smart device��� for collecting environmental data. The device is designed to be able to connect various sensors for data collection, such as temperature, humidity, speed and air direction sensors, to send data using the IoT communication protocol LoRa, to a network router and then to a server, for processing and storage. The device was developed with the aim of low power consumption, as well as autonomy that would exceed 10 years of life in areas inaccessible to humans.

We propose a real-time pedestrian detection system for the embedded Nvidia Tegra X1 GPU-CPU hybrid platform. The pipeline is composed by the following state-of-the-art algorithms: Histogram of Local Binary Patterns (LBP) and Histograms of Oriented Gradients (HOG) features extracted from the input image; Pyramidal Sliding Window technique for candidate generation; and Support Vector Machine (SVM) for classification. Results show a 8x speedup in the target Tegra X1 platform and a better performance/watt ratio than desktop CUDA platforms in study., 10 pages

International audience; This communication deals with the lability of categorizations and its articulation with the research question. The research context is related to the future designed by a public policy aiming at being able to identify unoccupied housing to offer solutions regarding the lack of housing. The primary objective is creating, testing and validating a methodology to do so, and understanding why these housing are unoccupied. The data were collected in Charleroi, Belgium, between June 2014 and February 2015.At the first sight, language is primary both researched and unresearched as the identification of given, labeled, situation (unoccupied housing) is implemented without researching the (unexpected) diversity that might be related to it. The landlords are contacted on the basis of low water or electricity consumption for the concerned housing. During the research, several landlords refused categorizing the concerned housing as unoccupied, but agree for instance in categorizing this housing as uninhabited. Also, several landlords, immediately after having underlined that the concerned housing was in fact occupied, were asking what would be the consequences in the case the concerned housing would have been unoccupied. The objective of this communication is to shed light on what is as stake through this, including a critical analysis of the consequence of having missed to include from the beginning the issue of language in the research. Thus, a secondary analysis of the data was implemented and focused on the sociological dimension of language to understand when, who, and why landlords shifted from a label to another. The results help to reframe the research question and give more insight regarding the results of the primary research.Presentation at RC25 Roundtable I. Language and Representation: Struggles in the Global Age

Esta tese estuda o projecto e o comportamento de filtros em tempo contínuo de muito-alta-frequência. A motivação deste trabalho foi a investigação de soluções de filtragem para canais de leitura em sistemas de gravação e reprodução de dados em suporte magnético, com custos e consumo (tamanho total inferior a 1 mm2 e consumo inferior a 1mW/polo), inferiores aos circuitos existentes. Nesse sentido, tal como foi feito neste trabalho, o rápido desenvolvimento das tecnologias de microelectrónica suscitou esforços muito significativos a nível mundial com o objectivo de se investigarem novas técnicas de realização de filtros em circuito integrado monolítico, especialmente em tecnologia CMOS (Complementary Metal Oxide Semiconductor). Apresenta-se um estudo comparativo a diversos níveis hierárquicos do projecto, que conduziu à realização e caracterização de soluções com as características desejadas. Num primeiro nível, este estudo aborda a questão conceptual da gravação e transmissão de sinal bem como a escolha de bons modelos matemáticos para o tratamento da informação e a minimização de erro inerente às aproximações na conformidade aos princípios físicos dos dispositivos caracterizados. O trabalho principal da tese é focado nos níveis hierárquicos da arquitectura do canal de leitura e da realização em circuito integrado do seu bloco principal – o bloco de filtragem. Ao nível da arquitectura do canal de leitura, apresenta-se um estudo alargado sobre as metodologias existentes de adaptação de sinal e recuperação de dados em suporte magnético. Este desígnio aparece no âmbito da proposta de uma solução de baixo custo, baixo consumo, baixa tensão de alimentação e baixa complexidade, alicerçada em tecnologia digital CMOS, para a realização de um sistema DFE (Decision Feedback Equalization) com base na igualização de sinal utilizando filtros integrados analógicos em tempo contínuo. Ao nível do projecto de realização do bloco de filtragem e das técnicas de implementação de filtros e dos seus blocos constituintes em circuito integrado, concluiu-se que a técnica baseada em circuitos de transcondutância e condensadores, também conhecida como filtros gm-C (ou transcondutância-C), é a mais adequada para a realização de filtros adaptativos em muito-alta-frequência. Definiram-se neste nível hierárquico mais baixo, dois subníveis de aprofundamento do estudo no âmbito desta tese, nomeadamente: a pesquisa e análise de estruturas ideais no projecto de filtros recorrendo a representações no espaço de estados; e, o estudo de técnicas de realização em tecnologia digital CMOS de circuitos de transcondutância para a implementação de filtros integrados analógicos em tempo contínuo. Na sequência deste estudo, apresentam-se e comparam-se duas estruturas de filtros no espaço de estados, correspondentes a duas soluções alternativas para a realização de um igualador adaptativo realizado por um filtro contínuo passa-tudo de terceira ordem, para utilização num canal de leitura de dados em suporte magnético. Como parte constituinte destes filtros, apresenta-se uma técnica de realização de circuitos de transcondutância, e de realização de condensadores lineares usando matrizes de transístores MOSFET para processamento de sinal em muito-alta-frequência realizada em circuito integrado usando tecnologia digital CMOS submicrométrica. Apresentam-se métodos de adaptação automática capazes de compensar os erros face aos valores nominais dos componentes, devidos às tolerâncias inerentes ao processo de fabrico, para os quais apresentamos os resultados de simulação e de medição experimental obtidos. Na sequência deste estudo, resultou igualmente a apresentação de um circuito passível de constituir uma solução para o controlo de posicionamento da cabeça de leitura em sistemas de gravação/reprodução de dados em suporte magnético. O bloco proposto é um filtro adaptativo de primeira ordem, com base nos mesmos circuitos de transcondutância e técnicas de igualação propostos e utilizados na implementação do filtro adaptativo de igualação do canal de leitura. Este bloco de filtragem foi projectado e incluído num circuito integrado (Jaguar) de controlo de posicionamento da cabeça de leitura realizado para a empresa ATMEL em Colorado Springs, e incluído num produto comercial em parceria com uma empresa escocesa utilizado em discos rígidos amovíveis. This thesis studies the design and behavior of continuous-time very-high-frequency filters. The motivation of this work was the search for filtering solutions for the readchannel in recording and reproduction of data on magnetic media systems, with costs and consumption (total size less than 1 mm2 and consumption under 1mW/pole), lower than the available circuits. Accordingly, as was done in this work, the rapid development of microelectronics technology raised very significant efforts worldwide in order to investigate new techniques for implementing such filters in monolithic integrated circuit, especially in CMOS technology (Complementary Metal Oxide Semiconductor). We present a comparative study on different hierarchical levels of the project, which led to the realization and characterization of solutions with the desired characteristics. In the first level, this study addresses the conceptual question of recording and transmission of signal and the choice of good mathematical models for the processing of information and minimization of error inherent in the approaches and in accordance with the principles of the characterized physical devices. The main work of this thesis is focused on the hierarchical levels of the architecture of the read channel and the integrated circuit implementation of its main block - the filtering block. At the architecture level of the read channel this work presents a comprehensive study on existing methodologies of adaptation and signal recovery of data on magnetic media. This project appears in the sequence of the proposed solution for a lowcost, low consumption, low voltage, low complexity, using CMOS digital technology for the performance of a DFE (Decision Feedback Equalization) based on the equalization of the signal using integrated analog filters in continuous time. At the project level of implementation of the filtering block and techniques for implementing filters and its building components, it was concluded that the technique based on transconductance circuits and capacitors, also known as gm-C filters is the most appropriate for the implementation of very-high-frequency adaptive filters. We defined in this lower level, two sub-levels of depth study for this thesis, namely: research and analysis of optimal structures for the design of state-space filters, and the study of techniques for the design of transconductance cells in digital CMOS circuits for the implementation of continuous time integrated analog filters. Following this study, we present and compare two filtering structures operating in the space of states, corresponding to two alternatives for achieving a realization of an adaptive equalizer by the use of a continuous-time third order allpass filter, as part of a read-channel for magnetic media devices. As a constituent part of these filters, we present a technique for the realization of transconductance circuits and for the implementation of linear capacitors using arrays of MOSFET transistors for signal processing in very-high-frequency integrated circuits using sub-micrometric CMOS technology. We present methods capable of automatic adjustment and compensation for deviation errors in respect to the nominal values of the components inherent to the tolerances of the fabrication process, for which we present the simulation and experimental measurement results obtained. Also as a result of this study, is the presentation of a circuit that provides a solution for the control of the head positioning on recording/playback systems of data on magnetic media. The proposed block is an adaptive first-order filter, based on the same transconductance circuits and equalization techniques proposed and used in the implementation of the adaptive filter for the equalization of the read channel. This filter was designed and included in an integrated circuit (Jaguar) used to control the positioning of the read-head done for ATMEL company in Colorado Springs, and part of a commercial product used in removable hard drives fabricated in partnership with a Scottish company.

The environmental awareness of the promoters is one of the fundamental pieces to enable the sustainable development of our cities and it is also a vital work of the technicians involved in the building process to encourage and enliven this awareness among our customers. We know the tools needed to provide housing systems to make them more efficient, by involving and implicating the promoter throughout the process. Furtehermore, we are able to design and build homes that contribute to improve the environment in which they are located, not only by reducing our own consumption but also through direct interaction processes on the boundary conditions as environmental decontamination. In this way, we can create homes that become vectors of sustainability which in turn could lead to synergies in their environment. The property shown below has been designed by LAC-architecture and it is located in a peri-urban area of the city of Granada, with a mediterranean-continental climate in which there are alternating periods of temperaturas below zero with others which are above 40 º C. Due to these conditions, the materials and systems that control the inner housing conditions are subjected to a very wide range of actions. Attached to these systems, a photocatalytic cement based coating will be used and will be able to become a degradation source of the harmful organic and inorganic substances coming into contact with it. These substances are the NOX, SOX, NH3, CO, volatile organic compounds (VOCs), chlorinated organic compounds, aldehydes and aromatic polycondensation which are responsible for air pollution in our cities. La concienciación medioambiental de los promotores es una de las piezas fundamentales para hacer posible el desarrollo sostenible de nuestras ciudades y es labor fundamental de los técnicos que intervienen en el proceso edificatorio fomentar y avivar dicha concienciación entre nuestros clientes. Conocemos las herramientas necesarias para dotar a las viviendas de los sistemas que las hagan más eficientes, haciendo partícipe e implicando al promotor en todo el proceso. De esta manera somos capaces de diseñar y construir viviendas que contribuyan a la mejora del entorno en el que se ubican, no sólo mediante la reducción de los consumos propios sino también mediante procesos de interacción directa sobre las condiciones de contorno como la descontaminación medioambiental. Podremos así crear viviendas que se conviertan en vectores de sostenibilidad que a su vez puedan provocar sinergias en su entorno. La vivienda que se ha diseñado y construido desde LACarquitectura y que se expone a continuación se sitúa en una zona periurbana de la ciudad de Granada, con un clima mediterráneo-continental en el que se alternan épocas de temperaturas bajo cero con otras en las que se superan los 40ºC con lo que los materiales y sistemas de control de las condiciones internas de la vivienda se someten a un rango de acción muy amplio. Unido a estos sistemas se utilizará un revestimiento con base de cemento FOTOCATALITICO que será capaz de convertirse en fuente de degradación de las sustancias orgánicas e inorgánicas nocivas con las que entren en contacto, como serán los NOX, SOX, NH3, CO, compuestos orgánicos volátiles (COV), compuestos orgánicos clorados, aldehídos y compuestos aromáticos policondensados, que son los responsables de la contaminación atmosférica de nuestras ciudades.

This work deals with the feasibility study of a radio architecture dedicated to mobile WPAN applications at 60 GHz and characterized by a low power consumption. Data rates of the order of Gbps, high compactness and low power consumption are obtained by co-designing the antenna and the front-end. Before proposing the architecture matching the specification needs, a preliminary study of the propagation channel at 60 GHz is made. The two main standards IEEE 802.15.3c and 802.11.ad the channel are studied. The analysis of a single-band architecture suitable for low-power systems shows a data rate limitation when directional antennas are used in the standard channel 802.11.ad. To address this problem, a multi-band impulse architecture MBOOK using a non-coherent receiver is proposed. This architecture allows high throughput with the use of four sub-bands. It also leads to a low power consumption through the use of a non-coherent receiver and a differential transmitter topology avoiding combiners. To validate the concept of the proposed architecture, differential antennas dedicated to the differential architecture are designed. Patch antennas excited by differential microstrip lines fulfil the needs of the specifications but occupy a large area. In order to miniaturize the antenna, slot-fed patch antennas are designed using two orthogonal linear polarizations excited by a pair of differential inputs. To achieve the high directivity required in LOS scenarios without using antenna arrays or dielectric lenses, metamaterials are used. The antenna measurement is based on the realization of a WR-15 waveguide-to-microstrip line transition to connect the antenna to the network analyzer. The differential measurement of the antenna patch exhibits a good agreement with the simulated results. The TriQuint's TQP15 technology is used to design the various circuits of the front-end. The emitter architecture is validated once the overall consumption has been evaluated. This work ends with an evaluation of the throughput of the system taking into account the influence of the antenna and the propagation channel. This evaluation shows the potential of the architecture in terms of high throughput. We finally propose an approach based on the LTCC technology for the antenna / front-end assembly, Ce travail porte sur l'étude de faisabilité d'une architecture radio, dédiée aux applications WPANs nomades et faible consommation en utilisant la bande autour de 60 GHz. Des débits de l'ordre de Gbps, une compacité élevée et une consommation de puissance faible sont obtenus en réalisant une conception conjointe front-end antenne. Avant de proposer l'architecture adaptée au cahier de charge, une étude préalable du canal de propagation à 60 GHz est faite. Les deux principales normes de canal IEEE, le 802.15.3c et le 802.11.ad, sont étudiées. L'analyse d'une architecture impulsionnelle mono-bande adaptée aux systèmes à faible consommation montre une limitation du débit quand des antennes non directives sont utilisées dans la norme de canal 802.11.ad. Afin de remédier à ce problème, une architecture multi-bande impulsionnelle MBOOK à récepteur non-cohérent est proposée. Cette architecture autorise un haut débit avec l'utilisation de quatre sous bandes. Elle conduit également à une consommation faible grâce à l'utilisation d'un récepteur non-cohérent et d'une topologie différentielle de l'émetteur évitant l'intégration de combineurs. Pour valider le concept d'architecture proposée, des antennes différentielles dédiées à l'architecture différentielle sont conçues. Les premières antennes sont de type patch différentiel excité par des lignes microrubans. Ces dernières présentent des caractéristiques de rayonnement adaptées aux besoins du cahier de charge. Néanmoins elles occupent une surface importante. Afin d'avoir une meilleure compacité, un patch alimenté par couplage à fente est développé. Il exploite deux polarisations linéaires orthogonales excitées par une paire d'entrées différentielles. Afin d'obtenir la directivité élevée nécessaire pour les scénarios LOS à 60 GHz sans utiliser de réseaux d'antennes ou de lentilles diélectriques, des métamatériaux sont utilisés. La mesure des antennes est basée sur la réalisation d'une transition guide d'onde WR-15 ligne microruban pour connecter l'antenne à l'analyseur de réseau. La mesure de l'antenne patch différentielle présente une bonne concordance avec les résultats de simulations. La technologie TQP15 de TriQuint est utilisée pour concevoir les différents éléments de la partie front-end. L'évaluation de la consommation globale d'émetteur valide l'architecture proposée en termes de faible consommation. Ce travail se termine par une évaluation du débit du système en tenant en compte de l'influence de l'antenne et du canal de propagation. Cette évaluation prouve la potentialité de l'architecture en termes de haut débit. On propose finalement une technique basée sur la technologie LTCC pour l'assemblage antenne/front-end

Non-destructive structural health monitoring of civil engineering structures is based on vibrations masurements of objects during dynamic tests or during theirexploitation. Wireless sensor networks are increasingly being used for this purpose. They make flexibleand inexpensive measurement systems because large cables to connect the sensors are avoided. This paper presents a vibration monitoring wireless system developed at the Faculty of Civil engineering in Belgrade. The structure and characteristics of the measurement system, based on low consumption electronic components and original embedded software real time operating system, are described.

Στην παρούσα διπλωματική εργασία εκπονείται μελέτη που αφορά την σχεδίαση αναλογικών ηλεκτρονικών κυκλωμάτων για βιοϊατρικές εφαρμογές. Δίνεται μεγαλύτερη βαρύτητα στην υλοποίηση διαγωγών χαμηλής τροφοδοσίας και ενισχυτών ρεύματος οδηγούμενων από το υπόστρωμα. Όπως σε όλα τα διαφορικά κυκλώματα, έτσι και στους διαφορικούς διαγωγούς κύριο μέλημα των σχεδιαστών είναι η γραμμικότητα τους και οι παράμετροι που την επηρεάζουν. Προτείνεται ένας διαγωγός χαμηλής τροφοδοσίας που βασίζεται στην βαθμίδα ακόλουθου τάσης με αναστροφή και προσομοιώνεται για να μελετηθεί το εύρος της γραμμικότητας του, η απόκριση συχνότητας και η συμπεριφορά του σε χρονικά μεταβαλλόμενο ημιτονοειδές σήμα. Ο ενισχυτής ρεύματος οδηγούμενος από το υπόστρωμα που παρουσιάζεται σε αυτήν την εργασία εκμεταλλεύεται όλους τους βαθμούς ελευθερίας ενός MOS τρανζίστορ πολωμένου στην ασθενή αναστροφή και στον κόρο. Η τεχνική οδήγησης από το υπόστρωμα χρησιμοποιείται ευρέως στην σχεδίαση κυκλωμάτων χαμηλής τροφοδοσίας, αφού έχει μειωμένες απαιτήσεις τάσης, ενώ είναι και ανεξάρτητη από περιορισμούς σχετικούς με την τάση κατωφλίου. Επιπρόσθετα, τα τρανζίστορ με οδήγηση από το υπόστρωμα διατηρούνται στην περιοχή κόρου για αρνητικές, μηδενικές και σχετικά μικρές θετικές τιμές της τάσης πόλωσης VBS. Έτσι, μπορούν να επεξεργάζονται σήματα εισόδου κοινού τρόπου (common-mode input range) μεγάλης τιμής και με μεγάλο εύρος κυμάτωσης κάτι που δεν θα μπορούσε να επιτευχθεί με συμβατικές κυκλωματικές τεχνικές σε τόσο χαμηλή τάση τροφοδοσίας. Όμως, τα τρανζίστορ με οδήγηση από το υπόστρωμα έχουν μικρή τιμή διαγωγιμότητας και είναι ευαίσθητα στον θόρυβο. Άλλο μειονέκτημα της τεχνικής με οδήγηση από το υπόστρωμα είναι ότι η πόλωση των τρανζίστορ εξαρτάται από την τεχνολογία ολοκλήρωσης. Το κέρδος του ενισχυτή ρεύματος οδηγούμενου από το υπόστρωμα μεταβάλλεται με εκθετικό τρόπο. Αυτή η ιδιότητα είναι σημαντική και χρησιμοποιείται ευρέως σε συστήματα αυτομάτου ελέγχου κέρδους όπου το σήμα εισόδου μεταβάλλεται αρκετές τάξεις μεγέθους. Σε ένα παρόμοιο σύστημα χρησιμοποιούμε και τα προαναφερθέντα κυκλώματα και εξετάζουμε την συνολική συμπεριφορά του. Οι προδιαγραφές αυτών των κυκλωμάτων επιτρέπουν την εφαρμογή τους στην βιοϊατρική, αφού εμφυτεύσιμα συστήματα, βίο-αισθητήρες και βοηθητικά ακοής επεξεργάζονται σήματα σχετικά χαμηλών συχνοτήτων με χαμηλή τάση τροφοδοσίας. This diploma thesis forms a study on the design of analog circuits for biomedical applications. We focus on the realization of low voltage transconductors and Bulk-Driven current amplifiers. Like all the differential circuits, the designers’ main concern for a differential transconductor is its linearity and the parameters that affect it. We propose a low voltage transconductor based on Flipped Voltage Follower topology and we simulate it in order to study the range of the linearity, frequency response and its behavior in temporally varying sinusoidal signal. The Bulk-Driven current amplifier presented in this thesis takes advantage of all degrees of freedom of a MOS transistor biased in weak inversion and in saturation. The Bulk-Driven technique is widely used in the design of low voltage supply, because it has reduced demands on voltage and is independent of restrictions related to the threshold voltage. Moreover, Bulk-Driven transistors are maintained in saturation for negative, zero and even small positive values of the bias voltage VBS. Consequently, they can process large input common mode signals and signals with large swing voltage range, a property that could not be achieved with conventional circuit techniques at low power supply voltages. However, the transconductance of a Bulk –Driven transistor is smaller and is sensitive to noise. Another disadvantage of the Bulk-Driven technique is that the polarity of the transistor is process related. The gain of the Bulk-Driven current amplifier varies exponentially. This property is important and it is used widely in systems of automatic gain control where input signals can range several orders of magnitude. The specifications of these circuits allow their appliance in biomedicine, because implanted systems, biosensors and hearing aids process signals of relatively small frequencies with low voltage supply.

[EN] During the last years, the preservation of the atmospheric environment has played an increasingly important role in society. The Diesel engine can be considered an environmentally friendly engine because of its low consumption and the subsequent carbon dioxide (CO2) emissions reduction. However, in the near future it will face strong restrictive emission standards, which demand that the current nitrogen oxides (NOx) and soot emissions are halved. To comply with these restrictions new combustion concepts are emerging, such as PCCI (premixed charge compression ignition), in which the fuel burns in premixed conditions. Combustion noise is thus deteriorated and consequently end-users could be reluctant to drive vehicles powered with Diesel engines and their potential for environment preservation could be missed. In this paper, Diesel combustion is addressed through the analysis of performance, emissions and combustion noise in order to evaluate the suitability of PCCI engines for automotive applications. The results show that PCCI combustion offers great possibilities to fulfill future emission restrictions, but the engine noise is strongly deteriorated. The great sensitivity of users to this factor requires vehicle manufacturers to focus their efforts on the optimization of passive solutions for implementing the PCCI concept in passenger car and light-duty engines, even with the subsequent increase in the cost of vehicle. This aspect is less restrictive in heavy-duty engines, since the great benefits in emissions reduction compensate the deterioration of engine noise. © 2010 Elsevier Ltd., This work has been partially supported by Ministerio de Educacion y Ciencia through grant No. TRA2006-13782. L.F. Monico holds the grant 2009/003 from Santiago Grisolia Program of Generalitat Valenciana.

The need securitaire links to the developpement of cards has flea clever impose strong quant pressures has the robustness of functioning of these implements afin to guarantee optimum performances in an environment continuously unsettle. For Three years, effects of announcements,; Le besoin securitaire lie au developpement des cartes a puce intelligentes impose de fortes contraintes quant a la robustesse de fonctionnement de ces dispositifs afin de garantir des performances optimales dans un environnement sans cesse perturbe. Depuis Trois ans, des effets d'annonces, suivies de prudentes introductions commerciales, se sont multiplies pour promouvoir aupres des operateurs telecoms un nouveau concept de carte SIM : une carte, Mega, Very Large ou SuperSIM, offrant des capacites memoires etendues aptes a supporter de nouveaux services de gestion de contenus et, surtout, disposant d'un protocole de communication bien plus rapide que celui specifie par l'ISO7816-3 (9, 6kbits/s en standard). L'augmentation de ce taux de transfert est donc un enjeu important pour ce marche. Une des solutions envisagees serait d'utiliser la performance de la norme USB (Universal Serial Bus) qui est une interface rapide, bidirectionnelle, isochrone et de faible cout, dont les connections sont gerees dynamiquement. En depit de sa simplicite, cette solution a un cout. En effet, l'isochronisme n'est pas assure par le transfert d'une base de temps au travers de la connexion. Ainsi le lecteur et l'element connecte (host et device) doivent generer leurs propre reference. Cependant, celles-ci doivent avoir une precision compatible, aussi bien au niveau des taux de transfert que du nombre d'elements faisant partie de la chaine de communication. L'objectif de cette these est d'une part, la recherche de solutions innovantes et de faible cout permettant la recuperation d'horloge lors de la transmition de donnees entre la carte a puce et son lecteur en se servant du protocole USB, et d'autre part, de demontrer la faisabilite de la solution par l'implementation d'une structure robuste, a faible puissance, pour les applications Smart-Card.