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Design of systems in the low-end nanometer domain has introduced new dimensions in power consumption and dissipation in CMOS devices. With continued and aggressive scaling, using low thickness SiO2 for the transistor gates, gate leakage due to gate oxide direct tunneling current has emerged as the major component of leakage in the CMOS circuits. Therefore, providing a solution to the issue of gate oxide leakage has become one of the key concerns in achieving low power and high performance CMOS VLSI circuits. In this thesis, a new approach is proposed involving dual dielectric of dual thicknesses (DKDT) for the reducing both ON and OFF state gate leakage. It is claimed that the simultaneous utilization of SiON and SiO2 each with multiple thicknesses is a better approach for gate leakage reduction than the conventional usage of a single gate dielectric (SiO2), possibly with multiple thicknesses. An algorithm is developed for DKDT assignment that minimizes the overall leakage for a circuit without compromising with the performance. Extensive experiments were carried out on ISCAS'85 benchmarks using 45nm technology which showed that the proposed approach can reduce the leakage, as much as 98% (in an average 89.5%), without degrading the performance.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-06-15T13:45:40Z No. of bitstreams: 1 Mariana Moreira da Silva.pdf: 2627073 bytes, checksum: 8b556a25b3da990d9fcef2fc095004ad (MD5) / Made available in DSpace on 2018-06-15T13:45:40Z (GMT). No. of bitstreams: 1 Mariana Moreira da Silva.pdf: 2627073 bytes, checksum: 8b556a25b3da990d9fcef2fc095004ad (MD5) Previous issue date: 2015-06-29 / Introduction: Fibromyalgia (FM) is a syndrome characterized by chronic widespread pain, with prevalence in women. An important issue is that many patients with FM also have the diagnosis of temporomandibular disorders (TMD) and the coexistence of these conditions generates a clinical result of high complexity. Exercise and phototherapy (low level laser therapy / LED) are two areas used for the treatment of chronic pain and may be promising in the rehabilitation of these comorbidities. In a protocol (1) the objective was to verify if the phototherapy and exercise program in a single application can increase or decrease the sensitivity of pain in patients with FM associated with TMD. Objective of the protocol two (2) was to evaluate the potential of physical exercise program and phototherapy on condition of chronic pain in women with FM associated with TMD. Methods / Study Design: Randomized clinical trial, double-blind and controlled. Protocol 1 was conducted involving 80 women aged ≥ 35 years old with a diagnosis of FM TMD. Patients were randomly allocated to one of four groups: CON (have not undergone any operation); PHO group (intervention with phototherapy); EXT group (intervention with exercise); PHO + EXT group (more intervention exercise phototherapy). One session of the treatments and the revaluation was carried out was after thirty (30) minutes of application, with analysis of algometry. In Protocol 2 used the same methodology to protocol 1, but the revaluation was after ten (10) weeks of treatment, with addition of other evaluative tools algometry. Statistical analysis was performed using Student's t-test, one-tailed and paired and was held Gaussian distribution: Shapiro-Wilk and Kruskal Wallis test (Dunnes post-test), and even the use of the Wilcoxon test and the significance of statistical analysis 0.05 for all tests. The study protocol is registered with the World Health Organization under protocol number NCT02279225. Results: Groups with active intervention, had a good response on the group without intervention and even the combination of therapeutic resources was more effective in the two periods evaluated, there was a significant improvement from the point corresponding to DTM in the intervention groups. Discussion: This is the first randomized controlled trial to evaluate the role of phototherapy, a physical exercise program and the combination of these interventions for pain in fibromyalgia patients with TMD in assessment baseline and after longitudinal treatment. The results provide valuable clinical evidence for objective assessment of the potential benefits and risks of the procedures. Conclusion: The therapy associated with specific exercise program improves the painful condition FM patient with TMD. Perspectives: Check the role of phototherapy, the exercise program and these therapies in combination in the hormone changes that may be related to quality of life of patients. / Introdução: A Fibromialgia (FM) é uma síndrome caracterizada pela dor crônica generalizada, com prevalência em mulheres. Uma questão importante é que vários pacientes com FM também apresentam o diagnóstico de disfunção temporomandibular (DTM) e a coexistência dessas patologias gera um resultado clínico de alta complexidade. O exercício físico e a fototerapia (laserterapia de baixa potência/ diodo emissor de luz) são duas áreas utilizadas para o tratamento da dor crônica, podendo ser promissores na reabilitação dessas comorbidades. No protocolo um (1) o objetivo foi verificar se a fototerapia e o programa de exercício físico em uma única aplicação pode aumentar ou diminuir a sensibilidade da dor no paciente com FM associado a DTM. Objetivo do protocolo dois (2) foi avaliar o potencial do programa de exercício físico e da fototerapia na condição de dor crônica em mulheres com FM associado a DTM. Métodos / Desenho do estudo: Ensaio clínico randomizado, duplo-cego e controlado. O protocolo 1 foi realizado envolvendo 80 mulheres com ≥ 35 anos de idade com diagnóstico de FM com DTM. Os pacientes foram alocados aleatoriamente para um dos quatro grupos: Grupo CON (não foram submetidas a qualquer intervenção); Grupo PHO (intervenção com a fototerapia); Grupo EXT (intervenção com exercícios físicos); Grupo PHO + EXT (fototerapia mais intervenção do exercício). Foi realizado uma única sessão dos tratamentos e a reavaliação foi após trinta (30) minutos da aplicação, com analise da algometria. No Protocolo 2 usou a mesma metodologia que o protocolo 1, mas as reavaliações foram após dez (10) semanas de tratamento, com outras ferramentas avaliativas além da algometria. Para análise estatística foi utilizado o teste t-Student, unicaudal e pareado e foi realizada a distribuição Gaussiana: Shapiro-Wilk e teste Kruskall Wallis (pós-teste de Dunnes), e ainda a utilização do teste Wilcoxon, sendo a analise estatística de significância 0,05 para todos os testes. O protocolo deste estudo está registrado com a Organização Mundial de Saúde sob protocolo número NCT02279225. Resultados: Os grupos com intervenção ativa, tiveram uma boa resposta sobre o grupo sem intervenção e ainda a combinação de recursos terapêuticos mostrou ser mais eficaz nos dois momentos avaliados, houve uma melhora significante quanto ao ponto correspondente a DTM nos grupos de intervenção. Discussão: Este é o primeiro estudo controlado randomizado avaliando o papel da fototerapia, de um programa de exercício físico e a combinação dessas intervenções para a dor em pacientes fibromiálgicos com DTM, em avaliação em linha de base e após tratamento longitudinal. Os resultados oferecem evidências clínicas valiosas para avaliação objetiva dos potenciais benefícios e riscos dos procedimentos. Conclusão: A fototerapia associada ao programa de exercício físico específico melhora a condição dolorosa do paciente de FM com DTM. Perspectivas: Verificar o papel da fototerapia, do programa de exercícios e essas terapias de forma combinada na alteração de hormônios que podem estar relacionados a qualidade de vida destes pacientes.

This assignment was given by Nordic Semiconductor. In this project a radio frequency energy harvesting system able to harvest ambient power at 900 MHz (GSM) was simulated and designed. A Villard voltage multiplier, boost converter and power management circuit was implemented for the harvesting system. The intention was to implement a system which would give sufficient output power and voltage to supply a load (nRF52810) at all times. The nRF52810 is a power efficient multi protocol SoC made by Nordic Semiconductor. Since the power harvested by the antenna is of AC power, a recti er was needed. A Villard voltage multiplier was proposed as the most suitable application. It not only recti es the voltage, but the voltage doubles for every stage. A 2-stage Villard voltage multiplier was proposed with the advantage that in theory the output voltage should be four times higher in magnitude than the input voltage. There exists several other ways to boost a voltage, a voltage boost converter was combined with the Villard Voltage multiplier. According to calculations the boost converter should boost the voltage up to 2.3 V. Since the assumed power from the harvesting system may be lower than the power consumed by the load, a power managing circuit was also needed, which would avoid the load to drain the current from the storage element before the voltage level was sufficient. Different solutions for a power management circuit was proposed using different variations of MOSFETs. A real-life design was implemented, but the Villard voltage multiplier gave out a much lower e efficiency than expected from simulations. The output power of the VVM was too low to supply the load (nRF52810).

Les travaux de cette thèse se concentrent sur la réduction de l'énergie consommée et l'amélioration des temps de réveil du microcontrôleur par des innovations au niveau de l'architecture, du circuit et de la gestion de l'énergie. Ces travaux proposent une architecture de microcontrôleur partitionnée entre un processeur de réveil programmable, appelé Wake Up Controller, s'occupant des tâches courantes du nœud de capteurs et un processeur principal gérant les tâches irrégulières. Le Wake Up Controller proposé dans ces travaux de thèse est un processeur RISC 16-bit dont le jeu d'instructions a été adapté pour gérer les tâches régulières du nœud, et n'exécute que du code sur interruptions. Il est implémenté en logique mixte asynchrone/synchrone. Un circuit a été fabriqué en technologie UTBB FDSOI 28nm intégrant le Wake-Up Controller. Le cœur atteint une performance de 11,9 MIPS pour 125μW de consommation moyenne en phase active et un réveil depuis le mode de veille en 55ns pour huit sources de réveil possibles. La consommation statique est d'environ 4μW pour le cœur logique asynchrone à 0,6V sans utilisation de gestion d'alimentation (power gating) et d'environ 500nW avec. / This PhD work focuses on the reduction of energy consumption and wake up time reduction of a WSN node microcontroller through innovations at architectural, circuit and power management level. This work proposes a partitioned microcontroller architecture between a programmable wake up processor, named Wake Up Controller on which this work is focused, and a main processor. The first deals with the common tasks of a wireless sensor node while the second manages the irregular tasks. TheWake Up Controller proposed in this work is a 16-bit RISC processor whose instruction set has been adapted to handle regular tasks of a sensor node. It only executes code on interruptions. It is implemented in asynchronous / synchronous mixed logic to improve wake up time and energy. A circuit was fabricated in a 28nm UTBB FDSOI technology integrating the Wake Up Controller. The core reaches 11,9 MIPS for 125 μW average power consumption in active phase and wakes up from sleep mode in 55ns from eight possible interruption sources. The static power consumption is around 4μW for the asynchronous logic core at 0.6V without power gating and 500nW when gated.

This thesis investigates the possibility of porting a neural network model trained and modeled in TensorFlow to a low-power AI inference accelerator for IoT edge computing. A slightly modified LeNet-5 neural network model is presented and implemented such that an input frequency of 10 frames per second is possible while consuming 4mW of power. The system is simulated in software and synthesized using the FreePDK45 technology library. The simulation result shows no loss of accuracy, but the synthesis results do not show the same positive results for the area and power. The default version of the accelerator uses single-precision floating-point format, float32, while a modified accelerator using the bfloat16 number representation shows significant improvements in area and power with almost no additional loss of accuracy.

Tato práce je zaměřena na návrh terénní bezdrátové senzorové sítě pro mikroklimatologická měření, zejména výronů juvenilního oxidu uhličitho v oblasti hydrotermílního krasu, založené na LoRaWAN. V teoretické části práce je předložen přehled cílové oblasti, možností řešení měření, získávání a přenosu dat. Praktická část se pak věnuje kompletnímu návrhu celého systému, to znamená od měřicího zařízení přes koncentrátor a gateway až po backend odesílání dat do cloudového úložiště. Výsledky tohoto komplexního problému jsou prezentovány průběžně a přílohy obsahují detailnější a názornější ukázky.

This thesis focuses on the design and implementation of the wireless localization module, using UWB technology with emphases on low-power firmwre based on RTOS. Wireless localization is based on TDoA algorithm.  The resulting HW module is designed as a four layer PCB, based on MCU crf52832 (ARM Cortex M4) and UWB module DevaWave DW1000. Firmware is implemented using FreeRTOS with emphasis on low power consumption. For hardware implementation, Eagle CAD was used. Firmware is implemented in C and Assembly programming languages.

This document describes a device capable to determine geographical position thanks to its GNSS module and measure the change of movement with the help of an accelerometer and gyroscope. Outputs of these integrated circuits are combined, data are processed and fused thanks to a numerical integration and mathematical filters. Results are stored on a memory card. The whole development is described from a concept, through the making of the device and software algorithms to the testing of its functions.

This thesis deals with thermal stabilization of crystal oscillators. A simple thermostat of piezoelectric crystal unit is designed in first part. Main emphasis is set to low input power. The second part deals with crystal oscillators with 102,5MHz and 10MHz frequency. They are simulated with Ansoft Designer software. Both of these oscilators are measured for short term and midterm frequency stability.