Time-encoded audio MEMS sensors optimized for edge computing

Proceedings of XXXVII Conference on desing of circuits and integrated systems (DCIS 2022), 16-18 November 2022, Pamplona, Spain.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 956601

VCO-based ADC with a simplified DAC for non-linearity correction

The performance of open-loop ADCs implemented with VCOs is limited by VCO non-linearity and first-order noise shaping. The resolution limitation imposed by first-order noise shaping can be compensated by a ring oscillator VCO with many output phases. Linearity can also be improved by using a feedback loop around the VCO closed with a DAC. However, a long ring oscillator may require a DAC with a prohibitive number of bits if feedback is used to compensate distortion. This Letter proposes an ADC architecture based on the Leslie-Singh Sigma-Delta (Σ∆) modulator that allows to implement a distortion correction loop around a VCO with a simplified DAC of few levels, yet keeping a large number of output quantisation levels to maintain resolution. The Letter discusses the system-level architecture and shows an implementation circuit example to verify the effective correction of distortion.This work has been supported by the CICYT project TEC2014-56879-R, Spain

A VCO-based CMOS readout circuit for capacitive MEMS microphones

Microelectromechanical systems (MEMS) microphone sensors have significantly improved in the past years, while the readout electronic is mainly implemented using switched-capacitor technology. The development of new battery powered 'always-on” applications increasingly requires a low power consumption. In this paper, we show a new readout circuit approach which is based on a mostly digital Sigma Delta (SigmaDelta) analog-to-digital converter (ADC). The operating principle of the readout circuit consists of coupling the MEMS sensor to an impedance converter that modulates the frequency of a stacked-ring oscillator—a new voltage-controlled oscillator (VCO) circuit featuring a good trade-off between phase noise and power consumption. The frequency coded signal is then sampled and converted into a noise-shaped digital sequence by a time-to-digital converter (TDC). A time-efficient design methodology has been used to optimize the sensitivity of the oscillator combined with the phase noise induced by 1/𝑓 and thermal noise. The circuit has been prototyped in a 130 nm CMOS process and directly bonded to a standard MEMS microphone. The proposed VCO-based analog-to-digital converter (VCO-ADC) has been characterized electrically and acoustically. The peak signal-to-noise and distortion ratio (SNDR) obtained from measurements is 77.9 dB-A and the dynamic range (DR) is 100 dB-A. The current consumption is 750 muA at 1.8 V and the effective area is 0.12 mm2. This new readout circuit may represent an enabling advance for low-cost digital MEMS microphones.This research was funded by project TEC2017-82653-R of CICYT, Spain

Proposal for the design of a sports school for soccer and volleyball for children and young people aged 6 to 14 years with a focus on constructivism

La presente investigación: “Propuesta para el diseño de una escuela deportiva de futbol y voleibol para niños y jóvenes en edades de 6 a 14 años con enfoque en el constructivismo”, realizada entre los años 2019 y 2020, tiene como objetivo, proponer el diseño de una escuela deportiva de fútbol y voleibol relacionada con un modelo constructivista, como una estrategia para el aprovechamiento libre de los niños y jóvenes en edades de 6 a 14 años del Instituto Caldas. La metodología desarrollada se basó en un enfoque cualitativo y cuantitativo, diseño no experimental y descriptivo, a partir de la búsqueda bibliográfica se presentan los conceptos relevantes para la investigación con aportes teóricos sobre constructivismo, como modelo en la enseñanza deportiva, así mismo los tópicos y reglamentos necesarios para la implementación de una escuela deportiva, como la motivación, el deporte, los principios básicos de la práctica deportiva, la importancia de las actividades extraescolares, hábitos saludables y el aprovechamiento del tiempo libre. Se definieron categorías axiales con las que se construyó la interpretación a la luz de la teoría, en donde se retoman los autores relacionados en los marcos, tanto teórico como conceptual y se triangula la información que es la construcción teórica de los investigadores. Se concluye que el diseño de la escuela deportiva es una estrategia positiva para el aprovechamiento del tiempo libre y del desarrollo personal, ya que los estudiantes en la entrevista manifestaron motivación por hacer parte de ella, recalcando que pueden mejorar las relaciones interpersonales, crear vínculos para fortalecer el trabajo en equipo y tener una sana convivencia con alumnos de otros grados. De igual manera la escuela de formación deportiva permitirá que los estudiantes tengan un óptimo desarrollo físico, emocional, social y deportivo.Introducción 13 Capítulo 1: Descripción del problema 16 1.1 Planteamiento del problema 16 1.2 Objetivos 18 1.2.1 Objetivo general 18 1.2.2 Objetivos específicos 19 1.3 Manejo de supuestos de investigación 19 1.4 Justificación 20 Capítulo 2: Fundamentación teórica y referencial 23 2.1 Antecedentes de Investigación 23 2.2 Marco teórico 33 2.2.1 Constructivismo como modelo creativo 33 2.3 Marco conceptual 42 2.3.1 El deporte, importancia y clasificación 43 2.3.1.1 El deporte recreativo 45 2.3.1.2 Las habilidades motrices 45 2.3.2 Las capacidades coordinativas 46 2.3.3 Educación física 47 2.3.3.3 Estilos de enseñanza en la educación física 51 2.3.4 Formación integral 55 2.3.5 Escuelas deportivas 56 2.3.6 Iniciación deportiva 57 2.3.7 Beneficios de la actividad física y estilos de vida saludables 59 2.3.8 El tiempo libre y su importancia 60 2.4 Marco legal 62 Capítulo 3: Metodología 68 3.1 Método de investigación 68 3.2 Población, participantes y selección de la muestra 71 3.2.1 Macro escenario 72 3.2.2 Micro escenario 73 3.3 Instrumentos de Recolección de Datos 73 3.3.1 La encuesta 73 3.3.2 Entrevista semiestructurada 75 Desarrollo de la entrevista 75 3.4 Código ético del investigador 76 Capítulo 4: Análisis y resultados 77 4.1 Técnica de análisis de resultados 77 4.2 Análisis de la encuesta 78 4.3 Técnica de análisis de la entrevista 81 4.4 Resultados 83 4.4.1 Triangulación 88 4.4.2 Confiabilidad y validez de los resultados 95 4.5 Propuesta para el diseño de la escuela de formación deportiva Instituto Caldas 96 4.5.1 Organización del proyecto 97 4.5.2 Deportes 98 4.5.3 Estructura organizacional de la escuela deportiva 99 4.5.4 Valores corporativos 100 4.5.5 Metodología de la propuesta 105 4.5.6 Planes de clase 117 Capítulo 5: Conclusiones y recomendaciones 122 5.1 Conclusiones 122 5.2 Recomendaciones 124 Bibliografía 125 Apéndices 135MaestríaThe present research: Proposal for the design of a sports school for soccer and volleyball for children and young people aged 6 to 14 years with a focus on constructivism, carried out between 2019 and 2020, aims to propose the design of a soccer and volleyball sports school related to a constructivist model, as a strategy for the free use of children and young people aged 6 to 14 years of the Caldas Institute. The methodology developed was based on a quantitative approach, non-experimental and descriptive design, based on the bibliographic search, the relevant concepts for the investigation are presented with theoretical contributions on constructivism, as a model in sports teaching, as well as the necessary topics and regulations for the implementation of a sports school, such as motivation, sports, the basic principles of sports practice, the importance of extracurricular activities, healthy habits and the use of free time. Axial categories were defined with which the interpretation was constructed in the light of the theory, where the related authors are retaken in both the theoretical and conceptual frameworks and the information that is the theoretical construction of the researchers is triangulated. It is concluded that the design of the sports school is a positive strategy for the use of free time and personal development, since the students in the interview expressed motivation to be part of it, emphasizing that they can improve interpersonal relationships, create links to strengthen teamwork and have a healthy coexistence with students from other grades. Similarly, the sports training school will allow students to have optimal physical, emotional, social and sports development

A Time-Encoded Capacitance-to-Digital Converter Based on a Switched-Capacitor Feedback

An innovative method to perform capacitance-to-digital conversion without requiring sensor biasing circuitry is proposed. This letter is intended for the readout of MEMS capacitive microphones used in human-to-machine interface applications, where the main constraints are low power consumption and small chip area. The time-encoded sigma-delta ADC described here employs a switched-capacitor-based feedback to linearize the voltage-controlled oscillator and to couple the capacitive sensor to the readout. A prototype was fabricated to test the concept with a CMOS 130-nm process. The achieved relative capacitance resolution is 14.7 b with a rest capacitance value of 2.575pF and a total power consumption of 343μW . Linearity measurements ( SNDRpeak=51.5 dB in the bandwidth from 300Hz to 6.8kHz ) are limited by the test fixture due to the nonlinearity of the varactor introduced in lieu of a testing input sensor.The project funded from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 956601, involves the collaboration between Universidad Carlos III de Madrid and Infineon Technologies AG Austria

Promotion of Direct Electron Transfer to Cytochrome c by Functionalized Thiophene-based Conducting Polymers

Controlling direct electron transfer (DET) to redox proteins is of great interest for fundamental studies on biochemical processes and the development of biotechnological devices, such as biosensors or enzymatic fuel cells. Cytochrome c is a classical model protein for studying DET reactions that plays a key role in the onset of cellular apoptosis and the mitochondrial respiratory chain. In this contribution, we explored DET between cyt c and conducting polymers bearing the chemical structure of thiophene, specifically PEDOT, and its OH-containing derivative, PHMeEDOT. The combination of electrochemistry and in situ FTIR spectroscopy allowed us to gain more insight into the inner mechanism of DET at physiological pH. Hydrophilic interactions favour the correct orientation of the heme crevice of cytochrome c towards the polymer surface. When a positive charge is injected into the conducting polymer, the increasing electrostatic repulsion between protein and surface induces the desorption of lysine residues near the heme group and stimulates protein flipping. This effect was more pronounced at PEDOT- than PHMeEDOT-modified electrodes since the latter shows stronger interactions with lysine residues, partially hindering protein rotation at moderate potential. The potential-induced reorientation process was similar on both polymer surfaces, only at high positive potentials.Financial support by Spanish Ministry of Science (projects TED2021-129894B-I00 and PDC2021-120884-I00), Generalitat Valenciana (projects GVA-THINKINAZUL/2021/015, MFA/2022/058 and CIPROM/2021/62) and European Union (NextGenerationEU PRTR-C17.I1) is gratefully acknowledged. A.G.-Q. acknowledges funding received from his Marie Skłodowska-Curie Postdoctoral Fellowship (Grant Number MSCA-IF-EF-ST 2020/101018277)

Atrial Fibrillation Originating in the Inferior Vena Cava

Recurrence of atrial fibrillation (AF) despite successful isolation of the pulmonary veins (PVs) represents a great challenge. We present a patient with recurrent episodes of paroxysmal AF despite PV isolation in which a non-PV trigger was identified in the inferior vena cava. (Level of Difficulty: Intermediate.

De la responsabilidad social empresarial a la responsabilidad ambiental universitaria

Este artículo indaga inicialmente por la categoría Responsabilidad Social Universitaria, cuyo primer hallazgo identifica dos grandes tradiciones de su emergencia, una derivada-de, que se fundamenta en tres perspectivas de la Responsabilidad Social Empresarial: teorías de la agencia, teorías de la legitimidad y teorías de la institucionalidad; y la otra tradición es denominada, originaria-en la universidad latinoamericana, que promueve el surgimiento de la Responsabilidad Ambiental Universitaria. A partir de un enfoque cualitativo el diseño documental que permite el abordaje de diversas bases de datos: informes, proyectos y programas ambientales en el interior de un caso de manejo de residuos sólidos en una universidad colombiana. Se puede destacar que en el marco general de las prácticas y acciones ambientales de la universidad se hibridan de forma alternada perspectivas de Responsabilidad Ambiental Universitaria matizadas desde las perspectivas de la Responsabilidad Social Empresarial y la Responsabilidad Social Universitaria.This article initially investigates the category of University Social Responsibility, whose first finding identifies two great traditions of its emergence, one derived from three perspectives of Corporate Social Responsibility: theories of the agency, theories of legitimacy and theories of the institutionality; and another original tradition-in the Latin American University that promotes the emergence of the University Environmental Responsibility. From a qualitative approach, the documentary design allows the approach of diverse data bases: reports, projects and environmental programs within a solid waste management case in a Colombian university. It is possible to emphasize that in the general framework of the environmental practices of the university perspectives of University Environmental Responsibility are alternately hybridized, nuanced from the perspectives of the Corporate Social Responsibility and the University Social Responsibility

Limpia más

Limpia Más nace pensando en la necesidad de las personas y familias que no disponen de tiempo para mantener sus hogares limpios y saludables por lo que necesitan contratar especialistas de la limpieza profunda. La pandemia actual del Covid-19, que venimos atravesando ha creado nuevas necesidades teniendo a la limpieza recurrente y desinfección como una de sus principales, manteniendo el hogar libre de gérmenes, virus, ácaros y bacterias. A esto se suma la necesidad de proteger al medioambiente con productos no tóxicos, no corrosivos y no invasivos. El objetivo del negocio es atender las necesidades de salud y bienestar en el hogar, a través del servicio de limpieza profunda a domicilio. Por otro lado, el nombre Limpia Más fue creado pensando en el servicio que nuestra empresa ofrecerá, un servicio de limpieza profunda usando máquinas e insumos eco amigables con el medioambiente. Este servicio está dirigido a las personas de nivel socioeconómico A y B entre hombres y mujeres con edades entre 25 y 55 años de edad residentes en Lima, Perú, con estilos de vida moderno. Este grupo de personas no cuentan con tiempo para realizar la limpieza en el hogar y cuentan con interés de contratar una empresa que brinda servicios de limpieza profunda en sus hogares. Los canales de comunicación que Limpia Más usará son página web, Facebook, Instagram, WhatsApp y correo electrónico, de esa manera tendremos una comunicación constante. Finalmente, los ingresos de Limpia Más serán percibidos a través de la prestación de servicios de limpieza en el hogar.Limpia Más was born thinking in the need of people and families who do not have time to keep their homes clean and healthy so they need to hire deep cleaning specialists. The current pandemic of Covid-19, which we have been going through, has created new needs having recurrent cleaning and disinfection as one of its main needs, keeping the home free of germs, viruses, mites and bacteria. Added to this is the need to protect the environment with non-toxic, non-corrosive and non-invasive products. The objective of the business is to meet the needs of health and well-being in the home, through home cleaning and disinfection services. On the other hand, the name Limpia Más was created thinking about the service that our company will offer, a deep cleaning service using environmentally friendly machines and supplies. This service is aimed at people of socioeconomic level A and B between men and women between 25 and 55 years of age living in Lima, Peru, with modern lifestyles. This group of people do not have time to clean their homes and are interested in hiring a company that provides deep cleaning services in their homes. The communication channels that Limpia Más will use are website, Facebook, Instagram, WhatsApp and email, that way we will have constant communication. Finally, the income of Limpia Más will be perceived through the provision of home cleaning services.Trabajo de investigació