Pixel design and evaluation in CMOS image sensor technology

A chip designed in a 0.18 μm CMOS Image Sensor Technology (CIS) is presented which incorporates different pixel design alternatives for Active Pixel Sensor (APS). CIS technology improves characteristics such as sensitivity, dark current and noise, that are strongly layout dependent. This chip includes a set of pixel architectures where different parameters have been modified: layout of active diffusion, threshold voltage of the source follower transistor and the use of microlenses. Besides, structures to study the influence of crosstalk between pixels have been incorporated

Job market candidates 2016: Gustavo Bonifaz Moreno

In the Department of Government we continue to support early stage researchers after they complete their PhD studies. In this series, we speak to Government PhD graduates entering the job market to learn more about their research and its impact, and what makes them exemplary candidates for employment in academia globally. Here, Gustavo Bonifaz Moreno tells us about his research on the gap between legality and legitimacy in moments of political crisis and how he teaches students to examine literature through the lens of current affairs to facilitate engagement with complex problems

Bragg spectroscopy for measuring Casimir-Polder interactions with Bose-Einstein condensates above corrugated surfaces

We propose a method to probe dispersive atom-surface interactions by measuring via two-photon Bragg spectroscopy the dynamic structure factor of a Bose-Einstein condensate above corrugated surfaces. This method takes advantage of the condensate coherence to reveal the spatial Fourier components of the lateral Casimir-Polder interaction energy.Fil: Moreno, Gustavo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Dalvit, Diego A. R.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Calzetta, Esteban Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Procesador segmentado para fines académicos usando HDL

El documento digital no refiere asesorPublicación a texto completo no autorizada por el autorDesarrolla el diseño de un procesador segmentado con la finalidad de ayudar a los estudiantes en el aprendizaje del desempeño de este tipo de procesadores, principalmente cuando se presentan conflictos con relación a la secuencia de instrucciones utilizadas y sus dependencias. Para ello se utilizan técnicas hardware, tales como el adelantamiento de datos, inserción de burbujas, y anticipación de riesgos. Estos métodos se aplican para la arquitectura MIPS que consta de una segmentación de 5 etapas y cumple con las características de la arquitectura ISA tipo RISC empleada ampliamente en la temática de “Arquitectura de Computadoras”. El método empleado es desarrollar cada vez una nueva versión del procesador adaptado para solucionar el nuevo paradigma mostrando la mejora en su desempeño luego de hacerlo, así tendremos una versión que muestra la solución por riesgos de dependencia de datos. Otra versión del procesador para el caso en que una instrucción dependa del dato de una instrucción de carga, para finalmente realizar una última versión que solucione las dependencias debido a las bifurcaciones, que vienen a ser las más características y que presenta dificultad de asimilar en esta parte de la temática, tanto por la poca afición a la lectura del estudiantado como a la baja comprensión lectora que se tiene. El proceso de ver los eventos y simularlos más que solo verlos estáticamente permitirá una mejor y rápida comprensión de estos fenómenos así como su interacción al modificar los programas y el hardware del procesador respectivo.Tesi

Macromodelling for analog design and robustness boosting in bio-inspired computing models

Setting specifications for the electronic implementation of biological neural-network-like vision systems on-chip is not straightforward, neither it is to simulate the resulting circuit. The structure of these systems leads to a netlist of more than 100.000 nodes for a small array of 100×150 pixels. Moreover, introducing an optical input in the low level simulation is nowadays not feasible with standard electrical simulation environments. Given that, to accomplish the task of integrating those systems in silicon to build compact, low power consuming, and reliable systems, a previous step in the standard analog electronic design flux should be introduced. Here a methodology to make the translation from the biological model to circuit-level specifications for electronic design is proposed. The purpose is to include non ideal effects as mismatching, noise, leakages, supply degradation, feedthrough, and temperature of operation in a high level description of the implementation, in order to accomplish behavioural simulations that require less computational effort and resources. A particular case study is presented, the analog electronic implementation of the locust's Lobula Giant Movement Detector (LGMD), a neural structure that fires a collision alarm based on visual information. The final goal is a collision threat detection vision system on-chip for automotive applications.European Union IST-2001-38097, TIC2003 - 09817-C02-0

Neural and Behavioral Mechanisms of Interval Timing in the Striatum

To guide behavior and learn from its consequences, the brain must represent time over many scales. Yet, the neural signals used to encode time in the seconds to minute range are not known. The striatum is the major input area of the basal ganglia; it plays important roles in learning, motor function and normal timing behavior in the range of seconds to minutes. We investigated how striatal population activity might encode time. To do so, we recorded the electrical activity from striatal neurons in rats performing the serial fixed interval task, a dynamic version of the fixed Interval schedule of reinforcement. The animals performed in conformity with proportional timing, but did not strictly conform to scalar timing predictions, which might reflect a parallel strategy to optimize the adaptation to changes in temporal contingencies and consequently to improve reward rate over the session. Regarding the neural activity, we found that neurons fired at delays spanning tens of seconds and that this pattern of responding reflected the interaction between time and the animals’ ongoing sensorimotor state. Surprisingly, cells rescaled responses in time when intervals changed, indicating that striatal populations encoded relative time. Moreover, time estimates decoded from activity predicted trial-bytrial timing behavior as animals adjusted to new intervals, and disrupting striatal function with local infusion of muscimol led to a decrease in timing performance. Because of practical limitations in testing for sufficiency a biological system, we ran a simple simulation of the task; we have shown that neural responses similar to those we observe are conceptually sufficient to produce temporally adaptive behavior. Furthermore, we attempted to explain temporal processes on the basis of ongoing behavior by decoding temporal estimates from high-speed videos of the animals performing the task; we could not explain the temporal report solely on basis of ongoing behavior. These results suggest that striatal activity forms a scalable population firing rate code for time, providing timing signals that animals use to guide their actions

Geometría experimental y contextos matemáticos: estudio de la congruencia a través del diseño de logos

Esta propuesta de cursillo busca que los profesores de matemáticas desarrollen un conocimiento fundamentado acerca de la integración de contextos realistas en la enseñanza y el aprendizaje de la geometría. Se lleva a cabo a través del planteamiento de tareas matemáticas cuyas soluciones vinculen diferentes tipos de estrategias y procedimientos y que promuevan el tratamiento experimental de ciertas propiedades geométricas, en particular la de congruencia de figuras geométricas, presentes en logotipos publicitarios

Political cleavages in motion: Bolivia in 2021

We analyze recent developments in Bolivia’s politics through the lens of political cleavage theory, in particular cleavage displacement. Bolivia’s current party system is characterized by a stable and dominant MAS at one end of the spectrum, and at the other a fractious, unstable collection of parties, movements, and other vehicles that have failed to articulate a coherent set of political ideas. It emerged when the previous party system collapsed in 2003-05, shifting politics from a conventional left-right axis of competition unsuited to Bolivian society, to an ethnic/rural vs. cosmopolitan/urban axis closely aligned with its major social cleavage. But society did not freeze in 2005. We analyze the deep roots of Bolivia’s current politics, and explore emerging or changing generational, ethnic, urban-rural, regional, class, and religious divides. Understanding how cleavages interact to determine political outcomes allows us to make sense of the deep tensions and sources of instability that both Bolivia, and the MAS internally, currently face, and to shine a light on major coming challenges

Political Cleavages in Motion: Bolivia in 2021

We analyze recent developments in Bolivia’s politics through the lens of political cleavage theory, in particular cleavage displacement. Bolivia’s current party system is characterized by a stable and dominant MAS at one end of the spectrum, and at the other a fractious, unstable collection of parties, movements, and other vehicles that have failed to articulate a coherent set of political ideas. It emerged when the previous party system collapsed in 2003-05, shifting politics from a conventional left-right axis of competition unsuited to Bolivian society, to an ethnic/ rural vs. cosmopolitan/urban axis closely aligned with its major social cleavage. But society did not freeze in 2005. We analyze the deep roots of Bolivia’s current politics, and explore emerging or changing generational, ethnic, urban-rural, regional, class, and religious divides. Understanding how cleavages interact to determine political outcomes allows us to make sense of the deep tensions and sources of instability that both Bolivia, and the MAS internally, currently face, and to shine a light on major coming challenges

Revenue sharing at music streaming platforms

We study the problem of sharing the revenues raised from subscriptions to music streaming platforms among content providers. We provide direct, axiomatic and game-theoretical foundations for two focal (and somewhat polar) methods widely used in practice: pro-rata and user-centric. The former rewards artists proportionally to their number of total streams. With the latter, each user's subscription fee is proportionally divided among the artists streamed by that user. We also provide foundations for a family of methods compromising among the previous two, which addresses the rising concern in the music industry to explore new streaming models that better align the interests of artists, fans and streaming services.Comment: 30 page