CMOS design of cellular APAPs and FPAPAPs: an overview

CNN-based analog visual microprocessors have similarities with the so-called Single Instruction Multiple Data systems, although they work directly on analog signal representations obtained through embedded optical sensors and hence do not need a frontend sensory plane or analog-to-digital converters. The architecture of these visual microprocessors is illustrated in the paper through two prototype chips, namely: ACE4K and ACE16K. In both cases, as in other related chips the architecture includes a core array of interconnected elementary processing units, surrounded by a global circuitry.Office of Naval Research N00014-00-10429Comisión Interministerial de Ciencia y Tecnología TIC-1999-082

Accurate and simple modeling of amplifier dc gain nonlinearity in switched-capacitor circuits

This paper presents an accurate and simple model for dc gain nonlinearity of operational amplifiers used in the switched-capacitor circuits such as the sigma-delta modulators. The proposed model can simply be used in the time-domain system level simulation of sigma-delta modulators to evaluate the effect of amplifier's dc gain nonlinearity on the overall linearity of the modulator as well as in the other switched- capacitor circuits as explored in the paper.Comisión Interministerial de Ciencia y Tecnología TIC2003-0235

Evaluación de la competencia investigativa en el campo educativo: un análisis de los instrumentos de medición

There is a growing interest in the acquisition, promotion, and assessment of the competencies necessary for research among university students. However, within the field of educational evaluation, one confronts the complexity of establishing precise measures that inform about the performance of this competence. This study examined the measurement instruments employed to assess the research competence of university students in the educational field. The research followed the PRISMA protocol for conducting systematic literature reviews and performed a critical analysis of the identified measurement instruments. The aspects under investigation included: proposed use, target population, construct’s conceptualization, instrument format, and validity evidence’s generation. Findings indicated that these instruments are employed both to assess the acquisition and mastery of research competence and to evaluate the effectiveness of pedagogical interventions aimed at fostering it. A lack of representativeness of the student population in disciplines with an educational focus was identified. The components and indicators of research competence share a common organization into dimensions spanning from metacognitive skills to contextual conditions within which research is practiced. There was an observed tendency towards the use of questionnaires and a prevalence of traditional approaches in validation procedures.Existe un creciente interés en la adquisición, promoción y evaluación de las competencias necesarias para la investigación en estudiantes universitarios. Sin embargo, en el ámbito de la evaluación educativa, se enfrenta a la complejidad de establecer medidas precisas que informen sobre el desempeño de esta competencia. Este trabajo examinó los instrumentos de medición utilizados para evaluar la competencia investigativa de estudiantes universitarios en el campo educativo. El estudio siguió el protocolo PRISMA para la conducción de revisiones sistemáticas de literatura y realizó un análisis crítico de los instrumentos de medición identificados. Los aspectos bajo estudio fueron: uso propuesto, población objetivo, conceptualización del constructo, formato del instrumento y generación de evidencias de validez. Los hallazgos indicaron que los instrumentos se utilizan tanto para evaluar la adquisición y dominio de la competencia investigativa como para valorar la efectividad de intervenciones pedagógicas destinadas a fomentarla. Se identificó una falta de representatividad de la población estudiantil en disciplinas con enfoque educativo. Los componentes e indicadores de la competencia investigativa comparten una organización común en dimensiones que abarcan desde habilidades meta-cognitivas hasta condiciones contextuales donde se practica la investigación. Se observó una tendencia hacia el uso de cuestionarios y una prevalencia del enfoque tradicional en los procedimientos de validación

Switched-Current Chaotic Neurons

The Letter presents two nonlinear CMOS current-mode circuits that implement neuron soma equations for chaotic neural networks. They have been fabricated in a double-metal, single-poly 1.6µm CMOS technology. The neuron soma circuits use a novel, highly accurate CMOS circuit strategy to realise piecewise-linear characteristics in the current-mode domain. Their prototypes obtain reduced area and low voltage power supply (down to 3V) with a clock frequency of 500 kHz

Learning in neuro/fuzzy analog chips

This paper focus on the design of adaptive mixed-signal fuzzy chips. These chips have parallel architecture and feature electrically-controlable surface maps. The design methodology is based on the use of composite transistors - modular and well suited for design automation. This methodology is supported by dedicated, hardware-compatible learning algorithms that combine weight-perturbation and outstar

Modular Design of Adaptive Analog CMOS Fuzzy Controller Chips

Analog circuits are natural candidates to design fuzzy chips with optimum speed/power figures for precision up to about 1%. This paper presents a methodology and circuit blocks to realize fuzzy controllers in the form of analog CMOS chips. These chips can be made to adapt their function through electrical control. The proposed design methodology emphasizes modularity and simplicity at the circuit level -- prerequisites to increasing processor complexity and operation speed. The paper include measurements from a silicon prototype of a fuzzy controller chip in CMOS 1.5μm single-poly technology

CMOS current-mode chaotic neurons

This paper presents two nonlinear CMOS current-mode circuits that implement neuron soma equations for chaotic neural networks, and another circuit to realize programmable current-mode synapse using CMOS-compatible BJT's. They have been fabricated in a double-metal, single-poly 1.6 /spl mu/m CMOS technology and their measured performance reached the expected function and specifications. The neuron soma circuits use a novel, highly accurate CMOS circuit strategy to realize piecewise-linear characteristics in the current-mode domain. Their prototypes obtain reduced area and low voltage power supply (down to 3 V) with clock frequency of 500 kHz. As regard to the synapse circuit, it obtains large linearity and continuous, linear, weight adjustment by exploration of the exponential-law operation of CMOS-BJT's. The full accordance observed between theory and measurements supports the development of future analog VLSI chaotic neural networks to emulate biological systems and advanced computation

Integrated chaos generators

This paper surveys the different design issues, from mathematical model to silicon, involved on the design of integrated circuits for the generation of chaotic behavior.Comisión Interministerial de Ciencia y Tecnología 1FD97-1611(TIC)European Commission ESPRIT 3110