Gas sensor array system inspired on the sensory diversity and redundancy of the olfactory epithelium

AbstractThis paper presents a chemical sensing system that takes inspiration from the combination of sensory diversity and redundancy at the olfactory epithelium to enhance the chemical information obtained from the odorants. The system is based on commercial MOS sensors and achieves, first, diversity trough different types of MOS along with modulation of their temperatures, and second redundancy including 12 MOS sensors for each type (12×8) combined with a high-speed multiplexing system that allows connecting 16 load resistors with each and every one of the 96 sensors in about two seconds. Exposition of the system to ethanol, ammonia, and acetone at different concentrations shows how the system is able to capture a large amount of information of the identity and the concentration of the odorant

Coding and learning of chemosensor array patterns in a neurodynamic model of the olfactory system

Arrays of broadly-selective chemical sensors, also known as electronic noses, have been developed during the past two decades as a low-cost and high-throughput alternative to analytical instruments for the measurement of odorant chemicals. Signal processing in these gas-sensor arrays has been traditionally performed by means of statistical and neural pattern recognition techniques. The objective of this dissertation is to develop new computational models to process gas sensor array signals inspired by coding and learning mechanisms of the biological olfactory system. We have used a neurodynamic model of the olfactory system, the KIII, to develop and demonstrate four odor processing computational functions: robust recovery of overlapping patterns, contrast enhancement, background suppression, and novelty detection. First, a coding mechanism based on the synchrony of neural oscillations is used to extract information from the associative memory of the KIII model. This temporal code allows the KIII to recall overlapping patterns in a robust manner. Second, a new learning rule that combines Hebbian and anti-Hebbian terms is proposed. This learning rule is shown to achieve contrast enhancement on gas-sensor array patterns. Third, a new local learning mechanism based on habituation is proposed to perform odor background suppression. Combining the Hebbian/anti-Hebbian rule and the local habituation mechanism, the KIII is able to suppress the response to continuously presented odors, facilitating the detection of the new ones. Finally, a new learning mechanism based on anti-Hebbian learning is proposed to perform novelty detection. This learning mechanism allows the KIII to detect the introduction of new odors even in the presence of strong backgrounds. The four computational models are characterized with synthetic data and validated on gas sensor array patterns obtained from an e-nose prototype developed for this purpose

Evaluación crediticia y riesgo crediticio en los clientes de la CRAC Raíz S.A.A, Agencia Pichanaki - 2021

El problema general de esta investigación fue responder a la interrogante ¿Qué relación existe entre la evaluación crediticia y el riesgo crediticio en los clientes de la CRAC Raíz S.A.A., Agencia Pichanaki - 2021? Tuvo como objetivo general establecer la relación que existe entre la evaluación crediticia y el riesgo crediticio en los clientes de la CRAC Raíz S.A.A., Agencia Pichanaki – 2021. Como objetivos específicos, buscó establecer la relación existente entre la evaluación crediticia con la morosidad y provisiones; así como establecer la relación entre la situación económica del negocio, la voluntad de pago, y la capacidad de pago; con el riesgo crediticio. Se utilizo el método científico; y como método específico se utilizó el método inductivo. El tipo de investigación fue básica, de un nivel correlacional, de diseño no experimental, transversal y correlacional. La muestra fueron 260 expedientes crediticios; y como instrumento de recolección de datos, se utilizaron listas de cotejo. Como resultado se encontró que el nivel de evaluación crediticia en la CRAC Raíz es alta; y el riesgo crediticio es bajo. Se concluye que existe relación significativa negativa alta (Tau-b de Kendall = -0.952, p valor < 0.05) entre la evaluación crediticia y el riesgo crediticio. Además, se encontró una relación significativa negativa alta entre la evaluación crediticia y el ratio de morosidad y las provisiones

Violencia de género y miopía fiscal: análisis de investigaciones archivadas

La presente investigación se desarrolló en torno a la siguiente interrogante ¿existen vicios de motivación interna en las disposiciones de archivo, en relación con el delito de agresiones contra las mujeres o integrantes del grupo familiar, emitidas por el Ministerio Público-distrito fiscal de Ayacucho, Huamanga, durante el periodo 2020. El objetivo general de la presente investigación es determinar si existen vicios de motivación interna en las disposiciones de archivo del delito de agresiones contra las mujeres o integrantes del grupo familiar, emitidas por el Ministerio Público-distrito fiscal de Ayacucho, Huamanga, durante el periodo 2020. El desarrollo de la investigación se realiza en torno al enfoque cualitativo con una óptica hermenéutica, siendo el modelo de investigación no experimental, y como instrumento de recolección de datos se hizo uso de la ficha de análisis documental. Además, a fin de concretar los objetivos de la presente investigación, fueron analizadas trece disposiciones fiscales de archivo, haciendo uso de la ficha de análisis documental, donde se encontraban aspectos relevantes de la investigación, esto es, los hechos, elementos de convicción, la norma y razón suficiente de por qué se archivó el caso, las disposiciones fueron recabadas mediante el procedimiento que nos exigió el Ministerio Público, asignándole a cada unidad de análisis un código (A1 hasta A13) a fin de evitar que se pueda vincular cada relato a las personas involucradas. Luego de realizar la investigación se detallaron las conclusiones en relación con los objetivos, determinando que existen vicios de motivación interna, ya que el Ministerio Público no realiza una valoración adecuada de los presupuestos fácticos, así como de los hechos y elementos probatorios que se hallan durante la investigación xvi preliminar, con el fin de obtener una disposición debidamente motivada de manera lógica, coherente y razonable., consecuentemente afectando derecho a la debida motivación. Palabras claves: debida motivación, vicios de motivación, disposición de archivo, diligencias preliminares, agresiones contra las mujeres o integrantes del grupo familiar

Gestión administrativa y relaciones humanas en administrativos y docentes de la Institución Educativa José Carlos Mariategui del distrito de Villa María del Triunfo 2013

La investigación titulada “Gestión administrativa y relaciones humanas entre administrativos y docentes de la institución educativa José Carlos Mariátegui del distrito de Villa María del Triunfo, 2013, se propone determinar en qué medida se relaciona la gestión administrativa con las relaciones humanas de administrativos y docentes. La población está constituida por 105 docentes y administrativos de la institución José Carlos Mariátegui distrito de Villa María del Triunfo. La muestra la constituyeron 60 docentes y administrativos, y el método de muestreo fue aleatorio simple, el diseño es correlacional causal, los instrumentos que se utilizó para cada variable fue de 20 ítems, el instrumento constatado fue confiable y validado por el juicio de expertos y el Alpha de Cronbach. La hipótesis se sometió a prueba determinándose que existe relación significativa en la gestión administrativa con las relaciones humanas de los administrativos y docentes cuyos resultados de la correlación de Pearson para la prueba de hipótesis, es en el nivel de significancia de 0,01% de margen de error (bilateral) y 99% de confiabilidad de los datos en las variables de estudio demuestran que la r = 0,989 y ajustado la r = 0,915, es decir, existe correlación positiva medianamente alta

Description and Characterisation of a Large Array of Sensors Mimicking an Artifical Olfactory Epithelium

Biological olfactory systems show high sensitivity and exquisite discriminatory capacity to odorants. These characteristics are due to hierarchical signal processing of the large numbers of sensory inputs that occurs within the olfactory system. In testing realistic computational models of the olfactory system, large numbers of chemical sensor inputs are required. So far, sensory devices that may serve as model inputs to an artificial olfactory system do not exist. The development of a large scale array of chemical sensors able to mimic the olfactory receptor neurons is described, and these have been characterised in terms of their variability and degree of redundancy. Using this device it is possible to start testing computational hypotheses appropriate to biological chemosensory systems and adapt them to the artificial olfaction

A practical method to estimate the resolving power of a chemical sensor array: application to feature selection

A methodology to calculate analytical figures of merit is not well established for detection systems that are based on sensor arrays with low sensor selectivity. In this work, we present a practical approach to estimate the Resolving Power of a sensory system, considering non-linear sensors and heteroscedastic sensor noise. We use the definition introduced by Shannon in the field of communication theory to quantify the number of symbols in a noisy environment, and its version adapted by Gardner and Barlett for chemical sensor systems. Our method combines dimensionality reduction and the use of algorithms to compute the convex hull of the empirical data to estimate the data volume in the sensor response space. We validate our methodology with synthetic data and with actual data captured with temperature-modulated MOX gas sensors. Unlike other methodologies, our method does not require the intrinsic dimensionality of the sensor response to be smaller than the dimensionality of the input space. Moreover, our method circumvents the problem to obtain the sensitivity matrix, which usually is not known. Hence, our method is able to successfully compute the Resolving Power of actual chemical sensor arrays. We provide a relevant figure of merit, and a methodology to calculate it, that was missing in the literature to benchmark broad-response gas sensor arrays.Peer ReviewedPostprint (published version

Bioinspired early detection through gas flow modulation in chemo-sensory systems

The design of bioinspired systems for chemical sensing is an engaging line of research in machine olfaction. Developments in this line could increase the lifetime and sensitivity of artificial chemo-sensory systems. Such approach is based on the sensory systems known in live organisms, and the resulting developed artificial systems are targeted to reproduce the biological mechanisms to some extent. Sniffing behaviour, sampling odours actively, has been studied recently in neuroscience, and it has been suggested that the respiration frequency is an important parameter of the olfactory system, since the odour perception, especially in complex scenarios such as novel odourants exploration, depends on both the stimulus identity and the sampling method. In this work we propose a chemical sensing system based on an array of 16 metal-oxide gas sensors that we combined with an external mechanical ventilator to simulate the biological respiration cycle. The tested gas classes formed a relatively broad combination of two analytes, acetone and ethanol, in binary mixtures. Two sets of low-frequency and high-frequency features were extracted from the acquired signals to show that the high-frequency features contain information related to the gas class. In addition, such information is available at early stages of the measurement, which could make the technique suitable in early detection scenarios. The full data set is made publicly available to the community. (C) 2014 Elsevier B.V. All rights reserved.Postprint (author's final draft

Construyendo el espacio público universitario del siglo XXI

The public space in the university campus is a relevant factor for a better functioning of this type of infrastructure, in benefit of the university community. However, the university public space often does not have comprehensive planning to develop all its potential. It must be understood that university public space, including its green areas, has spaces such as circulation, meeting and other places produced by the new needs of its new users, which are constantly being renewed. Therefore, this investigation aims to analyze the changes applied in the use of potential university public spaces within the framework of the 21st century. The study is of the basic type, with a qualitative approach, with a comparative methodological analysis. The actions taken at Harvard University, the University of Berkeley and the Faculty of Architecture and Urban Planning of the Ricardo Palma University will be studied; and how these impacted the work of the university public space. The results of the study offer different ways of intervention in the university public spaces, but with the same purpose: to enhance student life both academically and socially. The intervention strategies of the new century are focused on the user's comfort, their green perception of the landscape, the use of new potential spaces and the placement of furniture for different purposes. User perceptions and impacts could be studied in forward researches.El espacio público del campus universitario es un factor relevante para un mejor funcionamiento de la universidad, en beneficio de la comunidad universitaria. Sin embargo, el espacio público universitario en muchas ocasiones no tiene una planificación integral para el desarrollo de todas sus potencialidades. Se debe comprender que el espacio público universitario, además de sus áreas verdes, poseen otros espacios como de circulación, de estancias y otros espacios que se forman por las nuevas necesidades de sus nuevos usuarios, que van renovándose constantemente. Por ello, la presente investigación tiene como objetivo analizar sobre los cambios aplicados en el uso de potenciales espacios públicos universitarios en el marco del siglo XXI. El estudio es del tipo básico, con un enfoque cualitativo, con un análisis metodológico comparativo. Se estudiarán las acciones tomadas en la Universidad de Harvard, la Universidad de Berkeley y la Facultad de Arquitectura y Urbanismo de la Universidad Ricardo Palma; y cómo estas impactaron en el quehacer del espacio público universitario. Los resultados del estudio ofrecen distintas maneras de intervenir el espacio público universitario, pero con un mismo propósito: elevar la vida estudiantil tanto en lo académico como en lo social. Las estrategias de intervención del nuevo siglo están centradas en el confort del usuario, su percepción verde del paisaje, el uso de nuevos espacios potenciales y la colocación de mobiliarios para diferentes propósitos

EMOTIONAL PERCEPTION AND CULTURAL MOTIVATION ON LOYALTY TO A WORLD HERITAGE SITES DESTINATION

The aim of this paper is to contribute to the scientific literature in the field of tourism in Latin America (Sucre, Bolivia was named a World Heritage Site (WHS) by UNESCO). This study analyses the relevance of the cultural motivation and emotional experience of the tourist to positively influence the image or the perceived value of the heritage site visited. The research shall also analyse other relationships, such as the positive effect of the perceived value on the loyalty of tourists and the influence of the visitor’s place of origin as a moderating variable in the formation of the image and loyalty to the destination. The analysis was performed by means of structural equation models (SEMs). The data were extracted through fieldwork consisting of interviews with visitors to the city. The results of the research revealed that the perceived value of a heritage destination not only depends on the functional and tangible aspects of the attributes but also on the emotional experience and cultural interest regarding the heritage site visited. Similarly, there is evidence of a relationship between perceived value and a loyal attitude and that it is moderated by the origin of the tourist, this being a great influence in the case of the domestic tourist