1,626 research outputs found

    A multiobjective credibilistic portfolio selection model. Empirical study in the Latin American Integrated Market

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    [EN] This paper extends the stochastic mean-semivariance model to a fuzzy multiobjective model, where apart from return and risk, also liquidity is considered to measure the performance of a portfolio. Uncertainty of future return and liquidity of each asset are modeled using L-R type fuzzy numbers that belong to the power reference function family. The decision process of this novel approach takes into account not only the multidimensional nature of the portfolio selection problem but also realistic constraints by investors. Particularly, it optimizes the expected return, the semivariance and the expected liquidity of a given portfolio, considering cardinality constraint and upper and lower bound constraints. The constrained portfolio optimization problem resulting is solved using the algorithm NSGA-II. As a novelty, in order to select the optimal portfolio, this study defines the credibilistic Sortino ratio as the ratio between the credibilistic risk premium and the credibilistic semivariance. An empirical study is included to show the effectiveness and efficiency of the model in practical applications using a data set of assets from the Latin American Integrated Market.García García, F.; Gonzalez-Bueno, J.; Guijarro, F.; Oliver-Muncharaz, J. (2020). A multiobjective credibilistic portfolio selection model. Empirical study in the Latin American Integrated Market. Enterpreneurship and Sustainability Issues. 8(2):1027-1046. https://doi.org/10.9770/jesi.2020.8.2(62)S102710468

    Say what? : On the transmission of acoustic signals in a Neotropical green city

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    Cities do not only represent noisy systems, but also limit acoustic communication given the complex array of artificial structures through which signals can be trapped or obscured. In this study we performed a field experiment to evaluate the loss of energy of a standardized acoustic emission (generated with notes and a call of the Clay-colored Thrush - Turdus grayi). For this, we emitted the acoustic signal and recovered it at increasing radial distances from 26 fixed emission points (i.e., 10 m, 20 m, 40 m, 80 m, 120 m, 160 m) located across the city of Xalapa (Mexico). Our results show that the emitted signal was not recorded beyond 80 m from the emission point. The number and height of the assessed physical obstacles between the emitted signal and the receiving equipment showed to drive our main result, with built elements representing a major barrier than vegetation ones in terms of the recovered energy of the emitted signal. Interestingly, we found that, for both types of physical obstacles, a height of similar to 7 m was a common threshold influencing the recovered energy of the emitted signal.Peer reviewe

    Intenciones futuras de participar en un pequeño evento deportivo sostenible: influencia de la motivación, afición y satisfacción de los participantes en carreras solidarias

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    Small-scale sustainable sporting events have limited impact on the community, but there can be great benefits from holding them. For this reason, the celebration of this type of event has increased in recent years, on multiple occasions with solidarity purposes. However, few studies have been found which analyze the assessments of the participants. Therefore, it is the objective of this study to analyze the evaluations in reference to the motivation to participate, the liking for the sport practice and their satisfaction with the celebration of the event with respect to the future intentions of participation in this one. The results indicate that satisfaction with the event is the main variable that predicts future intentions of participating in this type of event. The aim is to provide information to the organizers of this type of event in order to improve organizational aspects that promote sustainability.La celebración de eventos deportivos sostenibles de pequeña escala presenta un impacto limitado en la comunidad, pero a su vez, su celebración puede ocasionar grandes beneficios. Es por ello que la celebración de este tipo de eventos se ha incrementado en los últimos años, en múltiples ocasiones con fines solidarios. Sin embargo, son escasos los estudios encontrados que analizan las valoraciones de los participantes. Por lo tanto, es el objetivo de este estudio analizar las valoraciones en referencias a la motivación por participar, la afición por la práctica deportiva y su satisfacción con la celebración del evento respecto a las intenciones futuras de participación en este. Los resultados señalan que la satisfacción con el evento es la principal variable que predice las intenciones futuras de participar en este tipo de eventos. Con ello se pretende aportar información a los organizadores de este tipo de eventos para mejorar aspectos organizativos que potencien la sostenibilidad.Actividad Física y Deport

    The role of Artificial Intelligence and Distributed computing in IoT applications

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    [ES] La serie «El rol de la inteligencia artificial y la computación distribuida en las aplicaciones IoT» contiene publicaciones sobre la teoría y aplicaciones de la computación distribuida y la inteligencia artificial en el Internet de las cosas. Prácticamente todas las disciplinas como la ingeniería, las ciencias naturales, la informática y las ciencias de la información, las TIC, la economía, los negocios, el comercio electrónico, el medio ambiente, la salud y las ciencias de la vida están cubiertas. La lista de temas abarca todas las áreas de los sistemas inteligentes modernos y la informática como: inteligencia computacional, soft computing incluyendo redes neuronales, inteligencia social, inteligencia ambiental, sistemas auto-organizados y adaptativos, computación centrada en el ser humano y centrada en el ser humano, sistemas de recomendación, control inteligente, robótica y mecatrónica, incluida la colaboración entre el ser humano y la máquina, paradigmas basados en el conocimiento, paradigmas de aprendizaje, ética de la máquina, análisis inteligente de datos, gestión del conocimiento, agentes inteligentes, toma de decisiones inteligentes y apoyo, seguridad de la red inteligente, gestión de la confianza, entretenimiento interactivo, inteligencia de la Web y multimedia. Las publicaciones en el marco de «El rol de la inteligencia artificial y la computación distribuida en las aplicaciones IoT» son principalmente las actas de seminarios, simposios y conferencias. Abarcan importantes novedades recientes en la materia, tanto de naturaleza fundacional como aplicable. Un importante rasgo característico de la serie es el corto tiempo de publicación. Esto permite una rápida y amplia difusión de los resultados de las investigaciones[EN] The series «The Role of Artificial Intelligence and Distributed Computing in IoT Applications» contains publications on the theory and applications of distributed computing and artificial intelligence in the Internet of Things. Virtually all disciplines such as engineering, natural sciences, computer and information sciences, ICT, economics, business, e-commerce, environment, health and life sciences are covered. The list of topics covers all areas of modern intelligent systems and computer science: computational intelligence, soft computing including neural networks, social intelligence, ambient intelligence, self-organising and adaptive systems, human-centred and people-centred computing, recommendation systems, intelligent control, robotics and mechatronics including human-machine collaboration, knowledge-based paradigms, learning paradigms, machine ethics, intelligent data analysis, knowledge management, intelligent agents, intelligent decision making and support, intelligent network security, trust management, interactive entertainment, web intelligence, and multimedia. The publications in the framework of «The Role of Artificial Intelligence and Distributed Computing in IoT Applications» are mainly the proceedings of seminars, symposia and conferences. They cover important recent developments in the field, whether of a foundational or applicable character. An important feature of the series is the short publication time. This allows for the rapid and wide dissemination of research results

    Preface

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    [ES] La serie «El rol de la inteligencia artificial y la computación distribuida en las aplicaciones IoT» contiene publicaciones sobre la teoría y aplicaciones de la computación distribuida y la inteligencia artificial en el Internet de las cosas. Prácticamente todas las disciplinas como la ingeniería, las ciencias naturales, la informática y las ciencias de la información, las TIC, la economía, los negocios, el comercio electrónico, el medio ambiente, la salud y las ciencias de la vida están cubiertas. La lista de temas abarca todas las áreas de los sistemas inteligentes modernos y la informática como: inteligencia computacional, soft computing incluyendo redes neuronales, inteligencia social, inteligencia ambiental, sistemas auto-organizados y adaptativos, computación centrada en el ser humano y centrada en el ser humano, sistemas de recomendación, control inteligente, robótica y mecatrónica, incluida la colaboración entre el ser humano y la máquina, paradigmas basados en el conocimiento, paradigmas de aprendizaje, ética de la máquina, análisis inteligente de datos, gestión del conocimiento, agentes inteligentes, toma de decisiones inteligentes y apoyo, seguridad de la red inteligente, gestión de la confianza, entretenimiento interactivo, inteligencia de la Web y multimedia. Las publicaciones en el marco de «El rol de la inteligencia artificial y la computación distribuida en las aplicaciones IoT» son principalmente las actas de seminarios, simposios y conferencias. Abarcan importantes novedades recientes en la materia, tanto de naturaleza fundacional como aplicable. Un importante rasgo característico de la serie es el corto tiempo de publicación. Esto permite una rápida y amplia difusión de los resultados de las investigaciones[EN] The series «The Role of Artificial Intelligence and Distributed Computing in IoT Applications» contains publications on the theory and applications of distributed computing and artificial intelligence in the Internet of Things. Virtually all disciplines such as engineering, natural sciences, computer and information sciences, ICT, economics, business, e-commerce, environment, health and life sciences are covered. The list of topics covers all areas of modern intelligent systems and computer science: computational intelligence, soft computing including neural networks, social intelligence, ambient intelligence, self-organising and adaptive systems, human-centred and people-centred computing, recommendation systems, intelligent control, robotics and mechatronics including human-machine collaboration, knowledge-based paradigms, learning paradigms, machine ethics, intelligent data analysis, knowledge management, intelligent agents, intelligent decision making and support, intelligent network security, trust management, interactive entertainment, web intelligence, and multimedia. The publications in the framework of «The Role of Artificial Intelligence and Distributed Computing in IoT Applications» are mainly the proceedings of seminars, symposia and conferences. They cover important recent developments in the field, whether of a foundational or applicable character. An important feature of the series is the short publication time. This allows for the rapid and wide dissemination of research results

    Maxillary Sinus Lateral Wall Thickness and Morphologic Patterns in the Atrophic Posterior Maxilla

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141013/1/jper0676.pd

    Study of size effects on the peak and residual strength of intact and artificially fissured granite samples

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    There are not many studies on jointed rock specimens, which can be considered small scale rock mass analogs. On the other hand, the scale effects in the mechanical properties of such samples have seldom been studied. With the aim of continuing previous research on intact granite rocks, the authors have carried out sets of 25 stress-strain triaxial compressive tests on 1 sub-vertical and 2 sub-horizontal 38 mm, 54 mm and 84 mm diameter jointed granite specimens at various confinements. Peak and residual strength values were obtained and compared to those recovered form intact rock samples. Results suggest that peak strength follows similar trends with scale to those observed on intact rock, even if lower strength values are logically recorded. Regarding residual strength, the obtained results are in line with those observed trends for standard size samples, showing a similar trend for all cases independently of scale, even if we observe larger variability for jointed samples. The authors have also compared the values fitting the generalized Hoek-Brown criterion for rock masses to better understand the behavior in relation to sample size. So scale effects clearly appear on jointed rock peak strength of jointed sample; even if residual strength seems hardly affected by scale.Agencia Estatal de Investigación | Ref. RTI2018-093563-B-I0

    WEBSEIDF: A web-based system for the estimation of IDF curves in Central Chile

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    The lack of reliable continuous rainfall records can exacerbate the negative impact of extreme storm events. The inability to describe the continuous characteristics of rainfall from storm events increases the likelihood that the design of hydraulic structures will be inadequate. To mitigate extreme storm impacts and improve water governance at the catchment scale, it is vital to improve the availability of data and the array of tools used to model and forecast hydrological processes. In this paper, we describe and discuss the implementation of a web-based system for the estimation of intensity–duration–frequency (IDF) curves (WEBSEIDF) in Chile. The web platform was constructed using records from 47 pluviographic gauges available in central Chile (30–40° S), with at least 15 years of reliable records. IDF curves can be generated for durations ranging from 15 min to 24 h. In addition, the extrapolation of rainfall intensity from pluviograph to pluviometric gauges (i.e., 24-h rainfall accumulation) can be carried out using the storm index (SI) method. IDF curves can also be generated for any spatial location within central Chile using the ordinary Kriging method. These procedures allow the generation of numerical and graphical displays of IDF curves, for any selected spatial location, and for any combination of probability distribution function (PDF), parameter estimation method, and type of IDF model. One of the major advantages of WEBSEIDF is the flexibility of its database, which can be easily modified and saved to generate IDF curves under user-defined scenarios, that is, changing climate conditions. The implementation and validation of WEBSEIDF serves as a decision support system, providing an important tool for improving the ability of the Chilean government to mitigate the impact of extreme hydrologic events in central Chile. The system is freely available for students, researchers, and other relevant professionals, to improve technical decisions of public and private institutions

    Frequency of hereditary transthyretin amyloidosis among elderly patients with transthyretin cardiomyopathy

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    Transthyretin amyloid cardiomyopathy (ATTR-CM) is increasingly recognized as a cause of heart failure in the elderly. Although wild-type transthyretin amyloidosis is the most frequent form of ATTR-CM found in the elderly, hereditary transthyretin amyloidosis (ATTRv) can also occur. We sought to determine the prevalence of ATTRv among elderly ATTR-CM patients, identify predictors of ATTRv and evaluate the clinical consequences of positive genetic testing in this population. Prevalence of ATTRv in elderly ATTR-CM patients (≥70 years) was assessed in a cohort of 300 consecutive ATTR-CM patients (median age 78 years at diagnosis, 82% ≥70 years, 16% female, 99% Caucasian). ATTRv was diagnosed in 35 (12%; 95% confidence interval [CI] 3.1–8.8) and 13 (5.3%; 95% CI 5.6–26.7) patients in the overall cohort and in those ≥70 years, respectively. Prevalence of ATTRv among elderly female patients with ATTR-CM was 13% (95% CI 2.1–23.5). Univariate analysis identified female sex (odds ratio [OR] 3.66; 95% CI 1.13–11.85; p = 0.03), black ancestry (OR 46.31; 95% CI 3.52–Inf; p = 0.005), eye symptoms (OR 6.64; 95% CI 1.20–36.73; p = 0.03) and polyneuropathy (OR 10.05; 95% CI 3.09–32.64; p<0.001) as the only factors associated with ATTRv in this population. Diagnosis of ATTRv in elderly ATTR-CM patients allowed initiation of transthyretin-specific drug treatment in 5 individuals, genetic screening in 33 relatives from 13 families, and identification of 9 ATTRv asymptomatic carriers. Hereditary transthyretin amyloidosis is present in a substantial number of ATTR-CM patients aged ≥70 years. Identification of ATTRv in elderly patients with ATTR-CM has clinical meaningful therapeutic and diagnostic implications. These results support routine genetic testing in patients with ATTR-CM regardless of ageThis study has been funded by Instituto de Salud Carlos III (ISCIII) through the projects ‘PI18/0765 & PI20/01379’ (co-funded by European Regional Development Fund/European Social Fund ‘A way to make Europe’/‘Investing in your future’). AMB receives grant support by ISCIII (CM20/002209). The CNIC is supported by the ISCIII, MCIN, the Pro-CNIC Foundation, and the Severo Ochoa grant (CEX2020-001041-S

    Determinación de los componentes entrópicos de la accidentalidad: el trinomio vehículo/usuario/camino en la metrópoli de Guadalajara, México

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    Context: The recent increase in accidents, mishaps or road accidents in urban systems with metropolitan characteristics has caused concern in the authorities responsible for planning the issue of mobility and transport subsystems. Indeed, there is convergence that the occurrence of this type of events is away from purely stochastic factors, but are the result of anomalies associated with the intrasystemic interaction of the vehicle, the user and the road. In this sense, the objective of this work is to determine through systemic analysis the components that are causing entropy in the second most important metropolis in Mexico.Method: In this analysis the precepts of systems theory are used; in such a way that through the tringulation of data obtained in situ and solved documentarily the causal components of intrasystemic entropy are determined. To do this, a modified derivation of the Pressure-State-Response model that identifies homeostasis in the urban system is elaborated.Results: The high exposure rates force the user to occupy the road subsystem for long periods of time, which triggers voluntary and involuntary human errors complemented by the lax requirements for obtaining driving licenses. From here, the components that produce accidents include in the road part the pavements in poor condition, absence of signaling, poor design of intersections, among others; in the vehicle part, mechanical failures due to the useful life of the internal components, flexible regulatory frameworks, and other; in the part of the user for breach of the regulations, physiological factors among others.Conclusions: From the systemic analysis, mobility is a subject of valuable study to detect the imbalances in the trinomial Vehicle-User-Road (V-C-U), which lead us to generate preventive and corrective measures that suppress metropolitan accidents, morbidity and mortality in the metropolis; or in our terms to reduce entropy levels in the system.Contexto: El reciente incremento de accidentes, percances o siniestros viales en los sistemas urbanos con características metropolitanas ha originado preocupación en las autoridades encargadas de planificar la movilidad y los subsistemas de transporte. Efectivamente, se tiene convergencia que la ocurrencia de este tipo de eventos se aleja de factores puramente estocásticos, sino son resultado de anomalías asociadas con la interacción intrasistémica del vehículo, el usuario y el camino. En este sentido, el objetivo de este trabajo consiste en determinar por medio del análisis sistémico los componentes que están provocando entropía en la segunda metrópoli más importante de México.Método: En este análisis se utilizan los preceptos de la teoría de los sistemas; de tal forma que a través de la triangulación de datos obtenidos in situ y solventados documentalmente se determinan los componentes causales de entropía intrasistémica. Para ello, se elabora una derivación modificada del modelo presión/estado/respuesta que identifica la homeostasia en la que se encuentra el sistema urbano.Resultados: Las altas tasas de exposición obliga al usuario a ocupar el subsistema vial por largos periodos de tiempo, lo cual detona en errores humanos voluntarios e involuntarios complementados con los requisitos laxos para la obtención de permisos de conducción. De aquí, los componentes que producen accidentes engloban en la parte camino a los pavimentos en mal estado, ausencia de señalización, diseño deficiente de intersecciones, entre otras; en la parte del vehículo, fallas mecánicas por vida útil de los componentes internos, marcos normativos flexibles, etc.; en la parte del usuario por incumplimiento de la normatividad, factores fisiológicos entre otros.Conclusiones: Desde el análisis sistémico la movilidad es una temática de estudio valiosa para detectar los desequilibrios en el trinomio vehículo/usuario/camino (V-U-C), que nos lleven a generar medidas preventivas y correctivas que supriman la accidentalidad, la morbilidad y la mortalidad en la metrópolis; o en otros términos para reducir los niveles de entropía en el sistema
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