Distributed synchronization algorithms for wireless sensor networks

The ability to distribute time and frequency among a large population of interacting agents is of interest for diverse disciplines, inasmuch as it enables to carry out complex cooperative tasks. In a wireless sensor network (WSN), time/frequency synchronization allows the implementation of distributed signal processing and coding techniques, and the realization of coordinated access to the shared wireless medium. Large multi-hop WSN\u27s constitute a new regime for network synchronization, as they call for the development of scalable, fully distributed synchronization algorithms. While most of previous research focused on synchronization at the application layer, this thesis considers synchronization at the lowest layers of the communication protocol stack of a WSN, namely the physical and the medium access control (MAC) layer. At the physical layer, the focus is on the compensation of carrier frequency offsets (CFO), while time synchronization is studied for application at the MAC layer. In both cases, the problem of realizing network-wide synchronization is approached by employing distributed clock control algorithms based on the classical concept of coupled phase and frequency locked loops (PLL and FLL). The analysis takes into account communication, signaling and energy consumption constraints arising in the novel context of multi-hop WSN\u27s. In particular, the robustness of the algorithms is checked against packet collision events, infrequent sync updates, and errors introduced by different noise sources, such as transmission delays and clock frequency instabilities. By observing that WSN\u27s allow for greater flexibility in the design of the synchronization network architecture, this work examines also the relative merits of both peer-to-peer (mutually coupled - MC) and hierarchical (master-slave - MS) architectures. With both MC and MS architectures, synchronization accuracy degrades smoothly with the network size, provided that loop parameters are conveniently chosen. In particular, MS topologies guarantee faster synchronization, but they are hindered by higher noise accumulation, while MC topologies allow for an almost uniform error distribution at the price of much slower convergence. For all the considered cases, synchronization algorithms based on adaptive PLL and FLL designs are shown to provide robust and scalable network-wide time and frequency distribution in a WSN

“Follow Me So I Can DM You Back”: An Exploratory Analysis of a Female Pro- ISIS Twitter Network

The purpose of this study is to explore a network of female pro-Islamic State of Syria and Iraq (ISIS) supporters on Twitter. To do so, I identified twenty Twitter accounts (n=20) through snowball sampling, and analyzed their network comprising 5,861 vertices and 12,034 edges. I studied the network using three social network analysis metrics—Freeman’s normalized betweenness centrality, average geodesic distance, and tie strength. Females in the sample were more influential than males, and as a result, had a greater ability to radicalize other females within their network. Further, I observed that it took females longer than expected to send information within the network, according to the Three Degrees of Influence Theory. Finally, I found that most ties within the network were not reciprocated. In line with the Strength of Weak Ties Theory, Pro-ISIS females have a unique ability to radicalize others to support pro-jihadist terrorism on Twitter. I conclude that despite the long average geodesic distance, certain pro-ISIS females can successfully encourage other women to radicalize. Public safety officials, Twitter, and other researchers must respond to this phenomenon accordingly

La Gestión de la Educación Superior Universitaria como Derecho Humano y Bien Público Social

Se presentan los instrumentos y mecanismos institucionales que deberían ser creados o mejorados para revertir preservando la calidad - la excesiva disparidad entre los indicadores de entrada y salida a las carreras de grado de la Facultad Regional Delta de la Universidad Tecnológica Nacional, y por extensión a las Facultades de Ingeniería de América del Sur Se analizan los objetivos e impactos de las acciones de gestión académica propuestas para los factores incidentes en la permanencia de alumnos que se definen y caracterizan con un claro sentido de origen en el seno de un grupo de investigación de una institución definida, pero también con una intención de buscar elementos comunes para pensar los problemas de deserción y desgranamiento, de gran importancia estratégica en nuestra región. Año tras año se registra un crecimiento de la matrícula, pero también se observa que no aumenta proporcionalmente la tasa de graduación. La universidad masiva plantea desafíos complejos que van a exigir la aplicación de instrumentos sofisticados para lograr obtener información relevante que permita formular los diagnósticos certeros y las herramientas adecuadas que mejoren las tasas de permanencia y graduación desde una perspectiva inclusiva

Treatment of Advanced Parkinson's Disease

Patients at late stage Parkinson's disease (PD) develop several motor and nonmotor complications, which dramatically impair their quality of life. These complications include motor fluctuations, dyskinesia, unpredictable or absent response to medications, falls, dysautonomia, dementia, hallucinations, sleep disorders, depression, and psychosis. The therapeutic management should be driven by the attempt to create a balance between benefit and side effects of the pharmacological treatments available. Supportive care, including physical and rehabilitative interventions, speech therapy, occupational therapy, and nursing care, has a key role in the late stage of disease. In this review we discuss the several complications experienced by advance PD patients and their management. The importance of an integrative approach, including both pharmacological and supportive interventions, is emphasized

LA GESTION DEL CONOCIMIENTO Y EL ACCESO A LAS CARRERAS DE GRADO EN LA FACULTAD REGIONAL DELTA DE LA UNIVERSIDAD TECNOLOGICA NACIONAL.

Este trabajo es la síntesis de un proyecto de investigación realizado el la Facultad Regional Delta de la Universidad Tecnológica Nacional entre el año 2003 y 2005. La complejidad que presenta en la actualidad a nivel de las instituciones educativas de nivel superior universitario en la argentina, las realidades emergentes de los procesos de acceso y permanencia en la vida académica universitaria, se traduce desde múltiples perspectivas, que se abordan específicamente desde las tendencias actuales de la investigación educativa, aplicada en forma específica a una coyuntura propia de la Facultad Regional Delta, pero de la cual pueden extraerse características y tendencias que adaptadas a otras realidades, propongan tentativas de solución a una cuestión de centralidad en las instituciones universitarias

Irrelevant Features of a Stimulus Can Either Facilitate or Disrupt Performance in a Working Memory Task: The Role of Fluid Intelligence

It has been shown that fluid intelligence (gf) is fundamental to overcome interference due to information of a previously encoded item along a task-relevant domain. However, the biasing effect of task-irrelevant dimensions is still unclear as well as its relation with gf. The present study aimed at clarifying these issues. Gf was assessed in 60 healthy subjects. In a different session, the same subjects performed two versions (letter-detection and spatial) of a three-back working memory task with a set of physically identical stimuli (letters) presented at different locations on the screen. In the letter-detection task, volunteers were asked to match stimuli on the basis of their identity whereas, in the spatial task, they were required to match items on their locations. Cross-domain bias was manipulated by pseudorandomly inserting a match between the current and the three back items on the irrelevant domain. Our findings showed that a task-irrelevant feature of a salient stimulus can actually bias the ongoing performance. We revealed that, at trials in which the current and the three-back items matched on the irrelevant domain, group accuracy was lower (interference). On the other hand, at trials in which the two items matched on both the relevant and irrelevant domains, the group showed an enhancement of the performance (facilitation). Furthermore, we demonstrated that individual differences in fluid intelligence covaries with the ability to override cross-domain interference in that higher gf subjects showed better performance at interference trials than low gf subjects. Altogether, our findings suggest that stimulus features irrelevant to the task can affect cognitive performance along the relevant domain and that gf plays an important role in protecting relevant memory contents from the hampering effect of such a bias

Impacto del vuelco de efluentes industriales y cloacales en la calidad de las aguas del río Paraná de las Palmas

Es internacionalmente reconocido el valor estratégico de un recurso hídrico para asegurar la calidad de vida de la población y la biodiversidad de ecosistemas. En la subcuenca del Paraná el desarrollo antrópico es intenso y sus consecuencias ambientales son desconocidas a largo plazo, lo que destaca la necesidad de su estudio para identificar parámetros de mayor impacto y proponer un programa que permita soluciones. Se realizó el relevamiento y evaluación de información de industrias ubicadas en la margen del río Paraná De Las Palmas que vierten sus efluentes en el mismo y de vuelcos de efluentes cloacales. Se concluyó que los valores obtenidos para descargas industriales y cloacales resultaron admisibles desde el punto de vista de la calidad de las aguas del río, determinándose dos zonas de máximo impacto. Con la información obtenida se aplicarán modelos matemáticos de dispersión de contaminantes para lograr una mayor comprensión de la dinámica de contaminantes en la zona.The strategic value of a water resource is internationally recognized to ensure the people´s quality of life and the biodiversity of ecosystems. In the basin of Paraná the anthropic development is intense and its long-term environmental consequences are unknown, which emphasizes the need to study in order to identify major impact parameters and propose a solution program. A survey was conducted and the information obtained from industries located on the banks of Paraná De Las Palmas River’s that discharge into it and sewage dumps was evaluated. It was concluded that the values obtained from industrial discharges and sewage were acceptable from the quality of the river point of view, and two areas of maximum impact were determined. With the information obtained we will apply mathematical models of pollutant dispersion for a better understanding of the pollutants dynamics of in the area.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

LE MAPPE CONCETTUALI COME STRATEGIA PER ORIENTARE LA LETTURA DEI DOCUMENTI IPERTESTUALI

Il tentativo di ripercorrere con la lettura dell'ipertesto il tragitto della letturatradizionale può sortire un esito infelice. L'ipertesto ha un'identità propria ancoranon ben definita che rende più complessa l'attività di lettura e l'estrazione delleinformazioni rilevanti per l'utente; i lettori di ipertesti trovano una diversità dipercorsi possibili e una grandissima quantità di informazioni, da filtrare eorganizzare per essere capite e utilizzate. Poiché priva di sequenzialità automatica,l'idea ipertestuale deve essere trasformata in una struttura con senso compiuto perl'utente. In questa ricerca si presenta l'uso delle mappe concettuali [nel corsodell'articolo MC] come 'grapho' che facilita la lettura ipertestuale. Si delineal'utilizzo delle MC come strategia costruttivista per lo sviluppo della lettura,manifestandone vantaggi e svantaggi; si illustra altresì la sequenza operativa per lacreazione di MC. Infine, si offrono suggerimenti per la valutazione sia delle MC chedelle mappe mentali

Implementación de un sistema de gestión de residuos en unidades educativas

Se ha considerado una revisión ambiental inicial a los distintos sectores del establecimiento identificando los aspectos ambientales asociados a la generación de residuos no especiales valorando y jerarquizando los mismos para determinar si son o no significativos. Para mitigar el impacto ambiental generado por los aspectos significativos del papel, cartón, plásticos y ordinarios no reciclables se plantearon objetivos, metas y programas de acción. Para lograr la mejora continua del sistema se estableció un convenio con una cooperativa de reciclado de la ciudad de Campana, quien retira los residuos clasificados dos veces en la semana, mientras que la capacitación, sensibilización y formación ambiental en forma continua a toda la comunidad universitaria, contribuye al cumplimiento de los objetivos no alcanzados del programa de reducción de los residuos generados. Por otra parte se ha elaborado un Manual de Gestión de residuos el cual ha sido transferido a otras unidades educativas.It has been considered a revision environmental initial to the different sectors of the establishment identifying the environmental aspects associated to the generation of non special residues valuing and arranging hierarchically the same ones to determine if they are or not significant. To mitigate the environmental impact generated by the significant aspects of paper, cardboard, plastics and ordinary they thought about objectives, goals and action programs. To achieve the continuous improvement of system an agreement settled down with a cooperative of Campana city who retires the residues classified twice in the week, while the training, sensitization and environmental formation in continuous form to the whole university community, contribute to the execution of not reached objectives of reduction program. On the other hand a Residues Management Manual has been elaborated which has been transferred to other educational units.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES