A Wireless Mesh Network NS-3 Simulation Model: Implementation and Performance Comparison With a Real Test-Bed

Wireless mesh networks present an attractive communication solution for various research and industrial projects. However, in many cases, the appropriate preliminary calculations which allow predicting the network behavior have to be made before the actual deployment. For such purposes, network simulation environments emulating the real network operation are often used. Within this paper, a behavior comparison of real wireless mesh network (based on 802.11s amendment) and the simulated one has been performed. The main objective of this work is to measure performance parameters of a real 802.11s wireless mesh network (average UDP throughput and average one-way delay) and compare the derived results with characteristics of a simulated wireless mesh network created with the NS-3 network simulation tool. Then, the results from both networks are compared and the corresponding conclusion is made. The corresponding results were derived from simulation model and real-worldtest-bed, showing that the behavior of both networks is similar. It confirms that the NS-3 simulation model is accurate and can be used in further research studies.

Additions to our knowledge of the American and Hawaiian floras, by Earl Edward Sherff.

v.22:no.7(1941)

Factory Acceptance Test des Prozessleitsystems PCS 7 und Anlagenfeld Simulation mit WinMOD

Das Prozessleitsystem PCS 7 beinhaltet softwaretechnische Lösungen für alle Hierarchieebenen der industriellen Automatisierung von der Unternehmensleitebene bis zur Anlagenfeldebene. Mit der Simulationssoftware WinMOD können Komponenten,Signale und Prozesse einer Industrieanlage nachgebildet werden. Zudem bietet WinMOD Schnittstellenlösungen für gängige Speicherprogrammierbare Steuerungen und eignet sich somit für den Factory Acceptance Test (FAT) von Prozessleitsystemen. Die FATs sollen sich hauptsächlich auf die Überprüfung von Signaladressierungen und von Ursache und Wirkung konzentrieren. Im Rahmen der vorliegenden Arbeit wurden ausgewählte PCS 7–Projekte untersucht und auf deren Grundlage Aussagen getroffen wie zukünftig Simulationen effektiv erstellt werden können. Hierzu wurden mithilfe von WinMOD Simulationsmodule angelegt - welche reale Komponenten des Anlagenfeldes ersetzen – , ihr Aufbau beschrieben und in einer Bibliothek zusammengefasst. Im Anschluss wird auf die Verwendung der Bibliothek für verschiedene Anwendungsfälle eingegangen und eine Lösung präsentiert, welche das Erstellen einer Simulation für spezifische Projekte optimiert. Das Ergebnis zeigt auf, dass WinMOD sowohl neue Möglichkeiten der Durchführung für einen FAT liefert, wobei die Simulationserstellung nur einen geringen Mehraufwand bedeutet und sich die Durchführung der Simulation ergonomischer und kürzer gestaltet.

Studies on the neotropical species of Stenus described by Bernhauer (Coleoptera, Staphylinidae) : seventy-eighth contribution to the knowledge of Steninae / Volker Puthz.

v.65:no.5(1974)

Galictis cuja (Mammalia): an update of current knowledge and geographic distribution

The lesser grison (Galictis cuja) is one of the least-known mustelids in the Neotropics, despite its broad range across South America. This study aimed to explore current knowledge of the distribution of the species to identify gaps in knowledge and anticipate its full geographic distribution. Eighty-nine articles have mentioned G. cuja since 1969, but only 13 focused on the species. We generated a detailed model of the species' potential distribution that validated previous maps, but with improved detail, supporting previous southernmost records, and providing a means of identifying priority sites for conservation and management of the species.

Eliciting and fostering learners' metacognitive knowledge about language learning in self-directed learning programs: a review of data collection methods and procedures

Són molts els estudis que avui en dia incideixen en la necessitat d’oferir un suport metodològic i psicològic als aprenents que treballen de manera autònoma. L’objectiu d’aquest suport és ajudar-los a desenvolupar les destreses que necessiten per dirigir el seu aprenentatge així com una actitud positiva i una major conscienciació envers aquest aprenentatge. En definitiva, aquests dos tipus de preparació es consideren essencials per ajudar els aprenents a esdevenir més autònoms i més eficients en el seu propi aprenentatge. Malgrat això, si bé és freqüent trobar estudis que exemplifiquen aplicacions del suport metodològic dins els seus programes, principalment en la formació d’estratègies o ajudant els aprenents a desenvolupar un pla de treball, aquest no és el cas quan es tracta de la seva preparació psicològica. Amb rares excepcions, trobem estudis que documentin com s’incideix en les actituds i en les creences dels aprenents, també coneguts com a coneixement metacognitiu (CM), en programes que fomenten l’autonomia en l’aprenentatge. Els objectius d’aquest treball son dos: a) oferir una revisió d’estudis que han utilitzat diferents mitjans per incidir en el CM dels aprenents i b) descriure les febleses i avantatges dels procediments i instruments que utilitzen, tal com han estat valorats en estudis de recerca, ja que ens permetrà establir criteris objectius sobre com i quan utilitzar-los en programes que fomentin l’aprenentatge autodirigit.

A topological proof that surface relators are test words

Vegeu el resum a l'inici del document del fitxer adjunt.

Creating and using a non-dedicated HPC cluster with ParallelKnoppix

This note describes ParallelKnoppix, a bootable CD that allows econometricians with average knowledge of computers to create and begin using a high performance computing cluster for parallel computing in very little time. The computers used may be heterogeneous machines, and clusters of up to 200 nodes are supported. When the cluster is shut down, all machines are in their original state, so their temporary use in the cluster does not interfere with their normal uses. An example shows how a Monte Carlo study of a bootstrap test procedure may be done in parallel. Using a cluster of 20 nodes, the example runs approximately 20 times faster than it does on a single computer.

Human capital in a global and knowledge-based economy. Part 2. Asssessment at the EU country level.

This report is an extension and partial update of de la Fuente and Ciccone (2002). It constructs estimates of the private and social rates of return on schooling for fourteen EU countries using microeconometric estimates of Mincerian wage equations, the results of cross-country growth regressions and OECD data on educational expenditures, tax rates and social benefits. The results are used to draw some tentative conclusions regarding the optimality of observed investment patterns and educational subsidy levels.

Human capital in a global and knowledge-based economy

This document is a report prepared for the DG for Employment and Social Affairs of the European Commission. It surveys the available evidence on the contribution of investment in human capital to aggregate productivity growth and on its impact on wages and other labour outcomes at the individual level. It also draws some tentative policy conclusions for an average European country.

A contribution to the knowledge of the Brazilian Strepsiptera: (Insecta)

Neste trabalho procuramos atualizar e acrescentar observações novas ao conhecimento dos Strepsiptera do Brasil. Descrevemos 4 espécies novas da família Myrmecolacidae, representados apenas por machos e uma espécie nova da família Halictophagidae, representada por macho, fêmea e hospedador. Registramos a ocorrência, no Brasil, de uma espécie da família Stylopidae, conhecida anteriormente da Argentina e fornecemos dados adicionais sôbre uma espécie da família Mengeidae, Triozocera paulistana Kogan, 1958. Baseados em HOFENEDER & FULMEK (1942-43) damos a lista dos hospedadores encontrados estilopizados no Brasil.