This master’s thesis delves into the possibilities of the open-source Private Branch Exchange Asterisk, elaborates on its features and compares it with several other distros. The term SIP stack is explained here with the mention of two of its representatives. Further in the thesis, the security risks of the VoIP technology are explained, and specific attacks are described and then realized. As a part of the testing process, the possibilities of a custom module and its following implementation are explored, as well as the portability between the individual distros and its proper functioning.

The rapid development of technology and the digitalization of learning in today’s societyopens up for challenges and possibilities for the workplace related to creating a learning community.To create a social learning community that highlights open communication and group coherency,which is central when it comes to achieving good results connected to learning. However there aresome doubts if it is possible to create a social presence in network based learning without any physicalmeetings. The purpose of this study was to investigate how interactions, design and course layout onan online course linked to workplaces can affect collaborative learning according to participants. Thefocus has been in searching for patterns with a focus on collaborative learning amongst theparticipants. The study takes a qualitative and quantitative approach, namely mixed methods. Whathas guided the choice of mixed methods lies in the methods that are needed to answer the researchquestions. Through existing material for analysis, literatur and planned interviews. These methodshave been used to generate new knowledge, expand existing knowledge and give new hypothesis forfuture research. The analysis showed that collaborative learning did not reach wanted levels. Theresult also showed that the teachers' different experiences with traditional classroom learning hasbeen a big factor on how they contributed with E-learning towards the participants. The use oftechnical tools has not been easy for some teachers, the analysis of the result showed this to be a keyfactor in the result because teacher presence is important for E-learning. There were also manyindependent variables that have been identified in conjunction with key factors for success inE-learning. / Den snabba teknikutvecklingen och digitalisering av lärandet innebär idag nya utmaningarsamt möjligheter för arbetsplatser vad gäller att skapa en lärgemenskap. Att skapa en stödjande socialgemenskap uppmanar till öppen kommunikation och sammanhållning, vilket är centralt för att uppnåbra resultat när det gäller lärande. Det råder viss tveksamhet till om det går att skapa social närvaro iE-lärande utan fysiska träffar. Syftet med denna studie har varit att undersöka hur interaktioner,design och kursupplägg på en onlinekurs länkad till arbetsplatser kan påverka lärandet hosdeltagarna. Fokus har legat på att söka mönster i det materialet med fokus på det kollaborativalärandet bland deltagarna. Studien tar en kvalitativ och kvantitativ ansats, mixad metod. Det som harvarit styrande av detta val ligger i metoderna som behövts för att besvara studiens forskningsfrågor.Detta genom befintlig föremål för analys, litteraturanalys och planerade intervjuer, två övervideokonferens och en genom mail. Dessa metoder har använts till att generera ny kunskap, ökabefintlig kunskap samt ge hypoteser att undersöka vidare. Analysen visade att det kollaborativalärandet inte har nått upp till önskade nivåer. Resultatet visar att lärarnas olika erfarenheter av vanligklassrumsundervisning har påverkat hur de bidragit till E-lärande bland deltagarna. Användandet avtekniken har inte varit lätt för vissa lärare, som i sin tur påverkat hur deltagarna upplever lärarensnärvaro i kursrummet vilket är en nyckelfaktor för E-lärande. Det finns många förändringspunktersom identifierats för att lyckas bättre med E-lärande och därmed har intressanta nyckelfaktorer ocksåframkommit. / <p>Betygsdatum 2021-07-01</p>

This thesis deals with usage of bypass diodes in photovoltaic panels. Familiarize us with principles of photovoltaic modules and functions, their electrical characteristics and features. The central objective of this work is description of influence of bypass diodes on particularly shading photovoltaic panels and its volt-ampere characteristics. By the help of created software in Agilent VEE 8.0 simulate the shading panel and compare with real measurement.

Soit X une courbe projective lisse et irréductible munie d'une involution σ. Dans cette thèse, nous étudions les fibrés vectoriels invariants and anti-invariants sur X sous l'action induite par σ. On introduit la notion de modules σ-quadratiques et on l'utilise, avec GIT, pour construire ces espaces de modules, puis on en étudie certaines propriétés. Ces espaces de modules correspondent aux espaces de modules de G-torseurs parahoriques sur la courbe X/σ , pour certains schémas en groupes parahoriques G de type Bruhat-Tits, qui sont twistés dans le cas des anti-invariants. Nous développons les systèmes de Hitchin sur ces espaces de modules et on les utilise pour dériver une classification de leurs composantes connexes en les dominant par des variétés de Prym. On étudie aussi le fibré déterminant sur les espaces de modules des fibrés vectoriels anti-invariants. Dans certains cas, ce fibré en droites admet certaines racines carrées appelées fibrés Pfaffiens. On montre que les espaces des sections globales des puissances de ces fibrés en droites (les espaces des fonctions thêta généralisées) peuvent être canoniquement identifier avec les blocs conformes associés aux algèbres de Kac-Moody affines twistées de type A(2). / Let X be a smooth irreducible projective curve with an involution σ. In this dissertation, we studythe moduli spaces of invariant and anti-invariant vector bundles over X under the induced action of σ. We introduce the notion of σ-quadratic modules and use it, with GIT, to construct these moduli spaces, and than we study some of their main properties. It turn out that these moduli spaces correspond to moduli spaces of parahoric G-torsors on the quotient curve X/σ, for some parahoric Bruhat-Tits group schemes G, which are twisted in the anti-invariant case.We study the Hitchin system over these moduli spaces and use it to derive a classification of theirconnected components using dominant maps from Prym varieties. We also study the determinant of cohomology line bundle on the moduli spaces of anti-invariant vector bundles. In some cases this line bundle admits some square roots called Pfaffian of cohomology line bundles. We prove that the spaces of global sections of the powers of these line bundles (spaces of generalized theta functions) can be canonically identified with the conformal blocks for some twisted affine Kac-Moody Lie algebras of type A(2).

Let R be a domain, V a left R-module, and L a composition series of direct summands of V. Our main results show that if U is a stabilizer group of L containing the McLain-group associated with L , then U determines the chain (L,⊆) uniquely up to isomorphism or anti-isomorphism.

No description available.

During papermaking, the internal structure of the fibrenetwork constituting the paper is to a dominating extentdetermined in the forming zone of the paper machine. Thisthesis is aimed at studying the pressure distribution in bladeforming sections, which is commonly considered to be a keyquantity of the process. Previous work has provided insight into the physics ofdifferent devices employed in blade forming. However, there hasbeen a lack of models enabling studies of the effects of theinteraction between different components on the pressuredistribution. In the thesis, a model is presented for a genericblade forming section consisting of three blades. The positionsof two of the blades are fix, and in between them is located asuction box. The third blade is applied by a prescribed forceto the opposing wire, in a position facing the suction box. Themodel admits the study of the interaction between the pulsesfrom the different blades in the blade/counterbladeconfiguration, and between the pulses and one-sidedsuction. The wires are modelled as tensioned and perfectly flexibleEuler-Bernoulli beams of negligible mass. The suspension istreated like an inviscid fluid. Consideration is taken to theinfluence of fibre deposition on the permeability of thefabrics. By assuming the ratio between the length scales in thethickness direction and the machine direction to be small, aquasi one-dimensional model is obtained. For maximum flexibility, the model domain is divided intomodules. Each module is solved individually using a finitedifference based discretisation. The solutions for thedifferent modules are matched with each other iteratively. A comparison with published results for a single bladeindicates that the model can be used to obtain qualitativelycorrect predictions of the pressure distribution. New resultsinclude a series of calculations showing the non-trivialinteraction between the pressure pulses when the blades arepositioned successively closer together, the effects of suctionon the pressure pulse generated by a blade applied to theopposing wire, and how blades of modest curvature do notnecessarily stay in contact with the fabric along their fullwidth and the implication of this on the pressure gradient. <b>Descriptors:</b>fluid mechanics, blade forming, pressuredistribution, suction, interaction, permeable fabric,modules / NR 20140805

No description available.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Este documento surge por la aparición de una vivienda social inadecuada en Ica, por no responder al estilo de vida del usuario y por no entender su desarrollo económico en el tiempo. El estado a través de la empresa privada busca solucionar la demanda existente de vivienda presentando una estandarización de módulos de vivienda para agilizar su construcción, y llegar a las metas establecidas. Se entregan módulos básicos construidos con la opción de expandirlos a través del tiempo, sin embargo, los módulos entregados no suelen entender el contexto inmediato donde se emplazan y tampoco comprenden el estilo de vida de las familias causando una inversión adicional a pesar de poder expandirlos en el tiempo, porque los residentes al expandirlos, tratan de moldear estos módulos con su identidad probando soluciones informales y a veces arriesgadas, demostrando el desinterés del estado y la empresa privada por la realidad del usuario y su desarrollo económico. Esta investigación se hizo para demostrar la importancia de entender al ser humano, para comprender su realidad, y para precisar que el arquitecto tiene un rol social importante en mejorar la vida de las personas. / This document arises from the appearance of inadequate social housing in Ica, for not responding to the user's lifestyle and for not understanding their economic development over time. The state, through private companies, seeks to solve the existing demand for housing by presenting a standardization of housing modules to speed up their construction and reach the established goals. Basic modules built with the option of expanding them over time are delivered, however, the modules delivered do not usually understand the immediate context where they are located nor do they understand the lifestyle of families causing an additional investment despite being able to expand them in over time, because residents, by expanding them, try to mold these modules with their identity, testing informal and sometimes risky solutions, demonstrating the disinterest of the state and private companies for the reality of the user and their economic development. This research was done to demonstrate the importance of understanding the human being, to understand his reality, and to specify that the architect has an important social role in improving people's lives. / Tesis