Magister Scientiae - MSc / SIP is receiving much attention these days and it seems to be the most promising candidate as a signaling protocol for the current and future IP telephony services. Realizing this, there is the obvious need to provide a certain level of quality comparable to the traditional telephone service signalling system. Thus, we identified the major costs of SIP, which were found to be delay and security. This thesis discusses the costs of SIP, the solutions for the major costs, and the development of a low cost SIP application. The literature review of the components used to develop such a service is discussed, the networks in which the SIP is used are outlined, and some SIP applications and services previously designed are discussed. A simulation environment is then designed and implemented for the instant messaging service for wireless devices. This environment simulates the average delay in LAN and WLAN in different scenarios, to analyze in which scenario the system has the lowest costs and delay constraints. / South Africa

Radioactive decay of nuclei via emission of ??-particles is studied using three different theoretical approaches, viz: the quasi-bound state wavefunction approach (QSWA), the superasymmetric ??ssion model (SAFM) and the semiclassical approximation (QCA). The half-lives of the radioactive nuclei, calculated using these methods, are compared with each other and with available experimental data. The resonance wavefunction is obtained by numerically integrating the Schrödinger equation with outgoing boundary conditions. The sensitivity of the calculated decay widths to two particular parameter sets of the Woods-Saxon (WS) optical potentials are studied. Double folding (DF) model calculations to obtain the bare ??-nucleus potential have been carried out with the Reid M3Y effective nucleon-nucleon (NN) interactions. The exchange part of the interaction was taken to be of zero-range pseudo-potential and the density dependence of the NN interaction is accounted for. The effectiveness of the method is demonstrated using both even-even and odd-mass spherical nuclei. / Physics / MSC (PHYSICS)

abstract: Emerging information and communication technology (ICT) has had an enormous effect on the building architecture, engineering, construction and operation (AECO) fields in recent decades. The effects have resonated in several disciplines, such as project information flow, design representation and communication, and Building Information Modeling (BIM) approaches. However, these effects can potentially impact communication and coordination of the virtual design contents in both design and construction phases. Therefore, and with the great potential for emerging technologies in construction projects, it is essential to understand how these technologies influence virtual design information within the organizations as well as individuals’ behaviors. This research focusses on understanding current emerging technologies and its impacts on projects virtual design information and communication among projects stakeholders within the AECO organizations. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2017

abstract: A Virtual Private Network (VPN) is the traditional approach for an end-to-end secure connection between two endpoints. Most existing VPN solutions are intended for wired networks with reliable connections. In a mobile environment, network connections are less reliable and devices experience intermittent network disconnections due to either switching from one network to another or experiencing a gap in coverage during roaming. These disruptive events affects traditional VPN performance, resulting in possible termination of applications, data loss, and reduced productivity. Mobile VPNs bridge the gap between what users and applications expect from a wired network and the realities of mobile computing. In this dissertation, MobiVPN, which was built by modifying the widely-used OpenVPN so that the requirements of a mobile VPN were met, was designed and developed. The aim in MobiVPN was for it to be a reliable and efficient VPN for mobile environments. In order to achieve these objectives, MobiVPN introduces the following features: 1) Fast and lightweight VPN session resumption, where MobiVPN is able decrease the time it takes to resume a VPN tunnel after a mobility event by an average of 97.19\% compared to that of OpenVPN. 2) Persistence of TCP sessions of the tunneled applications allowing them to survive VPN tunnel disruptions due to a gap in network coverage no matter how long the coverage gap is. MobiVPN also has mechanisms to suspend and resume TCP flows during and after a network disconnection with a packet buffering option to maintain the TCP sending rate. MobiVPN was able to provide fast resumption of TCP flows after reconnection with improved TCP performance when multiple disconnections occur with an average of 30.08\% increase in throughput in the experiments where buffering was used, and an average of 20.93\% of increased throughput for flows that were not buffered. 3) A fine-grained, flow-based adaptive compression which allows MobiVPN to treat each tunneled flow independently so that compression can be turned on for compressible flows, and turned off for incompressible ones. The experiments showed that the flow-based adaptive compression outperformed OpenVPN's compression options in terms of effective throughput, data reduction, and lesser compression operations. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2017

Made available in DSpace on 2014-06-11T19:24:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-04-22Bitstream added on 2014-06-13T18:21:18Z : No. of bitstreams: 1 martinho_lr_me_bauru.pdf: 1985844 bytes, checksum: 8bab86fe89c638bf650a18d6be367497 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho investigou-se as representações sociais sobre meio ambiente de um total de 42 alunos de 4ªs séries do Ensino Fundamental, provenientes de duas Escolas Públicas localizadas nas zonas Rural e Urbana, de um município do interior paulista. A metodologia utilizada foi a de pesquisa social, com abordagem qualitativa, embora alguns dados quantitativos também sejam apresentados de forma complementar. A coleta de dados foi realizada através de pesquisas bibliográfica e suplementar de dados e de pesquisa de campo. Nesta última, visando à verificação e à validação da pesquisa, foram utilizadas diferentes formas de abordagem investigativa, tais como: observações, rodas de conversa, entrevistas individuais, desenhos e questionários. A análise de conteúdo dos dados obtidos revelou que as possíveis origens para aquelas representações, categorizadas em naturalistas e antropocêntricas, estão associadas, principalmente, às influências da mídia, da família e da religião. Buscou-se, através da análise dos resultados e das discussões, contribuir com sugestões que possam promover, nos docentes daquelas escolas, reflexões sobre suas práticas educativas, visando à melhoria do ensino do tema considerado. Neste sentido, a expectativa é que esta pesquisa possa efetivamente representar uma contribuição para os profissionais interessados em trabalhar a partir dos saberes acumulados pela vivência de diferentes experiências que as crianças têm com o mundo e que trazem para a escola, desenvolvendo ações educativas ambientalmente comprometidas com a formação de indivíduos responsáveis pela criação e manutenção de melhores condições de vida e de desenvolvimento adequado, num contexto em que a prática pedagógica seja criativa, democrática e fundamentada no diálogo entre gerações e culturas e, tendo como perspectiva, estimular a ética nas relações entre os homens e entre estes e o meio ambiente / On this work it was searched into representations about environment in a total of 42 4th graded students of elementary school, proceeding from two public schools located in the rural and urban areas of a town in countryside of São Paulo State. The methodology used was a social research with the quality approach, although some quantitative data are also presented as a supplementary way. The data collection was carried out through bibliographical, data supplemental and field research. On the field research, aiming the examination and validation of the research, it was used different ways of investigation approach such as: observation, talk session circles, individual interviews, drawings and questionnaires. The analyses of data content achieved, showed that possible origins to those representations, rated in naturalist and anthropocentric, are associated, mainly to the media, family and religion influence. It was searched through the results and discussion analyses to contribute with suggestions that may promote in the teachers from those schools reflections about their teaching practice, aiming the teaching improvement on the considered theme. This way, the expectations are that this research may represent an effective contribution to the professional interested in working starting from the accumulated knowledge by the different life experiences that children have with the world and they bring to school, developing educative actions environmentally engaged with the individual formation responsible for the creation and maintenance for better life conditions and suitable development, in a context on which the pedagogical practice is creative, democratic and based on the dialogue between generations and cultures and, having as perspective, stimulate the ethical in the relationships among the mankind and between these ones and the environment

Context. Colossal systems that are evolving are primarily system of systems (SOS). The system of systems are characteristic of functionally independent subsystems. These subsystems exhibit heterogeneity in terms of software or hardware. Each subsystem may reflect heterogeneity in dimensions such as the system complexity, system configuration, programming language and platforms, etc. Exploratory testing (ET) is perceived to be the best for testing such systems. An enhancement to exploratory testing is the session-based test management (SBTM) where several activities form a part of each session. These activities are mainly dependent on tester and the test charter of that session. There is lack of information in existing literature regarding a standard framework to design test charters for exploratory testing which forms the main area of focus of this thesis research. Objectives. Firstly, to investigate the design of test charters in general. Secondly, to find out the factors influencing the design of test charters. Lastly, to develop a framework to design effective test charters in SOS context. Methods. A mixed method approach that incorporates both qualitative and quantitative research methods is used. This research includes the quantitative leg of the online survey along with the interviews and literature review that are qualitative in nature. Literature review has been chosen to investigate the test charter design in general. Besides, interviews and online surveys  have been used to research regarding the factors and test charter framework.  Snowball sampling method and convenience sampling method have been used to sample the research data. Moreover, thematic analysis method is used for analyzing the qualitative data while descriptive statistics is used for quantitative data analysis. Results. The design aspects of test charter are documented, the factors influencing test charter design and the framework for effective test charter design for exploratory testing are presented. Conclusions. The thesis objectives are fulfilled. The findings on how the test charters are generally designed have helped in gaining insight on the primary elements that constitute a test charter design. Further, investigating the factors influencing the test charter design has helped in knowing the main elements affecting the test charter design. Finally, the main contribution of this thesis, the developed flexible test charter framework for exploratory testing encapsulates variables that should be considered, controlled or varied systematically during the course of testing. It is deemed to act as a guideline for practitioners for effective test charter design.

Esta dissertação de mestrado aborda a introdução de reconhecimento de sessões http em um modelo de servidor web com serviços diferenciados (SWDS). Algumas técnicas foram desenvolvidas com o objetivo de produzir diferenciação de serviços junto com garantias de que novas sessões poderiam ser aceitas no sistema. Esses objetivos constituem requisitos essenciais na Internet atual, especialmente para aplicações web modernas. Um novo esquema para controle de admissão de sessões foi desenvolvido e introduzido no modelo SWDS, considerando dois mecanismos para aceitar novas sessões, com garantia de nalização. O mecanismo que estima a capacidade do sistema de aceitar novas sessões, baseado em um modelo de sessão construído dinamicamente a partir da carga do sistema, é destacado. A proposta global deste trabalho também considera um controle de admissão de requisições, baseado em sessões, onde a nova política de atendimento criada mantém o sistema livre de sobrecargas e oferece atendimento diferenciado para as sessões. As políticas de negociação desenvolvidas para o controle de admissão de requisições tiveram um papel importante neste trabalho, contribuindo para a priorização do atendimento das sessões. Os resultados obtidos mostram que os controles propostos constituem estruturas fundamentais para a estabilidade do desempenho do sistema, tanto quanto os mecanismos desenvolvidos têm grande importância no atendimento das sessões e, portanto de seus clientes, através de uma abordagem baseada em diferenciação. / This MSc dissertation approaches the introduction of the HTTP sessions recognition in a web server model with diferentiated services (SWDS). Some techniques have been developed aiming at issuing diferentiation of services together with guarantees that new sessions could be accepted in the system. These aims constitute essential requirements for the current Internet, especially for modern web applications. A new scheme for the admission control system has been developed and introduced in the SWDS model, considering two mechanisms for accepting new sessions, with guarantee of their nalizations. The mechanism that estimates the system capacity of acceptance of a new session, based on a session model built dynamically from system workload information, is highlighted. The global propose of this work also considers a request admission control, based on sessions, where the new attendance polices created keep the system free from overloads and over diferentiated attendance for the sessions. The negotiation polices developed for request admission control had an important place in this work, contributing for the session attendance prioritization. The results reached show that the controls proposed comprise fundamental structures for system performance stability, as well as the mechanisms developed have great importance in attending sessions and, therefore, their clients by means of a diferentiation-based approach.

Session Initiation Protocol (SIP) arises as a new standard of establishing and releasing connections for vast variety of multimedia applications. The protocol may be used for voice calls, video calls, video conferencing, gaming and many more. The 3GPP (3rd Generation Partnership Project) suggests SIP as the signalling solution for 3rd generation telephony. Thereby, this purely IP-centric protocol appears as a promising alternative to older signalling systems such as H.323, SS7 or analog signals in PSTN. In contrast to them, SIP does not focus on communication with PSTN network. It is more similar to HTTP than to any of the mentioned protocols. The main standardisation body behind Session Initiation Protocol is The Internet Engineering Task Force (IETF). The most recent paper published on SIP is RFC 3261 [5]. Moreover, there are working groups within IETF that publish suggestions and extensions to the main standard. One of those extensions is “Caller Preferences for the Session Initiation Protocol (SIP)” [1]. This document describes a set of new rules that allow a caller to express preferences about request handling in servers. They give ability to select which Uniform Resource Identifiers (URI) a request gets routed to, and to specify certain request handling directives in proxies and redirect servers. It does so by defining three new request header fields, Accept-Contact, Reject-Contact, and Request-Disposition, which specify the caller preferences. [1]. The aim of this project is to extend the existing software with caller preferences and evaluate the new functionality.

HMK Geodesi, GPS publicerades år 1996 och är fortfarande det regelverk som idag tillämpas vid statisk mätning med GNSS. Studien genomförs för att bidra med rekommendationer till nya HMK-Stommätning för statisk GNSS-mätning.   Studiens syfte var att undersöka baslinje- och sessionslängdens påverkan på lägesosäkerheten vid mätning av korta baslinjer. Eftersom studien skulle efterlikna mätning under praktiska förhållanden undersöktes baslinjelängder 0,7–100 km och sessionstider 20 min–6 h. Syftet var också att undersöka om lägesosäkerheten påverkas olika vid beräkning med de olika frekvenserna, L1, L1+L2 eller L3.   Två delstudier genomfördes i två olika geografiska områden. I Gävleområdet användes data från egna mätningar i kombination med data från en SWEPOS-station för beräkning av spridningen i position för korta baslinjer. I Göteborgsområdet har data erhållits från och beräknats mellan 14 SWEPOS-stationer. En felvektor har beräknats mellan stationens beräknade position i studien och en given position beräknad av SWEPOS.   I Gävleområdet var skillnaden i standardosäkerhet för koordinaterna mellan olika sessionstider mindre än 3 och 7 mm i plan respektive i höjd. För baslinjer upp till 5 km är spridningen i höjd i hälften av fallen mindre än i plan för frekvenserna L1, L1+L2 och L3. Vid längre sessioner gav frekvenserna likvärdiga resultat. I Göteborgsområdet ökade höjddifferensen i samband med baslinjelängden. Den tredimensionella avvikelsen för baslinjerna var 1–71 mm.   Lägesosäkerheten i plan påverkas inte nämnvärt av ökad baslinjelängd. Lägesosäkerheten i höjd blir större när baslinjelängden ökar. Till skillnad från tidigare studier ses ingen tydlig förbättring när sessionstiden ökar. / HMK Geodesy, GPS was published in 1996 and is still the regulations that currently apply to static measurement with GNSS. The study is conducted to provide recommendations for new HMK Control networks for static GNSS surveying.   The purpose of the study was to investigate how the baseline and session length influence the position uncertainty when measuring short baselines. A second purpose was to investigate whether there will be any difference in the position uncertainty when using different frequencies: L1, L1 + L2 or L3. The study investigates baseline lengths 0,7–100 km and session lengths 20 min–6 h. The study was designed to mimic measurements during practical conditions and investigate the position uncertainties that can be expected to be achieved by users.   Two sub-studies were conducted in two different geographical areas. In the Gävle area self-produced data was used combined with data from a SWEPOS station for calculating the spread in the position for short baselines. In the Gothenburg area the data was obtained from observations of known SWEPOS reference stations. An error vector was calculated between the station's estimated position of the study and a given position calculated by SWEPOS.   In the Gävle area the differences in standard uncertainty between different session lengths for the coordinates were less than 3 mm and 7 mm in plane and height. For baselines up to 5 km the spread in height in half of the cases was lower than in plane for the frequencies L1, L1+L2 and L3. During longer sessions the results for the different frequencies are equal. In the Gothenburg area the height differences increased when associated/combined/correlated with baseline length. The three-dimensional deviations of the base lines were 1–71 mm.   The position uncertainty in plane is not affected significantly by increased baseline length. Location Uncertainty in height becomes larger when baseline length increases. Unlike previous studies our study showed no clear improvement in position uncertainty when session length increases.

Inledning: Inom psykodynamisk teori är den psykoterapeutiska ramen ett centralt begrepp. Syftet med studien är att undersöka hur psykodynamiskt inriktade psykoterapeuter förhåller sig till den psykoterapeutiska ramen med fokus på tidsdimensionen i avslutet av terapitimmen.  Frågeställningar: Hur gör terapeuten för att avsluta en terapitimme? Hur ser terapeuten på avslutet av terapitimmen? Vilka känslor och reaktioner väcker avslutet hos terapeuten? Är avslutet av terapitimmen ett område som man kan prata med andra terapeuter om? Metod: Datainsamlingen genomfördes genom strukturerade intervjuer med kvalitativ forskningsmetod. Studien har en hermeneutisk ansats och resultatet har analyserats tematiskt. Resultat: Undersökningen visar att fyra av de fem intervjuade psykoterapeuterna förbereder patienten på terapitimmens avslut. Denna praktik har inte stöd i den psykodynamiska psykoterapeututbildning som ges vid S:t Lukas utbildningsinstitut. Under utbildningen betonas vikten av att hålla tidsramen noga, i betydelsen att arbeta psykoterapeutiskt tills den överenskomna tiden är slut. Diskussion: Samtliga intervjuade psykoterapeuter delar uppfattningen att de psykoterapeutiska tidsramarna i allmänhet inte tillämpas lika strikt idag som tidigare. Fyra av de fem terapeuterna har erfarenhet av att arbeta med andra terapimetoder än den psykodynamiska, vilket kan påverka deras förhållningssätt till avslutet av terapitimmen. / The psychotherapeutic framework is a central idea in psychodynamic theory. The purpose of the study is to examine how psychodynamically oriented psychotherapist relate to the psychotherapeutic framework with focus on the time dimension at the end of the therapy session. Questions: How does the therapist act to end a therapy session? How does the therapist regard the end of the therapy session? What feelings and reactions does the termination evoke in the therapist? Is the termination of the therapy session a subject you can talk to other therapists about?  Method: The data collection was conducted through structured interviews with a qualitative research method. The study has a hermeneutic approach and the result has been analysed thematically. Result: The study shows that four out of five interviewed psychotherapists prepare the patient for the end of the psychotherapy session. This practice lacks support in the psychodynamic psychotherapist education at St Lukas educational institution. The importance of holding the time frame, in the sense of working psychotherapeutically until the agreed time is over, is emphasized during the training. Discussion: The interviewed psychotherapists share the view that the psychotherapeutic timeframes are generally not applied as strictly today as before. Four out of five therapists have experience of working with other methods of therapy than the psychodynamic, which may affect their approach to the end of the therapy session.