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Role of television in social transformation:A study of rural-urban kashmirMufti, Sabeha 02 1900 (has links)
A study of rural-urban kashmir
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Real time communications over on-board mobile networksMalik, Muhammad Ali, Computer Science & Engineering, Faculty of Engineering, UNSW January 2007 (has links)
The Internet Engineering Task Force (IETF) has recently released routing standards that allow deployment of TCP/IP local area networks (LANs) onboard a moving vehicle and yet maintain permanent connectivity of the onboard LAN to the Internet via a vehicular mobile router. This recent development opens up new opportunities for providing efficient mobile computing for users on the move, especially for commuters traveling on public transports. Supporting real-time communications, e.g. IP Telephony, on-line video on demand, etc., over such onboard mobile networks is the main motivation of this thesis. Due to the volatility of the wireless bandwidth available to connect the moving LAN to the Internet at different locations of the trip, supporting on-line services that require bandwidth guarantees becomes a challenging task. The main problem investigated is how to provide bandwidth guarantee efficiently, effectively, and in a scalable manner in the context of moving onboard networks. To achieve the goal, a systematic approach is taken that involves (i) designing a signalling protocol that allows transparent bandwidth reservation for the aggregate demand of all onboard users in the vehicle, and (ii) proposing effective aggregation and bandwidth reservation policies that aim to maximize the chances of successful reservation and minimize the bandwidth and processing overhead in critical network elements. Mathematical models are derived to evaluate the performance of proposed solutions. These models are validated using discrete event simulation. One important conclusion reached is that onboard mobile communication provides significant aggregation and centralized management opportunities that must be exploited to provide a scalable solution to the bandwidth guarantee problem in mobile communications. The techniques proposed and analyzed in this thesis to exploit such aggregation opportunities constitute the original contribution to knowledge.
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Filtering and Model Predictive Control of Networked Nonlinear SystemsLi, Huiping 29 April 2013 (has links)
Networked control systems (NCSs) present many advantages such as easy installation and maintenance, flexible layouts and structures of components, and efficient allocation and distribution of resources. Consequently, they find potential applications in a variety of emerging industrial systems including multi-agent systems, power grids, tele-operations and cyber-physical systems. The study of NCSs with nonlinear dynamics (i.e., nonlinear NCSs) is a very significant yet challenging topic, and it not only widens application areas of NCSs in practice, but also extends the theoretical framework of NCSs with linear dynamics (i.e., linear NCSs). Numerous issues are required to be resolved towards a fully-fledged theory of industrial nonlinear NCS design. In this dissertation, three important problems of nonlinear NCSs are investigated: The robust filtering problem, the robust model predictive control (MPC) problem and the robust distributed MPC problem of large-scale nonlinear systems.
In the robust filtering problem of nonlinear NCSs, the nonlinear system model is subject to uncertainties and external disturbances, and the measurements suffer from time delays governed by a Markov process. Utilizing the Lyapunov theory, the algebraic Hamilton-Jacobi inequality (HJI)-based sufficient conditions are established for designing the H_infty nonlinear filter. Moreover, the developed results are specialized for a special type of nonlinear systems, by presenting the HJI in terms of matrix inequalities. For the robust MPC problem of NCSs, three aspects are considered. Firstly, to reduce the computation and communication load, the networked MPC scheme with an efficient transmission and compensation strategy is proposed, for constrained nonlinear NCSs with disturbances and two-channel packet dropouts. A novel Lyapunov function is constructed to ensure the input-to-state practical stability (ISpS) of the closed-loop system. Secondly, to improve robustness, a networked min-max MPC scheme are developed, for constrained nonlinear NCSs subject to external disturbances, input and state constraints, and network-induced constraints. The ISpS of the resulting nonlinear NCS is established by constructing a new Lyapunov function. Finally, to deal with the issue of unavailability of system state, a robust output feedback MPC scheme is designed for constrained linear systems subject to periodical measurement losses and external disturbances. The rigorous feasibility and stability conditions are established.
For the robust distributed MPC problem of large-scale nonlinear systems, three steps are taken to conduct the studies. In the first step, the issue of external disturbances is addressed. A robustness constraint is proposed to handle the external disturbances, based on which a novel robust distributed MPC algorithm is designed. The conditions for guaranteeing feasibility and stability are established, respectively. In the second step, the issue of communication delays are dealt with. By designing the waiting mechanism, a distributed MPC scheme is proposed, and the feasibility and stability conditions are established. In the third step, the robust distributed MPC problem for large-scale nonlinear systems subject to control input constraints, communication delays and external disturbances are studied. A dual-mode robust distributed MPC strategy is designed to deal with the communication delays and the external disturbances simultaneously, and the feasibility and the stability conditions are developed, accordingly. / Graduate / 0548 / 0544
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Real time communications over on-board mobile networksMalik, Muhammad Ali, Computer Science & Engineering, Faculty of Engineering, UNSW January 2007 (has links)
The Internet Engineering Task Force (IETF) has recently released routing standards that allow deployment of TCP/IP local area networks (LANs) onboard a moving vehicle and yet maintain permanent connectivity of the onboard LAN to the Internet via a vehicular mobile router. This recent development opens up new opportunities for providing efficient mobile computing for users on the move, especially for commuters traveling on public transports. Supporting real-time communications, e.g. IP Telephony, on-line video on demand, etc., over such onboard mobile networks is the main motivation of this thesis. Due to the volatility of the wireless bandwidth available to connect the moving LAN to the Internet at different locations of the trip, supporting on-line services that require bandwidth guarantees becomes a challenging task. The main problem investigated is how to provide bandwidth guarantee efficiently, effectively, and in a scalable manner in the context of moving onboard networks. To achieve the goal, a systematic approach is taken that involves (i) designing a signalling protocol that allows transparent bandwidth reservation for the aggregate demand of all onboard users in the vehicle, and (ii) proposing effective aggregation and bandwidth reservation policies that aim to maximize the chances of successful reservation and minimize the bandwidth and processing overhead in critical network elements. Mathematical models are derived to evaluate the performance of proposed solutions. These models are validated using discrete event simulation. One important conclusion reached is that onboard mobile communication provides significant aggregation and centralized management opportunities that must be exploited to provide a scalable solution to the bandwidth guarantee problem in mobile communications. The techniques proposed and analyzed in this thesis to exploit such aggregation opportunities constitute the original contribution to knowledge.
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Centralized Routing for Prolonged Network Lifetime in Wireless Sensor NetworksHansen, Ewa January 2008 (has links)
<p>In this thesis centralized routing methods for wireless sensor networks have been studied. The aim has been to prolong network lifetime by reducing the energy consumed by sensor-node communication.</p><p>Wireless sensor networks are rapidly becoming common in application areas where information from many sensors is to be collected and acted upon. The use of wireless sensor networks adds flexibility to the network, and the cost of cabling can be avoided.</p><p>Wireless sensor networks may consist of several hundreds of small devices, equipped with sensors (e.g. acoustic, seismic or image) that form a wireless network. Each sensor node collects information from its surroundings and sends it to a base station, either from sensor node to sensor node, or directly to the base station.</p><p>We have made simulations that show that asymmetric communication with multihop extends the lifetime of large wireless sensor networks. We have also investigated the usefulness of enforcing a minimum separation distance between cluster heads in a cluster based wireless sensor network. The results show that our sensor network performs up to 150% better when introducing a minimum separation distance between cluster heads. The simulations also show that the minimum separation distance resulting in the lowest energy consumption in our network varies with the number of clusters. We have also made an initial study of maximum lifetime routing in sparse wireless sensor networks to be able to see how different heuristic routing algorithms influence the energy consumption of individual sensor nodes, and thus the lifetime of a sparse sensor network. We have also compared the maximum lifetime of the heuristic algorithms to the maximum lifetime of an optimal routing solution. These simulations showed that for some types of applications the choice of heuristic algorithm is more important to prolong network lifetime, than for other types of applications.</p>
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Betydelsen av fastighetsmäklares kommunikativa färdigheter för bostadssäljarnas förtroende / The meaning of real estate agents communicative skills to create trust among home sellersBlixt, Johanna, Svensson, Caroline January 2015 (has links)
Problem formulation: ”What significance does the real estate agents communicative skills, to gain the confidence of home sellers during the sales process? Purpose: The purpose of this paper is to create a theoretical framework on the importance of real estate agents communication skills for home sellers confidence. The theoretical framework is expected to explain the interaction between real estate agents and home sellers to create an understanding of the real estate agents communicative skills but also home seller trust and the link between them. Theoretical framework: The theoretical framework aims to describe the sales process seven steps according to Moncrief & Marshall (2005). It also describes the parties that are relevant to the sales process based on our issue. Then the communicative skills and confidence sets of meaning and significance is explained. This culminates in an analysis which we assumed when we made the analysis. Methodology: To examine our issue, we have chosen to do a qualitative study in the form of interviews. We interviewed two home sellers and two real estate agents about communication skills and confidence. We also examine these concepts using secondary data in the form of scientific articles and books. Analysis: The analysis in this paper is divided into two sections. One part is focusing om house sellers and the other part is focusing om the real estate agents we interviewed. In this analysis the sales process and its seven steps is the starting point. We have also tried to include our key words in this analysis, especially communication skills and confidence. Conclutions: Based on previous research, empirical data and the analysis. This study show that the real estate agents communicative skills are important for the confidence of home sellers during the sales process. The communicative skill that proved to be most significant to confidence building was the communicative ability the ability to listen. / Frågeställning: ”Vilken betydelse har fastighetsmäklarens kommunikativa färdigheter, för att skapa förtroende hos bostadssäljare under säljprocessen? Syfte: Syftet med denna uppsats är att skapa ett teoretiskt ramverk kring betydelsen av mäklares kommunikativa färdigheter för säljarnas förtroende. Det teoretiska ramverket förväntas förklara interaktionen mellan fastighetsmäklare och bostadssäljare för att skapa förståelse för mäklarens kommunikativa färdighet men också bostadssäljarens förtroende och kopplingen däremellan. Teoretisk referensram: Den teoretiska referensramen syftat till att beskriva säljprocessens sju steg enligt Moncrief & Marshall (2005). Vidare beskrivs de parter som är aktuella för säljprocessen utifrån vår frågeställning. Därefter förklaras de kommunikativa färdigheterna och förtroendesets innebörd och betydelse. Detta mynnar ut i en analysmodell vilken vi utgått från när vi gjort analysen. Metod: För att undersöka vår frågeställning har vi valt att göra en kvalitativ undersökning i form av intervjuer. Vi har intervjuat två bostadssäljare och två fastighetsmäklare där vi ställt frågor kring kommunikativa färdigheter och förtroende. Vi har även undersökt dessa begrepp med hjälp av sekundärdata i form av vetenskapliga artiklar och böcker. Analys: Analysen i denna uppsats är indelad i två avsnitt. Ett om bostadssäljarna och ett om fastighetsmäklarna vi intervjuat. Vi har i denna analys utgått från säljprocessens sju steg och försökt koppla an till våra nyckelord, framförallt kommunikativa färdigheter och förtroende. Slutsatser: Utifrån tidigare forskning och empirisk datainsamling samt analysen av detta visar denna studie att fastighetsmäklarens kommunikativa färdigheter har betydelse för förtroendet hos bostadssäljarna under säljprocessen. Den kommunikativa färdighet som visade sig ha störst betydelse för förtroendeskapandet utifrån de genomförda intervjuerna var den kommunikativa färdigheten konsten att lyssna.
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Centralized Routing for Prolonged Network Lifetime in Wireless Sensor NetworksHansen, Ewa January 2008 (has links)
In this thesis centralized routing methods for wireless sensor networks have been studied. The aim has been to prolong network lifetime by reducing the energy consumed by sensor-node communication. Wireless sensor networks are rapidly becoming common in application areas where information from many sensors is to be collected and acted upon. The use of wireless sensor networks adds flexibility to the network, and the cost of cabling can be avoided. Wireless sensor networks may consist of several hundreds of small devices, equipped with sensors (e.g. acoustic, seismic or image) that form a wireless network. Each sensor node collects information from its surroundings and sends it to a base station, either from sensor node to sensor node, or directly to the base station. We have made simulations that show that asymmetric communication with multihop extends the lifetime of large wireless sensor networks. We have also investigated the usefulness of enforcing a minimum separation distance between cluster heads in a cluster based wireless sensor network. The results show that our sensor network performs up to 150% better when introducing a minimum separation distance between cluster heads. The simulations also show that the minimum separation distance resulting in the lowest energy consumption in our network varies with the number of clusters. We have also made an initial study of maximum lifetime routing in sparse wireless sensor networks to be able to see how different heuristic routing algorithms influence the energy consumption of individual sensor nodes, and thus the lifetime of a sparse sensor network. We have also compared the maximum lifetime of the heuristic algorithms to the maximum lifetime of an optimal routing solution. These simulations showed that for some types of applications the choice of heuristic algorithm is more important to prolong network lifetime, than for other types of applications.
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