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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Exploring UK consumer perceptions of mobile payments using smart phones and contactless consumer devices through an extended Technology Adoption Model

Hampshire, Chris January 2016 (has links)
Widespread adoption of mobile payments has not taken place despite a decade of trials in various countries based upon a mobile phone handset that does not have the technology capabilities of today’s smart phones. However, significant technology developments have led to widespread consumer adoption of smart phones and other devices that may now provide the foundation for wider consumer adoption of mobile payments. Understanding UK consumer cultural perceptions on the new phenomenon is one of the first steps to influencing purchase behaviour. This thesis is based upon a post-positivist philosophy and a social constructionist ontology that explores UK consumer perceptions of mobile payments through human cognitive and affective responses of consumer payment behaviour as these influence attitude that leads to adoption. However, UK consumer interest in mobile payments on its own is unlikely to be enough to change payment behaviour, although meeting specific payment needs can motivate consumers to amend their payment behaviour that can lead to widespread adoption. Inductive empirical research is used to explore UK consumer perceptions of mobile payments through sequential mixed methods. A questionnaire is used as the 1st research instrument with closed questions that explore various aspects of consumer interest in the mobile payments phenomenon. The key themes identified from the numerical analysis of the questionnaire data are used to guide the semi-structured interviews. Content analysis is then undertaken on the qualitative interview data from which new knowledge on consumer perceptions of mobile payments is identified. Analysis of the empirical data suggests that UK consumers have significant technology and security concerns which negatively affect consumer interest. Despite these concerns, UK consumers demonstrate interest in the mobile payments phenomenon when perceived usefulness benefits are identified. The perceived usefulness positively influences attitude that overcomes perceived risks which can lead to amended consumer payment behaviour and widespread adoption. In addition, UK consumers have a significant lack of trust towards unknown organisations as well as new market entrants although there is an increased level of trust in mobile payments provided by UK banks as well as other established organisations. This research fills an important gap in existing literature on consumer payment behaviour as it explores UK consumer cultural perceptions of the mobile payments phenomenon using smart phones and contactless consumer devices; whereas earlier consumer payment research is based upon a mobile phone handset that does not have the technology capabilities of today’s smart phones and has an Asian and Nordic cultural focus. Furthermore, this research provides UK empirical evidence that refines and extends existing research through the use of sequential mixed methods whilst adding to the understanding of UK consumer attitudes related to UK payment instruments.
252

PRIVACY PRESERVATION IN A HYBRID MULTI MESH-LTE AMI NETWORK FOR SMART GRID

Cakmak, Ozan 01 August 2015 (has links)
While the newly envisioned Smart(er) Grid (SG) will result in a more efficient and reliable power grid, its collection and use of fine-grained meter data has widely raised concerns on consumer privacy. While a number of approaches are available for preserving consumer privacy, these approaches are mostly not very practical to be used due to two reasons: First, since the data is hidden, this reduces the ability of the utility company to use the data for distribution state estimation. Secondly and more importantly, the approaches were not tested under realistic wireless infrastructures that are currently in use. In this thesis, a meter data obfuscation approach to preserve consumer privacy is proposed to implement that has the ability to perform distribution state estimation. Then, its performance on LTE and a large-scale Advanced Metering Infrastructure (AMI) network built upon the new IEEE 802.11s wireless mesh standard are assessed. LTE/EPC(Evolved Packet Core) model is used between the gateway and the utility. EPC's goal is to improve network performance by the separation of control and data planes and through a flattened IP architecture, which reduces the hierarchy between mobile data elements. Using obfuscation values provided via this approach, the meter readings are obfuscated to protect consumer privacy from eavesdroppers and the utility companies while preserving the utility companies' ability to use the data for state estimation.The impact of this approach on data throughput, delay and packet delivery ratio under a variety of conditions are assessed.
253

Preserving Consumer Privacy on IEEE 802.11s-Based Smart Grid AMI Networks

Beussink, Andrew 01 May 2014 (has links)
While the newly envisioned smart grid will result in a more efficient and reliable power grid, its use of fine-grained meter data has widely raised concerns of consumer privacy. This thesis implements a data obfuscation approach to preserve consumer privacy and assesses its feasibility on a large-scale advanced metering infrastructure (AMI) network built upon the new IEEE 802.11s wireless mesh standard. This obfuscation approach preserves consumer privacy from eavesdroppers and the utility companies while preserving the utility companies' ability to use the fine-grained meter data for state estimation. The impact of this privacy approach is assessed based on its impact on data throughput and delay performance. Simulation results have shown that the approach is feasible to be used even when the network size grows. Additional adaptations to the approach are analyzed for their feasibility in further research.
254

Smart HVAC Zoning For Residential Buildings

January 2018 (has links)
abstract: The concept of this thesis came up as a part of the efforts being devoted around the world to reduce energy consumption, CO2 emissions, global warming and ozone layer depletion. In the United States, HVAC units in residential buildings consumed about 350 billion kWh in 2017 [1],[2]. Although HVAC manufacturers are investing in new technologies and more efficient products to reduce energy consumption, there is still room for further improvement. One way of reducing cooling and heating energy in residential buildings is by allowing the centralized HVAC unit to supply conditioned air to only occupied portions of the house by applying smart HVAC zoning. According to the United States Energy Information Administration [3], the percentage of houses equipped with centralized HVAC units is over 70%, which makes this thesis applicable to the majority of houses in the United States. This thesis proposes to implement HVAC zoning in a smart way to eliminate all human errors, such as leaving the AC unit on all day, which turns out to be causing a serious amount of energy to be wasted. The total amount of energy that could be saved by implementing the concepts presented in this thesis in all single-family houses in the U.S. is estimated to be about 156 billion kWh annually. This amount of energy reduction is proportional to the electricity bills and the amount of dollars paid annually on energy that is technically being wasted. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2018
255

Development of a non-monochromatic lightwave sensor for applications in smart structures research

Kahn, Mohammed Tariq Ekeramodien January 1998 (has links)
Thesis (MTech (Electrical Engineering))--Peninsula Technikon, Cape Town, 1998 / The purpose of this study was to perform an investigation into advances in the field of opto-electronics and to develop a suitable lightwave sensor, for application in smart structures research. Included in the scope of this research was the theoretical development and analysis of an appropriate technology to lead to an implementation of such sensors. This project forms part of an overall plan to gain experience in optoelectronic (photonic) sensor design. In research done previously in smart structure monitoring, piezo-electric techniques with the usual electrical interconnections was used. In a highly distributed sensor system the problems of electromagnetic interference, the tribo-electric effect and noise could be problematic. In this research, opto electronic techniques were thoroughly researched and an improvement on laser based fibre-optic interferometers was made. A non monochromatic lightwave interferometer was developed from theory and a prototype tested. The results suggests that an interferometric sensor can be operated with a non monochromatic source by using a second interferometer to modulate the frequency spectrum of the light before it is detected by a photodetector. Various test and measurement circuits for improved photodetector performance were evaluated, as well as a study of signal processing techniques that would be of use for an upgrade of the project where specific feature detection and analysis using the sensor is envisaged. A specification for a computer based data acquisition system was developed to do initial tests. The project should continue, with the sensor head being improved and all the necessary signal processing routines programmed into a Labview based data acquisition system.
256

Miniaturised dedicated application opto-electronic sensors in the evolution of smart systems

Kahn, Mohammed Tariq Ekeramodien January 2002 (has links)
Thesis (DTech (Electrical Engineering))--Peninsula Technikon, Cape Town, 2002 / In the last decade, the South Amcan Electricity Supply Commission would have had their ability to serve an ever demanding public severely tested. With the dilemma of providing electricity supply through hazardous environmental conditions, and with prospects of supplying power even beyond South Afiican borders, the need for a comprehensive damage and power delivery assessment strategy becomes all the more relevant. The rapid growth being made in the evolution of so called "intelligent" structures, with inherent sensor, actuator and control mechanisms built in can have direct influence on a power distribution network. At least in the foreseeable future, the impact ofphotonic sensors with inherent miniaturization, a foremost candidate in Smart System technology, can play a vital role in damage assessment of a potentially large network such as that found in the supply ofelectricity. Smart systems are nonliving systems that integrate the functions of sensing, actuation, logic and control, to respond adaptively to changes in their condition or environment to which they are exposed, in a useful and usually repetitive manner. Sensors are a fundamental part of the evolution of such systems and form the basis for the topic of this dissertation. The use ofoptical fiber sensors is increasing widely mainly due to their (a) miniature size, (b) remote signal processing ability, and (c) multiplexing capabilities. Because of the above features a variety of optical fiber sensing techniques has evolved over the years having potential for a myriad of applications. In this work a systems model and equations was developed for modeling the propagation of light in a optical waveguide, in order to study a Fabry Perrot sensor topology for application as a miniaturised sensor in a new type of smart structure, namely a smart electrical power system.
257

The development of a computational design tool for use in the design of SMA actuator systems

Philander, Oscar January 2004 (has links)
Thesis (DTech (Mechanical Engineering))--Peninsula Technikon, 2004. / Engineers and Technologists have always been identified as those individuals that put into practice the theories developed by scientists and physicists to enhance the lives of human beings. In the same spirit as those that came before, this thesis describes the development of a computational engineering tool that will aid Engineers and Technologists to design smart or intelligent structures comprising of NiTi shape memory alloy rods for actuation purposes. The design of smart actuators consisting of NiTi shape memory alloy structural members will be beneficial to industries where light weight, compactness, reliability and failure tolerance is of utmost importance. This is mainly due to the unique material responses exhibited by this smart material. The shape memory effect, one of these material responses consists out of two stages: a low temperature load induced phase transformation causing a macroscopic deformation (either extension, contraction, etc.) also known as quasi-plasticity; and a high temperature phase transformation that erases the low temperature macroscopic deformation and reverts the material to some predefined geometry. When designing actuators consisting of this smart material, the quasi-plastic material response produces the actuation stroke while the high temperature phase transformation produces the actuation force. The successful engineering design of smart structures and devices particularly suited for applications where they operate in a capacity, as actuators harnessing the shape memory effect are dependent on a few important factors. These include the engineers familiarity with the type of smart material used, the availability of sound experimental data pertaining to the complex material responses exhibited by the smart material, the engineers level of proficiency with existing constitutive models available to simulates these material responses, and the engineers knowledge of simulation tools consisting of a suitable control algorithm fo~ the modeling of not only the device or structure itself but also the actuator involved in the design.
258

SmartSharing: a content delivery network with local sharing of over-the-top devices

Fan, Jiamin 01 October 2018 (has links)
Content delivery networks (CDNs) depend on distributed cache servers to reduce the content delivery distance and latency to end users. Nevertheless, a CDN's cache footprint is greatly limited by the high cost in deploying and maintaining large- scale cache servers. To break the limit, CDN providers adopt a new content caching strategy that allows end users to share their storage/bandwidth resources with each other. Two core questions need to answer in this CDN strategy: (1) how to incentivize end users to contribute their resources? and (2) how to facilitate transparent, secure content exchange among end users? We propose a new CDN solution, called SmartSharing, where users contribute their Over-the-top (OTT) devices as mini cache servers. With SmartSharing, an OTT device can share the content the OTT owner is downloading and in addition can cache content for neighboring OTT devices in the same area. To incentivize end users to contribute their resources, SmartSharing uses game theory and the Expectation- Maximization (EM) algorithm to determine content delivery schedule and the pricing scheme. To facilitate content trading among end users, SmartSharing uses smart contracts in Ethereum to create a transparent and safe transaction platform. We evaluate SmartSharing with real-world trace driven simulation as well as smart con- tract prototype in Ethereum using content meta-data and the derived pricing scheme. By disclosing the internal dynamics in content delivery schedule and pricing scheme and analyzing the overhead in content trading, we show that SmartSharing is an effective new CDN solution that benefi ts content providers, CDN, and end users. / Graduate
259

Efeito Toxico-Genético dos Larvicidas Dilapiol e Espinosade em Células Somáticas de Drosophila Melanogaster

ACIOLE, Eliézer Henrique Pires 31 January 2012 (has links)
Submitted by Nayara Passos (nayara.passos@ufpe.br) on 2015-03-04T12:31:30Z No. of bitstreams: 2 2012-Dissertação-Eliezer-Aciole.pdf: 1597994 bytes, checksum: 6ff6a025f1d71b08d85b1065d3c92474 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-04T12:31:30Z (GMT). No. of bitstreams: 2 2012-Dissertação-Eliezer-Aciole.pdf: 1597994 bytes, checksum: 6ff6a025f1d71b08d85b1065d3c92474 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012 / CAPES, FACEPE. / O uso constante de inseticidas em programas de saúde pública tem sido a principal medida para o controle de insetos vetores de doenças epidêmicas em países tropicais e subtropicais. Anualmente toneladas de inseticidas sintéticos, sobretudo os organofosforados, são lançadas ao meio ambiente na tentativa de controlar o crescimento populacional dos vetores. Os larvicidas são compostos capazes de matar larvas que se desenvolvem em reservatórios grandes ou pequenos, naturais ou artificiais de água, muitas vezes própria ao consumo humano. Os compostos dilapiol e espinosade são classificados como larvicidas, sendo o dilapiol um óleo essencial extraído da espécie vegetal Piper aduncum e o espinosad uma combinação de dois metabólitos produzidos pela bactéria Saccharopolyspora spinosa. O objetivo deste trabalho foi avaliar os efeitos genotóxicos do dilapiol e do espinosade, por meio do teste de mutação e recombinação somática (SMART) de asa de Drosophila melanogaster. Na metodologia foi utilizado o cruzamento padrão, sendo as larvas com 72h de vida submetidas durante 48h à exposição crônica a três diferentes concentrações não letais do dilapiol (3,2, 16 e 80 um/mL) e do espinosade (0,32, 0,96 e 1,6 ug/mL). Para avaliação do efeito genotóxico, as frequências das manchas de pelos mutantes nas asas dos indivíduos tratados foram comparadas com os respectivos controles negativos. Os resultados indicam que ambos compostos tiveram atividade toxico-genética positiva, em todas as concentrações testadas, exceto o espinosade a 0,96ug/mL. A atividade genotóxica se deu, principalmente, à indução de recombinação e, em menor escala, à mutação somática, verificada apenas para o espinosade. Os resultados aqui apresentados contribuem para o conhecimento dos riscos genotóxicos do uso destes dois inseticidas, que merecem ainda mais estudos, feitos em outros modelos experimentais e outras condições e metodologias para que sejam considerados seguros para a saúde humana e o meio ambiente.
260

Knowledge needs analysis for simultaneously multi-agent real-time systems

Scown, Philip J. A. January 1997 (has links)
A set of systems are considered where there are multiple agents simultaneously active within real-time a environment. These systems are termed SMART systems and are found in domains as diverse as office administration, process control and aviation. Such systems place particular demands on agents that are not present in non-SMART systems. Actions may be time constrained in two ways: i) an action appropriate at one time may not be appropriate at another; ii) the time available for a required action may approximate to the time in which an agent is able to perform that action. In order to be able to function in such environments agents, both human and computer, must be aware of time constraints and the actions necessary to ensure that they do not compromise system goals.

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