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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.
11

An efficient communication interface and protocol for motor protection relays

Mouton, A.J.J., Smith, C.J., Smith, G.E.; January 2009 (has links)
Published Article / A company in South Africa is a three-phase induction motor protection relay manufacturer. The function of the protection relay is to capture running data, to provide protection against possible damage, to control an electric motor and to communicate this data to the System Control and Data Acquisition (SCADA) system in a control room. In the case of remote sites e.g. a pump station, the protection relays are used as standalone units. The protection relays are equipped with communication facilities to be used in an instrumentation environment. If a trip occurs or settings need to be changed a technician has to visit the remote site and address the problem. The ideal cost and time effective solution is to perform these tasks remotely via a reliable wireless network. A study was conducted to ascertain the viability of using the standard GSM cellular networks in South Africa to effectively control electric motors and to communicate with the Motor Protection Relays (MPRs) controlling the electric motors in order to determine the status of a motor, settings of the motor, trips that occurred and time of occurrence. It was shown that a node controller could be used to store all the data from various electric motors at a single location. It was also shown that the data from the different electric motors could be analysed at the node controller and that communication can then be initiated from the controller to a responsible person via the GSM network. It was further illustrated that, by making use of the GSM networks in South Africa together with the short message service (SMS), communication and control can be effectively established. SMSs proved to be a reliable means of communication between cellular phones, an embedded network and MPRs. It was shown that software protocols, although slower in communication speed, proved to be reliable and effective for the purpose of transferring information between the node controller and the motor protection relays connected to the electric motors.
12

A novel platform incorporating multiple forms of communication to support applications in a mobile environment

Elton, James January 2014 (has links)
This thesis discusses the creation of a novel platform that incorporates multiple communication methods, including SMS, email and web-based technologies, for interacting with users of mobile communication devices. The platform utilises people in a mobile environment to solve a range of different application problems, where each problem is a separate and distinct scenario type with unique objectives. There are existing applications available that interact with users of mobile communication devices to provide a service, such as regular weather updates to the users. Other applications have been designed to manage and coordinate the users to perform tasks within a mobile environment, such as performing field studies for scientific purposes. However, the existing applications are designed for only one specific scenario, with the design and implementation solely focused on solving the objectives of that scenario. Each component of these applications needs to be developed from scratch in order to cater for the application s requirements. There is currently no integrated communications platform that offers a framework for supporting a range of different scenario types. The new platform, entitled the Connected-Mobile Platform, aims to support the rapid development and implementation of new scenarios. This platform is composed of a framework of generic components that enable the active running of multiple scenarios concurrently, with the ability to tailor to the requirements of new scenarios as they arise via a structured process. The platform facilitates a means to coordinate its users in order to tackle the objectives of a scenario. The thesis investigates several system architectures to determine an appropriate architectural design for constructing the proposed platform. The platform has a generic framework, based on a client-server architecture, to facilitate the inclusion of a multitude of scenarios. A scenario represents a problem or an event, whereby the platform can utilise and interact with users of mobile communication devices to attempt to solve the objectives of the scenario. Three mobile communication methods are supported; the Short Message Service, electronic mail and web-forms via the mobile internet. Users are able to select and switch between the different methods. The thesis describes the platform s tailored communication structure for scenarios and autonomous analysis of messages. The thesis discusses case studies of two different scenarios to evaluate the platform s facilities for rapid scenario development. The Diet Diary scenario, which is for individual users, aims to manage a user s daily calorie intake to help them reach their desired weight goal. The focus is on the platform s functionality for analysing and responding to messages autonomously. The Missing Persons scenario, which utilises multiple users, involves tracking and locating people who have been reported missing. The focus is on the platform s functionality for coordinating the multiple users, through the creation of assignments, in order to distribute the scenario objectives. The thesis concludes by highlighting the novel features of the platform and identifying opportunities for future work.
13

"Ja bare skrivar som e låter" : En studie av en grupp Närpesungdomars skriftpraktiker på dialekt med fokus på sms

Greggas Bäckström, Anna January 2011 (has links)
The thesis studies the literacy practices of a group of young people in Närpes in southern Ostrobothnia, Finland with focus on SMS (Short Message Service), both in Standard Swedish and in dialect, but for the most part written in dialect. The aim of the investigation is to describe this writing as a social marker (young people against adults) and its function as an identity act. In addition the study investigates the orthographic norms and conventions that the young people use in their writing. The material consists of 520 SMS and such material as was collected through inquiries and interviews. In Närpes, as in many other Finland Swedish dialect areas, the dialect has got widened areas of usage and is well established and accepted in more domains than before. It is used in the new media and is thereby also gaining larger scope in public space. This also applies to writing SMS in dialect. The theoretical points of departure are taken from sociolinguistics and literacy research. A central concept is the new writing, i.e. writing in electronic media such as e.g. SMS and e-mail, which are somewhere between speech and writing. This has given speech and writing new forms with new preconditions, forms that the new media have “triggered” forth and that the language is adapting itself to. In the first investigative chapter (Ch. 3) eleven literacy practices divided into five groups are analysed: I electronic literacy practices (SMS, e-mail, chat), II hand-written slips of paper (reminder slips, purchase lists, slips to parents and friends respectively), III picture postcards and letters, IV diaries and V school assignments. The informants participate with one exception, group V, in all literacy practices in dialect to a greater or lesser extent. The second investigative chapter (Ch. 4) accounts for the dialect features, diphthongs and consonant combinations that were concretely investigated in the SMS material. The young people’s writing in dialect is functional and shows that the dialect is an important identity marker. The lack of shared conventions for spelling is not conceived of as a problem but allows everyone to create their own conventions, which in its turn has resulted in the tolerance level for variations in orthography being high. One group think that they write as it sounds, while another think that they do not follow any rules. The dialect is reserved for everyday matters, while Standard Swedish is used in more formal writing situations. The literacy practice may be the same, but the choice of language variety varies with the aim, content and length.
14

The business model transformation of web portals:a research of Taiwan and China portals

Cheng, Chao-Wen 03 August 2004 (has links)
As the change of external environment and internal resources, web portals have transformed their business models from online advertisement model into others, such as electronic commerce model, online game model and short message service model. Different external environment, as well as diverse resources of the main web portals of Taiwan and Mainland China , leads the different transformation process across the Taiwan Strait. Generally, the main web portals in Taiwan like Yahoo! Kimo, PC home and Yam, have chosen online advertisement and electronic commerce model as their main business. On the contrary, Sina, Sohu and NetEase, the main web portals in China, which have transformed their business model into online game and short message service model. This research explores some factors which may influence the transformation of web portals in Taiwan and China, and constructs the internal and external conditions which could successfully transform the web portals to their business models by secondary data analysis and case analysis. There are several factors which influence the web portals to adopt certain business to run their business models.
15

The efficacy of short-messaging service in a weight reduction programme amongst women in a general practice

Guidozzi, Rosetta 03 1900 (has links)
Thesis (MNutr)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Obesity has become one of the major conditions contributing towards chronic lifestyle diseases. The management of obesity, in order to prevent chronic lifestyle disease, requires a combination of treatment modalities. There is therefore a constant need to search for innovative behavioural and awareness programmes regarding the treatment of obesity, and to develop innovative strategies to improve compliance and ultimately to change lifestyles. The notion of utilizing short message services (SMS), during a weight reduction progamme to provide regular reminders and information to achieve the aforementioned goals, was therefore used as an intervention in the study. Furthermore a questionnaire validating the effectiveness of the short message service was devised and completed by the recipients of the intervention. The purpose of the questionnaire was to statistically quantify the effectiveness of the SMS as an intervention. Each question had four graded answers, with a score allocated to each - 1 being the least effective and 4 being the most. These values were converted to percentages and according to these percentages a rating of effectiveness was ascertained. Ultimately the study set out to determine whether the intervention had a statistically significant effect on weight reduction, compliance in attending appointments and on the attrition rate. This was a double blinded randomized, controlled study in which 75 participants were recruited at a general medical practice in Gauteng. The sample comprised of three groups. Group 1 (N = 25) had no intervention; Group 2 (N = 25) received a SMS weekly and Group 3 (N = 25) received a SMS three times per week. The weight reduction programme, which included dietary modifications and lifestyle advice was standardized and remained the same for each group. The programme extended over a 12 week period and the questionnaire was completed at the end of the programme. Upon analysis of the results there was a decrease in the mean BMI and waist circumference for all the three groups, with no statistically significant difference (p-value > 0.05) between them. The percentages of the participants completing the programme in each group were – Group 1: 44%, Group 2: 60% and Group 3: 68%. The effectiveness of the intervention was manifested by the compliance of attendance at each visit and the reduced attrition rate in the intervention groups, although this was not found to be statistically significant. The analysis of the scores allocated to the responses of the questionnaire, equated to an outcome of above 75% and was assessed as being very successful in both the intervention groups. In conclusion the use of short message servicing in this weight reduction programme improved the compliance and reduced the attrition rate although not statistically and was perceived by the participants as a successful intervention. / AFRIKAANSE OPSOMMING: Vetsug (obesiteit) het een van die primêre kondisies geword wat bydrae tot chroniese leefstyl siektes. Die hantering van obesiteit vereis 'n kombinasie van behandelingsmodaliteite, ten einde hierdie siektes te voorkom, Daar is dus 'n konstante soeke na innoverende gedrags- en bewustheidsprogramme rakende die behandeling van obesiteit, asook 'n behoefte om innoverende strategieë te ontwikkel om inskiklikheid te verbeter en uiteindelik leefstyle te verander. Die idee om kortboodskapdienste (SMS) gedurende 'n gewigsverliesprogramme te gebruik om gereelde aanmanings en inligting te kommunikeer ten einde die genoemde doelwitte te bereik, is aangewend as intervensie in hierdie studie. 'n Vraelys is ontwikkel wat die effektiwiteit van die kortboodskapdiens valideer, en is voltooi deur die ontvangers van die intervensie. Die doel van die vraelys was om die effektiwiteit van die SMS as 'n intervensie te kwantifiseer. Elke vraag het vier gegradeerde antwoorde gehad, met 'n telling wat aan elk toegeken is – 1 wat aandui minste effektief en 4 wat aandui die meeste. Hierdie waardes was omgeskakel tot persentasies en na aanleiding van die persentasies is 'n waarde van effektiwiteit bepaal. Uiteindelik was die doel van die studie dus om vas te stel of die intervensie ʼn statisties beduidende effek op gewigsverlies, die nakom van afsprake en uitvalskoerse het. Hierdie was 'n dubbelblind, ewekansige gekontroleerde studie waarin 75 deelnemers gewerf was by 'n algemene mediese praktyk in Gauteng. Die steekproef het bestaan uit 3 groepe. Groep 1 (N = 25) het geen intervensie gehad nie; Groep 2 (N = 25) het 'n weeklikse SMS ontvang en Groep 3 (N = 25) het 'n SMS ontvang drie keer per week. Die gewigsverliesprogramme, wat dieetaanpassings en leefstyl advies ingesluit het, was gestandardiseer en het dieselfde gebly vir elke groep. Die programme het gestrek oor 'n 12 weke periode en die vraelys was voltooi aan die einde van die programme. Analise van die resultate het 'n afname getoon in die gemiddelde LMI (Liggaamsmassa indeks) en middelomtrek vir al drie groepe, met geen statisties beduidende verskil (p-waarde > 0.05) tussen groepe nie. Die persentasies van die deelnemers wat die programme voltooi het in elke groep was Groep 1: 44%, Groep 2: 60% en Groep 3: 68%. Die effektiwiteit van die intervensie was gemanifesteer deur die inskiklikheid van bywoning tydens elke besoek en die verlaagde uitvalkoers in die intervensie groepe, alhoewel dit nie statisties beduidend was nie. 'n Analise van die tellings geallokeer aan die response tot die vraeslys, dui 'n uitkoms aan van bo 75% en was beskou as baie suksesvol in albei die intervensie groepe. Die gebruik van kortboodskapdienste (SMS) in hierdie gewigsverliesprogramme het inskiklikheid verbeter en uitvalskoerse verlaag, alhoewel nie statisties beduidend nie, en was deur die deelnemers beskou as 'n suksesvolle intervensie.
16

Location tracing from communicatingav ailable satellites

Sri Venkata Vamsi, Veeramreddy January 2021 (has links)
This paper represents the android mobile application which is built to track thelast position of the user through satellites which are available for communication.Today mobile applications are becoming an important role in our daily lives andthere is an app for everything you imagine. This app was focusing to get thedevice location with available satellites if internet connection in the device andwith telephone network when there is no internet connection in the device.The main idea of this application was give help to the every women a helpin dangerous situations, whenever the user triggers the alert icon on the androidapplication it creates communication between satellite and database. As androidusers increasing day by day this application gives the security for women in dangerous situations. If there is an internet connection in the android device it usesavailable GNSS satellites to send position of the device otherwise. If the internetconnection was not stable in the device then it sends the location through a shortmessage service (SMS) it gives more reliability for users to use this application.Ifthe internet in the android device was stable then the database server automatically updates the position of the user in google sheets. This information givesthe exact position of the user in dangerous situations. As there are so manyother application with same working function this application was different fromall others. This application has some unique features in it, as it stores the everynew location of the user for every 5minutes this tells the exact location of theuser.This application uses the all available GNSS satellites to get the location ofthe user
17

Short Message ServiceVulnerability Analysis : An attempt to attack the Serial Line on Symbian Smartphone In Orderto Inject Arbitrary SMS

Ilaghi, Mahya January 2011 (has links)
Short Message Service (SMS) is a permanently available service on mobile phone networks. In addition to text messages, it supports binary messages to provide various services to mobile phones. SMS security has a strong relationship to the security of mobile phones. Due to the open functionality of mobile phone networks, SMS can be exposed to dierent kind of attacks. To cope with the increasing demand for secure SMS, it is crucial to perform a vulnerability analysis of SMS-implementations to nd out potential security vulnerabilities that smartphones may be exposed to. Conducting vulnerability analyses of SMS is dicult, as one would need to send a large amount of SMS through the mobile phone network in order to conduct such analyses. However, if the need for a mobile phone network is removed from the vulnerability analysis, the diculties of performing it can be considerably reduced. Collin Mulliner and Challie Miller (2009) presented a testing platform (without the engagement of a mobile phone network) for this purpose in three popular mobile phone operating systems: the iPhone, Android and Windows Mobile. They claimed that their testing platform could be ported to other smartphone operating systems (OS). Since the Symbian operating system is one of the most popular smartphone platforms, this thesis focuses on how to port this testing platform to the Symbian OS for vulnerability analysis of SMS-implementations. The research methodology behind this study was an experimental research method, conducted by presenting a hypothesis and developing an artifact to test it. This research produced a key finding: that it is not feasible to implement this vulnerability analysis for SMS-implementations on the Symbian OS, when considering the prerequisites that Collin Mulliner and Charlie Miller dened in their work. They claimed that, if there is an application level access to the serial line for the modem or the ability to add or remove the arbitrary driver, then it is feasible to port their testing framework to other operating systems. This research discovers that neither of these conditions exists in the Symbian OS.
18

Lightweight Message Authentication for the Internet of Things

Höglund, Rikard January 2014 (has links)
During the last decade, the number of devices capable of connecting to the Internet has grown enormously. The Internet of Things describes a scenario where Internet connected devices are ubiquitous and even the smallest device has a connection to the Internet. Many of these devices will be running on constrained platforms with limited power and computing resources. Implementing protocols that are both secure and resource efficient is challenging. Current protocols have generally been designed for mains powered devices; hence, they are not optimized for running on constrained devices. The Constrained Application Protocol (CoAP) is a protocol for network communication specifically designed for constrained devices. This thesis project examines CoAP and presents an extension that adds authentication in a way that is suitable for constrained devices, with respect to minimizing resource use. The proposed solution has been compared and contrasted with other alternatives for authentication, particularly those alternatives used with CoAP. It has also been implemented in code and experimentally evaluated with regards to performance versus vanilla CoAP. The main goal of this project is to implement a lightweight authentication extension for CoAP to be deployed and evaluated on constrained devices. This extension, called Short Message Authentication ChecK (SMACK), can be used on devices that require a method for secure authentication of messages while using only limited power. The main goal of the extension is to protect against battery exhaustion and denial of sleep attacks. Other benefits are that the extension adds no additional overhead when compared with the packet structure described in the latest CoAP specification. Minimizing overhead is important since some constrained networks may only support low bandwidth communication. / Under det senaste århundradet har antalet enheter som kan ansluta sig till Internet ökat enormt. ”The Internet of Things” beskriver ett scenario där Internet-anslutna enheter är närvarande överallt och även den minsta enhet har en uppkoppling till Internet. Många av dessa enheter kommer att vara begränsade plattformar med restriktioner på både kraft- och beräkningsresurser. Att implementera protokoll som både är säkra och resurseffektiva är en utmaning. Tillgängliga protokoll har i regel varit designade för enheter med anslutning till det fasta kraftnätet; på grund av detta är de inte optimerade för att köras på begränsade plattformar. Constrained Application Protocol (CoAP) är ett protokoll för nätverkskommunikation speciellt framtaget för begränsade plattformar. Denna uppsats undersöker CoAP protokollet och presenterar ett tillägg som erbjuder autentisering på ett sätt som passar begränsade plattformar, med avseende på att minimera resursanvändning. Den föreslagna lösningen har blivit beskriven och jämförd med andra alternativ för autentisering, speciellt de alternativ som används med CoAP. Lösningen har också implementerats i kod och blivit experimentellt utvärderad när det gäller prestanda jämfört med standardversionen av CoAP. Det huvudsakliga målet för detta projekt är att implementera en lättviktslösning för autentisering till CoAP som ska installeras och utvärderas på begränsade plattformar. Detta tillägg, Short Message Authentication checK (SMACK), kan användas på enheter som behöver en metod för säker autentisering av meddelanden samtidigt som kraftåtgången hålls låg. Huvudmålet för detta tillägg är att skydda mot batteridräneringsattacker och attacker som hindrar en enhet från att gå i viloläge. Andra fördelar är att tillägget inte kräver någon extra dataanvändning jämfört med paketstrukturen som beskrivs i den senaste CoAP-specifikationen. Att minimera overhead i kommunikationsprotokoll är viktigt eftersom vissa begränsade nätverk endast stödjer kommunikation över låg bandbredd.
19

Consumer behaviour in the context of SMS-based marketing

Shareef, M.A., Dwivedi, Y.K., Rana, Nripendra P. 27 September 2020 (has links)
Yes / Given the potential benefits such as time and location-based advertisements, the scope of interactivity and customisation through one-to-one target marketing, SMS-based (Short Messaging Service) advertisement, is now being considered as an important alternative marketing channel. This has raised a real challenge for marketers to harness the potential of this alternative channel by overcoming several limiting issues such as security, privacy, authenticity, and irritation of unknown senders. The main objective of this study is to identify and review relevant research issues faced by wireless marketing (particularly via SMS-based advertisement) as an aide to identify potential research gaps and for developing future guiding principles. The review and analysis of literature suggest that there is scope of undertaking further research on issues related to different cultures reflecting ubiquitous traits of mobile phone, SMS advertisement, market segmentation, location and time sensitive delivery, content and context of advertisement, language and appropriate delivery.
20

[en] SMS ADOPTION BY MOBILE USERS: A PROPOSAL BASED ON THE TECHNOLOGY ACCEPTANCE MODEL / [pt] ADOÇÃO DO SERVIÇO DE MENSAGENS DE TEXTO (SMS) PELOS USUÁRIOS DE TELEFONIA MÓVEL: UMA PROPOSTA BASEADA NO MODELO DE ACEITAÇÃO DA TECNOLOGIA

JESSICA MATTOSO DA FONSECA 21 August 2006 (has links)
[pt] As operadoras celulares estão vivendo um momento no qual a comunicação por voz praticamente já chegou ao seu ápice e os serviços de valor agregado estão se tornando peças fundamentais para o sucesso de uma empresa móvel. O Serviço de Mensagem de Texto (SMS) é o serviço de valor agregado mais difundido atualmente, sendo responsável por aproximadamente 80% da receita de dados da maioria das operadoras móveis no Brasil e no mundo. Esta dissertação busca compreender os motivadores que levam os usuários de celular a adotarem o Serviço de Mensagem de Texto. Para compreendê-los foi realizada uma análise baseada no Modelo de Aceitação da Tecnologia (TAM - Technology Acceptance Model) incluindo as variáveis qualidade do serviço percebida e custo percebido. A análise de dados foi feita por meio de análise multivariada utilizando o software estatístico SPSS 13.0, e o sistema de equações estruturais foi suportado pelo software AMOS 4.0. Constatou-se no modelo que, apesar das variáveis Facilidade Percebida, Qualidade do Serviço Percebida e Custo Percebido influenciarem a Atitude em Relação ao Uso; a Utilidade Percebida é o constructo mais relevante na determinação da Atitude em Relação ao Uso e da Intenção de Uso, e que a Intenção de Uso é fundamental para o constructo Uso Real. / [en] Mobile operators have been challenged since voice communication reached its peak and value added services became crucial for success. SMS is the most adopted value added service and responds for 80% of mobile data revenues in Brazil and in the world. This essay tries to understand customer`s motivation for adopting SMS service. An extended version of TAM - Technology Acceptance Model that includes the Perceived Quality Service and the Perceived Cost variables was analyzed in order to understand these factors. The software SPSS 13.0 helped to perform a multivariate data analysis and the structured equations were supported by the software AMOS 4.0. The analysis of results provides the following conclusions: Perceived Ease of Use, Perceived Service Quality and Perceived Cost influence the Attitude toward Using; Perceived Usefulness is the most relevant construct to determine the Attitude toward Using and the Behavioral Intention to Use; Behavioral Intention to Use is key driver to the construct Actual Use.

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