Made available in DSpace on 2014-12-17T14:52:42Z (GMT). No. of bitstreams: 1 PatrickRA.pdf: 1597143 bytes, checksum: be7cb13888aef28762e6bca5f5f95882 (MD5) Previous issue date: 2008-12-05 / One of the best examples of the Information and Communication Technology (ICT) evolutions is on the high capability of storing and processing data into smaller devices, creating a new business condition, the mobility . This mobility in a deeper analysis proposes a business remodeling in many different areas (business segmentations), through the Internet anywhere at any time, allowing managers and researchers to think again their actual models that work nowadays in companies and public institutions, modifying the way internal and external clients can be attended. This thesis analyzes issues on mobile business adoption, technological evolutions and the impacts caused by this new reality the access to information anywhere at any time . This research is exploratory and shows a compilation of similar papers and thesis describing how was conducted the survey within 50 companies in the states of Rio Grande do Norte, Pernambuco and Cear?. The statistics analysis showed the different level of mobile technology usage from simple voice communications to wide band data transmission. The analysis pointed that canonic correlation was the most effective type of analysis to describe the relations among all groups of variables showing which of them are relevant, or not, for mobile technology adoption / Um dos principais exemplos da velocidade com que as mudan?as acontecem na Tecnologia da Informa??o e Comunica??o (TIC) est? na sua maior capacidade de processamento e armazenamento em dispositivos cada vez menores, criando uma nova condi??o para diversos neg?cios, a mobilidade. Esta mobilidade, que em uma an?lise mais aprofundada pode propor inclusive uma remodelagem de muitos neg?cios atrav?s do acesso ? internet em qualquer lugar e a qualquer tempo, permitir? ainda que gestores e pesquisadores repensem os modelos atuais de funcionamento de empresas e organiza??es al?m do atendimento a clientes internos e externos. Este trabalho avalia fatores que influenciam a ado??o de tecnologias m?veis, evolu??o tecnol?gica e o impacto provocado nas empresas por esta nova realidade a de acesso ? informa??o em qualquer lugar e a qualquer momento . O trabalho cita o que outros pesquisadores j? identificaram dentro do tema de tecnologias m?veis e como foi realizada esta pesquisa explorat?ria, que foi aplicada nas empresas atrav?s de question?rios do tipo survey em um universo de 50 empresas dos estados do Rio Grande do Norte, Pernambuco e Cear?. A an?lise dos resultados foi dividida em an?lise descritiva, an?lise de correspond?ncia, an?lise de agrupamento (por vari?veis e por caso) e an?lise de correla??o can?nica, sendo esta a que melhor permitiu identificar os diferentes n?veis de utiliza??o das tecnologias m?veis que v?o desde a utiliza??o para voz at? aplica??es que demandam grandes volumes de transmiss?o de dados e as caracter?sticas das empresas, empres?rios, e da utiliza??o da TIC que influenciam, ou n?o, na ado??o de tecnologias m?veis

Multi-antenna wireless communication systems that employ a large number of antennas have recently stirred a lot of research interest. This is mainly due to the possibility of achieving very high spectral efficiency, power efficiency, and link reliability in such large-scale multiple-input multiple-output (MIMO) systems. An emerging architecture for large-scale multiuser MIMO communications is one where each base station (BS) is equipped with a large number of antennas (tens to hundreds of antennas) and the user terminals are equipped with fewer antennas (one to four antennas) each. The backhaul communication between base stations is also carried out using large number of antennas. Because of the high dimensionality of large-scale MIMO signals, the computational complexity of various transceiver operations can be prohibitively large. Therefore, low complexity techniques that scale well for transceiver signal processing in such large-scale MIMO systems are crucial. The transceiver operations of interest include signal encoding at the transmitter, and channel estimation, detection and decoding at the receiver. This thesis focuses on the design and analysis of novel low-complexity transceiver signal processing schemes for large-scale MIMO systems. In this thesis, we consider two types of large-scale MIMO systems, namely, massive MIMO systems and generalized spatial modulation MIMO (GSM-MIMO) systems. In massive MIMO, the mapping of information bits to modulation symbols is done using conventional modulation alphabets (e.g., QAM, PSK). In GSM-MIMO, few of the avail-able transmit antennas are activated in a given channel use, and information bits are conveyed through the indices of these active antennas, in addition to the bits conveyed through conventional modulation symbols. We also propose a novel modulation scheme named as precoder index modulation, where information bits are conveyed through the index of the chosen precoder matrix as well as the modulation symbols transmitted. Massive MIMO: In this part of the thesis, we propose a novel MIMO receiver which exploits channel hardening that occurs in large-scale MIMO channels. Channel hardening refers to the phenomenon where the off-diagonal terms of HH H become much weaker compared to the diagonal terms as the size of the channel gain matrix H increases. We exploit this phenomenon to devise a low-complexity channel estimation scheme and a message passing algorithm for signal detection at the BS receiver in massive MIMO systems. We refer to the proposed receiver as the channel hardening-exploiting message passing (CHEMP) receiver. The key novelties in the proposed CHEMP receiver are: (i) operation on the matched filtered system model, (ii) Gaussian approximation on the off-diagonal terms of the HH H matrix, and (iii) direct estimation of HH H instead of H and use of this estimate of HH H for detection The performance and complexity results show that the proposed CHEMP receiver achieves near-optimal performance in large-scale MIMO systems at complexities less than those of linear receivers like minimum mean squared error (MMSE) receiver. We also present a log-likelihood ratio (LLR) analysis that provides an analytical reasoning for this better performance of the CHEMP receiver. Further, the proposed message passing based detection algorithm enables us to combine it with low density parity check (LDPC) decoder to formulate a joint message passing based detector-decoder. For this joint detector-decoder, we design optimized irregular binary LDPC codes specific to the massive MIMO channel and the proposed receiver through EXIT chart matching. The LDPC codes thus obtained are shown to achieve improved coded bit error rate (BER) performance compared to off-the-shelf irregular LDPC codes. The performance of the CHEMP receiver degrades when the system loading factor (ratio of the number of users to the number of BS antennas) and the modulation alpha-bet size are large. It is of interest to devise receiver algorithms that work well for high system loading factors and modulation alphabet sizes. For this purpose, we propose a low-complexity factor-graph based vector message passing algorithm for signal detection. This algorithm uses a scalar Gaussian approximation of interference on the basic sys-tem model. The performance results show that this algorithm performs well for large modulation alphabets and high loading factors. We combine this detection algorithm with a non-binary LDPC decoder to obtain a joint detector-decoder, where the field size of the non-binary LDPC code is same as the size of the modulation alphabet. For this joint message passing based detector-decoder, we design optimized non-binary irregular LDPC codes tailored to the massive MIMO channel and the proposed detector. GSM-MIMO: In this part of the thesis, we consider GSM-MIMO systems in point-to-point as well as multiuser communication settings. GSM-MIMO has the advantage of requiring only fewer transmit radio frequency (RF) chains than the number of transmit antennas. We analyze the capacity of point-to-point GSM-MIMO, and obtain lower and upper bounds on the GSM-MIMO system capacity. We also derive an upper bound on the BER performance of maximum likelihood detection in GSM-MIMO systems. This bound is shown to be tight at moderate to high signal-to-noise ratios. When the number of transmit and receive antennas are large, the complexity of en-coding and decoding of GSM-MIMO signals can be prohibitively high. To alleviate this problem, we propose a low complexity GSM-MIMO encoding technique that utilizes com-binatorial number system for bits-to-symbol mapping. We also propose a novel layered message passing (LaMP) algorithm for decoding GSM-MIMO signals. Low computational complexity is achieved in the LaMP algorithm by detecting the modulation bits and the antenna index bits in two deferent layers. We then consider large-scale multiuser GSM-MIMO systems, where multiple users employ GSM at their transmitters to communicate with a BS having a large number of receive antennas. For this system, we develop computationally efficient message passing algorithms for signal detection using vector Gaussian approximation of interference. The performance results of these algorithms show that the GSM-MIMO system outperforms the massive MIMO system by several dBs for the same spectral efficiency. Precoder index modulation: It is known that the performance of a communication link can be enhanced by exploiting time diversity without reducing the rate of transmission using pseudo random phase preceding (PRPP). In order to further improve the performance of GSM-MIMO, we apply PRPP technique to GSM-MIMO systems. PRPP provides additional diversity advantage at the receiver and further improves the performance of GSM-MIMO systems. For PRPP-GSM systems, we propose methods to simultaneously precode both the antenna index bits and the modulation symbols using rectangular precoder matrices. Finally, we extend the idea of index modulation to pre-coding and propose a new modulation scheme referred to as precoder index modulation (PIM). In PIM, information bits are conveyed through the index of a prehared PRPP matrix, in addition to the information bits conveyed through the modulation symbols. PIM is shown to increase the achieved spectral efficiency, in addition to providing diver-sity advantages.

Detta projekt har utförts på uppdrag av Saab Dynamics. Syftet med projektet var att skapa ett system för att ersätta den befintliga utrustning som fanns för att simulera radar vid testning av vissa vapensystem.   Systemet byggdes upp med hjälp av GPRS, GPS och transportprotokollen TCP och UDP. Huvuddelen av arbetet berörde GPS och GPRS.   Denna rapport är en redogörelse för systemets framtagning och de verktyg och metoder som användes, samt en fördjupning i ämnena GPS, GPRS och deras olika protokoll. Rapporten tar även kort upp alternativa lösningar till datasamtal.   Slutsatsen som kan dras utifrån resultatet av detta projekt är att systemet fungerar och kan vara användbart i framtiden efter vidareutveckling. / This project has been carried out on behalf of Saab Dynamics. The purpose of the project was to create a system to replace the existing equipment for simulating radar when testing certain weapon systems.   The system was created using GPRS, GPS and the transport protocols TCP and UDP. GPS and GPRS were used the most.   This report is a description of the system's design and the tools and methods used to create it, as well as an in depth look into the subjects of GPS, GPRS and their various protocols. The report also briefly discusses some alternative solutions that could have been used instead of data calls.   The conclusion that can be drawn from the results of this project is that the system works and can be useful in the future with further development.

Le brouillard électromagnétique dans lequel nous vivons en permanence estaujourd’hui montré du doigt car, outre les risques sanitaires qu’il pourrait engendrer, illimite l’usage de certaines technologies. L’importance des interférences entre réseauxsans fil, ou la peur du piratage sur ces mêmes réseaux, en sont deux exemples. Cetravail de thèse vise à développer un nouveau moyen de protection contre certaines deces ondes électromagnétiques. Plus spécifiquement, ce travail se focalise sur unetechnologie capable de filtrer uniquement les ondes WiFi et GSM à travers de grandessurfaces d’une habitation, comme un mur. Pour ce faire, la fonctionnalisation d’uncomposant standard des bâtiments, le papier-peint, a été étudié.L’utilisation de surfaces sélectives en fréquence a été retenue. Ces motifs sontdirectement imprimés sur du papier à l’aide d’encre conductrice et de la techniqued’impression flexographique. L’étude s’est également portée sur la réalisation de motifsde filtrage innovants. Les résultats de simulation montrent qu’ils sont capables de filtrerdeux ou trois bandes, qu’ils sont quasiment insensibles à la polarisation et à l’angled’incidence dans une plage allant de 0° à ± 80°. Le travail a ensuite permis dedémontrer la faisabilité pratique de ce concept aux stades laboratoire et industriel.Ensuite, nous avons démontré expérimentalement l’efficacité de ce concept dans lesbandes WiFi. La transmission atteint alors -30 dB. Enfin, une validation expérimentaledu produit en situation réelle a été menée, à savoir la pose du papier-peint sur du plâtre,du bois, l’influence de la colle ou encore la pose d’une couche de papier-peint décoratifpar-dessus le produit.En conclusion, les résultats pratiques obtenus confirment les résultats théoriquesestimés et, permettent à ce nouveau concept, appelé métapapier, d’être suffisammentefficace pour permettre la réduction des ondes WiFi ou GSM. / The electromagnetic smog in which we live today is nowadays a real issue because it limits the use of certain technologies and also because there are some potential health risks associated with it, even if the latter is still a controversial subject. The importance of the interferences between wireless networks or the possibility of data hacking on the same networks are two examples. The aim of this thesis is to develop a new way to protect buildings against some of these electromagnetic waves. More specifically, this work focuses on a technology able to filter only the WiFi and the GSM waves through large areas of a home, like a wall for example. To do this, the functionalization of a standard component of buildings, the wallpaper, was studied. The use of frequency selective surface (FSS) was chosen. These patterns are printed directly on paper with a conductive ink printing technology: the flexography. The study also focuses on the realization of innovative filter designs. Simulation results show that these novel FSS are able to filter two or three bands. They are almost insensitive to the polarization and to the angle of incidence in the range of 0° to ±80°. The realization feasibility of this concept in a laboratory or in industrial conditions was demonstrated. Next, an experimental demonstration of this concept in the WiFi bands was carried out. In this context, the transmission coefficient was reached -30 dB. Finally, an experimental validation of the product in real conditions of use was conducted, namely the wallpaper was put over plasterboards or over wood panels. Also, the influence of the glue on the general performances and the placement of a decorative wallpaper over the FSS wallpaper were studied. In conclusion, the practical results obtained confirm and validate the theoretical predictions of this new concept, called metapaper, and show that the practical realizations are efficient enough to allow the reduction of WiFi or GSM signals.

The main goal of this master’s thesis is to represent the development of accounting softwares depending on the development of electronic banking. Particular chapters subsequently deal with direct banking - its formation, services and security, concerning accounting software as well as the interconnection of banks and the company accountancy using conversion applications integrated into the economical software.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: This thesis investigate the di erent available GSM bearer channels that can be used to launch a cellphone banking application. Speci c attention is given to launch such a cellphone banking application to the so called \bottom of the pyramid". In South Africa, there are an estimate 11 to 13 million people with no bank accounts. The cellphone create an ideal opportunity to be used as a tool to reach this untapped market segment that today mainly uses cash to pay for day to day living expenses. The thesis provide more information on the cellphone banking arena in South Africa as well as certain projects in other parts of the world. The thesis also highlight new devel- opments on cellphone technology that include Android and IPhone delivery channels. Focus is placed on how the cellphone banking presentation layer must be delivered through the USSD GSM bearer channel. USSD is at the current moment the ultimate channel to consider due to its extensive reach and ability to work on any GSM cellphone handset. In conclusion, although cellphone banking can be used by any person, the bene t to bring nancial services to the bottom end of the pyramid must be considered to achieve nancial inclusion. The cellphone due to its reach is the ideal medium to access this lower end market. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek beskikbare GSM selfoon kanale wat gebruik kan word om 'n selfoon bankdienste toepassing te initieer. Spesi eke aandag word gegee om so 'n selfoon bankdienste toepassing uit te rol na die sogenaamde onderste gedeelte van die bevolkings piramiede. Die tesis verskaf meer informasie oor die selfoon bankdienste arena in Suid Africa maar dit brei ook ooit oor sekere soortgelyke projekte in ander dele van die wereld. Die tesis lig ook nuwe ontwikkelings uit in selfoon tegnologie wat Android en IPhone mediums insluit. Fokus word geplaas op die selfoon bankdienste vertoning deur die USSD GSM kanaal. USSD is huidiglik die beste kanaal om te oorweeg as gevolg van die wydverspreide beskik- baarheid omdat die tegnologie op enige selfoon handstuk werk. Die uiteindelike gevolgtrekking uit die werkstuk is dat selfoon bankdienste deur enige persoon gebruik kan word, maar selfoon bankdienste is 'n goeie idee om te oorweeg om mense in te sluit uit die onderste gedeelte van die bevolkings piramiede. Die selfoon kan dus as 'n ideale medium gebruik word om hierdie mense te betrek by nansiele dienste.

The rapidly growing demand for UWB as high data rates wireless communications technology, since the Federal Communications Commission (FCC) allocated the bandwidth of UWB from 3.1GHz to 10.6 GHz. Antenna also plays an essential role in UWB system. However, there are some difficulties in designing UWB antenna as compared to narrowband antenna. The primary requirement of UWB antennas is be able to operate over frequencies released by the FCC. Moreover, the satisfaction of radiation properties and good time domain performance over the entire frequency range are also necessary. In this thesis, designing and analysing printed crescent shape monopole antenna, Planar Inverted F-L Antenna (PIFLA) and Planar Inverted FF Antenna (PIFFA) are focused. A Planar Inverted FF Antenna (PIFFA) can be created to reduce the potential for interference between a UWB system and other communications protocols by using spiral slot. The antennas exhibits broadside directional pattern. The performances such as return loss, radiation pattern and current distribution of the UWB antennas are extensively investigated and carried out. All the results have been demonstrated using simulation and experimentally whereby all results satisfy the performance under - 10dB point in the bandwidth of UWB. In addition the miniaturization of MIMO/diversity Planar Inverted-F antenna (PIFA) which is suitable for pattern diversity in UWB applications is presented. This antenna assembly is formed by two identical PIFAs, a T-shaped decoupling structure which connects the two PIFAs and a finite ground plane with a total compact envelope dimension of 50 x 90 x 7.5mm³. The radiation performance of the proposed MIMO antenna was quite encouraging and provided an acceptable agreement between the computed and measured envelope correlation coefficient and channel capacity loss.

This study explores complexity metrics for business artifact process models described by Case Management Model and Notation (CMMN). Process models are usually described using Business Process Management (BPM), which is a relatively mature discipline with a large number of practitioners. Over the last few decades a new way of describing data intensive business processes has emerged in BPM literature, for which traditional BPM is no longer adequate. This emerging method, used to describe more flexible processes, is called business artifacts with Guard-Stage-Milestone (GSM). The work on GSM influenced CMMN, which was created to fill a market need for more flexible case management processes for knowledge workers. Complexity metrics have been developed for traditional BPM models, such as the Business Process Model and Notation (BPMN). However, traditional BPM is not suitable for describing GSM or CMMN process models. Therefore, complexity metrics developed for traditional process models may not be applicable to business artifact process models such as CMMN. This study addresses this gap by exploring complexity metrics for business artifact process models using CMMN. The findings of this study have practical implications for the CMMN standard and for the commercial products implementing CMMN. This research makes the following contributions: • The development of a formal description of CMMN using first-order logic. • An exploration of the relationship between CMMN and GSM and the development of transformation procedures between them. • A comparison between the method complexity of CMMN and other popular process methods, including BPMN, Unified Modeling Language (UML) Activity diagrams, and Event-driven Process Charts (EPC). • The creation of a systematic literature review of complexity metrics for process models, which was conducted in order to inform the creation of CMMN metrics. • The identification of a set of complexity metrics for the CMMN standard, which underwent theoretical and empirical validation. This research advances literature in the areas of method complexity, complexity metrics for process models, declarative processes, and research on CMMN by characterizing CMMN method complexity, identifying complexity metrics for CMMN, and exploring the relationship between CMMN and GSM. / School of Computing / Ph. D. (Computer Science)

This thesis examines the marginal cost of congested travel to a variety of businesses by observing time spent in congestion and estimating excess labor costs based upon the relevant value of time. The fleets in the scoping study represented commercial deliveries of goods and services, government agencies, and transit systems. Observations on limited-access expressways within the 13-county Atlanta metropolitan region were used in the analysis. Vehicles were monitored by using a passive GPS assembly that transmitted speed and location data in real-time to an off-site location. Installation and operation during the observation period required no interaction from the driver. Over 217 hours of good freeway movement during 354 vehicle-days was recorded. Rates of delay, expressed as a unit of lost minutes per mile traveled, were calculated by taking the difference in speeds observed during congestion from an optimal free-flow speed of 45 mph and dividing that by the distance traveled per segment. The difference between the 50th and 95th percentile delay rates was used as the measure for travel unreliability. Daily average values of extra time needed per fleet vehicle to ensure on-time arrivals were derived, and the median buffer across all fleets was 1.65 hours of added time per vehicle. Weekly marginal costs per fleet vehicle were estimated by factoring in the corresponding driver wages or hourly operation costs (for transit fleets). Equivalent toll rates were calculated by multiplying the 95th percentile delay rate by the hourly costs. The equivalent toll per mile traveled was representative of an equal relationship between the marginal costs of congestion experienced and a hypothetical state of free-flow travel (under first-best rules of marginal cost pricing). The median equivalent toll rates across all fleets was $0.43 per mile for weekday mornings, $0.13 per mile for midday weekdays, $0.53 per mile for afternoon weekdays and $0.01 per mile for weekday nights and weekends.

To support video communication over mobile environments has been one of the objectives of many engineers of telecommunication networks and it has become a basic requirement of a third generation of mobile communication systems. This dissertation explores the possibility of optimizing the utilization of shared scarce radio channels for live video transmission over a GSM (Global System for Mobile telecommunications) network and realizing error resilient video communication in unfavorable channel conditions, especially in mobile radio channels. The main contribution describes the adoption of a SEC (Second Error Correction) approach using ECC (Error Correction Coding) based on a Punctured Convolutional Coding scheme, to cope with residual errors at the application layer and enhance the error resilience of a compressed video bitstream. The approach is developed further for improved performance in different circumstances, with some additional enhancements involving Intra Frame Relay and Interleaving, and the combination of the approach with Packetization. Simulation results of applying the various techniques to test video sequences Akiyo and Salesman are presented and analyzed for performance comparisons with conventional video coding standard. The proposed approach shows consistent improvements under these conditions. For instance, to cope with random residual errors, the simulation results show that when the residual BER (Bit Error Rate) reaches 10-4, the video output reconstructed from a video bitstream protected using the standard resynchronization approach is of unacceptable quality, while the proposed scheme can deliver a video output which is absolutely error free in a more efficient way. When the residual BER reaches 10-3, the standard approach fails to deliver a recognizable video output, while the SEC scheme can still correct all the residual errors with modest bit rate increase. In bursty residual error conditions, the proposed scheme also outperforms the resynchronization approach. Future works to extend the scope and applicability of the research are suggested in the last chapter of the thesis.