There is evidence that athermal radiofrequency radiation can alter Heat Shock Protein (HSP) expression or protein phosphorylation, or alter MAP kinase signalling. Effects of long-term exposure in brain tissue due to repeated HSP perturbation (eg an inhibition of apoptosis) have been hypothesised (French et al, 2001). This study aimed to investigate the RNA expression profile (12,000 genes) and HSP family protein expression levels after either acute 1-hour or chronic 4-day intermittent exposures to simulated GSM radiation in a human primary fibroblast model. The results found minimal or no effects of GSM. Flasks were exposed to 900 MHz (217 Hz modulation) at 0.18 W/kg SAR within a Transverse Electromagnetic Mode chamber (TEM cell). Cultures rested for 2 hours before exposures. Affymetrix U95A microarray analysis of a single pilot set of experiments showed that about 40 genes were reported as upregulated &gt=2.5 fold in each condition. There was no evidence of altered expression of any MAPK-associated genes. Target genes reported in both conditions (CBFA2T1, ZNF148, ITGA1), and genes altered in one condition (CCS, PLEC1, BIRC5), and marginally altered HSP72 were selected for PCR analysis. No other members of the HSP family were altered. In three replicate experiments assayed by real-time PCR, six genes were either unchanged or showed randomly variable expression. However HSP72 RNA showed possible consistent slight upregulation of 1.37 +/- 0.21 in the chronic condition. Western immunoblots of HSP-60, -70, -72 and -V90 proteins showed no significant changes 5 hours after exposure. In preliminary studies using a serum starvation protocol, ERK-1 phosphorylation was unaltered after 5 or 30 minutes GSM (single experiments). When flasks were transiently cooled, ERK-1 phosphorylation was increased 20 minutes later, indicating a source of artefact in some protocols. An inflammatory challenge experiment with a low-dose of the cytokine IL-1???? found that acute GSM exposure post-challenge inhibited NF????B-mediated GRO???? induction by 1.5 fold (2 experiments). Preconditioning with mild heat induces transient inhibition of both NF????B signalling and apoptosis. Other studies indicate that EMF exposures similarly evoke cytoprotection. It is suggested that GSM evoked cytoprotective signalling in this inflammatory model.

<p>Market information and established communication between seller and buyer play an important role in business activities. This thesis investigates the Transkei area in the Eastern Cape&nbsp / Province, South Africa to find out how to empower rural farmers by providing them with less-expensive mobile technology enabling them to post and advertise their produce, access market&nbsp / information on a common database, and find and communicate with potential customers. The farmers&rsquo / requirements were identified using quantitative and qualitative methods and a prototype&nbsp / consisting of USSD and web applications was developed. It allows the farmer to follow a sequence of menu commands to send a request to the database and access market information, such&nbsp / as commodity prices, and post information about their own produce so as to attract more customers. The low cost of USSD and the ubiquity of mobile phones enable the system to be usable, affordable and effective. During the final stage of development, the system was tested successfully and addressed a major problem faced by farmers, i.e. lack of access to market information.</p>

<p>Market information and established communication between seller and buyer play an important role in business activities. This thesis investigates the Transkei area in the Eastern Cape&nbsp / Province, South Africa to find out how to empower rural farmers by providing them with less-expensive mobile technology enabling them to post and advertise their produce, access market&nbsp / information on a common database, and find and communicate with potential customers. The farmers&rsquo / requirements were identified using quantitative and qualitative methods and a prototype&nbsp / consisting of USSD and web applications was developed. It allows the farmer to follow a sequence of menu commands to send a request to the database and access market information, such&nbsp / as commodity prices, and post information about their own produce so as to attract more customers. The low cost of USSD and the ubiquity of mobile phones enable the system to be usable, affordable and effective. During the final stage of development, the system was tested successfully and addressed a major problem faced by farmers, i.e. lack of access to market information.</p>

There is evidence that athermal radiofrequency radiation can alter Heat Shock Protein (HSP) expression or protein phosphorylation, or alter MAP kinase signalling. Effects of long-term exposure in brain tissue due to repeated HSP perturbation (eg an inhibition of apoptosis) have been hypothesised (French et al, 2001). This study aimed to investigate the RNA expression profile (12,000 genes) and HSP family protein expression levels after either acute 1-hour or chronic 4-day intermittent exposures to simulated GSM radiation in a human primary fibroblast model. The results found minimal or no effects of GSM. Flasks were exposed to 900 MHz (217 Hz modulation) at 0.18 W/kg SAR within a Transverse Electromagnetic Mode chamber (TEM cell). Cultures rested for 2 hours before exposures. Affymetrix U95A microarray analysis of a single pilot set of experiments showed that about 40 genes were reported as upregulated &gt=2.5 fold in each condition. There was no evidence of altered expression of any MAPK-associated genes. Target genes reported in both conditions (CBFA2T1, ZNF148, ITGA1), and genes altered in one condition (CCS, PLEC1, BIRC5), and marginally altered HSP72 were selected for PCR analysis. No other members of the HSP family were altered. In three replicate experiments assayed by real-time PCR, six genes were either unchanged or showed randomly variable expression. However HSP72 RNA showed possible consistent slight upregulation of 1.37 +/- 0.21 in the chronic condition. Western immunoblots of HSP-60, -70, -72 and -V90 proteins showed no significant changes 5 hours after exposure. In preliminary studies using a serum starvation protocol, ERK-1 phosphorylation was unaltered after 5 or 30 minutes GSM (single experiments). When flasks were transiently cooled, ERK-1 phosphorylation was increased 20 minutes later, indicating a source of artefact in some protocols. An inflammatory challenge experiment with a low-dose of the cytokine IL-1???? found that acute GSM exposure post-challenge inhibited NF????B-mediated GRO???? induction by 1.5 fold (2 experiments). Preconditioning with mild heat induces transient inhibition of both NF????B signalling and apoptosis. Other studies indicate that EMF exposures similarly evoke cytoprotection. It is suggested that GSM evoked cytoprotective signalling in this inflammatory model.

Magister Scientiae - MSc / Market information and established communication between seller and buyer play an important role in business activities. This thesis investigates the Transkei area in the Eastern Cape Province, South Africa to find out how to empower rural farmers by providing them with less-expensive mobile technology enabling them to post and advertise their produce, access market information on a common database, and find and communicate with potential customers. The farmers’ requirements were identified using quantitative and qualitative methods and a prototype consisting of USSD and web applications was developed. It allows the farmer to follow a sequence of menu commands to send a request to the database and access market information, such as commodity prices, and post information about their own produce so as to attract more customers. The low cost of USSD and the ubiquity of mobile phones enable the system to be usable, affordable and effective. During the final stage of development, the system was tested successfully and addressed a major problem faced by farmers, i.e. lack of access to market information. / South Africa

A South African GSM telecommunications market consisting of two incumbents and an entering third player, is modelled utilising a non-linear, system dynamics approach. The model calculates subscriber choice based on a calculated utility. The utility is used to obtain a probability which is fed into a Bass type differential equation relating the different states in the model to their time derivatives. The model encapsulates all the prominent postpaid price plans in the market, as well as five different demographic market segments. Model Predictive Control is used to synthesise a linear feedback controller which uses the observed market state to optimally determine a price time series for one of the operators’ products. The series will maximise Average Revenue Per User (ARPU) for the operator over the simulation time interval. Besides ARPU, the controller is also able to increase total revenue and minimise churn over the simulated interval for the optimising operator, and thus provides valuable decision support to the marketing management of such an operator. / Dissertation (MEng (Electronic))--University of Pretoria, 2004. / Electrical, Electronic and Computer Engineering / unrestricted

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.

Thesis (M.S.) -- Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.

This thesis addresses the phenomena of Mobile Virtual Network Operators (MVNO): often MVNO do not come from the telecom sector but they rent the network to mobile operators to become fully mobile operators on their own. So they compete directly not only with the other mobile operators but also with their hosting mobile operator.<p><p>Hosting MVNOs, supporting them from both operational and commercial perspectives are new challenges for the mobile operators: they have to set up a specific internal organization because they used to be a vertically integrated industrial structure. All of this represents tremendous changes for them.<p><p>This thesis describes first the strategic models for hosting MVNOs. The regulatory aspects, that are an essential driver for the liberalization of network economies, are then analyzed. The key point is: are the MVNO able to increase the efficiency and competitiveness of mobile markets.<p><p>Another important aspect is the modelling of a mobile network: the MVNOs will use some components while other components are unuseful for them. Without such model, it is impossible to derive the right costs and price to be charged to the MVNO in order to have a win win industrial model for both the MVNO and its hosting operator.<p><p>A case study of a corporate MVNO focusing on needs of multinationals is analyzed. Such case study describes all the steps for an economic actor to become MVNO from scratch. Such MVNO are not yet present although there is a market demand.<p>The last chapter makes a comparative study of the MVNO markets in the European Union.<p><p>Cette étude aborde le phénomène des opérateurs de réseaux mobiles virtuels ;il s’agit d’acteurs économiques - parfois sans lien aucun avec les télécommunications - qui louent le réseau d’opérateurs mobiles ;ils deviennent à leur tour opérateurs à part entière au point de devenir concurrent non seulement des autres opérateurs mobiles mais aussi de l’opérateur mobile qui leur a loué une partie de son réseau.<p><p>L’hébergement technique de l’opérateur virtuel, son support opérationnel et commercial, l’organisation que doit mettre en place l’opérateur mobile pour héberger son opérateur virtuel afin de partager avec lui son réseau sont des nouveaux défis auxquels les opérateurs mobiles, habitués à être des structures industrielles totalement intégrées verticalement, font face pour la première fois.<p><p>Cette étude traite des modèles d’implémentation des opérateurs de réseaux mobiles virtuels :elle aborde d’abord les aspects stratégiques qui fixent le cadre pour les opérateurs mobiles qui veulent ou sont forcés à héberger des opérateurs virtuels. Les aspects réglementaires, une composante essentielle des économies de réseaux en voie de libéralisation, sont ensuite étudiés, en particulier, comment les opérateurs virtuels peuvent contribuer à améliorer la compétitivité et la libéralisation de ces marchés.<p><p>L’étude modélise ensuite le réseau d’un opérateur mobile de façon à mettre en évidence les éléments à partager qui seront utilisés par l’opérateur virtuel. Cette modélisation est essentielle pour déterminer le coût de l’hébergement et du partage du réseau de façon à créer les conditions de rentabilité de ce modèle d’opérateur virtuel.<p><p>On aborde enfin un cas d’étude d’un candidat à devenir opérateur de réseau mobile virtuel qui souhaite répondre à la demande transnationale des grandes entreprises. Ce type d’opérateur virtuel est encore inexistant de nos jours.<p>Enfin, nous terminons par une étude comparée de la situation des opérateurs mobiles virtuels à travers l’Union Européenne.<p><p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished