Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 1998. / Bibliogr.: f. [83-88]. Document électronique également accessible en format PDF. CaQCU

Thesis (M.Sc.)--University of Waikato, 2007. / Title from PDF cover (viewed May 15, 2009) Includes bibliographical references (p. 99-100)

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 138-145). Also available via the Internet.

En el documento "Instalación del servicio de telefonía móvil para la conectividad y desarrollo social en las localidades de Apurímac, Ayacucho y Huancavelica", se puede observar que el trabajo realizado ha podido cuantificar los efectos relacionados a esta tecnología en los beneficios sociales de la población (ahorro en costo de transportes y ahorro en tiempo) y el nivel de inversión requerido para implementarlo, por parte de los operadores privados a través del mecanismo de subvención de la inversión. Esto demuestra, como la introducción de la telefonía móvil juega un rol relevante en la reducción de la pobreza en especial la rural. Por un lado, este medio de comunicación promueve el acceso a mercados de creación de empresas, reduce los problemas de información asimétrica y sustituye la necesidad de transportarse, increment{andose la productividad y la eficiencia. Por el otro, es una herramienta que ayuda en caso de desastres, permite la difusión de información ligada a la salud y educación, y promueve la creación de capital social. / Trabajo de investigación

El presente estudio tiene como objetivos: conocer las consecuencias del uso del Smartphone en el rendimiento académico de los estudiantes, identificar las razones que generan la necesidad de utilizar constantemente el celular, describir la influencia del Smartphone en su rendimiento académico y finalmente, identificar si el uso del Smartphone es percibido como beneficioso o perjudicial por los estudiantes en el rendimiento académico. / Tesis

<p>With the development of wireless communication technology, second-, third-, fourth-generation transmission systems based on electromagnetic (EM) waves are widely used. At the same time, public concerns have been raised about whether the use of such systems will have an impact on health and safety standards. The heating effect is the most prominent and scientifically verifiable biological effect. So, the influence of EM waves on human body is addressed by studying the heating characteristics on head models.</p> <p>The objective of this thesis is to study the effects of radio frequency (RF) waves radiation from mobile phones on the human head under different transmission generations. The six-layer head model is used to evaluate the specific absorption rate (SAR) distribution and thermal effect. This model allows to study the effects of SAR and temperature rise without the need for high computational resources. In order to find the effect of temperature rise and exposure time, the finite difference time domain (FDTD) method was used to solve the biothermal equation with appropriate boundary conditions.</p> <p>Also, different age-dependent head models are used to study the differences of SAR for children at different ages.</p> <p>In general, the results show that with the increase in frequency, the influence of the EM wave is more pronounced, as demonstrated by the SAR and temperature rise distribution. In addition, SAR distribution of younger ages show a significant increase, which indicates that children exposed to EM waves are subject to more harmed. </p>

Information appliances such as notebook computers and cellular telephones are becoming integral to the lives of many. These devices facilitate a variety of communication tasks, and are used for employment, education, and entertainment. Those with disabilities, however, have limited access to these devices, due in part to product designs that do not consider their special needs. A usability evaluation can help identify the needs and difficulties those with disabilities have when using a product and universal design principles can then be applied to enhance accessibility and usability. This study addresses the usability of two of the most common information appliances - notebook computers and cellular telephones. The usability of notebook computers was evaluated using a remote ethnographic method where participants recorded usability-related critical incidents. Participants included those with a wide range of abilities, such as legal blindness, total blindness, and upper extremity physical disabilities. Objective and subjective measures were used to determine the effects of several specific design parameters for cellular telephones. The notebook computer study revealed that participants have difficulty with non-standard keyboard layouts, the use of isometric pointing devices, case latches, and inadequate system feedback. User performance and ratings in the cellular telephone study were the best with the 12 mm lateral pitch and 0.7 mm key height, while the fewest task failures were committed using the 0.5 mm keystroke. Participants also preferred telephone models with large <Power>, <Send> and <End> keys located in prominent locations, and 22-point and 36-point display fonts. These results were used to generate product-specific design guidelines that can be used to design notebook computers and cellular telephones that are more usable and accessible for users with visual and upper extremity physical disabilities. Universal design implications are also discussed. / Master of Science

No description available.

This thesis investigates drivers willingness to engage with a mobile phone while driving. Many studies have looked into the effects on driving performance that can result from phone usage, but few studies have directly considered what can encourage or inhibit phone engagement behaviours in the first place. An initial exploratory study (Study 1) was conducted, for which a photo elicitation interview (N=20) was designed and implemented. This aimed to find the extent to which factors influencing phone use transferred from out of the car to the driving environment. In particular, the study aimed to explore whether the driving environment could be considered unique. The results indicated that the high demands placed on the driver by the road environment clearly distinguished it from the other environments and the reported propensity to use a phone seemed to reflect this. Only factors which either changed the level of attention required by the task, such as a change in task demand as a result of changes in the traffic environment, had any substantial influence on willingness to engage. Driving may not be unique in terms of the overall factors influencing phone use but it is unique in the extent to which this particular factor seems to have such a strong bearing on interaction. Building on findings from Study 1, that the demand and attention required seemed to influence willingness to engage, it was noted that Fuller s (2005) Task Capability Interface model would serve as a useful framework for the remainder of the thesis. This model suggests that driver behaviour is dictated by the level of task difficulty perceived; an interaction between task demand and capability. Therefore, the effects these two elements might have on willingness to engage with mobile phones while driving were tested separately in the two remaining studies. Previous research suggested that task demand should comprise a combination of roadway demand and the intended phoning task. Study 2, therefore, experimentally tested the extent to which road demand and phone function intended to be used influenced drivers decisions to engage with their phone. Participants (N=20) viewed video clips of real road environments of varying demand. Rating scales were used by participants to rate their willingness to engage with various phone functions according to the scenario they had just viewed. It was found both roadway demand and phone functionality affected willingness to engage with a mobile phone whilst driving. There was a higher propensity to engage in phone use in road environments perceived to have a lower demand and lower propensity to engage in phone use in the highest demand scenarios. Answering a call was the most likely function to be engaged with by the participants and sending a text message was the least likely. The final study investigated how capability (comprising both phone and driving capability) influenced willingness to engage. Participants (N=40) were required to drive in a simulator under two conditions, simulated low and high road demand. Their willingness to interact with their phones, when faced with a number of phone tasks, was then observed. It was found that driving capability had an effect on willingness to engage in high demand scenarios with the less capable, novice, drivers having a higher propensity to engage with placing a call, sending a text message and reading a text message than the more experienced drivers. Novice drivers were willing to engage with some functions on their phone at possibly inappropriate times. It was further found that, in the simulated low demand road environment, phone capability influenced willingness to engage, with those who were more capable at placing a call and sending a text message found to be more willing to engage with these functions. The research reported in this thesis represents the first attempt in the literature to study, in depth, the factors which can influence phone engagement behaviour while driving. Novel contributions include investigating if factors influencing phone use transferred from out of the car to the driving environment. Further novel contributions included whether the phone function and road demand interact to influence willingness to engage and whether capability can affect phone engagement behaviour while driving. Extending the model developed by Fuller, the thesis offers an original model that describes the factors affecting phone engagement behaviour while driving. Suggestions are proposed for how the findings presented in this thesis can effectively be used and how future work should build on these initial foundations.

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.