Background: Digital advertising has changed the way businesses market their goods or services, providing an attractive approach for clients to interact with content. The rapid growth of digital advertising is also associated with its efficacy and cost-savings measures which have seen an increase in digital ads’ exposure among users. However, this could result in negative attitudes towards adverts leading to ad avoidance as a growing trend. Many users apply self-control strategies to prevent the appearance of digital ads through ad-blocking technologies or subscriptions. This movement of ad avoidance incurs financial costs, and loss of revenue and makes it difficult to impact consumer behavior. Consequently, customer engagement becomes poor since users often find it hard to convince probable buyers not to view commercials therefore destroying the notion that advertising is a tool for promotion.   Purpose: This study explores ad avoidance and consumer choice in digital advertisements. It seeks to determine the influence of ad avoidance on consumers’ alternatives, and how it impacts their attitude, perception, and behavior regarding a particular product or service. The research will integrate what we already know and give recommendations on how marketing strategies can be used to mitigate negative outcomes arising from ad avoidance while increasing the involvement of customers with digital ads. Method: A qualitative method with an abductive approach conducted through semi-structured interviews with a focus group was carried through to examine the behaviors and motivations of people who avoid ads. Conclusion: In this study, the effect of ad avoidance on consumers’ mobile phone decision-making journey was explored. The study focuses on the consumer decision-making journey and its effects on purchase decisions. It is established that consumers consciously shun irritating ads which affect all the stages of the decision-making process. Ad avoidance influences the initial phases such as need recognition, information seeking, and evaluation of alternatives. Moreover, it also investigates advertising types, ad blockers, and people's views toward mobile versus desktop ads. Mainly, it highlights trust in advertising as crucial, especially in influencer marketing, difficulties posed by intrusive mobile advertisements as well as constraints inherent to ad-blockers.

This research addressed how older adults experience their mobile phones in their everyday lives and how mobile phones could be designed to best meet their needs. Two studies were conducted using a mixed-research method to identify representative user clusters and to understand user experiences. In Study 1, 154 older adult mobile phone users completed a questionnaire to investigate 1) functional usage, 2) perception about mobile phone quality, and 3) other aspects of user experiences (e.g., motivations of acquisition and learning method). Results showed that older adults are generally conservative mobile phone users who use a few functions of mobile phones and perceive their phone to be difficult to use. Understanding error messages, menu navigation, and text input were found to be most difficult for them. Female users perceived their phones to be more difficult to use than male users. Three user clusters (explorers, basicians, and minimalists) were identified based on mobile phone usage behavior, and their characteristics were described. User satisfaction was effected by three attributes of mobile phones: usefulness, ease of use, and pleasure of use, indicating that developers need to focus on improving all factors when designing a mobile phone for older adults. Study 2 used a more holistic approach to describe older adults' user experiences. The aims of Study 2 were 1) to capture stories that reflected user experiences, 2) to identify barriers that older adults faced through the course of user experience and 3) to provide recommendations to improve user experiences. Qualitative data was collected in the form of existential phenomenology-based interviews. Twelve older adult mobile phone users (over age 56), representing the three clusters found from Study 1, participated in this study. The domestication of technology theory was adopted as a framework to describe instances and themes represented in users' utterances and behaviors. Results showed that, regardless of their abilities to operate technology, older adults used a limited number of mobile phone functions because of their parsimonious cost-benefit analyses when integrating technologies into their lives. A theoretical explanation for this phenomenon was provided using socio-emotional selectivity theory. Barriers (perceptual, cognitive, attitudinal, knowledge, and information barriers) were found to hinder older adults' utilization of mobile phone technology over the four dimensions of the domestication process (appropriation, objectification, incorporation, and conversion). Recommendations to resolve those barriers were provided and related to published literature. This study proved that the domestication of technology theory can be a useful analytical tool for describing and understanding user experiences and capturing users' needs. Detailed discussion about its applicability to user needs analysis process was provided. A set of user requirements along with diverse user profiles were developed as outcomes of this research. / Ph. D.

This thesis proposes a multistage RAKE receiver for use at the base station of a Code Division Multiple Access (CDMA) cellular communications system. This receiver combines the interference rejection capability of multiuser receivers with the robust performance of a RAKE receiver in the presence of multipath interference. Unlike previous multiuser receiver designs, this multistage RAKE receiver requires no a priori information about the time-vary multipath radio channel. The thesis presents a mathematical description of the multistage receiver, and a software simulation of the receiver performance. A wide range of channel models are considered which include the effects of Gaussian noise, multipath propagation, imperfect power control and multiple access interference for the reverse link CDMA channel. Under a wide range of conditions, the multistage RAKE receiver is able to support two to three times as many users as a conventional single stage RAKE receiver. The receiver is also shown to be robust to the near-far problem. / Master of Science

With the commercialization of virtual/augmented reality (VR/AR) devices, there is an increasing interest in combining immersive and non-immersive devices (e.g., desktop computers, mobile devices) for asymmetric collaborations. While such asymmetric settings have been examined in social platforms, questions surrounding collaborative view dimensionalities in data-driven decision-making and interaction from non-immersive devices remain under-explored. A crucial inquiry arises: although presenting a consistent 3D virtual world on both immersive and non-immersive platforms has been a common practice in social applications, does the same guideline apply to lay out data? Or should data placement be optimized locally according to each device's display capacity? To this effect, a user study was conducted to provide empirical insights into the user experience of asymmetric collaboration in data-driven decision-making. The user study tested practical dimensionality combinations between PC and VR, resulting in three conditions: PC2D+VR2D, PC2D+VR3D, and PC3D+VR3D. The results revealed a preference for PC2D+VR3D, and PC2D+VR2D led to the quickest task completion. Similarly, mobile devices have become an inclusive alternative to head-worn displays in virtual reality (VR) environments, enhancing accessibility and allowing cross-device collaboration. Object manipulation techniques in mobile Augmented Reality (AR) have been typically evaluated in table-top scale and we lack an understanding of how these techniques perform in room-scale environments. Two studies were conducted to analyze object translation tasks, each with 30 participants, to investigate how different techniques impact usability and performance for room-scale mobile VR object translations. Results indicated that the Joystick technique, which allowed translation in relation to the user's perspective, was the fastest and most preferred, without difference in precision. These findings provide insight for designing collaborative, asymmetric VR environments. / Master of Science / With the commercialization of virtual/augmented reality (VR/AR) devices, there is an increasing interest in combining immersive and non-immersive devices (e.g., desktop computers, mobile devices) for collaborations across different devices. While such asymmetric settings have been examined in social platforms, questions surrounding collaborative view differences in 2D views or 3D views affect data-driven decision-making and interaction remain under-explored. A crucial inquiry arises: although presenting a consistent 3D virtual world on both immersive and non-immersive platforms has been a common practice in social applications, does the same guideline apply to lay out data? Or should data placement be optimized on each device according to each device's display capacity? To this effect, a user study was conducted to provide insights into the user experience of collaboration across different devices in data-driven decision-making. The user study tested different combinations of 2D and 3D layouts between PC and VR, resulting in three conditions: PC2D+VR2D, PC2D+VR3D, and PC3D+VR3D. The results revealed a preference for PC2D+VR3D, and PC2D+VR2D led to the quickest task completion. Similarly, mobile devices have become an inclusive alternative to head-worn displays in virtual reality (VR) environments, enhancing accessibility and allowing cross-device collaboration. Object manipulation techniques in mobile Augmented Reality (AR) have been typically evaluated in table-top scale and we lack an understanding of how these techniques perform in room-scale environments. Two studies were conducted to analyze object translation tasks, each with 30 participants, to investigate how different techniques impact usability and performance for room-scale mobile VR object translations. Results indicated that the Joystick technique, which allowed translation in relation to the user's perspective, was the fastest and most preferred, without difference in precision. These findings provide insight for designing collaborative, asymmetric VR environments.

This research aims at solving an engineering design problem encountered in the field of wireless communication systems using mathematical programming techniques. The problem addressed is an indispensable part of micro-cellular radio system design. It involves an optimal location of radio transmitters, given a distribution of receivers and desired signal characteristics. The study has been conducted with the intent of making this problem an integral part of a CAD system for designing radio communication systems. The tool that has been developed for locating a transmitter in such a context is sensitive to different needs of coverage at different locations in the design space. The physical nature of this problem enables it to be conceptualized as a traditional facility location problem. The transmitter is a service facility responsible for serving all the receivers in the design space. A cost is incurred in terms of path-loss, delay spread, and other separation-based measures, whenever service is extended to a receiver. The objective is to place this transmitter in such a way that it optimally serves all the receivers, as measured according to some merit function. However, the nature of the latter merit or objective function, and the nature of the acceptable region for transmitter placement, imparts a special structure to the problem that distinguishes it from traditional facility location problems. The aim of this research effort is to construct a suitable representative mathematical model for this problem, and to design and compare various solution methodologies that are computationally competitive, numerically stable, and accurate. / Master of Science

The design of cellular wireless communication systems is influenced by the propagation characteristics of the channel and their effect on transmitted signals. The multipath propagation characteristics of a channel, except under simple transmission conditions, limits the design of emerging cellular systems. Once the propagation conditions are understood, systems can be designed more efficiently in terms of site layout and frequency planning, to reduce deployment costs and improve performance. A software tool for site specific radio propagation prediction is being developed at the Mobile and Portable Radio Group, Virginia Tech. The objective of this research is to develop re-usable program modules that can be utilized to implement several functional features of the software. This thesis describes the raster and vector programming libraries that have been developed during this research. These libraries are utilized in the database module, user interface and graphics module and propagation prediction module of the software. Significant among the capabilities that these libraries provide are the ability to store and retrieve raster and vector data from the database, import measured and predicted data available in standard data formats into the database, obtain user inputs through an interactive mechanism, display images of site specific information at various resolutions, and enable the user to view and analyze measured and predicted data. This thesis also presents the data format, that has been defined during this research, to acquire and import contour and elevation information of buildings. The SISP General Data Format (GDF), that has been developed, to facilitate import of measured and predicted data has also been described. The Hierarchical Data Format (HDF), developed by the National Center for Supercomputing Applications (NCSA), has been adopted to store measured and predicted data in the database. The programming techniques used to retrieve and display data stored in this format are also outlined in this thesis. SISP has been developed on Sun Sparc workstations. Details of the function libraries that have been developed, programming methodologies employed, and data formats that have been defined for site specific and measured and predicted RF data are included in this thesis. / Master of Science

Our society is undergoing a wireless revolution in which there is a rapidly increasing demand for personal communication services (PCS). Several alternate technologies have been proposed to meet this demand, including a 1.25 MHz CDMA system. It is important to provide system designers with tools to accurately predict system performance. Analytical techniques are useful for providing general information on system performance, but may not fully capture the complexities of the mobile radio channel needed to accurately predict the performance of complex system designs. This thesis presents a novel simulation technique in which a CDMA system is modeled by software, but the channel impulse response model is derived from actual measurements. This thesis describes a bit error simulation tool for a 1.25 MHz bandwidth CDMA system. The simulator incorporates measurement-based channel impulse response data with the simulated CDMA system. Bit error rate for COMA is simulated under a variety of actual channel conditions, including heavy urban, urban, suburban and rural environments. Simulation results for both 915 MHz and 1920 MHz are presented. Vertical and circular antenna polarization are compared. In the simulation, a RAKE receiver is implemented, the advantage of this RAKE receiver implementation is demonstrated by comparison to a single correlation receiver. Results for outage probability are also presented. / Master of Science

No description available.

Yes / Consumer brand preference is an essential step towards understanding consumer choice behaviour, and has therefore always received great attention from marketers. However, the study of brand preference has been limited to traditional marketing focusing on functional attributes to maximise utility. But now the shift to experiential marketing broadens the role of the brand from a bundle of attributes to experiences. Technological advancements have helped to increase the similarities between brand attributes and product commoditisation. Consequently, consumers cannot shape their preferences among brands using rational attributes only. They seek out brands that create experiences; that intrigue them in a sensorial, emotional and creative way. This study seeks to develop a model that provides an understanding of how brand knowledge and brand experience determine brand preference and to investigate its impact on brand repurchase intention. Accordingly, exploratory focus group discussions are employed followed by a survey of mobile phone users in Egypt. The findings provide insights into the relative importance of consumer perceptions on different brand knowledge factors in shaping brand preferences. It also demonstrates the significance of consumers’ experiential responses towards brands in developing their brand preferences that in turn influence brand repurchase intention. The model therefore offers managers a new perspective for building strong brands able to gain consumer preferences.

The objective of this research is to compare radio channel impulse response measurements with site-specific radio wave propagation prediction techniques. A wide band spread spectrum measurement system was developed, and desirable measurement locations were selected on the Virginia Tech campus. These measurements are designed togo beyond statistical characterizations of the channel and will aid in determining how the propagation environment is influencing the multi path propagation. The objective is to not only measure the delays and relative powers of multi path components, but to carefully document their angles of arrival and resolve the overall paths that these multipaths had to take to reach the receiver. This information will be used to compare with propagation prediction simulations using the modeled environment, and therefore, provide new insight into the nature of reflection and scattering of radio propagation in typical microcellular environments. As a first step in this endeavor, building surface characterizations are made in order to determine empirical reflection coefficients of common building materials. Propagation experiments have been designed to determine applicability of Fresnel reflection formulas to non-ideal conditions, such as waves that are not perfect plane waves, rough surfaces, etc. This information allows propagation prediction techniques to further quantify the site-specific mobile radio environment and yield more accurate propagation estimates. For this endeavor, Whittemore Hall and Squires Student Center were Chosen to provide reflection measurements from rough stone, glass, and brick surfaces. Detailed descriptions of measurement techniques, analysis and results are included. / Master of Science