The purpose of this study was to examine the relationship between teenagers’ use of mobile Internet devices and their involvement in risky digital behaviors, including problematic Internet use, exposure to pornography, and participation in sexting. A crosssectional correlational design using a sample (N = 97) of teens aged 13-18 was used. Linear regression analyses revealed that teens using smartphones as their primary source of Internet access were most likely to receive sexting requests, while teens using computers to access the Internet were most likely to intentionally view pornography. Additionally, teens who used multiple mobile devices to connect to the Internet and teens who had owned at least one mobile Internet device for longer periods of time were most likely to have higher levels of problematic Internet use. Contextual factors such as age, gender, family structure, religious commitment, attachment to parents, and parental monitoring of online activities were also examined to determine their relationship to the aforementioned outcomes. Consistent with adolescent developmental trajectories, older teens reported higher rates of pornography exposure and sexting requests, and indicated a greater willingness to participate in sexting. However, younger teens who used smartphones as their primary source of Internet access were just as likely as older teens to have received requests to sext. Males had higher rates of pornography exposure and were more willing than females to send sexual messages to their significant other. Females, on other hand, were asked to sext more frequently. Teens with high levels of religious commitment had the lowest levels of pornography exposure and participation in sexting. Among the parental variables examined, teens’ attachment to their parents was most significantly related to the studies’ outcomes. Strongly attached teens had lower levels of problematic Internet use, pornography exposure, and participation in sexting than their peers who were not as strongly attached to their parents.

Sensory deficits represent a major global public health problem. According to the World Health Organization, vision impairment affects an estimated 300 million people worldwide, and hearing impairment affects an estimated 360 million people worldwide. Consistent clinical evaluations for all individuals with sensory deficits cannot be practically realized due to the rising costs of healthcare, capital and labor limitations, and inaccessibility to healthcare due to a multitude of factors including proximity. The high prevalence of visual and hearing deficits can be lessened through consistent, comprehensive, at-home testing which can allow a larger amount of the affected and at-risk populations to be screened for abnormal function earlier and prior to permanent loss, and provide a wealth of patient-specific data that can be used to understand the time-scale of diseases and monitor the effectiveness of clinical interventions in unprecedented detail. While health-oriented smartphone applications exhibit a strong presence on the app stores, these applications are seldom vetted by expert scientists, engineers, and clinicians, and there are considerable opportunities for methodological improvements. The present work discusses the creation, calibration, and proof-of-concept, preliminary validation of a suite of psychophysical tests implemented as smartphone applications that can be utilized to rapidly and objectively quantify several functional sensory behaviors including flicker sensitivity, contrast sensitivity, visual acuity, and hearing-in-noise. Rigorous steps were undertaken to perform the necessary calibrations (a feat not routinely achieved by the creators of existing medical smartphone applications), and ensure the technical validity of the varying stimuli presented. Preliminary tests in the clinic have documented the potential of these tests to objectively provide numerous quantifications of, but not limited to, individual visual and hearing function, and variation between normal and abnormal subjects and function. The foundation laid by this work allows novel psychophysical tests to rapidly be implemented, vetted, and added to this battery of publicly and universally accessible medical smartphone applications.

Quantifying human posture and range of motion remains challenging due to the need for specific technologies, time for data collection and analysis, and space requirements. The demand for affordable and accessible human body position measurement requires alternative methods that cost less, are portable, and provide similar accuracy to expensive multi-camera systems. This thesis developed and evaluated a novel augmented reality mobile app for human posture measurement to bring marker-based body segment measurement to the point of patient contact. The augmented reality app provides live video of the person being measured, AprilTag2 fiducial markers locations in the video, processes marker data, and calculates angles and distances between markers. Results demonstrated that the mobile app can identify, track, and measure angles and distances between AprilTag2 markers attached to a human body in real-time with millimetre accuracy, thereby allowing researchers and clinicians to quantify posture measurements anywhere, at anytime.

<p>Recent research in the usability engineering field tends to emphasize, somewhat neglected, the need of incorporating the joy-of-use factor (the hedonic dimension of usability) into the design of user interfaces. However such design decisions have to be applied with care and proper modesty as they may diminish the product’s overall quality of use. Notions of pleasure and joy are non-task related and partially incompatible with pragmatic usability qualities hence achieving a proper balance is essential. </p><p>The thesis explores the question of how to establish a balance between pragmatic and hedonic dimensions of usability and whether it is possible to design a user interface which is both highly usable and enjoyable. </p><p>In order to address these questions a case study was performed, which required further development of an existing prototype, the Zenterio Halfpipe Desktop; an innovative, patented, cross-platform user interface. To achieve high product usability, principles of Human-Computer Interaction and User-Centered Design were applied. </p><p>The results of the study suggest that ensuring a high level of both aspects of usability: the pragmatic values (such as simplicity or controllability) as well as the hedonic values (such as originality or innovativeness), can result in a product which is perceived as highly usable and fun-to-use. The practical application of involving the joy-of-use factor shows a significant increase in the perceived software appeal. </p><p>Finally, shortcomings and limitations of the study are discussed followed by future work proposals.</p>

<p>Internetanvändning med mobila enheter såsom PDAs och smartphones är idag vanligt. De flesta webbsidor är dock designade för att visas på stationära datorer med stora skärmar. När användare med mobila enheter besöker webbsidorna uppstår ofta användbarhetsproblem som i främsta hand kan kopplas till de mobila enheternas små skärmar. </p><p>Syftet med denna studie var att undersöka vilka faktorer som är viktiga att ta hänsyn till, då en söksida på Internet skall anpassas för att presenteras på mobila enheter med små skärmar.</p><p>Studien bestod av tre olika faser, där den första var en litteraturstudie som syftade till att samla in information som berör design och omvandling av webbsidor mot små skärmar. I den andra fasen utvecklades två olika prototyper av en befintlig söksida på Internet, anpassade för små skärmar. I den tredje och sista fasen, utvärderades prototyperna på ett antal respondenter. Utvärderingarna bestod av uppgiftsbaserade utvärderingar med efterföljande intervjuer. Därefter analyserades resultatet av utvärderingarna utefter begrepp som behandlats i uppsatsens teoretiska del.</p><p>En slutsats som kunde dras var att flera av de designriktlinjer som idag finns för små skärmar även är lämpliga för en söksida. Studien har även resulterat i egna rekommendationer för hur en söksida kan migreras till mobila enheter med små skärmar för att vara användbar. En av dessa är att resultaten av en sökning bör presenteras kompakt så att användarna kan få en god överblick och inte behöva skrolla för mycket för att läsa dem.</p>

Today's smartphones are equipped with a variety of different sensors such as GPS receivers, accelerometers, gyroscopes and magnetometers, making smartphones viable tools in many applications. The computational capacity of smartphones allows for software applications running advanced signal processing algorithms. Thus, attaching a smartphone inside a car makes it possible to estimate kinematics of the vehicle by fusing information from the different sensors inside the smartphone. Fusing information from different sources for improving estimation quality is a well-known problem and there exist a lot of methods and algorithms in this area. This thesis approaches the sensor fusion problem of estimating kinematics of cars using smartphones for the purpose of analysing driving performance. Different varieties of the coordinated turn model for describing the vehicle dynamics are investigated. Also, different measurement models are evaluated where bias errors of the sensors are taken into consideration. Pre-filtering and construction of pseudo-measurements are also considered which allow for use of state space models with a lower dimension. / Dagens smartphones är utrustade med en rad olika typer av sensorer såsom GPS mottagare, accelerometrar, gyroskop och magnetometrar vilket medför ett stort användningsområde. Beräkningskapaciteten hos smartphones gör det möjligt för mjukvaruapplikationer att använda sig av avancerade algoritmer för signalbehandling. Det är därför möjligt att placera en smartphone inuti en bil och skatta bilens kinematik genom att kombinera informationen från de olika sensorerna. Att fusionera information från olika källor för att erhålla bättre skattningar är ett välkänt område där det finns många metoder och algoritmer utvecklade. Detta examensarbete behandlar sensorfusionsproblemet att skatta bilars kinematik med hjälp av smartphones för syftet att kunna analysera körprestanda. Olika varianter av en coordinated turn modell för att beskriva bilens dynamik undersöks. Dessutom testas olika modeller för sensorerna där hänsyn till exempelvis biasfel tas. Förbehandling av data och pseudomätningar testas också vilket gör det möjligt att använda tillståndsmodeller med låg dimension.

A Wearable Mobility Monitoring System (WMMS) can be an advantageous device for rehabilitation decision-making. This thesis presents the design and evaluation of a proof-of-concept WMMS that uses the BlackBerry Smartphone platform. A Java program was developed for the BlackBerry 9550, using the integrated tri-axial accelerometer, Global Positioning System sensor (GPS), CMOS digital video camera, and timer to identify change-of-state (CoS) among static states, dynamic states, small activity of daily living (ADL) movements, and car riding. Static states included sitting, lying, standing, and taking an elevator. Dynamic states included walking on level ground, walking on stairs, and walking on a ramp. Small activity of daily living movements included bathroom activities, working in the kitchen, and meal preparation. Following feature extraction from the sensor data, two decision trees were used to distinguish CoS and mobility activities. CoS identification subsequently triggered video recording for improved mobility context analysis during post-processing.

With advances in hardware miniaturization and wireless communication technologies even small portable wireless devices have much communication bandwidth and computing power. These devices include smartphones, tablet computers, and personal digital assistants. Users of these devices expect to run software applications that they usually have on their desktop computers as well as the new applications that are being developed for mobile devices. Web browsing, social networking, gaming, online multimedia playing, global positioning system based navigation, and accessing emails are examples of a few popular applications. Mobile versions of thousands of desktop applications are already available in mobile application markets, and consequently, the expected operational time of smartphones is rising rapidly. At the same time, the complexity of these applications is growing in terms of computation and communication needs, and there is a growing demand for energy in smartphones. However, unlike the exponential growth in computing and communication technologies, in terms of speed and packaging density, battery technology has not kept pace with the rapidly growing energy demand of these devices. Therefore, designers are faced with the need to enhance the battery life of smartphones. Knowledge of how energy is used and lost in the system components of the devices is vital to this end. With this view, we focus on modeling and evaluating the energy performance of smartphones in this thesis. We also propose techniques for enhancing the energy efficiency and functionality of smartphones. The detailed contributions of the thesis are as follows: (i) we present a nite state machine based model to estimate the energy cost of an application running on a smartphone, and provide practical approaches to extract model parameters; (ii) the concept of energy cost pro le is introduced to assess the impact of design decisions on energy cost at an early stage of software design; (iii) a generic architecture is proposed and implemented for enhancing the capabilities of smartphones by sharing resources; (iv) we have analyzed the Internet tra c of smartphones to observe the energy saving potentials, and have studied the implications on the existing energy saving techniques; and nally, (v) we have provided a methodology to select user level test cases for performing energy cost evaluation of applications. All of our concepts and proposed methodology have been validated with extensive measurements on a real test bench. Our work contributes to both theoretical understanding of energy e ciency of software applications and practical methodologies for evaluating energy e ciency. In summary, the results of this work can be used by application developers to make implementation level decisions that affect the energy efficiency of software applications on smartphones. In addition, this work leads to the design and implementation of energy e cient smartphones.

A Wearable Mobility Monitoring System (WMMS) can be an advantageous device for rehabilitation decision-making. This thesis presents the design and evaluation of a proof-of-concept WMMS that uses the BlackBerry Smartphone platform. A Java program was developed for the BlackBerry 9550, using the integrated tri-axial accelerometer, Global Positioning System sensor (GPS), CMOS digital video camera, and timer to identify change-of-state (CoS) among static states, dynamic states, small activity of daily living (ADL) movements, and car riding. Static states included sitting, lying, standing, and taking an elevator. Dynamic states included walking on level ground, walking on stairs, and walking on a ramp. Small activity of daily living movements included bathroom activities, working in the kitchen, and meal preparation. Following feature extraction from the sensor data, two decision trees were used to distinguish CoS and mobility activities. CoS identification subsequently triggered video recording for improved mobility context analysis during post-processing.

This case study tells the story of the smartphone market from the perspective of HTC, one of the manufacturers, who has been there from the beginning of the modern smartphone era. The case study is divided into the following sections: I. HTC Growth – We start by looking at the early history of the smartphone and HTC’s role as a trailblazer. It describes the first mover advantages, which helped HTC rise from obscurity into a significant player in the market. II. Market Changed – Next we examine how established electronics players enter a ripening market and quickly carve out majority of the market share for them. III. Key HTC Problems – Here we investigate some of the critical challenges faced by a smaller, less known player in the smartphone market. IV. HTC’s Options Today – We end by reviewing the current status of HTC in the smartphone market and the options available to it going forward.