Browsing by Subject "Mobile"
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Item Bridging the gap between mobile CPU design and user satisfaction via crowdsourcing(2016-05) Halpern, Matthew Franklin; Janapa Reddi, Vijay; Tiwari, MohitThis report aims to provide an understanding of how the mobile CPU designs have evolved and its influence on end-user satisfaction. To that end, a quantitative performance analysis is conducted across ten cutting-edge mobile CPU designs studied within top-selling off-the-shelf smartphones released over the past seven years. This analysis is then used to guide a large-scale user study spanning over 25,000 participants via crowdsourcing on the Amazon Mechanical Turk service. The user study asks participants to assess the responsiveness of interactive application use cases for a set of current-generation applications (e.g. Angry Birds and FaceBook) and next-generation applications (i.e. face recognition and augmented reality) relative to the performance capabilities of the devices studied. This framework allows us to quantitatively link how the mobile CPU designs studied impacted end-user satisfaction. The study results indicate that mobile CPU designs have exhibited signifiant performance improvements through aggressive core scaling techniques prevalent in desktop CPUs. Just as was observed in desktop CPU design, these same techniques have lead to excessive mobile CPU power consumption. However, from an end-user perspective this power consumption was not without success. Mobile CPUs have evolved to provide satisfactory experiences for the studied current- generation applications. The reason is that many of these applications rely heavily on single-threaded performance. Other, more recent applications, actually multi-thread user-critical parts of the applications, which also demonstrates that multi- core mobile CPUs are an important design consideration – contrary to conventional wisdom. However, looking ahead, the same mobile CPUs where not able to provide satisfactory experiences for many of the next-generation applications studied, questioning the sustainability of these power-hungry design techniques in future mobile CPU designs.Item A case study of the use of professional development to support mobile technology integration(2012-08) Maradiegue, Erin Kelsey; Liu, Min, Ed. D.; Palmer, DeborahMobile devices are playing an increasingly prevalent role in K-12 education, as school systems are adopting the technology to enhance student learning. Consequently, teachers have to learn how to incorporate the devices into their classrooms, with the help of professional development activities. This case study examined the professional development of four teachers who participated in their school district’s iPod touch initiative for English Language Learners (ELLs), as well as the perspective of the instructional media specialist charged with assisting the teachers. The study aimed to understand what district-led and independent training activities K-12 teachers engage in and the influence the activities have on how mobile devices are used by the teachers. The educational activities of the teachers and their impact on the teachers’ technology integration were documented through a series of interviews, a training observation, and teacher questionnaires. The research identified four types of professional development support provided by the district and five types of self-guided or incidental learning activities that teachers engaged in that directly impacted the way they used the device. The district-led trainings are 1) group trainings 2) in-class demonstrations 3) one-on-one training and 4) ongoing support. The self-guided and incidental learning activities found are 1) research for resources and ideas 2) brainstorming 3) experimenting with apps and activities 4) collaboration with others and 5) students serving as trainers. Increased personal instruction, cultivating formal learning through mentoring and an online forum, and developing online training resources for a mobile format are proposed for professional development that would aid in the integration of mobile devices in a K-12 environment.Item Civic engagement in a mobile landscape : testing the roles of duration and frequency in learning from news(2015-08) Molyneux, Logan Ken; Poindexter, Paula MaurieConsuming the news is often seen as preparing a person to participate in a democracy by giving them the information they need to make choices and provide input. This relationship has varied depending on the ways in which news is delivered, with different news platforms delivering different results in terms of learning from the news. As society changes and people's news consumption habits shift toward mobile, it is necessary to re-examine this relationship in a mobile age. This dissertation conducts surveys of two samples of U.S. adults one year apart in order to examine civic engagement in a mobile news landscape. Study 1, given to a nationally representative sample of U.S. adults in 2014, tests the Mobile News Dependency Model. The model predicts that reliance on mobile devices for news consumption will lead people to consume news in shorter, inattentive sessions, which should have detrimental effects on news knowledge and therefore civic engagement. Study 2, given in 2015 to a different sample of U.S. adults, refines the tests conducted in Study 1 using updated measures to identify those who snack on the news and compare them with those who get news in larger portions. Results show that news sessions on smartphone are indeed shorter than on other platforms, and that smartphone news use is associated with snacking on the news. But those who get news from smartphones are not significantly less knowledgeable and are in fact slightly more civically engaged than those who do not. Links between smartphone news use and short sessions or snacking are supported, but the overall Mobile News Dependency Model is not supported. The overall relationship between mobile news use and civic engagement appears to take a different path than the one specified. Finally, results show that most people consume news on multiple platforms, perhaps normalizing the effects of any one platform on knowledge. Implications for news consumers, news producers, and democracy in a mobile age are discussed.Item Distributed control of multi-agent networks(2020-12-10) Abdulghafoor, Alaa Zaki Abdulrahman; Bakolas, Efstathios; Zanetti, RenatoMotivated by the challenges that arise in controlling mobile agents operating in areas with nonuniform time-varying densities, in this paper we propose a distributed steering control framework for a network of autonomous mobile multi-agents whose members have to deploy and allocate themselves in critical positions over a given region in accordance with a time-varying coverage density function. Our method is based on a two-level description of the multi-agent network. The second level reflects the macroscopic description of the network which corresponds to the probability distribution of the agents' locations over a given region in which the network of multi-agents is treated as one unit. The second level reflects the microscopic description of the network which is described in terms of the collection of all individual positions of all of its agents. Thus, the goal of the multi-agent network is to attain a spatial distribution that matches the reference coverage density function (macroscopic high-level control problem) through the local interactions of the agents at the individual level (microscopic low-level control problem). The high-level control problem is addressed by associating it with a desired reference Gaussian probability density. Moreover, the low control problem is addressed by utilizing the Lloyd's algorithm with a time-varying coverage density function. Therefore, the control laws provided would allow the agents to achieve a desired macroscopic behavior of the network, using only distributed algorithms and local information. Each agent will control its own velocity, based only on knowledge of a few neighboring agents, but in such a way that a desired probability distribution is obtained. Finally, a set of simulation results are provided to show the convergence of the mobile agents to their critical locations and to show the effectiveness of the proposed approach.Item Empowering video applications for mobile devices(2020-05-14) He, Jian (Ph. D. in computer science); Qiu, Lili, Ph. D.; Zhu, Xiaoqing; Gouda, Mohamed G.; Mok, AloysiusThe popularity of video applications has grown rapidly. There are two main trends in the development of video applications: (i) video streaming supporting higher-resolution videos and 360° videos, (ii) providing video analytics (e.g., running object detection on video frames). In this dissertation, we focus on how to improve performance of streaming 360° and 4K videos and running real-time video analytics on mobile devices. We identify a few major challenges to guarantee high user experience for running video applications on mobile devices. First, existing video applications call for high-resolution videos(e.g., 4K). Due to limited hardware resource on mobile devices, it is slow to code high-resolution videos. It is critical to design a light-weight video codec to provide fast video coding as well as high compression e ciency for mobile devices. Second, wireless channels have unpredictable throughput fluctuation. It is necessary to design a robust rate adaptation algorithm to adjust video quality according to the varying network condition. Third, streaming entire panoramic video views wastes lots of bandwidth, while only transmitting the portion visible to the users FoV significantly degrades video quality. It is hard to save bandwidth while maintaining high video quality with inevitable head movement prediction error. Last, motion based object tracking can speed up video analytics, but existing motion estimation is noisy due to the presence of complex background and object size or shape changes. In this dissertation, we will show how to address the above mentioned challenges. We propose a new layered coding design to code high-resolution video data. It can effectively adapt to varying data rates on demand by first sending the base layer and then opportunistically sending more layers whenever the link allows. We further design an optimization algorithm to decide which video layers to send according to available throughput. Compared with existing rate adaptation algorithm, our algorithm includes the new dimension of deciding the number of layers to transmit. We design a novel layered tile-based encoding framework for 360° videos. It can achieve efficient video coding, bandwidth saving, and robustness against head movement prediction error. Moreover, we design a robust technique to extract reliable motion from video frames. We use a combination of feature maps and motion to generate a representative mask which can reliably capture the motion of object pixels and the changes of the overall object shape or size. First, we implement our tile-based layered encoding framework Rubiks on mobile devices for 360° video streaming. We exploit spatial and temporal characteristics of 360° videos for encoding. Specifically, Rubiks splits the 360° video spatially into tiles and temporally into layers. The client runs an optimization routine to determine the video data that needs to be fetched to optimize user QoE. Using this encoding approach, we can send the video portions that have a high probability of viewing at a higher quality and the portion that has a lower probability of viewing at a lower quality. By controlling the amount of data sent, the data can be decoded in time. Rubiks can save significant bandwidth while maximizing the users QoE and decoding the video in a timely manner. Compared with existing approaches, Rubiks can achieve up to 69% improvement in user QoE and 49% in bandwidth savings over existing approaches. Next, we design a system Jigsaw to support live 4K video streaming over wireless networks using commodity mobile devices. Given the high data rate requirement of 4K videos, 60GHz is appealing, but its large and unpredictable throughput fluctuation makes it hard to provide desirable user experience. We propose a novel system Jigsaw, which consists of (i) easy-to-compute layered video coding to seamlessly adapt to unpredictable wireless link fluctuations, (ii) efficient client GPU implementation of video coding on commodity mobile devices, and (iii) effectively leveraging both WiFi and WiGig through delayed video adaptation and smart scheduling. Using real experiments and emulation, we demonstrate the feasibility and effectiveness of Jigsaw. Our results show that it improves PSNR by 6-15dB and improves SSIM by 0.011-0.217 over state-of-the-art approaches. Finally, we develop a novel mobile video analytics system Sight. Its unique features include (i) high accuracy, (ii) real-time, and (iii) running exclusively on a mobile device without the need of edge/cloud server or network connectivity. At its heart lies an effective technique to reliably extract motion from video frames and use the motion to speed up video analytics. Unlike the existing motion extraction, our technique is robust to background noise and changes in object sizes. Using extensive evaluation, we show that Sight can support real-time object tracking at 30 frames/second (fps) on Nvidia Jetson TX2. For single-object tracking, Sight improves the average Intersection-over-Union (IoU) by 88%, improves the mean Average Precision (mAP) by 207% and reduces the average hardware resource usage by 45% over state-of-the-art approach. For multi-object tracking, Sight improves IoU by 69%, improves mAP by 173% and reduces resource usage by around 32%.Item Energy-efficient mobile Web computing(2017-05) Zhu, Yuhao; Janapa Reddi, Vijay; Chiou, Derek; John, Lizy; Julien, Christine; Mahlke, ScottNext-generation Web services will be primarily accessed through mobile devices. However, mobile devices are low-performance and stringently energy-constrained. In my dissertation, I propose the design of a high-performance and energy-efficient mobile Web computing substrate. It is a hardware/software co-designed system that delivers satisfactory user quality-of-service (QoS) experience on a mobile energy budget. The key insight is that the traditional interfaces between different Web stacks need to be enhanced with new abstractions that express user QoS experience and that expose architectural-level complexities. On the basis of the enhanced interfaces, I propose synergistic cross-layer optimizations across the processor architecture, Web runtime, programming language, and application layers to maximize the whole system efficiency. The contributions made in this dissertation will likely have a long-term impact because the target application domain, the Web, is becoming a universal mobile development platform, and because our solutions target the fundamental computation layers of the Web domain.Item A framework for spatio-temporal querying amongst mobile devices(2012-05) Cochran, Benjamin Mark, 1982-; Julien, Christine, D. Sc.; Bard, WilliamWith mobile web browsers holding around eight percent of the global browser market share in terms of usage, web development for these platforms is becoming critically important as usage moves from the desktop towards mobile devices. Recent advances in client side browser technology like HTML5 and WebSockets have allowed web browser applications to approach feature parity with thick client desktop applications. This paper explores the possibility of a real-time online multiplayer game playable from just a mobile device's web browser. It does not focus on gameplay or graphics, rather it focuses on the backend infrastructure needed to support such a game. The framework devised to support this sort of interaction, Marionette, is well suited towards addressing sharing of location-specific, short-lived information between people using their smartphones without the use of any external software or proprietary software packages on the client side.Item Mobile Advertising(2013-05) Adams, Angela Rae; Wilcox, Gary B.Mobile advertising has grown rapidly in the United States from a marketing, technology, and consumer acceptance point of view. This professional report will begin with an overview of the current mobile landscape, including device and network history. Various techniques will then be covered, including formats such as messaging (SMS), mobile search, display, and video advertising. Each of these methods will be discussed in detail, highlighting benefits and drawbacks, followed by typical monetization and measurement for each format. This report will then shift from a marketer point of view to a consumer point of view, highlighting consumer use statistics and citing examples of consumer response to specific mobile advertising campaigns. While the majority of this report is focused on the United States and business-to-consumer marketing, global mobile advertising and mobile advertising in a business-to-business context will also be discussed. This report concludes with recommendations for professionals, resulting in a usable guide to creating successful mobile campaigns.Item Mobile technology in secondary education : utilizing the Android development environment to teach Texas Paleontology(2011-08) Mattingly, Anne Katherine; Wilson, Clark R.; Molineux, AnnThe purpose of this project was to create an Android phone application that could be used to teach Texas Paleontology in a secondary school classroom. Since experienced teachers have reported that many students who do not have personal computers at home still have their own cell phones, the concept of using mobile devices for science education is very attractive to educators. In order to test out this idea the project had to include not only a mobile app, but also a webqest to help seamlessly integrate that app into Earth Science curriculum. To begin the project, I developed the Texas Paleontology webquest as a frame for the cell phone integration. In this activity the students are required to create their own field trip to explore relevant paleontological locations in Texas. They are required to document their field trip using Google Maps. These field trips could eventually be used to enhance the Android Application. The development of the Android Application represents the majority of this project. It was designed to be an app that can either stand alone or work with the Texas Paleontology webquest. In order to create this application I had to learn the XML and JAVA programming languages and become familiar with the Eclipse Integrated Development Environment and the Android Software Development Kit. The results of the project can be downloaded from the Android Market b searching for "Texas Paleontology." This report not only includes a description of how the application could be integrated into the classroom, but also an instruction guide for how to create an Android Application in a similar way. As cell phone technology becomes even more prevalent it is likely that more educators will want to utilize mobile application development in their own classrooms. This report provides a starting point for accomplishing this integration.Item MobiShare : mobile computing with no strings attached(2013-12) Castillo, Jason Moses; Julien, Christine, D. Sc.In today’s world, technology is growing at a fast rate compared at other times. Sales have increased in the smart phone market, which has created new opportunities in pervasive computing. In pervasive computing, nodes enter and leave a network at any time. Within the network, nodes can transfer data to other nodes. The information is not retained in any static location such as a server. The mobile infrastructure requires a way to handle all the information in a dynamic way. The use of a centralized server in a mobile environment creates deterioration in the performance of obtaining information. The main goal of this paper is to provide data persistence using a “substrate” that is inherently not persistent. The data will be stored within the network for availability to all users. Saving data within a network would provide a means to obtain any type of information without relying on the source of where the data came from in the network. Users would also be able to continue downloading where they left off when they return to the network. Consider an environment where people can share music or books. For example, say that John Doe was searching for a particular song to download and in the network Jane has the song that was requested. John decides to download the song without knowing that it is from Jane. Then John decides to leave the network and the download stops. Whenever John rejoins the network the download of his song will continue where he left off, and his ability to access the information will not depend whether or not Jane is present in the network. John may retrieve the file from any other user who has the exact same file. The requested information that the user queries in a search engine will be stored as a metadata within the network, either by other nodes or a temporary server. This allows data to be obtained without relying on the "main user" or creator of the data to be present in the network. The users would also be able to retrieve the data at multiple times.Item Optimizing mobile multimedia content delivery(2013-08) Seung, Yousuk; Zhang, Yin, doctor of computer scienceWith the advent of mobile Internet the amount of time people spend with multimedia applications in the mobile environment is surging and demand for high quality multimedia data over the Internet in the mobile environment is growing rapidly. However the mobile environment is significantly more unfriendly than the wired environment for multimedia applications in many ways. Network resources are limited and the condition is harder to predict. Also multimedia applications are generally delay intolerant and bandwidth demanding, and with users moving, their demand could be much more dynamic and harder to anticipate. Due to such reasons many existing mobile multimedia applications show unsatisfactory performance in the mobile environment. We target three multimedia content delivery applications and optimize with limited and unpredictable network conditions typical in the mobile Internet environment. Vehicular networks have emerged from the strong desire to communicate on the move. We explore the potential of supporting high-bandwidth applications such as video streaming in vehicular networks. Challenges include limited and expensive cellular network, etc. Internet video conferencing has become popular over the past few years, but supporting high-quality large video conferences at a low cost remains a significant challenge due to stringent performance requirements, limited and heterogeneous client. We develop a simple yet effective Valiant multicast routing to select application-layer routes and adapt streaming rates according to dynamically changing network condition in a swift and lightweight way enough to be implemented on mobile devices. Bitrate adaptive video streaming is rapidly gaining popularity. However recent measurements show weaknesses in bitrate selection strategies implemented in today's streaming players especially in the mobile environment. We propose a novel rate adaptation scheme that classifies the network condition into stable and unstable periods and optimizes video quality with different strategies based on the classification.Item ProxStor : flexible scalable proximity data storage & analysis(2014-12) Giannoules, James Peter; Aziz, AdnanProxStor is a cloud-based human proximity storage and query informational system taking advantage of both the near ubiquity of mobile devices and the growing digital infrastructure in our everyday physical world, commonly referred to as the Internet of Things (IoT). The combination provides the opportunity for mobile devices to identify when entering and leaving the proximity of a space based upon this unique identifying infrastructure information. ProxStor provides a low-overhead interface for storing these proximity events while additionally offering search and query capabilities to enable a richer class of location aware applications. ProxStor scales up to store and manage more than one billion objects, while enabling future horizontal scaling to expand to multiple systems working together supporting even more objects. A single seamless web interface is presented to clients system.. More than 18 popular graph database systems are supported behind ProxStor. Performance benchmarks while running on Neo4j and OrientDB graph database systems are compared to determine feasibility of the design.Item Revolver : synchronized visual event capture using mobile devices and cloud services(2012-12) Stathopoulos, Michael; Khurshid, Sarfraz; Aziz, AdnanThe proliferation of mobile computing devices with powerful sensing and communication capabilities has created an immense social landscape of awareness and connectedness. Social media applications have been largely designed for asynchronous expression and collaboration among individuals. Though these models have served as suitable surrogates for social interaction in a rapidly evolving digital age, they have been insufficient at connecting people spatially and temporally. This report describes Revolver: an appli- cation utilizing the state-of-the-art in mobile and distributed computing to provide users with a shared sense of time and space. Revolver allows users to synchronously capture image data of their surroundings with the ability to virtually reconstruct an event from the separate sources. We present the ratio- nale for the project, design considerations, implementation details, results of the prototyping effort, and conclusions to carry this project to future phases of development for viable deployment.