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Description
Software has a great impact on the energy efficiency of any computing system--it can manage the components of a system efficiently or inefficiently. The impact of software is amplified in the context of a wearable computing system used for activity recognition. The design space this platform opens up is immense and encompasses sensors, feature calculations, activity classification algorithms, sleep schedules, and transmission protocols. Design choices in each of these areas impact energy use, overall accuracy, and usefulness of the system. This thesis explores methods software can influence the trade-off between energy consumption and system accuracy. In general the more energy a system consumes the more accurate will be. We explore how finding the transitions between human activities is able to reduce the energy consumption of such systems without reducing much accuracy. We introduce the Log-likelihood Ratio Test as a method to detect transitions, and explore how choices of sensor, feature calculations, and parameters concerning time segmentation affect the accuracy of this method. We discovered an approximate 5X increase in energy efficiency could be achieved with only a 5% decrease in accuracy. We also address how a system's sleep mode, in which the processor enters a low-power state and sensors are turned off, affects a wearable computing platform that does activity recognition. We discuss the energy trade-offs in each stage of the activity recognition process. We find that careful analysis of these parameters can result in great increases in energy efficiency if small compromises in overall accuracy can be tolerated. We call this the ``Great Compromise.'' We found a 6X increase in efficiency with a 7% decrease in accuracy. We then consider how wireless transmission of data affects the overall energy efficiency of a wearable computing platform. We find that design decisions such as feature calculations and grouping size have a great impact on the energy consumption of the system because of the amount of data that is stored and transmitted. For example, storing and transmitting vector-based features such as FFT or DCT do not compress the signal and would use more energy than storing and transmitting the raw signal. The effect of grouping size on energy consumption depends on the feature. For scalar features energy consumption is proportional in the inverse of grouping size, so it's reduced as grouping size goes up. For features that depend on the grouping size, such as FFT, energy increases with the logarithm of grouping size, so energy consumption increases slowly as grouping size increases. We find that compressing data through activity classification and transition detection significantly reduces energy consumption and that the energy consumed for the classification overhead is negligible compared to the energy savings from data compression. We provide mathematical models of energy usage and data generation, and test our ideas using a mobile computing platform, the Texas Instruments Chronos watch.
ContributorsBoyd, Jeffrey Michael (Author) / Sundaram, Hari (Thesis advisor) / Li, Baoxin (Thesis advisor) / Shrivastava, Aviral (Committee member) / Turaga, Pavan (Committee member) / Arizona State University (Publisher)
Created2014
Description
With the advent of technologies such as web services, service oriented architecture and cloud computing, modern organizations have to deal with policies such as Firewall policies to secure the networks, XACML (eXtensible Access Control Markup Language) policies for controlling the access to critical information as well as resources. Management of these policies is an extremely important task in order to avoid unintended security leakages via illegal accesses, while maintaining proper access to services for legitimate users. Managing and maintaining access control policies manually over long period of time is an error prone task due to their inherent complex nature. Existing tools and mechanisms for policy management use different approaches for different types of policies. This research thesis represents a generic framework to provide an unified approach for policy analysis and management of different types of policies. Generic approach captures the common semantics and structure of different access control policies with the notion of policy ontology. Policy ontology representation is then utilized for effectively analyzing and managing the policies. This thesis also discusses a proof-of-concept implementation of the proposed generic framework and demonstrates how efficiently this unified approach can be used for analysis and management of different types of access control policies.
ContributorsKulkarni, Ketan (Author) / Ahn, Gail-Joon (Thesis advisor) / Yau, Stephen S. (Committee member) / Huang, Dijiang (Committee member) / Arizona State University (Publisher)
Created2011
Description
Electronic waste (E-waste) is a concern, because of the increasing volume of materials being disposed of. There are economical, social and environmental implications derived from these materials. For example, the international trade of used computers creates jobs, but the recovery from valuable materials is technically challenging and currently there are environmental and health problems derived from inappropriate recycling practices. Forecasting the flows of used computers and e-waste materials supports the prevention of environmental impacts. However, the nature of these material flows is complex. There are technological geographical and cultural factors that affect how users purchase, store or dispose of their equipment. The result of these dynamics is a change in the composition and volume of these flows. Collectors are affected by these factors and the presence of markets, labor and transportation costs. In northern Mexico, there is an international flow of new and used computers between Mexico and the United States and an internal flow of materials and products among Mexican cities. In order to understand the behavior of these flows a field study was carried out in 8 different Mexican cities. Stake holders were interviewed and through a structured analysis the system and the relevant stakeholders were expressed as Data Flow Diagrams in order; to understand the critical parts from the system. The results show that Mexican cities have important qualitative differences. For example, location and size define the availability of resources to manage e-waste. Decisions to dispose a computer depend on international factors such as the price of new computers, but also on regional factors such as the cost to repair them. Decisions to store a computer depend on external factors such as markets, but also internal factors such as how users perceive the value of old equipment. E-waste collection depends on the value of e-waste, but also on costs to collect and extract value from them. The main implication is that a general policy base on how E-waste is managed at a big city might not be the most efficient for a small one. More over combining strengths from different cities might overcome respective weaknesses and create new opportunities; this integration can be stimulated by designing policies that consider diversity
ContributorsEstrada Ayub, Jesus Angel (Author) / Allenby, Braden R. (Thesis advisor) / Ramzy, Kahhat A (Thesis advisor) / Kahhat, Ramzy A (Committee member) / Williams, Eric (Committee member) / Arizona State University (Publisher)
Created2012
Description
Access control is one of the most fundamental security mechanisms used in the design and management of modern information systems. However, there still exists an open question on how formal access control models can be automatically analyzed and fully realized in secure system development. Furthermore, specifying and managing access control policies are often error-prone due to the lack of effective analysis mechanisms and tools. In this dissertation, I present an Assurance Management Framework (AMF) that is designed to cope with various assurance management requirements from both access control system development and policy-based computing. On one hand, the AMF framework facilitates comprehensive analysis and thorough realization of formal access control models in secure system development. I demonstrate how this method can be applied to build role-based access control systems by adopting the NIST/ANSI RBAC standard as an underlying security model. On the other hand, the AMF framework ensures the correctness of access control policies in policy-based computing through automated reasoning techniques and anomaly management mechanisms. A systematic method is presented to formulate XACML in Answer Set Programming (ASP) that allows users to leverage off-the-shelf ASP solvers for a variety of analysis services. In addition, I introduce a novel anomaly management mechanism, along with a grid-based visualization approach, which enables systematic and effective detection and resolution of policy anomalies. I further evaluate the AMF framework through modeling and analyzing multiparty access control in Online Social Networks (OSNs). A MultiParty Access Control (MPAC) model is formulated to capture the essence of multiparty authorization requirements in OSNs. In particular, I show how AMF can be applied to OSNs for identifying and resolving privacy conflicts, and representing and reasoning about MPAC model and policy. To demonstrate the feasibility of the proposed methodology, a suite of proof-of-concept prototype systems is implemented as well.
ContributorsHu, Hongxin (Author) / Ahn, Gail-Joon (Thesis advisor) / Yau, Stephen S. (Committee member) / Dasgupta, Partha (Committee member) / Ye, Nong (Committee member) / Arizona State University (Publisher)
Created2012
Description
As technology becomes more available to the public, cybercriminals are able to utilize these tools to circumvent outdated modes of protection and steal this information. My aim with my thesis is to understand the effects of cyberterror and cybercrime on the United States and the world and help spread awareness to the public and encourage proactivity in taking the proper steps to protect your information and stop those who would try and take it.
ContributorsLeung, Kevin (Author) / Fehler, Michelle (Thesis director) / Heywood, William (Committee member) / Barrett, The Honors College (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / The Design School (Contributor)
Created2015-05
Description
Journalism, by its very nature, is limited, often adhering to a repetitive format and narration style. Consequently, the depth of journalistic stories will always hit a barrier. Fiction, on the other hand, provides an elegant solution by exploring the world through a myriad point of views including complete omniscience. This thesis explores the link between journalism and fiction by taking real-world scenarios and exploring them without journalism's limitations. It includes three novellas totaling 25,000 words drawn from true-to-life research papers, news stories and manifestos to paint a realistic picture of a technological reality in the near future, a style of writing one might call futurecasting. The thesis also contains an analysis of the techniques used in contemporary fiction and an analysis of their implementation within the novellas. The goal of the novellas is to let researchers to explore the impact of their work before its mass dissemination in order to shape societal, national and international policy responsibly. Similarly, novellas like this and others similar allow society to discover the beauty of science through fiction. These are some of fiction's greatest roles in science and society.
ContributorsPacini, Jason Daniel (Author) / Zachary, Gregg (Thesis director) / Russell, Dennis (Committee member) / Giarrusso, Theresa Walsh (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2013-05
Description
The Mobile Waterway Monitor seeks to monitor water in an unexplored way. The module is buoyant and will float with the current as well as harvests solar energy. In short, the Mobile Waterway Monitor excels in size constraints, flexibility, extensibility, and capability. This current following monitor can show both measured trends like pH and interpolated trends like water speed, river contours, and elevation drop. The MWM strikes a balance between accuracy, portability, and being multi-purpose.
ContributorsStribrny, Kody John (Author) / Vrudhula, Sarma (Thesis director) / Wu, Carole-Jean (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
How prepared are individuals to work in an environment with sensitive information? Do business students believe a data security course would be a valuable addition to their curriculum? This study investigates W.P. Carey's role in preparing its students for jobs in which they most likely will have to handle large amounts of important data. Roughly 500 students across varying majors and years of education in the W.P. Carey School of Business answered an assortment of questions on their computer habits, and responded to various scenarios to test their knowledge. The survey targeted three specific areas (Software Updates, Password Protection, and Phishing) which was believed to be most pertinent to the students' future roles as professionals. While a large number of those surveyed (roughly 65%) responded well to most questions, nearly a third of all the responses received indicated cause for concern or an indication of a lack of knowledge. It was suggested (and many respondents agreed) that further education be provided to students for their own well-being in addition to the wellbeing of their future employers.
ContributorsVaughan, Nathaniel D (Author) / Lin, Elva (Thesis director) / Doupé, Adam (Committee member) / School of Accountancy (Contributor) / Department of Information Systems (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
ContributorsEvans, Bartlett R. (Conductor) / Schildkret, David (Conductor) / Glenn, Erica (Conductor) / Concert Choir (Performer) / Chamber Singers (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-16
Description
Connie McNeill came to ASU in the summer of 1976 as head of the payroll project and retired in the summer of 2006 as the West Campus Assistant Vice Provost for Information Technology. Interesting stories include:
1) her role in developing both academic and administrative computing services on the Tempe and West Campuses
2) bringing PC’s onto the Tempe Campus
3) the “Space Wars”
4) short stories about Roland Haden and Darel Eschbach
ContributorsGooding, Elmer (Interviewer) / Scheatzle, David (Interviewer) / Arizona State University Retirees Association (Producer)
Created2012-02-29