Matching Items (3)
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Description
This project explores how web applications can structure their User Interfaces to best accommodate their users who may not be able to use standard input devices like a mouse and keyboard, or differentiate subtle color differences in text, or who may be overwhelmed with heavy animation or auto-play videos. This

This project explores how web applications can structure their User Interfaces to best accommodate their users who may not be able to use standard input devices like a mouse and keyboard, or differentiate subtle color differences in text, or who may be overwhelmed with heavy animation or auto-play videos. This project serves as a proof-of-concept of an accessible Virtual Learning Environment to be used by students of online classes, particularly at younger grade levels. It is a functional application that handles user login, lecture presentations and materials, and quizzes. The development of the front-end is done through the React JS library, an open source library from Facebook used for building UIs. This project finds that React has strong capabilities of building accessible UIs that is consistent with modern accessibility web standards. As React is one of the most popular emerging JavaScript libraries that is already being incorporated to large-scale web pages and applications, this project hopes to inform other developers on some of the tools and techniques that can make their work accessible to all users.
ContributorsTerzic, Philip Mico (Author) / Balasooriya, Janaka (Thesis director) / Tadayon-Navabi, Farideh (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
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Description
Ad hoc wireless networks present several interesting problems, one of which is Medium Access Control (MAC). Medium Access Control is a fundamental problem deciding who get to transmit next. MAC protocols for ad hoc wireless networks must also be distributed, because the network is multi-hop. The 802.11 Wi-Fi protocol is

Ad hoc wireless networks present several interesting problems, one of which is Medium Access Control (MAC). Medium Access Control is a fundamental problem deciding who get to transmit next. MAC protocols for ad hoc wireless networks must also be distributed, because the network is multi-hop. The 802.11 Wi-Fi protocol is often used in ad hoc networking. An alternative protocol, REACT, uses the metaphor of an auction to compute airtime allocations for each node, then realizes those allocations by tuning the contention window parameter using a tuning protocol called SALT. 802.11 is inherently unfair due to how it returns the contention window to its minimum size after successfully transmitting, while REACT’s distributed auction nature allows nodes to negotiate an allocation where all nodes get a fair portion of the airtime. A common application in the network is audio streaming. Audio streams are dependent on having good Quality of Service (QoS) metrics, such as delay or jitter, due to their real-time nature.

Experiments were conducted to determine the performance of REACT/SALT compared to 802.11 in a streaming audio application on a physical wireless testbed, w-iLab.t. Four experiments were designed, using four different wireless node topologies, and QoS metrics were collected using Qosium. REACT performs better in these these topologies, when the mean value is calculated across each run. For the butterfly and star topology, the variance was higher for REACT even though the mean was lower. In the hidden terminal and exposed node topology, the performance of REACT was much better than 802.11 and converged more tightly, but had drops in quality occasionally.
ContributorsKulenkamp, Daniel (Author) / Syrotiuk, Violet R. (Thesis director) / Colbourn, Charles J. (Committee member) / Computer Science and Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
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Description
REACT is a distributed resource allocation protocol that can be used to negotiate airtime among nodes in a wireless network. In this thesis, REACT is extended to support quality of service (QoS) airtime in an updated version called REACT QoS . Nodes can request the higher airtime class to receive

REACT is a distributed resource allocation protocol that can be used to negotiate airtime among nodes in a wireless network. In this thesis, REACT is extended to support quality of service (QoS) airtime in an updated version called REACT QoS . Nodes can request the higher airtime class to receive priority in the network. This differentiated service is provided by using the access categories (ACs) provided by 802.11, where one AC represents the best effort (BE) class of airtime and another represents the QoS class. Airtime allocations computed by REACT QoS are realized using an updated tuning algorithm and REACT QoS is updated to allow for QoS airtime along multi-hop paths. Experimentation on the w-iLab.t wireless testbed in an ad-hoc setting shows that these extensions are effective. In a single-hop setting, nodes requesting the higher class of airtime are guaranteed their allocation, with the leftover airtime being divided fairly among the remaining nodes. In the multi-hop scenario, REACT QoS is shown to perform better in each of airtime allocation and delay, jitter, and throughput, when compared to 802.11. Finally, the most influential factors and 2-way interactions are identified through the use of a locating array based screening experiment for delay, jitter, and throughput responses. The screening experiment includes a factor on how the channel is partitioned into data and control traffic, and its effect on the responses is determined.
ContributorsKulenkamp, Daniel J (Author) / Syrotiuk, Violet R (Thesis advisor) / Colbourn, Charles J (Committee member) / Tinnirello, Ilenia (Committee member) / Arizona State University (Publisher)
Created2021