Ph.D. Dissertation Defense

Context-dependent privacy and security management on mobile devices

Prajit Kumar Das

8:00-11:00am Tuesday, 22 August 2017, ITE325b, UMBC

There are ongoing security and privacy concerns regarding mobile platforms which are being used by a growing number of citizens. Security and privacy models typically used by mobile platforms use one-time permission acquisition mechanisms. However, modifying access rights after initial authorization in mobile systems is often too tedious and complicated for users. User studies show that a typical user does not understand permissions requested by applications or are too eager to use the applications to care to understand the permission implications. For example, the Brightest Flashlight application was reported to have logged precise locations and unique user identifiers, which have nothing to do with a flashlight application’s intended functionality, but more than 50 million users used a version of this application which would have forced them to allow this permission. Given the penetration of mobile devices into our lives, a fine-grained context-dependent security and privacy control approach needs to be created.

We have created Mithril as an end-to-end mobile access control framework that allows us to capture access control needs for specific users, by observing violations of known policies. The framework studies mobile application executables to better inform users of the risks associated with using certain applications. The policy capture process involves an iterative user feedback process that captures policy modifications required to mediate observed violations. Precision of policy is used to determine convergence of the policy capture process. Policy rules in the system are written using Semantic Web technologies and the Platys ontology to define a hierarchical notion of context. Policy rule antecedents are comprised of context elements derived using the Platys ontology employing a query engine, an inference mechanism and mobile sensors. We performed a user study that proves the feasibility of using our violation driven policy capture process to gather user-specific policy modifications.

We contribute to the static and dynamic study of mobile applications by defining “application behavior” as a possible way of understanding mobile applications and creating access control policies for them. Our user study also shows that unlike our behavior-based policy, a “deny by default” mechanism hampers usability of access control systems. We also show that inclusion of crowd-sourced policies leads to further reduction in user burden and need for engagement while capturing context-based access control policy. We enrich knowledge about mobile “application behavior” and expose this knowledge through the Mobipedia knowledge-base. We also extend context synthesis for semantic presence detection on mobile devices by combining Bluetooth, low energy beacons and Nearby Messaging services from Google.

Committee: Drs. Anupam Joshi (chair), Tim Finin (co-chair), Tim Oates, Nilanjan Banerjee, Arkady Zaslavsky, (CSIRO), Dipanjan Chakraborty (Shopperts)

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Ph.D. Dissertation Defense

Identifying and Ordering Scalar Adjectives using Lexical Substitution

Bryan Wilkinson

1:00pm Friday, 18 August 2017, ITE 325b, UMBC

Lexical semantics provides many important resources in natural language processing, despite the recent preferences for distributional methods. In this dissertation we investigate an under-represented lexical relationship, that of scalarity. We define sclarity as it relates to adjectives and introduce novel methods to identify words belonging to a particular scale and to order those words once they are found. This information has important uses in both traditional linguistics as well as natural language processing. We focus on solving both these problems using lexical substitution, a technique that allows us to determine the best substitute word for a given word in a sentence. We also produce two new datasets: a gold standard of scalar adjectives for use in the development and evaluation of methods like the ones introduces here, and a test set of indirect question-answer pairs, one possible application of scalar adjectives.

Committee: Drs. Tim Oates, CSEE (Chair), Charles Nicholas, Tim Finin, Shimei Pan (IS) and Mona Diab (GWU CS)

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Over the past year, proactive and reactive acts of resistance have electrified our country and world. Immediate images that flash through our minds include the water protectors at Standing Rock, the millions around the world who participated in the Women’s March, those who rushed to the airports to volunteer translation and legal assistance to immigrants and refugees in the immediate aftermath of the travel ban.  

As these images of mass protests and large-scale actions continue to capture our attention, we also recognize the power of everyday acts of resistance. Social justice movements have been infused with a renewed sense of urgency, and for an ever-growing number of people, there is the will to be counted, to find voice, and to rise up.

While many are new to the struggle, the struggle itself is not new. We’re reminded by those who have long been active in these movements that the fight for justice is neither in its first breaths nor last gasps.

For the fifth annual Critical Social Justice, we’ll explore opportunities for building individual and collective resistance and resilience. Events throughout the week will challenge us to think about how we can do better, do more, and persist in doing it. How do we rise to meet the challenges of this particular cultural moment to work toward a vision of inclusive excellence—whether it’s in the classroom, online, or in our communities?

We’re excited to announce that our keynote speaker will be Native scholar and activist Dr. Adrienne Keene (Cherokee Nation), who writes about cultural appropriation and stereotypes of Native peoples in pop culture on her blog Native Appropriations. Keene examines the way Indigenous peoples are using new media to challenge racism, present authentic counter-narratives, and create innovative spaces for art and activism. The keynote lecture and reception will be held on Tuesday, October 24th at 6pm in the UC Ballroom.

Critical Social Justice: Rise will be held on October 23rd through 27th, 2017. Follow our blog, Facebook, and Twitter (#csjrise) for our calendar of events, updates and other news. For more information about the Critical Social Justice initiative, please email womenscenter@umbc.edu.

Critical Social Justice is a Women’s Center initiative with The Mosaic: Center for Culture and Diversity.

A reflection written by Women’s Center director, Jess Myers, tag-teamed with friend, Priscilla.

A few weeks ago, my dear friend, Priscilla, and I headed out on a road trip of a lifetime through Colorado, Utah, and Arizona. And, because we both solidly identify as feminists, this, my friends, was a Feminist Road Trip. We had a blast hiking through four national parks, camping under the stars, and being amazed by the vast beauty of nature.

As the mileage left on our trip got smaller and smaller, in addition to reflecting on our favorite moments, we began to reflect on our journey and what specifically made it feminist. We compiled quite a long list and what we each uniquely brought to our trip as intersectional feminists. For example, I wasn’t as conscientious about ensuring we were making an investment in the local economy when we booked our lodging and Priscilla wasn’t aware about the $5 a day campaign to ensure hotel workers are being fairly compensated for their efforts. We challenged each other along the way to think more critically about our feminist values and what that looks like in practice. For example, getting your truck stuck in the mud doesn’t have to be a women-only experience in getting un-stuck and accepting help from men doesn’t have to be un-feminist (even if you have to “uuuuggggh” it out together when you get back to the safety of your un-stuck truck – which by the way, we affectionately named Carol).

Here we are in Fort Collins, Colorado on Day 1 of our road trip with Carol!

At the Grand Canyon taking our official 10 year anniversary celebration photo complete with a handmade heart.

Learn the history of the place and space you’re traveling through… and then dig deeper. Honor who came before you and learn about the native and indigenous people who first called these places home. Where the story of women are not present, ask why, and when their stories are present, pause to read and reflect with each other. We particularly enjoyed the story of Sharlot Hall and the Vermillion Cliffs in AZ.

Support local businesses. Tip your guides and servers generously and leave at least $5 a day for your housekeeper for each day you stay in your hotel/motel.

Encourage other women on the trail and on the road.

Share your growing edges with each other and then keep reflecting and constructing a counter-narrative. For example, a theme throughout our trip as women traveling without our significant others was being mindful of saying “I” instead of “we” when recounting personal stories, goals, and hopes and the importance we hold in maintaining our individuality in a long-term relationship.

Gracefully accept help as needed.

Be body positive and affirming. Don’t judge other women for taking selfies. You never know what it may have taken for another woman to get to that summit.

Four Corners selfie with a selfie stick!

Play excellent women-empowered playlists and sing your hearts out (for some great ideas, check out NPR’s Turning Tables: 150 Greatest Albums Made by Women)

Honor your friendships with women and celebrate your milestones. Friendships can be just as valid and important as our romantic and/or blood-family relationships.

Here we are at Lower Antelope Canyon in Arizona. We had the best the guide who took this awesome photo of us.

For those planning your next feminist road trip, here’s some of our favorite travel blogs and hashtags (links do not represent endorsements) we used to prepare for our road trip state of mind:

• On She Goes: Travel Stories for All Women of Color
• Bearfoot Theory: Outdoor Adventure for the Everyday Adventurer
• #brownpeoplecamping
• #FatGirlsHiking
• Field Tripping – a bi-weekly column in Baltimore’s City Paper written by UMBC’s very own Dr. Kate Drabinski

Happy traveling to all our feminist wanderlusts out there!