ZapDroid: Managing Infrequently Used Applications on Smartphones

ABSTRACT User surveys have shown that a typical user has over a hundred apps on her smartphone [1], but stops using many of them. We conduct a user study to identify such unused apps, which we call zombies, and show via experiments that zombie apps consume significant resources on a user's smartphone and access her private information. We then design and build ZapDroid, which enables users to detect and silo zombie apps in an e↵ective way to prevent their undesired activities. If and when the user wishes to resume using such an app, ZapDroid restores the app quickly and e↵ectively. Our evaluations show that: (i) ZapDroid saves twice the energy from unwanted zombie app behaviors as compared to apps from the Play Store that kill background unwanted processes, and (ii) it e↵ectively prevents zombie apps from using undesired permissions. In addition, ZapDroid is energye cient, consuming < 4% of the battery per day

Consumption of low-moderate level arsenic contaminated water does not increase spontaneous pregnancy loss: a case control study

Previous work suggests an increased risk for spontaneous pregnancy loss linked to high levels of inorganic arsenic (iAs) in drinking water sources (\u3e10 μg/L). However, there has been little focus to date on the impact of low-moderate levels of iAs in drinking water (\u3c10 \u3eμg/L). To address this data gap we conducted a hospital-based case–control study in Timis County, Romania

Practical Dynamic Software Updating

This dissertation makes the case that programs can be updated while they run, with modest programmer effort, while providing certain update safety guarantees, and without imposing a significant performance overhead. Few systems are designed with on-the-fly updating in mind. Those systems that permit it support only a very limited class of updates, and generally provide no guarantees that following the update, the system will behave as intended. We tackle the on-the-fly updating problem using a compiler-based approach called dynamic software updating (DSU), in which a program is patched with new code and data while it runs. The challenge is in making DSU practical: it should support changes to programs as they occur in practice, yet be safe, easy to use, and not impose a large overhead. This dissertation makes both theoretical contributions—formalisms for reasoning about, and ensuring update safety—and practical contributions—Ginseng, a DSU implementation for C. Ginseng supports a broad range of changes to C programs, and performs a suite of safety analyses to ensure certain update safet