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Deploying auxiliary location-based services to complement GPS-based services has been a recent phenomenon to enable greater independence in navigation and wayfinding for persons with disabilities in unfamiliar environments. All work in this domain has been technical in nature with little known about the perceptions of city planners and non-profit agencies about the long-term sustainability and impact of such technologies on their communities. This work presents results and insights from a study on the perceptions of both city planners and non-profit agency personnel from a medium-sized city in the U.S.A about the importance of auxiliary location-based services and their potential impact. 

Certain Android applications, such as but not limited to malware, conceal their presence from the user, exhibiting a self-hiding behavior. Consequently, these apps put the user's security and privacy at risk by performing tasks without the user's awareness. Static analysis has been used to analyze apps for self-hiding behavior, but this approach is prone to false positives and suffers from code obfuscation. This research proposes a set of three tools utilizing a dynamic analysis method of detecting self-hiding behavior of an app in the home, installed, and running application lists on an Android emulator. Our approach proves both highly accurate and efficient, providing tools usable by the Android marketplace for enhanced security screening. 

GPS accuracy is poor in indoor environments and around buildings. Thus, reading and following signs still remains the most common mechanism for providing and receiving wayfinding information in such spaces. This puts individuals who are blind or visually impaired (BVI) at a great disadvantage. This work designs, implements, and evaluates a wayfinding system and smartphone application called CityGuide that can be used by BVI individuals to navigate their surroundings beyond what is possible with just a GPS-based system. CityGuide enables an individual to query and get turn-by-turn shortest route directions from an indoor location to an outdoor location. CityGuide leverages recently developed indoor wayfinding solutions in conjunction with GPS signals to provide a seamless indoor-outdoor navigation and wayfinding system that guides a BVI individual to their desired destination through the shortest route. Evaluations of CityGuide with BVI human subjects navigating between an indoor starting point to an outdoor destination within an unfamiliar university campus scenario showed it to be effective in reducing end-to-end navigation times and distances of almost all participants. 

This paper presents a brief overview of the various (related) research the author has been involved with in the area of navigation and wayfinding for people with visual impairments. The first major piece of research presented is that of the building and deployment of a beacon-based indoor navigation and wayfinding system called GuideBeacon for people with visual impairments. The second major piece of research presented is a broader community-based effort called CityGuide to enable various location-based services (including navigation and wayfinding) in both indoor and outdoor environments for people with disabilities. The paper concludes by summarizing a specific challenge in the area that warrant future research attention. 

Indoor wayfinding has remained a challenge for people with disabilities in unfamiliar environments. With some accessible indoor wayfinding systems coming to the fore recently, a major application of interest is that of emergency evacuation due to natural or man-made threats to safety. Independent emergency evacuations can be particularly challenging for persons with disabilities as there is usually a requirement to quickly gather and use alternative wayfinding information to exit the indoor space safely. This paper presents the design and evaluation of an inclusive emergency evacuation system called SafeExit4All that empowers people with disabilities (in addition to the general population) to independently find a safe exit under emergency scenarios. The Safe-Exit4All application drives an underlying accessible indoor wayfinding system with the necessary emergency evacuation system parameters customized to an individual's preferences and needs for exiting safely from a premise. Upon receiving an emergency alert, a user accesses the SafeExit4All system through an app on their smartphone that has access to real-time information about the threat, and simply follows on-screen turn-by-turn navigation instructions towards the closest safe exit. Human subject evaluations show Safe-Exit4All to be effective not just in terms of reducing evacuation time, but also in providing guidance that results in users taking deterministic, shorter, and safer paths to the exit most suitable for them. 

Blind or Visually Impaired (BVI) individuals often face many challenges while performing daily tasks or exploring new places. Assistive technologies can help independently address some of these challenges, but there remain many tasks that still require some sort of human assistance. Some current approaches to provide remote assistance through video calls are either too expensive or do not use helpers whom a BVI individual can fully trust. This work develops an Android application called GuideCall that enables BVI individuals to draw assistance through a video call with a single volunteer helper selected from one of many pre-constructed situation-appropriate groups of trusted individuals. Guide- Call provides is specifically built to meet the needs of BVI individuals and has some features not present in commodity video-calling applications.