Terry Griffin

Routing-based map matching for extracting routes from GPS trajectories

This paper introduces a novel offline map matching approach. We develop a routing-based map matching approach for standardizing identified routes in a collected set of GPS trajectories. Our approach first identifies key waypoints in a users GPS trajectory using a modified Peucker curve reduction algorithm. Subsequently, it sends the key waypoints to a black-box driving directions service which returns a route utilizing each of the key waypoints. The returned route is a standardized representation of the original GPS trajectory constructed using the minimum necessary set of points. A filter-and-refine approach is used to identify the incorrect portion of the returned route and a refine step is carried out by eliminating the waypoints what leads to the incorrect matching. Experiments results showed that the proposed approach works well for a data-set of 10 volunteers each collecting data an average of 34.3 days.

Querying geospatial data streams in SECONDO

In this demo paper, we report our experience of designing and implementing a geospatial data stream query engine in SECONDO. Compared with current data stream and moving object query systems, our query engine not only supports point geo-streams that represent continuously moving points, but also line and region geo-streams that represent complex spatio-temporal phenomena elevated from geo-referenced raw readings. We implement the data types, operators, and language extensions as a modular algebra in SECONDO. We also provide an independent SQL parser for specifying continuous queries using SQL-like syntax as well as an Ajax-driven web interface for dynamic visualization of steaming results.

Instructional testing through wireless handheld devices

In the educational field, students and faculty are looking for tools that may help to improve the learning process. Todays students, however, are usually too busy to follow a plan of study. Practice tests and questions are becoming an essential requirement of textbooks to allow the students to evaluate their current knowledge. Wireless access to the Internet has opened the door to a new range of computer applications, designed to satisfy the requirement of mobile users, equipped with a cell phone device. This paper describes the use of mobile devices as a medium for a self-evaluation tool complete with study guidelines feedback. Such an application is designed and implemented using many traditional Web methodologies, allowing a fast transition from the current wired Web system to the cell phone environment. This paper briefly discusses the Web tools used in such an implementation and presents an example of a test-feedback application appropriate for cell phone access.

Creating a framework for data sharing in cochlear implant research

Objectives: To summarize the development process of a national database that was designed to facilitate communication and collaboration, improve care, and create a framework for aggregate data sharing in cochlear implant (CI) research. Methods: A group of nationally represented, multidisciplinary CI providers cooperated to define a standard set of data elements to incorporate into a database built by them in association with a group of computer scientists and software designers. CI centers across the USA, then, joined the non-profit Auditory Implant Initiative to use the database for their own clinical purposes and to help contribute to the national de-identified dataset for research and analytics. Results: Approximately 12 months after the full release of the database, clinical information on 373 patients has been entered from 17 different CI centers representing 61 hearing professionals. A blend of six academic, seven private, and four non-profit CI centers participated in this phase of the data sharing network. Discussion: The adoption of a single, standardized database by 17 centers throughout the USA has begun a framework for data sharing in CI research. Future steps include (1) expanding adoption, (2) scaling the database to include more patients, (3) streamlining the legal hurdles required for adoption, and (4) integrating the database with other software platforms (e.g. electronic health records, processors). Conclusion: A standardized clinical outcomes database that is utilized by a growing network of CI centers can help strengthen research through aggregate data sharing.

Pilot study on the use of data mining to identify cochlear implant candidates

Objectives: The goal of this pilot study was to determine the clinical utility of data-mining software that screens for cochlear implant (CI) candidacy. Methods: The Auditory Implant Initiative developed a software module that screens for CI candidates via integration with a software system (Noah 4) that serves as a depository for hearing test data. To identify candidates, patient audiograms from one practice were exported into the screening module. Candidates were tracked to determine if any eventually underwent implantation. Results: After loading 4836 audiograms from the Noah 4 system, the screening module identified 558 potential CI candidates. After reviewing the data for the potential candidates, 117 were targeted and invited to an educational event. Following the event, a total of six candidates were evaluated, and two were implanted. Discussion: This objective approach to identifying candidates has the potential to address the gross underutilization of CIs by removing any bias or lack of knowledge regarding the management of severe to profound sensorineural hearing loss with CIs. Conclusion: The screening module was an effective tool for identifying potential CI candidates at one ENT practice. On a larger scale, the screening module has the potential to impact thousands of CI candidates worldwide.

Intelligent System for Locating, Labeling, and Logging ( ISL 3 )

As mobile smart devices become ubiquitous in our society, users will be able to receive location based information on the fly. A model that is able to predict a user’s next destination will make location based services more effective by providing personalized information to the user. The implementation of such a location prediction model requires a set of correctly labeled destinations collected from users to tune the prediction model to an acceptable level of accuracy. A large collection of data will allow researchers to derive the parameters required to train predication models and also get the trends of user behaviors in general. ISL 3 will allow researchers to do just this by easily allowing them to collect user activity data to create location prediction models.

Mobile web caching in a hostile environment

In the wired Internet, it is common practice to use Web caching to reduce network utilization and improve access time to a Web page. Mobile users introduce new variables in the communication process due to the fact that a user may dynamically change its contact point within the network, accessing the Web server through a different path, which may not have access to cached pages. In hostile environments such as domestic catastrophic emergencies, field units must have a higher priority to significant information available through Web servers, requiring lower response times and reliable access via Internet enabled cell phones. In foreign lands, specific infrastructure must be implemented and activated, which requires extensive work currently being researched by defense contractors. In domestic situations, the infrastructure exists and must be equipped to provide the necessary priority to civil defense personnel. This study discusses mechanisms used in Web caching and suggests features that should be added to current cache management algorithms to provide the necessary priority, including the use of standard protocol commands to identify cacheable information and establishment of priority and aging policies to control the length of time data should be maintained in the cache.