Prize-Based Contingency Management: A Vehicle Miles of Travel Reduction Intervention

During the past 50 years, air pollution has become a growing problem throughout the Intermountain West because of increases in personal vehicle ownership and usage. Scientists continue to design interventions to improve air quality by encouraging people to reduce their personal vehicle miles of travel (VMT). However, results of these interventions have only seen modest reductions in VMT because of some methodological and measurement issues. To address these limitations, a 14-week driving reduction intervention was conducted in Cache County, Utah. This intervention employed a prizebased contingency management system within a single-subject, A-B-A withdrawal research design that rewarded participants with prizes if they were able to reduce their VMT below their baseline mean. The VMT was measured each day with an in-car GPS electronic tracking device. Results of this intervention indicate both short- and long-term reductions in VMT as a result of the treatment. Specifically, 6 of the 10 participants showed a statistically significant reduction from the baseline to the intervention stage and maintenance of this reduction during the return-to-baseline stage. The other four participants exhibited a similar pattern but their change in vehicle miles of travel was not statistically significant. Interaction effects were not found between the quo;Choose Clean Airquo; social marketing campaign, gas prices, temperature, and PM 2.5 levels. Despite some problems with the transmission and recording of VMT data, this intervention provides further evidence for the application of prize-based contingency management systems to the reduction of a problematic behavior or encouragement of proenvironmental or pro-social behaviors. The in-car GPS devices improved VMT data collection and quality of the data but hardware and software improvements are still needed to prevent data loss. Further replication is necessary to determine the efficacy of driving reduction intervention that employs prize-based contingency management systems at the community or group level. Future research should also test the possible demographic differences between those that respond favorably to this type of intervention and those that do not, and the differences between prize delivery systems (immediate versus delayed) and prize magnitude (low- versus high-dollar amounts) on driving behaviors

Advanced Transport Protocols for Wireless and Mobile Ad Hoc Networks

This thesis comprises transport protocols in the following different areas of research: Fast Handover allows mobile IP end-devices to roam between wireless access routers without interruptions while communicating to devices in an infrastructure (e.g., in the Internet). This work optimizes the Fast Handover algorithm and evaluates the performance of the transport protocols UDP and TCP during fast handovers via measurements. The following part of the thesis focuses on vehicular ad hoc networks. The thesis designs and evaluates through simulations a point-to-point transport protocol for vehicular ad hoc networks and an algorithm to facilitate the reliable and efficient distribution of information in a geographically scoped target area. Finally, the thesis evaluates the impact of wireless radio fluctuations on the performance of an Ad Hoc Network. Measurements quantify the wireless radio fluctuations. Based on these results, the thesis develops a simple but realistic radio model that evaluates by means of simulations the impact on the performance of an ad hoc network. As a result, the work provides guidelines for future ad hoc protocol design

Exploiting Mobile Social Networks from Temporal Perspective:A Survey

With the popularity of smart mobile devices, information exchange between users has become more and more frequent, and Mobile Social Networks (MSNs) have attracted significant attention in many research areas. Nowadays, discovering social relationships among people, as well as detecting the evolution of community have become hotly discussed topics in MSNs. One of the major features of MSNs is that the network topology changes over time. Therefore, it is not accurate to depict the social relationships of people based on a static network. In this paper, we present a survey of this emerging field from a temporal perspective. The state-of-the-art research of MSNs is reviewed with focus on four aspects: social property, time-varying graph, temporal social property, and temporal social properties-based applications. Some important open issues with respect to MSNs are discussed