Exploring historical location data for anonymity preservation in location-based services

We present a new approach for K-anonymity protection in Location-Based Services (LBSs). Specifically, we depersonalize location information by ensuring that each location reported for LBSs is a cloaking area that contains K different footprints--- historical locations of different mobile nodes. Therefore, the exact identity and location of the service requestor remain anonymous from LBS service providers. Existing techniques, on the other hand, compute the cloaking area using current locations of K neighboring hosts of the service requestor. Because of this difference, our approach significantly reduces the cloaking area, which in turn decreases query processing and communication overhead for returning query results to the requesting host. In addition, existing techniques also require frequent location updates from all nodes, regardless of whether or not these nodes are requesting LBSs. Most importantly, our approach is the first practical solution that provides K-anonymity trajectory protection needed to ensure anonymity when the mobile host requests LBSs continuously as it moves. Our solution depersonalizes a user\u27s trajectory (a time-series of the user\u27s locations) based on the historical trajectories of other users

Managing motion triggered executables in distributed mobile databases

Mobile devices have brought new applications into our daily life. However, ecient man- agement of these objects to support new applications is challenging due to the distributed nature and mobility of mobile objects. This dissertation describes a new type of mobile peer- to-peer (M-P2P) computing, namely geotasking, and presents ecient management of mobile objects to support geotasking. Geotasking mimics human interaction with the physical world. Humans generate information using sensing ability and store information to geographical lo- cations. Humans also retrieve this information from the physical locations. For instance, an installation of a new stop sign at some intersection in town is analogous to an insertion of a new data item into the database. Instead of processing regular data as in traditional data management systems, geotasking manages a collection of geotasks, each dened as a computer program bound to a geographical region. The hardware platform for geotasking consists of popular networked position-aware mobile devices such as cell phones, personal digital assis- tants, and laptops. We design and implement novel system software to facilitate programming and ecient management of geotasks. Such management includes inserts, deletes, updates, retrieval and execution of a geotask triggered by mobile object correlations, geotask mobil- ity, and geotask dependency. Geotasking enables useful applications ranging from warning of dangerous areas for military and search-and-rescue missions to monitoring the population in a certain area for trac management to informing tourists of exciting events in an area and other such applications. Geotasking provides a distributed and unied solution for supporting various types of applications

EVIDENCE OF THE EFFECTS OF WATER QUALITY ON RESIDENTIAL LAND PRICES

We use hedonic techniques to show that water quality has a significant effect on property values along the Chesapeake Bay. Mindful of the limitations of using hedonic methods for welfare analysis, we calculate the potential benefits from an illustrative (but limited) water quality improvement. Past hedonic studies have almost entirely ignored the potential for omitted variables bias -- the possibility that pollution sources, in addition to emitting undesirable substances, are likely to be unpleasant neighbors. We discuss the implications of this oversight, and we provide an application that addresses the problem head-on.water quality, hedonic models, residential land prices, Environmental Economics and Policy,

Real-Time Short-Term Travel Time Prediction

Real-time short-term travel time prediction is a critical component of the Intelligent Transportation System (ITS) and an important element of the Advanced Traveler Information System (ATIS). Accurate and reliable travel time prediction enables both user and system controller to be well informed of the likely future conditions on roadways, so that pre-trip plans and traffic control strategies can be made accordingly in order to reduce travel time and relieve traffic congestion. With these travel time predictions, roads may be used more efficiently with better overall network performance. This research will study short-term travel time prediction for freeway applications using various sources of real time travel time data. The integrated prediction model proposed here will put emphasis on travel time prediction under various traffic and weather scenarios and especially inclement weather conditions

A Survey on Topology and Position Based Routing Protocols in Vehicular Ad hoc Network (VANET)

Vehicular Ad Hoc Networks (VANET) is a subclass of Mobile ad hoc networks. It is a developing new technology in which vehicles interchange the information from one vehicle to another vehicle within a network. VANET is responsible for providing an illustrated approach for Intelligent Transport System (ITS). The main use of VANET is to save life and prevent the accidents. This Paper describes a survey of routing protocols in vehicular ad hoc networks. The survey of routing protocols in VANET is significant and essential for smart ITS. The routing protocols are divided into two categories of topology-based and position-based routing for VANETs. This review discusses the advantages and disadvantages of these routing protocols

Synchronization in complex networks

Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.Comment: Final version published in Physics Reports. More information available at http://synchronets.googlepages.com