Houtan Shirani-Mehr

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With many location-based services, it is implicitly assumed that the location server receives actual users locations to respond to their spatial queries. Consequently, information customized to their locations, such as nearest points of interest can be provided. However, there is a major privacy concern over sharing such sensitive information with(More)
In this paper we propose a fundamental approach to perform the class of Range and Nearest Neighbor (NN) queries, the core class of spatial queries used in location-based services, without revealing any location information about the query in order to preserve users' private location information. The idea behind our approach is to utilize the power of(More)
We envision participatory texture documentation (PTD) as a process in which a group of users (dedicated individuals and/or general public) with camera-equipped mobile phones participate in collaborative collection of urban texture information. PTD enables inexpensive, scalable and high resolution urban texture documentation. We have proposed to implement(More)
We envision participatory texture documentation (PTD) as a process in which a group of participants (dedicated individuals and/or general public) with camera-equipped mobile phones participate in collaborative/social collection of the urban texture information. PTD enables inexpensive, scalable and high resolution urban texture documentation. PTD is(More)
In many data-publishing applications, the data owner needs to protect sensitive information pertaining to individuals. Meanwhile, certain information is required to be published. The sensitive information could be considered as leaked, if an adversary can infer the real value of a sensitive entry with a high confidence. In this paper we study how to protect(More)
With the advent of reliable positioning technologies and prevalence of location-based services, it is now feasible to accurately study the propagation of items such as infectious viruses, sensitive information pieces, and malwares through a population of moving objects, e.g., individuals, mobile devices, and vehicles. In such application scenarios, an item(More)
Participatory texture documentation (PTD) is a geospatial data collection process in which a group of users (dedicated individuals and/or general public) with camera-equipped mobile phones participate in collaborative collection of urban texture information. PTD enables inexpensive, scalable and high resolution data collection for urban texture mapping. In(More)
The sensing systems that monitor physical environments rely on communication infrastructures (wired or wireless) to collect data from the sensors embedded in the environment. However, in many urban environments pre-existing communication infrastructures are not available, and installing and using new infrastructures is unjustifiably expensive and/or(More)
The goal of this paper is to develop a framework for designing good data repositories for Web applications. The central theme of our approach is to employ statistical methods to predict quality metrics. These prediction quantities can be used to answer important questions such as: How soon should the local repository be synchronized to have a quality of at(More)
In the age of Internet, the performance of many Web-based applications critically depend on the quality of local repositories. Due to the dynamics of remote Web sources, applications have to crawl information periodically to ensure the high quality of repositories. In this paper, we use the general quality-aware principle to strike balances between the(More)