Uichin Lee

There has been recent interests in studying the "goal" behind a user's Web query, so that this goal can be used to improve the quality of a search engine's results. Previous studies have mainly focused on using manual query-log investigation to identify Web query goals. In this paper we study whether and how we can automate this goal-identification process. We first present our results from a human subject study that strongly indicate the feasibility of automatic query-goal identification. We th

Vehicular sensor networks are emerging as a new network paradigm of primary relevance, especially for proactively gathering monitoring information in urban environments. Vehicles typically have no strict constraints on processing power and storage capabilities. They can sense events (e.g., imaging from streets), process sensed data (e.g., recognizing license plates), and route messages to other vehicles (e.g., diffusing relevant notification to drivers or police agents). In this novel and challe

Mobile peer-to-peer systems have recently got in the lime-light of the research community that is striving to build efficient and effective mobile content addressable networks. Along this line of research, we propose a network coding based file swarming protocol targeting vehicular ad hoc net-works (VANET). We argue that file swarming protocols in VANET should deal with typical mobile network issues such as dynamic topology and intermittent connectivity as well as various other issues that have

Recent advances in vehicular communications make it possible to realize vehicular sensor networks, i.e., collaborative environments where mobile vehicles that are equipped with sensors of different nature (from toxic detectors to still/video cameras) interwork to implement monitoring applications. In particular, there is an increasing interest in proactive urban monitoring, where vehicles continuously sense events from urban streets, autonomously process sensed data (e.g., recognizing license pl

The negative aspects of smartphone overuse on young adults, such as sleep deprivation and attention deficits, are being increasingly recognized recently. This emerging issue motivated us to analyze the usage patterns related to smartphone overuse. We investigate smartphone usage for 95 college students using surveys, logged data, and interviews. We first divide the participants into risk and non-risk groups based on self-reported rating scale for smartphone overuse. We then analyze the usage dat

Our energy efficiency analysis of various content dissemination strategies reveals that a change in network architecture from host-oriented to content-centric networking (CCN) can open new possibilities for energy-efficient content dissemination. In this paper, we consider energy-efficient CCN architecture and validate its energy efficiency via trace-based simulations. The results confirm that CCN is more energy efficient than conventional CDNs and P2P networks, even under incremental deployment

In this study, we introduce the concept of a virtual ¿flea market¿ over a vehicular ad hoc network (VANET) called FleaNet. FleaNet customers express their demands/offers to buy/sell items via radio queries. These queries are opportunistically disseminated, exploiting the mobility of other customers, until a matching customer/vendor is found. We identify the key performance metrics, namely, query resolution latency, scalability, mobility, and churning, and evaluate their impact on performance usi

A major role of today's Internet is to provide efficient content dissemination among users, such as distributing multimedia content and sharing user generated data. To meet the ever increasing demands, the Internet has been rapidly growing, and it now includes a web of tens of millions of networked devices ranging from content servers to core and edge routers to home gateways. Due to the sheer numbers, however, it is reported that these devices, such as those used for content delivery, consume a

Mobile wireless networks with intermittent connectivity, often called Delay/Disruption Tolerant Networks (DTNs), have recently received a lot of attention because of their applicability in various applications, including multicasting. To overcome intermittent connectivity, DTN routing protocols utilize mobility-assist routing by letting the nodes carry and forward the data. In this paper, we study the scalability of DTN multicast routing. As Gupta and Kumar showed that unicast routing is not sca

In this paper we study the use of vehicles as sensors in a "vehicular sensor network" a new network paradigm that is critical for gathering valuable information in urban environments. In a vehicular sensor network, each vehicle is responsible for sensing one or more events, routing messages to other vehicles or infostations and processing sensed data. There are several critical differences between a vehicular sensor network and a "traditional" wireless sensor network, namely: 1) the vehicular ne

Pollution in P2P file sharing occurs when a large number of decoy files are injected into the P2P system. Since peers “serve ” each other in the P2P file sharing system, it is obvious that pollution dynamics are closely related to user behavior. Therefore, we first conduct a human subject study to investigate user behavior. We identify the factors that are key to model user behavior, e.g., cooperativeness and awareness of pollution. Our results show that users are quite insensitive to pollution,

Over recent years, mobile Internet devices such as laptops, PDAs, smart phones etc, have become extremely popular and widespread. Once on board of a vehicle, these devices can automatically connect to the vehicle processor and thus greatly amplify the communications and processing capabilities available to the owner in a "pedestrian mode". We envision that this "amplification" opportunity will be one of the drivers of car to car and car to curb communications. In fact, the car communications sys

Safe navigation support through wireless car-to-car and car-to-curb communications has become an important priority for car manufacturers as well as transportation authorities and communications standards organizations. New standards are emerging for car-to-car communications (DSRC and more recently IEEE 802.11p) [8]. There have been several well publicized testbeds aimed at demonstrating the feasibility and effectiveness of car-to-car communication safety; for instance, the ability to rapidly p