Sentiment-based topic suggestion for micro-reviews

Location-based social sites, such as Foursquare or Yelp, are gaining increasing popularity. These sites allow users to check in at venues and leave a short commentary in the form of a micro-review. Micro-reviews are rich in content as they offer a distilled and concise account of user experience. In this paper we consider the problem of predicting the topic of a micro-review by a user who visits a new venue. Such a prediction can help users make informed decisions, and also help venue owners personalize users' experiences. However, topic modeling for micro-reviews is particularly difficult, due to their short and fragmented nature. We address this issue using pooling strategies, which aggregate micro-reviews at the venue or user level, and we propose novel probabilistic models based on Latent Dirichlet Allocation (LDA) for extracting the topics related to a user-venue pair. Our best topic model integrates influences from both venue inherent properties and user preferences, considering at the same the sentiment orientation of the users. Experimental results on real datasets demonstrate the superiority of this model compared to simpler models and previous work; they also show that venue-inherent properties have higher influence on the topics of micro-reviews. © Copyright 2016, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved.postprin

Academic careers in Computer Science: Continuance and transience of lifetime co-authorships

International audienceScholarly publications reify fruitful collaborations between co-authors. A branch of research in the Science Studies focuses on analyzing the co-authorship networks of established scientists. Such studies tell us about how their collaborations developed through their careers. This paper updates previous work by reporting a transversal and a longitudinal studies spanning the lifelong careers of a cohort of researchers from the DBLP bibliographic database. We mined 3,860 researchers' publication records to study the evolution patterns of their co-authorships. Two features of co-authors were considered: 1) their expertise, and 2) the history of their partnerships with the sampled researchers. Our findings reveal the ephemeral nature of most collaborations: 70% of the new co-authors were only one-shot partners since they did not appear to collaborate on any further publications. Overall, researchers consistently extended their co-authorships 1) by steadily enrolling beginning researchers (i.e., people who had never published before), and 2) by increasingly working with confirmed researchers with whom they already collaborated

Business models and transactions in mobile electronic commerce: requirements and properties

Advances in wireless network technology and the continuously increasing number of users of hand-held terminals make the latter a possible channel for offering personalized services to mobile users and give pace to the rapid development of mobile electronic commerce (MEC). MEC operates partially in a different environment than Internet e-commerce due to the special characteristics and constraints of mobile terminals and wireless networks and the context, situations and circumstances in which people use their hand-held terminals. In this paper, we discuss the business models in MEC and transaction modeling issues pertinent for the business models and the environment. (C) 2001 Elsevier Science B.V. All rights reserved

Metadata Modeling in a Global Computing Environment

Emerging computational paradigms such as global and ubiquitous computing require some rethinking and innovative research ideas in many computer science areas. In this work, we aim at studying a mobile computing scenario from a database perspective. Given a global computing environment in which data is kept in a number of small-scale, data-charged, mobile devices that use, e.g., wireless networks, for communication, we want to assess the overall data scenario. We use the example application of tourist information services to abstract the requirements to such a computing environment. Using this more concrete handle, we outline the various existing types of data. Included here are some metadata proposals related to the actual data stored in the device (content data) as well as to the data necessary to the functioning of the device within the computing environment (profile data). The metadata proposals are based on well-known languages and tools such as XML, RDF, UML, and the concept of ontologies. 1

An Access Control Mechanism for Large Scale Data Dissemination Systems

IEEE Computer Society Pres

Data Consistency in Intermittently Connected Distributed Systems

Abstract-Mobile computing introduces a new form of distributed computation in which communication is most often intermittent, low-bandwidth, or expensive, thus providing only weak connectivity. In this paper, we present a replication scheme tailored for such environments. Bounded inconsistency is defined by allowing controlled deviation among copies located at weakly connected sites. A dual database interface is proposed that in addition to read and write operations with the usual semantics supports weak read and write operations, In contrast to the usual read and write operations that read consistent values and perform permanent updates, weak operations access only local and potentially inconsistent copies and perform updates that are only conditionally committed. Exploiting weak operations supports disconnected operation since mobile clients can employ them to continue to operate even while disconnected. The extended database interface coupled with bounded inconsistency offers a flexible mechanism for adapting replica consistency to the networking conditions by appropriately balancing the use of weak and normal operations, Adjusting the degree of divergence among copies provides additional support for adaptivity. We present transaction-oriented correctness criteria for the proposed schemes, introduce corresponding serializability-based methods, and outline protocols for their implementation. Then, some practical examples of their applicability are provided. The performance of the scheme is evaluated for a range of networking conditions and varying percentages of weak transactions by using an analytical model developed for this purpose

One is enough: distributed filtering for duplicate elimination

The growth of online services has created the need for duplicate elimination in high-volume streams of events. The sheer volume of data in applications such as pay-per-click clickstream processing, RSS feed syndication and notification services in social sites such Twitter and Facebook makes traditional centralized solutions hard to scale. In this paper, we propose an approach based on distributed filtering. To this end, we introduce a suite of distributed Bloom filters that exploit different ways of partitioning the event space. To address the continuous nature of event delivery, the filters are extended to support sliding window semantics. Moreover, we examine locality-related tradeoffs and propose a tree-based architecture to allow for duplicate elimination across geographic locations. We cast the design space and present experimental results that demonstrate the pros and cons of our various solutions in different settings