George Lekakos

A taxonomy of indoor and outdoor positioning techniques for mobile location services

Wireless positioning determination has received increased attention during the past few years. Several wireless applications have been envisaged when mobile terminal location can be determined with sufficient accuracy at any time. In this paper, we attempt to identify the various indoor and outdoor positioning techniques that can be used for the provision of mobile and wireless applications and services. In order to maximize the benefits of this research in the area of positioning technologies, we propose a novel taxonomy with detailed analysis and evaluation of these techniques based on the accuracy that is needed for various mobile location-based services.

Improving the prediction accuracy of recommendation algorithms: Approaches anchored on human factors

Recommender systems are a special class of personalized systems that aim at predicting a users interest on available products and services by relying on previously rated items or item features. Human factors associated with a users personality or lifestyle, although potential determinants of user behavior are rarely considered in the personalization process. In this paper, we demonstrate how the concept of lifestyle can be incorporated in the recommendation process to improve the prediction accuracy by efficiently managing the problem of limited data availability. We propose two approaches: one relying on lifestyle alone and another integrating lifestyle within the nearest neighbor approach. Both approaches are empirically tested in the domain of recommendations for personalized television advertisements and are shown to outperform existing nearest neighborhood approaches in most cases.

Determinants of Effective SMS Advertising: An Experimental Study

ABSTRACT Mobile advertising has become one of the most popular applications in mobile commerce, particularly in the form of text advertising through SMS (Short Messaging Service). However, in the study of mobile advertising little is known regarding the effectiveness of SMS advertising and the factors contributing to its success. This research investigates the significance of a number of factors associated with SMS advertising effectiveness through an experimental study. The findings indicate that incentive, interactivity, appeal, product involvement, and attitude toward SMS advertising in general directly influence attitude toward the advertisement, attitude toward the brand, and purchase intention. The results of the study suggest that a stronger focus on these factors is necessary to improve the effectiveness of SMS advertising campaigns.

A hybrid approach for movie recommendation

Collaborative and content-based filtering are the major methods in recommender systems that predict new items that users would find interesting. Each method has advantages and shortcomings of its own and is best applied in specific situations. Hybrid approaches use elements of both methods to improve performance and overcome shortcomings. In this paper, we propose a hybrid approach based on content-based and collaborative filtering, implemented in MoRe, a movie recommendation system. We also provide empirical comparison of the hybrid approach to the base methods of collaborative and content-based filtering and draw useful conclusions upon their performance.

A hybrid approach for improving predictive accuracy of collaborative filtering algorithms

Recommender systems represent a class of personalized systems that aim at predicting a user’s interest on information items available in the application domain, operating upon user-driven ratings on items and/or item features. One of the most widely used recommendation methods is collaborative filtering that exploits the assumption that users who have agreed in the past in their ratings on observed items will eventually agree in the future. Despite the success of recommendation methods and collaborative filtering in particular, in real-world applications they suffer from the insufficient number of available ratings, which significantly affects the accuracy of prediction. In this paper, we propose recommendation approaches that follow the collaborative filtering reasoning and utilize the notion of lifestyle as an effective user characteristic that can group consumers in terms of their behavior as indicated in consumer behavior and marketing theory. Emanating from a basic lifestyle-based recommendation algorithm we incrementally proceed to the development of hybrid recommendation approaches that address certain dimensions of the sparsity problem and empirically evaluate them providing further evidence of their effectiveness.

Introduction to Social TV: Enhancing the Shared Experience with Interactive TV

Previous research on the social impact of communication technologies has followed two distinct directions and has considered independently either the interpersonal communication or the mass communication. In this context, the human–computer interaction aspects of integrated media and social communication are examined. The design of “Social TV” systems that support interpersonal communication, which is motivated by mass media consumption and which takes place within colocated groups or over distance, is explored. In terms of the temporal dimension, Social TV might be synchronous, which happens in real time, or asynchronous, which happens with a time difference. This article provides an overview of research findings and outlines evaluation methods and user requirements for usability and sociability in interactive TV.

Personalized Interactive TV Advertising: The iMEDIA Business Model

Interactive TV, also referred to as iTV, combines the appeal and mass audience of traditional TV with the interactive nature of the Web. As such, it offers viewers an active entertainment experience and industry players new business opportunities to learn better about and serve their audience and prospective customers. Interactivity, in particular, implies a two-way communication between the viewer and the medium, allowing for unprecedented personalization of programming and services. In this paper we deal with the topic of advertising over digital interactive TV and describe a specific approach to the delivery of personalized interactive advertisement content to viewers based on their individual profiles. The emphasis is placed on the transformation of industry business models that the new technological developments imply. The main implication of iTV advertising is a whole new set of information and information flows among industry players that are introduced to take advantage of interactivity and person...

Demystifying the design of mobile augmented reality applications

This research proposes a set of interaction design principles for the development of mobile augmented reality (MAR) applications. The design recommendations adopt a user-centered perspective and, thus, they focus on the necessary actions to ensure high-quality MAR user experiences. To formulate our propositions we relied on theoretical grounding and an evaluation of eight MAR applications that provide published records of their design properties. The design principles have then been applied to guide the development of a MAR travel application. We performed a field study with 33 tourists in order to elicit whether our design choices effectively lead to enhanced satisfaction and overall user experience. Results suggest that the proposed principles contribute to ensuring high usability and performance of the MAR application as well as evoking positive feelings during user and system interactions. Our prescriptions may be employed either as a guide during the initial stages of the design process (ex-ante usage) or as a benchmark to assess the performance (ex-post usage) of MAR applications.

Exploiting RFID digital information in enterprise collaboration

Purpose – The purpose of this paper is to investigate how a distributed network architecture, building on web‐service orchestration, data‐stream management systems and smart‐tagging technologies, can be employed to enable enterprise collaboration and decision making.Design/methodology/approach – The methodology is based on a technology review in order to propose a network design as well as a field survey to identify and evaluate the relevance of radio frequency identification (RFID)‐enabled collaboration and decision‐support scenarios to industry executives.Findings – The paper demonstrates the relevance of the proposed architecture and corresponding RFID‐enabled collaboration to business executives of the grocery retail sector. The responses show that some scenarios are more appealing to retailers than to suppliers and that certain processes should be done in collaboration.Research limitations/implications – Research limitations and future research directions involve the evaluation of specific design alt...

Intelligent user interfaces in the living room: usability design for personalized television applications

The purpose of this paper is to present our experience from the design of a personalized television application, and the implications for the design of interactive television applications in general. Personalized advertising is a gentle introduction to interactive television applications through a push paradigm that is closer to the established patterns of television use. While personalization is a practice widely used on the Internet, applying personalization techniques over digital television infrastructures presents significant obstacles, which we address with explicit design moves