An Ontology-Based Recommender System with an Application to the Star Trek Television Franchise

Collaborative filtering based recommender systems have proven to be extremely successful in settings where user preference data on items is abundant. However, collaborative filtering algorithms are hindered by their weakness against the item cold-start problem and general lack of interpretability. Ontology-based recommender systems exploit hierarchical organizations of users and items to enhance browsing, recommendation, and profile construction. While ontology-based approaches address the shortcomings of their collaborative filtering counterparts, ontological organizations of items can be difficult to obtain for items that mostly belong to the same category (e.g., television series episodes). In this paper, we present an ontology-based recommender system that integrates the knowledge represented in a large ontology of literary themes to produce fiction content recommendations. The main novelty of this work is an ontology-based method for computing similarities between items and its integration with the classical Item-KNN (K-nearest neighbors) algorithm. As a study case, we evaluated the proposed method against other approaches by performing the classical rating prediction task on a collection of Star Trek television series episodes in an item cold-start scenario. This transverse evaluation provides insights into the utility of different information resources and methods for the initial stages of recommender system development. We found our proposed method to be a convenient alternative to collaborative filtering approaches for collections of mostly similar items, particularly when other content-based approaches are not applicable or otherwise unavailable. Aside from the new methods, this paper contributes a testbed for future research and an online framework to collaboratively extend the ontology of literary themes to cover other narrative content.Comment: 25 pages, 6 figures, 5 tables, minor revision

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Key challenges in agent-based modelling for geo-spatial simulation

Agent-based modelling (ABM) is fast becoming the dominant paradigm in social simulation due primarily to a worldview that suggests that complex systems emerge from the bottom-up, are highly decentralised, and are composed of a multitude of heterogeneous objects called agents. These agents act with some purpose and their interaction, usually through time and space, generates emergent order, often at higher levels than those at which such agents operate. ABM however raises as many challenges as it seeks to resolve. It is the purpose of this paper to catalogue these challenges and to illustrate them using three somewhat different agent-based models applied to city systems. The seven challenges we pose involve: the purpose for which the model is built, the extent to which the model is rooted in independent theory, the extent to which the model can be replicated, the ways the model might be verified, calibrated and validated, the way model dynamics are represented in terms of agent interactions, the extent to which the model is operational, and the way the model can be communicated and shared with others. Once catalogued, we then illustrate these challenges with a pedestrian model for emergency evacuation in central London, a hypothetical model of residential segregation tuned to London data which elaborates the standard Schelling (1971) model, and an agent-based residential location built according to spatial interactions principles, calibrated to trip data for Greater London. The ambiguities posed by this new style of modelling are drawn out as conclusions

Two worlds:design relativity in the complex world

This paper proposes that there could be ‘relative’ meanings of design in organizations, according to the different national cultures in which the organizations predominantly reside, due to the different organizational vocabulary that is used in the design of a ‘complex product’. The paper suggests that under complex conditions, different meanings of design according to national cultures could influence, not only the development of an organization, but also the design of these complex products. The author contends that much research on the meaning of design and its use in design-led innovation takes a Western perspective; however this paper discusses how different national cultures influence the construction of product design and how different national cultures could influence the meaning of design in complex organizations. This is achieved by examining a case study in Samsung, which has been involved in a global dispute regarding its product design patents with Apple. This paper explores how this lens might help to understand how design-led innovation is viewed differently and how the resulting product design is influenced by national and derived organizational cultures

Artificial and Natural Genetic Information Processing

Conventional methods of genetic engineering and more recent genome editing techniques focus on identifying genetic target sequences for manipulation. This is a result of historical concept of the gene which was also the main assumption of the ENCODE project designed to identify all functional elements in the human genome sequence. However, the theoretical core concept changed dramatically. The old concept of genetic sequences which can be assembled and manipulated like molecular bricks has problems in explaining the natural genome-editing competences of viruses and RNA consortia that are able to insert or delete, combine and recombine genetic sequences more precisely than random-like into cellular host organisms according to adaptational needs or even generate sequences de novo. Increasing knowledge about natural genome editing questions the traditional narrative of mutations (error replications) as essential for generating genetic diversity and genetic content arrangements in biological systems. This may have far-reaching consequences for our understanding of artificial genome editing

u-Help: supporting helpful communities with information technology

When people need help with day-to-day tasks they turn to family, friends or neighbours to help them out. Finding someone to help out can be a stressful waste of time. Despite an increasingly networked world, technology falls short in supporting such daily irritations. u-Help provides a platform for building a community of helpful people and supports them in finding help for day-to-day tasks. It relies on a trio of techniques that allow a requester and volunteer to find one another easily, and build up a community around such provision of services. First, we use an ontology to distinguish between the various tasks that u-Help allows people to provide. Second, a computational trust model is used to aggregate feedback from community members and allows people to discover who are good or bad at performing the various tasks. Last, a flooding algorithm, similar to the popular Gnutella algorithm, quickly disseminates requests for help through the community. This paper describes these three techniques in detail. This work is implemented as an iPhone application that we also describe in this paper.This work is supported by the Generalitat de Catalunya grant 2009-SGR-1434, the CBIT project (TIN2010-16306), the Agreement Technologies project (CONSOLIDER CSD2007-0022, INGENIO 2010), and the ACE ERA-Net project.Peer Reviewe

Social Media as a Driver for Societal Value Degradation: the Nigerian Perspective

Social Media facilitates the creation and sharing of information, ideas, interests to virtual communities and networks using interactive technologies. The benefits of such seamless communication are immense and critical to national growth and development. However national growth and development cannot be achieved without a sound value and moral system guiding the conducts of its people. This article investigates the role social media plays in eroding the value system of Nigerian youths. It highlights problematic areas and concludes by making suggestions for the regulation of social media content through content filtering based on generally acceptable cultural values