Enhancing information retrieval in folksonomies using ontology of place constructed from Gazetteer information

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial TechnologiesFolksonomy (from folk and taxonomy) is an approach to user metadata creation where users describe information objects with a free-form list of keywords (‘tags’). Folksonomy has have proved to be a useful information retrieval tool that support the emergence of “collective intelligence” or “bottom-up” light weight semantics. Since there are no guiding rules or restrictions on the users, folksonomy has some drawbacks and problems as lack of hierarchy, synonym control, and semantic precision. This research aims at enhancing information retrieval in folksonomy, particularly that of location information, by establishing explicit relationships between place name tags. To accomplish this, an automated approach is developed. The approach starts by retrieving tags from Flickr. The tags are then filtered to identify those that represent place names. Next, the gazetteer service that is a knowledge organization system for spatial information is used to query for the place names. The result of the search from the gazetteer and the feature types are used to construct an ontology of place. The ontology of place is formalized from place name concepts, where each place has a “Part-Of” relationship with its direct parent. The ontology is then formalized in OWL (Web Ontology Language). A search tool prototype is developed that extracts a place name and its parent name from the ontology and use them for searching in Flickr. The semantic richness added to Flickr search engine using our approach is tested and the results are evaluated

A Survey of Volunteered Open Geo-Knowledge Bases in the Semantic Web

Over the past decade, rapid advances in web technologies, coupled with innovative models of spatial data collection and consumption, have generated a robust growth in geo-referenced information, resulting in spatial information overload. Increasing 'geographic intelligence' in traditional text-based information retrieval has become a prominent approach to respond to this issue and to fulfill users' spatial information needs. Numerous efforts in the Semantic Geospatial Web, Volunteered Geographic Information (VGI), and the Linking Open Data initiative have converged in a constellation of open knowledge bases, freely available online. In this article, we survey these open knowledge bases, focusing on their geospatial dimension. Particular attention is devoted to the crucial issue of the quality of geo-knowledge bases, as well as of crowdsourced data. A new knowledge base, the OpenStreetMap Semantic Network, is outlined as our contribution to this area. Research directions in information integration and Geographic Information Retrieval (GIR) are then reviewed, with a critical discussion of their current limitations and future prospects

Assessment of metadata associated with geotag pictures

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.The past decade web has seen a major transformations in development and design to facilitate a user interactive environment commonly referred as Web 2.0. Web 2.0 services include web-based communities, hosted services, social-networking sites, media-sharing sites, wikis, bogs and mashups. Member contributions feed these online communities and are the force behind the increased volume of multimedia resources that are available on the web. In 2006 Time Magazine selected users of Web 2.0 for ‘esteemed person of the year’ award for their active involvement in generating web resources and shaping these resources into collective intelligence

Dijital Sergiler ve Anahtar Resim Ontolojisi

The Age of Image predates and is currently contemporaneous with the Information Age. In our times the explosive expansion of Web 2.0 Social Space, typified by the phenomena of De.licio.us, Flickr, MySpace, YouTube…, and the concomitant emergence of folksonomy, present interesting challenges in the management of this information. One key process by which to accomplish this in Social Space, is the wedding of folksonomy (of the people) with ontology (of the machine). Such a wedding must necessarily be conducted in the shared physicality of the word, of language. In this respect, WordNet together with OWL, play the role of matchmaker. But the same Social Space also provides an opportunity for natural folksonomical tagging by digiFoto (key)image. The research harness for experimental keyimage tagging consists of Flickr as the main (digiFoto image) Social Space testbed and De.licio.us as the auxillary outreach secondary Social Space. Protégé Editor with OWL-DL provides the support for the bridge from keyimage to the formal ontology. The primary end user application domain is the keyimage tagging of paintings in an online art gallery.Görüntü Çağı, Bilgi Çağından önce gelir ve günümüzde Bilgi Çağıyla çağdaştır. De.licio.us, Flickr, MySpace, YouTube. . . gibi olgularla örneklenen Web 2.0 Sosyal Uzayının tahminlerin ötesinde büyümesi ve bununla birlikte ortaya çıkan etiketleme bilgi yönetiminde ilginç gelişmelere sahne olmaktadır. Sosyal Uzayda bilgi yönetimini başarmak (insanlar tarafından gerçekleştirilen) etiketleme ve (makineler tarafından gerçekleştirilen) ontolojinin birleştirilmesini gerektirmektedir. Böyle bir birleştirme mutlaka sözün ve dilin ortak fizikselliğiyle gerçekleştirilmelidir. Bu hususta Web Ontoloji Dili1 (OWL) ile WordNet çöpçatan rolü oynarlar. Öte yandan aynı Sosyal Uzay dijiFoto (anahtar) resimle doğal folksonomik işaretleme yapmak için de bir fırsat sağlar. Deneysel anahtar resim işaretlemesi yapmak için kullanılan araştırma araçları ana (dijiFoto görüntü) Sosyal Uzay sınama ortamı olan Flickr ile yardımcı ikincil Sosyal Uzay sınama ortamı olan De.licio.us’dan oluşmaktadır. OWL-DL (OWL Betimleme Mantığı) ile Protégé Editor anahtar resimden biçimsel (formal) ontolojiye köprü kurmak için destek sağlar. Başlıca son kullanıcı uygulama alanı bir çevrimiçi sanat galerisindeki tabloların anahtar resim işaretlemesidir

Enriching user profiles using geo-social place semantics in geo-folksonomies

Geo-folksonomies link social web users to geographic places through the tags users choose to label the places with. These tags can be a valuable source of information about the user’s perception of place and can reflect their experiences and activities in the places they label. By analysing the associations between users, places and tags, an understanding of a place and its relationships with other places can be drawn. This place characterisation is unique, dynamic and reflects the perception of a particular user community that generated the geo-folksonomy. In this work, an approach is proposed to analysing geo-folksonomies that builds on and extends existing statistical methods by considering specific concepts of relevance to geographic place resources, namely, place types and place-related activities, and by building a place ontology to encode those concepts and relationships. The folksonomy analysis and evaluation are demonstrated using a realistic geo-folksonomy data set. The resulting ontology is used to build user profiles from the folksonomy. The derived profiles reflect the association between users and the specific places they tag as well as other places with relevant associated place type and activities. The methods proposed here provide the potential for many interesting and useful applications, including the harvesting of useful insight on geographic space and employing the derived user profiles to enhance the search experience and to identify similarities between users based on their association to geographic places

Extracting place semantics from geo-folksonomies

Massive interest in geo-referencing of personal resources is evident on the web. People are collaboratively digitising maps and building place knowledge resources that document personal use and experiences in geographic places. Understanding and discovering these place semantics can potentially lead to the development of a different type of place gazetteer that holds not only standard information of place names and geographic location, but also activities practiced by people in a place and vernacular views of place characteristics. The main contributions of this research are as follows. A novel framework is proposed for the analysis of geo-folksonomies and the automatic discovery of place-related semantics. The framework is based on a model of geographic place that extends the definition of place as defined in traditional gazetteers and geospatial ontologies to include the notion of place affordance. A method of clustering place resources to overcome the inaccuracy and redundancy inherent in the geo-folksonomy structure is developed and evaluated. Reference ontologies are created and used in a tag resolution stage to discover place-related concepts of interest. Folksonomy analysis techniques are then used to create a place ontology and its component type and activity ontologies. The resulting concept ontologies are compared with an expert ontology of place type and activities and evaluated through a user questionnaire. To demonstrate the utility of the proposed framework, an application is developed to illustrate the possible enrichment of search experience by exposing the derived semantics to users of web mapping abstract applications. Finally, the value of using the discovered place semantics is also demonstrated by proposing two semantic based similarity approaches; user similarity and place similarity. The validity of the approaches was confirmed by the results of an experiment conducted on a realistic folksonomy dataset

Creation and extension of ontologies for describing communications in the context of organizations

Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfillment of the requirements for the degree of Master in Computer ScienceThe use of ontologies is nowadays a sufficiently mature and solid field of work to be considered an efficient alternative in knowledge representation. With the crescent growth of the Semantic Web, it is expectable that this alternative tends to emerge even more in the near future. In the context of a collaboration established between FCT-UNL and the R&D department of a national software company, a new solution entitled ECC – Enterprise Communications Center was developed. This application provides a solution to manage the communications that enter, leave or are made within an organization, and includes intelligent classification of communications and conceptual search techniques in a communications repository. As specificity may be the key to obtain acceptable results with these processes, the use of ontologies becomes crucial to represent the existing knowledge about the specific domain of an organization. This work allowed us to guarantee a core set of ontologies that have the power of expressing the general context of the communications made in an organization, and of a methodology based upon a series of concrete steps that provides an effective capability of extending the ontologies to any business domain. By applying these steps, the minimization of the conceptualization and setup effort in new organizations and business domains is guaranteed. The adequacy of the core set of ontologies chosen and of the methodology specified is demonstrated in this thesis by its effective application to a real case-study, which allowed us to work with the different types of sources considered in the methodology and the activities that support its construction and evolution