This thesis investigates the argument structure of transitive particle constructions with the adverb bort, meaning ‘away’, ‘off’. On the basis of approximately 2000 authentic instances of the partially schematic structure [subject verb bort object], I have identified a number of constructions at different levels of abstraction. The overall aim of the thesis is to account for the argument structure of the bort-constructions and to provide an overview of the relation between verb meaning and constructional meaning. Based on the empirical investigation, the argument structure of these constructions seems most adequately accounted for by combining lexical and constructional factors. The investigation shows that the argument structure forms a lexical-constructional continuum: some constructions clearly have verb-specific meaning, whereas others have meaning more or less independently of the verb. In between we find constructions exhibiting various degrees of influence over the lexical properties of the verb. Verb meaning is analyzed within a causative semantic framework, and I assume an association between causation and argument structure. The bort-constructions form a causative continuum ranging from direct, physical to indirect, abstract causation. By analyzing the verbs’ semantics in relation to these different causative structures (semantic frames), I demonstrate that the causative continuum and the argument structure continuum are aligned: the more indirect the causation, the more constructionally dependent (less verb-specific) the argument structure.

This thesis examines the various approaches which have been taken to investigate the concrete/abstract word distinction both in normal subjects and in patients who, as a result of brain damage, have an impairment of lexical semantic representations. The nature of the definition task as a tool for assessing the semantic representations of concrete and abstract terms was examined. It was found that definitions for abstract words differed from those of concrete words only in style, not in semantic content. The metalinguistic demands of the definition task therefore make it inappropriate for assessing the semantic representations of concrete and abstract terms in patients with any form of language impairment. The performance of four patients with semantic impairments was examined using a variety of tasks designed to assess concrete and abstract word comprehension. While some of the data can be accommodated within the framework of several theories, no single theory can adequately account for the patterns of performance in all four patients. An alternative model of semantic memory is therefore proposed in which concreteness and frequency interact at the semantic level. Jones' Ease of Predication Hypothesis, which states that the difference between concrete and abstract terms can be explained in terms of disproportionate numbers of underlying semantic features (or "predicates") was also investigated. It was found that the ease of predication variable does not accurately reflect either predicate or feature distributions, and is simply another index of concreteness. As such, the validity of this concept as the basis of theories of semantic representation should be questioned. Models based on the assumption of a "richer" semantic representation for concrete words (e.g.: Plaut & Shallice, 1993) are therefore undermined by these data. The possibility that concrete and abstract concepts can be accessed from their most salient predicates and/or features was examined in a series of semantic priming experiments. It was concluded that it is not possible to prime either concrete or abstract concepts from their constituent parts. Significant facilitation only occurred for items in which the prime and target were synonymous and therefore map onto concepts which share almost identical semantic representations. In summary, it is apparent that no current theory of semantic representation can adequately account for the range of findings with regard to the concrete/abstract word distinction. The most plausible account is some form of distributed connectionist model. However, such models are based on unsubstantiated assumptions about the nature of abstract word representations in the semantic network. Alternative proposals are therefore discussed.

published_or_final_version / abstract / toc / Computer Science and Information Systems / Master / Master of Philosophy

Η συγκεκριμένη μεταπτυχιακή διπλωματική εργασία ασχολείται με την αλληλεπίδραση δύο παράλληλων διεργασιών στην προσπάθεια αξιοποίησης του Παγκόσμιου Ιστού (Web): (α) τη διεργασία μετεξέλιξης του Παγκόσμιου Ιστού στο σημασιολογικό Παγκόσμιο Ιστό, (β) τη διεργασία βελτίωσης των διαδικασιών διαπέρασης (crawling) και ψαξίματος (searching) στον Παγκόσμιο Ιστό. Στα πρώτα βήματα του Παγκόσμιου Ιστού το σημαντικότερο ίσως πρόβλημα για τους χρήστες που ήθελαν να αναζητήσουν πληροφορίες σε αυτό ήταν η έλλειψη πολλών και χρήσιμων πηγών. Σταδιακά, αλλά με ιδιαίτερα γρήγορους ρυθμούς ο Παγκόσμιος Ιστός μετατράπηκε σε μία από τις μεγαλύτερες πηγές πληροφοριών που χρησιμοποιεί ο άνθρωπος καθώς όλο και περισσότεροι εισάγουν δεδομένα για κάθε είδους δραστηριότητα και θέμα. Το πρόβλημα των χρηστών λοιπόν που αναζητούν πληροφορίες ανάχθηκε στη γρήγορη εξαγωγή των χρήσιμων, από τον τεράστιο όγκο των παρεχόμενων, πληροφοριών. Όροι και τεχνικές όπως Data Mining (Εξόρυξη Δεδομένων), Information Retrieval (Ανάκτηση Πληροφορίας), Knowledge Management (Διαχείριση Γνώσης) επεκτάθηκαν για να καλύψουν και το νεοεμφανιζόμενο μέσο. Επιπλέον, στην προσπάθεια για καλύτερη ποιότητα των παρεχόμενων αποτελεσμάτων στο χρήστη σημαντικό ρόλο διαδραμάτισε η εκμετάλλευση των ιδιαίτερων στοιχείων που μπορούν να εξαχθούν για τα ενδιαφέροντά του, τόσο στο στάδιο της διαπέρασης, όπου συγκεντρώνονται σελίδες συγκεκριμένης θεματολογίας (topic-focused crawling), όσο και στο στάδιο της αναζήτησης μέσα από αυτές των πιο σημαντικών για τον εκάστοτε χρήστη (personalization). Παράλληλα, καθώς ο Παγκόσμιος Ιστός σταδιακά μετεξελίσσεται στο Σημασιολογικό Παγκόσμιο Ιστό (Semantic Web) νέα μοντέλα και πρότυπα (XML, RDF, OWL) αναπτύσσονται για την προώθηση αυτής της διαδικασίας. Η έκφραση, μετάδοση και αναζήτηση πληροφοριών με χρήση αυτών των προτύπων ανοίγει νέους ορίζοντες στη χρήση του Διαδικτύου. Το βασικό αντικείμενο της εργασίας αυτής είναι η αξιοποίηση των παρεχόμενων μοντέλων και προτύπων του Σημασιολογικού Ιστού σε συνδυασμό με ήδη εφαρμοσμένες ιδέες και αλγορίθμους στον απλό Παγκόσμιο Ιστό ώστε να είναι εφικτή η ταχύτερη και ακριβέστερη ανάκτηση και επεξεργασία πληροφοριών. Δόθηκε επίσης προσπάθεια στην αξιοποίηση τεχνικών που εκμεταλλεύονται τις ιδιαίτερες προτιμήσεις κάθε χρήστη, και στη διερεύνηση της χρήσης των νέων μοντέλων και προτύπων του Σημασιολογικού Ιστού για την προώθηση της διαδικασίας αυτής. / The presented master thesis examines the interaction between two parallel tasks aiming to the better utilization of the World Wide Web: (a) the task of transforming the World Wide Web into Semantic Web, (b) the task of improving the results of crawling and searching methods on the Web. In the advent of the World Wide Web the most disconcerting problem for the users searching for information in the Web was the lack of useful and sufficient sources of information. Gradually, though in really fast pace, the World Wide Web transformed into the biggest storage of information that humans can use. More and more people contribute new data on the web about every aspect of their life, activity, job or interest. Eventually, users searching for information have to deal with another problem, quite the opposite than the one mentioned above. They need to find the information they are looking for through an enormous amount of data in the minimum amount of time spend in browsing. Terms and techniques such as Data Mining, Information Retrieval, Knowledge Management were extended to be applicable and to the newly presented media. Moreover, on the strive for better quality of the results returned to users, the utilization of user’s special interests that can be extracted played an important role both in the field of crawling, where pages of a certain subject are gathered (topic-focused crawling), and in the field of searching, where pages are valued according to each user’s needs (personalization). At the same time, while the World Wide Web gradually transforms into Semantic Web, new standards and models (XML, RDF, OWL) are evolving in order to launch this inquiry. The storage, presentation, transmission and search of information according to those standards open up new horizons in the utilization of the Web. The principal effort of this master thesis is the utilization of the newly provided models and standards of the Semantic Web in conjunction with already tested, positively evaluated and applicable ideas and algorithms of the World Wide Web, in order to achieve higher speed in retrieval and accuracy of information. Moreover, strong efforts were given in integrating techniques that take into account the special preferences of each user and in the exploration of the benefits that come from the adaptation of these new models of the Semantic Web.

The main problem in the semantic technology today is semantic metadata extraction and description. There is no general method used to extract any type of semantics. The main objective of this research is to analyze existing methods that are used for describing and extracting semantic metadata and to design a metadata extraction system for Lithuanian. The quality analysis of designed system is carried out according to ISO/IEC 9126 standard. The objective of this standard is to provide a framework for the evaluation of software quality. ISO/IEC 9126 does not provide requirements for software, but it defines a quality model, which is applicable to every kind of software.

Recruitment service domain is one of the most relevant domains, where more advanced and effective semantic search methods and complex matching techniques must be applied. Recruitment system is a specific portal, designated for job seekers and employers. The main goal of this work is to create online recruitment system based on semantic search for preselecting candidates and to investigate the principles for creating such systems. We analyze semantic matching algorithm witch would improve query results, the realization chances of such a scenario from the technological viewpoint and describe a prototypical implementation of the required technological infrastructure. Using current standards and classifications it is possible to create human resource ontology allowing semantic annotation of job postings and applications. This work is devoted for requirements specification, design and implementation of recruitment system, allowing to deploy and examine various semantic matching techniques. Using Semantic Web technologies in the domain of online recruitment, could substantially increase market transparency, lower the transaction costs for employers, and change the business models of the intermediaries involved.

The Semantic Web is the future of the Internet. It is the extension to the Internet in which information will be given well-defined meaning, enabling not only humans but also machines to find, share and combine information more easily. In the Semantic Web documents are not merely pages containing a set of words that form their content. They also encode the meaning and structure of those words. This enables various information retrieval techniques to be performed on the documents in addition to the ones restricted to keywords. The goal of this research is to explore a method for querying the Semantic Web using relational database theory and source transformation techniques. We take as input, documents annotated with XML mark-up and the information tags that we are interested in. We then extract and populate a relational view on the annotated XML documents using these tags and the implicit relations in the XML documents. We evaluate the feasibility of our system by testing on a variety of input and we also explore the kinds of queries that can be made on the extracted relational view. / Thesis (Master, Computing) -- Queen's University, 2007-09-27 10:56:13.513

Meaningful semantic context has been shown to improve comprehension of spoken sentences by young and old adults, especially in difficult listening conditions. Whether older adults benefit differently than younger adults is a topic of some controversy. I asked young (14 participants, 18-25) and older adults (20 participants, 60-75) to report entire sentences which contained either a coherent or anomalous global semantic context (e.g. coherent: “Her new skirt was made of denim”, anomalous: “Her good slope was done in carrot”). Sentences were mixed with signal-correlated noise, at 10 signal-to-noise ratios (-6 to +2 dB and clear speech). Percentage scores were converted to rationalized arcsine units and subjected to a repeated-measures ANOVA; slopes from psychometric functions fitted to the transformed data were also analyzed. Cognitive and hearing threshold differences were considered as factors influencing results. Finally, individual variability in the use of context was explored. Comprehension by both groups benefited from meaningful context, without a clear difference in the overall amount of benefit obtained. Cognitive factors did not appear to influence the results, although differences in hearing thresholds likely contributed to the consistent performance decrement for older adults. Individuals varied greatly in their use of context, a possible explanation for inconsistent results in studies comparing context use by young and older people. fMRI was then used to look at neural activity associated with deriving benefit from meaningful context. Whole-brain EPI data were acquired from young (16 participants, 19-26) adults using a sparse imaging design. Participants heard coherent and anomalous sentences in the scanner, and were asked to report what they heard on half of the trials. Individual’s word-report data obtained in the scanner were used to model intelligibility in the analysis and results were compared to an analysis conducted using intelligibility estimates based on group data from another study. In addition to bilateral temporal activity associated with increasing intelligibility, I observe a large left inferior-frontal region in which BOLD signal correlated more strongly with highly intelligible anomalous compared to highly intelligible coherent prose, presumably reflecting challenged semantic integration and supporting Hagoort’s (2005) model of semantic unification. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2008-09-18 23:01:40.979

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