Stamatia Dasiopoulou

Stamatia Dasiopoulou
University Pompeu Fabra | UPF · Department of Information and Communication Technologies (DTIC)

PhD

About

57
Publications
8,041
Reads
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912
Citations
Additional affiliations
April 2014 - present
University Pompeu Fabra
Position
  • Researcher
October 2008 - November 2013
Information Technologies Institute (ITI)
Position
  • Postdoctoral Research Fellow
January 2004 - September 2008
Information Technologies Institute (ITI)
Position
  • PhD. Candidate, Research Asssociate

Publications

Publications (57)
Conference Paper
In this paper, we report on adapting a Natural Language Generation system to Semantic Web datasets, and on the results obtained in two triple verbalization challenges.
Conference Paper
Full-text available
During climate-related crises vast volumes of heterogeneous multimodal information are generated. Meaningfully processing and communicating this information for efficient decision support is a key challenge. The paper describes applying Semantic Web technologies for decision support during such crises. We are proposing the application of these tech...
Conference Paper
We present work in progress on (verbal, facial, and gestural) modality selection in an embodied multilingual and multicultural conversation agent. In contrast to most of the recent proposals, which consider non-verbal behavior as being superimposed on and/or derived from the verbal modality, we argue for a holistic model that assigns modalities to...
Conference Paper
We present an intelligent embodied conversation agent with linguistic, social and emotional competence. Unlike the vast majority of the state-of-the-art conversation agents, the proposed agent is constructed around an ontology-based knowledge model that allows for flexible reasoning-driven dialogue planning, instead of using predefined dialogue scr...
Article
Full-text available
We present work in progress on an intelligent embodied conversation agent that is supposed to act as a social companion with linguistic and emotional competence in the context of basic and health care. The core of the agent is an ontology-based knowledge model that supports flexible reasoning-driven conversation planning strategies. A dedicated sea...
Conference Paper
Full-text available
In this paper we present an ontology-driven framework for natural language question analysis and answering over user models (e.g. preferences, habits and health problems of individuals) that are formally captured using ontology design patterns. Pattern-based modelling is extremely useful for capturing n-ary relations in a well-defined and axiomatis...
Conference Paper
Full-text available
We present work in progress on an intelligent embodied conversation agent in the basic care and healthcare domain. In contrast to most of the existing agents, the presented agent is aimed to have linguistic cultural, social and emotional competence needed to interact with elderly and migrants. It is composed of an ontology-based and reasoning-drive...
Conference Paper
Full-text available
In this paper, we describe the principles and technologies that underpin the development of an adaptive dialogue manager framework, tailored to carrying out human-agent conversations in a natural, robust and exible manner. Our research focus is twofold. First, the investigation of dialogue strategies that can handle dynamically created user and sy...
Conference Paper
Full-text available
We present work in progress on an intelligent embodied conversation agent in the basic care and healthcare domain. In contrast to most of the existing agents, the presented agent is aimed to have linguistic cultural, social and emotional competence needed to interact with elderly and migrants. It is composed of an ontology-based and reasoning-drive...
Article
Full-text available
In this paper we describe MetaQ, an ontology-based hybrid framework for activity recognition in Ambient Assisted Living (AAL) environments that combines SPARQL queries and OWL 2 activity patterns. SPARQL is used as a standardized declarative language for aggregating, interpreting and enriching low-level contextual RDF knowledge bases with higher le...
Article
Pervasive and sensor-driven systems are by nature open and extensible, both in terms of input and tasks they are required to perform. Data streams coming from sensors are inherently noisy, imprecise and inaccurate, with differing sampling rates and complex correlations with each other. These characteristics pose a significant challenge for traditio...
Article
This paper presents preliminary results on a framework for the representation and visualization of text as OWL ontologies under an open-domain paradigm, where no a priori schema for the facts to be extracted is available. The extracted ontology is visually represented as a specifically tailored node-link diagram. The applicability of the approach i...
Conference Paper
Full-text available
In this paper we present LiFR, a lightweight DL reasoner capable of performing in resource-constrained devices, that implements a fuzzy extension of Description Logic Programs. Preliminary evaluation against two existing fuzzy DL reasoners and within a real-world use case has shown promising results.
Conference Paper
Full-text available
In this paper we propose an activity patterns ontology to formally represent the relationships that drive the derivation of complex activities in terms of the activity types and temporal relations that need to be satisfied. The patterns implement the descriptions and situations (DnS) ontology pattern of DOLCE Ultra Lite, modelling activity classes...
Conference Paper
Full-text available
In this paper we describe SP-ACT, a hybrid framework for the derivation of high-level activity interpretations in context-aware environments, by defining a combination of OWL ontologies and SPARQL CONSTRUCT graph patterns. More specifically, the native semantics of OWL is used to formally represent and integrate activity-related information origina...
Conference Paper
Full-text available
Multimedia documents constitute extremely rich information resources, whose efficacious management is intertwined with the effective capturing of the underlying semantics. The conveyed meaning may span along multiple levels and relates to search and retrieval tasks, much as to the very extraction and interpretation of content descriptions. In this...
Conference Paper
Full-text available
The availability of semantically annotated image and video assets constitutes a critical prerequisite for the realisation of intelligent knowledge management services pertaining to realistic user needs. Given the extend of the challenges involved in the automatic extraction of such descriptions, manually created metadata play a significant role, fu...
Chapter
Full-text available
This chapter turns to the application of semantic technologies to areas where text is not dominant, but rather audiovisual content in the form of images, 3D objects, audio, and video/television. Non-textual digital content raises new challenges for semantic technology in terms of capturing the meaning of that content and expressing it in the form o...
Article
Full-text available
Recent advances in semantic image analysis have brought forth generic methodologies to support concept learning at large scale. The attained performance however is highly variable, reflecting effects related to similarities and variations in the visual manifestations of semantically distinct concepts, much as to the limitations issuing from conside...
Conference Paper
Full-text available
Description Logics have recently attracted significant interest as the underlying formalism for conceptual modelling in the context of high-level image interpretation. Differences in the formulation of image interpretation semantics have resulted in varying configurations with respect to the adopted modelling paradigm, the utilised form of reasonin...
Article
Machine understandable metadata forms the main prerequisite for the intelligent services envisaged in a Web, which going beyond mere data exchange and provides for effective content access, sharing and reuse. MPEG-7, despite providing a comprehensive set of tools for the standardised description of audiovisual content, is largely compromised by the...
Article
Full-text available
Statistical learning approaches, bounded mainly to knowledge related to perceptual manifestations of semantics, fall short to adequately utilise the meaning and logical connotations pertaining to the extracted image semantics. Instigated by the Semantic Web, ontologies have appealed to a significant share of synergistic approaches towards the combi...
Conference Paper
Full-text available
Research in image analysis has reached a point where detectors can be learned in a generic fashion for a significant number of conceptual entities. The obtained performance however exhibits versatile behaviour, reflecting implications over the training set selection, similarities in visual manifestations of distinct conceptual entities, and appeara...
Chapter
Full-text available
The amount of multimedia content produced and made available on theWorldWide Web, and in professional and, not least, personal collections, is constantly growing, resulting in equally increasing needs in terms of efficient and effective ways to access it. Enabling smooth access at a level that meets user expectations and needs has been the holy gra...
Conference Paper
Full-text available
Semantic analysis of multimedia data, such as images, image databases and videos, has attracted much attention in the past years. The extraction of human centered descriptions, matching end users cognition, and specifically the detection and identification of events in videos is a particularly challenging problem, due to the volume and diversity of...
Conference Paper
Full-text available
In this paper we present an approach that combines multimedia reasoning and natural language processing for the semantic integration of automatic and manual image annotations based on domain ontologies. We discuss how to apply natural language processing to transform natural language descriptions and queries into an ontological representation that...
Conference Paper
The task of resource retrieval and composition is particularly challenging in the case of multimedia resources. Usual approaches focus on the use of textual multimedia annotations to enable computer-based management of multimedia repositories. In this paper, we introduce two approaches which make use of a logical formalism called an ontology to imp...
Conference Paper
The ambiguities due to the purely syntactical nature of MPEG- 7 have hindered its widespread application as they lead to serious in- teroperability issues in sharing and managing multimedia metadata. Ac- knowledging these limitations, a number of initiatives have been reported towards attaching formal semantics to the MPEG-7 speciflcations. In this...
Chapter
To overcome the limitations of keyword- and content-based visual information access, an ontology-driven framework is developed. Under the proposed framework, an appropriately defined ontology infrastructure is used to drive the generation of manual and automatic image annotations and to enable semantic retrieval by exploiting the formal semantics o...
Conference Paper
Full-text available
In this paper, a learning approach coupling Support Vector Machines (SVMs) and a Genetic Algorithm (GA) is presented for knowledge-assisted semantic image analysis in specific domains. Explicitly defined domain knowledge under the proposed approach includes objects of the domain of interest and their spatial relations. SVMs are employed using low-l...
Article
Full-text available
Knowledge representation and semantic annotation of multimedia documents typically have been pursued in two different directions. Previous approaches have focused either on low-level descriptors, such as dominant colour, or on the semantic content dimension and corresponding manual annotations, such as person or vehicle. Here, a knowledge infrastru...
Conference Paper
Full-text available
In this paper, an ontology infrastucture for multimedia reasoning is presented, making it possible to combine low-level visual descriptors with domain specific knowledge and subsequently analyze multimedia content with a generic algorithm that makes use of this knowledge. More specifically, the ontology infrastructure consists of a domain-specific...
Conference Paper
Full-text available
In this paper, a learning approach coupling Support Vector Machines (SVMs) and a Genetic Algorithm (GA) is presented for knowledge-assisted semantic image analysis in specific domains. Explicitly defined domain knowledge under the proposed approach includes objects of the domain of interest and their spatial relations. SVMs are employed using low-l...
Conference Paper
Full-text available
Abstract—In this poster, we present an approach to contex- tualized semantic,image,annotation,as an optimization,problem. Ontologies are used to capture general and contextual knowledge of the domain considered, and a genetic algorithm is applied to realize the final annotation. Experiments,with images,from the beach,vacation domain,demonstrate,the...
Chapter
To overcome the limitations of keyword- and content-based visual information access, an ontology-driven framework is developed. Under the proposed framework, an appropriately defined ontology infrastructure is used to drive the generation of manual and automatic image annotations and to enable semantic retrieval by exploiting the formal semantics o...
Article
An approach to knowledge-assisted semantic video object detection based on a multimedia ontology infrastructure is presented. Semantic concepts in the context of the examined domain are defined in an ontology, enriched with qualitative attributes (e.g., color homogeneity), low-level features (e.g., color model components distribution), object spati...
Conference Paper
Full-text available
Efficient video content management and exploitation requires extraction of the underlying semantics, a non-trivial task associating low-level features of the image domain and high-level semantic descriptions. In this paper, a knowledge-assisted approach for extracting semantics of domain-specific video content is presented. Domain knowledge conside...
Conference Paper
Full-text available
This paper surveys the approaches to video representation, focusing on semantic analysis for content-based indexing and retrieval. A problem of adaptive representation of digital multimedia is critically assessed and some novel ideas are presented. Furthermore, the concept of video multimodality is reevaluated and redefined in order to introduce mo...
Article
Full-text available
Efficient video content management and exploitation requires extraction of the underlying semantics, which is a non-trivial task involving the association of low-level features with high-level concepts. In this paper, a knowledge-assisted approach for extracting semantic information of domain-specific video content is presented. Domain knowledge co...
Conference Paper
The Semantic Web is about adding formal structure and explicit semantics to web content for the purpose of more efficient information management and access by both humans and computers. Through the use of machine understandable semantics, web resources become much easier and more readily accessible. Populating the Semantic Web with multimedia metad...
Conference Paper
Full-text available
This paper gives an overview of approaches to video representation targeting semantic analysis for content-based indexing and retrieval. It highlights the major achievements of the existing methodologies and sheds new light to the challenges that are still unsolved. The problem of adaptive representation of digital multimedia is critically assessed...
Article
An approach for knowledge assisted semantic analysis and annotation of video content, based on an ontology infrastructure is pre-sented. Semantic concepts in the context of the examined domain are defined in an ontology, enriched with qualitative attributes of the se-mantic objects (e.g. color homogeneity), multimedia processing methods (color clus...
Article
EU-IST Network of Excellence (NoE) IST-2004-507482 KWEB Deliverable D2.3.2 (WP2.3) In this deliverable, specification of knowledge acquisition and modeling of the process of consensus is provided.
Article
This deliverable continues with the definition of the SWF and its architecture. This framework contains the definition of the semantic-related components, the dependencies that exist between these components, and the implementations of components that could be used.

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