About
61
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509
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Introduction
My name is Panagiotis Papadakos and I am currently a post-doc researcher at the Information Systems Lab of the Institute of Computer Science at FORTH. I obtained my PhD in Computer Science from the University of Crete, Greece, in 2013, under the supervision of Prof. Yannis Tzitzikas. The title of my PhD thesis is "Interactive Exploration of Multi-Dimensional Information Spaces with Preference Support".
Curriculum Vitae http://users.ics.forth.gr/~papadako/files/cv.pdf
Additional affiliations
February 2015 - September 2015
Position
- Lecturer
Description
- CS359 - Web Programming https://elearn.uoc.gr/course/view.php?id=411
January 2008 - December 2009
January 2005 - September 2014
Position
- Research Assistant
Description
- Teaching assistant in courses: Information Retrieval, Object Oriented Programming, Advance Database Topics, Web Programming, Data Structures, Programming in C, Human Computer Interaction
Education
February 2008 - November 2013
Nov 2007 Edit University of Crete
Field of study
- Computer Science
February 2005 - November 2007
September 1999 - September 2004
Publications
Publications (61)
The Sternes cave is located on the Lefka Ori massif of Crete at the altitude of 2095m. The cave was explored in the early nineties by GSO, but abandoned in 1992. Greek teams ‘rediscovered’ the cave in 2005 and until 2012, conducted numerous expeditions (some international), to clear the meander at ‐428m. The fact that the two deepest caves in Greec...
The wine industry has evolved thanks to the introduction of new technologies (e.g., sensors, digital tools). Since the competition in the wine sector is extremely high, transparency via digital means is one of the methods that wine enterprises employ to increase their competitiveness, customer loyalty, and market share. The MiB system, developed in...
In this work we consider the collection of deceptive April Fools' Day(AFD) news articles as a useful addition in existing datasets for deception detection tasks. Such collections have an established ground truth and are relatively easy to construct across languages. As a result, we introduce a corpus that includes diachronic AFD and normal articles...
Automatic deception detection is a crucial task that has many applications both in direct physical and in computer-mediated human communication. Our focus is on automatic deception detection in text across cultures. In this context, we view culture through the prism of the individualism/collectivism dimension, and we approximate culture by using co...
Deception detection is a task with many applications both in direct physical and in computer-mediated communication. Our focus is on automatic deception detection in text across cultures. We view culture through the prism of the individualism/collectivism dimension and we approximate culture by using country as a proxy. Having as a starting point r...
With the explosion of social networks, the web has been transformed into an arena of inappropriate interactions and content, such as fake news and misinformation, deception, hate speech, inauthentic online behaviour, proselytism, slander, and mobbing. In this demo we present Chattack, a first step towards our aim of providing publicly available dat...
Gravitational waves (GWs) were observed for the first time in 2015, one century after Einstein predicted their existence. There is now growing interest to extend the detection bandwidth to low frequency. The scientific potential of multi-frequency GW astronomy is enormous as it would enable to obtain a more complete picture of cosmic events and mec...
The task of accessing knowledge graphs through structured query languages like SPARQL is rather demanding for ordinary users. Consequently, there are various approaches that attempt to exploit the simpler and widely used keyword-based search paradigm, either by translating keyword queries to structured queries, or by adopting classical information...
In the originally published version, the title of the paper starting on p. 66 contained a technical mistake. The title has been corrected as “bias goggles: Exploring the Bias of Web Domains Through the Eyes of Users”.
Ethical issues, along with transparency, disinformation and bias are in the focus of our information society. In this demo, we will present the Open image in new window system, that based on the web graph computes the bias characteristics of web domains to user-defined concepts. Our approach uses adaptations of propagation models and a variation of...
We proposed the European Laboratory for Gravitation and Atom-interferometric Research (ELGAR), an array of atom gradiometers aimed at studying space-time and gravitation with the primary goal of observing gravitational waves (GWs) in the infrasound band with a peak strain sensitivity of $3.3 \times 10^{-22}/\sqrt{\text{Hz}}$ at 1.7 Hz. In this pape...
The task of accessing knowledge graphs through structured query languages like SPARQL is rather demanding for ordinary users. Consequently, there are various approaches that attempt to exploit the simpler and widely used keyword-based search paradigm, either by translating keyword queries to structured queries, or by adopting classical information...
For ordinary users, the task of accessing knowledge graphs through structured query languages like SPARQL is rather demanding. As a result, various approaches exploit the simpler and widely used keyword-based search paradigm, either by translating keyword queries to structured queries, or by adopting classical information retrieval (IR) techniques....
For ordinary users, the task of accessing knowledge graphs through structured query languages like SPARQL is rather demanding. As a result, various approaches exploit the simpler and widely used keyword-based search paradigm, either by translating keyword queries to structured queries, or by adopting classical information retrieval (IR) techniques....
Ethical issues, along with transparency, disinformation, and bias, are in the focus of our information society. In this work, we propose the bias goggles model, for computing the bias characteristics of web domains to user-defined concepts based on the structure of the web graph. For supporting the model, we exploit well-known propagation models an...
There are several concepts whose interpretation and meaning is defined through their binary opposition with other opposite concepts. To this end, in this paper we elaborate on the idea of leveraging the available antonyms of the original query terms for eventually producing an answer which provides a better overview of the related conceptual and in...
Gravitational Waves (GWs) were observed for the first time in 2015, one century after Einstein predicted their existence. There is now growing interest to extend the detection bandwidth to low frequency. The scientific potential of multi-frequency GW astronomy is enormous as it would enable to obtain a more complete picture of cosmic events and mec...
There is a lack of high-quality corpora for the purposes of training task-oriented, end-to-end dialogue systems. This paper describes a dialogue collection process which used crowd-sourcing and a Wizard-of-Oz set-up to collect written human-human dialogues for a task-oriented, multi-domain scenario. The context is a tourism agency, where users try...
In an increasingly instrumented and inter-connected digital world, citizens generate vast amounts of data, much of it being valuable and a significant part of it being personal. However, controlling who can collect it, limiting what they can do with it, and determining how best to protect it, remain deeply undecided issues. This paper proposes CAPr...
Humans have used caves throughout history for a wide variety of needs, showcasing the importance of caves in human evolution. Nowadays, speleological clubs organize expeditions around and under the globe in an effort to understand, study and record the still unexplored and complex network of caves that lies underneath. Unfortunately, a common vocab...
The CAPrice initiative brings to the fore the creativity of the community towards privacy via specific co-creation tools (structured debates, annotation tools, reward mechanisms and others). Our objective is to improve citizen awareness on privacy issues, and leverage this awareness to motivate the market to adopt more privacy-friendly practices.
The LOD (Linked Open Data) cloud currently contains thousands of published datasets. Existing visualizations, like the Linking Open Data cloud diagram, are useful for getting an overview of its size, the datasets and their connectivity. An interesting question is whether we could come up with more informative and more interactive visualizations tha...
In this work we discuss the related challenges and describe an approach towards the fusion of state-of-the-art technologies from the Spoken Dialogue Systems (SDS) and the Semantic Web and Information Retrieval domains. We envision a dialogue system named LD-SDS that will support advanced, expressive, and engaging user requests, over multiple, compl...
Bias in online information has recently become a pressing issue, with search engines, social networks and recommendation services being accused of exhibiting some form of bias. In this vision paper, we make the case for a systematic approach towards measuring bias. To this end, we discuss formal measures for quantifying the various types of bias, w...
The amounts of available Semantic Web (SW) data (including Linked Open Data) constantly increases. Users would like to browse and explore effectively such information spaces without having to be acquainted with the various vocabularies and query language syntaxes. This paper discusses the work that has been done in the area for the case of RDF/S da...
In the linked open data cloud, the biggest open data graph that currently exists, a remarkable percentage of data are unnamed resources, also called blank nodes. Several fundamental tasks, such as graph isomorphism checking and RDF data versioning, require computing a map between the sets of blank nodes of two graphs. This map aims at minimizing th...
Background
Biodiversity data is characterized by its cross-disciplinary character, the extremely broad range of data types and structures, and the variety of semantic concepts that it encompasses. Furthermore there is a plethora of different data sources providing resources for the same piece of information in a heterogeneous way. Even if we restri...
Many works have proposed the enrichment of database query languages with preferences, aiding the user to better rank the results. In this work we propose and examine the hypothesis that effective preference specification in many cases presupposes knowledge of the information space and the available choices. Otherwise, the expression of intentional...
Species identification is essentially a decision-making process comprising steps in which the user makes a selection of characters, figures or photographs, or provides an input, that restricts other choices, until reaching one species. In some identification methods such decisions should have a specific order. Consequently, a wrong decision at the...
There are various ways and corresponding tools that the marine biologist community uses for identifying one species. Species identification is essentially a decision making process comprising steps in which the user makes a selection of characters, figures or photographs, or provides an input that restricts other choices, and so on, until reaching...
There are various ways and corresponding tools that the marine biologist community uses for identifying one species. Species identification is essentially a decision making process comprising steps in which the user makes a selection of characters, figures or photographs, or provides an input that restricts other choices, and so on, until reaching...
The integration of the classical Web (of documents) with the emerging Web of Data is a challenging vision. In this paper we focus on an integration approach during searching which aims at enriching the responses of non-semantic search systems with semantic information, i.e. Linked Open Data (LOD), and exploiting the outcome for offering advanced ex...
Many works have proposed the enrichment of database query languages with preferences, aiding the user to better rank the results. In this work we propose and examine the hypothesis that effective preference specification in many cases presupposes knowledge of the information space and the available choices. Otherwise, the expression of intentional...
Users access large amounts of information resources mainly through search functions, where they type a few keywords and the web search or query engine returns a linear list of hits. While this is often satisfactory for focalized search, it does not provide enough support for exploratory information needs. Faceted and Dynamic Taxonomies (FDT) is a h...
Theophrastus is a system that supports the automatic annotation of (web) documents through entity mining and provides exploration services by exploiting Linked Open Data (LOD), in real-time and only when needed. The system, that aims at assisting biologists in their research on species and biodiversity, was based on requirements coming from the bio...
Users access large amounts of information resources (documents or data) mainly through search functions, where they type a few words and the system (web search engine, query engine) returns a linear list of hits. While this is often satisfactory for focalized search, it does not provide enough support for recall-oriented (exploratory) information n...
This video demonstrates Hippalus. Hippalus is a exploratory system enriched with preferences. This system allows the expression of preference actions over faceted and dynamic taxonomies (FDT) (even over hierarchically-organized values) using the framework described in the paper
"Y. Tzitzikas and P. Papadakos. Interactive Exploration of Multidimens...
This video demonstrates Hippalus. Hippalus is a exploratory system enriched with preferences. This system allows the expression of preference actions over faceted and dynamic taxonomies (FDT) (even over hierarchically-organized values) using the framework described in the paper
"Y. Tzitzikas and P. Papadakos. Interactive Exploration of Multidimen...
A small video demonstrating Hippalus. Hippalus is a system that supports the framework described in the paper. It allows the expression of preference actions over faceted and dynamic taxonomies, supporting also hierarchically-organized values.
Current proposals for preference-based information access seem to ignore that users should be acquainted with the information space and the available choices for describing effectively their preferences. Furthermore users rarely formulate complex (preference or plain) queries. The interaction paradigm of Faceted Dynamic Taxonomies (FDT) allows user...
Current proposals for preference-based information access [4] seem to ignore that users should be acquainted with the information space and the available choices for describing effectively their preferences. Furthermore, users rarely formulate complex (preference or plain) queries, because it is a laborious and difficult task for them. We will demo...
Most Web Search Engines (WSEs) are appropriate for focalized search, i.e., they make the assumption that users can accurately describe their information need using a small sequence of terms. However, as several user studies have shown, a high percentage of search tasks are exploratory, and focalized search very commonly leads to inadequate interact...
Results clustering in Web Searching is useful for providing users with overviews of the results and thus allowing them to restrict their focus to the desired parts. However, the task of deriving single- word or multiple-word names for the clusters (usually referred as cluster labeling) is di-cult, because they have to be syntactically correct and p...
This paper proposes exploiting both explicit and mined meta- data for enriching Web searching with exploration services. On-line re- sults clustering is useful for providing users with overviews of the results and thus allowing them to restrict their focus to the desired parts. On the other hand, the various metadata that are available to a WSE (We...
The general objective of this dissertation is to elaborate on methods and techniques for exploring and progressively refining large volumes of heterogeneous information, through the provision of appro-priate models of interaction and visualization techniques. The goal is to support advanced in accuracy and completeness answers, appropriate for supp...
One of the distinctive features of Information Retrieval systems comparing to Database Management systems, is that they offer better compression for posting lists, resulting in better I/O performance and thus faster query evaluation. In this paper, we introduce database representations of the index that reduce the size (and thus the disk I/Os) of t...
In software design, physical CRC cards (Classes – Responsibilities - Collaborators) is a well-known method for rapid software-design
prototyping, heavily relying on visualization and metaphors. The method is commonly applied with heuristics for encoding design
semantics or denoting architectural relationships, such as card coloring, size variations...
Faceted and dynamic taxonomies are increasingly used nowadays in a plethora of applications. For developing user interfaces grounded on this interaction paradigm, it is advantageous to have a framework that enables the manipulation of the underlying information structure and provides the basic functionalities required. This paper introduces a forma...
Engineering a Web search engine offering effective and efficient information retrieval is a challenging task. Mitos is a recently developed search engine that offers a wide spectrum of functionalities. A rather unusual design choice is that its index is based on an object-relational database system, instead of the classical inverted file. This pape...
Engineering a Web search engine offering effective and efficient information retrieval is a challenging task. This document presents our experiences from designing and developing a Web search engine offering a wide spectrum of functionalities and we report some interesting experimental results. A rather peculiar design choice of the engine is that...
Physical CRC cards (Classes -- Responsibilities - Collaborators) is a well-known method for rapid software-design prototyping. It is commonly applied with numeric heuristics to encode design semantics and denote architectural relationships through card coloring, size variations and spatial grouping. Existing CRC design tools are weak in terms of in...
Virtual Prints are a mechanism for supporting navigation, orientation, way-finding and a number of other functions in virtual environments. This paper presents the results of an evaluation experiment of a prototype virtual environment equipped with part of the Virtual Prints mechanism. The objectives of the study were to assess the prototype's usab...
The concept of Virtual Prints (ViPs), as digital counterparts of real-life tracks that people leave behind, has been introduced for supporting navigation, orientation and wayfinding in Virtual Environments (VEs) and has been explored using a prototype VE equipped with a simplified ViPs mechanism. This paper describes an elaboration of the ViPs mech...
In this paper the concept of Virtual Prints (ViPs) is introduced and alternative ways in which they can be used are suggested. The design and required functionality of a software mechanism for creating and interact-ing with ViPs in Virtual Environments are presented along with techniques and methods for overcoming re-lated issues. Finally, the find...
Projects
Projects (4)
An international cave expedition that aims to fully explore and map the sixth deepest cave of Greece, located at the south-eastern part of Crete Island as well as caves of its surrounding area. Among the scopes of this expedition is also to investigate the geological stratification and study the biodiversity of the Sternes cave.
The Message in a Bottle (MiB) project is a system for providing specialized traceability information at the bottle level. This is an application, which will give a new "form" to the wines produced by the Lyraraki winery - GEA SA, providing the possibility of interaction of the final consumer with the bottle. At the same time, the MiB project will contribute to the increase of fidelity to the product (wine), providing augmented reality functions to the consumer, but also a wealth of information that will be available for each bottle separately. The aim of the project is to use traceability data, as well as geological, historical, meteorological and other data, in order to produce a personalized bottle story, both for the ordinary consumer and for the specialized oenologist and wine expert. The story of the bottle tells how a specific wine was produced, at the bottle level, connecting the bottle (and its contents) with its oenological, cultural, geographical, historical and ecological context. Apart from telling the wine story, the system suggests ways of consuming it, so that its special characteristics are highlighted. In this way the winery will be able to highlight all the quality characteristics of the wines it produces, adding value to its products, but also to come close to its customers by making them part of his story.