Ioannis Karydis | Ionian University (original) (raw)

Papers by Ioannis Karydis

ionio.gr

The development of an interactive Internet-based TV system designed to cover the broadcasting nee... more The development of an interactive Internet-based TV system designed to cover the broadcasting needs for new media artwork introduces various complexities accross the organisation, production and interaction forefronts. Our work presents and discusses real-life strategies and solutions employed during the development of iMediaTV, an open-source academic broadcasting system that permits various presentation modes to be employed, extending the presentation needs for artistic and non-uniform content. We demonstrate how an open-source Internet-based production/broadcasting system may be customised to include advanced content enhancing features, enabling interactive new media arts presentation over the Web.

International Journal of Advanced Computer Science and Applications, 2016

Internet-based interactive TV is an emerging field affected by advances in various research areas... more Internet-based interactive TV is an emerging field affected by advances in various research areas including communication, interactivity, network efficiency, content management and aesthetics. Despite constantly reducing costs in the area of broadcast infrastructure development, this new medium has yet to claim its market position and recognition. The large marketshare of existing non-interactive technologies may be identified as the principal factor for non-adoption of new broadcasting technologies, followed by various quality-of-service issues and the absence of a widely accepted standard for interactive broadcasting that does not permit the development of devices that support interaction in an out-of-the-box user-experience. On the experimental forefront, educational institutions are exploring the capabilities of highbandwidth networks and experimental interactive content, setting the standards for the development of new digital services. Particular types of content such as interactive installation art, games and multimedia presentations that require synchronised content communication are aided by the development of custombuilt interactive broadcasting infrastructures offering alternative methods of content deployment, presentation and interaction. In this work we are mainly concerned with the development strategy of an interactive TV studio, the integration of existing technologies under common environments, user-related usability issues and aesthetics, while open source software solutions are employed to reduce cost. The reduction of development, production and broadcasting costs offers new opportunities that enable user groups to clearly expand and offer a high-quality media experience in global scale.

Proceedings of the 16th International Conference on Engineering Applications of Neural Networks (INNS) - EANN '15, 2015

To further the interests of the computing professionals engaged in the development of new computi... more To further the interests of the computing professionals engaged in the development of new computing applications and to transfer the capabilities of computing technology to new problem domains.

The ease of content distribution through the web in addition to the ubiquitous mobile devices tha... more The ease of content distribution through the web in addition to the ubiquitous mobile devices that not only consume but also create content, have allowed for an ever increasing availability of information. Moreover, following the paradigm of social networking, this information is considered of variable flow rate and transient in nature. The resulting information volume has, paradoxically, lead to distracting and negatively impacting productivity and decision-making. To compensate, content curation has emerged as a prominent process engulfing a range of activities and procedures done to manage and enhance information and inform interested parties. In the context of this work the utilisation of widely employed syndication protocol Really Simple Syndication (RSS) is examined. During the curation key processes of collection, storage, customisation, inference extraction and redistribution of information flows' entities a litany of legal issues arise. As these issues present an increased complexity, this research focuses on the presentation of the associated to information flow curation legal issues as a starting point of further research, bridging thus the two disciplines.

Lecture Notes in Computer Science, 2006

This paper presents a music genre classification system that relies on note pitch and duration fe... more This paper presents a music genre classification system that relies on note pitch and duration features, derived from their respective histograms. Feature histograms provide a simple but yet effective classifier for the purposes of genre classification in intra-classical genres such as sonatas, fugues, mazurkas, etc. Detailed experimental results illustrate the significant performance gains due to the proposed features, compared to existing baseline features.

Proceedings - International Symposium on Computers and Communications

This paper presents the use of a novel Peer to Peer (P2P) infrastructure in order to provide rapi... more This paper presents the use of a novel Peer to Peer (P2P) infrastructure in order to provide rapid broad digital content exchange, digital rights protection and efficient transaction management through watermarking technologies. Copyright owners use digital watermarking techniques so as to encrypt copyright information to the content. This information is represented by multiple watermarking keys used, amongst other reasons, for proof of ownership, unique identification and transaction management. Especially for transaction management the watermarking keys used are constantly changing following the content's route from user to user. The challenges for this research are a) the use of P2P technologies for efficient Digital Rights Management (DRM), b) to apply a robust watermarking algorithm to digital content which successfully embeds and detects multiple keys for each use case and c) to successfully maintain consistent the P2P system when watermarking keys are changing during cont...

We consider the problem of constructing efficient P2P overlays for sensornets providing "Ene... more We consider the problem of constructing efficient P2P overlays for sensornets providing "Energy-Level Application and Services". In this context, assuming that a sensor is responsible for executing some program task but unfortunately it's energy-level is lower than a pre-defined threshold. Then, this sensor should be able to introduce a query to the whole system in order to discover efficiently another sensor with the desired energy level, in which the task overhead must be eventually forwarded. In this way, the "Life-Expectancy" of the whole network could be increased. Sensor nodes are mapped to peers based on their energy level. As the energy levels change, the sensor nodes would have to move from one peer to another and this operation is very crucial for the efficient scalability of the proposed system. Similarly, as the energy level of a sensor node becomes extremely low, that node may want to forward it's task to another node with the desired energy ...

We consider the problem of constructing efficient P2P overlays for sensornets providing "Ene... more We consider the problem of constructing efficient P2P overlays for sensornets providing "Energy-Level Application and Services". The method presented in \cite{SOPXM09} presents a novel P2P overlay for Energy Level discovery in a sensornet. However, this solution is not dynamic, since requires periodical restructuring. In particular, it is not able to support neither join of sensor\_nodes with energy level out of the ranges supported by the existing p2p overlay nor leave of \emph{empty} overlay\_peers to which no sensor\_nodes are currently associated. On this purpose and based on the efficient P2P method presented in \cite{SPSTMT10}, we design a dynamic P2P overlay for Energy Level discovery in a sensornet, the so-called SART (Sensors' Autonomous Range Tree). The adaptation of the P2P index presented in \cite{SPSTMT10} guarantees the best-known dynamic query performance of the above operation. We experimentally verify this performance, via the D-P2P-Sim simulator (D-P2...

Communications in Computer and Information Science, 2013

Proceedings of the 1st ACM workshop on Audio and music computing multimedia - AMCMM '06, 2006

This paper presents a genre classification algorithm for symbolic music data. The proposed method... more This paper presents a genre classification algorithm for symbolic music data. The proposed methodology relies on note pitch and duration features, derived from the repeating patterns and duration histograms of a musical piece, respectively. Note-information histograms have a great capability in capturing a fair amount of information regarding harmonic as well as rhythmic features of different musical genres and pieces, while repeating patterns refer to segments of the piece that are semantically important. Detailed experimental results on intra-classical genres illustrate the significant performance gains due to the proposed features.

IFIP Advances in Information and Communication Technology, 2011

Similarity measurement between two musical pieces is a hard problem. Humans perceive such similar... more Similarity measurement between two musical pieces is a hard problem. Humans perceive such similarity by employing a large amount of contextually semantic information. Commonly used content-based methodologies rely on information that includes little or no semantic information, and thus are reaching a performance "upper bound". Recent research pertaining to contextual information assigned as free-form text (tags) in social networking services has indicated tags to be highly effective in improving the accuracy of music similarity. In this paper, we perform a large scale (20k real music data) similarity measurement using mainstream content and context methodologies. In addition, we test the accuracy of the examined methodologies against not only objective metadata but real-life user listening data as well. Experimental results illustrate the conditionally substantial gains of the context-based methodologies and a not so close match these methods with the real user listening data similarity.

Artificial Intelligence Review, 2013

In this work we present a novel approach for evaluating job applicants in online recruitment syst... more In this work we present a novel approach for evaluating job applicants in online recruitment systems, using machine learning algorithms to solve the candidate ranking problem and performing semantic matching techniques. An application of our approach is implemented in the form of a prototype system, whose functionality is showcased and evaluated in a real-world recruitment scenario. The 2 Evanthia Faliagka et al.

Lecture Notes in Computer Science, 2011

We present NEFOS (NEsted FOrest of balanced treeS), a new cache-aware indexing scheme that suppor... more We present NEFOS (NEsted FOrest of balanced treeS), a new cache-aware indexing scheme that supports insertions and deletions in O(1) worst-case block transfers for rebalancing operations (given and update position) and searching in O(log B log n) expected block transfers, (B= disk block size and n= number of stored elements). The expected search bound holds with high probability for any (unknown) realistic input distribution. Our expected search bound constitutes an improvement over the O(log B log n) expected bound for search achieved by the ISB-tree (Interpolation Search B-tree), since the latter holds with high probability for the class of smooth only input distributions. We define any unknown distribution as realistic if the smoothness doesn't appear in the whole data set, still it may appear locally in small spatial neighborhoods. This holds for a variety of real-life non-smooth distributions like skew, zipfian, powlaw, beta e.t.c.. The latter is also verified by an accompanying experimental study. Moreover, NEFOS is a B-parametrized concrete structure, which works for both I/O and RAM model, without any kind of transformation or adaptation. Also, it is the first time an expected sub-logarithmic bound for search operation was achieved for a broad family of non-smooth input distributions.

IFIP Advances in Information and Communication Technology, 2012

Lecture Notes in Computer Science, 2010

In this work, we study the problem of anonymity-preserving data publishing in moving objects data... more In this work, we study the problem of anonymity-preserving data publishing in moving objects databases. In particular, the trajectory of a mobile user on the plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface: we know that the trajectory of the mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatio-temporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatio-temporal range queries executed on the original database and on the anonymized one.

This work presents an integrated web geographical information system aiming at managing the simul... more This work presents an integrated web geographical information system aiming at managing the simulation of the pests' lifecycle and control in a "Software as a Service" fashion. The approach adopted herein assumes that simulation processes take place in black-box functions and focuses on the management of all related information through thin clients such as common Internet browsers. In addition, in the proposed service a small framework is designed and implemented aiming at inherently handling the associated geographical data of the service in a visual manner.

ionio.gr

The development of an interactive Internet-based TV system designed to cover the broadcasting nee... more The development of an interactive Internet-based TV system designed to cover the broadcasting needs for new media artwork introduces various complexities accross the organisation, production and interaction forefronts. Our work presents and discusses real-life strategies and solutions employed during the development of iMediaTV, an open-source academic broadcasting system that permits various presentation modes to be employed, extending the presentation needs for artistic and non-uniform content. We demonstrate how an open-source Internet-based production/broadcasting system may be customised to include advanced content enhancing features, enabling interactive new media arts presentation over the Web.

International Journal of Advanced Computer Science and Applications, 2016

Internet-based interactive TV is an emerging field affected by advances in various research areas... more Internet-based interactive TV is an emerging field affected by advances in various research areas including communication, interactivity, network efficiency, content management and aesthetics. Despite constantly reducing costs in the area of broadcast infrastructure development, this new medium has yet to claim its market position and recognition. The large marketshare of existing non-interactive technologies may be identified as the principal factor for non-adoption of new broadcasting technologies, followed by various quality-of-service issues and the absence of a widely accepted standard for interactive broadcasting that does not permit the development of devices that support interaction in an out-of-the-box user-experience. On the experimental forefront, educational institutions are exploring the capabilities of highbandwidth networks and experimental interactive content, setting the standards for the development of new digital services. Particular types of content such as interactive installation art, games and multimedia presentations that require synchronised content communication are aided by the development of custombuilt interactive broadcasting infrastructures offering alternative methods of content deployment, presentation and interaction. In this work we are mainly concerned with the development strategy of an interactive TV studio, the integration of existing technologies under common environments, user-related usability issues and aesthetics, while open source software solutions are employed to reduce cost. The reduction of development, production and broadcasting costs offers new opportunities that enable user groups to clearly expand and offer a high-quality media experience in global scale.

Proceedings of the 16th International Conference on Engineering Applications of Neural Networks (INNS) - EANN '15, 2015

To further the interests of the computing professionals engaged in the development of new computi... more To further the interests of the computing professionals engaged in the development of new computing applications and to transfer the capabilities of computing technology to new problem domains.

The ease of content distribution through the web in addition to the ubiquitous mobile devices tha... more The ease of content distribution through the web in addition to the ubiquitous mobile devices that not only consume but also create content, have allowed for an ever increasing availability of information. Moreover, following the paradigm of social networking, this information is considered of variable flow rate and transient in nature. The resulting information volume has, paradoxically, lead to distracting and negatively impacting productivity and decision-making. To compensate, content curation has emerged as a prominent process engulfing a range of activities and procedures done to manage and enhance information and inform interested parties. In the context of this work the utilisation of widely employed syndication protocol Really Simple Syndication (RSS) is examined. During the curation key processes of collection, storage, customisation, inference extraction and redistribution of information flows' entities a litany of legal issues arise. As these issues present an increased complexity, this research focuses on the presentation of the associated to information flow curation legal issues as a starting point of further research, bridging thus the two disciplines.

Lecture Notes in Computer Science, 2006

This paper presents a music genre classification system that relies on note pitch and duration fe... more This paper presents a music genre classification system that relies on note pitch and duration features, derived from their respective histograms. Feature histograms provide a simple but yet effective classifier for the purposes of genre classification in intra-classical genres such as sonatas, fugues, mazurkas, etc. Detailed experimental results illustrate the significant performance gains due to the proposed features, compared to existing baseline features.

Proceedings - International Symposium on Computers and Communications

This paper presents the use of a novel Peer to Peer (P2P) infrastructure in order to provide rapi... more This paper presents the use of a novel Peer to Peer (P2P) infrastructure in order to provide rapid broad digital content exchange, digital rights protection and efficient transaction management through watermarking technologies. Copyright owners use digital watermarking techniques so as to encrypt copyright information to the content. This information is represented by multiple watermarking keys used, amongst other reasons, for proof of ownership, unique identification and transaction management. Especially for transaction management the watermarking keys used are constantly changing following the content's route from user to user. The challenges for this research are a) the use of P2P technologies for efficient Digital Rights Management (DRM), b) to apply a robust watermarking algorithm to digital content which successfully embeds and detects multiple keys for each use case and c) to successfully maintain consistent the P2P system when watermarking keys are changing during cont...

We consider the problem of constructing efficient P2P overlays for sensornets providing "Ene... more We consider the problem of constructing efficient P2P overlays for sensornets providing "Energy-Level Application and Services". In this context, assuming that a sensor is responsible for executing some program task but unfortunately it's energy-level is lower than a pre-defined threshold. Then, this sensor should be able to introduce a query to the whole system in order to discover efficiently another sensor with the desired energy level, in which the task overhead must be eventually forwarded. In this way, the "Life-Expectancy" of the whole network could be increased. Sensor nodes are mapped to peers based on their energy level. As the energy levels change, the sensor nodes would have to move from one peer to another and this operation is very crucial for the efficient scalability of the proposed system. Similarly, as the energy level of a sensor node becomes extremely low, that node may want to forward it's task to another node with the desired energy ...

We consider the problem of constructing efficient P2P overlays for sensornets providing "Ene... more We consider the problem of constructing efficient P2P overlays for sensornets providing "Energy-Level Application and Services". The method presented in \cite{SOPXM09} presents a novel P2P overlay for Energy Level discovery in a sensornet. However, this solution is not dynamic, since requires periodical restructuring. In particular, it is not able to support neither join of sensor\_nodes with energy level out of the ranges supported by the existing p2p overlay nor leave of \emph{empty} overlay\_peers to which no sensor\_nodes are currently associated. On this purpose and based on the efficient P2P method presented in \cite{SPSTMT10}, we design a dynamic P2P overlay for Energy Level discovery in a sensornet, the so-called SART (Sensors' Autonomous Range Tree). The adaptation of the P2P index presented in \cite{SPSTMT10} guarantees the best-known dynamic query performance of the above operation. We experimentally verify this performance, via the D-P2P-Sim simulator (D-P2...

Communications in Computer and Information Science, 2013

Proceedings of the 1st ACM workshop on Audio and music computing multimedia - AMCMM '06, 2006

This paper presents a genre classification algorithm for symbolic music data. The proposed method... more This paper presents a genre classification algorithm for symbolic music data. The proposed methodology relies on note pitch and duration features, derived from the repeating patterns and duration histograms of a musical piece, respectively. Note-information histograms have a great capability in capturing a fair amount of information regarding harmonic as well as rhythmic features of different musical genres and pieces, while repeating patterns refer to segments of the piece that are semantically important. Detailed experimental results on intra-classical genres illustrate the significant performance gains due to the proposed features.

IFIP Advances in Information and Communication Technology, 2011

Similarity measurement between two musical pieces is a hard problem. Humans perceive such similar... more Similarity measurement between two musical pieces is a hard problem. Humans perceive such similarity by employing a large amount of contextually semantic information. Commonly used content-based methodologies rely on information that includes little or no semantic information, and thus are reaching a performance "upper bound". Recent research pertaining to contextual information assigned as free-form text (tags) in social networking services has indicated tags to be highly effective in improving the accuracy of music similarity. In this paper, we perform a large scale (20k real music data) similarity measurement using mainstream content and context methodologies. In addition, we test the accuracy of the examined methodologies against not only objective metadata but real-life user listening data as well. Experimental results illustrate the conditionally substantial gains of the context-based methodologies and a not so close match these methods with the real user listening data similarity.

Artificial Intelligence Review, 2013

In this work we present a novel approach for evaluating job applicants in online recruitment syst... more In this work we present a novel approach for evaluating job applicants in online recruitment systems, using machine learning algorithms to solve the candidate ranking problem and performing semantic matching techniques. An application of our approach is implemented in the form of a prototype system, whose functionality is showcased and evaluated in a real-world recruitment scenario. The 2 Evanthia Faliagka et al.

Lecture Notes in Computer Science, 2011

We present NEFOS (NEsted FOrest of balanced treeS), a new cache-aware indexing scheme that suppor... more We present NEFOS (NEsted FOrest of balanced treeS), a new cache-aware indexing scheme that supports insertions and deletions in O(1) worst-case block transfers for rebalancing operations (given and update position) and searching in O(log B log n) expected block transfers, (B= disk block size and n= number of stored elements). The expected search bound holds with high probability for any (unknown) realistic input distribution. Our expected search bound constitutes an improvement over the O(log B log n) expected bound for search achieved by the ISB-tree (Interpolation Search B-tree), since the latter holds with high probability for the class of smooth only input distributions. We define any unknown distribution as realistic if the smoothness doesn't appear in the whole data set, still it may appear locally in small spatial neighborhoods. This holds for a variety of real-life non-smooth distributions like skew, zipfian, powlaw, beta e.t.c.. The latter is also verified by an accompanying experimental study. Moreover, NEFOS is a B-parametrized concrete structure, which works for both I/O and RAM model, without any kind of transformation or adaptation. Also, it is the first time an expected sub-logarithmic bound for search operation was achieved for a broad family of non-smooth input distributions.

IFIP Advances in Information and Communication Technology, 2012

Lecture Notes in Computer Science, 2010

In this work, we study the problem of anonymity-preserving data publishing in moving objects data... more In this work, we study the problem of anonymity-preserving data publishing in moving objects databases. In particular, the trajectory of a mobile user on the plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface: we know that the trajectory of the mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatio-temporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatio-temporal range queries executed on the original database and on the anonymized one.

This work presents an integrated web geographical information system aiming at managing the simul... more This work presents an integrated web geographical information system aiming at managing the simulation of the pests' lifecycle and control in a "Software as a Service" fashion. The approach adopted herein assumes that simulation processes take place in black-box functions and focuses on the management of all related information through thin clients such as common Internet browsers. In addition, in the proposed service a small framework is designed and implemented aiming at inherently handling the associated geographical data of the service in a visual manner.