Graph Signal Representation with Wasserstein Barycenters

In many applications signals reside on the vertices of weighted graphs. Thus, there is the need to learn low dimensional representations for graph signals that will allow for data analysis and interpretation. Existing unsupervised dimensionality reduction methods for graph signals have focused on dictionary learning. In these works the graph is taken into consideration by imposing a structure or a parametrization on the dictionary and the signals are represented as linear combinations of the atoms in the dictionary. However, the assumption that graph signals can be represented using linear combinations of atoms is not always appropriate. In this paper we propose a novel representation framework based on non-linear and geometry-aware combinations of graph signals by leveraging the mathematical theory of Optimal Transport. We represent graph signals as Wasserstein barycenters and demonstrate through our experiments the potential of our proposed framework for low-dimensional graph signal representation

Alcohol and the risk of sleep apnoea: a systematic review and meta-analysis

Objective: A systematic review and meta-analysis of the association between alcohol consumption and risk of sleep apnoea in adults. Methods: We searched Medline, EMBASE and Web of Science databases from 1985 to 2015 for comparative epidemiological studies assessing the relation between alcohol consumption and sleep apnoea. Two authors independently screened and extracted data. Random effects meta-analysis was used to estimate pooled effect sizes with 95% confidence intervals (CI). Heterogeneity was quantified using I[superscript]2 and explored using subgroup analyses based on study exposure and outcome measures, quality, design, adjustment for confounders and geographical location. Publication bias was assessed using a funnel plot and Egger’s test. Results: We identified 21 studies from which estimates of relative risk could be obtained. Meta-analysis of these estimates demonstrated that higher levels of alcohol consumption increased the risk of sleep apnoea by 25% (RR 1.25, 95%CI 1.13-1.38, I[superscript]2=82%, p<0.0001). This estimate’s differences were robust in alcohol consumption and sleep apnoea definitions, study design and quality but was greater in Low and Middle Income Country locations. We detected evidence of publication bias (p=0.001). A further eight included studies reported average alcohol consumption in people with and without sleep apnoea. Meta-analysis revealed that mean alcohol intake was two units/week higher in those with sleep apnoea, but this difference was not statistically significant (p=0.41). Conclusion: These findings suggest that alcohol consumption is associated with a higher risk of sleep apnoea, further supporting evidence that reducing alcohol intake is of potential therapeutic and preventive value in this condition

A Novel Approach to Multimedia Ontology Engineering for Automated Reasoning over Audiovisual LOD Datasets

Multimedia reasoning, which is suitable for, among others, multimedia content analysis and high-level video scene interpretation, relies on the formal and comprehensive conceptualization of the represented knowledge domain. However, most multimedia ontologies are not exhaustive in terms of role definitions, and do not incorporate complex role inclusions and role interdependencies. In fact, most multimedia ontologies do not have a role box at all, and implement only a basic subset of the available logical constructors. Consequently, their application in multimedia reasoning is limited. To address the above issues, VidOnt, the very first multimedia ontology with SROIQ(D) expressivity and a DL-safe ruleset has been introduced for next-generation multimedia reasoning. In contrast to the common practice, the formal grounding has been set in one of the most expressive description logics, and the ontology validated with industry-leading reasoners, namely HermiT and FaCT++. This paper also presents best practices for developing multimedia ontologies, based on my ontology engineering approach

A framework for designing cloud forensic‑enabled services (CFeS)

Cloud computing is used by consumers to access cloud services. Malicious actors exploit vulnerabilities of cloud services to attack consumers. The link between these two assumptions is the cloud service. Although cloud forensics assists in the direction of investigating and solving cloud-based cyber-crimes, in many cases the design and implementation of cloud services falls back. Software designers and engineers should focus their attention on the design and implementation of cloud services that can be investigated in a forensic sound manner. This paper presents a methodology that aims on assisting designers to design cloud forensic-enabled services. The methodology supports the design of cloud services by implementing a number of steps to make the services cloud forensic-enabled. It consists of a set of cloud forensic constraints, a modelling language expressed through a conceptual model and a process based on the concepts identified and presented in the model. The main advantage of the proposed methodology is the correlation of cloud services’ characteristics with the cloud investigation while providing software engineers the ability to design and implement cloud forensic-enabled services via the use of a set of predefined forensic related task

A Model for Integration and Interlinking of Idea Management Systems

This paper introduces the use of Semantic Web technologies for the Idea Management Systems as a gap closer between heterogeneous software and achieving interoperability. We present a model that proposes how and what kind of rich metadata annotations to apply in the domain of Idea Management Systems. In addition, as a part of our model, we present a Generic Idea and Innovation Management Ontology (GI2MO). The described model is backed by a set of use cases followed by evaluations that prove how Semantic Web can work as tool to create new opportunities and leverage the contemporary Idea Management legacy systems into the next level

The Old Navarino fortification (Palaiokastro) at Pylos (Greece). Adaptation to early artillery

[EN] Old Navarino fortification (Palaiokastro) is located on the promontory supervising the naturally endowed Navarino-bay at the south-western foot of Peloponnese peninsula, near the contemporary city of Pylos. The cliff where it is built and where ancient relics lie, was fortified by Frankish in the thirteenth century. The fortification though knows significant alterations firstly by Serenissima Republic of Venice from the fifteenth century that aims to dominate the naval routes of Eastern Mediterranean by establishing a system of coastal fortifications and later by the Ottomans after the conquest of Venice’s possessions at Messenia in 1500. Between fifteenth and seventeenth century, apart from important modifications at the initial enceinte of the northern Upper City, the most notable transformation of Old Navarino is the construction of the new Lower fortification area at the south and the southern outwork ending up to the coastline. Especially the Lower fortification is a sample of multiple and large-scale successive alterations for the adjustment to technological advances of artillery (fortification walls reinforcement, modification of tower-bastions, early casemates, gate complex enforcements). The current essay focuses on the study of these specific elements of the early artillery period and the examination of Old Navarino’s strategic role at the time of transition before the adaptation of “bastion-front” fortification patterns, such as those experimented in the design of the fortified city of New Navarino, constructed at the opposite side of the Navarino gulf by the Ottomans (1573).The PhD research is co-financed by Greece and the European Union (European Social FundESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning” in the context of the project “Strengthening Human Resources Research Potential via Doctorate Research” (MIS-5000432), implemented by the State Scholarships Foundation (ΙΚΥ).Simou, X. (2020). The Old Navarino fortification (Palaiokastro) at Pylos (Greece). Adaptation to early artillery. Editorial Universitat Politècnica de València. 1401-1408. https://doi.org/10.4995/FORTMED2020.2020.11389OCS1401140

The emergence and potential of climate change litigation: methodological and theoretical legal challenges

Nearly twenty years have passed since the timid appearance of the first-wave climate change cases. Within this period, legal literature and practitioners have progressively identified in climate litigation a useful tool to reinforce the global public-private efforts in the fight against climate change. There can be no doubt that climate litigation sparks fervent debate and promotes social debate by elevating public awareness on the topic. Climate litigation’s strategic character aims at making science and information more accessible to public opinion in democratic regimes. However, the lack of concrete empirical studies that could measure its overall effectiveness in promoting climate goals, the delimitation of the margin of control that judges hold when adjudicating political-scientific issues and the legal theoretical hurdles in rights-based litigation are a constant source of debate between scholars. Despite all the controversy, it is an undeniable fact that strategic climate litigation has been following a clear upward trend in the last seven years undergoing a dynamic process of transformation with an impact on diverse legal issues such as: the relation between politics, science and law, the principle of separation of powers, the causation rules, the rules on proof and access to justice in climate matters. This article intends to offer an overall view of all the above issues in an attempt to better define - from a comparative transnational perspective - the current state of the phenomenon by emphasizing the type of grounds that plaintiffs invoke in judicial processes to favor their claimsThe present article is supported by the Autonomous Community of Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with the Universidad Autónoma de Madrid in the line for the Excellence of the University Teaching Staff, in the context of the V PRICIT (Regional Program of Research and Technological Innovation). The research for this article was also conducted within the framework of the Research Project “Regeneración Urbana Climática”, Spanish Ministry of Science, Innovation and Universities (TED2021-130900B-I00), Main researchers: Felipe Iglesias González and Juan Antonia Chinchilla Peinado. Special acknowledgments to Prof. Dr. Francisco Velasco Caballero for enriching the research with his always valuable comments and idea

A Revised Forensic Process for Aligning the Investigation Process with the Design of Forensic-Enabled Cloud Services

© Springer Nature Switzerland AG 2020. The design and implementation of cloud services, without taking under consideration the forensic requirements and the investigation process, makes the acquisition and examination of data, complex and demanding. The evidence gathered from the cloud may not become acceptable and admissible in the court. A literature gap in supporting software engineers so as to elicit and model forensic-related requirements exists. In order to fill the gap, software engineers should develop cloud services in a forensically sound manner. In this paper, a brief description of the cloud forensic-enabled framework is presented (adding some new elements) so as to understand the role of the design of forensic-enabled cloud services in a cloud forensic investigation. A validation of the forensic requirements is also produced by aligning the stages of cloud forensic investigation process with the framework’s forensic requirements. In this way, on one hand, a strong relationship is built between these two elements and emphasis is given to the role of the forensic requirements and their necessity in supporting the investigation process. On the other hand, the alignment assists towards the identification of the degree of the forensic readiness of a cloud service against a forensic investigation

An architecture for mining resources complementary to audio-visual streams

In this paper we attempt to characterize resources of information complementary to audio-visual (A/V) streams and propose their usage for enriching A/V data with semantic concepts in order to bridge the gap between low-level video detectors and high-level analysis. Our aim is to extract cross-media feature descriptors from semantically enriched and aligned resources so as to detect finer-grained events in video.We introduce an architecture for complementary resource analysis and discuss domain dependency aspects of this approach related to our domain of soccer broadcasts

HISTORICAL TRACES' INTERPRETATION AND VIRTUAL RECONSTRUCTION - THE CASE OF ACROCORINTH CASTLE

[EN] When archival information misses or is insufficient, the structure itself becomes the most valuable archive unfolding stories of monument's life. The current essay examines how the building traces can be used as tools of historical interpretation and how important is digital survey in this respect through the presentation 3d virtual documentation of the castle of Acrocorinth. The overall venture was initiated by the 25th Ephorate of Byzantine Antiquities under the supervision of the Ephorate dr archaeologist Demetrios Athanasoulis on the occasion of developing the web-platform ecastles.culture.gr for the Digital Enhancement of the Castles of Peloponnese (Athanasoulis et al. 2015).Athanasoulis, D.; Simou, X.; Zirogianni, T. (2016). HISTORICAL TRACES' INTERPRETATION AND VIRTUAL RECONSTRUCTION - THE CASE OF ACROCORINTH CASTLE. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 288-290. https://doi.org/10.4995/arqueologica8.2015.3437OCS28829