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AbstractTetramorium Mayr, 1855 is a worldwide distributed and hyperdiverse ant genus consisting of almost 600 taxa manifesting various life history strategies. Species of the Tetramorium inquilinum species-group represents one of the most extreme forms of parasitism and consist of degenerate workerless social parasites of several Tetramorium species. So far, its members have been recorded in the Palearctic from montane to alpine zones and reveal an interesting disjunction in host selection observed between eastern-Mediterranean and western-Mediterranean species. We describe a fifth member of the Tetramorium inquilinum species-group: Tetramorium albenae Salata, van Delft & Borowiec sp. n. The species morphologically differs from the remaining members of the group by the combination of the following characters: dense and erect pilosity of appendages and the whole body, smooth head sculpture, predominantly smooth anepisternum and katepisternum, lack of blunt teeth on propodeum, and presence of distinct carianae on the dorsolateral margins of the propodeum. Tetramorium albenae Salata, van Delft & Borowiec sp. n. was collected in a lowland olive grove, a site so far not associated with the Tetramorium inquilinum species-group, from a nest of Tetramorium kephalosi (a new host species for the group). The data presented in this paper provide new insights into the habitat preferences of the species of the Tetramorium inquilinum species-group and extend our knowledge on the potential host species of these parasites.http://zoobank.org/urn:lsid:zoobank.org:pub:62610BFE-7BF4-44E7-ADB5-3DD6A9B759C0

Smart Eye is a research project focused on developing and operating, in real-time, an innovative system, that allows the visualization of invisible, known, covered by the ground or by constructions, monuments and finds in an archaeological site, using an Augmented Reality (AR) environment. The visitors of an archaeological site will be able to observe the covered antiquities (3D models and descriptive information) on the screen of their mobile device (smart phone and/or tablet). The system integrates mobile positioning and pose estimation technologies, AR algorithms, Geographic Information Systems (GIS) and spatial databases. The AR application is implemented by IT scientists and is subsequently evaluated in the field to identify both technical problems (e.g. are files uploaded at high speed?) and problems identified by the average user of the AR application (e.g. would it be better if the button to display the 3D model of the archaeological excavation was larger on the screen or of a different color?). The paper will present, on one hand, the validation and evaluation protocols according to the relevant literature, and on the other, the exact evaluation methodology of the Smart Eye system. In addition, the problems identified and the way they were solved during the 1st evaluation of the application will be presented, as well as the problems identified during the 2nd evaluation.

DIGI-ORCH is a research project with objectives, on one hand, to design and develop "smart" brochures for concerts and educational programs of the State Conservatory of Thessaloniki (Greece), and, on the other, to develop an innovative system for the visualization of information on smart mobile devices (smartphones and tablets). The application of Augmented Reality (AR) provides free access to the information and content of the above concerts and educational programs, combining the information of a robust data server and an easy-to-use user interface of the smart device in real-time.The pilot implementation of the system in real conditions took place at the beginning of December 2022, in an event held at the facilities of the State Conservatory of Thessaloniki. The event was an evening of Chamber Music entitled Musical Kaleidoscope, with the internationally acclaimed artists Simos Papanas (violin), Dimos Goundaroulis (violoncello), and Vassilis Varvaresos (piano). They performed the Piano Trio no. 3 in G minor, Robert Schumann's opus 110, and the Piano Trio no. 2 in E flat major, Op. 100 D. 929 by Franz Schubert. The concert was attended by over 150 attendees.The paper will present the chaîne-operatoire of the development of the system, from the acquisition of raw data (text, video, image, and sound) to the methodology used to produce the "smart" event brochure and the AR application for the above concert. Essentially, this large amount of information that cannot be assessed by a regular printed concert brochure is included in the smart system and displayed on the mobile device when the user locates the appropriate AR patterns on the surface of the analog concert poster and/or on the pages of the brochure.This information comprised of ie. additional text and images about the composers and their musical projects, about the musicians of the concert (e.g. biographies), their interviews and rehearsals (video) before the concert, information about the State Conservatory of Thessaloniki (text, video, image, and sound), 3D models of musical instruments, 360° of the concert space, etc. diverse multimedia material.

Nowadays, there are many methods and techniques for the documentation and the restoration of historic structures and historical artifacts that are commonly used due to their completeness, accuracy and fastness. The use of advanced 3D measurement technologies, by either using terrestrial or aerial means of acquiring digital data, has become an efficient and reliable documentation tool. Within this context, this study focuses on combining terrestrial laser scanning, unmanned aerial vehicle photogrammetry, close-range photogrammetry and topographic surveying, and comparing the associated digital data for archaeological fieldwork documentation. The data collected during the Thessaloniki Toumba Excavation (Greece) provided accurate digital surface models and photo-realistic three-dimensional outputs of archaeological trenches. The data elaboration enabled new inferences and knowledge to be gained through the implementation of advanced technologies in heritage documentation.

In recent years advances in Earth Observation (EO) have increased our ability to inventory, monitor, and understand Earth’s natural and artificial ecosystems. In particular, recent technological developments in the instrument characteristics of the remote sensing systems enabled large-scale usage of EO in environmental governance and protection. Remote sensing can be a potent tool employed in the field of environmental compliance. However, to extract and distribute relevant information to potential stakeholders, simple, yet efficient and robust approaches are needed. The focus of our research is the development of EO algorithms and the corresponding EO processing chains that could be used operationally for providing cost-efficient information to end-users to address environmental compliance and tackle environmental violations over specific thematic domains using freely available Copernicus data. The EO algorithms and the relevant EO processing chains have been developed as part of the EU-H2020 funded project: “EnviroLENS-Copernicus for environmental law enforcement support” where the demonstration area of our approach is in the Montenegro – Albania border. The case considers several sites along the border to Albania, from the coastal area of Velika Plaža to the North Lake Skadar National Park. All sites have been designated in the past as protected areas, due to their rich biodiversity and threatened habitats. The focus of this contribution is on the deforestation detection processing chain. The developed EO processing chains rely on the use and analysis of multi-temporal Sentinel-2 images, while it adopts an object-based perspective for detecting, quantifying, and mapping potential environmental violations.

Three dimensional modelling of artefacts and building interiors is a highly active research field in our days. Several techniques are being utilized to perform such a task, spanning from traditional surveying techniques and photogrammetry to structured light scanners, laser scanners and so on. New technological advancements in both hardware and software create new recording techniques, tools and approaches. In this paper we present a new recording and modelling approach based on the SwissRanger SR4000 range camera coupled with a Canon 400D dSLR camera. The hardware component of our approach consists of a fixed base, which encloses the range and SLR cameras. The two sensors are fully calibrated and registered to each other thus we were able to produce colorized point clouds acquired from the range camera. In this paper we present the initial design and calibration of the system along with experimental data regarding the accuracy of the proposed approach. We are also providing results regarding the modelling of interior spaces and artefacts accompanied with accuracy tests from other modelling approaches based on photogrammetry and laser scanning.

There is a continuous and increasing demand for solutions, both software and hardware-based, that are able to productively handle underground utilities geospatial data. Innovative approaches that are based on the use of the European GNSS, Galileo and EGNOS, sensor technologies and LBS, are able to monitor, document and manage utility infrastructures’ data with an intuitive 3D augmented visualisation and navigation/positioning technology. A software and hardware-based system called LARA, currently under develop- ment through a H2020 co-funded project, aims at meeting that demand. The concept of LARA is to integrate the different innovative components of existing technologies in order to design and develop an integrated navigation/positioning and information system which coordinates GNSS, AR, 3D GIS and geodatabases on a mobile platform for monitoring, documenting and managing utility infrastruc- tures on-site. The LARA system will guide utility field workers to locate the working area by helping them see beneath the ground, rendering the complexity of the 3D models of the underground grid such as water, gas and electricity. The capacity and benefits of LARA are scheduled to be tested in two case studies located in Greece and the United Kingdom with various underground utilities. The paper aspires to present the first results from this initiative. The project leading to this application has received funding from the European GNSS Agency under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 641460.

Remote sensing facilitates the extraction of information for earth’s surface through its capability of acquiring images covering large areas and the availability of commercial software for their processing. The aim of this study is the feature extraction from three Geoeye-1 stereo pairs for forested area. The study area is located in central mountainous forested peninsula of Chalkidiki, in northern Greece. Dominant forest tree species of the site are oak (Quercus conferta), beech (Fagus moesiaca), black pine (Pinus nigra) and calabrian pine (Pinus brutia). Very High Resolution (VHR) Geoeye-1 stereo pair satellite images were utilized in panchromatic and multispectral mode. The panchromatic mode was employed for Digital Surface Model (DSM) generation and its evaluation. In this study the High Pass Filter (HPF) data fusion technique was applied between panchromatic and multispectral mode for acquiring a new image with the benefits of both contracting images. Because of the fact that the feature extraction was attempted in a forested region, NDVI index and Tasseled Cap transformation were applied in the fused images’ evaluation procedure. Optical assessment was also applied. The accuracy of the generated DSM and the evaluation results of the fused images were remarkable.

In recent years, the ever-increasing research interest in various aspects of the electricity pool-based markets has generated a plethora of complementarity-based approaches to determine participating agents’ optimal offering/bidding strategies and model players’ interactions. In particular, the integration of multiple and diversified market agents, such as conventional generation companies, renewable energy sources, electricity storage facilities and agents with a mixed generation portfolio has instigated significant competition, as each player attempts to establish their market dominance and realize substantial financial benefits. The employment of complementarity modelling approaches can also prove beneficial for the optimal coordination of the electricity and natural gas market coupling. Linear and nonlinear programming as well as complementarity modelling, mainly in the form of mathematical programs with equilibrium constraints (MPECs), equilibrium programs with equilibrium constraints (EPECs) and conjectural variations models (CV) have been widely employed to provide effective market clearing mechanisms, enhance agents’ decision-making process and allow them to exert market power, under perfect and imperfect competition and various market settlements. This work first introduces the theoretical concepts that regulate the majority of contemporary competitive electricity markets. It then presents a comprehensive review of recent advances related to complementarity-based modelling methodologies and their implementation in current competitive electricity pool-based markets applications.