516 research outputs found

    On the Evaluation of a Cluster-based Reputation Assessment Mechanism for Carpooling Applications

    No full text
    Carpooling is a mobility concept that appears to be the answer when it comes to challenges in urban mobility derived by population growth. In carpooling, the same amount of people move with fewer vehicles leading to reduced traffic congestion and consequently to less CO2 emissions, fuel consumption and drivers frustration. However, there has always been scepticism around carpooling due to the inherent mistrust between drivers and passengers. In recent years, some reputation systems have been proposed to reduce the impact of mistrust on carpooling applications. Among them, the work of Salamanis et al. (Salamanis, 2018), in which a reputation assessment mechanism based on clustering users travel preferences, was introduced. In this paper, we provide an extended version of the previous mechanism and we thoroughly evaluate its robustness in relation with different types of malicious attacks and clustering algorithms. In addition, we compare our mechanism with a benchmarking reputation system that utilizes the simple arithmetic mean to calculate reputation values based on users ratings. The evaluation results indicate that the extended reputation assessment mechanism exhibits more robust behavior compared to the benchmarking system in all types of attacks when using the hierarchical clustering algorithm

    The Δρομοδείχτης της Ελλάδος of 1824 and Athanasios Stageirites (Τίτλος περίληψης)

    No full text
    σ. [281]-290Κείμενο στα ελληνικά με περίληψη στα αγγλικά με τον τίτλο: The Δρομοδείχτης της Ελλάδος of 1824 and Athanasios StageiritesThe article first examines the close relationship between the publication “Δρομοδείχτης της Ελλάδος” [1824] and the publication “Ηπειρωτικά” (1819) by Athanasios Stageirites and then suggests that Athanasios Stageirites is the likeliest author of the “Δρομοδείχτης της Ελλάδος”.Δωδώνη: Τεύχος Πρώτο: επιστημονική επετηρίδα του Τμήματος Ιστορίας και Αρχαιολογίας της Φιλοσοφικής Σχολής του Πανεπιστημίου Ιωαννίνων; Τόμ. 43-44 (2014-2015

    Dataset in support of the Southampton doctoral thesis 'The boatbuilding tradition of the Aegean during the Late Neolithic – Early Bronze Age periods. Typological classification, digital reconstruction and seakeeping assessment'

    No full text
    Dataset in support of the Southampton doctoral thesis &#39;The boatbuilding tradition of the Aegean during the Late Neolithic &ndash; Early Bronze Age periods. Typological classification, digital reconstruction and seakeeping assessment&#39; Appendix D - Resistance data and Appendix C - Stability data. This dataset is focused on two appendices: Appendix D - Resistance data. D.1 Resistance data produced by the author via MAXSURF Resistance for this thesis. Appendix C - Stability data C1. Stability data &ndash; STIX and ISO criteria, produced by the author via MAXSURF Stability software for his thesis This research was funded by Southampton Marine and Maritime Institute (SMMI), Vice-Chancellor&#39;s Scholarship, Greek Archaeological Committee UK (GACUK) </span

    A Probabilistic Framework for the Reliability Assessment of Crowd Sourcing Urban Traffic Reports

    No full text
    AbstractIncidents produce heavy congestion in large urban traffic networks and therefore real time information about them (e.g. location, timestamp, type) can be very useful for the drivers. An efficient way of gathering this type of information is through a crowd sourcing reporting system that multimodal travellers may utilise for providing information about various incidents they witness to other interconnected users in the same network. After the incoming traffic reports are evaluated, they can be shared to other travellers who are approaching the location of the reported incidents. Travelers can use the reported information for improving their mobility status. Collecting information using crowd sourcing techniques has implications and risks that need to be addressed. One of the most important challenges in this regard is the estimation of the reliability of the incoming information, usually related to individual user reputation. To this end, the exploitation of a reliability assessment system is of profound importance for assuring that only accurate information is shared between interconnected users. This paper introduces an innovative crowd sourcing information assessment mechanism for urban travellers. The purpose of the proposed probabilistic framework is to estimate if a user-generated report is true or false, given a set of static and dynamic parameters. The latter describe contextual conditions occurring at the time when an incident is reported. The proposed model takes into account the current location and speed of the reporting user due to their impact on the reliability of an incoming report. The proposed probabilistic model was evaluated in a simulation environment. Preliminary results show that, based on a set of rational assumptions, the estimated reliability decreases with the distance from the reported event and the speed of the reporting user. Based on the estimates that our model produces, a reliable true/false recommendation system can be devised for evaluating the user generated reports

    Peak power reduction algorithms in asymmetric digital subscriber line modems

    No full text
    Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaves 94-96).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.This thesis investigates peak-to-average ratio (PAR) reduction techniques for multicarrier modulation systems, such as discrete multitone (DMT) modems and orthogonal frequency-division multiplexed (OFDM) terrestrial broadcast transmitters. Through simulation and test implementation on a state-of-the-art programmable ADSL development platform, this thesis pursues a suitable solution for minimizing PAR given the resources of a programmable platform. This solution is integrated as a prototype implementation into a fully-functional ADSL modem and optimized for maximum PAR reduction performance within modem complexity constraints.by Athanasios Dimitri Dousis.M.Eng

    Homophobic Statements, a Bishop, and the Limits of Freedom of Expression. An In-Depth Commentary on ECtHR 31.08.2023, Amvrosios-Athanasios Lenis v. Greece, no. 47833/20

    No full text
    Dichiarazioni omofobe, un vescovo e i limiti della libertà di espressione. Un commento approfondito su CEDU 31.08.2023, Amvrosios-Athanasios Lenis v. Greece, no. 47833/20. ABSTRACT: The decision of the ECtHR of 31.08.2023, Amvrosios-Athanasios Lenis v. Greece (no. 47833/20), is a further step toward an increasingly dense jurisprudence on “hate speech” and the limits of freedom of expression. The public proclamation of religious doctrines that are in conflict with the values of the contracting States enshrined in the ECHR is protected to a certain extent by the fundamental right of freedom of religion and belief. However, the qualification of a statement as religious does not justify “hate speech.” The AUTHOR shows the tension between freedom of religion, freedom of expression, and protection against discrimination, and analyzes the decision against the backdrop of Article 17 of the ECHR (prohibition of abuse of rights). SOMMARIO: 1. Preliminary Remarks - 2. The Concept of Hate Speech - 3. The Facts of the Case - 4. The Procedure and Reasoning of the Court - 4.1 The ECtHR’s Preliminary Considerations on Fundamental Rights - 4.2 Legal assessment - 4.3 Some Remarks on (the Non-Invoked) Article 9 of the ECHR - 5. Concluding Remarks

    La tomba III di Haghios Athanasios e il valore semantico dell'incarnato

    No full text
    The tomb III at Haghios Athanasios stands out among the Macedonian tombs for the exceptional painted decoration of the temple-like façade. Excavated in the '90s by M. Tsimbidou-Avloniti it has been published by the scholar in full detail and the iconographic program of the monument has been the object of many publications. This article re-examines the different ways of reproducing the skin color (το ανδρείκελον) in the figures of the miniature frieze and in the megalographic figures beside the door. The realistic rendering of the megalographic figures of armed men in Macedonian attire, showing their sorrow for the lost of an etairos, is contrasting with the pale color of the participants to the symposion in the frieze above the door, a scene whose illusionistic overtone has been yet perceived by the critics. This symposion is articulated in three scenes and it can be interpeted as a necrodeipnon, but in the same time as a celebration of the Macedonian banquet style, centered on the royal court. The author suggests that the first figure on the right of the frieze, related to the group of armed men looking towards the banqueters feasting in the center of the frieze, can be read as the dead himself, for the particular rendering of his ανδρείκελον, showing the typical ochròtes or necròdes face color, according to the contemporary medical lexicon. The pathetic stance assumed by the same figure, the sole in the group which is not bearing arms, seems to confirm his role in the context of the scene

    A Maintainable and Secure Backend Infrastructure for Carpooling Applications

    No full text
    Nowadays, carpooling is one of the most widely promoted options for urban and inter-urban mobility due to a number of advantages, such as reduction of travel cost and CO2 emissions. As a result, many carpooling services and associated supporting applications have been developed with various technical characteristics. One of the most critical components of these systems is the backend infrastructure, which acts as an orchestrator of the overall system’s functionality, having as main objective the integrity, security and maintainability of the information exchanged. In this technical report, we present the backend infrastructure of the SocialCar carpooling application, a European-funded research and innovation project aiming to incorporate carpooling into existing mobility systems, by means of powerful planning algorithms and big data integration from public transport, carpooling systems, and crowd sourcing
    corecore