533 research outputs found
The Δρομοδείχτης της Ελλάδος of 1824 and Athanasios Stageirites (Τίτλος περίληψης)
No full textσ. [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
On the energy efficiency of spatial modulation concepts
No full textSpatial Modulation (SM) is a Multiple-Input Multiple-Output (MIMO) transmission technique
which realizes low complexity implementations in wireless communication systems. Due the
transmission principle of SM, only one Radio Frequency (RF) chain is required in the transmitter.
Therefore, the complexity of the transmitter is lower compared to the complexity of
traditional MIMO schemes, such as Spatial MultipleXing (SMX). In addition, because of the
single RF chain configuration of SM, only one Power Amplifier (PA) is required in the transmitter.
Hence, SM has the potential to exhibit significant Energy Efficiency (EE) benefits. At
the receiver side, due to the SM transmission mechanism, detection is conducted using a low
complexity (single stream) Maximum Likelihood (ML) detector. However, despite the use of a
single stream detector, SM achieves a multiplexing gain.
A point-to-point closed-loop variant of SM is receive space modulation. In receive space modulation,
the concept of SMis extended at the receiver side, using linear precoding with Channel
State Information at the Transmitter (CSIT). Even though receive space modulation does not
preserve the single RF chain configuration of SM, due to the deployed linear precoding, it
can be efficiently incorporated in a Space Division Multiple Access (SDMA) or in a Virtual
Multiple-Input Multiple-Output (VMIMO) architecture.
Inspired by the potentials of SM, the objectives of this thesis are the evaluation of the EE of
SM and its extension in different forms of MIMO communication. In particular, a realistic
power model for the power consumption of a Base Station (BS) is deployed in order to assess
the EE of SM in terms of Mbps/J. By taking into account the whole power supply of a BS and
considering a Time Division Multiple Access (TDMA) multiple access scheme, it is shown that
SM is significantly more energy efficient compared to the traditional MIMO techniques. In
the considered system setup, it is shown that SM is up to 67% more energy efficient compared
to the benchmark systems. In addition, the concept of space modulation is researched at the
receiver side. Specifically, based on the union bound technique, a framework for the evaluation
of the Average Bit Error Probability (ABEP), diversity order, and coding gain of receive space
modulation is developed. Because receive space modulation deploys linear precoding with
CSIT, two new precoding methods which utilize imperfect CSIT are proposed. Furthermore, in
this thesis, receive space modulation is incorporated in the broadcast channel. The derivation of
the theoretical ABEP, diversity order, and coding gain of the new broadcast scheme is provided.
It is concluded that receive space modulation is able to outperform the corresponding traditional
MIMO scheme. Finally, SM, receive space modulation, and relaying are combined in order
to form a novel virtual MIMO architecture. It is shown that the new architecture practically
eliminates or reduces the problem of the inefficient relaying of the uncoordinated virtual MIMO
space modulation architectures. This is undertaken by using precoding in a novel fashion. The
evaluation of the new architecture is conducted using simulation and theoretical results
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 textDataset 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' 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 – 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's Scholarship, Greek Archaeological Committee UK (GACUK)
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Multi-user spatial modulation MIMO
No full textSpatial Modulation (SM) is a recently proposed single-RF multiple-input-multiple-output (MIMO) technique, which is capable of outperforming many conventional MIMO transmission schemes with low implementation and computational complexity. Recently, there have been some attempts in understanding the performance of SM in multi-user environments. However, most of the work has been oriented towards uplink multi-access scenarios. Also, conventional downlink/broadcast MIMO precoding techniques such as Zero Forcing (ZF) or Minimum Mean Square Error (MMSE) cannot be used in Multi-User SM (MU-SM), as part of the data in SM is also encoded into the Channel Impulse Responses (CIRs). In this paper, a novel precoding scheme for single-cell downlink MU-SM systems is proposed with a two-fold objective: i) the precoder needs to be able to completely eliminate the Multi-User Interference (MUI) by taking advantage of the Channel State Information (CSI) at the transmitter and ii) it needs to allow the users to use a single-user Maximum Likelihood (ML) optimum detector while achieving the same performance as interference-free point-to-point SM transmission. Finally, we also develop an interference-aware multi-user detection scheme, which does not require any CSI at the transmitter, and compare its performance with that of single-user detection schemes based on precoding
Peak power reduction algorithms in asymmetric digital subscriber line modems
No full textThesis (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
Performance Evaluation of Space Modulation Techniques in VLC Systems
No full textIn this paper, the Bit Error Rate (BER) performanceof three major space modulation techniques in a Multiple-InputMultiple-Output (MIMO) Visible Light Communication (VLC)system is studied. The considered space modulation techniquesare Optical Spatial Modulation (OSM); Optical GeneralizedSpatial Modulation (OGeSM); and Optical Multi-Stream SpatialModulation (OMS-SM). The space modulation techniques areevaluated against two benchmark systems: Optical Spatial MultipleXing(OSMX) and Optical Repetition Coding (ORC). Theperformance assessment, for both the space modulation schemesand the benchmark systems, is undertaken using simulation andanalytical results. For the considered system setup, it is concludedthat, in relative low Signal-to-Noise Ratio (SNR), OSM offers thebest performance. Whereas, in relative high SNR and for highspectral efficiency, OMS-SM is the most efficient scheme in termsof BER
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 textDichiarazioni 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 textThe 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
O LABORATÓRIO DE CIÊNCIAS DA ESCOLA DO FUTURO - TECNOLOGIAS E CONTEÚDOS EMERGENTES
No full textEste artigo investiga as tendências atuais na transformação de laboratórios STEM na era da digitalização devido à integração de tecnologias digitais e ao reconhecimento da importância do desenvolvimento de habilidades metacognitivas. O artigo examina o papel da metacognição e seu impacto no processo de aprendizagem, bem como o uso de tecnologias digitais, como laboratórios remotos, laboratórios virtuais, realidade aumentada, realidade virtual e dispositivos móveis na educação STEM. Os resultados desta pesquisa sugerem que o uso dessas tecnologias digitais pode ser benéfico para a aprendizagem de ciências no ensino superior e secundário. Além disso, essas tecnologias podem ser usadas para promover o engajamento, a colaboração e o acesso dos alunos ao conhecimento científico. Além disso, a metacognição é uma habilidade importante para professores e alunos, e pode ser desenvolvida através do uso da pirâmide do conhecimento, pirâmide de inteligência emocional, pirâmide metacognitiva e modelos de pirâmide de superdotação.Este artículo investiga las tendencias actuales en la transformación de los laboratorios STEM en la era de la digitalización debido a la integración de tecnologías digitales y al reconocimiento de la importancia del desarrollo de habilidades metacognitivas. El documento examina el papel de la metacognición y su impacto en el proceso de aprendizaje, así como el uso de tecnologías digitales como laboratorios remotos, laboratorios virtuales, realidad aumentada, realidad virtual y dispositivos móviles en la educación STEM. Los resultados de esta investigación sugieren que el uso de estas tecnologías digitales puede ser beneficioso para el aprendizaje de las ciencias tanto en la educación superior como en la secundaria. Además, estas tecnologías pueden utilizarse para promover la participación, colaboración y acceso al conocimiento científico por parte de los estudiantes. Además, la metacognición es una habilidad importante tanto para profesores como para estudiantes y puede desarrollarse mediante el uso de los modelos de pirámide del conocimiento, pirámide de inteligencia emocional, pirámide metacognitiva y pirámide de talento.This paper investigates the current trends in the transformation of STEM laboratories in the age of digitization due to the integration of digital technologies and the recognition of the importance of developing metacognitive skills. The paper examines the role of metacognition and its impact on the learning process, as well as the use of digital technologies such as remote labs, virtual labs, augmented reality, virtual reality, and mobile devices in STEM education. Results from this research suggest that the use of these digital technologies can be beneficial for science learning in both higher and secondary education. Additionally, these technologies can be used to promote student engagement, collaboration, and access to scientific knowledge. Furthermore, metacognition is an important skill for both teachers and students, and can be developed through the use of the knowledge pyramid, emotional intelligence pyramid, metacognitive pyramid, and giftedness pyramid models.Este artigo investiga as tendências atuais na transformação de laboratórios STEM na era da digitalização devido à integração de tecnologias digitais e ao reconhecimento da importância do desenvolvimento de habilidades metacognitivas. O artigo examina o papel da metacognição e seu impacto no processo de aprendizagem, bem como o uso de tecnologias digitais, como laboratórios remotos, laboratórios virtuais, realidade aumentada, realidade virtual e dispositivos móveis na educação STEM. Os resultados desta pesquisa sugerem que o uso dessas tecnologias digitais pode ser benéfico para a aprendizagem de ciências no ensino superior e secundário. Além disso, essas tecnologias podem ser usadas para promover o engajamento, a colaboração e o acesso dos alunos ao conhecimento científico. Além disso, a metacognição é uma habilidade importante para professores e alunos, e pode ser desenvolvida através do uso da pirâmide do conhecimento, pirâmide de inteligência emocional, pirâmide metacognitiva e modelos de pirâmide de superdotação
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