1,035 research outputs found
Introduction:De te fabula narratur? Ethnography of and during the Greek crisis
No full textThis introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book assesses the strategic changes in the neoliberal state's modalities of power as they are located in the realms of brutal repression, the production of neoliberal subjectivities and discourses of legitimation. It discusses the intensification of anti-migrant policies as aspects of the authoritarian distillation of the neoliberal context. The book deals with constructions of the self and the individual and focuses on correlation between the economic crisis and its repercussions and increasing rates of mental disorders within the Greek population. It also focuses on the paradigmatic shift of the state's repressive strategy concerning squatted public buildings that are used as self-organized social-cultural-political centers by the antagonist movement in Athens. The book explores the dialects between the construction of a hostile status for increasing numbers of immigrants that have entered Greece in recent years and the rise and dissemination of grassroots solidarity politics
Human-Robot Dialogue that Elicits The Alignment of Moral Principles For Driverless Vehicles
No full textThe emergence of autonomous vehicles has raised ethical considerations regarding their controlling software. The focus is on defining ethical settings that determine the response to moral dilemmas, akin to the Trolley Problem. The study explores the interaction with a robot that engages users in a dialogue about such ethical dilemmas, allowing users to align vehicles' behaviour with their ethical preferences. Additionally, providers of these vehicles can have a codified version of user preferences to address potential real-world issues, for instance, by adjusting insurance premiums. The research details designing and implementing a human-robot interaction system for eliciting ethical settings in autonomous vehicles.No Full Tex
PRAC: Exploiting partial packets without cross-layer or feedback information
No full textThis paper proposes a partial packet recovery scheme, called Packetized Rateless Algebraic Consistency (PRAC). PRAC exploits intra and inter-packet consistency to identify and recover erroneous packet segments, without recourse to cross-layer or detailed feedback information. In the absence of cross-layer coordination or detailed feedback, the prevailing methods proposed in the literature have discarded packets with errors. PRAC uses a rateless linear packet code for data encoding and an iterative decoding process consisting of a search algorithm and an algebraic consistency rule (ACR) check. It allows, but not relies upon, the use of any PHY FEC code, requires no feedback other than a notification of completion and, in the absence of partial packets, incurs no overhead. Our implementation and experimental results in a 7-node indoor testbed using wireless boards equipped with CC2500 radio transceivers reveal that PRAC offers an average throughput gain of 35% compared to a baseline ARQ scheme discarding partial packets and 13% compared to an ideal genie-aided HARQ (iHARQ) scheme. Specifically for links with high PERs, PRAC significantly enhances their robustness and its maximum throughput gain is 148% and 34% compared against the baseline and iHARQ schemes, respectively.Focus Center Research Program (Award 017894-010
Energy Savings via Harnessing Partial Packets in Body Area Networks
No full textThis work considers the incorporation, implications and potential energy savings of partial packet recovery schemes in Body Area Networks (BANs). Received packets which have not been fully corrected by the physical layer, called partial, are discarded by the vast majority of BAN protocols, as opposed to valid packets, which satisfy the error detection check and are propagated to higher layers. In typical networks using ARQ protocols, dropping partial packets results in retransmissions. However, because these packets contain useful information, partial packet recovery schemes have been proposed with demonstrated throughput and reliability benefits, targeting mostly wireless LANs. In order to quantify the potential energy benefits of harnessing partial packets in BANs, we use an experimental setup with four sensors mounted on a human body, transmitting information to a receiving node in a typical office environment. By precisely modeling the state transitions and energy consumption of sensors, we compare the efficiency of a baseline ARQ protocol against a scheme which leverages information in partial packets. Our results indicate that exploiting partial packets reduces on average the energy consumption of our sensors by 8--20%. The energy savings are pronounced in challenged channel conditions of high PER, where they can be up to 50%
Experimental study of the interplay of channel and network coding in low power sensor applications
No full textIn this paper, we evaluate the performance of random linear network coding (RLNC) in low data rate indoor sensor applications operating in the ISM frequency band. We also investigate the results of its synergy with forward error correction (FEC) codes at the PHY-layer in a joint channel-network coding (JCNC) scheme. RLNC is an emerging coding technique which can be used as a packet-level erasure code, usually implemented at the network layer, which increases data reliability against channel fading and severe interference, while FEC codes are mainly used for correction of random bit errors within a received packet. The hostile wireless environment that low power sensors usually operate in, with significant interference from nearby networks, motivates us to consider a joint coding scheme and examine the applicability of RLNC as an erasure code in such a coding structure. Our analysis and experiments are performed using a custom low power sensor node, which integrates on-chip a low-power 2.4 GHz transmitter and an accelerator implementing a multi-rate convolutional code and RLNC, in a typical office environment. According to measurement results, RLNC of code rate 4/8 can provide an effective SNR improvement of about 3.4 dB, outperforming a PHY-layer FEC code of the same code rate, at a PER of 10[superscript -2]. In addition, RLNC performs very well when used in conjunction with a PHY-layer FEC code as a JCNC scheme, offering an overall coding gain of 5.6 dB.Focus Center Research Program. Focus Center for Circuit & System Solutions. Semiconductor Research Corporation. Interconnect Focus Cente
AdaptCast: An integrated source to transmission scheme for wireless sensor networks
No full textThis paper introduces AdaptCast, an integrated source to transmission scheme for wireless sensor networks (WSNs) that efficiently represents collected data and increases their robustness against channel errors across a wide range of signal to noise (SNR) values in a rateless fashion. AdaptCast leverages sparsity inherent in the majority of physical signals in order to parsimoniously represent them without relying on a specific signal model. The proposed scheme does not suffer from the sudden degradation in the tradeoff between distortion and SNR of rated channel coding schemes due to its direct, relative bit importance preserving modulation mapping. In addition, it does not require continuous feedback or channel state information (CSI) as a result of its rateless operation. Apart from point-to-point transmission, AdaptCast enables efficient multicasting to a set of nodes, serving each of them at a rate commensurate to its individual channel quality. We demonstrate AdaptCast's application-independent operation by using several typical signals captured in WSNs. Based on our analysis and simulation results, considering the tradeoff between distortion and channel quality, AdaptCast performs close in a point-to-point scenario to an idealized layered transmission scheme with instantaneous CSI and offers significant benefits in multiuser settings
Catalogue of Greek Magic Folktales
No full textMegas, Georgios A.; Anna Angelopoulos; Aigli Brouskou; Marianthi Kaplanoglou; Emmanouela Katrinaki: Catalogue of Greek Magic Folktales. Folklore Fellows’ Communications 303. Hèlsinki: Suomalainen Tiedeakatemia, 2012, 350 p
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