Robust Brain-computer interface for virtual Keyboard (RoBIK): project results

Special issue : ANR TECSAN : Technologies for Health and AutonomyNational audienceBrain-ComputerInterface (BCI)is a technology that translatesthe brain electrical activity into a command for a device such as a robotic arm, a wheelchair or a spelling device. BCIs have long been described as an assistive technology forseverely disabled patients because they completely bypass the need for muscular activity. The clinical reality is however dramatically different and most patients who use BCIs today are doing so as part of constraining clinical trials. To achieve the technological transfer from bench to bedside, BCI must gain ease of use and robustness of bothmeasure (electroencephalography [EEG]) and interface (signal processing and applications).TheRobustBrain-computerInterface for virtual Keyboard (RoBIK) project aimed atthe development of aBCIsystemfor communication that could be used on a daily basis by patientswithoutthe help of a trained teamofresearchers.To guide further developments cliniciansfirst assessed patients' needs.The prototype subsequently developed consisted in a 14 felt-pad electrodes EEG headsetsampling at 256Hz by an electronic component capable of transmitting signals wirelessly. The application was a virtual keyboard generating a novelstimulation paradigm to elicit P300 Evoked Related Potentials(ERPs) for communication. Raw EEG signals were treated with OpenViBE open-source software including novelsignal processing and stimulation techniques

Minimizing Single-Usage Cache Pollution for Effective Cache Hierarchy Management

Efficient cache hierarchy management is of a paramount importance when designing high performance processors. Upon a miss, the conventional operation mode of a cache hierarchy is to retrieve back the missing block from higher levels and to store the block into all hierarchy levels. It is however difficult to assert that storing the block into intermediate levels will be really useful. In the literature, this phenomenon, referred to as cache pollution, is often associated with prefetching techniques, that is, a prefetched block could evict data that is more likely to be reused in a near future. Cache pollution could cause severe performance degradation. This paper is typically concerned with addressing this phenomenon in the highest level of cache hierarchy. Unlike past studies that treat polluting cache blocks as blocks that are never accessed (i.e. only due to prefetching), our proposal rather attempts to eliminate cache pollution that is inherent to the application. Our observations did indeed reveal that cache blocks that are only accessed once - single-usage blocks - are quite significant at runtime and especially in the highest level of cache hierarchy. In addition, most single-usage cache blocks are data that can be prefetched. We show that employing a simple prediction mechanism is sufficient to uncover most of the single-usage blocks. For a two-level cache hierarchy, these blocks are directly sent from main memory to L1 cache. Performing data bypassing on L2 cache maximizes memory hierarchy and allows hard-toprefetch memory references to remain into this cache hierarchy level. Our experimental results show that minimizing single-usage cache pollution in the L2 cache leads to a significant decrease in its miss rate; resulting therefore in noticeable performance gains

A Case for a Complexity-Effective, Width-partitioned Microarchitecture

Current superscalar processors feature 64-bit datapaths to execute the program instructions, regardless of their operands size. Our analysis indicates, however, that most executions comprise a large amount (40%) of narrow-width operations; i.e. instructions which exclusively process narrow-width operands and results. We further noticed that these operations are well distributed across a program run. In this paper, we exploit these properties to master the hardware complexity of superscalar processors. We propose a width-partitioned microarchitecture (WPM) to decouple the treatment of narrow-width operations from that of the other program instructions. We split a 4-way issue processor into two clusters: one executing 64-bit operations, load/store and complex operations and the other treating the 16-bit operations. We show that revealing the narrow-width operations to the hardware is sufficient to keep the workload balanced and the communications minimized between clusters. Using a WPM reduces the complexity of several critical processor components: register file and bypass network. A WPM also lowers the complexity of the interconnection fabric since the 16-bit cluster is only able to propagate narrow-width data. We examine simple configurations of WPM while discussing their tradeoffs. We evaluate a speculative heuristic to steer the narrow-width operations towards clusters. A detailed complexity analysis shows using a WPM model saves power and area with a minimal impact on performance. \\ Les processeurs superscalaires actuels implémentent des chemins de données 64-bit pour exécuter les instructions d'un programme, indépendamment de la taille des opérandes. Notre analyse indique toutefois que la plupart des exécutions comportent une fraction considérable (40%) en opérations tronquées ; c-à-d. les instructions manipulant exclusivement des opérandes et des résultats de petite dimension. Nous avons aussi remarqué que les opérations tronquées sont bien distribuées au cours d'une exécution. Cette étude exploite ces propriétés pour maîtriser la complexité des processeurs superscalaires. Pour ce faire, nous proposons une microarchitecture clusterisée (WPM) pour découpler le traitement des opérations tronquées de celui des autres instructions du programme. Nous partitionnons ainsi le processeur entre deux clusters : un cluster 64-bit exécutant les opérations 64-bit, load/store et complexes, et un cluster 16-bit traitant les opérations 16-bit. Considérant les propriétés relatives aux opérations tronquées, nous montrons que révéler ces dernières au matériel est suffisant pour maintenir l'équilibrage des charges et minimiser les communications entre les clusters. Le modèle WPM réduit efficacement la complexité de plusieurs composants critiques du processeur : fichier de registres, réseau de bypass. Ce modèle réduit aussi la complexité du réseau d'interconnexion car le cluster 16-bit peut uniquement propager des données 16-bit. Nous examinons différentes configurations du WPM en discutant de leurs compromis. Nous évaluons une heuristique spéculative pour distribuer les instructions vers les clusters. Une analyse détaillée de la complexité indique que le modèle WPM réduit la consommation et la surface de silicium avec un impact minimal sur les performances

Angela Sophia La Loggia, Engineering and Construction in Egypt's Early Dynastic Period, Peeters, Orientalia Lovaniensia Analecta 239. Leuven, Paris, Bristol, CT, 2015

Rochecouste Olivier. Angela Sophia La Loggia, Engineering and Construction in Egypt's Early Dynastic Period, Peeters, Orientalia Lovaniensia Analecta 239. Leuven, Paris, Bristol, CT, 2015. In: Archéo-Nil. Revue de la société pour l'étude des cultures prépharaoniques de la vallée du Nil, n°26, 2016. Naissance de l'état, naissance de l’administration : le rôle de l'écriture en Égypte, au Proche-Orient et en Chine / Emergence of the state and development of the administration: the role of writing in Egypt, Near East and China. pp. 225-226

Who are the early dynastic elite?: Evaluating Egyptian elite cemeteries dated to the First, Second and Third Dynasties

Theoretical thesis.Bibliography: pages330-380Part one: The predicament of Early Dynastic elite tombs. Chapter 1. Introduction -- 2. Literature review -- Part two: Archaeological descriptions of royal and elite Early Dynastic tombs. 3. The royal tombs of the Early Dynastic period -- 4. The Nile delta region -- 5. The Memphis region -- 6. The region of Middle Egypt -- 7. The Abydos region -- 8. The Nubt and Nekhen regions -- Part three: Thematic discussions -- 9. Mortuary provisions of the Early Dynastic elite -- 10. Tomb distinctions of the Early Dynastic elite -- 11. Embodied signs of the Early Dynastic elite -- 12. Vicarious displays of the Early Dynastic elite -- 13. Conclusion -- Appendix.The aim of this thesis is to review the archaeological evidence we have for elites during the Early Dynastic period of ancient Egypt, especially mortuary contexts. The archaeological evidence itself mostly comes from mortuary contexts which is the main point of reference for discussions surrounding social developments for ancient Egyptian studies. Numerous analogies have been used from Sociology, Anthropology and Archaeology to emphasise markers of social differentiation from mortuary contexts to distinguish the presence of social groups, including elites. The term "elites" became a fixture of Early Dynastic literature when a category was needed to label the tombs and associated archaeological material from North Saqqara, against the evidence for the royal tombs located in the Early Dynastic necropolis at Abydos. However, the theme of elite tombs has been rarely questioned for the Early Dynastic period, especially since there are other contemporary tombs across Egypt which are comparable to the tombs at North Saqqara. Considering the literature which points out these elite tombs, this thesis questions the theme of identifying elites from the mortuary record and attempts to ask who this elite group was. This will be done by reviewing the archaeological data from a variety of Early Dynastic cemetery sites located from the Nile Delta to Upper Egypt. This data will then be evaluated using an inductive approach to test the authenticity of the mortuary evidence used to accentuate the presence and influence of elites upon Early Dynastic society. The expected outcome is to provide an evaluation on whether the analogy of elites is suitable for Early Dynastic studies, especially since the presence of elites are a crucial component for the origins of the first Egyptian state.Mode of access: Internet.1 online resource (xi, 381 pages

Architecture et bits significatifs

Maîtriser la complexité matérielle et la consommation d'énergie est devenu essentiel dans la conception de processeurs modernes. Cette thèse propose deux approches pour ce faire. Leur fondement découle de la propriété des programmes à s'exécuter avec une fraction importante en données tronquées, celles comportant un nombre restreint de bits significatifs. Nous utilisons cette propriété pour gérer la consommation du chemin de données au niveau logiciel. La forte localité des données tronquées permet de découper un programme en régions pouvant être traitées avec une largeur d'exécution optimisée. Nous montrons aussi que les opérations tronquées, celles manipulant exclusivement des données tronquées, sont fréquentes et bien distribuées au cours de l'exécution. Nous proposons alors le modèle WPM pour découpler le traitement de ces opérations sur des clusters appropriés. Nos analyses révèlent une complexité et consommation réduites pour une faible dégradation des performances.RENNES1-BU Sciences Philo (352382102) / SudocRENNES-INRIA Rennes Irisa (352382340) / SudocSudocFranceF

Tomb story: the elite of early Egypt : an investigation concerning the influence of 'elite theory' upon interpretations of elite mortuary evidence from the Predynastic and Early Dynastic periods (4000-2545 BC)

Theoretical thesis.Bibliography: pages 51-60.Introduction. Egyptology and the word 'elite' -- Chapter 1. Marx, Childe and the predynastic elite revolution -- Chapter 2. 'Patrician', 'Ruling class', and 'Elite' -- Chapter 3. A game of chiefs, masters and pendragons -- Chapter 4. Concluding discussion. What stories are we trying to tell?The word ‘elite’ has been used since the late 19th century as a social category to define the ruling minority of modern society. The term however, has also been used by archaeologists to socially categorise individuals from the mortuary evidence who may represent institutions or ruling minorities of ancient societies. This has been applied to the study of the Egyptian Predynastic and Early Dynastic periods (4000–2545 BC) in order to outline the role of elite interaction within the development of the state. But textual sources are too vague to provide an explanation of elite interaction within various state formation theories, which can lead to numerous conclusions concerning the archaeological evidence. This thesis will discuss how the concept of elite theory has been utilised by Early Egyptian archaeologists, to interpret the material and textual evidence that is available at numerous sites; such as Hierakonpolis, Saqqara and Naqada. I will also focus on how modern terms, such as ‘elite’, are obstacles for interpreting the archaeological record and prevent a thoughtful recount of the people who lived during ancient Egypt’s earliest known times.Mode of access: World wide web1 online resource (viii, 60 pages

Egypte antérieure. Mélanges de préhistoire et d'archéologie offerts à Béatrix Midant-Reynes par ses étudiants, collègues et amis

International audienc

Egypte antérieure. Mélanges de préhistoire et d'archéologie offerts à Béatrix Midant-Reynes par ses étudiants, collègues et amis

International audienc