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Sample records for byzantine asynchronous unison

  1. Byzantine Neumes

    DEFF Research Database (Denmark)

    Troelsgård, Christian

    musikeksempler med transskription til moderne linjenotation og en detaljeret bibliografi. Bogen er tænkt som en opdatering og uddybning af H.J.W. Tillyards Handbook of the Middle Byzantine Musical Notation (København 1935), en af de første udgivelser i serien Monumenta Musicae Byzantinae. Udgivelsen opsummerer...

  2. Notes on byzantine Panagiaria

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    Drpić Ivan

    2011-01-01

    Full Text Available The article offers some new insights into the significance and function of Byzantine panagiaria, small-scale containers for the bread sanctified in honor of the Virgin in a rite known as the Elevation of the Panagia. This rite, it is argued, was not limited to monastic and courtly contexts or to routine liturgical observance, as is often assumed, but could be performed by the laity as well. Proposing that the use of panagiaria as personal devotional instruments was fairly common in Byzantium, the article explores the interplay between the design, materiality, epigraphic enhancement, and ritual and devotional use of these objects.

  3. Byzantine Theme of Chios

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    Anton S. Mokhov

    2016-11-01

    Full Text Available The article is devoted to the study of the Byzantine theme system in the 10th - 11th centuries. The author believes that the reign of Basil II (976-1025 was marked by the mikra themata in Balkans and on Aegean Sea islands. They were in need of effective border defense. Theme of Chios was one of the mikra militaryadministrative districts, which were created in this period. The author detected five leaders of the theme in accordance with the historical sources: protospatharios and strategos Theodoros Beriboes; protospatharios, tagmatophylax and strategos Leon Karikes; protospatharios, tagmatophylax and strategos Bardas Mersiniotes; vestarches and strategos Ioannes Aristenos; vestes and strategos Michael Maurikas. The analysis of the sigillographic data led to the conclusion that the regular tagmata were the base of the military force of theme of Chios. Moreover, the fortress of Volissos was located in the northwest of Chios. The area around the fortress was inhabited by representatives of one ethnic group. They were under the leadership of doux, which was subordinate to the strategos of the theme. The famous officials of the civil administration of Chios included fiscal clerks – dioiketes, horreiarios and judicial clerks – krites of the velon. Theme of Chios had existed for about one hundred years. It was liquidated during the war between Byzantine and Tzachas, Turkish amir of Smyrna.

  4. Byzantine gold coins and jewellery

    International Nuclear Information System (INIS)

    Oddy, A.; La Niece, S.

    1986-01-01

    The article deals with the dating of Byzantine gold coinage. The results of such a study are of fundamental importance for the study of the economic history of the later Byzantine Empire and they are also of importance for the historian of technology when studying the composition of the contemporary Byzantine jewellery. Although Carbon-14 dating cannot be used as a method af dating, historians can still benefit from the analysis of the alloy of which the antiquity is made, as this is sometimes characteristic of the period in which it was used. A number of pieces of Byzantine jewellery has been analysed by x-ray fluorescence analysis, after first gently abrading a small area of the surface of the gold with the carborundum paper in an inconspicious position on the back or side of the object. A table is given on the results of this analysis

  5. Transcription of Byzantine Chant - Problems, Possibilities, Formats

    DEFF Research Database (Denmark)

    Troelsgård, Christian

    2007-01-01

    Discusses the problems and possibilities for transsription of Byzantine chant on the basis of medieval musical manuscripts. A relatively 'neutral' style of transcription is suggested for musicological purposes.......Discusses the problems and possibilities for transsription of Byzantine chant on the basis of medieval musical manuscripts. A relatively 'neutral' style of transcription is suggested for musicological purposes....

  6. Byzantine Parthenogenesis as Hierotopy of Fluid Brilliance

    DEFF Research Database (Denmark)

    Isar, Nicoletta

    2014-01-01

    Images Borne on Dewy Lightning Byzantine παρθένογένεσις as Hierotopy of Fluid Brilliance......Images Borne on Dewy Lightning Byzantine παρθένογένεσις as Hierotopy of Fluid Brilliance...

  7. Early Byzantine steelyard from Belgrade

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    Vujović Miroslav

    2014-01-01

    Full Text Available The initial aim of this paper was to present scholarly circles with a detailed report about the insufficiently known Early Byzantine steelyard beam (Figs. 2-5; Pl. I/1 treasured in Belgrade City Museum (further in the text BCM together with a small counterweight (Fig. 6; Pl. I/2 which, judging by its dimensions and weight, does not belong to it. However, after inspecting the documentation of BCM and the National Museum in Belgrade (further in the text NMB, the supposition that the steelyard beam from BCM represents a part of the same hoard with the well known counterweight (Fig. 7 in the form of a bust of a Byzantine empress, and the unpublished chain system with hooks for hanging loads (Fig. 8; Pl. IV, which are kept in NMB, was confirmed. The detailed examination of the museum inventory records shed light on the set of circumstances which led to the separation of the parts of the Belgrade steelyard. [Projekat Ministarstva nauke Republike Srbije, br. 177007: Romanizacija, urbanizacija i transformacija urbanih centara civilnog,vojnog i rezidencijalnog karaktera u rimskim provincijama na tlu Srbije

  8. Political instability and the ability of local government to respond to reputational threats in unison

    DEFF Research Database (Denmark)

    Grøn, Caroline Louise Howard; Salomonsen, Heidi Houlberg

    2017-01-01

    This article investigates whether local governments are able to act in a unified manner when responding to reputational threats posed by negative media coverage. Based on an argument that local governments facing political instability are less able to perform in unison, the article investigates a...

  9. Modeling and Analysis of Asynchronous Systems Using SAL and Hybrid SAL

    Science.gov (United States)

    Tiwari, Ashish; Dutertre, Bruno

    2013-01-01

    We present formal models and results of formal analysis of two different asynchronous systems. We first examine a mid-value select module that merges the signals coming from three different sensors that are each asynchronously sampling the same input signal. We then consider the phase locking protocol proposed by Daly, Hopkins, and McKenna. This protocol is designed to keep a set of non-faulty (asynchronous) clocks phase locked even in the presence of Byzantine-faulty clocks on the network. All models and verifications have been developed using the SAL model checking tools and the Hybrid SAL abstractor.

  10. Generalized Asynchronous Systems

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    E. S. Kudryashova

    2012-01-01

    Full Text Available The paper consider a mathematical model of a concurrent system, the special case of which is an asynchronous system. Distributed asynchronous automata are introduced here. It is proved that Petri nets and transition systems with independence can be considered as distributed asynchronous automata. Time distributed asynchronous automata are defined in a standard way by correspondence which relates events with time intervals. It is proved that the time distributed asynchronous automata generalize time Petri nets and asynchronous systems.

  11. Addressing Unison and Uniqueness of Reliability and Safety for Better Integration

    Science.gov (United States)

    Huang, Zhaofeng; Safie, Fayssal

    2015-01-01

    For a long time, both in theory and in practice, safety and reliability have not been clearly differentiated, which leads to confusion, inefficiency, and sometime counter-productive practices in executing each of these two disciplines. It is imperative to address the uniqueness and the unison of these two disciplines to help both disciplines become more effective and to promote a better integration of the two for enhancing safety and reliability in our products as an overall objective. There are two purposes of this paper. First, it will investigate the uniqueness and unison of each discipline and discuss the interrelationship between the two for awareness and clarification. Second, after clearly understanding the unique roles and interrelationship between the two in a product design and development life cycle, we offer suggestions to enhance the disciplines with distinguished and focused roles, to better integrate the two, and to improve unique sets of skills and tools of reliability and safety processes. From the uniqueness aspect, the paper identifies and discusses the respective uniqueness of reliability and safety from their roles, accountability, nature of requirements, technical scopes, detailed technical approaches, and analysis boundaries. It is misleading to equate unreliable to unsafe, since a safety hazard may or may not be related to the component, sub-system, or system functions, which are primarily what reliability addresses. Similarly, failing-to-function may or may not lead to hazard events. Examples will be given in the paper from aerospace, defense, and consumer products to illustrate the uniqueness and differences between reliability and safety. From the unison aspect, the paper discusses what the commonalities between reliability and safety are, and how these two disciplines are linked, integrated, and supplemented with each other to accomplish the customer requirements and product goals. In addition to understanding the uniqueness in

  12. [Byzantine therapeutics in the Ottoman world].

    Science.gov (United States)

    Varella, E A

    1999-01-01

    The medical literature of the greek speaking ottoman world was deeply influenced by its byzantine heritage: the major authors were copied and commented, while practical manuals containing recipes and therapies - the iatrosophia- kept being enlarged with useful information. Furthermore, during the first centuries hospitals closely followed the models of their glorious past in what concerns architecture, scientific level, means and targets. In fact, only the years after 1770 rely on occidental academic knowledge and adopt modern conceptions.

  13. FUZZY DECISION MAKING MODEL FOR BYZANTINE AGREEMENT

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    S. MURUGAN

    2014-04-01

    Full Text Available Byzantine fault tolerance is of high importance in the distributed computing environment where malicious attacks and software errors are common. A Byzantine process sends arbitrary messages to every other process. An effective fuzzy decision making approach is proposed to eliminate the Byzantine behaviour of the services in the distributed environment. It is proposed to derive a fuzzy decision set in which the alternatives are ranked with grade of membership and based on that an appropriate decision can be arrived on the messages sent by the different services. A balanced decision is to be taken from the messages received across the services. To accomplish this, Hurwicz criterion is used to balance the optimistic and pessimistic views of the decision makers on different services. Grades of membership for the services are assessed using the non-functional Quality of Service parameters and have been estimated using fuzzy entropy measure which logically ranks the participant services. This approach for decision making is tested by varying the number of processes, varying the number of faulty services, varying the message values sent to different services and considering the variation in the views of the decision makers about the services. The experimental result shows that the decision reached is an enhanced one and in case of conflict, the proposed approach provides a concrete result, whereas decision taken using the Lamport’s algorithm is an arbitrary one.

  14. Addressing Uniqueness and Unison of Reliability and Safety for a Better Integration

    Science.gov (United States)

    Huang, Zhaofeng; Safie, Fayssal

    2016-01-01

    Over time, it has been observed that Safety and Reliability have not been clearly differentiated, which leads to confusion, inefficiency, and, sometimes, counter-productive practices in executing each of these two disciplines. It is imperative to address this situation to help Reliability and Safety disciplines improve their effectiveness and efficiency. The paper poses an important question to address, "Safety and Reliability - Are they unique or unisonous?" To answer the question, the paper reviewed several most commonly used analyses from each of the disciplines, namely, FMEA, reliability allocation and prediction, reliability design involvement, system safety hazard analysis, Fault Tree Analysis, and Probabilistic Risk Assessment. The paper pointed out uniqueness and unison of Safety and Reliability in their respective roles, requirements, approaches, and tools, and presented some suggestions for enhancing and improving the individual disciplines, as well as promoting the integration of the two. The paper concludes that Safety and Reliability are unique, but compensating each other in many aspects, and need to be integrated. Particularly, the individual roles of Safety and Reliability need to be differentiated, that is, Safety is to ensure and assure the product meets safety requirements, goals, or desires, and Reliability is to ensure and assure maximum achievability of intended design functions. With the integration of Safety and Reliability, personnel can be shared, tools and analyses have to be integrated, and skill sets can be possessed by the same person with the purpose of providing the best value to a product development.

  15. Byzantine Oecumene in the Iconoclast Controversy

    OpenAIRE

    Lev Lukhovitskiy

    2017-01-01

    In 754 emperor Constantine V sought to defame the iconophile opposition by labeling John Damascene an agent of Arab influence. The fathers of Nicaenum II in 787 made a case for justifying external interference in the religious life of the Byzantine Empire. This stance was nuanced in polemical writings of the early 9th century. The author of the Life of St. Stephen the Younger presented external political pressure as internal by making the saint deliver a sermon on the geography of the iconocl...

  16. The Byzantine Chant Heritage in Sicily

    DEFF Research Database (Denmark)

    Sanfratello, Giuseppe

    historical development, and function as marker of identity among the Arbëreshe community in Sicily. Therefore, the Byzantine chant heritage in Sicily is not an inflexible and static musical tradition, but it envisages a dynamic mode of existence, susceptible to changes, and maintained by interior principles...... of organisation. After five centuries of oral transmission, it still lives, despite, or maybe thanks to the lack of ‘original’ written sources, and it might thus be seen as a multi-layered musical tradition, featuring multiple versions and encompassing a certain degree of melodic heterogeneity....

  17. Middle Byzantine Historiography: Tradition, Innovation, and Reception

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    Staffan Wahlgren

    2015-10-01

    Full Text Available This paper provides an overview of Greek historical writing of the Middle Byzantine period (approx. 800 until 1000 A.D., with a particular focus on the major chronicles, such as Theophanesthe Confessor (early 9th c., George the Monk (probably late 9th c., and Symeon the Logothete (second half of the 10th c.. On the one hand, it is discussed how the chroniclers engage with tradition and either accept it or reject it. Acceptance of tradition is illustrated by many cases where chroniclers keep very close to the narrative modes of their predecessors and in particular where they copy them extensively. Rejection of, or at least deviation from tradition is illustrated by many cases where new narrative techniques and modes of expression are apparent. Particular attention is paid to some aspects of narrative technique which seem to be innovative. In short, there seems to be an increased tendency towards greater logical (and hence, narrative coherence in the chronicles and an increased tendency towards concentration on a small number of settings, issues and persons (in particular, there is an increased concentration on the Capital of Constantinople and the Emperor’s person. Further, reception is discussed, and especially how Middle Byzantine historical texts were read and used in later writings, including the Slavic literatures. The need for further research in order to understand the transmission processes, especially in the form of the philological study of manuscripts, is stressed.

  18. Byzantine Oecumene in the Iconoclast Controversy

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    Lev Lukhovitskiy

    2017-12-01

    Full Text Available In 754 emperor Constantine V sought to defame the iconophile opposition by labeling John Damascene an agent of Arab influence. The fathers of Nicaenum II in 787 made a case for justifying external interference in the religious life of the Byzantine Empire. This stance was nuanced in polemical writings of the early 9th century. The author of the Life of St. Stephen the Younger presented external political pressure as internal by making the saint deliver a sermon on the geography of the iconoclast world in which political borders and ecclesiastical jurisdictions were deliberately tempered with. In late 810ies Theodore Studite and Patriarch Nicephorus launched a diplomatic enterprise aiming to increase the political pressure exercised from abroad over the recently reestablished iconoclast regime of Leo V. A close reading of Theodore’s letters and Nicephorus’ writings from exile sheds light on the underlying ideological basis of this trend. Michael II in his turn appropriated his opponents’ stratagem and tried to win over to his side an expanding external power -- the Carolingian empire -- and use it to suppress the iconophile opposition. In spite of the fact that the iconophile diplomatic efforts had negative rebound effects during the reign of Michael II, they were allotted a proper place in Byzantine cultural memory.

  19. Better with Byzantine: Manipulation-Optimal Mechanisms

    Science.gov (United States)

    Othman, Abraham; Sandholm, Tuomas

    A mechanism is manipulable if it is in some agents’ best interest to misrepresent their private information. The revelation principle establishes that, roughly, anything that can be accomplished by a manipulable mechanism can also be accomplished with a truthful mechanism. Yet agents often fail to play their optimal manipulations due to computational limitations or various flavors of incompetence and cognitive biases. Thus, manipulable mechanisms in particular should anticipate byzantine play. We study manipulation-optimal mechanisms: mechanisms that are undominated by truthful mechanisms when agents act fully rationally, and do better than any truthful mechanism if any agent fails to act rationally in any way. This enables the mechanism designer to do better than the revelation principle would suggest, and obviates the need to predict byzantine agents’ irrational behavior. We prove a host of possibility and impossibility results for the concept which have the impression of broadly limiting possibility. These results are largely in line with the revelation principle, although the considerations are more subtle and the impossibility not universal.

  20. The 'Byzantinisms' of king Stefan Radoslav

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    Maksimović Ljubomir

    2009-01-01

    Full Text Available The life-style and politics of Stefan Radoslav bear the mark of activities that indicated his special attachment to the Byzantine world. These activities were prompted by a combination of ideological ambitions and political reality, but they were not in keeping with the modest achievements of Radoslav's reign. Moreover, most of these activities belong to the time when Radoslav was heir to the throne. There is no doubt that Stefan Nemanjić the Grand Zhupan and subsequently the first crowned king, had exclusive connections with the Byzantine dynasty of the Angeloi, especially with the emperor Alexios III (1195-1203. In that context, the donor's inscription in the basic ring of the dome in the Church of the Mother of God in Studenica (1208, in which his father Stefan Nemanja, is mentioned as (former 'veleslavni gospodin vse srbske zemlje veli(ki župan i svat cara grčkog kir Alesija', is quite indicative. This ideological construction would acquire a contour in reality by means of a political marriage with one of the female offspring of Angeloi lineage, which would represent an alternative solution to Stefan's failed marriage with Eudocia, daughter of the emperor Alexios. Instead, several years elapsed in waging war with the Latins, the Bulgarians and the State of Epiros. However, efforts to create firmer, more tangible ties with the Angeloi dynasty from Epiros were not forgotten. Therefore, the Serbian monarch brought his eldest son Radoslav into play, intending to have him act as a link with the Angeloi bloodline. As a result of all this, the final attempt to have Radoslav become the husband of a princess from the Angelos dynasty is not surprising. At the end of 1219 or the beginning of 1220, he married Anna Doukaina, the daughter of the epirotic ruler Theodore I Angelos Doukas Komnenos, which at that point represented a marriage connection of the highest possible level between two ruling houses. Stefan's insistence on Serbia acquiring a stake

  1. Ontological-epistemological views of the beautiful Byzantine aesthetics

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    Vilić Nataša

    2015-01-01

    Full Text Available The paper approaches the ontological-epistemology aspects of the beauty of Byzantine art. Byzantine aesthetics and Byzantine art are unjustly neglected in the history of aesthetic thought. Christian aestheticians have an ambivalent attitude towards art. Because, Byzantine painting represents reality show based on the Christians view, where absolutizs a new dimension of spirituality and aesthetics deriving from the ontological-epistemological positions. The phenomenon of beauty in Byzantine art is primarily deposited in epistemological components, where everything is directed to the knowledge of the truth. In Byzantine art beauty has, above all, spiritual character; it does not have a classical aesthetic dimension, but primarily because the ontological character is recognized as one of the innumerable divine energies and of phenomena. The Byzantine painter makes an effort to realize the creative transformation of matter into a unique experience community and relationship with God, who volatility of the world beyond the ontological light that is converted from non-being into being.

  2. BESSARABIAN RELIGIOUS MUSIC OF BYZANTINE TRADITION REFLECTED IN AUTOCHTHONOUS MUSICOLOGY

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    BARBANOI HRISTINA

    2015-06-01

    Full Text Available The article below presents an overview of the main musicological studies that aim Bessarabian religious music of Byzantine tradition, developed by musicologists from the Republic of Moldova and Romania. The author emphasizes the idea that although the study of Byzantine religious music in the Bessarabian space is carried out by a limited number of people, their research results deserve attention, being of high scientific value. Some of these results are even internationally recognized. At the same time, the author notes that Bessarabian religious music of Byzantine tradition is not sufficiently researched.

  3. Asynchronous LMS adaptive equalization

    NARCIS (Netherlands)

    Bergmans, J.W.M.; Lin, M.Y.; Modrie, D.; Otte, R.

    2005-01-01

    Digital data receivers often operate at a fixed sampling rate 1/Ts that is asynchronous to the baud rate 1/T. A digital equalizer that processes the incoming signal will also operate in the asynchronous clock domain. Existing adaptation techniques for this equalizer involve an error sequence ek that

  4. Arab-Byzantine War, 629-644 AD

    National Research Council Canada - National Science Library

    Kunselman, David E

    2007-01-01

    .... In the course of just a few years the Arabs had conquered the valuable territories of modern day Palestine, Syria, Jordan and Lebanon from the Byzantines who in turn withdrew to Anatolia after great losses...

  5. A BRIEF INTRODUCTION TO THE BYZANTINE PORTRAIT ART

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    Irina-Andreea STOLERIU

    2016-07-01

    Full Text Available Guided by the Christian faith, Byzantine art has attached special meaning to the representation of the human figure. Grounded on aesthetic principles, the artistic representation of the human face relinquished on the physical materiality of the represented model, searching for its essences and resemblances to the divine world. Subject to specific representation rules, Byzantine portraiture bears a series of peculiar characteristics that mark it out among other images of this kind belonging to other spirituality areas, periods and artistic styles. Both in icons, where it highlights a series of particular significances describing the divine nature of saints, and in other fields of Byzantine arts – such as mural painting or mosaic –the portrait stands out due to its importance. This paper intends to present a few of the defining characteristics of portraiture in Byzantine art, exemplifying the evolution of this artistic genre by analysing some of the most representative creations of this field.

  6. The Cosmological Potential of Byzantine Ascetic Aesthetics

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    Аndrey Tsarenok

    2017-09-01

    Full Text Available The study explores the peculiarities of the cosmological senses, which exist in Byzantine ascetic aesthetical doctrine. Underlining the obvious strong connection between theological aesthetics, ontology and cosmology, the author of the article points out the interpretation of world’s beauty, order and harmony by representatives of ascetic culture of Byzantium (sts. Grigoriy the Theologian, Grigoriy, bishop of Niss, Ioann Chrysostom, Ioann Damaskin, Simeon the New Theologian and others. The aesthetics of the asceticism is characterized as theocentrical ontology of beauty. Its development has been influenced by theism, trinitary monotheism and theocentrism of Christian world-view tradition. The theologians speak about the existence of the Highest Absolute Beauty, Who is the cause of the beautiful things in created reality. The impressive qualities of cosmos are considered as evidence of being of their Almighty Creator. Therefore, the sensual cognition can help believer in his or her search of God. At the same time, ascetic aesthetics prevents from unreasonable enjoying of the sensual (material, somatic beauty for such enjoying is able to make the true person’s spiritual perfection impossible. Moreover, according to Christian theology, absolutization of the cosmical beauty regularly distorts the person’s belief: Byzantine ascetics point out the “aesthetical” cause of paganism appearance. Appealing to Bible, theologians differentiate two periods in history of cosmos, which can be interpreted as the pre-sin and the post-sin ones. The beginning of visible world existence was marked with being of original beauty, order and harmony, but the transgression, committed by the first people, distorted the cosmos to a great degree. Acknowledging of this sorrowful fact does not ruin quite an optimistic character of ascetic aesthetical, ontological and cosmological conceptions of Byzantium. According to them, the beauty of Universe will be completely

  7. Diverse Legal Significance of a Document in Byzantine Private Law

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    Tamara M. Matović

    2017-11-01

    Full Text Available Byzantine, Graeco-Roman, law is the organic continuation of Roman law. However, the legal system itself, and many legal institutions in it, had gone through certain evolution. In this article, by researching Greek acts conserved in various monastic arhives, and confronting them with stipulations in the Byzantine law codes, we question the issues of consensuality of a contract, form of a legal deed, and acquisation of a real right in Byzantine private law. The nature of contracts in Byzantine law has not been sufficiently studied. Richful theoretical studies had been written in regards to the contract of purchase in Roman and Justinians law, however various and sometimes confronting information from the later Greek codes did not give definite answers to this question. Byzantine codices on this theme encompass already familiar stipulations and legal institutes. The attention of the lawgiver was on the notary system, on the mechanism which produced a written instrument. We believe that the issue of the παράδοσις δι̉ ἐγγράφου was not sufficiently highlighted in the field of Byzantine studies mostly due to the lack of information in the sources. However, when regarding the Athonite documents, it can be seen that the formulae describing the act of law transfer could be concidered as a relevant material to comment on this legal institute.

  8. The Aeolian Asynchronous Generator

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    Ionel Dragomirescu

    2008-10-01

    Full Text Available The production of the electric energy with lower costs could be realized with the help of the aeolian electric central. In these centrals we can use the squirrel cage asynchronous generators, because these machines are the most safety in function and easy exploited. This work show the function analyzing of the asynchronous generator having on involving torque depending on the square wind speed, the air-density and on the construction of the wing spiral.

  9. Low latency asynchronous interface circuits

    Science.gov (United States)

    Sadowski, Greg

    2017-06-20

    In one form, a logic circuit includes an asynchronous logic circuit, a synchronous logic circuit, and an interface circuit coupled between the asynchronous logic circuit and the synchronous logic circuit. The asynchronous logic circuit has a plurality of asynchronous outputs for providing a corresponding plurality of asynchronous signals. The synchronous logic circuit has a plurality of synchronous inputs corresponding to the plurality of asynchronous outputs, a stretch input for receiving a stretch signal, and a clock output for providing a clock signal. The synchronous logic circuit provides the clock signal as a periodic signal but prolongs a predetermined state of the clock signal while the stretch signal is active. The asynchronous interface detects whether metastability could occur when latching any of the plurality of the asynchronous outputs of the asynchronous logic circuit using said clock signal, and activates the stretch signal while the metastability could occur.

  10. Lycanthropy in Byzantine times (AD 330-1453).

    Science.gov (United States)

    Poulakou-Rebelakou, E; Tsiamis, C; Panteleakos, L G; Ploumpidis, D

    2009-12-01

    In this paper, the original Greek language texts of the Byzantine medical literature about lycanthropy are reviewed. The transformation of a human being into a wolf and the adoption of animal-like behaviour, which were already known from mythology and had been presented in the scientific works of ancient Greek and Roman physicians, were examined by six Byzantine physicians and explained as a type of melancholic depression or mania. In spite of the influence of Byzantine medicine, its rationality in the interpretation of lycanthropy was forgotten in medieval and Renaissance times when it was replaced by explanations based on demonic possession and witchcraft. More recently psychiatry has treated the phenomenon as a subject of medical inquiry and has again explained the condition in terms of mental disorder.

  11. Asynchronized synchronous machines

    CERN Document Server

    Botvinnik, M M

    1964-01-01

    Asynchronized Synchronous Machines focuses on the theoretical research on asynchronized synchronous (AS) machines, which are "hybrids” of synchronous and induction machines that can operate with slip. Topics covered in this book include the initial equations; vector diagram of an AS machine; regulation in cases of deviation from the law of full compensation; parameters of the excitation system; and schematic diagram of an excitation regulator. The possible applications of AS machines and its calculations in certain cases are also discussed. This publication is beneficial for students and indiv

  12. Asynchronous SAR ADC

    NARCIS (Netherlands)

    2011-01-01

    An asynchronous analog to digital convertor for converting an analog input signal into a digital output is presented. According to an embodiment, the analog to digital convertor comprises a clock input operable to receive an external clock signal having a clock period, a comparator operable to

  13. Mission and/or conversion: strategies of Byzantine diplomacy

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    Marius Telea

    2015-10-01

    Full Text Available The religious element has always represented, inevitably, a feature of Byzantine diplomacy, offering it the instruments necessary for a fruitful dialogue with the pagan peoples in Eastern Europe. As one could notice, the classical policies of Constantinople involved different strategies, as well as exorbitant expenses, which did not always ensure long-term peace. On the other hand, religion operated at an abstract level, and in the medieval mentality, celebrating rituals such as baptism or marriage to a Byzantine Porphyrogenita established a stronger connection than the one constituted through peace treaties. Although one cannot assert a decisive opinion concerning the spread of eastern Christianity, whether it was a purpose of the external Byzantine politics or just a means of obtaining peace, one thing is certain: preaching the Gospel represented a diplomatic practice with an immense power of persuasion. These successes of the mission patronized by the Patriarchate of Constantinople, especially in the IXth and Xth centuries show us that in this direction, the Byzantines were one step ahead of the Western world.

  14. Contesting Conceptual Boundaries: Byzantine Literature and Its History

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    Panagiotis A. Agapitos

    2015-07-01

    Full Text Available The paper presents the problems of writing a history of Byzantine literature in the context of postmodern anxieties about canonization, authority and narrative histories of literature. An essential difficulty for such a project is the fact that Byzantine literature has been viewed as a continuation of or appendix to Ancient Greek literature, while, on the other, it has been divided into 'learned' and 'vernacular', the latter category having been defined as Modern Greek since the middle of the nineteenth century. The paper offers two sets of criteria for establishing new concepts of periodization and taxonomy. A series of examples are indicatively adduced in order to explain the scientific and ideological impasse in which Byzantine Studies have found themselves at the end of the previous century, while delineating a proposal for a different approach to content and structure of a wider synthesis. Writing a ‘new’ history of Byzantine literature is an experiment in proposing a radical paradigm shift by means of which this particular literary production in Medieval Greek can be studied within the broader context of Medieval European literatures as an integrated entity rather than as a separate and peripheral phase in the histories of Ancient or Modern Greek literature.

  15. Multiparty Asynchronous Session Types

    DEFF Research Database (Denmark)

    Honda, Kohei; Yoshida, Nobuko; Carbone, Marco

    2016-01-01

    . This work extends the foregoing theories of binary session types to multiparty, asynchronous sessions, which often arise in practical communication-centered applications. Presented as a typed calculus for mobile processes, the theory introduces a new notion of types in which interactions involving multiple......Communication is a central elements in software development. As a potential typed foundation for structured communication-centered programming, session types have been studied over the past decade for a wide range of process calculi and programming languages, focusing on binary (two-party) sessions...... peers are directly abstracted as a global scenario. Global types retain the friendly type syntax of binary session types while specifying dependencies and capturing complex causal chains of multiparty asynchronous interactions. A global type plays the role of a shared agreement among communication peers...

  16. Behavioral synthesis of asynchronous circuits

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard

    2005-01-01

    This thesis presents a method for behavioral synthesis of asynchronous circuits, which aims at providing a synthesis flow which uses and tranfers methods from synchronous circuits to asynchronous circuits. We move the synchronous behavioral synthesis abstraction into the asynchronous handshake...... is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration...

  17. Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus

    OpenAIRE

    Abraham, Ittai; Malkhi, Dahlia; Nayak, Kartik; Ren, Ling; Spiegelman, Alexander

    2018-01-01

    The decentralized cryptocurrency Bitcoin has experienced great success but also encountered many challenges. One of the challenges has been the long confirmation time. Another chal- lenge is the lack of incentives at certain steps of the protocol, raising concerns for transaction withholding, selfish mining, etc. To address these challenges, we propose Solida, a decentralized blockchain protocol based on reconfigurable Byzantine consensus augmented by proof-of-work. Solida improves on Bitcoin...

  18. Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus

    OpenAIRE

    Abraham, Ittai; Malkhi, Dahlia; Nayak, Kartik; Ren, Ling; Spiegelman, Alexander

    2016-01-01

    The decentralized cryptocurrency Bitcoin has experienced great success but also encountered many challenges. One of the challenges has been the long confirmation time. Another challenge is the lack of incentives at certain steps of the protocol, raising concerns for transaction withholding, selfish mining, etc. To address these challenges, we propose Solida, a decentralized blockchain protocol based on reconfigurable Byzantine consensus augmented by proof-of-work. Solida improves on Bitcoin i...

  19. Accessibility improvement interventions realised in Byzantine monuments of Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    Aristotelis Naniopoulos

    2015-10-01

    Full Text Available Purpose – Access to culture is a fundamental right of people with disabilities and a significant aspect in the development of accessible tourism. A visit to a monument provides an authentic experience which cannot be substituted by any representation. However, any interventions to improve accessibility should be made carefully, so as not to alter the monument�s character, or damage it visually or structurally. The paper aims to discuss these issues. Design/methodology/approach – A theoretical approach model was defined in the PROSPELASIS project for the improvement of accessibility in monuments which was applied in Byzantine monuments of Thessaloniki. This approach contains the following steps: evaluation of existing accessibility level; definition of alternative solutions; creation of final studies, approval by archaeological authorities and implementation of interventions. Findings – In six major Byzantine monuments significant improvements were realized which include: installation of two lifts and creation of a new staircase at Acheiropoietos; creation of a metal bridge, a new staircase and installation of a lift at Rotunda; opening of the secondary gate and creation of a ramp at the Heptapyrgion fortress; creation of an accessible toilet at the Saint Demetrios church; installation in the six monuments of a WiFi system providing text and audible information as well as information in Greek and International Sign Language; creation of two tactile models; creation of a �cultural route� connecting three major Byzantine monuments. Originality/value – For the first time, to the knowledge, a set of interventions has been realized in Byzantine monuments focusing on various categories of people with disabilities, i.e. motor, visual, hearing and cognitive.

  20. Asynchronous Multiparty Computation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Geisler, Martin; Krøigaard, Mikkel

    2009-01-01

    guarantees termination if the adversary allows a preprocessing phase to terminate, in which no information is released. The communication complexity of this protocol is the same as that of a passively secure solution up to a constant factor. It is secure against an adaptive and active adversary corrupting...... less than n/3 players. We also present a software framework for implementation of asynchronous protocols called VIFF (Virtual Ideal Functionality Framework), which allows automatic parallelization of primitive operations such as secure multiplications, without having to resort to complicated...... multithreading. Benchmarking of a VIFF implementation of our protocol confirms that it is applicable to practical non-trivial secure computations....

  1. Female incompetence, misogyny and xenophobia, or a faulty marital policy on the part of the late Byzantine emperors?

    Czech Academy of Sciences Publication Activity Database

    Melichar, Petra

    74, 2016 (2016), s. 58-70 ISSN 0007-7712. [Lives Roles and Actions of the Byzantine Empress es. Praha, 11.09.2015-12.09.2015] R&D Projects: GA ČR(CZ) GP14-08304P Institutional support: RVO:68378017 Keywords : Byzantine empress es * Late Byzantine empire * medieval women Subject RIV: AB - History

  2. [The establishment of the hospital-system in the Byzantine Empire].

    Science.gov (United States)

    Józsa, László

    2011-01-01

    Byzantine hospitals developed out of Christian institutions for the poor and homeless. Philanthropy provided the initial impulse to create hospices (xenons) and to expand these institutions into specialized medical centers (iatreons or nosokomeions). However the Byzantine nosocomeions resemble more closely modern hospitals than they do any of the institutions of Greek-Roman antiquity or any of the houses of charity in the Latin West during the Middle Ages. Since the 4th century the Byzantine hospitals have stressed the central position of the nosocomeion in Byzantine society at the intersection of state, ecclesiastical and professional interest. In the great cities and in the capital, more than hundred hospitals worked in the East-Roman Empire. The Byzantine hospital rules guaranted patients private beds, required physicians to wash their hands after each examination and arranged the physical plant to keep all the sick warm. The Byzantine hospitals had separate sections (in modern terms: surgery-trauma surgery, internal medicine, ophthalmology, etc.) and at the beginning of the sixth century a separate institution for women. From the sixth century at least, bathing facilities normally adjoined Byzantine nosocomeia. By the twelfth century Byzantine hospitals also set aside a room or perhaps a separate building to treat outpatients. In addition to the main dormitories the surgery, baths and outpatient clinic, the large parts of hospitals also had separate rooms (or adjoining buildings) for library, for lecture hall, for administrative functions and record keeping for storage and for other services.

  3. Pro asynchronous programming with .NET

    CERN Document Server

    Blewett, Richard; Ltd, Rock Solid Knowledge

    2014-01-01

    Pro Asynchronous Programming with .NET teaches the essential skill of asynchronous programming in .NET. It answers critical questions in .NET application development, such as: how do I keep my program responding at all times to keep my users happy how do I make the most of the available hardware how can I improve performanceIn the modern world, users expect more and more from their applications and devices, and multi-core hardware has the potential to provide it. But it takes carefully crafted code to turn that potential into responsive, scalable applications.With Pro Asynchronous Programming

  4. Legendary genealogies of Byzantine Emperors and their families

    Directory of Open Access Journals (Sweden)

    Krsmanović Bojana T.

    2004-01-01

    Full Text Available Theoretically, the Byzantine Emperor was, just like in the times of the Roman Empire, chosen on the basis of his personal qualities and merits — by the grace of God, of course. Practically, the factors which determined the ascension of a person to the throne were much more complex, the methods of gaining power being multifarious. In consequence, the political philosophy was confronted with the question of whether it is virtue (aretç or origin (génoz that defines an Emperor. Independently of this rather theoretical question, however, and despite the claims that the personal qualities are decisive in the choice of the Emperor, the origin of the ruler played an important role in the consciousness of the Byzantines of all epochs. This is why great attention was paid to the creation of family trees, especially in the cases when the Emperor was of low origin (homo novus or when it was for some reason necessary to strengthen his legitimacy. The choice of the genealogy was not random: since it carried a clear political message, it was of utmost importance with whom the Emperor in power would be associated and whose historical deeds or legendary personality would serve as a moral model. Also important is the fact that the search of a "good family" was as a rule triggered by the need to confirm one's own virtue. Thus, genealogies often reflect a certain system of values, usually emphasizing morality, courage in war, care for the welfare of the country, piety, etc. The choice of the archetype depended, of course, on the needs of the ruler for whom the genealogy was created. All this allows us to consider legendary genealogies as an expression of the imperial ideology. Notwithstanding their chronological diversity, the Byzantine imperial genealogies display very similar characteristics, i.e. they contain stereotypical elements, many of which had been established already in the first centuries of the Eastern Empire. In the early Byzantine period, when

  5. Iatromathematica (medical astrology) in late antiquity and the Byzantine period.

    Science.gov (United States)

    Papathanassiou, M

    1999-01-01

    Byzantium inherited the rich astrological tradition of Late Antiquity, especially that of Alexandria, where even in the 6th century A.D., astrology was taught in philosophical schools. The great number of Byzantine astrological MSS, which preserve works of famous authors and many anonymous treatises, shows the survival and continuity of astrology in Byzantium. Through medical astrology physicians can better understand the temperament of an individual man and find out about his bodily constitution and psychic faculties, his inclination to chronic and acute diseases, the possibilities of curable or incurable cases, and finally the periods of major danger for his health. They can conjecture about the evolution of a disease, choose a favorable time for an operation, or initiate a cure.

  6. HANS GEORG BECKAND BYZANTINE THEOLOGY. ON THE OCCASION OF THE 100TH ANNIVERSARY OF HIS BIRTH

    Directory of Open Access Journals (Sweden)

    PETER SCHREINER

    2011-08-01

    Full Text Available The life of Hans Georg Beck may be divided into two parts. Until 1944, he was known by his religious name of Hildebrand as a Benedictine monk and priest and was the product of a thorough theological education. He then abandoned both the priesthood and the Church and began a university career devoted to Byzantine studies, eventually emerging as one of the most outstanding authorities in his fi eld. In spite of this all, theology remained for him a principle focus of his interest and it guided his entire academic work, even when it was really not expected to play a role. Beck obviously did not want to be theologian but he did much to convince others that “Byzantine studies without any knowledge of Byzantine theology and the Church in the Byzantine Empire is quite a hopeless aff air, however hard one may try”

  7. Asynchronous design of Networks-on-Chip

    DEFF Research Database (Denmark)

    Sparsø, Jens

    2007-01-01

    -synchronous, mesochronous, globally-asynchronous locally-synchronous and fully asynchronous), discusses the circuitry needed to implement these timing methodologies, and provides some implementation details for a couple of asynchronous NoCs designed at the Technical University of Denmark (DTU). The paper is written...... to support an invited talk at the NORCHIP’2007 conference....

  8. Les aspects matériels de la taxis byzantine The material aspects of the Byzantine taxis

    Directory of Open Access Journals (Sweden)

    Marie‑France Auzépy

    2008-06-01

    Full Text Available La taxis grecque – correspondant exact de l’ordo latin – est un aspect essentiel de la civilisation byzantine : elle organise cette société de manière à ce que celle-ci soit un reflet aussi exact que possible de la société céleste, décrite en particulier par Denys l’Aréopagite. La taxis est donc à la fois précise et contraignante et nous a été transmise dans des livres décrivant le protocole : le De Cerimoniis au Xe siècle, le Traité du pseudo-Kodinos au XIVe siècle. Au cours de cérémonies où tous les aspects matériels – l’habit, la couronne, le trône, les acclamations à la gloire de l’empereur, l’orgue qui les accompagne, les gestes accomplis par l’empereur comme par ceux qui l’entourent – ont un sens, l’Empire byzantin affirme ainsi son équilibre et sa qualité de peuple élu. Jusqu’en 1204, les autres nations ont jalousé la qualité que s’était octroyée l’Empire romain d’Orient : celle d’image de la cour céleste, qui est figurée dans le cérémonial. Cette jalousie a pris d’autres formes après 1453, et l’on s’intéressera aux souverains européens qui, tel Louis XIV, ont voulu faire figure d’héritiers de l’empire défunt et relever ses cérémonies.The Greek taxis(order– the exact equivalent of the Latin ordo – is an essential aspect of Byzantine civilization: it organized society in such a way that it would reflect the celestial society as closely as possible, as has been described by Dionysius the Areopagite. The taxis is therefore both precise and restrictive and has been passed down to us through writings describing the protocol: the De Cerimoniis in the tenth century and the treatise of Pseudo-Kodinos in the fourteenth century. Through ceremonies in which all the material aspects have a meaning – the dress, the crown, the throne, the proclaiming of the glory of the emperor, the accompanying organ, the gestures of the emperor and of those around

  9. Computational Aspects of Asynchronous CA

    OpenAIRE

    Chandesris, Jérôme; Dennunzio, Alberto; Formenti, Enrico; Manzoni, Luca

    2011-01-01

    This work studies some aspects of the computational power of fully asynchronous cellular automata (ACA). We deal with some notions of simulation between ACA and Turing Machines. In particular, we characterize the updating sequences specifying which are "universal", i.e., allowing a (specific family of) ACA to simulate any TM on any input. We also consider the computational cost of such simulations.

  10. Asynchronous control for networked systems

    CERN Document Server

    Rubio, Francisco; Bencomo, Sebastián

    2015-01-01

    This book sheds light on networked control systems; it describes different techniques for asynchronous control, moving away from the periodic actions of classical control, replacing them with state-based decisions and reducing the frequency with which communication between subsystems is required. The text focuses specially on event-based control. Split into two parts, Asynchronous Control for Networked Systems begins by addressing the problems of single-loop networked control systems, laying out various solutions which include two alternative model-based control schemes (anticipatory and predictive) and the use of H2/H∞ robust control to deal with network delays and packet losses. Results on self-triggering and send-on-delta sampling are presented to reduce the need for feedback in the loop. In Part II, the authors present solutions for distributed estimation and control. They deal first with reliable networks and then extend their results to scenarios in which delays and packet losses may occur. The novel ...

  11. [Hospitals and other philanthropic foundations in early Byzantine period].

    Science.gov (United States)

    Yildirim, R Vedat; Ataç, Adnan

    Early Byzantine Period includes between A.D. 330 when Constantinople was established and A.D. 518 when Justinus I became emperor. In this time period, a lot of philanthropic foundations such as hospitals, hospices, orphanages, rest homes and soup kitchens are established. Many of patriarchs and religious men opened them. In some of them, it refers to there was patients' care. The oldest hospital in Constantinople was established by Hasios Marcianos, and was next to Saint Irene Church. In addition to this Empress Flacilla wife of Theodosius the Great made hospitals restored and visited patients regularly. Hospitals were not limited in the center of Empire. Hospitals and other philanthropic foundations were established in Antiochia, Alexandria, Nikea, Adrianopolis, Castoria and Jerusalem. The concept of the modern hospital (the actual care, 'hospitality' and treatment of visitors) for the civilian masses in Europe didn't come to fruition until post Constantine and the rise of Christianity. While these early Christian hospitals were grossly over their heads regarding medical capability (they essentially served as last stops for the dying or quarantine centers), the concept of providing care to the public was the actual intent. In this regard, the first civilian hospitals were developed.

  12. The Serbian state in the work of Byzantine historian Doucas

    Directory of Open Access Journals (Sweden)

    Nikolić Maja

    2007-01-01

    Full Text Available While the first two chapters of Doucas's historical work present a meagre outline of world history - a sketch which becomes a little more detailed from 1261 on, when the narration reaches the history of the Turks and their conquests in Asia Minor - the third chapter deals with the well-known battle of Kosovo, which took place in 1389. From that point on, the Byzantine historian gives much important information on Serbia, as well as on the Ottoman advances in the Balkans, and thus embarks upon his central theme - the rise of the Turks and the decline of Byzantium. Doucas considers the battle of Kosovo a key event in the subjugation of the Balkan peoples by the Turks, and he shows that after the battle of Kosovo the Serbs were the first to suffer that fate. At the beginning, Doucas says that after the death of Orhan, the ruler (o archgos of the Turks, his son and successor Murad conquered the Thracian towns, Adrianople and the whole Thessaly, so that he mastered almost all the lands of the Byzantines, and finally reached the Triballi (Triballous. He devastated many of their towns and villages sending the enslaved population beyond Chersonesus, until Lazar, son of King Stefan of Serbia (Serbias, who ruled (kraleyōn in Serbia at that time decided to oppose him with all the might he could muster. The Serbs were often called Triballi by Byzantine authors. For the fourteenth century writers Pachymeres, Gregoras, Metochites and Kantakouzenos the Serbs were Triballi. However, Pachymeres and Gregoras refer to the rulers of the Triballi as the rulers of Serbia. Fifteenth century writers, primarily Chalcondyles and Critobulos, use only that name. It seems, nevertheless, that Doucas makes a distinction between the Triballi and the Serbs. As it is known, the conquest of the Serbian lands by the Turks began after the battle on the river Marica in 1371. By 1387. the Turks had mastered Serres(1388 Bitola and Štip (1385, Sofia (1385, Niš (1386 and several

  13. Developing asynchronous online interprofessional education.

    Science.gov (United States)

    Sanborn, Heidi

    2016-09-01

    For many health programmes, developing interprofessional education (IPE) has been a challenge. Evidence on the best method for design and implementation of IPE has been slow to emerge, with little research on how to best incorporate IPE in the asynchronous online learning environment. This leaves online programmes with no clear guidance when embarking upon an initiative to integrate IPE into the curriculum. One tool that can be effective at guiding the incorporation of IPE across all learning platforms is the Interprofessional Education Collaborative (IPEC) competencies. A project was designed to integrate the nationally defined IPEC competencies throughout an asynchronous, online baccalaureate nursing completion programme. A programme-wide review led to targeted revision of course and unit-level objectives, learning experiences, and assessments based on the IPEC framework. As a result of this effort, the programme curriculum now provides interprofessional learning activities across all courses. This report provides a method for using the IPEC competencies to incorporate IPE within various asynchronous learning assessments, assuring students learn about, with, and from other professions.

  14. Abandonment of terminally ill patients in the Byzantine era. An ancient tradition?

    Science.gov (United States)

    Lascaratos, J; Poulakou-Rebelakou, E; Marketos, S

    1999-06-01

    Our research on the texts of the Byzantine historians and chroniclers revealed an apparently curious phenomenon, namely, the abandonment of terminally ill emperors by their physicians when the latter realised that they could not offer any further treatment. This attitude tallies with the mentality of the ancient Greek physicians, who even in Hippocratic times thought the treatment and care of the terminally ill to be a challenge to nature and hubris to the gods. Nevertheless, it is a very curious attitude in the light of the concepts of the Christian Byzantine physicians who, according to the doctrines of the Christian religion, should have been imbued with the spirit of philanthropy and love for their fellowmen. The meticulous analysis of three examples of abandonment of Byzantine emperors, and especially that of Alexius I Comnenus, by their physicians reveals that this custom, following ancient pagan ethics, in those times took on a ritualised form without any significant or real content.

  15. Classicisation or representation? Mimesis in Byzantine pictorial arts as a derivative of style

    Directory of Open Access Journals (Sweden)

    Grotowski Piotr Ł.

    2013-01-01

    Full Text Available The idea of mimesis in art theory has been neglected by Byzantine scholars. Reasons for this may lie in the fact that the understanding of the term in Byzantium was very complex and that it changed over time. In the Early Byzantine period and the so-called Macedonian Renaissance, a tendency to use tonal modelling, which was inherited from ancient Greco-Roman art, can still be observed. Starting in the late tenth century they give way to a more linear style. Simultaneously, a change in the understanding of mimesis in theological writings can also be observed. The aim of this paper is to introduce the problem of a mimetic approach in visual arts as a phenomenon in Byzantine culture.

  16. EPOS for Coordination of Asynchronous Sensor Webs

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop, integrate, and deploy software-based tools to coordinate asynchronous, distributed missions and optimize observation planning spanning simultaneous...

  17. Menander Protector. History: On the Turkish Embassy to the Persians and Byzantines in 568 A.C. (translation and commentary

    Directory of Open Access Journals (Sweden)

    Olesia Zhdanovich

    2014-01-01

    Full Text Available The article presents annotated translation from ancient Greek into Russian of the book of Menander Protector. In this text Menander Protector describes first the Turkish embassy to the Persians, and then to the Byzantines. The Great Turkic Khanate was the first Steppe empire in history. The relationship between Turkic Khanate and Byzantine Empire began from the middle of 6th century, parallel to the establishment of the Steppe empire. The purpose of the first Turkish embassies to the Byzantines was conclusion of an alliance against the Persians. Since the end of the 4th century Sassanid Empire and Byzantium challenged each other for the territory of Armenia, part of Georgia and the lands of southern Arabia. At the same time the Byzantine Empire’s relationship with the barbarians in the West were problematic. In addition it was going through a difficult economical and political period inside Empire. Another side of antagonism between Persian and Byzantine Empire was silk trade. Persian Empire had a monopoly on it. Byzantine Empire was in dire need of silk and was forced to buy it overpriced. Turks had silk and proposed it to Byzantines at a bargain price. This article contains the view of the problems of relationship between European Byzantine and Asian Nomadic civilizations in terms of Byzantine author. Previously the Russian translation of Menander Protector was done in the middle of the 19th century by Spiridon Destunis. However, his translation was fragmented and unprofessional containing many imprecisions. Our versions have many rectifications and important comments to some elements of Nomadic and Byzantine style of life. This research should help to understand some part of life, customs and diplomacy of ancient Turks.

  18. Avoiding "culture rejection" in healthcare mergers and acquisitions: how New Heights Community Health Centres and York Community Services minimized the culture risk when forming Unison Health and Community Services.

    Science.gov (United States)

    Chan, Jeff

    2013-01-01

    Among the requirements for a successful merger or acquisition are strategic rationale, rigorous due diligence, the right price and revenue and cost synergies. However, bridging the culture gap between organizations is frequently overlooked. The leaders of New Heights Community Health Centres and York Community Services explicitly considered culture in their merger to form Unison Health and Community Services, and they used employee engagement surveys to assess culture in their merger planning and post-merger integration. How Unison Health leaders avoided the risk of culture rejection to achieve a successful merger, and the lessons learned from their experience, is the focus of this article.

  19. The schemata of the stars Byzantine astronomy from 1300 A.D.

    CERN Document Server

    Paschos, E A

    1998-01-01

    Most of the knowledge of ancient Greek science survived through Byzantine codices. A short Byzantine article, extant in three manuscripts, contains advanced astronomical ideas and pre-Copernican diagrams; it presents improvements on ancient and medieval astronomy. This important book includes the edited version and translation of the text and analyzes its content. It surveys the development of astronomical models from Ptolemy to Byzantium and compares them mathematically with several works of Arab astronomers, as well as with the heliocentric system of Copernicus and Newton.

  20. Experiences in adapting post-byzantine chant into foreign languages: Research and praxis

    Directory of Open Access Journals (Sweden)

    Olkinuora Jaakko

    2011-01-01

    Full Text Available This article presents the current state of the research and practical methodology of the adaptation of Byzantine melodies written in the “New Method” into foreign languages, with Romanian, English and Finnish serving as examples. The adaptation of independent, “fixed” melodies as well as metrical liturgical texts (prosomoia and canons are examined. The challenges emerging in adapting Byzantine chant into Finnish are also discussed. The author also suggests some future subjects for research, which include the synthesis of examining arrangements in both “Old” and “New Method”.

  1. Short Notes on the Prosopography of the Byzantine Theme of Koloneia (Part I

    Directory of Open Access Journals (Sweden)

    Pantelis CHARALAMPAKIS

    2016-12-01

    Full Text Available This study, the first part of two, presents short notes and comments on the officials of the Byzantine theme of Koloneia. Two Byzantine lead seals are published here for the first time. One belongs to Leon, krites of Koloneia, the other to Michael, anagrapheus and krites of Koloneia and Sebasteia. The lost inscription of Ioannes, droungarios of Koloneia is also presented here, together with a previously unnoticed reference to another droungarios in the Passio of the 42 Martyrs of Amorion. The lists of the kritai and strategoi of Koloneia are completed on the basis of recently discovered and published, but also unpublished evidence.

  2. Byzantine-fault tolerant self-stabilizing protocol for distributed clock synchronization systems

    Science.gov (United States)

    Malekpour, Mahyar R. (Inventor)

    2010-01-01

    A rapid Byzantine self-stabilizing clock synchronization protocol that self-stabilizes from any state, tolerates bursts of transient failures, and deterministically converges within a linear convergence time with respect to the self-stabilization period. Upon self-stabilization, all good clocks proceed synchronously. The Byzantine self-stabilizing clock synchronization protocol does not rely on any assumptions about the initial state of the clocks. Furthermore, there is neither a central clock nor an externally generated pulse system. The protocol converges deterministically, is scalable, and self-stabilizes in a short amount of time. The convergence time is linear with respect to the self-stabilization period.

  3. Asynchronous communication in real space process algebra

    NARCIS (Netherlands)

    Baeten, J.C.M.; Bergstra, J.A.

    1991-01-01

    A version of classical real space process algebra is given in which messages travel with constant speed through a three-dimensional medium. It follows that communication is asynchronous and has a broadcasting character. A state operator is used to describe asynchronous message transfer and a

  4. Asynchronous communication in real space process algebra

    NARCIS (Netherlands)

    Bergstra, J.A.; Baeten, J.C.M.

    1992-01-01

    A version of classical real space process algebra is given in which messages travel with constant speed through a three-dimensional medium. It follows that communication is asynchronous and has a broadcasting character. A state operator is used to describe asynchronous message transfer and a

  5. Asynchronous zero-forcing adaptive equalization

    NARCIS (Netherlands)

    Bergmans, J.W.M.; Pozidis, H.; Lin, M.Y.

    2005-01-01

    Digital data receivers often operate at a fixed sampling rate 1/Ts that is asynchronous to the baud rate 1/T. A digital equalizer that processes the incoming signal will also be asynchronous, and its adaptation is commonly based on extensions of the LMS algorithm. In this paper, we develop and

  6. A Byzantine chant collection from Sicily: a collaboration between Copenhagen and Piana degli Albanesi (Palermo)

    DEFF Research Database (Denmark)

    Sanfratello, Giuseppe

    2016-01-01

    The aim of this paper is to give an account of the collaboration between a collector of the Byzantine chant tradition of Piana degli Albanesi (Palermo) in Sicily, namely fr. Bartolomeo Di Salvo, and the editorial board of the Monumenta Musicae Byzantinae, i.e. an institution under the aegis...

  7. The Byzantine Office  for the Translation of Saint Nicholas to Bari (AD 1087)

    DEFF Research Database (Denmark)

    Troelsgård, Christian

    2007-01-01

    The contribution includes a historical introduction, transcriptions of selections of the music and tranlations of the texts for the Byzantine office composed on the occasion of the translation of the relics of St Nicholas to Bari in AD 1087. Texts and music is interpreted in relation...

  8. Western European influences on Post-Byzantine panel painting technique through binding media identification

    International Nuclear Information System (INIS)

    Kouloumpi, E.; Lawson, G.; Pavlidis, B.

    2006-01-01

    Post-Byzantine is called the period after the invasion of the Ottomans in Constantinople, the capital of Byzantium in 1453, which lasted until the establishment of the first Greek State in 1836. The Post - Byzantine era is one of the most important artistic periods of the Neo-Hellenic Pictorial Art, since, through cultural exchanges with Western Europe, it sets the fundaments for oil painting. The thematology changes from religious to civil, the technique changes from egg yolk to egg-oil emulsion in order to end up to pure oil painting and finally, it opens 'the gates' for the modern artistic movements of the world. The current research is focused on the study of the effects of western influences on the technique and pictorial characteristics of the post-Byzantine icons by the study of any changes in the pigment's binding media through scientific analyses (SEM-EDX, micro-FTIR and GC), as well as of any changes in the painting style of the icons through comparison with both Byzantine and western painting standards. Research never ends and the results of this work give rise to further analysis, in order to throw some light to this transitional period of art. (Author)

  9. Gynaecomastia and scrotal rhacosis: two aesthetic surgical operations for men in Byzantine times.

    Science.gov (United States)

    Papadakis, Marios; Manios, Andreas; de Bree, Eelco; Trompoukis, Constantinos; Tsiftsis, Dimitris D

    2010-08-01

    Nowadays, as in the past, much attention is paid to aesthetic operations in women, while only infrequently have such operations been referred to in males. Generally, male aesthetic surgery was introduced to surgical practise during the 19th century. In this study, we analysed the practise of such operations in Byzantine times and in other ancient cultures with surgical knowledge, i.e. ancient India and China The sixth book of Paul of Aegina's "Epitome of Medicine" was studied for description of aesthetic operations in males in the Byzantine period, since this book is completely devoted to surgery and is generally considered to be the most important reference for surgery in Byzantine times. The original text and its excellent translation by Francis Adams were used. References concerning aesthetic operations for males were identified. Accordingly, historical work and reviews on plastic surgery in ancient India and China were studied. Mainly, two aesthetic surgical procedures for males in the Byzantine period were identified. These two procedures comprise gynaecomastia and rhacosis (scrotal relaxation). Two different techniques were reported for the surgical management of gynaecomastia, through sub-mammary or supra-mammary access. Two procedures were noted for rhacosis, for which Paul of Aegina reproduced the respective chapters from Leonides' and Antyllus' works. Evidence supporting male aesthetic surgery in ancient India and China or elsewhere was not found. Despite the dubious aesthetic result, the existence of different aesthetic surgical techniques in males substantiate the advanced level of surgery achieved by physicians in the Byzantine period. Copyright 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. Burst-Mode Asynchronous Controllers on FPGA

    Directory of Open Access Journals (Sweden)

    Duarte L. Oliveira

    2008-01-01

    Full Text Available FPGAs have been mainly used to design synchronous circuits. Asynchronous design on FPGAs is difficult because the resulting circuit may suffer from hazard problems. We propose a method that implements a popular class of asynchronous circuits, known as burst mode, on FPGAs based on look-up table architectures. We present two conditions that, if satisfied, guarantee essential hazard-free implementation on any LUT-based FPGA. By doing that, besides all the intrinsic advantages of asynchronous over synchronous circuits, they also take advantage of the shorter design time and lower cost associated with FPGA designs.

  11. Asynchronous Parallelization of a CFD Solver

    OpenAIRE

    Abdi, Daniel S.; Bitsuamlak, Girma T.

    2015-01-01

    The article of record as published may be found at http://dx.doi.org/10.1155/2015/295393 A Navier-Stokes equations solver is parallelized to run on a cluster of computers using the domain decomposition method. Two approaches of communication and computation are investigated, namely, synchronous and asynchronous methods. Asynchronous communication between subdomains is not commonly used inCFDcodes; however, it has a potential to alleviate scaling bottlenecks incurred due to process...

  12. Asynchronous networks: modularization of dynamics theorem

    Science.gov (United States)

    Bick, Christian; Field, Michael

    2017-02-01

    Building on the first part of this paper, we develop the theory of functional asynchronous networks. We show that a large class of functional asynchronous networks can be (uniquely) represented as feedforward networks connecting events or dynamical modules. For these networks we can give a complete description of the network function in terms of the function of the events comprising the network: the modularization of dynamics theorem. We give examples to illustrate the main results.

  13. Asynchronous communication in real space process algebra

    OpenAIRE

    Baeten, JCM Jos; Bergstra, JA Jan

    1990-01-01

    A version of classical real space process algebra is given in which messages travel with constant speed through a three-dimensional medium. It follows that communication is asynchronous and has a broadcasting character. A state operator is used to describe asynchronous message transfer and a priority mechanism allows to express the broadcasting mechanism. As an application, a protocol is specified in which the receiver moves with respect to the sender.

  14. Synchronous and Asynchronous ATM Multiplexor Properties Comparsion

    OpenAIRE

    Jan Zabka

    2006-01-01

    The article is aimed to ATM multiplexor computer model utilisation. Based on simulation runs we try to review aspects of use a synchronous and asynchronous ATM multiplexors. ATM multiplexor is the input queuing model with three inputs. Synchronous multiplexor works without an input priority. Multiplexor inputs are served periodically. Asynchronous multiplexor model supports several queuing and priority mechanisms. CLR and CTD are basic performance parameters. Input cell flows are genera...

  15. Securing ad hoc wireless sensor networks under Byzantine attacks by implementing non-cryptographic method

    Directory of Open Access Journals (Sweden)

    Shabir Ahmad Sofi

    2017-05-01

    Full Text Available Ad Hoc wireless sensor network (WSN is a collection of nodes that do not need to rely on predefined infrastructure to keep the network connected. The level of security and performance are always somehow related to each other, therefore due to limited resources in WSN, cryptographic methods for securing the network against attacks is not feasible. Byzantine attacks disrupt the communication between nodes in the network without regard to its own resource consumption. This paper discusses the performance of cluster based WSN comparing LEACH with Advanced node based clusters under byzantine attacks. This paper also proposes an algorithm for detection and isolation of the compromised nodes to mitigate the attacks by non-cryptographic means. The throughput increases after using the algorithm for isolation of the malicious nodes, 33% in case of Gray Hole attack and 62% in case of Black Hole attack.

  16. Early byzantine lamellar armour from Carthago Spartaria (Cartagena, Spain

    Directory of Open Access Journals (Sweden)

    Vizcaíno Sánchez, Jaime

    2008-12-01

    Full Text Available This article presents an Early Byzantine lamellar armour, retrieved in the excavations at the quarter built over the Roman Theatre of Cartagena. The armour has close parallels with contemporary known material from the central and eastern Mediterranean or other sites, and it is an important find which increases the body of archeological evidence about Byzantine presence in Spania.

    Este artículo presenta una coraza laminar protobizantina hallada en las excavaciones del barrio construido sobre el teatro romano de Cartagena. La coraza tiene estrechos paralelos con materiales contemporáneos del Mediterráneo Central y Oriental u otros lugares, y es un importante hallazgo que incrementa la nómina de evidencias arqueológicas acerca de la presencia bizantina en Spania.

  17. The Catholic of Stilo. Survey and analysis of a Byzantine monument.

    Directory of Open Access Journals (Sweden)

    Marinella Arena

    2015-07-01

    Full Text Available The Cattolica di Stilo, one of the greatest monu-ments of Calabria, is the most important example of the secular Byzantine influence on this region. The Greek cross inscribed in a square, with its five domes, denounces his connection with an archi-tectural style of oriental origin. Although built in a remote province of the Empire, the Catho-lic is not the expression of a poor art; all poetics typical of Byzantine architecture are manifested with originality. The first paragraph, written by Domenico Mediati, analyzes the geometries and correlates with contemporary buildings (X-XI cen-tury and similar in size and shape. The second paragraph, written by Marinella Arena, highlights the differences of construction compared to the theoretical form. The third paragraph, written by Daniele Colistra, reviews some representations of the monument trying to identify those who most influenced the collective imagination.

  18. Sacred byzantine music and its influence on old East Slavic Orthodox music

    Directory of Open Access Journals (Sweden)

    Włodzimierz Wołosiuk

    2014-11-01

    Full Text Available Sacred Byzantine music originates from three sources: “the liturgy of heaven”, synagogue music as well as old Greek theory of music and lays at the bottom of the East Slavs liturgical chant. The tonal base of the Byzantine music formed tetrachords. From them the so called Diatonic mode took shape. It was the easiest and the most popular sound arrangement steming from Greek music. The Cristian Church considered it to be in accordance with its Spirit and needs. From the tetrachords mentioned above other tones were created, namely Doric tones, Lydian, Phrygian and Mixolydian and, together withall their derivatives they gave beginning to the Oktoechos tradition. Byzantine music was flourishing in monasteries and in town areas andmany different forms were elaborated on like troparions, kontakions, stichiry, canons, etc. If one speaks about composers then certainly some names cannot be omitted. These are: St. Anatolius (Patriarchof Constantinople, St. Andrew of Crete, St. Romanos the Melodist,St. Sophronius of Jerusalem and, above all, St. John of Damascus who collected and systematized the liturgical chants creating mentioned Oktoechos. The acceptance of the Greek form of Christianity by Rus’ caused a cultivation of the sacred Greek vocal art on its territory which manifested in a form of so called Znamenny chant. This type of chant was at first similar to the Greek model but later on it moved away from it. Musical notation of the Old East Slavic singing was based on neumes which names in Old East Slavic have changed a little and only few survived. Furthermore, liturgical note books together with their genre and music content have been taken over from Byzantium. Especially visible in the Old East Slavic monody, Byzantine patterns were pervading also the later polyphony which proves they were always current. Moreover, this allows to claim that Rus’ became the real successor of the Greek Orthodox traditions in new circumstances of sacral

  19. Bibliography of the Latest Russian Literature (2010-2015 on the Problems of Byzantine Military Organization

    Directory of Open Access Journals (Sweden)

    Pavel Ivanovich Lysikov

    2015-10-01

    Full Text Available The present outline deals with the bibliographical review of Russian literature on the history of Byzantium published during the period from 2010 to 2015 and concerned with the problems of Byzantine military organization. All of the mentioned scientific works are divided into four parts for ease of data presentation: monographs, translations of sources (both of these two divisions are accompanied with the brief abstracts which reveal contents of the works indicated here, articles and theses.

  20. The Byzantine wall-paintings in the church of Saint Theodore at Platanos, Kynouria (Arcadia

    Directory of Open Access Journals (Sweden)

    Agrevi Maria

    2015-01-01

    Full Text Available The church of St Theodore (also known as "Sts Theodoroi" at Platanos, Kynouria, is a single-nave building of small dimensions. The interior surfaces of its walls preserve their Byzantine paintings, which are partially visible under the coat of plaster that covers most of them. The paintings exhibit affinity with wall-paintings of churches in the Peloponnese (neighbouring Laconia included, and can be dated to the last quarter of the thirteenth century.

  1. RITMO Y ESPACIO EN LA PINTURA BIZANTINA Rhythm and space in byzantine painting

    Directory of Open Access Journals (Sweden)

    Federico José Xamist

    2011-10-01

    Full Text Available Durante el siglo XX se lleva a cabo una revalorización de la pintura del medioevo heleno, ignorada durante todo el clasicismo europeo. AAnte la constatación de que el espacio representado en la pintura bizantina no reproduce el espacio natural se llega a la conclusión de que las operaciones pictóricas aplicadas por los pintores bizantinos tienen como objeto simbolizar un espacio sobrenatural. En las siguientes líneas intentaremos abrir la problemática del espacio en la pintura bizantina a una interpretación plástica, es decir, intentaremos presentar una lectura de las operaciones pictóricas en cuanto tales siguiendo los planteamientos de Georgos Kordis, profesor de la cátedra Eikonografia de la Facultad de Teología de la Universidad de Atenas y destacado pintor griego. Nuestro objetivo es plantear algunas directrices para introducirnos en la problemática pictórica de la representación del espacio en la pintura bizantina.During the twentieth century is carried out a revaluation of the Hellenic medieval painting, ignored during the European classicism. Given the finding that the space represented in Byzantine painting does not reproduce the natural space leads to the conclusion that painting operations implemented by the Byzantine painters are intended to symbolize a supernatural space. The following lines try to open the question of space in painting plastic Byzantine interpretation, ie to try to present a reading of the painting operations as such, following the approach of Georges Kordis, chair professor of the Faculty Eikonografia Theology of the University of Athens and prominent Greek painter. Our goal is to propose some guidelines for introducing us to the problem of pictorial representation of space in the Byzantine painting.

  2. A Byzantine resilient fault tolerant computer for nuclear power plant applications

    International Nuclear Information System (INIS)

    Lala, J.H.

    1986-01-01

    A quadruply redundant synchronous fault tolerant processor, capable of tolerating Byzantine faults, is now under fabrication at the C.S. Draper Laboratory to be used initially as a trip monitor for the Experimental Breeder Reactor EBR-II operated by the Argonne National Laboratory in Idaho Falls, Idaho. This paper describes the hardware architecture of this processor and discusses certain issues unique to quadruply redundant computers

  3. A Case Study in Byzantine Dragon-Slaying: Digenes and the Serpent

    Directory of Open Access Journals (Sweden)

    Christopher Livanos

    2011-03-01

    Full Text Available The Byzantine epic Digenes Akrites has similarities with ancient and medieval Iranian traditions that, in consideration of the epic’s Eastern settings, suggest Iranian influences. Digenes resembles dragon-slaying heroes of other Indo-European traditions. He also resembles the Irish hero Cú Chulainn in that he is not psychologically fit to live in the midst of the community that depends on his protection. Freudian readings of Digenes’ encounters with the dragon and the Amazon Maximou are proposed.

  4. Cucurbits depicted in Byzantine mosaics from Israel, 350–600 ce

    Science.gov (United States)

    Avital, Anat; Paris, Harry S.

    2014-01-01

    Background and Aims Thousands of floor mosaics were produced in lands across the Roman and Byzantine empires. Some mosaics contain depictions of agricultural produce, potentially providing useful information concerning the contemporary presence and popularity of crop plants in a particular geographical region. Hundreds of floor mosaics produced in Israel during the Byzantine period have survived. The objective of the present work was to search these mosaics for Cucurbitaceae in order to obtain a more complete picture of cucurbit crop history in the eastern Mediterranean region. Results and Conclusions Twenty-three mosaics dating from 350–600 ce were found that had images positively identifiable as cucurbits. The morphological diversity of the cucurbit fruits in the mosaics of Israel is greater than that appearing in mosaics from any other Roman or Byzantine provincial area. The depicted fruits vary in shape from oblate to extremely long, and some are furrowed, others are striped and others lack definite markings. The cucurbit taxa depicted in the mosaics are Cucumis melo (melon), Citrullus lanatus (watermelon), Luffa aegyptiaca (sponge gourd) and Lagenaria siceraria (bottle gourd). Cucumis melo is the most frequently found taxon in the mosaics and is represented by round dessert melons and long snake melons. Fruits of at least two cultivars of snake melons and of watermelons are represented. To our knowledge, images of sponge gourds have not been found in Roman and Byzantine mosaics elsewhere. Indeed, the mosaics of Israel contain what are probably the oldest depictions of Luffa aegyptiaca in Mediterranean lands. Sponge gourds are depicted often, in 11 of the mosaics at eight localities, and the images include both mature fruits, which are useful for cleaning and washing, and immature fruits, which are edible. Only one mosaic has images positively identifiable as of bottle gourds, and these were round–pyriform and probably used as vessels. PMID:24948671

  5. Cucurbits depicted in Byzantine mosaics from Israel, 350-600 ce.

    Science.gov (United States)

    Avital, Anat; Paris, Harry S

    2014-08-01

    Thousands of floor mosaics were produced in lands across the Roman and Byzantine empires. Some mosaics contain depictions of agricultural produce, potentially providing useful information concerning the contemporary presence and popularity of crop plants in a particular geographical region. Hundreds of floor mosaics produced in Israel during the Byzantine period have survived. The objective of the present work was to search these mosaics for Cucurbitaceae in order to obtain a more complete picture of cucurbit crop history in the eastern Mediterranean region. Twenty-three mosaics dating from 350-600 ce were found that had images positively identifiable as cucurbits. The morphological diversity of the cucurbit fruits in the mosaics of Israel is greater than that appearing in mosaics from any other Roman or Byzantine provincial area. The depicted fruits vary in shape from oblate to extremely long, and some are furrowed, others are striped and others lack definite markings. The cucurbit taxa depicted in the mosaics are Cucumis melo (melon), Citrullus lanatus (watermelon), Luffa aegyptiaca (sponge gourd) and Lagenaria siceraria (bottle gourd). Cucumis melo is the most frequently found taxon in the mosaics and is represented by round dessert melons and long snake melons. Fruits of at least two cultivars of snake melons and of watermelons are represented. To our knowledge, images of sponge gourds have not been found in Roman and Byzantine mosaics elsewhere. Indeed, the mosaics of Israel contain what are probably the oldest depictions of Luffa aegyptiaca in Mediterranean lands. Sponge gourds are depicted often, in 11 of the mosaics at eight localities, and the images include both mature fruits, which are useful for cleaning and washing, and immature fruits, which are edible. Only one mosaic has images positively identifiable as of bottle gourds, and these were round-pyriform and probably used as vessels. © The Author 2014. Published by Oxford University Press on behalf of

  6. Pronoia in the Military Organization of the Byzantine Empire at Early Palaeologian Period. Part 1

    Directory of Open Access Journals (Sweden)

    Vladimir Alekseevich Zolotovskiy

    2015-10-01

    Full Text Available In the present study the author disclosed the role of pronoia in the military organization of the Byzantine Empire at early Palaeologian period. The concrete cases of the award allow recognizing the proniarety as the Byzantine military institution dealing exclusively with the military leadership. The grant of pronoia was a replacement for traditional rewards of military commanders of noble birth. However, in some cases it was identified that compulsory military service was a function of power which was granted to the proniares in addition to the tax quota. Holders of pronoia were not only the Romans military commanders but also the mercenaries. Such awards could reduce the costs of imperial treasury for direct payments. In the case of proniares-Byzantines, depending on posotis, we can talk about the conferring upon pronoia the representatives of various levels of the military leadership. The pronoias granted as a reward or the compensation for losses incurred as a result of the performance of official engagements, could be transferred to the commanders of low levels which were recruited from among stratiotes (obviously, dekarhes.

  7. Cosmological Symbolism in the Decorative Cycles of Mid-Byzantine Churches

    Science.gov (United States)

    Shrimplin, V.

    2016-01-01

    Fundamental links between theology and astronomy are widely reflected in the Judaeo-Christian tradition. From Genesis to Revelation, the great mysteries of the beginning and end of the universe, and the cycles of birth and death of individuals, are explained in terms of cosmological concepts. These are in turn reflected in art and architecture and nowhere more broadly, perhaps, than in Byzantine architecture and decoration. Following the Iconoclast prohibition of images in the Orthodox church (726-843), the mid-Byzantine period (843-1204) witnessed the primacy of the representation of the heavens in art and architecture. Reinforced by such writers as Cosmas Indicopleustes and Pseudo-Dionysius the Areopagite, not only were individual images reflective of the heavens (nativity and rebirth at the winter solstice, and rebirth/resurrection at the spring equinox) but entire cycles of church decoration were devised so as to reflect the ordering of God's universe. The architecture and decoration of the quintessential mid-Byzantine cross-in-square church was symbolic itself of the universe, as at Hosios Loukas and Daphni (eleventh century). From the location of the Pantocrator in the central celestial dome, to the descending zones of squinches and pendentives and the lowest earthly zones, decorative schemes are used to reflect the view of the sky/heavens above earth. Hierarchical systems depicting the life of Christ and ascending/descending ranks of saints and angels were rigorously adhered to, with Mary in the apse as bridge between heaven and earth.

  8. Pronoia in the Military Organization of the Byzantine Empire at Early Palaeologian Period (Part 2

    Directory of Open Access Journals (Sweden)

    Zolotovskiy Vladimir A.

    2016-06-01

    Full Text Available In the present study the author disclosed the role of pronoia in the military organization of the Byzantine Empire at early Palaeologian period. The concrete cases of the award allow recognizing the proniarety as the Byzantine military institution dealing exclusively with the military leadership. The grant of pronoia was a replacement for traditional rewards of military commanders of noble origin. However, in some cases it was identified that compulsory military service was a function of power which was granted to the proniares in addition to the tax quota. Holders of pronoia were not only the Romans military commanders but also the mercenaries. Such awards could reduce the costs of imperial treasury for direct payments. In the case of proniares-Byzantines, depending on posotis, we can talk about the conferring upon pronoia the representatives of various levels of the military leadership. The pronoias granted as a reward or the compensation for losses incurred as a result of the performance of official engagements, could be transferred to the commanders of low levels which were recruited from among stratiotes (obviously, dekarhes. Definition of the role of pronoia in military practice of the early palaeologian period which would be possible in the identification of the proportion of pronoiares and strateia contingents and the correlation of victories and defeats, won by them, is impossible in practice.

  9. Asynchronous decentralized method for interconnected electricity markets

    International Nuclear Information System (INIS)

    Huang, Anni; Joo, Sung-Kwan; Song, Kyung-Bin; Kim, Jin-Ho; Lee, Kisung

    2008-01-01

    This paper presents an asynchronous decentralized method to solve the optimization problem of interconnected electricity markets. The proposed method decomposes the optimization problem of combined electricity markets into individual optimization problems. The impact of neighboring markets' information is included in the objective function of the individual market optimization problem by the standard Lagrangian relaxation method. Most decentralized optimization methods use synchronous models of communication to exchange updated market information among markets during the iterative process. In this paper, however, the solutions of the individual optimization problems are coordinated through an asynchronous communication model until they converge to the global optimal solution of combined markets. Numerical examples are presented to demonstrate the advantages of the proposed asynchronous method over the existing synchronous methods. (author)

  10. CCS, locations and asynchronous transition systems

    DEFF Research Database (Denmark)

    Mukund, Madhavan; Nielsen, Mogens

    1992-01-01

    We provide a simple non-interleaved operational semantics for CCS in terms of asynchronous transition systems. We identify the concurrency present in the system in a natural way, in terms of events occurring at independent locations in the system. We extend the standard interleaving transition...... system for CCS by introducing labels on the transitions with information about the locations of events. We then show that the resulting transition system is an asynchronous transition system which has the additional property of being elementary, which means that it can also be represented by a 1-safe net....... We also introduce a notion of bisimulation on asynchronous transition systems which preserves independence. We conjecture that the induced equivalence on CCS processes coincides with the notion of location equivalence proposed by Boudol et al....

  11. Asynchronous Message Service Reference Implementation

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    This software provides a library of middleware functions with a simple application programming interface, enabling implementation of distributed applications in conformance with the CCSDS AMS (Consultative Committee for Space Data Systems Asynchronous Message Service) specification. The AMS service, and its protocols, implement an architectural concept under which the modules of mission systems may be designed as if they were to operate in isolation, each one producing and consuming mission information without explicit awareness of which other modules are currently operating. Communication relationships among such modules are self-configuring; this tends to minimize complexity in the development and operations of modular data systems. A system built on this model is a society of generally autonomous, inter-operating modules that may fluctuate freely over time in response to changing mission objectives, modules functional upgrades, and recovery from individual module failure. The purpose of AMS, then, is to reduce mission cost and risk by providing standard, reusable infrastructure for the exchange of information among data system modules in a manner that is simple to use, highly automated, flexible, robust, scalable, and efficient. The implementation is designed to spawn multiple threads of AMS functionality under the control of an AMS application program. These threads enable all members of an AMS-based, distributed application to discover one another in real time, subscribe to messages on specific topics, and to publish messages on specific topics. The query/reply (client/server) communication model is also supported. Message exchange is optionally subject to encryption (to support confidentiality) and authorization. Fault tolerance measures in the discovery protocol minimize the likelihood of overall application failure due to any single operational error anywhere in the system. The multi-threaded design simplifies processing while enabling application nodes to

  12. An Overview of the Asynchronous Digital Systems – Part 3

    Directory of Open Access Journals (Sweden)

    Mihai Timis

    2008-01-01

    Full Text Available Implementation methods for the digital asynchronous systems use different predefined models like self timed circuits, speed independent circuits, delay insensitive circuits, handshake protocol implementation in asynchronous systems,C Muller circuits.

  13. An Overview of the Asynchronous Digital Systems – Part 2

    Directory of Open Access Journals (Sweden)

    Mihai Timis

    2008-01-01

    Full Text Available Implementation methods for the digital asynchronous systems use different predefined models like self timed circuits, speed independent circuits, delay insensitive circuits, handshake protocol implementation in asynchronous systems,C Muller circuits.

  14. Interpolation algorithm for asynchronous ADC-data

    Directory of Open Access Journals (Sweden)

    S. Bramburger

    2017-09-01

    Full Text Available This paper presents a modified interpolation algorithm for signals with variable data rate from asynchronous ADCs. The Adaptive weights Conjugate gradient Toeplitz matrix (ACT algorithm is extended to operate with a continuous data stream. An additional preprocessing of data with constant and linear sections and a weighted overlap of step-by-step into spectral domain transformed signals improve the reconstruction of the asycnhronous ADC signal. The interpolation method can be used if asynchronous ADC data is fed into synchronous digital signal processing.

  15. Handbook of asynchronous machines with variable speed

    CERN Document Server

    Razik, Hubert

    2013-01-01

    This handbook deals with the asynchronous machine in its close environment. It was born from a reflection on this electromagnetic converter whose integration in industrial environments takes a wide part. Previously this type of motor operated at fixed speed, from now on it has been integrated more and more in processes at variable speed. For this reason it seemed useful, or necessary, to write a handbook on the various aspects from the motor in itself, via the control and while finishing by the diagnosis aspect. Indeed, an asynchronous motor is used nowadays in industry where variation speed a

  16. Asynchronous Operators of Sequential Logic Venjunction & Sequention

    CERN Document Server

    Vasyukevich, Vadim

    2011-01-01

    This book is dedicated to new mathematical instruments assigned for logical modeling of the memory of digital devices. The case in point is logic-dynamical operation named venjunction and venjunctive function as well as sequention and sequentional function. Venjunction and sequention operate within the framework of sequential logic. In a form of the corresponding equations, they organically fit analytical expressions of Boolean algebra. Thus, a sort of symbiosis is formed using elements of asynchronous sequential logic on the one hand and combinational logic on the other hand. So, asynchronous

  17. Chants of the Byzantine Rite: the Italo-Albanian Tradition in Sicily / Canti Ecclesiastici della Tradizione Italo-Albanese in Sicilia

    DEFF Research Database (Denmark)

    Troelsgård, Christian; Garofalo, Girolamo

    Chants of the Byzantine Rite: The Italo-Albanian Tradition in Sicily offers for the first time transcriptions of the full repertory of orally transmitted hymns for the celebration of the Byzantine Rite in Sicily. This little-known chant tradition has without interruption been cultivated by the Al...

  18. Increasing Student Engagement Using Asynchronous Learning

    Science.gov (United States)

    Northey, Gavin; Bucic, Tania; Chylinski, Mathew; Govind, Rahul

    2015-01-01

    Student engagement is an ongoing concern for educators because of its positive association with deep learning and educational outcomes. This article tests the use of a social networking site (Facebook) as a tool to facilitate asynchronous learning opportunities that complement face-to-face interactions and thereby enable a stronger learning…

  19. Basic Algorithms for the Asynchronous Reconfigurable Mesh

    Directory of Open Access Journals (Sweden)

    Yosi Ben-Asher

    2002-01-01

    Full Text Available Many constant time algorithms for various problems have been developed for the reconfigurable mesh (RM in the past decade. All these algorithms are designed to work with synchronous execution, with no regard for the fact that large size RMs will probably be asynchronous. A similar observation about the PRAM model motivated many researchers to develop algorithms and complexity measures for the asynchronous PRAM (APRAM. In this work, we show how to define the asynchronous reconfigurable mesh (ARM and how to measure the complexity of asynchronous algorithms executed on it. We show that connecting all processors in a row of an n×n ARM (the analog of barrier synchronization in the APRAM model can be solved with complexity Θ(nlog⁡n. Intuitively, this is average work time for solving such a problem. Next, we describe general a technique for simulating T -step synchronous RM algorithms on the ARM with complexity of Θ(T⋅n2log⁡n. Finally, we consider the simulation of the classical synchronous algorithm for counting the number of non-zero bits in an n bits vector using (k

  20. Emphasis on the Impact of Asynchronous Media

    African Journals Online (AJOL)

    ICTs and their utilization is one of the most pertinent issues in the education industry today. ... The paper pointed out specific impact of asynchronous ICT media in ... The paper finally noted that the struggle to be part of the digital world is ...

  1. Asynchronous versus Synchronous Learning in Pharmacy Education

    Science.gov (United States)

    Motycka, Carol A.; St. Onge, Erin L.; Williams, Jennifer

    2013-01-01

    Objective: To better understand the technology being used today in pharmacy education through a review of the current methodologies being employed at various institutions. Also, to discuss the benefits and difficulties of asynchronous and synchronous methodologies, which are being utilized at both traditional and distance education campuses.…

  2. Adaptive hatching hypotheses do not explain asynchronous ...

    African Journals Online (AJOL)

    At the core of the suite of adaptive hatching hypotheses advanced to explain asynchronous hatching in birds is the assumption that if food is not limited then all the hatchlings will develop normally to adulthood. In this study Brown-headed Parrot Poicephalus cryptoxanthus chicks were hand fed and weighed on a daily basis.

  3. Dynamic Performances of Asynchronous Machines | Ubeku ...

    African Journals Online (AJOL)

    The per-phase parameters of a 1.5 hp, 380 V, 50 Hz, 4 poles, 3 phase asynchronous machine used in the simulation were computed with reading obtained from a dc, no-load and blocked rotor tests carried out on the machine in the laboratory. The results obtained from the computer simulations confirmed the capabilities ...

  4. Asynchronous stream processing with S-Net

    NARCIS (Netherlands)

    Grelck, C.; Scholz, S.-B.; Shafarenko, A.

    2010-01-01

    We present the rationale and design of S-Net, a coordination language for asynchronous stream processing. The language achieves a near-complete separation between the application code, written in any conventional programming language, and the coordination/communication code written in S-Net. Our

  5. Late Byzantine mineral soda high alumina glasses from Asia Minor: a new primary glass production group.

    Directory of Open Access Journals (Sweden)

    Nadine Schibille

    Full Text Available The chemical characterisation of archaeological glass allows the discrimination between different glass groups and the identification of raw materials and technological traditions of their production. Several lines of evidence point towards the large-scale production of first millennium CE glass in a limited number of glass making factories from a mixture of Egyptian mineral soda and a locally available silica source. Fundamental changes in the manufacturing processes occurred from the eight/ninth century CE onwards, when Egyptian mineral soda was gradually replaced by soda-rich plant ash in Egypt as well as the Islamic Middle East. In order to elucidate the supply and consumption of glass during this transitional period, 31 glass samples from the assemblage found at Pergamon (Turkey that date to the fourth to fourteenth centuries CE were analysed by electron microprobe analysis (EPMA and by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS. The statistical evaluation of the data revealed that the Byzantine glasses from Pergamon represent at least three different glass production technologies, one of which had not previously been recognised in the glass making traditions of the Mediterranean. While the chemical characteristics of the late antique and early medieval fragments confirm the current model of glass production and distribution at the time, the elemental make-up of the majority of the eighth- to fourteenth-century glasses from Pergamon indicate the existence of a late Byzantine glass type that is characterised by high alumina levels. Judging from the trace element patterns and elevated boron and lithium concentrations, these glasses were produced with a mineral soda different to the Egyptian natron from the Wadi Natrun, suggesting a possible regional Byzantine primary glass production in Asia Minor.

  6. The agreement to exchange (permutatio in roman, Byzantine and Serbian mediaeval law

    Directory of Open Access Journals (Sweden)

    Šarkić Srđan

    2015-01-01

    Full Text Available The first part of this paper is dedicated to the definition of the agreement to exchange (permutatio and emphasizes the difference, made by Roman lawyers, between exchange (barter and sale (emptio-venditio. The second part analyses Byzantine legal sources that mention this old contract, while the third part is dedicated to Serbian legal documents. In Serbian legal documents the exchange was mentioned as the agreement between a monarch and a monastery or a natural person (individual, concerning donations that were given to the Church.

  7. AUGUSTINIAN MODEL IN THE BYZANTINE POLITICAL THINKING. CASE STUDY: THE ELEMENTS OF POLITICAL AUGUSTINISM IN THE CURRENT ROMANIAN MENTALITY

    OpenAIRE

    ANDREI TINU; CATALIN BOBOC; ANDREI-SEBASTIAN DUMITRESCU; VIOLETA IOSEFIDIS-SERGHEI

    2012-01-01

    The byzantine society, de jure and de facto heir of the Greco-Roman world, has it’s own philosophy, it’s own structure model and policy thinking. Without doubt, for the New Rome this model is that sprang from the Christian teachings, and as a philosophy it harmoniously blends the legacy of the Roman world with Blessed Augustine’s thinking about man and city which itself is a symbiosis between the acquired pagan knowledge and Christian experience of the latter. The Byzantine fortress (The Empi...

  8. The Use of Monograms on Byzantine Seals in the Early Middle-Ages (6th to 9th Centuries)

    OpenAIRE

    Werner Seibt

    2016-01-01

    The paper deals especially with monograms on Byzantine lead seals. The early form was the block monogram, a type used already in Classical times, which came into fashion in the Byzantine world in the 6th or already in the 5th century and remained important till the early 7th century. Such monograms hide normally a name, a title or an office, the Greek ones in genitive, the Latin ones in nominative or genitive. Many of them can be read in different ways. For the double using of parts of letter...

  9. The reform of Byzantine military and territorial organization under Justinian II

    Directory of Open Access Journals (Sweden)

    Cvetković Miloš

    2016-01-01

    Full Text Available This paper offers a contribution to the research of the initial stages in the evolution of the thematic system. It focuses on the role of Emperor Justinian II in the formation of the new imperial military and territorial organization. Byzantine scholars have determined a long time ago that it is Justinian II who should be credited with the founding of new military districts (themes in Hellas and Sicily. This paper, however, suggests that the formation of the themes in Thrace and Kibyrrhaiotai could also be considered a part of Justinian’s policy. In addition, the paper aims to highlight Justinian’s role in the formation of the frontier military and administrative system (the kleisourai of Strymon and Cappadocia, as well as in the reform of military and territorial organization in the Aegean basin. By creating new army units which were not based on the Late Roman heritage, Justinian essentially abandoned the principles that the Byzantine army had previously functioned on. Finally, the paper highlights the fact that the establishment of new thematic units under Emperor Justinian II was coupled with his extensive colonization measures. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 177032: Tradicija, inovacija i identitet u vizantijskom svetu

  10. Archaeometric studies of Byzantine pottery from Hârşova-Carsium, Romania

    Energy Technology Data Exchange (ETDEWEB)

    Bugoi, Roxana, E-mail: bugoi@nipne.ro [Horia Hulubei National Institute for Nuclear Physics and Engineering, Mǎgurele 077125 (Romania); Talmaţchi, Cristina, E-mail: ctalmatchi@gmail.com [Museum of National History and Archaeology, Constanţa 900745 (Romania); Haitǎ, Constantin, E-mail: costel_haita@yahoo.com [National Museum of Romania History, Bucharest 030026 (Romania); Ceccato, Daniele, E-mail: daniele.ceccato@lnl.infn.it [Università di Padova, Dipartimento di Fisica e Astronomia “Galileo Galilei”, Padova 35131 (Italy); INFN – LNL, Legnaro 35020 (Italy)

    2015-04-01

    A set of 36 ceramic shards excavated at Hârşova, Romania, dated to the 11th century A.D., was investigated using Optical Microscopy (OM) and PIXE (Particle Induced X-ray Emission). The study aimed at revealing the raw materials and the manufacturing techniques employed by the potters from the Lower Danube zone during the Byzantine period and to distinguish the local products from the supposedly imported ones. The division of the ceramic shards based on stylistic grounds was refined by the petrographic observations that identified four types of fabrics. Principal Component Analysis (PCA) of the PIXE data singled out two categories of ceramic: one made from kaolinitic clays and another produced from local sedimentary resources, with or without temper addition. Micro-PIXE scans of the interfaces between the green glaze and the underlying ceramic body indicated a high Pb content in the decorative layers. Glazing was made through the application of PbO onto a non-calcareous clay body. The petrographic and compositional data interpreted in correlation with archaeological information led to the characterization of a representative assemblage of ceramic finds from the Byzantine period, subject rarely tackled in the scientific literature.

  11. L’impératrice byzantine et la cour (XIIIe-XVe siècle

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    Malamut Élisabeth

    2013-01-01

    Full Text Available The article focuses on the Byzantine empress and the court in the empire of the Lascarides and under the Palaiologoi. It studies the arrival of the Byzantine imperial princess, the ceremonial of her marriage and her coronation. All sources emphasize the prokypsis of the newly crowned bride and the role of the mother-in-law. Orthodox ceremony remains in force and the latitude granted to the early fifteenth century Latin princesses to dispense appears not to be respected. Then the author examines clothing and insignia of the Empress of the time of the Palaiologoi, then questions the role of the Empress in the march of the empire: receiving the women at the court, assistance at the counseling, at last in her presence in urban life. Finally it seems that the empresses from the West kept with them the retinue that had accompanied them from their country of origin and practiced a way of life freer than the princesses that came from the Orthodox world. The author concludes with the «noise of the Gynekeion».

  12. Byzantine influence on the Serbian customary law in the 9th century

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    Đekić Đorđe N.

    2016-01-01

    Full Text Available By the 10th century Serbian law recognized the following ways of dispute resolution: revenge and appeasement, and it may be indirectly proved that there was a system of compensation. As punishments, there was banishment into exile, blinding and a death sentence. Since revenge, appeasement and compensation system appear in the pre-state period, while the death penalty has its roots in the blood feud, that indicates they are all of local origin. A question remains about the origin of banishment and blinding a fallen ruler, that is, a rival to the throne. In the first half of the 9th century the Byzantine Empire managed to reinstate its power over the Adriatic Sea, to impose itself over the Serbian states, to Christianise them and to legalise ruling families in the Serbian lands. Suffice to say that in 869 the Serbian states fight wars on the Byzantine side. Origin of influences on the ways of the punishment we seek in Byzantium, or better still, in its legal practice. It has been found that Byzantium used to send their conquered rivals to the throne into exile, punishing them by blinding them, so we draw a conclusion that in the matter of punishment, i.e. in the customary law, it exercised its influence on Serbia.

  13. Aspects of computation on asynchronous parallel processors

    International Nuclear Information System (INIS)

    Wright, M.

    1989-01-01

    The increasing availability of asynchronous parallel processors has provided opportunities for original and useful work in scientific computing. However, the field of parallel computing is still in a highly volatile state, and researchers display a wide range of opinion about many fundamental questions such as models of parallelism, approaches for detecting and analyzing parallelism of algorithms, and tools that allow software developers and users to make effective use of diverse forms of complex hardware. This volume collects the work of researchers specializing in different aspects of parallel computing, who met to discuss the framework and the mechanics of numerical computing. The far-reaching impact of high-performance asynchronous systems is reflected in the wide variety of topics, which include scientific applications (e.g. linear algebra, lattice gauge simulation, ordinary and partial differential equations), models of parallelism, parallel language features, task scheduling, automatic parallelization techniques, tools for algorithm development in parallel environments, and system design issues

  14. Asynchronous Gossip for Averaging and Spectral Ranking

    Science.gov (United States)

    Borkar, Vivek S.; Makhijani, Rahul; Sundaresan, Rajesh

    2014-08-01

    We consider two variants of the classical gossip algorithm. The first variant is a version of asynchronous stochastic approximation. We highlight a fundamental difficulty associated with the classical asynchronous gossip scheme, viz., that it may not converge to a desired average, and suggest an alternative scheme based on reinforcement learning that has guaranteed convergence to the desired average. We then discuss a potential application to a wireless network setting with simultaneous link activation constraints. The second variant is a gossip algorithm for distributed computation of the Perron-Frobenius eigenvector of a nonnegative matrix. While the first variant draws upon a reinforcement learning algorithm for an average cost controlled Markov decision problem, the second variant draws upon a reinforcement learning algorithm for risk-sensitive control. We then discuss potential applications of the second variant to ranking schemes, reputation networks, and principal component analysis.

  15. Computing by Temporal Order: Asynchronous Cellular Automata

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    Michael Vielhaber

    2012-08-01

    Full Text Available Our concern is the behaviour of the elementary cellular automata with state set 0,1 over the cell set Z/nZ (one-dimensional finite wrap-around case, under all possible update rules (asynchronicity. Over the torus Z/nZ (n<= 11,we will see that the ECA with Wolfram rule 57 maps any v in F_2^n to any w in F_2^n, varying the update rule. We furthermore show that all even (element of the alternating group bijective functions on the set F_2^n = 0,...,2^n-1, can be computed by ECA57, by iterating it a sufficient number of times with varying update rules, at least for n <= 10. We characterize the non-bijective functions computable by asynchronous rules.

  16. "Just Keep Going, Stay Together, and Sing OUT." Learning Byzantine Music in an Informal and Situated Community of Practice

    Science.gov (United States)

    Brashier, Rachel

    2016-01-01

    This project examines the communal process of music learning as it occurs in a Byzantine chant learning group at a Greek Orthodox Church. The goal of this project was to investigate the act of music making, as situated in a particular sociocultural context, in order to address the question: Through what processes do individuals share music…

  17. Blending Online Asynchronous and Synchronous Learning

    Directory of Open Access Journals (Sweden)

    Lisa C. Yamagata-Lynch

    2014-04-01

    Full Text Available In this article I will share a qualitative self-study about a 15-week blended 100% online graduate level course facilitated through synchronous meetings on Blackboard Collaborate and asynchronous discussions on Blackboard. I taught the course at the University of Tennessee (UT during the spring 2012 semester and the course topic was online learning environments. The primary research question of this study was: How can the designer/instructor optimize learning experiences for students who are studying about online learning environments in a blended online course relying on both synchronous and asynchronous technologies? I relied on student reflections of course activities during the beginning, middle, and the end of the semester as the primary data source to obtain their insights regarding course experiences. Through the experiences involved in designing and teaching the course and engaging in this study I found that there is room in the instructional technology research community to address strategies for facilitating online synchronous learning that complement asynchronous learning. Synchronous online whole class meetings and well-structured small group meetings can help students feel a stronger sense of connection to their peers and instructor and stay engaged with course activities. In order to provide meaningful learning spaces in synchronous learning environments, the instructor/designer needs to balance the tension between embracing the flexibility that the online space affords to users and designing deliberate structures that will help them take advantage of the flexible space.

  18. Comparing the force ripple during asynchronous and conventional stimulation.

    Science.gov (United States)

    Downey, Ryan J; Tate, Mark; Kawai, Hiroyuki; Dixon, Warren E

    2014-10-01

    Asynchronous stimulation has been shown to reduce fatigue during electrical stimulation; however, it may also exhibit a force ripple. We quantified the ripple during asynchronous and conventional single-channel transcutaneous stimulation across a range of stimulation frequencies. The ripple was measured during 5 asynchronous stimulation protocols, 2 conventional stimulation protocols, and 3 volitional contractions in 12 healthy individuals. Conventional 40 Hz and asynchronous 16 Hz stimulation were found to induce contractions that were as smooth as volitional contractions. Asynchronous 8, 10, and 12 Hz stimulation induced contractions with significant ripple. Lower stimulation frequencies can reduce fatigue; however, they may also lead to increased ripple. Future efforts should study the relationship between force ripple and the smoothness of the evoked movements in addition to the relationship between stimulation frequency and NMES-induced fatigue to elucidate an optimal stimulation frequency for asynchronous stimulation. © 2014 Wiley Periodicals, Inc.

  19. Current Trends in High-Level Synthesis of Asynchronous Circuits

    DEFF Research Database (Denmark)

    Sparsø, Jens

    2009-01-01

    This paper is a survey paper presenting what the author sees as two major and promising trends in the current research in CAD-tools and design-methods for asynchronous circuits. One branch of research builds on top of existing asynchronous CAD-tools that perform syntax directed translation, e...... a conventional synchronous circuit as the starting point, and then adds some form of handshake-based flow-control. One approach keeps the global clock and implements discrete-time asynchronous operation. Another approach substitutes the clocked registers by asynchronous handshake-registers, thus creating truly...

  20. Byzantine Music

    OpenAIRE

    Charalampous, Charalampos

    2007-01-01

    Magdalény Rettigové 4, 116 39 Praha 1 tel.: +420 221 900 111 www.pedf.cuni.cz IČ 00216208 DIČ CZ00216208 Dle čl. 4 Opatření rektora č. 6/2010 o Zpřístupnění elektronické databáze závěrečných prací http://www.cuni.cz/UK-3470.html a čl. 1 Opatření děkana 17/2010 se z časového hlediska závěrečné práce dělí do tří skupin: a. "nové práce", tj. práce odevzdávané k obhajobě počínaje 29. 9. 2010, b. "starší práce", tj. práce odevzdané k obhajobě od 1. 1. 2006 do 28. 9. 2010, c. "práce před rokem 2006...

  1. Earthquakes and plague during Byzantine times: can lessons from the past improve epidemic preparedness.

    Science.gov (United States)

    Tsiamis, Costas; Poulakou-Rebelakou, Effie; Marketos, Spyros

    2013-01-01

    Natural disasters have always been followed by a fear of infectious diseases. This raised historical debate about one of the most feared scenarios: the outbreak of bubonic plague caused by Yersinia pestis. One such event was recorded in the Indian state Maharashtra in 1994 after an earthquake. In multidisciplinary historical approach to the evolution of plague, many experts ignore the possibility of natural foci and their activation. This article presents historical records from the Byzantine Empire about outbreaks of the Plague of Justinian occurring months or even up to a year after high-magnitude earthquakes. Historical records of plague outbreaks can be used to document existence of natural foci all over the world. Knowledge of these historical records and the contemporary examples of plague support the assumption that, in terms of organising humanitarian aid, poor monitoring of natural foci could lead to unpredictable epidemiological consequences after high-magnitude earthquakes.

  2. Colchicum genus in the writings of ancient Greek and Byzantine physicians.

    Science.gov (United States)

    Tsoucalas, Gregory; Papaioannou, Theodoros; Panayiotakopoulos, George; Saridaki, Zenia; Vrachatis, Dimitrios A; Karamanou, Marianna

    2018-01-14

    The plants of the Colchicum family were known during the archaic period in Greece for their deleterious properties. Later on, they were used for the treatment of podagra. The treatment was introduced by the ancient Greek physicians and passed on to the Byzantine and Arabian physicians to endure until nowadays. The first plant was most probably named "Medea" from the notorious Colchican witch. As the most common member of the family blossoms in autumn, the plant was named Colchicum autumnale. Various nominations were also used, such as Ephemeron, Hermodactyl, Anima articulorum and Surugen. Our article discusses them, while at the same time presents the most notable authorities who have used Colchicum plants in herbal medicine and toxicology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Military Equipment in the Byzantine Manuscript of Scylitzes in Biblioteca Nacional de Madrid

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    Bruhn Hoffmeyer, Ada

    1966-12-01

    Full Text Available The purpose of the present paper is to provide an introduction to the military equipment of the Second Golden Age of the Byzantine empire as represented not by the text of Scylitzes but by the illuminators of this marvellous manuscript, the relations of the illuminations to the actual weapons and their chronology.

    El propósito de este trabajo es proporcionar una introducción al equipamiento militar durante la Segunda Edad de Oro del Imperio Bizantino, tal y como se representa no a través del texto, sino de las iluminaciones, del manuscrito Scylitzes de la Biblioteca Nacional de Madrid, y la comparación de las iluminaciones con el armamento auténtico y su cronología. [traducción para esta edición electrónica

  4. A computational comparison of theory and practice of scale intonation in Byzantine chant

    DEFF Research Database (Denmark)

    Panteli, Maria; Purwins, Hendrik

    2013-01-01

    Byzantine Chant performance practice is quantitatively compared to the Chrysanthine theory. The intonation of scale degrees is quantified, based on pitch class profiles. An analysis procedure is introduced that consists of the following steps: 1) Pitch class histograms are calculated via non-parametric...... kernel smoothing. 2) Histogram peaks are detected. 3) Phrase ending analysis aids the finding of the tonic to align histogram peaks. 4) The theoretical scale degrees are mapped to the practical ones. 5) A schema of statistical tests detects significant deviations of theoretical scale tuning from...... the estimated ones in performance practice. The analysis of 94 echoi shows a tendency of the singer to level theoretic particularities of the echos that stand out of the general norm in the octoechos: theoretically extremely large scale steps are diminished in performance....

  5. La vision de Saint Eustathe dans la peinture post-byzantine

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    Amprazogoula Katerina

    2008-01-01

    Full Text Available (francuski L'article étudie l'évolution de la Vision de saint Eustathe dans une série de peintures murales et d'icônes portatives - allant du XVIe au XVIIIe siècle - les formules iconographiques adoptées et leurs particularités ainsi que la place et la fonction de cette image dans la peinture murale. Le matériel étudié a montré une diversité de formules iconographiques qui exploitent pour l'essentiel la tradition byzantine et orientale du sujet, en manifestant en même temps ses propres traits ainsi que l'influence des images occidentales. .

  6. Byzantine history and the discourse of the Russian political/intellectual underground

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    Dmitry Shlapentokh

    2012-01-01

    In the view of the producer, the Byzantine Empire was strong when it followed its autocratic tradition and was attached to Orthodoxy. The movie generated extensive discussions, including among those who belong to Russia's political and intellectual fringe. Quite a few of them were neo-pagans; for them, Christianity, including Orthodox Christianity, was Russia's curse. For them, it was an Asian creed foreign to Aryan Russians. The fact that it was accepted by Russians implied that Russians had been subjugated by an alien, Asiatic, force. Many of these neo-pagans were quite pessimistic in regard to the country's future; and, indeed, their response indicates the deep alienation of quite a few Russians, which hardly bodes well for the country's future.

  7. Traces of 'Simple Psalmody' in late- and post-Byzantine musical manuscripts. Melodic, modal and textual analysis of the Kekragarion tradition

    DEFF Research Database (Denmark)

    Sanfratello, Giuseppe

    2017-01-01

    The study of the Kekragarion chant tradition has over time become an important aspect of Byzantine musicology, especially regarding the development of “simple psalmody”. Simple psalmody describes the functional side of Byzantine “psalm tones”, pointing out a set of recurrent behaviours in the ada......The study of the Kekragarion chant tradition has over time become an important aspect of Byzantine musicology, especially regarding the development of “simple psalmody”. Simple psalmody describes the functional side of Byzantine “psalm tones”, pointing out a set of recurrent behaviours......, but for the actual analysis two manuscripts representing the Kekragaria versions contained in the whole group of manuscripts were selected for transcription. My survey shows how the melodic tradition of the late medieval Kekragarion has been partly maintained and partly developed over four centuries, and it also...

  8. A repertoire of comic figures of the antique theatre in miniatures of Byzantine Psalters with marginal

    Directory of Open Access Journals (Sweden)

    Bemabò Massimo

    2004-01-01

    Full Text Available Recent investigations on ninth-century Byzantine Psalters have focused mostly on the impact of the iconoclast controversy on the iconography of the marginal illustrations in these manuscripts. In fact this impact has been greatly exaggerated and the Psalter illustrations that can be connected to the debates on icon are less than a dozen out of a total of a few hundreds. The present article focuses on the iconography of figures illustrating social and moral types in the psalms. These figures cannot be considered as novel inventions of the ninth-century artists who painted our manuscripts. Their origin must be drawn back to late antique prototypes; in particular it is inferred that most of these figures represent characters that were originally modeled after the moral and social types acted on stage in late antique theater, mime and pantomime. A number of examples out of the miniatures in the Carolingian manuscripts of Terence and other media provides parallels to gestures, postures and features of the figures in the Psalter illustrations. The iconographical invention of these characters for the psalms must date from fourth to sixth century, a period during which theater was still very popular, notwithstanding the strong opposition of the Christian Fathers. Chroricius of Gaza' Apologia memoriam and other late antique writings witness the popularity of mime up to the middle sixth century and the ample variety of types that were acted on stage. The figures scissor out of marginal illustrations in the Byzantine Psalters are arranged in five plates collecting examples of, respectively, moral types, emotions caricatures, social types and professions, gods and devils.

  9. Pass-transistor asynchronous sequential circuits

    Science.gov (United States)

    Whitaker, Sterling R.; Maki, Gary K.

    1989-01-01

    Design methods for asynchronous sequential pass-transistor circuits, which result in circuits that are hazard- and critical-race-free and which have added degrees of freedom for the input signals, are discussed. The design procedures are straightforward and easy to implement. Two single-transition-time state assignment methods are presented, and hardware bounds for each are established. A surprising result is that the hardware realizations for each next state variable and output variable is identical for a given flow table. Thus, a state machine with N states and M outputs can be constructed using a single layout replicated N + M times.

  10. Massive Asynchronous Parallelization of Sparse Matrix Factorizations

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Edmond [Georgia Inst. of Technology, Atlanta, GA (United States)

    2018-01-08

    Solving sparse problems is at the core of many DOE computational science applications. We focus on the challenge of developing sparse algorithms that can fully exploit the parallelism in extreme-scale computing systems, in particular systems with massive numbers of cores per node. Our approach is to express a sparse matrix factorization as a large number of bilinear constraint equations, and then solving these equations via an asynchronous iterative method. The unknowns in these equations are the matrix entries of the factorization that is desired.

  11. AUGUSTINIAN MODEL IN THE BYZANTINE POLITICAL THINKING. CASE STUDY: THE ELEMENTS OF POLITICAL AUGUSTINISM IN THE CURRENT ROMANIAN MENTALITY

    Directory of Open Access Journals (Sweden)

    ANDREI TINU

    2012-05-01

    Full Text Available The byzantine society, de jure and de facto heir of the Greco-Roman world, has it’s own philosophy, it’s own structure model and policy thinking. Without doubt, for the New Rome this model is that sprang from the Christian teachings, and as a philosophy it harmoniously blends the legacy of the Roman world with Blessed Augustine’s thinking about man and city which itself is a symbiosis between the acquired pagan knowledge and Christian experience of the latter. The Byzantine fortress (The Empire-n.n. will use religion as the main instrument for political and social consolidation. Religion (Christianity – n.n. is, for the Byzantine monarchy , the path to divinity, immortality... The Byzantine Christianity is not just a "phrase invented by them" as in the words of Eminescu, but a complex mechanism which represents the totality of good concepts about the world and about life of the constantinopolitan city.In preparing this study we started from the model offered by St. Augustine, "De Civitate Dei", a model which compares the two types of cities - people's city, with all its flaws, and the City of God, personified by the Church to which the Christian Roman Empire provides the Regnum. Our study tries to reflect how the model of the two cities becomes a political ideology of the Byzantine Empire and, arch over time, how it is manifested in the public and political mind of the Romanian society. This research tries to increase the understanding of the mental archetypes amongst those who are active participants in public life in Romania. However, we want our message to be disseminated in a wider public and to provide the possibility of assimilation, as much as it can, of the participatory political culture. Thus, the study becomes an attempt of reporting the Byzantine society, respectively the current Romanian society, to the model of the three types of political culture offered by Almond and Verba - participatory, parochial and dependent.

  12. MODELING AND INVESTIGATION OF ASYNCHRONOUS TWO-MACHINE SYSTEM MODES

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    V. S. Safaryan

    2014-01-01

    Full Text Available The paper considers stationary and transient processes of an asynchronous two-machine system. A mathematical model for investigation of stationary and transient modes, static characteristics and research results of dynamic process pertaining to starting-up the asynchronous two-machine system has been given in paper.

  13. Two Studies Examining Argumentation in Asynchronous Computer Mediated Communication

    Science.gov (United States)

    Joiner, Richard; Jones, Sarah; Doherty, John

    2008-01-01

    Asynchronous computer mediated communication (CMC) would seem to be an ideal medium for supporting development in student argumentation. This paper investigates this assumption through two studies. The first study compared asynchronous CMC with face-to-face discussions. The transactional and strategic level of the argumentation (i.e. measures of…

  14. Designing Asynchronous Circuits for Low Power: An IFIR Filter

    DEFF Research Database (Denmark)

    Nielsen, Lars Skovby; Sparsø, Jens

    1999-01-01

    This paper addresses the design of asynchronous circuits for low power through an example: a filter bank for a digital hearing aid. The asynchronous design re-implements an existing synchronous circuit which is used in a commercial product. For comparison, both designs have been fabricated...

  15. Evaluation of discrete modeling efficiency of asynchronous electric machines

    OpenAIRE

    Byczkowska-Lipińska, Liliana; Stakhiv, Petro; Hoholyuk, Oksana; Vasylchyshyn, Ivanna

    2011-01-01

    In the paper the problem of effective mathematical macromodels in the form of state variables intended for asynchronous motor transient analysis is considered. Their comparing with traditional mathematical models of asynchronous motors including models built into MATLAB/Simulink software was carried out and analysis of their efficiency was conducted.

  16. Asynchronous Learning Sources in a High-Tech Organization

    Science.gov (United States)

    Bouhnik, Dan; Giat, Yahel; Sanderovitch, Yafit

    2009-01-01

    Purpose: The purpose of this study is to characterize learning from asynchronous sources among research and development (R&D) personnel. It aims to examine four aspects of asynchronous source learning: employee preferences regarding self-learning; extent of source usage; employee satisfaction with these sources and the effect of the sources on the…

  17. Integrating Asynchronous Digital Design Into the Computer Engineering Curriculum

    Science.gov (United States)

    Smith, S. C.; Al-Assadi, W. K.; Di, J.

    2010-01-01

    As demand increases for circuits with higher performance, higher complexity, and decreased feature size, asynchronous (clockless) paradigms will become more widely used in the semiconductor industry, as evidenced by the International Technology Roadmap for Semiconductors' (ITRS) prediction of a likely shift from synchronous to asynchronous design…

  18. Localized radio frequency communication using asynchronous transfer mode protocol

    Science.gov (United States)

    Witzke, Edward L.; Robertson, Perry J.; Pierson, Lyndon G.

    2007-08-14

    A localized wireless communication system for communication between a plurality of circuit boards, and between electronic components on the circuit boards. Transceivers are located on each circuit board and electronic component. The transceivers communicate with one another over spread spectrum radio frequencies. An asynchronous transfer mode protocol controls communication flow with asynchronous transfer mode switches located on the circuit boards.

  19. The Determination of the Asynchronous Traction Motor Characteristics of Locomotive

    Directory of Open Access Journals (Sweden)

    Pavel Grigorievich Kolpakhchyan

    2017-01-01

    Full Text Available The article deals with the problem of the locomotive asynchronous traction motor control with the AC diesel-electric transmission. The limitations of the torque of the traction motor when powered by the inverter are determined. The recommendations to improve the use of asynchronous traction motor of locomotives with the AC diesel-electric transmission are given.

  20. Exploring Asynchronous and Synchronous Tool Use in Online Courses

    Science.gov (United States)

    Oztok, Murat; Zingaro, Daniel; Brett, Clare; Hewitt, Jim

    2013-01-01

    While the independent contributions of synchronous and asynchronous interaction in online learning are clear, comparatively less is known about the pedagogical consequences of using both modes in the same environment. In this study, we examine relationships between students' use of asynchronous discussion forums and synchronous private messages…

  1. Asynchronous and Synchronous Online Discussion: Real and Perceived Achievement Differences

    Science.gov (United States)

    Johnson, Genevieve Marie; Buck, George H.

    2007-01-01

    Students in an introductory educational psychology course used two WebCT communication tools (synchronous chat and asynchronous discussion) to discuss four case studies. In response to the item, "I learned the case studies best when using," 39 students selected synchronous chat and 51 students selected asynchronous discussion. Students who…

  2. Regression analysis of sparse asynchronous longitudinal data.

    Science.gov (United States)

    Cao, Hongyuan; Zeng, Donglin; Fine, Jason P

    2015-09-01

    We consider estimation of regression models for sparse asynchronous longitudinal observations, where time-dependent responses and covariates are observed intermittently within subjects. Unlike with synchronous data, where the response and covariates are observed at the same time point, with asynchronous data, the observation times are mismatched. Simple kernel-weighted estimating equations are proposed for generalized linear models with either time invariant or time-dependent coefficients under smoothness assumptions for the covariate processes which are similar to those for synchronous data. For models with either time invariant or time-dependent coefficients, the estimators are consistent and asymptotically normal but converge at slower rates than those achieved with synchronous data. Simulation studies evidence that the methods perform well with realistic sample sizes and may be superior to a naive application of methods for synchronous data based on an ad hoc last value carried forward approach. The practical utility of the methods is illustrated on data from a study on human immunodeficiency virus.

  3. Asynchronous schemes for CFD at extreme scales

    Science.gov (United States)

    Konduri, Aditya; Donzis, Diego

    2013-11-01

    Recent advances in computing hardware and software have made simulations an indispensable research tool in understanding fluid flow phenomena in complex conditions at great detail. Due to the nonlinear nature of the governing NS equations, simulations of high Re turbulent flows are computationally very expensive and demand for extreme levels of parallelism. Current large simulations are being done on hundreds of thousands of processing elements (PEs). Benchmarks from these simulations show that communication between PEs take a substantial amount of time, overwhelming the compute time, resulting in substantial waste in compute cycles as PEs remain idle. We investigate a novel approach based on widely used finite-difference schemes in which computations are carried out asynchronously, i.e. synchronization of data among PEs is not enforced and computations proceed regardless of the status of messages. This drastically reduces PE idle time and results in much larger computation rates. We show that while these schemes remain stable, their accuracy is significantly affected. We present new schemes that maintain accuracy under asynchronous conditions and provide a viable path towards exascale computing. Performance of these schemes will be shown for simple models like Burgers' equation.

  4. Odd Topics, Old Methods and the Cradle of the Ius Commune: Byzantine Law and the Italian City-States

    Directory of Open Access Journals (Sweden)

    Daphne Penna

    2017-12-01

    Full Text Available In this paper I try to demonstrate how Byzantine law, a subject odd and exotic at first sight provides a piece of the puzzle that helps us to complete the big picture, the origins of our European legal identity. I refer to some concrete examples of legal interaction between the Byzantine and the Western side of Europe in the tenth, eleventh and twelfth centuries – a period in which the ius commune began to take shape – and explain the method I used step by step, the specific challenges I confronted in the sources and the outcomes of this approach. The comparative legal study of documents of the medieval period at a European level can help us to answer the question whether, long before the making of today’s Europe, today’s European countries were already connected by common legal forms.

  5. PIXE and PGAA - Complementary methods for studies on ancient glass artefacts (from Byzantine, late medieval to modern Murano glass)

    Science.gov (United States)

    Constantinescu, Bogdan; Cristea-Stan, Daniela; Szőkefalvi-Nagy, Zoltán; Kovács, Imre; Harsányi, Ildikó; Kasztovszky, Zsolt

    2018-02-01

    Combined external milli-beam Particle Induced X-ray Emission (PIXE) and Prompt Gamma Activation Analysis (PGAA) analysis was applied to characterize the composition of paste and colorants from some fragments of Byzantine bracelets (10th-12th Centuries AD), late medieval (17th-18th Centuries AD) and modern Murano glass pieces. As fluxes, PGAA revealed the samples are soda-lime glass, except four samples - two medieval vessel white shards and two dark Byzantine fragments of bracelets - which have potash flux. Aluminium was detected in various proportions in all samples indicating different sources for the added sand. The presence of Magnesium is relevant only in one bracelet fragment suggesting the use of plant (wood?) ash and confirming that the Byzantine bracelet is manufactured from the mixture of both types of glass (natron and plant ash based). PGAA also indicated the presence of low quantities of Cadmium, high level of Arsenic and Lead (possibly lead arsenate) in one medieval sample and of ZnO in Murano glass, and of CoO traces (maximum 0.1%) in all blue-colored Byzantine, late medieval to modern Murano glass artefacts. PIXE confirmed the use of small quantities of CoO for blue color, indicated Manganese combined with Iron for dark glass, Copper for green, Lead, Tin and an Arsenic compound (orpiment?) for yellow and in the case of modern Murano glass Selenium and Cadmium to obtain a reddish color. Despite PIXE - PIGE combination is probably the best one for glass analysis, our external milli-PIXE - PGAA methods proved to be adequate complementary tools to determine many chemical elements from glass composition - Si, Na, K, Ca, Al, Mg, various metallic oxides.

  6. The Effect of the Sasanian-Byzantine Wars (A.D. 603-628 on the Collapse of Sasanian Empire

    Directory of Open Access Journals (Sweden)

    Mehrdad Ghodrat Dizaji

    2016-12-01

    Full Text Available Sasanian Empire in the early 7th century AD, due to long years of wars with Byzantine Empire (603-626 AD and its later defeat, lost its military and defensive strength, and went through a political crisis. Before this time, based on numismatic studies, it was revealed that following this defeat, only some provinces of the empire minted coins in the name of the Sasanian emperors, and it shows that other provinces were out of Sasanian’s control. Furthermore, literary sources have illustrated that Arab regions of the Sasanian Empire, after Sasanian’s defeat from Byzantine were out of Sasanian’s rule. The author, in this article has showed that according to archeological and numismatic evidence, Azerbaijan province which was the scene of Sasanian-Byzantine battlefield, received the most damages, and since about 623 AD was out of Sasanian’s control. The fall of the Sasanian hegemony in the provinces, was undoubtedly an important factor in weakening of Sasanian military and financial power and consequently contributed considerably to its defeat by Arab Muslims. This factor had also a significant role in Arabs’ penetration in the provinces which were out of Sasanian rule

  7. Asynchronous and corrected-asynchronous numerical solutions of parabolic PDES on MIMD multiprocessors

    Science.gov (United States)

    Amitai, Dganit; Averbuch, Amir; Itzikowitz, Samuel; Turkel, Eli

    1991-01-01

    A major problem in achieving significant speed-up on parallel machines is the overhead involved with synchronizing the concurrent process. Removing the synchronization constraint has the potential of speeding up the computation. The authors present asynchronous (AS) and corrected-asynchronous (CA) finite difference schemes for the multi-dimensional heat equation. Although the discussion concentrates on the Euler scheme for the solution of the heat equation, it has the potential for being extended to other schemes and other parabolic partial differential equations (PDEs). These schemes are analyzed and implemented on the shared memory multi-user Sequent Balance machine. Numerical results for one and two dimensional problems are presented. It is shown experimentally that the synchronization penalty can be about 50 percent of run time: in most cases, the asynchronous scheme runs twice as fast as the parallel synchronous scheme. In general, the efficiency of the parallel schemes increases with processor load, with the time level, and with the problem dimension. The efficiency of the AS may reach 90 percent and over, but it provides accurate results only for steady-state values. The CA, on the other hand, is less efficient, but provides more accurate results for intermediate (non steady-state) values.

  8. Asynchronous machines. Direct torque control; Machines asynchrones. Commande par controle direct de couple

    Energy Technology Data Exchange (ETDEWEB)

    Fornel, B. de [Institut National Polytechnique, 31 - Toulouse (France)

    2006-05-15

    The asynchronous machine, with its low cost and robustness, is today the most widely used motor to make speed variators. However, its main drawback is that the same current generates both the magnetic flux and the torque, and thus any torque variation creates a flux variation. Such a coupling gives to the asynchronous machine a nonlinear behaviour which makes its control much more complex. The direct self control (DSC) method has been developed to improve the low efficiency of the scalar control method and for the specific railway drive application. The direct torque control (DTC) method is derived from the DSC method but corresponds to other type of applications. The DSC and DTC algorithms for asynchronous motors are presented in this article: 1 - direct control of the stator flux (DSC): principle, flux control, torque control, switching frequency of the inverter, speed estimation; 2 - direct torque control (DTC): principle, electromagnetic torque derivative, signals shape and switching frequency, some results, DTC speed variator without speed sensor, DTC application to multi-machine multi-converter systems; 3 - conclusion. (J.S.)

  9. Asynchronous discrete event schemes for PDEs

    Science.gov (United States)

    Stone, D.; Geiger, S.; Lord, G. J.

    2017-08-01

    A new class of asynchronous discrete-event simulation schemes for advection-diffusion-reaction equations is introduced, based on the principle of allowing quanta of mass to pass through faces of a (regular, structured) Cartesian finite volume grid. The timescales of these events are linked to the flux on the face. The resulting schemes are self-adaptive, and local in both time and space. Experiments are performed on realistic physical systems related to porous media flow applications, including a large 3D advection diffusion equation and advection diffusion reaction systems. The results are compared to highly accurate reference solutions where the temporal evolution is computed with exponential integrator schemes using the same finite volume discretisation. This allows a reliable estimation of the solution error. Our results indicate a first order convergence of the error as a control parameter is decreased, and we outline a framework for analysis.

  10. Error characterization for asynchronous computations: Proxy equation approach

    Science.gov (United States)

    Sallai, Gabriella; Mittal, Ankita; Girimaji, Sharath

    2017-11-01

    Numerical techniques for asynchronous fluid flow simulations are currently under development to enable efficient utilization of massively parallel computers. These numerical approaches attempt to accurately solve time evolution of transport equations using spatial information at different time levels. The truncation error of asynchronous methods can be divided into two parts: delay dependent (EA) or asynchronous error and delay independent (ES) or synchronous error. The focus of this study is a specific asynchronous error mitigation technique called proxy-equation approach. The aim of this study is to examine these errors as a function of the characteristic wavelength of the solution. Mitigation of asynchronous effects requires that the asynchronous error be smaller than synchronous truncation error. For a simple convection-diffusion equation, proxy-equation error analysis identifies critical initial wave-number, λc. At smaller wave numbers, synchronous error are larger than asynchronous errors. We examine various approaches to increase the value of λc in order to improve the range of applicability of proxy-equation approach.

  11. Detection of Failure in Asynchronous Motor Using Soft Computing Method

    Science.gov (United States)

    Vinoth Kumar, K.; Sony, Kevin; Achenkunju John, Alan; Kuriakose, Anto; John, Ano P.

    2018-04-01

    This paper investigates the stator short winding failure of asynchronous motor also their effects on motor current spectrums. A fuzzy logic approach i.e., model based technique possibly will help to detect the asynchronous motor failure. Actually, fuzzy logic similar to humanoid intelligent methods besides expected linguistic empowering inferences through vague statistics. The dynamic model is technologically advanced for asynchronous motor by means of fuzzy logic classifier towards investigate the stator inter turn failure in addition open phase failure. A hardware implementation was carried out with LabVIEW for the online-monitoring of faults.

  12. Searching the seat of the soul in Ancient Greek and Byzantine medical literature.

    Science.gov (United States)

    Lykouras, Eleftherios; Poulakou-Rebelakou, Effie; Ploumpidis, Demetrios N

    2010-12-01

    The objective of this paper was to examine the ancient and medieval concepts about the seat of the mental functions, as exposed in Greek texts from Antiquity to Byzantine times. The review of the philosophical and medical literature from the original ancient Greek language from the Homeric epics to the Holy Fathers of Christianity, as the problem of the seat of the soul remained without a certain answer through the centuries. Primitive concepts attributed great significance to the soul and dictated cannibal behaviours for the possession and eating of the defeated enemy's heart. Mental functions, such as thinking, feeling and mainly those related to affective manifestations, were attributed to the heart and to some other internal organs (liver, diaphragm) from the times of Greek mythology. Philosophy and empirical medicine had underestimated the brain probably because it is a 'silent' organ, contrary to the palpitating heart, with its obvious participations in the emotional reactions. The role of the brain as the mental organ and the seat of emotions has been gradually recognized. The permanent question of the seat of the soul had been for many centuries a critical dispute and the contribution of Greek philosophical and medical thought was decisive for the contemporary transformation of the whole concept.

  13. A comparison between two migrations in the Byzantine Empire: the Goths and the Pechenegs

    Directory of Open Access Journals (Sweden)

    Alexandru Madgearu

    2015-12-01

    Full Text Available The study compares from several points of view two migratory movements across the Lower Danube: the Tervingi Goths in 376 and the Pechenegs in 1045-1047. In both cases the imperial authorities hoped they would gain supplementary military forces, but the events turned both migratory groups into internal enemies. There are some similarities in the causes of the aforementioned migrations, in the way the Danube was crossed, and as concerns the places granted for settlement, and the integration in the Roman /Byzantine army. In other respects, the movements differed, especially because of the nomadic type of life of the Pechenegs, the Goths being sedentary people who moved from a homeland to another. Both migrations had disastrous effects for the empire, because the emperors were not able to foresee or to prevent the rebellions of these warrior people received as refugees. Instead of more economic and military resources, both the Goths and the Pechenegs caused much trouble in the South-East European provinces.

  14. The Cultural Landscape Past of the Eastern Mediterranean: The Border Lord’s Gardens and the Common Landscape Tradition of the Arabic and Byzantine Culture

    Directory of Open Access Journals (Sweden)

    Konstantinos Moraitis

    2018-02-01

    Full Text Available An evaluation of landscape tradition, in Near and Middle East area, could emphasize a profound past of agricultural experience, as well as of landscape and garden art. In reference to this common past, Byzantine and Arabic landscape and garden art paradigms appear to be geographically and culturally correlated, as proved by a Byzantine 12th century folksong, presenting the construction of a villa, with its surrounding gardens and landscape formations, in the territory of Euphrates River. This song refers to Vasilios Digenes Akritas or ‘Border Lord’, a legendary hero of mixed Byzantine-Greek and Arab blood; ‘Digenes’ meaning a person of dual genes, both of Byzantine and Arabic origin, and ‘Akritas’ an inhabitant of the borderline. At the end of the narration of the song, contemporary reader feels skeptical. Was modern landscape and garden art born in the European continent or was it transferred to Western world through an eastern originated lineage of Byzantine and Arabic provenance?

  15. Verification and Planning for Stochastic Processes with Asynchronous Events

    National Research Council Canada - National Science Library

    Younes, Hakan L

    2005-01-01

    .... The most common assumption is that of history-independence: the Markov assumption. In this thesis, the author considers the problems of verification and planning for stochastic processes with asynchronous events, without relying on the Markov assumption...

  16. TCDQ-TCT retraction and losses during asynchronous beam dump

    CERN Document Server

    Bracco, Chiara; Quaranta, Elena; CERN. Geneva. ATS Department

    2016-01-01

    The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the β* reach.

  17. Supporting collaborative discussions on asynchronous time: a technological perspective

    OpenAIRE

    Caballé, Santi

    2011-01-01

    The aim of this paper is to report on an experience of using an innovative on-line learning tool to support real, collaborative learning through discussion in asynchronous time. While asynchronous interaction gives rise to unique opportunities that support active, collaborative learning, unique problems also arise, such as frustration, caused by waiting for other peoples' reactions and feedback and the consequent loss of motivation, which has a negative impact on learning outcomes. In order t...

  18. A Block-Asynchronous Relaxation Method for Graphics Processing Units

    OpenAIRE

    Anzt, H.; Dongarra, J.; Heuveline, Vincent; Tomov, S.

    2011-01-01

    In this paper, we analyze the potential of asynchronous relaxation methods on Graphics Processing Units (GPUs). For this purpose, we developed a set of asynchronous iteration algorithms in CUDA and compared them with a parallel implementation of synchronous relaxation methods on CPU-based systems. For a set of test matrices taken from the University of Florida Matrix Collection we monitor the convergence behavior, the average iteration time and the total time-to-solution time. Analyzing the r...

  19. Functional asynchronous networks: Factorization of dynamics and function

    Directory of Open Access Journals (Sweden)

    Bick Christian

    2016-01-01

    Full Text Available In this note we describe the theory of functional asynchronous networks and one of the main results, the Modularization of Dynamics Theorem, which for a large class of functional asynchronous networks gives a factorization of dynamics in terms of constituent subnetworks. For these networks we can give a complete description of the network function in terms of the function of the events comprising the network and thereby answer a question originally raised by Alon in the context of biological networks.

  20. Novel Asynchronous Wrapper and Its Application to GALS Systems

    Institute of Scientific and Technical Information of China (English)

    Zhuang Shengxian; Peng Anjin; Lars Wanhammar

    2006-01-01

    An asynchronous wrapper with novel handshake circuits for data communication in globally asynchronous locally synchronous (GALS) systems is proposed. The handshake circuits include two communication ports and a local clock generator. Two approaches for the implementation of communication ports are presented, one with pure standard cells and the others with Müller-C elements. The detailed design methodology for GALS systems is given and the circuits are validated with VHDL and circuits simulation in standard CMOS technology.

  1. Commande adaptive d'une machine asynchrone

    Science.gov (United States)

    Slama-Belkhodja, I.; de Fornel, B.

    1996-06-01

    The paper deals with an indirect self-tuning speed control for an induction motor supplied by a chopper-filter-inverter system. Input/Output models are identified with the recursive least squares algorithm and the controller adaptation is based on a pole assignement strategy. Emphasis is put on the evaluation of the parameter identification in order to avoid instabilities because of disturbances or insufficient excitations. This is especially of importance when the adaptive control is carried out in closed loop systems and without additional test signals. Simulation results show the improvement of the dynamic responses and the robustness against load variations or parameters variations (rotor resistance, inertia). Cat article décrit une stratégie de commande adaptive indirecte à Placement de Pôles (PP), appliquée à la commande en vitesse d'une machine asynchrone alimentée par un ensemble hacheur-filtre-onduleur de tension. L'algorithme des Moindres Carrés Récursifs (MCR) est utilisé pour l'identification des modèles de comportement type entrées/sorties. Un intérêt particulier est porté à la mise en oeuvre de cet algorithme et à la discussion de ses résultats, tenant compte des erreurs de modélisation et de la nature peu riche en excitations des entrées du processus. Différents régimes transitoires ont été simulés pour apprécier l'apport de cette association (MCR-PP) : démarrages et inversion des sens de rotation, à vide et en charges, applications d'échelons de couple résistant, variations paramétriques. Les résultats permettent d'illustrer, tant au niveau des performances que de la robustesse, l'apport d'une telle commande adaptive pour des entraînements électriques avec une machine asynchrone.

  2. A Quantitative Comparison of Chrysanthine Theory and Performance Practice of Scale Tuning, Steps, and Prominence of the Octoechos in Byzantine Chant

    DEFF Research Database (Denmark)

    Panteli, Maria; Purwins, Hendrik

    2013-01-01

    Byzantine Chant performance practice is computationally compared to the Chrysanthine theory of the eight Byzantine Tones (octoechos). Intonation, steps, and prominence of scale degrees are quantified, based on pitch class profiles. The novel procedure introduced here comprises the following...... analysis steps: 1) The pitch trajectory is extracted and post processed with music-specific filters. 2) Pitch class histograms are calculated by kernel smoothing. 3) Histogram peaks are detected. 4) Phrase ending analysis aids the finding of the tonic to align pitch histograms. 5) The theoretical scale....... The analysis of 94 Byzantine Chants performed by 4 singers shows a tendency of the singers to level theoretic particu- larities of the echos that stand out of the general norm in the octoechos: theoretically extremely large steps are diminished in performance. The empirical intonation of the IV. scale degree...

  3. Asynchronous Rate Chaos in Spiking Neuronal Circuits.

    Directory of Open Access Journals (Sweden)

    Omri Harish

    2015-07-01

    Full Text Available The brain exhibits temporally complex patterns of activity with features similar to those of chaotic systems. Theoretical studies over the last twenty years have described various computational advantages for such regimes in neuronal systems. Nevertheless, it still remains unclear whether chaos requires specific cellular properties or network architectures, or whether it is a generic property of neuronal circuits. We investigate the dynamics of networks of excitatory-inhibitory (EI spiking neurons with random sparse connectivity operating in the regime of balance of excitation and inhibition. Combining Dynamical Mean-Field Theory with numerical simulations, we show that chaotic, asynchronous firing rate fluctuations emerge generically for sufficiently strong synapses. Two different mechanisms can lead to these chaotic fluctuations. One mechanism relies on slow I-I inhibition which gives rise to slow subthreshold voltage and rate fluctuations. The decorrelation time of these fluctuations is proportional to the time constant of the inhibition. The second mechanism relies on the recurrent E-I-E feedback loop. It requires slow excitation but the inhibition can be fast. In the corresponding dynamical regime all neurons exhibit rate fluctuations on the time scale of the excitation. Another feature of this regime is that the population-averaged firing rate is substantially smaller in the excitatory population than in the inhibitory population. This is not necessarily the case in the I-I mechanism. Finally, we discuss the neurophysiological and computational significance of our results.

  4. Managing Asynchronous Data in ATLAS's Concurrent Framework

    CERN Document Server

    Baines, John; The ATLAS collaboration

    2016-01-01

    In order to be able to make effective use of emerging hardware, where the amount of memory available to any CPU is rapidly decreasing as the core count continues to rise, ATLAS has begun a migration to a concurrent, multi-threaded software framework, known as AthenaMT. Significant progress has been made in implementing AthenaMT - we can currently run realistic Geant4 simulations on massively concurrent machines. the migration of realistic prototypes of reconstruction workflows is more difficult, given the large amounts of legacy code and the complexity and challenges of reconstruction software. These types of workflows, however, are the types that will most benefit from the memory reduction features of a multi-threaded framework. One of the challenges that we will report on in this paper is the re-design and implementation of several key asynchronous technologies whose behaviour is radically different in a concurrent environment than in a serial one, namely the management of Conditions data and the Detector D...

  5. Rapid, generalized adaptation to asynchronous audiovisual speech.

    Science.gov (United States)

    Van der Burg, Erik; Goodbourn, Patrick T

    2015-04-07

    The brain is adaptive. The speed of propagation through air, and of low-level sensory processing, differs markedly between auditory and visual stimuli; yet the brain can adapt to compensate for the resulting cross-modal delays. Studies investigating temporal recalibration to audiovisual speech have used prolonged adaptation procedures, suggesting that adaptation is sluggish. Here, we show that adaptation to asynchronous audiovisual speech occurs rapidly. Participants viewed a brief clip of an actor pronouncing a single syllable. The voice was either advanced or delayed relative to the corresponding lip movements, and participants were asked to make a synchrony judgement. Although we did not use an explicit adaptation procedure, we demonstrate rapid recalibration based on a single audiovisual event. We find that the point of subjective simultaneity on each trial is highly contingent upon the modality order of the preceding trial. We find compelling evidence that rapid recalibration generalizes across different stimuli, and different actors. Finally, we demonstrate that rapid recalibration occurs even when auditory and visual events clearly belong to different actors. These results suggest that rapid temporal recalibration to audiovisual speech is primarily mediated by basic temporal factors, rather than higher-order factors such as perceived simultaneity and source identity. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  6. Parallel asynchronous systems and image processing algorithms

    Science.gov (United States)

    Coon, D. D.; Perera, A. G. U.

    1989-01-01

    A new hardware approach to implementation of image processing algorithms is described. The approach is based on silicon devices which would permit an independent analog processing channel to be dedicated to evey pixel. A laminar architecture consisting of a stack of planar arrays of the device would form a two-dimensional array processor with a 2-D array of inputs located directly behind a focal plane detector array. A 2-D image data stream would propagate in neuronlike asynchronous pulse coded form through the laminar processor. Such systems would integrate image acquisition and image processing. Acquisition and processing would be performed concurrently as in natural vision systems. The research is aimed at implementation of algorithms, such as the intensity dependent summation algorithm and pyramid processing structures, which are motivated by the operation of natural vision systems. Implementation of natural vision algorithms would benefit from the use of neuronlike information coding and the laminar, 2-D parallel, vision system type architecture. Besides providing a neural network framework for implementation of natural vision algorithms, a 2-D parallel approach could eliminate the serial bottleneck of conventional processing systems. Conversion to serial format would occur only after raw intensity data has been substantially processed. An interesting challenge arises from the fact that the mathematical formulation of natural vision algorithms does not specify the means of implementation, so that hardware implementation poses intriguing questions involving vision science.

  7. Asynchronous Rate Chaos in Spiking Neuronal Circuits

    Science.gov (United States)

    Harish, Omri; Hansel, David

    2015-01-01

    The brain exhibits temporally complex patterns of activity with features similar to those of chaotic systems. Theoretical studies over the last twenty years have described various computational advantages for such regimes in neuronal systems. Nevertheless, it still remains unclear whether chaos requires specific cellular properties or network architectures, or whether it is a generic property of neuronal circuits. We investigate the dynamics of networks of excitatory-inhibitory (EI) spiking neurons with random sparse connectivity operating in the regime of balance of excitation and inhibition. Combining Dynamical Mean-Field Theory with numerical simulations, we show that chaotic, asynchronous firing rate fluctuations emerge generically for sufficiently strong synapses. Two different mechanisms can lead to these chaotic fluctuations. One mechanism relies on slow I-I inhibition which gives rise to slow subthreshold voltage and rate fluctuations. The decorrelation time of these fluctuations is proportional to the time constant of the inhibition. The second mechanism relies on the recurrent E-I-E feedback loop. It requires slow excitation but the inhibition can be fast. In the corresponding dynamical regime all neurons exhibit rate fluctuations on the time scale of the excitation. Another feature of this regime is that the population-averaged firing rate is substantially smaller in the excitatory population than in the inhibitory population. This is not necessarily the case in the I-I mechanism. Finally, we discuss the neurophysiological and computational significance of our results. PMID:26230679

  8. The Byzantine Silver Bowls in the Sutton Hoo Ship Burial and Tree-Worship in Anglo-Saxon England

    Directory of Open Access Journals (Sweden)

    Michael D. J. Bintley

    2011-12-01

    Full Text Available The ten Byzantine silver bowls included amongst the grave goods interred in the chamber of the Mound 1 ship burial at Sutton Hoo remain one of the most puzzling features of this site. It has been suggested that these items, which lay separated from the rest of the silver in the burial and close to the head of the body-space (where no body was found, may have had some special meaning which has never been discovered. This paper will argue that one of the possible keys to unlocking their significance may be found in the central roundel that adorns the centre of each bowl in the form of a rosette. These bowls, which are thought to have been manufactured in the eastern provinces of the Byzantine Empire in c. 600, entered the British Isles in unknown circumstances before coming into the possession of the man buried in (or commemorated by the Mound 1 burial. Through comparison with contemporary sculpture and vernacular literature, I will suggest that this central rosette, which was associated with both the cross of Christ and sacred trees in Byzantine sculpture, may have served as a conventional bridge between Christian and pre-Christian religious traditions associated with sacred trees in Anglo-Saxon England. The central rosettes adorning each of these bowls may have been understood as the flower of a sacred tree. Since the latter appears to have figured in Anglian paganism it is possible that the bowls may helped to convert the Anglian aristocracy, bridging a gap between Germanic insular religious traditions and those that were being introduced to Britain at the time that the ship burial itself took place.

  9. The “Whirling Disk” in the Byzantine Iconography. Search for Meaning

    Directory of Open Access Journals (Sweden)

    Leshcheva Yana Igorevna

    2014-09-01

    Full Text Available Τhe article studies the plot of «whirling disk», as an example of light symbolics of the Byzantine iconography of the 11-14th centuries. The author brings up the existing hypotheses of interpretations of this phenomenon and analyzes theological sources which serve as the basis for conclusion about possible symbolic value of this iconographic plot. The author studies the specific iconographic monuments of Cappadocia, Sinai, Thessalonica, Serbia. The analysis of disks’ images allows to make the following supervision: disks were often represented in the most important places of temple space and significant iconographic plots; disks had various art execution and color scheme; the form of disk and idea of whirling were common for all examples. When the disk consists of three segments, it makes sense to assume this trinity, as a symbol of the Holy Trinity. The form of a rotating or shining disk, especially on the Sinai monuments where gold color is the main and form-building element of a luminescence suggests symbolical parallels with a solar disk especially as both in the Scriptus, and in theological works the sun is the image of God or sanctity and good fortune granted by Him. The following assumption of symbolics of rotating or shining disks is consolidated to understanding them as Divine energy. Considering all possible options, the most convincing assumption, from our point of view, is that understanding of rotating disks as Divine energy it has rather serious theological justification in the developed orthodox doctrine about Divine light and energies.

  10. Ekphrasis Earos. Le topos de la venue du printemps chez des auteurs byzantins

    Directory of Open Access Journals (Sweden)

    Marina Loukaki

    2013-04-01

    Full Text Available La description de la venue du printemps (ekphrasis earos, un topos aux composantes spécifiques dans la littérature de la seconde sophistique, devint l’ objet d’ enseignement reproduit de façon stéréotypée dans les écoles de Rhétorique protobyzantines. La symbolique de la renaissance de la nature s’ est révélée particulièrement favorable à la didascalie chrétienne comme image du Christ ressuscité ; ainsi, l’ekphrasis earos se retrouve dans plusieurs homélies sur Pâques, le Baptême, la Nativité du Christ, l’Annonciation de la Vierge, etc. La jonction de la tradition chrétienne avec la tradition païenne dans la composition des descriptions du printemps semble qu’ elle fut favorisée dans le milieu scolaire de l’ époque médio-byzantine. Les ekphraseis earos de Libanius (Progym. XII 7, de Grégoire de Nazianze (Or. 44 et de Pseudo-Méléagre (AP IX 363 furent des modèles. À partir du XIIe siècle, les nouvelles tendances de la littérature, qui ont remis à l’honneur le roman d’ amour, le monde naturel et les détails de la vie quotidienne, ont donné lieu à des compositions dépourvues de toute allusion chrétienne.

  11. The Byzantine Empress Zoe Porphyrogenita and the quest for eternal youth.

    Science.gov (United States)

    Panas, Marios; Poulakou-Rebelakou, Effie; Kalfakis, Nicoalos; Vassilopoulos, Dimitrios

    2012-09-01

    The diachronically continuous struggle for eternal youth as represented by the Byzantine Empress Zoe Porphyrogenita (978-1050). The presentation of a beautiful empress, trying to keep her youth appearance until a prolonged age, applying on herself cosmetic essences and fragrances made in her personal laboratory into the imperial palace. The review of the relevant literature and the historical evidence derived from the historians and chroniclers of her era, as well as the surviving images of Zoe. The eye-witness chroniclers of the era describe her as blonde, with bright white skin, lack of wrinkles, and a very young girl appearance, preserving her beauty even into her 60s. All the historical sources agree that her main occupation was the manufacture of cosmetic essences, and for this purpose, she had installed a laboratory (myrepseion) in her private quarters, where she prepared various drugs and perfumes, spending much of her time for these activities. It is noteworthy that her first two husbands died under circumstances that aroused suspicions of Zoe's involvement in their deaths, as she had parallel love affairs. The best known image of Zoe is the mosaic panel in Saint Sophia, the cathedral Church of Constantinople and her representation has been long discussed, as she was 64 years old at the time of the scene apparently depicted in the panel, and maybe she took the opportunity of adding a more pleasing portrait of herself. The preservation of beauty is a timeless quest and cosmetic dermatology has its origins in antiquity and medieval times. © 2012 Wiley Periodicals, Inc.

  12. The Power of the Dramatic «Auctoritas»: Francisco de Rojas Zorrilla in front of the Byzantine Comedy

    Directory of Open Access Journals (Sweden)

    Julián González-Barrera

    2018-01-01

    Full Text Available Francisco de Rojas Zorrilla was one of the poets most favoured by the Court, even more than Calderón de la Barca. That royal favour gave him a creative freedom that lead to experiment with new methods, genres and motifs. That was the case of Persiles and Sigismunda, not only a mere adaptation of the cervantine novel, but also an attempt to surpass the model that Lope de Vega had created for the byzantine comedy, adding new formulas to a genre considered closed.

  13. Antikos tradicijos ir naujos tendencijos Bizantijos rašytinėje kalboje | Traditions of Antiquity and New Tendencies in Written Greek of the Byzantine Period

    Directory of Open Access Journals (Sweden)

    Kristina Svarevičiūtė

    2013-12-01

    Full Text Available In the Byzantine period, the norms of written Greek were primarily rooted in the ancient Greek literary tradition and not in the native linguistic competence. The article touches upon the questions linked to the role of rhetorical theory and techniques reinforced by the Greek educational system and the Byzantine Atticism. Particular attention is paid to the different written registers – low, middle, and high –, different styles according to genre and period, and the lack of consistency in writing at all levels.

  14. Effect of asynchronous updating on the stability of cellular automata

    International Nuclear Information System (INIS)

    Baetens, J.M.; Van der Weeën, P.; De Baets, B.

    2012-01-01

    Highlights: ► An upper bound on the Lyapunov exponent of asynchronously updated CA is established. ► The employed update method has repercussions on the stability of CAs. ► A decision on the employed update method should be taken with care. ► Substantial discrepancies arise between synchronously and asynchronously updated CA. ► Discrepancies between different asynchronous update schemes are less pronounced. - Abstract: Although cellular automata (CAs) were conceptualized as utter discrete mathematical models in which the states of all their spatial entities are updated simultaneously at every consecutive time step, i.e. synchronously, various CA-based models that rely on so-called asynchronous update methods have been constructed in order to overcome the limitations that are tied up with the classical way of evolving CAs. So far, only a few researchers have addressed the consequences of this way of updating on the evolved spatio-temporal patterns, and the reachable stationary states. In this paper, we exploit Lyapunov exponents to determine to what extent the stability of the rules within a family of totalistic CAs is affected by the underlying update method. For that purpose, we derive an upper bound on the maximum Lyapunov exponent of asynchronously iterated CAs, and show its validity, after which we present a comparative study between the Lyapunov exponents obtained for five different update methods, namely one synchronous method and four well-established asynchronous methods. It is found that the stability of CAs is seriously affected if one of the latter methods is employed, whereas the discrepancies arising between the different asynchronous methods are far less pronounced and, finally, we discuss the repercussions of our findings on the development of CA-based models.

  15. ASCERTAINMENT OF THE EQUIVALENT CIRCUIT PARAMETERS OF THE ASYNCHRONOUS MACHINE

    Directory of Open Access Journals (Sweden)

    V. S. Safaryan

    2015-01-01

    Full Text Available The article considers experimental and analytical determination of the asynchronous machine equivalent-circuit parameters with application of the reference data. Transient processes investigation of the asynchronous machines necessitates the equivalent circuit parameters (resistance impedance, inductances and coefficient of the stator-rotor contours mutual inductance that help form the transitory-process mathematical simulation model. The reference books do not provide those parameters; they instead give the rated ones (active power, voltage, slide, coefficient of performance and capacity coefficient as well as the ratio of starting and nominal currents and torques. The noted studies on the asynchronous machine equivalent-circuits parametrization fail to solve the problems ad finem or solve them with admissions. The paper presents experimental and analytical determinations of the asynchronous machine equivalent-circuit parameters: the experimental one based on the results of two measurements and the analytical one where the problem boils down to solving a system of nonlineal algebraic equations. The authors investigate the equivalent asynchronous machine input-resistance properties and adduce the dependence curvatures of the input-resistances on the slide. They present a symbolic model for analytical parameterization of the asynchronous machine equivalent-circuit that represents a system of nonlineal equations and requires one of the rotor-parameters arbitrary assignment. The article demonstrates that for the asynchronous machine equivalent-circuit experimental parameterization the measures are to be conducted of the stator-circuit voltage, current and active power with two different slides and arbitrary assignment of one of the rotor parameters. The paper substantiates the fact that additional measurement does not discard the rotor-parameter choice arbitrariness. The authors establish that in motoring mode there is a critical slide by which the

  16. IHadoop: Asynchronous iterations for MapReduce

    KAUST Repository

    Elnikety, Eslam Mohamed Ibrahim

    2011-11-01

    MapReduce is a distributed programming frame-work designed to ease the development of scalable data-intensive applications for large clusters of commodity machines. Most machine learning and data mining applications involve iterative computations over large datasets, such as the Web hyperlink structures and social network graphs. Yet, the MapReduce model does not efficiently support this important class of applications. The architecture of MapReduce, most critically its dataflow techniques and task scheduling, is completely unaware of the nature of iterative applications; tasks are scheduled according to a policy that optimizes the execution for a single iteration which wastes bandwidth, I/O, and CPU cycles when compared with an optimal execution for a consecutive set of iterations. This work presents iHadoop, a modified MapReduce model, and an associated implementation, optimized for iterative computations. The iHadoop model schedules iterations asynchronously. It connects the output of one iteration to the next, allowing both to process their data concurrently. iHadoop\\'s task scheduler exploits inter-iteration data locality by scheduling tasks that exhibit a producer/consumer relation on the same physical machine allowing a fast local data transfer. For those iterative applications that require satisfying certain criteria before termination, iHadoop runs the check concurrently during the execution of the subsequent iteration to further reduce the application\\'s latency. This paper also describes our implementation of the iHadoop model, and evaluates its performance against Hadoop, the widely used open source implementation of MapReduce. Experiments using different data analysis applications over real-world and synthetic datasets show that iHadoop performs better than Hadoop for iterative algorithms, reducing execution time of iterative applications by 25% on average. Furthermore, integrating iHadoop with HaLoop, a variant Hadoop implementation that caches

  17. IHadoop: Asynchronous iterations for MapReduce

    KAUST Repository

    Elnikety, Eslam Mohamed Ibrahim; El Sayed, Tamer S.; Ramadan, Hany E.

    2011-01-01

    MapReduce is a distributed programming frame-work designed to ease the development of scalable data-intensive applications for large clusters of commodity machines. Most machine learning and data mining applications involve iterative computations over large datasets, such as the Web hyperlink structures and social network graphs. Yet, the MapReduce model does not efficiently support this important class of applications. The architecture of MapReduce, most critically its dataflow techniques and task scheduling, is completely unaware of the nature of iterative applications; tasks are scheduled according to a policy that optimizes the execution for a single iteration which wastes bandwidth, I/O, and CPU cycles when compared with an optimal execution for a consecutive set of iterations. This work presents iHadoop, a modified MapReduce model, and an associated implementation, optimized for iterative computations. The iHadoop model schedules iterations asynchronously. It connects the output of one iteration to the next, allowing both to process their data concurrently. iHadoop's task scheduler exploits inter-iteration data locality by scheduling tasks that exhibit a producer/consumer relation on the same physical machine allowing a fast local data transfer. For those iterative applications that require satisfying certain criteria before termination, iHadoop runs the check concurrently during the execution of the subsequent iteration to further reduce the application's latency. This paper also describes our implementation of the iHadoop model, and evaluates its performance against Hadoop, the widely used open source implementation of MapReduce. Experiments using different data analysis applications over real-world and synthetic datasets show that iHadoop performs better than Hadoop for iterative algorithms, reducing execution time of iterative applications by 25% on average. Furthermore, integrating iHadoop with HaLoop, a variant Hadoop implementation that caches

  18. THE ANDREIOS EUNUCH-COMMANDER NARSES: SIGN OF A DECOUPLING OF MARTIAL VIRTUES AND MASCULINITY IN THE EARLY BYZANTINE EMPIRE?

    Directory of Open Access Journals (Sweden)

    Michael Edward Stewart

    2015-12-01

    Full Text Available The sixth-century Byzantine general Narses (478-573 has long earned historians’ respect. This acclaim is deserved since his major victories over the Goths in 552 and versus the Franks and Alamanni in 554, helped to secure the Emperor Justinian I’s (ruled 527-565 reconquest of Italy. So too did Narses perform admirably for twelve years in his role as prefect of Italy. Of course, it has always been important to emphasize that Narses was a eunuch. Indeed, for many modern historians, Narses’ identity as a castrate is more important for study than his military deeds and political achievements that proved ephemeral. For some, the presence of a eunuch in such an essential military role indicates a turning away from codes of generalship based on traditional martial courage and manliness. This paper questions such a view. It suggests that Byzantium had a much more flexible notion of the gender status of eunuchs than some recent scholarship allows. Indeed, I will show that Narses fits into a continuing hegemony of traditional masculine values based on the supremacy of Byzantine men’s martial virtues.

  19. New Sphragistic Finds from the Environs of Byzantine Cherson (to the iIssue of the Correspondence Addressees

    Directory of Open Access Journals (Sweden)

    Nikolay A. Alekseenko

    2016-11-01

    Full Text Available Increased interest to the sigillographic artifacts found over the large areas adjacent to the chief administrative and economic centers of medieval Crimea currently allows to expand greatly the geographical map of the molybdoboulloi finds in this region. The topography of the finds in the areas surrounding Cherson had recently expanded significantly as well. Seals originating apparently from the settlements adjacent immediately to the ancient city, as well as from the places very remote from it became known. New finds of Byzantine seals (for instance, the seals of kommerkiarios Theodore, the end of the 6th century, of patrikios and genikos logothetes Petronas, the first half of the 9th century, of anthypatos, patrikios, imperial protospatharios and genikos logothetes Elissios, the second half of the 10th century, of (protospatharios and strategos of Cefalonia, of imperial protospatharios ™pr toà Crusotriklßnou and strategos of Cherson Theodore, the 10th – 11th centuries, as well as of protospatharios and strategos Joseph, with a sufficiently accurate localization of their origin provide new information about this sigillographic artifacts themselves, as well as clarify the geography of the Byzantine presence in the southwestern Taurica, particularly showing places yet poorly highlighted by other types of sources.

  20. Barbarians in the City: Burials of the Germans in the Urban Cemeteries of Northern Illyricum in the Early Byzantine Period

    Directory of Open Access Journals (Sweden)

    Miсhеl Kazanskiy

    2017-11-01

    Full Text Available In this paper we consider the topography of the burials of the Early Byzantine period (5th – 6th centuries, containing in their inventory items of German origin found in some cities of Northern Illyricum, whose necropolises were subjected to extensive excavations: Sirmium, Singidunum, Viminacium (present-day Northern Serbia. Two different types of burial places with German objects were witnessed on these city burials: isolated burials on cemeteries common to the whole population and separate cemeteries with the predominance of the German element. It can be assumed that these different types of organization of the funerary space correspond to different forms of settling of barbarians in the cities of the northern borderland of the Late Roman / Early Byzantine Illyricum. The barbarous presence in the urban burial context is very slight. In Syrmium, which repeatedly fell under the power of the barbarians (priests, gepids, a few barbarous burials were committed in cemeteries, which belonged mainly to the Roman city population, which indicates a fairly deep integration of the outgoing barbarians into the urban late-antique environment. In Singidunum and Viminacium, the frontier fortresses on the Danube, special “barbarian” cemeteries stand out, since the barbarians settled here were primarily a military force, that is, a separate social group with its own structure. It is also possible that unlike Sirmium, where archaeological traces of the presence of the Roman population are clearly revealed, barbarian mercenaries and their families accounted for a numerical majority in the garrison towns of the Danube borderland.

  1. Simulating fail-stop in asynchronous distributed systems

    Science.gov (United States)

    Sabel, Laura; Marzullo, Keith

    1994-01-01

    The fail-stop failure model appears frequently in the distributed systems literature. However, in an asynchronous distributed system, the fail-stop model cannot be implemented. In particular, it is impossible to reliably detect crash failures in an asynchronous system. In this paper, we show that it is possible to specify and implement a failure model that is indistinguishable from the fail-stop model from the point of view of any process within an asynchronous system. We give necessary conditions for a failure model to be indistinguishable from the fail-stop model, and derive lower bounds on the amount of process replication needed to implement such a failure model. We present a simple one-round protocol for implementing one such failure model, which we call simulated fail-stop.

  2. The Design of Finite State Machine for Asynchronous Replication Protocol

    Science.gov (United States)

    Wang, Yanlong; Li, Zhanhuai; Lin, Wei; Hei, Minglei; Hao, Jianhua

    Data replication is a key way to design a disaster tolerance system and to achieve reliability and availability. It is difficult for a replication protocol to deal with the diverse and complex environment. This means that data is less well replicated than it ought to be. To reduce data loss and to optimize replication protocols, we (1) present a finite state machine, (2) run it to manage an asynchronous replication protocol and (3) report a simple evaluation of the asynchronous replication protocol based on our state machine. It's proved that our state machine is applicable to guarantee the asynchronous replication protocol running in the proper state to the largest extent in the event of various possible events. It also can helpful to build up replication-based disaster tolerance systems to ensure the business continuity.

  3. PsychVACS: a system for asynchronous telepsychiatry.

    Science.gov (United States)

    Odor, Alberto; Yellowlees, Peter; Hilty, Donald; Parish, Michelle Burke; Nafiz, Najia; Iosif, Ana-Maria

    2011-05-01

    To describe the technical development of an asynchronous telepsychiatry application, the Psychiatric Video Archiving and Communication System. A client-server application was developed in Visual Basic.Net with Microsoft(®) SQL database as the backend. It includes the capability of storing video-recorded psychiatric interviews and manages the workflow of the system with automated messaging. Psychiatric Video Archiving and Communication System has been used to conduct the first ever series of asynchronous telepsychiatry consultations worldwide. A review of the software application and the process as part of this project has led to a number of improvements that are being implemented in the next version, which is being written in Java. This is the first description of the use of video recorded data in an asynchronous telemedicine application. Primary care providers and consulting psychiatrists have found it easy to work with and a valuable resource to increase the availability of psychiatric consultation in remote rural locations.

  4. The Byzantine Narration of Our Father Agapius and Its Slavonic Translation

    Directory of Open Access Journals (Sweden)

    Daria S. Penskaya

    2017-12-01

    Full Text Available The paper introduces the Greek original of the hagiographic text The Narration of Our Father Agapius (presumably from the 5th–6th centuries, which was widely known in Slavonic tradition but remains almost unknown neither to historians of Byzantine culture and to Slavists. The paper consists of two parts. Drawing upon the critical edition of the text, the first part discusses the peculiarities of the Greek tradition. The manuscript from Athens is much more accurate than the second of the two existing Greek manuscripts, from St. Petersburg. Nevertheless, in some cases the Athenian manuscript is defective. Thus, the first culmination of the narrative, the description of the theophany in the Garden of Paradise, is absent. The episode of the raising of the dead son of a widow is also reduced, probably due to its somewhat magical flavor. However, the manuscript from St. Petersburg in its second part is inferior to the Athenian manuscript reducing vast descriptions—prayers and various details of the rites. A comparison of the two Greek manuscripts reveals vivid folkloric and evangelic images of the Greek original that were concealed by various mistakes made by scribes. The second part of the article compares the Greek original of the Narration with the Slavonic translation. The text from the Uspenskij Sbornik is the main focus of the comparison, but other evidence from the South and East Slavonic traditions are also taken into account. The translation eliminated quite a few major traces of the Greek original. Thus, an intimate first-person narration and a striking detail in which the main character himself tells about his death are eliminated. The names of Paradise sites, theological discourses, exhortations, any vast descriptions disappear. The adjusted symbolic structure of the Narration that reveals the transformation of the character from myst to mystagogue is eliminated in the Slavonic tradition and the main idea of the Greek text

  5. Are the classical historical geography of the Byzantine world and Gis technology a contradiction? On the usage of contemporary technologies in the humanities

    Directory of Open Access Journals (Sweden)

    Popović St. Mihailo

    2013-01-01

    Full Text Available The article highlights the latest developments in the field of Digital Humanities. It indicates in which ways these technologies are already used in the historical and geographical science throughout the world and how they could be integrated systematically into Byzantine Studies. In the first part of the article international projects, which are based on GIS (Geographic Information Systems, and their links in the World Wide Web are presented. In the second part the author shows on the basis of his scholarly results on the historical geography of Byzantine Macedonia, how medieval written sources can be transferred into digital format in order to achieve a higher level of spatial data analysis. The neglect of this important and recent scholarly approach in the 21st century could lead to the marginalisation of Byzantine Studies in general, and of the historical geography of the Byzantine Empire in particular. [Projekat Ministarstva nauke Republike Srbije, br. 177015: Hrišćanska kultura na Balkanu u srednjem veku: Vizantijsko carstvo, Srbi i Bugari od 9. do 15. veka

  6. Antonio Muñoz (1884-1960 and the history of Byzantine illumination: a new field of research in Italy under the aegis of Adolfo Venturi

    Directory of Open Access Journals (Sweden)

    Giovanni Gasbarri

    2015-12-01

    Full Text Available Antonio Muñoz (1884-1960 is usually remembered for his successful career in the administration and conservation of the monumental heritage in Rome during the Fascist era. His brief yet relevant activity as a Byzantinist is often underestimated in the secondary literature, despite the fact that, before the 1914-18 war, he was unanimously considered as the most promising Italian specialist in Byzantine art. From 1903 onwards, after completing his studies with Adolfo Venturi, Muñoz developed an interest in Byzantine illumination, which became his primary area of expertise. At this early stage, his most important work was without doubt the new edition of the Rossano Gospels (1907, which was internationally praised as a significant step forward in the history of Byzantine illumination. With the support of previously unpublished or little-known documents, this article aims to provide a new critical analysis of Muñoz’s research on Byzantine illumination, as well as a more balanced evaluation of its impact on the scholarly community at the turn of the twentieth century.

  7. Asynchronous glaciations in arid continental climate

    Science.gov (United States)

    Batbaatar, Jigjidsurengiin; Gillespie, Alan R.; Fink, David; Matmon, Ari; Fujioka, Toshiyuki

    2018-02-01

    Mountain glaciers at ∼26-19 ka, during the global Last Glacial Maximum near the end of the last 105 yr glacial cycle, are commonly considered on the basis of dating and field mapping in several well-studied areas to have been the largest of the late Quaternary and to have advanced synchronously from region to region. However, a numerical sensitivity model (Rupper and Roe, 2008) predicts that the fraction of ablation due to melting varies across Central Asia in proportion to the annual precipitation. The equilibrium-line altitude of glaciers across this region likely varies accordingly: in high altitude, cold and arid regions sublimation can ablate most of the ice, whereas glaciers fed by high precipitation cannot ablate completely due to sublimation alone, but extend downhill until higher temperatures there cause them to melt. We have conducted field studies and 10Be dating at five glaciated sites along a precipitation gradient in Mongolia to test the Rupper/Roe model. The sites are located in nearby 1.875 × 1.875° cells of the Rupper/Roe model, each with a different melt fraction, in this little-studied region. The modern environment of the sites ranges from dry subhumid in the north (47.7° N) to arid in the south (45° N). Our findings show that the maximum local advances in the dry subhumid conditions predated the global Last Glacial Maximum and were likely from MIS 3. However, we also found that at ∼8-7 ka a cirque glacier in one mountain range of the arid Gobi desert grew to a magnitude comparable to that of the local maximum extent. This Holocene maximum occurred during a regional pluvial period thousands of years after the retreat of the Pleistocene glaciers globally. This asynchronous behavior is not predicted by the prevailing and generally correct presumption that glacier advances are dominantly driven by temperature, although precipitation also plays a role. Our findings are consistent with and support the Rupper/Roe model, which calls for

  8. The brain and heart: dancing in unison?

    Science.gov (United States)

    Erasmus, Rajiv T

    2009-02-01

    Coronary artery disease (CAD) and its main complication myocardial infarction are the leading causes of death globally. Environmental factors don't explain the large amount of variance seen in the development of the disease. Given the strong heritability of CAD, some of the unexplained variance may be due to genetic factors. In this issue of the Journal, Jiang and colleagues report a strong association between brain derived neurotrophic factor (BDNF) Val66Met polymorphism and CAD. There is increasing evidence that BDNF is not only involved in neuronal development but also energy expenditure. The results of this study are likely to give further impetus to researching the complex mechanisms and crosstalk that contribute to the pathogenesis of various polygenic disorders.

  9. On the Convergence of Asynchronous Parallel Pattern Search

    International Nuclear Information System (INIS)

    Tamara Gilbson Kolda

    2002-01-01

    In this paper the authors prove global convergence for asynchronous parallel pattern search. In standard pattern search, decisions regarding the update of the iterate and the step-length control parameter are synchronized implicitly across all search directions. They lose this feature in asynchronous parallel pattern search since the search along each direction proceeds semi-autonomously. By bounding the value of the step-length control parameter after any step that produces decrease along a single search direction, they can prove that all the processes share a common accumulation point and that such a point is a stationary point of the standard nonlinear unconstrained optimization problem

  10. Application of intelligent soft start in asynchronous motor

    Science.gov (United States)

    Du, Xue; Ye, Ying; Wang, Yuelong; Peng, Lei; Zhang, Suying

    2018-05-01

    The starting way of three phase asynchronous motor has full voltage start and step-down start. Direct starting brings large current impact, causing excessive local temperature to the power grid and larger starting torque will also impact the motor equipment and affect the service life of the motor. Aim at the problem of large current and torque caused by start-up, an intelligent soft starter is proposed. Through the application of intelligent soft start on asynchronous motor, highlights its application advantage in motor control.

  11. DESIGN METHODOLOGY OF SELF-EXCITED ASYNCHRONOUS GENERATOR

    Directory of Open Access Journals (Sweden)

    Berzan V.

    2012-04-01

    Full Text Available The paper sets out the methodology of designing an asynchronous generator with capacitive self-excitation. It is known that its design is possible on the basis of serial synchronous motor with squirrel cage rotor. With this approach, the design reworked only the stator winding of electrical machines, making it cost-effectively implement the creation of the generator. Therefore, the methodology for the design, optimization calculations, the development scheme and the stator winding excitation system gain, not only of practical interest, and may also be useful for specialists in the field of electrical machines in the design of asynchronous generators.

  12. Reliable self-replicating machines in asynchronous cellular automata.

    Science.gov (United States)

    Lee, Jia; Adachi, Susumu; Peper, Ferdinand

    2007-01-01

    We propose a self-replicating machine that is embedded in a two-dimensional asynchronous cellular automaton with von Neumann neighborhood. The machine dynamically encodes its shape into description signals, and despite the randomness of cell updating, it is able to successfully construct copies of itself according to the description signals. Self-replication on asynchronously updated cellular automata may find application in nanocomputers, where reconfigurability is an essential property, since it allows avoidance of defective parts and simplifies programming of such computers.

  13. On the theoretical gap between synchronous and asynchronous MPC protocols

    DEFF Research Database (Denmark)

    Beerliová-Trubíniová, Zuzana; Hirt, Martin; Nielsen, Jesper Buus

    2010-01-01

    that in the cryptographic setting (with setup), the sole reason for it is the distribution of inputs: given an oracle for input distribution, cryptographically-secure asynchronous MPC is possible with the very same condition as synchronous MPC, namely t ..., we show that such an input-distribution oracle can be reduced to an oracle that allows each party to synchronously broadcast one single message. This means that when one single round of synchronous broadcast is available, then asynchronous MPC is possible at the same condition as synchronous MPC...

  14. Design issues in the semantics and scheduling of asynchronous tasks.

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, Stephen L.

    2013-07-01

    The asynchronous task model serves as a useful vehicle for shared memory parallel programming, particularly on multicore and manycore processors. As adoption of model among programmers has increased, support has emerged for the integration of task parallel language constructs into mainstream programming languages, e.g., C and C++. This paper examines some of the design decisions in Cilk and OpenMP concerning semantics and scheduling of asynchronous tasks with the aim of informing the efforts of committees considering language integration, as well as developers of new task parallel languages and libraries.

  15. The Use of Monograms on Byzantine Seals in the Early Middle-Ages (6th to 9th Centuries

    Directory of Open Access Journals (Sweden)

    Werner Seibt

    2016-06-01

    Full Text Available The paper deals especially with monograms on Byzantine lead seals. The early form was the block monogram, a type used already in Classical times, which came into fashion in the Byzantine world in the 6th or already in the 5th century and remained important till the early 7th century. Such monograms hide normally a name, a title or an office, the Greek ones in genitive, the Latin ones in nominative or genitive. Many of them can be read in different ways. For the double using of parts of letters for other ones the well-known Latin monogram of Theoderich is explained in detail.  But the “typical Byzantine monogram” became the cross monogram, with letters more or less affixed on the arms of a Greek cross. The earliest example stems from a coin of Justinus I, starting 522, quite earlier than Theodora’s monograms on capitals in the Hagia Sophia. These cruciform monograms presented in the beginning also a name, a title or an office, but in the 8th century already often a combination of them; these monograms with prosopographical information stopped in Byzantium at the end of the 8th century.  On the other hand invocative monograms (like Θεοτόκε βοήθει, often with the tetragram τῷ σῷ δούλῳ in the free quarters of the monogram, started around the middle of the 7th century and can be found till the earlier 11th century. The most common ones were collected by V. Laurent – we use this system till today, though there are much more types documented.  An important problem is that sometimes single letters are “hidden” in another letter, e. g. Lambda in Alpha or Delta, Epsilon in a Kappa on the left bar of a cross monogram, Sigma in Epsilon, Sigma in Kappa, Omikron in Rho, etc. In Vienna we developed a special program to solve many monograms. If we bring all the readable letters of a monogram (including the possibly additional ones in an alphabetical order, and do the same with the letters of names, titles and offices

  16. Adding the Human Touch to Asynchronous Online Learning

    Science.gov (United States)

    Glenn, Cynthia Wheatley

    2018-01-01

    For learners to actively accept responsibility in a virtual classroom platform, it is necessary to provide special motivation extending across the traditional classroom setting into asynchronous online learning. This article explores specific ways to do this that bridge the gap between ground and online students' learning experiences, and how…

  17. Miscellany of Students' Satisfaction in an Asynchronous Learning Environment

    Science.gov (United States)

    Larbi-Siaw, Otu; Owusu-Agyeman, Yaw

    2017-01-01

    This study investigates the determinants of students' satisfaction in an asynchronous learning environment using seven key considerations: the e-learning environment, student-content interaction, student and student interaction, student-teacher interaction, group cohesion and timely participation, knowledge of Internet usage, and satisfaction. The…

  18. An improved modelling of asynchronous machine with skin-effect ...

    African Journals Online (AJOL)

    The conventional method of analysis of Asynchronous machine fails to give accurate results especially when the machine is operated under high rotor frequency. At high rotor frequency, skin-effect dominates causing the rotor impedance to be frequency dependant. This paper therefore presents an improved method of ...

  19. Content Analysis Coding Schemes for Online Asynchronous Discussion

    Science.gov (United States)

    Weltzer-Ward, Lisa

    2011-01-01

    Purpose: Researchers commonly utilize coding-based analysis of classroom asynchronous discussion contributions as part of studies of online learning and instruction. However, this analysis is inconsistent from study to study with over 50 coding schemes and procedures applied in the last eight years. The aim of this article is to provide a basis…

  20. Reconceptualising Moderation in Asynchronous Online Discussions Using Grounded Theory

    Science.gov (United States)

    Vlachopoulos, Panos; Cowan, John

    2010-01-01

    This article reports a grounded theory study of the moderation of asynchronous online discussions, to explore the processes by which tutors in higher education decide when and how to moderate. It aims to construct a theory of e-moderation based on some key factors which appear to influence e-moderation. It discusses previous research on the…

  1. Asynchronous Assessment in a Large Lecture Marketing Course

    Science.gov (United States)

    Downey, W. Scott; Schetzsle, Stacey

    2012-01-01

    Asynchronous assessment, which includes quizzes or exams online or outside class, offers marketing educators an opportunity to make more efficient use of class time and to enhance students' learning experiences by giving them more flexibility and choice in their assessment environment. In this paper, we examine the performance difference between…

  2. Asynchronous Group Review of EFL Writing: Interactions and Text Revisions

    Science.gov (United States)

    Saeed, Murad Abdu; Ghazali, Kamila

    2017-01-01

    The current paper reports an empirical study of asynchronous online group review of argumentative essays among nine English as foreign language (EFL) Arab university learners joining English in their first, second, and third years at the institution. In investigating online interactions, commenting patterns, and how the students facilitate text…

  3. Turing Incompleteness of Asynchronous P Systems with Active Membranes

    OpenAIRE

    Leporati, Alberto; Manzoni, Luca; Porreca, Antonio E.

    2013-01-01

    We prove that asynchronous P systems with active membranes without divi- sion rules can be simulated by place/transition Petri nets, and hence are computationally weaker than Turing machines. This result holds even if the synchronisation mechanisms provided by electrical charges and membrane dissolution are exploited.

  4. Asynchronous online foresight panels: the case of wildfire management

    Science.gov (United States)

    David N. Bengston; Robert L. Olson

    2015-01-01

    Text-based asynchronous online conferencing involves structured online discussion and deliberation among multiple participants from multiple sites in which there is a delay in interaction between contributors. This method has been widely used for a variety of purposes in higher education and other settings, but has not been commonly used in futures research. This paper...

  5. OFDM with Index Modulation for Asynchronous mMTC Networks.

    Science.gov (United States)

    Doğan, Seda; Tusha, Armed; Arslan, Hüseyin

    2018-04-21

    One of the critical missions for next-generation wireless communication systems is to fulfill the high demand for massive Machine-Type Communications (mMTC). In mMTC systems, a sporadic transmission is performed between machine users and base station (BS). Lack of coordination between the users and BS in time destroys orthogonality between the subcarriers, and causes inter-carrier interference (ICI). Therefore, providing services to asynchronous massive machine users is a major challenge for Orthogonal Frequency Division Multiplexing (OFDM). In this study, OFDM with index modulation (OFDM-IM) is proposed as an eligible solution to alleviate ICI caused by asynchronous transmission in uncoordinated mMTC networks. In OFDM-IM, data transmission is performed not only by modulated subcarriers but also by the indices of active subcarriers. Unlike classical OFDM, fractional subcarrier activation leads to less ICI in OFDM-IM technology. A novel subcarrier mapping scheme (SMS) named as Inner Subcarrier Activation is proposed to further alleviate adjacent user interference in asynchronous OFDM-IM-based systems. ISA reduces inter-user interference since it gives more activation priority to inner subcarriers compared with the existing SMS-s. The superiority of the proposed SMS is shown through both theoretical analysis and computer-based simulations in comparison to existing mapping schemes for asynchronous systems.

  6. Designing a Web-Based Asynchronous Innovation/Entrepreneurism Course

    Science.gov (United States)

    Ghandforoush, Parviz

    2017-01-01

    Teaching an online fully asynchronous information technology course that requires students to ideate, build an e-commerce website, and develop an effective business plan involves a well-developed and highly engaging course design. This paper describes the design, development, and implementation of such a course and presents information on…

  7. Study of a centrifugal pump, asynchronous motor and inverter, using ...

    African Journals Online (AJOL)

    The signals generated by the micro controller have been used to program the parallel port of a computer. By reading the recorded bits of the parallel port in LabVIEW software, the signals from the micro controller have been restored and made available to the simulation model of the three-phase inverter, asynchronous ...

  8. Optimization of parameters of special asynchronous electric drives

    Science.gov (United States)

    Karandey, V. Yu; Popov, B. K.; Popova, O. B.; Afanasyev, V. L.

    2018-03-01

    The article considers the solution of the problem of parameters optimization of special asynchronous electric drives. The solution of the problem will allow one to project and create special asynchronous electric drives for various industries. The created types of electric drives will have optimum mass-dimensional and power parameters. It will allow one to realize and fulfill the set characteristics of management of technological processes with optimum level of expenses of electric energy, time of completing the process or other set parameters. The received decision allows one not only to solve a certain optimizing problem, but also to construct dependences between the optimized parameters of special asynchronous electric drives, for example, with the change of power, current in a winding of the stator or rotor, induction in a gap or steel of magnetic conductors and other parameters. On the constructed dependences, it is possible to choose necessary optimum values of parameters of special asynchronous electric drives and their components without carrying out repeated calculations.

  9. Positive semidefinite integrated covariance estimation, factorizations and asynchronicity

    DEFF Research Database (Denmark)

    Boudt, Kris; Laurent, Sébastien; Lunde, Asger

    2017-01-01

    An estimator of the ex-post covariation of log-prices under asynchronicity and microstructure noise is proposed. It uses the Cholesky factorization of the covariance matrix in order to exploit the heterogeneity in trading intensities to estimate the different parameters sequentially with as many...

  10. Positive Semidefinite Integrated Covariance Estimation, Factorizations and Asynchronicity

    DEFF Research Database (Denmark)

    Boudt, Kris; Laurent, Sébastien; Lunde, Asger

    An estimator of the ex-post covariation of log-prices under asynchronicity and microstructure noise is proposed. It uses the Cholesky factorization on the correlation matrix in order to exploit the heterogeneity in trading intensity to estimate the different parameters sequentially with as many...

  11. Developing a Successful Asynchronous Online Extension Program for Forest Landowners

    Science.gov (United States)

    Zobrist, Kevin W.

    2014-01-01

    Asynchronous online Extension classes can reach a wide audience, is convenient for the learner, and minimizes ongoing demands on instructor time. However, producing such classes takes significant effort up front. Advance planning and good communication with contributors are essential to success. Considerations include delivery platforms, content…

  12. First Foreign-Policy Success of Kievan Commanding Elite in Europe: Byzantine Military Campaign of 860 and Askold's Christianization

    Directory of Open Access Journals (Sweden)

    Igor A. Melnichuk

    2013-01-01

    Full Text Available The article, using annalistic sources and Byzantine literary monuments of VIII–IX centuries, attempts to conduct historical and political analysis and estimate major successes of Rus under Askol'd’s reign: Rusichi march on Constantinople in 860 and as a result Christianization of prince and his druzhina. The article presents obvious success of Askold and military and political elite of Rus:- Breakthrough of Russia to the European political space and, consequently, access to economic space: extremely important markets of Byzantium and other states.- Launch of the irreversible process of Christianization of the state, which has become one of the key stages of its development and the important step towards equal access of Russia to the European family of nations.- Selection of Eastern (Orthodox version of Christian doctrine.

  13. Characterization of Byzantine pottery from Oltina (Constanţa County), Romania, using PIXE and Optical Microscopy

    Science.gov (United States)

    Bugoi, Roxana; Talmaţchi, Cristina; Haitǎ, Constantin; Ceccato, Daniele

    2018-02-01

    An assemblage of 58 ceramic shards discovered in archaeological excavations at Oltina, Romania, dated to the 10th-11th century CE, was subjected to archaeometric investigations in order to reveal the raw materials and manufacturing techniques employed by the potters from the Lower Danube zone during the Byzantine ruling. The initial grouping of the shards according to stylistic criteria was refined by the subsequent petrographic study. Optical Microscopy (OM) detailed the general mineralogy and the pottery fabric, i.e. the textural characteristics, porosity and microstructure, surface treatments and firing. The PIXE analyses of potteries performed at AN2000 accelerator of LNL, INFN, Italy led to the identification of the chemical composition of the ceramic shards. The Hierarchical Cluster Analysis of the PIXE data evidenced several categories of shards with distinct compositional signatures, the main division being the one separating the ceramic fragments made of kaolinitic clays from the rest of the Oltina potteries.

  14. ANALYSIS OF THE CULTURAL AND HISTORICAL TOURIST RESOURCE OF THE ROMAN LEGIONARY FORTRESS AND EARLY BYZANTINE TOWN OF NOVAE

    Directory of Open Access Journals (Sweden)

    Plamen Lakov

    2017-12-01

    Full Text Available The article is part of a research series for ancient Roman sites in Northern Bulgaria which aim to present the possibilities of creating a specialized form of cultural and historical product that ensures sustainable utilization of tangible heritage on the Bulgarian coast of the Danube. The methodology applied in assessing the potential of the Roman legionary fortress and Early Byzantine town of Novae is primarily designed for historical and cultural sites. An evaluation is made under the following criteria: potential for development, degree of impact / interaction, degree of modification with relevant indicators. The fieldwork and surveys were made in the summer of 2017 before the active archaeological season. The opportunities for creating a regional tourism product is analysed to ensure the region's recognition and sustainable development as a tourist destination.

  15. The impact of financial institutions on the development of the Byzantine economy (10th-12th centuries

    Directory of Open Access Journals (Sweden)

    Maniatis George C.

    2016-01-01

    Full Text Available This article attempts to ascertain the nature of the financial institutions fashioned diachronically to ensure the orderly operation of the Byzantine economy, encompassing the currency in circulation, credit availability, and the nexus of financial services; to analyze their role and evolution over time; to examine their ability to make rational use of the available financial resources; and ultimately to assess their contribution in ensuring the effective functioning of the marketplace and the economy in the 10th-12th centuries. Emphasis is placed on the effectiveness of the monetary system in providing the requisite liquidity to meet the needs of the productive sectors of the economy; the determining factors of money supply and its sectorial penetration; the measures taken to prevent hoarding and alleviate the gold-dependence of the fiscus; the functional distinction between money-changing and moneylending and its rationale; the rules established for the orderly conduct of currency transactions to prevent unsavory practices; the participants involved in lending operations and the extent of market competition; the importance of credit (and hence debt financing in promoting agriculture, manufacturing, and trade; and the role of the state in safeguarding the soundness of the monetary system, banking services, deals in precious metals and valuables, and in the pricing of capital. Moreover, the paper addresses collateral issues in dispute providing more cogent answers, identifies misinterpreted sources and unsupported assertions, and fills in lacunae. It is hoped that the searching examination of the design and operation of the enacted financial institutional arrangements will provide valuable insights as to their genesis, adaptation over time, and likely performance in light of the Byzantine economic, social and political realities.

  16. The Slavs and Vlachs in the Byzantine system of provincial organization in the Southern Balkans until the XI century: Similarities and differencies

    Directory of Open Access Journals (Sweden)

    Cvetković Miloš

    2012-01-01

    Full Text Available The paper is devoted to establishing the circumstances and manner under which the Slav tribes and Vlachs in the southern Balkans were being integrated into the Byzantine system of provincial administration. Constantinople militarily imposed sovereignty on the settled Slavs, which was the first step towards their integration into the Byzantine state and society. When it comes to Vlachs, there was no use of military force. Special methods were applied to fit their autonomous organization into the frames oh the empire. In this regard, the paper compares the patterns of the integration processes of the two mentioned ethnic groups. [Projekat Ministarstva nauke Republike Srbije, br. 177032: Tradicija, inovacija i identitet u vizantijskom svetu

  17. Asynchronous decision making in a memorized paddle pressing task.

    Science.gov (United States)

    Dankert, James R; Olson, Byron; Si, Jennie

    2008-12-01

    This paper presents a method for asynchronous decision making using recorded neural data in a binary decision task. This is a demonstration of a technique for developing motor cortical neural prosthetics that do not rely on external cued timing information. The system presented in this paper uses support vector machines and leaky integrate-and-fire elements to predict directional paddle presses. In addition to the traditional metrics of accuracy, asynchronous systems must also optimize the time needed to make a decision. The system presented is able to predict paddle presses with a median accuracy of 88% and all decisions are made before the time of the actual paddle press. An alternative bit rate measure of performance is defined to show that the system proposed here is able to perform the task with the same efficiency as the rats.

  18. Parallel, Asynchronous Executive (PAX): System concepts, facilities, and architecture

    Science.gov (United States)

    Jones, W. H.

    1983-01-01

    The Parallel, Asynchronous Executive (PAX) is a software operating system simulation that allows many computers to work on a single problem at the same time. PAX is currently implemented on a UNIVAC 1100/42 computer system. Independent UNIVAC runstreams are used to simulate independent computers. Data are shared among independent UNIVAC runstreams through shared mass-storage files. PAX has achieved the following: (1) applied several computing processes simultaneously to a single, logically unified problem; (2) resolved most parallel processor conflicts by careful work assignment; (3) resolved by means of worker requests to PAX all conflicts not resolved by work assignment; (4) provided fault isolation and recovery mechanisms to meet the problems of an actual parallel, asynchronous processing machine. Additionally, one real-life problem has been constructed for the PAX environment. This is CASPER, a collection of aerodynamic and structural dynamic problem simulation routines. CASPER is not discussed in this report except to provide examples of parallel-processing techniques.

  19. Ultra Low Energy FDSOI Asynchronous Reconfiguration Network for Adaptive Circuits

    Directory of Open Access Journals (Sweden)

    Soundous Chairat

    2017-05-01

    Full Text Available This paper introduces a plug-and-play on-chip asynchronous communication network aimed at the dynamic reconfiguration of a low-power adaptive circuit such as an internet of things (IoT system. By using a separate communication network, we can address both digital and analog blocks at a lower configuration cost, increasing the overall system power efficiency. As reconfiguration only occurs according to specific events and has to be automatically in stand-by most of the time, our design is fully asynchronous using handshake protocols. The paper presents the circuit’s architecture, performance results, and an example of the reconfiguration of frequency locked loops (FLL to validate our work. We obtain an overall energy per bit of 0.07 pJ/bit for one stage, in a 28 nm Fully Depleted Silicon On Insulator (FDSOI technology at 0.6 V and a 1.1 ns/bit latency per stage.

  20. L’église Sainte Sophie de Trébizonde – un repère dans l’architecture religieuse byzantine

    Directory of Open Access Journals (Sweden)

    Vasile M. Demciuc

    2012-07-01

    Full Text Available The historical monument presented in this study is considered by specialists a true landmark in the Byzantine ecclesiastical architecture.The Church of St. Sophia in Trabzon, restored in the mid-twentieth century by specialists from the UK, is now a real attraction not only for historians, but also for tourists because an unique historical, artistic, iconographic and theological message. Basically, this message is given by an iconography program from the 13th century.

  1. A debt in Gonzalo de Céspedes y Meneses: the vitality of the Byzantine model in Historias peregrinas y ejemplares

    Directory of Open Access Journals (Sweden)

    Julián González-Barrera

    2010-12-01

    Full Text Available The generic vagueness of Historias peregrinas y ejemplares (1623 would be a convincing evidence of the experimentation that characterizes the whole prose of Gonzalo de Céspedes y Meneses. Among the confluence of different genres, opposite tendencies and literary trends that make up Historias peregrinas y ejemplares, the vigour of the Greek model is specially outstanding, to such an extent that some of them may be even regarded as genuine short Byzantine novels.

  2. Teleoperation system using Asynchronous transfer mode, ATM network

    International Nuclear Information System (INIS)

    Mohd Dani Baba; A Nasoruddin Mohamad

    1999-01-01

    This paper examines the application of Asynchronous Transfer Mode (ATM) in a distributed industrial environment such as in teleoperation, which performs real time control manipulation from a remote location. In our study, two models of teleoperation are proposed; the first model is a point to point connection and the second model is through an ATM network. The performance results are analysed as to determine whether the two models can support the teleoperation traffics via simulation using commercial software design tool. (Author)

  3. Asynchronous Multi-Party Computation with Quadratic Communication

    DEFF Research Database (Denmark)

    Hirt, Martin; Nielsen, Jesper Buus; Przydatek, Bartosz

    2008-01-01

    We present an efficient protocol for secure multi-party computation in the asynchronous model with optimal resilience. For n parties, up to t < n/3 of them being corrupted, and security parameter κ, a circuit with c gates can be securely computed with communication complexity O(cn^2k) bits, which...... circuit randomization due to Beaver (Crypto’91), and an abstraction of certificates, which can be of independent interest....

  4. Psychophysiological effects of synchronous versus asynchronous music during cycling.

    Science.gov (United States)

    Lim, Harry B T; Karageorghis, Costas I; Romer, Lee M; Bishop, Daniel T

    2014-02-01

    Synchronizing movement to a musical beat may reduce the metabolic cost of exercise, but findings to date have been equivocal. Our aim was to examine the degree to which the synchronous application of music moderates the metabolic demands of a cycle ergometer task. Twenty-three recreationally active men made two laboratory visits. During the first visit, participants completed a maximal incremental ramp test on a cycle ergometer. At the second visit, they completed four randomized 6-min cycling bouts at 90% of ventilatory threshold (control, metronome, synchronous music, and asynchronous music). Main outcome variables were oxygen uptake, HR, ratings of dyspnea and limb discomfort, affective valence, and arousal. No significant differences were evident for oxygen uptake. HR was lower under the metronome condition (122 ± 15 bpm) compared to asynchronous music (124 ± 17 bpm) and control (125 ± 16 bpm). Limb discomfort was lower while listening to the metronome (2.5 ± 1.2) and synchronous music (2.3 ± 1.1) compared to control (3.0 ± 1.5). Both music conditions, synchronous (1.9 ± 1.2) and asynchronous (2.1 ± 1.3), elicited more positive affective valence compared to metronome (1.2 ± 1.4) and control (1.2 ± 1.2), while arousal was higher with synchronous music (3.4 ± 0.9) compared to metronome (2.8 ± 1.0) and control (2.8 ± 0.9). Synchronizing movement to a rhythmic stimulus does not reduce metabolic cost but may lower limb discomfort. Moreover, synchronous music has a stronger effect on limb discomfort and arousal when compared to asynchronous music.

  5. Asynchronous monitoring of the quality of multilevel optical PAM signals

    Science.gov (United States)

    Siuzdak, J.

    2017-08-01

    In the paper, there is analyzed the signal quality assessment method based on delay tap asynchronous sampling, both for binary and multilevel PAM signals. The obtained multilevel phase diagrams are far more complicated than binary ones. The phase diagrams are affected by the signal distortions but it is difficult to relate reliably the phase diagram form to the distortion type and its influence on the signal quality.

  6. Asynchronous Execution of the Fast Multipole Method Using Charm++

    OpenAIRE

    AbdulJabbar, Mustafa; Yokota, Rio; Keyes, David

    2014-01-01

    Fast multipole methods (FMM) on distributed mem- ory have traditionally used a bulk-synchronous model of com- municating the local essential tree (LET) and overlapping it with computation of the local data. This could be perceived as an extreme case of data aggregation, where the whole LET is communicated at once. Charm++ allows a much finer control over the granularity of communication, and has a asynchronous execution model that fits well with the structure of our FMM code. Unlike previous ...

  7. A novel asynchronous access method with binary interfaces

    Directory of Open Access Journals (Sweden)

    Torres-Solis Jorge

    2008-10-01

    Full Text Available Abstract Background Traditionally synchronous access strategies require users to comply with one or more time constraints in order to communicate intent with a binary human-machine interface (e.g., mechanical, gestural or neural switches. Asynchronous access methods are preferable, but have not been used with binary interfaces in the control of devices that require more than two commands to be successfully operated. Methods We present the mathematical development and evaluation of a novel asynchronous access method that may be used to translate sporadic activations of binary interfaces into distinct outcomes for the control of devices requiring an arbitrary number of commands to be controlled. With this method, users are required to activate their interfaces only when the device under control behaves erroneously. Then, a recursive algorithm, incorporating contextual assumptions relevant to all possible outcomes, is used to obtain an informed estimate of user intention. We evaluate this method by simulating a control task requiring a series of target commands to be tracked by a model user. Results When compared to a random selection, the proposed asynchronous access method offers a significant reduction in the number of interface activations required from the user. Conclusion This novel access method offers a variety of advantages over traditionally synchronous access strategies and may be adapted to a wide variety of contexts, with primary relevance to applications involving direct object manipulation.

  8. Pseudo Asynchronous Level Crossing adc for ecg Signal Acquisition.

    Science.gov (United States)

    Marisa, T; Niederhauser, T; Haeberlin, A; Wildhaber, R A; Vogel, R; Goette, J; Jacomet, M

    2017-02-07

    A new pseudo asynchronous level crossing analogue-to-digital converter (adc) architecture targeted for low-power, implantable, long-term biomedical sensing applications is presented. In contrast to most of the existing asynchronous level crossing adc designs, the proposed design has no digital-to-analogue converter (dac) and no continuous time comparators. Instead, the proposed architecture uses an analogue memory cell and dynamic comparators. The architecture retains the signal activity dependent sampling operation by generating events only when the input signal is changing. The architecture offers the advantages of smaller chip area, energy saving and fewer analogue system components. Beside lower energy consumption the use of dynamic comparators results in a more robust performance in noise conditions. Moreover, dynamic comparators make interfacing the asynchronous level crossing system to synchronous processing blocks simpler. The proposed adc was implemented in [Formula: see text] complementary metal-oxide-semiconductor (cmos) technology, the hardware occupies a chip area of 0.0372 mm 2 and operates from a supply voltage of [Formula: see text] to [Formula: see text]. The adc's power consumption is as low as 0.6 μW with signal bandwidth from [Formula: see text] to [Formula: see text] and achieves an equivalent number of bits (enob) of up to 8 bits.

  9. A Synchronous-Asynchronous Particle Swarm Optimisation Algorithm

    Science.gov (United States)

    Ab Aziz, Nor Azlina; Mubin, Marizan; Mohamad, Mohd Saberi; Ab Aziz, Kamarulzaman

    2014-01-01

    In the original particle swarm optimisation (PSO) algorithm, the particles' velocities and positions are updated after the whole swarm performance is evaluated. This algorithm is also known as synchronous PSO (S-PSO). The strength of this update method is in the exploitation of the information. Asynchronous update PSO (A-PSO) has been proposed as an alternative to S-PSO. A particle in A-PSO updates its velocity and position as soon as its own performance has been evaluated. Hence, particles are updated using partial information, leading to stronger exploration. In this paper, we attempt to improve PSO by merging both update methods to utilise the strengths of both methods. The proposed synchronous-asynchronous PSO (SA-PSO) algorithm divides the particles into smaller groups. The best member of a group and the swarm's best are chosen to lead the search. Members within a group are updated synchronously, while the groups themselves are asynchronously updated. Five well-known unimodal functions, four multimodal functions, and a real world optimisation problem are used to study the performance of SA-PSO, which is compared with the performances of S-PSO and A-PSO. The results are statistically analysed and show that the proposed SA-PSO has performed consistently well. PMID:25121109

  10. Data Collection for Mobile Group Consumption: An Asynchronous Distributed Approach

    Directory of Open Access Journals (Sweden)

    Weiping Zhu

    2016-04-01

    Full Text Available Mobile group consumption refers to consumption by a group of people, such as a couple, a family, colleagues and friends, based on mobile communications. It differs from consumption only involving individuals, because of the complex relations among group members. Existing data collection systems for mobile group consumption are centralized, which has the disadvantages of being a performance bottleneck, having single-point failure and increasing business and security risks. Moreover, these data collection systems are based on a synchronized clock, which is often unrealistic because of hardware constraints, privacy concerns or synchronization cost. In this paper, we propose the first asynchronous distributed approach to collecting data generated by mobile group consumption. We formally built a system model thereof based on asynchronous distributed communication. We then designed a simulation system for the model for which we propose a three-layer solution framework. After that, we describe how to detect the causality relation of two/three gathering events that happened in the system based on the collected data. Various definitions of causality relations based on asynchronous distributed communication are supported. Extensive simulation results show that the proposed approach is effective for data collection relating to mobile group consumption.

  11. Data Collection for Mobile Group Consumption: An Asynchronous Distributed Approach.

    Science.gov (United States)

    Zhu, Weiping; Chen, Weiran; Hu, Zhejie; Li, Zuoyou; Liang, Yue; Chen, Jiaojiao

    2016-04-06

    Mobile group consumption refers to consumption by a group of people, such as a couple, a family, colleagues and friends, based on mobile communications. It differs from consumption only involving individuals, because of the complex relations among group members. Existing data collection systems for mobile group consumption are centralized, which has the disadvantages of being a performance bottleneck, having single-point failure and increasing business and security risks. Moreover, these data collection systems are based on a synchronized clock, which is often unrealistic because of hardware constraints, privacy concerns or synchronization cost. In this paper, we propose the first asynchronous distributed approach to collecting data generated by mobile group consumption. We formally built a system model thereof based on asynchronous distributed communication. We then designed a simulation system for the model for which we propose a three-layer solution framework. After that, we describe how to detect the causality relation of two/three gathering events that happened in the system based on the collected data. Various definitions of causality relations based on asynchronous distributed communication are supported. Extensive simulation results show that the proposed approach is effective for data collection relating to mobile group consumption.

  12. The Byzantine ceramics from Pergamon excavations. Characterization of local and imported productions by elementary analysis using PIXE and INAA methods and by petrography

    International Nuclear Information System (INIS)

    Waksman, S.Y.

    1995-01-01

    An important ceramics material dated back to the 12th-14th centuries has been excavated in Pergamon (Turkey). Among these findings, wasters, tripod stilts and unfinished ware attest to local production in the Byzantine period. Elemental analysis by the methods PIXE (Particle Induced X-ray Emission) and INAA (Instrumental Neutron Activation Analysis) has been performed on a representative sampling of 160 sherds, including attested local material. Multivariate statistical techniques were used to classify the sherds into groups of similar composition and thus to distinguish ceramics made in Pergamon from imported wares. Several groups of local production have been constituted, which correspond to wares differing in date and fabric. The geochemical characterization of the pastes, complemented with petrographical and mineralogical data, shows that specific raw materials have been used to manufacture each ware. The analytical data related to ceramics made in Pergamon will serve as reference data for future provenance studies. Such reference groups of Byzantine ceramics are very rare, and therefore the ceramics imported into Pergamon cannot be attributed as to their origin. Among the ceramics widely diffused in the Byzantine world, some importations belonging to the ''fine sgraffito'' and ''Zeuxippus ware'' types have been identified. The latter type has been a source of stylistic influence for the workshops of Pergamon, since the analyses show that imitated ''Zeuxippus ware'' has been produced there. These imitations were probably themselves diffused on a regional scale. (author). 238 refs., 48 figs., 53 tabs., 22 photos., 8 appends

  13. A novel painted monument. Byzantine Art between Aesthetic Redefining and Dogmatic Perennity. The church Saint John the Baptist of Bârnova

    Directory of Open Access Journals (Sweden)

    Mihail M. Gheaţău

    2015-11-01

    Full Text Available Being remarkable through the monumentality and elegance of proportions, the architecture of the Church “Saint John the Baptist” from Bârnova derives from the so-called old Wallachian style, skillfully reshaping a structure which combines elements which are specific to Byzantine Balkanic ecclesiastical buildings. The unseen pictural work of Ștefan Constantinescu is characterized by the attempt to associate the results of experiencing freedom of interpretation and expression with the rules of the iconographic canon, inside the same ensemble. Its representations do not reproduce the traditional Byzantine manner, nor it is delivered as a form of quoting reality, but it is filtered and interpreted. From a theological point of view, the author respects the iconographic program, except for the topographic placement of some episodes, adapting the discourse according to the configuration and features of the liturgical space. We are in front of a case which places us in the position of managing the relationship between the value of artistic creation and the meticulosity of theological involvement. Neither Byzantine, nor realistic, the artistic solution of the mural painting from Bârnova is closer to the manner of iconic transfiguration than to the one of improvisation or artistic intermediation through which the daily tridimensional world is reflected.

  14. Dynamic modeling of an asynchronous squirrel-cage machine; Modelisation dynamique d'une machine asynchrone a cage

    Energy Technology Data Exchange (ETDEWEB)

    Guerette, D.

    2009-07-01

    This document presented a detailed mathematical explanation and validation of the steps leading to the development of an asynchronous squirrel-cage machine. The MatLab/Simulink software was used to model a wind turbine at variable high speeds. The asynchronous squirrel-cage machine is an electromechanical system coupled to a magnetic circuit. The resulting electromagnetic circuit can be represented as a set of resistances, leakage inductances and mutual inductances. Different models were used for a comparison study, including the Munteanu, Boldea, Wind Turbine Blockset, and SimPowerSystem. MatLab/Simulink modeling results were in good agreement with the results from other comparable models. Simulation results were in good agreement with analytical calculations. 6 refs, 2 tabs, 9 figs.

  15. [A development of Byzantine Christian charities during the 4(th)-7(th) centuries and the birth of the hospital].

    Science.gov (United States)

    Nam, Sung Hyun

    2015-04-01

    This study aims to examine the beginning and the development of Christian Charities during the 4(th)-6(th) centuries which would eventually result in the birth of the hospital in modern sense in the first half of the 7(th) century. For this purpose, I looked carefully into various primary sources concerning the early Christian institutions for the poor and the sick. Above all, it's proper to note that the first xenodocheion where hospitality was combined with a systematic caring, is concerned with the Trinitarian debate of the 4(th) century. In 356, Eustathios, one of the leaders of homoiousios group, established xenodocheion to care for the sick and the lepers in Sebaste of Armenia, whereas his opponent Aetios, doctor and leader of the heteroousios party, was reckoned to have combined the medical treatment with his clerical activities. Then, Basil of Caesarea, disciple of Eustathios of Sebaste, also founded in 372 a magnificent benevolent complex named 'Basileias' after its founder. I scrupulously analysed several contemporary materials mentioning the charitable institution of Caesarea which was called alternatively katagogia, ptochotropheion, xenodocheion. John Chrysostome also founded several nosokomeia in Constantinople at the end of the 4(th) century and the beginning of the 5(th) century. Apparently, the contemporary sources mention that doctors existed for these Charities, but there is no sufficient proof that these 'Christian Hospitals,' Basileias or nosokomeia of Constantinople were hospitals in modern sense. Imperial constitutions began to mention ptochotropheion, xenodocheion and orphanotropheion since the second half of the 5(th) century and then some Justinian laws evoked nosokomium, brephotrophia, gerontocomia. These laws reveal that 'Christian Hospitals' were well clarified and deeply rooted in Byzantine society already in these periods. And then, new benevolent institutions emerged in the 6(th) century: nosokomeia for a specific class and

  16. ON THE ISSUE OF VECTOR CONTROL OF THE ASYNCHRONOUS MOTORS

    Directory of Open Access Journals (Sweden)

    B. I. Firago

    2015-01-01

    Full Text Available The paper considers the issue of one of the widespread types of vector control realization for the asynchronous motors with a short-circuited rotor. Of all more than 20 vector control types known presently, the following are applied most frequently: direct vector control with velocity pickup (VP, direct vector control without VP, indirect vector control with VP and indirect vector control without VP. Despite the fact that the asynchronous-motor indirect vector control without VP is the easiest and most spread, the absence of VP does not allow controlling the motor electromagnetic torque at zero velocity. This is the reason why for electric motor drives of such requirements they utilize the vector control with a velocity transducer. The systems of widest dissemination became the direct and indirect vector control systems with X-axis alignment of the synchronously rotating x–y-coordinate frame along the rotor flux-linkage vector inasmuch as this provides the simplest correlations for controlling variables. Although these two types of vector control are well presented in literature, a number of issues concerning their realization and practical application require further elaboration. These include: the block schemes adequate representation as consisted with the modern realization of vector control and clarification of the analytical expressions for evaluating the regulator parameters.The authors present a technique for evaluating the dynamics of an asynchronous electric motor drive with direct vector control and x-axis alignment along the vector of rotor flux linkage. The article offers a generalized structure of this vector control type with detailed description of its principal blocks: controlling system, frequency converter, and the asynchronous motor.The paper presents a direct vector control simulating model developed in the MatLab environment on the grounds of this structure. The authors illustrate the described technique with the results

  17. Pharmacists' perception of synchronous versus asynchronous distance learning for continuing education programs.

    Science.gov (United States)

    Buxton, Eric C

    2014-02-12

    To evaluate and compare pharmacists' satisfaction with the content and learning environment of a continuing education program series offered as either synchronous or asynchronous webinars. An 8-lecture series of online presentations on the topic of new drug therapies was offered to pharmacists in synchronous and asynchronous webinar formats. Participants completed a 50-question online survey at the end of the program series to evaluate their perceptions of the distance learning experience. Eighty-two participants completed the survey instrument (41 participants from the live webinar series and 41 participants from the asynchronous webinar series.) Responses indicated that while both groups were satisfied with the program content, the asynchronous group showed greater satisfaction with many aspects of the learning environment. The synchronous and asynchronous webinar participants responded positively regarding the quality of the programming and the method of delivery, but asynchronous participants rated their experience more positively overall.

  18. Resource-aware system architecture model for implementation of quantum aided Byzantine agreement on quantum repeater networks

    Science.gov (United States)

    Taherkhani, Mohammand Amin; Navi, Keivan; Van Meter, Rodney

    2018-01-01

    Quantum aided Byzantine agreement is an important distributed quantum algorithm with unique features in comparison to classical deterministic and randomized algorithms, requiring only a constant expected number of rounds in addition to giving a higher level of security. In this paper, we analyze details of the high level multi-party algorithm, and propose elements of the design for the quantum architecture and circuits required at each node to run the algorithm on a quantum repeater network (QRN). Our optimization techniques have reduced the quantum circuit depth by 44% and the number of qubits in each node by 20% for a minimum five-node setup compared to the design based on the standard arithmetic circuits. These improvements lead to a quantum system architecture with 160 qubits per node, space-time product (an estimate of the required fidelity) {KQ}≈ 1.3× {10}5 per node and error threshold 1.1× {10}-6 for the total nodes in the network. The evaluation of the designed architecture shows that to execute the algorithm once on the minimum setup, we need to successfully distribute a total of 648 Bell pairs across the network, spread evenly between all pairs of nodes. This framework can be considered a starting point for establishing a road-map for light-weight demonstration of a distributed quantum application on QRNs.

  19. Characterization of paint and varnish on a medieval Coptic-Byzantine icon: Novel usage of dammar resin

    Science.gov (United States)

    Abdel-Ghani, M.; Edwards, H. G. M.; Stern, B.; Janaway, R.

    2009-08-01

    A comprehensive study has been undertaken into a 13th century Coptic-Byzantine icon from the St. Mercurius Church, St. Mercurius monastery, Old Cairo, Egypt. The layered structure, pigment composition and varnish identification were revealed by means of optical and Raman microscopy and gas chromatography-mass spectrometry (GC-MS). The structure of the icon comprised six layers; wooden panel, canvas, white ground, two bole layers and a single paint layer. Azurite (2CuCO 3·Cu(OH) 2), cinnabar (mercuric (II) sulfide α-HgS), yellow ochre (Fe 2O 3·H 2O), hydromagnesite Mg 5(CO 3) 4(OH) 2·4H 2O and lamp black (carbon, C) are the pigments identified in the icon. The green paint area is of interest as it is applied neither with a green pigment nor with a mixture of a blue and yellow pigment. Instead, a yellow layer of dammar resin was applied on top of blue azurite to obtain the green colour. Pinaceae sp. resin mixed with drying oil was used as a protective varnish.

  20. Investigation of the gilding technique in two post-Byzantine wall paintings using micro-analytical techniques

    International Nuclear Information System (INIS)

    Katsibiri, Olga; Boon, Jaap J.

    2004-01-01

    The main churches of two important monasteries in Thessalia, Central Greece, are decorated with wall paintings that hail from the post-Byzantine period. The mural decoration of the main church of the St. Byssarionas Monastery at Doussiko has been attributed to the iconographer Tzortzis. The same painter is believed to have also operated in the main church of the Transfiguration Monastery at the monastic community of Meteora. The light microscopic (LM) examination of the cross-sections of samples taken from the gilded areas of the wall paintings, together with the direct temperature resolved mass spectrometric (DTMS) and scanning electron microscopy-energy dispersive X-ray spectroscopic (SEM-EDX) analysis, revealed a further resemblance of the materials and the methodology employed. The gold leaf was applied to the paintings by means of a mordant, which contains linseed oil mixed with a lead-containing dryer and an earth pigment or clay. The present study can constitute additional evidence to reinforce the idea that the two churches may have been painted by the same painter or workshop

  1. Impact of earthquakes on agriculture during the Roman-Byzantine period from pollen records of the Dead Sea laminated sediment

    Science.gov (United States)

    Leroy, Suzanne A. G.; Marco, Shmuel; Bookman, Revital; Miller, Charlotte S.

    2010-03-01

    The Dead Sea region holds the archives of a complex relationship between an ever-changing nature and ancient civilisations. Regional pollen diagrams show a Roman-Byzantine period standing out in the recent millennia by its wetter climate that allowed intensive arboriculture. During that period, the Dead Sea formed laminites that display mostly a seasonal character. A multidisciplinary study focused on two earthquakes, 31 BC and AD 363, recorded as seismites in the Ze'elim gully A unit III which has been well dated by radiocarbon in a previous study. The sampling of the sediment was done at an annual resolution starting from a few years before and finishing a decade after each earthquake. A clear drop in agricultural indicators (especially Olea and cereals) is shown. These pollen indicators mostly reflect human activities in the Judean Hills and coastal oases. Agriculture was disturbed in large part of the rift valley where earthquake damage affected irrigation and access to the fields. It took 4 to 5 yr to resume agriculture to previous conditions. Earthquakes must be seen as contributors to factors damaging societies. If combined with other factors such as climatic aridification, disease epidemics and political upheaval, they may lead to civilisation collapse.

  2. The Mechanical Transient Process at Asynchronous Motor Oscillating Mode

    Science.gov (United States)

    Antonovičs, Uldis; Bražis, Viesturs; Greivulis, Jānis

    2009-01-01

    The research object is squirrel-cage asynchronous motor connected to single-phase sinusoidal. There are shown, that by connecting to the stator windings a certain sequence of half-period positive and negative voltage, a motor rotor is rotated, but three times slower than in the three-phase mode. Changing the connecting sequence of positive and negative half-period voltage to stator windings, motor can work in various oscillating modes. It is tested experimentally. The mechanical transient processes had been researched in rotation and oscillating modes.

  3. Asynchronous variational integration using continuous assumed gradient elements.

    Science.gov (United States)

    Wolff, Sebastian; Bucher, Christian

    2013-03-01

    Asynchronous variational integration (AVI) is a tool which improves the numerical efficiency of explicit time stepping schemes when applied to finite element meshes with local spatial refinement. This is achieved by associating an individual time step length to each spatial domain. Furthermore, long-term stability is ensured by its variational structure. This article presents AVI in the context of finite elements based on a weakened weak form (W2) Liu (2009) [1], exemplified by continuous assumed gradient elements Wolff and Bucher (2011) [2]. The article presents the main ideas of the modified AVI, gives implementation notes and a recipe for estimating the critical time step.

  4. Electrotechnics - AC motors. Asynchronous and brush-less motors - Lecture and exercises with solutions; Electrotechnique - Moteurs a courant alternatif. Moteurs asynchrones et brushless - Cours et problemes resolus

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, D.

    2005-07-01

    This book proposes a presentation of AC electric motors essentially based on physics and technology. Its originality consists in avoiding to use mathematical formulations (like Park's transformation). The modeling retained, which only uses magnetic momentum, magnetic fields and reluctance concepts, leads simply and naturally to the vectorial control principle. The book develops some lecture elements which includes some topics rarely considered like the dimensioning of an asynchronous motor or of a single-phase brush-less motor. Experimental results illustrate the physical phenomena described and many original problems are resolved and commented at the end of each chapter. Content: signals and systems in electrotechnics, torque and rotating magnetic fields generation, asynchronous machine in permanent regime, speed variation of the asynchronous motor, special asynchronous motors, synchronous machine in permanent regime, brush-less motor, note about step motors, note about inverters, index. (J.S.)

  5. Towards behavioral synthesis of asynchronous circuits - an implementation template targeting syntax directed compilation

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Sparsø, Jens; Madsen, Jan

    2004-01-01

    This paper presents a method for behavioral synthesis of asynchronous circuits. Our approach aims at providing a synthesis flow which is very similar to what is found in existing synchronous design tools. We adapt the synchronous behavioral synthesis abstraction into the asynchronous handshake...

  6. Using Television Sitcoms to Facilitate Asynchronous Discussions in the Online Communication Course

    Science.gov (United States)

    Tolman, Elizabeth; Asbury, Bryan

    2012-01-01

    Asynchronous discussions are a useful instructional resource in the online communication course. In discussion groups students have the opportunity to actively participate and interact with students and the instructor. Asynchronous communication allows for flexibility because "participants can interact with significant amounts of time between…

  7. The design of an asynchronous Tiny RISC TM/TR4101 microprocessor core

    DEFF Research Database (Denmark)

    Christensen, Kåre Tais; Jensen, P.; Korger, P.

    1998-01-01

    This paper presents the design of an asynchronous version of the TR4101 embedded microprocessor core developed by LSI Logic Inc. The asynchronous processor, called ARISC, was designed using the same CAD tools and the same standard cell library that was used to implement the TR4101. The paper repo...

  8. Byzantine Glazed Ceramics in the Cities of the Northern Black Sea Region in the Golden Horde Period (Second Half of the 13th to the Late 14th Century

    Directory of Open Access Journals (Sweden)

    Bocharov Sergei G.

    2012-03-01

    Full Text Available Glazed ceramics of Byzantine origin, which came has been found on town sites of the Northern Black Sea region referring to the Golden Horde period (second half of the 13th – late 14th cc., is characterized in the article. Materials from the urban centers of the Crimea (Solkhat, Sudak, Kaffa, Chersonese, Cembalo, the Azov Sea region (Azaq, and the lower reaches of the Don and Kuban rivers are discussed. The applied principles of ceramics classification have been formulated. On their basis, six major groups of Byzantine ceramic imports have been identified. For each group, a description of morphological and technological features, ornamentation methods and motifs has been provided; chronological framework of their arrival in the region has been specified. Conclusions have been offered as to the extent of distribution and the role played by diverse groups of Byzantine glazed ceramics in the cities of the Northern Black Sea region.

  9. Algebraic Number Precoded OFDM Transmission for Asynchronous Cooperative Multirelay Networks

    Directory of Open Access Journals (Sweden)

    Hua Jiang

    2014-01-01

    Full Text Available This paper proposes a space-time block coding (STBC transmission scheme for asynchronous cooperative systems. By combination of rotated complex constellations and Hadamard transform, these constructed codes are capable of achieving full cooperative diversity with the analysis of the pairwise error probability (PEP. Due to the asynchronous characteristic of cooperative systems, orthogonal frequency division multiplexing (OFDM technique with cyclic prefix (CP is adopted for combating timing delays from relay nodes. The total transmit power across the entire network is fixed and appropriate power allocation can be implemented to optimize the network performance. The relay nodes do not require decoding and demodulation operation, resulting in a low complexity. Besides, there is no delay for forwarding the OFDM symbols to the destination node. At the destination node the received signals have the corresponding STBC structure on each subcarrier. In order to reduce the decoding complexity, the sphere decoder is implemented for fast data decoding. Bit error rate (BER performance demonstrates the effectiveness of the proposed scheme.

  10. Asynchronous Channel-Hopping Scheme under Jamming Attacks

    Directory of Open Access Journals (Sweden)

    Yongchul Kim

    2018-01-01

    Full Text Available Cognitive radio networks (CRNs are considered an attractive technology to mitigate inefficiency in the usage of licensed spectrum. CRNs allow the secondary users (SUs to access the unused licensed spectrum and use a blind rendezvous process to establish communication links between SUs. In particular, quorum-based channel-hopping (CH schemes have been studied recently to provide guaranteed blind rendezvous in decentralized CRNs without using global time synchronization. However, these schemes remain vulnerable to jamming attacks. In this paper, we first analyze the limitations of quorum-based rendezvous schemes called asynchronous channel hopping (ACH. Then, we introduce a novel sequence sensing jamming attack (SSJA model in which a sophisticated jammer can dramatically reduce the rendezvous success rates of ACH schemes. In addition, we propose a fast and robust asynchronous rendezvous scheme (FRARS that can significantly enhance robustness under jamming attacks. Our numerical results demonstrate that the performance of the proposed scheme vastly outperforms the ACH scheme when there are security concerns about a sequence sensing jammer.

  11. Formation of the wide asynchronous binary asteroid population

    International Nuclear Information System (INIS)

    Jacobson, Seth A.; Scheeres, Daniel J.; McMahon, Jay

    2014-01-01

    We propose and analyze a new mechanism for the formation of the wide asynchronous binary population. These binary asteroids have wide semimajor axes relative to most near-Earth and main belt asteroid systems. Confirmed members have rapidly rotating primaries and satellites that are not tidally locked. Previously suggested formation mechanisms from impact ejecta, from planetary flybys, and directly from rotational fission events cannot satisfy all of the observations. The newly hypothesized mechanism works as follows: (1) these systems are formed from rotational fission, (2) their satellites are tidally locked, (3) their orbits are expanded by the binary Yarkovsky-O'Keefe-Radzievskii-Paddack (BYORP) effect, (4) their satellites desynchronize as a result of the adiabatic invariance between the libration of the secondary and the mutual orbit, and (5) the secondary avoids resynchronization because of the YORP effect. This seemingly complex chain of events is a natural pathway for binaries with satellites that have particular shapes, which define the BYORP effect torque that acts on the system. After detailing the theory, we analyze each of the wide asynchronous binary members and candidates to assess their most likely formation mechanism. Finally, we suggest possible future observations to check and constrain our hypothesis.

  12. An Asynchronous IEEE Floating-Point Arithmetic Unit

    Directory of Open Access Journals (Sweden)

    Joel R. Noche

    2007-12-01

    Full Text Available An asynchronous floating-point arithmetic unit is designed and tested at the transistor level usingCadence software. It uses CMOS (complementary metal oxide semiconductor and DCVS (differentialcascode voltage switch logic in a 0.35 µm process using a 3.3 V supply voltage, with dual-rail data andsingle-rail control signals using four-phase handshaking.Using 17,085 transistors, the unit handles single-precision (32-bit addition/subtraction, multiplication,division, and remainder using the IEEE 754-1985 Standard for Binary Floating-Point Arithmetic, withrounding and other operations to be handled by separate hardware or software. Division and remainderare done using a restoring subtractive algorithm; multiplication uses an additive algorithm. Exceptionsare noted by flags (and not trap handlers and the output is in single-precision.Previous work on asynchronous floating-point arithmetic units have mostly focused on single operationssuch as division. This is the first work to the authors' knowledge that can perform floating-point addition,multiplication, division, and remainder using a common datapath.

  13. Asynchronous Task-Based Polar Decomposition on Manycore Architectures

    KAUST Repository

    Sukkari, Dalal

    2016-10-25

    This paper introduces the first asynchronous, task-based implementation of the polar decomposition on manycore architectures. Based on a new formulation of the iterative QR dynamically-weighted Halley algorithm (QDWH) for the calculation of the polar decomposition, the proposed implementation replaces the original and hostile LU factorization for the condition number estimator by the more adequate QR factorization to enable software portability across various architectures. Relying on fine-grained computations, the novel task-based implementation is also capable of taking advantage of the identity structure of the matrix involved during the QDWH iterations, which decreases the overall algorithmic complexity. Furthermore, the artifactual synchronization points have been severely weakened compared to previous implementations, unveiling look-ahead opportunities for better hardware occupancy. The overall QDWH-based polar decomposition can then be represented as a directed acyclic graph (DAG), where nodes represent computational tasks and edges define the inter-task data dependencies. The StarPU dynamic runtime system is employed to traverse the DAG, to track the various data dependencies and to asynchronously schedule the computational tasks on the underlying hardware resources, resulting in an out-of-order task scheduling. Benchmarking experiments show significant improvements against existing state-of-the-art high performance implementations (i.e., Intel MKL and Elemental) for the polar decomposition on latest shared-memory vendors\\' systems (i.e., Intel Haswell/Broadwell/Knights Landing, NVIDIA K80/P100 GPUs and IBM Power8), while maintaining high numerical accuracy.

  14. Continuous EEG signal analysis for asynchronous BCI application.

    Science.gov (United States)

    Hsu, Wei-Yen

    2011-08-01

    In this study, we propose a two-stage recognition system for continuous analysis of electroencephalogram (EEG) signals. An independent component analysis (ICA) and correlation coefficient are used to automatically eliminate the electrooculography (EOG) artifacts. Based on the continuous wavelet transform (CWT) and Student's two-sample t-statistics, active segment selection then detects the location of active segment in the time-frequency domain. Next, multiresolution fractal feature vectors (MFFVs) are extracted with the proposed modified fractal dimension from wavelet data. Finally, the support vector machine (SVM) is adopted for the robust classification of MFFVs. The EEG signals are continuously analyzed in 1-s segments, and every 0.5 second moves forward to simulate asynchronous BCI works in the two-stage recognition architecture. The segment is first recognized as lifted or not in the first stage, and then is classified as left or right finger lifting at stage two if the segment is recognized as lifting in the first stage. Several statistical analyses are used to evaluate the performance of the proposed system. The results indicate that it is a promising system in the applications of asynchronous BCI work.

  15. Spatiotemporal Features for Asynchronous Event-based Data

    Directory of Open Access Journals (Sweden)

    Xavier eLagorce

    2015-02-01

    Full Text Available Bio-inspired asynchronous event-based vision sensors are currently introducing a paradigm shift in visual information processing. These new sensors rely on a stimulus-driven principle of light acquisition similar to biological retinas. They are event-driven and fully asynchronous, thereby reducing redundancy and encoding exact times of input signal changes, leading to a very precise temporal resolution. Approaches for higher-level computer vision often rely on the realiable detection of features in visual frames, but similar definitions of features for the novel dynamic and event-based visual input representation of silicon retinas have so far been lacking. This article addresses the problem of learning and recognizing features for event-based vision sensors, which capture properties of truly spatiotemporal volumes of sparse visual event information. A novel computational architecture for learning and encoding spatiotemporal features is introduced based on a set of predictive recurrent reservoir networks, competing via winner-take-all selection. Features are learned in an unsupervised manner from real-world input recorded with event-based vision sensors. It is shown that the networks in the architecture learn distinct and task-specific dynamic visual features, and can predict their trajectories over time.

  16. A Parallel Particle Swarm Optimization Algorithm Accelerated by Asynchronous Evaluations

    Science.gov (United States)

    Venter, Gerhard; Sobieszczanski-Sobieski, Jaroslaw

    2005-01-01

    A parallel Particle Swarm Optimization (PSO) algorithm is presented. Particle swarm optimization is a fairly recent addition to the family of non-gradient based, probabilistic search algorithms that is based on a simplified social model and is closely tied to swarming theory. Although PSO algorithms present several attractive properties to the designer, they are plagued by high computational cost as measured by elapsed time. One approach to reduce the elapsed time is to make use of coarse-grained parallelization to evaluate the design points. Previous parallel PSO algorithms were mostly implemented in a synchronous manner, where all design points within a design iteration are evaluated before the next iteration is started. This approach leads to poor parallel speedup in cases where a heterogeneous parallel environment is used and/or where the analysis time depends on the design point being analyzed. This paper introduces an asynchronous parallel PSO algorithm that greatly improves the parallel e ciency. The asynchronous algorithm is benchmarked on a cluster assembled of Apple Macintosh G5 desktop computers, using the multi-disciplinary optimization of a typical transport aircraft wing as an example.

  17. Asynchronous cracking with dissimilar paths in multilayer graphene.

    Science.gov (United States)

    Jang, Bongkyun; Kim, Byungwoon; Kim, Jae-Hyun; Lee, Hak-Joo; Sumigawa, Takashi; Kitamura, Takayuki

    2017-11-16

    Multilayer graphene consists of a stack of single-atomic-thick monolayer graphene sheets bound with π-π interactions and is a fascinating model material opening up a new field of fracture mechanics. In this study, fracture behavior of single-crystalline multilayer graphene was investigated using an in situ mode I fracture test under a scanning electron microscope, and abnormal crack propagation in multilayer graphene was identified for the first time. The fracture toughness of graphene was determined from the measured load-displacement curves and the realistic finite element modelling of specimen geometries. Nonlinear fracture behavior of the multilayer graphene is discussed based on nonlinear elastic fracture mechanics. In situ scanning electron microscope images obtained during the fracture test showed asynchronous crack propagation along independent paths, causing interlayer shear stress and slippages. We also found that energy dissipation by interlayer slippages between the graphene layers is the reason for the enhanced fracture toughness of multilayer graphene. The asynchronous cracking with independent paths is a unique cracking and toughening mechanism for single-crystalline multilayer graphene, which is not observed for the monolayer graphene. This could provide a useful insight for the design and development of graphene-based composite materials for structural applications.

  18. Parallel asynchronous hardware implementation of image processing algorithms

    Science.gov (United States)

    Coon, Darryl D.; Perera, A. G. U.

    1990-01-01

    Research is being carried out on hardware for a new approach to focal plane processing. The hardware involves silicon injection mode devices. These devices provide a natural basis for parallel asynchronous focal plane image preprocessing. The simplicity and novel properties of the devices would permit an independent analog processing channel to be dedicated to every pixel. A laminar architecture built from arrays of the devices would form a two-dimensional (2-D) array processor with a 2-D array of inputs located directly behind a focal plane detector array. A 2-D image data stream would propagate in neuron-like asynchronous pulse-coded form through the laminar processor. No multiplexing, digitization, or serial processing would occur in the preprocessing state. High performance is expected, based on pulse coding of input currents down to one picoampere with noise referred to input of about 10 femtoamperes. Linear pulse coding has been observed for input currents ranging up to seven orders of magnitude. Low power requirements suggest utility in space and in conjunction with very large arrays. Very low dark current and multispectral capability are possible because of hardware compatibility with the cryogenic environment of high performance detector arrays. The aforementioned hardware development effort is aimed at systems which would integrate image acquisition and image processing.

  19. Router Designs for an Asynchronous Time-Division-Multiplexed Network-on-Chip

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia; Sparsø, Jens; Sørensen, Rasmus Bo

    2013-01-01

    In this paper we explore the design of an asynchronous router for a time-division-multiplexed (TDM) network-on-chip (NOC) that is being developed for a multi-processor platform for hard real-time systems. TDM inherently requires a common time reference, and existing TDM-based NOC designs are either....... This adds hardware complexity and increases area and power consumption. We propose to use asynchronous routers in order to achieve a simpler, more robust and globally-asynchronous NOC, and this represents an unexplored point in the design space. The paper presents a range of alternative router designs. All...... routers have been synthesized for a 65nm CMOS technology, and the paper reports post-layout figures for area, speed and energy and compares the asynchronous designs with an existing mesochronous clocked router. The results show that an asynchronous router is 2 times smaller, marginally slower...

  20. The Byzantine ceramics from Pergamon excavations. Characterization of local and imported productions by elementary analysis using PIXE and INAA methods and by petrography; Les ceramiques byzantines des fouilles de Pergame. Caracterisation des productions locales et importees par analyse elementaire par les methodes PIXE et INAA et par petrographie

    Energy Technology Data Exchange (ETDEWEB)

    Waksman, S Y

    1995-01-12

    An important ceramics material dated back to the 12th-14th centuries has been excavated in Pergamon (Turkey). Among these findings, wasters, tripod stilts and unfinished ware attest to local production in the Byzantine period. Elemental analysis by the methods PIXE (Particle Induced X-ray Emission) and INAA (Instrumental Neutron Activation Analysis) has been performed on a representative sampling of 160 sherds, including attested local material. Multivariate statistical techniques were used to classify the sherds into groups of similar composition and thus to distinguish ceramics made in Pergamon from imported wares. Several groups of local production have been constituted, which correspond to wares differing in date and fabric. The geochemical characterization of the pastes, complemented with petrographical and mineralogical data, shows that specific raw materials have been used to manufacture each ware. The analytical data related to ceramics made in Pergamon will serve as reference data for future provenance studies. Such reference groups of Byzantine ceramics are very rare, and therefore the ceramics imported into Pergamon cannot be attributed as to their origin. Among the ceramics widely diffused in the Byzantine world, some importations belonging to the ``fine sgraffito`` and ``Zeuxippus ware`` types have been identified. The latter type has been a source of stylistic influence for the workshops of Pergamon, since the analyses show that imitated ``Zeuxippus ware`` has been produced there. These imitations were probably themselves diffused on a regional scale. (author). 238 refs., 48 figs., 53 tabs., 22 photos., 8 appends.

  1. A study of gemstones of the I. D. Passa collection, hosted at the Byzantine and Christian Museum of Greece.

    Science.gov (United States)

    Griva, Eirini; Perraki, Maria; Katsaros, Thomas; Ganetsos, Theodoros

    2017-04-01

    Eight sculptures, of the large gemstone art collection of Ioannis D. Passas hosted at the Byzantine and Christian Museum of Greece, were studied by means of portable Raman spectroscopy and X-Ray Fluorescence to identify the type and, if possible, the origin of the gemstones they are made of. The application of portable Raman spectroscopy and X-Ray fluorescence have been proven to be rapid and successful analytical methods to study gemstones, with main advantage their non- destructive character. The eight sculptures of the I.D. Passa collection examined herein, based on their Raman features and XRF data, were confirmed to be nephrite, fluorite, lapis lazuli, rhodonite and turquoise. The Raman spectrum of specimen BXM 23989a is characterized by peaks at approximately 244, 378 and 685 cm-1 assigned to nephrite. In the XRF spectrum, the most intense emission lines were those of Ca and Fe at 3.69 and 6.36 keV, respectively. The Raman spectra of specimens BXM 24357-8a and BXM 24354 are characterized by peaks at 731, 1122, 1364, 1778 and 1880 cm-1attributed to fluorite. As for the XRF spectra, F and Ca have strong peaks at 0.60 keV and 3.69 keV, respectively. The Raman spectra of specimens BXM 24201a,b and BXM 24198 are characterized by strong peaks at 553 and 1319.1 cm-1 assigned to Lapis Lazuli, whereas the respective XRF spectra are characterized by strong peaks at 1.74 keV (Si) and 3.69 keV (Ca). A representative Raman spectrum of specimen BXM 24289 has given a strong peak at 633 cm-1, attributed to rhodonite. The respective XRF spectrum is characterized by strong peaks at 5.87 keV and 1.74 keV, pointing to the presence of Mn and Si, respectively. A typical Raman spectrum of specimens BXM 24142a and BXM 24139a exhibit strong peaks at 231, 417 and 1042 cm-1, characteristic of turquoise. In the XRF spectra, the most intense emission lines are those of Cu and Zn at 8.04 and 8.63 keV respectively. Regarding the origin of the above-mentioned gemstones, one could assume the

  2. Byzantine Taurica in the Second Half of the 11th Century and New Seal of Leon Aliates from Cherson

    Directory of Open Access Journals (Sweden)

    Nikolay A. Alekseenko

    2017-11-01

    Full Text Available he discovery of a valuable and important sphragistic source in Cherson – the seal of Strategos and Patrikios Leon Aliates, known by the inscription of 1059, brings us back to the old problems of the development of the administrative system of the Crimean region. Basing the research on the other data as well, today we can confidently state that the presence of the imperial administration in Taurica in the second half of the 11th century does not only decrease, but even expands and reinforces. This is associated, firstly, with Sougdea joining Cherson, and, secondly, with the creation of Cherson katepanate and making Sougdea an independent theme. The seal of vetarch Nicephorus Alan, catepan of Cherson and Khazaria, proves the existence of a new military administrative district in Taurica in the second half of the 11th – at the turn of the 11th / 12th centuries. This fact makes it necessary not only to look in a new way at the history of the region during the collapse of the feudal system, but also in a certain sense to reestimate the role and significance of Cherson in Byzantine politics and diplomacy of that time. The appearance of the katepanate in Taurica, which included not only the traditional regions around Cherson, but also the vast Khazar lands of the Steppe and Northeast Crimea in the sphere of its jurisdiction, was caused by the need to increase the military force of borderlands in the face of an ever-increasing threat from the nomads of the north. For the same reason, Sougdea becomes an independent theme, designed to control the East-Crimean region, the Azov Sea and the Caucasian coast of Ponta. It is possible that a similar situation could apply to Bosporus. The finds of the seals of Russian princes and governors of Tmutarakan in the very area of Bosporus and Sougdea serve as indirect evidence in favor of this fact.

  3. Digital surveying and new perspectives on the Byzantine Oratory of the Catacomb of Saint Lucia in Syracuse

    Directory of Open Access Journals (Sweden)

    Mariateresa Galizia

    2014-10-01

    Full Text Available The study conducted Oratory Byzantine catacombs of Saint Lucia in Syracuse comes from the observation of the precarious condition of the underground funerary complex from the point of view of the static structures, which have undergone several alterations over the centuries due to landslides, blockages, collapses and subsequent excavations, conservation of the frescoes found that as a result of survey campaigns that have occurred intermittently on the monument. These difficulties have conditioned the public opening of only a part of the catacombs -la region A and the Oratory of the Forty Martiri- leaving hidden the community many significant spaces including the Oratory. The research will then, through the survey instrument with laser scanner, acquire a geometric-formal documentation of this important area through a 3D model on which to investigate aspects of a static nature, geological, material, historical, archaeological, necessary for a proper design of future interventions for the protection and consolidation of the catacomb. In fact, the 3D model obtained is a virtual copy of the recorded space through which it is possible to speculate on some design and physical environmental conditions of the sites, such as lighting and ventilation, and on some solutions distribution-functional, providing also a possible model for 3D navigation allows the virtual tour of the places underground. The location of the site, the distribution of the planimetric and static environmental conditions represented in research critical issues to be addressed in the survey phase of underground sites, providing for the research group of the fixed points on which to structure a possible protocol operating acquisition, integration, management and processing of the acquired data subject to change.

  4. Nicephorus Blemmydes on the Holy Trinity and the Paraconsistent Notion of Numbers: A Logical Analysis of a Byzantine Approach to the Filioque

    Directory of Open Access Journals (Sweden)

    Lourié Basil

    2016-03-01

    Full Text Available The paper deals with the most controversial - in the modern scholarly discussion - episode within the Byzantine polemics on the Filioque, Nicephorus Blemmydes‘ acknowledgement of proceeding of the Spirit through the Son providing that the Son be considered as generated through the Spirit. The logical intuition behind this theological idea is explicated in the terms of paraconsistent logic and especially of a kind of paraconsistent numbers called by the author “pseudo-natural numbers”. Such numbers could not be interpreted via the notion of ordered pair. Instead, they imply a known (first described by Emil Post in 1941 but still little studied logical connective ternary exclusive OR.

  5. Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xuanhua; Luo, Xuan; Liang, Junling; Zhao, Peng; Di, Sheng; He, Bingsheng; Jin, Hai

    2018-01-01

    GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weight asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications and

  6. A prototype pixel readout chip for asynchronous detection applications

    International Nuclear Information System (INIS)

    Raymond, D.M.; Hall, G.; Lewis, A.J.; Sharp, P.H.

    1991-01-01

    A two-dimensional array of amplifier cells has been fabricated as a prototype readout system for a matching array of silicon diode detectors. Each cell contains a preamplifier, shaping amplifier, comparator and analogue signal storage in an area of 300 μmx320 μm using 3 μm CMOS technology. Full size chips will be bump bonded to pixel detector arrays. Low noise and asynchronous operation are novel design features. With noise levels of less than 250 rms electrons for input capacitances up to 600 fF, pixel detectors will be suitable for autoradiography, synchrotron X-ray and high energy particle detection applications. The design of the prototype chip is presented and future developments and prospects for applications are discussed. (orig.)

  7. Asynchronous sampled-data approach for event-triggered systems

    Science.gov (United States)

    Mahmoud, Magdi S.; Memon, Azhar M.

    2017-11-01

    While aperiodically triggered network control systems save a considerable amount of communication bandwidth, they also pose challenges such as coupling between control and event-condition design, optimisation of the available resources such as control, communication and computation power, and time-delays due to computation and communication network. With this motivation, the paper presents separate designs of control and event-triggering mechanism, thus simplifying the overall analysis, asynchronous linear quadratic Gaussian controller which tackles delays and aperiodic nature of transmissions, and a novel event mechanism which compares the cost of the aperiodic system against a reference periodic implementation. The proposed scheme is simulated on a linearised wind turbine model for pitch angle control and the results show significant improvement against the periodic counterpart.

  8. Asynchronous emergence by loggerhead turtle (Caretta caretta) hatchlings.

    Science.gov (United States)

    Houghton, J D; Hays, G C

    2001-03-01

    For many decades it has been accepted that marine turtle hatchlings from the same nest generally emerge from the sand together. However, for loggerhead turtles (Caretta caretta) nesting on the Greek Island of Kefalonia, a more asynchronous pattern of emergence has been documented. By placing temperature loggers at the top and bottom of nests laid on Kefalonia during 1998, we examined whether this asynchronous emergence was related to the thermal conditions within nests. Pronounced thermal variation existed not only between, but also within, individual nests. These within-nest temperature differences were related to the patterns of hatchling emergence, with hatchlings from nests displaying large thermal ranges emerging over a longer time-scale than those characterised by more uniform temperatures. In many egg-laying animals, parental care of the offspring may continue while the eggs are incubating and also after they have hatched. Consequently, the importance of the nest site for determining incubation conditions may be reduced since the parents themselves may alter the local environment. By contrast, in marine turtles, parental care ceases once the eggs have been laid and the nest site covered. The positioning of the nest site, in both space and time, may therefore have profound effects for marine turtles by affecting, for example, the survival of the eggs and hatchlings as well as their sex (Janzen and Paukstis 1991). During incubation, sea turtle embryos grow from a few cells at oviposition to a self-sufficient organism at hatching some 50-80 days later (Ackerman 1997). After hatching, the young turtles dig up through the sand and emerge typically en masse at the surface 1-7 nights later, with a number of stragglers following over the next few nights (Christens 1990). This contrasts with the frequently observed pattern of hatching asynchrony in birds. It has been suggested that the cause of mass emergence in turtles is that eggs within a clutch are fertilised

  9. Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

    Directory of Open Access Journals (Sweden)

    Mark P. Nelder

    2009-01-01

    Full Text Available Succession patterns of adult blow flies (Diptera: Calliphoridae on decaying alligators were investigated in Mobile (Ala, USA during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart, Cochliomyia macellaria (Fabricus, Chrysomya megacephala (Fabricus, Phormia regina (Meigen, and Lucilia coeruleiviridis (Macquart. Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., Cochliomyia macellaria, and Phormia regina in the later stages. Lucilia coeruleiviridis was the only synchronous blow fly on the three carcasses; other blow fly species exhibited only site-specific synchrony. Using dichotomous correlations and analyses of variance, we demonstrated that blow fly-community succession was asynchronous among three alligators; however, Monte Carlo simulations indicate that there was some degree of synchrony between the carcasses.

  10. Asynchronous data-driven classification of weapon systems

    International Nuclear Information System (INIS)

    Jin, Xin; Mukherjee, Kushal; Gupta, Shalabh; Ray, Asok; Phoha, Shashi; Damarla, Thyagaraju

    2009-01-01

    This communication addresses real-time weapon classification by analysis of asynchronous acoustic data, collected from microphones on a sensor network. The weapon classification algorithm consists of two parts: (i) feature extraction from time-series data using symbolic dynamic filtering (SDF), and (ii) pattern classification based on the extracted features using the language measure (LM) and support vector machine (SVM). The proposed algorithm has been tested on field data, generated by firing of two types of rifles. The results of analysis demonstrate high accuracy and fast execution of the pattern classification algorithm with low memory requirements. Potential applications include simultaneous shooter localization and weapon classification with soldier-wearable networked sensors. (rapid communication)

  11. Asynchronous machine rotor speed estimation using a tabulated numerical approach

    Science.gov (United States)

    Nguyen, Huu Phuc; De Miras, Jérôme; Charara, Ali; Eltabach, Mario; Bonnet, Stéphane

    2017-12-01

    This paper proposes a new method to estimate the rotor speed of the asynchronous machine by looking at the estimation problem as a nonlinear optimal control problem. The behavior of the nonlinear plant model is approximated off-line as a prediction map using a numerical one-step time discretization obtained from simulations. At each time-step, the speed of the induction machine is selected satisfying the dynamic fitting problem between the plant output and the predicted output, leading the system to adopt its dynamical behavior. Thanks to the limitation of the prediction horizon to a single time-step, the execution time of the algorithm can be completely bounded. It can thus easily be implemented and embedded into a real-time system to observe the speed of the real induction motor. Simulation results show the performance and robustness of the proposed estimator.

  12. Induction motor for superconducting synchronous/asynchronous motor

    International Nuclear Information System (INIS)

    Litz, D.C.; Haller, H.E. III.

    1975-01-01

    An induction motor structure for use on the outside of a superconducting rotor comprising a cylindrical shell of solid and laminated, magnetic iron with squirrel cage windings embedded in the outer circumference of said shell is described. The sections of the shell between the superconducting windings of the rotor are solid magnetic iron. The sections of the shell over the superconducting windings are made of laminations of magnetic iron. These laminations are parallel to the axis of the machine and are divided in halves with the laminations in each half oriented in diagonal opposition so that the intersection of the laminations forms a V. This structure presents a relatively high reluctance to leakage flux from the superconducting windings in the synchronous operating mode, while presenting a low reluctance path to the stator flux during asynchronous operation

  13. Exploring Asynchronous Many-Task Runtime Systems toward Extreme Scales

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Samuel [O8953; Baker, Gavin Matthew; Gamell, Marc [Rutgers U; Hollman, David [08953; Sjaardema, Gregor [SNL; Kolla, Hemanth [SNL; Teranishi, Keita; Wilke, Jeremiah J; Slattengren, Nicole [SNL; Bennett, Janine Camille

    2015-10-01

    Major exascale computing reports indicate a number of software challenges to meet the dramatic change of system architectures in near future. While several-orders-of-magnitude increase in parallelism is the most commonly cited of those, hurdles also include performance heterogeneity of compute nodes across the system, increased imbalance between computational capacity and I/O capabilities, frequent system interrupts, and complex hardware architectures. Asynchronous task-parallel programming models show a great promise in addressing these issues, but are not yet fully understood nor developed su ciently for computational science and engineering application codes. We address these knowledge gaps through quantitative and qualitative exploration of leading candidate solutions in the context of engineering applications at Sandia. In this poster, we evaluate MiniAero code ported to three leading candidate programming models (Charm++, Legion and UINTAH) to examine the feasibility of these models that permits insertion of new programming model elements into an existing code base.

  14. Indoor Positioning for Smartphones Using Asynchronous Ultrasound Trilateration

    Directory of Open Access Journals (Sweden)

    James D. Carswell

    2013-06-01

    Full Text Available Modern smartphones are a great platform for Location Based Services (LBS. While outdoor LBS for smartphones has proven to be very successful, indoor LBS for smartphones has not yet fully developed due to the lack of an accurate positioning technology. In this paper we present an accurate indoor positioning approach for commercial off-the-shelf (COTS smartphones that uses the innate ability of mobile phones to produce ultrasound, combined with Time-Difference-of-Arrival (TDOA asynchronous trilateration. We evaluate our indoor positioning approach by describing its strengths and weaknesses, and determine its absolute accuracy. This is accomplished through a range of experiments that involve variables such as position of control point microphones, position of phone within the room, direction speaker is facing and presence of user in the signal path. Test results show that our Lok8 (locate mobile positioning system can achieve accuracies better than 10 cm in a real-world environment.

  15. Bio-Inspired Asynchronous Pixel Event Tricolor Vision Sensor.

    Science.gov (United States)

    Lenero-Bardallo, Juan Antonio; Bryn, D H; Hafliger, Philipp

    2014-06-01

    This article investigates the potential of the first ever prototype of a vision sensor that combines tricolor stacked photo diodes with the bio-inspired asynchronous pixel event communication protocol known as Address Event Representation (AER). The stacked photo diodes are implemented in a 22 × 22 pixel array in a standard STM 90 nm CMOS process. Dynamic range is larger than 60 dB and pixels fill factor is 28%. The pixels employ either simple pulse frequency modulation (PFM) or a Time-to-First-Spike (TFS) mode. A heuristic linear combination of the chip's inherent pseudo colors serves to approximate RGB color representation. Furthermore, the sensor outputs can be processed to represent the radiation in the near infrared (NIR) band without employing external filters, and to color-encode direction of motion due to an asymmetry in the update rates of the different diode layers.

  16. Operational aspects of asynchronous filtering for flood forecasting

    Science.gov (United States)

    Rakovec, O.; Weerts, A. H.; Sumihar, J.; Uijlenhoet, R.

    2015-06-01

    This study investigates the suitability of the asynchronous ensemble Kalman filter (AEnKF) and a partitioned updating scheme for hydrological forecasting. The AEnKF requires forward integration of the model for the analysis and enables assimilation of current and past observations simultaneously at a single analysis step. The results of discharge assimilation into a grid-based hydrological model (using a soil moisture error model) for the Upper Ourthe catchment in the Belgian Ardennes show that including past predictions and observations in the data assimilation method improves the model forecasts. Additionally, we show that elimination of the strongly non-linear relation between the soil moisture storage and assimilated discharge observations from the model update becomes beneficial for improved operational forecasting, which is evaluated using several validation measures.

  17. Operational aspects of asynchronous filtering for hydrological forecasting

    Science.gov (United States)

    Rakovec, O.; Weerts, A. H.; Sumihar, J.; Uijlenhoet, R.

    2015-03-01

    This study investigates the suitability of the Asynchronous Ensemble Kalman Filter (AEnKF) and a partitioned updating scheme for hydrological forecasting. The AEnKF requires forward integration of the model for the analysis and enables assimilation of current and past observations simultaneously at a single analysis step. The results of discharge assimilation into a grid-based hydrological model for the Upper Ourthe catchment in the Belgian Ardennes show that including past predictions and observations in the data assimilation method improves the model forecasts. Additionally, we show that elimination of the strongly non-linear relation between the soil moisture storage and assimilated discharge observations from the model update becomes beneficial for improved operational forecasting, which is evaluated using several validation measures.

  18. Label-acquired magnetorotation for biosensing: An asynchronous rotation assay

    International Nuclear Information System (INIS)

    Hecht, Ariel; Kinnunen, Paivo; McNaughton, Brandon; Kopelman, Raoul

    2011-01-01

    This paper presents a novel application of magnetic particles for biosensing, called label-acquired magnetorotation (LAM). This method is based on a combination of the traditional sandwich assay format with the asynchronous magnetic bead rotation (AMBR) method. In label-acquired magnetorotation, an analyte facilitates the binding of a magnetic label bead to a nonmagnetic solid phase sphere, forming a sandwich complex. The sandwich complex is then placed in a rotating magnetic field, where the rotational frequency of the sandwich complex is a function of the amount of analyte attached to the surface of the sphere. Here, we use streptavidin-coated beads and biotin-coated particles as analyte mimics, to be replaced by proteins and other biological targets in future work. We show this sensing method to have a dynamic range of two orders of magnitude.

  19. An Asynchronous Cellular Automata-Based Adaptive Illumination Facility

    Science.gov (United States)

    Bandini, Stefania; Bonomi, Andrea; Vizzari, Giuseppe; Acconci, Vito

    The term Ambient Intelligence refers to electronic environments that are sensitive and responsive to the presence of people; in the described scenario the environment itself is endowed with a set of sensors (to perceive humans or other physical entities such as dogs, bicycles, etc.), interacting with a set of actuators (lights) that choose their actions (i.e. state of illumination) in an attempt improve the overall experience of these users. The model for the interaction and action of sensors and actuators is an asynchronous Cellular Automata (CA) with memory, supporting a self-organization of the system as a response to the presence and movements of people inside it. The paper will introduce the model, as well as an ad hoc user interface for the specification of the relevant parameters of the CA transition rule that determines the overall system behaviour.

  20. Realization of station for testing asynchronous three-phase motors

    Science.gov (United States)

    Wróbel, A.; Surma, W.

    2016-08-01

    Nowadays, you cannot imagine the construction and operation of machines without the use of electric motors [13-15]. The proposed position is designed to allow testing of asynchronous three-phase motors. The position consists of a tested engine and the engine running as a load, both engines combined with a mechanical clutch [2]. The value of the load is recorded by measuring shaft created with Strain Gauge Bridge. This concept will allow to study the basic parameters of the engines, visualization motor parameters both vector and scalar controlled, during varying load drive system. In addition, registration during the variable physical parameters of the working electric motor, controlled by a frequency converter or controlled by a contactor will be possible. Position is designed as a teaching and research position to characterize the engines. It will be also possible selection of inverter parameters.

  1. Asynchronous learning: student utilization out of sync with their preference

    Directory of Open Access Journals (Sweden)

    Edward K. Lew

    2016-06-01

    Full Text Available Background: Asynchronous learning is gaining popularity. Data are limited regarding this learning method in medical students rotating in emergency medicine (EM. In EM, faculty time is limited to give in-person lectures. The authors sought to create an online curriculum that students could utilize as an additional learning modality. Objective: The goal was to evaluate effectiveness, participation, and preference for this mode of learning. Methods: We developed five online, narrated PowerPoint presentations. After orientation, access to the online curriculum was provided to the students, which they could review at their leisure. Results: One hundred and seven fourth-year medical students participated. They reported the curriculum to be of high quality. Pretest scores were similar for those that viewed all lectures – compliant group (CG (9.5 [CI 4.8–14.1] and those that did not view any – non-compliant group (NCG (9.6 [CI 5.9–13.4]. There was no statistical significant difference in posttest scores between the groups although there was improvement overall: CG 14.6 (CI 6.9–22.1; NCG 11.4 (CI 5.7–17.1. A majority (69.2% favored inclusion of asynchronous learning, but less than a quarter (22.4% reported viewing all five modules and more than a third (36.4% viewed none. Conclusion: Despite student-expressed preference for an online curriculum, they used the online resource less than expected. This should give pause to educators looking to convert core EM topics to an online format. However, when high-quality online lectures are utilized as a learning tool, this study demonstrates that they had neither a positive nor a negative impact on test scores.

  2. Episodes in «Persiles and Sigismunda» shaped by ‘Byzantine tales’ from the «Gesta Romanorum»

    Directory of Open Access Journals (Sweden)

    Clark Andrews Colahan

    2015-05-01

    Full Text Available Only recently has there been a recognition of the literary influence in Spain of the ‘examples’ found in the Gesta Romanorum, a collection of tales widely spread and fertile in adaptations throughout Medieval and Renaissance northern Europe. Just as other Hispanic writers did who were contemporaries of Cervantes, he would have been able to read them without difficulty in the original Latin, which is highly simplified for the use of preachers. The plot and images of two of the gesta written in the style of a Byzantine novel shape corresponding episodes in the Persiles, which is well known for Cervantes’ statement that in it he sought to compete with the Byzantine novel set in Ethiopia by Heliodorus. A whale swallowing Auristela’s ship in one of the tales, like her rescue and subsequent forced choice between suitors, provide situations and phrases used by Cervantes to portray the intense love between Persiles and his sweetheart/pretended sister, Sigismunda, as was done also in other Hispanic adaptations of the legend.

  3. Two hegemonies, one island: Cyprus as a “Middle Ground” between the Byzantines and the Arabs (650-850 A.D.

    Directory of Open Access Journals (Sweden)

    Luca Zavagno

    2013-10-01

    Full Text Available This paper aims to assess the political and cultural status of the island of Cyprus as the only place within the Mediterranean where Christian heirs of Romans and Muslims shared the local tax revenue to create a buffer zone between two empires. Geographically isolated between the Constantinopolitan and Damascene hegemonies, and marginalized by emperors and caliphs alike, the development of Cyprus was destined to take a unique, perhaps problematic, trajectory. Detailed examination of archaeological material (seals, coins, ceramics and material artifacts suggests a different interpretative scheme to the one traditionally adopted to interpret the declining fate of Cyprus after the Muslim raids and the occupation of Syria and Palestine. Instead, I propose, Cyprus and its cities were still active from late antiquity to the early middle ages, preserving a variable but still traceable degree of economic vitality (benefitting from the circulation of Byzantine and Arab coinage, which infers the maintenance of complex political, commercial and cultural relations (implicit in issues of imagery and prototypes of coins between the Byzantine Empire and the Umayyad Caliphate.

  4. UNIVERSAL REGULAR AUTONOMOUS ASYNCHRONOUS SYSTEMS: ω-LIMIT SETS, INVARIANCE AND BASINS OF ATTRACTION

    Directory of Open Access Journals (Sweden)

    Serban Vlad

    2011-07-01

    Full Text Available The asynchronous systems are the non-deterministic real timebinarymodels of the asynchronous circuits from electrical engineering.Autonomy means that the circuits and their models have no input.Regularity means analogies with the dynamical systems, thus such systems may be considered to be real time dynamical systems with a’vector field’, Universality refers to the case when the state space of the system is the greatest possible in the sense of theinclusion. The purpose of this paper is that of defining, by analogy with the dynamical systems theory, the omega-limit sets, the invariance and the basins of attraction of the universal regular autonomous asynchronous systems.

  5. Byzantine People’s Anthropology. The Force of the Foot And Its Reflection in the Life of St. Theodore Sikeot

    Directory of Open Access Journals (Sweden)

    Nikolay Dmitrievich Barabanov

    2015-10-01

    Full Text Available The article deals with one aspect of Byzantine folk anthropology in its religious incarnation. We are speaking about human limbs, feet of the Saint, who showed specific ability of miracles using them. Among the many wonders which were committed by Holy Theodore Sikeot, who was Abbot of Sikeon monastery and former Bishop of Anastasiopol (date of death – April 22, 613, three of them deserve special attention. In the narration of life of the Saint it is told about healing the patients who suffered from paralysis of limbs and, consequently, were deprived of their ability to move. Saint Theodore saved them from illness not only by the power of prayer. In all cases he put his foot on the body of the patient, in particular, on chest and knees. This kind of touch makes us think about the meaning of committed ritual and about that complex of ideas which was connected with it. Presumably, the described action reflected not only the individual attitude of the hagiographer but also an attitude of the audience, to which it was addressed. For this reason, this phenomenon should be considered not as a hagiographic topos, but as an element of the mythological-ritual continuum, which is connected with religious contemplation of the specificity of the different parts of the human body, in particular, of the lower limbs. The tradition of honoring the legs and their prints are well known and are rooted in “deep antiquity”. In the pre-Christian world of the Graeco- Roman time there was the cult of the legs, the image of which was regarded as an amulet, which had an apotropaic power. The feet can be associated with different deities, however, most of all, the following cult was associated with Serapis, the God of fertility, underworld and healing. It was believed that the right foot of Serapis had healing force. However, the process of transferring of the properties of Serapis foot to the foot of Christian Saint raises some questions. First of all, about

  6. Continuity and change in ceramic manufacture: Archaeometric study of Late Byzantine-Early Islamic transition in Jordan

    Science.gov (United States)

    Alawneh, Firas Mohamad

    This thesis investigates continuity and change of ceramics from Late Byzantine-Early Islamic transition period Jordan. The transition period has been characterized largely by an overlap of two ceramic traditions. The material culture of this period has been primarily viewed through formal and stylistic changes. However, ceramic technology and distribution have never been subjected to rigorous analytical study. In order to explain continuity and change in ceramic tradition the undertaken study has focused on the provenance and technology, using multifaceted analytical approach. This study of the transition period pottery has focused on the classification and technological features of potsherds from selected sites in Jordan (Amman, Aqaba, Beit Ras, Khirbet el-Nawafleh, Jarash, Jericho, Pella, Madaba, Gharndal, Humaimah, Um er-Rassas and Um el-Waleed). Samples were studied by particle-induced X-ray emission spectroscopy, X-ray powder diffraction, and optical microscopy to analyze their chemical, mineralogical and textural features in the aim of determining their possible provenance and production technology. Compositional data were statistically processed with multivariate analysis using SYSTAT II software 2006. To obtain further information about possible source areas of raw materials used in ceramic production, clays were also sampled in the studied areas. Firing experiments were conducted for clays with compositions comparable with those of ceramic sherds, to better understand the firing technology of the pottery. The multifaceted analytical approach has revealed important information on ceramic production in Transjordan. Khirbet el-Nawafleh and Aqaba in the south, Jarash and Pella in the north, Amman and Madaba in the middle are possibly just a few important production centers during this period. The study shows a multidirectional socio-cultural exchange and economic trade patterns within each region and between adjacent regions, as well. Also, importation from

  7. Droit déguisé : Quelques considérations sur le rôle du droit byzantin dans la genèse des codes en Europe orientale au XIXe siècle

    NARCIS (Netherlands)

    Penna, Daphne

    2015-01-01

    This paper attempts to examine some first questions related to the use of Byzantine law in the codes that emerged during the 19th century in South-Eastern Europe. It focuses on the introductory acts to the codes of Moldavie (1817) and Valachie (1818) and an episode related to the involvement of

  8. Transition to Asynchronous Transfer Mode (ATM) an Implementation Model for NPS Software Metrics Lab

    National Research Council Canada - National Science Library

    Carney, Cameron

    1999-01-01

    With Asynchronous Transfer Mode (ATM), we are experiencing the emergence of a network technology that has the potential of satisfying the requirement for a worldwide standard to allow interoperability of information, regardless...

  9. Integration of asynchronous knowledge sources in a novel speech recognition framework

    OpenAIRE

    Van hamme, Hugo

    2008-01-01

    Van hamme H., ''Integration of asynchronous knowledge sources in a novel speech recognition framework'', Proceedings ITRW on speech analysis and processing for knowledge discovery, 4 pp., June 2008, Aalborg, Denmark.

  10. Determining sociability, social space, and social presence in (A)synchronous collaborative groups

    NARCIS (Netherlands)

    Kreijns, K.; Kirschner, P.A.; Jochems, W.; Buuren, H. van

    2004-01-01

    The effectiveness of group learning in asynchronous distributed learning groups depends on the social interaction that takes place. This social interaction affects both cognitive and socioemotional processes that take place during learning, group forming, establishment of group structures, and group

  11. Students experiences with collaborative learning in asynchronous computer-supported collaborative learning environments.

    NARCIS (Netherlands)

    Dewiyanti, Silvia; Brand-Gruwel, Saskia; Jochems, Wim; Broers, Nick

    2008-01-01

    Dewiyanti, S., Brand-Gruwel, S., Jochems, W., & Broers, N. (2007). Students experiences with collaborative learning in asynchronous computer-supported collaborative learning environments. Computers in Human Behavior, 23, 496-514.

  12. ZONES OF STEADY CAPACITOR EXCITATION IN A MODE OF GENERATION OF TYPICAL ASYNCHRONOUS MACHINES

    Directory of Open Access Journals (Sweden)

    Postoronca Sv.

    2009-12-01

    Full Text Available In work some features of a mode of capacitor excitation of industrial asynchronous electric motors, and also generators made on their base which can be used in wind installations of low power are considered. Borders of zones of steady capacitor excitation of asynchronous electric motors in rated power of 0,25-22,0 kW and generators made on their base, and also character of influence of own losses and active capacity of loading of the equivalent circuit of the asynchronous machine resulted in parameters have been determined. Some recommendations after maintenance of stability of capacitor excitation of asynchronous machines for work in a mode of generation of electric energy are given.

  13. Behavioral Synthesis of Asynchronous Circuits Using Syntax Directed Translation as Backend

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Sparsø, Jens; Madsen, Jan

    2009-01-01

    The current state-of-the art in high-level synthesis of asynchronous circuits is syntax directed translation, which performs a one-to-one mapping of a HDL-description into a corresponding circuit. This paper presents a method for behavioral synthesis of asynchronous circuits which builds on top...... description language Balsa [1]. This ”conventional” template architecture allows us to adapt traditional synchronous synthesis techniques for resource sharing, scheduling, binding etc, to the domain of asynchronous circuits. A prototype tool has been implemented on top of the Balsa framework, and the method...... is illustrated through the implementation of a set of example circuits. The main contributions of the paper are: the fundamental idea, the template architecture and its implementation using asynchronous handshake components, and the implementation of a prototype tool....

  14. Distributed Consensus of Stochastic Delayed Multi-agent Systems Under Asynchronous Switching.

    Science.gov (United States)

    Wu, Xiaotai; Tang, Yang; Cao, Jinde; Zhang, Wenbing

    2016-08-01

    In this paper, the distributed exponential consensus of stochastic delayed multi-agent systems with nonlinear dynamics is investigated under asynchronous switching. The asynchronous switching considered here is to account for the time of identifying the active modes of multi-agent systems. After receipt of confirmation of mode's switching, the matched controller can be applied, which means that the switching time of the matched controller in each node usually lags behind that of system switching. In order to handle the coexistence of switched signals and stochastic disturbances, a comparison principle of stochastic switched delayed systems is first proved. By means of this extended comparison principle, several easy to verified conditions for the existence of an asynchronously switched distributed controller are derived such that stochastic delayed multi-agent systems with asynchronous switching and nonlinear dynamics can achieve global exponential consensus. Two examples are given to illustrate the effectiveness of the proposed method.

  15. Determining sociability, social space, and social presence in (a)synchronous collaborating groups

    NARCIS (Netherlands)

    Kreijns, C.J.; Kirschner, P.A.; Jochems, W.M.G.; Buuren, van H.

    2004-01-01

    The effectiveness of group learning in asynchronous distributed learning groups depends on the social interaction that takes place. This social interaction affects both cognitive and socioemotional processes that take place during learning, group forming, establishment of group structures, and group

  16. Low-power Implementation of an Encryption/Decryption System with Asynchronous Techniques

    Directory of Open Access Journals (Sweden)

    Nikos Sklavos

    2002-01-01

    Full Text Available An asynchronous VLSI implementation of the International Data Encryption Algorithm (IDEA is presented in this paper. In order to evaluate the asynchronous design a synchronous version of the algorithm was also designed. VHDL hardware description language was used in order to describe the algorithm. By using Synopsys commercial available tools the VHDL code was synthesized. After placing and routing both designs were fabricated with 0.6 μm CMOS technology. With a system clock of up to 8 MHz and a power supply of 5 V the two chips were tested and evaluated comparing with the software implementation of the IDEA algorithm. This new approach proves efficiently the lowest power consumption of the asynchronous implementation compared to the existing synchronous. Therefore, the asynchronous chip performs efficiently in Wireless Encryption Protocols and high speed networks.

  17. Asynchronous Sensor fuSion for Improved Safety of air Traffic (ASSIST), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — SSCI proposes to develop, implement and test a collision detection system for unmanned aerial vehicles (UAV), referred to as the Asynchronous Sensor fuSion for...

  18. Operational aspects of asynchronous filtering for improved flood forecasting

    Science.gov (United States)

    Rakovec, Oldrich; Weerts, Albrecht; Sumihar, Julius; Uijlenhoet, Remko

    2014-05-01

    Hydrological forecasts can be made more reliable and less uncertain by recursively improving initial conditions. A common way of improving the initial conditions is to make use of data assimilation (DA), a feedback mechanism or update methodology which merges model estimates with available real world observations. The traditional implementation of the Ensemble Kalman Filter (EnKF; e.g. Evensen, 2009) is synchronous, commonly named a three dimensional (3-D) assimilation, which means that all assimilated observations correspond to the time of update. Asynchronous DA, also called four dimensional (4-D) assimilation, refers to an updating methodology, in which observations being assimilated into the model originate from times different to the time of update (Evensen, 2009; Sakov 2010). This study investigates how the capabilities of the DA procedure can be improved by applying alternative Kalman-type methods, e.g., the Asynchronous Ensemble Kalman Filter (AEnKF). The AEnKF assimilates observations with smaller computational costs than the original EnKF, which is beneficial for operational purposes. The results of discharge assimilation into a grid-based hydrological model for the Upper Ourthe catchment in Belgian Ardennes show that including past predictions and observations in the AEnKF improves the model forecasts as compared to the traditional EnKF. Additionally we show that elimination of the strongly non-linear relation between the soil moisture storage and assimilated discharge observations from the model update becomes beneficial for an improved operational forecasting, which is evaluated using several validation measures. In the current study we employed the HBV-96 model built within a recently developed open source modelling environment OpenStreams (2013). The advantage of using OpenStreams (2013) is that it enables direct communication with OpenDA (2013), an open source data assimilation toolbox. OpenDA provides a number of algorithms for model calibration

  19. Violation of the equivalence principle for stressed bodies in asynchronous relativity

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Martins, R. de (Centro de Logica, Epistemologia e Historia da Ciencia, Campinas (Brazil))

    1983-12-11

    In the recently developed asynchronous formulation of the relativistic theory of extended bodies, the inertial mass of a body does not explicitly depend on its pressure or stress. The detailed analysis of the weight of a box filled with a gas and placed in a weak gravitational field shows that this feature of asynchronous relativity implies a breakdown of the equivalence between inertial and passive gravitational mass for stressed systems.

  20. An Evaluation of Parallel Synchronous and Conservative Asynchronous Logic-Level Simulations

    Directory of Open Access Journals (Sweden)

    Ausif Mahmood

    1996-01-01

    a circuit remain fixed during the entire simulation. We remove this limitation and, by extending the analyses to multi-input, multi-output circuits with an arbitrary number of input events, show that the conservative asynchronous simulation extracts more parallelism and executes faster than synchronous simulation in general. Our conclusions are supported by a comparison of the idealized execution times of synchronous and conservative asynchronous algorithms on ISCAS combinational and sequential benchmark circuits.

  1. Asynchronous Free-Space Optical CDMA Communications System for Last-mile Access Network

    DEFF Research Database (Denmark)

    Jurado-Navas, Antonio; Raddo, Thiago R.; Sanches, Anderson L.

    2016-01-01

    We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed.......We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed....

  2. Strict optical orthogonal codes for purely asynchronous code-division multiple-access applications

    Science.gov (United States)

    Zhang, Jian-Guo

    1996-12-01

    Strict optical orthogonal codes are presented for purely asynchronous optical code-division multiple-access (CDMA) applications. The proposed code can strictly guarantee the peaks of its cross-correlation functions and the sidelobes of any of its autocorrelation functions to have a value of 1 in purely asynchronous data communications. The basic theory of the proposed codes is given. An experiment on optical CDMA systems is also demonstrated to verify the characteristics of the proposed code.

  3. The study of transient processes in the asynchronous starting of the synchronous motor

    OpenAIRE

    Alexandru Bârlea; Olivian Chiver

    2012-01-01

    Starting synchronous motors can be achieved by several ethods: starting with an auxiliary motor launch, starting in asynchronous regim, by feeding from a variable frequency source, auto-synchronization with the network.. In our case we study the transient processes in a asynchronous regim . In this case the synchronous motor is started like a squirrel cage induction motor . To start, the synchronous motor is equipped with a starting winding cage placed in the pole pieces of polar inducers; la...

  4. MED5/355: Using Web-technology for Asynchronous Telemedicine Consulting

    OpenAIRE

    Reviakin, Y; Sukhanov, A

    1999-01-01

    Introduction Common telemedicine consultations can be divided in two classes: real-time telemedicine consultations and asynchronous telemedicine consultations. The advantage of real-time consultations is obvious - this is a natural discussion between physicians, which may be realised on the basis of desktop videoconferences. But the problems are also obvious: the necessity of additional hardware and the elevated demands for channel bandwidth. Because of the latter, the use of asynchronous tel...

  5. Simulating Quantitative Cellular Responses Using Asynchronous Threshold Boolean Network Ensembles

    Directory of Open Access Journals (Sweden)

    Shah Imran

    2011-07-01

    Full Text Available Abstract Background With increasing knowledge about the potential mechanisms underlying cellular functions, it is becoming feasible to predict the response of biological systems to genetic and environmental perturbations. Due to the lack of homogeneity in living tissues it is difficult to estimate the physiological effect of chemicals, including potential toxicity. Here we investigate a biologically motivated model for estimating tissue level responses by aggregating the behavior of a cell population. We assume that the molecular state of individual cells is independently governed by discrete non-deterministic signaling mechanisms. This results in noisy but highly reproducible aggregate level responses that are consistent with experimental data. Results We developed an asynchronous threshold Boolean network simulation algorithm to model signal transduction in a single cell, and then used an ensemble of these models to estimate the aggregate response across a cell population. Using published data, we derived a putative crosstalk network involving growth factors and cytokines - i.e., Epidermal Growth Factor, Insulin, Insulin like Growth Factor Type 1, and Tumor Necrosis Factor α - to describe early signaling events in cell proliferation signal transduction. Reproducibility of the modeling technique across ensembles of Boolean networks representing cell populations is investigated. Furthermore, we compare our simulation results to experimental observations of hepatocytes reported in the literature. Conclusion A systematic analysis of the results following differential stimulation of this model by growth factors and cytokines suggests that: (a using Boolean network ensembles with asynchronous updating provides biologically plausible noisy individual cellular responses with reproducible mean behavior for large cell populations, and (b with sufficient data our model can estimate the response to different concentrations of extracellular ligands. Our

  6. Comparing face-to-face, synchronous, and asynchronous learning: postgraduate dental resident preferences.

    Science.gov (United States)

    Kunin, Marc; Julliard, Kell N; Rodriguez, Tobias E

    2014-06-01

    The Department of Dental Medicine of Lutheran Medical Center has developed an asynchronous online curriculum consisting of prerecorded PowerPoint presentations with audio explanations. The focus of this study was to evaluate if the new asynchronous format satisfied the educational needs of the residents compared to traditional lecture (face-to-face) and synchronous (distance learning) formats. Lectures were delivered to 219 dental residents employing face-to-face and synchronous formats, as well as the new asynchronous format; 169 (77 percent) participated in the study. Outcomes were assessed with pretests, posttests, and individual lecture surveys. Results found the residents preferred face-to-face and asynchronous formats to the synchronous format in terms of effectiveness and clarity of presentations. This preference was directly related to the residents' perception of how well the technology worked in each format. The residents also rated the quality of student-instructor and student-student interactions in the synchronous and asynchronous formats significantly higher after taking the lecture series than they did before taking it. However, they rated the face-to-face format as significantly more conducive to student-instructor and student-student interaction. While the study found technology had a major impact on the efficacy of this curricular model, the results suggest that the asynchronous format can be an effective way to teach a postgraduate course.

  7. Understanding and Optimizing Asynchronous Low-Precision Stochastic Gradient Descent

    Science.gov (United States)

    De Sa, Christopher; Feldman, Matthew; Ré, Christopher; Olukotun, Kunle

    2018-01-01

    Stochastic gradient descent (SGD) is one of the most popular numerical algorithms used in machine learning and other domains. Since this is likely to continue for the foreseeable future, it is important to study techniques that can make it run fast on parallel hardware. In this paper, we provide the first analysis of a technique called Buckwild! that uses both asynchronous execution and low-precision computation. We introduce the DMGC model, the first conceptualization of the parameter space that exists when implementing low-precision SGD, and show that it provides a way to both classify these algorithms and model their performance. We leverage this insight to propose and analyze techniques to improve the speed of low-precision SGD. First, we propose software optimizations that can increase throughput on existing CPUs by up to 11×. Second, we propose architectural changes, including a new cache technique we call an obstinate cache, that increase throughput beyond the limits of current-generation hardware. We also implement and analyze low-precision SGD on the FPGA, which is a promising alternative to the CPU for future SGD systems. PMID:29391770

  8. Identity Presentation: The Construction of Identity in Asynchronous Discussion

    Directory of Open Access Journals (Sweden)

    Brian Morgan

    2008-08-01

    Full Text Available This study examines the use of e-mail as a tool for long term discussion between teachers and grade six students. E-mail messages between grade six students and teachers were collected over the course of one academic year. Methods of conversation analysis within a framework of social practice are used to examine the data. While identity is more readily constructed and more fully developed in contexts which allow for physical embodiment such as face-to-face discussion, this analysis found that identity can be constructed in a context that does not provide for the physical embodiment of identity: Identity was constructed using the social, cultural, and technological tools provided and supported by e-mail to develop social practices germane to the e-mail discussion. This study has implications for further understanding the relation between identity, goals, constraints and affordances, and the collaborative creation of social practices in asynchronous computer mediated communication. URN: urn:nbn:de:0114-fqs0803185

  9. FACT. Normalized and asynchronous mirror alignment for Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Sebastian Achim [ETH Zurich (Switzerland); Buss, Jens [TU Dortmund (Germany)

    2016-07-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need fast and large imaging optics to map the faint Cherenkov light emitted in cosmic ray air showers onto their image sensors. Segmented reflectors are inexpensive, lightweight and offer good image quality. However, alignment of the mirror facets remains a challenge. A good alignment is crucial in IACT observations to separate gamma rays from hadronic cosmic rays. We present a star tracking alignment method which is not restricted to clear nights. It normalizes the mirror facet reflections to be independent of the reference star or the cloud coverage. It records asynchronously of the telescope drive which makes the method easy to integrate in existing telescopes. It can be combined with remote facet actuation, but it does not need one to work. Furthermore, it can reconstruct all individual mirror facet point spread functions. We present the method and alignment results on the First Geiger-mode Photo Diode Avalanche Cherenkov Telescope (FACT) on the Canary Island of La Palma, Spain.

  10. Preparation for an online asynchronous university doctoral course. Lessons learned.

    Science.gov (United States)

    Milstead, J A; Nelson, R

    1998-01-01

    This article addresses the development of the initial course in the first completely online doctoral program in nursing. Synchronous and asynchronous methods of distance education were assessed. Planning focused at the university, school, and course levels. University planning involved the technical infrastructure, registration, student services, and library services. School planning examined administrative commitment and faculty commitment and willingness. Course planning focused on marketing, precourse information, time frame, modular design, planned interaction, and professor availability and support. Implementation issues centered on getting students connected, learning the software, changing instructional methods, and managing chats. Traditional methods of evaluating student learning and course evaluation were supplemented with the development of qualitative and quantitative tools to gather data for making administrative decisions. The Dean and faculty agreed that the internet was an effective method of delivering content in the initial Health Policy course. The Dean and faculty agreed to continue the PhD program online for one cohort and continue to evaluate student progress and faculty and student satisfaction.

  11. Performance Studies for Protection Against Asynchronous Dumps in the LHC

    CERN Document Server

    Kramer, T; Bracco, C; Goddard, B; Meddahi, M

    2010-01-01

    The LHC beam dump system has to safely dispose all beams in a wide energy range of 450 GeV to 7 TeV. A 3 ms abort gap in the beam structure for the switch-on of the extraction kicker field ideally allows a loss-free extraction under normal operating conditions. However, a low number of asynchronous beam aborts is to be expected from reliability calculations and from the first year's operational experience with the beam dump kickers. For such cases, MAD-X simulations including all optics and alignment errors have been performed to determine loss patterns around the LHC as a function of the position of the main protection elements in interaction region six. Special attention was paid to the beam load on the tungsten collimators which protect the triplets in the LHC experimental insertions, and the tracking results compared with semi-analytical numerical estimates. The simulations are also compared to the results of beam commissioning of these protection devices.

  12. Asynchronous vehicle pose correction using visual detection of ground features

    International Nuclear Information System (INIS)

    Harnarinesingh, Randy E S; Syan, Chanan S

    2014-01-01

    The inherent noise associated with odometry manifests itself as errors in localization for autonomous vehicles. Visual odometry has been previously used in order to supplement classical vehicle odometry. However, visual odometry is limited in its ability to reduce errors in localization for large travel distances that entail the cumulative summing of individual frame-to-frame image errors. In this paper, a novel machine vision approach for tiled surfaces is proposed to address this problem. Tile edges in a laboratory environment are used to define a travel trajectory for the Quansar Qbot (autonomous vehicle) built on the iRobot iRoomba platform with a forward facing camera. Tile intersections are used to enable asynchronous error recovery for vehicle position and orientation. The proposed approach employs real-time image classification and is feasible for error mitigation for large travel distances. The average position error for an 8m travel distance using classical odometry was measured to be 0.28m. However, implementation of the proposed approach resulted in an error of 0.028m. The proposed approach therefore significantly reduces pose estimation error and could be used to supplement existing modalities such as GPS and Laser-based range sensors

  13. Combining Synchronous and Asynchronous Collaboration within 3D City Models

    Science.gov (United States)

    Klimke, Jan; Döllner, Jürgen

    This paper presents an approach for combining spatially distributed synchronous and asynchronous collaboration within 3D city models. Software applications use these models as additional communication medium to facilitate communication of georeferenced and geospatial information. Collaboration tools should support both the communication with other collaborators and their awareness of the current collaboration context. To support collaborative knowledge construction and gathering, we have designed a collaboration system to facilitate (a) creation of annotations that have 3D references to the virtual 3D city model and (b) collection information about the context in which these annotations are created. Our approach supports synchronous collaboration in connection with the creation of non volatile, precisely georeferenced units of information allow for a comprehensible form of cooperation in spatially distributed settings. Storage and retrieval of this information is provided through a Web Feature Service, which eases integration of collaboration data into existing applications. We further introduce a visualization technique that integrates annotations as complex structured data into the 3D visualization. This avoids media breaks and disruptions in working processes and creates a spatial coherence between annotation and annotated feature or geometry.

  14. Synchronous versus asynchronous modeling of gene regulatory networks.

    Science.gov (United States)

    Garg, Abhishek; Di Cara, Alessandro; Xenarios, Ioannis; Mendoza, Luis; De Micheli, Giovanni

    2008-09-01

    In silico modeling of gene regulatory networks has gained some momentum recently due to increased interest in analyzing the dynamics of biological systems. This has been further facilitated by the increasing availability of experimental data on gene-gene, protein-protein and gene-protein interactions. The two dynamical properties that are often experimentally testable are perturbations and stable steady states. Although a lot of work has been done on the identification of steady states, not much work has been reported on in silico modeling of cellular differentiation processes. In this manuscript, we provide algorithms based on reduced ordered binary decision diagrams (ROBDDs) for Boolean modeling of gene regulatory networks. Algorithms for synchronous and asynchronous transition models have been proposed and their corresponding computational properties have been analyzed. These algorithms allow users to compute cyclic attractors of large networks that are currently not feasible using existing software. Hereby we provide a framework to analyze the effect of multiple gene perturbation protocols, and their effect on cell differentiation processes. These algorithms were validated on the T-helper model showing the correct steady state identification and Th1-Th2 cellular differentiation process. The software binaries for Windows and Linux platforms can be downloaded from http://si2.epfl.ch/~garg/genysis.html.

  15. [System of telesonography with synchronous teleconsultations and asynchronous telediagnoses (Togo)].

    Science.gov (United States)

    Adambounou, K; Farin, F; Boucher, A; Adjenou, K V; Gbeassor, M; N'dakena, K; Vincent, N; Arbeille, P

    2012-01-01

    Ultrasonography is an important nonirradiating diagnostic medical imaging procedure, frequently used, especially in urgent circumstances. This relatively inexpensive noninvasive examination makes it possible to diagnose disorders in various parts of the human body, by examining, for example, the abdomen and pelvis, the cardiovascular system, and the muscles and joints. Ultrasound is also an operator-dependent examination, in that the quality of the result depends on precision in the manipulation of the probe. Unfortunately, many small medical centers and isolated sites do not have an appropriate well-trained sonographer to perform initial evaluations, and an untrained operator cannot capture the appropriate echographic views required for a safe diagnosis of current patients, even with realtime vocal guidance (personal data). The lack of experienced physicians or qualified technicians means that diagnostic ultrasound is not always accessible to patients for rapid examination worldwide, especially in Africa, Amazonia or near the North or South Poles. This situation has led to the development of a new concept of telemedicine: telesonography, with a remote ultrasound diagnosis either in real time (synchronous) or delayed (asynchronous; store-and-forward). These systems of real-time telesonography and data transmission require expensive and complex technology with sophisticated equipment not available in many developing countries. The purpose of this study is to design a low-cost real-time system of telesonography for teleconsultations with experts and a delayed telediagnostic mode between isolated peripheral hospitals and a University Hospital center (UHC). An IP camera and an internet video server were installed in a geographically isolated site equipped with an ultrasound machine and an operator with basic training in its use. Synchronous teleconsultation (second-opinion diagnosis) is possible via internet with a UHC expert. If no ultrasound operator is available at

  16. Asynchronous vs didactic education: it’s too early to throw in the towel on tradition

    Science.gov (United States)

    2013-01-01

    Background Asynchronous, computer based instruction is cost effective, allows self-directed pacing and review, and addresses preferences of millennial learners. Current research suggests there is no significant difference in learning compared to traditional classroom instruction. Data are limited for novice learners in emergency medicine. The objective of this study was to compare asynchronous, computer-based instruction with traditional didactics for senior medical students during a week-long intensive course in acute care. We hypothesized both modalities would be equivalent. Methods This was a prospective observational quasi-experimental study of 4th year medical students who were novice learners with minimal prior exposure to curricular elements. We assessed baseline knowledge with an objective pre-test. The curriculum was delivered in either traditional lecture format (shock, acute abdomen, dyspnea, field trauma) or via asynchronous, computer-based modules (chest pain, EKG interpretation, pain management, trauma). An interactive review covering all topics was followed by a post-test. Knowledge retention was measured after 10 weeks. Pre and post-test items were written by a panel of medical educators and validated with a reference group of learners. Mean scores were analyzed using dependent t-test and attitudes were assessed by a 5-point Likert scale. Results 44 of 48 students completed the protocol. Students initially acquired more knowledge from didactic education as demonstrated by mean gain scores (didactic: 28.39% ± 18.06; asynchronous 9.93% ± 23.22). Mean difference between didactic and asynchronous = 18.45% with 95% CI [10.40 to 26.50]; p = 0.0001. Retention testing demonstrated similar knowledge attrition: mean gain scores −14.94% (didactic); -17.61% (asynchronous), which was not significantly different: 2.68% ± 20.85, 95% CI [−3.66 to 9.02], p = 0.399. The attitudinal survey revealed that 60.4% of students believed the asynchronous

  17. Asynchronous vs didactic education: it's too early to throw in the towel on tradition.

    Science.gov (United States)

    Jordan, Jaime; Jalali, Azadeh; Clarke, Samuel; Dyne, Pamela; Spector, Tahlia; Coates, Wendy

    2013-08-08

    Asynchronous, computer based instruction is cost effective, allows self-directed pacing and review, and addresses preferences of millennial learners. Current research suggests there is no significant difference in learning compared to traditional classroom instruction. Data are limited for novice learners in emergency medicine. The objective of this study was to compare asynchronous, computer-based instruction with traditional didactics for senior medical students during a week-long intensive course in acute care. We hypothesized both modalities would be equivalent. This was a prospective observational quasi-experimental study of 4th year medical students who were novice learners with minimal prior exposure to curricular elements. We assessed baseline knowledge with an objective pre-test. The curriculum was delivered in either traditional lecture format (shock, acute abdomen, dyspnea, field trauma) or via asynchronous, computer-based modules (chest pain, EKG interpretation, pain management, trauma). An interactive review covering all topics was followed by a post-test. Knowledge retention was measured after 10 weeks. Pre and post-test items were written by a panel of medical educators and validated with a reference group of learners. Mean scores were analyzed using dependent t-test and attitudes were assessed by a 5-point Likert scale. 44 of 48 students completed the protocol. Students initially acquired more knowledge from didactic education as demonstrated by mean gain scores (didactic: 28.39% ± 18.06; asynchronous 9.93% ± 23.22). Mean difference between didactic and asynchronous = 18.45% with 95% CI [10.40 to 26.50]; p = 0.0001. Retention testing demonstrated similar knowledge attrition: mean gain scores -14.94% (didactic); -17.61% (asynchronous), which was not significantly different: 2.68% ± 20.85, 95% CI [-3.66 to 9.02], p = 0.399. The attitudinal survey revealed that 60.4% of students believed the asynchronous modules were educational and 95

  18. Etude dynamique de l’environnement des villages romano-byzantins de Syrie du Nord ; localisation des structures parcellaires et cadastrales qui leurs sont liées

    Directory of Open Access Journals (Sweden)

    Georges Tate

    2000-05-01

    Full Text Available L’étude porte sur une région de 30.000 km2, allant de la frontière turque à Homs, et communément appelé "le Plateau Calcaire". Sept cents villages, d’époque romaine et byzantine y ont été recensés. Les objectifs Ils sont de deux types : comprendre l’histoire du peuplement, en particulier l’abondon progressif de très nombreux villages entre le 8éme et le 10ème siècle. A cette fin sont notamment indispensables les connaissances relatives, aux terroirs et aux terres arables effectivement disponi...

  19. Recherches sur l’apocalyptique syriaque et byzantine au viie siècle : la place de l’Empire romain dans une histoire du salut

    Directory of Open Access Journals (Sweden)

    Pablo Ubierna

    2009-02-01

    Full Text Available L’occupation perse et la littérature apocalyptiqueLa perception des événements militaires du début du viie siècle – d’abord l’occupation perse et ensuite la guerre arabe – n’est pas écartée, chez les contemporains, de la vision d’un empire, l’empire byzantin, secoué par de fortes controverses religieuses.La préoccupation intellectuelle à propos de la situation de l’Empire fut extrêmement marquée au commencement du viie siècle. Une vie anonyme de l’empereur Maurice inclut un récit de sa mort d...

  20. Pediatric emergency medicine asynchronous e-learning: a multicenter randomized controlled Solomon four-group study.

    Science.gov (United States)

    Chang, Todd P; Pham, Phung K; Sobolewski, Brad; Doughty, Cara B; Jamal, Nazreen; Kwan, Karen Y; Little, Kim; Brenkert, Timothy E; Mathison, David J

    2014-08-01

    Asynchronous e-learning allows for targeted teaching, particularly advantageous when bedside and didactic education is insufficient. An asynchronous e-learning curriculum has not been studied across multiple centers in the context of a clinical rotation. We hypothesize that an asynchronous e-learning curriculum during the pediatric emergency medicine (EM) rotation improves medical knowledge among residents and students across multiple participating centers. Trainees on pediatric EM rotations at four large pediatric centers from 2012 to 2013 were randomized in a Solomon four-group design. The experimental arms received an asynchronous e-learning curriculum consisting of nine Web-based, interactive, peer-reviewed Flash/HTML5 modules. Postrotation testing and in-training examination (ITE) scores quantified improvements in knowledge. A 2 × 2 analysis of covariance (ANCOVA) tested interaction and main effects, and Pearson's correlation tested associations between module usage, scores, and ITE scores. A total of 256 of 458 participants completed all study elements; 104 had access to asynchronous e-learning modules, and 152 were controls who used the current education standards. No pretest sensitization was found (p = 0.75). Use of asynchronous e-learning modules was associated with an improvement in posttest scores (p effect (partial η(2) = 0.19). Posttest scores correlated with ITE scores (r(2) = 0.14, p e-learning is an effective educational tool to improve knowledge in a clinical rotation. Web-based asynchronous e-learning is a promising modality to standardize education among multiple institutions with common curricula, particularly in clinical rotations where scheduling difficulties, seasonality, and variable experiences limit in-hospital learning. © 2014 by the Society for Academic Emergency Medicine.

  1. [A novel proposal explaining sleep disturbance of children in Japan--asynchronization].

    Science.gov (United States)

    Kohyama, Jun

    2008-07-01

    It has been reported that more than half of the children in Japan suffer from daytime sleepiness. In contrast, about one quarter of junior high-school students in Japan complain of insomnia. According to the International Classification of Sleep Disorders (Second edition), these children could be diagnosed as having behaviorally-induced insufficient sleep syndrome due to inadequate sleeping habits. Getting on adequate amount of sleep should solve such problems;however, such a therapeutic approach often fails. Although social factors are involved in these sleep disturbances, I feel that a novel notion - asynchronization - leads to an understanding of the pathophysiology of disturbances in these children. Further, it could contribute to resolve their problems. The essence of asynchronization is a disturbance of various aspects (e.g., cycle, amplitude, phase, and interrelationship) of the biological rhythms that normally exhibits circadian oscillation. The main cause of asynchronization is hypothesized to be the combination of light exposure during night and the lack of light exposure in the morning. Asynchronization results in the disturbance of variable systems. Thus, symptoms of asynchronization include disturbances of the autonomic nervous system (sleepiness, insomnia, disturbance of hormonal excretion, gastrointestinal problems, etc.) and higher brain function (disorientation, loss of sociality, loss of will or motivation, impaired alertness and performance, etc.). Neurological (attention deficit, aggression, impulsiveness, hyperactivity, etc.), psychiatric (depressive disorders, personality disorders, anxiety disorders, etc.) and somatic (tiredness, fatigue, etc.) disturbances could also be symptoms of asynchronization. At the initial phase of asynchronization, disturbances are functional and can be resolved relatively easily, such as by the establishment of a regular sleep-wakefulness cycle;however, without adequate intervention the disturbances could gradually

  2. Asynchronous Task-Based Parallelization of Algebraic Multigrid

    KAUST Repository

    AlOnazi, Amani A.

    2017-06-23

    As processor clock rates become more dynamic and workloads become more adaptive, the vulnerability to global synchronization that already complicates programming for performance in today\\'s petascale environment will be exacerbated. Algebraic multigrid (AMG), the solver of choice in many large-scale PDE-based simulations, scales well in the weak sense, with fixed problem size per node, on tightly coupled systems when loads are well balanced and core performance is reliable. However, its strong scaling to many cores within a node is challenging. Reducing synchronization and increasing concurrency are vital adaptations of AMG to hybrid architectures. Recent communication-reducing improvements to classical additive AMG by Vassilevski and Yang improve concurrency and increase communication-computation overlap, while retaining convergence properties close to those of standard multiplicative AMG, but remain bulk synchronous.We extend the Vassilevski and Yang additive AMG to asynchronous task-based parallelism using a hybrid MPI+OmpSs (from the Barcelona Supercomputer Center) within a node, along with MPI for internode communications. We implement a tiling approach to decompose the grid hierarchy into parallel units within task containers. We compare against the MPI-only BoomerAMG and the Auxiliary-space Maxwell Solver (AMS) in the hypre library for the 3D Laplacian operator and the electromagnetic diffusion, respectively. In time to solution for a full solve an MPI-OmpSs hybrid improves over an all-MPI approach in strong scaling at full core count (32 threads per single Haswell node of the Cray XC40) and maintains this per node advantage as both weak scale to thousands of cores, with MPI between nodes.

  3. iHadoop: Asynchronous Iterations Support for MapReduce

    KAUST Repository

    Elnikety, Eslam

    2011-08-01

    MapReduce is a distributed programming framework designed to ease the development of scalable data-intensive applications for large clusters of commodity machines. Most machine learning and data mining applications involve iterative computations over large datasets, such as the Web hyperlink structures and social network graphs. Yet, the MapReduce model does not efficiently support this important class of applications. The architecture of MapReduce, most critically its dataflow techniques and task scheduling, is completely unaware of the nature of iterative applications; tasks are scheduled according to a policy that optimizes the execution for a single iteration which wastes bandwidth, I/O, and CPU cycles when compared with an optimal execution for a consecutive set of iterations. This work presents iHadoop, a modified MapReduce model, and an associated implementation, optimized for iterative computations. The iHadoop model schedules iterations asynchronously. It connects the output of one iteration to the next, allowing both to process their data concurrently. iHadoop\\'s task scheduler exploits inter- iteration data locality by scheduling tasks that exhibit a producer/consumer relation on the same physical machine allowing a fast local data transfer. For those iterative applications that require satisfying certain criteria before termination, iHadoop runs the check concurrently during the execution of the subsequent iteration to further reduce the application\\'s latency. This thesis also describes our implementation of the iHadoop model, and evaluates its performance against Hadoop, the widely used open source implementation of MapReduce. Experiments using different data analysis applications over real-world and synthetic datasets show that iHadoop performs better than Hadoop for iterative algorithms, reducing execution time of iterative applications by 25% on average. Furthermore, integrating iHadoop with HaLoop, a variant Hadoop implementation that caches

  4. [Cost-effectiveness of Synchronous vs. Asynchronous Telepsychiatry in Prison Inmates With Depression].

    Science.gov (United States)

    Barrera-Valencia, Camilo; Benito-Devia, Alexis Vladimir; Vélez-Álvarez, Consuelo; Figueroa-Barrera, Mario; Franco-Idárraga, Sandra Milena

    Telepsychiatry is defined as the use of information and communication technology (ICT) in providing remote psychiatric services. Telepsychiatry is applied using two types of communication: synchronous (real time) and asynchronous (store and forward). To determine the cost-effectiveness of a synchronous and an asynchronous telepsychiatric model in prison inmate patients with symptoms of depression. A cost-effectiveness study was performed on a population consisting of 157 patients from the Establecimiento Penitenciario y Carcelario de Mediana Seguridad de Manizales, Colombia. The sample was determined by applying Zung self-administered surveys for depression (1965) and the Hamilton Depression Rating Scale (HDRS), the latter being the tool used for the comparison. Initial Hamilton score, arrival time, duration of system downtime, and clinical effectiveness variables had normal distributions (P>.05). There were significant differences (P<.001) between care costs for the different models, showing that the mean cost of the asynchronous model is less than synchronous model, and making the asynchronous model more cost-effective. The asynchronous model is the most cost-effective model of telepsychiatry care for patients with depression admitted to a detention centre, according to the results of clinical effectiveness, cost measurement, and patient satisfaction. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  5. FPGA BASED ASYNCHRONOUS PIPELINED MB-OFDM UWB TRANSMITTER BACKEND MODULES

    Directory of Open Access Journals (Sweden)

    M. Santhi

    2010-03-01

    Full Text Available In this paper, a novel scheme is proposed which comprises the advantages of asynchronous pipelining techniques and the advantages of FPGAs for implementing a 200Mbps MB-OFDM UWB transmitter digital backend modules. In asynchronous pipelined system, registers are used as in synchronous system. But they are controlled by handshaking signals. Since FPGAs are rich in registers, design and implementation of asynchronous pipelined MBOFDM UWB transmitter on FPGA using four-phase bundled-data protocol is considered in this paper. Novel ideas have also been proposed for designing asynchronous OFDM using Modified Radix-24 SDF and asynchronous interleaver using two RAM banks. Implementation has been performed on ALTERA STRATIX II EP2S60F1020C4 FPGA and it is operating at a speed of 350MHz. It is assured that the proposed MB-OFDM UWB system can be made to work on STRATIX III device with the operating frequency of 528MHz in compliance to the ECMA-368 standard. The proposed scheme is also applicable for FPGA from other vendors and ASIC.

  6. Features of the Asynchronous Correlation between the China Coal Price Index and Coal Mining Accidental Deaths

    Science.gov (United States)

    Huang, Yuecheng; Cheng, Wuyi; Luo, Sida; Luo, Yun; Ma, Chengchen; He, Tailin

    2016-01-01

    The features of the asynchronous correlation between accident indices and the factors that influence accidents can provide an effective reference for warnings of coal mining accidents. However, what are the features of this correlation? To answer this question, data from the China coal price index and the number of deaths from coal mining accidents were selected as the sample data. The fluctuation modes of the asynchronous correlation between the two data sets were defined according to the asynchronous correlation coefficients, symbolization, and sliding windows. We then built several directed and weighted network models, within which the fluctuation modes and the transformations between modes were represented by nodes and edges. Then, the features of the asynchronous correlation between these two variables could be studied from a perspective of network topology. We found that the correlation between the price index and the accidental deaths was asynchronous and fluctuating. Certain aspects, such as the key fluctuation modes, the subgroups characteristics, the transmission medium, the periodicity and transmission path length in the network, were analyzed by using complex network theory, analytical methods and spectral analysis method. These results provide a scientific reference for generating warnings for coal mining accidents based on economic indices. PMID:27902748

  7. Analysis and application of two recursive parametric estimation algorithms for an asynchronous machine

    International Nuclear Information System (INIS)

    Damek, Nawel; Kamoun, Samira

    2011-01-01

    In this communication, two recursive parametric estimation algorithms are analyzed and applied to an squirrelcage asynchronous machine located at the research ''Unit of Automatic Control'' (UCA) at ENIS. The first algorithm which, use the transfer matrix mathematical model, is based on the gradient principle. The second algorithm, which use the state-space mathematical model, is based on the minimization of the estimation error. These algorithms are applied as a key technique to estimate asynchronous machine with unknown, but constant or timevarying parameters. Stator voltage and current are used as measured data. The proposed recursive parametric estimation algorithms are validated on the experimental data of an asynchronous machine under normal operating condition as full load. The results show that these algorithms can estimate effectively the machine parameters with reliability.

  8. Determination of power and moment on shaft of special asynchronous electric drives

    Science.gov (United States)

    Karandey, V. Yu; Popov, B. K.; Popova, O. B.; Afanasyev, V. L.

    2018-03-01

    In the article, questions and tasks of determination of power and the moment on a shaft of special asynchronous electric drives are considered. Use of special asynchronous electric drives in mechanical engineering and other industries is relevant. The considered types of electric drives possess the improved mass-dimensional indicators in comparison with singleengine systems. Also these types of electric drives have constructive advantages; the improved characteristics allow one to realize the technological process. But creation and design of new electric drives demands adjustment of existing or development of new methods and approaches of calculation of parameters. Determination of power and the moment on a shaft of special asynchronous electric drives is the main objective during design of electric drives. This task has been solved based on a method of electromechanical transformation of energy.

  9. Gigabit Ethernet signal transmission using asynchronous optical code division multiple access.

    Science.gov (United States)

    Ma, Philip Y; Fok, Mable P; Shastri, Bhavin J; Wu, Ben; Prucnal, Paul R

    2015-12-15

    We propose and experimentally demonstrate a novel architecture for interfacing and transmitting a Gigabit Ethernet (GbE) signal using asynchronous incoherent optical code division multiple access (OCDMA). This is the first such asynchronous incoherent OCDMA system carrying GbE data being demonstrated to be working among multi-users where each user is operating with an independent clock/data rate and is granted random access to the network. Three major components, the GbE interface, the OCDMA transmitter, and the OCDMA receiver are discussed in detail. The performance of the system is studied and characterized through measuring eye diagrams, bit-error rate and packet loss rate in real-time file transfer. Our Letter also addresses the near-far problem and realizes asynchronous transmission and detection of signal.

  10. Methodological Reflections on the Use of Asynchronous Online Focus Groups in Health Research

    Directory of Open Access Journals (Sweden)

    Sarah Williams PhD

    2012-09-01

    Full Text Available The Internet is increasingly used as a tool in qualitative research. In particular, asynchronous online focus groups are used when factors such as cost, time, or access to participants can make conducting face-to-face research difficult. In this article we consider key methodological issues involved in using asynchronous online focus groups to explore experiences of health and illness. The written nature of Internet communication, the lack of physical presence, and the asynchronous, longitudinal aspects enable participants who might not normally contribute to research studies to reflect on their personal stories before disclosing them to the researcher. Implications for study design, recruitment strategies, and ethics should be considered when deciding whether to use this method.

  11. THE ROLE OF OFFLINE METALANGUAGE TALK IN ASYNCHRONOUS COMPUTER-MEDIATED COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Keiko Kitade

    2008-02-01

    Full Text Available In order to demonstrate how learners utilize the text-based asynchronous attributes of the Bulletin Board System, this study explored Japanese-as-a-second-language learners' metalanguage episodes (Swain & Lapkin, 1995, 1998 in offline verbal peer speech and online asynchronous discussions with their Japanese key pals. The findings suggest the crucial role of offline collaborative dialogue, the interactional modes in which the episodes occur, and the unique discourse structure of metalanguage episodes concerning online and offline interactions. A high score on the posttest also suggests the high retention of linguistic knowledge constructed through offline peer dialogue. In the offline mode, the learners were able to collaboratively construct knowledge with peers in the stipulated time, while simultaneously focusing on task content in the online interaction. The retrospective interviews and questionnaires reveal the factors that could affect the benefits of the asynchronous computer-mediated communication medium for language learning.

  12. Asynchronous Cholinergic Drive Correlates with Excitation-Inhibition Imbalance via a Neuronal Ca2+ Sensor Protein

    Directory of Open Access Journals (Sweden)

    Keming Zhou

    2017-05-01

    Full Text Available Excitation-inhibition imbalance in neural networks is widely linked to neurological and neuropsychiatric disorders. However, how genetic factors alter neuronal activity, leading to excitation-inhibition imbalance, remains unclear. Here, using the C. elegans locomotor circuit, we examine how altering neuronal activity for varying time periods affects synaptic release pattern and animal behavior. We show that while short-duration activation of excitatory cholinergic neurons elicits a reversible enhancement of presynaptic strength, persistent activation results to asynchronous and reduced cholinergic drive, inducing imbalance between endogenous excitation and inhibition. We find that the neuronal calcium sensor protein NCS-2 is required for asynchronous cholinergic release in an activity-dependent manner and dampens excitability of inhibitory neurons non-cell autonomously. The function of NCS-2 requires its Ca2+ binding and membrane association domains. These results reveal a synaptic mechanism implicating asynchronous release in regulation of excitation-inhibition balance.

  13. Argo: A Time-Elastic Time-Division-Multiplexed NOC using Asynchronous Routers

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia; Sparsø, Jens

    2014-01-01

    are either synchronous or mesochronous. We use asynchronous routers to achieve a simpler, smaller, and more robust, self-timed design. Our design exploits the fact that pipelined asynchronous circuits also behave as ripple FIFOs. Thus, it avoids the need for explicit synchronization FIFOs between the routers......In this paper we explore the use of asynchronous routers in a time-division-multiplexed (TDM) network-on-chip (NOC), Argo, that is being developed for a multi-processor platform for hard real-time systems. TDM inherently requires a common time reference, and existing TDM-based NOC designs...... delays derived from a 65nm CMOS implementation, a worstcase analysis shows that a typical design can tolerate a skew of 1-5 cycles (depending on FIFO depths and NI clock frequency). Simulation results of a 2 x 2 NOC confirm this....

  14. Network evolution induced by asynchronous stimuli through spike-timing-dependent plasticity.

    Directory of Open Access Journals (Sweden)

    Wu-Jie Yuan

    Full Text Available In sensory neural system, external asynchronous stimuli play an important role in perceptual learning, associative memory and map development. However, the organization of structure and dynamics of neural networks induced by external asynchronous stimuli are not well understood. Spike-timing-dependent plasticity (STDP is a typical synaptic plasticity that has been extensively found in the sensory systems and that has received much theoretical attention. This synaptic plasticity is highly sensitive to correlations between pre- and postsynaptic firings. Thus, STDP is expected to play an important role in response to external asynchronous stimuli, which can induce segregative pre- and postsynaptic firings. In this paper, we study the impact of external asynchronous stimuli on the organization of structure and dynamics of neural networks through STDP. We construct a two-dimensional spatial neural network model with local connectivity and sparseness, and use external currents to stimulate alternately on different spatial layers. The adopted external currents imposed alternately on spatial layers can be here regarded as external asynchronous stimuli. Through extensive numerical simulations, we focus on the effects of stimulus number and inter-stimulus timing on synaptic connecting weights and the property of propagation dynamics in the resulting network structure. Interestingly, the resulting feedforward structure induced by stimulus-dependent asynchronous firings and its propagation dynamics reflect both the underlying property of STDP. The results imply a possible important role of STDP in generating feedforward structure and collective propagation activity required for experience-dependent map plasticity in developing in vivo sensory pathways and cortices. The relevance of the results to cue-triggered recall of learned temporal sequences, an important cognitive function, is briefly discussed as well. Furthermore, this finding suggests a potential

  15. FAST: A fully asynchronous and status-tracking pattern for geoprocessing services orchestration

    Science.gov (United States)

    Wu, Huayi; You, Lan; Gui, Zhipeng; Gao, Shuang; Li, Zhenqiang; Yu, Jingmin

    2014-09-01

    Geoprocessing service orchestration (GSO) provides a unified and flexible way to implement cross-application, long-lived, and multi-step geoprocessing service workflows by coordinating geoprocessing services collaboratively. Usually, geoprocessing services and geoprocessing service workflows are data and/or computing intensive. The intensity feature may make the execution process of a workflow time-consuming. Since it initials an execution request without blocking other interactions on the client side, an asynchronous mechanism is especially appropriate for GSO workflows. Many critical problems remain to be solved in existing asynchronous patterns for GSO including difficulties in improving performance, status tracking, and clarifying the workflow structure. These problems are a challenge when orchestrating performance efficiency, making statuses instantly available, and constructing clearly structured GSO workflows. A Fully Asynchronous and Status-Tracking (FAST) pattern that adopts asynchronous interactions throughout the whole communication tier of a workflow is proposed for GSO. The proposed FAST pattern includes a mechanism that actively pushes the latest status to clients instantly and economically. An independent proxy was designed to isolate the status tracking logic from the geoprocessing business logic, which assists the formation of a clear GSO workflow structure. A workflow was implemented in the FAST pattern to simulate the flooding process in the Poyang Lake region. Experimental results show that the proposed FAST pattern can efficiently tackle data/computing intensive geoprocessing tasks. The performance of all collaborative partners was improved due to the asynchronous mechanism throughout communication tier. A status-tracking mechanism helps users retrieve the latest running status of a GSO workflow in an efficient and instant way. The clear structure of the GSO workflow lowers the barriers for geospatial domain experts and model designers to

  16. Comparison between Synchronous and Asynchronous Instructional Delivery Method of Training Programme on In-Service Physical Educators' Knowledge

    Science.gov (United States)

    Emmanouilidou, Kyriaki; Derri, Vassiliki; Antoniou, Panagiotis; Kyrgiridis, Pavlos

    2012-01-01

    The purpose of the study was to compare the influences of a training programme's instructional delivery method (synchronous and asynchronous) on Greek in-service physical educators' cognitive understanding on student assessment. Forty nine participants were randomly divided into synchronous, asynchronous, and control group. The experimental groups…

  17. Evaluation of asynchronous E-learning in the geography curriculum: enriching learning quality in Saudi high schools

    OpenAIRE

    Al Dobaikhi, Hend; Woollard, John

    2011-01-01

    The impacts of emerging ICT into educational curricula Asynchronous discussion forumDiscussion groups via e-learning environmentPosting questions and commentsSelf-efficacy in asynchronous e-learning Web community participationCollaborative learning can be fosteredPositive impacts on objectives of educational curriculum

  18. Laser dynamics of asynchronous rational harmonic mode-locked fiber soliton lasers

    International Nuclear Information System (INIS)

    Jyu, Siao-Shan; Jiang, Guo-Hao; Lai, Yinchieh

    2013-01-01

    Laser dynamics of asynchronous rational harmonic mode-locked (ARHM) fiber soliton lasers are investigated in detail. In particular, based on the unique laser dynamics of asynchronous mode-locking, we have developed a new method for determining the effective active modulation strength in situ for ARHM lasers. By measuring the magnitudes of the slowly oscillating pulse timing position and central frequency, the effective phase modulation strength at the multiplication frequency of rational harmonic mode-locking can be accurately inferred. The method can be a very useful tool for developing ARHM fiber lasers. (paper)

  19. Heating calculation features at self-start of large asynchronous motor

    Science.gov (United States)

    Shevchenko, A. A.; Temlyakova, Z. S.; Grechkin, V. V.; Vilberger, M. E.

    2017-10-01

    The article proposes a method for optimizing the incremental heating calculation in the active volume of a large asynchronous motor for certain kinds of load characteristics. The incremental heating calculation is conditioned by the need to determine the aging level of the insulation and to predict a decrease in the electric machine service life. The method for optimizing the incremental heating calculation of asynchronous motor active volume is based on the automation of calculating the heating when simulating the self-starting process of the motor after eliminating an AC drop.

  20. Simulation models of a drive with an asynchronous electric engine for students of electrical engineering faculties

    Directory of Open Access Journals (Sweden)

    Romanenko N. G.

    2017-10-01

    Full Text Available the application of virtual laboratories will allow to show different transition processes, as well as to carry out experiments that are very expensive in real electrical machines’ labs, for example, to calculate the energy costs in electric drives. Models of non-regulation asynchronous drive and frequency-regulated asynchronous electric drive are examined in this article. The author has calculated and compared the energy losses of these systems with various types of loads and this lets us to evaluate work processes of many technical devices.

  1. Asynchronous teaching of psychomotor skills through VR annotations: evaluation in digital rectal examination.

    Science.gov (United States)

    Rissanen, Mikko J; Kume, Naoto; Kuroda, Yoshihiro; Kuroda, Tomohiro; Yoshimura, Koji; Yoshihara, Hiroyuki

    2008-01-01

    Many VR technology based training systems use expert's motion data as the training aid, but would not provide any short-cut to teaching medical skills that do not depend on exact motions. Earlier we presented Annotated Simulation Records (ASRs), which can be used to encapsulate experts' insight on psychomotor skills. Annotations made to behavioural parameters in training simulators enable asynchronous teaching instead of just motion training in a proactive way to the learner. We evaluated ASRs for asynchronous teaching of Digital Rectal Examination (DRE) with 3 urologists and 8 medical students. The ASRs were found more effective than motion-based training with verbal feedback.

  2. A low-power asynchronous data-path for a FIR filter bank

    DEFF Research Database (Denmark)

    Nielsen, Lars Skovby; Sparsø, Jens

    1996-01-01

    This paper describes a number of design issues relating to the implementation of low-power asynchronous signal processing circuits. Specifically, the paper addresses the design of a dedicated processor structure that implements an audio FIR filter bank which is part of an industrial application....... The algorithm requires a fixed number of steps and the moderate speed requirement allows a sequential implementation. The latter, in combination with a huge predominance of numerically small data values in the input data stream, is the key to a low-power asynchronous implementation. Power is minimized in two...

  3. Efficiency of three-phase asynchronous motors. Energy loss reduction by means of overdimensioning; Efficientie van driefasen asynchrone motoren. SinuMEC beperkt energieverlies door overdimensionering

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, J.; Van Dorst, C. [Hyteps, Gemert (Netherlands)

    2008-10-15

    The three phase asynchronous motor has been applied in various installations since time immemorial. Although the motor is more efficient at full mechanical load, this is not always applied efficiently. Can the efficiency of low load motors be improved or is this a utopia? The Sinusoidal Motor Controller (SinuMEC) improves efficiency, saves energy and lengthens the life span. [mk]. [Dutch] De driefasen asynchrone motor wordt sinds mensenheugenis in uiteenlopende installaties toegepast. Hoewel de motor met een volle mechanische belasting efficient is, wordt deze niet altijd efficient toegepast. Kan de efficiency van laag belaste motoren worden verbeterd of is dit een utopie? De Sinusoidal Motor efficiency controller (SinuMEC) verbetert de efficiency, bespaart energie en verlengt de levensduur.

  4. Comparing Face-To-Face and Asynchronous Online Communication as Mechanisms for Critical Reflective Dialogue

    Science.gov (United States)

    Salter, Susan; Douglas, Tracy; Kember, David

    2017-01-01

    Two mechanisms for engaging in critical reflective dialogue are discussed and compared: face-to-face meetings and asynchronous online discussion. The context is an umbrella action research project, with over 20 participants, which aimed to improve practices in online teaching and contribute to the development of graduate attributes. The article…

  5. A feedback-retransmission based asynchronous frequency hopping MAC protocol for military aeronautical ad hoc networks

    Directory of Open Access Journals (Sweden)

    Jinhui TANG

    2018-05-01

    Full Text Available Attacking time-sensitive targets has rigid demands for the timeliness and reliability of information transmission, while typical Media Access Control (MAC designed for this application works well only in very light-load scenarios; as a consequence, the performances of system throughput and channel utilization are degraded. For this problem, a feedback-retransmission based asynchronous FRequency hopping Media Access (FRMA control protocol is proposed. Burst communication, asynchronous Frequency Hopping (FH, channel coding, and feedback retransmission are utilized in FRMA. With the mechanism of asynchronous FH, immediate packet transmission and multi-packet reception can be realized, and thus the timeliness is improved. Furthermore, reliability can be achieved via channel coding and feedback retransmission. With theories of queuing theory, Markov model, packets collision model, and discrete Laplace transformation, the formulas of packet success probability, system throughput, average packet end-to-end delay, and delay distribution are obtained. The approximation accuracy of theoretical derivation is verified by experimental results. Within a light-load network, the proposed FRMA has the ability of millisecond delay and 99% reliability as well as outperforms the non-feedback-retransmission based asynchronous frequency hopping media access control protocol. Keywords: Ad hoc networks, Aeronautical communications, Frequency hopping, Media Access Control (MAC, Time-sensitive

  6. Multithreaded Asynchronous Graph Traversal for In-Memory and Semi-External Memory

    KAUST Repository

    Pearce, Roger

    2010-11-01

    Processing large graphs is becoming increasingly important for many domains such as social networks, bioinformatics, etc. Unfortunately, many algorithms and implementations do not scale with increasing graph sizes. As a result, researchers have attempted to meet the growing data demands using parallel and external memory techniques. We present a novel asynchronous approach to compute Breadth-First-Search (BFS), Single-Source-Shortest-Paths, and Connected Components for large graphs in shared memory. Our highly parallel asynchronous approach hides data latency due to both poor locality and delays in the underlying graph data storage. We present an experimental study applying our technique to both In-Memory and Semi-External Memory graphs utilizing multi-core processors and solid-state memory devices. Our experiments using synthetic and real-world datasets show that our asynchronous approach is able to overcome data latencies and provide significant speedup over alternative approaches. For example, on billion vertex graphs our asynchronous BFS scales up to 14x on 16-cores. © 2010 IEEE.

  7. Embedded Vehicle Speed Estimation System Using an Asynchronous Temporal Contrast Vision Sensor

    Directory of Open Access Journals (Sweden)

    D. Bauer

    2007-01-01

    Full Text Available This article presents an embedded multilane traffic data acquisition system based on an asynchronous temporal contrast vision sensor, and algorithms for vehicle speed estimation developed to make efficient use of the asynchronous high-precision timing information delivered by this sensor. The vision sensor features high temporal resolution with a latency of less than 100 μs, wide dynamic range of 120 dB of illumination, and zero-redundancy, asynchronous data output. For data collection, processing and interfacing, a low-cost digital signal processor is used. The speed of the detected vehicles is calculated from the vision sensor's asynchronous temporal contrast event data. We present three different algorithms for velocity estimation and evaluate their accuracy by means of calibrated reference measurements. The error of the speed estimation of all algorithms is near zero mean and has a standard deviation better than 3% for both traffic flow directions. The results and the accuracy limitations as well as the combined use of the algorithms in the system are discussed.

  8. The Role of Beliefs and Motivation in Asynchronous Online Learning in College-Level Classes

    Science.gov (United States)

    Xie, Kui; Huang, Kun

    2014-01-01

    Epistemic and learning beliefs were found to affect college students' cognitive engagement and study strategies, as well as motivation in classroom settings. However, the relationships between epistemic and learning beliefs, motivation, learning perception, and students' actual learning participation in asynchronous online settings have been…

  9. A Coding Scheme to Analyse the Online Asynchronous Discussion Forums of University Students

    Science.gov (United States)

    Biasutti, Michele

    2017-01-01

    The current study describes the development of a content analysis coding scheme to examine transcripts of online asynchronous discussion groups in higher education. The theoretical framework comprises the theories regarding knowledge construction in computer-supported collaborative learning (CSCL) based on a sociocultural perspective. The coding…

  10. Introducing group-based asynchronous learning to business education : Reflections on effective course design and delivery

    NARCIS (Netherlands)

    Arnold, I.J.M.; Walker, R.

    2004-01-01

    This paper explores the contribution of virtual tools to student learning within full-time management programmes. More specifically, the paper focuses on asynchronous communication tools, considering the scope they offer for group-based collaborative learning outside the classroom. We report on the

  11. Theoretically Based Pedagogical Strategies Leading to Deep Learning in Asynchronous Online Gerontology Courses

    Science.gov (United States)

    Majeski, Robin; Stover, Merrily

    2007-01-01

    Online learning has enjoyed increasing popularity in gerontology. This paper presents instructional strategies grounded in Fink's (2003) theory of significant learning designed for the completely asynchronous online gerontology classroom. It links these components with the development of mastery learning goals and provides specific guidelines for…

  12. Peer Moderation of Asynchronous Online Discussions: An Exploratory Study of Peer E-Moderating Behaviour

    Science.gov (United States)

    Ghadirian, Hajar; Ayub, Ahmad Fauzi Mohd

    2017-01-01

    This study explored patterns of e-moderating behaviour students performed when they were assigned as peer moderators of asynchronous online discussions in a reciprocal manner. Eighty-four students from an undergraduate blended course were observed during a 7-week-long online discussions. Using quantitative content analysis peer moderators'…

  13. Growth Patterns and E-Moderating Supports in Asynchronous Online Discussions in an Undergraduate Blended Course

    Science.gov (United States)

    Ghadirian, Hajar; Ayub, Ahmad Fauzi Mohd; Bakar, Kamariah Binti Abu; Hassanzadeh, Maryam

    2016-01-01

    This study presents a case study of asynchronous online discussions' (AOD) growth patterns in an undergraduate blended course to address the gap in our current understanding of how threads are developed in peer-moderated AODs. Building on a taxonomy of thread pattern proposed by Chan, Hew and Cheung (2009), growth patterns of thirty-six forums…

  14. Students' Learning in Asynchronous Discussion Forums: A Meta-Analysis

    Science.gov (United States)

    Martono, Fkipuntan; Salam, Urai

    2017-01-01

    Asynchronous discussion forums are among the most preferred tools chosen to foster learning opportunities and knowledge construction. To reveal the cognitive engagement evidenced in the transcripts of the discussion forums, this study presents 51 papers. 17 papers reported research on students' attitude toward the use of ICT for learning, 16…

  15. Hand-Rim Forces and Gross Mechanical Efficiency in Asynchronous and Synchronous Wheelchair Propulsion : A Comparison

    NARCIS (Netherlands)

    Lenton, J. P.; Fowler, N.; Nicholson, G.; Tolfrey, K.; Goosey-Tolfrey, V.; van der Woude, Lucas

    To compare the force application characteristics at various push frequencies of asynchronous (ASY) and synchronous (SYN) hand-rim propulsion, 8 able-bodied participants performed a separate sub-maximal exercise test on a wheelchair roller ergometer for each propulsion mode. Each test consisted of a

  16. Factor Validity of the Motivated Strategies for Learning Questionnaire (MSLQ) in Asynchronous Online Learning Environments (AOLE)

    Science.gov (United States)

    Cho, Moon-Heum; Summers, Jessica

    2012-01-01

    The purpose of this study was to investigate the factor validity of the Motivated Strategies for Learning Questionnaire (MSLQ) in asynchronous online learning environments. In order to check the factor validity, confirmatory factor analysis (CFA) was conducted with 193 cases. Using CFA, it was found that the original measurement model fit for…

  17. Evaluating the Quality of Interaction in Asynchronous Discussion Forums in Fully Online Courses

    Science.gov (United States)

    Nandi, Dip; Hamilton, Margaret; Harland, James

    2012-01-01

    Fully online courses are becoming progressively more popular because of their "anytime anywhere" learning flexibility. One of the ways students interact with each other and with the instructors within fully online learning environments is via asynchronous discussion forums. However, student engagement in online discussion forums does not…

  18. Student Outcomes Associated with Use of Asynchronous Online Discussion Forums in Gross Anatomy Teaching

    Science.gov (United States)

    Green, Rodney A.; Hughes, Diane L.

    2013-01-01

    Asynchronous online discussion forums are increasingly common in blended learning environments but the relationship to student learning outcomes has not been reported for anatomy teaching. Forums were monitored in two multicampus anatomy courses; an introductory first year course and a second year physiotherapy-specific course. The forums are…

  19. An corrective method to correct of the inherent flaw of the asynchronization direct counting circuit

    International Nuclear Information System (INIS)

    Wang Renfei; Liu Congzhan; Jin Yongjie; Zhang Zhi; Li Yanguo

    2003-01-01

    As a inherent flaw of the Asynchronization Direct Counting Circuit, the crosstalk, which is resulted from the randomicity of the time-signal always exists between two adjacent channels. In order to reduce the counting error derived from the crosstalk, the author propose an effective method to correct the flaw after analysing the mechanism of the crosstalk

  20. An Asynchronous P300 BCI With SSVEP-Based Control State Detection

    DEFF Research Database (Denmark)

    Panicker, Rajesh C.; Puthusserypady, Sadasivan; Sun, Ying

    2011-01-01

    In this paper, an asynchronous brain–computer interface (BCI) system combining the P300 and steady-state visually evoked potentials (SSVEPs) paradigms is proposed. The information transfer is accomplished using P300 event-related potential paradigm and the control state (CS) detection is achieved...

  1. Exploring effectiveness of team communication: Balancing synchronous and asynchronous communication in design teams

    NARCIS (Netherlands)

    Otter, den A.F.H.J.; Emmitt, S.

    2007-01-01

    Purpose – Effective teams use a balance of synchronous and asynchronous communication. Team communication is dependent on the communication acts of team members and the ability of managers to facilitate, stimulate and motivate them. Team members from organizations using different information systems

  2. Pedagogical dimensions of effective online asynchronous teacher communication in higher education

    NARCIS (Netherlands)

    Smits, A.; Voogt, J.; Rutledge, D.; Slykhuis, D.

    2015-01-01

    In this research teacher behaviour in online asynchronous discussions is studied. To this end teachers’ online messages were analyzed and correlated to measures of student satisfaction. Findings show a positive relation between student satisfaction and the presence of content knowledge, multiple

  3. Effects of Asynchronous Music on Students' Lesson Satisfaction and Motivation at the Situational Level

    Science.gov (United States)

    Digelidis, Nikolaos; Karageorghis, Costas I.; Papapavlou, Anastasia; Papaioannou, Athanasios G.

    2014-01-01

    The aim of this study was to examine the effects of asynchronous (background) music on senior students' motivation and lesson satisfaction at the situational level. A counterbalanced mixed-model design was employed with two factors comprising condition (three levels) and gender (two levels). Two hundred students (82 boys, 118 girls; M [subscript…

  4. The Effect of Synchronous and Asynchronous Participation on Students' Performance in Online Accounting Courses

    Science.gov (United States)

    Duncan, Keith; Kenworthy, Amy; McNamara, Ray

    2012-01-01

    This article examines the relationship between MBA students' performance and participation in two online environments: a synchronous forum (chat room) and an asynchronous forum (discussion board) at an Australian university. The "quality" and "quantity" of students' participation is used to predict their final examination and…

  5. Introducing Group-Based Asynchronous Learning to Business Education. Reflections on Effective Course Design and Delivery

    Science.gov (United States)

    Walker, Richard; Arnold, Ivo

    2004-01-01

    This paper explores the contribution of virtual tools to student learning within full-time management programmes. More specifically, the paper focuses on asynchronous communication tools, considering the scope they offer for group-based collaborative learning outside the classroom. We report on the effectiveness of this approach for an economics…

  6. Flipping the Online Classroom with Web 2.0: The Asynchronous Workshop

    Science.gov (United States)

    Cummings, Lance

    2016-01-01

    This article examines how Web 2.0 technologies can be used to "flip" the online classroom by creating asynchronous workshops in social environments where immediacy and social presence can be maximized. Using experience teaching several communication and writing classes in Google Apps (Google+, Google Hangouts, Google Drive, etc.), I…

  7. Students' Desired and Experienced Levels of Connectivity to an Asynchronous, Online, Distance Degree Program

    Science.gov (United States)

    Schroeder, Shawnda; Baker, Mary; Terras, Katherine; Mahar, Patti; Chiasson, Kari

    2016-01-01

    This study examined graduate students' desired and experienced levels of connectivity in an online, asynchronous distance degree program. Connectivity was conceptualized as the students' feelings of community and involvement, not their level of access to the Internet. Graduate students enrolled in a distance degree program were surveyed on both…

  8. Wind generator based on cascade connection of two asynchronized synchronous machines

    International Nuclear Information System (INIS)

    Dzhagarov, N.; Dzhagarova, Yu.

    2000-01-01

    A model of a wind generator with two asynchronized synchronous machines presented and different regimes are investigated. The analysis shows that the suggested scheme of a brushless generator works and has more advantages (reliability, easy for operation) in comparison with the known ones

  9. Novel Simplified Model for Asynchronous Machine with Consideration of Frequency Characteristic

    Directory of Open Access Journals (Sweden)

    Changchun Cai

    2014-01-01

    Full Text Available The frequency characteristic of electric equipment should be considered in the digital simulation of power systems. The traditional asynchronous machine third-order transient model excludes not only the stator transient but also the frequency characteristics, thus decreasing the application sphere of the model and resulting in a large error under some special conditions. Based on the physical equivalent circuit and Park model for asynchronous machines, this study proposes a novel asynchronous third-order transient machine model with consideration of the frequency characteristic. In the new definitions of variables, the voltages behind the reactance are redefined as the linear equation of flux linkage. In this way, the rotor voltage equation is not associated with the derivative terms of frequency. However, the derivative terms of frequency should not always be ignored in the application of the traditional third-order transient model. Compared with the traditional third-order transient model, the novel simplified third-order transient model with consideration of the frequency characteristic is more accurate without increasing the order and complexity. Simulation results show that the novel third-order transient model for the asynchronous machine is suitable and effective and is more accurate than the widely used traditional simplified third-order transient model under some special conditions with drastic frequency fluctuations.

  10. Credit Hours with No Set Time: A Study of Credit Policies in Asynchronous Online Education

    Science.gov (United States)

    Prasuhn, Frederick Carl

    2014-01-01

    U.S. public university system policies were examined to learn how credit hours were determined for asynchronous online education. Findings indicated that (a) credit hour meaning and use are not consistent, (b) primary responsibility for credit hour decisions was at the local level, and (c) no policies exist to guide credit hour application for…

  11. From discrete-time models to continuous-time, asynchronous modeling of financial markets

    NARCIS (Netherlands)

    Boer, Katalin; Kaymak, Uzay; Spiering, Jaap

    2007-01-01

    Most agent-based simulation models of financial markets are discrete-time in nature. In this paper, we investigate to what degree such models are extensible to continuous-time, asynchronous modeling of financial markets. We study the behavior of a learning market maker in a market with information

  12. From Discrete-Time Models to Continuous-Time, Asynchronous Models of Financial Markets

    NARCIS (Netherlands)

    K. Boer-Sorban (Katalin); U. Kaymak (Uzay); J. Spiering (Jaap)

    2006-01-01

    textabstractMost agent-based simulation models of financial markets are discrete-time in nature. In this paper, we investigate to what degree such models are extensible to continuous-time, asynchronous modelling of financial markets. We study the behaviour of a learning market maker in a market with

  13. Reactors: A data-oriented synchronous/asynchronous programming model for distributed applications

    DEFF Research Database (Denmark)

    Field, John; Marinescu, Maria-Cristina; Stefansen, Christian Oskar Erik

    2009-01-01

    of messages. Similarly, the interface to a reactor is simply its state, rather than a collection of message channels, ports, or methods. One novel feature of our model is the ability to compose behaviors both synchronously and asynchronously. Also, our use of Datalog-style rules allows aspect-like composition...

  14. Asynchronous social search as a single point of access to information

    NARCIS (Netherlands)

    Buijs, M.P.; Spruit, M.

    2017-01-01

    The purpose of this paper is to present asynchronous social search as a novel and intuitive approach to search for information in which people collaborate to find the information they are looking for. Design/methodology/approach A prototype was built to test the feasibility in a business

  15. 1 Commande multivariable du moteur asynchrone triphasé à cage ...

    African Journals Online (AJOL)

    AKA BOKO

    Correspondance, courriel : rabenarivo.michel@yahoo.fr. Résumé. La commande du moteur asynchrone triphasé à ... synthèse du système à l'aide du logiciel MATLAB. Mots-clés : commande, système multivariable, variation de ... of the system by MATLAB software. Keywords : control, MIMO system, frequency variation, ...

  16. Investigation of a photo-voltaic pump station with asynchronous electric drive

    International Nuclear Information System (INIS)

    Dzhagarov, N.; Vladimirov, P.

    2000-01-01

    A scheme of a photo-voltaic pump station with constant current drive is presented. The requirements for reliability and minimal maintenance necessitate the use of asynchronous drive which has been studied. The studies of the system's model for various regimes show its adequacy. The model can be used for determination of the optimal conditions providing maximal working efficiency

  17. Synthesis and Layout of an Asynchronous Network-on-Chip using Standard EDA Tools

    DEFF Research Database (Denmark)

    Müller, Christoph; Kasapaki, Evangelia; Sørensen, Rasmus Bo

    2014-01-01

    is the key role that clock signals play in specifying time-constraints for the synthesis. In this paper explain how we handled the synthesis and layout of an asynchronous network-on-chip for a multi-core platform. Focus is on the design process while the actual NOC-design and its performance are presented...

  18. Toward Personal and Emotional Connectivity in Mobile Higher Education through Asynchronous Formative Audio Feedback

    Science.gov (United States)

    Rasi, Päivi; Vuojärvi, Hanna

    2018-01-01

    This study aims to develop asynchronous formative audio feedback practices for mobile learning in higher education settings. The development was conducted in keeping with the principles of design-based research. The research activities focused on an inter-university online course, within which the use of instructor audio feedback was tested,…

  19. BER and total throughput of asynchronous DS-OCDMA/WDM systems with multiple user interference

    OpenAIRE

    Ghiringhelli, F.; Zervas, M.N.

    2003-01-01

    The BER and throughput of Direct-Sequence OCDMA/WDM systems based on quadripolar codes and superstructured fiber Bragg gratings are statistically derived under asynchronous operation, intensity detection, and Multiple User Interference. Performance improvements with Forward Error Correction are included.

  20. An Integrated Approach to Preempt Cheating on Asynchronous, Objective, Online Assessments in Graduate Business Classes

    Science.gov (United States)

    Sullivan, Daniel P.

    2016-01-01

    Cheating, left untended, erodes the validity of evaluation and, ultimately, corrupts the legitimacy of a course. We profile an approach to manage, with an eye toward preempting, cheating on asynchronous, objective, online quizzes. This approach taps various technological and social solutions to academic dishonesty, integrating them into a…

  1. Cultural Influences on Chinese Students' Asynchronous Online Learning in a Canadian University

    Science.gov (United States)

    Zhao, Naxin; McDougall, Douglas

    2008-01-01

    This study explored six Chinese graduate students' asynchronous online learning in a large urban Canadian university. Individual interviews in Mandarin elicited their perceptions of online learning, their participation in it, and the cultural factors that influenced their experiences. In general, the participants had a positive attitude towards…

  2. Temperature, paternity and asynchronous hatching influence early developmental characteristics of larval Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Dahlke, Flemming T.; Butts, Ian A.E.

    2014-01-01

    Offspring, especially during early development, are influenced by both intrinsic properties endowed to them by their parents, extrinsic environmental factors as well as the interplay between genes and the environment. We investigated the effects of paternity (P), temperature (T), and asynchronous...

  3. Asynchronous CMC, Collaboration and the Development of Critical Thinking in a Graduate Seminar in Applied Linguistics

    Science.gov (United States)

    Abrams, Zsuzsanna I.

    2005-01-01

    A primary objective of graduate education, and often promoted by peer collaboration tasks, is the development of critical thinking skills. The present study compares how graduate students enrolled in a qualitative research design course in applied linguistics utilized asynchronous computer-mediated communication (ACMC) and face-to-face…

  4. Beyond Social Presence: Facelessness and the Ethics of Asynchronous Online Education

    Science.gov (United States)

    Rose, Ellen

    2017-01-01

    In this position paper, I argue that a focus on achieving and increasing social presence in online courses tends to derail a consideration of the ethical implications and dimensions of the essential facelessness of asynchronous education. Drawing upon the work of Emmanuel Levinas and Nel Noddings, who contended that the face is the basis of…

  5. Computer Learner Corpora: Analysing Interlanguage Errors in Synchronous and Asynchronous Communication

    Science.gov (United States)

    MacDonald, Penny; Garcia-Carbonell, Amparo; Carot, Sierra, Jose Miguel

    2013-01-01

    This study focuses on the computer-aided analysis of interlanguage errors made by the participants in the telematic simulation IDEELS (Intercultural Dynamics in European Education through on-Line Simulation). The synchronous and asynchronous communication analysed was part of the MiLC Corpus, a multilingual learner corpus of texts written by…

  6. Defining the Symmetry of the Universal Semi-Regular Autonomous Asynchronous Systems

    Directory of Open Access Journals (Sweden)

    Serban E. Vlad

    2012-02-01

    Full Text Available The regular autonomous asynchronous systems are the non-deterministic Boolean dynamical systems and universality means the greatest in the sense of the inclusion. The paper gives four definitions of symmetry of these systems in a slightly more general framework, called semi-regularity, and also many examples.

  7. Student Perceptions of Asynchronous and Synchronous Web Based Tools and Perceived Attainment of Academic Outcomes

    Science.gov (United States)

    Parenti, Melissa A.

    2013-01-01

    With an increasing presence and continual adaptations related to distance learning, there is a recognized need for up-to-date research in the area of effectiveness of online education programs. More specifically, assessing the capacity to attain academic goals by use of asynchronous and synchronous web based tools within Learning Management…

  8. Multithreaded Asynchronous Graph Traversal for In-Memory and Semi-External Memory

    KAUST Repository

    Pearce, Roger; Gokhale, Maya; Amato, Nancy M.

    2010-01-01

    . Our highly parallel asynchronous approach hides data latency due to both poor locality and delays in the underlying graph data storage. We present an experimental study applying our technique to both In-Memory and Semi-External Memory graphs utilizing

  9. Cooperative Learning in Graduate Student Projects: Comparing Synchronous versus Asynchronous Collaboration

    Science.gov (United States)

    Strang, Kenneth

    2013-01-01

    Cooperative learning was applied in a graduate project management course to compare the effectiveness of asynchronous versus synchronous online team meetings. An experiment was constructed to allocate students to project teams while ensuring there was a balance of requisite skills, namely systems analysis and design along with HTML/Javascript…

  10. Learning about the Literacy Development of English Language Learners in Asynchronous Online Discussions

    Science.gov (United States)

    De Oliveira, Luciana C.; Olesova, Larisa

    2013-01-01

    This study examined asynchronous online discussions in the online course "English Language Development" to identify themes related to participants' learning about the language and literacy development of English Language Learners when they facilitated online discussions to determine whether the participants developed sufficient…

  11. Study on the Implications of Asynchronous GMO Approvals for EU Imports of Animal Feed Products

    NARCIS (Netherlands)

    Nowicki, P.L.; Aramyan, L.H.; Baltussen, W.H.M.; Dvortsin, L.; Jongeneel, R.A.; Perez Dominguez, I.; Wagenberg, van C.P.A.; Kalaitzandonakes, N.; Kaufman, J.; Miller, D.; Franke, L.; Meerbeek, B.

    2010-01-01

    The aim of this study is to understand the implications of asynchronous approvals for genetically modified organisms (GMOs) that are imported to the European Union for use within animal feed products, specifically with regard to the EU livestock sector, as well as upon the upstream and downstream

  12. A Study of Synchronous versus Asynchronous Collaboration in an Online Business Writing Class

    Science.gov (United States)

    Mabrito, Mark

    2006-01-01

    A case study examined the collaborative experiences of students in an online business writing classroom. The purpose was to examine the same groups of students working on collaborative writing assignments in both a synchronous (real-time) and an asynchronous (non-real-time) discussion forum. This study focused on examining the amount, pattern, and…

  13. Asynchronous Knowledge Sharing and Conversation Interaction Impact on Grade in an Online Business Course

    Science.gov (United States)

    Strang, Kenneth David

    2011-01-01

    Student knowledge sharing and conversation theory interactions were coded from asynchronous discussion forums to measure the effect of learning-oriented utterances on academic performance. The sample was 3 terms of an online business course (in an accredited MBA program) at a U.S.-based university. Correlation, stepwise regression, and multiple…

  14. A Comparison of Asynchronous Online Text-Based Lectures and Synchronous Interactive Web Conferencing Lectures

    Science.gov (United States)

    Skylar, Ashley Ann

    2009-01-01

    Online learning environments are more prevalent in teacher education than ever before. In 2009, many instructors are attempting to emulate traditional instructional methods in the online learning environment as much as possible. Online courses are separated into two categories, (1) asynchronous; and (2) synchronous, depending on the nature of the…

  15. Asynchronous L1-gain control of uncertain switched positive linear systems with dwell time.

    Science.gov (United States)

    Li, Yang; Zhang, Hongbin

    2018-04-01

    In this paper, dwell time (DT) stability, L 1 -gain performance analysis and asynchronous L 1 -gain controller design problems of uncertain switched positive linear systems (SPLSs) are investigated. Via a time-scheduled multiple linear co-positive Lyapunov function (TSMLCLF) approach, convex sufficient conditions of DT stability and L 1 -gain performance of SPLSs with interval and polytopic uncertainties are presented. Furthermore, by utilizing the feature that the TSMLCLF keeps decreasing even if the controller is running asynchronously with the system, the asynchronous L 1 -gain controller design problem of SPLSs with interval and polytopic uncertainties is investigated. Convex sufficient conditions of the existence of time-varying asynchronous state-feedback controller which can ensure the closed-loop system's positivity, stability and L 1 -gain performance are established, and the controller gain matrices can be calculated instantaneously online. The obtained L 1 -gain in the paper is standard. All the results are presented in terms of linear programming. A practical example is provided to show the effectiveness of the results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  16. An Efficient Algorithm for Computing Attractors of Synchronous And Asynchronous Boolean Networks

    Science.gov (United States)

    Zheng, Desheng; Yang, Guowu; Li, Xiaoyu; Wang, Zhicai; Liu, Feng; He, Lei

    2013-01-01

    Biological networks, such as genetic regulatory networks, often contain positive and negative feedback loops that settle down to dynamically stable patterns. Identifying these patterns, the so-called attractors, can provide important insights for biologists to understand the molecular mechanisms underlying many coordinated cellular processes such as cellular division, differentiation, and homeostasis. Both synchronous and asynchronous Boolean networks have been used to simulate genetic regulatory networks and identify their attractors. The common methods of computing attractors are that start with a randomly selected initial state and finish with exhaustive search of the state space of a network. However, the time complexity of these methods grows exponentially with respect to the number and length of attractors. Here, we build two algorithms to achieve the computation of attractors in synchronous and asynchronous Boolean networks. For the synchronous scenario, combing with iterative methods and reduced order binary decision diagrams (ROBDD), we propose an improved algorithm to compute attractors. For another algorithm, the attractors of synchronous Boolean networks are utilized in asynchronous Boolean translation functions to derive attractors of asynchronous scenario. The proposed algorithms are implemented in a procedure called geneFAtt. Compared to existing tools such as genYsis, geneFAtt is significantly faster in computing attractors for empirical experimental systems. Availability The software package is available at https://sites.google.com/site/desheng619/download. PMID:23585840

  17. An Examination of Computer Engineering Students' Perceptions about Asynchronous Discussion Forums

    Science.gov (United States)

    Ozyurt, Ozcan; Ozyurt, Hacer

    2013-01-01

    This study was conducted in order to reveal the usage profiles and perceptions of Asynchronous Discussion Forums (ADFs) of 126 computer engineering students from the Computer Engineering Department in a university in Turkey. By using a mixed methods research design both quantitative and qualitative data were collected and analyzed. Research…

  18. NUMERICAL WITHOUT ITERATION METHOD OF MODELING OF ELECTROMECHANICAL PROCESSES IN ASYNCHRONOUS ENGINES

    Directory of Open Access Journals (Sweden)

    D. G. Patalakh

    2018-02-01

    Full Text Available Purpose. Development of calculation of electromagnetic and electromechanic transients is in asynchronous engines without iterations. Methodology. Numeral methods of integration of usual differential equations, programming. Findings. As the system of equations, describing the dynamics of asynchronous engine, contents the products of rotor and stator currents and product of rotation frequency of rotor and currents, so this system is nonlinear one. The numeral solution of nonlinear differential equations supposes an iteration process on every step of integration. Time-continuing and badly converging iteration process may be the reason of calculation slowing. The improvement of numeral method by the way of an iteration process removing is offered. As result the modeling time is reduced. The improved numeral method is applied for integration of differential equations, describing the dynamics of asynchronous engine. Originality. The improvement of numeral method allowing to execute numeral integrations of differential equations containing product of functions is offered, that allows to avoid an iteration process on every step of integration and shorten modeling time. Practical value. On the basis of the offered methodology the universal program of modeling of electromechanics processes in asynchronous engines could be developed as taking advantage on fast-acting.

  19. How to share concurrent asynchronous wait-free variables: Preliminary version

    NARCIS (Netherlands)

    M. Li (Ming); P.M.B. Vitányi (Paul)

    1989-01-01

    textabstractWe use a structured top-down approach to develop algorithms for atomic variables shared by concurrent asynchronous wait-free processes, starting from the problem specification. By this design we obtain a better understanding of what the algorithms do, why they do it, and that they

  20. Synchronous and Asynchronous Communication in Distance Learning: A Review of the Literature

    Science.gov (United States)

    Watts, Lynette

    2016-01-01

    Distance learning is commonplace in higher education, with increasing numbers of students enjoying the flexibility e-learning provides. Keeping students connected with peers and instructors has been a challenge with e-learning, but as technology has advanced, the methods by which educators keep students engaged, synchronously and asynchronously,…

  1. Holy land, lost lands, Realpolitik. Imperial Byzantine thinking about Syria and Palestine in the later 10th and 11th centuries

    Directory of Open Access Journals (Sweden)

    Shepard, Jonathan

    2013-02-01

    Full Text Available This study reviews Byzantine attitudes and state policy towards the region between Antioch and Mount Sinai, stressing the general cautiousness of imperial strategy and, from the late tenth century onwards, the government’s preference for peaceful coexistence and commerce with the Fatimid caliphate. Caliph al-Ḥākim’s destruction of the church of the Holy Sepulchre in 1009 did not overturn this state of affairs, and the main bone of contention between Cairo and Constantinople was the city of Aleppo, not Jerusalem. Even here, the two powers were inclined to leave the initiative to local parties, rather than insisting on direct rule, and communications between Muslim and Byzantine-ruled territories were mostly fairly straightforward. During the relative détente of the first half of the eleventh century, pilgrimages to the Holy Land increased, and it may well have been primarily in order to impress pilgrims – those travelling from Byzantium itself, but especially those from the Christian west – that emperors lavished resources on reconstructing the church of the Holy Sepulchre in the 1030s and 1040s. Militant intervention on behalf of the Christian populations of south ern Syria and Palestine was not on their agenda. These conclusions rest on the collation of miscellaneous evidence, whose components are mostly well-known but have seldom received consideration side by side. The study highlights the value of trade to Fatimids and Byzantines alike, the esteem for ‘the holy places’ among Byzantines besides westerners, and the emperors’ desire to demonstrate concern for the Holy Sepulchre without jeopardising relations with the FatimidsEste estudio pasa revista a la política oficial del estado bizantino con respecto a la región situada entre Antioquía y el Monte Sinaí, haciendo énfasis en la prudencia adoptada por lo general en la estrategia imperial así como, a partir de finales del siglo X, en la voluntad del gobierno a favor de

  2. Area/latency optimized early output asynchronous full adders and relative-timed ripple carry adders.

    Science.gov (United States)

    Balasubramanian, P; Yamashita, S

    2016-01-01

    This article presents two area/latency optimized gate level asynchronous full adder designs which correspond to early output logic. The proposed full adders are constructed using the delay-insensitive dual-rail code and adhere to the four-phase return-to-zero handshaking. For an asynchronous ripple carry adder (RCA) constructed using the proposed early output full adders, the relative-timing assumption becomes necessary and the inherent advantages of the relative-timed RCA are: (1) computation with valid inputs, i.e., forward latency is data-dependent, and (2) computation with spacer inputs involves a bare minimum constant reverse latency of just one full adder delay, thus resulting in the optimal cycle time. With respect to different 32-bit RCA implementations, and in comparison with the optimized strong-indication, weak-indication, and early output full adder designs, one of the proposed early output full adders achieves respective reductions in latency by 67.8, 12.3 and 6.1 %, while the other proposed early output full adder achieves corresponding reductions in area by 32.6, 24.6 and 6.9 %, with practically no power penalty. Further, the proposed early output full adders based asynchronous RCAs enable minimum reductions in cycle time by 83.4, 15, and 8.8 % when considering carry-propagation over the entire RCA width of 32-bits, and maximum reductions in cycle time by 97.5, 27.4, and 22.4 % for the consideration of a typical carry chain length of 4 full adder stages, when compared to the least of the cycle time estimates of various strong-indication, weak-indication, and early output asynchronous RCAs of similar size. All the asynchronous full adders and RCAs were realized using standard cells in a semi-custom design fashion based on a 32/28 nm CMOS process technology.

  3. The Interplay of Content and Community in Synchronous and Asynchronous Communication: Virtual Communication in a Graduate Seminar

    Directory of Open Access Journals (Sweden)

    Richard A. Schwier

    2002-06-01

    Full Text Available A group of graduate students and an instructor at the University of Saskatchewan experimented with the use of synchronous communication (chat and asynchronous communication (bulletin board in a theory course in Educational Communications and Technology for an eight-month period. Synchronous communication contributed dramatically to the continuity and convenience of the class, and promoted a strong sense of community. At the same time, it was viewed as less effective than asynchronous communication for dealing with content and issues deeply, and it introduced a number of pedagogical and intellectual limitations. We concluded that synchronous and asynchronous strategies were suitable for different types of learning, and what we experienced was a balancing act between content and community in our group. A combination of synchronous and asynchronous experiences seems to be necessary to promote the kind of engagement and depth required in a graduate seminar.

  4. Performance analysis of 2D asynchronous hard-limiting optical code-division multiple access system through atmospheric scattering channel

    Science.gov (United States)

    Zhao, Yaqin; Zhong, Xin; Wu, Di; Zhang, Ye; Ren, Guanghui; Wu, Zhilu

    2013-09-01

    Optical code-division multiple access (OCDMA) systems usually allocate orthogonal or quasi-orthogonal codes to the active users. When transmitting through atmospheric scattering channel, the coding pulses are broadened and the orthogonality of the codes is worsened. In truly asynchronous case, namely both the chips and the bits are asynchronous among each active user, the pulse broadening affects the system performance a lot. In this paper, we evaluate the performance of a 2D asynchronous hard-limiting wireless OCDMA system through atmospheric scattering channel. The probability density function of multiple access interference in truly asynchronous case is given. The bit error rate decreases as the ratio of the chip period to the root mean square delay spread increases and the channel limits the bit rate to different levels when the chip period varies.

  5. Model for Investigation of Operational Wind Power Plant Regimes with Doubly–Fed Asynchronous Machine in Power System

    Directory of Open Access Journals (Sweden)

    R. I. Mustafayev

    2012-01-01

    Full Text Available The paper presents methodology for mathematical modeling of power system (its part when jointly operated with wind power plants (stations that contain asynchronous doubly-fed machines used as generators. The essence and advantage of the methodology is that it allows efficiently to mate equations of doubly-fed asynchronous machines, written in the axes that rotate with the machine rotor speed with the equations of external electric power system, written in synchronously rotating axes.

  6. Synchronization, retiming and OTDM of an asynchronous 10 Gigabit Ethernet NRZ packet using a time lens for Terabit Ethernet

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Mulvad, Hans Christian Hansen

    2011-01-01

    An asynchronous 10G Ethernet packet is synchronized and retimed to a master clock using a time lens. The NRZ packet is converted into an RZ packet and multiplexed with a serial 1.28 Tb/s signal.......An asynchronous 10G Ethernet packet is synchronized and retimed to a master clock using a time lens. The NRZ packet is converted into an RZ packet and multiplexed with a serial 1.28 Tb/s signal....

  7. Asynchronous hatching provides females with a means for increasing male care but incurs a cost by reducing offspring fitness.

    Science.gov (United States)

    Ford, L E; Smiseth, P T

    2016-02-01

    In species with biparental care, sexual conflict occurs because the benefit of care depends on the total amount of care provided by the two parents while the cost of care depends on each parent's own contribution. Asynchronous hatching may play a role in mediating the resolution of this conflict over parental care. The sexual conflict hypothesis for the evolution of asynchronous hatching suggests that females adjust hatching patterns in order to increase male parental effort relative to female effort. We tested this hypothesis in the burying beetle Nicrophorus vespilloides by setting up experimental broods with three different hatching patterns: synchronous, asynchronous and highly asynchronous broods. As predicted, we found that males provided care for longer in asynchronous broods whereas the opposite was true of females. However, we did not find any benefit to females of reducing their duration of care in terms of increased lifespan or reduced mass loss during breeding. We found substantial negative effects of hatching asynchrony on offspring fitness as larval mass was lower and fewer larvae survived to dispersal in highly asynchronous broods compared to synchronous or asynchronous broods. Our results suggest that, even though females can increase male parental effort by hatching their broods more asynchronously, females pay a substantial cost from doing so in terms of reducing offspring growth and survival. Thus, females should be under selection to produce a hatching pattern that provides the best possible trade-off between the benefits of increased male parental effort and the costs due to reduced offspring fitness. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  8. An Asynchronous Time-Division-Multiplexed Network-on-Chip for Real-Time Systems

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia

    is an important part of the T-CREST paltform and used in a number of configurations. The flexible timing organization of Argo combines asynchronous routers with mesochronous NIs, which are connected to individually clocked cores, supporting a GALS system organization. The mesochronous NIs operate at the same......Multi-processor architectures using networks-on-chip (NOCs) for communication are becoming the standard approach in the development of embedded systems and general purpose platforms. Typically, multi-processor platforms follow a globally asynchronous locally synchronous (GALS) timing organization....... This thesis focuses on the design of Argo, a NOC targeted at hard real-time multi-processor platforms with a GALS timing organization. To support real-time communication, NOCs establish end-to-end connections and provide latency and throughput guarantees for these connections. Argo uses time division...

  9. Fluka studies of the Asynchronous Beam Dump Effects on LHC Point 6

    CERN Document Server

    Versaci, R; Goddard, B; Mereghetti, A; Schmidt, R; Vlachoudis, V; CERN. Geneva. ATS Department

    2011-01-01

    The LHC is a record-breaking machine for beam energy and intensity. An intense effort has therefore been deployed in simulating critical operational scenarios of energy deposition. Using FLUKA Monte Carlo simulations, we have investigated the effects of an asynchronous beam dump at the LHC Point 6 where beams, with a stored energy of 360 MJ, can instantaneously release up to a few J cm^-3 in the cryogenic magnets which have a quench limit of the order of the mJ cm^-3. In the present paper we will describe the simulation approach, and discuss the evaluated maximum energy release onto the superconducting magnets during an asynchronous beam dump. We will then analyze the shielding provided by collimators installed in the area and discuss safety limits for the operation of the LHC.

  10. Quorum system and random based asynchronous rendezvous protocol for cognitive radio ad hoc networks

    Directory of Open Access Journals (Sweden)

    Sylwia Romaszko

    2013-12-01

    Full Text Available This paper proposes a rendezvous protocol for cognitive radio ad hoc networks, RAC2E-gQS, which utilizes (1 the asynchronous and randomness properties of the RAC2E protocol, and (2 channel mapping protocol, based on a grid Quorum System (gQS, and taking into account channel heterogeneity and asymmetric channel views. We show that the combination of the RAC2E protocol with the grid-quorum based channel mapping can yield a powerful RAC2E-gQS rendezvous protocol for asynchronous operation in a distributed environment assuring a rapid rendezvous between the cognitive radio nodes having available both symmetric and asymmetric channel views. We also propose an enhancement of the protocol, which uses a torus QS for a slot allocation, dealing with the worst case scenario, a large number of channels with opposite ranking lists.

  11. Simulation of the Dynamic Behavior of an Asynchronous Machine Using Direct Self-Control

    Directory of Open Access Journals (Sweden)

    Cristian Paul Chioncel

    2007-01-01

    Full Text Available The paper presents the major steps that have to be gone for the implementation of the mathematical model of the asynchronous machine in SciLab / Scicos. This implemented ASM model, will be used to check the dynamic behavior of the system, the current diagrams as well as the behavior motor speed and the torque, if the input signal has a pulsation form. This implementation’s are made in Scilab / Scicos environment, a clone of the MATLAB, which provides number-crunching power similar to MATLAB, at a much better cost/performance ratio. The implemented model offers the possibility to analyze the behaviors of the asynchronous machine in different dynamic situations: speed, torques, current in motor or generator regime and to study its behavior in different possible control schemes.

  12. Synaptotagmin-7 Is an Asynchronous Calcium Sensor for Synaptic Transmission in Neurons Expressing SNAP-23

    DEFF Research Database (Denmark)

    Weber, Jens P; Toft-Bertelsen, Trine L; Mohrmann, Ralf

    2014-01-01

    Synchronization of neurotransmitter release with the presynaptic action potential is essential for maintaining fidelity of information transfer in the central nervous system. However, synchronous release is frequently accompanied by an asynchronous release component that builds up during repetitive...... stimulation, and can even play a dominant role in some synapses. Here, we show that substitution of SNAP-23 for SNAP-25 in mouse autaptic glutamatergic hippocampal neurons results in asynchronous release and a higher frequency of spontaneous release events (mEPSCs). Use of neurons from double-knock-out (SNAP......, while synaptotagmin-7 barely displayed activity-dependent trafficking between vesicle and plasma membrane, implying that it acts as a plasma membrane calcium sensor. Overall, these findings support the idea of alternative syt∶SNARE combinations driving release with different kinetics and fidelity....

  13. The queueing perspective of asynchronous network coding in two-way relay network

    Science.gov (United States)

    Liang, Yaping; Chang, Qing; Li, Xianxu

    2018-04-01

    Asynchronous network coding (NC) has potential to improve the wireless network performance compared with a routing or the synchronous network coding. Recent researches concentrate on the optimization between throughput/energy consuming and delay with a couple of independent input flow. However, the implementation of NC requires a thorough investigation of its impact on relevant queueing systems where few work focuses on. Moreover, few works study the probability density function (pdf) in network coding scenario. In this paper, the scenario with two independent Poisson input flows and one output flow is considered. The asynchronous NC-based strategy is that a new arrival evicts a head packet holding in its queue when waiting for another packet from the other flow to encode. The pdf for the output flow which contains both coded and uncoded packets is derived. Besides, the statistic characteristics of this strategy are analyzed. These results are verified by numerical simulations.

  14. Distributed embedded controller development with petri nets application to globally-asynchronous locally-synchronous systems

    CERN Document Server

    Moutinho, Filipe de Carvalho

    2016-01-01

    This book describes a model-based development approach for globally-asynchronous locally-synchronous distributed embedded controllers.  This approach uses Petri nets as modeling formalism to create platform and network independent models supporting the use of design automation tools.  To support this development approach, the Petri nets class in use is extended with time-domains and asynchronous-channels. The authors’ approach uses models not only providing a better understanding of the distributed controller and improving the communication among the stakeholders, but also to be ready to support the entire lifecycle, including the simulation, the verification (using model-checking tools), the implementation (relying on automatic code generators), and the deployment of the distributed controller into specific platforms. Uses a graphical and intuitive modeling formalism supported by design automation tools; Enables verification, ensuring that the distributed controller was correctly specified; Provides flex...

  15. Dual stator winding variable speed asynchronous generator: optimal design and experiments

    International Nuclear Information System (INIS)

    Tutelea, L N; Deaconu, S I; Popa, G N

    2015-01-01

    In the present paper is carried out a theoretical and experimental study of dual stator winding squirrel cage asynchronous generator (DSWA) behavior in the presence of saturation regime (non-sinusoidal) due to the variable speed operation. The main aims are the determination of the relations of calculating the equivalent parameters of the machine windings to optimal design using a Matlab code. Issue is limited to three phase range of double stator winding cage-induction generator of small sized powers, the most currently used in the small adjustable speed wind or hydro power plants. The tests were carried out using three-phase asynchronous generator having rated power of 6 [kVA]. (paper)

  16. High-speed asynchronous optical sampling for high-sensitivity detection of coherent phonons

    International Nuclear Information System (INIS)

    Dekorsy, T; Taubert, R; Hudert, F; Schrenk, G; Bartels, A; Cerna, R; Kotaidis, V; Plech, A; Koehler, K; Schmitz, J; Wagner, J

    2007-01-01

    A new optical pump-probe technique is implemented for the investigation of coherent acoustic phonon dynamics in the GHz to THz frequency range which is based on two asynchronously linked femtosecond lasers. Asynchronous optical sampling (ASOPS) provides the performance of on all-optical oscilloscope and allows us to record optically induced lattice dynamics over nanosecond times with femtosecond resolution at scan rates of 10 kHz without any moving part in the set-up. Within 1 minute of data acquisition time signal-to-noise ratios better than 10 7 are achieved. We present examples of the high-sensitivity detection of coherent phonons in superlattices and of the coherent acoustic vibration of metallic nanoparticles

  17. Sum rates of asynchronous GFDMA and SC-FDMA for 5G uplink

    Directory of Open Access Journals (Sweden)

    Woojin Park

    2015-12-01

    Full Text Available The fifth generation (5G of mobile communication envisions ultralow latency less than 1 ms for radio interface. To this end, frameless asynchronous multiple access may be needed to allow users to transmit instantly without waiting for the next frame start. In this paper, generalized frequency division multiple-access (GFDMA, one of the promising multiple-access candidates for 5G mobile, is compared with the conventional single-carrier FDMA (SC-FDMA in terms of the uplink sum rate when both techniques are adapted for the asynchronous scenario. In particular, a waveform windowing technique is applied to both schemes to mitigate the inter-user interference due to non-zero out-of-band emission.

  18. Application of Artificial Intelligence Techniques for the Control of the Asynchronous Machine

    Directory of Open Access Journals (Sweden)

    F. Khammar

    2016-01-01

    Full Text Available The induction machine is experiencing a growing success for two decades by gradually replacing the DC machines and synchronous in many industrial applications. This paper is devoted to the study of advanced methods applied to the command of the asynchronous machine in order to obtain a system of control of high performance. While the criteria for response time, overtaking, and static error can be assured by the techniques of conventional control, the criterion of robustness remains a challenge for researchers. This criterion can be satisfied only by applying advanced techniques of command. After mathematical modeling of the asynchronous machine, it defines the control strategies based on the orientation of the rotor flux. The results of the different simulation tests highlight the properties of robustness of algorithms proposed and suggested to compare the different control strategies.

  19. Asynchronous Magnetic Bead Rotation (AMBR Microviscometer for Label-Free DNA Analysis

    Directory of Open Access Journals (Sweden)

    Yunzi Li

    2014-03-01

    Full Text Available We have developed a label-free viscosity-based DNA detection system, using paramagnetic beads as an asynchronous magnetic bead rotation (AMBR microviscometer. We have demonstrated experimentally that the bead rotation period is linearly proportional to the viscosity of a DNA solution surrounding the paramagnetic bead, as expected theoretically. Simple optical measurement of asynchronous microbead motion determines solution viscosity precisely in microscale volumes, thus allowing an estimate of DNA concentration or average fragment length. The response of the AMBR microviscometer yields reproducible measurement of DNA solutions, enzymatic digestion reactions, and PCR systems at template concentrations across a 5000-fold range. The results demonstrate the feasibility of viscosity-based DNA detection using AMBR in microscale aqueous volumes.

  20. Involving the users remotely: an exploratory study using asynchronous usability testing

    Directory of Open Access Journals (Sweden)

    Beth Filar Williams

    2015-02-01

    Full Text Available Open Educational Resources (OER are increasingly used in the higher education landscape as a solution for a variety of copyright, publishing and cost-prohibiting issues. While OERs are becoming more common, reports of usability tests that evaluate how well learners can use them to accomplish their learning tasks have lagged behind. Because both the researchers and the learners in this study use resources and tools remotely, asynchronous usability testing of a prototype OER and MOOC online guide was conducted with an exploratory group of users to determine the guide’s ease of use for two distinct groups of users: Educators and Learners. In this article, we share the background and context of this usability project, suggest best methods for asynchronous remote usability testing, and share challenges and insights of the process and results of the testing

  1. APPLYING SATELLITE DATA SOURCES IN THE DOCUMENTATION AND LANDSCAPE MODELLING FOR GRAECO-ROMAN/BYZANTINE FORTIFIED SITES IN THE TŪR ABDIN AREA, EASTERN TURKEY

    Directory of Open Access Journals (Sweden)

    K. Silver

    2017-08-01

    Full Text Available In 2015-2016 the Finnish-Swedish Archaeological Project in Mesopotamia (FSAPM initiated a pilot study of an unexplored area in the Tūr Abdin region in Northern Mesopotamia (present-day Mardin Province in southeastern Turkey. FSAPM is reliant on satellite image data sources for prospecting, identifying, recording, and mapping largely unknown archaeological sites as well as studying their landscapes in the region. The purpose is to record and document sites in this endangered area for saving its cultural heritage. The sites in question consist of fortified architectural remains in an ancient border zone between the Graeco-Roman/Byzantine world and Parthia/Persia. The location of the archaeological sites in the terrain and the visible archaeological remains, as well as their dimensions and sizes were determined from the ortorectified satellite images, which also provided coordinates. In addition, field documentation was carried out in situ with photographs and notes. The applicability of various satellite data sources for the archaeological documentation of the project was evaluated. Satellite photographs from three 1968 CORONA missions, i.e. the declassified US government satellite photograph archives were acquired. Furthermore, satellite images included a recent GeoEye-1 Satellite Sensor Image from 2010 with a resolution of 0.5 m. Its applicability for prospecting archaeological sites, studying the terrain and producing landscape models in 3D was confirmed. The GeoEye-1 revealed the ruins of a fortified town and a fortress for their documentation and study. Landscape models for the area of these sites were constructed fusing GeoEye-1 with EU-DEM (European Digital Elevation Model data using SRTM and ASTER GDEM data in order to understand their locations in the terrain.

  2. Byzantium and Armenia: Metamarphosis of Military Connections (The Readers’ Opinion About the Book: Ayvazyan, A. The Armenian Military in the Byzantine Empire. Conflict and Alliance Under Justinian and Maurice [Text] / A. Ayvazyan. – Alfortville : Editions Sigest, 2014. – 152 p.

    Directory of Open Access Journals (Sweden)

    Nikolay D. Barabanov

    2016-11-01

    Full Text Available The article provides a critical analysis of the monography of Armen Ayvazyan “The Armenian Military in the Byzantine Empire. Conflict and Alliance under Justinian and Maurice” (Alfortville, 2014. The conclusion of non-conformity of the title and its content is made. The structure and logic of the work are considered. Examples of unjustified unambiguous interpretation of controversial issues are given. The authors detected the narrative character of the work, which brought the relatively small contribution to the Armenian studies and military-historical science.

  3. Synchronization of Hierarchical Time-Varying Neural Networks Based on Asynchronous and Intermittent Sampled-Data Control.

    Science.gov (United States)

    Xiong, Wenjun; Patel, Ragini; Cao, Jinde; Zheng, Wei Xing

    In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.

  4. Information flow vs resource access in the asynchronous pi-calculus.

    OpenAIRE

    HENNESSY, MATTHEW

    2002-01-01

    PUBLISHED We propose an extension of the asynchronous ?-calculus in which a variety of security properties may be captured using types. These are an extension of the input/output types for the ?-calculus in which I/O capabilities are assigned specific security levels. The main innovation is a uniform typing system that, by varying slightly the allowed set of types, captures different notions of security.We first define a typing system that ensures that processes running at security level ?...

  5. Synaptotagmin-7 is an asynchronous calcium sensor for synaptic transmission in neurons expressing SNAP-23.

    Directory of Open Access Journals (Sweden)

    Jens P Weber

    Full Text Available Synchronization of neurotransmitter release with the presynaptic action potential is essential for maintaining fidelity of information transfer in the central nervous system. However, synchronous release is frequently accompanied by an asynchronous release component that builds up during repetitive stimulation, and can even play a dominant role in some synapses. Here, we show that substitution of SNAP-23 for SNAP-25 in mouse autaptic glutamatergic hippocampal neurons results in asynchronous release and a higher frequency of spontaneous release events (mEPSCs. Use of neurons from double-knock-out (SNAP-25, synaptotagmin-7 mice in combination with viral transduction showed that SNAP-23-driven release is triggered by endogenous synaptotagmin-7. In the absence of synaptotagmin-7 release became even more asynchronous, and the spontaneous release rate increased even more, indicating that synaptotagmin-7 acts to synchronize release and suppress spontaneous release. However, compared to synaptotagmin-1, synaptotagmin-7 is a both leaky and asynchronous calcium sensor. In the presence of SNAP-25, consequences of the elimination of synaptotagmin-7 were small or absent, indicating that the protein pairs SNAP-25/synaptotagmin-1 and SNAP-23/synaptotagmin-7 might act as mutually exclusive calcium sensors. Expression of fusion proteins between pHluorin (pH-sensitive GFP and synaptotagmin-1 or -7 showed that vesicles that fuse using the SNAP-23/synaptotagmin-7 combination contained synaptotagmin-1, while synaptotagmin-7 barely displayed activity-dependent trafficking between vesicle and plasma membrane, implying that it acts as a plasma membrane calcium sensor. Overall, these findings support the idea of alternative syt∶SNARE combinations driving release with different kinetics and fidelity.

  6. A Novel Approach to Asynchronous MVP Data Interpretation Based on Elliptical-Vectors

    Science.gov (United States)

    Kruglyakov, M.; Trofimov, I.; Korotaev, S.; Shneyer, V.; Popova, I.; Orekhova, D.; Scshors, Y.; Zhdanov, M. S.

    2014-12-01

    We suggest a novel approach to asynchronous magnetic-variation profiling (MVP) data interpretation. Standard method in MVP is based on the interpretation of the coefficients of linear relation between vertical and horizontal components of the measured magnetic field.From mathematical point of view this pair of linear coefficients is not a vector which leads to significant difficulties in asynchronous data interpretation. Our approach allows us to actually treat such a pair of complex numbers as a special vector called an ellipse-vector (EV). By choosing the particular definitions of complex length and direction, the basic relation of MVP can be considered as the dot product. This considerably simplifies the interpretation of asynchronous data. The EV is described by four real numbers: the values of major and minor semiaxes, the angular direction of the major semiaxis and the phase. The notation choice is motivated by historical reasons. It is important that different EV's components have different sensitivity with respect to the field sources and the local heterogeneities. Namely, the value of major semiaxis and the angular direction are mostly determined by the field source and the normal cross-section. On the other hand, the value of minor semiaxis and the phase are responsive to local heterogeneities. Since the EV is the general form of complex vector, the traditional Schmucker vectors can be explicitly expressed through its components.The proposed approach was successfully applied to interpretation the results of asynchronous measurements that had been obtained in the Arctic Ocean at the drift stations "North Pole" in 1962-1976.

  7. Asynchronous Gossip-Based Gradient-Free Method for Multiagent Optimization

    OpenAIRE

    Deming Yuan

    2014-01-01

    This paper considers the constrained multiagent optimization problem. The objective function of the problem is a sum of convex functions, each of which is known by a specific agent only. For solving this problem, we propose an asynchronous distributed method that is based on gradient-free oracles and gossip algorithm. In contrast to the existing work, we do not require that agents be capable of computing the subgradients of their objective functions and coordinating their...

  8. Conditions for Model Matching of Switched Asynchronous Sequential Machines with Output Feedback

    OpenAIRE

    Jung–Min Yang

    2016-01-01

    Solvability of the model matching problem for input/output switched asynchronous sequential machines is discussed in this paper. The control objective is to determine the existence condition and design algorithm for a corrective controller that can match the stable-state behavior of the closed-loop system to that of a reference model. Switching operations and correction procedures are incorporated using output feedback so that the controlled switched machine can show the ...

  9. Determining sociability, social space, and social presence in (A)synchronous collaborative groups

    OpenAIRE

    Kreijns, K.; Kirschner, P.A.; Jochems, W.; Buuren, H. van

    2004-01-01

    The effectiveness of group learning in asynchronous distributed learning groups depends on the social interaction that takes place. This social interaction affects both cognitive and socioemotional processes that take place during learning, group forming, establishment of group structures, and group dynamics. Though now known to be important, this aspect is often ignored, denied or forgotten by educators and researchers who tend to concentrate on cognitive processes and on-task contexts. This...

  10. Asynchronous transfer mode and Local Area Network emulation standards, protocols, and security implications

    OpenAIRE

    Kirwin, John P.

    1999-01-01

    A complex networking technology called Asynchronous Transfer Mode (ATM) and a networking protocol called Local Area Network Emulation (LANE) are being integrated into many naval networks without any security-driven naval configuration guidelines. No single publication is available that describes security issues of data delivery and signaling relating to the transition of Ethernet to LANE and ATM. The thesis' focus is to provide: (1) an overview and security analysis of standardized protocols ...

  11. MODELING OF SYMMETRIC THREE-PHASE ASYNCHRONOUS ELECTRIC MOTOR IN ASYMMETRIC CONNECTION TO NETWORK

    Directory of Open Access Journals (Sweden)

    V. I. Lukovnikov

    2005-01-01

    Full Text Available The paper shows how to solve the problem concerning reveal of changes in mathematical models and electric parameters of symmetric three-phase short-circuited asynchronous electric motors in case of their connection to single- or two-phase network in comparison with their connection to three-phase network. The uniform methodological approach permitting to generalize the known data and receive new results is offered in the paper.

  12. A Methodology for the Design and Verification of Globally Asynchronous/Locally Synchronous Architectures

    Science.gov (United States)

    Miller, Steven P.; Whalen, Mike W.; O'Brien, Dan; Heimdahl, Mats P.; Joshi, Anjali

    2005-01-01

    Recent advanced in model-checking have made it practical to formally verify the correctness of many complex synchronous systems (i.e., systems driven by a single clock). However, many computer systems are implemented by asynchronously composing several synchronous components, where each component has its own clock and these clocks are not synchronized. Formal verification of such Globally Asynchronous/Locally Synchronous (GA/LS) architectures is a much more difficult task. In this report, we describe a methodology for developing and reasoning about such systems. This approach allows a developer to start from an ideal system specification and refine it along two axes. Along one axis, the system can be refined one component at a time towards an implementation. Along the other axis, the behavior of the system can be relaxed to produce a more cost effective but still acceptable solution. We illustrate this process by applying it to the synchronization logic of a Dual Fight Guidance System, evolving the system from an ideal case in which the components do not fail and communicate synchronously to one in which the components can fail and communicate asynchronously. For each step, we show how the system requirements have to change if the system is to be implemented and prove that each implementation meets the revised system requirements through modelchecking.

  13. Diagnosis of hearing loss using automated audiometry in an asynchronous telehealth model: A pilot accuracy study.

    Science.gov (United States)

    Brennan-Jones, Christopher G; Eikelboom, Robert H; Swanepoel, De Wet

    2017-02-01

    Introduction Standard criteria exist for diagnosing different types of hearing loss, yet audiologists interpret audiograms manually. This pilot study examined the feasibility of standardised interpretations of audiometry in a telehealth model of care. The aim of this study was to examine diagnostic accuracy of automated audiometry in adults with hearing loss in an asynchronous telehealth model using pre-defined diagnostic protocols. Materials and methods We recruited 42 study participants from a public audiology and otolaryngology clinic in Perth, Western Australia. Manual audiometry was performed by an audiologist either before or after automated audiometry. Diagnostic protocols were applied asynchronously for normal hearing, disabling hearing loss, conductive hearing loss and unilateral hearing loss. Sensitivity and specificity analyses were conducted using a two-by-two matrix and Cohen's kappa was used to measure agreement. Results The overall sensitivity for the diagnostic criteria was 0.88 (range: 0.86-1) and overall specificity was 0.93 (range: 0.86-0.97). Overall kappa ( k) agreement was 'substantial' k = 0.80 (95% confidence interval (CI) 0.70-0.89) and significant at p loss. This method has the potential to improve synchronous and asynchronous tele-audiology service delivery.

  14. Asynchronous replication and autosome-pair non-equivalence in human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Devkanya Dutta

    Full Text Available A number of mammalian genes exhibit the unusual properties of random monoallelic expression and random asynchronous replication. Such exceptional genes include genes subject to X inactivation and autosomal genes including odorant receptors, immunoglobulins, interleukins, pheromone receptors, and p120 catenin. In differentiated cells, random asynchronous replication of interspersed autosomal genes is coordinated at the whole chromosome level, indicative of chromosome-pair non-equivalence. Here we have investigated the replication pattern of the random asynchronously replicating genes in undifferentiated human embryonic stem cells, using fluorescence in situ hybridization based assay. We show that allele-specific replication of X-linked genes and random monoallelic autosomal genes occur in human embryonic stem cells. The direction of replication is coordinated at the whole chromosome level and can cross the centromere, indicating the existence of autosome-pair non-equivalence in human embryonic stem cells. These results suggest that epigenetic mechanism(s that randomly distinguish between two parental alleles are emerging in the cells of the inner cell mass, the source of human embryonic stem cells.

  15. The aspect of vector control using the asynchronous traction motor in locomotives

    Directory of Open Access Journals (Sweden)

    L. Liudvinavičius

    2009-12-01

    Full Text Available The article examines curves controlling asynchronous traction motors increasingly used in locomotive electric drives the main task of which is to create a tractive effort-speed curve of an ideal locomotive Fk = f(v, including a hyperbolic area the curve of which will create conditions showing that energy created by the diesel engine of diesel locomotives (electric locomotives and in case of electric trains, electricity taken from the contact network over the entire range of locomotive speed is turned into efficient work. Mechanical power on wheel sets is constant Pk = Fkv = const, the power of the diesel engine is fully used over the entire range of locomotive speed. Tractive effort-speed curve Fk(v shows the dependency of locomotive traction power Fk on movement speed v. The article presents theoretical and practical aspects relevant to creating the structure of locomotive electric drive and selecting optimal control that is especially relevant to creating the structure of locomotive electric drive using ATM (asynchronous traction motor that gains special popularity in traction rolling stock replacing DC traction motors having low reliability. The frequency modes of asynchronous motor speed regulation are examined. To control ATM, the authors suggest the method of vector control presenting the structural schemes of a locomotive with ATM and control algorithm.

  16. An Asynchronous Multi-Sensor Micro Control Unit for Wireless Body Sensor Networks (WBSNs

    Directory of Open Access Journals (Sweden)

    Ching-Hsing Luo

    2011-07-01

    Full Text Available In this work, an asynchronous multi-sensor micro control unit (MCU core is proposed for wireless body sensor networks (WBSNs. It consists of asynchronous interfaces, a power management unit, a multi-sensor controller, a data encoder (DE, and an error correct coder (ECC. To improve the system performance and expansion abilities, the asynchronous interface is created for handshaking different clock domains between ADC and RF with MCU. To increase the use time of the WBSN system, a power management technique is developed for reducing power consumption. In addition, the multi-sensor controller is designed for detecting various biomedical signals. To prevent loss error from wireless transmission, use of an error correct coding technique is important in biomedical applications. The data encoder is added for lossless compression of various biomedical signals with a compression ratio of almost three. This design is successfully tested on a FPGA board. The VLSI architecture of this work contains 2.68-K gate counts and consumes power 496-μW at 133-MHz processing rate by using TSMC 0.13-μm CMOS process. Compared with the previous techniques, this work offers higher performance, more functions, and lower hardware cost than other micro controller designs.

  17. A modular control architecture for real-time synchronous and asynchronous systems

    International Nuclear Information System (INIS)

    Butler, P.L.; Jones, J.P.

    1993-01-01

    This paper describes a control architecture for real-time control of complex robotic systems. The Modular Integrated Control Architecture (MICA), which is actually two complementary control systems, recognizes and exploits the differences between asynchronous and synchronous control. The asynchronous control system simulates shared memory on a heterogeneous network. For control information, a portable event-scheme is used. This scheme provides consistent interprocess coordination among multiple tasks on a number of distributed systems. The machines in the network can vary with respect to their native operating systems and the intemal representation of numbers they use. The synchronous control system is needed for tight real-time control of complex electromechanical systems such as robot manipulators, and the system uses multiple processors at a specified rate. Both the synchronous and asynchronous portions of MICA have been developed to be extremely modular. MICA presents a simple programming model to code developers and also considers the needs of system integrators and maintainers. MICA has been used successfully in a complex robotics project involving a mobile 7-degree-of-freedom manipulator in a heterogeneous network with a body of software totaling over 100,000 lines of code. MICA has also been used in another robotics system, controlling a commercial long-reach manipulator

  18. A Scalable Multicore Architecture With Heterogeneous Memory Structures for Dynamic Neuromorphic Asynchronous Processors (DYNAPs).

    Science.gov (United States)

    Moradi, Saber; Qiao, Ning; Stefanini, Fabio; Indiveri, Giacomo

    2018-02-01

    Neuromorphic computing systems comprise networks of neurons that use asynchronous events for both computation and communication. This type of representation offers several advantages in terms of bandwidth and power consumption in neuromorphic electronic systems. However, managing the traffic of asynchronous events in large scale systems is a daunting task, both in terms of circuit complexity and memory requirements. Here, we present a novel routing methodology that employs both hierarchical and mesh routing strategies and combines heterogeneous memory structures for minimizing both memory requirements and latency, while maximizing programming flexibility to support a wide range of event-based neural network architectures, through parameter configuration. We validated the proposed scheme in a prototype multicore neuromorphic processor chip that employs hybrid analog/digital circuits for emulating synapse and neuron dynamics together with asynchronous digital circuits for managing the address-event traffic. We present a theoretical analysis of the proposed connectivity scheme, describe the methods and circuits used to implement such scheme, and characterize the prototype chip. Finally, we demonstrate the use of the neuromorphic processor with a convolutional neural network for the real-time classification of visual symbols being flashed to a dynamic vision sensor (DVS) at high speed.

  19. Asynchronous data change notification between database server and accelerator controls system

    International Nuclear Information System (INIS)

    Fu, W.; Morris, J.; Nemesure, S.

    2011-01-01

    Database data change notification (DCN) is a commonly used feature. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/server architectures (such as CDEV, EPICS, and ADO) that can be used to implement data reflection servers that transfer data asynchronously to any client using the standard SET/GET API. This paper describes a method for using such a data reflection server to set up asynchronous DCN (ADCN) between a DBMS and clients. This method works well for all DBMS systems which provide database trigger functionality. Asynchronous data change notification (ADCN) between database server and clients can be realized by combining the use of a database trigger mechanism, which is supported by major DBMS systems, with server processes that use client/server software architectures that are familiar in the accelerator controls community (such as EPICS, CDEV or ADO). This approach makes the ADCN system easy to set up and integrate into an accelerator controls system. Several ADCN systems have been set up and used in the RHIC-AGS controls system.

  20. Chick Development and Asynchroneous Hatching in the Zebra Finch (Taeniopygia guttata castanotis).

    Science.gov (United States)

    Ikebuchi, Maki; Okanoya, Kazuo; Hasegawa, Toshikazu; Bischof, Hans-Joachim

    2017-10-01

    The mode of hatching in birds has important impacts on both parents and chicks, including the costs and risks of breeding for parents, and sibling competition in a clutch. Birds with multiple eggs in a single clutch often begin incubating when most eggs are laid, thereby reducing time of incubation, nursing burden, and sibling competition. In some songbirds and some other species, however, incubation starts immediately after the first egg is laid, and the chicks thus hatch asynchronously. This may result in differences in parental care and in sibling competition based on body size differences among older and younger chicks, which in turn might produce asynchronous development among siblings favoring the first hatchling, and further affect the development and fitness of the chicks after fledging. To determine whether such processes in fact occur in the zebra finch, we observed chick development in 18 clutches of zebra finches. We found that there were effects of asynchronous hatching, but these were smaller than expected and mostly not significant. Our observations suggest that the amount of care given to each chick may be equated with such factors as a camouflage effect of the down feathers, and that the low illumination within the nest also complicates the determination of the hatching order by the parents.

  1. AP-IO: asynchronous pipeline I/O for hiding periodic output cost in CFD simulation.

    Science.gov (United States)

    Xiaoguang, Ren; Xinhai, Xu

    2014-01-01

    Computational fluid dynamics (CFD) simulation often needs to periodically output intermediate results to files in the form of snapshots for visualization or restart, which seriously impacts the performance. In this paper, we present asynchronous pipeline I/O (AP-IO) optimization scheme for the periodically snapshot output on the basis of asynchronous I/O and CFD application characteristics. In AP-IO, dedicated background I/O processes or threads are in charge of handling the file write in pipeline mode, therefore the write overhead can be hidden with more calculation than classic asynchronous I/O. We design the framework of AP-IO and implement it in OpenFOAM, providing CFD users with a user-friendly interface. Experimental results on the Tianhe-2 supercomputer demonstrate that AP-IO can achieve a good optimization effect for the periodical snapshot output in CFD application, and the effect is especially better for massively parallel CFD simulations, which can reduce the total execution time up to about 40%.

  2. AP-IO: Asynchronous Pipeline I/O for Hiding Periodic Output Cost in CFD Simulation

    Directory of Open Access Journals (Sweden)

    Ren Xiaoguang

    2014-01-01

    Full Text Available Computational fluid dynamics (CFD simulation often needs to periodically output intermediate results to files in the form of snapshots for visualization or restart, which seriously impacts the performance. In this paper, we present asynchronous pipeline I/O (AP-IO optimization scheme for the periodically snapshot output on the basis of asynchronous I/O and CFD application characteristics. In AP-IO, dedicated background I/O processes or threads are in charge of handling the file write in pipeline mode, therefore the write overhead can be hidden with more calculation than classic asynchronous I/O. We design the framework of AP-IO and implement it in OpenFOAM, providing CFD users with a user-friendly interface. Experimental results on the Tianhe-2 supercomputer demonstrate that AP-IO can achieve a good optimization effect for the periodical snapshot output in CFD application, and the effect is especially better for massively parallel CFD simulations, which can reduce the total execution time up to about 40%.

  3. Full-load converter connected asynchronous generators for MW class wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Akhmatov, Vladislav

    2005-06-15

    Wind turbines equipped with full-load converter-connected asynchronous generators are a known concept. These have rating up to hundreds of kW and are a feasible concept for MW class wind turbines and may have advantages when compared to conventional wind turbines with directly connected generators. The concept requires the use of full-scale frequency converters, but the mechanical gearbox is smaller than in conventional wind turbines of the same rating. Application of smaller gearbox may reduce the no-load losses in the wind turbines, which is why such wind turbines with converter connected generators may start operation at a smaller wind speed. Wind turbines equipped with such converted connected asynchronous generators are pitch-controlled and variable-speed. This allows better performance and control. The converter control may be applied to support the grid voltage at short-circuit faults and to improve the fault-ride-through capability of the wind turbines, which makes the concepts relevant for large wind farms. The Danish transmission system operator Energinet-DK has implemented the general model of wind turbines equipped with converter connected asynchronous generators with the simulation tool Powerfactory (DlgSilent). The article presents Energinet-DK's experience of modeling this feasible wind turbine concept. (Author)

  4. Data Collection for Mobile Group Consumption: An Asynchronous Distributed Approach †

    Science.gov (United States)

    Zhu, Weiping; Chen, Weiran; Hu, Zhejie; Li, Zuoyou; Liang, Yue; Chen, Jiaojiao

    2016-01-01

    Mobile group consumption refers to consumption by a group of people, such as a couple, a family, colleagues and friends, based on mobile communications. It differs from consumption only involving individuals, because of the complex relations among group members. Existing data collection systems for mobile group consumption are centralized, which has the disadvantages of being a performance bottleneck, having single-point failure and increasing business and security risks. Moreover, these data collection systems are based on a synchronized clock, which is often unrealistic because of hardware constraints, privacy concerns or synchronization cost. In this paper, we propose the first asynchronous distributed approach to collecting data generated by mobile group consumption. We formally built a system model thereof based on asynchronous distributed communication. We then designed a simulation system for the model for which we propose a three-layer solution framework. After that, we describe how to detect the causality relation of two/three gathering events that happened in the system based on the collected data. Various definitions of causality relations based on asynchronous distributed communication are supported. Extensive simulation results show that the proposed approach is effective for data collection relating to mobile group consumption. PMID:27058544

  5. An Asynchronous Circuit Design Technique for a Flexible 8-Bit Microprocessor

    Science.gov (United States)

    Karaki, Nobuo; Nanmoto, Takashi; Inoue, Satoshi

    This paper presents an asynchronous design technique, an enabler for the emerging technology of flexible microelectronics that feature low-temperature processed polysilicon (LTPS) thin-film transistors (TFT) and surface-free technology by laser annealing/ablation (SUFTLA®). The first design instance chosen is an 8-bit microprocessor. LTPS TFTs are good for realizing displays having integrated VLSI circuit at lower costs. However, LTPS TFTs have drawbacks, including substantial deviations in characteristics and the self-heating phenomenon. To solve these problems, the authors adopted the asynchronous circuit design technique and developed an asynchronous design language called Verilog+, which is based on a subset of Verilog HDL® and includes minimal primitives used for describing the communications between modules, and the dedicated tools including a translator called xlator and a synthesizer called ctrlsyn. The flexible 8-bit microprocessor stably operates at 500kHz, drawing 180μA from a 5V power source. The microprocessor's electromagnetic emissions are 21dB less than those of the synchronous counterpart.

  6. Βιβλιοκρισία του: R. GOUNELLE (ed., Les recensions byzantines de l’Évangile de Nicodème [Corpus Christianorum. Series apocryphorum, Instrumenta 3], Turnhout, Brepols 2008

    Directory of Open Access Journals (Sweden)

    Στυλιανός ΛΑΜΠΑΚΗΣ

    2010-11-01

    Full Text Available  Βιβλιοκρισία του: R. Gounelle,     Les recensions byzantines de l’Évangile de Nicodème [Corpus Christianorum. Series apocryphorum, Instrumenta 3], Turnhout, Brepols 2008, σσ. 332, ΙSΒΝ 978-2-503-52813-7.

  7. Asynchronous P300-based brain-computer interface to control a virtual environment: initial tests on end users.

    Science.gov (United States)

    Aloise, Fabio; Schettini, Francesca; Aricò, Pietro; Salinari, Serenella; Guger, Christoph; Rinsma, Johanna; Aiello, Marco; Mattia, Donatella; Cincotti, Febo

    2011-10-01

    Motor disability and/or ageing can prevent individuals from fully enjoying home facilities, thus worsening their quality of life. Advances in the field of accessible user interfaces for domotic appliances can represent a valuable way to improve the independence of these persons. An asynchronous P300-based Brain-Computer Interface (BCI) system was recently validated with the participation of healthy young volunteers for environmental control. In this study, the asynchronous P300-based BCI for the interaction with a virtual home environment was tested with the participation of potential end-users (clients of a Frisian home care organization) with limited autonomy due to ageing and/or motor disabilities. System testing revealed that the minimum number of stimulation sequences needed to achieve correct classification had a higher intra-subject variability in potential end-users with respect to what was previously observed in young controls. Here we show that the asynchronous modality performed significantly better as compared to the synchronous mode in continuously adapting its speed to the users' state. Furthermore, the asynchronous system modality confirmed its reliability in avoiding misclassifications and false positives, as previously shown in young healthy subjects. The asynchronous modality may contribute to filling the usability gap between BCI systems and traditional input devices, representing an important step towards their use in the activities of daily living.

  8. An Asynchronous Low Power and High Performance VLSI Architecture for Viterbi Decoder Implemented with Quasi Delay Insensitive Templates

    Directory of Open Access Journals (Sweden)

    T. Kalavathi Devi

    2015-01-01

    Full Text Available Convolutional codes are comprehensively used as Forward Error Correction (FEC codes in digital communication systems. For decoding of convolutional codes at the receiver end, Viterbi decoder is often used to have high priority. This decoder meets the demand of high speed and low power. At present, the design of a competent system in Very Large Scale Integration (VLSI technology requires these VLSI parameters to be finely defined. The proposed asynchronous method focuses on reducing the power consumption of Viterbi decoder for various constraint lengths using asynchronous modules. The asynchronous designs are based on commonly used Quasi Delay Insensitive (QDI templates, namely, Precharge Half Buffer (PCHB and Weak Conditioned Half Buffer (WCHB. The functionality of the proposed asynchronous design is simulated and verified using Tanner Spice (TSPICE in 0.25 µm, 65 nm, and 180 nm technologies of Taiwan Semiconductor Manufacture Company (TSMC. The simulation result illustrates that the asynchronous design techniques have 25.21% of power reduction compared to synchronous design and work at a speed of 475 MHz.

  9. Participation in asynchronous online discussion forums does improve student learning of gross anatomy.

    Science.gov (United States)

    Green, Rodney A; Farchione, Davide; Hughes, Diane L; Chan, Siew-Pang

    2014-01-01

    Asynchronous online discussion forums are common in blended learning models and are popular with students. A previous report has suggested that participation in these forums may assist student learning in a gross anatomy subject but it was unclear as to whether more academically able students post more often or whether participation led to improved learning outcomes. This study used a path model to analyze the contribution of forum participation, previous academic ability, and student campus of enrolment to final marks in a multicampus gross anatomy course for physiotherapy students. The course has a substantial online learning management system (LMS) that incorporates asynchronous forums as a learning tool, particularly to answer learning objectives. Students were encouraged to post new threads and answer queries in threads started by others. The forums were moderated weekly by staff. Discussion forums were the most used feature of the LMS site with 31,920 hits. Forty-eight percent of the students posted at least once with 186 threads initiated by students and a total of 608 posts. The total number of posts made a significant direct contribution to final mark (P = 0.008) as did previous academic ability (P = 0.002). Although campus did not contribute to final mark, there was a trend for students at the campus where the course coordinator was situated to post more often than those at the other campus (P = 0.073). These results indicate that asynchronous online discussion forums can be an effective tool for improving student learning outcomes as evidenced by final marks in gross anatomy teaching. Copyright © 2013 American Association of Anatomists.

  10. XMPP for cloud computing in bioinformatics supporting discovery and invocation of asynchronous web services

    Directory of Open Access Journals (Sweden)

    Willighagen Egon L

    2009-09-01

    Full Text Available Abstract Background Life sciences make heavily use of the web for both data provision and analysis. However, the increasing amount of available data and the diversity of analysis tools call for machine accessible interfaces in order to be effective. HTTP-based Web service technologies, like the Simple Object Access Protocol (SOAP and REpresentational State Transfer (REST services, are today the most common technologies for this in bioinformatics. However, these methods have severe drawbacks, including lack of discoverability, and the inability for services to send status notifications. Several complementary workarounds have been proposed, but the results are ad-hoc solutions of varying quality that can be difficult to use. Results We present a novel approach based on the open standard Extensible Messaging and Presence Protocol (XMPP, consisting of an extension (IO Data to comprise discovery, asynchronous invocation, and definition of data types in the service. That XMPP cloud services are capable of asynchronous communication implies that clients do not have to poll repetitively for status, but the service sends the results back to the client upon completion. Implementations for Bioclipse and Taverna are presented, as are various XMPP cloud services in bio- and cheminformatics. Conclusion XMPP with its extensions is a powerful protocol for cloud services that demonstrate several advantages over traditional HTTP-based Web services: 1 services are discoverable without the need of an external registry, 2 asynchronous invocation eliminates the need for ad-hoc solutions like polling, and 3 input and output types defined in the service allows for generation of clients on the fly without the need of an external semantics description. The many advantages over existing technologies make XMPP a highly interesting candidate for next generation online services in bioinformatics.

  11. XMPP for cloud computing in bioinformatics supporting discovery and invocation of asynchronous web services.

    Science.gov (United States)

    Wagener, Johannes; Spjuth, Ola; Willighagen, Egon L; Wikberg, Jarl E S

    2009-09-04

    Life sciences make heavily use of the web for both data provision and analysis. However, the increasing amount of available data and the diversity of analysis tools call for machine accessible interfaces in order to be effective. HTTP-based Web service technologies, like the Simple Object Access Protocol (SOAP) and REpresentational State Transfer (REST) services, are today the most common technologies for this in bioinformatics. However, these methods have severe drawbacks, including lack of discoverability, and the inability for services to send status notifications. Several complementary workarounds have been proposed, but the results are ad-hoc solutions of varying quality that can be difficult to use. We present a novel approach based on the open standard Extensible Messaging and Presence Protocol (XMPP), consisting of an extension (IO Data) to comprise discovery, asynchronous invocation, and definition of data types in the service. That XMPP cloud services are capable of asynchronous communication implies that clients do not have to poll repetitively for status, but the service sends the results back to the client upon completion. Implementations for Bioclipse and Taverna are presented, as are various XMPP cloud services in bio- and cheminformatics. XMPP with its extensions is a powerful protocol for cloud services that demonstrate several advantages over traditional HTTP-based Web services: 1) services are discoverable without the need of an external registry, 2) asynchronous invocation eliminates the need for ad-hoc solutions like polling, and 3) input and output types defined in the service allows for generation of clients on the fly without the need of an external semantics description. The many advantages over existing technologies make XMPP a highly interesting candidate for next generation online services in bioinformatics.

  12. XMPP for cloud computing in bioinformatics supporting discovery and invocation of asynchronous web services

    Science.gov (United States)

    Wagener, Johannes; Spjuth, Ola; Willighagen, Egon L; Wikberg, Jarl ES

    2009-01-01

    Background Life sciences make heavily use of the web for both data provision and analysis. However, the increasing amount of available data and the diversity of analysis tools call for machine accessible interfaces in order to be effective. HTTP-based Web service technologies, like the Simple Object Access Protocol (SOAP) and REpresentational State Transfer (REST) services, are today the most common technologies for this in bioinformatics. However, these methods have severe drawbacks, including lack of discoverability, and the inability for services to send status notifications. Several complementary workarounds have been proposed, but the results are ad-hoc solutions of varying quality that can be difficult to use. Results We present a novel approach based on the open standard Extensible Messaging and Presence Protocol (XMPP), consisting of an extension (IO Data) to comprise discovery, asynchronous invocation, and definition of data types in the service. That XMPP cloud services are capable of asynchronous communication implies that clients do not have to poll repetitively for status, but the service sends the results back to the client upon completion. Implementations for Bioclipse and Taverna are presented, as are various XMPP cloud services in bio- and cheminformatics. Conclusion XMPP with its extensions is a powerful protocol for cloud services that demonstrate several advantages over traditional HTTP-based Web services: 1) services are discoverable without the need of an external registry, 2) asynchronous invocation eliminates the need for ad-hoc solutions like polling, and 3) input and output types defined in the service allows for generation of clients on the fly without the need of an external semantics description. The many advantages over existing technologies make XMPP a highly interesting candidate for next generation online services in bioinformatics. PMID:19732427

  13. Fast Simulation of Mechanical Heterogeneity in the Electrically Asynchronous Heart Using the MultiPatch Module.

    Directory of Open Access Journals (Sweden)

    John Walmsley

    2015-07-01

    Full Text Available Cardiac electrical asynchrony occurs as a result of cardiac pacing or conduction disorders such as left bundle-branch block (LBBB. Electrically asynchronous activation causes myocardial contraction heterogeneity that can be detrimental for cardiac function. Computational models provide a tool for understanding pathological consequences of dyssynchronous contraction. Simulations of mechanical dyssynchrony within the heart are typically performed using the finite element method, whose computational intensity may present an obstacle to clinical deployment of patient-specific models. We present an alternative based on the CircAdapt lumped-parameter model of the heart and circulatory system, called the MultiPatch module. Cardiac walls are subdivided into an arbitrary number of patches of homogeneous tissue. Tissue properties and activation time can differ between patches. All patches within a wall share a common wall tension and curvature. Consequently, spatial location within the wall is not required to calculate deformation in a patch. We test the hypothesis that activation time is more important than tissue location for determining mechanical deformation in asynchronous hearts. We perform simulations representing an experimental study of myocardial deformation induced by ventricular pacing, and a patient with LBBB and heart failure using endocardial recordings of electrical activation, wall volumes, and end-diastolic volumes. Direct comparison between simulated and experimental strain patterns shows both qualitative and quantitative agreement between model fibre strain and experimental circumferential strain in terms of shortening and rebound stretch during ejection. Local myofibre strain in the patient simulation shows qualitative agreement with circumferential strain patterns observed in the patient using tagged MRI. We conclude that the MultiPatch module produces realistic regional deformation patterns in the asynchronous heart and that

  14. Effects of synchronous versus asynchronous mode of propulsion on wheelchair basketball sprinting.

    Science.gov (United States)

    Faupin, Arnaud; Borel, Benoit; Meyer, Christophe; Gorce, Philippe; Watelain, Eric

    2013-11-01

    This study aimed to first investigate synchronous (SYN) versus asynchronous (ASY) mode of propulsion and, second, investigate the wheel camber effects on sprinting performance as well as temporal parameters. Seven wheelchair basketball players performed four maximal eight-second sprints on a wheelchair ergometer. They repeated the test according to two modes of propulsion (SYN and ASY) and two wheel cambers (9° and 15°). The mean maximal velocity and push power output was greater in the synchronous mode compared to the asynchronous mode for both camber angles. However, the fluctuation in the velocity profile is inferior for ASY versus SYN mode for both camber angles. Greater push time/cycle time (Pt/Ct) and arm frequency (AF) for synchronous mode versus asynchronous mode and inversely, lesser Ct and rest time (Rt) values for the synchronous mode, for which greater velocity were observed. SYN mode leads to better performance than ASY mode in terms of maximal propulsion velocity. However, ASY propulsion allows greater continuity of the hand-rim force application, reducing fluctuations in the velocity profile. The camber angle had no effect on ASY and SYN mean maximal velocity and push power output. The study of wheelchair propulsion strategies is important for better understanding physiological and biomechanical impacts of wheelchair propulsion for individuals with disabilities. From a kinematical point of view, this study highlights synchronous mode of propulsion to be more efficient, with regards to mean maximal velocity reaching during maximal sprinting exercises. Even if this study focuses on well-trained wheelchair athletes, results from this study could complement the knowledge on the physiological and biomechanical adaptations to wheelchair propulsion and therefore, might be interesting for wheelchair modifications for purposes of rehabilitation.

  15. Paphlagonia Bölgesi’nde Geç Antik ve Erken Bizans Yerleşimi: Sora / Late Antique and Early Byzantine Settlement in Paphlagonia Region: Sora

    Directory of Open Access Journals (Sweden)

    Durmuş Gür

    2017-06-01

    Full Text Available Abstract The late antique, early Byzantine settlement area locates at 12 km. distance to southwest of Karabuk Central District, on a sloping land with an altitude of 700 meters piedmont of Keltepe mountain. This settlement area, called as Zora, Zara, Zopran, Sora, Sopran or some other similar names by the researchers, locates within the boundaries of Akören (Kaleköy and Zopran today. This area is one of the five central eparchies bounded to Paphlagonia district of Gangra (Çankırı. Various column headers, inscriptions, sculptures, Hellenistic sepulchres and architectural ruins belonging to Roman age are identified there. The settlement area called as Sora since the 4th century is observed by Doublet (1889, Mendel (1901, Gökoğlu (1952, Marek (1993, 2003, Belke (1996 and Umar (2007, and they found out that it used to be called Zobran in the records of 16th century Ottoman archive. Within the scope of this research, Sora is observed in details for the periods of Roman, Byzantine and Ottoman. The life of St. Autonomous, who had came there in the 4th century to proselytize Christianity and became a martyre, their sepulchre constructions, the bishops of the city, architectural plastic works and scriptures are all researched. Moreover, the problem of naming the area which was confusing for many years is tried to be solved by this research beside documenting the present condition of the architectural ruin on their original places. Öz Karabük’ün 12 km. güneybatısında bulunan geç Antik-erken Bizans dönemi yerleşim alanı Sora (günümüzde Zopran ve Akören, Keltepe Dağı’nın eteklerinde ortalama 700 m. rakımda eğimli bir arazi üzerinde yer almaktadır. Araştırmacılar tarafından Zora, Zara, Zopran, Sora, Sopran gibi çeşitli isimlerle adlandırılan yerleşim, günümüzde Akören (Kaleköy ve Zopran sınırlarında kalmaktadır. Sora, Paphlagonia bölgesinde Gangra (Çankırı Metropolitliğine bağlı beş Piskoposluk

  16. Investigation of periodically driven systems by x-ray absorption spectroscopy using asynchronous data collection mode

    Science.gov (United States)

    Singh, H.; Donetsky, D.; Liu, J.; Attenkofer, K.; Cheng, B.; Trelewicz, J. R.; Lubomirsky, I.; Stavitski, E.; Frenkel, A. I.

    2018-04-01

    We report the development, testing, and demonstration of a setup for modulation excitation spectroscopy experiments at the Inner Shell Spectroscopy beamline of National Synchrotron Light Source - II. A computer algorithm and dedicated software were developed for asynchronous data processing and analysis. We demonstrate the reconstruction of X-ray absorption spectra for different time points within the modulation pulse using a model system. This setup and the software are intended for a broad range of functional materials which exhibit structural and/or electronic responses to the external stimulation, such as catalysts, energy and battery materials, and electromechanical devices.

  17. Asynchronous asymmetric form of heterogeneous osteopetrosis: initial case expanded and a new case

    International Nuclear Information System (INIS)

    Young, L.W.; Lachman, R.S.

    2001-01-01

    We have discovered additional serial radiographs and clinical information on the initial case of ''regional osteopetrosis tarda'' that has been included in several editions of Caffey's Pediatric X-Ray Diagnosis. A definite second case was found after a search of radiology teaching files of other selected medical centers and the International Skeletal Dysplasia Registry. Analysis of the sequential unusual radiographic findings of the initial case and the equivalent compelling findings of the second case justifies renewed attention to an asynchronous asymmetric form of heterogeneous osteopetrosis. (orig.)

  18. Information flow vs. resource access in the asynchronous pi-calculus

    OpenAIRE

    Hennessy, Matthew; Riely, James

    2002-01-01

    We propose an extension of the asynchronous π-calculus in which a variety of security properties may be captured using types. These are an extension of the input/output types for the π-calculus in which I/O capabilities are assigned specific security levels. The main innovation is a uniform typing system that, by varying slightly the allowed set of types, captures different notions of security.We first define a typing system that ensures that processes running at security level σ cannot acces...

  19. An asynchronous rapid single-flux-quantum demultiplexer based on dual-rail information coding

    International Nuclear Information System (INIS)

    Dimov, B; Khabipov, M; Balashov, D; Brandt, C M; Buchholz, F-Im; Niemeyer, J; Uhlmann, F H

    2005-01-01

    We present a novel asynchronous RSFQ demultiplexer based on dual-rail information coding. The electrical scheme of the circuit is designed and optimized to maximize the margins of its elements and to improve the fabrication yield. This optimized scheme has been fabricated with the 4 μm 1 kA cm -2 Nb/Al 2 O 3 -Al/Nb technology of PTB-Braunschweig. The demultiplexer has been tested with different samples of the low-speed incoming data stream and in all cases a correct circuit functionality has been observed

  20. Proximity-Based Asynchronous Messaging Platform for Location-Based Internet of Things Service

    Directory of Open Access Journals (Sweden)

    Hyeong gon Jo

    2016-07-01

    Full Text Available The Internet of Things (IoT opens up tremendous opportunities to provide location-based applications. However, despite the services around a user being physically adjacent, common IoT platforms use a centralized structure, like a cloud-computing architecture, which transfers large amounts of data to a central server. This raises problems, such as traffic concentration, long service latency, and high communication cost. In this paper, we propose a physical distance-based asynchronous messaging platform that specializes in processing personalized data and location-based messages. The proposed system disperses traffic using a location-based message-delivery protocol, and has high stability.

  1. A solid rotor iron free asynchronous generator for the production of high energy pulses

    International Nuclear Information System (INIS)

    Rioux, C.; Sultanem, F.

    1976-01-01

    A rotating machine capable of charging a noncooled magnetic storage coil is described. The rotor of the machine which is formed by metallic cylinder rotating at high speed, also behaves as a flywheel. The stator is composed of a three-phase winding connected to a system of rectifiers and power factor correcting condensers, thus forming an auto excited asynchronous generator. A very high power density is achieved because the machine has non ferrous winding, which permits a magnetic field of a few teslas. The basic machine theory and experimental model built are described

  2. Survey is based on Synchronized and Asynchronized Approach of MAC Protocols in WSN

    Directory of Open Access Journals (Sweden)

    Soni Chaurasia

    2010-07-01

    Full Text Available A wireless network is made of spatially distributed autonomous devices. These devices are called sensors. The sensor is used for monitoring physical or environmental conditions. The potential application of wireless sensor network is environmental monitoring, healthcare applications and tactical systems. In this paper focus is on the MAC protocol for WSN. Wireless sensor network is deployed for wide range to send and receive data with the help of medium. Here literature survey of MAC protocol based on the synchronized and asynchronized approach is described which is used to meet different objective like access a medium, statistical channel allocation, spectrum utilization

  3. High-quality asynchronous heralded single-photon source at telecom wavelength

    International Nuclear Information System (INIS)

    Fasel, Sylvain; Alibart, Olivier; Tanzilli, Sebastien; Baldi, Pascal; Beveratos, Alexios; Gisin, Nicolas; Zbinden, Hugo

    2004-01-01

    We report on the experimental realization and characterization of an asynchronous heralded single-photon source based on spontaneous parametric down-conversion. Photons at 1550 nm are heralded as being inside a single-mode fibre with more than 60% probability, and the multi-photon emission probability is reduced by a factor of up to more than 500 compared to Poissonian light sources. These figures of merit, together with the choice of telecom wavelength for the heralded photons, are compatible with practical applications needing very efficient and robust single-photon sources

  4. Specification and verification of gate-level VHDL models of synchronous and asynchronous circuits

    Science.gov (United States)

    Russinoff, David M.

    1995-01-01

    We present a mathematical definition of hardware description language (HDL) that admits a semantics-preserving translation to a subset of VHDL. Our HDL includes the basic VHDL propagation delay mechanisms and gate-level circuit descriptions. We also develop formal procedures for deriving and verifying concise behavioral specifications of combinational and sequential devices. The HDL and the specification procedures have been formally encoded in the computational logic of Boyer and Moore, which provides a LISP implementation as well as a facility for mechanical proof-checking. As an application, we design, specify, and verify a circuit that achieves asynchronous communication by means of the biphase mark protocol.

  5. High precision simple interpolation asynchronous FIFO based on ACEX1K30 for HIRFL-CSRe

    International Nuclear Information System (INIS)

    Li Guihua; Qiao Weimin; Jing Lan

    2008-01-01

    High precision simple interpolation asynchronous FIFO of HIRFL-CSRe was developed based on the ACEX1K30 FPGA in VHDL Hardware Description language. The FIFO runs in FPGA of DSP module of HIRFL-CSRe. The input data of FIFO is from DSP data bus and the output data is to DAC data bus. It's kernel adopts double buffer ping-pong mode and it can implement simple interpolation inside FPGA. The module can control out- put data time delay in 40 ns. The experimental results indicate that this module is practical and accurate to HIRFL-CSRe. (authors)

  6. Exploring effectiveness of team communication: Balancing synchronous and asynchronous communication in design teams

    DEFF Research Database (Denmark)

    den Otter, Ad; Emmitt, Stephen

    2007-01-01

    Effective teams use a balance of synchronous and asynchronous communication. Team communication is dependent on the communication acts of team members and the ability of managers to facilitate, stimulate and motivate them. Team members from organizations using different information systems tend...... to have different understanding, opinions, and rates of adoption and skills levels regarding specific IT tools. The purpose of this paper is to explore the effective use of tools for communication in design teams and the strategies for the use of specific tools....

  7. The use of Facebook for virtual asynchronous focus groups in qualitative research.

    Science.gov (United States)

    Biedermann, Narelle

    2018-02-01

    The Internet and the development of more user-engaging applications have opened a whole new world for researchers as a means of recruitment and data collection source. This paper describes the methodological approach of a research study that explored the experiences of Australian military spouses who packed up their family and home to accompany their spouse on an overseas posting. The study used Facebook as a recruitment tool and then as a data source through the conduct of an asynchronous virtual focus group. This paper outlines the advantages and disadvantages of this unique data source as a means of capturing the voices of a hard-to-reach population.

  8. Evolution of asynchronous motor activity in paired muscles: effects of ecology, morphology, and phylogeny.

    Science.gov (United States)

    Gerry, Shannon P; Ramsay, Jason B; Dean, Mason N; Wilga, Cheryl D

    2008-08-01

    Many studies of feeding behavior have implanted electrodes unilaterally (in muscles on only one side of the head) to determine the basic motor patterns of muscles controlling the jaws. However, bilateral implantation has the potential to achieve a more comprehensive understanding of modification of the motor activity that may be occurring between the left and right sides of the head. In particular, complex processing of prey is often characterized by bilaterally asynchronous and even unilateral activation of the jaw musculature. In this study, we bilaterally implant feeding muscles in species from four orders of elasmobranchs (Squaliformes, Orectolobiformes, Carcharhiniformes, Rajoidea) in order to characterize the effects of type of prey, feeding behavior, and phylogeny on the degree of asynchronous muscle activation. Electrodes were implanted in three of the jaw adductors, two divisions of the quadratomandibularis and the preorbitalis, as well as in a cranial elevator in sharks, the epaxialis. The asynchrony of feeding events (measured as the degree to which activity of members of a muscle pair is out of phase) was compared across species for capture versus processing and simple versus complex prey, then interpreted in the contexts of phylogeny, morphology, and ecology to clarify determinants of asynchronous activity. Whereas capture and processing of prey were characterized by statistically similar degrees of asynchrony for data pooled across species, events involving complex prey were more asynchronous than were those involving simple prey. The two trophic generalists, Squalus acanthias and Leucoraja erinacea, modulated the degree of asynchrony according to type of prey, whereas the two behavioral specialists, Chiloscyllium plagiosum and Mustelus canis, activated the cranial muscles synchronously regardless of type of prey. These differences in jaw muscle activity would not have been detected with unilateral implantation. Therefore, we advocate bilateral

  9. Fair Leader Election for Rational Agents in Asynchronous Rings and Networks

    OpenAIRE

    Yifrach, Assaf; Mansour, Yishay

    2018-01-01

    We study a game theoretic model where a coalition of processors might collude to bias the outcome of the protocol, where we assume that the processors always prefer any legitimate outcome over a non-legitimate one. We show that the problems of Fair Leader Election and Fair Coin Toss are equivalent, and focus on Fair Leader Election. Our main focus is on a directed asynchronous ring of $n$ processors, where we investigate the protocol proposed by Abraham et al. \\cite{abraham2013distributed} an...

  10. Clonal expansion and linear genome evolution through breast cancer progression from pre-invasive stages to asynchronous metastasis

    DEFF Research Database (Denmark)

    Krøigård, Anne Bruun; Larsen, Martin Jakob; Lænkholm, Anne Vibeke

    2015-01-01

    Evolution of the breast cancer genome from pre-invasive stages to asynchronous metastasis is complex and mostly unexplored, but highly demanded as it may provide novel markers for and mechanistic insights in cancer progression. The increasing use of personalized therapy of breast cancer necessita......Evolution of the breast cancer genome from pre-invasive stages to asynchronous metastasis is complex and mostly unexplored, but highly demanded as it may provide novel markers for and mechanistic insights in cancer progression. The increasing use of personalized therapy of breast cancer...... progression from one breast cancer patient, including two different regions of Ductal Carcinoma In Situ (DCIS), primary tumor and an asynchronous metastasis. We identify a remarkable landscape of somatic mutations, retained throughout breast cancer progression and with new mutational events emerging at each...

  11. An improved asynchronous brain interface: making use of the temporal history of the LF-ASD feature vectors

    Science.gov (United States)

    Bashashati, Ali; Mason, Steve; Ward, Rabab K.; Birch, Gary E.

    2006-06-01

    The low-frequency asynchronous switch design (LF-ASD) has been introduced as a direct brain interface (BI) for asynchronous control applications. Asynchronous interfaces, as opposed to synchronous interfaces, have the advantage of being operational at all times and not only at specific system-defined periods. This paper modifies the LF-ASD design by incorporating into the system more knowledge about the attempted movements. Specifically, the history of feature values extracted from the EEG signal is used to detect a right index finger movement attempt. Using data collected from individuals with high-level spinal cord injuries and able-bodied subjects, it is shown that the error characteristics of the modified design are significantly better than the previous LF-ASD design. The true positive rate percentage increased by up to 15 which corresponds to 50% improvement when the system is operating with false positive rates in the 1-2% range.

  12. Merging the Forces of Asynchronous Tutoring and Synchronous Conferencing: A Qualitative Study of Arab ESL Academic Writers Using E-Tutoring

    Science.gov (United States)

    Alqadoumi, Omar Mohamed

    2012-01-01

    Previous studies in the field of e-tutoring dealt either with asynchronous tutoring or synchronous conferencing as modes for providing e-tutoring services to English learners. This qualitative research study reports the experiences of Arab ESL tutees with both asynchronous tutoring and synchronous conferencing. It also reports the experiences of…

  13. Accelerator physics studies on the effects from an asynchronous beam dump onto the LHC experimental region collimators

    CERN Document Server

    Lari, L; Boccone, V; Bruce, R; Cerutti, F; Rossi, A; Vlachoudis, V; Mereghetti, A; Faus-Golfe, A

    2012-01-01

    Asynchronous beam aborts at the LHC are estimated to occur on average once per year. Accelerator physics studies of asynchronous dumps have been performed at different beam energies and beta-stars. The loss patterns are analyzed in order to identify the losses in particular on the Phase 1 Tertiary Collimators (TCT), since their tungsten-based active jaw insert has a lower damage threshold than the carbon-based other LHC collimators. Settings of the tilt angle of the TCTs are discussed with the aim of reducing the thermal loads on the TCT themselves.

  14. Sensor placement on Canton Tower for health monitoring using asynchronous-climb monkey algorithm

    Science.gov (United States)

    Yi, Ting-Hua; Li, Hong-Nan; Zhang, Xu-Dong

    2012-12-01

    Heuristic optimization algorithms have become a popular choice for solving complex and intricate sensor placement problems which are difficult to solve by traditional methods. This paper proposes a novel and interesting methodology called the asynchronous-climb monkey algorithm (AMA) for the optimum design of sensor arrays for a structural health monitoring system. Different from the existing algorithms, the dual-structure coding method is designed and adopted for the representation of the design variables. The asynchronous-climb process is incorporated in the proposed AMA that can adjust the trajectory of each individual dynamically in the search space according to its own experience and other monkeys. The concept of ‘monkey king’ is introduced in the AMA, which reflects the Darwinian principle of natural selection and can create an interaction network to correctly guide the movement of other monkeys. Numerical experiments are carried out using two different objective functions by considering the Canton Tower in China with or without the antenna mast to evaluate the performance of the proposed algorithm. Investigations have indicated that the proposed AMA exhibits faster convergence characteristics and can generate sensor configurations superior in all instances when compared to the conventional monkey algorithm. For structures with stiffness mutation such as the Canton Tower, the sensor placement needs to be considered for each part separately.

  15. Sensor placement on Canton Tower for health monitoring using asynchronous-climb monkey algorithm

    International Nuclear Information System (INIS)

    Yi, Ting-Hua; Li, Hong-Nan; Zhang, Xu-Dong

    2012-01-01

    Heuristic optimization algorithms have become a popular choice for solving complex and intricate sensor placement problems which are difficult to solve by traditional methods. This paper proposes a novel and interesting methodology called the asynchronous-climb monkey algorithm (AMA) for the optimum design of sensor arrays for a structural health monitoring system. Different from the existing algorithms, the dual-structure coding method is designed and adopted for the representation of the design variables. The asynchronous-climb process is incorporated in the proposed AMA that can adjust the trajectory of each individual dynamically in the search space according to its own experience and other monkeys. The concept of ‘monkey king’ is introduced in the AMA, which reflects the Darwinian principle of natural selection and can create an interaction network to correctly guide the movement of other monkeys. Numerical experiments are carried out using two different objective functions by considering the Canton Tower in China with or without the antenna mast to evaluate the performance of the proposed algorithm. Investigations have indicated that the proposed AMA exhibits faster convergence characteristics and can generate sensor configurations superior in all instances when compared to the conventional monkey algorithm. For structures with stiffness mutation such as the Canton Tower, the sensor placement needs to be considered for each part separately. (paper)

  16. A BMI-based occupational therapy assist suit: asynchronous control by SSVEP

    Directory of Open Access Journals (Sweden)

    Takeshi eSakurada

    2013-09-01

    Full Text Available A brain-machine interface (BMI is an interface technology that uses neurophysiological signals from the brain to control external machines. Recent invasive BMI technologies have succeeded in the asynchronous control of robot arms for a useful series of actions, such as reaching and grasping. In this study, we developed non-invasive BMI technologies aiming to make such useful movements using the subject's own hands by preparing a BMI-based occupational therapy assist suit (BOTAS. We prepared a pre-recorded series of useful actionsa grasping-a-ball movement and a carrying-the-ball movementand added asynchronous control using steady-state visual evoked potential (SSVEP signals. A SSVEP signal was used to trigger the grasping-a-ball movement and another SSVEP signal was used to trigger the carrying-the-ball movement. A support vector machine was used to classify EEG signals recorded from the visual cortex (Oz in real time. Untrained, able-bodied participants (n = 12 operated the system successfully. Classification accuracy and time required for SSVEP detection were approximately 88% and 3 s, respectively. We further recruited three patients with upper cervical spinal cord injuries; they also succeeded in operating the system without training. These data suggest that our BOTAS system is potentially useful in terms of rehabilitation of patients with upper limb disabilities.

  17. Asynchronous web-based learning, a practical method to enhance teaching in emergency medicine.

    Science.gov (United States)

    Pourmand, Ali; Lucas, Raymond; Nouraie, Mehdi

    2013-03-01

    Abstract Objective: To compare medical knowledge acquisition among emergency medicine (EM) residents who attend weekly core content lectures with those absent but asynchronously viewing the same lectures in a Web-based electronic platform. During the study period all EM residents attending or absent from weekly educational conferences were given a quiz on the covered material. During Phase 1, absentees were not given supplemental educational content for missed lectures. During Phase 2, absentees were sent a link to an online multimedia module containing an audiovisual recording of the actual missed lecture with presentation slides. Scores between attendees and absentees during both phases were compared using a repeated-measures analysis to evaluate the effect of the supplemental online module on knowledge acquisition. Thirty-nine EM residents (equally distributed in postgraduate years 1-4) were studied during a 15-week period. Overall and after adjusting for sex and postgraduate year level, both lecture attendance (b=27; 95% confidence interval, 22-32; pcontent lectures. The percentage of curriculum delivery by asynchronous learning that may be used to achieve overall terminal learning objectives in medical knowledge acquisition requires further study.

  18. FLUKA Studies of the Asynchronous Beam Dump Effects on LHC Point 6

    CERN Document Server

    Versaci, R; Goddard, B; Schmidt, R; Vlachoudis, V; Mereghetti, A

    2011-01-01

    The LHC is a record-breaking machine for beam energy and intensity. An intense effort has therefore been deployed in simulating critical operational scenarios of energy deposition. FLUKA is the most widely used code for this kind of simulations at CERN because of the high reliability of its results and the ease to custom detailed simulations all along hundreds of meters of beam line. We have investigated the effects of an asynchronous beam dump on the LHC Point 6 where, beams with a stored energy of 360 MJ, can instantaneously release up to a few J cm−3 in the cryogenic magnets which have a quench limit of the order of the mJ cm−3. In the present paper we will describe the simulation approach, and discuss the evaluated maximum energy release onto the superconducting magnets during an asynchronous beam dump. We will then analyse the shielding provided by collimators installed in the area and discuss safety limits for the operation of the LHC.

  19. Asynchronous Amazon forest canopy phenology indicates adaptation to both water and light availability

    International Nuclear Information System (INIS)

    Jones, Matthew O; Kimball, John S; Nemani, Ramakrishna R

    2014-01-01

    Amazon forests represent nearly half of all tropical vegetation biomass and, through photosynthesis and respiration, annually process more than twice the amount of estimated carbon (CO 2 ) from fossil fuel emissions. Yet the seasonality of Amazon canopy cover, and the extent to which seasonal fluctuations in water availability and photosynthetically available radiation influence these processes, is still poorly understood. Implementing six remotely sensed data sets spanning nine years (2003–2011), with reported field and flux tower data, we show that southern equatorial Amazon forests exhibit a distinctive seasonal signal. Seasonal timing of water availability, canopy biomass growth and net leaf flush are asynchronous in regions with short dry seasons and become more synchronous across a west-to-east longitudinal moisture gradient of increasing dry season. Forest cover is responsive to seasonal disparities in both water and solar radiation availability, temporally adjusting net leaf flush to maximize use of these generally abundant resources, while reducing drought susceptibility. An accurate characterization of this asynchronous behavior allows for improved understanding of canopy phenology across contiguous tropical forests and their sensitivity to climate variability and drought. (letter)

  20. Asynchronous Amazon Forest Canopy Phenology Indicates Adaptation to Both Water and Light Availability

    Science.gov (United States)

    Jones, M. O.; Kimball, J. S.; Nemani, R. R.

    2015-12-01

    Amazon forests represent nearly half of all tropical vegetation biomass and, through photosynthesis and respiration, annually process more than twice the amount of estimated carbon (CO2) from fossil fuel emissions. Yet the seasonality of Amazon canopy cover, and the extent to which seasonal fluctuations in water availability and photosynthetically active radiation influence these processes, is still poorly understood. Implementing six remotely sensed data sets spanning nine years (2003-2011), with reported field and flux tower data, we show that southern equatorial Amazon forests exhibit a distinctive seasonal signal. Seasonal timing of water availability, canopy biomass growth and net leaf flush are asynchronous in regions with short dry seasons and become more synchronous across a west-to-east longitudinal moisture gradient of increasing dry season length. Forest cover is responsive to seasonal disparities in both water and solar radiation availability, temporally adjusting net leaf flush to maximize use of these generally abundant resources, while reducing drought susceptibility. An accurate characterization of this asynchronous behavior allows for improved understanding of canopy phenology across contiguous tropical forests and their sensitivity to climate variability and drought. These insights can also inform land surface models to provide a more accurate representation of seasonal forest carbon allocation strategies responsive to environmental drivers.

  1. Forced synchronization and asynchronous quenching in a thermo-acoustic system

    Science.gov (United States)

    Mondal, Sirshendu; Pawar, Samadhan A.; Sujith, Raman

    2017-11-01

    Forced synchronization, which has been extensively studied in theory and experiments, occurs through two different mechanisms known as phase locking and asynchronous quenching. The latter indicates the suppression of oscillation amplitude. In most practical combustion systems such as gas turbine engines, the main concern is high amplitude pressure oscillations, known as thermo-acoustic instability. Thermo-acoustic instability is undesirable and needs to be suppressed because of its damaging consequences to an engine. In the present study, a systematic experimental investigation of forced synchronization is performed in a prototypical thermo-acoustic system, a Rijke tube, in its limit cycle operation. Further, we show a qualitatively similar behavior using a reduced order model. In the phase locking region, the simultaneous occurrence of synchronization and resonant amplification leads to high amplitude pressure oscillations. However, a reduction in the amplitude of natural oscillations by about 78% of the unforced amplitude is observed when the forcing frequency is far lower than the natural frequency. This shows the possibility of suppression of the oscillation amplitude through asynchronous quenching in thermo-acoustic systems.

  2. Asynchronous Task-Based Polar Decomposition on Single Node Manycore Architectures

    KAUST Repository

    Sukkari, Dalal E.; Ltaief, Hatem; Faverge, Mathieu; Keyes, David E.

    2017-01-01

    This paper introduces the first asynchronous, task-based formulation of the polar decomposition and its corresponding implementation on manycore architectures. Based on a formulation of the iterative QR dynamically-weighted Halley algorithm (QDWH) for the calculation of the polar decomposition, the proposed implementation replaces the original LU factorization for the condition number estimator by the more adequate QR factorization to enable software portability across various architectures. Relying on fine-grained computations, the novel task-based implementation is capable of taking advantage of the identity structure of the matrix involved during the QDWH iterations, which decreases the overall algorithmic complexity. Furthermore, the artifactual synchronization points have been weakened compared to previous implementations, unveiling look-ahead opportunities for better hardware occupancy. The overall QDWH-based polar decomposition can then be represented as a directed acyclic graph (DAG), where nodes represent computational tasks and edges define the inter-task data dependencies. The StarPU dynamic runtime system is employed to traverse the DAG, to track the various data dependencies and to asynchronously schedule the computational tasks on the underlying hardware resources, resulting in an out-of-order task scheduling. Benchmarking experiments show significant improvements against existing state-of-the-art high performance implementations for the polar decomposition on latest shared-memory vendors' systems, while maintaining numerical accuracy.

  3. Modifying Dialogical Strategy in Asynchronous Critical Discussions for Cross-Strait Chinese Learners

    Directory of Open Access Journals (Sweden)

    Jean Yiching Chiu

    2014-09-01

    Full Text Available In this global era, critical thinking has become crucial for educators and learners. The purpose of this research was to explore how modifying a dialogical strategy in asynchronous online discussion forums impacted Chinese learners’ critical thinking. Due to the Chinese cultural impact of social harmony, the majority of learners tend to maintain silent and avoid critical discussions in instructional settings. The author deployed an affectively supportive model in a modified dialogical strategy to structure Chinese EFL learners’ asynchronous critical postings by probing and questioning while requiring labeling of each cross-referencing posting as Agree/Disagree/Challenge/New Perspective. The participants were two cohorts of similar cultural background but under different political systems in China and Taiwan, here engaged together in cultural interactions. This study employed two research methods: standardized critical thinking tests, and focus groups. Findings reveal that learners in both cohorts indicated some improvement in their critical thinking skills. Nevertheless, there remain affective and cultural issues. Future studies are thus recommended to further investigate the potential of an adaptive model to engage critical discussions with English native speakers and optimize critical thinking for Chinese learners in an EFL environment.

  4. An Autonomous Wireless Sensor Node With Asynchronous ECG Monitoring in 0.18 μ m CMOS.

    Science.gov (United States)

    Mansano, Andre L; Li, Yongjia; Bagga, Sumit; Serdijn, Wouter A

    2016-06-01

    The design of a 13.56 MHz/402 MHz autonomous wireless sensor node with asynchronous ECG monitoring for near field communication is presented. The sensor node consists of an RF energy harvester (RFEH), a power management unit, an ECG readout, a data encoder and an RF backscattering transmitter. The energy harvester supplies the system with 1.25 V and offers a power conversion efficiency of 19% from a -13 dBm RF source at 13.56 MHz. The power management unit regulates the output voltage of the RFEH to supply the ECG readout with VECG = 0.95 V and the data encoder with VDE = 0.65 V . The ECG readout comprises an analog front-end (low noise amplifier and programmable voltage to current converter) and an asynchronous level crossing ADC with 8 bits resolution. The ADC output is encoded by a pulse generator that drives a backscattering transmitter at 402 MHz. The total power consumption of the sensor node circuitry is 9.7 μ W for a data rate of 90 kb/s and a heart rate of 70 bpm. The chip has been designed in a 0.18 μm CMOS process and shows superior RF input power sensitivity and lower power consumption when compared to previous works.

  5. Asynchronous detection of kinesthetic attention during mobilization of lower limbs using EEG measurements

    Science.gov (United States)

    Melinscak, Filip; Montesano, Luis; Minguez, Javier

    2016-02-01

    Objective. Attention is known to modulate the plasticity of the motor cortex, and plasticity is crucial for recovery in motor rehabilitation. This study addresses the possibility of using an EEG-based brain-computer interface (BCI) to detect kinesthetic attention to movement. Approach. A novel experiment emulating physical rehabilitation was designed to study kinesthetic attention. The protocol involved continuous mobilization of lower limbs during which participants reported levels of attention to movement—from focused kinesthetic attention to mind wandering. For this protocol an asynchronous BCI detector of kinesthetic attention and deliberate mind wandering was designed. Main results. EEG analysis showed significant differences in theta, alpha, and beta bands, related to the attentional state. These changes were further pinpointed to bands relative to the frequency of the individual alpha peak. The accuracy of the designed BCI ranged between 60.8% and 68.4% (significantly above chance level), depending on the used analysis window length, i.e. acceptable detection delay. Significance. This study shows it is possible to use self-reporting to study attention-related changes in EEG during continuous mobilization. Such a protocol is used to develop an asynchronous BCI detector of kinesthetic attention, with potential applications to motor rehabilitation.

  6. A BMI-based occupational therapy assist suit: asynchronous control by SSVEP.

    Science.gov (United States)

    Sakurada, Takeshi; Kawase, Toshihiro; Takano, Kouji; Komatsu, Tomoaki; Kansaku, Kenji

    2013-01-01

    A brain-machine interface (BMI) is an interface technology that uses neurophysiological signals from the brain to control external machines. Recent invasive BMI technologies have succeeded in the asynchronous control of robot arms for a useful series of actions, such as reaching and grasping. In this study, we developed non-invasive BMI technologies aiming to make such useful movements using the subject's own hands by preparing a BMI-based occupational therapy assist suit (BOTAS). We prepared a pre-recorded series of useful actions-a grasping-a-ball movement and a carrying-the-ball movement-and added asynchronous control using steady-state visual evoked potential (SSVEP) signals. A SSVEP signal was used to trigger the grasping-a-ball movement and another SSVEP signal was used to trigger the carrying-the-ball movement. A support vector machine was used to classify EEG signals recorded from the visual cortex (Oz) in real time. Untrained, able-bodied participants (n = 12) operated the system successfully. Classification accuracy and time required for SSVEP detection were ~88% and 3 s, respectively. We further recruited three patients with upper cervical spinal cord injuries (SCIs); they also succeeded in operating the system without training. These data suggest that our BOTAS system is potentially useful in terms of rehabilitation of patients with upper limb disabilities.

  7. Scalability of Several Asynchronous Many-Task Models for In Situ Statistical Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Pebay, Philippe Pierre [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bennett, Janine Camille [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Kolla, Hemanth [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Borghesi, Giulio [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-05-01

    This report is a sequel to [PB16], in which we provided a first progress report on research and development towards a scalable, asynchronous many-task, in situ statistical analysis engine using the Legion runtime system. This earlier work included a prototype implementation of a proposed solution, using a proxy mini-application as a surrogate for a full-scale scientific simulation code. The first scalability studies were conducted with the above on modestly-sized experimental clusters. In contrast, in the current work we have integrated our in situ analysis engines with a full-size scientific application (S3D, using the Legion-SPMD model), and have conducted nu- merical tests on the largest computational platform currently available for DOE science ap- plications. We also provide details regarding the design and development of a light-weight asynchronous collectives library. We describe how this library is utilized within our SPMD- Legion S3D workflow, and compare the data aggregation technique deployed herein to the approach taken within our previous work.

  8. Asynchronous data change notification between database server and accelerator control systems

    International Nuclear Information System (INIS)

    Wenge Fu; Seth Nemesure; Morris, J.

    2012-01-01

    Database data change notification (DCN) is a commonly used feature, it allows to be informed when the data has been changed on the server side by another client. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/server architectures (such as CDEV, EPICS, and ADO) that can be used to implement data reflection servers that transfer data asynchronously to any client using the standard SET/GET API. This paper describes a method for using such a data reflection server to set up asynchronous DCN (ADCN) between a DBMS and clients. This method works well for all DBMS systems which provide database trigger functionality. (authors)

  9. Asynchronous timing and Doppler recovery in DSP based DPSK modems for fixed and mobile satellite applications

    Science.gov (United States)

    Koblents, B.; Belanger, M.; Woods, D.; McLane, P. J.

    While conventional analog modems employ some kind of clock wave regenerator circuit for synchronous timing recovery, in sampled modem receivers the timing is recovered asynchronously to the incoming data stream, with no adjustment being made to the input sampling rate. All timing corrections are accomplished by digital operations on the sampled data stream, and timing recovery is asynchronous with the uncontrolled, input A/D system. A good timing error measurement algorithm is a zero crossing tracker proposed by Gardner. Digital, speech rate (2400 - 4800 bps) M-PSK modem receivers employing Gardner's zero crossing tracker were implemented and tested and found to achieve BER performance very close to theoretical values on the AWGN channel. Nyguist pulse shaped modem systems with excess bandwidth factors ranging from 100 to 60 percent were considered. We can show that for any symmetric M-PSK signal set Gardner's NDA algorithm is free of pattern jitter for any carrier phase offset for rectangular pulses and for Nyquist pulses having 100 percent excess bandwidth. Also, the Nyquist pulse shaped system is studied on the mobile satellite channel, where Doppler shifts and multipath fading degrade the pi/4-DQPSK signal. Two simple modifications to Gardner's zero crossing tracker enable it to remain useful in the presence of multipath fading.

  10. Asynchronous Task-Based Polar Decomposition on Single Node Manycore Architectures

    KAUST Repository

    Sukkari, Dalal E.

    2017-09-29

    This paper introduces the first asynchronous, task-based formulation of the polar decomposition and its corresponding implementation on manycore architectures. Based on a formulation of the iterative QR dynamically-weighted Halley algorithm (QDWH) for the calculation of the polar decomposition, the proposed implementation replaces the original LU factorization for the condition number estimator by the more adequate QR factorization to enable software portability across various architectures. Relying on fine-grained computations, the novel task-based implementation is capable of taking advantage of the identity structure of the matrix involved during the QDWH iterations, which decreases the overall algorithmic complexity. Furthermore, the artifactual synchronization points have been weakened compared to previous implementations, unveiling look-ahead opportunities for better hardware occupancy. The overall QDWH-based polar decomposition can then be represented as a directed acyclic graph (DAG), where nodes represent computational tasks and edges define the inter-task data dependencies. The StarPU dynamic runtime system is employed to traverse the DAG, to track the various data dependencies and to asynchronously schedule the computational tasks on the underlying hardware resources, resulting in an out-of-order task scheduling. Benchmarking experiments show significant improvements against existing state-of-the-art high performance implementations for the polar decomposition on latest shared-memory vendors\\' systems, while maintaining numerical accuracy.

  11. Non-fragile switched H∞ control for morphing aircraft with asynchronous switching

    Directory of Open Access Journals (Sweden)

    Haoyu CHENG

    2017-06-01

    Full Text Available This paper deals with the problem of non-fragile linear parameter-varying (LPV H∞ control for morphing aircraft with asynchronous switching. The switched LPV model of morphing aircraft is established by Jacobian linearization approach according to the nonlinear model. The data missing is taken into account in the link from sensors to controllers and the link from controllers to actuators, which satisfies Bernoulli distribution. The non-fragile switched LPV controllers are constructed with consideration of the uncertainties of controllers and asynchronous switching phenomenon. The parameter-dependent Lyapunov functional method and mode-dependent average dwell time (MDADT method are combined to guarantee the stability and prescribed performance of the system. The sufficient conditions on the solvability of the problem are derived in the form of linear matrix inequalities (LMI. In order to achieve higher efficiency of the designing process, an algorithm is applied to divide the whole set into subsets automatically. Simulation results are provided to verify the effectiveness and superiority of the method in the paper.

  12. Data-Aware Retrodiction for Asynchronous Harmonic Measurement in a Cyber-Physical Energy System

    Science.gov (United States)

    Liu, Youda; Wang, Xue; Liu, Yanchi; Cui, Sujin

    2016-01-01

    Cyber-physical energy systems provide a networked solution for safety, reliability and efficiency problems in smart grids. On the demand side, the secure and trustworthy energy supply requires real-time supervising and online power quality assessing. Harmonics measurement is necessary in power quality evaluation. However, under the large-scale distributed metering architecture, harmonic measurement faces the out-of-sequence measurement (OOSM) problem, which is the result of latencies in sensing or the communication process and brings deviations in data fusion. This paper depicts a distributed measurement network for large-scale asynchronous harmonic analysis and exploits a nonlinear autoregressive model with exogenous inputs (NARX) network to reorder the out-of-sequence measuring data. The NARX network gets the characteristics of the electrical harmonics from practical data rather than the kinematic equations. Thus, the data-aware network approximates the behavior of the practical electrical parameter with real-time data and improves the retrodiction accuracy. Theoretical analysis demonstrates that the data-aware method maintains a reasonable consumption of computing resources. Experiments on a practical testbed of a cyber-physical system are implemented, and harmonic measurement and analysis accuracy are adopted to evaluate the measuring mechanism under a distributed metering network. Results demonstrate an improvement of the harmonics analysis precision and validate the asynchronous measuring method in cyber-physical energy systems. PMID:27548171

  13. Realistic modelling of the effects of asynchronous motion at the base of bridge piers

    International Nuclear Information System (INIS)

    Romanelli, F.; Panza, G.F.; Vaccari, F.

    2002-11-01

    Frequently long-span bridges provide deep valley crossings, which require special consideration due to the possibility of local amplification of the ground motion as a consequence of topographical irregularities and local soil conditions. This does in fact cause locally enhanced seismic input with the possibility for the bridge piers to respond asynchronously. This introduces special design requirements so that possible out-of-phase ground displacements and the associated large relative displacements of adjacent piers can be accommodated without excessive damage. Assessment of the local variability of the ground motion due to local lateral heterogeneities and to attenuation properties is thus crucial toward the realistic definition of the asynchronous motion at the base of the bridge piers. We illustrate the work done in the framework of a large international cooperation to assess the importance of non-synchronous seismic excitation of long structures. To accomplish this task we compute complete synthetic accelerograms using as input a set of parameters that describes, to the best of our knowledge, the geological structure and seismotectonic setting of the investigated area. (author)

  14. Learner Perceptions of Asynchronous Oral Computer-mediated Communication: Proficiency and Second Langauge Selves

    Directory of Open Access Journals (Sweden)

    Jesse Gleason

    2012-06-01

    Full Text Available Abstract The present study addresses the perceptions of international teaching assistants regarding the role of language learning tasks using Wimba Voice (WV in aiding the improvement of their second language (L2 oral skills. It specifically examines how this asynchronous computer-mediated communication (CMC technology can foster the development of these learners’ L2 selves. According to Dörnyei (2009, the more clearly learners can envision their future L2 selves, the more motivated they will be to achieve their L2 goals. With increased planning of oral production, access to instructor and peer feedback, and additional opportunities for self-reflection, asynchronous CMC technologies have been found to enable L2 learners to express their thoughts at their own pace and feel more relaxed and confident than in more threatening face-to-face situations (Sun, 2009. The findings suggest that learners have a variety of opinions regarding the role of asynchronous WV tasks in motivating them to develop their L2 oral proficiency. Also, many may prefer oral CMC environments that facilitate interaction and meaning negotiation. Results were inconclusive concerning the effect of WV-based tasks on students' perceptions of their future L2 selves; however, this may have been due to the short time frame in which these activities were employed. Résumé Nous étudions ici les perceptions d’un groupe d’assistants internationaux sur le rôle des tâches d’apprentissage linguistique à l’aide de Wimba Voice (WV. Le projet avait pour but d’améliorer les compétences orales des participants dans leur langue seconde. La présente étude examine en particulier la voie par laquelle cette technologie de la communication asynchrone par ordinateur peut favoriser l’évolution de la langue seconde des apprenants. Selon Dörnyei (2009, plus les apprenants peuvent envisager clairement un futur emploi de leur langue seconde, plus ils seront motivés à atteindre

  15. The Slavic Liturgy of the Byzantine Rite and the Corpus of Slavic Liturgical Books at the End of the 9th and the Beginning of the 10th Centuries

    Directory of Open Access Journals (Sweden)

    Aleksey M. Pentkovskiy

    2016-12-01

    Full Text Available Recent scholarship on the historical development of the Slavic liturgy in its early stage has shown that one of the important prerequisites for its practical implementation was the establishment, under the guidance of a bishop, of a church organization which was entitled to use Church Slavonic as a liturgical language. Research has also demonstrated that the methodological approach linking the history of the Slavic liturgical texts with the development of the Slavic ecclesiastical structures administered by bishops offers valuable insights. The first Slavic corpus of liturgical books of Byzantine rites (the so-called Corpus of Clement, CC came into being in the Slavic ethnic eparchy and then in the Slavic territorial dioceses which were to be integrated into the church organization of the First Bulgarian Empire. The core part of the CC, to which the complex of original Slavic hymnographic writings belongs, was created in the years between 893 and 916 in the Slavic ethnic eparchy of St. Clement of Ohrid in the western part of the First Bulgarian Empire (in the region of southern Albania, northwestern Greece, and southwestern Macedonia. The supplementary part of the CC, which contains the complex of the word-by-word translations of hymnographic writings, originated in the mid-10th century in Slavic territorial dioceses located at that time in the western part of the First Bulgarian Empire. This two-stage formation of the CC was due to the two-stage development of the Slavic church organizations, and it was thus neither linguistic nor literary in nature. Having special features characteristic of the western Byzantine liturgy, the CC differed from both its preceding and subsequent corpora of Slavic liturgical books in its liturgical, textological, and linguistic character. Every subsequent corpus of Slavic liturgical texts, however, built upon the preceding one, and this ensured the continuity of the Slavic liturgical and, consequently, linguistic

  16. Effects of Synchronous and Asynchronous Computer-Mediated Communication (CMC) Oral Conversations on English Language Learners' Discourse Functions

    Science.gov (United States)

    AbuSeileek, Ali Farhan; Qatawneh, Khaleel

    2013-01-01

    This study aimed to explore the effects of synchronous and asynchronous computer mediated communication (CMC) oral discussions on question types and strategies used by English as a Foreign Language (EFL) learners. The participants were randomly assigned to two treatment conditions/groups; the first group used synchronous CMC, while the second…

  17. An Investigation of Native and Nonnative English Speakers' Levels of Written Syntactic Complexity in Asynchronous Online Discussions

    Science.gov (United States)

    Mancilla, Rae L.; Polat, Nihat; Akcay, Ahmet O.

    2017-01-01

    This manuscript reports on a corpus-based comparison of native and nonnative graduate students' language production in an asynchronous learning environment. Using 486 discussion board postings from a five-year period (2009-2013), we analyzed the extent to which native and nonnative university students' writing differed in 10 measures of syntactic…

  18. RESEARCH INTO VALVE-ENGINE TRANSDUCERS OF BRUSHLESS SYNCHRONOUS AND ASYNCHRONIZED MACHINES IN A CIRCUIT SIMULATION SYSTEM.

    Directory of Open Access Journals (Sweden)

    A.M. Galynovskiy

    2013-10-01

    Full Text Available Designing features for valve-engine transducers of brushless synchronous and asynchronized machines are described. Global analysis of research results on the transducer models in a MicroCap circuit simulation system is made, recommendations on the simulation system application in both scientific research and educational process given.

  19. Students' Perceptions of Online Discussions, Participation and E-Moderation Behaviours in Peer-Moderated Asynchronous Online Discussions

    Science.gov (United States)

    Ghadirian, Hajar; Fauzi Mohd Ayub, Ahmad; Salehi, Keyvan

    2018-01-01

    The aim of this study was to investigate the relationships between students' perceptions of online discussions, participation and e-moderation behaviours in peer-moderated asynchronous online discussions. Using survey data, the learning system's activity log and discussion transcripts, the authors analysed how 84 learners' perceptions of online…

  20. Torque harmonics of an asynchronous motor supplied by a voltage- or current-sourced inverter quasi-square operation

    Energy Technology Data Exchange (ETDEWEB)

    Kyyrae, J. [Helsinki University of Technology, Institute of Intelligent Power Electronics, Espoo (Finland)

    1997-12-31

    Voltage- and current-sourced dc-ac converters operating in quasi-square area are compared. Their characteristics are calculated with switching vector, which is space-vector of switching functions. When the load is an asynchronous motor various analytical equations, including torque, are calculated efficiently. Motor current and torque approximations are compared with the simulated ones. (orig.) 6 refs.