A war psychiatry approach to warfare in the Middle Byzantine period.

PubMed

Ntafoulis, Pavlos

2016-12-01

Combat stress cases were traced in historical texts and military manuals on warfare from the Middle Byzantine period; they were mainly labelled as cowardice. Soldiers suffered from nostalgia or exhaustion; officers looked stunned, or could not speak during the battle. Cruel punishments were often enforced. Suicide and alcohol abuse were rarely mentioned. The Byzantines' evacuation system for battle casualties was well organized. Psychological operations were conducted and prisoners-of-war were usually part of them. The Byzantine army had 'parakletores', officers assigned to encourage soldiers before combat. The leaders dealt with combat stress by using their rhetoric skills and emphasizing religious faith in eternal life. The treatment of the 'cowards' was rather similar to modern war psychiatry principles of treatment. No description of PTSD was found. © The Author(s) 2016.

The fatal disease of the Byzantine Emperor Andronicus III Palaeologus (1328-1341 AD).

PubMed Central

Lascaratos, J; Marketos, S

1997-01-01

The Byzantine Emperor Andronicus III Palaeologus (1328-1341 AD) died at age 45 from a disease the nature of which is unknown. However, light is thrown on this by the texts of the Byzantine historians John Cantacuzenus (who became Emperor under the name of John VI) and Nicephorus Gregoras, both of whom belonged to the immediate entourage of the Emperor. From their descriptions of the symptoms it appears that Andronicus suffered from malaria for 20 years (1321-1341). The coma that preceded the Emperor's death was probably a cerebral manifestation of chronic malaria. Images Figure 1 PMID:9068444

The Medieval Climate Anomaly and Byzantium: A review of the evidence on climatic fluctuations, economic performance and societal change

NASA Astrophysics Data System (ADS)

Xoplaki, Elena; Fleitmann, Dominik; Luterbacher, Juerg; Wagner, Sebastian; Haldon, John F.; Zorita, Eduardo; Telelis, Ioannis; Toreti, Andrea; Izdebski, Adam

2016-03-01

At the beginning of the Medieval Climate Anomaly, in the ninth and tenth century, the medieval eastern Roman empire, more usually known as Byzantium, was recovering from its early medieval crisis and experiencing favourable climatic conditions for the agricultural and demographic growth. Although in the Balkans and Anatolia such favourable climate conditions were prevalent during the eleventh century, parts of the imperial territories were facing significant challenges as a result of external political/military pressure. The apogee of medieval Byzantine socio-economic development, around AD 1150, coincides with a period of adverse climatic conditions for its economy, so it becomes obvious that the winter dryness and high climate variability at this time did not hinder Byzantine society and economy from achieving that level of expansion. Soon after this peak, towards the end of the twelfth century, the populations of the Byzantine world were experiencing unusual climatic conditions with marked dryness and cooler phases. The weakened Byzantine socio-political system must have contributed to the events leading to the fall of Constantinople in AD 1204 and the sack of the city. The final collapse of the Byzantine political control over western Anatolia took place half century later, thus contemporaneous with the strong cooling effect after a tropical volcanic eruption in AD 1257. We suggest that, regardless of a range of other influential factors, climate change was also an important contributing factor to the socio-economic changes that took place in Byzantium during the Medieval Climate Anomaly. Crucially, therefore, while the relatively sophisticated and complex Byzantine society was certainly influenced by climatic conditions, and while it nevertheless displayed a significant degree of resilience, external pressures as well as tensions within the Byzantine society more broadly contributed to an increasing vulnerability in respect of climate impacts. Our interdisciplinary analysis is based on all available sources of information on the climate and society of Byzantium, that is textual (documentary), archaeological, environmental, climate and climate model-based evidence about the nature and extent of climate variability in the eastern Mediterranean. The key challenge was, therefore, to assess the relative influence to be ascribed to climate variability and change on the one hand, and on the other to the anthropogenic factors in the evolution of Byzantine state and society (such as invasions, changes in international or regional market demand and patterns of production and consumption, etc.). The focus of this interdisciplinary study was to address the possible causal relationships between climatic and socio-economic change and to assess the resilience of the Byzantine socio-economic system in the context of climate change impacts.

The Medieval Climate Anomaly and Byzantium: A review of the evidence on climatic fluctuations, economic performance and societal change

NASA Astrophysics Data System (ADS)

Xoplaki, Elena; Fleitmann, Dominik; Luterbacher, Juerg; Wagner, Sebastian; Haldon, John F.; Zorita, Eduardo; Telelis, Ioannis; Toreti, Andrea; Izdebski, Adam

2016-04-01

At the beginning of the Medieval Climate Anomaly, in the ninth and tenth century, the medieval eastern Roman empire, more usually known as Byzantium, was recovering from its early medieval crisis and experiencing favourable climatic conditions for the agricultural and demographic growth. Although in the Balkans and Anatolia such favourable climate conditions were prevalent during the eleventh century, parts of the imperial territories were facing significant challenges as a result of external political/military pressure. The apogee of medieval Byzantine socio-economic development, around AD 1150, coincides with a period of adverse climatic conditions for its economy, so it becomes obvious that the winter dryness and high climate variability at this time did not hinder Byzantine society and economy from achieving that level of expansion. Soon after this peak, towards the end of the twelfth century, the populations of the Byzantine world were experiencing unusual climatic conditions with marked dryness and cooler phases. The weakened Byzantine socio-political system must have contributed to the events leading to the fall of Constantinople in AD 1204 and the sack of the city. The final collapse of the Byzantine political control over western Anatolia took place half century later, thus contemporaneous with the strong cooling effect after a tropical volcanic eruption in AD 1257. We suggest that, regardless of a range of other influential factors, climate change was also an important contributing factor to the socio-economic changes that took place in Byzantium during the Medieval Climate Anomaly. Crucially, therefore, while the relatively sophisticated and complex Byzantine society was certainly influenced by climatic conditions, and while it nevertheless displayed a significant degree of resilience, external pressures as well as tensions within the Byzantine society more broadly contributed to an increasing vulnerability in respect of climate impacts. Our interdisciplinary analysis is based on all available sources of information on the climate and society of Byzantium, that is textual (documentary), archaeological, environmental, climate and climate model-based evidence about the nature and extent of climate variability in the eastern Mediterranean. The key challenge was, therefore, to assess the relative influence to be ascribed to climate variability and change on the one hand, and on the other to the anthropogenic factors in the evolution of Byzantine state and society (such as invasions, changes in international or regional market demand and patterns of production and consumption, etc.). The focus of this interdisciplinary study was to address the possible causal relationships between climatic and socio-economic change and to assess the resilience of the Byzantine socio-economic system in the context of climate change impacts.

Abnormal fault-recovery characteristics of the fault-tolerant multiprocessor uncovered using a new fault-injection methodology

NASA Technical Reports Server (NTRS)

Padilla, Peter A.

1991-01-01

An investigation was made in AIRLAB of the fault handling performance of the Fault Tolerant MultiProcessor (FTMP). Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once in every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles Byzantine or lying faults. Byzantine faults behave such that the faulted unit points to a working unit as the source of errors. The design's problems involve: (1) the design and interface between the simplex error detection hardware and the error processing software, (2) the functional capabilities of the FTMP system bus, and (3) the communication requirements of a multiprocessor architecture. These weak areas in the FTMP's design increase the probability that, for any hardware fault, a good line replacement unit (LRU) is mistakenly disabled by the fault management software.

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

PubMed

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.

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

PubMed Central

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

1999-01-01

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. PMID:10390682

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

NASA Technical Reports Server (NTRS)

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.

Adversaries in Networks

DTIC Science & Technology

2010-08-01

between east and west. In 330 AD, the emperor Constantine I moved the capital of the eastern part to Byzantium, and renamed the city Constantinople . In...Byzantium was renamed. Long after the empire collapsed after Constantinople fell to the Ottomans in 1453, the Byzantine Empire became known for being...It was shown in [19] that standard network coding problems fall into three categories: (1) coding is un- necessary, and routing is enough to achieve

77 FR 65245 - Culturally Significant Objects Imported for Exhibition Determinations: “Late Roman and Early...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-25

... DEPARTMENT OF STATE [Public Notice 8069] Culturally Significant Objects Imported for Exhibition Determinations: ``Late Roman and Early Byzantine Treasures From The British Museum'' SUMMARY: Notice is hereby... objects to be included in the exhibition ``Late Roman and Early Byzantine Treasures From The British...

75 FR 5637 - Culturally Significant Objects Imported for Exhibition Determinations: “Architecture as Icon...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

... Determinations: ``Architecture as Icon: Perception and Representation of Architecture in Byzantine Art'' SUMMARY... objects to be included in the exhibition ``Architecture as Icon: Perception and Representation of Architecture in Byzantine Art,'' imported from abroad for temporary exhibition within the United States, are of...

The Birth of Hospital, Asclepius cult and Early Christianity.

PubMed

Yeo, In-Sok

2017-04-01

History of hospital is one of main fields of researches in medical history. Besides writing a history of an individual hospital, considerable efforts have been made to trace the origin of hospital. Those who quest for the origin of hospital are faced with an inevitable problem of defining hospital. As the different definition can lead to a different outcome, it is important to make a clear definition. In this article, the hospital was defined as an institution in which patients are housed and given medical treatments. According to the definition, the Great Basilius is regarded to have created the first hospital in 369 CE. The creation of hospital is considered to be closely related with Christian philantrophy. However, the question is raised against this explanation. As the religious philantrophy does not exclusively belong to the Christianity alone, more comprehensive and persuasive theory should be proposed to explain why the first hospital was created in the Christian World, not in the Buddhistic or other religious world. Furthermore, in spite of sharing the same Christian background, why the first hospital appeared in Byzantine Empire, not in Western Roman Empire, also should be explained. My argument is that Asclepius cult and the favorable attitude toward medicine in Greek world are responsible to the appearance of the first hospital in Byzantine Empire. The evangelic work of Jesus was heavily depended on healing activities. The healing activities of Jesus and his disciples were rivalled by Asclepius cult which had been widely spread and practiced in the Hellenistic world. The temples of Asclepius served as a model for hospital, for the temples were the institution exclusively reserved for the patients. The exclusive housing of patients alone in the temples of Asclepius is clearly contrasted with the other early forms of hospitals in which not only patients but also the poor, foreigners and pilgrims were housed altogether. Toward the healing god Asclepius, the Latin Church fathers and Greek Church fathers showed significant difference of attitudes. The Latin fathers were generally very critical on Asclepius while the Greek fathers were more favorable to the same healing god. This difference is also considered to be an important factor that can explain why the first hospital appeared in the Byzantine Empire.

A Self-Stabilizing Byzantine-Fault-Tolerant Clock Synchronization Protocol

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar R.

2009-01-01

This report presents a rapid Byzantine-fault-tolerant self-stabilizing clock synchronization protocol that is independent of application-specific requirements. It is focused on clock synchronization of a system in the presence of Byzantine faults after the cause of any transient faults has dissipated. A model of this protocol is mechanically verified using the Symbolic Model Verifier (SMV) [SMV] where the entire state space is examined and proven to self-stabilize in the presence of one arbitrary faulty node. Instances of the protocol are proven to tolerate bursts of transient failures and deterministically converge with a linear convergence time with respect to the synchronization period. This protocol does not rely on assumptions about the initial state of the system other than the presence of sufficient number of good nodes. All timing measures of variables are based on the node s local clock, and no central clock or externally generated pulse is used. The Byzantine faulty behavior modeled here is a node with arbitrarily malicious behavior that is allowed to influence other nodes at every clock tick. The only constraint is that the interactions are restricted to defined interfaces.

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

NASA Astrophysics Data System (ADS)

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.

Is consent in medicine a concept only of modern times?

PubMed Central

Dalla-Vorgia, P; Lascaratos, J; Skiadas, P; Garanis-Papadatos, T

2001-01-01

Although the issue of consent in medical practice has grown immensely in recent years, and it is generally believed that historical cases are unknown, our research amongst original ancient Greek and Byzantine historical sources reveals that it is a very old subject which ancient philosophers and physicians have addressed. Plato, in ancient Greece, connected consent with the quality of a free person and even before him, Hippocrates had advocated seeking the patient's cooperation in order to combat the disease. In Alexander the Great's era and later on in Byzantine times, not only was the consent of the patient necessary but physicians were asking for even more safeguards before undertaking a difficult operation. Our study has shown that from ancient times physicians have at least on occasion been driven to seek the consent of their patient either because of respect for the patient's autonomy or from fear of the consequences of their failure. Key Words: Consent • history of medicine • medical ethics PMID:11233382

[Medical sciences in the Byzantine-Ottoman area, from the emergence of Anatolian emirats to the Fall of Constantinople (end 13th -half 15th)].

PubMed

Balivet, M

1999-01-01

This article is a short analysis of the first activities of Medecine and Hospitals in the Turcoman and Ottoman Anatolia (end of XIIIth-middle of XVth). We also ask the question of relationships between Turkish and Byzantine Medical Sciences until the Fall of Constantinople.

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

ERIC Educational Resources Information Center

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…

19 CFR 12.104g - Specific items or categories designated by agreements or emergency actions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... representing the Byzantine period ranging from approximately the 4th century A.D. through approximately the... Byzantine culture (approximately the 4th century through the 15th century A.D.) CBP Dec. 11-25 Guatemala... periods ranging approximately from the 9th century B.C. to the 4th century A.D. T.D. 01-06 extended by CBP...

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

NASA Astrophysics Data System (ADS)

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.

From the Byzantine Empire to Afghanistan: A Theme for Success

DTIC Science & Technology

2010-04-15

military districts within these new zones.24 The strategus , or general in charge of each zone, would exercise the highest military and civil power...provincial governance and organization, but continued it, though now within the theme’s governing framework. 29 The strategus was in "supreme command" and...the strategus , while various classes of officials served the strategus by overseeing the day-to-day governance. 31 To limit the propensity for

Mechanically verified hardware implementing an 8-bit parallel IO Byzantine agreement processor

NASA Technical Reports Server (NTRS)

Moore, J. Strother

1992-01-01

Consider a network of four processors that use the Oral Messages (Byzantine Generals) Algorithm of Pease, Shostak, and Lamport to achieve agreement in the presence of faults. Bevier and Young have published a functional description of a single processor that, when interconnected appropriately with three identical others, implements this network under the assumption that the four processors step in synchrony. By formalizing the original Pease, et al work, Bevier and Young mechanically proved that such a network achieves fault tolerance. We develop, formalize, and discuss a hardware design that has been mechanically proven to implement their processor. In particular, we formally define mapping functions from the abstract state space of the Bevier-Young processor to a concrete state space of a hardware module and state a theorem that expresses the claim that the hardware correctly implements the processor. We briefly discuss the Brock-Hunt Formal Hardware Description Language which permits designs both to be proved correct with the Boyer-Moore theorem prover and to be expressed in a commercially supported hardware description language for additional electrical analysis and layout. We briefly describe our implementation.

The Vertical Sundial of the Monastery of Panaghia Scripou

NASA Astrophysics Data System (ADS)

Theodossiou, E.; Manimanis, V. N.

2006-08-01

As part of our ongoing project to correctly identify and describe all the Byzantine sundials in Greece, the vertical marble sundial in the main church of the ``Koimesis tis Theotokou'' (Dormition of the Virgin) or ``Panaghia Scripou'' monastery, in Orchomenos, Boeotia, central Greece, is presented. It is almost certainly the oldest (and arguably the most beautiful) Byzantine sundial in the whole Greece, being contemporary to the church (874 A.D.).

Epidemic waves of the Black Death in the Byzantine Empire (1347-1453 AD).

PubMed

Tsiamis, Costas; Poulakou-Rebelakou, Effie; Tsakris, Athanassios; Petridou, Eleni

2011-09-01

The lack of valid demographic data and the literary ambiguities of the Byzantine chroniclers raise questions about the actual size and mortality rate of the Black Death in the Byzantine Empire. This study presents for the first time a quantitative overview of the Black Death in Byzantium for the period 1347-1453. Our data were obtained from descriptions of the plague, by prominent Byzantine historians and scholars, grouped by time of appearance and geographical spread. During the period 1347-1453, a total of 61 plague reports were noted, which can be distinguished in nine major epidemic waves, 11 local outbreaks and 16 disease-free periods. The capital Constantinople and the Venetian colonies of the Ionian and Aegean Sea were the areas most affected by the plague. The epidemic waves of the Black Death in Byzantium had a total average duration of 3.2 years. Scientific ignorance of the nature of the disease, a turbulent period of warfare and an organized maritime network seem to have contributed to the spread of the disease. Employing quantitative analysis, our multidisciplinary study sheds light from various standpoints on the evolution and dynamic of the plague in the South-eastern Mediterranean during the 14th and 15th centuries, despite the lack of sound morbidity and mortality data.

Investigation of the foundations of a Byzantine church by three-dimensional seismic tomography

NASA Astrophysics Data System (ADS)

Polymenakos, L.; Papamarinopoulos, S.; Miltiadou, A.; Charkiolakis, N.

2005-02-01

Byzantine public buildings are of high historical and cultural value. Churches, in particular, are of high architectural and artistic value because they are built using various materials and construction techniques and may contain significant frescoes and mosaics. The knowledge of the state of foundations and ground material conditions is important for their proper restoration and preservation. Seismic tomography is employed to investigate the foundation structure and ground material of a Byzantine church. Energy sources are placed across the floor of the church and surrounding courts, while recorders are placed in a subterranean crypt. Travel time data are analyzed and processed with a three-dimensional (3D) tomographic inversion software in order to construct seismic velocity images at the foundation and below foundation level. Velocity variations are known to correlate well with the lithological character of the earth materials, thus providing important structural and lithological information. A case study from a Byzantine church of 11th c. A.D. in the suburbs of Athens, Greece, is presented. The objective of this research is the nondestructive investigation of unknown underground structures or void spaces, mainly under the floor of the building. The results are interpreted in terms of the foundation elements as well as of significant variations in the earth material character.

[Byzantine therapeutics in the Ottoman world].

PubMed

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.

Geoarchaeological evidence for dredging in Tyre's ancient harbour, Levant

NASA Astrophysics Data System (ADS)

Marriner, Nick; Morhange, Christophe

2006-01-01

Chrono-stratigraphic data from Tyre's ancient northern harbour delineate extensive dredging practices during the Greco-Roman and Byzantine periods. Radiocarbon dates from four cores consistently cluster between ca. 500 B.C. and 1000 A.D. and indicate rapid rates of sedimentation in the basin, namely ∼10 mm/yr during the Greco-Roman and Byzantine periods, compared to 0.5-1 mm/yr for the period 6000-4000 B.C. Absence of strata between 4000 B.C. and 500 B.C. is not consistent with a natural base-level sediment sink and cannot be interpreted as a depositional hiatus in the high-stand systems tract. Ancient dredging is further corroborated by persistent age-depth inversions within the fine-grained harbour facies. These data support removal of Middle Bronze Age to Persian period sediment strata, with deliberate overdeepening of the harbour bottom by Greco-Roman and Byzantine societies.

[The image of Byzantine medicine in the satire "Timarion"].

PubMed

Leven, K H

1990-01-01

Byzantine medicine is usually regarded as a static and non-creative descendant of classical Greek medicine, a point of view confirmed by the Byzantine medical texts. In this essay, the anonymous satire "Timarion" is analyzed in respect to its image of contemporary medical theory. Timarion, the fictive narrator, falls ill with a fever and is brought to Hades by two conductors of souls. They assert that he cannot survive, because he has secreted all his elementary bile. According to a decree by Asclepios and Hippocrates posted in Hades, any person that has lost one of his four elements may not live longer. In Hades Timarion sues to the court of judges of the dead. His lawyer, the sophist Theodore of Smyrna, persuades the judges that the bile excreted by Timarion has not been elementary in the sense of humoral pathology. So Timarion is allowed to return to life. The author of the satire ridicules the fundamental axiom of the four humours. Asclepios, Hippocrates and Erasistratos, who are attached to the infernal court as experts, cannot defend their theory against the convincing arguments of a sophist. The "divine" Galen, who probably would have been able to, is absent in order to complete a book of his. The "Timarion" with its harsh critique of medical theory is very amusing and a rare example of "actuality" in Byzantine literature.

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

PubMed

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 the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

PubMed Central

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

The association between mental disorder and crime during the Byzantine Empire.

PubMed

Tzeferakos, George; Vlahou, Elina; Troianos, Spyros; Douzenis, Athanasios

2011-12-01

From a social, administrative and political point of view, the Byzantine Empire was a direct continuation of the Greco-Roman world, with the Greek-Orthodox Church playing an important role in the formation of the Byzantium's unique identity. This continuity is obvious when one studies the legislation of the Empire. This legislation had specific provisions for insane offenders with regard to their legal and social handling. In this article we review these laws and present some interesting legal, psychiatric and social issues.

Better with Byzantine: Manipulation-Optimal Mechanisms

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

Cosmological Symbolism in the Decorative Cycles of Mid-Byzantine Churches

NASA Astrophysics Data System (ADS)

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.

Late Byzantine Mineral Soda High Alumina Glasses from Asia Minor: A New Primary Glass Production Group

PubMed Central

Schibille, Nadine

2011-01-01

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. PMID:21526144

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

PubMed

Schibille, Nadine

2011-04-19

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.

Self-stabilizing byzantine-fault-tolerant clock synchronization system and method

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar R. (Inventor)

2012-01-01

Systems and methods for rapid Byzantine-fault-tolerant self-stabilizing clock synchronization are provided. The systems and methods are based on a protocol comprising a state machine and a set of monitors that execute once every local oscillator tick. The protocol is independent of specific application specific requirements. The faults are assumed to be arbitrary and/or malicious. All timing measures of variables are based on the node's local clock and thus no central clock or externally generated pulse is used. Instances of the protocol are shown to tolerate bursts of transient failures and deterministically converge with a linear convergence time with respect to the synchronization period as predicted.

Pigeons at the edge of the empire: Bioarchaeological evidences for extensive management of pigeons in a Byzantine desert settlement in the southern Levant

PubMed Central

Rosen, Baruch; Tepper, Yotam; Bar-Oz, Guy

2018-01-01

Metric data of 6th century CE pigeons from the Negev Desert, Israel, are employed to test competing hypotheses on flock management strategies: that directed selection for size or shape took place under intensive management; or, alternatively, that stabilizing selection was a stronger determinant of size and shape under extensive management conditions. The results of the analysis support the second hypothesis by demonstrating that the Byzantine Negev pigeons were like wild pigeon (Columba livia) in shape, albeit small-sized. The inferred extensive management system is then discussed in the context of pigeon domestication and human micro-ecologies in marginal regions. PMID:29561880

Astronomy at the dawn of the Renaissance. Proceedings. Symposium, Liège (Belgium), 23 - 24 Jul 1997, as part of the 20th International Congress of History of Science.

NASA Astrophysics Data System (ADS)

Mercier, R.

1998-05-01

Recent investigations of the astronomical work of the Byzantine Platonist George Gemistus Plethon provided the motivation, for Plethon's work encapsulated to many of the cross-currents flowing in astronomy in the early fifteenth century. At a time when the Byzantine world was in a state of collapse, and perhaps for that reason was more susceptible to foreign influence, Plethon drew not only on Ptolemy, but on the Greek Persian Syntaxis, and on al-Bāttani mediated through Hebrew. Both Plethon and his star pupil Cardinal Bessarion were great benefactors of scholarship, science, and philosophy in Renaissance Italy.

A glimpse of an ancient agricultural ecosystem based on remains of micromammals in the Byzantine Negev Desert

PubMed Central

Weissbrod, Lior; Tepper, Yotam; Bar-Oz, Guy

2018-01-01

It is widely believed that Byzantine agriculture in the Negev Desert (fourth to seventh century Common Era; CE), with widespread construction of terraces and dams, altered local landscapes. However, no direct evidence in archaeological sites yet exists to test this assumption. We uncovered large amounts of small mammalian remains (rodents and insectivores) within agricultural installations built near fields, providing a new line of evidence for reconstructing anthropogenic impact on local habitats. Abandonment layers furnished high abundances of remains, whereas much smaller numbers were retrieved from the period of human use of the structures. Digestion marks are present in low frequencies (20% of long bones and teeth), with a light degree of impact, which indicate the role of owls (e.g. Tyto alba) as the principal means of accumulation. The most common taxa—gerbils (Gerbillus spp.) and jirds (Meriones spp.)—occur in nearly equal frequencies, which do not correspond with any modern Negev communities, where gerbils predominate in sandy low-precipitation environments and jirds in loessial, higher-precipitation ones. Although low-level climate change cannot be ruled out, the results suggest that Byzantine agriculture allowed jirds to colonize sandy anthropogenic habitats with other gerbilids and commensal mice and rats. PMID:29410856

Mitochondrial analysis of a Byzantine population reveals the differential impact of multiple historical events in South Anatolia

PubMed Central

Ottoni, Claudio; Ricaut, François-X; Vanderheyden, Nancy; Brucato, Nicolas; Waelkens, Marc; Decorte, Ronny

2011-01-01

The archaeological site of Sagalassos is located in Southwest Turkey, in the western part of the Taurus mountain range. Human occupation of its territory is attested from the late 12th millennium BP up to the 13th century AD. By analysing the mtDNA variation in 85 skeletons from Sagalassos dated to the 11th–13th century AD, this study attempts to reconstruct the genetic signature potentially left in this region of Anatolia by the many civilizations, which succeeded one another over the centuries until the mid-Byzantine period (13th century BC). Authentic ancient DNA data were determined from the control region and some SNPs in the coding region of the mtDNA in 53 individuals. Comparative analyses with up to 157 modern populations allowed us to reconstruct the origin of the mid-Byzantine people still dwelling in dispersed hamlets in Sagalassos, and to detect the maternal contribution of their potential ancestors. By integrating the genetic data with historical and archaeological information, we were able to attest in Sagalassos a significant maternal genetic signature of Balkan/Greek populations, as well as ancient Persians and populations from the Italian peninsula. Some contribution from the Levant has been also detected, whereas no contribution from Central Asian population could be ascertained. PMID:21224890

Comprehensive Chemical Characterisation of Byzantine Glass Weights

PubMed Central

Schibille, Nadine; Meek, Andrew; Tobias, Bendeguz; Entwistle, Chris; Avisseau-Broustet, Mathilde; Da Mota, Henrique; Gratuze, Bernard

2016-01-01

The understanding of the glass trade in the first millennium CE relies on the characterisation of well-dated compositional groups and the identification of their primary production sites. 275 Byzantine glass weights from the British Museum and the Bibliothèque nationale de France dating to the sixth and seventh century were analysed by LA-ICP-MS. Multivariate statistical and graphical data analysis discriminated between six main primary glass types. Primary glass sources were differentiated based on multi-dimensional comparison of silica-derived elements (MgO, Al2O3, CaO, TiO2, Fe2O3, ZrO2) and components associated with the alkali source (Li2O, B2O3). Along with Egyptian and Levantine origins of the glassmaking sands, variations in the natron source possibly point to the exploitation of two different natron deposits. Differences in strontium to calcium ratios revealed variations in the carbonate fractions in the sand. At least two cobalt sources were employed as colouring agents, one of which shows strong correlations with nickel, indicating a specific post-Roman cobalt source. Typological evidence identified chronological developments in the use of the different glass groups. Throughout the sixth century, Byzantine glass weights were predominately produced from two glasses that are probably of an Egyptian origin (Foy-2 and Foy-2 high Fe). Towards the second half of the sixth century a new but related plant-ash glass type emerged (Magby). Levantine I was likewise found among the late sixth- to early seventh-century samples. The use of different dies for the same batch testifies to large-scale, centralised production of the weights, while the same die used for different primary production groups demonstrates the co-existence of alternative sources of supply. Given the comprehensive design of our study, these results can be extrapolated to the wider early Byzantine glass industry and its changes at large. PMID:27959963

Comprehensive Chemical Characterisation of Byzantine Glass Weights.

PubMed

Schibille, Nadine; Meek, Andrew; Tobias, Bendeguz; Entwistle, Chris; Avisseau-Broustet, Mathilde; Da Mota, Henrique; Gratuze, Bernard

2016-01-01

The understanding of the glass trade in the first millennium CE relies on the characterisation of well-dated compositional groups and the identification of their primary production sites. 275 Byzantine glass weights from the British Museum and the Bibliothèque nationale de France dating to the sixth and seventh century were analysed by LA-ICP-MS. Multivariate statistical and graphical data analysis discriminated between six main primary glass types. Primary glass sources were differentiated based on multi-dimensional comparison of silica-derived elements (MgO, Al2O3, CaO, TiO2, Fe2O3, ZrO2) and components associated with the alkali source (Li2O, B2O3). Along with Egyptian and Levantine origins of the glassmaking sands, variations in the natron source possibly point to the exploitation of two different natron deposits. Differences in strontium to calcium ratios revealed variations in the carbonate fractions in the sand. At least two cobalt sources were employed as colouring agents, one of which shows strong correlations with nickel, indicating a specific post-Roman cobalt source. Typological evidence identified chronological developments in the use of the different glass groups. Throughout the sixth century, Byzantine glass weights were predominately produced from two glasses that are probably of an Egyptian origin (Foy-2 and Foy-2 high Fe). Towards the second half of the sixth century a new but related plant-ash glass type emerged (Magby). Levantine I was likewise found among the late sixth- to early seventh-century samples. The use of different dies for the same batch testifies to large-scale, centralised production of the weights, while the same die used for different primary production groups demonstrates the co-existence of alternative sources of supply. Given the comprehensive design of our study, these results can be extrapolated to the wider early Byzantine glass industry and its changes at large.

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

PubMed

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.

Towards scalable Byzantine fault-tolerant replication

NASA Astrophysics Data System (ADS)

Zbierski, Maciej

2017-08-01

Byzantine fault-tolerant (BFT) replication is a powerful technique, enabling distributed systems to remain available and correct even in the presence of arbitrary faults. Unfortunately, existing BFT replication protocols are mostly load-unscalable, i.e. they fail to respond with adequate performance increase whenever new computational resources are introduced into the system. This article proposes a universal architecture facilitating the creation of load-scalable distributed services based on BFT replication. The suggested approach exploits parallel request processing to fully utilize the available resources, and uses a load balancer module to dynamically adapt to the properties of the observed client workload. The article additionally provides a discussion on selected deployment scenarios, and explains how the proposed architecture could be used to increase the dependability of contemporary large-scale distributed systems.

A molecular portrait of maternal sepsis from Byzantine Troy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devault, Alison M.; Mortimer, Tatum D.; Kitchen, Andrew

Pregnancy complications are poorly represented in the archeological record, despite their importance in contemporary and ancient societies. While we excavated a Byzantine cemetery in Troy, we discovered calcified abscesses among a woman’s remains. Scanning electron microscopy of the tissue revealed ‘ghost cells’, resulting from dystrophic calcification, which preserved ancient maternal, fetal and bacterial DNA of a severe infection, likely chorioamnionitis.Gardnerella vaginalisandStaphylococcus saprophyticusdominated the abscesses. Phylogenomic analyses of ancient, historical, and contemporary data showed thatG. vaginalisTroy fell within contemporary genetic diversity, whereasS. saprophyticusTroy belongs to a lineage that does not appear to be commonly associated with human disease today. We speculatemore » that the ecology ofS. saprophyticusinfection may have differed in the ancient world as a result of close contacts between humans and domesticated animals. Our results highlight the complex and dynamic interactions with our microbial milieu that underlie severe maternal infections.« less

A molecular portrait of maternal sepsis from Byzantine Troy

DOE PAGES

Devault, Alison M.; Mortimer, Tatum D.; Kitchen, Andrew; ...

2017-01-10

Pregnancy complications are poorly represented in the archeological record, despite their importance in contemporary and ancient societies. While we excavated a Byzantine cemetery in Troy, we discovered calcified abscesses among a woman’s remains. Scanning electron microscopy of the tissue revealed ‘ghost cells’, resulting from dystrophic calcification, which preserved ancient maternal, fetal and bacterial DNA of a severe infection, likely chorioamnionitis.Gardnerella vaginalisandStaphylococcus saprophyticusdominated the abscesses. Phylogenomic analyses of ancient, historical, and contemporary data showed thatG. vaginalisTroy fell within contemporary genetic diversity, whereasS. saprophyticusTroy belongs to a lineage that does not appear to be commonly associated with human disease today. We speculatemore » that the ecology ofS. saprophyticusinfection may have differed in the ancient world as a result of close contacts between humans and domesticated animals. Our results highlight the complex and dynamic interactions with our microbial milieu that underlie severe maternal infections.« less

BFT replication resistant to MAC attacks

NASA Astrophysics Data System (ADS)

Zbierski, Maciej

2016-09-01

Over the last decade numerous Byzantine fault-tolerant (BFT) replication protocols have been proposed in the literature. However, the vast majority of these solutions reuse the same authentication scheme, which makes them susceptible to a so called MAC attack. Such vulnerability enables malicious clients to undetectably prevent the replicated service from processing incoming client requests, and consequently making it permanently unavailable. While some BFT protocols attempted to address this issue by using different authentication mechanisms, they at the same time significantly degraded the performance achieved in correct environments. This article presents a novel adaptive authentication mechanism which can be combined with practically any Byzantine fault-tolerant replication protocol. Unlike previous solutions, the proposed scheme dynamically switches between two operation modes to combine high performance in correct environments and liveness during MAC attacks. The experiment results presented in the article demonstrate that the proposed mechanism can sufficiently tolerate MAC attacks without introducing any observable overhead whenever no faults are present.

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

PubMed

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.

Formal verification of an oral messages algorithm for interactive consistency

NASA Technical Reports Server (NTRS)

Rushby, John

1992-01-01

The formal specification and verification of an algorithm for Interactive Consistency based on the Oral Messages algorithm for Byzantine Agreement is described. We compare our treatment with that of Bevier and Young, who presented a formal specification and verification for a very similar algorithm. Unlike Bevier and Young, who observed that 'the invariant maintained in the recursive subcases of the algorithm is significantly more complicated than is suggested by the published proof' and who found its formal verification 'a fairly difficult exercise in mechanical theorem proving,' our treatment is very close to the previously published analysis of the algorithm, and our formal specification and verification are straightforward. This example illustrates how delicate choices in the formulation of the problem can have significant impact on the readability of its formal specification and on the tractability of its formal verification.

Preserving a Heritage the Ukranian Way

ERIC Educational Resources Information Center

Skodyn, Celine

1975-01-01

An ethnic studies program, developed at St. Josaphat's Ukrainian Catholic School in Parma, Ohio, was developed in order to instill in students an appreciation of the Byzantine Ukrainian Catholic rite, the Ukrainian language, and the uniqueness of their cultural heritage. (Author/RK)

Isotopic Geochemistry Applied on Mortars of the Katholikon of the Monastery of Timios Prodromos in the Prefecture of Serres, Greece

NASA Astrophysics Data System (ADS)

Dotsika, Elissavet; Iliadis, Efstathios; Kyropoulou, Daphne; Karalis, Petros

2017-12-01

The Monastery of Timios Prodromos is the most important Byzantine monument in the prefecture of Serres and one of the most important monastic foundations of Byzantine times in Northern Greece. It was founded in the late 13th century from Ioannikios and then renovated by his nephew, Joachim. The catholic dates back to the 14th century, and specifically between 1300-1333, under the rule of the second founder Joachim. Considering the pathology of Byzantine mural, for the most effective work on removal of over-paintings layer, fixing, restoration, recovery and maintenance of the painted surface and the substrate, it was decided the sampling from exact points of the mural painting representing the different phases, in order to determine their composition, the technology of construction materials, corrosion mechanisms and the proposal for restoration methodology. The methods to be used require very small quantities of material. The measurements are considered almost non-destructive and based on isotopic geochemistry. The techniques used are X-ray diffraction (XRD), scanning electron microscopy (SEM / EDXA) and isotopic analyzes (d18O and d13C) in a mass spectrometer (IRMS). The study of the samples was carried out by scanning electron microscopy with X-ray microanalyser and analysis of stable isotopes. The study shows that apart from the calcite present in all pigment samples, straw was used as a binder. There is also a mixing of dyes to produce the desired tint while in many cases there are different colour layers. The decay in the mural is extensive, especially in the lower layers of the wall, which have been severely affected by humidity and candle smoke. The creation of gypsum on the surface of the murals is intense and evident in most of the spectra taken

A molecular portrait of maternal sepsis from Byzantine Troy

PubMed Central

Devault, Alison M; Mortimer, Tatum D; Kitchen, Andrew; Kiesewetter, Henrike; Enk, Jacob M; Golding, G Brian; Southon, John; Kuch, Melanie; Duggan, Ana T; Aylward, William; Gardner, Shea N; Allen, Jonathan E; King, Andrew M; Wright, Gerard; Kuroda, Makoto; Kato, Kengo; Briggs, Derek EG; Fornaciari, Gino; Holmes, Edward C; Poinar, Hendrik N; Pepperell, Caitlin S

2017-01-01

Pregnancy complications are poorly represented in the archeological record, despite their importance in contemporary and ancient societies. While excavating a Byzantine cemetery in Troy, we discovered calcified abscesses among a woman’s remains. Scanning electron microscopy of the tissue revealed ‘ghost cells’, resulting from dystrophic calcification, which preserved ancient maternal, fetal and bacterial DNA of a severe infection, likely chorioamnionitis. Gardnerella vaginalis and Staphylococcus saprophyticus dominated the abscesses. Phylogenomic analyses of ancient, historical, and contemporary data showed that G. vaginalis Troy fell within contemporary genetic diversity, whereas S. saprophyticus Troy belongs to a lineage that does not appear to be commonly associated with human disease today. We speculate that the ecology of S. saprophyticus infection may have differed in the ancient world as a result of close contacts between humans and domesticated animals. These results highlight the complex and dynamic interactions with our microbial milieu that underlie severe maternal infections. DOI: http://dx.doi.org/10.7554/eLife.20983.001 PMID:28072390

Surface-enhanced Raman scattering in art and archaeology

NASA Astrophysics Data System (ADS)

Leona, Marco

2005-11-01

The identification of natural dyes found in archaeological objects and in works of art as textile dyes and lake pigments is a demanding analytical task. To address the problems raised by the very low dye content of dyed fibers and lake pigments, and by the requirement to remove only microscopic samples, surface enhanced Raman scattering techniques were investigated for application to museum objects. SERS gives excellent results with the majority of natural dyes, including: alizarin, purpurin, laccaic acid, carminic acid, kermesic acid, shikonin, juglone, lawsone, brazilin and brazilein, haematoxylin and haematein, fisetin, quercitrin, quercetin, rutin, and morin. In this study, limits of detection were determined for representative dyes and different SERS supports such as citrate reduced Ag colloid and silver nanoisland films. SERS was successfully used to identify natural madder in a microscopic fragment from a severely degraded 11th Century Byzantine textile recently excavated in Amorium, Turkey.

Fault recovery characteristics of the fault tolerant multi-processor

NASA Technical Reports Server (NTRS)

Padilla, Peter A.

1990-01-01

The fault handling performance of the fault tolerant multiprocessor (FTMP) was investigated. Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles byzantine or lying faults. It is pointed out that these weak areas in the FTMP's design increase the probability that, for any hardware fault, a good LRU (line replaceable unit) is mistakenly disabled by the fault management software. It is concluded that fault injection can help detect and analyze the behavior of a system in the ultra-reliable regime. Although fault injection testing cannot be exhaustive, it has been demonstrated that it provides a unique capability to unmask problems and to characterize the behavior of a fault-tolerant system.

A Short History of the Chemistry of Painting.

ERIC Educational Resources Information Center

Friedstein, Harriet G.

1981-01-01

Includes information on: (1) relationship of art and science; (2) paintings' early history; (3) Egyptian, Greek, Chinese, Byzantine, and Medieval painting; (4) chemical analysis of pigments; (5) chemistry of early pigments; and (6) paint media. Tabular data are provided on chemical names for artists' pigments with their earliest known dates. (CS)

Istanbul (Not Constantinople)

ERIC Educational Resources Information Center

Kail, Candice A.

2010-01-01

Turkey is one of the ancient areas of the Western world. It has been a crossroads of culture throughout its rich history. Its art and architecture have been influenced by powers such as the Byzantine Empire, the Roman Empire, and the Ottoman Empire. The history of Turkey's libraries goes back to the second century B.C. according to the…

Using Participatory Design to Improve Web Sites

ERIC Educational Resources Information Center

Nikolova-Houston, Tatiana

2005-01-01

In this article, the author, a doctoral candidate from the School of Information at the University of Texas-Austin, describes the experience gathered from her attempt to redesign her existing Web sites in order to supply online resources for Slavic and Byzantine studies. The use of participatory design, which involves the users in creating the…

Visible induced luminescence reveals invisible rays shining from Christ in the early Christian wall painting of the Transfiguration in Shivta

PubMed Central

Tepper, Yotam; Bar-Oz, Guy

2017-01-01

The Transfiguration scene depicted in a Byzantine church at Shivta, Israel, is one of two figurative examples of the scene from the early Christian period. The use of Egyptian blue pigment in the wall painting was investigated with various analytical methods. Visible Induced Luminescence (VIL) imaging was used in-situ in order to map the distribution of the Egyptian blue pigment in the painting. The VIL imaging revealed surprising insights into the understanding of the iconography and the technology of this rare painting. Previously undetected elements of the painting include rays of light that were discovered emerging from the body of Christ and illuminating the other figures in the painting. Although this motif is an important part of the Transfiguration narrative and appears in most of its scenes depicted elsewhere, it had not been previously identified in this painting as it was undetectable by any other inspection technique. Another important result is the identification of Egyptian blue as a common blue pigment used at Shivta during the Byzantine period, when it is considered to be very rare. PMID:28949982

The Royal Book by Haly Abbas from the 10th century: one of the earliest illustrations of the surgical approach to skull fractures.

PubMed

Aciduman, Ahmet; Arda, Berna; Kahya, Esin; Belen, Deniz

2010-12-01

Haly Abbas was one of the pioneering physicians and surgeons of the Eastern world in the 10th century who influenced the Western world by his monumental work, The Royal Book. The book was first partly translated into Latin by Constantinus Africanus in the 11th century without citing the author's name. Haly Abbas was recognized in Europe after full translation of The Royal Book by Stephen of Antioch in 1127. The Royal Book has been accepted as an early source of jerrah-names (surgical books) in the Eastern world. The chapters regarding cranial fractures in Haly Abbas' work include unique management strategies for his period with essential quotations from Paul of Aegina's work Epitome. Both authors preferred free bone flap craniotomy in cranial fractures. Although Paul of Aegina, a Byzantine physician and surgeon, was a connection between ancient traditions and Islamic interpretation, Haly Abbas seemed to play a bridging role between the Roman-Byzantine and the School of Salerno in Europe.

Visible induced luminescence reveals invisible rays shining from Christ in the early Christian wall painting of the Transfiguration in Shivta.

PubMed

Linn, Ravit; Tepper, Yotam; Bar-Oz, Guy

2017-01-01

The Transfiguration scene depicted in a Byzantine church at Shivta, Israel, is one of two figurative examples of the scene from the early Christian period. The use of Egyptian blue pigment in the wall painting was investigated with various analytical methods. Visible Induced Luminescence (VIL) imaging was used in-situ in order to map the distribution of the Egyptian blue pigment in the painting. The VIL imaging revealed surprising insights into the understanding of the iconography and the technology of this rare painting. Previously undetected elements of the painting include rays of light that were discovered emerging from the body of Christ and illuminating the other figures in the painting. Although this motif is an important part of the Transfiguration narrative and appears in most of its scenes depicted elsewhere, it had not been previously identified in this painting as it was undetectable by any other inspection technique. Another important result is the identification of Egyptian blue as a common blue pigment used at Shivta during the Byzantine period, when it is considered to be very rare.

[Jean-Charles Sournia, resident of Lyon Hospitals and Surgeons in Alep].

PubMed

Fischer, L P; Rougier, Jacques; Schott, Bernard; Babik, Hany; Fischer, Bénédicte

2002-01-01

The article deals with the life and activity of J. Ch. Sournia from 1938 to 1966. Born in Bourges (France) in 1917, he studied at "l'Ecole du Service de Santé Militaire" in Lyon. In 1938 he became a non-resident student of Lyon Hospitals and a resident in 1943. Assistant of thoracic surgery by Professors Paul Santy and Marcel Bérard he underwent an advanced training course by Pr Crawford in Sweden. There he met his Swedish wife-to-be. Appointed professor of Surgery he taught Surgery in Alep and Anatomy in Beyrouth. In the same time he was interested in the History of Syria and its archeology during the Byzantine Centuries (from the IVth to the VIIth A. D.). While his wife was teaching literature at Rennes University he was appointed surgery professor at the Medical College in Rennes and wrote "the Middle-East of Primitive Christianity-History and Archaeology by Byzantine Syria" (Fayard 1966) in which he focused his study on monks who lived for long years on pillar top to be closer to God, like St Simeon.

Climate change and archaeological site distribution during the past four millennia in northern Jordan utilizing oxygen isotope analysis of human tooth enamel and geographic information system

NASA Astrophysics Data System (ADS)

Alakkam, Abdulla Ahmed

The enamels of one hundred and ninety two teeth were analyzed for their oxygen isotopic composition from five archaeological sites in northern Jordan (Ya'amoun, Pella, Yasieleh, Sa'ad and Waqqas) to reconstruct the climate from the Middle Bronze Age II (1800--1500 BCE) to the Late Byzantine Period (491--640 CE). Results showed that the Middle Bronze Age II delta 18O values were the highest indicating warmer and drier climate conditions. The Late Bronze Age II and the Iron Age I/II experienced more favorable climate conditions. The Early Byzantine period delta18O values indicate wetter conditions compared to the Late Byzantine period but the latter was wetter than the Middle Bronze Age II. The geographic distribution of the archaeological sites in Jordan was affected by climate that changed over the prehistory of the country (from the Paleolithic to the Ottoman Period). Archaeological sites decreased in number during dry periods like the Middle Bronze Age II but increased during wet periods like the Roman one. Proximity to water sources was favored during the various cultural periods, where the northwestern and the mid-western areas witnessed dense occupation. On the other hand, areas that presently receive less than 200mm annual rainfall were not favored even during the wet periods. There were major climate events that overran the whole Mediterranean region during the Holocene, where Jordan was subject to them as well. These climatic events (prolonged droughts and/or insufficient precipitation) were identified using Bryson's archaeoclimate model that simulates the amount of precipitation, evapotranspiration and temperature during the last 12,000 years. These climate events coincided with the collapse of many societies in the Levant, such as the Middle Bronze Age societies of Mesopotamian cities.

A Conceptual Design for a Reliable Optical Bus (ROBUS)

NASA Technical Reports Server (NTRS)

Miner, Paul S.; Malekpour, Mahyar; Torres, Wilfredo

2002-01-01

The Scalable Processor-Independent Design for Electromagnetic Resilience (SPIDER) is a new family of fault-tolerant architectures under development at NASA Langley Research Center (LaRC). The SPIDER is a general-purpose computational platform suitable for use in ultra-reliable embedded control applications. The design scales from a small configuration supporting a single aircraft function to a large distributed configuration capable of supporting several functions simultaneously. SPIDER consists of a collection of simplex processing elements communicating via a Reliable Optical Bus (ROBUS). The ROBUS is an ultra-reliable, time-division multiple access broadcast bus with strictly enforced write access (no babbling idiots) providing basic fault-tolerant services using formally verified fault-tolerance protocols including Interactive Consistency (Byzantine Agreement), Internal Clock Synchronization, and Distributed Diagnosis. The conceptual design of the ROBUS is presented in this paper including requirements, topology, protocols, and the block-level design. Verification activities, including the use of formal methods, are also discussed.

[Anonymous Londinensis and the Greek documentary papyrus of medicine at the CEDOPAL].

PubMed

Ricciardetto, Antonio

2015-01-01

The present paper proposes an account of my research on human and veterinary medicine in Graeco-Roman and Byzantine Egypt, undertaken since 2008 at the CEDOPAL at the University of Liège. This research focuses on literary papyri, particularly on the Anonymus Londiniensis (Hermopolis?, 2d half of the 1st).

Hunt the Shadow Not the Substance: The Rise of the Career Academic in Construction Education

ERIC Educational Resources Information Center

Tennant, Stuart; Murray, Mike; Forster, Alan; Pilcher, Nick

2015-01-01

Construction education is context-laden, navigating and reflecting the byzantine influences of period, place and person. Despite considerable rhetoric, in UK higher education and construction studies in particular the importance of contextualized teaching is being devalued. Over the past decade a growing number of new teaching staff to university…

Network-Aware Mechanisms for Tolerating Byzantine Failures in Distributed Systems

DTIC Science & Technology

2012-01-01

In Digest, we use SHA-256 as the collision-resistant hash function. We use the realization of SHA-256 from the OpenSSL toolkit [48]. The results...vol. 46, pp. 372–378, 1997. [48] “ Openssl project.” [Online]. Available: http://www.openssl.org/ 154 [49] M. J. Fischer, N. A. Lynch, and M. Merritt

A Recovery-Oriented Approach to Dependable Services: Repairing Past Errors with System-Wide Undo

DTIC Science & Technology

2003-12-01

54 4.5.3 Handling propagating paradoxes: the squash interface . . . . . . . . . . . . . . . . . . . 54 4.6 Discussion...84 6.3.3 Compensating for paradoxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 6.3.4 Squashing propagating...the service and comparing the behavior of the replicas to detect and squash misbehaving replicas. While on paper Byzantine fault tolerance may seem to

Efficient Byzantine Fault Tolerance for Scalable Storage and Services

DTIC Science & Technology

2009-07-01

most critical applications must survive in ever harsher environments. Less synchronous networking delivers packets unreliably and unpredictably, and... synchronous environments to allowing asynchrony, and from tolerating crashes to tolerating some corruptions through ad-hoc consistency checks. Ad-hoc...servers are responsive. To support this thesis statement, this disseration takes the following steps. First, it develops a new cryptographic primitive

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

PubMed

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.

Viking voyages: the origin of multiple sclerosis? An essay in medical history.

PubMed

Poser, C M

1995-01-01

Multiple sclerosis is most frequently found in Scandinavia, Iceland, the British Isles and the countries settled by their inhabitants and their descendants, i.e. the United States, Canada, Australia and New Zealand. This suggests that the Vikings may have been instrumental in disseminating genetic susceptibility to the disease in those areas, as well as in other parts of the world. The Vikings raided most European countries and settled in Normandy and in Sicily and southern Italy. They engaged in trade with the Arabs along the river routes to the Caucasus, to the Black and Caspian Seas, and penetrated Persia, India and probably China. They also migrated to the East and established the Russian state. Under the name Varangians, they became part of the Byzantine army and were active in all the military activities of the Byzantine Empire. They participated in the Crusades. Russians, many of Scandinavian origin also constituted a regiment of the Mongol army and roamed throughout that Empire as well. The custom of capturing and keeping or selling women and children, which was widespread in the early Middle Ages, as well as the flourishing slave trade in men, were important factors in this genetic dissemination.

An Overview.

PubMed

Nicolaidis, Efthymios; Delli, Eudoxie; Livanos, Nikolaos; Tampakis, Kostas; Vlahakis, George

2016-09-01

This essay offers an overview of the history of the relations between science and Eastern Christianity based on Greek-language sources. The civilizations concerned are the Byzantine Empire, the Christian Orthodox communities of the Ottoman Empire, and modern Greece, as a case study of a national state. Beginning with the Greek Church Fathers, the essay investigates the ideas of theologians and scholars on nature. Neoplatonism, the theological debates of Iconoclasm and Hesychasm, the proposed union of the Eastern and Western Churches, and the complex relations with the Hellenic past all had notable impacts on the conception of science held by the Byzantine Orthodox. From the sixteenth through the eighteenth centuries, the Christian Orthodox world did not actively participate in the making of the new science that was developing in modern Europe. It had to deal with the assimilation of scientific ideas produced by Western Christianity, and its main concern was the “legitimacy” of knowledge that did not originate directly from its own spiritual tradition. Finally, with regard to the Greek state, beyond the specific points of contact between the sciences and Orthodox Christianity—pertaining, for example, to materialism, evolution, and the calendar—the essay presents the constant background engagement with religion visible in most public pronouncements of scientists and intellectuals.

Magnetic and electromagnetic prospections at the Roman city of Hadrianopolis, southern Albania

NASA Astrophysics Data System (ADS)

Schettino, Antonio; Perna, Roberto; Pierantoni, Pietro Paolo; Ghezzi, Annalisa; Tassi, Luca; Sforzini, David

2017-04-01

We report on a combined magnetic-GPR survey performed in 2015-2017 at the ancient Roman city of Hadrianopolis, located in southern Albania, in the context of the project Teatri Antichi Riuniti (TAU). The collected data supplemented previous archaeological surveys performed by the University of Macerata with the aim of promoting the valley and starting the realization of an archaeological park. Hadrianopolis was founded through a reorganization of a previous Hellenistic settlement. Starting from 2015, magnetic and GPR surveys were carried out in Hadrianopolis in order to determine the urban framework. The collected data revealed the existence of structures organized along two main different patterns, which have been interpreted as due to the superposition of Roman buildings and Late Antiquity structures. In fact, the arrangement of structures in the studied area shows a regular urban organization of Roman type separated by a less regular disposition of the buildings that can be attributed to the Byzantine age. The latter arrangement is superimposed on the previous Roman structures. A stone wall, clearly identified by the combination of magnetic anomalies and GPR images, separates the Byzantine seattlement from the genuine Roman sector.

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

PubMed

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 lochokomeia for maternity. In addition, one of the important functions of Sampson Xenon was, according to Novel 59, to hold a funeral service for the people of Constantinople. Nevertheless, there is no sufficient literary material that could demonstrate the existence of a hospital in modern sense. The first hospital where outpatient service, hospitalization and surgery were confirmed was Sampson Xenon in the first half of the 7th century, figured in the tale of Stephanos of the The Miracles of St. Artemios. Why was the early Byzantine literary so reticent as to write the medical activities in the Christian Charities? It's because Christian innovation didn't rest on the medical treatment but caring for the poor and the sick, depending on the word of Mt. 25.35-36. In this meaning, I'd like to say that the Early Byzantine history of Christian Charities or 'Christian Hospitals' consists of only a footnote of the verse.

A Primer on Architectural Level Fault Tolerance

NASA Technical Reports Server (NTRS)

Butler, Ricky W.

2008-01-01

This paper introduces the fundamental concepts of fault tolerant computing. Key topics covered are voting, fault detection, clock synchronization, Byzantine Agreement, diagnosis, and reliability analysis. Low level mechanisms such as Hamming codes or low level communications protocols are not covered. The paper is tutorial in nature and does not cover any topic in detail. The focus is on rationale and approach rather than detailed exposition.

Perception and the art of depiction of cylindrical objects.

PubMed

Deregowski, Jan B; McGeorge, Peter

2008-01-01

Many works of art, notably those in the Byzantine tradition, contain depictions of upright cylindrical objects such that the outline of their top surfaces is incompatible with that of their bottom surfaces. We endeavour to elucidate whether this is a consequence of a painterly usage or a perceptual effect and conclude, on the basis of empirical evidence, that the latter cause is more likely.

Chapter 21: special hospitals in neurology and neurosurgery.

PubMed

Sammet, Kai

2010-01-01

Central to medicine is often where care and treatment are provided. Whereas today hospitals are the main locations to deliver medical help, in history we find different places for care and treatment. This chapter deals with these different places beginning in antiquity and sketching, e.g., the Greek asclepieion or the Roman valetudinarium. The roots of the modern hospital lie in the Middle Ages. Byzantine, Islamic as well as Christian hospitals are described. Around 1800 the rise of the general hospital began. Three ways into modernity are sketched: the British, the German and the French development of hospitals during the 18th and 19th century. Subsequently the emergence of special hospitals in Great Britain and in Germany is depicted. Whereas in Great Britain neurology had its roots as a specialty at the Queen Square Hospital, development in Germany differed. Here we can find different special neurological departments in general hospitals. The description of the emergence of neurotraumatological and neurosurgical special hospitals follows. Particularly World War I had a deep impact on the development of those facilities. Finally the history of neurotraumatology and neurology in Great Britain and Germany after World War II is sketched.

ROBUS-2: A Fault-Tolerant Broadcast Communication System

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo; Malekpour, Mahyar R.; Miner, Paul S.

2005-01-01

The Reliable Optical Bus (ROBUS) is the core communication system of the Scalable Processor-Independent Design for Enhanced Reliability (SPIDER), a general-purpose fault-tolerant integrated modular architecture currently under development at NASA Langley Research Center. The ROBUS is a time-division multiple access (TDMA) broadcast communication system with medium access control by means of time-indexed communication schedule. ROBUS-2 is a developmental version of the ROBUS providing guaranteed fault-tolerant services to the attached processing elements (PEs), in the presence of a bounded number of faults. These services include message broadcast (Byzantine Agreement), dynamic communication schedule update, clock synchronization, and distributed diagnosis (group membership). The ROBUS also features fault-tolerant startup and restart capabilities. ROBUS-2 is tolerant to internal as well as PE faults, and incorporates a dynamic self-reconfiguration capability driven by the internal diagnostic system. This version of the ROBUS is intended for laboratory experimentation and demonstrations of the capability to reintegrate failed nodes, dynamically update the communication schedule, and tolerate and recover from correlated transient faults.

Translating Ancient Alchemy: Fragments of Graeco-Egyptian Alchemy in Arabic Compendia.

PubMed

Martelli, Matteo

2017-11-01

Translation played a vital role in the development and transfer of alchemy in Antiquity and the Early Middle Ages. Since its origins in Graeco-Roman Egypt, alchemy was encapsulated in Greek texts which allegedly relied on Persian or Egyptian sources. Later, a variety of Greek and Byzantine writings were translated into Syriac and Arabic, and these translations were in turn fragmented and disseminated in later Arabic compendia. This paper will first review the main phases of this historical process of transmission of alchemy from one language and culture to another. Second, this process will be examined using two significant case studies: a close analysis of various quotations from Graeco-Egyptian authors (Pseudo-Democritus, Zosimus of Panopolis, and Synesius) as presented in two Arabic dialogues on alchemy, The Tome of Images and The Dialogue between Āras and the King Caesar. These sources demonstrate some of the concrete textual realities that underlie general patterns of translation and reception.

Groundhog Day: Expectation Management by Examining Warfare in the Early Twentieth Century Balkans

DTIC Science & Technology

2007-06-15

Balkan Peninsula around the Former Republic of Yugoslavia and its neighboring nations. This excludes Romania 7 and southern Hungary, but movement...of modern-day Romania . With the expansion to include more of the Peninsula, however, things began to change. Missionaries from Constantinople had...inclusion of Orthodox Christianity. Second, obviously using the Byzantine Empire as the model, the sovereign was the originator of law. However, the powers

The dissemination of multiple sclerosis: a Viking saga? A historical essay.

PubMed

Poser, C M

1994-12-01

The highest prevalence rates for multiple sclerosis are found in Iceland, Scandinavia, the British Isles, and the countries settled by their inhabitants and their descendants, that is, the United States, Canada, Australia, and New Zealand. This suggests that the Vikings may have been instrumental in disseminating the genetic susceptibility to the disease in those areas as well as in other parts of the world. The Vikings raided in most European countries and settled in Normandy and in Sicily and southern Italy. They engaged in trade with the Arabs along the river routes to the Caucasus and to the Black and Caspian Seas and penetrated into Persia, India, and probably China. They also migrated to the East and established the Russian state. Under the name Varangians, they became part of the Byzantine army and were active in all of the military activities of the Byzantine Empire. They participated in the Crusades. Russians, many of Scandinavian origin, also constituted a regiment of the Mongol army and roamed throughout that empire as well. The custom of capturing and keeping or selling women and children, which was widespread in the early Middle Ages, as well as the flourishing slave trade in men, were important factors in this genetic dissemination.

Comparing maternal genetic variation across two millennia reveals the demographic history of an ancient human population in southwest Turkey

PubMed Central

Ottoni, Claudio; Willet, Rinse; Claeys, Johan; Talloen, Peter; Van de Vijver, Katrien; Chikhi, Lounès; Poblome, Jeroen; Decorte, Ronny

2016-01-01

More than two decades of archaeological research at the site of Sagalassos, in southwest Turkey, resulted in the study of the former urban settlement in all its features. Originally settled in late Classical/early Hellenistic times, possibly from the later fifth century BCE onwards, the city of Sagalassos and its surrounding territory saw empires come and go. The Plague of Justinian in the sixth century CE, which is considered to have caused the death of up to a third of the population in Anatolia, and an earthquake in the seventh century CE, which is attested to have devastated many monuments in the city, may have severely affected the contemporary Sagalassos community. Human occupation continued, however, and Byzantine Sagalassos was eventually abandoned around 1200 CE. In order to investigate whether these historical events resulted in demographic changes across time, we compared the mitochondrial DNA variation of two population samples from Sagalassos (Roman and Middle Byzantine) and a modern sample from the nearby town of Ağlasun. Our analyses revealed no genetic discontinuity across two millennia in the region and Bayesian coalescence-based simulations indicated that a major population decline in the area coincided with the final abandonment of Sagalassos, rather than with the Plague of Justinian or the mentioned earthquake. PMID:26998313

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

NASA Astrophysics Data System (ADS)

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.

Art with Stones: From the Cave Age until Today with Parallels Seen in the Artistic, Symbolic and Creative Development of Young Children's Mosaic Making.

ERIC Educational Resources Information Center

Matejovsky-Nikoltsos, Catherine

This paper first gives a historical overview of mosaics, discussing mosaic masks made by the Aztecs and floor mosaics made by the Greeks, as well as the Roman mosaics at Pompeii and the Byzantine decorative mosaics exemplified by those at Ravenna. The paper then elaborates on children's mosaic making observed during research conducted between 1986…

Short Note on Complexity of Multi-Value Byzantine Agreement

DTIC Science & Technology

2010-07-27

which lead to nBl /D bits over the whole algorithm. Broadcasts in extended step: In the extended step, every node broadcasts D bits. Thus nDB bits...bits, as: (n− 1)l + n(n− 1)(k +D/k)l/D + nBl /D + nDBt(t+ 1) (4) = (n− 1)l +O(n2kl/D + n2l/k + nBl /D + n3BD). (5) Notice that broadcast algorithm of

Political Change in Morocco: Its Effect on the Traditional Monarchy.

DTIC Science & Technology

1984-06-01

been subjected to eight principal foriegn influences: the Phoenicians, Carthaginians, Romans, Vandals , Byzantines, Arabs, Turks, and French have all...percent are Jew. After the Romans, a quick succession of would-be conquerors and rulers entered the confines of Morocco’s borders. The Baltic Vandals , who...palace at Akhirat, fif- teen miles southwest of Rabat, to celebrate Hassan’s birthday. 117 At about 2:00 P.M. the garden party came under attack by troops

Presenting the City of Thessaloniki as a Byzantine Mosaic Center to Young Children: A Visual Arts Approach in and out of Museums.

ERIC Educational Resources Information Center

Nikoltsos, Catherine

This paper presents the observations and findings from case studies and projects with the theme of mosaic-making, which were conducted over a period of 10 years, 1987-1997, with young children ages 3 to 6. Emphasis is placed on the cultural heritage of the city of Thessaloniki as a center for the art of mosaic-making during the Early Christian and…

A Cyber Federal Deposit Insurance Corporation Achieving Enhanced National Security

DTIC Science & Technology

2017-12-21

cure-all. Most of the best practices around cybersecurity are entirely free and based more on education and behavioral hygiene than on technological...uncomfortable for most countries around the world, whose lead- ers have often profited handsomely in money or longevity from the opacity and byzantine...Disparte, “ Free , Fair and (Mostly) Unfettered,” International Policy Digest, November 16, 2016. 6 Phil Wahba, “Amazon Will Make Up 50% of All U.S. E

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

NASA Astrophysics Data System (ADS)

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.

[Metamorphosis of the uterus from Hippocrates to Ambroise Pare].

PubMed

Dasen, Véronique

2002-01-01

The treatise Des monstres et prodiges (1579, 1585) by Ambroise Paré includes a vignette depicting a monstrous embryo in the form of a human head surrounded by snakes. This picture belongs to the iconographic tradition relating to the Graeco-Roman mythology of sexuality and procreation. It derives from the belief in the womb's animal nature, illustrated on magic Graeco-Roman and Byzantine gemstones, where the uterus is shown in turn as a cupping vessel, a scarab-beetle, an octopus or the head of Gorgo.

Let's Sue Them All! The Byzantine Disaster. Grade 7 Lesson. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

ERIC Educational Resources Information Center

Otto, Gina

Who is responsible for loss of life and property when one empire is conquered by another? It is the year 1473 A.D., 20 years after the fall of Constantinople. On May 29, 1453, the Eastern Roman Empire came to an end with the military takeover of Constantinople by the Ottoman Turks. How could an empire cease to exist? What were the people in and…

Anthropogenic accumulation of metals and metalloids in carbonate-rich sediments: Insights from the ancient harbor setting of Tyre (Lebanon)

NASA Astrophysics Data System (ADS)

Elmaleh, A.; Galy, A.; Allard, T.; Dairon, R.; Day, J. A.; Michel, F.; Marriner, N.; Morhange, C.; Couffignal, F.

2012-04-01

The Antique and Byzantine sediments of the northern harbor of Tyre (Lebanon) store high amounts of metals and metalloids as the result of a millennial anthropogenic contamination as well as of efficient trapping and immobilization processes. Geochemical and mineralogical analyses reveal the contrasted patterns for the accumulation of trace metal(loid)s in the sedimentary sequence recovered by coring the inner part, now emerged, of the ancient harbor. Lead, Sn, Cu and Ag concentrations can be as high as 3000, 150, 1000, and 1.2 μg/g, respectively. Enrichment factors were calculated with respect to (1) Th and (2) the chemistry of the substratum and appear to be driven by anthropogenic inputs. Indeed, a drastic change in both excess concentrations and concentration ratios is observed through Roman and Byzantine times, pointing to major intensification of the trade and use of metals in Tyre, coherent with historical data. Good preservation of the archeological signal, despite (1) sediment disturbances that have caused age depth inversions, and (2) the large time lapse since the time of deposition of anthropogenic trace metal(loid)s is probably due to the reducing character of the sediments. Tyre's sedimentary sequence provides an interesting analog for modern carbonate-rich harbor environments, in which a millenary accumulation of trace metal(loid)s has been overall well preserved and suggests a restricted mobility of anthropogenic contamination for a period of time in excess of 1500 years.

[The Justinian plague (part one)].

PubMed

Sabbatani, Sergio; Manfredi, Roberto; Fiorino, Sirio

2012-06-01

In their medical-historical review, the authors assess the evolution of bubonic plague epidemics: after breaking out in the Egyptian port of Pelusium in October 541 AD, the epidemics hit several regions in the Mediterranean basin in a succession of waves. The so-called Justinian plague took its name from the Byzantine emperor of the period, and seriously conditioned the expansionary aims of the Eastern Roman empire towards Italy (which was occupied by Goths), and Northern Africa (where the Vandals had settled), during the first decades of its spread. In the Eastern Empire the plague played a considerable role in reducing the tensions between Persians and Byzantines, especially on the Syrian and Anatolian fronts. It had a major demographic impact, reducing the possibility of recruitment to the Roman legions and leading to a significant drop in tax revenues, which were essential to sustain the state and its military machine. Finally, the plague also took its toll on economic resources (especially agriculture), indirectly leading to a vicious inflationary circle. In the space of over two centuries, plague epidemics paralyzed most trade and commercial exchanges. Furthermore, the Justinian plague, halting the consolidation of the influence of the Eastern Roman empire over some Western regions (including Italy and Northern Africa, which were ruled by Barbarians), supported the development and rise of a number of Roman-Barbarian kingdoms. It may therefore be suggested that the Justinian plague occurred at a very critical historical moment, which represents the real watershed between the Ancient World and the upcoming Middle Ages.

Creating A 3D urban model by terrestrial laser scanners and photogrammetry techniques: a case study on the historical peninsula of Istanbul

NASA Astrophysics Data System (ADS)

Ergun, Bahadir

2007-07-01

Today, terrestrial laser scanning has been a frequently used methodology for the documentation of historical buildings and cultural heritages. The historical peninsula region is the documentation of historical buildings and cover approximately 1500 ha. Terrestrial laser scanning and close range image photogrammetry techniques are integrated to each other to create a 3D urban model of Istanbul including the most important landmarks and the buildings reflecting the most brilliant areas of Byzantine and Ottoman Empires.

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

PubMed

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.

Presence of dental signs of congenital syphilis in pre-modern specimens.

PubMed

Ioannou, Stella; Henneberg, Renata J; Henneberg, Maciej

2018-01-01

Tooth morphology can vary due to genetic factors, infectious diseases and other environmental stresses. Congenital syphilis is known to interrupt tooth formation i.e. odontogenesis and amelogenesis, producing specific dental characteristics. Variation of those characteristics can occur, resulting in dental signs "not typical" of the disease, however, they are described in the 19th century literature. Past treatments of congenital syphilis with mercury also interrupted dental processes resulting in significantly different dental signs. The aim of this study is to examine the dentition of the oldest (pre 15th century) cases attributed to congenital syphilis to determine whether their dental processes have been affected by either congenital syphilis itself, its treatments (mercury) or a combination of both (syphilitic-mercurial). Comparisons of dental signs of congenital syphilis and its mercuric treatments as described by Hutchinson, Moon and Fournier in the 1800s and in standardised methods as established by modern studies, are made with the dentition of specimens found in archaeological sites in Mexico, Italy, Turkey and Austria dating back to the Terminal Formative Period, Classical Antiquity, Byzantine times and Middle Ages. The dentitions of a child from Oaxaca, Mexico, St. Pölten, Austria, and two juveniles from Classical Antiquity site Metaponto, Italy, show signs attributed to syphilis only. One adolescent from Byzantine site Nicaea, Turkey, shows dental signs characterised as syphilitic-mercurial. Dental abnormalities observed in Mediterranean individuals match a range of signs attributable to congenital syphilis and its treatments, more so than the New World case. Therefore, it is likely that these individuals suffered from congenital syphilis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Verification of fault-tolerant clock synchronization systems. M.S. Thesis - College of William and Mary, 1992

NASA Technical Reports Server (NTRS)

Miner, Paul S.

1993-01-01

A critical function in a fault-tolerant computer architecture is the synchronization of the redundant computing elements. The synchronization algorithm must include safeguards to ensure that failed components do not corrupt the behavior of good clocks. Reasoning about fault-tolerant clock synchronization is difficult because of the possibility of subtle interactions involving failed components. Therefore, mechanical proof systems are used to ensure that the verification of the synchronization system is correct. In 1987, Schneider presented a general proof of correctness for several fault-tolerant clock synchronization algorithms. Subsequently, Shankar verified Schneider's proof by using the mechanical proof system EHDM. This proof ensures that any system satisfying its underlying assumptions will provide Byzantine fault-tolerant clock synchronization. The utility of Shankar's mechanization of Schneider's theory for the verification of clock synchronization systems is explored. Some limitations of Shankar's mechanically verified theory were encountered. With minor modifications to the theory, a mechanically checked proof is provided that removes these limitations. The revised theory also allows for proven recovery from transient faults. Use of the revised theory is illustrated with the verification of an abstract design of a clock synchronization system.

The utility and feasibility of business training for neurosurgeons.

PubMed

Giller, Cole A

2008-04-01

Socioeconomic changes have imposed many administrative demands on neurosurgeons, including managing facilities such as the intensive care unit without absolute authority and maintaining referrals, marketing in an increasingly competitive environment, effecting change within stubborn hospital systems, negotiating fair contracts with insurance companies, using financial statements to make financial decisions, managing small groups under new rules of human resources, navigating a Byzantine system of reimbursement, and assessing entrepreneurial opportunities. A set of new tools and skills has been developed by the business community in response to similar problems that may be of use to neurosurgeons. These advances are reviewed in a neurosurgical context, and routes to business training for the neurosurgeon are discussed. Recent advances in business are discussed with a focus on their relevance to neurosurgical practice. Current neurosurgical interest in business training and training opportunities for neurosurgeons are presented. Interest in business training within the neurosurgery community is keen, and advances in the field of business may be helpful in addressing the new tasks faced by neurosurgeons. New tools from advances in business are available which have been invaluable to corporations and may be helpful to neurosurgeons wanting to improve efficiency and maintain competitive advantage. Business training is available to neurosurgeons through a variety of routes.

Modeling and Analysis of Asynchronous Systems Using SAL and Hybrid SAL

NASA Technical Reports Server (NTRS)

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.

Inter-computer communication architecture for a mixed redundancy distributed system

NASA Technical Reports Server (NTRS)

Lala, Jaynarayan H.; Adams, Stuart J.

1987-01-01

The triply redundant intercomputer network for the Advanced Information Processing System (AIPS), an architecture developed to serve as the core avionics system for a broad range of aerospace vehicles, is discussed. The AIPS intercomputer network provides a high-speed, Byzantine-fault-resilient communication service between processing sites, even in the presence of arbitrary failures of simplex and duplex processing sites on the IC network. The IC network contention poll has evolved from the Laning Poll. An analysis of the failure modes and effects and a simulation of the AIPS contention poll, demonstrate the robustness of the system.

Surgery on the larynx and pharynx in Byzantium (AD 324-1453): early scientific descriptions of these operations.

PubMed

Lascaratos, J; Assimakopoulos, D

2000-04-01

We present the techniques of various operations on the larynx and pharynx (incision of abscesses of the tonsils, tonsillectomy, tracheotomy, uvulectomy, and removal of foreign bodies) found in the Greek texts of Byzantine physicians. The techniques of these operations were the first to be so meticulously described and were compiled from the texts, now lost, of the ancient Greek physicians. These medical texts, which followed and enriched the Hippocratic, Hellenistic, Roman, and Galenic medical traditions, later influenced medieval European surgery, either directly through Latin translations or indirectly through works of Arab physicians.

A historical outline of Greek ophthalmology from the Hellenistic period up to the establishment of the first universities.

PubMed

Lascaratos, J; Marketos, S

1988-01-01

The writers examine the course of Greek ophthalmology from the Hellenistic period to the foundation of the first universities (19th century). In particular, the study refers to Galen, Antyllus, the Byzantine doctors Oribasius, Aetius of Ameda, Paul of Aegina, Alexander of Tralles, Nonnus Theophanes, Theophilus Protospatharius, Michael Psellos, Meletius Monachus, Nemesius bishop of Emeses and John Actuarius. The practice of empirical ophthalmology during the Ottoman domination of Greece is also examined, as is the earliest available evidence of modern Greek ophthalmological knowledge, deriving from the Ionian Islands.

Facial image of Biblical Jews from Israel.

PubMed

Kobyliansky, E; Balueva, T; Veselovskaya, E; Arensburg, B

2008-06-01

The present report deals with reconstructing the facial shapes of ancient inhabitants of Israel based on their cranial remains. The skulls of a male from the Hellenistic period and a female from the Roman period have been reconstructed. They were restored using the most recently developed programs in anthropological facial reconstruction, especially that of the Institute of Ethnology and Anthropology of the Russian Academy of Sciences (Balueva & Veselovskaya 2004). The basic craniometrical measurements of the two skulls were measured according to Martin & Saller (1957) and compared to the data from three ancient populations of Israel described by Arensburg et al. (1980): that of the Hellenistic period dating from 332 to 37 B.C., that of the Roman period, from 37 B.C. to 324 C.E., and that of the Byzantine period that continued until the Arab conquest in 640 C.E. Most of this osteological material was excavated in the Jordan River and the Dead Sea areas. A sample from the XVIIth century Jews from Prague (Matiegka 1926) was also used for osteometrical comparisons. The present study will characterize not only the osteological morphology of the material, but also the facial appearance of ancient inhabitants of Israel. From an anthropometric point of view, the two skulls studied here definitely belong to the same sample from the Hellenistic, Roman, and Byzantine populations of Israel as well as from Jews from Prague. Based on its facial reconstruction, the male skull may belong to the large Mediterranean group that inhabited this area from historic to modern times. The female skull also exhibits all the Mediterranean features but, in addition, probably some equatorial (African) mixture manifested by the shape of the reconstructed nose and the facial prognatism.

Highlights in the evolution of diagnosis and treatment of laryngeal cancer.

PubMed

Assimakopoulos, Dimitrios; Patrikakos, George; Lascaratos, John

2003-03-01

To present selected highlights from the evolution of diagnosis of laryngeal disease and treatment of laryngeal cancer from ancient Greece until the 20th century. Historical study of diagnosis of laryngeal disease and treatment of laryngeal cancer from the ancient Greek medical scriptures until the most recent evolutional steps in the 20th century. Original Greek-language texts of ancient and Byzantine medical writers were studied and literature on history of medicine was investigated to reveal early knowledge of diagnostic and therapeutic techniques for laryngeal disease and cancer of the larynx. Diseases of the upper aerodigestive tract were known and treated by ancient Greek physicians, and, later, Byzantine doctors, apart from preserving ancient medical concepts, contributed their own ideas, mainly about surgery and postoperative care. The initial therapeutic approach for the disorders caused by laryngeal tumors was either tracheotomy or endotracheal intubation in an attempt to prevent suffocation. In more recent times, construction of the laryngoscope and other modern examination instruments, as well as the final acceptance of histological diagnosis based on tissue biopsy, has allowed for accurate diagnosis and successful treatment of laryngeal lesions. Preoperational biopsy, application of pharyngoesophageal speech and advanced vocal devices for the laryngectomees, and invention of antibiotic and anesthetic agents had led, by the middle of the 20th century, to the establishment of extended and radical surgical techniques as optional treatment for laryngeal cancer. In addition, the discovery of x-rays and radium introduced radiotherapy as an alternative in the treatment procedure for cancer of the larynx. Progress in the evolution of laryngological diagnosis and practice demanded efforts by many daring and courageous investigators and surgeons, contributing new ideas and techniques in the development of modern laryngology.

Therapeutic properties and uses of marine invertebrates in the ancient Greek world and early Byzantium.

PubMed

Voultsiadou, Eleni

2010-07-20

Marine organisms are currently investigated for the therapeutic potential of their natural products with very promising results. The human interest for their use in healing practices in the Eastern Mediterranean goes back to the antiquity. An attempt is made in the present work to investigate the therapeutic properties of marine invertebrates and the ways they were used in the medical practice during the dawn of the western medicine. The classical Greek texts of the Ancient Greek (Classical, Hellenistic and Roman) and early Byzantine period were studied and the data collected were analysed in order to extract detailed information on the parts of animal bodies and the ways they were used for healing purposes. Thirty-eight marine invertebrates were recorded for their therapeutic properties and uses in 40 works of 20 classical authors, covering a time period of 11 centuries (5th c. BC to 7th c. AD). The identified taxa were classified into 7 phyla and 11 classes of the animal kingdom, while molluscs were the dominant group. Marine invertebrates were more frequently used for their properties relevant to digestive, genitourinary and skin disorders. Flesh, broth, skeleton, or other special body parts of the animals were prepared as drinks, collyria, suppositories, cataplasms, compresses, etc. Marine invertebrates were well known for their therapeutic properties and had a prominent role in the medical practice during the Ancient Greek and the early Byzantine period. The diversity of animal species and their medicinal uses reflect the maritime nature of the Greek civilization, which flourished on the coasts and islands of the Aegean Sea. Most of them were common species exploited by humans for food or other everyday uses. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Human-climate-environment interactions during the past 4000 years in the Taurus Mountain Range, SW Turkey

NASA Astrophysics Data System (ADS)

Verstraeten, Gert; Broothaerts, Nils; Van Loo, Maarten; Poblome, Jeroen; Degryse, Patrick

2017-04-01

The Eastern Mediterranean has been an area of intense human occupation since the early Neolithic. However, contrary to many temperate environments in NW Europe, human pressure on the landscape did not follow a linear trajectory from the Neolithic to the present, but is rather characterised by cycles of land cover expansion and contraction. Here, we provide a synthesis of human-climate-environment interactions in the region of the antique city of Sagalassos in the Taurus mountain range of SW Turkey. The combination of archaeological, palynological and geomorphological data, together with geochemical sediment provenancing and spatial modelling techniques, enabled to reconstruct the relative importance of anthropogenic pressure and climatic changes on the environment. The sensitivity of the landscape towards anthropogenic disturbance is strongly controlled by the geomorphic-tectonic setting, as well as by important feedback mechanisms in the soil system. The first major clearing of the landscape in the Iron Age led to a peak in soil erosion, but also to soil exhaustion limiting erosion rates in subsequent periods. Soil erosion and sediment delivery is more limited during the main occupation phases of the Roman Imperial Period. Periods with more favorable climate in the Roman and Mid-Byzantine periods resulted in the occupation of more isolated parts of the territory (i.e. higher up in the mountains), whilst a decrease in human pressure can be observed during the Early Byzantine and Ottoman periods related to less favorable conditions. Such smaller and short-lasting bursts of human occupation did not significanlty impact the environment. Only in the last two hundred years, human pressure reached similar values as those encountered in the classical period.

Quantum Clock Synchronization with a Single Qudit

NASA Astrophysics Data System (ADS)

Tavakoli, Armin; Cabello, Adán; Żukowski, Marek; Bourennane, Mohamed

2015-01-01

Clock synchronization for nonfaulty processes in multiprocess networks is indispensable for a variety of technologies. A reliable system must be able to resynchronize the nonfaulty processes upon some components failing causing the distribution of incorrect or conflicting information in the network. The task of synchronizing such networks is related to Byzantine agreement (BA), which can classically be solved using recursive algorithms if and only if less than one-third of the processes are faulty. Here we introduce a nonrecursive quantum algorithm, based on a quantum solution of the detectable BA, which achieves clock synchronization in the presence of arbitrary many faulty processes by using only a single quantum system.

Cervical spine surgery in the ancient and medieval worlds.

PubMed

Goodrich, James Tait

2007-01-01

The early historical literature on cervical spine surgery lacks printed material for review, and we can rely only on pathological material from the prehistoric period that has survived as a result of anthropological investigations. After the introduction of Egyptian and early Hellenic medicine, some written material became available. This paper reviews these materials, from both books and manuscripts, in an effort to understand the development of cervical spine surgery from the perspectives of the personalities involved and the early surgical practices used. The review thus considers the following five eras of medicine: 1) prehistoric; 2) Egyptian and Babylonian; 3) Greek and early Byzantine; 4) Middle Eastern; and 5) medieval.

Design of the Protocol Processor for the ROBUS-2 Communication System

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo; Malekpour, Mahyar R.; Miner, Paul S.

2005-01-01

The ROBUS-2 Protocol Processor (RPP) is a custom-designed hardware component implementing the functionality of the ROBUS-2 fault-tolerant communication system. The Reliable Optical Bus (ROBUS) is the core communication system of the Scalable Processor-Independent Design for Enhanced Reliability (SPIDER), a general-purpose fault tolerant integrated modular architecture currently under development at NASA Langley Research Center. ROBUS is a time-division multiple access (TDMA) broadcast communication system with medium access control by means of time-indexed communication schedule. ROBUS-2 is a developmental version of the ROBUS providing guaranteed fault-tolerant services to the attached processing elements (PEs), in the presence of a bounded number of faults. These services include message broadcast (Byzantine Agreement), dynamic communication schedule update, time reference (clock synchronization), and distributed diagnosis (group membership). ROBUS also features fault-tolerant startup and restart capabilities. ROBUS-2 tolerates internal as well as PE faults, and incorporates a dynamic self-reconfiguration capability driven by the internal diagnostic system. ROBUS consists of RPPs connected to each other by a lower-level physical communication network. The RPP has a pipelined architecture and the design is parameterized in the behavioral and structural domains. The design of the RPP enables the bus to achieve a PE-message throughput that approaches the available bandwidth at the physical layer.

Bone Lose of the Ancient Mediterranean lumbar vertebrae : Iasos, 6th century ad.

NASA Astrophysics Data System (ADS)

Kaya, Serdar; Solmaz, Ilker; Ilıca, A. Turan; Karaçalıoğlu, Özgür; Damla Yılmaz, Nalan; Başoğlu, Okşan; Kılıc, Selim; Izci, Yusuf

Evaluation of bone mineral density (BMD) of the ancient peoples has received great interest by anthropologists. The aims of this study are to investigate the lumbar vertebrae of the Iasos people during the Byzantine period, in order to determine the prevalence of bone loss and to interpret dietary conditions of ancient Mediterranean populations. Lumbar vertebrae belonging to twenty eight skeletons of the 6th c AD were analyzed by radiographs and dual energy X-ray absorptiometry. The BMD values for each biologic sex and age group were compared. The correlation between the BMD and radiological features was also analyzed. The mean BMD was 0.940 g/cm2. BMD was decreased by aging in both sexes, but it was not significant. Osteopenia was found in 11 (39%) and osteoporosis in 4 (14.3%) out 28 vertebrae. The BMD was normal in 13 (46%) out of 28 vertebrae. Osteopenia was present in 7 (38%) of 18 male vertebrae and 4 (40%) of 10 female vertebrae. The spine score was high in the male group and there was a strong positive correlation between the BMD and spine score for both sexes. This study revealed that the BMD decreased by aging and that osteopenia was a problem in both sexes of the Iasos people during the 6th c AD. There was no correlation between the BMD and radiological features for age groups and biological sexes.

Tribute to a triad: history of splenic anatomy, physiology, and surgery--part 1.

PubMed

McClusky, D A; Skandalakis, L J; Colborn, G L; Skandalakis, J E

1999-03-01

The spleen is an enigmatic organ with a peculiar anatomy and physiology. Though our understanding of this organ has improved vastly over the years, the spleen continues to produce problems for the surgeon, the hematologist, and the patient. The history of the spleen is full of fables and myths, but it is also full of realities. In the Talmud, the Midrash, and the writings of Hippocrates, Plato, Aristotle, Galen, and several other giants of the past, one can find a lot of Delphian and Byzantine ambiguities. At that time, splenectomy was the art of surgery for many splenic diseases. From antiquity to the Renaissance, efforts were made to study the structure, functions, and anatomy of the spleen. Vesalius questioned Galen; and Malpighi, the founder of microscopic anatomy, gave a sound account of the histology and the physiologic destiny of the spleen. Surgical inquiry gradually became a focal point, yet it was still not clear what purpose the spleen served. It has been within the past 50 years that the most significant advances in the knowledge of the spleen and splenic surgery have been made. The work of Campos Christo in 1962 about the segmental anatomy of the spleen helped surgeons perform a partial splenectomy, thereby avoiding complications of postsplenectomy infection. With the recent successes of laparoscopic splenectomy in selected cases, the future of splenic surgery will undoubtedly bring many more changes.

Geoscience rediscovers Phoenicia's buried harbors

NASA Astrophysics Data System (ADS)

Marriner, Nick; Morhange, Christophe; Doumet-Serhal, Claude; Carbonel, Pierre

2006-01-01

After centuries of archaeological debate, the harbors of Phoenicia's two most important city states, Tyre and Sidon, have been rediscovered, and including new geoarcheological results reveal how, where, and when they evolved after their Bronze Age foundations. The early ports lie beneath their present urban centers, and we have indentified four harbor phases. (1) During the Bronze Age, Tyre and Sidon were characterized by semi-open marine coves that served as protoharbors. (2) Biostratigraphic and lithostratigraphic data indicate the presence of early artificial basins after the first millennium B.C. (3) The harbors reached their apogees during the Greco-Roman and Byzantine periods. (4) Silting up and coastal progradation led to burial of the medieval basins, lost until now.

Rapid landscape change in 6th century northern Jordan: interdisciplinary geoarchaeological perspectives

NASA Astrophysics Data System (ADS)

Lucke, Bernhard

2016-04-01

Landscapes of the ancient fertile crescent are considered affected by soil degradation as result of long-term farming since the Neolithic, and impressive ruins of antiquity led to assumptions that their abandonment must have been conntected with reduced agricultural productivity. In this context, a valley fill near the site of Abila of the Decapolis in northern Jordan was apparently deposited largely during the 6th century AD, and provides evidence for a rapid and intense landscape change during the Late Byzantine period. However, an interdisciplinary case study of land use, soil development, and sediments found that the valley fill cannot be connected with large-scale soil erosion in the vicinity of the site. On the one hand, this is indicated by the distribution of soil development and archaeological material as marker of past land use activity in the past, which suggests that the best soils were and still are used intensively. On the other hand, the sediments seem to point to the occurrence of climatic extremes such as heavy floods, the occurrence of soil creep after water saturation, but also a significant shift to aridity which may have triggered socio-economic changes of subsistence strategies from agriculture to pastoralism. The dates of sediments which are available so far indicate that the climatic change seemingly occurred rapidly within approximately 100 years during the late 6th and early 7th century AD, possibly connected with the "year without sun" or 'Mystery Veil' which the Byzantine historian Procopius described in the year 536 AD. Modern analogies of the Pinatubo eruption in 1991 let it seem possible that a volcanic event, perhaps the outbreak of the Ilopango volcano, was connected with these environmental turbulences. Such events cannot be understood by isolated studies: without a broad interdisciplinary framework, single archives are prone to misinterpretation, and our understanding of the environmental history of Abila is still very limited.

Acoustic characteristics of modern Greek Orthodox Church music.

PubMed

Delviniotis, Dimitrios S

2013-09-01

Some acoustic characteristics of the two types of vocal music of the Greek Orthodox Church Music, the Byzantine chant (BC) and ecclesiastical speech (ES), are studied in relation to the common Greek speech and the Western opera. Vocal samples were obtained, and their acoustic parameters of sound pressure level (SPL), fundamental frequency (F0), and the long-time average spectrum (LTAS) characteristics were analyzed. Twenty chanters, including two chanters-singers of opera, sang (BC) and read (ES) the same hymn of Byzantine music (BM), the two opera singers sang the same aria of opera, and common speech samples were obtained, and all audio were analyzed. The distribution of SPL values showed that the BC and ES have higher SPL by 9 and 12 dB, respectively, than common speech. The average F0 in ES tends to be lower than the common speech, and the smallest standard deviation (SD) of F0 values characterizes its monotonicity. The tone-scale intervals of BC are close enough to the currently accepted theory with SD equal to 0.24 semitones. The rate and extent of vibrato, which is rare in BC, equals 4.1 Hz and 0.6 semitones, respectively. The average LTAS slope is greatest in BC (+4.5 dB) but smaller than in opera (+5.7 dB). In both BC and ES, instead of a singer's formant appearing in an opera voice, a speaker's formant (SPF) was observed around 3300 Hz, with relative levels of +6.3 and +4.6 dB, respectively. The two vocal types of BM, BC, and ES differ both to each other and common Greek speech and opera style regarding SPL, the mean and SD of F0, the LTAS slope, and the relative level of SPF. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Soils, sediments and geoarchaeology in the vicinity of Caričin Grad (Iustiniana Prima), southern Serbia

NASA Astrophysics Data System (ADS)

Dotterweich, Markus; Köstelbauer, Felix; Schreg, Rainer

2017-04-01

Excavations at the early Byzantine hillfort-settlement Caričin Grad hint at a relatively short time of active settlement of only 90 years. The cause for abandonment is still unknown, though it is widely assumed that ecological and environmental factors played a pivotal role. This study aims to evaluate, if soils and sediments in the vicinity of the site can be used to gather information about the spatial and temporal impact of land use and whether that constituted to a higher rate of soil erosions and thus a possible decline of sustainability during the time of active occupation. A field campaign in 2016 documented the sediments of 15 exposures along riverbanks and erosional gullies as well as 15 core drillings. Samples for dating via radiocarbon and optically-stimulated luminescence (OSL) were also recovered. The field campaign was further supported by a DEM of the research area, archaeological reports, as well as geological, pedological and topographic maps. The heterogeneous stratigraphy of most of the documented sediments strongly reflects the clayey and loamy nature of the catchment areas. Inclusions of charcoal and fractured bricks can be found under two meters of overlaying colluvial and alluvial sediments. Floodplain sediments, especially those near a now bursted dam built in the Byzantine era, show inclusions of bigger stone blocks, hinting at several flashflood events, which occurred during historic times. Most of the topsoil in the catchment area, especially south-west of the site, is already strongly eroded, leaving only Ah-C sequences of Leptosols. The gathered data thus suggest that accelerated soil erosion during the time of occupation was very likely, probably caused by local brick production and deforestation. Exposed topsoil with a relative high amount of clay mineral further contributed to a marginal discharge to groundwater during rainfall, resulting in a stronger runoff and incision of gullies in the present-day landscape.

Binary Hypothesis Testing With Byzantine Sensors: Fundamental Tradeoff Between Security and Efficiency

NASA Astrophysics Data System (ADS)

Ren, Xiaoqiang; Yan, Jiaqi; Mo, Yilin

2018-03-01

This paper studies binary hypothesis testing based on measurements from a set of sensors, a subset of which can be compromised by an attacker. The measurements from a compromised sensor can be manipulated arbitrarily by the adversary. The asymptotic exponential rate, with which the probability of error goes to zero, is adopted to indicate the detection performance of a detector. In practice, we expect the attack on sensors to be sporadic, and therefore the system may operate with all the sensors being benign for extended period of time. This motivates us to consider the trade-off between the detection performance of a detector, i.e., the probability of error, when the attacker is absent (defined as efficiency) and the worst-case detection performance when the attacker is present (defined as security). We first provide the fundamental limits of this trade-off, and then propose a detection strategy that achieves these limits. We then consider a special case, where there is no trade-off between security and efficiency. In other words, our detection strategy can achieve the maximal efficiency and the maximal security simultaneously. Two extensions of the secure hypothesis testing problem are also studied and fundamental limits and achievability results are provided: 1) a subset of sensors, namely "secure" sensors, are assumed to be equipped with better security countermeasures and hence are guaranteed to be benign, 2) detection performance with unknown number of compromised sensors. Numerical examples are given to illustrate the main results.

Achieving Agreement in Three Rounds with Bounded-Byzantine Faults

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar, R.

2017-01-01

A three-round algorithm is presented that guarantees agreement in a system of K greater than or equal to 3F+1 nodes provided each faulty node induces no more than F faults and each good node experiences no more than F faults, where, F is the maximum number of simultaneous faults in the network. The algorithm is based on the Oral Message algorithm of Lamport, Shostak, and Pease and is scalable with respect to the number of nodes in the system and applies equally to traditional node-fault model as well as the link-fault model. We also present a mechanical verification of the algorithm focusing on verifying the correctness of a bounded model of the algorithm as well as confirming claims of determinism.

Towards Luminescence Dating Of Mosaic Glass

NASA Astrophysics Data System (ADS)

Galli, A.; Martini, M.; Sibila, E.; Villa, I.

The possibility of dating archaeological glass by means of luminescent techniques has been investigated in recent years, despite the difficulties of this application, mainly linked to the amorphous structure of the material. We focused in particular on mosaic glass, after the encouraging results obtained on byzantine and medieval samples. Further studies were devoted to the comprehension of the luminescent mechanisms in silica glasses, and to the investigation of the relationships between luminescence, colouring or opacifier ions and crystalline phase of the vitreous matrix. The results of a study on the dosimetric characteristics of thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) of a few medieval blue-green mosaic glasses from the San Lorenzo church (Milan) are presented, and the experimental protocols established to identify their suitability for dating are discussed.

A Unified Fault-Tolerance Protocol

NASA Technical Reports Server (NTRS)

Miner, Paul; Gedser, Alfons; Pike, Lee; Maddalon, Jeffrey

2004-01-01

Davies and Wakerly show that Byzantine fault tolerance can be achieved by a cascade of broadcasts and middle value select functions. We present an extension of the Davies and Wakerly protocol, the unified protocol, and its proof of correctness. We prove that it satisfies validity and agreement properties for communication of exact values. We then introduce bounded communication error into the model. Inexact communication is inherent for clock synchronization protocols. We prove that validity and agreement properties hold for inexact communication, and that exact communication is a special case. As a running example, we illustrate the unified protocol using the SPIDER family of fault-tolerant architectures. In particular we demonstrate that the SPIDER interactive consistency, distributed diagnosis, and clock synchronization protocols are instances of the unified protocol.

Influence of Judaism and Jewish physicians on Greek and Byzantine medicine and their contribution to nephrology.

PubMed

Massry, S G; Smogorzewski, M; Hazani, E; Shasha, S M

1997-01-01

Both the Old Testament and the Talmud contain a great deal of information on medicine, nephrology, health and disease. The basic premise of early Jewish medicine is based on the notion that disease is due to structural changes in internal organs. This is in contrast to the mythical dogma of humoralism as the basis of health and disease espoused by Hippocrates and Galen. The Old Testament and the Mosaic Codes provided the basis for modern public health and for the hygienic rules practised in our times. The Talmudists laid the foundations for the science of pathology as we know it today. These issues are discussed in detail and the contributions of three prominent medieval physicians (Asaph Judaeus, Isaac Judaeus and Maimonides) are presented.

A verified design of a fault-tolerant clock synchronization circuit: Preliminary investigations

NASA Technical Reports Server (NTRS)

Miner, Paul S.

1992-01-01

Schneider demonstrates that many fault tolerant clock synchronization algorithms can be represented as refinements of a single proven correct paradigm. Shankar provides mechanical proof that Schneider's schema achieves Byzantine fault tolerant clock synchronization provided that 11 constraints are satisfied. Some of the constraints are assumptions about physical properties of the system and cannot be established formally. Proofs are given that the fault tolerant midpoint convergence function satisfies three of the constraints. A hardware design is presented, implementing the fault tolerant midpoint function, which is shown to satisfy the remaining constraints. The synchronization circuit will recover completely from transient faults provided the maximum fault assumption is not violated. The initialization protocol for the circuit also provides a recovery mechanism from total system failure caused by correlated transient faults.

Accelerated convergence for synchronous approximate agreement

NASA Technical Reports Server (NTRS)

Kearns, J. P.; Park, S. K.; Sjogren, J. A.

1988-01-01

The protocol for synchronous approximate agreement presented by Dolev et. al. exhibits the undesirable property that a faulty processor, by the dissemination of a value arbitrarily far removed from the values held by good processors, may delay the termination of the protocol by an arbitrary amount of time. Such behavior is clearly undesirable in a fault tolerant dynamic system subject to hard real-time constraints. A mechanism is presented by which editing data suspected of being from Byzantine-failed processors can lead to quicker, predictable, convergence to an agreement value. Under specific assumptions about the nature of values transmitted by failed processors relative to those transmitted by good processors, a Monte Carlo simulation is presented whose qualitative results illustrate the trade-off between accelerated convergence and the accuracy of the value agreed upon.

Achieving Agreement in Three Rounds With Bounded-Byzantine Faults

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar R.

2015-01-01

A three-round algorithm is presented that guarantees agreement in a system of K (nodes) greater than or equal to 3F (faults) +1 nodes provided each faulty node induces no more than F faults and each good node experiences no more than F faults, where, F is the maximum number of simultaneous faults in the network. The algorithm is based on the Oral Message algorithm of Lamport et al. and is scalable with respect to the number of nodes in the system and applies equally to the traditional node-fault model as well as the link-fault model. We also present a mechanical verification of the algorithm focusing on verifying the correctness of a bounded model of the algorithm as well as confirming claims of determinism.

Investigations of Archaeological Glass Bracelets and Perfume Bottles Excavated in Ancient Ainos (Enez) by Multiple Analytical Techniques

NASA Astrophysics Data System (ADS)

Celik, S.; Akyuz, T.; Akyuz, S.; Ozel, A. E.; Kecel-Gunduz, S.; Basaran, S.

2018-03-01

Fragments of two perfume bottles belonging to the Hellenistic and Roman periods, and five bracelets belonging to the Roman, Byzantine, and Ottoman periods, excavated in the archaeological site of Enez during the excavations in 2000, have been investigated. The samples were analyzed using micro-Raman, FTIR, and energy dispersive X-ray fluorescence techniques, in order to study the ancient technology of glass production and to determine chemical compositions of the basic components and coloring elements of the glassware. All the investigated glasses can be characterized as low-magnesia-soda-lime silicate glasses, whose colors are induced by metal ions. The melting points of the investigated glasses are estimated to be quite close to each other and around 1000°C.

[An outline of odontoiatry and odontology in the ancient world].

PubMed

Musitelli, S

1996-01-01

Dentistry was surely practiced in ancient Egypt, Mesopotamia, Phoenicia, Etruria, Greece and Rome, but odontology arose only with the dawn of Greek science. One may find the first references to a rational odontology only in the fragments of the Pre-socratic philosophers and in the Corpus Hippocraticum. Aristotle was the first to treat odontology under a comparative anatomo-physiological point of view. Celsus and Scribonius Largus got their matter from Hippocrates, Aristotle, the Hellenistic anatomists as well as from folk-traditions, but payed attention rather to dentistry than to odontology. Finally Galen gathered all the knowledge about odontology and dentistry from Hippocrates up to the Hellenistic anatomists and organized all the matter in his monumental teleologic and theological system, that was inherited by both the so called iatrosophists and the Byzantine physicians.

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

NASA Astrophysics Data System (ADS)

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 following mines, based on their proximity (Griva, 2015).Nephrite from specimen BXM 23989 a might have been originated from a mine in Central China. Lapis Lazuli from specimen BXM 24201 a,b and BXM 24198 might have been originated either from mines in Afghanistan, in the Badakshan Province, or from Myanmar (Mandalay Division).Turquoise from specimen BXM 24142a and BXM 24139a might have been originated either from the Shaxi-Changpushang mine in East China (Anhui Province), or from the Tianhu mine in North China (Xinjiang Autonomous Region). Griva E., 2015. "Study of semi-precious stones and corals from the I. D. Passa collection, hosted at the Byzantine and Christian museum", Diploma Thesis, National and Technical University of Athens, School of Mining and Metallurgical Engineering, p. 218. Zeng Q., Zhang G., Tan J., Leung C. and Zuo J., 2011. 'Identification of pigments from the Shrine of Kaiping Diaolou by micro-Raman spectroscopy', Journal of RAMAN SPECTROSCOPY, 42, 1311-1316.

Paulus Aegineta, a seventh century encyclopedist and surgeon: his role in the history of plastic surgery.

PubMed

Gurunluoglu, R; Gurunluoglu, A

2001-12-01

Paulus Aegineta (625-690 ad), born on the island of Aegina, practiced medicine at Alexandria. The last of the eclectic Greek compilers in the Byzantine period, he wrote an Epitome of medicine in seven books. The sixth book, which is considered the best section of his work, is devoted mainly to surgery. The first edition, "editio princeps," of his Epitome was published in Greek by the Aldine press in Venice in 1528 and later translated into English for the Sydenham Society by Francis Adams of Banchory (1844-1847). Paulus was not only a compiler but also a competent and skillful surgeon. In addition to his achievements in general surgical progress, Paulus Aegineta, especially in the book on surgery, made valuable contributions in the history of plastic surgery. He may be considered as one of the originators of plastic surgery as it is known today. He described procedures varying from the treatment of nasal and jaw fractures to operations for gynecomastia, ganglion, and hypospadias. This Grecian master influenced not only his own but also the subsequent ages. Rhazes, Haly Abbas, Albucasis, Avicenna, and Fabricius ab Aquapendente were the greatest physicians influenced by Paulus Aegineta. Because the work of Paulus Aegineta was the only source for many of the surgical treatises of Arabian authors, his Epitome bridged Western and Eastern medicine and conveyed surgical experience and knowledge, including several plastic surgery procedures, to the subsequent ages.

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

NASA Astrophysics Data System (ADS)

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 adjacent provinces cannot be excluded for certain samples. Despite the different archaeological levels to which these samples belong to, this study illustrates some similarity in technological features and chemical composition. This in turn suggests that continuity is rather the trend in ceramic tradition of the society during the transition period. However, further work on clays, kilns, and pottery from other sites discovered in Jordan is necessary to confirm this conclusion.

[Miraculous recoveries in the frescoes of the Decani Monastery].

PubMed

Jović, N; Jancić-Stefanović, J

1999-01-01

Serbian medieval medicine can be said to have the same characteristics as western medicine of those times in terms of practical medical science, whereas the ancillary medical branches were under Byzantine influence. Besides the compositions of Christ's miracles and paraboles are underlying part of the fresco/painting, the scenes of Christ's miraculous recoveries have an important place in the christian iconography of the New Testament events. One of the most impressive cycles of Christ's miracles in the Serbian and Byzantine medieval art was painted in c. 1340 year in the church dedicated to the Ascension of Lord Christ at Dechani Monastery and constructed between 1327 and 1335. A considerable number of 22 frescoes of different artistic value and technique displays the miraculous recovery of patients afflicted by various chronic ailments: paralytics (razlabljeni), lepers, and handicapped (blind, lame and deaf). One scene presents the bleeding (krvotociva) women. Scenes of recovery from nervous and mental diseases are especially impressive. Patients with atrophic arm, these with hemiplegy, epilepsy, an somnambulist boy, lunatics and possessed are there painted. The magnificent compositions of the miraculous recovery of a patient with ascites (debela, vodena bolest) and these affected by disorders of mainly neuromuscular and locomotor systems are performed by talented masters. The King Stefan Urosh Dechanski Third (1322-1331) founded the hospital in the Dechani Monastery, as a purely medical institution for providing treatment. This hospital was organized and modelled on the hospital in the Pantocrator Monastery in Constantinople. His biographer Gregory Camblak described that this hospital took in patients suffering from epilepsy (svestenoga neduga radi stradalcem) and serious nervous disorders, lepers, cripples, paralytics and those with lung diseases. Regardless of differences in the artistic level, most of these frescoes are impressively natural and realistic. This supports the ascertain that masters painted even some of patients from Monastery Hospital. The scenes of Christ's miraculous recoveries in the Dechani Monastery are undoubtelly significant for both the cultural history and the Serbian medieval medicine. This considerable cycle of the monumental painting and frescoes with medical matter, constitutes the basis for research of the Serbian medicine of the Middle-Ages.

General Tricomi-Rassias problem and oblique derivative problem for generalized Chaplygin equations

NASA Astrophysics Data System (ADS)

Wen, Guochun; Chen, Dechang; Cheng, Xiuzhen

2007-09-01

Many authors have discussed the Tricomi problem for some second order equations of mixed type, which has important applications in gas dynamics. In particular, Bers proposed the Tricomi problem for Chaplygin equations in multiply connected domains [L. Bers, Mathematical Aspects of Subsonic and Transonic Gas Dynamics, Wiley, New York, 1958]. And Rassias proposed the exterior Tricomi problem for mixed equations in a doubly connected domain and proved the uniqueness of solutions for the problem [J.M. Rassias, Lecture Notes on Mixed Type Partial Differential Equations, World Scientific, Singapore, 1990]. In the present paper, we discuss the general Tricomi-Rassias problem for generalized Chaplygin equations. This is one general oblique derivative problem that includes the exterior Tricomi problem as a special case. We first give the representation of solutions of the general Tricomi-Rassias problem, and then prove the uniqueness and existence of solutions for the problem by a new method. In this paper, we shall also discuss another general oblique derivative problem for generalized Chaplygin equations.

[Magical and religious healing in Byzantium].

PubMed

Józsa, László

2010-01-01

Religious and magical ways of healing have been known and practiced since the very beginning of human history. In the present article, the Byzantine philosophical, cultural, historical and "methodological" aspects of this way of healing are discussed. The article outlines the development of magic healing in Byzantium from the 4th to the 15th century. During this period magical therapy included the cult of patron saints--listed by the author--and pleading for divine intervention as well. The activity of "anargyroi" and the use of magical objects and amulets is also discussed in detail. Exorcism was also a part of religious therapy both against psychical and somatical diseases. In early Christianity, and especially in Byzantium the devil or other demons were also supposed to cause various somatical or psychical illnesses by "intrusion" or "internalisation," i.e. by possession or obsession of their victims.

Verification of the FtCayuga fault-tolerant microprocessor system. Volume 1: A case study in theorem prover-based verification

NASA Technical Reports Server (NTRS)

Srivas, Mandayam; Bickford, Mark

1991-01-01

The design and formal verification of a hardware system for a task that is an important component of a fault tolerant computer architecture for flight control systems is presented. The hardware system implements an algorithm for obtaining interactive consistancy (byzantine agreement) among four microprocessors as a special instruction on the processors. The property verified insures that an execution of the special instruction by the processors correctly accomplishes interactive consistency, provided certain preconditions hold. An assumption is made that the processors execute synchronously. For verification, the authors used a computer aided design hardware design verification tool, Spectool, and the theorem prover, Clio. A major contribution of the work is the demonstration of a significant fault tolerant hardware design that is mechanically verified by a theorem prover.

Characterization of ancient glass excavated in Enez (Ancient Ainos) Turkey by combined Instrumental Neutron Activation Analysis and Fourier Transform Infrared spectrometry techniques

NASA Astrophysics Data System (ADS)

Akyuz, Sevim; Akyuz, Tanil; Mukhamedshina, Nuranya M.; Mirsagatova, A. Adiba; Basaran, Sait; Cakan, Banu

2012-05-01

Ancient glass fragments excavated in the archaeological district Enez (Ancient Ainos)-Turkey were investigated by combined Instrumental Neutron Activation Analysis (INAA) and Fourier Transform Infrared (FTIR) spectrometry techniques. Multi-elemental contents of 15 glass fragments that belong to Hellenistic, Roman, Byzantine, and Ottoman Periods, were determined by INAA. The concentrations of twenty six elements (Na, K, Ca, Sc, Cr, Mn, Fe, Co, Cu, Zn, As, Rb, Sr, Sb, Cs, Ba, Ce, Sm, Eu, Tb, Yb, Lu, Hf, Ta, Au and Th), which might be present in the samples as flux, stabilizers, colorants or opacifiers, and impurities, were examined. Chemometric treatment of the INAA data was performed and principle component analysis revealed presence of 3 distinct groups. The thermal history of the glass samples was determined by FTIR spectrometry.

Abstract generalized vector quasi-equilibrium problems in noncompact Hadamard manifolds.

PubMed

Lu, Haishu; Wang, Zhihua

2017-01-01

This paper deals with the abstract generalized vector quasi-equilibrium problem in noncompact Hadamard manifolds. We prove the existence of solutions to the abstract generalized vector quasi-equilibrium problem under suitable conditions and provide applications to an abstract vector quasi-equilibrium problem, a generalized scalar equilibrium problem, a scalar equilibrium problem, and a perturbed saddle point problem. Finally, as an application of the existence of solutions to the generalized scalar equilibrium problem, we obtain a weakly mixed variational inequality and two mixed variational inequalities. The results presented in this paper unify and generalize many known results in the literature.

Generalized vector calculus on convex domain

NASA Astrophysics Data System (ADS)

Agrawal, Om P.; Xu, Yufeng

2015-06-01

In this paper, we apply recently proposed generalized integral and differential operators to develop generalized vector calculus and generalized variational calculus for problems defined over a convex domain. In particular, we present some generalization of Green's and Gauss divergence theorems involving some new operators, and apply these theorems to generalized variational calculus. For fractional power kernels, the formulation leads to fractional vector calculus and fractional variational calculus for problems defined over a convex domain. In special cases, when certain parameters take integer values, we obtain formulations for integer order problems. Two examples are presented to demonstrate applications of the generalized variational calculus which utilize the generalized vector calculus developed in the paper. The first example leads to a generalized partial differential equation and the second example leads to a generalized eigenvalue problem, both in two dimensional convex domains. We solve the generalized partial differential equation by using polynomial approximation. A special case of the second example is a generalized isoperimetric problem. We find an approximate solution to this problem. Many physical problems containing integer order integrals and derivatives are defined over arbitrary domains. We speculate that future problems containing fractional and generalized integrals and derivatives in fractional mechanics will be defined over arbitrary domains, and therefore, a general variational calculus incorporating a general vector calculus will be needed for these problems. This research is our first attempt in that direction.

Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method

NASA Astrophysics Data System (ADS)

Kadioglu, S.

2009-04-01

Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method Selma KADIOGLU Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100 Tandogan/ANKARA-TURKEY kadioglu@eng.ankara.edu.tr Anatolia has always been more the point of transit, a bridge between West and East. Anatolia has been a home for ideas moving from all directions. So it is that in the Roman and post-Roman periods the role of Anatolia in general and of Ancyra (the Roman name of Ankara) in particular was of the greatest importance. Now, the visible archaeological remains of Roman period in Ankara are Roman Bath, Gymnasium, the Temple of Augustus of Rome, Street, Theatre, City Defence-Wall. The Caesar Augustus, the first Roman Emperor, conquered Asia Minor in 25 BC. Then a marble temple was built in Ancyra, the administrative capital of province, today the capital of Turkish Republic, Ankara. This monument was consecrated to the Empreror and to the Goddess Rome. This temple is supposed to have built over an earlier temple dedicated to Kybele and Men between 25 -20 BC. After the death of the Augustus in 14AD, a copy of the text of "Res Gestae Divi Augusti" was inscribed on the interior of the pronaos in Latin, whereas a Greek translation is also present on an exterior wall of the cella. In the 5th century, it was converted in to a church by the Byzantines. The aim of this study is to determine old buried archaeological remains in the Augustus temple, Roman Bath and in the governorship agora in Ulus district. These remains were imaged with transparent three dimensional (3D) visualization of the ground penetrating radar (GPR) data. Parallel two dimensional (2D) GPR profile data were acquired in the study areas, and then a 3D data volume were built using parallel 2D GPR data. A simplified amplitude-colour range and appropriate opacity function were constructed and transparent 3D image were obtained to activate buried remains. Interactive interpretation was done by using sub-blocks of the transparent 3D volume. The opacity function coefficients were increased while deep sub-blocks were visualized. Therefore amplitudes of electromagnetic wave field were controlled by changing opacity coefficients with depth. The transparent 3D visualization provided to identify the archaeological remains on native locations with depth in a 3D volume. According to the visualization results, in the governorship agora, the broken Roman Street was identified under the remnants of Ottoman, Seljuk's and Byzantine periods respectively at 4m depths and a colonnaded portico was determined in the governorship garden. Diggings encouraged the 3D image results. In the Augustus temple, very complex remnant structures including cubbies were determined in front of the east wall of the temple. The remnant walls very near to the surface were continued so deep in the 3D image. The transparent 3D visualization results overlapped with the digging results of the Augustus temple.

[Healing and the Roman imperial culture].

PubMed

Ziethen, G

1994-01-01

From the time of Augustus till Late Antiquity one of the important elements of Roman Imperial policy was the celebration of rituals honouring the Roman Emperor. Elements of Hellenistic ruler cult and traditions of the Roman Republican Age were connected with Roman administration, the economic life and military organisation. Thereby the Roman Emperor generally was considered not only as a powerful and legitimate political leader but also as a well-educated and informed princeps with some kind of ritual sphere. Continuing the traditions of kingship risen in the Oriental monarchies and traduced to the Hellenistic rulers, the Roman Emperor seemed--pictured as Asclepius or Sarapis--to be able to heal not only incurable persons by magic therapy, but also to give a cure to mishandled affairs of state. The hope of the people in the panacea founded on the Emperor's knowledge was explained differently on two intellectual levels: the belief in magical-medical practices against threatening demons and the sophisticated comparisons of the eras of the Roman Empire expressed as the progress of human life from the cradle of iuventus to the old age of senectus. With the image of the Roman State as a human being a tradition began which had been prepared by the parable of the body and the limbs since early Roman historiography. From paganism to the Christianisation of the Roman Empire the vocabulary of healing and therapy was used in papyrological, literary, juridical and theological texts expressing the expectation in impersonation and ceremony of the Roman and Byzantine Emperors till the godblessed monarchs in Christian Europe.

HISTORIA Alexandri Magni: Astronomy, Astrology and Tradition

NASA Astrophysics Data System (ADS)

Papathanassiou, M.

A popular text on the birth, life and death of Alexander the Great is that attributed to Pseudo-Callisthenes. According to this Byzantine text Alexander is the son of the last king of Egypt, the Pharao Nectanebo, who left his country and following Apollo's oracle visited Macedonia. Nectanebo was famous for his astronomical, astrological and magical knowledge which he used to prevent Alexander's birth for some hours until a favoured time comes. In only one manuscript (Paris. gr. 1711, 11th century) of this work there is a unique passage in which astronomical information is given regarding the positions of the Sun, the Moon, and the five planets at the time of Alexander's birth. In this paper I attempt a study of all information related to the astronomical instruments and their use as mentioned in the text as well as of the astronomical information regarding Alexander's birth.

Luminescence quartz dating of lime mortars. A first research approach.

PubMed

Zacharias, N; Mauz, B; Michael, C T

2002-01-01

Lime mortars mixed with sand are well suited for connecting structural materials, like stones and bricks, due to the mechanical properties this material exhibits. Their extensive use in architectural and decorative works during the last 4000 years motivated the introduction of the 'Luminescence clock' for age determination of mortars. The same principles as for quartz optically stimulated luminescence (OSL) dating of sediments were applied for age estimation of a mortar fragment removed from a Byzantine church monument dated by archaeological means to 1050-1100 years ago (the first half of the 10th century). The OSL from the quartz was monitored under blue light stimulation and UV detection, using a single-aliquot-regenerative-dose protocol. The quartz-OSL dating of the mortar resulted in 870 +/- 230 a. TL polymineral fine grain dating was also performed on a brick fragment which was connected to the mortar, resulting in a TL age of 1095 +/- 190 a.

Secret Forwarding of Events over Distributed Publish/Subscribe Overlay Network.

PubMed

Yoon, Young; Kim, Beom Heyn

2016-01-01

Publish/subscribe is a communication paradigm where loosely-coupled clients communicate in an asynchronous fashion. Publish/subscribe supports the flexible development of large-scale, event-driven and ubiquitous systems. Publish/subscribe is prevalent in a number of application domains such as social networking, distributed business processes and real-time mission-critical systems. Many publish/subscribe applications are sensitive to message loss and violation of privacy. To overcome such issues, we propose a novel method of using secret sharing and replication techniques. This is to reliably and confidentially deliver decryption keys along with encrypted publications even under the presence of several Byzantine brokers across publish/subscribe overlay networks. We also propose a framework for dynamically and strategically allocating broker replicas based on flexibly definable criteria for reliability and performance. Moreover, a thorough evaluation is done through a case study on social networks using the real trace of interactions among Facebook users.

Secret Forwarding of Events over Distributed Publish/Subscribe Overlay Network

PubMed Central

Kim, Beom Heyn

2016-01-01

Publish/subscribe is a communication paradigm where loosely-coupled clients communicate in an asynchronous fashion. Publish/subscribe supports the flexible development of large-scale, event-driven and ubiquitous systems. Publish/subscribe is prevalent in a number of application domains such as social networking, distributed business processes and real-time mission-critical systems. Many publish/subscribe applications are sensitive to message loss and violation of privacy. To overcome such issues, we propose a novel method of using secret sharing and replication techniques. This is to reliably and confidentially deliver decryption keys along with encrypted publications even under the presence of several Byzantine brokers across publish/subscribe overlay networks. We also propose a framework for dynamically and strategically allocating broker replicas based on flexibly definable criteria for reliability and performance. Moreover, a thorough evaluation is done through a case study on social networks using the real trace of interactions among Facebook users. PMID:27367610

The application of LIBS for the analysis of archaeological ceramic and metal artifacts

NASA Astrophysics Data System (ADS)

Melessanaki, Kristalia; Mateo, Maripaz; Ferrence, Susan C.; Betancourt, Philip P.; Anglos, Demetrios

2002-09-01

A bench-top laser-induced breakdown spectroscopy (LIBS) system has been used in the examination of pottery, jewelry and metal artifacts found in archaeological excavations in central and eastern Crete, Greece. The objects date from the Middle and Late Minoan periods (ca. 20th-13th century B. C.) through Byzantine and Venetian to Ottoman times (ca. 5th-19th century A.D.). The spectral data indicates the qualitative and often the semi-quantitative elemental composition of the examined materials. In the case of colored glazed ceramics, the identity of pigments was established while in the case of metal and jewelry analysis, the type of metal or metal alloy used was determined. The analyses demonstrate the potential of the LIBS technique for performing routine, rapid, on-site analysis of archaeological objects, which leads to the quick characterization or screening of different types of objects.

From antiquity to Olympic revival: sports and Greek national historiography (nineteenth-twentieth centuries).

PubMed

Koulouri, Christina

2010-01-01

This study investigates the evolution of the historiography of Greek sport from the foundation of the Greek state (1830) until 1982 and its links with Greek national history, which also took shape primarily during the nineteenth century. The gradual 'nationalisation' of sport as an element of Greek national character since antiquity corresponded to changes in perceptions of the national past reflected in historiography. The ancient Olympic Games, Byzantine contests and exercises, the competitions of the klephts and armatoloi (militia soldiers) during the Ottoman rule and the modern revival of the Olympic Games were all successively integrated in a national history of sport confirming national continuity and unity. However this particular genre of national historiography did not gain academic recognition until recently. The authors of histories of physical exercise and sport were amateurs or physical education instructors and could not ensure to their work the authority of a separate discipline.

A forensic hypothesis for the mystery of al-Hasan’s death in the 7th century: Mercury(I) chloride intoxication

PubMed Central

Burke, Nicole; Golas, Mitchell; Raafat, Cyrus L.

2015-01-01

The puzzle of a mysterious death in the Middle Ages has been hypothesized in terms of contemporary forensic legal and scientific methods. That al-Hasan ibn-‘Ali died in 669 aged just 45 has been forensically analyzed based on written sources that dictate eyewitness accounts of historical events. The report of the contemporaneous poisoning of another individual who resided under the same household as al-Hasan’s and experienced similar, yet non-lethal, symptoms has served as the beginning of the analysis. In light of ancient (medieval) documents and through using mineralogical, medical, and chemical facts, it has been hypothesized that mineral calomel (mercury(I) chloride, Hg2Cl2) from a certain region in the Byzantine Empire (present-day western Turkey) was the substance primarily responsible for the murder of al-Hasan. PMID:26377933

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan, Sisi; Li, Yun; Levitt, Karl N.

Consensus is a fundamental approach to implementing fault-tolerant services through replication where there exists a tradeoff between the cost and the resilience. For instance, Crash Fault Tolerant (CFT) protocols have a low cost but can only handle crash failures while Byzantine Fault Tolerant (BFT) protocols handle arbitrary failures but have a higher cost. Hybrid protocols enjoy the benefits of both high performance without failures and high resiliency under failures by switching among different subprotocols. However, it is challenging to determine which subprotocols should be used. We propose a moving target approach to switch among protocols according to the existing systemmore » and network vulnerability. At the core of our approach is a formalized cost model that evaluates the vulnerability and performance of consensus protocols based on real-time Intrusion Detection System (IDS) signals. Based on the evaluation results, we demonstrate that a safe, cheap, and unpredictable protocol is always used and a high IDS error rate can be tolerated.« less

Using a general problem-solving strategy to promote transfer.

PubMed

Youssef-Shalala, Amina; Ayres, Paul; Schubert, Carina; Sweller, John

2014-09-01

Cognitive load theory was used to hypothesize that a general problem-solving strategy based on a make-as-many-moves-as-possible heuristic could facilitate problem solutions for transfer problems. In four experiments, school students were required to learn about a topic through practice with a general problem-solving strategy, through a conventional problem solving strategy or by studying worked examples. In Experiments 1 and 2 using junior high school students learning geometry, low knowledge students in the general problem-solving group scored significantly higher on near or far transfer tests than the conventional problem-solving group. In Experiment 3, an advantage for a general problem-solving group over a group presented worked examples was obtained on far transfer tests using the same curriculum materials, again presented to junior high school students. No differences between conditions were found in Experiments 1, 2, or 3 using test problems similar to the acquisition problems. Experiment 4 used senior high school students studying economics and found the general problem-solving group scored significantly higher than the conventional problem-solving group on both similar and transfer tests. It was concluded that the general problem-solving strategy was helpful for novices, but not for students that had access to domain-specific knowledge. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Climate, environment and society in southern Italy during the last 2000 years. A review of the environmental, historical and archaeological evidence

NASA Astrophysics Data System (ADS)

Sadori, Laura; Giraudi, Carlo; Masi, Alessia; Magny, Michel; Ortu, Elena; Zanchetta, Giovanni; Izdebski, Adam

2016-03-01

This paper examines the interrelationship between the natural and human history of Sicily over the last 2000 years. It presents a close comparison of the data from the key multi-proxy site of Lago di Pergusa - located inland in the eastern part of Sicily - with the existing archaeological and textual evidence on the socio-economic processes. The article also includes a review of the available natural proxy archives from the Central Mediterranean. On the basis of the isotope and pollen data from the Lago di Pergusa core PRG2, we identified two humid periods (ca. 450-750 AD and ca. 1400-1800 AD) as well as a dry one (ca. 1100-1350 AD); our evidence corresponds closely with other environmental palaeoclimate proxies from the Mediterranean region. In our synthesis of the environmental, historical and archaeological evidence from southern Italy, we argue that during both periods of increased humidity - that is during the late antique-Byzantine times and during the late medieval and early modern periods - intense agricultural use of the Sicilian landscape developed on an unprecedented scale. This in turn contributed to the impressive demographic and economic expansion visible during these periods. A sudden period of aridity followed the first of these eras of humidity-related agricultural growth. This climatic shift, dated to around 750 AD, corresponds to a decrease in synanthropic taxa and a recovery of arboreal vegetation. We argue that in this case a climatic change contributed to socio-economic decline. Moreover, as this change occurred prior to the Arab invasion of Sicily in AD 827, the environmental processes may help to explain the collapse of Byzantine society on Sicily which, in turn made the Muslim conquest possible. After this event, there occurred a longer period of agricultural decline, lasting until around 1000 AD, after which we see the first signs of a slow recovery. Ongoing research in nearby archaeological sites will help defining if it was a local change or a regional, potentially climate-induced phenomenon. Although textual evidence records considerable population losses during the later Middle Ages as a result of the Black Death, the effects of the plague are not obviously apparent in the pollen data, except for some short term fluctuations.

Natural pigments and sacred art

NASA Astrophysics Data System (ADS)

Kelekian, Lena, ,, Lady

2010-05-01

Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The iconographer uses earthly creations to create divine images: "Thine own of Thine own we offer unto Thee." (Byzantine Liturgy). Thus, by combining geology with art and religion, I can render homage to God through His creation by using minerals of the Planet Earth, as natural pigments in painting His image.

Ethnopharmacological approach to the herbal medicines of the "Antidotes" in Nikolaos Myrepsos׳ Dynameron.

PubMed

Valiakos, E; Marselos, M; Sakellaridis, N; Constantinidis, Th; Skaltsa, H

2015-04-02

This paper focuses on the plants quoted in the recipes of the first chapter entitled "About the Antidotes" belonging to the first and largest section "Element Alpha" of Nikolaos Myrepsos׳ Dynameron, a medieval medical manuscript. Nikolaos Myrepsos was a Byzantine physician at the court of John III Doukas Vatatzes at Nicaea (13th century). He wrote in Greek a rich collection of 2667 recipes, the richest number known in late Byzantine era, conventionally known as Dynameron and divided into 24 sections, the "Elements". The only existing translation of this work is in Latin, released in 1549 in Basel by Leonhart Fuchs. Since no other translation has ever been made in any language, this work still remains poorly known. Our primary source material was the codex written in 1339 and kept in the National Library of France (in Paris) under the number grec. 2243. For comparison, all the other codices, which contain the entire manuscript, have also been studied, namely the codices EBE 1478 (National Library of Greece, Athens), grec. 2237 and grec. 2238 (both in Paris), Lavra Ε 192 (Mont Athos, Monastery of Megisti Lavra), Barocci 171 (Oxford) and Revilla 83 (Escorial). The exhaustive study of the "About the Antidotes" led us to the interpretation of 293 plant names among which we recognized 39 medicinal plants listed by the European Medicines Agency, (Herbal Medicines, www.ema.eu); the therapeutic indications of some of them provided by Myrepsos were similar or related to their current ones, as given in their monographs. The plants belong to various families of which the most frequent are: Apiaceae 10.6%; Lamiaceae 9.2%; Asteraceae 8.9%; Fabaceae 6.8% and Rosaceae 5.1%. The most frequently mentioned plants even under several different names are the following: Apium graveolens L., Crocus sativus L., Nardostachys jatamansi (D. Don) DC., Zingiber officinale Roscoe, Rosa centifolia L., Syzygium aromaticum (L.) Merr. & L.M. Perry, Papaver somniferum L., Costus sp., Petroselinum crispum (Mill.) Fuss, Anethum graveolens L., Foeniculum vulgare Mill., Daucus carota L. This research led us to the conclusion that the content of "About the Antidotes" is a valuable source for the study of recipes based mainly on medicinal plants, most of them inherited from classic ancient Greek and Hellenistic periods. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The Prisoner Problem--A Generalization.

ERIC Educational Resources Information Center

Gannon, Gerald E.; Martelli, Mario U.

2000-01-01

Presents a generalization to the classic prisoner problem, which is inherently interesting and has a solution within the reach of most high school mathematics students. Suggests the problem as a way to emphasize to students the final step in a problem-solver's tool kit, considering possible generalizations when a particular problem has been…

Auxiliary principle technique and iterative algorithm for a perturbed system of generalized multi-valued mixed quasi-equilibrium-like problems.

PubMed

Rahaman, Mijanur; Pang, Chin-Tzong; Ishtyak, Mohd; Ahmad, Rais

2017-01-01

In this article, we introduce a perturbed system of generalized mixed quasi-equilibrium-like problems involving multi-valued mappings in Hilbert spaces. To calculate the approximate solutions of the perturbed system of generalized multi-valued mixed quasi-equilibrium-like problems, firstly we develop a perturbed system of auxiliary generalized multi-valued mixed quasi-equilibrium-like problems, and then by using the celebrated Fan-KKM technique, we establish the existence and uniqueness of solutions of the perturbed system of auxiliary generalized multi-valued mixed quasi-equilibrium-like problems. By deploying an auxiliary principle technique and an existence result, we formulate an iterative algorithm for solving the perturbed system of generalized multi-valued mixed quasi-equilibrium-like problems. Lastly, we study the strong convergence analysis of the proposed iterative sequences under monotonicity and some mild conditions. These results are new and generalize some known results in this field.

Resins and Gums in Historical Iatrosophia Texts from Cyprus – A Botanical and Medico-pharmacological Approach

PubMed Central

Lardos, Andreas; Prieto-Garcia, José; Heinrich, Michael

2011-01-01

This study explores historical iatrosophia texts from Cyprus from a botanical and medico-pharmacological point of view focusing on remedies containing resins and gums. The iatrosophia are a genre of Greek medical literature of Byzantine origin and can be described as medicine handbooks which serve as therapeutic repositories containing recipes or advice. To extract and analyze information on plant usage in such sources – which are largely unedited texts and so far have not been translated – we investigate (i) the relationship of the iatrosophia to Dioscorides’ De Materia Medica as well as historic pharmaceutical books or standard texts on modern phytotherapy and (ii) the validity of the remedies by comparing them to modern scientific data on reported biological activities. In the six texts investigated 27 substances incorporating plant exudates are mentioned. They are obtained from over 43 taxa of higher plants and in particular are used to treat dermatological, gastrointestinal, and respiratory tract conditions. The comparison to historic pharmaceutical books and phytotherapy texts reflects the gradual decline of the use of plant exudates in Western medicine. While remarkable parallels to Dioscorides’ text exist, the non-Dioscoridean influence suggests a complex pattern of knowledge exchange. Overall, this resulted in an integration of knowledge from so far poorly understood sources. The comparison with bioscientific data reveals a fragmentary picture and highlights the potential of these unexplored substances and their uses. Where relevant bioscientific data are available, we generally found a confirmation. This points to a largely rational use of the associated remedies. Taken together, the iatrosophia are a valuable resource for ethnopharmacological and natural product research. Most importantly they contribute to the understanding of the development of herbal medicines in the (Eastern) Mediterranean and Europe. PMID:21772820

Resins and Gums in Historical Iatrosophia Texts from Cyprus - A Botanical and Medico-pharmacological Approach.

PubMed

Lardos, Andreas; Prieto-Garcia, José; Heinrich, Michael

2011-01-01

This study explores historical iatrosophia texts from Cyprus from a botanical and medico-pharmacological point of view focusing on remedies containing resins and gums. The iatrosophia are a genre of Greek medical literature of Byzantine origin and can be described as medicine handbooks which serve as therapeutic repositories containing recipes or advice. To extract and analyze information on plant usage in such sources - which are largely unedited texts and so far have not been translated - we investigate (i) the relationship of the iatrosophia to Dioscorides' De Materia Medica as well as historic pharmaceutical books or standard texts on modern phytotherapy and (ii) the validity of the remedies by comparing them to modern scientific data on reported biological activities. In the six texts investigated 27 substances incorporating plant exudates are mentioned. They are obtained from over 43 taxa of higher plants and in particular are used to treat dermatological, gastrointestinal, and respiratory tract conditions. The comparison to historic pharmaceutical books and phytotherapy texts reflects the gradual decline of the use of plant exudates in Western medicine. While remarkable parallels to Dioscorides' text exist, the non-Dioscoridean influence suggests a complex pattern of knowledge exchange. Overall, this resulted in an integration of knowledge from so far poorly understood sources. The comparison with bioscientific data reveals a fragmentary picture and highlights the potential of these unexplored substances and their uses. Where relevant bioscientific data are available, we generally found a confirmation. This points to a largely rational use of the associated remedies. Taken together, the iatrosophia are a valuable resource for ethnopharmacological and natural product research. Most importantly they contribute to the understanding of the development of herbal medicines in the (Eastern) Mediterranean and Europe.

A Fiducial Approach to Extremes and Multiple Comparisons

ERIC Educational Resources Information Center

Wandler, Damian V.

2010-01-01

Generalized fiducial inference is a powerful tool for many difficult problems. Based on an extension of R. A. Fisher's work, we used generalized fiducial inference for two extreme value problems and a multiple comparison procedure. The first extreme value problem is dealing with the generalized Pareto distribution. The generalized Pareto…

Understanding Adult Age Differences in the Frequency of Problems With Friends.

PubMed

Schlosnagle, Leo; Strough, JoNell

2017-01-01

We investigated characteristics of younger and older adults' friendships. Younger (N = 39) and older (N = 39) adults completed measures pertaining to a specific friend they had (i.e., contact frequency, positive friendship quality, and negative friendship quality) and their frequency of problems with friends in general. Older adults reported fewer problems with friends in general, and fewer negative friendship qualities, less frequent contact, and more positive friendship qualities with a specific friend than younger adults. Contact frequency, positive friendship quality, and negative friendship quality with a specific friend were related to frequency of problems with friends in general, but only contact frequency was a significant mediator of the relation between age and frequency of problems with friends in general. Results show that characteristics of a specific friendship relate to problems with friends in general, and that contact frequency with a specific friend mediates the relation between age and problems with friends in general. Implications are discussed. © The Author(s) 2016.

Step by Step: Biology Undergraduates’ Problem-Solving Procedures during Multiple-Choice Assessment

PubMed Central

Prevost, Luanna B.; Lemons, Paula P.

2016-01-01

This study uses the theoretical framework of domain-specific problem solving to explore the procedures students use to solve multiple-choice problems about biology concepts. We designed several multiple-choice problems and administered them on four exams. We trained students to produce written descriptions of how they solved the problem, and this allowed us to systematically investigate their problem-solving procedures. We identified a range of procedures and organized them as domain general, domain specific, or hybrid. We also identified domain-general and domain-specific errors made by students during problem solving. We found that students use domain-general and hybrid procedures more frequently when solving lower-order problems than higher-order problems, while they use domain-specific procedures more frequently when solving higher-order problems. Additionally, the more domain-specific procedures students used, the higher the likelihood that they would answer the problem correctly, up to five procedures. However, if students used just one domain-general procedure, they were as likely to answer the problem correctly as if they had used two to five domain-general procedures. Our findings provide a categorization scheme and framework for additional research on biology problem solving and suggest several important implications for researchers and instructors. PMID:27909021

Perceptions of general environmental problems, willingness to expend federal funds on these problems, and concerns regarding the Los Alamos National Laboratory: Hispanics are more concerned than Whites.

PubMed

Burger, Joanna; Myers, O; Boring, C S; Dixon, C; Lord, C; Ramos, R; Shukla, S; Gochfeld, Michael

2004-06-01

Perceptions about general environmental problems, governmental spending for these problems, and major concerns about the US Department of Energy's Los Alamos National Laboratory (LANL) were examined by interviewing 356 people attending a gun show in Albuquerque, New Mexico. The hypothesis that there are differences in these three areas as a function of ethnicity was examined. We predicted that if differences existed, they would exist for all three evaluations (general environmental problems, government spending, and environmental concerns about LANL). However, this was not the case; there were fewer ethnic differences concerning LANL. Hispanics rated most general environmental problems higher than Whites and rated their willingness to expend federal funds higher than Whites, although all groups gave a lower score on willingness than on concern. Further, the congruence between these two types of ratings was higher for Hispanics than for others. In general, the concerns expressed by subjects about LANL showed few ethnic differences, and everyone was most concerned about contamination. These data indicate that Hispanics attending a gun show are equally or more concerned than others about environmental problems generally but are not more concerned about LANL. The data can be useful for developing future research and stewardship plans and for understanding general environmental problems and their relationship to concerns about LANL. More generally, they indicate that the attitudes and perceptions of Hispanics deserve increased study in a general population.

A New On-Line Diagnosis Protocol for the SPIDER Family of Byzantine Fault Tolerant Architectures

NASA Technical Reports Server (NTRS)

Geser, Alfons; Miner, Paul S.

2004-01-01

This paper presents the formal verification of a new protocol for online distributed diagnosis for the SPIDER family of architectures. An instance of the Scalable Processor-Independent Design for Electromagnetic Resilience (SPIDER) architecture consists of a collection of processing elements communicating over a Reliable Optical Bus (ROBUS). The ROBUS is a specialized fault-tolerant device that guarantees Interactive Consistency, Distributed Diagnosis (Group Membership), and Synchronization in the presence of a bounded number of physical faults. Formal verification of the original SPIDER diagnosis protocol provided a detailed understanding that led to the discovery of a significantly more efficient protocol. The original protocol was adapted from the formally verified protocol used in the MAFT architecture. It required O(N) message exchanges per defendant to correctly diagnose failures in a system with N nodes. The new protocol achieves the same diagnostic fidelity, but only requires O(1) exchanges per defendant. This paper presents this new diagnosis protocol and a formal proof of its correctness using PVS.

A brief history of otorhinolaryngolgy: otology, laryngology and rhinology.

PubMed

Nogueira, João Flávio; Hermann, Diego Rodrigo; Américo, Ronaldo dos Reis; Barauna Filho, Iulo Sérgio; Stamm, Aldo Eden Cassol; Pignatari, Shirley Shizuo Nagata

2007-01-01

Ears, nose and throat have intrigued humanity since immemorial times. Treatments for the larynx, the nose and the ear and also surgeries were practiced by Greek, Hindu and Byzantine doctors. In the 20th century clinical and surgical innovations were incorporated, thanks to new anesthesia techniques, antibiotics, radiology and new technologies. show the evolution of this science throughout the times, recognizing important persons in otology, rhinology and laryngology. Understanding the evolutions in clinical and surgical anatomy, physiology, treatment modalities, and the personalities that lead to these advances is of great importance for the evolution of medical science. Otorhinolaryngology has a very rich history, with important collaborators and personalities in the history of medicine. The specialty was one of the first to use local anesthesia for procedures, pioneer in treatments with devices that recouped hearing and the use of microscopes in surgeries. Few medical specialties had suffered as many changes and scientific developments in these last decades as Otorhinolaryngology had, with the advantage of incorporating technologies such as endoscopy, radiology, microsurgery and information technology.

Impacts of climate change on Middle Eastern societies over the last 2700 years: new results from the Gejkar speleothem, Iraq

NASA Astrophysics Data System (ADS)

Flohr, Pascal; Fleitmann, Dominik; Bosomworth, Matt; Cheng, Hai; Sadekov, Aleksey; Matthews, Roger; Matthews, Wendy; Black, Stuart; Edwards, Lawrence

2016-04-01

Climatic and environmental changes are often cited as a major factor for past social, economic, and political changes. This is especially relevant in the semi-arid to arid Middle East, where, however, only few precisely dated, high-resolution climate records are available. Here we present new results from an up to annually resolved stalagmite from Gejkar Cave in the Kurdish Regional Government of Iraq region. Based on Uranium-series dating and annual layer counts, the record dates back ~2700 years, and its annual layer thickness and carbon and oxygen isotope profile appear indicative of precipitation and effective moisture. We also assess if observed decadal to multi-decadal shifts in precipitation are synchronous with socio-economic changes as observed in the archaeological and historical record in the wider Middle East over the last 2000 years, such as the largely prosperous Roman and Byzantine periods, the Seljuq invasion, and the decline of the Ottoman Empire.

Multi-approach characterization of the Rhodope marbles, Greece used in monuments

NASA Astrophysics Data System (ADS)

Dotsika, Elissavet; Raco, Brunella; Psomiadis, David; Poutoukis, Dimitrios; Zisi, Nikoleta

2010-05-01

Northern Greece has many archaeological sites featuring buildings and objects entirely or partly constructed from marble whose provenance is doubtful. In Northern Greece, the most probable source of such marble is the Rhodope Mountains. For the purpose of supporting further provenance studies, these marbles are fully scientifically characterized. The sampling took place in several ancient quarries which were on trade routes of Hellenistic, Roman or Byzantine settlements. Trade of marble in N. Greece is proved to have been equally important as in S. Greece, comparing the qualitative marble of Thassos with the best marbles of the south (e.g. Paros, Naxos etc.). The techniques used are petrographic and geochemical (microscope, X-Ray diffraction patterns, Scanning Electron Microscope) methods and stable isotope ratio analysis (δ13C and δ18O). The use of a multi-technique approach with combined parameters allows the best possible discrimination. This scientific investigation both supplements the isotopic database and proves that in N. Greece people used also imported marbles.

MAX - An advanced parallel computer for space applications

NASA Technical Reports Server (NTRS)

Lewis, Blair F.; Bunker, Robert L.

1991-01-01

MAX is a fault-tolerant multicomputer hardware and software architecture designed to meet the needs of NASA spacecraft systems. It consists of conventional computing modules (computers) connected via a dual network topology. One network is used to transfer data among the computers and between computers and I/O devices. This network's topology is arbitrary. The second network operates as a broadcast medium for operating system synchronization messages and supports the operating system's Byzantine resilience. A fully distributed operating system supports multitasking in an asynchronous event and data driven environment. A large grain dataflow paradigm is used to coordinate the multitasking and provide easy control of concurrency. It is the basis of the system's fault tolerance and allows both static and dynamical location of tasks. Redundant execution of tasks with software voting of results may be specified for critical tasks. The dataflow paradigm also supports simplified software design, test and maintenance. A unique feature is a method for reliably patching code in an executing dataflow application.

High resolution spectroscopic mapping imaging applied in situ to multilayer structures for stratigraphic identification of painted art objects

NASA Astrophysics Data System (ADS)

Karagiannis, Georgios Th.

2016-04-01

The development of non-destructive techniques is a reality in the field of conservation science. These techniques are usually not so accurate, as the analytical micro-sampling techniques, however, the proper development of soft-computing techniques can improve their accuracy. In this work, we propose a real-time fast acquisition spectroscopic mapping imaging system that operates from the ultraviolet to mid infrared (UV/Vis/nIR/mIR) area of the electromagnetic spectrum and it is supported by a set of soft-computing methods to identify the materials that exist in a stratigraphic structure of paint layers. Particularly, the system acquires spectra in diffuse-reflectance mode, scanning in a Region-Of-Interest (ROI), and having wavelength range from 200 up to 5000 nm. Also, a fuzzy c-means clustering algorithm, i.e., the particular soft-computing algorithm, produces the mapping images. The evaluation of the method was tested on a byzantine painted icon.

Practical State Machine Replication with Confidentiality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan, Sisi; Zhang, Haibin

2016-01-01

We study how to enable arbitrary randomized algorithms in Byzantine fault-tolerant (BFT) settings. We formalize a randomized BFT protocol and provide a simple and efficient construction that can be built on any existing BFT protocols while adding practically no overhead. We go one step further to revisit a confidential BFT protocol (Yin et al., SOSP '03). We show that their scheme is potentially susceptible to safety and confidentiality attacks. We then present a new protocol that is secure in the stronger model we formalize, by extending the idea of a randomized BFT protocol. Our protocol uses only efficient symmetric cryptography,more » while Yin et al.'s uses costly threshold signatures. We implemented and evaluated our protocols on microbenchmarks and real-world use cases. We show that our randomized BFT protocol is as efficient as conventional BFT protocols, and our confidential BFT protocol is two to three orders of magnitude faster than Yin et al.'s, which is less secure than ours.« less

The generalized quadratic knapsack problem. A neuronal network approach.

PubMed

Talaván, Pedro M; Yáñez, Javier

2006-05-01

The solution of an optimization problem through the continuous Hopfield network (CHN) is based on some energy or Lyapunov function, which decreases as the system evolves until a local minimum value is attained. A new energy function is proposed in this paper so that any 0-1 linear constrains programming with quadratic objective function can be solved. This problem, denoted as the generalized quadratic knapsack problem (GQKP), includes as particular cases well-known problems such as the traveling salesman problem (TSP) and the quadratic assignment problem (QAP). This new energy function generalizes those proposed by other authors. Through this energy function, any GQKP can be solved with an appropriate parameter setting procedure, which is detailed in this paper. As a particular case, and in order to test this generalized energy function, some computational experiments solving the traveling salesman problem are also included.

[Patient expectations about decision-making for various health problems].

PubMed

Delgado, Ana; López-Fernández, Luis Andrés; de Dios Luna, Juan; Saletti Cuesta, Lorena; Gil Garrido, Natalia; Puga González, Almudena

2010-01-01

To identify patient expectations of clinical decision-making at consultations with their general practitioners for distinct health problems and to determine the patient and general practitioner characteristics related to these expectations, with special focus on gender. We performed a multicenter cross-sectional study in 360 patients who were interviewed at home. Data on patients' sociodemographic, clinical characteristics and satisfaction were gathered. General practitioners supplied information on their gender and postgraduate training in family medicine. A questionnaire was used to collect data on patients' expectations that their general practitioner at consultations with their general practitioner for five problems or hypothetical clinical scenarios (strong chest pain/cold with fever/abnormal discharge/depression or sadness/severe family problem). Patients were asked to indicate their preference that decisions on diagnosis and treatment be taken by: a) the general practitioner alone; b) the general practitioner, taking account of the patient's opinion; c) the patient, taking account of the general practitioner's opinion and d) the patient alone. A logistic regression was performed for clinical decision-making. The response rate was 90%. The mean age was 47.3 + or - 16.5 years and 51% were female. Patients' expectations that their general practitioner listen, explain and take account of their opinions were higher than their expectations of participating in decision-making, depending on the problem in question: 32% wished to participate in chest pain and 49% in family problems. Women had lower expectations of participating in depression and family problems. Patients with female general practitioners had higher expectations of participating in family problems and colds. Most patients wished to be listened to, informed and taken into account by their general practitioners and, to a lesser extent, wished to take decisions autonomously, especially for biomedical problems. Copyright 2009 SESPAS. Published by Elsevier Espana. All rights reserved.

Towards A Theory of Autonomous Reconstitution of Compromised Cyber-Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramuhalli, Pradeep; Halappanavar, Mahantesh; Coble, Jamie B.

The ability to maintain mission-critical operations in cyber-systems in the face of disruptions is critical. Faults in cyber systems can come from accidental sources (e.g., natural failure of a component) or deliberate sources (e.g., an intelligent adversary). Natural and intentional manipulation of data, computing, or coordination are the most impactful ways that an attacker can prevent an infrastructure from realizing its mission goals. Under these conditions, the ability to reconstitute critical infrastructure becomes important. Specifically, the question is: Given an intelligent adversary, how can cyber systems respond to keep critical infrastructure operational? In cyber systems, the distributed nature of themore » system poses serious difficulties in maintaining operations, in part due to the fact that a centralized command and control apparatus is unlikely to provide a robust framework for resilience. Resilience in cyber-systems, in general, has several components, and requires the ability to anticipate and withstand attacks or faults, as well as recover from faults and evolve the system to improve future resilience. The recovery effort (and any subsequent evolution) may require significant reconfiguration of the system (at all levels – hardware, software, services, permissions, etc.) if the system is to be made resilient to further attack or faults. This is especially important in the case of ongoing attacks, where reconfiguration decisions must be taken with care to avoid further compromising the system while maintaining continuity of operations. Collectively, we will label this recovery and evolution process as “reconstitution”. Currently, reconstitution is performed manually, generally after-the-fact, and usually consists of either standing up redundant systems, check-points (rolling back the configuration to a “clean” state), or re-creating the system using “gold-standard” copies. For enterprise systems, such reconstitution may be performed either directly on hardware, or using virtual machines. A significant challenge within this context is the ability to verify that the reconstitution is performed in a manner that renders the cyber-system resilient to ongoing and future attacks or faults. Fundamentally, the need is to determine optimal configuration of the cyber system when a fault is determined to be present. While existing theories for fault tolerance (for example, Byzantine fault tolerance) can guarantee resilience under certain conditions, in practice, these theories can break down in the face of an intelligent adversary. Further, it is difficult, in a dynamically evolving environment, to determine whether the necessary conditions for resilience have been met, resulting in difficulties in achieving resilient operation. In addition, existing theories do not sufficiently take into account the cost for attack and defense (the adversary is generally assumed to have infinite resources and time), hierarchy of importance (all network resources are assumed to be equally important), and the dynamic nature of some attacks (i.e., as the attack evolves, can resilience be maintained?). Alternative approaches to resilience based on a centralized command and control structure suffer from a single-point-failure. This paper presents preliminary research towards concepts for effective autonomous reconstitution of compromised cyber systems. We describe a mathematical framework as a first step towards a theoretical basis for autonomous reconstitution in dynamic cyber-system environments. We then propose formulating autonomous reconstitution as an optimization problem and describe some of the challenges associated with this formulation. This is followed by a brief discussion on potential solutions to these challenges.« less

Problem solving therapy - use and effectiveness in general practice.

PubMed

Pierce, David

2012-09-01

Problem solving therapy (PST) is one of the focused psychological strategies supported by Medicare for use by appropriately trained general practitioners. This article reviews the evidence base for PST and its use in the general practice setting. Problem solving therapy involves patients learning or reactivating problem solving skills. These skills can then be applied to specific life problems associated with psychological and somatic symptoms. Problem solving therapy is suitable for use in general practice for patients experiencing common mental health conditions and has been shown to be as effective in the treatment of depression as antidepressants. Problem solving therapy involves a series of sequential stages. The clinician assists the patient to develop new empowering skills, and then supports them to work through the stages of therapy to determine and implement the solution selected by the patient. Many experienced GPs will identify their own existing problem solving skills. Learning about PST may involve refining and focusing these skills.

Marital adjustment, marital discord over childrearing, and child behavior problems: moderating effects of child age.

PubMed

Mahoney, A; Jouriles, E N; Scavone, J

1997-12-01

Examined whether marital discord over childrearing contributes to child behavior problems after taking into account general marital adjustment, and if child age moderates associations between child behavior problems and either general marital adjustment or marital discord over childrearing. Participants were 146 two-parent families seeking services for their child's (4 to 9 years of age) conduct problems. Data on marital functioning and child behavior problems were collected from both parents. Mothers' and fathers' reports of marital discord over childrearing related positively to child externalizing problems after accounting for general marital adjustment. Child age moderated associations between fathers' reports of general marital adjustment and both internalizing and externalizing child problems, with associations being stronger in families with younger children. The discussion highlights the role that developmental factors may play in understanding the link between marital and child behavior problems in clinic-referred families.

A New Approach for Solving the Generalized Traveling Salesman Problem

NASA Astrophysics Data System (ADS)

Pop, P. C.; Matei, O.; Sabo, C.

The generalized traveling problem (GTSP) is an extension of the classical traveling salesman problem. The GTSP is known to be an NP-hard problem and has many interesting applications. In this paper we present a local-global approach for the generalized traveling salesman problem. Based on this approach we describe a novel hybrid metaheuristic algorithm for solving the problem using genetic algorithms. Computational results are reported for Euclidean TSPlib instances and compared with the existing ones. The obtained results point out that our hybrid algorithm is an appropriate method to explore the search space of this complex problem and leads to good solutions in a reasonable amount of time.

Problem Solving in a Natural Language Environment.

DTIC Science & Technology

1979-07-21

another mapping that can map the "values" of those slots onto each other. 11.2 Kowledge Reoresentation Systems Several general knowledge...Hirach Frames The problem solving frames are general descriptions of problems (and solutions). Much more power could be milked from the concept of...general and powerful matching routines can be seen if the problem solving frames are going to work. The matcher must find matches between an element

48 CFR 2929.101 - Resolving tax problems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Resolving tax problems. 2929.101 Section 2929.101 Federal Acquisition Regulations System DEPARTMENT OF LABOR GENERAL CONTRACTING REQUIREMENTS TAXES General 2929.101 Resolving tax problems. Contract tax problems or questions...

Operator priming and generalization of practice in adults' simple arithmetic.

PubMed

Chen, Yalin; Campbell, Jamie I D

2016-04-01

There is a renewed debate about whether educated adults solve simple addition problems (e.g., 2 + 3) by direct fact retrieval or by fast, automatic counting-based procedures. Recent research testing adults' simple addition and multiplication showed that a 150-ms preview of the operator (+ or ×) facilitated addition, but not multiplication, suggesting that a general addition procedure was primed by the + sign. In Experiment 1 (n = 36), we applied this operator-priming paradigm to rule-based problems (0 + N = N, 1 × N = N, 0 × N = 0) and 1 + N problems with N ranging from 0 to 9. For the rule-based problems, we found both operator-preview facilitation and generalization of practice (e.g., practicing 0 + 3 sped up unpracticed 0 + 8), the latter being a signature of procedure use; however, we also found operator-preview facilitation for 1 + N in the absence of generalization, which implies the 1 + N problems were solved by fact retrieval but nonetheless were facilitated by an operator preview. Thus, the operator preview effect does not discriminate procedure use from fact retrieval. Experiment 2 (n = 36) investigated whether a population with advanced mathematical training-engineering and computer science students-would show generalization of practice for nonrule-based simple addition problems (e.g., 1 + 4, 4 + 7). The 0 + N problems again presented generalization, whereas no nonzero problem type did; but all nonzero problems sped up when the identical problems were retested, as predicted by item-specific fact retrieval. The results pose a strong challenge to the generality of the proposal that skilled adults' simple addition is based on fast procedural algorithms, and instead support a fact-retrieval model of fast addition performance. (c) 2016 APA, all rights reserved).

Generalized Reduction of Problem Behavior of Young Children with Autism: Building Trans-Situational Interventions

ERIC Educational Resources Information Center

Schindler, Holly Reed; Horner, Robert H.

2005-01-01

The effects of functional communication training on the generalized reduction of problem behavior with three 4- to 5-year-old children with autism and problem behavior were evaluated. Participants were assessed in primary teaching settings and in three secondary, generalization settings. Through baseline analysis, lower effort interventions in the…

Aeronautic instruments. Section I : general classification of instruments and problems including bibliography

NASA Technical Reports Server (NTRS)

Hersey, Mayo D

1923-01-01

This report is intended as a technical introduction to the series of reports on aeronautic instruments. It presents a discussion of those subjects which are common to all instruments. First, a general classification is given, embracing all types of instruments used in aeronautics. Finally, a classification is given of the various problems confronted by the instrument expert and investigator. In this way the following groups of problems are brought up for consideration: problems of mechanical design, human factor, manufacturing problems, supply and selection of instruments, problems concerning the technique of testing, problems of installation, problems concerning the use of instruments, problems of maintenance, and physical research problems. This enumeration of problems which are common to instruments in general serves to indicate the different points of view which should be kept in mind in approaching the study of any particular instrument.

Does Preschool Self-Regulation Predict Later Behavior Problems in General or Specific Problem Behaviors?

PubMed

Lonigan, Christopher J; Spiegel, Jamie A; Goodrich, J Marc; Morris, Brittany M; Osborne, Colleen M; Lerner, Matthew D; Phillips, Beth M

2017-11-01

Findings from prior research have consistently indicated significant associations between self-regulation and externalizing behaviors. Significant associations have also been reported between children's language skills and both externalizing behaviors and self-regulation. Few studies to date, however, have examined these relations longitudinally, simultaneously, or with respect to unique clusters of externalizing problems. The current study examined the influence of preschool self-regulation on general and specific externalizing behavior problems in early elementary school and whether these relations were independent of associations between language, self-regulation, and externalizing behaviors in a sample of 815 children (44% female). Additionally, given a general pattern of sex differences in the presentations of externalizing behavior problems, self-regulation, and language skills, sex differences for these associations were examined. Results indicated unique relations of preschool self-regulation and language with both general externalizing behavior problems and specific problems of inattention. In general, self-regulation was a stronger longitudinal correlate of externalizing behavior for boys than it was for girls, and language was a stronger longitudinal predictor of hyperactive/impulsive behavior for girls than it was for boys.

A trial of a self-assessment tool of problems following treatment of colorectal cancer: a prospective study in Australia primary care.

PubMed

Ngune, I; Jiwa, M; McManus, A; Parsons, R; Hodder, R

2016-01-01

Patients treated for colorectal cancer (CRC) experience considerable physical, social and psychological morbidity. In this study, 66 participants with stages I-III CRC were enrolled in this study. Participants completed the self-assessment tool for patients (SATp) over a 5-month period and visited a general practitioner with a copy of their SATp to assist in the management of any problems associated with CRC treatment. General practitioners' notes were reviewed for management actions. Of the 66 participants, 57 visited a general practitioner over the 5-month study period. A total of 547 problems were identified (median 7; IQR: 3-12.25). Participants with physical problems were more likely to consult their general practitioner (OR: 1.84, CI: 1.05-3.21, P = 0.03) compared to those with psychological problems. The number of problems experienced by participants did not have any influence on the decision to visit a general practitioner. Psychological problems (P < 0.01) significantly reduced over the 5-month study period. Regular use of the SATp facilitates the identification of long-term CRC treatment-related problems. Some of these problems could then be addressed in primary care. © 2015 John Wiley & Sons Ltd.

Algorithms for bilevel optimization

NASA Technical Reports Server (NTRS)

Alexandrov, Natalia; Dennis, J. E., Jr.

1994-01-01

General multilevel nonlinear optimization problems arise in design of complex systems and can be used as a means of regularization for multi-criteria optimization problems. Here, for clarity in displaying our ideas, we restrict ourselves to general bi-level optimization problems, and we present two solution approaches. Both approaches use a trust-region globalization strategy, and they can be easily extended to handle the general multilevel problem. We make no convexity assumptions, but we do assume that the problem has a nondegenerate feasible set. We consider necessary optimality conditions for the bi-level problem formulations and discuss results that can be extended to obtain multilevel optimization formulations with constraints at each level.

Further studies on the problems of geomagnetic field intensity determination from archaeological baked clay materials

NASA Astrophysics Data System (ADS)

Kostadinova-Avramova, M.; Kovacheva, M.

2015-10-01

Archaeological baked clay remains provide valuable information about the geomagnetic field in historical past, but determination of the geomagnetic field characteristics, especially intensity, is often a difficult task. This study was undertaken to elucidate the reasons for unsuccessful intensity determination experiments obtained from two different Bulgarian archaeological sites (Nessebar - Early Byzantine period and Malenovo - Early Iron Age). With this aim, artificial clay samples were formed in the laboratory and investigated. The clay used for the artificial samples preparation differs according to its initial state. Nessebar clay was baked in the antiquity, but Malenovo clay was raw, taken from the clay deposit near the site. The obtained artificial samples were repeatedly heated eight times in known magnetic field to 700 °C. X-ray diffraction analyses and rock-magnetic experiments were performed to obtain information about the mineralogical content and magnetic properties of the initial and laboratory heated clays. Two different protocols were applied for the intensity determination-Coe version of Thellier and Thellier method and multispecimen parallel differential pTRM protocol. Various combinations of laboratory fields and mutual positions of the directions of laboratory field and carried thermoremanence were used in the performed Coe experiment. The obtained results indicate that the failure of this experiment is probably related to unfavourable grain sizes of the prevailing magnetic carriers combined with the chosen experimental conditions. The multispecimen parallel differential pTRM protocol in its original form gives excellent results for the artificial samples, but failed for the real samples (samples coming from previously studied kilns of Nessebar and Malenovo sites). Obviously the strong dependence of this method on the homogeneity of the used subsamples hinders its implementation in its original form for archaeomaterials. The latter are often heterogeneous due to variable heating conditions in the different parts of the archaeological structures. The study draws attention to the importance of multiple heating for the stabilization of grain size distribution in baked clay materials and the need of elucidation of this question.

A case study on the historical peninsula of Istanbul based on three-dimensional modeling by using photogrammetry and terrestrial laser scanning.

PubMed

Ergun, Bahadir; Sahin, Cumhur; Baz, Ibrahim; Ustuntas, Taner

2010-06-01

Terrestrial laser scanning is a popular methodology that is used frequently in the process of documenting historical buildings and cultural heritage. The historical peninsula region sprawls over an area of approximately 1,500 ha and is one of the main aggregate areas of the historical buildings in Istanbul. In this study, terrestrial laser scanning and close range photogrammetry techniques are integrated into each other to create a 3D city model of this part of Istanbul, including some of the buildings that represent the most brilliant areas of Byzantine and Ottoman Empires. Several terrestrial laser scanners with their different specifications were used to solve various geometric scanning problems for distinct areas of the subject city. Photogrammetric method was used for the documentation of the façades of these historical buildings for architectural purposes. This study differentiates itself from the similar ones by its application process that focuses on the geometry, the building texture, and density of the study area. Nowadays, the largest-scale studies among 3D modeling studies, in terms of the methodology of measurement, are urban modeling studies. Because of this large scale, the application of 3D urban modeling studies is executed in a gradual way. In this study, a modeling method based on the façades of the streets was used. In addition, the complimentary elements for the process of modeling were combined in several ways. A street model was presented as a sample, as being the subject of the applied study. In our application of 3D modeling, the modeling based on close range photogrammetry and the data of combined calibration with the data of terrestrial laser scanner were used in a compatible way. The final work was formed with the pedestal data for 3D visualization.

Step by Step: Biology Undergraduates' Problem-Solving Procedures during Multiple-Choice Assessment.

PubMed

Prevost, Luanna B; Lemons, Paula P

2016-01-01

This study uses the theoretical framework of domain-specific problem solving to explore the procedures students use to solve multiple-choice problems about biology concepts. We designed several multiple-choice problems and administered them on four exams. We trained students to produce written descriptions of how they solved the problem, and this allowed us to systematically investigate their problem-solving procedures. We identified a range of procedures and organized them as domain general, domain specific, or hybrid. We also identified domain-general and domain-specific errors made by students during problem solving. We found that students use domain-general and hybrid procedures more frequently when solving lower-order problems than higher-order problems, while they use domain-specific procedures more frequently when solving higher-order problems. Additionally, the more domain-specific procedures students used, the higher the likelihood that they would answer the problem correctly, up to five procedures. However, if students used just one domain-general procedure, they were as likely to answer the problem correctly as if they had used two to five domain-general procedures. Our findings provide a categorization scheme and framework for additional research on biology problem solving and suggest several important implications for researchers and instructors. © 2016 L. B. Prevost and P. P. Lemons. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

A Descriptive Study of a Building-Based Team Problem-Solving Process

ERIC Educational Resources Information Center

Brewer, Alexander B.

2010-01-01

The purpose of this study was to empirically evaluate Building-Based Teams for General Education Intervention or BBT for GEI. BBT for GEI is a team problem-solving process designed to assist schools in conducting research-based interventions in the general education setting. Problem-solving teams are part of general education and provide support…

Examination of Turkish Junior High-School Students' Perceptions of the General Problem-Solving Process

ERIC Educational Resources Information Center

Ekici, Didem Inel

2016-01-01

This study aimed to determine Turkish junior high-school students' perceptions of the general problem-solving process. The Turkish junior high-school students' perceptions of the general problem-solving process were examined in relation to their gender, grade level, age and their grade point with regards to the science course identified in the…

The relation between the bifactor model of the Youth Psychopathic Traits Inventory and conduct problems in adolescence: Variations across gender, ethnic background, and age.

PubMed

Zwaanswijk, Wendy; Veen, Violaine C; van Geel, Mitch; Andershed, Henrik; Vedder, Paul

2017-08-01

The current study examines how the bifactor model of the Youth Psychopathic Traits Inventory (YPI) is related to conduct problems in a sample of Dutch adolescents (N = 2,874; 43% female). It addresses to what extent the YPI dimensions explain variance over and above a General Psychopathy factor (i.e., one factor related to all items) and how the general factor and dimensional factors are related to conduct problems. Group differences in these relations for gender, ethnic background, and age were examined. Results showed that the general factor is most important, but dimensions explain variance over and above the general factor. The general factor, and Affective and Lifestyle dimensions, of the YPI were positively related to conduct problems, whereas the Interpersonal dimension was not, after taking the general factor into account. However, across gender, ethnic background, and age, different dimensions were related to conduct problems over and above the general factor. This suggests that all 3 dimensions should be assessed when examining the psychopathy construct. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A comparative assessment of generalized anxiety, conduct and peer relationship problems among AIDS and other orphaned children in India.

PubMed

Sg, Prem Kumar; G, Anil Kumar; Sp, Ramgopal; V, Venkata Srinivas; Dandona, Rakhi

2016-09-21

Data on mental health among orphaned children in India are scanty. We compared the generalized anxiety, conduct and peer relationship problems and their associated risk factors among children orphaned by HIV/AIDS and those due to other reasons in the Indian city of Hyderabad. Four hundred orphaned children aged 12 to 16 years residing in orphanages in Hyderabad were sampled, half being AIDS orphans (COA) and the rest orphaned due to other reasons (COO). Interviews were done using standardized scales to assess generalized anxiety, conduct and peer relationship problems. A score >8, >4, and >5 was considered as indicator of generalized anxiety, conduct problem and peer relationship problem, respectively. Variations in the intensity of these three conditions due to possible factors including co-existing depression were assessed using multiple classification analysis (MCA). A total of 396 (99.3 %) orphans participated of whom 199 (50.3 %) were COA. The mean generalized anxiety, conduct and peer relationship problem scores were 11.1 (SD 5.2), 3.8 (SD 2.5) and 3.8 (SD 2.5) for COA; and 7.6 (SD 4), 2.6 (SD 2) and 2.3 (SD 1.8) for COO, respectively. Among COA, the prevalence of generalized anxiety score of >8 was 74.4 % (95 % CI 67.8-80.0 %), of conduct problem score of >4 was 33.2 % (95 % CI 26.9-40.1 %), and of peer relationship problem score of >5 was 27.6 %, (95 % CI 21.8-34.3 %), with these being significantly lower in COO. In MCA, a higher mean depression score had the highest effect on the intensity of generalized anxiety, conduct and peer relationship problem (Beta 0.477; 0.379 and 0.453 respectively); being COA and a girl had the most impact on generalized anxiety (0.100 and 0.115, respectively). A significantly high proportion of AIDS orphans deal with generalized anxiety, conduct and peer relationship problem as compared with other orphans highlighting the need to address the poor mental health of orphans in India.

Gambling problems among patients in primary care: a cross-sectional study of general practices.

PubMed

Cowlishaw, Sean; Gale, Lone; Gregory, Alison; McCambridge, Jim; Kessler, David

2017-04-01

Primary care is an important context for addressing health-related behaviours, and may provide a setting for identification of gambling problems. To indicate the extent of gambling problems among patients attending general practices, and explore settings or patient groups that experience heightened vulnerability. Cross-sectional study of patients attending 11 general practices in Bristol, South West England. Adult patients ( n = 1058) were recruited from waiting rooms of practices that were sampled on the basis of population characteristics. Patients completed anonymous questionnaires comprising measures of mental health problems (for example, depression) and addictive behaviours (for example, risky alcohol use). The Problem Gambling Severity Index (PGSI) measured gambling problems, along with a single-item measure of gambling problems among family members. Estimates of extent and variability according to practice and patient characteristics were produced. There were 0.9% of all patients exhibiting problem gambling (PGSI ≥5), and 4.3% reporting problems that were low to moderate in severity (PGSI 1-4). Around 7% of patients reported gambling problems among family members. Further analyses indicated that rates of any gambling problems (PGSI ≥1) were higher among males and young adults, and more tentatively, within a student healthcare setting. They were also elevated among patients exhibiting drug use, risky alcohol use, and depression. There is need for improved understanding of the burden of, and responses to, patients with gambling problems in general practices, and new strategies to increase identification to facilitate improved care and early intervention. © British Journal of General Practice 2017.

The Implementation of Physics Problem Solving Strategy Combined with Concept Map in General Physics Course

NASA Astrophysics Data System (ADS)

Hidayati, H.; Ramli, R.

2018-04-01

This paper aims to provide a description of the implementation of Physic Problem Solving strategy combined with concept maps in General Physics learning at Department of Physics, Universitas Negeri Padang. Action research has been conducted in two cycles where each end of the cycle is reflected and improved for the next cycle. Implementation of Physics Problem Solving strategy combined with concept map can increase student activity in solving general physics problem with an average increase of 15% and can improve student learning outcomes from 42,7 in the cycle I become 62,7 in cycle II in general physics at the Universitas Negeri Padang. In the future, the implementation of Physic Problem Solving strategy combined with concept maps will need to be considered in Physics courses.

Problems of Conducting Research in Organizations: The Case of Police Departments.

ERIC Educational Resources Information Center

Lefkowitz, Joel

This paper presents a description of police research problems in such fashion that it could be generalized to other types of organizations. A two-dimensional taxonomy of problems in conducting psychological research in police departments is discussed. The first dimension concerns generality-uniqueness of the problem, relative to formal…

Do different types of school mathematics development depend on different constellations of numerical versus general cognitive abilities?

PubMed

Fuchs, Lynn S; Geary, David C; Compton, Donald L; Fuchs, Douglas; Hamlett, Carol L; Seethaler, Pamela M; Bryant, Joan D; Schatschneider, Christopher

2010-11-01

The purpose of this study was to examine the interplay between basic numerical cognition and domain-general abilities (such as working memory) in explaining school mathematics learning. First graders (N = 280; mean age = 5.77 years) were assessed on 2 types of basic numerical cognition, 8 domain-general abilities, procedural calculations, and word problems in fall and then reassessed on procedural calculations and word problems in spring. Development was indexed by latent change scores, and the interplay between numerical and domain-general abilities was analyzed by multiple regression. Results suggest that the development of different types of formal school mathematics depends on different constellations of numerical versus general cognitive abilities. When controlling for 8 domain-general abilities, both aspects of basic numerical cognition were uniquely predictive of procedural calculations and word problems development. Yet, for procedural calculations development, the additional amount of variance explained by the set of domain-general abilities was not significant, and only counting span was uniquely predictive. By contrast, for word problems development, the set of domain-general abilities did provide additional explanatory value, accounting for about the same amount of variance as the basic numerical cognition variables. Language, attentive behavior, nonverbal problem solving, and listening span were uniquely predictive.

A generalized rotationally symmetric case of the centroaffine Minkowski problem

NASA Astrophysics Data System (ADS)

Lu, Jian

2018-05-01

In this paper the centroaffine Minkowski problem, a critical case of the Lp-Minkowski problem in the n + 1 dimensional Euclidean space, is studied. By its variational structure and the method of blow-up analyses, we obtain two sufficient conditions for the existence of solutions, for a generalized rotationally symmetric case of the problem.

Mathematical Giftedness, Problem Solving, and the Ability To Formulate Generalizations: The Problem-Solving Experiences of Four Gifted Students.

ERIC Educational Resources Information Center

Sriraman, Bharath

2003-01-01

Nine freshmen in a ninth-grade accelerated algebra class were asked to solve five nonroutine combinatorial problems. The four mathematically gifted students were successful in discovering and verbalizing the generality that characterized the solutions to the five problems, whereas the five nongifted students were unable to discover the hidden…

Generalized minimum dominating set and application in automatic text summarization

NASA Astrophysics Data System (ADS)

Xu, Yi-Zhi; Zhou, Hai-Jun

2016-03-01

For a graph formed by vertices and weighted edges, a generalized minimum dominating set (MDS) is a vertex set of smallest cardinality such that the summed weight of edges from each outside vertex to vertices in this set is equal to or larger than certain threshold value. This generalized MDS problem reduces to the conventional MDS problem in the limiting case of all the edge weights being equal to the threshold value. We treat the generalized MDS problem in the present paper by a replica-symmetric spin glass theory and derive a set of belief-propagation equations. As a practical application we consider the problem of extracting a set of sentences that best summarize a given input text document. We carry out a preliminary test of the statistical physics-inspired method to this automatic text summarization problem.

Four different ways of philanthropic aid to the blind in medieval eastern Christendom.

PubMed

Diamandopoulou-Drummond, A H; Diamandopoulos, A A; Marketos, S G

1995-11-01

The care of the blind, either as medical treatment or as divine therapy, has probably been the most ancient form of help for ill people. However, it was during the Byzantine Empire (325-1453 AD) that the state organized a 'blindness relief' plan as part of a widespread public health system. Our sources for the subject include medical writings, state decrees, Saint's 'vitae' and representations of relevant works of art. Based on the above data we classify the health care for the blind in Byzantium as: (a) support of ophthalmological education as evidenced by an abundance of medical writings on the subject; (b) establishment of charitable institutions exclusively or partially for the blind, where there was not only medical care but also provision for a wide range of social aid - the most advanced being specially trained escorts for each blind person; and (c) support by the state of an extended chain of religious institutions where miraculous help for the blind was promised. We conclude that the public health policy in Byzantium made adequate and very early provision for the blind.

Archaeometric characterization and provenance determination of sculptures and architectural elements from Gerasa, Jordan

NASA Astrophysics Data System (ADS)

Al-Bashaireh, Khaled

2018-02-01

This study aims at the identification of the provenance of white marble sculptures and architectural elements uncovered from the archaeological site of Gerasa and neighboring areas, north Jordan. Most of the marbles are probably of the Roman or Byzantine periods. Optical microscopy, X-ray diffraction, and mass spectrometry were used to investigate petrographic, mineralogical and isotopic characteristics of the samples, respectively. Analytical results were compared with the main reference databases of known Mediterranean marble quarries exploited in antiquity. The collected data show that the most likely main sources of the sculptures were the Greek marble quarries of Paros-2 (Lakkoi), Penteli (Mount Pentelikon, Attica), and Thasos-3 (Thasos Island, Cape Vathy, Aliki); the Asia Minor marble quarries of Proconessus-1 (Marmara) and Aphrodisias (Aphrodisias); and the Italian quarry of Carrara (Apuan Alps). Similarly, the Asia Minor quarries of the fine-grained Docimium (Afyon) and the coarse-grained Proconessus-1 (Marmara) and Thasos-3 are the most likely sources of the architectural elements. The results agree with published data on the wide use of these marbles for sculpture and architectural elements.

A multidisciplinary study of archaeological grape seeds

NASA Astrophysics Data System (ADS)

Cappellini, Enrico; Gilbert, M. Thomas P.; Geuna, Filippo; Fiorentino, Girolamo; Hall, Allan; Thomas-Oates, Jane; Ashton, Peter D.; Ashford, David A.; Arthur, Paul; Campos, Paula F.; Kool, Johan; Willerslev, Eske; Collins, Matthew J.

2010-02-01

We report here the first integrated investigation of both ancient DNA and proteins in archaeobotanical samples: medieval grape ( Vitis vinifera L.) seeds, preserved by anoxic waterlogging, from an early medieval (seventh-eighth century A.D.) Byzantine rural settlement in the Salento area (Lecce, Italy) and a late (fourteenth-fifteenth century A.D.) medieval site in York (England). Pyrolysis gas chromatography mass spectrometry documented good carbohydrate preservation, whilst amino acid analysis revealed approximately 90% loss of the original protein content. In the York sample, mass spectrometry-based sequencing identified several degraded ancient peptides. Nuclear microsatellite locus (VVS2, VVMD5, VVMD7, ZAG62 and ZAG79) analysis permitted a tentative comparison of the genetic profiles of both the ancient samples with the modern varieties. The ability to recover microsatellite DNA has potential to improve biomolecular analysis on ancient grape seeds from archaeological contexts. Although the investigation of five microsatellite loci cannot assign the ancient samples to any geographic region or modern cultivar, the results allow speculation that the material from York was not grown locally, whilst the remains from Supersano could represent a trace of contacts with the eastern Mediterranean.

Seismic and Restoration Assessment of Monumental Masonry Structures

PubMed Central

Asteris, Panagiotis G.; Douvika, Maria G.; Apostolopoulou, Maria; Moropoulou, Antonia

2017-01-01

Masonry structures are complex systems that require detailed knowledge and information regarding their response under seismic excitations. Appropriate modelling of a masonry structure is a prerequisite for a reliable earthquake-resistant design and/or assessment. However, modelling a real structure with a robust quantitative (mathematical) representation is a very difficult, complex and computationally-demanding task. The paper herein presents a new stochastic computational framework for earthquake-resistant design of masonry structural systems. The proposed framework is based on the probabilistic behavior of crucial parameters, such as material strength and seismic characteristics, and utilizes fragility analysis based on different failure criteria for the masonry material. The application of the proposed methodology is illustrated in the case of a historical and monumental masonry structure, namely the assessment of the seismic vulnerability of the Kaisariani Monastery, a byzantine church that was built in Athens, Greece, at the end of the 11th to the beginning of the 12th century. Useful conclusions are drawn regarding the effectiveness of the intervention techniques used for the reduction of the vulnerability of the case-study structure, by means of comparison of the results obtained. PMID:28767073

Seismic and Restoration Assessment of Monumental Masonry Structures.

PubMed

Asteris, Panagiotis G; Douvika, Maria G; Apostolopoulou, Maria; Moropoulou, Antonia

2017-08-02

Masonry structures are complex systems that require detailed knowledge and information regarding their response under seismic excitations. Appropriate modelling of a masonry structure is a prerequisite for a reliable earthquake-resistant design and/or assessment. However, modelling a real structure with a robust quantitative (mathematical) representation is a very difficult, complex and computationally-demanding task. The paper herein presents a new stochastic computational framework for earthquake-resistant design of masonry structural systems. The proposed framework is based on the probabilistic behavior of crucial parameters, such as material strength and seismic characteristics, and utilizes fragility analysis based on different failure criteria for the masonry material. The application of the proposed methodology is illustrated in the case of a historical and monumental masonry structure, namely the assessment of the seismic vulnerability of the Kaisariani Monastery, a byzantine church that was built in Athens, Greece, at the end of the 11th to the beginning of the 12th century. Useful conclusions are drawn regarding the effectiveness of the intervention techniques used for the reduction of the vulnerability of the case-study structure, by means of comparison of the results obtained.

Contribution of Microchemical Surface Analysis of Archaeological Artefacts

NASA Astrophysics Data System (ADS)

Mousser, H.; Madani, A.; Amri, R.; Mousser, A.; Darchen, A.

2009-11-01

Museum CIRTA of the town of Constantine has a collection of more than 35000 coins and statuettes going back to Numide, Roman, Republican, Vandal and Byzantine times and is struck in the name of the cities, of the kingdoms and the empires. Surface analysis of these coins gives information about the chemical composition and leads to recommendations for restoration and preservations. This work is a contribution of microchemical surface study of coin with the effigy of the Numide King Massinissa (Constantine between 3rd and 2nd century before Jesus Christ). The photographic and scanning electron microscopy coupled with energy dispersive spectrometry (SEM + EDS) and diffraction of X-ray (DRX) was used. The optic microscopy (OMP) and SEM pictures of coins showed heterogeneous surface. Scanning electron microscopy coupled with energy dispersive spectrometry identified three basic metals copper (46.06%), antimony (17.74%) and lead (12.06%), (Weight Percentage). The DRX identifies stages (copper and lead) and their crystalline oxides Bindheimite (Pb2Sb2O7) and Bystromite (MgSb2O6) on the coin's surface.

Medieval descriptions and doctrines of stroke: preliminary analysis of select sources. Part II: between Galenism and Aristotelism - Islamic theories of apoplexy (800-1200).

PubMed

Karenberg, A; Hort, I

1998-12-01

This second paper on medieval descriptions and doctrines of stroke reviews concepts outlined by famous Muslim physicians of the Middle Ages such as Rhazes, Haly Abbas, Avicenna, and Averroes. Contrary to a popular belief, Islamic neurological texts represent not only a bridge between ancient and western medieval medical knowledge, but also document remarkable advancements. Whereas statements on diagnosis and prognosis lack originality, the endeavors of physician-philosophers and medical authors led to substantial additions and important changes in theory. Such modifications include the integration of ventricular doctrine and particularly the attempt to unify Aristotelian and Galenic tenets which resulted in a complex discussion about the seats and causes of apoplexy. The fairly simple model handed down by Galenists of the Byzantine period was replaced by more detailed classifications, which proposed "cerebral" as well as "vascular" origins of the disease without suggesting a "cerebrovascular" etiology. Islamic therapeutic strategies included dietetic, pharmacological and surgical elements. The use of the cautery in "chronic apoplexy" was a special feature of Arabic surgery.

Optimizing Data Management in Grid Environments

NASA Astrophysics Data System (ADS)

Zissimos, Antonis; Doka, Katerina; Chazapis, Antony; Tsoumakos, Dimitrios; Koziris, Nectarios

Grids currently serve as platforms for numerous scientific as well as business applications that generate and access vast amounts of data. In this paper, we address the need for efficient, scalable and robust data management in Grid environments. We propose a fully decentralized and adaptive mechanism comprising of two components: A Distributed Replica Location Service (DRLS) and a data transfer mechanism called GridTorrent. They both adopt Peer-to-Peer techniques in order to overcome performance bottlenecks and single points of failure. On one hand, DRLS ensures resilience by relying on a Byzantine-tolerant protocol and is able to handle massive concurrent requests even during node churn. On the other hand, GridTorrent allows for maximum bandwidth utilization through collaborative sharing among the various data providers and consumers. The proposed integrated architecture is completely backwards-compatible with already deployed Grids. To demonstrate these points, experiments have been conducted in LAN as well as WAN environments under various workloads. The evaluation shows that our scheme vastly outperforms the conventional mechanisms in both efficiency (up to 10 times faster) and robustness in case of failures and flash crowd instances.

Brief Announcement: Induced Churn to Face Adversarial Behavior in Peer-to-Peer Systems

NASA Astrophysics Data System (ADS)

Anceaume, Emmanuelle; Brasileiro, Francisco; Ludinard, Romaric; Sericola, Bruno; Tronel, Frederic

Awerbuch and Scheideler [2] have shown that peer-to-peer overlays networks can only survive Byzantine attacks if malicious nodes are not able to predict what will be the topology of the network for a given sequence of join and leave operations. A prerequisite for this condition to hold is to guarantee that nodes identifiers randomness is continuously preserved. However targeted join/leave attacks may quickly endanger the relevance of such an assumption. Inducing churn has been shown to be the other fundamental ingredient to preserve randomness. Several strategies based on these principles have been proposed. Most of them are based on locally induced churn. However either they have been proven incorrect or they involve a too high level of complexity to be practically acceptable [2]. The other ones, based on globally induced churn, enforce limited lifetime for each node in the system. However, these solutions keep the system in an unnecessary hyper-activity, and thus need to impose strict restrictions on nodes joining rate which clearly limit their applicability to open systems.

Benefits of an automated GLP final report preparation software solution.

PubMed

Elvebak, Larry E

2011-07-01

The final product of analytical laboratories performing US FDA-regulated (or GLP) method validation and bioanalysis studies is the final report. Although there are commercial-off-the-shelf (COTS) software/instrument systems available to laboratory managers to automate and manage almost every aspect of the instrumental and sample-handling processes of GLP studies, there are few software systems available to fully manage the GLP final report preparation process. This lack of appropriate COTS tools results in the implementation of rather Byzantine and manual processes to cobble together all the information needed to generate a GLP final report. The manual nature of these processes results in the need for several iterative quality control and quality assurance events to ensure data accuracy and report formatting. The industry is in need of a COTS solution that gives laboratory managers and study directors the ability to manage as many portions as possible of the GLP final report writing process and the ability to generate a GLP final report with the click of a button. This article describes the COTS software features needed to give laboratory managers and study directors such a solution.

48 CFR 1329.101 - Resolving tax problems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Resolving tax problems. 1329.101 Section 1329.101 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE GENERAL CONTRACTING REQUIREMENTS TAXES General 1329.101 Resolving tax problems. Legal questions relating to tax issues...

A Projection free method for Generalized Eigenvalue Problem with a nonsmooth Regularizer.

PubMed

Hwang, Seong Jae; Collins, Maxwell D; Ravi, Sathya N; Ithapu, Vamsi K; Adluru, Nagesh; Johnson, Sterling C; Singh, Vikas

2015-12-01

Eigenvalue problems are ubiquitous in computer vision, covering a very broad spectrum of applications ranging from estimation problems in multi-view geometry to image segmentation. Few other linear algebra problems have a more mature set of numerical routines available and many computer vision libraries leverage such tools extensively. However, the ability to call the underlying solver only as a "black box" can often become restrictive. Many 'human in the loop' settings in vision frequently exploit supervision from an expert, to the extent that the user can be considered a subroutine in the overall system. In other cases, there is additional domain knowledge, side or even partial information that one may want to incorporate within the formulation. In general, regularizing a (generalized) eigenvalue problem with such side information remains difficult. Motivated by these needs, this paper presents an optimization scheme to solve generalized eigenvalue problems (GEP) involving a (nonsmooth) regularizer. We start from an alternative formulation of GEP where the feasibility set of the model involves the Stiefel manifold. The core of this paper presents an end to end stochastic optimization scheme for the resultant problem. We show how this general algorithm enables improved statistical analysis of brain imaging data where the regularizer is derived from other 'views' of the disease pathology, involving clinical measurements and other image-derived representations.

The existence results and Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces

NASA Astrophysics Data System (ADS)

Wang, Min

2017-06-01

This paper aims to establish the Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces. For this purpose, we firstly prove a very general existence result for generalized mixed variational inequalities, provided that the mapping involved has the so-called mixed variational inequality property and satisfies a rather weak coercivity condition. Finally, we establish the Tikhonov regularization method for generalized mixed variational inequalities. Our findings extended the results for the generalized variational inequality problem (for short, GVIP( F, K)) in R^n spaces (He in Abstr Appl Anal, 2012) to the generalized mixed variational inequality problem (for short, GMVIP(F,φ , K)) in reflexive Banach spaces. On the other hand, we generalized the corresponding results for the generalized mixed variational inequality problem (for short, GMVIP(F,φ ,K)) in R^n spaces (Fu and He in J Sichuan Norm Univ (Nat Sci) 37:12-17, 2014) to reflexive Banach spaces.

What makes a problem an ethical problem? An empirical perspective on the nature of ethical problems in general practice

PubMed Central

Braunack-Mayer, A. J.

2001-01-01

Whilst there has been considerable debate about the fit between moral theory and moral reasoning in everyday life, the way in which moral problems are defined has rarely been questioned. This paper presents a qualitative analysis of interviews conducted with 15 general practitioners (GPs) in South Australia to argue that the way in which the bioethics literature defines an ethical dilemma captures only some of the range of lay views about the nature of ethical problems. The bioethics literature has defined ethical dilemmas in terms of conflict and choice between values, beliefs and options for action. While some of the views of some of the GPs in this study about the nature of their ethical dilemmas certainly accorded with this definition, other explanations of the ethical nature of their problems revolved around the publicity associated with the issues they were discussing, concern about their relationships with patients, and anxiety about threats to their integrity and reputation. The variety of views about what makes a problem a moral problem indicates that the moral domain is perhaps wider and richer than mainstream bioethics would generally allow. Key Words: Empirical ethics • general practice • qualitative research PMID:11314166

Performance Analysis and the Generalization Problem.

ERIC Educational Resources Information Center

Wood, Scott; And Others

This document is intended to help school psychologists promote more effective generalization of school intervention programs for education students. Concepts (including transfer of training and response generalization) are reviewed. An approach is described which analyzes problem behavior according to its major controlling variables (skills or…

Analysis of general aviation single-pilot IFR incident data obtained from the NASA aviation safety reporting system

NASA Technical Reports Server (NTRS)

Bergeron, H. P.

1980-01-01

Data obtained from the NASA Aviation Safety Reporting System (ASRS) data base were used to determine problems in general aviation single pilot IFR operations. The data examined consisted of incident reports involving flight safety in the National Aviation System. Only those incidents involving general aviation fixed wing aircraft flying under IFR in instrument meteorological conditions were analyzed. The data were cataloged into one of five major problem areas: (1) controller judgement and response problems; (2) pilot judgement and response problems; (3) air traffic control intrafacility and interfacility conflicts; (4) ATC and pilot communications problems; and (5) IFR-VFR conflicts. The significance of the related problems, and the various underlying elements associated with each are discussed. Previous ASRS reports covering several areas of analysis are reviewed.

Study to determine the IFR operational profile and problems to the general aviation pilot

NASA Technical Reports Server (NTRS)

Weislogel, S.

1983-01-01

A study of the general aviation single pilot operating under instrument flight rules (GA SPIFR) has been conducted for NASA Langley Research Center. The objectives of the study were to (1) develop a GA SPIFR operational profile, (2) identify problems experienced by the GA SPIFR pilot, and (3) identify research tasks which have the potential for eliminating or reducing the severity of the problems. To obtain the information necessary to accomplish these objectives, a mail questionnaire survey of instrument rated pilots was conducted. Complete questionnaire data is reported in NASA CR-165805, "Statistical Summary: Study to Determine the IFR Operational Profile and Problems of the General Aviation Single Pilot'-Based upon the results of the GA SPIFR survey, this final report presents the general aviation IFR single pilot operational profile, illustrates selected data analysis, examples, identifies the problems which he is experiencing, and recommends further research.

Youth Education and Unemployment Problems. An International Perspective.

ERIC Educational Resources Information Center

Gordon, Margaret S.; Trow, Martin

Essays focusing on issues concerning youth education and unemployment problems are presented in this document. It is divided into three general areas. The first, Youth Unemployment in Western Industrial Countries, reviews general dimensions of the problem, the cyclical hypothesis, the demand hypothesis, the supply hypothesis, disaggregating…

48 CFR 2429.101 - Resolving tax problems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... DEVELOPMENT GENERAL CONTRACTING REQUIREMENTS TAXES General 2429.101 Resolving tax problems. In order to have uniformity in HUD's treatment of the tax aspects of contracting and ensure effective cooperation with other... within HUD for handling all those tax problems. Therefore, the contracting activity will not engage in...

Holocene beach buildup and coastal aeolian sand incursions off the Nile littoral cell

NASA Astrophysics Data System (ADS)

Roskin, Joel; Sivan, Dorit; Shtienberg, Gilad; Porat, Naomi; Bookman, Revital

2017-04-01

Israel's coastal plain is abundant with sand originating from the Nile littoral cell. The inland windblown loose sand has formed 3-6 km wide lobe-like sand and dune fields currently comprised of foredunes, linear and northeasterly facing transverse and parabolic dunes that are currently stabilized by vegetation. This study reviews the architecture and history of the these dune fields aiming to: (a) Date the timings of beach accretion, and sand and dune incursions. (b) Discriminate between natural and human-induced forcing factors of sand mobilization and stabilization in time and space. (c) Present a model of the dunescape development. (d) Assess scenarios of sand transport in the future charcaterized by intense human impact and climate change. Luminescence ages, radiocarbon dates and relative ages from previously published geological and archaeological reports, historical texts, together with new optically stimulated luminescence (OSL) ages and stratigraphic and sedimentological data are analyzed. The deposition, mobilizations and preservation of the sand bodies, initially induced by the decline in sea level rise at 6-4 ka, were later controlled by historic land-use intensity and modern land-use/negligence practices. At 6 ka, beach sand buildup rapidly started. Where aeolianite ridges bordered the coast, pulses of sand with biogenic carbonate grains unconformably draped the ridges and rapidly consolidated into a distinct sandy calcarenite unit. Further east, sand sheets and low dunes partly pedogenized following their incursion, but did not cement. The water retention capacities of the sand sheets enabled the establishment of a sand-stabilizing vegetation cover that probably became an attractive environment for fuel and grazing. The growing Hellenistic-Roman-Byzantine ( 2.4-1.3 ka) populations probably led to increased consumption and massive destruction of sand stabilizing vegetation, enabling sand erodibility and mobilization during winter storms. The sand gradually expanded to the current limits of today's dune fields. The gradual but unsteady post-Byzantine demographic drop enabled reestablishment of natural vegetation and rapid regosol development. This drop occurred differentially along the coast due to governance and land-use practices. We suggest that dune construction mainly evolved around the 19th century from the existing sand sheets and low dunes that intermittently developed since 6-5 ka. Human (Bedouin grazing influx and ethnic settlements) destruction of vegetation, in conjuction with the rapid 19th-20th century population growth made the sand prone to "in situ" transverse and linear dune formation in response to powerful winds further supported by increased storminess at this time. Inland dune mobilization and the artificial establishment of vegetated foredunes along the coast in the 1930's-1940's partly scalped the sand deposits by the coast.

General purpose force doctrine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weltman, J.J.

In contemporary American strategic parlance, the general purpose forces have come to mean those forces intended for conflict situations other than nuclear war with the Soviet Union. As with all military forces, the general purpose forces are powerfully determined by prevailing conceptions of the problems they must meet and by institutional biases as to the proper way to deal with those problems. This paper deals with the strategic problems these forces are intended to meet, the various and often conflicting doctrines and organizational structures which have been generated in order to meet those problems, and the factors which will influencemore » general purpose doctrine and structure in the future. This paper does not attempt to prescribe technological solutions to the needs of the general purpose forces. Rather, it attempts to display the doctrinal and institutional context within which new technologies must operate, and which will largely determine whether these technologies are accepted into the force structure or not.« less

Well-posed and stable transmission problems

NASA Astrophysics Data System (ADS)

Nordström, Jan; Linders, Viktor

2018-07-01

We introduce the notion of a transmission problem to describe a general class of problems where different dynamics are coupled in time. Well-posedness and stability are analysed for continuous and discrete problems using both strong and weak formulations, and a general transmission condition is obtained. The theory is applied to the coupling of fluid-acoustic models, multi-grid implementations, adaptive mesh refinements, multi-block formulations and numerical filtering.

The Effect of Using an Explicit General Problem Solving Teaching Approach on Elementary Pre-Service Teachers' Ability to Solve Heat Transfer Problems

ERIC Educational Resources Information Center

Mataka, Lloyd M.; Cobern, William W.; Grunert, Megan L.; Mutambuki, Jacinta; Akom, George

2014-01-01

This study investigate the effectiveness of adding an "explicit general problem solving teaching strategy" (EGPS) to guided inquiry (GI) on pre-service elementary school teachers' ability to solve heat transfer problems. The pre-service elementary teachers in this study were enrolled in two sections of a chemistry course for pre-service…

Learning dominance relations in combinatorial search problems

NASA Technical Reports Server (NTRS)

Yu, Chee-Fen; Wah, Benjamin W.

1988-01-01

Dominance relations commonly are used to prune unnecessary nodes in search graphs, but they are problem-dependent and cannot be derived by a general procedure. The authors identify machine learning of dominance relations and the applicable learning mechanisms. A study of learning dominance relations using learning by experimentation is described. This system has been able to learn dominance relations for the 0/1-knapsack problem, an inventory problem, the reliability-by-replication problem, the two-machine flow shop problem, a number of single-machine scheduling problems, and a two-machine scheduling problem. It is considered that the same methodology can be extended to learn dominance relations in general.

48 CFR 229.101 - Resolving tax problems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Resolving tax problems..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS TAXES General 229.101 Resolving tax problems. (a... information on fuel excise taxes, see PGI 229.101(b). (c) For guidance on directing a contractor to litigate...

Generalized Kustaanheimo-Stiefel transformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komarov, L.I.; Van Hoang, L.

1994-10-01

A theory is given for the construction of generalized Kustaanheimo-Stiefel (KS) transformations for dimensions q+1 (q=2{sup h}, h=0, 1, 2,...) of the Kepler problem, and the following proposition is proved: A connection between the Kepler problem in a real space of dimension q+1 and the problem of an isotropic harmonic oscillator in a real space dimension N exists and can be established by means of generalized KS transformations in the cases in which N=2q and q=2{sup h} (h=0, 1, 2,...). A simple graphical prescription for constructing generalized KS transformations that realize this connection is proposed.

On the solution of the generalized wave and generalized sine-Gordon equations

NASA Technical Reports Server (NTRS)

Ablowitz, M. J.; Beals, R.; Tenenblat, K.

1986-01-01

The generalized wave equation and generalized sine-Gordon equations are known to be natural multidimensional differential geometric generalizations of the classical two-dimensional versions. In this paper, a system of linear differential equations is associated with these equations, and it is shown how the direct and inverse problems can be solved for appropriately decaying data on suitable lines. An initial-boundary value problem is solved for these equations.

The Big Picture and Specifics of College General Education

ERIC Educational Resources Information Center

Gan, Yang

2018-01-01

In recent years, general education has developed considerably in Chinese universities, but it still faces many challenges and problems. Among the various negative factors, four problems may be the greatest challenges currently faced by Chinese university general education and ordinary undergraduate education: (1) In the era of massified higher…

Problem Solving with General Semantics.

ERIC Educational Resources Information Center

Hewson, David

1996-01-01

Discusses how to use general semantics formulations to improve problem solving at home or at work--methods come from the areas of artificial intelligence/computer science, engineering, operations research, and psychology. (PA)

The Classroom Strategy Study: Summary Report of General Findings. Research Series No. 187.

ERIC Educational Resources Information Center

Brophy, Jere; Rohrkemper, Mary

Described are the background, rationale, research design, data collection, analysis, and findings of the Classroom Strategy Study, an investigation of 98 elementary school teachers' general strategies for coping with problem students and their ways of dealing with typical problem behaviors associated with each of 12 types of problem students.…

Benchmarking Problems Used in Second Year Level Organic Chemistry Instruction

ERIC Educational Resources Information Center

Raker, Jeffrey R.; Towns, Marcy H.

2010-01-01

Investigations of the problem types used in college-level general chemistry examinations have been reported in this Journal and were first reported in the "Journal of Chemical Education" in 1924. This study extends the findings from general chemistry to the problems of four college-level organic chemistry courses. Three problem…

The application of generalized, cyclic, and modified numerical integration algorithms to problems of satellite orbit computation

NASA Technical Reports Server (NTRS)

Chesler, L.; Pierce, S.

1971-01-01

Generalized, cyclic, and modified multistep numerical integration methods are developed and evaluated for application to problems of satellite orbit computation. Generalized methods are compared with the presently utilized Cowell methods; new cyclic methods are developed for special second-order differential equations; and several modified methods are developed and applied to orbit computation problems. Special computer programs were written to generate coefficients for these methods, and subroutines were written which allow use of these methods with NASA's GEOSTAR computer program.

General aviation IFR operational problems

NASA Technical Reports Server (NTRS)

Bolz, E. H.; Eisele, J. E.

1979-01-01

Operational problems of general aviation IFR operators (particularly single pilot operators) were studied. Several statistical bases were assembled and utilized to identify the more serious problems and to demonstrate their magnitude. These bases include official activity projections, historical accident data and delay data, among others. The GA operating environment and cockpit environment were analyzed in detail. Solutions proposed for each of the problem areas identified are based on direct consideration of currently planned enhancements to the ATC system, and on a realistic assessment of the present and future limitations of general aviation avionics. A coordinated set of research program is suggested which would provide the developments necessary to implement the proposed solutions.

Workplace responsibility, stress, alcohol availability and norms as predictors of alcohol consumption-related problems among employed workers.

PubMed

Hodgins, David C; Williams, Robert; Munro, Gordon

2009-01-01

The objectives of this study were to determine the prevalence of alcohol use and problems among employed individuals in Alberta, Canada (N = 1,890), and to conduct a multivariate examination of predictors of alcohol consumption-related problems. General alcohol problems were identified by 10%, although very few workers described any specific work-related alcohol problems (1%). Structural equation modeling revealed that, as hypothesized, workplace alcohol availability predicted general alcohol problems. Job responsibility and workplace norms also predicted alcohol problems but only for men. Perceived work stress did not predict alcohol problems. Results support the development of interventions that focus on re-shaping alcohol use norms.

One-dimensional Gromov minimal filling problem

NASA Astrophysics Data System (ADS)

Ivanov, Alexandr O.; Tuzhilin, Alexey A.

2012-05-01

The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.

Behavior and Attention Problems in Eight-Year-Old Children with Prenatal Opiate and Poly-Substance Exposure: A Longitudinal Study

PubMed Central

Slinning, Kari; Moe, Vibeke; Walhovd, Kristine B.

2016-01-01

Multiple studies have found that children born to mothers with opioid or poly-substance use during pregnancy have more behavior and attention problems and lower cognitive functioning than non-exposed children. The present study aimed to investigate whether behavior and attention problems are more prominent than general cognitive deficits in this risk group and whether the problems wane or increase over time. This prospective longitudinal cross-informant study compared 72 children who were prenatally exposed to heroin and multiple drugs with a group of 58 children without known prenatal risk factors. Group differences in caregivers’ and teachers’ reports of the children’s behavior and attention problems based on the Child Behavior Check List and the ADHD Rating Scale were compared based on group differences in general cognitive functioning at 4 ½ and 8 ½ years of age. Both parent and teacher reports suggest that the exposed group has significantly more problems in several behavioral areas than the comparison group, particularly with regard to attention problems. The preschool teachers had already reported these problems when the children were 4 ½ years old, whereas the caregivers reported these problems mainly when the children were 8 ½ years old. The group differences in behavioral and attentional problems were not significantly greater and some were even significantly smaller than the group differences in general cognitive abilities. These findings suggest that children subject to prenatally drug exposure have increasing problems in multiple areas related to behavior from preschool age to 8 ½ years but that these problems do not seem to be specific; i.e., they are not more severe than the problems with general cognitive abilities found for this group. PMID:27336798

Behavior and Attention Problems in Eight-Year-Old Children with Prenatal Opiate and Poly-Substance Exposure: A Longitudinal Study.

PubMed

Nygaard, Egil; Slinning, Kari; Moe, Vibeke; Walhovd, Kristine B

2016-01-01

Multiple studies have found that children born to mothers with opioid or poly-substance use during pregnancy have more behavior and attention problems and lower cognitive functioning than non-exposed children. The present study aimed to investigate whether behavior and attention problems are more prominent than general cognitive deficits in this risk group and whether the problems wane or increase over time. This prospective longitudinal cross-informant study compared 72 children who were prenatally exposed to heroin and multiple drugs with a group of 58 children without known prenatal risk factors. Group differences in caregivers' and teachers' reports of the children's behavior and attention problems based on the Child Behavior Check List and the ADHD Rating Scale were compared based on group differences in general cognitive functioning at 4 ½ and 8 ½ years of age. Both parent and teacher reports suggest that the exposed group has significantly more problems in several behavioral areas than the comparison group, particularly with regard to attention problems. The preschool teachers had already reported these problems when the children were 4 ½ years old, whereas the caregivers reported these problems mainly when the children were 8 ½ years old. The group differences in behavioral and attentional problems were not significantly greater and some were even significantly smaller than the group differences in general cognitive abilities. These findings suggest that children subject to prenatally drug exposure have increasing problems in multiple areas related to behavior from preschool age to 8 ½ years but that these problems do not seem to be specific; i.e., they are not more severe than the problems with general cognitive abilities found for this group.

Contact and crack problems for an elastic wedge. [stress concentration in elastic half spaces

NASA Technical Reports Server (NTRS)

Erdogan, F.; Gupta, G. D.

1974-01-01

The contact and the crack problems for an elastic wedge of arbitrary angle are considered. The problem is reduced to a singular integral equation which, in the general case, may have a generalized Cauchy kernel. The singularities under the stamp as well as at the wedge apex were studied, and the relevant stress intensity factors are defined. The problem was solved for various wedge geometries and loading conditions. The results may be applicable to certain foundation problems and to crack problems in symmetrically loaded wedges in which cracks initiate from the apex.

A Focus on Problems of National Interest in the College General Chemistry Laboratory: The Effects of the Problem-Oriented Method Compared with Those of the Traditional Approach.

ERIC Educational Resources Information Center

Neman, Robert Lynn

This study was designed to assess the effects of the problem-oriented method compared to those of the traditional approach in general chemistry at the college level. The problem-oriented course included topics such as air and water pollution, drug addiction and analysis, tetraethyl-lead additives, insecticides in the environment, and recycling of…

A General Architecture for Intelligent Tutoring of Diagnostic Classification Problem Solving

PubMed Central

Crowley, Rebecca S.; Medvedeva, Olga

2003-01-01

We report on a general architecture for creating knowledge-based medical training systems to teach diagnostic classification problem solving. The approach is informed by our previous work describing the development of expertise in classification problem solving in Pathology. The architecture envelops the traditional Intelligent Tutoring System design within the Unified Problem-solving Method description Language (UPML) architecture, supporting component modularity and reuse. Based on the domain ontology, domain task ontology and case data, the abstract problem-solving methods of the expert model create a dynamic solution graph. Student interaction with the solution graph is filtered through an instructional layer, which is created by a second set of abstract problem-solving methods and pedagogic ontologies, in response to the current state of the student model. We outline the advantages and limitations of this general approach, and describe it’s implementation in SlideTutor–a developing Intelligent Tutoring System in Dermatopathology. PMID:14728159

Multi-level adaptive finite element methods. 1: Variation problems

NASA Technical Reports Server (NTRS)

Brandt, A.

1979-01-01

A general numerical strategy for solving partial differential equations and other functional problems by cycling between coarser and finer levels of discretization is described. Optimal discretization schemes are provided together with very fast general solvers. It is described in terms of finite element discretizations of general nonlinear minimization problems. The basic processes (relaxation sweeps, fine-grid-to-coarse-grid transfers of residuals, coarse-to-fine interpolations of corrections) are directly and naturally determined by the objective functional and the sequence of approximation spaces. The natural processes, however, are not always optimal. Concrete examples are given and some new techniques are reviewed. Including the local truncation extrapolation and a multilevel procedure for inexpensively solving chains of many boundary value problems, such as those arising in the solution of time-dependent problems.

Solution of monotone complementarity and general convex programming problems using a modified potential reduction interior point method

DOE PAGES

Huang, Kuo -Ling; Mehrotra, Sanjay

2016-11-08

We present a homogeneous algorithm equipped with a modified potential function for the monotone complementarity problem. We show that this potential function is reduced by at least a constant amount if a scaled Lipschitz condition (SLC) is satisfied. A practical algorithm based on this potential function is implemented in a software package named iOptimize. The implementation in iOptimize maintains global linear and polynomial time convergence properties, while achieving practical performance. It either successfully solves the problem, or concludes that the SLC is not satisfied. When compared with the mature software package MOSEK (barrier solver version 6.0.0.106), iOptimize solves convex quadraticmore » programming problems, convex quadratically constrained quadratic programming problems, and general convex programming problems in fewer iterations. Moreover, several problems for which MOSEK fails are solved to optimality. In addition, we also find that iOptimize detects infeasibility more reliably than the general nonlinear solvers Ipopt (version 3.9.2) and Knitro (version 8.0).« less

The Effect of Shift Work on Quality and Stability of Marital Relations.

ERIC Educational Resources Information Center

White, Lynn; Keith, Bruce

1990-01-01

Interviewed a national panel of 1,668 married women and men in 1980 and 1983 to assess effects of shift work on 6 measures of marital quality (marital happiness, interaction, disagreements, general problems, sexual problems, and child-related problems) and probability of divorce. Results suggested that shift work has a modest but general adverse…

An efficient method for generalized linear multiplicative programming problem with multiplicative constraints.

PubMed

Zhao, Yingfeng; Liu, Sanyang

2016-01-01

We present a practical branch and bound algorithm for globally solving generalized linear multiplicative programming problem with multiplicative constraints. To solve the problem, a relaxation programming problem which is equivalent to a linear programming is proposed by utilizing a new two-phase relaxation technique. In the algorithm, lower and upper bounds are simultaneously obtained by solving some linear relaxation programming problems. Global convergence has been proved and results of some sample examples and a small random experiment show that the proposed algorithm is feasible and efficient.

Adolescents’ Use of Care for Behavioral and Emotional Problems: Types, Trends, and Determinants

PubMed Central

Reijneveld, Sijmen A.; Wiegersma, P. Auke; Ormel, Johan; Verhulst, Frank C.; Vollebergh, Wilma A. M.; Jansen, Danielle E. M. C.

2014-01-01

Objective While adolescents use various types of care for behavioral and emotional problems, evidence on age trends and determinants per type is scarce. We aimed to assess use of care by adolescents because of behavioral and emotional problems, overall and by type, and its determinants, for ages 10–19 years. Methods We obtained longitudinal data on 2,230 adolescents during ages 10–19 from four measurements regarding use of general care and specialized care (youth social care and mental healthcare) in the preceding 6 months, the Child Behavior Checklist (CBCL) and Youth Self-Report, and child and family characteristics. We analyzed data by multilevel logistic regression. Results Overall rates of use increased from 20.1% at age 10/11 to 32.2% at age 19: general care was used most. At age 10/11 use was higher among boys, at age 19 among girls. Use of general care increased for both genders, whereas use of specialized care increased among girls but decreased among boys. This differential change was associated with CBCL externalizing and internalizing problems, school problems, family socioeconomic status, and parental divorce. Preceding CBCL problems predicted more use: most for mental health care and least for general care. Moreover, general care was used more frequently by low and medium socioeconomic status families, with odds ratios (95%-confidence intervals): 1.52 (1.23;1.88) and 1.40 (1.17;1.67); youth social care in case of parental divorce, 2.07 (1.36;3.17); and of special education, 2.66 (1.78;3.95); and mental healthcare in case of special education, 2.66 (1.60;4.51). Discussion Adolescents with behavioral and emotional problems use general care most frequently. Overall use increases with age. Determinants of use vary per type. PMID:24699408

Adolescents' use of care for behavioral and emotional problems: types, trends, and determinants.

PubMed

Reijneveld, Sijmen A; Wiegersma, P Auke; Ormel, Johan; Verhulst, Frank C; Vollebergh, Wilma A M; Jansen, Danielle E M C

2014-01-01

While adolescents use various types of care for behavioral and emotional problems, evidence on age trends and determinants per type is scarce. We aimed to assess use of care by adolescents because of behavioral and emotional problems, overall and by type, and its determinants, for ages 10-19 years. We obtained longitudinal data on 2,230 adolescents during ages 10-19 from four measurements regarding use of general care and specialized care (youth social care and mental healthcare) in the preceding 6 months, the Child Behavior Checklist (CBCL) and Youth Self-Report, and child and family characteristics. We analyzed data by multilevel logistic regression. Overall rates of use increased from 20.1% at age 10/11 to 32.2% at age 19: general care was used most. At age 10/11 use was higher among boys, at age 19 among girls. Use of general care increased for both genders, whereas use of specialized care increased among girls but decreased among boys. This differential change was associated with CBCL externalizing and internalizing problems, school problems, family socioeconomic status, and parental divorce. Preceding CBCL problems predicted more use: most for mental health care and least for general care. Moreover, general care was used more frequently by low and medium socioeconomic status families, with odds ratios (95%-confidence intervals): 1.52 (1.23;1.88) and 1.40 (1.17;1.67); youth social care in case of parental divorce, 2.07 (1.36;3.17); and of special education, 2.66 (1.78;3.95); and mental healthcare in case of special education, 2.66 (1.60;4.51). Adolescents with behavioral and emotional problems use general care most frequently. Overall use increases with age. Determinants of use vary per type.

Intuitive reasoning about abstract and familiar physics problems

NASA Technical Reports Server (NTRS)

Kaiser, Mary Kister; Jonides, John; Alexander, Joanne

1986-01-01

Previous research has demonstrated that many people have misconceptions about basic properties of motion. Two experiments examined whether people are more likely to produce dynamically correct predictions about basic motion problems involving situations with which they are familiar, and whether solving such problems enhances performance on a subsequent abstract problem. In experiment 1, college students were asked to predict the trajectories of objects exiting a curved tube. Subjects were more accurate on the familiar version of the problem, and there was no evidence of transfer to the abstract problem. In experiment 2, two familiar problems were provided in an attempt to enhance subjects' tendency to extract the general structure of the problems. Once again, they gave more correct responses to the familiar problems but failed to generalize to the abstract problem. Formal physics training was associated with correct predictions for the abstract problem but was unrelated to performance on the familiar problems.

Robust Adaptive Modified Newton Algorithm for Generalized Eigendecomposition and Its Application

NASA Astrophysics Data System (ADS)

Yang, Jian; Yang, Feng; Xi, Hong-Sheng; Guo, Wei; Sheng, Yanmin

2007-12-01

We propose a robust adaptive algorithm for generalized eigendecomposition problems that arise in modern signal processing applications. To that extent, the generalized eigendecomposition problem is reinterpreted as an unconstrained nonlinear optimization problem. Starting from the proposed cost function and making use of an approximation of the Hessian matrix, a robust modified Newton algorithm is derived. A rigorous analysis of its convergence properties is presented by using stochastic approximation theory. We also apply this theory to solve the signal reception problem of multicarrier DS-CDMA to illustrate its practical application. The simulation results show that the proposed algorithm has fast convergence and excellent tracking capability, which are important in a practical time-varying communication environment.

Generalizing Backtrack-Free Search: A Framework for Search-Free Constraint Satisfaction

NASA Technical Reports Server (NTRS)

Jonsson, Ari K.; Frank, Jeremy

2000-01-01

Tractable classes of constraint satisfaction problems are of great importance in artificial intelligence. Identifying and taking advantage of such classes can significantly speed up constraint problem solving. In addition, tractable classes are utilized in applications where strict worst-case performance guarantees are required, such as constraint-based plan execution. In this work, we present a formal framework for search-free (backtrack-free) constraint satisfaction. The framework is based on general procedures, rather than specific propagation techniques, and thus generalizes existing techniques in this area. We also relate search-free problem solving to the notion of decision sets and use the result to provide a constructive criterion that is sufficient to guarantee search-free problem solving.

Description and measurement of concentration problems in depressed patients.

PubMed

Watts, F N; Sharrock, R

1985-05-01

Depressed patients commonly complain of concentration problems, yet these have seldom been the focus of systematic investigation. A structured interview about concentration problems was administered to a group of relatively severely depressed patients. Problems in reading and watching television were the most common, and were highly correlated with each other. Direct report of the number of concentration lapses on a reading task was the most generally satisfactory task-performance correlate of complaints of reading/TV concentration problems. Evidence both from this task and from the interview suggests that depressive concentration problems may often be due to 'mind-wandering'. The correlations with concentration problems with the severity and endogeneity of depression and with state anxiety were generally similar.

Study to determine the IFR operational profile and problems of the general aviation single pilot

NASA Technical Reports Server (NTRS)

Weislogel, G. S.

1983-01-01

General aviation single pilot operating under instrument flight rules (GA SPIFR) was studied. The objectives of the study were to (1) develop a GA SPIFR operational profile, (2) identify problems experienced by the GA SPIFR pilot, and (3) identify research tasks which have the potential for eliminating or reducing the severity of the problems. To obtain the information necessary to accomplish these objectives, a mail questionnaire survey of instrument rated pilots was conducted. The general aviation IFR single pilot operational profile and selected data analysis examples are presented.

Local Conjecturing Process in the Solving of Pattern Generalization Problem

ERIC Educational Resources Information Center

Sutarto; Nusantara, Toto; Subanji; Sisworo

2016-01-01

This aim of this study is to describe the process of local conjecturing in generalizing patterns based on Action, Process, Object, Schema (APOS) theory. The subjects were 16 grade 8 students from a junior high school. Data collection used Pattern Generalization Problem (PGP) and interviews. In the first stage, students completed PGP; in the second…

New Existence Conditions for Order Complementarity Problems

NASA Astrophysics Data System (ADS)

Németh, S. Z.

2009-09-01

Complementarity problems are mathematical models of problems in economics, engineering and physics. A special class of complementarity problems are the order complementarity problems [2]. Order complementarity problems can be applied in lubrication theory [6] and economics [1]. The notion of exceptional family of elements for general order complementarity problems in Banach spaces will be introduced. It will be shown that for general order complementarity problems defined by completely continuous fields the problem has either a solution or an exceptional family of elements (for other notions of exceptional family of elements see [1, 2, 3, 4] and the related references therein). This solves a conjecture of [2] about the existence of exceptional family of elements for order complementarity problems. The proof can be done by using the Leray-Schauder alternative [5]. An application to integral operators will be given.

The formulation of dynamical contact problems with friction in the case of systems of rigid bodies and general discrete mechanical systems—Painlevé and Kane paradoxes revisited

NASA Astrophysics Data System (ADS)

Charles, Alexandre; Ballard, Patrick

2016-08-01

The dynamics of mechanical systems with a finite number of degrees of freedom (discrete mechanical systems) is governed by the Lagrange equation which is a second-order differential equation on a Riemannian manifold (the configuration manifold). The handling of perfect (frictionless) unilateral constraints in this framework (that of Lagrange's analytical dynamics) was undertaken by Schatzman and Moreau at the beginning of the 1980s. A mathematically sound and consistent evolution problem was obtained, paving the road for many subsequent theoretical investigations. In this general evolution problem, the only reaction force which is involved is a generalized reaction force, consistently with the virtual power philosophy of Lagrange. Surprisingly, such a general formulation was never derived in the case of frictional unilateral multibody dynamics. Instead, the paradigm of the Coulomb law applying to reaction forces in the real world is generally invoked. So far, this paradigm has only enabled to obtain a consistent evolution problem in only some very few specific examples and to suggest numerical algorithms to produce computational examples (numerical modeling). In particular, it is not clear what is the evolution problem underlying the computational examples. Moreover, some of the few specific cases in which this paradigm enables to write down a precise evolution problem are known to show paradoxes: the Painlevé paradox (indeterminacy) and the Kane paradox (increase in kinetic energy due to friction). In this paper, we follow Lagrange's philosophy and formulate the frictional unilateral multibody dynamics in terms of the generalized reaction force and not in terms of the real-world reaction force. A general evolution problem that governs the dynamics is obtained for the first time. We prove that all the solutions are dissipative; that is, this new formulation is free of Kane paradox. We also prove that some indeterminacy of the Painlevé paradox is fixed in this formulation.

IFLA General Conference, 1986. Pre-Conference Seminar on Automated Systems for Access to Multilingual and Multiscript Library materials: Problems and Solutions. Papers.

ERIC Educational Resources Information Center

International Federation of Library Associations and Institutions, The Hague (Netherlands).

A seminar which considered problems and solutions regarding automated systems for access to multilingual and multiscript library materials was held as a pre-session before the IFLA general conference in 1986. Papers presented include: (1) "Romanized and Transliterated Databases of Asian Language Materials--History, Problems, and…

Eigenmode computation of cavities with perturbed geometry using matrix perturbation methods applied on generalized eigenvalue problems

NASA Astrophysics Data System (ADS)

Gorgizadeh, Shahnam; Flisgen, Thomas; van Rienen, Ursula

2018-07-01

Generalized eigenvalue problems are standard problems in computational sciences. They may arise in electromagnetic fields from the discretization of the Helmholtz equation by for example the finite element method (FEM). Geometrical perturbations of the structure under concern lead to a new generalized eigenvalue problems with different system matrices. Geometrical perturbations may arise by manufacturing tolerances, harsh operating conditions or during shape optimization. Directly solving the eigenvalue problem for each perturbation is computationally costly. The perturbed eigenpairs can be approximated using eigenpair derivatives. Two common approaches for the calculation of eigenpair derivatives, namely modal superposition method and direct algebraic methods, are discussed in this paper. Based on the direct algebraic methods an iterative algorithm is developed for efficiently calculating the eigenvalues and eigenvectors of the perturbed geometry from the eigenvalues and eigenvectors of the unperturbed geometry.

Hybrid preconditioning for iterative diagonalization of ill-conditioned generalized eigenvalue problems in electronic structure calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Yunfeng, E-mail: yfcai@math.pku.edu.cn; Department of Computer Science, University of California, Davis 95616; Bai, Zhaojun, E-mail: bai@cs.ucdavis.edu

2013-12-15

The iterative diagonalization of a sequence of large ill-conditioned generalized eigenvalue problems is a computational bottleneck in quantum mechanical methods employing a nonorthogonal basis for ab initio electronic structure calculations. We propose a hybrid preconditioning scheme to effectively combine global and locally accelerated preconditioners for rapid iterative diagonalization of such eigenvalue problems. In partition-of-unity finite-element (PUFE) pseudopotential density-functional calculations, employing a nonorthogonal basis, we show that the hybrid preconditioned block steepest descent method is a cost-effective eigensolver, outperforming current state-of-the-art global preconditioning schemes, and comparably efficient for the ill-conditioned generalized eigenvalue problems produced by PUFE as the locally optimal blockmore » preconditioned conjugate-gradient method for the well-conditioned standard eigenvalue problems produced by planewave methods.« less

Criterion-Referenced Testing for College-Level General Education: Some Problems and Recommendations.

ERIC Educational Resources Information Center

Benoist, Howard

1979-01-01

The adoption of a criterion-referenced assessment system and the resulting disadvantages of this form of evaluation for the college general education program are discussed, including problems in identifying assessment validation procedures. (RAO)

Image size invariant visual cryptography for general access structures subject to display quality constraints.

PubMed

Lee, Kai-Hui; Chiu, Pei-Ling

2013-10-01

Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

Assimilating data into open ocean tidal models

NASA Astrophysics Data System (ADS)

Kivman, Gennady A.

The problem of deriving tidal fields from observations by reason of incompleteness and imperfectness of every data set practically available has an infinitely large number of allowable solutions fitting the data within measurement errors and hence can be treated as ill-posed. Therefore, interpolating the data always relies on some a priori assumptions concerning the tides, which provide a rule of sampling or, in other words, a regularization of the ill-posed problem. Data assimilation procedures used in large scale tide modeling are viewed in a common mathematical framework as such regularizations. It is shown that they all (basis functions expansion, parameter estimation, nudging, objective analysis, general inversion, and extended general inversion), including those (objective analysis and general inversion) originally formulated in stochastic terms, may be considered as utilizations of one of the three general methods suggested by the theory of ill-posed problems. The problem of grid refinement critical for inverse methods and nudging is discussed.

An Ada Based Expert System for the Ada Version of SAtool II. Volume 1 and 2

DTIC Science & Technology

1991-06-06

Integrated Computer-Aided Manufacturing (ICAM) (20). In fact, IDEF 0 stands for ICAM Definition Method Zero . IDEF0 defines a subset of SA that omits...reasoning that has been programmed). An expert’s knowledge is specific to one problem domain as opposed to knowledge about general problem-solving...techniques. General problem domains are medicine, finance, science or engineering and so forth in which an expert can solve specific problems very well

Robust Consumption-Investment Problem on Infinite Horizon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zawisza, Dariusz, E-mail: dariusz.zawisza@im.uj.edu.pl

In our paper we consider an infinite horizon consumption-investment problem under a model misspecification in a general stochastic factor model. We formulate the problem as a stochastic game and finally characterize the saddle point and the value function of that game using an ODE of semilinear type, for which we provide a proof of an existence and uniqueness theorem for its solution. Such equation is interested on its own right, since it generalizes many other equations arising in various infinite horizon optimization problems.

An Investigation of Joint Service Acquisition Logistics Issues/Problems and Automated Joint Program Support.

DTIC Science & Technology

1984-09-01

Management Information System (ALMIS) to address them. Literature was surveyed and problems were summarized and developed into a questionnaire. Structured interviews were then conducted with over 100 different Air Force and civilian upper and middle JSAP managers. Many general and specific problems and issues were identified and validated using statistical and qualitative methods. General use of ALMIS to address certain joint service problem areas was confirmed. Potential use and desirable capabilities for ALMIS were also determined. Recommendations for ALMIS

General aviation avionics equipment maintenance

NASA Technical Reports Server (NTRS)

Parker, C. D.; Tommerdahl, J. B.

1978-01-01

Maintenance of general aviation avionics equipment was investigated with emphasis on single engine and light twin engine general aviation aircraft. Factors considered include the regulatory agencies, avionics manufacturers, avionics repair stations, the statistical character of the general aviation community, and owners and operators. The maintenance, environment, and performance, repair costs, and reliability of avionics were defined. It is concluded that a significant economic stratification is reflected in the maintenance problems encountered, that careful attention to installations and use practices can have a very positive impact on maintenance problems, and that new technologies and a general growth in general aviation will impact maintenance.

Counting Pizza Pieces and Other Combinatorial Problems.

ERIC Educational Resources Information Center

Maier, Eugene

1988-01-01

The general combinatorial problem of counting the number of regions into which the interior of a circle is divided by a family of lines is considered. A general formula is developed and its use is illustrated in two situations. (PK)

Cognitive arithmetic and problem solving: a comparison of children with specific and general mathematics difficulties.

PubMed

Jordan, N C; Montani, T O

1997-01-01

This study examined problem-solving and number-fact skills in two subgroups of third-grade children with mathematics difficulties (MD): MD-specific (n = 12) and MD-general (n = 12). The MD-specific group had difficulties in mathematics but not in reading, and the MD-general group had difficulties in reading as well as in mathematics. A comparison group of nonimpaired children (n = 24) also was included. The findings showed that on both story and number-fact problems, the MD-specific group performed worse than the nonimpaired group in timed conditions but not in untimed conditions. The MD-general group, on the other hand, performed worse than the nonimpaired group, regardless of whether tasks were timed or not. An analysis of children's strategies in untimed conditions showed that both the MD-specific and the MD-general groups relied more on backup strategies than the nonimpaired group. However, children in the MD-specific group executed backup strategies more skillfully than children in the MD-general group, allowing them to achieve parity with children in the nonimpaired group when tasks were not timed. The findings suggest that children with specific MD have circumscribed deficits associated with fact retrieval, whereas children with general MD have more basic delays associated with problem conceptualization and execution of calculation procedures.

Parameterized Complexity Results for General Factors in Bipartite Graphs with an Application to Constraint Programming

NASA Astrophysics Data System (ADS)

Gutin, Gregory; Kim, Eun Jung; Soleimanfallah, Arezou; Szeider, Stefan; Yeo, Anders

The NP-hard general factor problem asks, given a graph and for each vertex a list of integers, whether the graph has a spanning subgraph where each vertex has a degree that belongs to its assigned list. The problem remains NP-hard even if the given graph is bipartite with partition U ⊎ V, and each vertex in U is assigned the list {1}; this subproblem appears in the context of constraint programming as the consistency problem for the extended global cardinality constraint. We show that this subproblem is fixed-parameter tractable when parameterized by the size of the second partite set V. More generally, we show that the general factor problem for bipartite graphs, parameterized by |V |, is fixed-parameter tractable as long as all vertices in U are assigned lists of length 1, but becomes W[1]-hard if vertices in U are assigned lists of length at most 2. We establish fixed-parameter tractability by reducing the problem instance to a bounded number of acyclic instances, each of which can be solved in polynomial time by dynamic programming.

Self-reported occupational exposure to chemical and physical factors and risk of skin problems: a 3-year follow-up study of the general working population of Norway.

PubMed

Alfonso, Jose Hernan; Thyssen, Jacob P; Tynes, Tore; Mehlum, Ingrid Sivesind; Johannessen, Håkon A

2015-11-01

Prospective studies on occupational dermatoses in the general working population are sparse. This study investigated prospectively the impact of self-reported occupational exposure to chemicals and physical factors on the risk of skin problems. The cohort comprised respondents drawn randomly from the general population in Norway, who were registered employed in 2006 and 2009 (n = 6,745). Indoor dry air (odds ratio (OR) 1.3; 95% confidence interval (95% CI) 1.1-1.6) was a significant baseline predictor of skin problems at follow-up, whereas exposure to cleaning products (OR 1.7; 95% CI 1.2-2.5), water (OR 1.4; 95% CI 1.1-1.9) and indoor dry air (OR 1.6; 95% CI 1.1-2.1) at both measurement time-points was significantly associated with skin problems. The population risk attributable to these factors was 16%. This study quantified the contribution of occupational exposure factors to skin problems in the general working population of Norway.

Gelfand-type problem for two-phase porous media

PubMed Central

Gordon, Peter V.; Moroz, Vitaly

2014-01-01

We consider a generalization of the Gelfand problem arising in Frank-Kamenetskii theory of thermal explosion. This generalization is a natural extension of the Gelfand problem to two-phase materials, where, in contrast to the classical Gelfand problem which uses a single temperature approach, the state of the system is described by two different temperatures. We show that similar to the classical Gelfand problem the thermal explosion occurs exclusively owing to the absence of stationary temperature distribution. We also show that the presence of interphase heat exchange delays a thermal explosion. Moreover, we prove that in the limit of infinite heat exchange between phases the problem of thermal explosion in two-phase porous media reduces to the classical Gelfand problem with renormalized constants. PMID:24611025

A weak Galerkin generalized multiscale finite element method

DOE PAGES

Mu, Lin; Wang, Junping; Ye, Xiu

2016-03-31

In this study, we propose a general framework for weak Galerkin generalized multiscale (WG-GMS) finite element method for the elliptic problems with rapidly oscillating or high contrast coefficients. This general WG-GMS method features in high order accuracy on general meshes and can work with multiscale basis derived by different numerical schemes. A special case is studied under this WG-GMS framework in which the multiscale basis functions are obtained by solving local problem with the weak Galerkin finite element method. Convergence analysis and numerical experiments are obtained for the special case.

A weak Galerkin generalized multiscale finite element method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mu, Lin; Wang, Junping; Ye, Xiu

In this study, we propose a general framework for weak Galerkin generalized multiscale (WG-GMS) finite element method for the elliptic problems with rapidly oscillating or high contrast coefficients. This general WG-GMS method features in high order accuracy on general meshes and can work with multiscale basis derived by different numerical schemes. A special case is studied under this WG-GMS framework in which the multiscale basis functions are obtained by solving local problem with the weak Galerkin finite element method. Convergence analysis and numerical experiments are obtained for the special case.

Total variation regularization of the 3-D gravity inverse problem using a randomized generalized singular value decomposition

NASA Astrophysics Data System (ADS)

Vatankhah, Saeed; Renaut, Rosemary A.; Ardestani, Vahid E.

2018-04-01

We present a fast algorithm for the total variation regularization of the 3-D gravity inverse problem. Through imposition of the total variation regularization, subsurface structures presenting with sharp discontinuities are preserved better than when using a conventional minimum-structure inversion. The associated problem formulation for the regularization is nonlinear but can be solved using an iteratively reweighted least-squares algorithm. For small-scale problems the regularized least-squares problem at each iteration can be solved using the generalized singular value decomposition. This is not feasible for large-scale, or even moderate-scale, problems. Instead we introduce the use of a randomized generalized singular value decomposition in order to reduce the dimensions of the problem and provide an effective and efficient solution technique. For further efficiency an alternating direction algorithm is used to implement the total variation weighting operator within the iteratively reweighted least-squares algorithm. Presented results for synthetic examples demonstrate that the novel randomized decomposition provides good accuracy for reduced computational and memory demands as compared to use of classical approaches.

Analysis of general aviation single-pilot IFR incident data obtained from the NASA Aviation Safety Reporting System

NASA Technical Reports Server (NTRS)

Bergeron, H. P.

1983-01-01

An analysis of incident data obtained from the NASA Aviation Safety Reporting System (ASRS) has been made to determine the problem areas in general aviation single-pilot IFR (SPIFR) operations. The Aviation Safety Reporting System data base is a compilation of voluntary reports of incidents from any person who has observed or been involved in an occurrence which was believed to have posed a threat to flight safety. This paper examines only those reported incidents specifically related to general aviation single-pilot IFR operations. The frequency of occurrence of factors related to the incidents was the criterion used to define significant problem areas and, hence, to suggest where research is needed. The data was cataloged into one of five major problem areas: (1) controller judgment and response problems, (2) pilot judgment and response problems, (3) air traffic control (ATC) intrafacility and interfacility conflicts, (4) ATC and pilot communication problems, and (5) IFR-VFR conflicts. In addition, several points common to all or most of the problems were observed and reported. These included human error, communications, procedures and rules, and work load.

Generalized Centroid Estimators in Bioinformatics

PubMed Central

Hamada, Michiaki; Kiryu, Hisanori; Iwasaki, Wataru; Asai, Kiyoshi

2011-01-01

In a number of estimation problems in bioinformatics, accuracy measures of the target problem are usually given, and it is important to design estimators that are suitable to those accuracy measures. However, there is often a discrepancy between an employed estimator and a given accuracy measure of the problem. In this study, we introduce a general class of efficient estimators for estimation problems on high-dimensional binary spaces, which represent many fundamental problems in bioinformatics. Theoretical analysis reveals that the proposed estimators generally fit with commonly-used accuracy measures (e.g. sensitivity, PPV, MCC and F-score) as well as it can be computed efficiently in many cases, and cover a wide range of problems in bioinformatics from the viewpoint of the principle of maximum expected accuracy (MEA). It is also shown that some important algorithms in bioinformatics can be interpreted in a unified manner. Not only the concept presented in this paper gives a useful framework to design MEA-based estimators but also it is highly extendable and sheds new light on many problems in bioinformatics. PMID:21365017

In science communication, why does the idea of a public deficit always return? The eternal recurrence of the public deficit.

PubMed

Cortassa, Carina

2016-05-01

After several years of loud and clear rejection, the idea of a public cognitive deficit insistently reappears in the agenda of Science Communication and Public Understanding of Science studies. This essay addresses two different kinds of reason - practical and epistemic - converging at that point. In the first part, it will be argued that the hypothesis of the lack of knowledge among laypeople and its controversial relationships with their interests and attitudes towards science prevails because it is an intuitive and optimistic way to frame the gap between science and society and, therefore, to cope with its causes and consequences. In the second part, a deeper level of reasons will be examined, in order to show that the persistence of the idea has its roots in the objective epistemic asymmetry between scientists and the public, the scope of which is not always properly judged. To recognize this asymmetry as a previous condition for their interactions may help to surpass the byzantine debate: deficit yes or no and open up original questions for the field, summarized in the closing remarks. © The Author(s) 2016.

Vascular knowledge in medieval times was the turning point for the humanistic trend.

PubMed

Ducasse, E; Speziale, F; Baste, J C; Midy, D

2006-06-01

Knowledge of the history of our surgical specialty may broaden our viewpoint for everyday practice. We illustrate the scientific progress made in medieval times relevant to the vascular system and blood circulation, progress made despite prevailing religious and philosophical dogma. We located all articles concerning vascular knowledge and historical reviews in databases such as MEDLINE, EMBASE and the database of abstracts of reviews (DARE). We also explored the database of the register from the French National Library, the French Medical Inter-University (BIUM), the Italian National Library and the French and Italian Libraries in the Vatican. All data were collected and analysed in chronological order. Medieval vascular knowledge was inherited from Greek via Byzantine and Arabic writings, the first controversies against the recognized vascular schema emanating from an Arabian physician in the 13th century. Dissection was forbidden and clerical rules instilled a fear of blood. Major contributions to scientific progress in the vascular field in medieval times came from Ibn-al-Nafis and Harvey. Vascular specialists today may feel proud to recall that once religious dogma declined in early medieval times, vascular anatomic and physiological discoveries led the way to scientific progress.

Secure and Fair Cluster Head Selection Protocol for Enhancing Security in Mobile Ad Hoc Networks

PubMed Central

Paramasivan, B.; Kaliappan, M.

2014-01-01

Mobile ad hoc networks (MANETs) are wireless networks consisting of number of autonomous mobile devices temporarily interconnected into a network by wireless media. MANETs become one of the most prevalent areas of research in the recent years. Resource limitations, energy efficiency, scalability, and security are the great challenging issues in MANETs. Due to its deployment nature, MANETs are more vulnerable to malicious attack. The secure routing protocols perform very basic security related functions which are not sufficient to protect the network. In this paper, a secure and fair cluster head selection protocol (SFCP) is proposed which integrates security factors into the clustering approach for achieving attacker identification and classification. Byzantine agreement based cooperative technique is used for attacker identification and classification to make the network more attack resistant. SFCP used to solve this issue by making the nodes that are totally surrounded by malicious neighbors adjust dynamically their belief and disbelief thresholds. The proposed protocol selects the secure and energy efficient cluster head which acts as a local detector without imposing overhead to the clustering performance. SFCP is simulated in network simulator 2 and compared with two protocols including AODV and CBRP. PMID:25143986

Spectroscopic analysis of XIV century wall paintings from Patriarchate of Peć Monastery, Serbia

NASA Astrophysics Data System (ADS)

Marić-Stojanović, M.; Bajuk-Bogdanović, D.; Uskoković-Marković, S.; Holclajtner-Antunović, I.

2018-02-01

The Church of the Holy Mother of God Hodegetria in Peć is decorated with wall paintings that date from the beginning of the 14th century. In terms of style they correspond to Byzantine wall paintings from the epoch of Paleologos. The painting technique and pigment pallete has been examined on micro fragments in thin cross-sections by means of optical microscopy (OM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and micro- Raman spectroscopy. Use of the fresco technique and two supporting plaster layers was noted on the majority of samples, while in large blue painted areas, a combination of fresco and secco techniques was used. The SEM-EDS results showed the presence of Ca as the main component of plaster besides the traces of Si and Mg. In some samples egg white as a binder was identified. The paint film is often multilayered. Twelve pigments were identified, mainly natural earth pigments such as red ochre, yellow ochre and green earth. A mixture of pigments was used for attaining desirable optical and aesthetical impressions. As decay product only weddelite was detected in many preparatory and painted samples.

Threshold q -voter model

NASA Astrophysics Data System (ADS)

Vieira, Allan R.; Anteneodo, Celia

2018-05-01

We introduce the threshold q -voter opinion dynamics where an agent, facing a binary choice, can change its mind when at least q0 among q neighbors share the opposite opinion. Otherwise, the agent can still change its mind with a certain probability ɛ . This threshold dynamics contemplates the possibility of persuasion by an influence group even when there is not full agreement among its members. In fact, individuals can follow their peers not only when there is unanimity (q0=q ) in the lobby group, as assumed in the q -voter model, but also, depending on the circumstances, when there is simple majority (q0>q /2 ), Byzantine consensus (q0>2 q /3 ), or any minimal number q0 among q . This realistic threshold gives place to emerging collective states and phase transitions which are not observed in the standard q voter. The threshold q0, together with the stochasticity introduced by ɛ , yields a phenomenology that mimics as particular cases the q voter with stochastic drivings such as nonconformity and independence. In particular, nonconsensus majority states are possible, as well as mixed phases. Continuous and discontinuous phase transitions can occur, but also transitions from fluctuating phases into absorbing states.

Moving formal methods into practice. Verifying the FTPP Scoreboard: Results, phase 1

NASA Technical Reports Server (NTRS)

Srivas, Mandayam; Bickford, Mark

1992-01-01

This report documents the Phase 1 results of an effort aimed at formally verifying a key hardware component, called Scoreboard, of a Fault-Tolerant Parallel Processor (FTPP) being built at Charles Stark Draper Laboratory (CSDL). The Scoreboard is part of the FTPP virtual bus that guarantees reliable communication between processors in the presence of Byzantine faults in the system. The Scoreboard implements a piece of control logic that approves and validates a message before it can be transmitted. The goal of Phase 1 was to lay the foundation of the Scoreboard verification. A formal specification of the functional requirements and a high-level hardware design for the Scoreboard were developed. The hardware design was based on a preliminary Scoreboard design developed at CSDL. A main correctness theorem, from which the functional requirements can be established as corollaries, was proved for the Scoreboard design. The goal of Phase 2 is to verify the final detailed design of Scoreboard. This task is being conducted as part of a NASA-sponsored effort to explore integration of formal methods in the development cycle of current fault-tolerant architectures being built in the aerospace industry.

King Solomon's miners--starvation and bioaccumulation? An environmental archaeological investigation in Southern Jordan.

PubMed

Pyatt, F B; Barker, G W; Birch, P; Gilbertson, D D; Grattan, J P; Mattingly, D J

1999-07-01

Copper mining and smelting were important activities in various predesert wadis during the Iron Age, Nabatean, Roman, and Byzantine periods in southern Jordan and major spoil tips together with slag heaps remain as a legacy of such enterprises. Barley has grown in the area for a prolonged period and currently wild barley plants are affected by toxic cations, which reduce their yields. It is considered that such plants provide an adequate model to assess how similar plants would have performed, in terms of productivity, in the past. The population of miners/slaves, guards, etc., would have been subject to bioaccumulation of heavy metals, which conceivably would have led to detrimental effects on their health. Inhalation and ingestion of particulate pollutants cannot be discounted. It is argued that the population may have been further weakened as a consequence of food shortage, due to reduced plant productivity, as cereals are important foods for both humans and the animals upon which they are dependent. A sizeable mining community could only have been maintained by large-scale importation of food or a massive intensification of agricultural activity. Copyright 1999 Academic Press.

Archaeoseismology in Algeria: observed damages related to probable past earthquakes on archaeological remains on Roman sites (Tel Atlas of Algeria)

NASA Astrophysics Data System (ADS)

Roumane, Kahina; Ayadi, Abdelhakim

2017-04-01

The seismological catalogue for Algeria exhibits significant lack for the period before 1365. Some attempts led to retrieve ancient earthquakes evidenced by historical documents and achieves. Archaeoseismology allows a study of earthquakes that have affected archaeological sites, based on the analysis of damage observed on remains. We have focused on the Antiquity period that include Roman, Vandal and Byzantine period from B.C 146 to A.D. 533. This will contribute significantly to the understanding of seismic hazard of the Tell Atlas region known as an earthquake prone area. The Tell Atlas (Algeria) experienced during its history many disastrous earthquakes their impacts are graved on landscape and archaeological monuments. On Roman sites such, Lambaesis (Lambèse), Thamugadi (Timgad) Thibilis (Salaoua Announa) or Thevest (Tebessa), damage were observed on monuments and remains related to seismic events following strong shacking or other ground deformation (subsidence, landslide). Examples of observed damage and disorders on several Roman sites are presented as a contribution to Archaeoseismology in Algeria based on effects of earthquakes on ancient structures and monuments. Keywords : Archaeoseismology. Lambaesis. Drop columns. Aspecelium. Ancient earthquakes

Secure and fair cluster head selection protocol for enhancing security in mobile ad hoc networks.

PubMed

Paramasivan, B; Kaliappan, M

2014-01-01

Mobile ad hoc networks (MANETs) are wireless networks consisting of number of autonomous mobile devices temporarily interconnected into a network by wireless media. MANETs become one of the most prevalent areas of research in the recent years. Resource limitations, energy efficiency, scalability, and security are the great challenging issues in MANETs. Due to its deployment nature, MANETs are more vulnerable to malicious attack. The secure routing protocols perform very basic security related functions which are not sufficient to protect the network. In this paper, a secure and fair cluster head selection protocol (SFCP) is proposed which integrates security factors into the clustering approach for achieving attacker identification and classification. Byzantine agreement based cooperative technique is used for attacker identification and classification to make the network more attack resistant. SFCP used to solve this issue by making the nodes that are totally surrounded by malicious neighbors adjust dynamically their belief and disbelief thresholds. The proposed protocol selects the secure and energy efficient cluster head which acts as a local detector without imposing overhead to the clustering performance. SFCP is simulated in network simulator 2 and compared with two protocols including AODV and CBRP.

Enhancement of overwritten text in the Archimedes Palimpsest

NASA Astrophysics Data System (ADS)

Knox, Keith T.

2008-02-01

The Archimedes Palimpsest is a thousand-year old overwritten parchment manuscript, containing several treatises by Archimedes. Eight hundred years ago, it was erased, overwritten and bound into a prayer book. In the middle of the twentieth century, a few pages were painted over with forged Byzantine icons. Today, a team of imagers, scholars and conservators is recovering and interpreting the erased Archimedes writings. Two different methods have been used to reveal the erased undertext. Spectral information is obtained by illuminating the manuscript with narrow-band light from the ultraviolet, through the visible wavebands and into the near-infrared wavelengths. Characters are extracted by combining pairs of spectral bands or by spectral unmixing techniques adapted from remote sensing. Lastly, since all of the text was written with iron gall ink, X-Ray fluorescence has been used to expose the ink underneath the painted icons. This paper describes the use of color to enhance the erased text in the processed images and to make it visible to the scholars. Special pseudocolor techniques have been developed that significantly increase the contrast of the erased text and make it possible to be read by the scholars despite the presence of the obscuring, overlaid text.

Hippocrates as Galen's teacher.

PubMed

Jouanna, Jacques

2010-01-01

Starting from the frescoes of the cathedral of Anagni which present an obvious relationship between Hippocrates as Galen's teacher and the medieval image of man's place in the universe dominated by the number four, this paper returns to the origins of this quaternary theory in Hippocratic medicine with the four humors (Nature of Man), then follows its evolution in Galen and finally into late Greek and Byzantine medicine where the quaternary division will have an unprecedented extension, with the four temperaments. In particular, a new piece of evidence from this late period attributed to Hippocrates (the small treatise of Greek Medicine The Pulse and the Human Temperament) appears as the veritable source of the Latin Letter attributed to Vindicianus. Therefore, contrary to what was believed until now, the doctrine of the four temperaments was not elaborated first in a Latin form. Throughout its history, the quaternary theory will remain connected to Hippocrates, but the image and teaching of the Father of Medicine will change as the theory evolves. A second rediscovered treatise of the late period (The Formation of Man) starts with this phrase: 'Words of Hippocrates to Galen his own pupil'. This seems a felicitous commentary to the medical scene in the cathedral of Anagni.

[Gynecology and obstetrics in Ancient Rome].

PubMed

Dumont, M

1992-10-01

Gods and Goddesses were invoked by the Romans for the termination of a good delivery. Diana, Juno, Lucina and Cybele were the preferred ones. Sterility was sometimes treated by the whip of the Lupercali of ministers of Pan. The first doctors in Rome were coming from Greece. Celsus, Pliny the Elder were encyclopedists, Rufus an anatomist, Dioscorides a pharmacologist. Archigenes, Aretaeus and Antyllus surgeons. Soranus from Ephesus, was the first to recommend podalic version. His works was a long time buried in a profound oblivion and discovered by scholars during the nineteenth century. Galen was looked as the most famous medical man after Hippocrates. During the Roman Empire of Occident (Byzantine Empire), Oribasius, Aurelianus Caelius, Moschion and above all Aetius and Paul of Aegina wrote many works which were many times plagiarized. Roman laws concerning public health were severe. Midwives took an important action in the care of pregnant women. Roman poets as Plautus, Terence, Lucilius, Catullus, Virgil, Tibullus, Ovid and Martial were many times concerned in their writings with gynecologic or obstetric subjects. Children were easily forsaken. Three Emperors, Trajan, Marcus-Aurelius and Alexander Severius, a writer, Aulu-Gelles, and a rhetor, Quintilian, took protection of them.

The contribution of demographic and morbidity factors to self-reported visit frequency of patients: a cross-sectional study of general practice patients in Australia

PubMed Central

Knox, Stephanie A; Britt, Helena

2004-01-01

Background Understanding the factors that affect patients' utilisation of health services is important for health service provision and effective patient management. This study aimed to investigate the specific morbidity and demographic factors related to the frequency with which general practice patients visit a general practitioner/family physician (GP) in Australia. Methods A sub-study was undertaken as part of an ongoing national study of general practice activity in Australia. A cluster sample of 10,755 general practice patients were surveyed through a random sample of 379 general practitioners. The patient reported the number of times he/she had visited a general practitioner in the previous twelve months. The GP recorded all the patient's major health problems, including those managed at the current consultation. Results Patients reported an average of 8.8 visits to a general practitioner per year. After adjusting for other patient demographics and number of health problems, concession health care card holders made on average 2.6 more visits per year to a general practitioner than did non-card holders (p < .001). After adjustment, patients from remote/very remote locations made 2.3 fewer visits per year than patients from locations where services were highly accessible (p < .001). After adjustment for patient demographics, patients with diagnosed anxiety made on average 2.7 more visits per year (p = 0.003), those with diagnosed depression 2.2 more visits than average (p < .0001), and those with back problems 2.4 more visits (p = 0.009) than patients without the respective disorders. Conclusions Anxiety, back pain and depression are associated with greater patient demand for general practice services than other health problems. The effect of sociodemographic factors on patient utilisation of general practice services is complex. Equity of access to general practice services remains an issue for patients from remote areas, while concession health care card holders are attending general practice more frequently than other patients relative to their number of health problems. PMID:15318948

Gestational age and chronic 'body-mind' health problems in childhood: dose-response association and risk factors.

PubMed

Cronin, Frances M; Segurado, Ricardo; McAuliffe, Fionnuala M; Kelleher, Cecily C; Tremblay, Richard E

2017-01-01

Understanding the developmental course of all health issues associated with preterm birth is important from an individual, clinical and public health point-of-view. Both the number of preterm births and proportion of survivors have increased steadily in recent years. The UK Millennium Cohort Study (n = 18,818) was used to examine the association of gestational age with maternal ratings of general health and behavior problems at ages 5 and 11 years using binary and multinomial logistic regression analyses. The association between mothers' ratings of general health and behavior problems was relatively weak at each time point. Children rated as being in poor general health remained constant over time (4.0 % at age 5, 3.8 % at age 11), but children rated as having behavioral problems increased by almost 100 % (5.6 % at 5; 10.5 % at 11). A gradient of increasing risk with decreasing gestational age was observed for a composite health measure (general health problems and/or behavior problems) at age 5, amplified at age 11 and was strongest for those with chronic problems (poor health at both age 5 and age 11). This association was found to be compounded by child sex, maternal characteristics at birth (education, employment, marital status) and duration of breast feeding. Integrated support to at-risk families initiated during, or soon after pregnancy, may prevent chronic problems and might potentially reduce long term health costs for both the individual and health services.

Generalizations of Tikhonov's regularized method of least squares to non-Euclidean vector norms

NASA Astrophysics Data System (ADS)

Volkov, V. V.; Erokhin, V. I.; Kakaev, V. V.; Onufrei, A. Yu.

2017-09-01

Tikhonov's regularized method of least squares and its generalizations to non-Euclidean norms, including polyhedral, are considered. The regularized method of least squares is reduced to mathematical programming problems obtained by "instrumental" generalizations of the Tikhonov lemma on the minimal (in a certain norm) solution of a system of linear algebraic equations with respect to an unknown matrix. Further studies are needed for problems concerning the development of methods and algorithms for solving reduced mathematical programming problems in which the objective functions and admissible domains are constructed using polyhedral vector norms.

Sleep and Mental Health in Undergraduate Students with Generally Healthy Sleep Habits

PubMed Central

Milojevich, Helen M.; Lukowski, Angela F.

2016-01-01

Whereas previous research has indicated that sleep problems tend to co-occur with increased mental health issues in university students, relatively little is known about relations between sleep quality and mental health in university students with generally healthy sleep habits. Understanding relations between sleep and mental health in individuals with generally healthy sleep habits is important because (a) student sleep habits tend to worsen over time and (b) even time-limited experience of sleep problems may have significant implications for the onset of mental health problems. In the present research, 69 university students with generally healthy sleep habits completed questionnaires about sleep quality and mental health. Although participants did not report clinically concerning mental health issues as a group, global sleep quality was associated with mental health. Regression analyses revealed that nighttime sleep duration and the frequency of nighttime sleep disruptions were differentially related to total problems and clinically-relevant symptoms of psychological distress. These results indicate that understanding relations between sleep and mental health in university students with generally healthy sleep habits is important not only due to the large number of undergraduates who experience sleep problems and mental health issues over time but also due to the potential to intervene and improve mental health outcomes before they become clinically concerning. PMID:27280714

Sleep and Mental Health in Undergraduate Students with Generally Healthy Sleep Habits.

PubMed

Milojevich, Helen M; Lukowski, Angela F

2016-01-01

Whereas previous research has indicated that sleep problems tend to co-occur with increased mental health issues in university students, relatively little is known about relations between sleep quality and mental health in university students with generally healthy sleep habits. Understanding relations between sleep and mental health in individuals with generally healthy sleep habits is important because (a) student sleep habits tend to worsen over time and (b) even time-limited experience of sleep problems may have significant implications for the onset of mental health problems. In the present research, 69 university students with generally healthy sleep habits completed questionnaires about sleep quality and mental health. Although participants did not report clinically concerning mental health issues as a group, global sleep quality was associated with mental health. Regression analyses revealed that nighttime sleep duration and the frequency of nighttime sleep disruptions were differentially related to total problems and clinically-relevant symptoms of psychological distress. These results indicate that understanding relations between sleep and mental health in university students with generally healthy sleep habits is important not only due to the large number of undergraduates who experience sleep problems and mental health issues over time but also due to the potential to intervene and improve mental health outcomes before they become clinically concerning.

Evolution of general surgical problems in patients with left ventricular assist devices.

PubMed

McKellar, Stephen H; Morris, David S; Mauermann, William J; Park, Soon J; Zietlow, Scott P

2012-11-01

Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. These patients may develop acute noncardiac surgical problems around the time of LVAD implantation or, as survival continues to improve, chronic surgical problems as ambulatory patients remote from the LVAD implant. Previous reports of noncardiac surgical problems in LVAD patients included patients with older, first-generation devices and do not address newer, second-generation devices. We describe the frequency and management of noncardiac surgical problems encountered during LVAD support with these newer-generation devices to assist noncardiac surgeons involved in the care of patients with LVADs. We retrospectively reviewed the medical records of consecutive patients receiving LVADs at our institution. We collected data for any consultation by noncardiac surgeons within the scope of general surgery during LVAD support and subsequent treatment. Ninety-nine patients received implantable LVADs between 2003 and 2009 (first-generation, n = 19; second-generation, n = 80). Excluding intestinal hemorrhage, general surgical opinions were rendered for 34 patients with 49 problems, mostly in the acute recovery phase after LVAD implantation. Of those, 27 patients underwent 28 operations. Respiratory failure and intra-abdominal pathologies were the most common problems addressed, and LVAD rarely precluded operation. Patients with second-generation LVADs were more likely to survive hospitalization (P = .04) and develop chronic, rather than emergent, surgical problems. Patients with LVADs frequently require consultation from noncardiac surgeons within the scope of general surgeons and often require operation. Patients with second-generation LVADs are more likely to become outpatients and develop more elective surgical problems. Noncardiac surgeons will be increasingly involved in caring for patients with LVADs and should anticipate the problems unique to this patient population. Copyright © 2012 Mosby, Inc. All rights reserved.

[Emergencies and urgent consultation in non-urban Swiss general practices].

PubMed

Meyer, R L; Marty, F

2007-03-07

The upcoming shortage of general practitioners in Switzerland will be a big challenge for medical out-of-hours services. Regionally ver different exists only few datas about organisational matters of and problems seen in "out-of-hours" care and "urgent consultations". Our Pilot present the prevalence of "out-of-hours care" in a general practitioner setting describes and classifies the problems seen using ICPC-2.

Optimized Waterspace Management and Scheduling Using Mixed-Integer Linear Programming

DTIC Science & Technology

2016-01-01

Complete [30]. Proposition 4.1 satisfies the first criterion. For the second criterion, we will use the Traveling Salesman Problem (TSP), which has been...A branch and cut algorithm for the symmetric generalized traveling salesman problem , Operations Research 45 (1997) 378–394. [33] J. Silberholz, B...Golden, The generalized traveling salesman problem : A new genetic algorithm ap- proach, Extended Horizons: Advances in Computing, Optimization, and

Mental health and health-care use of detainees in police custody.

PubMed

Dorn, Tina; Ceelen, Manon; Buster, Marcel; Stirbu, Irina; Donker, Gé; Das, Kees

2014-08-01

In many countries, forensic physicians function as primary care providers for detainees in police custody. Their task is comparable to the tasks of general practitioners. Nevertheless, problems presented by both patient populations may differ. We therefore aimed to systematically compare presented problems and medication use in a population of police detainees to those of regular patients in general practice. Health problems and prescription medications of 3232 detainees seen by the Amsterdam Forensic Medical Service were compared to those of general practice patients (n = 78,975) adjusted for age and gender during a 12-month period. Among those obtaining medical attention (28% of all detainees), almost 50% were diagnosed with mental health problems, with substance abuse as the leading reason for consultation. Forty-two percent received at least one prescription affecting the nervous system. In general practice, 17% (P < 0.001) of patients consulting their GP were diagnosed with mental health problems and 22% (P < 0.001) were prescribed medications affecting the nervous system. The magnitude of mental health problems among police detainees has significant implications for the qualifications of police health staff and those who provide health care in the police setting especially concerning substance abuse. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Asymptotic quantum inelastic generalized Lorenz Mie theory

NASA Astrophysics Data System (ADS)

Gouesbet, G.

2007-10-01

The (electromagnetic) generalized Lorenz-Mie theory describes the interaction between an electromagnetic arbitrary shaped beam and a homogeneous sphere. It is a generalization of the Lorenz-Mie theory which deals with the simpler case of a plane wave illumination. In a recent paper, we consider (i) elastic cross-sections in electromagnetic generalized Lorenz-Mie theory and (ii) elastic cross-sections in an associated quantum generalized Lorenz-Mie theory. We demonstrated that the electromagnetic problem is equivalent to a superposition of two effective quantum problems. We now intend to generalize this result from elastic cross-sections to inelastic cross-sections. A prerequisite is to build an asymptotic quantum inelastic generalized Lorenz-Mie theory, which is presented in this paper.

Interior point techniques for LP and NLP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evtushenko, Y.

By using surjective mapping the initial constrained optimization problem is transformed to a problem in a new space with only equality constraints. For the numerical solution of the latter problem we use the generalized gradient-projection method and Newton`s method. After inverse transformation to the initial space we obtain the family of numerical methods for solving optimization problems with equality and inequality constraints. In the linear programming case after some simplification we obtain Dikin`s algorithm, affine scaling algorithm and generalized primal dual interior point linear programming algorithm.

Does the non-identity problem block a class of arguments against cloning?

PubMed

Green, Richard

2004-01-01

One class of argument against cloning human beings in the contemporary literature focuses on the bad consequences that will befall the clone or "later-twin." In this paper I consider whether this line of argumentation can be blocked by invoking Parfit's non-identity problem. I canvass two general strategies for solving the non-identity problem: a consequentialist strategy and non-consequentialist, rights based strategy. I argue that while each general strategy offers a plausible solution to the non-identity problem as applied to the cases most frequently discussed in the non-identity problem literature, neither provides a reason for putting aside the non-identity problem when applied to cloning. I conclude (roughly) that the non-identity problem does serve to block this class of argument against cloning.

Generalized SMO algorithm for SVM-based multitask learning.

PubMed

Cai, Feng; Cherkassky, Vladimir

2012-06-01

Exploiting additional information to improve traditional inductive learning is an active research area in machine learning. In many supervised-learning applications, training data can be naturally separated into several groups, and incorporating this group information into learning may improve generalization. Recently, Vapnik proposed a general approach to formalizing such problems, known as "learning with structured data" and its support vector machine (SVM) based optimization formulation called SVM+. Liang and Cherkassky showed the connection between SVM+ and multitask learning (MTL) approaches in machine learning, and proposed an SVM-based formulation for MTL called SVM+MTL for classification. Training the SVM+MTL classifier requires the solution of a large quadratic programming optimization problem which scales as O(n(3)) with sample size n. So there is a need to develop computationally efficient algorithms for implementing SVM+MTL. This brief generalizes Platt's sequential minimal optimization (SMO) algorithm to the SVM+MTL setting. Empirical results show that, for typical SVM+MTL problems, the proposed generalized SMO achieves over 100 times speed-up, in comparison with general-purpose optimization routines.

Optimal steering for kinematic vehicles with applications to spatially distributed agents

NASA Astrophysics Data System (ADS)

Brown, Scott; Praeger, Cheryl E.; Giudici, Michael

While there is no universal method to address control problems involving networks of autonomous vehicles, there exist a few promising schemes that apply to different specific classes of problems, which have attracted the attention of many researchers from different fields. In particular, one way to extend techniques that address problems involving a single autonomous vehicle to those involving teams of autonomous vehicles is to use the concept of Voronoi diagram. The Voronoi diagram provides a spatial partition of the environment the team of vehicles operate in, where each element of this partition is associated with a unique vehicle from the team. The partition induces a graph abstraction of the operating space that is in an one-to-one correspondence with the network abstraction of the team of autonomous vehicles; a fact that can provide both conceptual and analytical advantages during mission planning and execution. In this dissertation, we propose the use of a new class of Voronoi-like partitioning schemes with respect to state-dependent proximity (pseudo-) metrics rather than the Euclidean distance or other generalized distance functions, which are typically used in the literature. An important nuance here is that, in contrast to the Euclidean distance, state-dependent metrics can succinctly capture system theoretic features of each vehicle from the team (e.g., vehicle kinematics), as well as the environment-vehicle interactions, which are induced, for example, by local winds/currents. We subsequently illustrate how the proposed concept of state-dependent Voronoi-like partition can induce local control schemes for problems involving networks of spatially distributed autonomous vehicles by examining a sequential pursuit problem of a maneuvering target by a group of pursuers distributed in the plane. The construction of generalized Voronoi diagrams with respect to state-dependent metrics poses some significant challenges. First, the generalized distance metric may be a function of the direction of motion of the vehicle (anisotropic pseudo-distance function) and/or may not be expressible in closed form. Second, such problems fall under the general class of partitioning problems for which the vehicles' dynamics must be taken into account. The topology of the vehicle's configuration space may be non-Euclidean, for example, it may be a manifold embedded in a Euclidean space. In other words, these problems may not be reducible to generalized Voronoi diagram problems for which efficient construction schemes, analytical and/or computational, exist in the literature. This research effort pursues three main objectives. First, we present the complete solution of different steering problems involving a single vehicle in the presence of motion constraints imposed by the maneuverability envelope of the vehicle and/or the presence of a drift field induced by winds/currents in its vicinity. The analysis of each steering problem involving a single vehicle provides us with a state-dependent generalized metric, such as the minimum time-to-go/come. We subsequently use these state-dependent generalized distance functions as the proximity metrics in the formulation of generalized Voronoi-like partitioning problems. The characterization of the solutions of these state-dependent Voronoi-like partitioning problems using either analytical or computational techniques constitutes the second main objective of this dissertation. The third objective of this research effort is to illustrate the use of the proposed concept of state-dependent Voronoi-like partition as a means for passing from control techniques that apply to problems involving a single vehicle to problems involving networks of spatially distributed autonomous vehicles. To this aim, we formulate the problem of sequential/relay pursuit of a maneuvering target by a group of spatially distributed pursuers and subsequently propose a distributed group pursuit strategy that directly derives from the solution of a state-dependent Voronoi-like partitioning problem. (Abstract shortened by UMI.)

48 CFR 229.101 - Resolving tax problems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Resolving tax problems. 229.101 Section 229.101 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM...) Within DoD, the agency-designated legal counsels are the defense agency General Counsels, the General...

Lightweight diesel aircraft engines for general aviation

NASA Technical Reports Server (NTRS)

Berenyi, S. G.

1983-01-01

Two different engines were studied. The advantages of a diesel to general aviation were reduced to fuel consumption, reduced operating costs, and reduced fire and explosion hazard. There were no ignition mixture control or inlet icing problems. There are fewer controls and no electrical interference problems.

Neural networks for feedback feedforward nonlinear control systems.

PubMed

Parisini, T; Zoppoli, R

1994-01-01

This paper deals with the problem of designing feedback feedforward control strategies to drive the state of a dynamic system (in general, nonlinear) so as to track any desired trajectory joining the points of given compact sets, while minimizing a certain cost function (in general, nonquadratic). Due to the generality of the problem, conventional methods are difficult to apply. Thus, an approximate solution is sought by constraining control strategies to take on the structure of multilayer feedforward neural networks. After discussing the approximation properties of neural control strategies, a particular neural architecture is presented, which is based on what has been called the "linear-structure preserving principle". The original functional problem is then reduced to a nonlinear programming one, and backpropagation is applied to derive the optimal values of the synaptic weights. Recursive equations to compute the gradient components are presented, which generalize the classical adjoint system equations of N-stage optimal control theory. Simulation results related to nonlinear nonquadratic problems show the effectiveness of the proposed method.

Cumulative contextual risk at birth in relation to adolescent substance use, conduct problems, and risky sex: General and specific predictive associations in a Finnish birth cohort.

PubMed

Mason, W Alex; January, Stacy-Ann A; Chmelka, Mary B; Parra, Gilbert R; Savolainen, Jukka; Miettunen, Jouko; Järvelin, Marjo-Riitta; Taanila, Anja; Moilanen, Irma

2016-07-01

Research indicates that risk factors cluster in the most vulnerable youth, increasing their susceptibility for adverse developmental outcomes. However, most studies of cumulative risk are cross-sectional or short-term longitudinal, and have been based on data from the United States or the United Kingdom. Using data from the Northern Finland Birth Cohort 1986 Study (NFBC1986), we examined cumulative contextual risk (CCR) at birth as a predictor of adolescent substance use and co-occurring conduct problems and risky sex to determine the degree to which CCR predicts specific outcomes over-and-above its effect on general problem behavior, while testing for moderation of associations by gender. Analyses of survey data from 6963 participants of the NFBC1986 followed from the prenatal/birth period into adolescence were conducted using structural equation modeling. CCR had long-term positive associations with first-order substance use, conduct problems, and risky sex factors, and, in a separate analysis, with a second-order general problem behavior factor. Further analyses showed that there was a positive specific effect of CCR on risky sex, over-and-above general problem behavior, for girls only. This study, conducted within the Finnish context, showed that CCR at birth had long-term general and specific predictive associations with substance use and co-occurring problem behaviors in adolescence; effects on risky sex were stronger for girls. Results are consistent with the hypothesis that early exposure to CCR can have lasting adverse consequences, suggesting the need for early identification and intervention efforts for vulnerable children. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of bariatric surgery on future general surgical procedures.

PubMed

Kini, Subhash; Kannan, Umashankkar

2011-04-01

Bariatric surgery is now accepted as a safe and effective procedure for morbid obesity. The frequency of bariatric procedures is increasing with the adoption of the laparoscopic approach. The general surgeons will be facing many more of such patients presenting with common general surgical problems. Many of the general surgeons, faced with such situations, may not be aware of the changes in the gastrointestinal anatomy following bariatric procedures and management of these clinical situations will therefore present diagnostic and therapeutic challenges. We hereby present a review of management of few common general surgical problems in patients with a history of bariatric surgery.

Some new results on the central overlap problem in astrometry

NASA Astrophysics Data System (ADS)

Rapaport, M.

1998-07-01

The central overlap problem in astrometry has been revisited in the recent last years by Eichhorn (1988) who explicitly inverted the matrix of a constrained least squares problem. In this paper, the general explicit solution of the unconstrained central overlap problem is given. We also give the explicit solution for an other set of constraints; this result is a confirmation of a conjecture expressed by Eichhorn (1988). We also consider the use of iterative methods to solve the central overlap problem. A surprising result is obtained when the classical Gauss Seidel method is used; the iterations converge immediately to the general solution of the equations; we explain this property writing the central overlap problem in a new set of variables.

Generalized Orienteering Problem with Resource Dependent Rewards

DTIC Science & Technology

2013-02-19

School, Monterey, California February 19, 2013 Abstract We introduce a generalized Orienteering Problem where, as usual, a vehicle is routed from a ...prescribed start node, through a directed network, to a prescribed destination node, collecting rewards at each node visited, in order to maximize the...total reward along the path. In our generalization, transit on arcs in the network and reward collection at nodes both consume a variable amount of the

Effects of the Multiple Solutions and Question Prompts on Generalization and Justification for Non-Routine Mathematical Problem Solving in a Computer Game Context

ERIC Educational Resources Information Center

Lee, Chun-Yi; Chen, Ming-Jang; Chang, Wen-Long

2014-01-01

The aim of this study is to investigate the effects of solution methods and question prompts on generalization and justification of non-routine problem solving for Grade 9 students. The learning activities are based on the context of the frog jumping game. In addition, related computer tools were used to support generalization and justification of…

On the generalized VIP time integral methodology for transient thermal problems

NASA Technical Reports Server (NTRS)

Mei, Youping; Chen, Xiaoqin; Tamma, Kumar K.; Sha, Desong

1993-01-01

The paper describes the development and applicability of a generalized VIrtual-Pulse (VIP) time integral method of computation for thermal problems. Unlike past approaches for general heat transfer computations, and with the advent of high speed computing technology and the importance of parallel computations for efficient use of computing environments, a major motivation via the developments described in this paper is the need for developing explicit computational procedures with improved accuracy and stability characteristics. As a consequence, a new and effective VIP methodology is described which inherits these improved characteristics. Numerical illustrative examples are provided to demonstrate the developments and validate the results obtained for thermal problems.

Moneymed: a game to develop management skills in general practice

PubMed Central

Essex, B.; Jackson, R. N.

1981-01-01

A game has been developed to train people in the financial and administrative skills needed for effective general practice management. These skills cover a wide range of legal, economic, administrative and personnel problems encountered in general practice. Thirty-four trainees and six trainers showed a highly significant improvement in knowledge and problem-solving skills after playing the game. The format and design of the game allow the problem type, complexity and solution to vary and to be readily updated. So far, this seems to be one of the most effective instruments yet developed for learning these skills. Imagesp736-a PMID:7338867

Primal-dual techniques for online algorithms and mechanisms

NASA Astrophysics Data System (ADS)

Liaghat, Vahid

An offline algorithm is one that knows the entire input in advance. An online algorithm, however, processes its input in a serial fashion. In contrast to offline algorithms, an online algorithm works in a local fashion and has to make irrevocable decisions without having the entire input. Online algorithms are often not optimal since their irrevocable decisions may turn out to be inefficient after receiving the rest of the input. For a given online problem, the goal is to design algorithms which are competitive against the offline optimal solutions. In a classical offline scenario, it is often common to see a dual analysis of problems that can be formulated as a linear or convex program. Primal-dual and dual-fitting techniques have been successfully applied to many such problems. Unfortunately, the usual tricks come short in an online setting since an online algorithm should make decisions without knowing even the whole program. In this thesis, we study the competitive analysis of fundamental problems in the literature such as different variants of online matching and online Steiner connectivity, via online dual techniques. Although there are many generic tools for solving an optimization problem in the offline paradigm, in comparison, much less is known for tackling online problems. The main focus of this work is to design generic techniques for solving integral linear optimization problems where the solution space is restricted via a set of linear constraints. A general family of these problems are online packing/covering problems. Our work shows that for several seemingly unrelated problems, primal-dual techniques can be successfully applied as a unifying approach for analyzing these problems. We believe this leads to generic algorithmic frameworks for solving online problems. In the first part of the thesis, we show the effectiveness of our techniques in the stochastic settings and their applications in Bayesian mechanism design. In particular, we introduce new techniques for solving a fundamental linear optimization problem, namely, the stochastic generalized assignment problem (GAP). This packing problem generalizes various problems such as online matching, ad allocation, bin packing, etc. We furthermore show applications of such results in the mechanism design by introducing Prophet Secretary, a novel Bayesian model for online auctions. In the second part of the thesis, we focus on the covering problems. We develop the framework of "Disk Painting" for a general class of network design problems that can be characterized by proper functions. This class generalizes the node-weighted and edge-weighted variants of several well-known Steiner connectivity problems. We furthermore design a generic technique for solving the prize-collecting variants of these problems when there exists a dual analysis for the non-prize-collecting counterparts. Hence, we solve the online prize-collecting variants of several network design problems for the first time. Finally we focus on designing techniques for online problems with mixed packing/covering constraints. We initiate the study of degree-bounded graph optimization problems in the online setting by designing an online algorithm with a tight competitive ratio for the degree-bounded Steiner forest problem. We hope these techniques establishes a starting point for the analysis of the important class of online degree-bounded optimization on graphs.

Assessing Students' Mathematical Problem Posing

ERIC Educational Resources Information Center

Silver, Edward A.; Cai, Jinfa

2005-01-01

Specific examples are used to discuss assessment, an integral part of mathematics instruction, with problem posing and assessment of problem posing. General assessment criteria are suggested to evaluate student-generated problems in terms of their quantity, originality, and complexity.

The Relationship between Students' Problem Posing and Problem Solving Abilities and Beliefs: A Small-Scale Study with Chinese Elementary School Children

ERIC Educational Resources Information Center

Limin, Chen; Van Dooren, Wim; Verschaffel, Lieven

2013-01-01

The goal of the present study is to investigate the relationship between pupils' problem posing and problem solving abilities, their beliefs about problem posing and problem solving, and their general mathematics abilities, in a Chinese context. Five instruments, i.e., a problem posing test, a problem solving test, a problem posing questionnaire,…

On a generalized Ablowitz-Kaup-Newell-Segur hierarchy in inhomogeneities of media: soliton solutions and wave propagation influenced from coefficient functions and scattering data

NASA Astrophysics Data System (ADS)

Zhang, Sheng; Hong, Siyu

2018-07-01

In this paper, a generalized Ablowitz-Kaup-Newell-Segur (AKNS) hierarchy in inhomogeneities of media described by variable coefficients is investigated, which includes some important nonlinear evolution equations as special cases, for example, the celebrated Korteweg-de Vries equation modeling waves on shallow water surfaces. To be specific, the known AKNS spectral problem and its time evolution equation are first generalized by embedding a finite number of differentiable and time-dependent functions. Starting from the generalized AKNS spectral problem and its generalized time evolution equation, a generalized AKNS hierarchy with variable coefficients is then derived. Furthermore, based on a systematic analysis on the time dependence of related scattering data of the generalized AKNS spectral problem, exact solutions of the generalized AKNS hierarchy are formulated through the inverse scattering transform method. In the case of reflectionless potentials, the obtained exact solutions are reduced to n-soliton solutions. It is graphically shown that the dynamical evolutions of such soliton solutions are influenced by not only the time-dependent coefficients but also the related scattering data in the process of propagations.

Selected psychiatric problems among college students in two Arab countries: comparison with the USA.

PubMed

Kronfol, Ziad; Khalifa, Batoul; Khoury, Brigitte; Omar, Omar; Daouk, Sariah; deWitt, J P; ElAzab, Nourehan; Eisenberg, Daniel

2018-05-24

Psychiatric problems among college students on USA campuses are common. Little is known about similar problems in developing countries, particularly the Arab region. The goal of this study was to assess the frequency of selected psychiatric problems among college students in two Arab countries: Qatar and Lebanon, and to compare them to the USA. The Healthy Minds Study, an online confidential survey of common psychiatric symptoms designed for college campuses was used. We used the Patient Health Questionnaire-9 (PHQ-9) to screen for major depression, the Generalized Anxiety Disorder-7 (GAD-7) to screen for generalized anxiety and the SCOFF questionnaire to screen for eating disorders. Comparisons were made using ANOVA, Chi-Square tests and logistic regressions. A total of 1841 students participated in the study. The rates of depression (PHQ-9 ≥ 12), generalized anxiety (GAD-7 ≥ 10) and eating disorders (SCOFF≥3) at the combined Arab universities were 34.6, 36.1 and 20.4% respectively. The corresponding rates in the USA were: 12.8, 15.9 and 6.8% (p < 0.001 for all measures). The impact of psychiatric problems on functioning in general and academic performance in particular was more severe in the Arab countries compared to the USA (p < 0.001). Independent predictors of psychiatric problems in general included location, female gender, financial difficulties and poor grades. Being religious had a protective association with mental health. The rates of depression, anxiety and eating disorders were significantly higher among college students in Qatar and Lebanon compared to the USA. Additional research is needed to determine whether these results reflect methodological limitations or true differences in psychopathology across these populations. If replicated, the results indicate that the psychiatric problems on college campuses in the USA are a microcosm of a global problem that needs global solutions.

Predicting Cost/Reliability/Maintainability of Advanced General Aviation Avionics Equipment

NASA Technical Reports Server (NTRS)

Davis, M. R.; Kamins, M.; Mooz, W. E.

1978-01-01

A methodology is provided for assisting NASA in estimating the cost, reliability, and maintenance (CRM) requirements for general avionics equipment operating in the 1980's. Practical problems of predicting these factors are examined. The usefulness and short comings of different approaches for modeling coast and reliability estimates are discussed together with special problems caused by the lack of historical data on the cost of maintaining general aviation avionics. Suggestions are offered on how NASA might proceed in assessing cost reliability CRM implications in the absence of reliable generalized predictive models.

Generalized Differential Calculus and Applications to Optimization

NASA Astrophysics Data System (ADS)

Rector, Robert Blake Hayden

This thesis contains contributions in three areas: the theory of generalized calculus, numerical algorithms for operations research, and applications of optimization to problems in modern electric power systems. A geometric approach is used to advance the theory and tools used for studying generalized notions of derivatives for nonsmooth functions. These advances specifically pertain to methods for calculating subdifferentials and to expanding our understanding of a certain notion of derivative of set-valued maps, called the coderivative, in infinite dimensions. A strong understanding of the subdifferential is essential for numerical optimization algorithms, which are developed and applied to nonsmooth problems in operations research, including non-convex problems. Finally, an optimization framework is applied to solve a problem in electric power systems involving a smart solar inverter and battery storage system providing energy and ancillary services to the grid.

Closed loop problems in biomechanics. Part II--an optimization approach.

PubMed

Vaughan, C L; Hay, J G; Andrews, J G

1982-01-01

A closed loop problem in biomechanics may be defined as a problem in which there are one or more closed loops formed by the human body in contact with itself or with an external system. Under certain conditions the problem is indeterminate--the unknown forces and torques outnumber the equations. Force transducing devices, which would help solve this problem, have serious drawbacks, and existing methods are inaccurate and non-general. The purposes of the present paper are (1) to develop a general procedure for solving closed loop problems; (2) to illustrate the application of the procedure; and (3) to examine the validity of the procedure. A mathematical optimization approach is applied to the solution of three different closed loop problems--walking up stairs, vertical jumping and cartwheeling. The following conclusions are drawn: (1) the method described is reasonably successful for predicting horizontal and vertical reaction forces at the distal segments although problems exist for predicting the points of application of these forces; (2) the results provide some support for the notion that the human neuromuscular mechanism attempts to minimize the joint torques and thus, to a certain degree, the amount of muscular effort; (3) in the validation procedure it is desirable to have a force device for each of the distal segments in contact with a fixed external system; and (4) the method is sufficiently general to be applied to all classes of closed loop problems.

Robot computer problem solving system

NASA Technical Reports Server (NTRS)

Becker, J. D.

1972-01-01

Continuing research is reported in a program aimed at the development of a robot computer problem solving system. The motivation and results are described of a theoretical investigation concerning the general properties of behavioral systems. Some of the important issues which a general theory of behavioral organization should encompass are outlined and discussed.

Problem-Based Learning in a General Psychology Course.

ERIC Educational Resources Information Center

Willis, Sandra A.

2002-01-01

Describes the adoption of problem-based learning (PBL) techniques in a general psychology course. States that the instructor used a combination of techniques, including think-pair-share, lecture/discussion, and PBL. Notes means and standard deviations for graded components of PBL format versus lecture/discussion format. (Contains 18 references.)…

Contributions of Domain-General Cognitive Resources and Different Forms of Arithmetic Development to Pre-Algebraic Knowledge

PubMed Central

Fuchs, Lynn S.; Compton, Donald L.; Fuchs, Douglas; Powell, Sarah R.; Schumacher, Robin F.; Hamlett, Carol L.; Vernier, Emily; Namkung, Jessica M.; Vukovic, Rose K.

2012-01-01

The purpose of this study was to investigate the contributions of domain-general cognitive resources and different forms of arithmetic development to individual differences in pre-algebraic knowledge. Children (n=279; mean age=7.59 yrs) were assessed on 7 domain-general cognitive resources as well as arithmetic calculations and word problems at start of 2nd grade and on calculations, word problems, and pre-algebraic knowledge at end of 3rd grade. Multilevel path analysis, controlling for instructional effects associated with the sequence of classrooms in which students were nested across grades 2–3, indicated arithmetic calculations and word problems are foundational to pre-algebraic knowledge. Also, results revealed direct contributions of nonverbal reasoning and oral language to pre-algebraic knowledge, beyond indirect effects that are mediated via arithmetic calculations and word problems. By contrast, attentive behavior, phonological processing, and processing speed contributed to pre-algebraic knowledge only indirectly via arithmetic calculations and word problems. PMID:22409764

An architectural approach to create self organizing control systems for practical autonomous robots

NASA Technical Reports Server (NTRS)

Greiner, Helen

1991-01-01

For practical industrial applications, the development of trainable robots is an important and immediate objective. Therefore, the developing of flexible intelligence directly applicable to training is emphasized. It is generally agreed upon by the AI community that the fusion of expert systems, neural networks, and conventionally programmed modules (e.g., a trajectory generator) is promising in the quest for autonomous robotic intelligence. Autonomous robot development is hindered by integration and architectural problems. Some obstacles towards the construction of more general robot control systems are as follows: (1) Growth problem; (2) Software generation; (3) Interaction with environment; (4) Reliability; and (5) Resource limitation. Neural networks can be successfully applied to some of these problems. However, current implementations of neural networks are hampered by the resource limitation problem and must be trained extensively to produce computationally accurate output. A generalization of conventional neural nets is proposed, and an architecture is offered in an attempt to address the above problems.

On the eigenfrequencies of elastic shear waves propagating in an inhomogeneous layer

NASA Astrophysics Data System (ADS)

Khachatryan, V. M.

2018-04-01

In this work, we consider the problem of eigenfrequencies of elastic shear waves propagating in a layer whose Young’s modulus and density are functions of the longitudinal coordinate. Taking into account the material inhomogeneity makes the problem of the eigenfrequencies of the waves propagating in the layer more complicated. In this paper, the problem of pure shear is considered. To solve the problem, we use an integral formula which allows us to represent the general solution of the original equation with variable coefficients in terms of the general solution of the accompanying equation with constant coefficients.

A study of general instability of box beams with truss-type ribs

NASA Technical Reports Server (NTRS)

Lundquist, Eugene E; Schwartz, Edward B

1942-01-01

The design of truss-type ribs for box beams is theoretically treated with regard to the function of the ribs in stabilizing the compression flange. The theory is applied to a design problem, and the results of this application are presented and discussed in relation to the general problem of rib design. The results of some tests made as a part of this general study are presented in an appendix.

Dynamical behavior for the three-dimensional generalized Hasegawa-Mima equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Ruifeng; Guo Boling; Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088

2007-01-15

The long time behavior of solution of the three-dimensional generalized Hasegawa-Mima [Phys. Fluids 21, 87 (1978)] equations with dissipation term is considered. The global attractor problem of the three-dimensional generalized Hasegawa-Mima equations with periodic boundary condition was studied. Applying the method of uniform a priori estimates, the existence of global attractor of this problem was proven, and also the dimensions of the global attractor are estimated.

Functional Techniques for Data Analysis

NASA Technical Reports Server (NTRS)

Tomlinson, John R.

1997-01-01

This dissertation develops a new general method of solving Prony's problem. Two special cases of this new method have been developed previously. They are the Matrix Pencil and the Osculatory Interpolation. The dissertation shows that they are instances of a more general solution type which allows a wide ranging class of linear functional to be used in the solution of the problem. This class provides a continuum of functionals which provide new methods that can be used to solve Prony's problem.

Child dental fear and general emotional problems: a pilot study.

PubMed

Krikken, J B; ten Cate, J M; Veerkamp, J S J

2010-12-01

This was to investigate the relation between general emotional and behavioural problems of the child and dental anxiety and dental behavioural management problems. Dental treatment involves many potentially unpleasant stimuli, which all may lead to the development of dental anxiety and behavioural management problems (BMP). It is still unclear why some children get anxious in the dental situation while others, with a comparable dental history, do not. Besides the latent inhibition theory it is suggested that this can be explained by differences in child rearing and personality traits. The sample consisted of 50 children (4-12 years old) and their parents participated in this study. Parents filled out the Child Fear Survey Schedule Dental Subscale (CFSS-DS) and the Child Behaviour Checklist (CBCL) on behalf of their child. Child behaviour during consecutive dental treatments was assessed using the Venham scale. There were 39 children subject to analysis (21 boys) with a mean CFSS score of 40.4. Children aged 4 and 5 years who had sleeping problems, attention problems and aggressive behaviour, as scored by parents on the CBCL, displayed more disruptive behaviour during dental treatment. Children with emotionally/ reactive and attention problems were more anxious. In this pilot study a possible relation between general emotional and behavioural problems of young children and dental anxiety was shown. Also a relation between emotional and behavioural problems and dental behavioural management problems was shown. Because of the small number of subjects in our study, further research will be needed to confirm these results.

Some investigations of the general instability of stiffened metal cylinders III : continuation of tests of wire-braced specimens and preliminary tests of sheet-covered specimens

NASA Technical Reports Server (NTRS)

1943-01-01

This is the third of a series of reports covering an investigation of the general instability problem by the California Institute of Technology. The first five reports of this series cover investigations of the general instability problem under the loading conditions of pure bending and were prepared under the sponsorship of the Civil Aeronautics Administration. The succeeding reports of this series cover the work done on other loading conditions under the sponsorship of the National Advisory Committee for Aeronautics. This report is concerned primarily with the continuation of the tests of wire-braced specimens, and preliminary tests of sheet-covered specimens that had been made in the experimental investigation on the problem of the general instability of stiffened metal cylinders at the C.I.T.

Travel Medicine Encounters of Australian General Practice Trainees-A Cross-Sectional Study.

PubMed

Morgan, Simon; Henderson, Kim M; Tapley, Amanda; Scott, John; van Driel, Mieke L; Spike, Neil A; McArthur, Lawrie A; Davey, Andrew R; Catzikiris, Nigel F; Magin, Parker J

2015-01-01

Travel medicine is a common and challenging area of clinical practice and practitioners need up-to-date knowledge and experience in a range of areas. Australian general practitioners (GPs) play a significant role in the delivery of travel medicine advice. We aimed to describe the rate and nature of travel medicine consultations, including both the clinical and educational aspects of the consultations. A cross-sectional analysis from an ongoing cohort study of GP trainees' clinical consultations was performed. Trainees contemporaneously recorded demographic, clinical, and educational details of consecutive patient consultations. Proportions of all problems/diagnoses managed in these consultations that were coded "travel-related" and "travel advice" were both calculated with 95% confidence intervals (CIs). Associations of a problem/diagnosis being "travel-related" or "travel advice" were tested using simple logistic regression within the generalized estimating equations (GEE) framework. A total of 856 trainees contributed data on 169,307 problems from 108,759 consultations (2010-2014). Travel-related and travel advice problems were managed at a rate of 1.1 and 0.5 problems per 100 encounters, respectively. Significant positive associations of travel-related problems were younger trainee and patient age; new patient to the trainee and practice; privately billing, larger, urban, and higher socioeconomic status practices; and involvement of the practice nurse. Trainees sought in-consultation information and generated learning goals in 34.7 and 20.8% of travel advice problems, respectively, significantly more than in non-travel advice problems. Significant positive associations of travel advice problems were seeking in-consultation information, generation of learning goals, longer consultation duration, and more problems managed. Our findings reinforce the importance of focused training in travel medicine for GP trainees and adequate exposure to patients in the practice setting. In addition, our findings have implications more broadly for the delivery of travel medicine in general practice. © 2015 International Society of Travel Medicine.

The male reproductive system - An overview of common problems.

PubMed

Wijesinha, Sanjiva; Piterman, Leon; Kirby, Catherine N

2013-05-01

Many male reproductive system problems could be perceived as being embarrassing, which may be one of the reasons that they are often not identified in general practice. This article provides an overview of some common problems affecting the male reproductive system, and outlines current treatment options. Erectile dysfunction, premature ejaculation, loss of libido, testicular cancer and prostate disease may cause embarrassment to the patient and, occasionally, the general practitioner. We describe how patients affected by these conditions may present to general practice, and discuss the reasons why they may not present. We also discuss how GPs can overcome difficulties in identifying and dealing with their male patients suffering from male reproductive system issues.

User's manual for MMLE3, a general FORTRAN program for maximum likelihood parameter estimation

NASA Technical Reports Server (NTRS)

Maine, R. E.; Iliff, K. W.

1980-01-01

A user's manual for the FORTRAN IV computer program MMLE3 is described. It is a maximum likelihood parameter estimation program capable of handling general bilinear dynamic equations of arbitrary order with measurement noise and/or state noise (process noise). The theory and use of the program is described. The basic MMLE3 program is quite general and, therefore, applicable to a wide variety of problems. The basic program can interact with a set of user written problem specific routines to simplify the use of the program on specific systems. A set of user routines for the aircraft stability and control derivative estimation problem is provided with the program.

Unraveling the Mystery of the Origin of Mathematical Problems: Using a Problem-Posing Framework with Prospective Mathematics Teachers

ERIC Educational Resources Information Center

Contreras, Jose

2007-01-01

In this article, I model how a problem-posing framework can be used to enhance our abilities to systematically generate mathematical problems by modifying the attributes of a given problem. The problem-posing model calls for the application of the following fundamental mathematical processes: proving, reversing, specializing, generalizing, and…

The ABCs of Math: A Genetic Analysis of Mathematics and Its Links With Reading Ability and General Cognitive Ability

PubMed Central

Hart, Sara A.; Petrill, Stephen A.; Thompson, Lee A.; Plomin, Robert

2009-01-01

The goal of this first major report from the Western Reserve Reading Project Math component is to explore the etiology of the relationship among tester-administered measures of mathematics ability, reading ability, and general cognitive ability. Data are available on 314 pairs of monozygotic and same-sex dizygotic twins analyzed across 5 waves of assessment. Univariate analyses provide a range of estimates of genetic (h2 = .00 –.63) and shared (c2 = .15–.52) environmental influences across math calculation, fluency, and problem solving measures. Multivariate analyses indicate genetic overlap between math problem solving with general cognitive ability and reading decoding, whereas math fluency shares significant genetic overlap with reading fluency and general cognitive ability. Further, math fluency has unique genetic influences. In general, math ability has shared environmental overlap with general cognitive ability and decoding. These results indicate that aspects of math that include problem solving have different genetic and environmental influences than math calculation. Moreover, math fluency, a timed measure of calculation, is the only measured math ability with unique genetic influences. PMID:20157630

Energy Efficient Data Transmission for Sensors with Wireless Charging

PubMed Central

Luo, Junzhou; Wu, Weiwei; Gao, Hong

2018-01-01

This paper studies the problem of maximizing the energy utilization for data transmission in sensors with periodical wireless charging process while taking into account the thermal effect. Two classes of problems are analyzed: one is the case that wireless charging can process for only a limited period of time, and the other is the case that wireless charging can process for a long enough time. Algorithms are proposed to solve the problems and analysis of these algorithms are also provided. For the first problem, three subproblems are studied, and, for the general problem, we give an algorithm that can derive a performance bound of (1−12m)(OPT−E) compared to an optimal solution. In addition, for the second problem, we provide an algorithm with 2m2m−1OPT+1 performance bound for the general problem. Simulations confirm the analysis of the algorithms. PMID:29419770

Energy Efficient Data Transmission for Sensors with Wireless Charging.

PubMed

Fang, Xiaolin; Luo, Junzhou; Wu, Weiwei; Gao, Hong

2018-02-08

This paper studies the problem of maximizing the energy utilization for data transmission in sensors with periodical wireless charging process while taking into account the thermal effect. Two classes of problems are analyzed: one is the case that wireless charging can process for only a limited period of time, and the other is the case that wireless charging can process for a long enough time. Algorithms are proposed to solve the problems and analysis of these algorithms are also provided. For the first problem, three subproblems are studied, and, for the general problem, we give an algorithm that can derive a performance bound of ( 1 - 1 2 m ) ( O P T - E ) compared to an optimal solution. In addition, for the second problem, we provide an algorithm with 2 m 2 m - 1 O P T + 1 performance bound for the general problem. Simulations confirm the analysis of the algorithms.

Models of resource allocation optimization when solving the control problems in organizational systems

NASA Astrophysics Data System (ADS)

Menshikh, V.; Samorokovskiy, A.; Avsentev, O.

2018-03-01

The mathematical model of optimizing the allocation of resources to reduce the time for management decisions and algorithms to solve the general problem of resource allocation. The optimization problem of choice of resources in organizational systems in order to reduce the total execution time of a job is solved. This problem is a complex three-level combinatorial problem, for the solving of which it is necessary to implement the solution to several specific problems: to estimate the duration of performing each action, depending on the number of performers within the group that performs this action; to estimate the total execution time of all actions depending on the quantitative composition of groups of performers; to find such a distribution of the existing resource of performers in groups to minimize the total execution time of all actions. In addition, algorithms to solve the general problem of resource allocation are proposed.

A general optimality criteria algorithm for a class of engineering optimization problems

NASA Astrophysics Data System (ADS)

Belegundu, Ashok D.

2015-05-01

An optimality criteria (OC)-based algorithm for optimization of a general class of nonlinear programming (NLP) problems is presented. The algorithm is only applicable to problems where the objective and constraint functions satisfy certain monotonicity properties. For multiply constrained problems which satisfy these assumptions, the algorithm is attractive compared with existing NLP methods as well as prevalent OC methods, as the latter involve computationally expensive active set and step-size control strategies. The fixed point algorithm presented here is applicable not only to structural optimization problems but also to certain problems as occur in resource allocation and inventory models. Convergence aspects are discussed. The fixed point update or resizing formula is given physical significance, which brings out a strength and trim feature. The number of function evaluations remains independent of the number of variables, allowing the efficient solution of problems with large number of variables.

SINGLE BUNCH BEAM BREAKUP - A GENERAL SOLUTION.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WANG,J.M.; MANE,S.R.; TOWNE,N.

2000-06-26

Caporaso, Barletta and Neil (CBN) found in a solution to the problem of the single-bunch beam breakup in a linac[1]. However, their method applies only to the case of a beam traveling in a strongly betatron-focused linac under the influence of the resistive wall impedance. We suggest in this paper a method for dealing with the same problem. Our methods is more general; it applies to the same problem under any impedance, and it applies to a linac with or without external betatron focusing.

On the characteristic exponents of the general three-body problem

NASA Technical Reports Server (NTRS)

Broucke, R.

1976-01-01

A description is given of some properties of the characteristic exponents of the general three-body problem. The variational equations on which the analysis is based are obtained by linearizing the Lagrangian equations of motion in the neighborhood of a given known solution. Attention is given to the fundamental matrix of solutions, the characteristic equation, the three trivial solutions of the variational equations of the three-body problem, symmetric periodic orbits, and the half-period properties of symmetric periodic orbits.

A path-integral approach to the problem of time

NASA Astrophysics Data System (ADS)

Amaral, M. M.; Bojowald, Martin

2018-01-01

Quantum transition amplitudes are formulated for model systems with local internal time, using intuition from path integrals. The amplitudes are shown to be more regular near a turning point of internal time than could be expected based on existing canonical treatments. In particular, a successful transition through a turning point is provided in the model systems, together with a new definition of such a transition in general terms. Some of the results rely on a fruitful relation between the problem of time and general Gribov problems.

An algorithm for full parametric solution of problems on the statics of orthotropic plates by the method of boundary states with perturbations

NASA Astrophysics Data System (ADS)

Penkov, V. B.; Ivanychev, D. A.; Novikova, O. S.; Levina, L. V.

2018-03-01

The article substantiates the possibility of building full parametric analytical solutions of mathematical physics problems in arbitrary regions by means of computer systems. The suggested effective means for such solutions is the method of boundary states with perturbations, which aptly incorporates all parameters of an orthotropic medium in a general solution. We performed check calculations of elastic fields of an anisotropic rectangular region (test and calculation problems) for a generalized plane stress state.

Artificial equilibrium points for a generalized sail in the elliptic restricted three-body problem

NASA Astrophysics Data System (ADS)

Aliasi, Generoso; Mengali, Giovanni; Quarta, Alessandro A.

2012-10-01

Different types of propulsion systems with continuous and purely radial thrust, whose modulus depends on the distance from a massive body, may be conveniently described within a single mathematical model by means of the concept of generalized sail. This paper discusses the existence and stability of artificial equilibrium points maintained by a generalized sail within an elliptic restricted three-body problem. Similar to the classical case in the absence of thrust, a generalized sail guarantees the existence of equilibrium points belonging only to the orbital plane of the two primaries. The geometrical loci of existing artificial equilibrium points are shown to coincide with those obtained for the circular three body problem when a non-uniformly rotating and pulsating coordinate system is chosen to describe the spacecraft motion. However, the generalized sail has to provide a periodically variable acceleration to maintain a given artificial equilibrium point. A linear stability analysis of the artificial equilibrium points is provided by means of the Floquet theory.

Association between Speech-Language, General Cognitive Functioning and Behaviour Problems in Individuals with Williams Syndrome

ERIC Educational Resources Information Center

Rossi, N. F.; Giacheti, C. M.

2017-01-01

Background: Williams syndrome (WS) phenotype is described as unique and intriguing. The aim of this study was to investigate the associations between speech-language abilities, general cognitive functioning and behavioural problems in individuals with WS, considering age effects and speech-language characteristics of WS sub-groups. Methods: The…

Adolescents' Suicidal Thinking and Reluctance to Consult General Medical Practitioners

ERIC Educational Resources Information Center

Wilson, Coralie J.; Deane, Frank P.; Marshall, Kellie L.; Dalley, Andrew

2010-01-01

Appropriate help-seeking is widely recognized as a protective factor, and vital for early treatment and prevention of mental health problems during adolescence. General medical practitioners (GPs), that is, family doctors, provide a vital role in the identification of adolescents with mental health problems and the provision of treatment as well…

Visual Representations in Mathematics Teaching: An Experiment with Students

ERIC Educational Resources Information Center

Debrenti, Edith

2015-01-01

General problem-solving skills are of central importance in school mathematics achievement. Word problems play an important role not just in mathematical education, but in general education as well. Meaningful learning and understanding are basic aspects of all kinds of learning and it is even more important in the case of learning mathematics. In…

IFLA General Conference, 1984. Bibliographic Control Division. Sections on Bibliography, Cataloging, and Classification. Part 2. Papers.

ERIC Educational Resources Information Center

International Federation of Library Associations, The Hague (Netherlands).

Papers on cataloging and national bibliography presented at the 1984 general conference of IFLA include: (1) "Pratiques et Problemes de Catalogage au Senegal" (Cataloging Practices and Problems in Senegal) (Marietou Diop Diongue, Senegal); (2) "The Consequences of New Technologies in Classification and Subject Cataloging in Third…

Ethical Issues in Paediatric Practice - Part I: General Principles

PubMed Central

Attard-Montalto, S

2001-01-01

Clinical problems with ethical implications pose an ever increasing dilemma in everyday medical practice, and this is particularly the case with ethical issues involving children and those unable to take their own decisions. In this editorial we shall review some of the general principles that guide medical ethical problems. PMID:22368603

General stochastic variational formulation for the oligopolistic market equilibrium problem with excesses

NASA Astrophysics Data System (ADS)

Barbagallo, Annamaria; Di Meglio, Guglielmo; Mauro, Paolo

2017-07-01

The aim of the paper is to study, in a Hilbert space setting, a general random oligopolistic market equilibrium problem in presence of both production and demand excesses and to characterize the random Cournot-Nash equilibrium principle by means of a stochastic variational inequality. Some existence results are presented.

A Concise Introduction to Colombeau Generalized Functions and Their Applications in Classical Electrodynamics

ERIC Educational Resources Information Center

Gsponer, Andre

2009-01-01

The objective of this introduction to Colombeau algebras of generalized functions (in which distributions can be freely multiplied) is to explain in elementary terms the essential concepts necessary for their application to basic nonlinear problems in classical physics. Examples are given in hydrodynamics and electrodynamics. The problem of the…

GENERAL REPORT OF MATHEMATICS CONFERENCE AND TWO SPECIFIC REPORTS. (TITLE SUPPLIED).

ERIC Educational Resources Information Center

Educational Services, Inc., Watertown, MA.

THE FIRST PAPER, "REPORT OF MATHEMATICS CONFERENCE," IS A SUMMARY OF DISCUSSIONS BY 29 PARTICIPANTS IN A CONFERENCE ON CURRENT PROBLEMS IN MATHEMATICS EDUCATION RESEARCH. REPORTED ARE (1) RECENT PROGRESS, PROBLEMS, AND PLANS OF CURRICULUM DEVELOPMENT GROUPS, (2) GENERAL FORMULATION OF CURRICULUM AND METHODS, (3) TEACHER TRAINING, (4)…

An Explanatory, Transformation Geometry Proof of a Classic Treasure-Hunt Problem and Its Generalization

ERIC Educational Resources Information Center

de Villiers, Michael

2017-01-01

This paper discusses an interesting, classic problem that provides a nice classroom investigation for dynamic geometry, and which can easily be explained (proved) with transformation geometry. The deductive explanation (proof) provides insight into why it is true, leading to an immediate generalization, thus illustrating the discovery function of…

Some Student Problems: Bungi Jumping, Maglev Trains, and Misaligned Computer Monitors.

ERIC Educational Resources Information Center

Whineray, Scott

1991-01-01

Presented are three physics problems from the New Zealand Entrance Scholarship examinations which are generally attempted by more able students. Problem situations, illustrations, and solutions are detailed. (CW)

On the foundations of general relativistic celestial mechanics

NASA Astrophysics Data System (ADS)

Battista, Emmanuele; Esposito, Giampiero; Dell'Agnello, Simone

2017-09-01

Towards the end of nineteenth century, Celestial Mechanics provided the most powerful tools to test Newtonian gravity in the solar system and also led to the discovery of chaos in modern science. Nowadays, in light of general relativity, Celestial Mechanics leads to a new perspective on the motion of satellites and planets. The reader is here introduced to the modern formulation of the problem of motion, following what the leaders in the field have been teaching since the nineties, in particular, the use of a global chart for the overall dynamics of N bodies and N local charts describing the internal dynamics of each body. The next logical step studies in detail how to split the N-body problem into two sub-problems concerning the internal and external dynamics, how to achieve the effacement properties that would allow a decoupling of the two sub-problems, how to define external-potential-effacing coordinates and how to generalize the Newtonian multipole and tidal moments. The review paper ends with an assessment of the nonlocal equations of motion obtained within such a framework, a description of the modifications induced by general relativity on the theoretical analysis of the Newtonian three-body problem, and a mention of the potentialities of the analysis of solar-system metric data carried out with the Planetary Ephemeris Program.

Molecular computation: RNA solutions to chess problems.

PubMed

Faulhammer, D; Cukras, A R; Lipton, R J; Landweber, L F

2000-02-15

We have expanded the field of "DNA computers" to RNA and present a general approach for the solution of satisfiability problems. As an example, we consider a variant of the "Knight problem," which asks generally what configurations of knights can one place on an n x n chess board such that no knight is attacking any other knight on the board. Using specific ribonuclease digestion to manipulate strands of a 10-bit binary RNA library, we developed a molecular algorithm and applied it to a 3 x 3 chessboard as a 9-bit instance of this problem. Here, the nine spaces on the board correspond to nine "bits" or placeholders in a combinatorial RNA library. We recovered a set of "winning" molecules that describe solutions to this problem.

Fast Optimization for Aircraft Descent and Approach Trajectory

NASA Technical Reports Server (NTRS)

Luchinsky, Dmitry G.; Schuet, Stefan; Brenton, J.; Timucin, Dogan; Smith, David; Kaneshige, John

2017-01-01

We address problem of on-line scheduling of the aircraft descent and approach trajectory. We formulate a general multiphase optimal control problem for optimization of the descent trajectory and review available methods of its solution. We develop a fast algorithm for solution of this problem using two key components: (i) fast inference of the dynamical and control variables of the descending trajectory from the low dimensional flight profile data and (ii) efficient local search for the resulting reduced dimensionality non-linear optimization problem. We compare the performance of the proposed algorithm with numerical solution obtained using optimal control toolbox General Pseudospectral Optimal Control Software. We present results of the solution of the scheduling problem for aircraft descent using novel fast algorithm and discuss its future applications.

A Generalization of the Karush-Kuhn-Tucker Theorem for Approximate Solutions of Mathematical Programming Problems Based on Quadratic Approximation

NASA Astrophysics Data System (ADS)

Voloshinov, V. V.

2018-03-01

In computations related to mathematical programming problems, one often has to consider approximate, rather than exact, solutions satisfying the constraints of the problem and the optimality criterion with a certain error. For determining stopping rules for iterative procedures, in the stability analysis of solutions with respect to errors in the initial data, etc., a justified characteristic of such solutions that is independent of the numerical method used to obtain them is needed. A necessary δ-optimality condition in the smooth mathematical programming problem that generalizes the Karush-Kuhn-Tucker theorem for the case of approximate solutions is obtained. The Lagrange multipliers corresponding to the approximate solution are determined by solving an approximating quadratic programming problem.

Adaptive functioning and behaviour problems in relation to level of education in children and adolescents with intellectual disability.

PubMed

de Bildt, A; Sytema, S; Kraijer, D; Sparrow, S; Minderaa, R

2005-09-01

The interrelationship between adaptive functioning, behaviour problems and level of special education was studied in 186 children with IQs ranging from 61 to 70. The objective was to increase the insight into the contribution of adaptive functioning and general and autistic behaviour problems to the level of education in children with intellectual disability (ID). Children from two levels of special education in the Netherlands were compared with respect to adaptive functioning [Vineland Adaptive Behavior Scales (VABS)], general behaviour problems [Child Behavior Checklist (CBCL)] and autistic behaviour problems [Autism Behavior Checklist (ABC)]. The effect of behaviour problems on adaptive functioning, and the causal relationships between behaviour problems, adaptive functioning and level of education were investigated. Children in schools for mild learning problems had higher VABS scores, and lower CBCL and ABC scores. The ABC had a significant effect on the total age equivalent of the VABS in schools for severe learning problems, the CBCL in schools for mild learning problems. A direct effect of the ABC and CBCL total scores on the VABS age equivalent was found, together with a direct effect of the VABS age equivalent on level of education and therefore an indirect effect of ABC and CBCL on level of education. In the children with the highest level of mild ID, adaptive functioning seems to be the most important factor that directly influences the level of education that a child attends. Autistic and general behaviour problems directly influence the level of adaptive functioning. Especially, autistic problems seem to have such a restrictive effect on the level of adaptive functioning that children do not reach the level of education that would be expected based on IQ. Clinical implications are discussed.

Different neurodevelopmental symptoms have a common genetic etiology.

PubMed

Pettersson, Erik; Anckarsäter, Henrik; Gillberg, Christopher; Lichtenstein, Paul

2013-12-01

Although neurodevelopmental disorders are demarcated as discrete entities in the Diagnostic Statistical Manual of mental disorders, empirical evidence indicates that there is a high degree of overlap among them. The first aim of this investigation was to explore if a single general factor could account for the large degree of observed overlap among neurodevelopmental problems, and explore whether this potential factor was primarily genetic or environmental in origin. The second aim was to explore whether there was systematic covariation, either genetic or environmental, over and above that contributed by the potential general factor, unique to each syndrome. Parents of all Swedish 9- and 12-year-old twin pairs born between 1992 and 2002 were targeted for interview regarding problems typical of autism spectrum disorders, ADHD and other neurodevelopmental conditions (response rate: 80 percent). Structural equation modeling was conducted on 6,595 pairs to examine the genetic and environmental structure of 53 neurodevelopmental problems. One general genetic factor accounted for a large proportion of the phenotypic covariation among the 53 symptoms. Three specific genetic subfactors identified 'impulsivity,' 'learning problems,' and 'tics and autism,' respectively. Three unique environment factors identified 'autism,' 'hyperactivity and impulsivity,' and 'inattention and learning problems,' respectively. One general genetic factor was responsible for the wide-spread phenotypic overlap among all neurodevelopmental symptoms, highlighting the importance of addressing broad patient needs rather than specific diagnoses. The unique genetic factors may help guide diagnostic nomenclature, whereas the unique environmental factors may highlight that neurodevelopmental symptoms are responsive to change at the individual level and may provide clues into different mechanisms and treatments. Future research would benefit from assessing the general factor separately from specific factors to better understand observed overlap among neurodevelopmental problems. © 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.

Social Case-work in General Practice: An Alternative Approach

PubMed Central

Ratoff, L.; Pearson, Barbara

1970-01-01

During a two-year period a senior case-worker was seconded by a voluntary family case-work agency, the Liverpool Personal Service Society, to work with three general practitioners. The commonest reasons for referral of the 157 new patients to the social worker over this study period were extreme poverty; housing, matrimonial, and psychiatric problems; and problems of fatherless families. The successful and valuable co-operation between the general practitioners, case-worker, and various specialist professional and financial services of the Society have proved that a professional social worker has an important role in the general-practice team. PMID:5420213

Developing Metacognitive and Problem-Solving Skills through Problem Manipulation

ERIC Educational Resources Information Center

Parker Siburt, Claire J.; Bissell, Ahrash N.; Macphail, Richard A.

2011-01-01

In a collaborative effort between the our university's department of chemistry and the academic resource center, we designed a model for general chemistry recitation based on a problem manipulation method in which students actively assess the skills and knowledge used to answer a chemical problem and then manipulate the problem to create a new…

The Motivation of Problem-Based Teaching and Learning in Translation

ERIC Educational Resources Information Center

Yingxue, Zheng

2013-01-01

Problem-Based Learning (PBL) has been one of the popular pedagogical strategies these years. PBL is about students connecting disciplinary knowledge to real-world problems--the motivation to solve a problem. To recognize general elements and typological differences of language in translation is the motivation to solve real problems such as…

Use of Invariant Manifolds for Transfers Between Three-Body Systems

NASA Technical Reports Server (NTRS)

Beckman, Mark; Howell, Kathleen

2003-01-01

The Lunar L1 and L2 libration points have been proposed as gateways granting inexpensive access to interplanetary space. To date, only individual solutions to the transfer between three-body systems have been found. The methodology to solve the problem for arbitrary three-body systems and entire families of orbits does not exist. This paper presents the initial approaches to solve the general problem for single and multiple impulse transfers. Two different methods of representing and storing 7-dimensional invariant manifold data are presented. Some particular solutions are presented for the transfer problem, though the emphasis is on developing methodology for solving the general problem.

Some solutions of the general three body problem in form space

NASA Astrophysics Data System (ADS)

Titov, Vladimir

2018-05-01

Some solutions of three body problem with equal masses are first considered in form space. The solutions in usual euclidean space may be restored from these form space solutions. If constant energy h < 0, the trajectories are located inside of Hill's surface. Without loss of generality due to scale symmetry we can set h = -1. Such surface has a simple form in form space. Solutions of isosceles and rectilinear three body problems lie within Hill's curve; periodic solutions of free fall three body problem start in one point of this curve, and finish in another. The solutions are illustrated by number of figures.

Representations of Invariant Manifolds for Applications in Three-Body Systems

NASA Technical Reports Server (NTRS)

Howell, K.; Beckman, M.; Patterson, C.; Folta, D.

2004-01-01

The Lunar L1 and L2 libration points have been proposed as gateways granting inexpensive access to interplanetary space. To date, only individual solutions to the transfer between three-body systems have been found. The methodology to solve the problem for arbitrary three-body systems and entire families of orbits is currently being studied. This paper presents an initial approach to solve the general problem for single and multiple impulse transfers. Two different methods of representing and storing the invariant manifold data are presented. Some particular solutions are presented for two types of transfer problems, though the emphasis is on developing the methodology for solving the general problem.

Multiobjective Aerodynamic Shape Optimization Using Pareto Differential Evolution and Generalized Response Surface Metamodels

NASA Technical Reports Server (NTRS)

Madavan, Nateri K.

2004-01-01

Differential Evolution (DE) is a simple, fast, and robust evolutionary algorithm that has proven effective in determining the global optimum for several difficult single-objective optimization problems. The DE algorithm has been recently extended to multiobjective optimization problem by using a Pareto-based approach. In this paper, a Pareto DE algorithm is applied to multiobjective aerodynamic shape optimization problems that are characterized by computationally expensive objective function evaluations. To improve computational expensive the algorithm is coupled with generalized response surface meta-models based on artificial neural networks. Results are presented for some test optimization problems from the literature to demonstrate the capabilities of the method.

Generalized Pattern Search methods for a class of nonsmooth optimization problems with structure

NASA Astrophysics Data System (ADS)

Bogani, C.; Gasparo, M. G.; Papini, A.

2009-07-01

We propose a Generalized Pattern Search (GPS) method to solve a class of nonsmooth minimization problems, where the set of nondifferentiability is included in the union of known hyperplanes and, therefore, is highly structured. Both unconstrained and linearly constrained problems are considered. At each iteration the set of poll directions is enforced to conform to the geometry of both the nondifferentiability set and the boundary of the feasible region, near the current iterate. This is the key issue to guarantee the convergence of certain subsequences of iterates to points which satisfy first-order optimality conditions. Numerical experiments on some classical problems validate the method.

Research and applications: Artificial intelligence

NASA Technical Reports Server (NTRS)

Raphael, B.; Fikes, R. E.; Chaitin, L. J.; Hart, P. E.; Duda, R. O.; Nilsson, N. J.

1971-01-01

A program of research in the field of artificial intelligence is presented. The research areas discussed include automatic theorem proving, representations of real-world environments, problem-solving methods, the design of a programming system for problem-solving research, techniques for general scene analysis based upon television data, and the problems of assembling an integrated robot system. Major accomplishments include the development of a new problem-solving system that uses both formal logical inference and informal heuristic methods, the development of a method of automatic learning by generalization, and the design of the overall structure of a new complete robot system. Eight appendices to the report contain extensive technical details of the work described.

Adolescents' suicidal thinking and reluctance to consult general medical practitioners.

PubMed

Wilson, Coralie J; Deane, Frank P; Marshall, Kellie L; Dalley, Andrew

2010-04-01

Appropriate help-seeking is widely recognized as a protective factor, and vital for early treatment and prevention of mental health problems during adolescence. General medical practitioners (GPs), that is, family doctors, provide a vital role in the identification of adolescents with mental health problems and the provision of treatment as well as access to other specialists in mental health care services. The current study examined the association between suicidal ideation and intentions to seek help from a GP for suicidal thoughts, emotional problems and physical health problems, using a sample of 590 Australian high school students that was 56.7% female and aged 13-18 years (M = 15.56 years, SD = .66 years). Higher levels of suicidal ideation and general psychological distress were related to lower intentions to seek help from a GP for suicidal and physical problems. The results suggest that even at subclinical levels, increases in suicidal ideation or psychological distress may lead to help avoidance. School personnel and other gatekeepers need to be aware of this trend in order to be more assertive in encouraging and supporting appropriate help-seeking for mental health problems. School health promotion programs should consider including information to explicitly address the help-negation process.

PowerPlay: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem

PubMed Central

Schmidhuber, Jürgen

2013-01-01

Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. Given a general problem-solving architecture, at any given time, the novel algorithmic framework PowerPlay (Schmidhuber, 2011) searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Newly invented tasks may require to achieve a wow-effect by making previously learned skills more efficient such that they require less time and space. New skills may (partially) re-use previously learned skills. The greedy search of typical PowerPlay variants uses time-optimal program search to order candidate pairs of tasks and solver modifications by their conditional computational (time and space) complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. This biases the search toward pairs that can be described compactly and validated quickly. The computational costs of validating new tasks need not grow with task repertoire size. Standard problem solver architectures of personal computers or neural networks tend to generalize by solving numerous tasks outside the self-invented training set; PowerPlay’s ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Gödel’s sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing repertoire of problem-solving procedures can be exploited by a parallel search for solutions to additional externally posed tasks. PowerPlay may be viewed as a greedy but practical implementation of basic principles of creativity (Schmidhuber, 2006a, 2010). A first experimental analysis can be found in separate papers (Srivastava et al., 2012a,b, 2013). PMID:23761771

48 CFR 29.101 - Resolving tax problems.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (d) Before purchasing goods or services from a foreign source, the contracting officer should consult... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Resolving tax problems. 29... CONTRACTING REQUIREMENTS TAXES General 29.101 Resolving tax problems. (a) Contract tax problems are...

The generalized pole assignment problem. [dynamic output feedback problems

NASA Technical Reports Server (NTRS)

Djaferis, T. E.; Mitter, S. K.

1979-01-01

Two dynamic output feedback problems for a linear, strictly proper system are considered, along with their interrelationships. The problems are formulated in the frequency domain and investigated in terms of linear equations over rings of polynomials. Necessary and sufficient conditions are expressed using genericity.

Specificity of interpersonal problems in generalized anxiety disorder versus other anxiety disorders and depression.

PubMed

Uhmann, Stefan; Beesdo-Baum, Katja; Becker, Eni S; Hoyer, Jürgen

2010-11-01

We examined the diagnostic specificity of interpersonal problems (IP) in generalized anxiety disorder (GAD). We expected generally higher interpersonal distress, and specifically higher levels of nonassertive, exploitable, overly nurturant, and intrusive behavior in n = 58 patients with Diagnostic and Statistical Manual of Mental Disorders, 4th Edition GAD compared with patients with post-traumatic stress disorder (n = 46), other anxiety disorders (n = 47), and unipolar depressive disorders (n = 47). IP were assessed with the Inventory of Interpersonal Problems. Specificity in the sense of heightened interpersonal distress for GAD was not supported in any of the aforementioned scales, neither for pure nor for comorbid GAD. This finding persisted after accounting for the degree of depressiveness (Beck Depression Inventory). GAD patients are rather not characterized by more self-ascribed IPs although they may worry more about interpersonal issues in general.

Research of generalized wavelet transformations of Haar correctness in remote sensing of the Earth

NASA Astrophysics Data System (ADS)

Kazaryan, Maretta; Shakhramanyan, Mihail; Nedkov, Roumen; Richter, Andrey; Borisova, Denitsa; Stankova, Nataliya; Ivanova, Iva; Zaharinova, Mariana

2017-10-01

In this paper, Haar's generalized wavelet functions are applied to the problem of ecological monitoring by the method of remote sensing of the Earth. We study generalized Haar wavelet series and suggest the use of Tikhonov's regularization method for investigating them for correctness. In the solution of this problem, an important role is played by classes of functions that were introduced and described in detail by I.M. Sobol for studying multidimensional quadrature formulas and it contains functions with rapidly convergent series of wavelet Haar. A theorem on the stability and uniform convergence of the regularized summation function of the generalized wavelet-Haar series of a function from this class with approximate coefficients is proved. The article also examines the problem of using orthogonal transformations in Earth remote sensing technologies for environmental monitoring. Remote sensing of the Earth allows to receive from spacecrafts information of medium, high spatial resolution and to conduct hyperspectral measurements. Spacecrafts have tens or hundreds of spectral channels. To process the images, the device of discrete orthogonal transforms, and namely, wavelet transforms, was used. The aim of the work is to apply the regularization method in one of the problems associated with remote sensing of the Earth and subsequently to process the satellite images through discrete orthogonal transformations, in particular, generalized Haar wavelet transforms. General methods of research. In this paper, Tikhonov's regularization method, the elements of mathematical analysis, the theory of discrete orthogonal transformations, and methods for decoding of satellite images are used. Scientific novelty. The task of processing of archival satellite snapshots (images), in particular, signal filtering, was investigated from the point of view of an incorrectly posed problem. The regularization parameters for discrete orthogonal transformations were determined.

Effectiveness and cost-effectiveness of a proactive, goal-oriented, integrated care model in general practice for older people. A cluster randomised controlled trial: Integrated Systematic Care for older People--the ISCOPE study.

PubMed

Blom, Jeanet; den Elzen, Wendy; van Houwelingen, Anne H; Heijmans, Margot; Stijnen, Theo; Van den Hout, Wilbert; Gussekloo, Jacobijn

2016-01-01

older people often experience complex problems. Because of multiple problems, care for older people in general practice needs to shift from a 'problem-based, disease-oriented' care aiming at improvement of outcomes per disease to a 'goal-oriented care', aiming at improvement of functioning and personal quality of life, integrating all healthcare providers. Feasibility and cost-effectiveness of this proactive and integrated way of working are not yet established. cluster randomised trial. all persons aged ≥75 in 59 general practices (30 intervention, 29 control), with a combination of problems, as identified with a structured postal questionnaire with 21 questions on four health domains. for participants with problems on ≥3 domains, general practitioners (GPs) made an integrated care plan using a functional geriatric approach. Control practices: care as usual. (i) quality of life (QoL), (ii) activities of daily living, (iii) satisfaction with delivered health care and (iv) cost-effectiveness of the intervention at 1-year follow-up. Netherlands trial register, NTR1946. of the 11,476 registered eligible older persons, 7,285 (63%) participated in the screening. One thousand nine hundred and twenty-one (26%) had problems on ≥3 health domains. For 225 randomly chosen persons, a care plan was made. No beneficial effects were found on QoL, patients' functioning or healthcare use/costs. GPs experienced better overview of the care and stability, e.g. less unexpected demands, in the care. GPs prefer proactive integrated care. 'Horizontal' care using care plans for older people with complex problems can be a valuable tool in general practice. However, no direct beneficial effect was found for older persons. © The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society.

General practitioners’ attitudes towards the management of dental conditions and use of antibiotics in these consultations: a qualitative study

PubMed Central

Cope, Anwen L; Wood, Fiona; Francis, Nick A; Chestnutt, Ivor G

2015-01-01

Objectives This study aimed to produce an account of the attitudes of general practitioners (GPs) towards the management of dental conditions in general practice, and sought to explore how GPs use antibiotics in the treatment of dental problems. Design Qualitative study employing semistructured telephone interviews and thematic analysis. Participants 17 purposively sampled GPs working in Wales, of which 9 were male. The median number of years since graduation was 21. Maximum variation sampling techniques were used to ensure participants represented different Rural–Urban localities, worked in communities with varying levels of deprivation, and had differing lengths of practising career. Results Most GPs reported regularly managing dental problems, with more socioeconomically deprived patients being particularly prone to consult. Participants recognised that dental problems are not optimally managed in general practice, but had sympathy with patients experiencing dental pain who reported difficulty obtaining an emergency dental consultation. Many GPs considered antibiotics an acceptable first-line treatment for acute dental problems and reported that patients often attended expecting to receive antibiotics. GPs who reported that their usual practice was to prescribe antibiotics were more likely to prioritise patients’ immediate needs, whereas clinicians who reported rarely prescribing often did so to encourage patients to consult a dental professional. Conclusions The presentation of patients with dental problems presents challenges to GPs who report concerns about their ability to manage such conditions. Despite this, many reported frequently prescribing antibiotics for patients with dental conditions. This may contribute to both patient morbidity and the emergence of antimicrobial resistance. This research has identified the need for quantitative data on general practice consultations for dental problems and qualitative research exploring patient perspectives on reasons for consulting. The findings of these studies will inform the design of an intervention to support patients in accessing appropriate care when experiencing dental problems. PMID:26428331

Entanglement bases and general structures of orthogonal complete bases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong Zaizhe

2004-10-01

In quantum mechanics and quantum information, to establish the orthogonal bases is a useful means. The existence of unextendible product bases impels us to study the 'entanglement bases' problems. In this paper, the concepts of entanglement bases and exact-entanglement bases are defined, and a theorem about exact-entanglement bases is given. We discuss the general structures of the orthogonal complete bases. Two examples of applications are given. At last, we discuss the problem of transformation of the general structure forms.

Effort-Reward Imbalance and Mental Health Problems in 1074 German Teachers, Compared with Those in the General Population.

PubMed

Hinz, Andreas; Zenger, Markus; Brähler, Elmar; Spitzer, Silvia; Scheuch, Klaus; Seibt, Reingard

2016-08-01

High degrees of premature retirement among teachers warrant investigating the occupational burden and the mental health status of this profession. A sample of 1074 German teachers participated in this study. Two samples of the general population (N = 824 and N = 792) were used as comparison groups. Work distress was assessed with the Effort-Reward-Imbalance questionnaire, and mental health problems were measured with the General Health Questionnaire (GHQ-12). Teachers reported more effort-reward imbalance (M = 0.64) compared with the general population (M = 0.57), and they perceived more mental health problems (GHQ: M = 12.1) than the comparison group (M = 9.5). School type was not associated with work stress and mental health. Teachers with leading functions perceived high degrees of effort and reward, resulting in a moderate effort-reward ratio and no heightened mental health problems. Teachers working full time reported more effort than teachers working part time, but the reward mean values of both groups were similar. This results in a somewhat unfavourable effort-reward ratio of teachers working full time. Moreover, teachers working full time reported more mental health problems. The results support the appropriateness of the effort-reward conception, applied to the profession of teachers. The higher degree of effort-reward imbalance and the level of mental health problems warrant preventive measures. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

The Convergence of Intelligences

NASA Astrophysics Data System (ADS)

Diederich, Joachim

Minsky (1985) argued an extraterrestrial intelligence may be similar to ours despite very different origins. ``Problem- solving'' offers evolutionary advantages and individuals who are part of a technical civilisation should have this capacity. On earth, the principles of problem-solving are the same for humans, some primates and machines based on Artificial Intelligence (AI) techniques. Intelligent systems use ``goals'' and ``sub-goals'' for problem-solving, with memories and representations of ``objects'' and ``sub-objects'' as well as knowledge of relations such as ``cause'' or ``difference.'' Some of these objects are generic and cannot easily be divided into parts. We must, therefore, assume that these objects and relations are universal, and a general property of intelligence. Minsky's arguments from 1985 are extended here. The last decade has seen the development of a general learning theory (``computational learning theory'' (CLT) or ``statistical learning theory'') which equally applies to humans, animals and machines. It is argued that basic learning laws will also apply to an evolved alien intelligence, and this includes limitations of what can be learned efficiently. An example from CLT is that the general learning problem for neural networks is intractable, i.e. it cannot be solved efficiently for all instances (it is ``NP-complete''). It is the objective of this paper to show that evolved intelligences will be constrained by general learning laws and will use task-decomposition for problem-solving. Since learning and problem-solving are core features of intelligence, it can be said that intelligences converge despite very different origins.

Doctors and baldness: a five thousand year old challenge.

PubMed

Campo, Daniele; D'Acunzo, Valeria

2016-02-01

The history of trichology follows a thread that continually intersects with that of the history of medicine in general. Even Hippocrates believed that the approach to baldness should be of a medical nature. This confrontation between doctors and hair loss, which has lasted for five thousand years, begins with the invocations of the head physicians in the Egyptian era and ends with the recent institution of postgraduate Master's degrees at Faculties of Medicine and Surgery. The biggest names in medicine concerned themselves with trichology beginning with Hippocrates, who dealt with the topic in his most famous work: the Aphorisms. Even the most celebrated doctors of the Roman era, such as Galen and Pliny the Elder, did not disdain considering hair loss, leaving important scientific contributions before passing on the baton to their distinguished colleagues of the Byzantine Empire. The narrative then flows through the most prestigious institutions of the Middle Ages, such as the Salerno School of Medicine and the Siena Accademia del Fisiocritici where, at the end of the 1600s, the distinguished anatomical describer Marcello Malpighi also taught trichology, and left his contribution to "Hair Science" with a fine description of the hair follicle in the pages of his Opera Posthuma. At the turn of the late Middle Ages and the early modern era, barbers formed the primordial nucleus of surgery and at the same time became the ones to concern themselves with hair loss. In the 1800s, several doctors published the first texts dealing with the anatomy and physiology of the hair and taking into account the principal forms of alopecia, but at the therapeutic level did not yet propose anything scientifically valid. Until a few decades ago trichology still lent itself to various commercial speculations. It was not until the twentieth century that the pathogenetic mechanisms of baldness were clarified in a scientific manner. With this knowledge, the pharmaceutical industry has been able, then, to develop the necessary drugs, and doctors have become willing and able to reappropriate treatments to counteract conditions that lead to hair loss.

Level of Satisfaction of Older Persons with Their General Practitioner and Practice: Role of Complexity of Health Problems

PubMed Central

Poot, Antonius J.; den Elzen, Wendy P. J.; Blom, Jeanet W.; Gussekloo, Jacobijn

2014-01-01

Background Satisfaction is widely used to evaluate and direct delivery of medical care; a complicated relationship exists between patient satisfaction, morbidity and age. This study investigates the relationships between complexity of health problems and level of patient satisfaction of older persons with their general practitioner (GP) and practice. Methods and Findings This study is embedded in the ISCOPE (Integrated Systematic Care for Older Persons) study. Enlisted patients aged ≥75 years from 59 practices received a written questionnaire to screen for complex health problems (somatic, functional, psychological and social). For 2664 randomly chosen respondents (median age 82 years; 68% female) information was collected on level of satisfaction (satisfied, neutral, dissatisfied) with their GP and general practice, and demographic and clinical characteristics including complexity of health problems. Of all participants, 4% was dissatisfied with their GP care, 59% neutral and 37% satisfied. Between these three categories no differences were observed in age, gender, country of birth or education level. The percentage of participants dissatisfied with their GP care increased from 0.4% in those with 0 problem domains to 8% in those with 4 domains, i.e. having complex health problems (p<0.001). Per additional health domain with problems, the risk of being dissatisfied increased 1.7 times (95% CI 1.4–2.14; p<0.001). This was independent of age, gender, and demographic and clinical parameters (adjusted OR 1.4, 95% CI 1.1–1.8; p = 0.021). Conclusion In older persons, dissatisfaction with general practice is strongly correlated with rising complexity of health problems, independent of age, demographic and clinical parameters. It remains unclear whether complexity of health problems is a patient characteristic influencing the perception of care, or whether the care is unable to handle the demands of these patients. Prospective studies are needed to investigate the causal associations between care organization, patient characteristics, indicators of quality, and patient perceptions. PMID:24710557

Level of satisfaction of older persons with their general practitioner and practice: role of complexity of health problems.

PubMed

Poot, Antonius J; den Elzen, Wendy P J; Blom, Jeanet W; Gussekloo, Jacobijn

2014-01-01

Satisfaction is widely used to evaluate and direct delivery of medical care; a complicated relationship exists between patient satisfaction, morbidity and age. This study investigates the relationships between complexity of health problems and level of patient satisfaction of older persons with their general practitioner (GP) and practice. This study is embedded in the ISCOPE (Integrated Systematic Care for Older Persons) study. Enlisted patients aged ≥75 years from 59 practices received a written questionnaire to screen for complex health problems (somatic, functional, psychological and social). For 2664 randomly chosen respondents (median age 82 years; 68% female) information was collected on level of satisfaction (satisfied, neutral, dissatisfied) with their GP and general practice, and demographic and clinical characteristics including complexity of health problems. Of all participants, 4% was dissatisfied with their GP care, 59% neutral and 37% satisfied. Between these three categories no differences were observed in age, gender, country of birth or education level. The percentage of participants dissatisfied with their GP care increased from 0.4% in those with 0 problem domains to 8% in those with 4 domains, i.e. having complex health problems (p<0.001). Per additional health domain with problems, the risk of being dissatisfied increased 1.7 times (95% CI 1.4-2.14; p<0.001). This was independent of age, gender, and demographic and clinical parameters (adjusted OR 1.4, 95% CI 1.1-1.8; p = 0.021). In older persons, dissatisfaction with general practice is strongly correlated with rising complexity of health problems, independent of age, demographic and clinical parameters. It remains unclear whether complexity of health problems is a patient characteristic influencing the perception of care, or whether the care is unable to handle the demands of these patients. Prospective studies are needed to investigate the causal associations between care organization, patient characteristics, indicators of quality, and patient perceptions.

Learning, Attention/Hyperactivity, and Conduct Problems as Sequelae of Excessive Daytime Sleepiness in a General Population Study of Young Children

PubMed Central

Calhoun, Susan L.; Fernandez-Mendoza, Julio; Vgontzas, Alexandros N.; Mayes, Susan D.; Tsaoussoglou, Marina; Rodriguez-Muñoz, Alfredo; Bixler, Edward O.

2012-01-01

Study Objectives: Although excessive daytime sleepiness (EDS) is a common problem in children, with estimates of 15%; few studies have investigated the sequelae of EDS in young children. We investigated the association of EDS with objective neurocognitive measures and parent reported learning, attention/hyperactivity, and conduct problems in a large general population sample of children. Design: Cross-sectional. Setting: Population based. Participants: 508 children from The Penn State Child Cohort. Interventions: N/A. Measurements and Results: Children underwent a 9-h polysomnogram, comprehensive neurocognitive testing, and parent rating scales. Children were divided into 2 groups: those with and without parent-reported EDS. Structural equation modeling was used to examine whether processing speed and working memory performance would mediate the relationship between EDS and learning, attention/hyperactivity, and conduct problems. Logistic regression models suggest that parent-reported learning, attention/hyperactivity, and conduct problems, as well as objective measurement of processing speed and working memory are significant sequelae of EDS, even when controlling for AHI and objective markers of sleep. Path analysis demonstrates that processing speed and working memory performance are strong mediators of the association of EDS with learning and attention/hyperactivity problems, while to a slightly lesser degree are mediators from EDS to conduct problems. Conclusions: This study suggests that in a large general population sample of young children, parent-reported EDS is associated with neurobehavioral (learning, attention/hyperactivity, conduct) problems and poorer performance in processing speed and working memory. Impairment due to EDS in daytime cognitive and behavioral functioning can have a significant impact on children's development. Citation: Calhoun SL; Fernandez-Mendoza J; Vgontzas AN; Mayes SD; Tsaoussoglou M; Rodriguez-Muñoz A; Bixler EO. Learning, attention/hyperactivity, and conduct problems as sequelae of excessive daytime sleepiness in a general population study of young children. SLEEP 2012;35(5):627-632. PMID:22547888

Children's Problems Predict Adults' "DSM-IV" Disorders across 24 Years

ERIC Educational Resources Information Center

Reef, Joni; van Meurs, Inge; Verhulst, Frank C.; van der Ende, Jan

2010-01-01

Objective: The goal of this study was to determine continuities of a broad range of psychopathology from childhood into middle adulthood in a general population sample across a 24-year follow-up. Method: In 1983, parent ratings of children's problems were collected with the Child Behavior Checklist (CBCL) in a general population sample of 2,076…

Supplemental treatments to aid planted Douglas-fir in dense bracken fern

Treesearch

Edward J. Dimock

1964-01-01

Why do some forest lands restock quickly and well after timber cutting but others do not? Answers have been slow in coming--partl y because of empiricism in research, partly because of the problem's general complexity, A part of the general problem concerns the poor survival of, planted Douglas-fir (Pseudotsuga menziesii var, menziesii) on...

Training Australian General Practitioners in Rural Public Health: Impact, Desirability and Adaptability of Hybrid Problem-Based Learning

ERIC Educational Resources Information Center

Gladman, Justin; Perkins, David

2013-01-01

Context and Objective: Australian rural general practitioners (GPs) require public health knowledge. This study explored the suitability of teaching complex public health issues related to Aboriginal health by way of a hybrid problem-based learning (PBL) model within an intensive training retreat for GP registrars, when numerous trainees have no…

Evaluating Treatments for Functionally Equivalent Problem Behavior Maintained by Adult Compliance with Mands during Interactive Play

ERIC Educational Resources Information Center

Schmidt, Jonathan D.; Bednar, Mary K.; Willse, Lena V.; Goetzel, Amanda L.; Concepcion, Anthony; Pincus, Shari M.; Hardesty, Samantha L.; Bowman, Lynn G.

2017-01-01

A primary goal of behavioral interventions is to reduce dangerous or inappropriate behavior and to generalize treatment effects across various settings. However, there is a lack of research evaluating generalization of treatment effects while individuals with functionally equivalent problem behavior interact with each other. For the current study,…

Using Student-Developed, Inquiry-Based Experiments to Investigate the Contributions of Ca and Mg to Water Hardness

ERIC Educational Resources Information Center

Yang, Shui-Ping; Li, Chung-Chia

2009-01-01

This study provided a challenging opportunity for general chemistry students to mimic the scientific research process by solving a water-quality problem concerning individual calcium and magnesium concentrations. We found that general chemistry students were able to develop their own experiments to solve real-world, multivariable problems through…

Problem-Based Learning in Web-Based Science Classroom.

ERIC Educational Resources Information Center

Kim, Heeyoung; Chung, Ji-Sook; Kim, Younghoon

The purpose of this paper is to discuss how general problem-based learning (PBL) models and social-constructivist perspectives are applied to the design and development of a Web-based science program, which emphasizes inquiry-based learning for fifth grade students. The paper also deals with the general features and learning process of a Web-based…

Generalized pseudopotential approach for electron-atom scattering.

NASA Technical Reports Server (NTRS)

Zarlingo, D. G.; Ishihara, T.; Poe, R. T.

1972-01-01

A generalized many-electron pseudopotential approach is presented for electron-neutral-atom scattering problems. A calculation based on this formulation is carried out for the singlet s-wave and p-wave electron-hydrogen phase shifts with excellent results. We compare the method with other approaches as well as discuss its applications for inelastic and rearrangement collision problems.

Younger Veterans - Older Veterans: A Comparison of Perceptions of Hospital Treatment, Problem Areas and Needs.

ERIC Educational Resources Information Center

Dickman, Harold R.; Pearson, Helen J.

The contention that younger veterans differ from their elders in their attitudes and expectations was shown to be an inaccurate generalization on the basis of this reported inquiry. Three general classes of informational data were collected from both younger and older veterans: (1) perception of hospital services; (2) patient problems and services…

A general solution to the hidden-line problem. [to graphically represent aerodynamic stability derivatives

NASA Technical Reports Server (NTRS)

Hedgley, D. R., Jr.

1982-01-01

The requirements for computer-generated perspective projections of three dimensional objects has escalated. A general solution was developed. The theoretical solution to this problem is presented. The method is very efficient as it minimizes the selection of points and comparison of line segments and hence avoids the devastation of square-law growth.

Addressing the Missing Instructional Data Problem: Using a Teacher Log to Document Tier 1 Instruction

ERIC Educational Resources Information Center

Kurz, Alexander; Elliott, Stephen N.; Roach, Andrew T.

2015-01-01

Response-to-intervention (RTI) systems posit that Tier 1 consists of high-quality general classroom instruction using evidence-based methods to address the needs of most students. However, data on the extent to which general education teachers provide such instruction are rarely collected. This missing instructional data problem may result in RTI…

Reasoning about emotional contents following shocking terrorist attacks: a tale of three cities.

PubMed

Blanchette, Isabelle; Richards, Anne; Melnyk, Laura; Lavda, Anastasia

2007-03-01

The authors examined reasoning following the terrorist attacks carried out in London in July 2005. They tested participants in London (United Kingdom), Manchester (United Kingdom), and London (Canada) within 1 week of the attacks and again 6 months later. Participants reasoned about syllogisms of 3 types: neutral, generally emotional, and emotionally related to terrorism. Participants also provided self-reports of emotion and risk estimates. Participants generally reasoned more accurately on neutral problems, compared with generally emotional and terrorism-related problems. However, participants in London (United Kingdom) provided more logically valid answers when reasoning about problems related to terrorism and were less likely to answer on the basis of beliefs, despite reporting higher levels of emotions. ((c) 2007 APA, all rights reserved).

Review and synthesis of problems and directions for large scale geographic information system development

NASA Technical Reports Server (NTRS)

Boyle, A. R.; Dangermond, J.; Marble, D.; Simonett, D. S.; Tomlinson, R. F.

1983-01-01

Problems and directions for large scale geographic information system development were reviewed and the general problems associated with automated geographic information systems and spatial data handling were addressed.

Problem Solving in the General Mathematics Classroom

ERIC Educational Resources Information Center

Troutman, Andria Price; Lichtenberg, Betty Plunkett

1974-01-01

Five steps common to different problem solving models are listed. Next, seven specific abilities related to solving problems are discussed and examples given. Sample activities, appropriate to help in developing these specific abilities, are suggested. (LS)

Problem drinking - detection and assessment in general practice.

PubMed

Demirkol, Apo; Haber, Paul; Conigrave, Katherine

2011-08-01

Alcohol has long been an integral part of the social life of many Australians. However, alcohol is associated with significant harm to drinkers, and also to nondrinkers. This article explores the role of the general practitioner in the detection and assessment of problem drinking. Excessive alcohol use is a major public health problem and the majority of people who drink excessively go undetected. General practitioners are in a good position to detect excessive alcohol consumption; earlier intervention can help improve outcomes. AUDIT-C is an effective screening tool for the detection of problem drinking. National Health and Medical Research Council guidelines suggest that no more than two standard drinks on each occasion will keep lifetime risk of death from alcohol related disease or injury at a low level. Once an alcohol problem is detected it is important to assess for alcohol dependence, other substance use, motivation to change, psychiatric comorbidities and examination and investigation findings that may be associated with excessive alcohol use. A comprehensive assessment of the impact and risk of harm of the patient's drinking to themselves and others is vital, and may require several consultations.

Problems Relating Mathematics and Science in the High School.

ERIC Educational Resources Information Center

Morrow, Richard; Beard, Earl

This document contains various science problems which require a mathematical solution. The problems are arranged under two general areas. The first (algebra I) contains biology, chemistry, and physics problems which require solutions related to linear equations, exponentials, and nonlinear equations. The second (algebra II) contains physics…

Mental health problems of undocumented migrants in the Netherlands: A qualitative exploration of recognition, recording, and treatment by general practitioners.

PubMed

Teunissen, Erik; Van Bavel, Eric; Van Den Driessen Mareeuw, Francine; Macfarlane, Anne; Van Weel-Baumgarten, Evelyn; Van Den Muijsenbergh, Maria; Van Weel, Chris

2015-06-01

To explore the views and experiences of general practitioners (GPs) in relation to recognition, recording, and treatment of mental health problems of undocumented migrants (UMs), and to gain insight in the reasons for under-registration of mental health problems in the electronic medical records. Qualitative study design with semi-structured interviews using a topic guide. Sixteen GPs in the Netherlands with clinical expertise in the care of UMs. GPs recognized many mental health problems in UMs. Barriers that prevented them from recording these problems and from delivering appropriate care were their low consultation rates, physical presentation of mental health problems, high number of other problems, the UM's lack of trust towards health care professionals, and cultural differences in health beliefs and language barriers. Referrals to mental health care organizations were often seen as problematic by GPs. To overcome these barriers, GPs provided personalized care as far as possible, referred to other primary care professionals such as social workers or mental health care nurses in their practice, and were a little less restrictive in prescribing psychotropics than guidelines recommended. GPs experienced a variety of barriers in engaging with UMs when identifying or suspecting mental health problems. This explains why there is a gap between the high recognition of mental health problems and the low recording of these problems in general practice files. It is recommended that GPs address mental health problems more actively, strive for continuity of care in order to gain trust of the UMs, and look for opportunities to provide mental care that is accessible and acceptable for UMs.

Ancient harbour infrastructure in the Levant: tracking the birth and rise of new forms of anthropogenic pressure.

PubMed

Marriner, Nick; Morhange, Christophe; Kaniewski, David; Carayon, Nicolas

2014-07-03

Beirut, Sidon and Tyre were major centres of maritime trade from the Bronze Age onwards. This economic prosperity generated increased pressures on the local environment, through urbanization and harbour development. Until now, however, the impact of expanding seaport infrastructure has largely been neglected and there is a paucity of data concerning the environmental stresses caused by these new forms of anthropogenic impacts. Sediment archives from Beirut, Sidon and Tyre are key to understanding human impacts in harbour areas because: (i) they lie at the heart of ancient trade networks; (ii) they encompass the emergence of early maritime infrastructure; and (iii) they enable human alterations of coastal areas to be characterized over long timescales. Here we report multivariate analyses of litho- and biostratigraphic data to probe human stressors in the context of their evolving seaport technologies. The statistical outcomes show a notable break between natural and artificial sedimentation that began during the Iron Age. Three anchorage phases can be distinguished: (i) Bronze Age proto-harbours that correspond to natural anchorages, with minor human impacts; (ii) semi-artificial Iron Age harbours, with stratigraphic evidence for artificial reinforcement of the natural endowments; and (iii) heavy human impacts leading to completely artificial Roman and Byzantine harbours.

Ancient harbour infrastructure in the Levant: tracking the birth and rise of new forms of anthropogenic pressure

PubMed Central

Marriner, Nick; Morhange, Christophe; Kaniewski, David; Carayon, Nicolas

2014-01-01

Beirut, Sidon and Tyre were major centres of maritime trade from the Bronze Age onwards. This economic prosperity generated increased pressures on the local environment, through urbanization and harbour development. Until now, however, the impact of expanding seaport infrastructure has largely been neglected and there is a paucity of data concerning the environmental stresses caused by these new forms of anthropogenic impacts. Sediment archives from Beirut, Sidon and Tyre are key to understanding human impacts in harbour areas because: (i) they lie at the heart of ancient trade networks; (ii) they encompass the emergence of early maritime infrastructure; and (iii) they enable human alterations of coastal areas to be characterized over long timescales. Here we report multivariate analyses of litho- and biostratigraphic data to probe human stressors in the context of their evolving seaport technologies. The statistical outcomes show a notable break between natural and artificial sedimentation that began during the Iron Age. Three anchorage phases can be distinguished: (i) Bronze Age proto-harbours that correspond to natural anchorages, with minor human impacts; (ii) semi-artificial Iron Age harbours, with stratigraphic evidence for artificial reinforcement of the natural endowments; and (iii) heavy human impacts leading to completely artificial Roman and Byzantine harbours. PMID:24989979

Advanced information processing system: The Army Fault-Tolerant Architecture detailed design overview

NASA Technical Reports Server (NTRS)

Harper, Richard E.; Babikyan, Carol A.; Butler, Bryan P.; Clasen, Robert J.; Harris, Chris H.; Lala, Jaynarayan H.; Masotto, Thomas K.; Nagle, Gail A.; Prizant, Mark J.; Treadwell, Steven

1994-01-01

The Army Avionics Research and Development Activity (AVRADA) is pursuing programs that would enable effective and efficient management of large amounts of situational data that occurs during tactical rotorcraft missions. The Computer Aided Low Altitude Night Helicopter Flight Program has identified automated Terrain Following/Terrain Avoidance, Nap of the Earth (TF/TA, NOE) operation as key enabling technology for advanced tactical rotorcraft to enhance mission survivability and mission effectiveness. The processing of critical information at low altitudes with short reaction times is life-critical and mission-critical necessitating an ultra-reliable/high throughput computing platform for dependable service for flight control, fusion of sensor data, route planning, near-field/far-field navigation, and obstacle avoidance operations. To address these needs the Army Fault Tolerant Architecture (AFTA) is being designed and developed. This computer system is based upon the Fault Tolerant Parallel Processor (FTPP) developed by Charles Stark Draper Labs (CSDL). AFTA is hard real-time, Byzantine, fault-tolerant parallel processor which is programmed in the ADA language. This document describes the results of the Detailed Design (Phase 2 and 3 of a 3-year project) of the AFTA development. This document contains detailed descriptions of the program objectives, the TF/TA NOE application requirements, architecture, hardware design, operating systems design, systems performance measurements and analytical models.

The botanical materia medica of the Iatrosophikon--a collection of prescriptions from a monastery in Cyprus.

PubMed

Lardos, Andreas

2006-04-06

This article analyses the botanical material that is contained in the Iatrosophikon, a collection of prescriptions from a monastery in Cyprus written down during the island's Ottoman period (1571-1878). A total of 494 herbal prescriptions were detected in the record and 231 plants belonging to 70 different botanical families, as well as 21 various substances of botanical or mixed origin were identified. The distribution of the plants, the plant part used, the use of the material, and the mode of application are discussed. Parallels with other medical writings of the Greek-speaking Ottoman world suggest a local popular as well as a classical Greek and Byzantine influence. The latter is particularly supported by the relationship of the majority of the plants described to plants mentioned by Dioscorides. Additionally the question of what other sources might have contributed to this herbal knowledge is discussed. The results also show that most of the plants described originated from the island itself, only a minority of the botanical material presumably had to be imported. All the mentioned plants of local origin are also cited in modern ethnopharmacological studies on Cyprus, the Iatrosophikon demonstrates their use at a time from which no other written source of comparable detail exists.

Ancient harbour infrastructure in the Levant: tracking the birth and rise of new forms of anthropogenic pressure

NASA Astrophysics Data System (ADS)

Marriner, Nick; Morhange, Christophe; Kaniewski, David; Carayon, Nicolas

2014-07-01

Beirut, Sidon and Tyre were major centres of maritime trade from the Bronze Age onwards. This economic prosperity generated increased pressures on the local environment, through urbanization and harbour development. Until now, however, the impact of expanding seaport infrastructure has largely been neglected and there is a paucity of data concerning the environmental stresses caused by these new forms of anthropogenic impacts. Sediment archives from Beirut, Sidon and Tyre are key to understanding human impacts in harbour areas because: (i) they lie at the heart of ancient trade networks; (ii) they encompass the emergence of early maritime infrastructure; and (iii) they enable human alterations of coastal areas to be characterized over long timescales. Here we report multivariate analyses of litho- and biostratigraphic data to probe human stressors in the context of their evolving seaport technologies. The statistical outcomes show a notable break between natural and artificial sedimentation that began during the Iron Age. Three anchorage phases can be distinguished: (i) Bronze Age proto-harbours that correspond to natural anchorages, with minor human impacts; (ii) semi-artificial Iron Age harbours, with stratigraphic evidence for artificial reinforcement of the natural endowments; and (iii) heavy human impacts leading to completely artificial Roman and Byzantine harbours.

Generalization of Social Skills: Strategies and Results of a Training Program in Problem Solving Skills.

ERIC Educational Resources Information Center

Paraschiv, Irina; Olley, J. Gregory

This paper describes the "Problem Solving for Life" training program which trains adolescents and adults with mental retardation in skills for solving social problems. The program requires group participants to solve social problems by practicing two prerequisite skills (relaxation and positive self-statements) and four problem solving steps: (1)…

A (New) Discursive Framework for Dealing with the Problem of Unsafe Schools

ERIC Educational Resources Information Center

van der Walt, Johannes L.

2015-01-01

The problem of unsafe schools, in the sense of schools being afflicted by incidences of violence, crime, and general anti-social behaviour, is a worldwide problem. Not surprisingly, the literature on the subject tends to centre on two issues: understanding the problem, and avoiding or combating the problem. This paper focuses on the second by…

Molecular computation: RNA solutions to chess problems

PubMed Central

Faulhammer, Dirk; Cukras, Anthony R.; Lipton, Richard J.; Landweber, Laura F.

2000-01-01

We have expanded the field of “DNA computers” to RNA and present a general approach for the solution of satisfiability problems. As an example, we consider a variant of the “Knight problem,” which asks generally what configurations of knights can one place on an n × n chess board such that no knight is attacking any other knight on the board. Using specific ribonuclease digestion to manipulate strands of a 10-bit binary RNA library, we developed a molecular algorithm and applied it to a 3 × 3 chessboard as a 9-bit instance of this problem. Here, the nine spaces on the board correspond to nine “bits” or placeholders in a combinatorial RNA library. We recovered a set of “winning” molecules that describe solutions to this problem. PMID:10677471

Inverse problems in quantum chemistry

NASA Astrophysics Data System (ADS)

Karwowski, Jacek

Inverse problems constitute a branch of applied mathematics with well-developed methodology and formalism. A broad family of tasks met in theoretical physics, in civil and mechanical engineering, as well as in various branches of medical and biological sciences has been formulated as specific implementations of the general theory of inverse problems. In this article, it is pointed out that a number of approaches met in quantum chemistry can (and should) be classified as inverse problems. Consequently, the methodology used in these approaches may be enriched by applying ideas and theorems developed within the general field of inverse problems. Several examples, including the RKR method for the construction of potential energy curves, determining parameter values in semiempirical methods, and finding external potentials for which the pertinent Schrödinger equation is exactly solvable, are discussed in detail.

DESCRIPTION OF THE ENIAC CONVERTER CODE

DTIC Science & Technology

The report is intended as a working manual for personnel preparing problems for the ENIAC . It should also serve as a guide to those groups who have...computing problems that could be solved on the ENIAC . The report discusses the ENIAC from the point of view of the coder, describing its memory as well...accomplishes as well as how to use each instruction. A few remarks are made on the more general subject of problem preparation for large scale computers in general based on the experience of operating the ENIAC . (Author)

TOPICAL REVIEW: The stability for the Cauchy problem for elliptic equations

NASA Astrophysics Data System (ADS)

Alessandrini, Giovanni; Rondi, Luca; Rosset, Edi; Vessella, Sergio

2009-12-01

We discuss the ill-posed Cauchy problem for elliptic equations, which is pervasive in inverse boundary value problems modeled by elliptic equations. We provide essentially optimal stability results, in wide generality and under substantially minimal assumptions. As a general scheme in our arguments, we show that all such stability results can be derived by the use of a single building brick, the three-spheres inequality. Due to the current absence of research funding from the Italian Ministry of University and Research, this work has been completed without any financial support.

An l1-TV algorithm for deconvolution with salt and pepper noise

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohlberg, Brendt; Rodriguez, Paul

2008-01-01

There has recently been considerable interest in applying Total Variation with an {ell}{sup 1} data fidelity term to the denoising of images subject to salt and pepper noise, but the extension of this formulation to more general problems, such as deconvolution, has received little attention, most probably because most efficient algorithms for {ell}{sup 1}-TV denoising can not handle more general inverse problems. We apply the Iteratively Reweighted Norm algorithm to this problem, and compare performance with an alternative algorithm based on the Mumford-Shah functional.

College Health: Health Services and Common Health Problems

MedlinePlus

... Guides Quizzes Parents About Us Donate General Health Sexual Health Medical Conditions Nutrition & Fitness Emotional Health College Health: ... disabilities, nutrition issues or eating disorders, relationship problems, sexual health issues, alcohol or drug problems, or sports injuries. ...

A Comparison of Two Mathematics Problem-Solving Strategies: Facilitate Algebra-Readiness

ERIC Educational Resources Information Center

Xin, Yan Ping; Zhang, Dake; Park, Joo Young; Tom, Kinsey; Whipple, Amanda; Si, Luo

2011-01-01

The authors compared a conceptual model-based problem-solving (COMPS) approach with a general heuristic instructional approach for teaching multiplication-division word-problem solving to elementary students with learning problems (LP). The results indicate that only the COMPS group significantly improved, from pretests to posttests, their…

A general CPL-AdS methodology for fixing dynamic parameters in dual environments.

PubMed

Huang, De-Shuang; Jiang, Wen

2012-10-01

The algorithm of Continuous Point Location with Adaptive d-ary Search (CPL-AdS) strategy exhibits its efficiency in solving stochastic point location (SPL) problems. However, there is one bottleneck for this CPL-AdS strategy which is that, when the dimension of the feature, or the number of divided subintervals for each iteration, d is large, the decision table for elimination process is almost unavailable. On the other hand, the larger dimension of the features d can generally make this CPL-AdS strategy avoid oscillation and converge faster. This paper presents a generalized universal decision formula to solve this bottleneck problem. As a matter of fact, this decision formula has a wider usage beyond handling out this SPL problems, such as dealing with deterministic point location problems and searching data in Single Instruction Stream-Multiple Data Stream based on Concurrent Read and Exclusive Write parallel computer model. Meanwhile, we generalized the CPL-AdS strategy with an extending formula, which is capable of tracking an unknown dynamic parameter λ in both informative and deceptive environments. Furthermore, we employed different learning automata in the generalized CPL-AdS method to find out if faster learning algorithm will lead to better realization of the generalized CPL-AdS method. All of these aforementioned contributions are vitally important whether in theory or in practical applications. Finally, extensive experiments show that our proposed approaches are efficient and feasible.

Internalizing and externalizing problems in adolescence: general and dimension-specific effects of familial loadings and preadolescent temperament traits.

PubMed

Ormel, J; Oldehinkel, A J; Ferdinand, R F; Hartman, C A; De Winter, A F; Veenstra, R; Vollebergh, W; Minderaa, R B; Buitelaar, J K; Verhulst, F C

2005-12-01

We investigated the links between familial loading, preadolescent temperament, and internalizing and externalizing problems in adolescence, hereby distinguishing effects on maladjustment in general versus dimension-specific effects on either internalizing or externalizing problems. In a population-based sample of 2230 preadolescents (10-11 years) familial loading (parental lifetime psychopathology) and offspring temperament were assessed at baseline by parent report, and offspring psychopathology at 2.5-years follow-up by self-report, teacher report and parent report. We used purified measures of temperament and psychopathology and partialled out shared variance between internalizing and externalizing problems. Familial loading of internalizing psychopathology predicted offspring internalizing but not externalizing problems, whereas familial loading of externalizing psychopathology predicted offspring externalizing but not internalizing problems. Both familial loadings were associated with Frustration, low Effortful Control, and Fear. Frustration acted as a general risk factor predicting severity of maladjustment; low Effortful Control and Fear acted as dimension-specific risk factors that predicted a particular type of psychopathology; whereas Shyness, High-Intensity Pleasure, and Affiliation acted as direction markers that steered the conditional probability of internalizing versus externalizing problems, in the event of maladjustment. Temperament traits mediated one-third of the association between familial loading and psychopathology. Findings were robust across different composite measures of psychopathology, and applied to girls as well as boys. With regard to familial loading and temperament, it is important to distinguish general risk factors (Frustration) from dimension-specific risk factors (familial loadings, Effortful Control, Fear), and direction markers that act as pathoplastic factors (Shyness, High-Intensity Pleasure, Affiliation) from both types of risk factors. About one-third of familial loading effects on psychopathology in early adolescence are mediated by temperament.

Identifying patient safety problems associated with information technology in general practice: an analysis of incident reports.

PubMed

Magrabi, Farah; Liaw, Siaw Teng; Arachi, Diana; Runciman, William; Coiera, Enrico; Kidd, Michael R

2016-11-01

To identify the categories of problems with information technology (IT), which affect patient safety in general practice. General practitioners (GPs) reported incidents online or by telephone between May 2012 and November 2013. Incidents were reviewed against an existing classification for problems associated with IT and the clinical process impacted. 87 GPs across Australia. Types of problems, consequences and clinical processes. GPs reported 90 incidents involving IT which had an observable impact on the delivery of care, including actual patient harm as well as near miss events. Practice systems and medications were the most affected clinical processes. Problems with IT disrupted clinical workflow, wasted time and caused frustration. Issues with user interfaces, routine updates to software packages and drug databases, and the migration of records from one package to another generated clinical errors that were unique to IT; some could affect many patients at once. Human factors issues gave rise to some errors that have always existed with paper records but are more likely to occur and cause harm with IT. Such errors were linked to slips in concentration, multitasking, distractions and interruptions. Problems with patient identification and hybrid records generated errors that were in principle no different to paper records. Problems associated with IT include perennial risks with paper records, but additional disruptions in workflow and hazards for patients unique to IT, occasionally affecting multiple patients. Surveillance for such hazards may have general utility, but particularly in the context of migrating historical records to new systems and software updates to existing systems. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Kuo -Ling; Mehrotra, Sanjay

We present a homogeneous algorithm equipped with a modified potential function for the monotone complementarity problem. We show that this potential function is reduced by at least a constant amount if a scaled Lipschitz condition (SLC) is satisfied. A practical algorithm based on this potential function is implemented in a software package named iOptimize. The implementation in iOptimize maintains global linear and polynomial time convergence properties, while achieving practical performance. It either successfully solves the problem, or concludes that the SLC is not satisfied. When compared with the mature software package MOSEK (barrier solver version 6.0.0.106), iOptimize solves convex quadraticmore » programming problems, convex quadratically constrained quadratic programming problems, and general convex programming problems in fewer iterations. Moreover, several problems for which MOSEK fails are solved to optimality. In addition, we also find that iOptimize detects infeasibility more reliably than the general nonlinear solvers Ipopt (version 3.9.2) and Knitro (version 8.0).« less

Solving a class of generalized fractional programming problems using the feasibility of linear programs.

PubMed

Shen, Peiping; Zhang, Tongli; Wang, Chunfeng

2017-01-01

This article presents a new approximation algorithm for globally solving a class of generalized fractional programming problems (P) whose objective functions are defined as an appropriate composition of ratios of affine functions. To solve this problem, the algorithm solves an equivalent optimization problem (Q) via an exploration of a suitably defined nonuniform grid. The main work of the algorithm involves checking the feasibility of linear programs associated with the interesting grid points. It is proved that the proposed algorithm is a fully polynomial time approximation scheme as the ratio terms are fixed in the objective function to problem (P), based on the computational complexity result. In contrast to existing results in literature, the algorithm does not require the assumptions on quasi-concavity or low-rank of the objective function to problem (P). Numerical results are given to illustrate the feasibility and effectiveness of the proposed algorithm.

Direct Method Transcription for a Human-Class Translunar Injection Trajectory Optimization

NASA Technical Reports Server (NTRS)

Witzberger, Kevin E.; Zeiler, Tom

2012-01-01

This paper presents a new trajectory optimization software package developed in the framework of a low-to-high fidelity 3 degrees-of-freedom (DOF)/6-DOF vehicle simulation program named Mission Analysis Simulation Tool in Fortran (MASTIF) and its application to a translunar trajectory optimization problem. The functionality of the developed optimization package is implemented as a new "mode" in generalized settings to make it applicable for a general trajectory optimization problem. In doing so, a direct optimization method using collocation is employed for solving the problem. Trajectory optimization problems in MASTIF are transcribed to a constrained nonlinear programming (NLP) problem and solved with SNOPT, a commercially available NLP solver. A detailed description of the optimization software developed is provided as well as the transcription specifics for the translunar injection (TLI) problem. The analysis includes a 3-DOF trajectory TLI optimization and a 3-DOF vehicle TLI simulation using closed-loop guidance.

EXAMINING THE ACCURACY OF ASTROPHYSICAL DISK SIMULATIONS WITH A GENERALIZED HYDRODYNAMICAL TEST PROBLEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raskin, Cody; Owen, J. Michael, E-mail: raskin1@llnl.gov, E-mail: mikeowen@llnl.gov

2016-11-01

We discuss a generalization of the classic Keplerian disk test problem allowing for both pressure and rotational support, as a method of testing astrophysical codes incorporating both gravitation and hydrodynamics. We argue for the inclusion of pressure in rotating disk simulations on the grounds that realistic, astrophysical disks exhibit non-negligible pressure support. We then apply this test problem to examine the performance of various smoothed particle hydrodynamics (SPH) methods incorporating a number of improvements proposed over the years to address problems noted in modeling the classical gravitation-only Keplerian disk. We also apply this test to a newly developed extension ofmore » SPH based on reproducing kernels called CRKSPH. Counterintuitively, we find that pressure support worsens the performance of traditional SPH on this problem, causing unphysical collapse away from the steady-state disk solution even more rapidly than the purely gravitational problem, whereas CRKSPH greatly reduces this error.« less

Gradient descent learning algorithm overview: a general dynamical systems perspective.

PubMed

Baldi, P

1995-01-01

Gives a unified treatment of gradient descent learning algorithms for neural networks using a general framework of dynamical systems. This general approach organizes and simplifies all the known algorithms and results which have been originally derived for different problems (fixed point/trajectory learning), for different models (discrete/continuous), for different architectures (forward/recurrent), and using different techniques (backpropagation, variational calculus, adjoint methods, etc.). The general approach can also be applied to derive new algorithms. The author then briefly examines some of the complexity issues and limitations intrinsic to gradient descent learning. Throughout the paper, the author focuses on the problem of trajectory learning.

Shape Optimization for Navier-Stokes Equations with Algebraic Turbulence Model: Existence Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bulicek, Miroslav; Haslinger, Jaroslav; Malek, Josef

2009-10-15

We study a shape optimization problem for the paper machine headbox which distributes a mixture of water and wood fibers in the paper making process. The aim is to find a shape which a priori ensures the given velocity profile on the outlet part. The mathematical formulation leads to an optimal control problem in which the control variable is the shape of the domain representing the header, the state problem is represented by a generalized stationary Navier-Stokes system with nontrivial mixed boundary conditions. In this paper we prove the existence of solutions both to the generalized Navier-Stokes system and tomore » the shape optimization problem.« less

On Born's Conjecture about Optimal Distribution of Charges for an Infinite Ionic Crystal

NASA Astrophysics Data System (ADS)

Bétermin, Laurent; Knüpfer, Hans

2018-04-01

We study the problem for the optimal charge distribution on the sites of a fixed Bravais lattice. In particular, we prove Born's conjecture about the optimality of the rock salt alternate distribution of charges on a cubic lattice (and more generally on a d-dimensional orthorhombic lattice). Furthermore, we study this problem on the two-dimensional triangular lattice and we prove the optimality of a two-component honeycomb distribution of charges. The results hold for a class of completely monotone interaction potentials which includes Coulomb-type interactions for d≥3 . In a more general setting, we derive a connection between the optimal charge problem and a minimization problem for the translated lattice theta function.

Assessment regarding the use of the computer aided analytical models in the calculus of the general strength of a ship hull

NASA Astrophysics Data System (ADS)

Hreniuc, V.; Hreniuc, A.; Pescaru, A.

2017-08-01

Solving a general strength problem of a ship hull may be done using analytical approaches which are useful to deduce the buoyancy forces distribution, the weighting forces distribution along the hull and the geometrical characteristics of the sections. These data are used to draw the free body diagrams and to compute the stresses. The general strength problems require a large amount of calculi, therefore it is interesting how a computer may be used to solve such problems. Using computer programming an engineer may conceive software instruments based on analytical approaches. However, before developing the computer code the research topic must be thoroughly analysed, in this way being reached a meta-level of understanding of the problem. The following stage is to conceive an appropriate development strategy of the original software instruments useful for the rapid development of computer aided analytical models. The geometrical characteristics of the sections may be computed using a bool algebra that operates with ‘simple’ geometrical shapes. By ‘simple’ we mean that for the according shapes we have direct calculus relations. In the set of ‘simple’ shapes we also have geometrical entities bounded by curves approximated as spline functions or as polygons. To conclude, computer programming offers the necessary support to solve general strength ship hull problems using analytical methods.

Mathematical improvement of the Hopfield model for feasible solutions to the traveling salesman problem by a synapse dynamical system.

PubMed

Takahashi, Y

1998-01-01

It is well known that the Hopfield Model (HM) for neural networks to solve the Traveling Salesman Problem (TSP) suffers from three major drawbacks. (1) It can converge on nonoptimal locally minimum solutions. (2) It can converge on infeasible solutions. (3) Results are very sensitive to the careful tuning of its parameters. A number of methods have been proposed to overcome (a) well. In contrast, work on (b) and (c) has not been sufficient; techniques have not been generalized to more general optimization problems. Thus this paper mathematically resolves (b) and (c) to such an extent that the resolution can be applied to solving with some general network continuous optimization problems including the Hopfield version of the TSP. It first constructs an Extended HM (E-HM) that overcomes both (b) and (c). Fundamental techniques of the E-HM lie in the addition of a synapse dynamical system cooperated with the current HM unit dynamical system. It is this synapse dynamical system that makes the TSP constraint hold at any final states for whatever choices of the IIM parameters and an initial state. The paper then generalizes the E-HM further to a network that can solve a class of continuous optimization problems with a constraint equation where both of the objective function and the constraint function are nonnegative and continuously differentiable.

A representation for error detection and recovery in robot task plans

NASA Technical Reports Server (NTRS)

Lyons, D. M.; Vijaykumar, R.; Venkataraman, S. T.

1990-01-01

A general definition is given of the problem of error detection and recovery in robot assembly systems, and a general representation is developed for dealing with the problem. This invariant representation involves a monitoring process which is concurrent, with one monitor per task plan. A plan hierarchy is discussed, showing how diagnosis and recovery can be handled using the representation.

Lobb's Generalization of Catalan's Parenthesization Problem

ERIC Educational Resources Information Center

Koshy, Thomas

2009-01-01

A. Lobb discovered an interesting generalization of Catalan's parenthesization problem, namely: Find the number L(n, m) of arrangements of n + m positive ones and n - m negative ones such that every partial sum is nonnegative, where 0 = m = n. This article uses Lobb's formula, L(n, m) = (2m + 1)/(n + m + 1) C(2n, n + m), where C is the usual…

"K"-Balance Partitioning: An Exact Method with Applications to Generalized Structural Balance and Other Psychological Contexts

ERIC Educational Resources Information Center

Brusco, Michael; Steinley, Douglas

2010-01-01

Structural balance theory (SBT) has maintained a venerable status in the psychological literature for more than 5 decades. One important problem pertaining to SBT is the approximation of structural or generalized balance via the partitioning of the vertices of a signed graph into "K" clusters. This "K"-balance partitioning problem also has more…

45 CFR 262.5 - Under what general circumstances will we determine that a State has reasonable cause?

Code of Federal Regulations, 2014 CFR

2014-10-01

... State if we determine that the State had reasonable cause for its failure. The general factors a State...., hurricanes, earthquakes, fire) whose disruptive impact was so significant as to cause the State's failure; (2... (3) Isolated problems of minimal impact that are not indicative of a systemic problem. (b)(1) We will...

A Jubilant Connection: General Jubal Early's Troops and the Golden Ratio

ERIC Educational Resources Information Center

Bolte, Linda A.; Noon, Tim R., Jr.

2012-01-01

The golden ratio, one of the most beautiful numbers in all of mathematics, arises in some surprising places. At first glance, we might expect that a General checking his troops' progress would be nothing more than a basic distance-rate-time problem. However, further exploration reveals a multi-faceted problem, one in which the ratio of rates…

Body Mass Index in Adults with Intellectual Disability: Distribution, Associations and Service Implications--A Population-Based Prevalence Study

ERIC Educational Resources Information Center

Bhaumik, S.; Watson, J. M.; Thorp, C. F.; Tyrer, F.; McGrother, C. W.

2008-01-01

Background: Previous studies of weight problems in adults with intellectual disability (ID) have generally been small or selective and given conflicting results. The objectives of our large-scale study were to identify inequalities in weight problems between adults with ID and the general adult population, and to investigate factors associated…

General form of a cooperative gradual maximal covering location problem

NASA Astrophysics Data System (ADS)

Bagherinejad, Jafar; Bashiri, Mahdi; Nikzad, Hamideh

2018-07-01

Cooperative and gradual covering are two new methods for developing covering location models. In this paper, a cooperative maximal covering location-allocation model is developed (CMCLAP). In addition, both cooperative and gradual covering concepts are applied to the maximal covering location simultaneously (CGMCLP). Then, we develop an integrated form of a cooperative gradual maximal covering location problem, which is called a general CGMCLP. By setting the model parameters, the proposed general model can easily be transformed into other existing models, facilitating general comparisons. The proposed models are developed without allocation for physical signals and with allocation for non-physical signals in discrete location space. Comparison of the previously introduced gradual maximal covering location problem (GMCLP) and cooperative maximal covering location problem (CMCLP) models with our proposed CGMCLP model in similar data sets shows that the proposed model can cover more demands and acts more efficiently. Sensitivity analyses are performed to show the effect of related parameters and the model's validity. Simulated annealing (SA) and a tabu search (TS) are proposed as solution algorithms for the developed models for large-sized instances. The results show that the proposed algorithms are efficient solution approaches, considering solution quality and running time.

Referrals from general practitioners to a social services department

PubMed Central

Sheppard, M. G.

1983-01-01

One year's referrals from general practitioners to a social services department were studied. There was a low referral rate and a bias towards women, the elderly and the less affluent. The referrals were predominantly made for practical help with problems of ill health. A high proportion of clients were allocated to non-social work staff, and the social service intervention, generally of short duration, showed a sympathetic response to the practical requests of general practitioners. The limited use of social workers by doctors is considered to be the result of ignorance or scepticism about psychodynamic social work skills. Closer liaison between general practitioners and social workers, and a clearer presentation by social workers of their professional skills, are suggested solutions to this problem. PMID:6854536

Training generalized improvisation of tools by preschool children1

PubMed Central

Parsonson, Barry S.; Baer, Donald M.

1978-01-01

The development of new, “creative” behaviors was examined in a problem-solving context. One form of problem solving, improvisation, was defined as finding a substitute to replace the specifically designated, but currently unavailable, tool ordinarily used to solve the problem. The study examined whether preschool children spontaneously displayed generalized improvisation skills, and if not, whether they could be trained to do so within different classes of tools. Generalization across different tool classes was monitored but not specifically trained. Five preschool children participated in individual sessions that first probed their skill at improvising tools, and later trained and probed generalized improvisation in one or more of three tool classes (Hammers, Containers, and Shoelaces), using a multiple-baseline design. All five children were trained with Hammers, two were trained in two classes, and two were trained in all three tool classes. Four of the five children improvised little in Baseline. During Training, all five showed increased generalized improvisation within the trained class, but none across classes. Tools fabricated by item combinations were rare in Baseline, but common in Training. Followup probes showed that the training effects were durable. PMID:16795596

Generalized continued fractions and ergodic theory

NASA Astrophysics Data System (ADS)

Pustyl'nikov, L. D.

2003-02-01

In this paper a new theory of generalized continued fractions is constructed and applied to numbers, multidimensional vectors belonging to a real space, and infinite-dimensional vectors with integral coordinates. The theory is based on a concept generalizing the procedure for constructing the classical continued fractions and substantially using ergodic theory. One of the versions of the theory is related to differential equations. In the finite-dimensional case the constructions thus introduced are used to solve problems posed by Weyl in analysis and number theory concerning estimates of trigonometric sums and of the remainder in the distribution law for the fractional parts of the values of a polynomial, and also the problem of characterizing algebraic and transcendental numbers with the use of generalized continued fractions. Infinite-dimensional generalized continued fractions are applied to estimate sums of Legendre symbols and to obtain new results in the classical problem of the distribution of quadratic residues and non-residues modulo a prime. In the course of constructing these continued fractions, an investigation is carried out of the ergodic properties of a class of infinite-dimensional dynamical systems which are also of independent interest.

Patterns and predictors of help-seeking contacts with health services and general practitioner detection of suicidality prior to suicide: a cohort analysis of suicides occurring over a two-year period.

PubMed

Leavey, Gerard; Rosato, Michael; Galway, Karen; Hughes, Lynette; Mallon, Sharon; Rondon, Janeet

2016-04-30

Contact with primary care and psychiatric services prior to suicide may be considerable, presenting opportunities for intervention. However, there is scant knowledge on the frequency, nature and determinants of contact. Retrospective cohort study-an analysis of deaths recorded as suicide by the Northern Ireland Coroner's Office linked with data from General Practice patient records over a 2 year period Eighty-seven per cent of suicides were in contact with General Practice services in the 12 months before suicide. The frequency of contact with services was considerable, particularly among patients with a common mental disorder or substance misuse problems. A diagnosis of psychiatric problems was absent in 40% of suicides. Excluding suicide attempts, the main predictors of a noted general practitioner concern for patient suicidality are male gender, frequency of consultations, diagnosis of mental illness and substance misuse. Despite widespread and frequent contact, a substantial proportion of suicidal people were undiagnosed and untreated for mental health problems. General Practitioner alertness to suicidality may be too narrowly focused.

Possible Side-Effects from Vaccines

MedlinePlus

... 1 child in 50) These problems generally occur 1-3 days after the shot. Moderate Problems (Uncommon) Seizure (jerking or staring) (about ... problems occur, they usually begin soon after the shot and last 1 or 2 days. Your doctor can tell you ...

Electromagnetism; Problems and solutions

NASA Astrophysics Data System (ADS)

Ilie, Carolina C.; Schrecengost, Zachariah S.

2016-11-01

Electromagnetism: Problems and solutions is an ideal companion book for the undergraduate student-sophomore, junior, or senior-who may want to work on more problems and receive immediate feedback while studying. Each chapter contains brief theoretical notes followed by the problem text with the solution and ends with a brief bibliography. Also presented are problems more general in nature, which may be a bit more challenging.

The Problem-Solving Process in Physics as Observed When Engineering Students at University Level Work in Groups

ERIC Educational Resources Information Center

Gustafsson, Peter; Jonsson, Gunnar; Enghag, Margareta

2015-01-01

The problem-solving process is investigated for five groups of students when solving context-rich problems in an introductory physics course included in an engineering programme. Through transcripts of their conversation, the paths in the problem-solving process have been traced and related to a general problem-solving model. All groups exhibit…

Integrating counselling into general practice.

PubMed

Stone, L; Blashki, G

2000-03-01

General practice counselling has many significant differences to counselling in other settings. General practitioners have long term relationships with their patients involving physical as well as mental health care. General practitioners are often the first point of contact for distressed patients who may not perceive their problem to have a psychological basis. There are barriers to counselling including time management and cultural expectations of the consultation. To outline a practical biopsychosocial model for counselling in the general practice setting using the knowledge and skills unique to each GP. Theoretical and practical barriers to counselling commonly encountered in general practice are discussed. Assessing the problem in a biopsychosocial format highlights strengths and skills the patient already possesses and involves consideration of physical sensations, emotions, behaviours, key relationships, family, social roles and resources. Counselling in general practice requires flexibility and an ability to adapt available resources to address patient needs in an individually appropriate way.

Problem of time: facets and Machian strategy.

PubMed

Anderson, Edward

2014-10-01

The problem of time is that "time" in each of ordinary quantum theory and general relativity are mutually incompatible notions. This causes difficulties in trying to put these two theories together to form a theory of quantum gravity. The problem of time has eight facets in canonical approaches. I clarify that all but one of these facets already occur at the classical level, and reconceptualize and re-name some of these facets as follows. The frozen formalism problem becomes temporal relationalism, the thin sandwich problem becomes configurational relationalism, via the notion of best matching. The problem of observables becomes the problem of beables, and the functional evolution problem becomes the constraint closure problem. I also outline how each of the global and multiple-choice problems of time have their own plurality of facets. This article additionally contains a local resolution to the problem of time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical, and a combined semiclassical-histories-timeless records scheme. I end by delineating the current frontiers of this program toward resolution of the problem of time in the cases of full general relativity and of slightly inhomogeneous cosmology. © 2014 New York Academy of Sciences.

Closed set of the uniqueness conditions and bifurcation criteria in generalized coupled thermoplasticity for small deformations

NASA Astrophysics Data System (ADS)

Śloderbach, Zdzisław

2016-05-01

This paper reports the results of a study into global and local conditions of uniqueness and the criteria excluding the possibility of bifurcation of the equilibrium state for small strains. The conditions and criteria are derived on the basis of an analysis of the problem of uniqueness of a solution involving the basic incremental boundary problem of coupled generalized thermo-elasto-plasticity. This work forms a follow-up of previous research (Śloderbach in Bifurcations criteria for equilibrium states in generalized thermoplasticity, IFTR Reports, 1980, Arch Mech 3(35):337-349, 351-367, 1983), but contains a new derivation of global and local criteria excluding a possibility of bifurcation of an equilibrium state regarding a comparison body dependent on the admissible fields of stress rate. The thermal elasto-plastic coupling effects, non-associated laws of plastic flow and influence of plastic strains on thermoplastic properties of a body were taken into account in this work. Thus, the mathematical problem considered here is not a self-conjugated problem.

On the inherent competition between valid and spurious inductive inferences in Boolean data

NASA Astrophysics Data System (ADS)

Andrecut, M.

Inductive inference is the process of extracting general rules from specific observations. This problem also arises in the analysis of biological networks, such as genetic regulatory networks, where the interactions are complex and the observations are incomplete. A typical task in these problems is to extract general interaction rules as combinations of Boolean covariates, that explain a measured response variable. The inductive inference process can be considered as an incompletely specified Boolean function synthesis problem. This incompleteness of the problem will also generate spurious inferences, which are a serious threat to valid inductive inference rules. Using random Boolean data as a null model, here we attempt to measure the competition between valid and spurious inductive inference rules from a given data set. We formulate two greedy search algorithms, which synthesize a given Boolean response variable in a sparse disjunct normal form, and respectively a sparse generalized algebraic normal form of the variables from the observation data, and we evaluate numerically their performance.

A comparison of morbidity in the Australian Defence Force with Australian general practice.

PubMed

Neath, A T; Quail, G G

2001-01-01

This study was designed to examine morbidity patterns among Australian Defence Forces members and to compare them with civilian general practice. The study was conducted in the outpatient departments of the Royal Australian Air Force (RAAF) No. 6 Hospital, Melbourne, Australia. The patients studied were male and female members of the RAAF (66%), Army (25%), and Navy (9%). The problems managed at all primary care consultations during 1993 and 1994 were coded using the Ninth Revision of the International Classification of Diseases (Clinical Modification). The codes were grouped and compared against a major study of Australian general practice. In the 6 Hospital study, 21,910 problems were managed at 19,909 consultations. The main differences found between the two studies were that service personnel had more medical examinations, more musculoskeletal and respiratory problems, and fewer psychological and cardiovascular problems. Most of the differences observed may reflect the Defence Force's recruitment selection criteria and the emphasis on physical fitness and diet.

Hybrid General Pattern Search and Simulated Annealing for Industrail Production Planning Problems

NASA Astrophysics Data System (ADS)

Vasant, P.; Barsoum, N.

2010-06-01

In this paper, the hybridization of GPS (General Pattern Search) method and SA (Simulated Annealing) incorporated in the optimization process in order to look for the global optimal solution for the fitness function and decision variables as well as minimum computational CPU time. The real strength of SA approach been tested in this case study problem of industrial production planning. This is due to the great advantage of SA for being easily escaping from trapped in local minima by accepting up-hill move through a probabilistic procedure in the final stages of optimization process. Vasant [1] in his Ph. D thesis has provided 16 different techniques of heuristic and meta-heuristic in solving industrial production problems with non-linear cubic objective functions, eight decision variables and 29 constraints. In this paper, fuzzy technological problems have been solved using hybrid techniques of general pattern search and simulated annealing. The simulated and computational results are compared to other various evolutionary techniques.

The contribution of general cognitive abilities and number abilities to different aspects of mathematics in children.

PubMed

Träff, Ulf

2013-10-01

This study examined the relative contributions of general cognitive abilities and number abilities to word problem solving, calculation, and arithmetic fact retrieval in a sample of 134 children aged 10 to 13 years. The following tasks were administered: listening span, visual matrix span, verbal fluency, color naming, Raven's Progressive Matrices, enumeration, number line estimation, and digit comparison. Hierarchical multiple regressions demonstrated that number abilities provided an independent contribution to fact retrieval and word problem solving. General cognitive abilities contributed to problem solving and calculation. All three number tasks accounted for a similar amount of variance in fact retrieval, whereas only the number line estimation task contributed unique variance in word problem solving. Verbal fluency and Raven's matrices accounted for an equal amount of variance in problem solving and calculation. The current findings demonstrate, in accordance with Fuchs and colleagues' developmental model of mathematical learning (Developmental Psychology, 2010, Vol. 46, pp. 1731-1746), that both number abilities and general cognitive abilities underlie 10- to 13-year-olds' proficiency in problem solving, whereas only number abilities underlie arithmetic fact retrieval. Thus, the amount and type of cognitive contribution to arithmetic proficiency varies between the different aspects of arithmetic. Furthermore, how closely linked a specific aspect of arithmetic is to the whole number representation systems is not the only factor determining the amount and type of cognitive contribution in 10- to 13-year-olds. In addition, the mathematical complexity of the task appears to influence the amount and type of cognitive support. Copyright © 2013 Elsevier Inc. All rights reserved.

A General Symbolic Method with Physical Applications

NASA Astrophysics Data System (ADS)

Smith, Gregory M.

2000-06-01

A solution to the problem of unifying the General Relativistic and Quantum Theoretical formalisms is given which introduces a new non-axiomatic symbolic method and an algebraic generalization of the Calculus to non-finite symbolisms without reference to the concept of a limit. An essential feature of the non-axiomatic method is the inadequacy of any (finite) statements: Identifying this aspect of the theory with the "existence of an external physical reality" both allows for the consistency of the method with the results of experiments and avoids the so-called "measurement problem" of quantum theory.

Theoretical foundations for traditional and generalized sensitivity functions for nonlinear delay differential equations.

PubMed

Banks, H Thomas; Robbins, Danielle; Sutton, Karyn L

2013-01-01

In this paper we present new results for differentiability of delay systems with respect to initial conditions and delays. After motivating our results with a wide range of delay examples arising in biology applications, we further note the need for sensitivity functions (both traditional and generalized sensitivity functions), especially in control and estimation problems. We summarize general existence and uniqueness results before turning to our main results on differentiation with respect to delays, etc. Finally we discuss use of our results in the context of estimation problems.

Some Investigations of the General Instability of Stiffened Metal Cylinders II : Preliminary Tests of Wire-braced Specimens and Theoretical Studies

NASA Technical Reports Server (NTRS)

1943-01-01

This is the second of a series of reports covering an investigation of the general instability problem by the California Institute of Technology. The first five reports of this series cover investigations of the general instability problem under the loading conditions of pure bending and were prepared under the sponsorship of the Civil Aeronautics Administration. The succeeding reports of this series cover the work done on other loading conditions under the sponsorship of the National Advisory Committee for Aeronautics.

The problem of seeing hospital staff without G.P. referral--the otolaryngological experience.

PubMed

Walshe, P; McGrain, S; Colgan, G; McShane, D

2001-01-01

Over a three month period, a record was kept of the number of hospital staff who approached the E.N.T. team requesting help for a medical problem. Staff members included doctors, nurses, clerical staff, paramedical staff and porters. The total number of employees in the hospital was recorded. The average General practitioner public patient list (General medical Service cardholders) for South Dublin was recorded (our hospital is in south west Dublin). The total number of hospital staff seen by E.N.T. in 3 months was seventy seven. The total number of hospital staff seen by other surgical specialties was approximately one hundred and sixty seven. Extrapolation of numbers seen by E.N.T. service in three months to numbers seen over a one year period is 308 patients. The numbers seen by the E.N.T. service in three months corresponds to 11.7% of the average South Dublin General Practitioner Medical card list. It has been estimated that approximately 20% of all problems the average General practitioner sees in a week are E.N.T. related. Those practices with a smaller paediatric population would have approximately 15% of the total practice concearned with E.N.T. problems. Therefore as 15% of 2,400 (total hospital staff) = 360, there is potentially a small General Practice which is 'hidden' within the hospital.

Links between Sleep and Daytime Behaviour Problems in Children with Down Syndrome

ERIC Educational Resources Information Center

Esbensen, A. J.; Hoffman, E. K.; Beebe, D. W.; Byars, K. C.; Epstein, J.

2018-01-01

Background: In the general population, sleep problems have an impact on daytime performance. Despite sleep problems being common among children with Down syndrome, the impact of sleep problems on daytime behaviours in school-age children with Down syndrome is an understudied topic. Our study examined the relationship between parent-reported and…

Time-domain finite elements in optimal control with application to launch-vehicle guidance. PhD. Thesis

NASA Technical Reports Server (NTRS)

Bless, Robert R.

1991-01-01

A time-domain finite element method is developed for optimal control problems. The theory derived is general enough to handle a large class of problems including optimal control problems that are continuous in the states and controls, problems with discontinuities in the states and/or system equations, problems with control inequality constraints, problems with state inequality constraints, or problems involving any combination of the above. The theory is developed in such a way that no numerical quadrature is necessary regardless of the degree of nonlinearity in the equations. Also, the same shape functions may be employed for every problem because all strong boundary conditions are transformed into natural or weak boundary conditions. In addition, the resulting nonlinear algebraic equations are very sparse. Use of sparse matrix solvers allows for the rapid and accurate solution of very difficult optimization problems. The formulation is applied to launch-vehicle trajectory optimization problems, and results show that real-time optimal guidance is realizable with this method. Finally, a general problem solving environment is created for solving a large class of optimal control problems. The algorithm uses both FORTRAN and a symbolic computation program to solve problems with a minimum of user interaction. The use of symbolic computation eliminates the need for user-written subroutines which greatly reduces the setup time for solving problems.

Domain General Mediators of the Relation between Kindergarten Number Sense and First-Grade Mathematics Achievement

PubMed Central

Hassinger-Das, Brenna; Jordan, Nancy C.; Glutting, Joseph; Irwin, Casey; Dyson, Nancy

2013-01-01

Domain general skills that mediate the relation between kindergarten number sense and first-grade mathematics skills were investigated. Participants were 107 children who displayed low number sense in the fall of kindergarten. Controlling for background variables, multiple regression analyses showed that attention problems and executive functioning both were unique predictors of mathematics outcomes. Attention problems were more important for predicting first-grade calculation performance while executive functioning was more important for predicting first-grade performance on applied problems. Moreover, both executive functioning and attention problems were unique partial mediators of the relationship between kindergarten and first-grade mathematics skills. The results provide empirical support for developing interventions that target executive functioning and attention problems in addition to instruction in number skills for kindergartners with initial low number sense. PMID:24237789

An expert system for choosing the best combination of options in a general purpose program for automated design synthesis

NASA Technical Reports Server (NTRS)

Rogers, J. L.; Barthelemy, J.-F. M.

1986-01-01

An expert system called EXADS has been developed to aid users of the Automated Design Synthesis (ADS) general purpose optimization program. ADS has approximately 100 combinations of strategy, optimizer, and one-dimensional search options from which to choose. It is difficult for a nonexpert to make this choice. This expert system aids the user in choosing the best combination of options based on the users knowledge of the problem and the expert knowledge stored in the knowledge base. The knowledge base is divided into three categories; constrained problems, unconstrained problems, and constrained problems being treated as unconstrained problems. The inference engine and rules are written in LISP, contains about 200 rules, and executes on DEC-VAX (with Franz-LISP) and IBM PC (with IQ-LISP) computers.

Domain-general mediators of the relation between kindergarten number sense and first-grade mathematics achievement.

PubMed

Hassinger-Das, Brenna; Jordan, Nancy C; Glutting, Joseph; Irwin, Casey; Dyson, Nancy

2014-02-01

Domain-general skills that mediate the relation between kindergarten number sense and first-grade mathematics skills were investigated. Participants were 107 children who displayed low number sense in the fall of kindergarten. Controlling for background variables, multiple regression analyses showed that both attention problems and executive functioning were unique predictors of mathematics outcomes. Attention problems were more important for predicting first-grade calculation performance, whereas executive functioning was more important for predicting first-grade performance on applied problems. Moreover, both executive functioning and attention problems were unique partial mediators of the relationship between kindergarten and first-grade mathematics skills. The results provide empirical support for developing interventions that target executive functioning and attention problems in addition to instruction in number skills for kindergartners with initial low number sense. Copyright © 2013 Elsevier Inc. All rights reserved.

Discovering Steiner Triple Systems through Problem Solving

ERIC Educational Resources Information Center

Sriraman, Bharath

2004-01-01

An attempt to implement problem solving as a teacher of ninth grade algebra is described. The problems selected were not general ones, they involved combinations and represented various situations and were more complex which lead to the discovery of Steiner triple systems.

Problem area descriptions : motor vehicle crashes - data analysis and IVI program analysis

DOT National Transportation Integrated Search

In general, the IVI program focuses on the more significant safety problem categories as : indicated by statistical analyses of crash data. However, other factors were considered in setting : program priorities and schedules. For some problem areas, ...

Spa therapy (balneotherapy) relieves mental stress, sleep disorder, and general health problems in sub-healthy people

NASA Astrophysics Data System (ADS)

Yang, Bei; Qin, Qi-zhong; Han, Ling-li; Lin, Jing; Chen, Yu

2018-02-01

To investigate the relieving effects of hot spring balneotherapy on mental stress, sleep disorder, general health problems, and women's health problems in sub-healthy people, we recruited 500 volunteers in sub-health in Chongqing, and 362 volunteers completed the project, including 223 in the intervention group and 139 in the control group. The intervention group underwent hot spring balneotherapy for 5 months, while the control group did not. The two groups took questionnaire investigation (general data, mental stress, emotional status, sleep quality, general health problems, as well as some women's health problems) and physical examination (height, weight, waist circumference, blood pressure, blood lipid, blood sugar) 5 months before and after the intervention, respectively. After intervention, sleep disorder (difficulty in falling asleep ( P = 0.017); dreaminess, nightmare suffering, and restless sleep ( P = 0.013); easy awakening ( P = 0.003) and difficulty in falling into sleep again after awakening( P = 0.016); and mental stress ( P = 0.031) and problems of general health (head pain ( P = 0.026), joint pain( P = 0.009), leg or foot cramps ( P = 0.001), blurred vision ( P = 0.009)) were relieved significantly in the intervention group, as compared with the control group. While other indicators (fatigue, eye tiredness, limb numbness, constipation, skin allergy) and women's health problems (breast distending pain; dysmenorrhea, irregular menstruation) were relieved significantly in the self-comparison of the intervention group before and after intervention ( P < 0.05), but showed no statistically significant difference between two groups ( P > 0.05). All indications (except bad mood, low mood, and worry or irritability) in the intervention group significantly improved, with effect size from 0.096 to 1.302. Multiple logistic regression analysis showed that the frequency, length, and location of balneotherapy in the intervention group were the factors influencing emotion, sleep, and health condition ( P < 0.05). Relief of insomnia, fatigue, and leg or foot cramps was greater in old-age group than in young-aged group ( P < 0.05). Physical examination found that waist circumferences in women of various ages under 55 years were significantly reduced in the intervention group ( P < 0.05), while that in men did not significantly change ( P > 0.05). Spa therapy (balneotherapy) relieves mental stress, sleep disorder, general health, and reduces women's waist circumferences in sub-healthy people.

Perceptions of emotion expression and sibling-parent emotion communication in Latino and non-Latino white siblings of children with intellectual disabilities.

PubMed

Long, Kristin A; Lobato, Debra; Kao, Barbara; Plante, Wendy; Grullón, Edicta; Cheas, Lydia; Houck, Christopher; Seifer, Ronald

2013-06-01

Examine general emotion expression and sibling-parent emotion communication among Latino and non-Latino white (NLW) siblings of children with intellectual disabilities (ID) and matched comparisons. 200 siblings (ages 8-15 years) completed the newly developed Sibling-Parent Emotion Communication Scale and existing measures of general emotion expression and psychosocial functioning. Preliminary analyses evaluated scale psychometrics across ethnicity. Structure and internal consistency of the emotion expression and communication measures differed by respondent ethnicity. Latino siblings endorsed more general emotion expression problems and marginally lower sibling-parent emotion communication than NLW siblings. Siblings of children with ID reported marginally more general emotion expression problems than comparisons. Emotion expression problems and lower sibling-parent emotion communication predicted more internalizing and somatic symptoms and poorer personal adjustment, regardless of ID status. Siblings of children with ID endorsed poorer personal adjustment. Cultural differences in emotion expression and communication may increase Latino siblings' risk for emotional adjustment difficulties.

Development of Curriculum in American Civilization for the General Student: Case Study Approach. Final Report.

ERIC Educational Resources Information Center

Gibson, John S.; Kenosian, Elisabeth M.

Case studies in each of the parts deal with specific problems in the mainstream of United States history and are designed to help the general level student relate the case study and the theme of the past to similar problems today. Each theme deals with the resolution of conflict in historical ideologies. 1) Studies on intolerance in American life…

Parent Training on Generalized Use of Behavior Analytic Strategies for Decreasing the Problem Behavior of Children with Autism Spectrum Disorder: A Data-Based Case Study

ERIC Educational Resources Information Center

Crone, Regina M.; Mehta, Smita Shukla

2016-01-01

Setting variables such as location of parent training, programming with common stimuli, generalization of discrete responses to non-trained settings, and subsequent reduction in child problem behavior may influence the effectiveness of interventions. The purpose of this study was to evaluate the effectiveness of home-versus clinic-based training…

Executive functions and behavioral problems in deaf and hard-of-hearing students at general and special schools.

PubMed

Hintermair, Manfred

2013-01-01

In this study, behavioral problems of deaf and hard-of-hearing (D/HH) school-aged children are discussed in the context of executive functioning and communicative competence. Teachers assessed the executive functions of a sample of 214 D/HH students from general schools and schools for the deaf, using a German version of the Behavior Rating Inventory of Executive Functions (BRIEF-D). This was complemented by a questionnaire that measured communicative competence and behavioral problems (German version of the Strengths and Difficulties Questionnaire; SDQ-D). The results in nearly all the scales show a significantly higher problem rate for executive functions in the group of D/HH students compared with a normative sample of hearing children. In the D/HH group, students at general schools had better scores on most scales than students at schools for the deaf. Regression analysis reveals the importance of executive functions and communicative competence for behavioral problems. The relevance of the findings for pedagogical work is discussed. A specific focus on competencies such as self-efficacy or self-control in educational concepts for D/HH students seems to be necessary in addition to extending language competencies.

Tobacco-related mortality among persons with mental health and substance abuse problems.

PubMed

Bandiera, Frank C; Anteneh, Berhanu; Le, Thao; Delucchi, Kevin; Guydish, Joseph

2015-01-01

The rate of cigarette smoking is greater among persons with mental health and/or substance abuse problems. There are few population-based datasets with which to study tobacco mortality in these vulnerable groups. The Oregon Health Authority identified persons who received publicly-funded mental health or substance abuse services from January 1996 through December 2005. These cases were then matched to Oregon Vital Statistics records for all deaths (N= 148,761) in the period 1999-2005. The rate of tobacco-related death rates was higher among persons with substance abuse problems only (53.6%) and those with both substance abuse and mental health problems (46.8%), as compared to the general population (30.7%). The rate of tobacco-related deaths among persons with mental health problems (30%) was similar to that in the general population. Persons receiving substance abuse treatment alone, or receiving both substance abuse and mental health treatment, were more likely to die and more likely to die prematurely of tobacco-related causes as compared to the general population. Persons receiving mental health services alone were not more likely to die of tobacco-related causes, but tobacco-related deaths occurred earlier in this population.

Run-time scheduling and execution of loops on message passing machines

NASA Technical Reports Server (NTRS)

Crowley, Kay; Saltz, Joel; Mirchandaney, Ravi; Berryman, Harry

1989-01-01

Sparse system solvers and general purpose codes for solving partial differential equations are examples of the many types of problems whose irregularity can result in poor performance on distributed memory machines. Often, the data structures used in these problems are very flexible. Crucial details concerning loop dependences are encoded in these structures rather than being explicitly represented in the program. Good methods for parallelizing and partitioning these types of problems require assignment of computations in rather arbitrary ways. Naive implementations of programs on distributed memory machines requiring general loop partitions can be extremely inefficient. Instead, the scheduling mechanism needs to capture the data reference patterns of the loops in order to partition the problem. First, the indices assigned to each processor must be locally numbered. Next, it is necessary to precompute what information is needed by each processor at various points in the computation. The precomputed information is then used to generate an execution template designed to carry out the computation, communication, and partitioning of data, in an optimized manner. The design is presented for a general preprocessor and schedule executer, the structures of which do not vary, even though the details of the computation and of the type of information are problem dependent.

Run-time scheduling and execution of loops on message passing machines

NASA Technical Reports Server (NTRS)

Saltz, Joel; Crowley, Kathleen; Mirchandaney, Ravi; Berryman, Harry

1990-01-01

Sparse system solvers and general purpose codes for solving partial differential equations are examples of the many types of problems whose irregularity can result in poor performance on distributed memory machines. Often, the data structures used in these problems are very flexible. Crucial details concerning loop dependences are encoded in these structures rather than being explicitly represented in the program. Good methods for parallelizing and partitioning these types of problems require assignment of computations in rather arbitrary ways. Naive implementations of programs on distributed memory machines requiring general loop partitions can be extremely inefficient. Instead, the scheduling mechanism needs to capture the data reference patterns of the loops in order to partition the problem. First, the indices assigned to each processor must be locally numbered. Next, it is necessary to precompute what information is needed by each processor at various points in the computation. The precomputed information is then used to generate an execution template designed to carry out the computation, communication, and partitioning of data, in an optimized manner. The design is presented for a general preprocessor and schedule executer, the structures of which do not vary, even though the details of the computation and of the type of information are problem dependent.

Discrete Time McKean–Vlasov Control Problem: A Dynamic Programming Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pham, Huyên, E-mail: pham@math.univ-paris-diderot.fr; Wei, Xiaoli, E-mail: tyswxl@gmail.com

We consider the stochastic optimal control problem of nonlinear mean-field systems in discrete time. We reformulate the problem into a deterministic control problem with marginal distribution as controlled state variable, and prove that dynamic programming principle holds in its general form. We apply our method for solving explicitly the mean-variance portfolio selection and the multivariate linear-quadratic McKean–Vlasov control problem.

Photometric theory for wide-angle phenomena

NASA Technical Reports Server (NTRS)

Usher, Peter D.

1990-01-01

An examination is made of the problem posed by wide-angle photographic photometry, in order to extract a photometric-morphological history of Comet P/Halley. Photometric solutions are presently achieved over wide angles through a generalization of an assumption-free moment-sum method. Standard stars in the field allow a complete solution to be obtained for extinction, sky brightness, and the characteristic curve. After formulating Newton's method for the solution of the general nonlinear least-square problem, an implementation is undertaken for a canonical data set. Attention is given to the problem of random and systematic photometric errors.

Modeling the missile-launch tube problem in DYSCO

NASA Technical Reports Server (NTRS)

Berman, Alex; Gustavson, Bruce A.

1989-01-01

DYSCO is a versatile, general purpose dynamic analysis program which assembles equations and solves dynamics problems. The executive manages a library of technology modules which contain routines that compute the matrix coefficients of the second order ordinary differential equations of the components. The executive performs the coupling of the equations of the components and manages the solution of the coupled equations. Any new component representation may be added to the library if, given the state vector, a FORTRAN program can be written to compute M, C, K, and F. The problem described demonstrates the generality of this statement.

Could HPS Improve Problem-Solving?

NASA Astrophysics Data System (ADS)

Coelho, Ricardo Lopes

2013-05-01

It is generally accepted nowadays that History and Philosophy of Science (HPS) is useful in understanding scientific concepts, theories and even some experiments. Problem-solving strategies are a significant topic, since students' careers depend on their skill to solve problems. These are the reasons for addressing the question of whether problem solving could be improved by means of HPS. Three typical problems in introductory courses of mechanics—the inclined plane, the simple pendulum and the Atwood machine—are taken as the object of the present study. The solving strategies of these problems in the eighteenth and nineteenth century constitute the historical component of the study. Its philosophical component stems from the foundations of mechanics research literature. The use of HPS leads us to see those problems in a different way. These different ways can be tested, for which experiments are proposed. The traditional solving strategies for the incline and pendulum problems are adequate for some situations but not in general. The recourse to apparent weights in the Atwood machine problem leads us to a new insight and a solving strategy for composed Atwood machines. Educational implications also concern the development of logical thinking by means of the variety of lines of thought provided by HPS.

Down Syndrome: A Current Perspective. Bulletin 1762.

ERIC Educational Resources Information Center

Louisiana State Dept. of Education, Baton Rouge.

This informational document is intended to help answer questions commonly asked by families, professionals, and the general public concerning Down Syndrome. Medical problems associated with Down Syndrome include heart conditions, upper respiratory disorders, ear infections and hearing loss, vision/eye problems, cervical problems, and…

Will there be a good general surgeon when you need one? (Part II) Solutions and taking back general surgery.

PubMed

Smith, Richard; Stain, Steven C; McFadden, David W; Finlayson, Samuel R G; Jones, Daniel B; Reid-Lombardo, K Marie

2014-07-01

Multiple reports have cited the looming shortage of physicians over the next decades related to increasing demand, an aging of the population, and a stagnant level in the production of new physicians. General surgery shares in this problem, and the specialty is "stressed" by a declining workforce related to increasing specialization that leaves gaps in emergency, trauma, and rural surgical care. The Society of Surgery of the Alimentary Tract (SSAT) Public Policy and Advocacy Committee sponsored panel discussions regarding the general surgery workforce shortage at the Digestive Disease Week 2012 and 2013 meetings. The 2012 panel focused on defining the problem. This is the summation of the series with the solutions to the general surgery workforce shortage as offered by the 2013 panel.

High prevalence of insomnia and hypnotic use in patients visiting their general practitioner.

PubMed

Bjorvatn, Bjørn; Meland, Eivind; Flo, Elisabeth; Mildestvedt, Thomas

2017-02-01

Sleep problems are common in the general population, but there are few prevalence studies among patients visiting their GP. Since sleep problems frequently co-occur with existing psychological and somatic conditions, the prevalence is likely to be higher in patients visiting their GPs compared to the prevalence in the general population. To estimate the prevalence of insomnia [based on the Diagnostic and Statistical Manual for Mental disorders (DSM)-version IV] and hypnotic use among patients in general practice and to evaluate whether the prevalence depended on sex and age. Questionnaire data were collected by 66 medical students while deployed in different general practices during their last year of school. A total of 1346 (response rate 74%) consecutive and unselected patients visiting their GPs answered the validated Bergen Insomnia Scale (BIS) and single questions on self-reported sleep problems and hypnotic use. The prevalence of insomnia according to BIS was 53.6%. Sleep problems (based on the single question) were self-reported by 55.8%, with 18.0% reporting to experience sleep problems a lot/very much. Hypnotic use was reported by 16.2% (daily use by 5.5%). Insomnia and hypnotic use were all more prevalent in females compared with males. Hypnotic use increased with age, whereas the prevalence of insomnia was highest in the younger age groups. Insomnia and hypnotic use were very prevalent among patients visiting their GPs. As insomnia can be effectively treated, we maintain that the diagnosis has a high pay-off and should earn greater awareness in GP's diagnostic evaluation and management. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A pressurized cylindrical shell with a fixed end which contains an axial part-through or through crack

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1985-01-01

In this paper a cylindrical shell having a very stiff end plate or a flange is considered. It is assumed that near the end the cylinder contains an axial flow which may be modeled as a part-through surface crack or through crack. The primary objective is to study the effect of the end constraining on the stress intensity factor which is the main fracture mechanics parameter. The applied loads acting on the cylinder are assumed to be axisymmetric. Thus the crack problem under consideration is symmetric with respect to the plane of the crack and consequently only the mode I stress intensity factors are nonzero. With this limitation, the general perturbation problem for a cylinder with a built-in end containing an axial crack is considered. Reissner's shell theory is used to formulate the problem. The part-through crack problem is treated by using a line-spring model. In the case of a crack tip terminating at the fixed end it is shown that the integral equation of the shell problem has the same generalized Cauchy kernel as the corresponding plane stress elasticity problem. Even though the problem is formulated for a general surface crack profile and arbitrary crack surface tractions, the numerical results are obtained only for a semielliptic part-through axial crack located at the inside or outside surface of the cylinder and for internal pressure acting on the cylinder. The stress intensity factors are calculated and presented for a relatively wide range of dimensionless length parameters of the problem.

Characteristics of primary care consultations for musculoskeletal foot and ankle problems in the UK.

PubMed

Menz, Hylton B; Jordan, Kelvin P; Roddy, Edward; Croft, Peter R

2010-07-01

Foot and ankle problems are highly prevalent in the general population; however, little is known about the characteristics of those seeking medical assessment for these problems. The objective of this study was to explore the extent and types of musculoskeletal foot and ankle problems in primary care. Consultation data related to musculoskeletal foot and ankle problems in 2006 were extracted from the Consultations in Primary Care Archive (CiPCA), which covers consultations in 12 general practices in North Staffordshire. Data were cross-tabulated by age and gender, and annual consultation prevalence per 10,000 registered persons was calculated. Of the 55,033 musculoskeletal consultations documented in CiPCA in 2006, 4500 (8%) related to foot and ankle problems. The most commonly documented Read term was 'foot pain' (1281 consultations; 28%), followed by 'ankle pain' [451 (10%)]. Most consultations [3538 (79%)] involved non-traumatic conditions. Females accounted for slightly more consultations than males (55 vs 45%), and the highest proportion of consultations involved people aged 45-64 years (36%). The number of consultations per patient ranged from 1 to 11. Annual consultation prevalence was 290 per 10,000 registered persons and increased with age, reaching a peak in the 65- to 74-year age group (411 per 10,000 registered persons). Foot and ankle problems account for a substantial number of consultations in primary care, and most frequently involve non-traumatic conditions. Further research is required to evaluate the factors that influence consultation for foot problems and strategies that general practitioners use to manage these conditions.

[Recommendations for overcoming interface problems in medical rehabilitation of federal pension funds and statutory health insurance].

PubMed

Pohontsch, N; Träder, J-M; Scherer, M; Deck, R

2013-10-01

Interface problems in medical rehabilitation are a consequence of problems with communication and cooperation, lack of information and transparency. Different stakeholders are trying to solve these problems since many years or decades respectively. Following a series of deficit-oriented studies we tried to develop recommendations for possible solutions of important interface problems together with affected people based on a qualitative analysis of main problem areas. 10 separate group discussions with rehabilitation patients, general practitioners and specialists in private practices, representatives of the federal pension fund and statutory health insurance as well as clinicians from rehabilitation clinics and 3 mixed group discussions (all before mentioned groups excluding rehabilitation patients) were conducted. These group discussions served to prepare a semidiurnal final conference. All meetings were recorded and content analyzed or summarized in protocols respectively. Results are recommendations on strategies to reduce interface problems in medical rehabilitation. Those are: development of a rehabilitation-information-website for insurees and general practitioners and specialists in private practices; changes in forms, applications, notifications; advanced training for general practitioners and specialists in private practices und support in detecting rehabilitation need. Due to divided structures of care provision and increasing specialization, overcoming interface problems is one of the main challenges in the provision of medical rehabilitation. It can be met if different stakeholder approach each other without prejudices, share instead of demarcate competencies and are willing to strike new paths. Our recommendations represent the first step to reaching this goal. © Georg Thieme Verlag KG Stuttgart · New York.

Association between speech-language, general cognitive functioning and behaviour problems in individuals with Williams syndrome.

PubMed

Rossi, N F; Giacheti, C M

2017-07-01

Williams syndrome (WS) phenotype is described as unique and intriguing. The aim of this study was to investigate the associations between speech-language abilities, general cognitive functioning and behavioural problems in individuals with WS, considering age effects and speech-language characteristics of WS sub-groups. The study's participants were 26 individuals with WS and their parents. General cognitive functioning was assessed with the Wechsler Intelligence Scale. Peabody Picture Vocabulary Test, Token Test and the Cookie Theft Picture test were used as speech-language measures. Five speech-language characteristics were evaluated from a 30-min conversation (clichés, echolalia, perseverative speech, exaggerated prosody and monotone intonation). The Child Behaviour Checklist (CBCL 6-18) was used to assess behavioural problems. Higher single-word receptive vocabulary and narrative vocabulary were negatively associated with CBCL T-scores for Social Problems, Aggressive Behaviour and Total Problems. Speech rate was negatively associated with the CBCL Withdrawn/Depressed T-score. Monotone intonation was associated with shy behaviour, as well as exaggerated prosody with talkative behaviour. WS with perseverative speech and exaggerated prosody presented higher scores on Thought Problems. Echolalia was significantly associated with lower Verbal IQ. No significant association was found between IQ and behaviour problems. Age-associated effects were observed only for the Aggressive Behaviour scale. Associations reported in the present study may represent an insightful background for future predictive studies of speech-language, cognition and behaviour problems in WS. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Characteristics of primary care consultations for musculoskeletal foot and ankle problems in the UK

PubMed Central

Jordan, Kelvin P.; Roddy, Edward; Croft, Peter R.

2010-01-01

Objective. Foot and ankle problems are highly prevalent in the general population; however, little is known about the characteristics of those seeking medical assessment for these problems. The objective of this study was to explore the extent and types of musculoskeletal foot and ankle problems in primary care. Methods. Consultation data related to musculoskeletal foot and ankle problems in 2006 were extracted from the Consultations in Primary Care Archive (CiPCA), which covers consultations in 12 general practices in North Staffordshire. Data were cross-tabulated by age and gender, and annual consultation prevalence per 10 000 registered persons was calculated. Results. Of the 55 033 musculoskeletal consultations documented in CiPCA in 2006, 4500 (8%) related to foot and ankle problems. The most commonly documented Read term was ‘foot pain’ (1281 consultations; 28%), followed by ‘ankle pain’ [451 (10%)]. Most consultations [3538 (79%)] involved non-traumatic conditions. Females accounted for slightly more consultations than males (55 vs 45%), and the highest proportion of consultations involved people aged 45–64 years (36%). The number of consultations per patient ranged from 1 to 11. Annual consultation prevalence was 290 per 10 000 registered persons and increased with age, reaching a peak in the 65- to 74-year age group (411 per 10 000 registered persons). Conclusion. Foot and ankle problems account for a substantial number of consultations in primary care, and most frequently involve non-traumatic conditions. Further research is required to evaluate the factors that influence consultation for foot problems and strategies that general practitioners use to manage these conditions. PMID:20403912

Sexual problems in people with refractory epilepsy.

PubMed

Henning, Oliver J; Nakken, Karl O; Træen, Bente; Mowinckel, Petter; Lossius, Morten

2016-08-01

Sexual dysfunction is an important but often neglected aspect of epilepsy. The objective of this study was to explore the prevalence and types of sexual problems in patients with epilepsy and compare the results with similar data obtained from a representative sample of the general population. At the National Centre for Epilepsy in Norway, 171 of 227 consecutive adult inpatients and outpatients with epilepsy (response rate: 75.3%) and their neurologists participated in a questionnaire study about epilepsy and sexuality. The results were compared with data available from 594 adult Norwegians who had completed the same questionnaire. Patients with epilepsy had a significantly higher prevalence of sexual problems (women: 75.3% vs. 12.0%; men: 63.3% vs. 9.6%). The most commonly reported problems (>30%) were reduced sexual desire, orgasm problems, erection problems, and vaginal dryness. The patients reported considerable dissatisfaction regarding sexual functioning. Significantly more sexual problems were found in patients of both sexes with reduced quality of life and in women with symptoms of depression. We found no significant association between sexual problems and age of epilepsy onset, type of epilepsy, or use of enzyme-inducing antiepileptic drugs. Whereas age at sexual debut did not differ between the patients with epilepsy and the general population, men with epilepsy had a lower number of partners during the last 12months, and the proportion of women with a low frequency of intercourse was higher in the group with epilepsy. In conclusion, sexual problems are significantly greater in Norwegian patients with epilepsy than in the general adult population. As no single epilepsy type or treatment could be identified as a specific predisposing factor, it seems likely that there are multiple causes underlying our results, including both organic and psychosocial factors. Copyright © 2016 Elsevier Inc. All rights reserved.

Priority setting in general practice: health priorities of older patients differ from treatment priorities of their physicians.

PubMed

Voigt, Isabel; Wrede, Jennifer; Diederichs-Egidi, Heike; Dierks, Marie-Luise; Junius-Walker, Ulrike

2010-12-01

To ascertain health priorities of older patients and treatment priorities of their general practitioners (GP) on the basis of a geriatric assessment and to determine the agreement between these priorities. The study included a sample of 9 general practitioners in Hannover, Germany, and a stratified sample of 35 patients (2-5 patients per practice, 18 female, average age 77.7 years). Patients were given a geriatric assessment using the Standardized Assessment for Elderly Patients in Primary Care (STEP) to gain an overview of their health and everyday problems. On the basis of these results, patients and their physicians independently rated the importance of each problem disclosed by the assessment. Whereas patients assessed the importance for their everyday lives, physicians assessed the importance for patients' medical care and patients' everyday lives. Each patient had a mean ± standard deviation of 18 ± 9.2 health problems. Thirty five patients disclosed a total of 634 problems; 537 (85%) were rated by patients and physicians. Of these 537 problems, 332 (62%) were rated by patients and 334 (62%) by physicians as important for patients' everyday lives. In addition, 294 (55%) were rated by physicians as important for patients' medical care. Although these proportions of important problems were similar between patients and physicians, there was little overlap in the specific problems that each group considered important. The chance-corrected agreement (Cohen κ) between patients and physicians on the importance of problems for patients' lives was low (κ=0.23). Likewise, patients and physicians disagreed on the problems that physicians considered important for patients' medical care (κ=0.18, P<0.001 for each). The low agreement on health and treatment priorities between patients and physicians necessitates better communication between the two parties to strengthen mutual understanding.

Cold intolerance

MedlinePlus

Some causes of cold intolerance are: Anemia Anorexia nervosa Blood vessel problems, such as Raynaud phenomenon Chronic severe illness General poor health Underactive thyroid ( hypothyroidism ) Problem with the hypothalamus (a part ...

Toward Modeling the Intrinsic Complexity of Test Problems

ERIC Educational Resources Information Center

Shoufan, Abdulhadi

2017-01-01

The concept of intrinsic complexity explains why different problems of the same type, tackled by the same problem solver, can require different times to solve and yield solutions of different quality. This paper proposes a general four-step approach that can be used to establish a model for the intrinsic complexity of a problem class in terms of…

Singular optimal control and the identically non-regular problem in the calculus of variations

NASA Technical Reports Server (NTRS)

Menon, P. K. A.; Kelley, H. J.; Cliff, E. M.

1985-01-01

A small but interesting class of optimal control problems featuring a scalar control appearing linearly is equivalent to the class of identically nonregular problems in the Calculus of Variations. It is shown that a condition due to Mancill (1950) is equivalent to the generalized Legendre-Clebsch condition for this narrow class of problems.

Usefulness of Cognitive Intervention Programmes for Socio-Emotional and Behaviour Problems in Children with Learning Disabilities

ERIC Educational Resources Information Center

Schnitzer, Gila; Andries, Caroline; Lebeer, Jo

2007-01-01

Behavioural and emotional problems occur more frequently in children with learning problems than in a cross-section of the general population, both at home and at school. While behaviour problems reportedly are a key obstructive factor impeding inclusive education, children with both behavioural and learning disabilities carry a high risk of…

Math Ties: Problem Solving, Logic Teasers, and Math Puzzles All "Tied" to the Math Curriculum. Book A1.

ERIC Educational Resources Information Center

Santi, Terri

This book contains a classroom-tested approach to the teaching of problem solving to all students in Grades 4-6, regardless of ability. Information on problem solving in general is provided, then mathematical problems on logic, whole numbers, number theory, fractions, decimals, geometry, ratio, proportion, percent, probability, sets, and…

CHEMEX; Understanding and Solving Problems in Chemistry. A Computer-Assisted Instruction Program for General Chemistry.

ERIC Educational Resources Information Center

Lower, Stephen K.

A brief overview of CHEMEX--a problem-solving, tutorial style computer-assisted instructional course--is provided and sample problems are offered. In CHEMEX, students receive problems in advance and attempt to solve them before moving through the computer program, which assists them in overcoming difficulties and serves as a review mechanism.…

Parent and Teacher Perspectives about Problem Behavior in Children with Williams Syndrome

ERIC Educational Resources Information Center

Klein-Tasman, Bonita P.; Lira, Ernesto N.; Li-Barber, Kirsten T.; Gallo, Frank J.; Brei, Natalie G.

2015-01-01

Problem behavior of 52 children with Williams syndrome ages 6 to 17 years old was examined based on both parent and teacher report. Generally good inter-rater agreement was found. Common areas of problem behavior based both on parent and teacher report included attention problems, anxiety difficulties, repetitive behaviors (e.g., obsessions,…

Rewarding Multitasking: Negative Effects of an Incentive on Problem Solving under Divided Attention

ERIC Educational Resources Information Center

Wieth, Mareike B.; Burns, Bruce D.

2014-01-01

Research has consistently shown negative effects of multitasking on tasks such as problem solving. This study was designed to investigate the impact of an incentive when solving problems in a multitasking situation. Incentives have generally been shown to increase problem solving (e.g., Wieth & Burns, 2006), however, it is unclear whether an…

Outcomes of childhood conduct problem trajectories in early adulthood: findings from the ALSPAC study.

PubMed

Kretschmer, Tina; Hickman, Matthew; Doerner, Rita; Emond, Alan; Lewis, Glyn; Macleod, John; Maughan, Barbara; Munafò, Marcus R; Heron, Jon

2014-07-01

Although conduct problems in childhood are stably associated with problem outcomes, not every child who presents with conduct problems is at risk. This study extends previous studies by testing whether childhood conduct problem trajectories are predictive of a wide range of other health and behavior problems in early adulthood using a general population sample. Based on 7,218 individuals from the Avon longitudinal study of parents and children, a three-step approach was used to model childhood conduct problem development and identify differences in early adult health and behavior problems. Childhood conduct problems were assessed on six occasions between age 4 and 13 and health and behavior outcomes were measured at age 18. Individuals who displayed early-onset persistent conduct problems throughout childhood were at greater risk for almost all forms of later problems. Individuals on the adolescent-onset conduct problem path consumed more tobacco and illegal drugs and engaged more often in risky sexual behavior than individuals without childhood conduct problems. Levels of health and behavior problems for individuals on the childhood-limited path were in between those for stable low and stable high trajectories. Childhood conduct problems are pervasive and substantially affect adjustment in early adulthood both in at-risk samples as shown in previous studies, but also in a general population sample. Knowing a child's developmental course can help to evaluate the risk for later maladjustment and be indicative of the need for early intervention.

Acting on Information: Representing Actions That Manipulate Information

NASA Technical Reports Server (NTRS)

Golden, Keith

1999-01-01

Information manipulation is the creation of new information based on existing information sources. This paper discusses problems that arise when planning for information manipulation, and proposes a novel action representation, called ADLIM, that addresses these problems, including: How to represent information in a way sufficient to express the effects of actions that modify the information. I present a simple, yet expressive, representation of information goals and effects that generalizes earlier work on representing sensing actions; How to concisely represent actions that copy information, or produce new information that is based on existing information sources. I show how this is a generalization of the frame problem, and present a solution based on generalized frame effects; and How to generate a pipeline of information-processing commands that will produce an output containing exactly the desired information. I present a new approach to goal regression.

Memory-dependent derivatives for photothermal semiconducting medium in generalized thermoelasticity with two-temperature

NASA Astrophysics Data System (ADS)

Lotfy, K.; Sarkar, N.

2017-11-01

In this work, a novel generalized model of photothermal theory with two-temperature thermoelasticity theory based on memory-dependent derivative (MDD) theory is performed. A one-dimensional problem for an elastic semiconductor material with isotropic and homogeneous properties has been considered. The problem is solved with a new model (MDD) under the influence of a mechanical force with a photothermal excitation. The Laplace transform technique is used to remove the time-dependent terms in the governing equations. Moreover, the general solutions of some physical fields are obtained. The surface taken into consideration is free of traction and subjected to a time-dependent thermal shock. The numerical Laplace inversion is used to obtain the numerical results of the physical quantities of the problem. Finally, the obtained results are presented and discussed graphically.