1,293 research outputs found
Calculating the Galois Group of Y′===AY+++B,Y′===AY Completely Reducible
No full textAbstractWe consider a special case of the problem of computing the Galois group of a system of linear ordinary differential equations Y′=MY, M∈C (x)n×n. We assume that C is a computable, characteristic-zero, algebraically closed constant field with a factorization algorithm. There exists a decision procedure, due to Compoint and Singer, to compute the group in case the system is completely reducible. Berman and Singer (1999, J. Pure Appl. Algebr., 139, 3–23) address the case in which M= [yjsco5390x.gif M 1 * 0 M 2 ], Y′=MiY completely reducible for i= 1, 2. Their article shows how to reduce that case to the case of an inhomogeneous system Y′=AY+B, A∈C (x)n×n, B∈C (x)n, Y′=AY completely reducible. Their article further presents a decision procedure to reduce this inhomogeneous case to the case of the associated homogeneous system Y′=AY. The latter reduction involves using a cyclic-vector algorithm to find an equivalent inhomogeneous scalar equation L(y) =b,L∈C(x)[ D ], b∈C (x), then computing a certain set of factorizations of L in C(x)[D ]; this set is very large and difficult to compute in general. In this article, we give a new and more efficient algorithm to reduce the case of a system Y′=AY+B,Y′=AY completely reducible, to that of the associated homogeneous systemY′=AY. The new method’s improved efficiency comes from replacing the large set of factorizations required by the Berman–Singer method with a single block-diagonal decomposition of the coefficient matrix satisfying certain properties
Computing Galois Groups for Certain Classes of Ordinary Differential Equations
No full textAs of now, it is an open problem to find an algorithmthat computes the Galois group G of an arbitrary linear ordinary differential operator L in C(x)[D]. We assume thatC is a computable, characteristic-zero,algebraically closed constant field with factorization algorithm.In this dissertation, we present new methods forcomputing differential Galois groups in two special cases.An article by Compoint and Singer presents a decision procedure to compute G in case L is completely reducible or, equivalently, G is reductive. Here, we present the results of an article by Berman and Singerthat reduces the case of a productof two completely reducible operators to thatof a single completely reducible operator;moreover, we give an optimization of that article's core decision procedure.These results rely on results from cohomologydue to Daniel Bertrand.We also give a set of criteria to compute the Galois group of a differential equation of the formy⁽³⁾ + ay' + by = 0, a, b in C[x].Furthermore, we present an algorithm to carry out this computation in case C is the field of algebraic numbers.This algorithm applies the approach used inan article by M. van der Put to study order-two equations with one or two singularpoints. Each step of the algorithm employs a simple, implementable test based on some combination of factorization properties, properties of associated operators,and testing of associated equations for rational solutions. Examples of the algorithm and a Maple implementation writtenby the author are provided
Por um projeto de tradução estrangeirizante: Dr. Faustus, uma tradução comentada e anotada
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-graduação em Estudos da TraduçãoConsiderando, de modo geral, as pesquisas realizadas acerca da tradução e das implicações que envolvem a sua realização, no Brasil, percebemos um intenso movimento de descrição dos processos tradutórios, análise dos estudos realizados por teóricos da tradução e análise de traduções cujo foco, normalmente, direciona-se aos chamados "problemas de tradução", como, por exemplo, a tradução de metáforas, a não correspondência entre os léxicos das línguas envolvidas e questões relacionadas aos aspectos culturais. Nesse contexto, torna-se quase inevitável nos questionarmos acerca da utilização das teorias de tradução como fundamentação da prática tradutória. Até que ponto uma teoria da tradução de textos literários pode auxiliar na realização do ofício do tradutor? Visando responder a esta indagação, a presente pesquisa conta com uma tradução comentada e anotada, ao português, da obra The tragical history of Doctor Faustus (1616), de Christopher Marlowe, elaborada como um instrumento de reflexão sobre a utilização prática dos conceitos tradutológicos de Friedrich Schleiermacher, Henri Meschonnic, Antoine Berman e Lawrence Venuti. Tal pesquisa apóia-se, ainda, nos estudos concernentes à tradução de textos dramáticos/ teatrais de Patrice Pavis e José Roberto O'Shea. Regarding the researches on translation and implications which involve its process, in Brazil we can notice an intense movement of the translation process' description, theoretical translation study analysis, and translation analysis which focuses normally on the so-called "translation problems", for instance, the translation of metaphors, the non-correspondence between the source and target language's lexicon and issues concerning cultural aspects. On this context, it is almost inevitable that we ask ourselves about the effective use of some translation theories as a base for the translation practice. To which extent a literary texts translation theory can help the translator accomplishes his/ her task? Aiming to answer this question, the present research counts on an annotated translation with commentaries of Christopher Marlowe's piece The tragical history of Doctor Faustus (1616) into Portuguese, written as an instrument of reflection on the practical use of the traductological concepts elaborated by Friedrich Schleiermacher, Henri Meschonnic, Antoine Berman and Lawrence Venuti. This research is also based on Patrice Pavis and José Roberto O'Shea's studies concerning drama/ theatre texts translation
Aye–ay: An Anglo-Frisian Parallel
No full textThe most widespread form for neutral “yes” in the Survey of English Dialects is not yea or yes, but aye. It is used not only in the North and Midlands, but also in areas of the South of England. It is a feature of Scottish English, and is familiar from government in many English-speaking countries. We also find the aye-like ayuh in Northeast America. “Aye” appears suddenly about 1575 and is “exceedingly common” around 1600; it is initially written I and its origin, like yes, is uncertain. Ay is also found in Old Frisian, as well as Sater Frisian today (öäi, a'äi etc.). This study reviews a number of proposed etymologies, examining which can account for the occurrence or development of ay(e) in both languages. Based on a wider study of change in forms of “yes” and “no” in English, the author argues that aye–ay is a parallel development of interjection + particle. The study also suggests functional and phonological overlap with the pronominal echo I in English, but not Frisian, with the vocalic form of the pronoun and diphthongisation in the “Great Vowel Shift”, accounting for the popularity and spelling I of “aye” around 1600.</jats:p
Fucoxanthin promotes translocation and induction of glucose transporter 4 in skeletal muscles of diabetic/obese KK-Ay mice
No full textFucoxanthin (Fx) isolated from Undaria pinnatifida suppresses the development of hyperglycemia and hyperinsulinemia of diabetic/obese KK-Ay mice after two weeks of feeding 0.2% Fx-containing diet. In the soleus muscle of KK-Ay mice that were fed Fx, glucose transporter 4 (GLUT4) translocation to plasma membranes from cytosol was promoted. On the other hand, Fx increased GLUT4 expression levels in the extensor digitorum longus (EDL) muscle, although GLUT4 translocation tended to increase. The expression levels of insulin receptor (IR) mRNA and phosphorylation of Akt, which are in upstream of the insulin signaling pathway regulating GLUT4 translocation, were also enhanced in the soleus and EDL muscles of the mice fed Fx. Furthermore, Fx induced peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α), which has been reported to increase GLUT4 expression, in both soleus and EDL muscles. These results suggest that in diabetic/obese KK-Ay mice, Fx improves hyperglycemia by activating the insulin signaling pathway, including GLUT4 translocation, and inducing GLUT4 expression in the soleus and EDL muscles, respectively, of diabetic/obese KK-Ay mice
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Riser Difference Uncertainty Methodology Based on Tank AY-101 Wall Thickness Measurements with Application to Tank AN-107
No full textThe DST Integrity Plan (RPP-7574, 2003, Double-Shell Tank Integrity Program Plan, Rev. 1A, CH2M HILL Hanford Group, Inc., Richland, Washington.) requires the ultrasonic wall thickness measurement of two vertical scans of the tank primary wall while using a single riser location. The resulting measurements are then used in extreme value methodology to predict the minimum wall thickness expected for the entire tank. The representativeness of using a single riser in this manner to draw conclusions about the entire circumference of a tank has been questioned. The only data available with which to address the representativeness question comes from Tank AY-101 since only for that tank have multiple risers been used for such inspection. The purpose of this report is to (1) further characterize AY-101 riser differences (relative to prior work); (2) propose a methodology for incorporating a ''riser difference'' uncertainty for subsequent tanks for which only a single riser is used, and (3) specifically apply the methodology to measurements made from a single riser in Tank AN-107
Experimental method to quantify the efficiency of the first two operational stages of nanosecond dielectric barrier discharge plasma actuators
No full textA method to quantify the efficiency of the first two operational stages of a nanosecond dielectric barrier discharge (ns-DBD) plasma actuator is proposed. The method is based on the independent measurements of the energy of electrical pulses and the useful part of the energy which heats up the gas in the discharge region. Energy input is calculated via a back current shunt technique as the difference between the energy given and the energy reflected back. The ratio of the difference of the latter two quantities and the energy input gives the electrical efficiency (η E) of a ns-DBD. The extent of the energy deposited is estimated via Schlieren visualizations and infrared thermography measurements. Then, the ideal power flux obtained if all the inputted energy was converted into heat is calculated. Transient surface temperature was measured via infrared thermography and used to solve a 1D inverse heat transfer problem in a direction normal to the surface. It gives as output the actual power flux. The estimated ratio between the two power fluxes represents a quantification of the mechanical fluid efficiency (η FM) of a ns-DBD plasma actuator. Results show an inverse proportionality between η E, and η FM, and the thickness of the barrier. The efficiency of the first two operational stages of a ns-DBD is further defined as η = η E centerdot η FM
Population health and status of epidemiology: WHO European Region I
No full textBackground This article of the International Epidemiological Association commissioned paper series stocktakes the population health and status of epidemiology in 21 of the 53 countries of the WHO European Region. By United Nations geographical classification, these countries belong to Eastern Europe, Western Asia and South-Central Asia. Methods Published data were used to describe population health indicators and risk factors. Epidemiological training and research was assessed based on author knowledge, information searches and E-mail survey of experts. Bibliometric analyses determined epidemiological publication outputs. Results Between-country differences in life expectancy, amount and profile of disease burden and prevalence of risk factors are marked. Epidemiological training is affected by ongoing structural reforms of educational systems. Training is advanced in Israel and several Eastern European countries. Epidemiological research is mainly university-based in most countries, but predominantly conducted by governmental research institutes in several countries of the former Soviet Union. Funding is generally external and limited, partially due to competition from and prioritization of biomedical research. Multiple relevant professional societies exist, especially in Poland, the Czech Republic and Hungary. Few of the region's 39 epidemiological academic journals have international currency. The number of epidemiological publications per population is highest for Israel and lowest for South-Central Asian countries. Conclusions Epidemiological capacity will continue to be heterogeneous across the region and depend more on countries' individual historical, social, political and economic conditions and contexts than their epidemiologists' successive efforts. National and international research funding, and within- and between-country collaborations should be enhanced, especially for South-Central Asian countries
Sequence effects in categorization of simple perceptual stimuli
No full textCategorization research typically assumes that the cognitive system has access to a (more or less noisy) representation of the absolute magnitudes of the properties of stimuli and that this information is used in reaching a categorization decision. However, research on identification of simple perceptual stimuli suggests that people have very poor representations of absolute magnitude information and that judgments about absolute magnitude are strongly influenced by preceding material. The experiments presented here investigate such sequence effects in categorization tasks. Strong sequence effects were found. Classification of a borderline stimulus was more accurate when preceded by a distant member of the opposite category than by a distant member of the same category. It is argued that this category contrast effect cannot be accounted for by extant exemplar or decision-bound models of categorization. The effect suggests the use of relative magnitude information in categorization. A memory and contrast model illustrates how relative magnitude information may be used in categorization
Evaluierung von sechs Fotofallenmodellen hinsichtlich der Eignung für Fang-Wiederfang Methoden beim Eurasischen Luchs (Lynx lynx)
No full textDigital outdoor cameras are increasingly used in wildlife research because they allow species inventories, population estimates, and behavior or activity observations. Which camera model is suitable and practical depends on environmental conditions, focus species and specific scientific questions posed. Here we focused on testing cameras appropriate for elusive species that can be identified visually owing to individual coat patterns. Specifically the camera should be adequate for calculating the minimum population of Eurasian Lynx (Lynx lynx) during a systematic monitoring with camera traps. Therefore we tested six digital camera models with regard to trigger speed and the image quality necessary for visual identification of pacing lynx on trails. The decision if a camera model is adequate for the scientific goal was regulated due to priority levels under laboratory conditions. Only one camera model proved to be suitable for camera-trap monitoring. Our practical camera test can be used to evaluate newer models of digital cameras as they become available. This application opens an avenue for a non-invasive population monitoring of rare and elusive species in a low mountain range area.Digitale Fotofallen werden weltweit in der Wildtierforschung eingesetzt. Die Einsatzgebiete sind vielfältig, sie reichen von Artenbestandsaufnahmen und Populationsschätzungen über die Verhaltensforschung bis hin zu Aktivitätsanalysen. Das jeweilig eingesetzte Kameramodell muss an die Aufnahmesituation und die Zielsetzung der Analyse angepasst sein. Das Ziel unseres Fotofallentests war es, ein Modell zu finden, welches für die visuelle Identifizierung von Fellmustern des Eurasischen Luchses geeignet ist. Die Fotofalle soll in einem systematischen Monitoring für die minimale Anzahl der im Gebiet vorkommenden Luchse und deren Populationsschätzung mit Fang-Wiederfang Methoden eingesetzt werden können. Bei dem Test von sechs Fotofallenmodellen, fiel das Hauptaugenmerk auf die Auslösegeschwindigkeit und die Bildqualität welche die nötigen Faktoren für die Sicherstellung der visuellen Identifikation von schreitenden Luchsen am Wildwechsel darstellen. Zur Entscheidungsfindung der Eignung eines Fotofallenmodells für die Fragestellung definierten wir Prioritätslevel unter Laborbedingungen. Es stellte sich heraus, dass nur ein Fotofallenmodell die Ansprüche erfüllte. Der praktische Fotofallentest kann für neuerscheinende Fotofallenmodelle adaptiert werden. Diese Anwendung eröffnet die Möglichkeit für ein nicht invasives Monitoring in Mittelgebirgslandschaften
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