1,721,093 research outputs found
Well-posedness for General 2x2 Systems of Conservation Laws
No full textABSTRACT. We consider the Cauchy problem for a strictly hyperbolic 2x2 system of conservation laws in one space dimension
u_t+[F(u)]_x=0,
u(0,x)=u_0(x),
which is neither linearly degenerate nor genuinely non-linear.
We make the following assumption on the characteristic fields.
If r_i(u), i=1,2, denotes the i-th right eigenvector of DF(u) and lambda_i(u) the corresponding eigenvalue, then the set {u : D lambda_i . r_i (u) = 0} is a smooth curve in the u-plane that is transversal to the vector field r_i(u).
Systems of conservation laws that fulfill such assumptions arise in studying elastodynamics or rigid heat conductors at low temperature.
For such systems we prove the existence of a closed domain D
in L^1, containing all functions with sufficiently small total
variation, and of a uniformly Lipschitz continuous semigroup
S: Dx [0,+infty) --->D with the following properties.
Each trajectory t --> S_t (u_0) of S is a weak solution of (1). Viceversa, if a piecewise Lipschitz, entropic solution u= u(t,x)
of (1) exists for
Magyarok a Marson - alkalmazott mérnöki tudományok versenyének koncepciója és eredményei
Full text linkAz Alkalmazott Mérnöki Tudományok Országos Robotversenye, avagy másnéven a Magyarok a Marson 2006-ban került először megszervezésre. A verseny alapítója és a kezdetek óta a kreatív feladatok megalkotója Sipos Attila villamosmérnök, aki magánszemélyként is 14 éve példaképként szolgál a
hallgatók számára. 2016 óta a Miskolci Egyetem vált a szakmai verseny befogadó intézményévé. A publikáció az elmúlt 4 év közös munkáját hivatott bemutatni, annak tapasztalatait, sikereit és hosszútávú eredményeit
Design of a robot remote controller for „Magyarok a Marson” competition
Full text linkThis paper is introducing a “Magyarok a Marson” robot, which is developed at the Institute of Automation and Infocommunication in University of Miskolc. The controller was built for “Magyarok a Marson” student competition. Our goal was to create a controller, which looks like a magic wand and it is able to control remotely a spherical robot. It was the expectation of the competition. My main task was the hardware design of the remote controller. This paper presents the requirements of the competition, the development of the PCB panel and the controller itself
Third meeting on Hyperbolic Conservation Laws: Recent results and Research perspectives
No full textThe meeting consisted on conferences and short communications by italian researchers aimed to overview the status and perspectives of this areas of research in PDEs. There were also few foreign invited
speakers that are among the leading experts in this area
Fourth meeting on Hyperbolic Conservation Laws: Recent results and Research perspectives
No full textThe meeting consisted on conferences and short communications by italian researchers aimed to overview the status and perspectives of this areas of research in PDEs. There were also few foreign invited
speakers that are among the leading experts in this area
A hidroszféra felszíni lefolyásnyomai - folyóvölgyek a Marson
Full text linkA marsi víz körforgása részben hasonló lehetett a földi víz körforgásához (vagy más néven hidrológiai ciklus, amely a víz természetes folytonos körforgása melyet a Nap sugárzáságából származó energia tart fenn), amelyben a felszíni lefolyás nyomai látványos folyóvölgyek formájában ma is megfigyelhetőek a Marson. A dolgozatban vizsgált marsi völgyet egy áradás hozhatta létre, de a benne található geomorfológiai formák a folyóvíz tartós jelenlétére utalnak. Megtalálható a földi folyóvölgyek számos jellemzője, kezdve a különböző völgytípusoktól, a keresztmetszeti hasonlóságokon át egészen a feltételezett hordalékkúp alakjáig. A völgy sok hasonlóságot mutat a földi, főleg a sivatagos félsivatagos területeken kialakult vádi típusú vízfolyásokkal. A vizsgált völgy hossza megközelítőleg 81 km, átlagos szélessége 1,85 km. A keresztszelvények alakja a völgy irányával együtt változik, a felső szakaszon ’V’, de egyre északabbra haladva folyamatosan kiszélesedik és ’U’ alakot vesz fel. A völgy kora a kráterstatisztikai vizsgálatok alapján egybeesik a vörös bolygó nedvesnek feltételezett (a felszínen nagyobb mennyiségű folyékony vízzel rendelkező) időszakával a Noachi korral
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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