cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Europa-Vorstellungen im Mittelalter
Creators: name: I, Deug-Su
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Nach Auffassung der Geschichtsforschung hat die karolingische Epoche einen wichtigen Anstoß für die moderne, westlich orientierte Konzeption der Europa-Idee gegeben, die bis heute nachwirkt. Anhand von breit angelegten Quellenrecherchen, welche den Zeitraum von der Spätantike bis zum Humanismus umfassen, gelingt Prof. Dr. I Deug-Su, Lehrstuhlinhaber für Mediävistik an der Universität Siena und seit 1996 Gastprofessor am Seminar für Mittellateinische Philologie der Freien Universität Berlin, der Nachweis, dass der mittelalterliche Europa-Begriff über diese westlich orientierte karolingische Europa-Konzeption wesentlich hinausgeht. Ergebnisse seiner Europa-Forschung stellte I Deug-Su in einem Vortrag in Berlin im Februar 2003 vor, der hier in leicht überarbeiteter Form abgedruckt wird. Für den schulischen Latein- und Griechischunterricht, aber auch für den Geschichtsunterricht dürften diese Forschungsergebnisse wichtige Anregungen zu einer Auseinandersetzung mit dem nach 1989 noch brisanter gewordenen Thema Europa in Geschichte und Gegenwart liefern.
description: Pegasus-Onlinezeitschrift, Bd. 3, Nr. 1 (2003): Pegasus-Onlinezeitschrift
Interesting paths in the mapper complex
Creators: name: Kalyanaraman, Ananth
name: Kamruzzaman, Methun
name: Krishnamoorthy, Bala
Publisher: name: Journal of Computational Geometry
Year: 2019

description: Given a high dimensional point cloud of data with functions defined on the points, the mapper algorithm produces a compact summary in the form of a simplicial complex connecting the points. This summary offers insightful data visualizations, which have been employed in applications to identify subsets of points, i.e., subpopulations, with interesting properties. These subpopulations typically appear as long paths, flares (i.e., branching paths), or loops in the mapper complex. We study the problem of quantifying the interestingness of subpopulations in a given mapper complex. First, we create a weighted directed graph G=(V,E) using the 1-skeleton of the mapper complex. We use the average values at the vertices (i.e., clusters) of the target function (i.e., a dependent variable) to direct the edges from low to high values. We set the difference between the average values at the vertices (high-low) as the weight of the edge. Covariation of the remaining h functions (i.e., independent variables) is captured by a h-bit binary signature assigned to the edge. An interesting path in G is a directed path whose edges all have the same signature. Further, we define the interestingness score of such a path as a sum of its edge weights multiplied by a nonlinear function of their corresponding ranks, i.e., the depths of the edges along the path. Such a nonlinear function could model application use-cases where the growth in the dependent variable values is expected to be concentrated in specific intervals of a path, e.g., plant growth accelerating later in the season, or a terminally ill patient's health condition deteriorating rapidly toward the end. Second, we study three optimization problems on this graph G to quantify interesting subpopulations. In the problem MaxIP, the goal is to find the most interesting path in G, i.e., an interesting path with the maximum interestingness score. For the case where G is a directed acyclic graph (DAG), which could be a typical setting in many applications, we show that MaxIP can be solved in polynomial time---in O(mnd_in) time and O(mn) space, where m,n, and d_in are the numbers of edges, vertices, and the maximum indegree of a vertex in G, respectively. In the more general problem IP, the goal is to find a collection of interesting paths that are edge-disjoint, and the sum of interestingness scores of all paths is maximized. We also study a variant of IP termed k-IP, where the goal is to identify a collection of edge-disjoint interesting paths each with k edges, and the total interestingness score of all paths is maximized. While k-IP can be solved in polynomial time for k <= 2, we show k-IP is NP-complete for k >= 3 even when G is a DAG. We develop heuristics for IP and k-IP on DAGs, which use the algorithm for MaxIP on DAGs as a subroutine, and run in O(mnd_in) and O(mkd_in) time for IP and k-IP, respectively.
description: Journal of Computational Geometry, Vol. 10 No. 1 (2019)
First step toward matter power spectrum reconstruction with Stage III weak gravitational lensing surveys
Creators: name: Broxterman, Jeger C.
name: Kuijken, Konrad
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Weak gravitational lensing (WL) surveys provide insight into the matter distribution over an extensive range of scales. Current WL results are in mild tension with cosmic microwave background measurements from the early Universe. Reconstructing the matter power spectrum from their measurements instead of condensing the information into a single cosmological parameter may help locate the origin of these differences. To investigate the cosmic shear measurements of Stage III WL surveys, we compared their tomographic data by assuming a simple parametric model for the matter power spectrum. The model allows the comparison of surveys with different characteristics and, in an agnostic approach, gives insight into the shape of the matter power spectrum preferred by the data. For the matter power spectrum, we assumed a double power-law model in scale factor and wavenumber. The best-fitting amplitude and exponents were inferred in an MCMC analysis. We identified the scales to which the data is most sensitive. We tested the sensitivity to different assumptions of the intrinsic alignment strength. We find that the constraining power of Stage III surveys on the power spectrum shape and evolution is still limited. Most information can be summarized as an overall amplitude at a pivot point in wavenumber and scale factor, while constraints on the power-law indices are considerably weaker. Nevertheless, all surveys show a weaker rate of growth from $z=$ 0.5 to 0.1 than predicted. The assumed intrinsic alignment strength is found to have no significant impact on the measured parameters and goodness of fit. Direct estimates of the matter power spectrum from Stage III weak lensing surveys can, in principle, be used to locate the physical origin of the observed $S_8$ tension. We present a simple methodology for the first steps in this direction, but find that current constraints are still weak.
description: 8 pages, 5 figures. Accepted for publication in A&A
„Acta diurna“ - Sonderausgabe einer römischen Tageszeitung zum Brand Roms. Überlegungen ausgehend von einer Facharbeit im Leistungskurs Latein
Creators: name: Hummel, Carola
name: Braun, Joseph
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: [nicht vorhanden / not available]
description: Pegasus-Onlinezeitschrift, Bd. 3, Nr. 2 (2003): Pegasus-Onlinezeitschrift
Dark Matter and Strong Electroweak Phase Transition in a Radiative Neutrino Mass Model
Creators: name: Ahriche, Amine
name: Nasri, Salah
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We consider an extension of the standard model (SM) with charged singlet scalars and right handed (RH) neutrinos all at the electroweak scale. In this model, the neutrino masses are generated at three loops, which provide an explanation for their smallness, and the lightest RH neutrino, $N_{1}$, is a dark matter candidate. We find that for three generations of RH neutrinos, the model can be consistent with the neutrino oscillation data, lepton flavor violating processes, $N_{1}$ can have a relic density in agreement with the recent Planck data, and the electroweak phase transition can be strongly first order. We also show that the charged scalars may enhance the branching ratio $h-->YY$, where as $h-->YZ$ get can get few percent suppression. We also discuss the phenomenological implications of the RH neutrinos at the collider.
description: published version, 23 pages, 13 figures
The relationship between the intrinsic Čech and persistence distortion distances for metric graphs
Creators: name: Gasparovic, Ellen
name: Gommel, Maria
name: Purvine, Emilie
name: Sazdanovic, Radmila
name: Wang, Bei
name: Wang, Yusu
name: Ziegelmeier, Lori
Publisher: name: Journal of Computational Geometry
Year: 2019

description: Metric graphs are meaningful objects for modeling complex structures that arise in many real-world applications, such as road networks, river systems, earthquake faults, blood vessels, and filamentary structures in galaxies. To study metric graphs in the context of comparison, we are interested in determining the relative discriminative capabilities of two topology-based distances between a pair of arbitrary finite metric graphs: the persistence distortion distance and the intrinsic Čech distance. We explicitly show how to compute the intrinsic Čech distance between two metric graphs based solely on knowledge of the shortest systems of loops for the graphs. Our main theorem establishes an inequality between the intrinsic Čech and persistence distortion distances in the case when one of the graphs is a bouquet graph and the other is arbitrary. The relationship also holds when both graphs are constructed via wedge sums of cycles and edges.
description: Journal of Computational Geometry, Vol. 10 No. 1 (2019)
Das Brandenburger Tor im Lateinunterricht
Creators: name: Dziallas-Barz, Constanze
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: [nicht vorhanden / not available]
description: Pegasus-Onlinezeitschrift, Bd. 4, Nr. 1 (2004): Pegasus-Onlinezeitschrift
Higher order approximate solutions for the flow in axial turbomachines
Creators: name: Monroe, Gerald M.
Publisher: name: California Institute of Technology
Year: 1949
Subjects: Aeronautics

description: The theory of the three-dimensional rotational flow of an incompressible and inviscid fluid through an axial turbomachine is described and the hydrodynamical equations are simplified by considering an infinite number of blades in each row. The forces of the blades on the fluid are treated as non-conservative body forces distributed uniformly about the axis.

Formulation of the mathematical problem leads to one non-linear partial differential equation and two integral equations for the three velocity components. A linearized solution of these simultaneous equations for any prescribed blade loading is based on the consideration that the vorticity generated by the blades is transported downstream by the mean axial velocity. An iteration process which leads to solutions of greater accuracy is developed by considering for each iteration that the vorticity is transported by the velocities found by the previous iteration.

The Bessel's functions which occur in the Green's function solution are replaced by their asymptotic values and the infinite series is summed to express the solution in closed form. The iteration process is then adapted to mechanical calculations by dividing the region of vorticity into small rings of rectangular cross-section and determining the influence on the velocity of a unit change of vorticity in each of these rings. Once this influence is established it is relatively easy to calculate the velocities in any axial flow machine with any prescribed blade loading.
A connection between the structural alpha-relaxation and the beta-relaxation found in bulk metallic glass-formers
Creators: name: Ngai, K. L.
name: Wang, Z.
name: Gao, X. Q.
name: Yu, H. B.
name: Wang, W. H.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: New metallic glasses containing La or Ce have been introduced that have dynamic properties bordering on extremes of conventional metallic glasses. This provides opportunity to test trends or correlations established before in molecular and polymeric glass-formers if exist the same exist in the broader family of metallic glasses. Due to the drastically different chemical and physical structure of metallic glass-formers than soft matter, there is no guarantee that any correlation found in the latter will hold in the former. If found, the result brings metallic glasses closer to the much wider classes of glass-formers by the similarity in properties, and possibly have the same explanation. In non-metallic glass-formers, a general and fundamental connection has been established between the non-exponentiality parameter of the structural alpha-relaxation and the separation between its relaxation time and the beta-relaxation time. In this paper we explore the experimental data of metallic glass-formers and show the correlation applies. An explanation of this correlation is given. The establishment of the correlation may facilitate the understanding of the roles played by the beta-relaxation observed in macroscopic properties of metallic glasses including the relations to shear transformation zone, ductile-brittle transition in deformation, crystallization, and diffusion.
description: 23 pages, 8 figures
Updated attachment for 'Demand for place-based representation: a pre-analysis plan for a conjoint experiment'
Creators: name: McKay, Lawrence
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Other Political Science
subject: Comparative Politics
subject: Political Science
subject: FOS: Political science
subject: Social and Behavioral Sciences

description: A new version of the pre-analysis plan PDF document for the pre-registration 'Demand for place-based representation: a pre-analysis plan for a conjoint experiment'.
Subquadratic encodings for point configurations
Creators: name: Cardinal, Jean
name: Chan, Timothy M.
name: Iacono, John
name: Langerman, Stefan
name: Ooms, Aurélien
Publisher: name: Journal of Computational Geometry
Year: 2019

description: For many algorithms dealing with sets of points in the plane, the only relevant information carried by the input is the combinatorial configuration of the points: the orientation of each triple of points in the set (clockwise, counterclockwise, or collinear). This information is called the order type of the point set. In the dual, realizable order types and abstract order types are combinatorial analogues of line arrangements and pseudoline arrangements. Too often in the literature we analyze algorithms in the real-RAM model for simplicity, putting aside the fact that computers as we know them cannot handle arbitrary real numbers without some sort of encoding. Encoding an order type by the integer coordinates of a realizing point set is known to yield doubly exponential coordinates in some cases. Other known encodings can achieve quadratic space or fast orientation queries, but not both. In this contribution, we give a compact encoding for abstract order types that allows an efficient query of the orientation of any triple: the encoding uses \( O(n^2) \) bits and an orientation query takes \(O(\log n)\) time in the word-RAM model with word size \(w \geq \log n\). This encoding is space-optimal for abstract order types. We show how to shorten the encoding to \(O(n^2 {(\log\log n)}^2 / \log n)\) bits for realizable order types, giving the first subquadratic encoding for those order types with fast orientation queries. We further refine our encoding to attain \(O(\log n/\log\log n)\) query time at the expense of a negligibly larger space requirement. In the realizable case, we show that all those encodings can be computed efficiently. Finally, we generalize our results to the encoding of point configurations in higher dimension.
description: Journal of Computational Geometry, Vol. 10 No. 2 (2019): Special Issue of Selected Papers from SoCG 2018
Habent sua fata epigrammata. Rezeption und Metamorphose von Martials Epigramm VIII 79 bei Baltasar Gracián und Arthur Schopenhauer
Creators: name: Lobe, Michael
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Michael Lobe (Bamberg) gibt einen Einblick in die Geschichte der Rezeption des Epigrammatikers Martial: In konzentrierter Darstellung wird der Leser mit dem Weiterleben und produktiven Umgestaltung des Epigrammes VIII 79 beim spanischen Jesuiten Baltasar Graciàn y Moreno (1601-1658) und dem Philosophen Arthur Schopenhauer bekannt gemacht.
description: Pegasus-Onlinezeitschrift, Bd. 4, Nr. 2 (2004): Pegasus-Onlinezeitschrift
Comparative investigation of the freezing phenomena for quantum correlations under nondissipative decoherence
Creators: name: Aaronson, Benjamin
name: Franco, Rosario Lo
name: Adesso, Gerardo
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We show that the phenomenon of frozen discord, exhibited by specific classes of two-qubit states under local nondissipative decoherent evolutions, is a common feature of all known bona fide measures of general quantum correlations. All those measures, despite inducing typically inequivalent orderings on the set of nonclassically correlated states, return a constant value in the considered settings. Every communication protocol which relies on quantum correlations as resource will run with a performance completely unaffected by noise in the specified dynamical conditions. We provide a geometric interpretation of this
description: 7 pages, 2 figures, 1 table; title changed to match published version
Investigation of the Alaskan earthquake of May 4, 1934.
Creators: name: Fillippone, Walter Ross
Publisher: name: California Institute of Technology
Year: 1944
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences

description: The shock investigated occurred on May 4, 1934 at 4h. 36m. 10s. The epicenter given in The International Seismological Summary for 1934 is 61.5 degrees north latitude, 147.5 degrees west longitude and the probably error of the epicenter is ± 0.21 degrees.

The procedure of investigation consisted of using the S-P interval to find the origin time and subtracting the mean from the given times of P. However, when the residuals of given distance minus calculated distance was plotted against the azimuth, the resulting sine curve was displaced from the zero residual by three (3) seconds, indicating an incorrect origin time. A second origin time, 0 = zero, was calculated from the equation, 0 = (pP+P)/2 – (t_p+c), and the residuals plotted. The resulting curve was symmetric to the zero residual line and showed the epicenter to be 0.3 degrees to the south of its given location.

The depth of focus was determined from the intervals of pP-P, sP-P, sS-S, PcP-P, and ScS-S, each interpolated from the corresponding tables in the reference papers.
"Hier werden Sie geholfen!" Latein und muttersprachliche Kompetenz
Creators: name: Natzel-Glei, Stephanie
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: In der fachdidaktischen Diskussion wurde immer schon betont, dass der Lateinunterricht auch die muttersprachliche Kompetenz fördere. Dabei dachte man vor allem an den metasprachlichen Wortschatz und an einen sprachreflektorischen Effekt des Lateinlernens, oftmals ohne dies konkret zu explizieren. Der Aufsatz versucht, ausgehend von der gegenwärtigen desolaten Situation der Deutschkenntnisse vieler Abiturienten, die Leistung des Lateinischen für die muttersprachliche Kompetenz didaktisch zu begründen und an Beispielen aus der Praxis aufzuzeigen. Es wird deutlich gemacht, dass schulischer Lateinunterricht die PISA-gebeutelten Sprachkenntnisse unserer ‚Bildungselite‘ ganz wesentlich verbessern könnte.
description: Pegasus-Onlinezeitschrift, Bd. 5, Nr. 1 (2005): Pegasus-Onlinezeitschrift
Magnetofluid-dynamic drag measurements on semi-infinite bodies in aligned fields
Creators: name: Suzuki, Bob Hiro
Publisher: name: California Institute of Technology
Year: 1967
Subjects: Aeronautics

description: NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

Experiments are described in which measurements were made of the drag of semi-infinite bodies moving parallel to a uniform magnetic field in a conducting fluid. Two of these bodies were moderately streamlined halfbodies and a third was a blunt halfbody. The drag coefficients of all three bodies were found to increase monotonically as a function of the interaction parameter, N. This parameter was varied in the experiments from 0 to about 24. The drag coefficients of the streamlined halfbodies were found to increase linearly with N for N >1, the drag coefficients of all three bodies were of 0(1) and appeared to be asymptotically converging to some common limiting value. Although the drag could not be calculated for large, finite values of N, an inviscid theoretical model of the flow is described from which it is concluded that the drag coefficient of any halfbody must approach unity as [...].

In addition to the experiments with the semi-infinite bodies, experiments are also described in which measurements were made of the non-magnetic drag of impulsively-started flat disks. Some unexpected and interesting transient variations in this drag were observed and are attributed to the vortex formation process in the wake.
On the treewidth of triangulated 3-manifolds
Creators: name: Huszár, Kristóf
name: Spreer, Jonathan
name: Wagner, Uli
Publisher: name: Journal of Computational Geometry
Year: 2019

description: In graph theory, as well as in 3-manifold topology, there exist several width-type parameters to describe how "simple" or "thin" a given graph or 3-manifold is. These parameters, such as pathwidth or treewidth for graphs, or the concept of thin position for 3-manifolds, play an important role when studying algorithmic problems; in particular, there is a variety of problems in computational 3-manifold topology - some of them known to be computationally hard in general - that become solvable in polynomial time as soon as the dual graph of the input triangulation has bounded treewidth. In view of these algorithmic results, it is natural to ask whether every 3-manifold admits a triangulation of bounded treewidth. We show that this is not the case, i.e., that there exists an infinite family of closed 3-manifolds not admitting triangulations of bounded pathwidth or treewidth (the latter implies the former, but we present two separate proofs). We derive these results from work of Agol, of Scharlemann and Thompson, and of Scharlemann, Schultens and Saito by exhibiting explicit connections between the topology of a 3-manifold M on the one hand and width-type parameters of the dual graphs of triangulations of M on the other hand, answering a question that had been raised repeatedly by researchers in computational 3-manifold topology. In particular, we show that if a closed, orientable, irreducible, non-Haken 3-manifold M has a triangulation of treewidth (resp. pathwidth) k then the Heegaard genus of M is at most 18(k+1) (resp. 4(3k+1)).
description: Journal of Computational Geometry, Vol. 10 No. 2 (2019): Special Issue of Selected Papers from SoCG 2018
Discord and information deficit in the XX chain
Creators: name: Ciliberti, L.
name: Canosa, N.
name: Rossignoli, R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We examine the quantum correlations of spin pairs in the cyclic $XX$ spin 1/2 chain in a transverse field, through the analysis of the quantum discord, the geometric discord and the information deficit. It is shown that while these quantities provide the same qualitative information, being non-zero for all temperatures and separations and exhibiting the same type of asymptotic behavior for large temperatures or separations, important differences arise in the minimizing local measurement that defines them. Whereas the quantum discord prefers a spin measurement perpendicular to the transverse field, the geometric discord and information deficit exhibit a perpendicular to parallel transition as the field increases, which subsists at all temperatures and for all separations. Moreover, it is shown that such transition signals the change from a Bell state to an aligned separable state of the dominant eigenstate of the reduced density matrix of the pair. Full exact results for both the thermodynamic limit and the finite chain are provided, through the Jordan-Wigner fermionization.
description: 23 pages, 6 figures. References added
Limits of Learning Dynamical Systems
Creators: name: Berry, Tyrus
name: Das, Suddhasattwa
Publisher: name: arXiv
Year: 2024
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37M99, 37N30, 37A20, 37D25

description: A dynamical system is a transformation of a phase space, and the transformation law is the primary means of defining as well as identifying the dynamical system. It is the object of focus of many learning techniques. Yet there are many secondary aspects of dynamical systems - invariant sets, the Koopman operator, and Markov approximations, which provide alternative objectives for learning techniques. Crucially, while many learning methods are focused on the transformation law, we find that forecast performance can depend on how well these other aspects of the dynamics are approximated. These different facets of a dynamical system correspond to objects in completely different spaces - namely interpolation spaces, compact Hausdorff sets, unitary operators and Markov operators respectively. Thus learning techniques targeting any of these four facets perform different kinds of approximations. We examine whether an approximation of any one of these aspects of the dynamics could lead to an approximation of another facet. Many connections and obstructions are brought to light in this analysis. Special focus is put on methods of learning of the primary feature - the dynamics law itself. The main question considered is the connection of learning this law with reconstructing the Koopman operator and the invariant set. The answers are tied to the ergodic and topological properties of the dynamics, and reveal how these properties determine the limits of forecasting techniques.
description: arXiv admin note: text overlap with arXiv:2208.05349
Minimizing crossings in constrained two-sided circular graph layouts
Creators: name: Klute, Fabian
name: Nöllenburg, Martin
Publisher: name: Journal of Computational Geometry
Year: 2019

description: Circular graph layout is a popular drawing style, in which vertices are placed on a circle and edges are drawn as straight chords. Crossing minimization in circular layouts is NP-hard. One way to allow for fewer crossings in practice are two-sided layouts, which draw some edges as curves in the exterior of the circle. In fact, one- and two-sided circular layouts are equivalent to one-page and two-page book drawings, i.e., graph layouts with all vertices placed on a line (the spine) and edges drawn in one or two distinct half-planes (the pages) bounded by the spine. In this paper we study the problem of minimizing the crossings for a fixed cyclic vertex order by computing an optimal $k$-plane set of exteriorly drawn edges for $k \ge 1$, extending the previously studied case $k=0$. We show that this relates to finding bounded-degree maximum-weight induced subgraphs of circle graphs, which is a graph-theoretic problem of independent interest. We show NP-hardness for arbitrary $k$, present an efficient algorithm for $k=1$, and generalize it to an explicit XP-time algorithm for any fixed $k$. For the practically interesting case $k=1$ we implemented our algorithm and present experimental results that confirm its applicability.
description: Journal of Computational Geometry, Vol. 10 No. 2 (2019): Special Issue of Selected Papers from SoCG 2018
Aut Caesar aut nihil? - Der Lateinunterricht im Wandel am Beispiel der Caesar- Lektüre
Creators: name: Kipf, Stefan
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Caesar nimmt in der Geschichte des Lateinunterrichts eine einzigartige Stellung ein: Wohl kein anderer Autor wurde und wird als der "römischste Römer" mit dem Lateinunterricht so identifiziert, dass beide wie selbstverständlich zusammenzugehören scheinen. In der Tat hat Caesar jedoch nicht nur Spracherwerb und Lektürepraxis, sondern darüberhinaus auch das Erscheinungsbild des gesamten Lateinunterrichts geprägt. Mit Sicherheit ist es vor allem der jahrzehntelangen Praxis der Caesar-Lektüre zu danken, dass auch heute noch mit dem Lateinischen zuallererst grammatischer Drill und militärische Taten, weniger Dichtung oder Philosophie identifiziert werden. Der Eindruck trügt nicht, als bündelten sich in der Lektüre des Bellum Gallicum wie in einem Brennglas alle wichtigen formalen und inhaltlichen Ziele, Fachleistungen und Wandlungen des Lateinunterrichts im Laufe seiner Geschichte. Am Beispiel der Caesar-Lektüre spürt der Vortrag diesen Wandlungen nach und schlägt dabei einen Bogen vom 18. Jahrhundert bis in die Gegenwart.
description: Pegasus-Onlinezeitschrift, Bd. 6, Nr. 2+3 (2006): Pegasus-Onlinezeitschrift
Lombardi drawings of knots and links
Creators: name: Kindermann, Philipp
name: Kobourov, Stephen
name: Löffler, Maarten
name: Nöllenburg, Martin
name: Schulz, André
name: Vogtenhuber, Birgit
Publisher: name: Journal of Computational Geometry
Year: 2019

description: Knot and link diagrams are projections of one or more 3-dimensional simple closed curves into IR^2, such that no more than two points project to the same point in IR^2. These diagrams are drawings of 4-regular plane multigraphs. Knots are typically smooth curves in IR^3, so their projections should be smooth curves in IR^2 with good continuity and large crossing angles: exactly the properties of Lombardi graph drawings (defined by circular-arc edges and perfect angular resolution). We show that several knots do not allow crossing-minimal plane Lombardi drawings. On the other hand, we identify a large class of 4-regular plane multigraphs that do have plane Lombardi drawings. We then study two relaxations of Lombardi drawings and show that every knot admits a crossing-minimal plane 2-Lombardi drawing (where edges are composed of two circular arcs). Further, every knot is near-Lombardi, that is, it can be drawn as a plane Lombardi drawing when relaxing the angular resolution requirement by an arbitrary small angular offset ε, while maintaining a 180° angle between opposite edges.
description: Journal of Computational Geometry, Vol. 10 No. 1 (2019)
Specular Andreev Reflection in Inversion-symmetric Weyl-semimetals
Creators: name: Chen, Wei
name: Jiang, Liang
name: Shen, R.
name: Sheng, L.
name: Wang, B. G.
name: Xing, D. Y.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The electron-hole conversion at the normal-metal superconductor interface in inversion-symmetric Weyl semimetals is investigated with an effective two-band model. We find that the specular Andreev reflection of Weyl fermions has two unusual features. The Andreev conductance for s-wave BCS pairing states is anisotropic, depending on the angle between the line connecting a pair of Weyl points and the normal of the junction, due to opposite chirality carried by the paired electrons. For the Fulde-Ferrell-Larkin-Ovchinnikov pairing states, the Andreev reflection spectrum is isotropic and is independent of the finite momentum of the Cooper pairs.
EPR Steering Inequalities from Entropic Uncertainty Relations
Creators: name: Schneeloch, James
name: Broadbent, Curtis J.
name: Walborn, Stephen P.
name: Cavalcanti, Eric G.
name: Howell, John C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We use entropic uncertainty relations to formulate inequalities that witness Einstein-Podolsky-Rosen (EPR) steering correlations in diverse quantum systems. We then use these inequalities to formulate symmetric EPR-steering inequalities using the mutual information. We explore the differing natures of the correlations captured by one-way and symmetric steering inequalities, and examine the possibility of exclusive one-way steerability in two-qubit states. Furthermore, we show that steering inequalities can be extended to generalized positive operator valued measures (POVMs), and we also derive hybrid-steering inequalities between alternate degrees of freedom.
description: 10 pages, 2 figures
Computing representative networks for braided rivers
Creators: name: Kleinhans, Maarten
name: Van Kreveld, Marc
name: Ophelders, Tim
name: Sonke, Willem
name: Speckmann, Bettina
name: Verbeek, Kevin
Publisher: name: Journal of Computational Geometry
Year: 2019

description: Drainage networks on terrains have been studied extensively from an algorithmic perspective. However, in drainage networks water flow cannot bifurcate and hence they do not model \emph{braided rivers} (multiple channels which split and join, separated by sediment bars). We initiate the algorithmic study of braided rivers by employing the descending quasi Morse-Smale complex on the river bed (a polyhedral terrain), and extending it with a certain ordering of bars from one river bank to the other. This allows us to compute a graph that models a representative channel network, consisting of lowest paths. To ensure that channels in this network are sufficiently different we define a \emph{sand function} that represents the volume of sediment separating them. We show that in general the problem of computing a maximum network of non-crossing channels which are $\delta$-different from each other (as measured by the sand function) is NP-hard. However, using our ordering between the river banks, we can compute a maximum $\delta$-different network that respects this order in polynomial time. We implemented our approach and applied it to simulated and real-world braided rivers.
description: Journal of Computational Geometry, Vol. 10 No. 1 (2019)
Approximate shortest distances among smooth obstacles in 3D
Creators: name: Scheffer, Christian
name: Vahrenhold, Jan
Publisher: name: Journal of Computational Geometry
Year: 2019

description: We consider the classic all-pairs-shortest-paths (APSP) problem in a three-dimensional environment where paths have to avoid a set of smooth obstacles whose surfaces are represented by discrete point sets with $n$ sample points in total. We show that if the point sets represent eps-amples of the underlying surfaces, $(1+/-O(\sqrt{eps}))$-approximations of the distances between all pairs of sample points can be computed in $O(n^{5/2} \log^2 n)$ time.
description: Journal of Computational Geometry, Vol. 10 No. 1 (2019)
A model for the multiwavelength radiation from tidal disruption event Swift J1644+57
Creators: name: Kumar, P.
name: Duran, R. Barniol
name: Bosnjak, Z.
name: Piran, T.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Gamma-ray observations of a stellar tidal disruption event (TDE) detected by the Swift satellite and follow up observations in radio, mm, infrared and x-ray bands have provided a rich data set to study accretion onto massive blackholes, production of relativistic jets and their interaction with the surrounding medium. The radio and x-ray data for TDE Swift J1644+57 provide a conflicting picture regarding the energy in relativistic jet produced in this event: x-ray data suggest jet energy declining with time as t^{-5/3} whereas the nearly flat lightcurves in radio and mm bands lasting for about 100 days have been interpreted as evidence for the total energy output increasing with time. We show in this work that flat lightcurves do not require addition of energy to decelerating external shock (which produced radio and mm emission via synchrotron process), instead the flat behavior is due to inverse-Compton cooling of electrons by x-ray photons streaming through the external shock; the higher x-ray flux at earlier times cools electrons more rapidly thereby reducing the emergent synchrotron flux, and this effect weakens as the x-ray flux declines with time.
description: 11 pages, 5 figures, expanded discussion on Sec. 4, MNRAS accepted
Augustus und der Principat. Materialien für eine Unterrichtseinheit [Teil 1]
Creators: name: Ruf, Nikolaus
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Kenntnis der soziokulturellen und politischen Rahmenbedingungen lateinischer Literatur ist bei Schülern oft nur mangelhaft oder gar nicht vorhanden. Dies wird immer wieder bei der Behandlung augusteischer Autoren deutlich. Der vorliegende arbeitsteilige Lernzirkel soll diesem Missstand abhelfen und die Schüler zu einem vertieften Verständnis der genannten Bedingungen führen. Dieses Verständnis erarbeiten sich die Schüler mit Hilfe vorgegebenen Materials und anhand von Leitfragen zu vier Themenkreisen weitestgehend selbst. Zur Erarbeitung der vier Themenkreise "Selbstdarstellung", "Repräsentationskunst", "Religiosität und Götterkult" und "Familienpolitik" werden lateinische Texte, die teils von den Schülern zu übersetzen sind, teils in Übersetzung geboten werden, zusammen mit antiken Plastiken, Bauwerken, Münzen, aber auch modernen fachwissenschaftlichen Texten interpretiert.
description: Pegasus-Onlinezeitschrift, Bd. 6, Nr. 2+3 (2006): Pegasus-Onlinezeitschrift
Polylogarithmic Cuts in Models of V^0
Creators: name: Müller, Sebastian
Publisher: name: arXiv
Year: 2013
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We study initial cuts of models of weak two-sorted Bounded Arithmetics with respect to the strength of their theories and show that these theories are stronger than the original one. More explicitly we will see that polylogarithmic cuts of models of $\mathbf{V}^0$ are models of $\mathbf{VNC}^1$ by formalizing a proof of Nepomnjascij's Theorem in such cuts. This is a strengthening of a result by Paris and Wilkie. We can then exploit our result in Proof Complexity to observe that Frege proof systems can be sub exponentially simulated by bounded depth Frege proof systems. This result has recently been obtained by Filmus, Pitassi and Santhanam in a direct proof. As an interesting observation we also obtain an average case separation of Resolution from AC0-Frege by applying a recent result with Tzameret.
description: 16 pages
Tulliola – die vergessene Tochter. Eine Spurensuche
Creators: name: Habermehl, Peter
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Peter Habermehl läßt in seinem Beitrag ein lebendiges Bild von Tullia, der Tochter Ciceros, entstehen: Ver­streut über Ciceros reiche Korrespondenz findet sich eine ganze Palette von Nach­richten über Tullia, die sich zu einem faszinierenden Mosaik ihres Lebens zusammenfügen. Eine Auswahl dieser Testimonien, samt Über­setzung und Kommentar, ist als Handreichung für Lehrerinnen und Lehrer gedacht, die z.B. im Rahmen einer thematischen Einheit zur Rolle der Frau in der römischen Gesell­schaft diese Texte mit ihrer Klasse lesen wollen. PD Dr. Peter Habermehl ist als Gräzist an der Berlin-Brandenburgischen Akademie der Wissenschaften tätig.
description: Pegasus-Onlinezeitschrift, Bd. 6, Nr. 1 (2006): Pegasus-Onlinezeitschrift
Optimal simple structures with bending and membrane stresses
Creators: name: Giraudbit, Jean-Noël
Publisher: name: California Institute of Technology
Year: 1972
Subjects: Aeronautics

description: Structural optimization of elastic solid structures with membrane and bending stresses is studied. A necessary and sufficient optimality condition for maximum stiffness is derived using an energy formulation (minimum potential energy). In the case of pure membrane or pure bending stress states, maximum stiffness and maximum strength are governed by the same optimality condition (uniform strength design). For mixed stress states (membrane and bending), this result is not true, and a general method of approach to find a necessary condition for maximum strength is developed by means of the calculus of variation. Two particular statically indeterminate problems with one design variable to be optimized (clamped-clamped beam, clamped-clamped arch) are treated by this method, and, in both examples, maximum. strength is achieved by a uniform strength design.
Study of phase diagram and superconducting states in LaFeAsO$_{1-x}$H$_x$ based on the multiorbital extended Hubbard model
Creators: name: Yamakawa, Y.
name: Onari, S.
name: Kontani, H.
name: Fujiwara, N.
name: Iimura, S.
name: Hosono, H.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: To understand the recently established unique magnetic and superconducting phase diagram of LaFeAsO$_{1-x}$H$_x$, we analyze the realistic multiorbital tight-binding model for $x=0 \sim 0.4$ beyond the rigid band approximation. Both the spin and orbital susceptibilities are calculated in the presence of the Coulomb and charge quadrupole interactions. It is found that both orbital and spin fluctuations strongly develop at both $x \sim 0$ and 0.4, due to the strong violation of the rigid band picture in LaFeAsO$_{1-x}$H$_x$. Based on this result, we discuss the experimental phase diagram, especially the double-dome superconducting phase. Moreover, we show that the quadrupole interaction is effectively produced by the vertex correction due to Coulomb interaction, resulting in the mutual development of spin and orbital fluctuations.
description: 5 pages, 5 figures, to be published in Phys. Rev. B (Rapid Communications)
Nüchterner Taumel
Creators: name: Baur, Detlev
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Detlev Baur vergleicht zwei münchner Inszenierungen der Euripidestragödie Die Bakchen, die Dieter Dorn am Residenztheater und Jossi Wieler in den Kammerspielen auf die Bühne gebracht haben. Dr. Detlev Baur, Gräzist und Theaterwissenschaftler in einer Person, ist in Köln Redakteur des Theatermagazins Die Deutsche Bühne.
description: Pegasus-Onlinezeitschrift, Bd. 6, Nr. 1 (2006): Pegasus-Onlinezeitschrift
Odysseus – Metamorphosen eines griechischen Helden Struktur und Leitmotive der Odyssee
Creators: name: Zimmermann, Bernhard
Publisher: name: Pegasus-Onlinezeitschrift
Year: 2017

description: Keine andere Gestalt der griechischen Mythologie hat die Phantasie so angeregt wie Odysseus. Seit den homerischen Epen bis in die Gegenwart hinein faszinierte er immer wieder Künstler, Komponisten und Literaten aufs neue. Bernhard Zimmermann stellt zunächst den Odysseus der Odyssee vor und gibt anschließend anhand zahlreicher Textbeispiele einen Einblick in die vielfältige Rezeption der Odysseus-Gestalt: Pindar, Sophokles, Euripides, Ovid, Boccaccio, D'Annunzio und Foscolo sind nur einige wichtige Stationen dieser bewegten Rezeptionsgeschichte.
description: Pegasus-Onlinezeitschrift, Bd. 7, Nr. 2 (2007): Pegasus-Onlinezeitschrift
Interaction effect in two-dimensional Dirac fermions
Creators: name: Jia, Yongfei
name: Guo, Huaiming
name: Chen, Ziyu
name: Shen, Shun-Qing
name: Feng, Shiping
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Based on the Dirac equations in the two-dimensional $π-$ flux model, we study the interaction effects both in nontrivial gapped and gapless Dirac equations with numerical exact diagonalization method. In the presence of the nearest and next nearest neighbor interactions: for nontrivial gapped Dirac equation, the topological phase is robust and persists in a finite region of the phase diagram; while for gapless Dirac equation, charge-density-wave and stripe phases are identified and the phase diagram in $(V_1, V_2)$ plane is obtained. When the next-next-nearest neighbor interaction is further included to gapless Dirac equation, the topological phase expected in the mean-field theory is absent. Our results are related to the possibility of dynamically generating topological phase from the electronic correlations.
description: 7 pages, 8 figures. More discussins are added; accepted for publication in Physical Review B
Separating overlapped intervals on a line
Creators: name: Li, Shimin
name: Wang, Haitao
Publisher: name: Journal of Computational Geometry
Year: 2019

description: Given n intervals on a line ℓ, we consider the problem of moving these intervals on ℓ such that after the movement no two intervals overlap and the maximum moving distance of the intervals is minimized. The difficulty for solving the problem lies in determining the order of the intervals in an optimal solution. By interesting observations, we show that it is sufficient to consider at most n “candidate” lists of ordered intervals. Further, although explicitly maintaining these lists takes Ω(n^2) time and space, by more observations and a pruning technique, we present an algorithm that can compute an optimal solution in O(n log n) time and O(n) space. We also prove an Ω(n log n) time lower bound for solving the problem, which implies the optimality of our algorithm.
description: Journal of Computational Geometry, Vol. 10 No. 1 (2019)
Orthogonal Terrain Guarding is NP-complete
Creators: name: Bonnet, Édouard
name: Giannopoulos, Panos
Publisher: name: Journal of Computational Geometry
Year: 2019

description: A terrain is an x-monotone polygonal curve, that is, every vertical line crosses the curve at most once. In the Terrain Guarding problem, a special case of the famous art gallery problem, one has to place at most $k$ guards on the vertices of a $n$-vertex terrain, in order to fully see it. In 2010, King and Krohn showed that Terrain Guarding is NP-hard [SODA '10, SIAM J. Comput. '11] thereby solving a long-standing open question. They observe that their proof does not settle the complexity of Orthogonal Terrain Guarding where the terrain only consists of horizontal or vertical segments; those terrains are called rectilinear or orthogonal. Recently, Ashok et al. [SoCG'17] presented an FPT algorithm running in time $k^{O(k)}n^{O(1)}$ for Dominating Set in the visibility graphs of rectilinear terrains without 180-degree vertices. They ask if Orthogonal Terrain Guarding is in P or NP-hard. In the same paper, they give a subexponential-time algorithm running in $n^{O(\sqrt n)}$ (actually even $n^{O(\sqrt k)}$) for the general Terrain Guarding and notice that the hardness proof of King and Krohn only disproves a running time $2^{o(n^{1/4})}$ under the ETH. Hence, there is a significant gap between their $2^{O(n^{1/2} \log n)}$-algorithm and the no $2^{o(n^{1/4})}$ ETH-hardness implied by King and Krohn's result. In this paper, we adapt the gadgets of King and Krohn to rectilinear terrains in order to prove that even Orthogonal Terrain Guarding is NP-complete. Then, we show how to obtain an improved ETH lower bound of $2^{\Omega(n^{1/3})}$ by refining the quadratic reduction from Planar 3-SAT into a cubic reduction from 3-SAT. [In the conference version of this paper, we mistakenly claim a tighter lower bound.] This works for both Orthogonal Terrain Guarding and Terrain Guarding.
description: Journal of Computational Geometry, Vol. 10 No. 2 (2019): Special Issue of Selected Papers from SoCG 2018