117,854 research outputs found
The Spider Poset Is Macaulay
No full textAbstractLet Q(k, l) be a poset whose Hasse diagram is a regular spider with k+1 legs having the same length l. We show that for any n⩾1 the nth cartesian power of the spider poset Q(k, l) is a Macaulay poset for any k⩾0 and l⩾1. In combination with our recent results (S. L. Bezrukov, 1998, J. Combin. Theory Ser. A84, 157–170) this provides a complete characterization of all Macaulay posets which are cartesian powers of upper semilattices, whose Hasse diagrams are trees
Partitioning the n-cube into sets with mutual distance 1
No full textBlokhuis A, Metsch K, Moorhouse GE, Ahlswede R, Bezrukov SL. Partitioning the n-cube into sets with mutual distance 1. Applied Mathematics Letters. 1993;6(4):17-19
Description and chemical composition of manganese nodules sampled during the R/V "Vityaz" Expedition Vityaz-35
No full textThis paper presents data on the chemical composition of iron-manganese nodules and associated sediments collected during the 35th voyage of the R/V "Vityaz" in 1962. The samples were made available to the author by Prof, P. L. Bezrukov. Data on the general distribution of manganese nodules at the bottom of the Indian Ocean were already given by P. L. Bezrukov (1962, 1963). Here the author analyzed the geochemistry of nodules samples from seven stations and four samples from the associated sediments. The analysis separates the outer layer of nodules from their apparent internal core
Edge isoperimetric theorems for integer point arrays
No full textAhlswede R, Bezrukov SL. Edge isoperimetric theorems for integer point arrays. Applied Mathematics Letters. 1995;8(2):75-80.We consider subsets of the n-dimensional grid with the Manhattan metrics, tile., the Cartesian product of chains of lengths k(1),..., k(n)) and study those of them which have maximal number of induced edges of the grid, and those which are separable from their complement by the least number of edges. The first problem was considered for k(1) = ... = k(n) by Bollobas and Leader [1]. Here we extend their result to arbitrary k(1),..., k(n), and give also a simpler proof based on a new approach. For the second problem, [1] offers only an inequality. We show that bur approach to the first problem also gives a solution for the second problem, if all k(i) = infinity. If all k(i)'s are finite, we present an exact solution for n = 2
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Can an odd number of fermions be created due to chiral anomaly?
No full textBezrukov F, Burnier Y, Shaposhnikov M. Can an odd number of fermions be created due to chiral anomaly? Phys .Rev. D. 2006;73(4): 45008.We describe a possibility of creation of an odd number of fractionallycharged fermions in 1+1 dimensional Abelian Higgs model. We point out that for1+1 dimensions this process does not violate any symmetries of the theory, normakes it mathematically inconsistent. We construct the proper definition of thefermionic determinant in this model and underline its non-trivial features thatare of importance for realistic 3+1 dimensional models with fermion numberviolation
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Towards a solution of the strong CP problem by compact extra dimensions
No full textBezrukov FL, Burnier Y. Towards a solution of the strong CP problem by compact extra dimensions. Physical Review D. 2009;80(12): 125004.We show that the strong CP problem can, in principle, be solved dynamicallyby adding extra-dimensions with compact topology. To this aim we consider a toymodel for QCD, which contains a vacuum angle and a strong CP like problem. Wefurther consider a higher dimensional theory, which has a trivial vacuumstructure and which reproduces the perturbative properties of the toy model inthe low-energy limit. In the weak coupling regime, where our computations arevalid, we show that the vacuum structure of the low-energy action is stilltrivial and the strong CP problem is solved. No axion-like particle occur inthis setup and therefore it is not ruled out by astrophysical bounds
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
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