نتایج جستجو برای: 2011 in addition

تعداد نتایج: 17016488  

Journal: :J. Comb. Theory, Ser. A 2009
Raman Sanyal

We show that for polytopes P1, P2, . . . , Pr ⊂ R, each having ni ≥ d + 1 vertices, the Minkowski sum P1 + P2 + · · · + Pr cannot achieve the maximum of ∏ i ni vertices if r ≥ d. This complements a recent result of Fukuda & Weibel (2006), who show that this is possible for up to d − 1 summands. The result is obtained by combining methods from discrete geometry (Gale transforms) and topological ...

Journal: :Discrete & Computational Geometry 2012
Christophe Weibel

It is known that in the Minkowski sum of r polytopes in dimension d, with r < d, the number of vertices of the sum can potentially be as high as the product of the number of vertices in each summand [2]. However, the number of vertices for sums of more polytopes was unknown so far. In this paper, we study sums of polytopes in general orientations, and show a linear relation between the number o...

Journal: :Inf. Process. Lett. 1998
Sándor P. Fekete William R. Pulleyblank

We consider the problem of traveling the contour of the set of all points that are within distance 1 of a connected planar curve arrangement P, forming an embedding of the graph G. We show that if the overall length of P is L, there is a closed roundtrip that visits all points of the contour and has length no longer than 2L + 2n. This result carries over in a more general setting: if R is a com...

Introduction: In the current study, we compared h5-index provided by Google Scholar (GS), impact factor (IF) provided by web of sciences (WOS), and SCImago journal rank indicator (SJR) provided by SCOPUS for quality assessment of nuclear medicine journals. Methods: 2013 h5-index, 2012 IF, and 2011 SJR of nuclear medicine journals were extracted from their publishers namely GS, WOS, and SCOPUS....

2003
PETER ADAMSON

The ‘Abb®sid caliphs al-Ma’m‚n and al-Mu‘ta◊im, who between them reigned from 198 to 227 A.H. (813-842 A.D.) are best-known to historians of philosophy for two things. First, they supported a massive translation project that had already begun in the previous century with al-Ma’m‚n’s grandfather, al-Man◊‚r. The result was that many of the most important works of Greek philosophy and science were...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

abstract ion selective electrodes (ises) are electrochemical sensors that respond selectivity to the activity of ionic species. an ion-selective electrode is an electrochemical device that uses a thin selective membrane or film as the recognition element, and is an electrochemical half-cell equivalent to other half-cells of the zeroth (inert metal in a redox electrolyte). in common methods o...

2008
Tadao Oda

submitted at the Oberwolfach Conference “Combinatorial Convexity and Algebraic Geometry” 26.10–01.11, 1997 Throughout, we fix the notation M := Z and MR := R . Given convex lattice polytopes P, P ′ ⊂ MR, we have (M ∩ P ) + (M ∩ P ) ⊂ M ∩ (P + P ), where P + P ′ is the Minkowski sum of P and P , while the left hand side means {m+m | m ∈ M ∩ P,m ∈ M ∩ P }. Problem 1 For convex lattice polytopes P...

Journal: :Combinatorica 2012
Paul N. Balister Béla Bollobás

In this paper we have shall generalize Shearer’s entropy inequality and its recent extensions by Madiman and Tetali, and shall apply projection inequalities to deduce extensions of some of the inequalities concerning sums of sets of integers proved recently by Gyarmati, Matolcsi and Ruzsa. We shall also discuss projection and entropy inequalities and their connections.

Journal: :Discrete & Computational Geometry 2009
Efi Fogel Dan Halperin Christophe Weibel

We present a tight bound on the exact maximum complexity of Minkowski sums of polytopes in R. In particular, we prove that the maximum number of facets of the Minkowski sum of k polytopes with m1,m2, . . . ,mk facets respectively is bounded from above by

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید