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321  Photo CJM
No abstract.


323  Dedication: Ted Bisztriczky Böröczky, K.; Böröczky, K. J.; Fodor, F.; Harborth, H.; Kuperberg, W.
No abstract.


327  Geometric ``Floral'' Configurations Berman, Leah Wrenn; Bokowski, Jürgen; Grünbaum, Branko; Pisanski, Toma\v{z}
With an increase in size, configurations of points and lines
in the plane usually become complicated and hard to analyze.
The ``floral'' configurations we are introducing here represent
a new type that makes accessible and visually intelligible
even configurations of considerable size. This is achieved
by combining a large degree of symmetry with a hierarchical
construction. Depending on the details of the interdependence
of these aspects, there are several subtypes that are described
and investigated.


342  On the Xray Number of Almost Smooth Convex Bodies and of Convex Bodies of Constant Width Bezdek, K.; Kiss, Gy.
The Xray numbers of some classes of convex bodies are investigated.
In particular, we give a proof of the Xray Conjecture as well as
of the Illumination Conjecture for almost smooth convex bodies
of any dimension and for convex bodies of constant width of
dimensions $3$, $4$, $5$ and $6$.


349  On Projection Bodies of Order One Campi, Stefano; Gronchi, Paolo
The projection body of order one $\Pi_1K$ of a convex body $K$ in
$\R^n$ is the body whose support function is, up to a constant, the
average mean width of the orthogonal projections of $K$ onto
hyperplanes through the origin.


361  A Note on Covering by Convex Bodies Tóth, Gábor Fejes
A classical theorem of Rogers states
that for any convex body $K$ in $n$dimensional Euclidean space
there exists a covering of the space by translates of $K$ with
density not exceeding $n\log{n}+n\log\log{n}+5n$. Rogers' theorem
does not say anything about the structure of such a covering. We
show that for sufficiently large values of $n$ the same bound can
be attained by a covering which is the union of $O(\log{n})$
translates of a lattice arrangement of $K$.


366  A Class of Cellulated Spheres with NonPolytopal Symmetries Gévay, Gábor
We construct, for all $d\geq 4$, a cellulation of $\mathbb S^{d1}$.
We prove that these cellulations cannot be polytopal with maximal
combinatorial symmetry. Such nonrealizability phenomenon was first
described in dimension 4 by Bokowski, Ewald and Kleinschmidt, and,
to the knowledge of the author, until now there have not been any
known examples in higher dimensions. As a starting point for the
construction, we introduce a new class of (Wythoffian) uniform
polytopes, which we call duplexes. In proving our main result,
we use some tools that we developed earlier while studying perfect
polytopes. In particular, we prove perfectness of the duplexes;
furthermore, we prove and make use of the perfectness of another
new class of polytopes which we obtain by a variant of the socalled
$E$construction introduced by Eppstein, Kuperberg and Ziegler.


380  Successive Minima and Radii Henk, Martin; Cifre, Mar\'\i a A. Hernández
In this note we present inequalities relating the successive minima of an
$o$symmetric convex body and the successive inner and outer radii of the
body. These inequalities join known inequalities involving only either
the successive minima or the successive radii.


388  Transversals with Residue in Moderately Overlapping $T(k)$Families of Translates Heppes, Aladár
Let $K$ denote an oval, a centrally symmetric compact convex domain
with nonempty interior. A family of translates of $K$ is said to have
property $T(k)$ if for every subset of at most $k$ translates there
exists a common line transversal intersecting all of them. The integer
$k$ is the stabbing level of the family.
Two translates $K_i = K + c_i$ and $K_j = K + c_j$ are said to be
$\sigma$disjoint if $\sigma K + c_i$ and $\sigma K + c_j$ are disjoint.
A recent Hellytype result claims that for every
$\sigma > 0 $ there exists an integer $k(\sigma)$ such that if a
family of $\sigma$disjoint unit diameter discs has property $T(k) k
\geq k(\sigma)$, then there exists a straight line meeting all members
of the family. In the first part of the paper we give the extension of
this theorem to translates of an oval $K$. The asymptotic behavior of
$k(\sigma)$ for $\sigma \rightarrow 0$ is considered as well.


403  Shaken Rogers's Theorem for Homothetic Sections JerónimoCastro, J.; Montejano, L.; MoralesAmaya, E.
We shall prove the following shaken Rogers's theorem for
homothetic sections: Let $K$ and $L$ be strictly convex bodies and
suppose that for every plane $H$ through the origin we can choose
continuously sections of $K $ and $L$, parallel to $H$, which are
directly homothetic. Then $K$ and $L$ are directly homothetic.


407  On the BezdekPach Conjecture for Centrally Symmetric Convex Bodies Lángi, Zsolt; Naszódi, Márton
The BezdekPach conjecture asserts that the maximum number of
pairwise touching positive homothetic copies of a convex body in
$\Re^d$ is $2^d$. Nasz\'odi proved that the quantity in question is
not larger than $2^{d+1}$. We present an improvement to this result by
proving the upper bound $3\cdot2^{d1}$ for centrally symmetric
bodies. Bezdek and Brass introduced the onesided Hadwiger number of a
convex body. We extend this definition, prove an upper bound on the
resulting quantity, and show a connection with the problem of touching
homothetic bodies.


416  Hamiltonian Properties of Generalized Halin Graphs Malik, Shabnam; Qureshi, Ahmad Mahmood; Zamfirescu, Tudor
A Halin graph is a graph $H=T\cup C$, where $T$ is a tree with no
vertex of degree two, and $C$ is a cycle connecting the endvertices
of $T$ in the cyclic order determined by a plane embedding of $T$.
In this paper, we define classes of generalized Halin graphs, called
$k$Halin graphs, and investigate their Hamiltonian properties.


424  Covering Discs in Minkowski Planes Martini, Horst; Spirova, Margarita
We investigate the following version of the circle covering
problem in strictly convex (normed or) Minkowski planes: to cover
a circle of largest possible diameter by $k$ unit circles. In
particular, we study the cases $k=3$, $k=4$, and $k=7$. For $k=3$
and $k=4$, the diameters under consideration are described in
terms of sidelengths and circumradii of certain inscribed regular
triangles or quadrangles. This yields also simple explanations of
geometric meanings that the corresponding homothety ratios have.
It turns out that basic notions from Minkowski geometry play an
essential role in our proofs, namely Minkowskian bisectors,
$d$segments, and the monotonicity lemma.


435  Modular Reduction in Abstract Polytopes Monson, B.; Schulte, Egon
The paper studies modular reduction techniques for abstract regular
and chiral polytopes, with two purposes in mind:\ first, to survey the
literature about modular reduction in polytopes; and second, to apply
modular reduction, with moduli given by primes in $\mathbb{Z}[\tau]$
(with $\tau$ the golden ratio), to construct new regular $4$polytopes
of hyperbolic types $\{3,5,3\}$ and $\{5,3,5\}$ with automorphism
groups given by finite orthogonal groups.


451  Indecomposable Coverings Pach, János; Tardos, Gábor; Tóth, Géza
We prove that for every $k>1$, there exist $k$fold coverings of the
plane (i) with strips, (ii) with axisparallel rectangles, and
(iii) with homothets of any fixed concave quadrilateral, that cannot
be decomposed into two coverings. We also construct for every
$k>1$ a set of points $P$ and a family of disks $\cal D$ in the
plane, each containing at least $k$ elements of $P$, such that, no
matter how we color the points of $P$ with two colors,
there
exists a disk $D\in{\cal D}$ all of whose points are of the same
color.


464  Two Volume Product Inequalities and Their Applications Stancu, Alina
Let $K \subset {\mathbb{R}}^{n+1}$ be a convex body of class $C^2$
with everywhere positive Gauss curvature. We show that there exists
a positive number $\delta (K)$ such that for any $\delta \in (0,
\delta(K))$ we have $\Volu(K_{\delta})\cdot
\Volu((K_{\delta})^{\sstar}) \geq \Volu(K)\cdot \Volu(K^{\sstar}) \geq
\Volu(K^{\delta})\cdot \Volu((K^{\delta})^{\sstar})$, where $K_{\delta}$,
$K^{\delta}$ and $K^{\sstar}$ stand for the convex floating body, the
illumination body, and the polar of $K$, respectively. We derive a
few consequences of these inequalities.

