scholarly journals Room n-cubes of lowe order

Author(s):  
Jeffrey H. Dinitz

AbstractA Room n-cube of side t is an n dimensional array of side t which satisfies the property that each two dimensional projection is a Room square. The existence of a Room n-cube of side t is equivalent to the existence of n pairwise orthgonal symmetric Latin squares (POSLS) of side t. The existence of n pairwise orthogonal starters of order t implies the existence of n POSLS of side t. Denote by v(n) the maximum number of POSLS of side t. In this paper, we use Galois fields and computer constructions to construct sets of pairwise orthogonal starters of order t ≤ 101. The existence of these sets of starters gives improved lower bounds for v(n). In particular, we show v(17) ≥ 5, v(21) ≥ 5, v(29) ≥ 13, v(37) ≥ 15 and v(41) ≥ 9, among others.

2008 ◽  
Vol 01 (01) ◽  
pp. 121-130 ◽  
Author(s):  
Sapna Jain

In [16], the author introduced a new pseudo-metric on the space Matm×s(Zq) which is the module space of all m × s matrices with entries from the finite ring Zq generalizing the classical Lee metric (see [17]) and the array RT- metric (see [19]) and named this pseudo-metric as the Generalized-Lee-RT-Pseudo-Metric (or the GLRTP-Metric). In this paper, we obtain some lower bounds for two dimensional array codes correcting burst errors (see [10]) with weight constraints under the GLRTP-metric.


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


2013 ◽  
Author(s):  
Roman Verba ◽  
Vasil Tiberkevich ◽  
Elena Bankowski ◽  
Thomas Meitzler ◽  
Gennadiy Melkov ◽  
...  

2021 ◽  
Vol 1106 (1) ◽  
pp. 012028
Author(s):  
A A Jasni ◽  
YS Yap ◽  
I H. Hashim ◽  
N E Ahmad ◽  
N Ramlee

2021 ◽  
Vol 118 (4) ◽  
pp. 044002
Author(s):  
F. van Riggelen ◽  
N. W. Hendrickx ◽  
W. I. L. Lawrie ◽  
M. Russ ◽  
A. Sammak ◽  
...  

Author(s):  
RANI SIROMONEY ◽  
K. G. SUBRAMANIAN ◽  
P. J. ABISHA

Language theoretic public key cryptosystems for strings and pictures are discussed. Two methods of constructing public key cryptosystems for the safe transmission or storage of chain code pictures are presented; the first one encrypts a chain code picture as a string and the second one as a two-dimensional array.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
R. J. E. Taylor ◽  
D. T. D. Childs ◽  
P. Ivanov ◽  
B. J. Stevens ◽  
N. Babazadeh ◽  
...  

Algorithmica ◽  
2021 ◽  
Author(s):  
Seungbum Jo ◽  
Rahul Lingala ◽  
Srinivasa Rao Satti

AbstractWe consider the problem of encoding two-dimensional arrays, whose elements come from a total order, for answering $${\text{Top-}}{k}$$ Top- k queries. The aim is to obtain encodings that use space close to the information-theoretic lower bound, which can be constructed efficiently. For an $$m \times n$$ m × n array, with $$m \le n$$ m ≤ n , we first propose an encoding for answering 1-sided $${\textsf {Top}}{\text {-}}k{}$$ Top - k queries, whose query range is restricted to $$[1 \dots m][1 \dots a]$$ [ 1 ⋯ m ] [ 1 ⋯ a ] , for $$1 \le a \le n$$ 1 ≤ a ≤ n . Next, we propose an encoding for answering for the general (4-sided) $${\textsf {Top}}{\text {-}}k{}$$ Top - k queries that takes $$(m\lg {{(k+1)n \atopwithdelims ()n}}+2nm(m-1)+o(n))$$ ( m lg ( k + 1 ) n n + 2 n m ( m - 1 ) + o ( n ) ) bits, which generalizes the joint Cartesian tree of Golin et al. [TCS 2016]. Compared with trivial $$O(nm\lg {n})$$ O ( n m lg n ) -bit encoding, our encoding takes less space when $$m = o(\lg {n})$$ m = o ( lg n ) . In addition to the upper bound results for the encodings, we also give lower bounds on encodings for answering 1 and 4-sided $${\textsf {Top}}{\text {-}}k{}$$ Top - k queries, which show that our upper bound results are almost optimal.


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