14,870 research outputs found
On the number of symbols that forces a transversal
Akbari and Alipour conjectured that any Latin array of order with at
least symbols contains a transversal. We confirm this conjecture for
large , and moreover, we show that symbols suffice.Comment: 6 pages, 1 figur
Latin transversals of rectangular arrays
Let m and n be integers, . An m by n array consists of mn
cells, arranged in m rows and n columns, and each cell contains exactly one
symbol. A transversal of an array consists of m cells, one from each row and no
two from the same column. A latin transversal is a transversal in which no
symbol appears more than once. We will establish a sufficient condition that a
3 by n array has a latin transversal.Comment: Theorem 4 has been added, which provides a lower bound on L(m,n
Parity of transversals of Latin squares
We introduce a notion of parity for transversals, and use it to show that in
Latin squares of order , the number of transversals is a multiple of
4. We also demonstrate a number of relationships (mostly congruences modulo 4)
involving , where is the number of diagonals of a given
Latin square that contain exactly different symbols.
Let denote the matrix obtained by deleting row and column
from a parent matrix . Define to be the number of transversals
in , for some fixed Latin square . We show that for all and . Also, if has odd order then the
number of transversals of equals mod 2. We conjecture that for all .
In the course of our investigations we prove several results that could be of
interest in other contexts. For example, we show that the number of perfect
matchings in a -regular bipartite graph on vertices is divisible by
when is odd and . We also show that for all , when is an integer matrix of odd
order with all row and columns sums equal to
Racing car chassis
Cílem této bakalářské práce je analýza současných konceptů podvozků závodních okruhových aut. V první části práce je zpracován historický vývoj, charakteristika kol a pneumatik s reprezentací dobře známých produktů. V druhé části je popsán systém odpružení, pružné média a tlumící členy. Systémy odpružení je zde rozdělen na nezávisle a polozávislé zavěšení kol a odpružení pevných náprav. Následující oddíl této práce je zaměřený na standardní kontrolní systémy, jako jsou ABS, ESC a TSC. Závěr přináší rychlé shrnutí této problematiky.The aim of this bachelor thesis is to analyse contemporary concepts of circuit race car chassis. In the first part of the thesis, the historical evolution is described and then wheels and tires characteristic within some well-known brand products are represented. The second important part includes the suspension systems, springing medium and damping members. The suspension systems are further divided to independent and semi-independent solutions and rigid axle suspensions. The end of this thesis deals with the standard braking control systems, such as ABS, ESC and TCS. The conclusion brings the quick summary of this subject.
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