A problem of arrangements on chessboards and generalizations
نویسنده
چکیده
For a unified approach to the study of the distributions of like objects on chessboards, the numbers defined by where A, denotes the partial Cwith respect to u) difference operator, are examined. This approach facilitates the treatment of further generalizations of such problems.
منابع مشابه
A Mathematical Optimization Model for Solving Minimum Ordering Problem with Constraint Analysis and some Generalizations
In this paper, a mathematical method is proposed to formulate a generalized ordering problem. This model is formed as a linear optimization model in which some variables are binary. The constraints of the problem have been analyzed with the emphasis on the assessment of their importance in the formulation. On the one hand, these constraints enforce conditions on an arbitrary subgraph and then g...
متن کاملAn Optimization Model for Epidemic Mitigation and Some Theoretical and Applied Generalizations
In this paper, we present a binary-linear optimization model to prevent the spread of an infectious disease in a community. The model is based on the remotion of some connections in a contact network in order to separate infected nodes from the others. By using this model we nd an exact optimal solution and determine not only the minimum number of deleted links but also their exact positions. T...
متن کاملDeriving Formulas for the Pentomino Exclusion Problem
Existence of constant time algorithms for the ∆-dislocation problem on fasciaand rotagraphs is proved. Application to the Pentommino exclusion problem yields formulas for 6× n and 7× n chessboards.
متن کاملOn generalizations of semiperfect and perfect rings
We call a ring $R$ right generalized semiperfect if every simple right $R$-module is an epimorphic image of a flat right $R$-module with small kernel, that is, every simple right $R$-module has a flat $B$-cover. We give some properties of such rings along with examples. We introduce flat strong covers as flat covers which are also flat $B$-covers and give characterizations of $A$-perfe...
متن کاملOn two generalizations of semi-projective modules: SGQ-projective and $pi$-semi-projective
Let $R$ be a ring and $M$ a right $R$-module with $S=End_R(M)$. A module $M$ is called semi-projective if for any epimorphism $f:Mrightarrow N$, where $N$ is a submodule of $M$, and for any homomorphism $g: Mrightarrow N$, there exists $h:Mrightarrow M$ such that $fh=g$. In this paper, we study SGQ-projective and $pi$-semi-projective modules as two generalizations of semi-projective modules. A ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Discrete Mathematics
دوره 27 شماره
صفحات -
تاریخ انتشار 1979