Let $T$ be a tree of order $n$ and $S_2(T)$ the sum two largest Laplacian eigenvalues $T$. Fritscher et al. proved that for any $n$, $S_2(T) \leq n+2-\frac{2}{n}$. Guan determined with maximum among all trees $n$. In this paper, we characterize \geq n+1$ except some trees. Moreover, also determine first $\lfloor\frac{n-2}{2}\rfloor$ according to their $S_2(T)$. This extends result

in this paper we show that if q is a power of a prime p , then the projective special linear group psl(2, q) and the stabilizer of a point of the projective line have maximum sum element orders among all proper subgroups of projective general linear group pgl(2, q) for q odd and even respectively

this paper addresses the problem of minimizing the sum of maximum earliness and tardiness on identical parallel machines scheduling problem. each job has a processing time and a due date. since this problem is trying to minimize and diminish the values of earliness and tardiness, the results can be useful for just–in-time production systems. it is shown that the problem is np-hard. using effici...

in this paper we show that if q is a power of a prime p , then the projective special linear group psl(2, q) and the stabilizer of a point of the projective line have maximum sum element orders among all proper subgroups of projective general linear group pgl(2, q) for q odd and even respectively

In this paper we show that if q is a power of a prime p , then the projective special linear group PSL(2, q) and the stabilizer of a point of the projective line have maximum sum element orders among all proper subgroups of projective general linear group PGL(2, q) for q odd and even respectively