We address the no-wait k-stage flexible flowshop scheduling problem where there are m identical machines at each stage. The objectives are to schedule the available n jobs so that makespan and mean tardiness of n jobs are minimized. Sequence-dependent setup times are treated in this problem as one of the prominent practical assumptions. This problem is NP-hard, and therefore we present a new mu...

abstract the results of an integrated study aimed at restoring water quality in a large watershed including seven catchments in north east iran are presented in this paper. this case study demonstrates how landscape metrics reflect direct or surrogate causes of the land use practices that are the determinants of water quality parameters. water quality factors included ec, ph, cl-1, hco3-1, so4-...

We study the minimum diameter color-spanning set problem which has recently drawn some attention in the database community. We show that the problem can be solved in polynomial time for L1 and L∞ metrics, while it is NP-hard for all other Lp metrics even in two dimensions. However, we can efficiently compute a constant factor approximation.

landscape metrics quantifies structural features of the landscape. one of the advantages of these metrics is a possibility to use them in fast cumulative assessment of the development activities in the environment. in this paper, the cumulative effects of road network expansion on the tree cover of gorgan, kordkuy, aliabad townships in golestan province were investigated. to prepare the require...

A metric d is h-embeddable if it can be isometrically embedded in some hypercube. Equivalently, d is h-embeddable if d can be written as a nonnegative integer combination of cut metrics. The problem of testing h-embeddability is NP-complete (Chvbta!, 1980). A good characterization of h-embeddability permitting a polynomial-time algorithm was given for several classes of metrics, in particular, ...

Abstract The results of an integrated study aimed at restoring water quality in a large watershed including seven catchments in north east Iran are presented in this paper. This case study demonstrates how landscape metrics reflect direct or surrogate causes of the land use practices that are the determinants of water quality parameters. Water quality factors included EC, pH, Cl-1, HCO3-1, SO4-...

Increasing economy’s resistance against the menace of sanctions, various risks, shocks, and internal and external threats are one of the main national policies which can be implemented through bank investments. Investment project selection is a complex and multi-criteria decision-making process that is influenced by multiple and often some conflicting objectives. This paper studies portfolio inve...