clustering technique is one of the most important techniques of data mining and is the branch of multivariate statistical analysis and a method for grouping similar data in to same clusters. with the databases getting bigger, the researchers try to find efficient and effective clustering methods so that they can make fast and real decisions. thus, in this paper, we proposed an improved ant syst...

Four pigeons were given simultaneous discrimination training with visual patterns arbitrarily divided into two sets, with the stimuli in one set designated A1, B1, C1, and D1 and those in the other set designated A2, B2, C2, and D2. In sequentially introduced training phases, the pigeons were exposed to a series of reversals to establish AB and then CD equivalences. In subsequent testing sessio...

Repeat proteins are composed of tandem structural modules in which close contacts do not extend beyond adjacent repeats. Despite the local nature of these close contacts, repeat proteins often unfold as a single, highly coupled unit. Previous studies on the Notch ankyrin domain suggest that this lack of equilibrium unfolding intermediates results both from stabilizing interfaces between each re...

this study presents an overview of the different strategies that persian learners of english employ to deal with initial clusters. while vowel epenthesis appears to be the most widespread repair strategy to conform such clusters to persian phonotactics, the location of the epenthetic vowel varies. in this paper, we investigate two approaches that seek to explain the epenthetic site. the first o...

o ne of the effective strategies for economic development of clusters is the conduct of networking activities by cluster members. indeed, the majority of cluster members are micro and small enterprises, so, should attempt to overcome their inherent constraints and influence the market through networking activities. in addition, these enterprises lack an intra-firm research and development unit ...

O ne of the effective strategies for economic development of clusters is the conduct of networking activities by cluster members. Indeed, the majority of cluster members are micro and small enterprises, so, should attempt to overcome their inherent constraints and influence the market through networking activities. In addition, these enterprises lack an intra-firm research and develo...

We have carried out a series of small scale collisional N-body calculations of single-mass star clusters to investigate the dependence of the lifetime of star clusters on their initial parameters. Our models move through an external galaxy potential with a logarithmic density profile and they are limited by a cut-off radius. In order to find scaling relations between the lifetime of star cluste...

In this study, electronic structures of ground state of pure vanadium sub-nano clusters, Vn (n=2-5), and their interactions with small ligands for example CO and triplet O2 molecules are investigated by using density functional theory (DFT) calibration at the mPWPW91/QZVP level of theory. The favorable orientations of these ligands in interaction with pure vanadium sub-nano clusters were determ...