clustering is a widespread data analysis and data mining technique in many fields of study such as engineering, medicine, biology and the like. the aim of clustering is to collect data points. in this paper, a cultural algorithm (ca) is presented to optimize partition with n objects into k clusters. the ca is one of the effective methods for searching into the problem space in order to find a n...

Clustering problems appear in a wide range of unsupervised classification applications such as pattern recognition, vector quantization, data mining and knowledge discovery. The k-means algorithm is one of the most widely used clustering techniques. Unfortunately, k-means is extremely sensitive to the initial choice of centers and a poor choice of centers may lead to a local optimum that is qui...

The Boolean network can be used as a mathematical model for gene regulatory networks. An attractor, which is a state of a Boolean network repeating itself periodically, can represent a stable stage of a gene regulatory network. It is known that the problem of finding an attractor of the shortest period is NP-hard. In this article, we give a fixed-parameter algorithm for detecting a singleton at...

We analyze a simple sequential algorithm (SA) for allocating indivisible items that are strictly ranked by n ≥ 2 players. It yields at least one Pareto-optimal allocation which, when n = 2, is envy-free unless no envy-free allocation exists. However, an SA allocation may not be maximin or Borda maximin—maximize the minimum rank, or the Borda score, of the items received by a player. Although SA...

The analog circuit design is a hard complex and time consuming task. Recently, Ant Colony Optimization algorithm (ACO) has emerged as a powerful and useful method for optimal design of analog circuits, based on the finding of the good compromise between the most important performances or merits figure of a given circuit. As a drawback it needs longer time execution when compared for instance to...

It is not rare that the performance of one metaheuristic algorithm can be improved by incorporating ideas taken from another. In this article we present how Simulated Annealing (SA) can be used to improve the efficiency of the Ant Colony System (ACS) and Enhanced ACS when solving the Sequential Ordering Problem (SOP). Moreover, we show how the very same ideas can be applied to improve the conve...

In this paper, a model is presented to locate ambulances, considering backup facility (to increase reliability) and the restriction of ambulance capacity. This model is designed for emergencies. In this model the covered demand for each demand point depends on the number of coverage times and the amount of demand. The demand amount and ambulance coverage radius are considered...

In the framework of the ongoing MPEG–4 standardization phase of ISO/IEC Sikora and Makai suggested a shape–adaptive DCT algorithm (SA–DCT) for efficient and low–complexity coding of arbitrarily shaped video objects. Referring to this algorithmic approach, the objective of the underlying contribution is to emphasize a performance limitation of conventional SA–DCT definition and to propose an ext...

Abstract: In this paper, an exergy analysis approach is proposed for optimal design of distillation column by using simulated annealing algorithm. First, the simulation of a distillation column was performed by using the shortcut results and irreversibility in each tray was obtained. The area beneath the exergy loss profile was used as Irreversibility Index in the whole column. Then, First Opti...

An elegant and intuitive method to control a neuroprosthesis is to use S(urface)EMG activity of voluntary controllable muscles [1]. Since in such applications the voluntary SEMG activity is contaminated with much higher stimulation artifacts (SA) than the SEMG signal, the artifact somehow has to be eliminated. Well-established SA removal techniques are artifact blanking or filtering methods. Re...