In this work we consider spatial clustering problem with no a priori information. The number of clusters is unknown, and clusters may have arbitrary shapes and density differences. The proposed clustering methodology addresses several challenges of the clustering problem including solution evaluation, neighborhood construction, and data set reduction. In this context, we first introduce two obj...

A combinatorial auction is an auction where the bidders have the choice to bid on bundles of items. The WDP in combinatorial auctions is the problem of finding winning bids that maximize the auctioneer’s revenue under the constraint that each item can be allocated to at most one bidder. The WDP is known as an NP-hard problem with practical applications like electronic commerce, production manag...

The fixed-charge Capacitated Multi-commodity Network Design (CMND) is a well-known problem of both practical and theoretical significance. Network design models represent a wide variety of planning and operation management issues in transportation telecommunication, logistics, production and distribution. In this paper, Ant Colony Optimization (ACO) based neighborhoods are proposed for CMND pro...

A combinatorial auction is an auction where the bidders have the choice to bid on bundles of items. The Winner Determination Problem (WDP) in combinatorial auctions is the problem of finding winning bids that maximize the auctioneer’s revenue under constraint, where each item can be allocated to at most one bidder. WDP is known as an NP-hard problem with practical applications like electronic c...

For reliability-based topology optimization (RBTO) of double layer grids, a two-stage optimization method is presented by applying “Solid Isotropic Material with Penalization” and “Ant Colony Optimization” (SIMP-ACO method). To achieve this aim, first, the structural stiffness is maximized using SIMP. Then, the characteristics of the obtained topology are used to enhance ACO through six modific...

abstract urban neighborhoods are as the smallest unit of spatial organization in the city to urban stability. neighborhoods development will be considered one of the main goals of planning the urban stability development and, it is key action to achieve stable development. stable community development perspective, will strengthen the new approach, that the solving of the urban problems is perce...

Kriging is an advanced geostatistical procedure that generates an estimated surface or 3D model from a scattered set of points. This method can be used for estimating resources using a grid of sampled boreholes. However, conventional ordinary kriging (OK) is unable to take locally varying anisotropy (LVA) into account. A numerical approach has been presented that generates an LVA field by calcu...

Ant Colony Optimization (ACO) algorithms are widely used in medical imaging, especially for image edge detection and image segmentation. In this paper, fundamentally we use ACO algorithm for lung nodule detection and compare the performance against three other algorithms namely Otsu algorithm, Watershed algorithm, Global region based segmentation. In addition, we suggest a novel approach which ...

A hybrid population based Ant Colony Optimization (ACO) algorithm PFold-P-ACO for protein folding in the HP model is proposed in this paper. This is the first population based ACO algorithm in the bioinformatics. It is shown experimentally that the algorithms achieves on nearly all test sequences at least comparable results to other state of the art algorithms. Compared to the state of the art ...