KGSA: A Gravitational Search Algorithm for Multimodal Optimization based on K-Means Niching Technique and a Novel Elitism Strategy

Gravitational Search Algorithm (GSA) is a metaheuristic for solving unimodal problems. In this paper, a K-means based GSA (KGSA) for multimodal optimization is proposed. This algorithm incorporates K-means and a new elitism strategy called “loop in loop” into the GSA. First in KGSA, the members of the initial population are clustered by K-means. Afterwards, new population is created and divided in different niches (or clusters) to expand the search space. The “loop in loop” technique guides the members of each niche to the optimum direction according to their clusters. This means that lighter members move faster towards the optimum direction of each cluster than the heavier members. For evaluations, KGSA is benchmarked on well-known functions and is compared with some of the state-of-the-art algorithms. Experiments show that KGSA provides better results than the other algorithms in finding local and global optima of constrained and unconstrained multimodal functions.

Extraction of Blood Vessels in Retina

This article presents a novel method to extract retinal vascular tree automatically. The proposed method consists of four steps; smoothing image using low pass spatial filter to reduce spurious noise in the image; extracting candidate borders of the vessels based on a local window property; tracking process, starting with a candidate pixel and following in the optimum direction with monitoring the connectivity of the vessel twin border; constructing the whole tree of retinal blood vessels by connecting the vessel segments based on their spatial locations, widths and directions. The algorithm was trained with 20 images from the DRIVE dataset, and tested using the remaining 20 images.

Numerical Analysis of the Pendulous Installation Method in Deep Water

This paper mainly studies the numerical analysis of the Pendulous Installation Method of a pump module in 1,500 meter water. A nonlinear time-domain coupled vessel and the pump installation system is established using ORCAFLEX riser program to simulate the pendulous free-fall motion of the pump module. The analysis studies the effect of environmental loads and vessel’s dynamic response on the entire installation system. Different directions of environmental loads and a series of sea-states defined using significant wave heights are taken into consideration. The results show that the optimum direction of the environmental loads is taken as 180 degrees (aganist vessel length), and the dynamic response of the vessel has a great impact on the entire system and should not be neglected.

Killer Whale Algorithm: An Algorithm Inspired by the Life of Killer Whale

This paper proposed a new algorithm inspired by the life of Killer Whale. A group of Killer Whale called Matriline that consist of a leader and members. The leader’s duty searches prey position and the optimum direction to chase the prey, meanwhile chase the prey is performed by the members. Optimum direction means minimum direction and maximum velocity. Global optimum is obtained by comparing the results of member’s actions. In this algorithm, if value of objective function of members more than leader, hence the leader must find out another new potential prey. In order to obtain the performance of proposed algorithm, it is necessary to test the new algorithm together with other algorithm using known mathematical function that available in Comparing Continuous Optimizers (COCO) especially Black Box Optimization Benchmarking (BBOB). Optimization results show that the performances of purposed algorithm has outperformed than others algorithms such as Genetic Algorithm (GA), Imperialist Competitive Algorithm (ICA) and Simulated Annealing (SA).

Intergenerational Diversity Management – Terminal and Instrumental Values in the Opinion of Future Employees of Generation Y Entering the European Labour Market

The presented article is an analysis of the study on the structure of terminal and instrumental values in the opinion of future employees of Generation Y who in the next few years will enter the European labour market. The presented results show the impact of cultural differences (Poland, Italy, Ukraine, Russia, Belarus) on the above mentioned issues. The results of the research were compared with the results of the research conducted by the authors in previous years, and hence, has shown the optimum direction to shape the intergenerational diversity management system. The aim of the analysis was to identify strategies for managing employees of Generation Y coming from different European countries.

An Analysis Of The Industrial Forging Process Of Flange In Order To Reduce The Weight Of The Input Material

This paper presents an analysis of the industrial process of hot forging a flange. The authors developed several thermomechanical models of the forging process for which they carried out computer simulations using the MSC.Marc 2013 software. In the Jawor Forge flanges with a neck are manufactured by hot forging in crank presses with a maximum load of 25 MN. The input material, in the form of a square bar, is heated up to a temperature of 1150°C and then formed in three operations: upsetting, preliminary die forging and finishing die forging. The main aim of the studies and the numerical analyses, in which the geometry of the tools would be modified, was to maximally reduce the amount of the input material taking into account the capabilities of the Jawor Forge, and consequently to significantly reduce the production costs. Besides the Forge’s equipment resources, the main constraint for modifications was the flange-with-neck forging standard which explicitely defines the tolerances for this element. The studies, which included numerical modelling, infrared measurements and technological tests, consisted in changing the geometry of the tools and that of the forging preform. As a result, the optimum direction for modifications aimed at reducing the mass of the input material was determined. The best of the solutions, making it possible to produce a correct forging in the Jawor Forge operating conditions, were adopted whereby the weight of the preform was reduced by 6.11%. Currently research is underway aimed at the application of the proposed and verified modifications to other flange forgings.

The Applications of GA-BP Neural Networks in Option Direction for Catalytic Agent

Although the application of the BP neural network can assist researching on catalytic agent and methods of synthesizing material, but because of slow convergence, in some cases, it can not work efficiently. The paper presents a design method for the application of GA-BP Neutral Network in optimum direction for catalytic agent and material. The simulation result shows that the application of the GA-BP neural network can improve the accuracy and versatility of the catalyst compounding.

Optimum Connection Positions for the Redundant Limb in Cable-Based Parallel Manipulators

Cable-based Parallel Manipulators (CPM) are light-weight manipulators that can reach high accelerations. The difference between the design of CPM and that of rigid-link parallel manipulators is due to the fact that cables can only perform while under tension. Keeping the cables under tension can be achieved by applying a force to the mobile platform by a redundant limb (e.g., cable, spring, or a cylinder) to generate tensile forces in the cables. In this study, an optimization procedure is developed to determine the optimum direction and connection position for the redundant limb. The optimum solution is that at which the difference between the largest and smallest tensions generated in the cables is minimized. The optimization procedure is based on a bounded-search algorithm that minimizes an objective function that represents the difference in the cable tensions generated due to the redundantlimb force. The bounds established in this study on the search increases the speed and efficiency of the search algorithm. The optimization procedure is successfully applied to a spatial 6degree-of-freedom cable parallel manipulator for demonstration.