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Performance Research on Magnetotactic Bacteria Optimization Algorithm with the Best Individual-Guided Differential Interaction Energy  [PDF]
Hongwei Mo, Lili Liu, Jiao Zhao
Journal of Computer and Communications (JCC) , 2015, DOI: 10.4236/jcc.2015.35016
Abstract:

Magnetotactic bacteria optimization algorithm (MBOA) is a new optimization algorithm inspired by the characteristics of magnetotactic bacteria, which is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. The original Magnetotactic Bacteria Optimization Algorithm (MBOA) and several new variants of MBOA mimics the interaction energy between magnetosomes chains to obtain moments for solving problems. In this paper, Magnetotactic Bacteria Optimization Algorithm with the Best Individual-guided Differential Interaction Energy (MBOA-BIDE) is proposed. We improved interaction energy calculation by using the best individual-guided?differential interaction energy formation. We focus on analyzing the performance of different parameters settings. The experiment results show that the proposed algorithm is sensitive to parameters settings on some functions.

Research of Function Optimization Algorithm  [cached]
Qinghua Wu,Hanmin Liu,Yuxin Sun,Fang Xie
TELKOMNIKA : Indonesian Journal of Electrical Engineering , 2012, DOI: 10.11591/telkomnika.v10i4.877
Abstract: Traditional evolutionary algorithm trapped into the local minimum easily. Therefore, based on a simple evolutionary algorithm and combine the base ideology of orthogonal test then applied it to the population initialization, crossover operator, as well as the introduction of Inver-Over operator to prevent local convergence to form a new evolutionary algorithm. Through the series of numerical experiments, the new algorithm has been proved is efficiency for function optimization.
Bus Dispatching Interval Optimization Based on Adaptive Bacteria Foraging Algorithm  [PDF]
Zhong-hua Wei,Xia Zhao,Ke-wen Wang,Yan Xiong
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/389086
Abstract: The improved bacterial foraging algorithm was applied in this paper to schedule the bus departing interval. Optimal interval can decrease the total operation cost and passengers’ mean waiting time. The principles of colony sensing, chemotactic action, and improved foraging strategy made this algorithm adaptive. Based on adaptive bacteria foraging algorithm (ABFA), a model on one bus line in Hohhot city in China was established and simulated. Two other algorithms, original bacteria foraging algorithm (BFA) and genetic algorithm (GA), were also used in this model to decide which one could greatly accelerate convergence speed, improve searching precision, and strengthen robustness. The final result showed that ABFA was most feasible in optimizing variables. 1. Introduction Traffic demand becomes increasingly higher with the great development of social economy and urbanization. With the large amount of private cars and limited road facilities, severe traffic congestion occurs inevitably. Municipal governments and road transport authority have strongly recommended public transportation for its higher passenger capacity and smaller coverage area. So it is necessary to improve the quality of bus dispatching management, and a wholesome and intelligent bus scheduling scheme is needed. Bus interval scheduling is a complex optimization problem for its nonlinear and multiobjective characteristics. It requires traffic planners to take round consideration of multi-interests, such as bus operating enterprises and passengers. The relationship between the two is contradictory. Obviously, bus operating enterprises always try to dispatch buses as few as possible with the longest intervals and the highest profit, whereas passengers are the opposite. According to the two contradictory characteristics, an optimal bus dispatching interval model is urgent to be established to benefit both sides. As to the optimal algorithms, lots of intelligent algorithms have been adopted to solve transportation optimal problems [1]. Intelligent algorithms enlightened by bacterium have become fashionable recently. Back to the history of bacteria foraging algorithm (BFA), it was initially proposed in 2002 by Passino [2] and applied to dealing with several engineering problems [3–5] successfully. However, it was limited to solo modal function optimization for its poor convergence behavior. So effort to pursue more adaptive algorithms goes on. Mu?oz et al. [6] proposed some methods to simplify the algorithm while maintaining its core elements. These included the simplification of the algorithm
Magnetotactic Bacteria from Extreme Environments  [PDF]
Dennis A. Bazylinski,Christopher T. Lefèvre
Life , 2013, DOI: 10.3390/life3020295
Abstract: Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe 3O 4) or greigite (Fe 3S 4) and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI) in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes- Verrucomicrobia- Chlamydiae (PVC) bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.
SVC Damping Controller Design Based on Bacteria Foraging Optimization Algorithm for a Multimachine Power System
E.S. Ali,S.M. Abd-Elazim
International Journal of Electrical and Power Engineering , 2012, DOI: 10.3923/ijepe.2011.116.124
Abstract: Social foraging behavior of Escherichia coli bacteria has recently been explored to develop a novel algorithm for distributed optimization and control. The Bacterial Foraging Optimization Algorithm (BFOA) as it is called now is currently gaining popularity in the community of researchers for its effectiveness in solving certain difficult real world optimization problems. This study proposes BFOA based Static Var Compensator (SVC) for the suppression of oscillations in power system. The proposed design problem of SVC over a wide range of loading conditions and different disturbances is formulated as an optimization problem. BFOA is employed to search for optimal controller parameters by minimizing the time domain objective function. The performance of the proposed technique has been evaluated with the performance of the conventional controller tuned by Ziegler-Nichols (ZN) and Genetic Algorithm (GA) in order to demonstrate the superior efficiency of the proposed BFOA in tuning SVC controller. Simulation results emphasis on the better performance of the optimized SVC controller based on BFOA in compare to optimized SVC controller based on GA and conventional one over wide range of operating conditions.
Velocity condensation for magnetotactic bacteria  [PDF]
Jean-Francois Rupprecht,Nicolas Waisbord,Lydéric Bocquet
Physics , 2015,
Abstract: Magnetotactic swimmers tend to align along magnetic field lines against stochastic reorientations. We show that the swimming strategy, e.g. active Brownian motion versus run-and-tumble dynamics, strongly affects the orientation statistics. The latter can exhibit a velocity condensation whereby the alignment probability density diverges. As a consequence, we find that the swimming strategy affects the nature of the phase transition to collective motion, indicating that L\'evy run-and-tumble walks can outperform active Brownian processes as strategies to trigger collective behavior.
CHARACTERIZATION OF NATURAL MICROCOSMS OF ESTUARINE MAGNETOTACTIC BACTERIA
SALAZAR,ALEJANDRO; MORALES,ALVARO; MáRQUEZ,MARCO;
DYNA , 2011,
Abstract: to date, no complete study of magnetotactic bacteria's (mtb) natural microcosms in estuarine or tropical environments has been reported. besides, almost all the studies around magnetotactic bacteria have been based on fresh waters away from the equator. in this work, we focused the experimental region at the equator and present a comprehensive mineralogical and physicochemical characterization of two estuarine bacterial microcosms. the results show that mineral lixiviation in the sediments may be an important factor in the solubilization of elements required by magnetotactic bacteria. specifically, we show that clinochlore, phlogopite, nontronite, and halloysite could be among the main minerals that lixiviate iron to the estuarine microcosms. we conclude that nitrate concentration in the water should not be as low as those that have been reported for other authors to achieve optimal bacteria growth. it is confirmed that magnetotactic bacteria do not need large amounts of dissolved iron to grow or to synthesize magnetosomes.
Micromanipulation of magnetotactic bacteria with a microelectromagnet matrix  [PDF]
H. Lee,A. M. Purdon,V. Chu,R. M. Westervelt
Physics , 2004,
Abstract: Micromanipulation of magnetotactic bacteria with a microelectromagnet matrix was demonstrated. Magnetotactic bacteria synthesize a chain of magnetic nanoparticles inside their body to guide their motion in the geomagnetic field. A microelectromagnet matrix consists of two arrays of lithographically patterned wires, one array perpendicular to the other, that are separated and covered by insulating layers. By adjusting the current in each wire, a matrix can create versatile magnetic field patterns on microscopic length scale. Using a matrix, magnetotactic bacteria were trapped, continuously moved, rotated, and assembled in water at room temperature.
Intracellular inclusions of uncultured magnetotactic bacteria
Keim,Carolina N.; Solórzano,Guilhermo; Farina,Marcos; Lins,Ulysses;
International Microbiology , 2005,
Abstract: magnetotactic bacteria produce magnetic crystals in organelles called magnetosomes. the bacterial cells may also have phosphorus-containing granules, sulfur globules, or polyhydroxyalkanoate inclusions. in the present study, the ultrastructure and elemental composition of intracellular inclusions from uncultured magnetotactic bacteria collected in a marine environment are described. magnetosomes contained mainly defect-free, single magnetite crystals with prismatic morphologies. two types of phosphorus-containing granules were found in magnetotactic cocci. the most common consisted of phosphorus-rich granules containing p, o, and mg; and sometimes also c, na, al, k, ca, mn, fe, zn, and small amounts of s and cl were also found. in phosphorus-sulfur-iron granules, p, o, s, na, mg, ca, fe, and frequently cl, k, and zn, were detected. most cells had two phosphorus-rich granules, which were very similar in elemental composition. in rod-shaped bacteria, these granules were positioned at a specific location in the cell, suggesting a high level of intracellular organization. polyhydroxyalkanoate granules and sulfur globules were less commonly seen in the cells and had no fixed number or specific location. the presence and composition of these intracellular structures provide clues regarding the physiology of the bacteria that harbor them and the characteristics of the microenvironments where they thrive.
Comment on: "On the swimming motion of spheroidal magnetotactic bacteria" [arXiv:1302.5787]  [PDF]
B. U. Felderhof
Physics , 2013,
Abstract: It is pointed out that a recent article [arXiv:1302.5787] on swimming of magnetotactic bacteria is conceptually wrong.
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