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https://www.readbyqxmd.com/read/28436915/an-adaptive-multiobjective-particle-swarm-optimization-based-on-multiple-adaptive-methods
#1
Honggui Han, Wei Lu, Junfei Qiao
Multiobjective particle swarm optimization (MOPSO) algorithms have attracted much attention for their promising performance in solving multiobjective optimization problems (MOPs). In this paper, an adaptive MOPSO (AMOPSO) algorithm, based on a hybrid framework of the solution distribution entropy and population spacing (SP) information, is developed to improve the search performance in terms of convergent speed and precision. First, an adaptive global best (gBest) selection mechanism, based on the solution distribution entropy, is introduced to analyze the evolutionary tendency and balance the diversity and convergence of nondominated solutions in the archive...
April 17, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28434877/one-enzyme-three-metabolites-shewanella-algae-controls-siderophore-production-via-the-cellular-substrate-pool
#2
Sina Rütschlin, Sandra Gunesch, Thomas Böttcher
Shewanella algae B516 produces avaroferrin, an asymmetric hydroxamate siderophore, which has been shown to inhibit swarming motility of Vibrio alginolyticus. We aimed to elucidate the biosynthesis of this siderophore and to investigate how S. algae coordinates the production of avaroferrin and its two symmetric counterparts. We reconstituted the reaction in vitro with the main enzyme AvbD and the putative biosynthetic precursors, and demonstrate that multispecificity of this enzyme results in the production of all three cyclic hydroxamate siderophores that were previously isolated as natural products from S...
April 17, 2017: Cell Chemical Biology
https://www.readbyqxmd.com/read/28433870/automated-detection-of-premature-delivery-using-empirical-mode-and-wavelet-packet-decomposition-techniques-with-uterine-electromyogram-signals
#3
U Rajendra Acharya, Vidya K Sudarshan, Soon Qing Rong, Zechariah Tan, Choo Min Lim, Joel Ew Koh, Sujatha Nayak, Sulatha V Bhandary
An accurate detection of preterm labor and the risk of preterm delivery before 37 weeks of gestational age is crucial to increase the chance of survival rate for both mother and the infant. Thus, the uterine contractions measured using uterine electromyogram (EMG) or electro hysterogram (EHG) need to have high sensitivity in the detection of true preterm labor signs. However, visual observation and manual interpretation of EHG signals at the time of emergency situation may lead to errors. Therefore, the employment of computer-based approaches can assist in fast and accurate detection during the emergency situation...
April 18, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28430239/research-on-intelligent-algorithms-for-amplitude-optimization-of-wavefront-shaping
#4
Qi Feng, Bin Zhang, Zhipeng Liu, Chengyou Lin, Yingchun Ding
This paper demonstrates further research on intelligent algorithms of binary amplitude optimization for wavefront shaping by numerical simulations. A better fitness function of the genetic algorithm (GA) has been presented after a comparative analysis of enhancement. With this new discriminant, we have achieved a relative enhancement of 0.225, which is higher than the theoretical value (0.159). In addition, we have also proposed a kind of modified particle swarm optimization algorithm (PSO), which has a higher enhancement than the unmodified PSO and a faster convergence speed than the GA...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430146/a-new-method-for-single-epoch-ambiguity-resolution-with-indoor-pseudolite-positioning
#5
Xin Li, Peng Zhang, Jiming Guo, Jinling Wang, Weining Qiu
Ambiguity resolution (AR) is crucial for high-precision indoor pseudolite positioning. Due to the existing characteristics of the pseudolite positioning system, such as the geometry structure of the stationary pseudolite which is consistently invariant, the indoor signal is easy to interrupt and the first order linear truncation error cannot be ignored, and a new AR method based on the idea of the ambiguity function method (AFM) is proposed in this paper. The proposed method is a single-epoch and nonlinear method that is especially well-suited for indoor pseudolite positioning...
April 21, 2017: Sensors
https://www.readbyqxmd.com/read/28429807/prediction-of-a-new-bec-monolayer-with-perfectly-planar-tetracoordinate-carbons
#6
Chun-Sheng Liu, Hao-Hao Zhu, Xiao-Juan Ye, Xiao-Hong Yan
Recently, there has been a growing interest in exploring planar hypercoordinate carbons in two-dimensional nanostructures. However, atomic monolayers with ideal planar hypercoordinate carbon are quite rare due to the challenge in stabilizing the exotic motifs. We predicted a global minimum two-dimensional BeC monolayer using the global particle-swarm optimization method. Each carbon binds peripheral four atoms in the same plane, forming a perfectly planar tetracoordinate carbon moiety. The cohesive energy, phonon-spectrum and mechanical stability criteria confirm the stability of monolayer BeC...
April 21, 2017: Nanoscale
https://www.readbyqxmd.com/read/28425443/hybridization-of-strength-pareto-multiobjective-optimization-with-modified-cuckoo-search-algorithm-for-rectangular-array
#7
Khairul Najmy Abdul Rani, Mohamedfareq Abdulmalek, Hasliza A Rahim, Neoh Siew Chin, Alawiyah Abd Wahab
This research proposes the various versions of modified cuckoo search (MCS) metaheuristic algorithm deploying the strength Pareto evolutionary algorithm (SPEA) multiobjective (MO) optimization technique in rectangular array geometry synthesis. Precisely, the MCS algorithm is proposed by incorporating the Roulette wheel selection operator to choose the initial host nests (individuals) that give better results, adaptive inertia weight to control the positions exploration of the potential best host nests (solutions), and dynamic discovery rate to manage the fraction probability of finding the best host nests in 3-dimensional search space...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28424524/hqia-a-novel-quorum-quenching-enzyme-which-expands-the-ahl-lactonase-family
#8
Marta Torres, Stéphane Uroz, Rafael Salto, Laure Fauchery, Emilia Quesada, Inmaculada Llamas
The screening of a metagenomic library of 250,000 clones generated from a hypersaline soil (Spain) allowed us to identify a single positive clone which confers the ability to degrade N-acyl homoserine lactones (AHLs). The sequencing of the fosmid revealed a 42,318 bp environmental insert characterized by 46 ORFs. The subcloning of these ORFs demonstrated that a single gene (hqiA) allowed AHL degradation. Enzymatic analysis using purified HqiA and HPLC/MS revealed that this protein has lactonase activity on a broad range of AHLs...
April 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28422670/observer-based-robust-coordinated-control-of-multiagent-systems-with-input-saturation
#9
Xiaoling Wang, Housheng Su, Michael Z Q Chen, Xiaofan Wang
This paper addresses the robust semiglobal coordinated control of multiple-input multiple-output multiagent systems with input saturation together with dead zone and input additive disturbance. Observer-based coordinated control protocol is constructed, by combining the parameterized low-and-high-gain feedback technique and the high-gain observer design approach. It is shown that, under some mild assumptions on agents' intrinsic dynamics, the robust semiglobal consensus or robust semiglobal swarm can be approached for undirected connected multiagent systems...
April 13, 2017: IEEE Transactions on Neural Networks and Learning Systems
https://www.readbyqxmd.com/read/28422080/study-on-temperature-and-synthetic-compensation-of-piezo-resistive-differential-pressure-sensors-by-coupled-simulated-annealing-and-simplex-optimized-kernel-extreme-learning-machine
#10
Ji Li, Guoqing Hu, Yonghong Zhou, Chong Zou, Wei Peng, Jahangir Alam Sm
As a high performance-cost ratio solution for differential pressure measurement, piezo-resistive differential pressure sensors are widely used in engineering processes. However, their performance is severely affected by the environmental temperature and the static pressure applied to them. In order to modify the non-linear measuring characteristics of the piezo-resistive differential pressure sensor, compensation actions should synthetically consider these two aspects. Advantages such as nonlinear approximation capability, highly desirable generalization ability and computational efficiency make the kernel extreme learning machine (KELM) a practical approach for this critical task...
April 19, 2017: Sensors
https://www.readbyqxmd.com/read/28421612/prospective-bacterial-quorum-sensing-inhibitors-from-indian-medicinal-plant-extracts
#11
Bipransh Kumar Tiwary, Runu Ghosh, Saurav Moktan, Vivek Kumar Ranjan, Priyankar Dey, Dibakar Choudhury, Somit Dutta, Dipanwita Deb, Abhaya Prasad Das, Ranadhir Chakraborty
As virulence of many pathogenic bacteria is regulated by the phenomenon of quorum sensing (QS), the present study aimed to find the QS-inhibiting (QS-I) property (if any) in sixty-one Indian medicinal plants. The presence of QS-I compound in the leaf-extract was evaluated by its ability to inhibit production of pigment in Chromobacterium violaceum MTCC 2656 (violacein) and Pseudomonas aeruginosa MTCC 2297 (pyocyanin) or swarming of P. aeruginosa MTCC 2297. Extracts of three plants, Astilbe rivularis, Fragaria nubicola and Osbeckia nepalensis have shown a dose- dependent inhibition of violacein production with no negative effect on bacterial growth...
April 19, 2017: Letters in Applied Microbiology
https://www.readbyqxmd.com/read/28417322/are-midge-swarms-bound-together-by-an-effective-velocity-dependent-gravity
#12
Andrew M Reynolds, Michael Sinhuber, Nicholas T Ouellette
Midge swarms are a canonical example of collective animal behaviour where local interactions do not clearly play a major role and yet the animals display group-level cohesion. The midges appear somewhat paradoxically to be tightly bound to the swarm whilst at the same time weakly coupled inside it. The microscopic origins of this behaviour have remained elusive. Models based on Newtonian gravity do, however, agree well with experimental observations of laboratory swarms. They are biologically plausible since gravitational interactions have similitude with long-range acoustic and visual interactions, and they correctly predict that individual attraction to the swarm centre increases linearly with distance from the swarm centre...
April 2017: European Physical Journal. E, Soft Matter
https://www.readbyqxmd.com/read/28415295/emergence-of-l%C3%A3-vy-walks-in-systems-of-interacting-individuals
#13
Sergei Fedotov, Nickolay Korabel
We propose a model of superdiffusive Lévy walk as an emergent nonlinear phenomenon in systems of interacting individuals. The aim is to provide a qualitative explanation of recent experiments [G. Ariel et al., Nat. Commun. 6, 8396 (2015)2041-172310.1038/ncomms9396] revealing an intriguing behavior: swarming bacteria fundamentally change their collective motion from simple diffusion into a superdiffusive Lévy walk dynamics. We introduce microscopic mean-field kinetic equations in which we combine two key ingredients: (1) alignment interactions between individuals and (2) non-Markovian effects...
March 2017: Physical Review. E
https://www.readbyqxmd.com/read/28415180/reversals-and-collisions-optimize-protein-exchange-in-bacterial-swarms
#14
Aboutaleb Amiri, Cameron Harvey, Amy Buchmann, Scott Christley, Joshua D Shrout, Igor S Aranson, Mark Alber
Swarming groups of bacteria coordinate their behavior by self-organizing as a population to move over surfaces in search of nutrients and optimal niches for colonization. Many open questions remain about the cues used by swarming bacteria to achieve this self-organization. While chemical cue signaling known as quorum sensing is well-described, swarming bacteria often act and coordinate on time scales that could not be achieved via these extracellular quorum sensing cues. Here, cell-cell contact-dependent protein exchange is explored as a mechanism of intercellular signaling for the bacterium Myxococcus xanthus...
March 2017: Physical Review. E
https://www.readbyqxmd.com/read/28414371/flexible-global-calibration-of-multiple-cameras-with-nonoverlapping-fields-of-view-using-circular-targets
#15
Zheng Gong, Zhen Liu, Guangjun Zhang
Global calibration of multicamera systems is a difficult problem. The key is to find an appropriate calibration target. This paper proposes a flexible method to construct a global calibration target with circular targets. Any object that is to be measured by the system can be used as a calibration target with the help of a hand-held scanner. The calibration method does not need a special calibration target or multiple shots, which makes it flexible in applications. Circular targets pasted on the calibration target are used as features that are captured by cameras...
April 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/28406258/a-new-dirac-cone-material-a-graphene-like-be3c2-monolayer
#16
Bing Wang, Shijun Yuan, Yunhai Li, Li Shi, Jinlan Wang
Two-dimensional (2D) materials with Dirac cones exhibit rich physics and many intriguing properties, but the search for new 2D Dirac materials is still a current hotspot. Using the global particle-swarm optimization method and density functional theory, we predict a new stable graphene-like 2D Dirac material: a Be3C2 monolayer with a hexagonal honeycomb structure. The Dirac point occurs exactly at the Fermi level and arises from the merging of the hybridized pz bands of Be and C atoms. Most interestingly, this monolayer exhibits a high Fermi velocity in the same order of graphene...
April 13, 2017: Nanoscale
https://www.readbyqxmd.com/read/28406173/emergence-of-a-coherent-and-cohesive-swarm-based-on-mutual-anticipation
#17
Hisashi Murakami, Takayuki Niizato, Yukio-Pegio Gunji
Collective behavior emerging out of self-organization is one of the most striking properties of an animal group. Typically, it is hypothesized that each individual in an animal group tends to align its direction of motion with those of its neighbors. Most previous models for collective behavior assume an explicit alignment rule, by which an agent matches its velocity with that of neighbors in a certain neighborhood, to reproduce a collective order pattern by simple interactions. Recent empirical studies, however, suggest that there is no evidence for explicit matching of velocity, and that collective polarization arises from interactions other than those that follow the explicit alignment rule...
April 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28404990/aseismic-transient-during-the-2010-2014-seismic-swarm-evidence-for-longer-recurrence-of-m%C3%A2-%C3%A2-%C3%A2-6-5-earthquakes-in-the-pollino-gap-southern-italy
#18
Daniele Cheloni, Nicola D'Agostino, Giulio Selvaggi, Antonio Avallone, Gianfranco Fornaro, Roberta Giuliani, Diego Reale, Eugenio Sansosti, Pietro Tizzani
In actively deforming regions, crustal deformation is accommodated by earthquakes and through a variety of transient aseismic phenomena. Here, we study the 2010-2014 Pollino (Southern Italy) swarm sequence (main shock M W 5.1) located within the Pollino seismic gap, by analysing the surface deformation derived from Global Positioning System and Synthetic Aperture Radar data. Inversions of geodetic time series show that a transient slip, with the same mechanism of the main shock, started about 3-4 months before the main shock and lasted almost one year, evolving through time with acceleration phases that correlate with the rate of seismicity...
April 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28403224/hstlbo-a-hybrid-algorithm-based-on-harmony-search-and-teaching-learning-based-optimization-for-complex-high-dimensional-optimization-problems
#19
Shouheng Tuo, Longquan Yong, Fang'an Deng, Yanhai Li, Yong Lin, Qiuju Lu
Harmony Search (HS) and Teaching-Learning-Based Optimization (TLBO) as new swarm intelligent optimization algorithms have received much attention in recent years. Both of them have shown outstanding performance for solving NP-Hard optimization problems. However, they also suffer dramatic performance degradation for some complex high-dimensional optimization problems. Through a lot of experiments, we find that the HS and TLBO have strong complementarity each other. The HS has strong global exploration power but low convergence speed...
2017: PloS One
https://www.readbyqxmd.com/read/28402888/influence-of-physical-effects-on-the-swarming-motility-of-pseudomonas-aeruginosa
#20
Alexander Yang, Wai Shing Tang, Tieyan Si, Jay X Tang
Many species of bacteria can spread over a moist surface via a particular form of collective motion known as "surface swarming". This form of motility is typically studied by inoculating bacteria on a gel formed by 0.4-1.5% agar, which contains essential nutrients for their growth and proliferation. Using Pseudomonas aeruginosa and its pili-less mutant, ΔPilA, we investigate physical factors that either facilitate or restrict the swarming motility, measured by the rate of increase in area covered by a spreading bacterial colony, i...
April 11, 2017: Biophysical Journal
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