IN SILICO GENE DELETION OF ESCHERICHIA COLI FOR OPTIMAL ETHANOL PRODUCTION USING A HYBRID ALGORITHM OF PARTICLE SWARM OPTIMIZATION AND FLUX BALANCE ANALYSIS

2016 ◽  
Vol 78 (12-3) ◽  
Author(s):  
Mei Jing Liew ◽  
Abdul Hakim Mohamed Salleh ◽  
Mohd Saberi Mohamad ◽  
Yee Wen Choon ◽  
Safaai Deris ◽  
...  

Metabolic engineering of microorganism is widely used to enhance the production of metabolites that is useful in food additives, pharmaceutical, supplements, cosmetics, and polymer materials. One of the approaches for enhancing the biomass production is to utilize gene deletion strategies. Flux Balance Analysis is introduced to delete the gene that eventually leads the overproduction of the biomass and then to increase the biomass production. However, the result of biomass production obtained does not achieve the optimal production. Therefore, we proposed a hybrid algorithm of Particle Swarm Optimization and Flux Balance Analysis to attain an optimal gene deletion that is able to produce a higher biomass production. In this research, Particle Swarm Optimization is introduced as an optimization algorithm to obtain optimal gene deletions while Flux Balance Analysis is used to evaluate the fitness (biomass production or growth rate) of gene deletions. By performing an experiment on Escherichia coli, the results indicate that the proposed hybrid algorithm of Particle Swarm Optimization and Flux Balance Analysis is able to obtain optimal gene deletions that can produce the highest ethanol production. A hybrid algorithm is suggested due to its ability in seeking a higher ethanol production and growth rate than OptReg methods.

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Weijie Xia ◽  
Xue Jin ◽  
Fawang Dou

It should be noted that the peak sidelobe level (PSLL) significantly influences the performance of the multibeam imaging sonar. Although a great amount of work has been done to suppress the PSLL of the array, one can verify that these methods do not provide optimal results when applied to the case of multiple patterns. In order to suppress the PSLL for multibeam imaging sonar array, a hybrid algorithm of binary particle swarm optimization (BPSO) and convex optimization is proposed in this paper. In this algorithm, the PSLL of multiple patterns is taken as the optimization objective. BPSO is considered as a global optimization algorithm to determine best common elements’ positions and convex optimization is considered as a local optimization algorithm to optimize elements’ weights, which guarantees the complete match of the two factors. At last, simulations are carried out to illustrate the effectiveness of the proposed algorithm in this paper. Results show that, for a sparse semicircular array with multiple patterns, the hybrid algorithm can obtain a lower PSLL compared with existing methods and it consumes less calculation time in comparison with other hybrid algorithms.


Author(s):  
Yongbin Sun ◽  
Haibin Duan

Autonomous aerial refueling (AAR) is an essential application of unmanned aerial vehicles for both military and civilian domains. In this paper, a hybrid algorithm of the pigeon-inspired optimization (PIO) and lateral inhibition (LI), called LI-PIO, is proposed for image matching problem of AAR. LI is adopted for image pre-processing to enhance the edges and contrast of images. PIO, inspired from the homing characteristics of pigeons, is a novel bio-inspired swarm intelligence algorithm. To demonstrate the effectiveness and feasibility of our proposed algorithm, we make extensive comparative experiments with particle swarm optimization (PSO), particle swarm optimization based on lateral inhibition (LI-PSO), and PIO. It can be concluded from the experimental results that our proposed LI-PIO has excellent performances for image matching problem of AAR, especially in convergent rate and computation speed.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4607
Author(s):  
Jian Zhang ◽  
Mingjian Cui ◽  
Yigang He

As wind farms have great influences on power system stability, it is essential to develop an adaptive as well as robust equivalent model of it. In this paper, a detailed equivalent model of PMSG wind farm and initialization method is developed. The trajectory sensitivity of parameters is analyzed. Then, the key parameters are estimated using improved Genetic Learning Particle Swarm Optimization (GLPSO) hybrid algorithm with phasor measurement unit (PMU). The description and generalization capability, stability for parameter identification of the equivalent model under wake effects, and when some wind turbines are off-line or wind speed is unknown after an event are analyzed. The maximum differences between the values of estimated parameters and their real ones are less than 10% for the proportional magnification constant of DC voltage controller Kp2 and grid side current controller Kp3. The convergence rate and global optimization performance of the improved GLPSO hybrid algorithm is 0.5 times higher than the classical particle swarm optimization algorithm (PSO) and genetic algorithm (GA).


2018 ◽  
Vol 10 (01) ◽  
pp. 1850009 ◽  
Author(s):  
Zhe Xiong ◽  
Xiao-Hui Li ◽  
Jing-Chang Liang ◽  
Li-Juan Li

In this study, a novel multi-objective hybrid algorithm (MHGH, multi-objective HPSO-GA hybrid algorithm) is developed by crossing the heuristic particle swarm optimization (HPSO) algorithm with a genetic algorithm (GA) based on the concept of Pareto optimality. To demonstrate the effectiveness of the MHGH, the optimizations of four unconstrained mathematical functions and four constrained truss structural problems are tested and compared to the results using several other classic algorithms. The results show that the MHGH improves the convergence rate and precision of the particle swarm optimization (PSO) and increases its robustness.


Sign in / Sign up

Export Citation Format

Share Document