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Hybrid MPPT Algorithm for PV Systems Under Partially Shaded Conditions Using a Stochastic Evolutionary Search and a Deterministic Hill Climbing

Abstract

A hybrid maximum power point tracking method has been proposed for the photovoltaic system using a stochastic evolutionary search and a deterministic hill climbing algorithm. The proposed approach employs the particle swarm optimizer (PSO) to solve a dynamic optimization problem related to the control task in a PV system. The position of the best particle is updated by the hill climbing algorithm, and the position of the rest of the particles by the classic PSO rule. The presented method uses the re-randomization mechanism, which places five consecutive particles randomly, but in specified intervals. This mechanism helps track the maximum power point under partially shaded conditions.

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Probability Density Functions of Voltage Sags Measured Indices

Probability Density Functions of Voltage Sags Measured Indices

Voltage sags can cause interruptions of industrial processes, which could result as a malfunction of equipment and considerable economic losses. Thus, it is very useful to see certain rules of voltage sags occurrence due to duration and depth.

This paper presents statistical analyses of voltage sags in several domestic and industrial transformer stations. Voltage sag probability functions are calculated from actual measurement data, by means of a hill climbing algorithm. Lognormal and Weibull frequency distribution functions are used to describe distribution of measured voltage dips.

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Cryptanalysis of the Columnar Transposition Using Meta-Heuristics

Abstract

The most commonly used methods for solving classical (historical) ciphers are based on global optimization (meta-heuristic methods). Despite the fact that global optimization is a well-studied problem, in the case of classical ciphers, there are still many open questions such as the construction of fitness functions or efficient transformation of the cryptanalysis (breaking attempt) to an optimization problem. Therefore the transformation of a cryptanalytical task to an optimization problem and the choice of a suitable fitness function form an important part of the topic. In this paper, we focus on the simple columnar transposition in depth. Our main contribution is a detailed analysis and comparison of different fitness functions, fitness landscape analysis and solving experiments.

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AN IMPROVED PERTURB AND OBSERVE MPPT ALGORITHM WITH VARIABLE STEP

Abstract

The algorithm for maximum power point tracking (MPPT) using a fixed is widely used because of its simplicity and easyness to implement. This paper presents an improvement consisting in a variable step (VS) applied to the standard Hill Climbing MPPT technique to improve both accuracy and tracking speed. Drawbacks will still be encountered in VS tracking algorithms, between response time and power oscillation.

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Tuning Mazda B6 Engine for Sports Competitions

Tuning Mazda B6 Engine for Sports Competitions

Improving output parameters of the Mazda B6 combustion engine from the vehicle Mazda 323 for amateur "hill climb" and "rally" competitions has been analysed. Tuning of such an engine for sport competitions means the optimisation of its parameters at the lowest possible economic costs, within the revolution range 4000 - 6000 min-1, where the engine during competition works most often. With the help of the program Lotus Engine Simulations, the construction of the exhaust manifold has been optimised, together with valve timing and other adjustments, listed in the work, on output parameters of the engine. The optimum combinations of parameters were experimentally verified on a chassis dynamometer. Final adaptations have led within the previously specified range of revolutions to an improvement between 5 and 22% in power and torque.

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Interchange Opportunity in Average Bandwidth Reduction in Sparse Matrices

, (1969), 157-172. 4. G. M. Del Corso and G. Manzini, Finding exact solutions to the bandwidth minimization problem, Computing, (1999), 189-203. 5. N. E. Gibbs, W. G. Poole, and P. K. Stockmeyer, An algorithm for reducing the bandwidth and profile of a sparse matrix, SIAM Journal on Numerical Analysis, (1976), 236-250. 6. A. Lim, J. Lin, and F. Xiao, Particle swarm optimization and hill climbing for the bandwidth minimization problem, Applied Intelligence, 26/3, (2007), 175-182. 7. A. Lim, B

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Comparison of Prototype Selection Algorithms Used in Construction of Neural Networks Learned by SVD

.S. and Lowe, D. (1988). Multivariable functional interpolation and adaptive networks, Complex Systems 2(3): 321-355. Cameron-Jones, R.M. (1995). Instance selection by encoding length heuristic with random mutation hill climbing, Proceedings of the 8th Australian Joint Conference on Artificial Intelligence, Canberra, Australia, pp. 99-106. Cano, J.-R., Herrera, F. and Lozano, M. (2003). Using evolutionary algorithms as instance selection for data reduction in KDD: An experimental study, IEEE Transactions on Evolutionary Computation 7

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Machine Learning Methods in Algorithmic Trading Strategy Optimization – Design and Time Efficiency

important problems are the sensitivity of a strategy performance to little parameter changes and numerous local extrema distributed over the solution space in an irregular way. The methods were designed for the purpose of significant shortening of the computation time, without a substantial loss of a strategy quality. The efficiency of methods was compared for three different pairs of assets in case of moving averages crossover system. Considered algorithms – the Extended Hill Climbing, Grid Method and Differential Evolution Method are based on the well-known machine

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Application of agent-based simulated annealing and tabu search procedures to solving the data reduction problem

a genetic algorithm, Intelligent Data Analysis   7 (4): 291-304. Sahel, Z., Bouchachia, A., Gabrys, B. and Rogers, P. (2007). Adaptive mechanisms for classification problems with drifting data, in B. Apolloni, R. Howlett and L. Jain (Eds.), KES 2007 , Lecture Notes in Artificial Intelligence, Vol. 4693, Springer-Verlag, Berlin/Heidelberg, pp. 419-426. Skalak, D. (1994). Prototype and feature selection by sampling and random mutation hill climbing algorithm, Proceedings of the International Conference on

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Morphological characteristics and power output in professional road cyclists during the competition phase

in male adolescent cyclists. Nutr. Hosp., 28(3): 1049-1052. 9. González-Alonso J., Teller C., Andersen S.L., Jensen F.B., Hyldig T., Nielsen B. (1999) Influence of body tempera­ture on the development of fatigue during prolonged ex­ercise in the heat. J. Appl. Physiol., 86(3): 1032-1039. 10. Harnish C., King D., Swensen T. (2007) Effect of cy­cling position on oxygen uptake and preferred cadence in trained cyclists during hill climbing at various power outputs. Eur. J. Appl. Physiol., 99: 387-391. 11. Hug F., Bendahan

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