scholarly journals Evolutionary Algorithms for Community Detection in Continental-Scale High-Voltage Transmission Grids

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1472 ◽  
Author(s):  
Manuel Guerrero ◽  
Raul Baños ◽  
Consolación Gil ◽  
Francisco G. Montoya ◽  
Alfredo Alcayde
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Power Systems ◽  
Community Detection ◽  
North American ◽  
Flow Analysis ◽  
Power Grids ◽  
Improved Genetic Algorithm ◽  
Continental Scale ◽  
The North

Symmetry is a key concept in the study of power systems, not only because the admittance and Jacobian matrices used in power flow analysis are symmetrical, but because some previous studies have shown that in some real-world power grids there are complex symmetries. In order to investigate the topological characteristics of power grids, this paper proposes the use of evolutionary algorithms for community detection using modularity density measures on networks representing supergrids in order to discover densely connected structures. Two evolutionary approaches (generational genetic algorithm, GGA+, and modularity and improved genetic algorithm, MIGA) were applied. The results obtained in two large networks representing supergrids (European grid and North American grid) provide insights on both the structure of the supergrid and the topological differences between different regions. Numerical and graphical results show how these evolutionary approaches clearly outperform to the well-known Louvain modularity method. In particular, the average value of modularity obtained by GGA+ in the European grid was 0.815, while an average of 0.827 was reached in the North American grid. These results outperform those obtained by MIGA and Louvain methods (0.801 and 0.766 in the European grid and 0.813 and 0.798 in the North American grid, respectively).

An efficient intelligent decision method for bionic motion unmanned system

2021 ◽  
pp. 095965182110655
Author(s):  
Haipeng Chen ◽  
Wenxing Fu ◽  
Yuze Feng ◽  
Jia Long ◽  
Kang Chen
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Path Planning ◽  
Motion Control ◽  
Control Method ◽  
Improved Genetic Algorithm ◽  
Decision Method ◽  
Multiple Traveling Salesman Problem ◽  
Intelligent Decision ◽  
Unmanned System

In this article, we propose an efficient intelligent decision method for a bionic motion unmanned system to simulate the formation change during the hunting process of the wolves. Path planning is a burning research focus for the unmanned system to realize the formation change, and some traditional techniques are designed to solve it. The intelligent decision based on evolutionary algorithms is one of the famous path planning approaches. However, time consumption remains to be a problem in the intelligent decisions of the unmanned system. To solve the time-consuming problem, we simplify the multi-objective optimization as the single-objective optimization, which was regarded as a multiple traveling salesman problem in the traditional methods. Besides, we present the improved genetic algorithm instead of evolutionary algorithms to solve the intelligent decision problem. As the unmanned system’s intelligent decision is solved, the bionic motion control, especially collision avoidance when the system moves, should be guaranteed. Accordingly, we project a novel unmanned system bionic motion control of complex nonlinear dynamics. The control method can effectively avoid collision in the process of system motion. Simulation results show that the proposed simplification, improved genetic algorithm, and bionic motion control method are stable and effective.

scholarly journals North American CO<sub>2</sub> exchange: inter-comparison of modeled estimates with results from a fine-scale atmospheric inversion

2012 ◽  
Vol 9 (1) ◽  
pp. 457-475 ◽  
Author(s):  
S. M. Gourdji ◽  
K. L. Mueller ◽  
V. Yadav ◽  
D. N. Huntzinger ◽  
A. E. Andrews ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
North American ◽  
Co2 Fluxes ◽  
Fine Scale ◽  
Bottom Up ◽  
Near Surface ◽  
Continental Scale ◽  
The North ◽  
Atmospheric Observations ◽  
Atmospheric Inversion

Abstract. Atmospheric inversion models have the potential to quantify CO2 fluxes at regional, sub-continental scales by taking advantage of near-surface CO2 mixing ratio observations collected in areas with high flux variability. This study presents results from a series of regional geostatistical inverse models (GIM) over North America for 2004, and uses them as the basis for an inter-comparison to other inversion studies and estimates from biospheric models collected through the North American Carbon Program Regional and Continental Interim Synthesis. Because the GIM approach does not require explicit prior flux estimates and resolves fluxes at fine spatiotemporal scales (i.e. 1° × 1°, 3-hourly in this study), it avoids temporal and spatial aggregation errors and allows for the recovery of realistic spatial patterns from the atmospheric data relative to previous inversion studies. Results from a GIM inversion using only available atmospheric observations and a fine-scale fossil fuel inventory were used to confirm the quality of the inventory and inversion setup. An inversion additionally including auxiliary variables from the North American Regional Reanalysis found inferred relationships with flux consistent with physiological understanding of the biospheric carbon cycle. Comparison of GIM results with bottom-up biospheric models showed stronger agreement during the growing relative to the dormant season, in part because most of the biospheric models do not fully represent agricultural land-management practices and the fate of both residual biomass and harvested products. Comparison to earlier inversion studies pointed to aggregation errors as a likely source of bias in previous sub-continental scale flux estimates, particularly for inversions that adjust fluxes at the coarsest scales and use atmospheric observations averaged over long periods. Finally, whereas the continental CO2 boundary conditions used in the GIM inversions have a minor impact on spatial patterns, they have a substantial impact on the continental carbon budget, with a difference of 0.8 PgC yr−1 in the total continental flux resulting from the use of two plausible sets of boundary CO2 mixing ratios. Overall, this inter-comparison study helps to assess the state of the science in estimating regional-scale CO2 fluxes, while pointing towards the path forward for improvements in future top-down and bottom-up modeling efforts.

The Lithoprobe trans-continental lithospheric cross sections: imaging the internal structure of the North American continentThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent.Lithoprobe Publication 1487.

2010 ◽  
Vol 47 (5) ◽  
pp. 821-857 ◽  
Author(s):  
Philip T.C. Hammer ◽  
Ron M. Clowes ◽  
Fred A. Cook ◽  
Arie J. van der Velden ◽  
Kris Vasudevan
Keyword(s):  
Cross Sections ◽  
North American ◽  
Lithospheric Mantle ◽  
Large Scale ◽  
Passive Margin ◽  
Cascadia Subduction Zone ◽  
American Continent ◽  
North American Continent ◽  
Continental Scale ◽  
The North

Three lithospheric cross sections provide a continental-scale synthesis of more than two decades of coordinated multidisciplinary research during the Canadian Lithoprobe project. The sections are based on seismic reflection and refraction data combined with a broad range of geological, geochemical, geochronological, and geophysical data. The dataset is derived from remnants of nearly every kind of tectonic regime, and the geologic history of the entrained rocks spans the Present to the Mesoarchean. The longest of the three cross sections is located within a 6000 km long Trans-Canada corridor traversing the North American continent at 45°N–55°N. From west to east, the profile crosses the Juan de Fuca ridge and active Cascadia subduction zone, the Cordilleran, Albertan, and Trans-Hudson orogens, the Superior Province, the Midcontinent rift, the Grenville and Appalachian orogens, and the Atlantic passive margin. The two northern cross sections include (i) a 2000 km long corridor in northwestern Canada (54°N–63°N) crossing the Cordilleran, Wopmay, and Slave orogens; and (ii) a 1600 km long corridor in northeastern Canada (52°N–61°N) crossing the New Quebec and Torngat orogens, the Nain craton, and the Makkovik and Grenville orogens. The unprecedented scale of the cross sections illuminates the assembly of the North American continent. Relationships between orogens are emphasized; plate collisions and accretions have sequentially stacked orogen upon orogen such that the older crust forms basement to the next younger. The large-scale perspective of these regional sections highlights the subhorizontal Moho that is indicative of either structural or thermal re-equilibration (or both), as few crustal roots beneath orogens are preserved. In contrast, heterogeneities in the lithospheric mantle suggest that, in certain situations, relict subducted or delaminated lithosphere can remain intact beneath and eventually within cratonic lithospheric mantle.

Community detection based on modularity and an improved genetic algorithm

2013 ◽  
Vol 392 (5) ◽  
pp. 1215-1231 ◽  
Author(s):  
Ronghua Shang ◽  
Jing Bai ◽  
Licheng Jiao ◽  
Chao Jin
Keyword(s):  
Genetic Algorithm ◽  
Community Detection ◽  
Improved Genetic Algorithm

scholarly journals OPTIMIZATION OF PIECEWISE NON-LINEAR MULTI CONSTRAINED ECONOMIC POWER DISPATCH PROBLEM USING AN IMPROVED GENETIC ALGORITHM

2010 ◽  
pp. 320-326
Author(s):  
B. Padmanabhan ◽  
R. S. SivaKumar ◽  
J. Jasper
Keyword(s):  
Genetic Algorithm ◽  
Power Systems ◽  
Optimal Solution ◽  
Inequality Constraints ◽  
Local Optimum ◽  
Improved Genetic Algorithm ◽  
Non Linear ◽  
Equality And Inequality Constraints ◽  
Loading Effects ◽  
Economic Power Dispatch

In this paper, a more realistic formulation of the Economic Dispatch problem is proposed, which considers practical constraints and non linear characteristics. The proposed ED formulation includes ramp rate limits, valve loading effects, equality and inequality constraints, which usually are found simultaneously in realistic power systems. This paper presents a novel Genetic Algorithm to solve the economic load dispatch (ELD) problem of thermal generators of a power system. This method provides an almost global optimal solution, since they don’t get stuck at local optimum. The proposed method and its variants are validated for the two test systems consisting of 3 and 10 thermal units whose incremental fuel cost functions takes into account the valve-point loading effects.

An Effective Community Detection Method Based on Improved Genetic Algorithm

2014 ◽  
Vol 568-570 ◽  
pp. 852-857
Author(s):  
Lu Wang ◽  
Yong Quan Liang ◽  
Qi Jia Tian ◽  
Jie Yang ◽  
Chao Song ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Community Structure ◽  
Community Detection ◽  
Detection Method ◽  
Initial Population ◽  
Crossover Operator ◽  
Improved Genetic Algorithm ◽  
Mutation Process ◽  
Effective Community ◽  
New Community

Detecting community structure from complex networks has triggered considerable attention in several application domains. This paper proposes a new community detection method based on improved genetic algorithm (named CDIGA), which tries to find the best community structure by maximizing the network modularity. String encoding is used to realize genetic representation. Parts of nodes assign their community identifiers to all of their neighbors to ensure the convergence of the algorithm and eliminate unnecessary iterations when initial population is created. Crossover operator and mutation operator are improved too, one-way crossover strategy is introduced to crossover process, the Connect validity of mutation node is ensured in mutation process. We compared it with three other algorithms in computer generated networks and real world networks, Experiment Results show that the improved algorithm is highly effective for discovering community structure.

scholarly journals Spatiotemporal distribution of Holocene populations in North America

2015 ◽  
Vol 112 (39) ◽  
pp. 12127-12132 ◽  
Author(s):  
Michelle A. Chaput ◽  
Björn Kriesche ◽  
Matthew Betts ◽  
Andrew Martindale ◽  
Rafal Kulik ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Kernel Method ◽  
Temporal Frequency ◽  
Human Populations ◽  
Human Occupation ◽  
Migration Routes ◽  
Frequency Distributions ◽  
Continental Scale ◽  
The North

As the Cordilleran and Laurentide Ice Sheets retreated, North America was colonized by human populations; however, the spatial patterns of subsequent population growth are unclear. Temporal frequency distributions of aggregated radiocarbon (14C) dates are used as a proxy of population size and can be used to track this expansion. The Canadian Archaeological Radiocarbon Database contains more than 35,000 14C dates and is used in this study to map the spatiotemporal demographic changes of Holocene populations in North America at a continental scale for the past 13,000 y. We use the kernel method, which converts the spatial distribution of 14C dates into estimates of population density at 500-y intervals. The resulting maps reveal temporally distinct, dynamic patterns associated with paleodemographic trends that correspond well to genetic, archaeological, and ethnohistoric evidence of human occupation. These results have implications for hypothesizing and testing migration routes into and across North America as well as the relative influence of North American populations on the evolution of the North American ecosystem.

scholarly journals An Improved Genetic Algorithm for Developing Deterministic OTP Key Generator

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Ashish Jain ◽  
Narendra S. Chaudhari
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Experimental Work ◽  
Computer Hardware ◽  
Future Research ◽  
Key Generation ◽  
Improved Genetic Algorithm ◽  
Linear Congruential Generator ◽  
The One ◽  
Linear Congruential

Recently, a genetic-based random key generator (GRKG) for the one-time pad (OTP) cryptosystem has been proposed in the literature which has certain limitations. In this paper, two main characteristics (speed and randomness) of the GRKG method are significantly improved by presenting the IGRKG method (improved genetic-based random key generator method). The proposed IGRKG method generates an initial pad by using linear congruential generator (LCG) and improves the randomness of the initial pad using genetic algorithm. There are three reasons behind the use of LCG: it is easy to implement, it can run efficiently on computer hardware, and it has good statistical properties. The experimental results show the superiority of the IGRKG over GRKG in terms of speed and randomness. Hereby we would like to mention that no prior experimental work has been presented in the literature which is directly related to the OTP key generation using evolutionary algorithms. Therefore, this work can be considered as a guideline for future research.

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