Differential Evolution (DE) is a global optimization process that uses population search to find the best solution. It offers characteristics such as fast convergence time, simple and understood algorithm, few paramet...
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Conic optimization is the minimization of a convex quadratic function subject to conic constraints. We introduce a novel first-order method for conic optimization, named extrapolated proportional-integral projected gr...
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Conic optimization is the minimization of a convex quadratic function subject to conic constraints. We introduce a novel first-order method for conic optimization, named extrapolated proportional-integral projected gradient method (xPIPG), that automatically detects infeasibility. The iterates of xPIPG either asymptotically satisfy a set of primal-dual optimality conditions, or generate a proof of primal or dual infeasibility. We demonstrate the application of xPIPG using benchmark problems in model predictive control. xPIPG outperforms many state-of-the-art conic optimization solvers, especially when solving large-scale problems.
Recently, fracture energy has received considerable attention owing to its importance in crack propagation in concrete structures. However, measuring fracture energy of concrete require experimental tests, causes cost...
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Recently, fracture energy has received considerable attention owing to its importance in crack propagation in concrete structures. However, measuring fracture energy of concrete require experimental tests, causes cost and time. The alternative ways could be effective such as machine learning methods. So, this study concentrated on the developing prediction models to estimate the preliminary (G(f)) and total (G(F)) fracture energy of concrete. This research integrates the radial foundation function nervous network (RBF) with the equilibrium optimizer (EO) and the salp swarm optimization algorithm (SSOA), abbreviated EORB and SSRB, respectively, to get a more in-depth understanding of G(f) and G(F). The 264 research recordings were used to build and examine theories from previous research. optimization procedures were used to determine the best propagation value and concealed substrate neuron count. Estimates demonstrate that both the improved EORB and SSRB were able to operate very well throughout the whole estimating procedure of G(f), with coefficient of determination (R-2) values of 0.9578 and 0.9907 and 0.8851, and 0.9617 for the training and assessment data subsets, respectively. Regarding G(F), R-2 values of 0.9119 and 0.8763, and 0.8586 and 0.8097 for the training and assessment data subsets were obtained. The comparison with the literature depicted a significant improvement in the efficacy of the EORB simulation, with R-2 going up from 0.8281 to 0.9119 related to G(f) and from 0.9025 to 0.9907 related to G(F). Given the logic and ease of model processing, the EORB analysis seems to be highly reliable for computing G(f) and G(F), even though the SSRB technique has distinctive features for simulating.
作者:
Rokhlin, D.B.Institute of Mathematics
Mechanics and Computer Sciences and Regional Scientific and Educational Mathematical Center of the Southern Federal University Rostov-on-Don344090 Russia
Abstract: We consider a sequence of block-separable convex programming problems describing theresource allocation in multiagent systems. We construct several iterative algorithms for setting theresource prices. Under ...
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Precast I girders provide rapid construction and structural simplicity, making them an increasingly popular choice for bridge construction. The current standard sections adopted by the American Association of State Hi...
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Precast I girders provide rapid construction and structural simplicity, making them an increasingly popular choice for bridge construction. The current standard sections adopted by the American Association of State Highway and Transportation Officials (AASHTO) are not SI friendly and may be improved utilizing increasingly efficient metaheuristic optimization algorithms. Thus, this research study aims to obtain the optimum shape of Precast I (PCI) bridge girders commonly used in bridge construction due to various advantages. The optimization problem is solved using a modified metaheuristic optimization algorithm considering a number of constraints that are stipulated by the AASHTO LRFD code requirements. To show the capabilities of the utilized modified optimization algorithm, a comparison is performed with its baseline counterpart. The structural design optimization of bridge superstructures is performed with the objective of minimizing the total cost of the resulting superstructure. Consequently, the most economical shape of the PCI girders is obtained. The results of this analysis are then compared AASHTO and the California Department of Transportation (Caltrans) PCI girders. The new I girder sections exhibits 13-17% and 5-16% better structural efficiency factor (rho) as well as 14-19% and 4-21% structural efficiency ratio (alpha) than Caltrans and AASHTO girders, respectively. Thus, new sections for PCI girders are developed having various heights to facilitate more economical design of bridges having various geometric properties such as span length, girder spacing and slab thickness.
In this letter we address nonconvex distributed consensus optimization, a popular framework for distributed big-data analytics and learning. We consider the Gradient Tracking algorithm and, by resorting to an elegant ...
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In this letter we address nonconvex distributed consensus optimization, a popular framework for distributed big-data analytics and learning. We consider the Gradient Tracking algorithm and, by resorting to an elegant system theoretical analysis, we show that agent estimates asymptotically reach consensus to a stationary point. We take advantage of suitable coordinates to write the Gradient Tracking as the interconnection of a fast dynamics and a slow one. To use a singular perturbation analysis, we separately study two auxiliary subsystems called boundary layer and reduced systems, respectively. We provide a Lyapunov function for the boundary layer system and use Lasalle-based arguments to show that trajectories of the reduced system converge to the set of stationary points. Finally, a customized version of a Lasalle's Invariance Principle for singularly perturbed systems is proved to show the convergence properties of the Gradient Tracking.
We propose and analyze a generalized framework for distributed, delayed, and approximate stochastic gradient descent. Our framework considers n local agents who utilize their local data and computation to collectively...
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We propose and analyze a generalized framework for distributed, delayed, and approximate stochastic gradient descent. Our framework considers n local agents who utilize their local data and computation to collectively assist a central server tasked with optimizing a global cost function composed of local cost functions accessible to the local agents. This framework is very general, subsuming a great variety of algorithms in federated learning and distributed optimization. In particular, this framework allows each local agent to approximate and share a stochastic (possibly biased) and delayed estimate of its local function gradient. Focusing on strongly convex functions with sufficient degree of smoothness, we characterize the mean square error in terms of the varying step-size, the approximation error (bias), and the delay in computing the gradients. This characterization, together with a careful design of step size process, establishes an optimal convergence rate that aligns with centralized stochastic gradient descent (SGD).
Control chart is an important method in Statistical Process Control, which is used to study how a process changes over time. The exponential distribution is one of the commonly used models for fitting data, especially...
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Control chart is an important method in Statistical Process Control, which is used to study how a process changes over time. The exponential distribution is one of the commonly used models for fitting data, especially in areas such as component life, aviation accidents, or health-care processes. In order to further improve the sensitivity of the control chart, we propose an exponentially weighted moving average control chart with a variable sampling interval scheme, denoted as VSIEWMA-T control chart, for monitoring exponentially distributed quality characteristics (e.g. Urinary Tract Infections data). In this paper, the average time to signal property of the proposed control chart is investigated using the Markov chain method. In addition, parameter optimization algorithms for known or unknown shift levels are provided. Subsequently, numerical analysis shows that the proposed control chart outperforms other competitive control charts. Finally, an example of urinary tract infections data is provided for illustration.
Distributed generators (DGs), which can be traditional fossil fuel generators or renewable energy sources (RES), must be appropriately planned in order to reduce a power network's overall generating cost. Renewabl...
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Distributed generators (DGs), which can be traditional fossil fuel generators or renewable energy sources (RES), must be appropriately planned in order to reduce a power network's overall generating cost. Renewable energy sources (RES) should be prioritized because they provide a clean and sustainable energy supply and are abundant in nature. Demand side management (DSM) optimizes the scheduling of flexible loads to reduce peak demand and improve the load factor, while keeping daily demand unchanged. The test system in this research employs a dependable and effective hybrid optimization tool to plan the DGs of a dynamic system in a way that matches low active power production costs with low pollutant emissions. The fitness functions used in the test system were non-linear due to the presence of the valve point effect (VPE). The costs and emissions were evaluated for various fitness functions which included involvement of wind, DSM, and different types of combined economic emission dispatch (CEED) methods. The test system's peak demand was cut by 12% and the load factor was raised from 0.7528 to 0.85 when DSM technique was used. The generation cost has been reduced from $1,014,996 to $1,012,182 using CSAJAYA algorithm which was further reduced to $1,007,441 after incorporating DSM. Likewise, the CEEDppf was also observed to be reduced to $1,231,435 and $1,216,885 with and without DSM compared to $1,232,001 from reported literature. Numerical results show that both the cost and emission were reduced significantly using the proposed CSAJAYA compared to a long-sighted list of algorithms published in literature.
High-performance concrete (HPC) outperforms regular concrete due to incorporating additional components that go beyond the typical ingredients used in standard concrete. Various artificial analytical methods were empl...
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High-performance concrete (HPC) outperforms regular concrete due to incorporating additional components that go beyond the typical ingredients used in standard concrete. Various artificial analytical methods were employed to assess the compressive strength (CS) of high-performance concrete containing fly ash (FA) and blast furnace slag (BFS). The primary objective of this study was to present a practical approach for a comprehensive evaluation of machine learning algorithms in predicting the CS of HPC. The study focuses on utilizing the adaptive neuro-fuzzy inference system (ANFIS) to develop models for predicting HPC characteristics. To enhance the performance of ANFIS methods, the study incorporates the arithmetic optimization algorithm (AOA) and equilibrium optimizer (EO) (abbreviated as ANAO and ANEO, respectively). Notably, this research introduces novelty through the application of the AOA and EO, the evaluation of HPC with additional components, the comparison with prior literature, and the utilization of a large dataset with multiple input variables. The results indicate that the combined ANAO and ANEO systems demonstrated strong estimation capabilities, with R-2 values of 0.9941 and 0.9975 for the training and testing components of ANAO, and 0.9878 and 0.9929 for ANEO, respectively. The results comparison of this study presented the comprehensiveness and reliability of the created ANFIS model optimized with AOA for predicting the HPC's CS improved with FA and BFS, which could be applicable for practical usages.
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