This paper proposes an innovative indirect monitoring system for bridge foundation scour damage detection. The Rail Infrastructure Alignment Acquisition system, a mobile mapping system that can be attached to the fron...
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This paper proposes an innovative indirect monitoring system for bridge foundation scour damage detection. The Rail Infrastructure Alignment Acquisition system, a mobile mapping system that can be attached to the front or rear of an operating train, is used for data acquisition. The difference between healthy and damaged pier stiffness responses is utilized as the scour indicator. A cross-entropy optimization algorithm finds the pier stiffness values that minimize the difference between the displacements computed with a numerical model and the measurements. The numerical model adopts the unit load theorem to determine the Moving Reference Influence Lines for a six-axle vehicle crossing the bridge, simulating Rail Infrastructure Alignment Acquisition system displacement measurements on a railway bridge in the UK. The measurements provided belong to the after-repair, i.e., the healthy stage, of the bridge. Due to the absence of scoured-stage measurements, the displacement response of the damaged bridge is synthetically generated using a vehicle-bridge interaction model. Foundation scour is modeled by reducing the vertical pier stiffness. With healthy-bridge field data and synthetically generated damaged-bridge responses superposed with rail irregularities, it is possible to detect the presence of the scour. This approach not only facilitates the early detection of foundation scour but also enhances infrastructure maintenance strategies by enabling the implementation of timely and targeted repairs, thereby improving the safety and resilience of railway operations.
Discovering concrete properties takes time, money, laboratory design, material preparation, and testing with adequate equipment at the right ages. As a consequence, in the concrete sector, solutions that minimize or r...
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Discovering concrete properties takes time, money, laboratory design, material preparation, and testing with adequate equipment at the right ages. As a consequence, in the concrete sector, solutions that minimize or reduce cost, time, and other downsides are essential. So, utilizing forecasting systems to compute concrete characteristics based on historical data is quite advantageous. Employing the rapid chloride penetration test (RCPT), this study proposed novel classification models for predicting chloride penetration into self-compacting concrete (SCC). Designs for predicting the quantity of RCPT are constructed utilizing optimized random forest (RF) classifications, which have not yet been outlined in the literature. The fundamental objective of this research is to build innovative combined classification models that combine RF with optimization techniques such as particle swarm optimization (PSO), whale optimization algorithm (WOA), and Harris hawks optimization (HHO) for better approximation of RCPT. Using PSO, WOA, and HHO, five critical RF model hyperparameters were fine-tuned to provide the most powerful and dependable RF models ever. Considered combined classifications were trained by seven variables, namely cement content, fly ash, silica fume, a ratio of coarse and fine aggregates, water to cement ratio, and temperature. The findings reveal that in the training/testing phases, all three approaches had appropriate efficiency in estimating the RCPT, reflecting the allowable correlation among actual and anticipated values. HHO - RF outperforms the other versions in both stages, with R-2 and RMSE of 0.9854 and 28.6 for the learning phase and 0.9645 and 41.44 for the assessment phase, respectively. Although the performance evaluator indices for PSO - RF are lower than HHO - RF and WOA - RF models, it has acceptable results with R-2 larger than 0.9243. Overall, the findings show that the HHO method is more capable than PSO and WOA at calculating the ideal valu
Most of the current literature focused on centralized learning is centered around the celebrated average-consensus paradigm and less attention is devoted to scenarios where the communication between the agents may be ...
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Most of the current literature focused on centralized learning is centered around the celebrated average-consensus paradigm and less attention is devoted to scenarios where the communication between the agents may be imperfect. This letter presents three different algorithms of Decentralized Federated Learning (DFL) in the presence of imperfect information sharing modeled as noisy communication channels. The first algorithm, Federated Noisy Decentralized Learning (FedNDL1) comes from the literature, where the noise is added to the algorithm parameters to simulate the scenario of the presence of noisy communication channels. This algorithm shares parameters to form a consensus with the clients based on a communication graph topology through a noisy communication channel. The proposed second algorithm (FedNDL2) is similar to the first algorithm but with added noise to the parameters and it performs the gossip averaging before the gradient optimization. The proposed third algorithm (FedNDL3), on the other hand, shares the gradients through noisy communication channels instead of the parameters. Theoretical and experimental results show that under imperfect information sharing, the third scheme that mixes gradients is more robust in the presence of a noisy channel compared with the algorithms from the literature that mix the parameters.
We present a novel method for estimating the circulations and positions of point vortices in a two-dimensional (2D) environment using trajectory data of passive particles in the presence of Gaussian noise. The method ...
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We present a novel method for estimating the circulations and positions of point vortices in a two-dimensional (2D) environment using trajectory data of passive particles in the presence of Gaussian noise. The method comprises two algorithms: the first one calculates the vortex circulations, while the second one reconstructs the vortex trajectories. This reconstruction is done thanks to a hierarchy of optimization problems, involving the integration of systems of differential equations, over time sub-intervals all with the same amplitude defined by the autocorrelation function for the advected passive particles' trajectories. Our findings indicate that accurately tracking the position of vortices and determining their circulations is achievable, even when passive particle trajectories are affected by noise.
We consider online optimization problems with time-varying linear equality constraints. In this framework, an agent makes sequential decisions using only prior information. At every round, the agent suffers an environ...
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We consider online optimization problems with time-varying linear equality constraints. In this framework, an agent makes sequential decisions using only prior information. At every round, the agent suffers an environment-determined loss and must satisfy time-varying constraints. Both the loss functions and the constraints can be chosen adversarially. We propose the Online Projected Equality-constrained Newton Method (OPEN-M) to tackle this family of problems. We obtain sublinear dynamic regret and constraint violation bounds for OPEN-M under mild conditions. Namely, smoothness of the loss function and boundedness of the inverse Hessian at the optimum are required, but not convexity. Finally, we show OPEN-M outperforms state-of-the-art online constrained optimization algorithms in a numerical network flow application.
This letter addresses the problem of nonconvex nonsmooth decentralised optimisation in multi-agent networks with undirected connected communication graphs. Our contribution lies in introducing an algorithmic framework...
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This letter addresses the problem of nonconvex nonsmooth decentralised optimisation in multi-agent networks with undirected connected communication graphs. Our contribution lies in introducing an algorithmic framework designed for the distributed minimisation of the sum of a smooth (possibly nonconvex and non-separable) function and a convex (possibly nonsmooth and non-separable) regulariser. The proposed algorithm can be seen as a modified version of the ADMM algorithm where, at each step, an "inner loop" needs to be iterated for a number of iterations. The role of the inner loop is to aggregate and disseminate information across the network. We observe that a naive decentralised approach (one iteration of the inner loop) may not converge. We establish the asymptotic convergence of the proposed algorithm to the set of stationary points of the nonconvex problem where the number of iterations of the inner loop increases logarithmically with the step count of the ADMM algorithm. We present numerical results demonstrating the proposed method's correctness and performance.
In the past decade, the number of battery electric vehicles (BEVs) on the road has been growing rapidly in response to global climate change and cyclic gasoline shortages. Due to the limited driving range of most comm...
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We present a learning algorithm for players to converge to their stationary policies in a general sum stochastic sequential Stackelberg game. The algorithm is a two time scale implicit policy gradient algorithm that p...
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ISBN:
(纸本)9798350382662;9798350382655
We present a learning algorithm for players to converge to their stationary policies in a general sum stochastic sequential Stackelberg game. The algorithm is a two time scale implicit policy gradient algorithm that provably converges to stationary points of the optimization problems of the two players. Our analysis allows us to move beyond the assumptions of zero-sum or static Stackelberg games made in the existing literature for learning algorithms to converge.
Internet of Vehicles (IoV) presents a new generation of vehicular communications with limited computation offloading, energy and memory resources with 5G/6G technologies that have grown enormously and are being used i...
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Internet of Vehicles (IoV) presents a new generation of vehicular communications with limited computation offloading, energy and memory resources with 5G/6G technologies that have grown enormously and are being used in wide variety of Intelligent Transportation Systems (ITS). Due to the limited battery power in smart vehicles, the concept of energy consumption is one of the main and critical challenges of the IoV environments. Optimizing resource management strategies for improving the energy consumption using AI-based methods is one of important solutions in the IoV environments. There are various machine learning algorithms for selecting optimal solutions for energy-efficient resource management strategies. This paper presents the existing energy-aware resource management strategies for the IoV case studies, and performs a comparative analysis among their applied AI-based methods and machine learning algorithms. This analysis presents a technical and deeper understanding of the technical aspects of existing machine learning and AI-based algorithms that will be helpful in design of new hybrid AI approaches for optimizing resource management strategies with reducing their energy consumption.
Partially Observable Markov Decision Processes (POMDPs) provide an efficient way to model real-world sequential decision making processes. Motivated by the problem of maintenance and inspection of a group of infrastru...
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Partially Observable Markov Decision Processes (POMDPs) provide an efficient way to model real-world sequential decision making processes. Motivated by the problem of maintenance and inspection of a group of infrastructure components with independent dynamics, this letter presents an algorithm to find the optimal policy for a multi-component budget-constrained POMDP. We first introduce a budgeted-POMDP model (b-POMDP) which enables us to find the optimal policy for a POMDP while adhering to budget constraints. Next, we prove that the value function or maximal collected reward for a special class of b-POMDPs is a concave function of the budget for the finite horizon case. Our second contribution is an algorithm to calculate the optimal policy for a multi-component budget-constrained POMDP by finding the optimal budget split among the individual component POMDPs. The optimal budget split is posed as a welfare maximization problem and the solution is computed by exploiting the concavity of the value function. We illustrate the effectiveness of the proposed algorithm by proposing a maintenance and inspection policy for a group of real-world infrastructure components with different deterioration dynamics, inspection and maintenance costs. We show that the proposed algorithm vastly outperforms the policies currently used in practice.
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