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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Electric control and hydraulic steering control method for corn combine harvester</title>
      <link>https://trid.trb.org/View/2677529</link>
      <description><![CDATA[In order to improve the accuracy of steering control for corn combine harvesters, a proportional integral derivative (PID) algorithm based fully hydraulic steering control method for corn combine harvesters is proposed. Firstly, by analysing the steering process, a steering dynamics model is constructed. Secondly, clarify the relevant variables and parameters, and derive the calculation formula for the electro-hydraulic steering control model. Again, the PID algorithm was used to design the steering controller, calculate the angular velocity deviation value, and design proportional, integral, and derivative control functions. Finally, by transforming the transfer function through Laplace transform, optimising the parameters of the PID controller, and considering practical factors such as delay for correction, the optimisation of the electronic control full hydraulic steering control was ultimately achieved. The experimental results show that the steering control accuracy of the proposed method is always above 90%, with low steering angle control error and good stability.]]></description>
      <pubDate>Wed, 24 Jun 2026 13:22:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2677529</guid>
    </item>
    <item>
      <title>Physics-informed Laplace neural operator-CNN hybrid model for wheel-rail force identification on high-speed railway bridges</title>
      <link>https://trid.trb.org/View/2610978</link>
      <description><![CDATA[Accurate identification of vertical wheel-rail forces is critical for structural safety assessment and the reliable operation of high-speed railways. However, direct measurements are often infeasible, and traditional inverse methods suffer from ill-posedness and sensitivity to operational variability. To overcome these limitations, this study proposes a physics-informed Laplace neural operator-CNN hybrid model (PhysiLNO-CNN) that reconstructs wheel-rail forces from bridge displacement responses. By incorporating structural vibration principles via a Laplace-domain pole-residue formulation, the model captures essential modal dynamics across transient and steady-state regimes. A multiscale CNN encoder-decoder further enhances spatiotemporal feature extraction under sparse sensor layouts. Validation is conducted on a high-speed railway box girder bridge using both train-track-bridge interaction (TTBI) simulations and field measurements. Compared to LSTM, CNN, Transformer, and DeepONet, PhysiLNO-CNN reduces prediction errors by 25.00 %, 93.75 %, 85.71 %, and 96.90 %, respectively, while requiring over 85 % fewer trainable parameters (excluding DeepONet). These improvements originate from the integration between physics-based constraints and data-driven learning. Additionally, a gradient-based interpretability framework is introduced to evaluate sensor importance and guide optimal sensor placement. The proposed framework provides a lightweight and physically consistent solution for high-fidelity force identification in complex environments.]]></description>
      <pubDate>Mon, 15 Dec 2025 10:32:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2610978</guid>
    </item>
    <item>
      <title>Semi-analytical solution for the transient response of saturated viscoelastic porous media based on fractional Poynting-Thomson model</title>
      <link>https://trid.trb.org/View/2476641</link>
      <description><![CDATA[The vibration and deformation of subgrade soil under the dynamic load is the main research topic in transportation geotechnics, yet existing studies rarely provide analytical solutions for viscoelastic transient response problems. Building on the Biot wave equations and considering the material’s compressibility, this work introduces the fractional Poynting-Thomson viscoelastic model to establish a transient response model for a saturated viscoelastic single-layer porous medium under typical boundary conditions. By integrating the state-space method, Laplace transform, and the elasticity-viscoelasticity correspondence principle, an analytical solution in the Laplace domain is derived. Employing the inverse Laplace transform, the time-domain solution to the original problem is obtained. The correctness of the solution is verified through comparison with existing solutions. Analysis of numerical examples indicates that the fractional time parameter αf significantly influences the medium’s long-term response. The dash-pot viscosity coefficients have a pronounced effect on the hysteresis of P2 wave.]]></description>
      <pubDate>Tue, 18 Feb 2025 10:56:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2476641</guid>
    </item>
    <item>
      <title>A Developed Tunnel Ventilation System Modeling for an Intelligent Transportation System</title>
      <link>https://trid.trb.org/View/2399918</link>
      <description><![CDATA[This paper presents a Laplace transform model for an urban tunnel ventilation system. This model allows one to witness higher performance for supervisory control and data acquisition (SCADA) in terms of monitoring and control of an urban area tunnel based on measurement systems. This proposed model illustrates the ventilation control system framework as well as the emergency response system for urban area tunnels such that smoother controllability and higher security in the operation of tunnels can be envisioned. The salient contributions of this work can be stated as a novel method for modeling tunnel ventilation systems and the implementation of an emergency response plan for a futuristic intelligent transportation system. The simulation results exhibit that the proposed model outperforms the ventilation system in the high-density traffic jams and further the efficient operation of the tunnel. Likewise, comparison results and experimental results are addressed to emphasize the validation of this method and to be helpful in proving the reliability of the results obtained in this study. These results show that the ventilation control system reaches the desired CO value either in high-traffic volume conditions or in normal traffic conditions.]]></description>
      <pubDate>Thu, 11 Jul 2024 13:52:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2399918</guid>
    </item>
    <item>
      <title>Improvement of Bivariate Cross-Correlated Random Field Modeling Based on Archimedean Copulas</title>
      <link>https://trid.trb.org/View/2216533</link>
      <description><![CDATA[In this study, the bivariate random field modelling method considering different dependent structures between soil parameters based on Laplace-transformed Archimedean copulas (LT-ACs) is improved and employed to investigate the soil deformation performance caused by shield tunnelling. Firstly, based on copula theory and the two-step idea, a bivariate joint cumulative distribution function (CDF) is constructed by combining marginal distributions and LT-ACs. The marginal distributions are used to characterize the randomness of a single geotechnical parameter, and the LT-ACs are used to characterize the dependences between geotechnical parameters. Next, to improve the sampling efficiency, the Marshall-Olkin (M-O) algorithm based on the inverse Laplace transform is employed to sample the LT-ACs. Combined with the covariance matrix decomposition method, the improved approach is utilized to generate a bivariate cross-correlated random field. The modelling feasibility and efficiency superiority of the proposed approach is verified through comparative analysis. Finally, the improved cross-correlated random field modelling method is employed to investigate the surface settlement caused by shield tunnel construction. The effects of different LT-ACs of (c, ϕ), (c, E), and (ϕ, E) on the surface deformation of shield tunnel excavation are revealed.]]></description>
      <pubDate>Wed, 24 Jan 2024 16:55:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2216533</guid>
    </item>
    <item>
      <title>Semi-analytical solutions to the one-dimensional consolidation for double-layered unsaturated ground with a horizontal drainage layer</title>
      <link>https://trid.trb.org/View/2089984</link>
      <description><![CDATA[In order to accelerate the consolidation rate of double-layered unsaturated ground with poor hydraulic conductivity, the sand blanket is always set between two adjacent unsaturated soil layers to produce drainage paths along the horizontal direction in practical engineering. Based on the one-dimensional consolidation theory of unsaturated soil proposed by Fredlund and Hassan(1979), the semi-analytical solutions of excess pore-air and pore-water pressures, and settlement of the double-layered unsaturated ground with the horizontal drainage blanket are obtained by Laplace transform technique in this paper. Additionally, the current solutions can degenerate into those under the single-layered unsaturated model, which are then utilized to compare with existing solutions in literature, the significant agreement indicates that the present solutions are reliable and general. At last, a case study is adopted to investigate the influence of the vertical position of the drainage blanket, and permeability coefficients ratio of two adjacent soil layers on the consolidation of the double-layered unsaturated ground. Results show that the horizontal drainage layer will effectively accelerate the consolidation process, and the setting depth of 0.7H works best. Moreover, the smaller the ratio of the permeability coefficient of the upper layer to that of the lower layer (with the permeability coefficient of the upper layer remaining constant), the faster consolidation will develop.]]></description>
      <pubDate>Fri, 27 Jan 2023 10:46:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2089984</guid>
    </item>
    <item>
      <title>Performance of a Link in a Field of Vehicular Interferers With Hardcore Headway Distance</title>
      <link>https://trid.trb.org/View/1928959</link>
      <description><![CDATA[The Poisson point process (PPP) is not always a realistic model for the locations of vehicles along a road, because it does not account for the safety distance a driver maintains from the vehicle ahead. In this article, the authors model the inter-vehicle distance equal to the sum of a constant hardcore distance and a random distance following the exponential distribution. Unfortunately, the probability generating functional of this point process is unknown. To approximate the Laplace transform of interference at the origin, the authors devise simple approximations for the variance and skewness of interference, and select suitable probability functions to model the interference distribution. When the coefficient-of-variation and the skewness of interference distribution are high, the PPP (of equal intensity) approximation of the outage probability becomes loose in the upper tail. Relevant scenarios are associated with urban microcells and highway macrocells with a low density of vehicles. The predictions of PPP deteriorate with a multi-antenna maximum ratio combining receiver and temporal indicators related to the performance of retransmission schemes. The approximations generate good predictions in all considered cases.]]></description>
      <pubDate>Fri, 20 May 2022 09:32:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1928959</guid>
    </item>
    <item>
      <title>Rapid decoupling Laplace-domain algorithm for dynamic response estimation of offshore structures with asymmetric system matrices</title>
      <link>https://trid.trb.org/View/1908685</link>
      <description><![CDATA[The vibrating differential equation of offshore structures with asymmetric system matrices cannot be decoupled using normal or complex modes. The dynamic response analysis of offshore structures is employed only using the frequency-domain method or step-by-step integration method, owing to which the authors cannot avoid the limitations of those methods, such as relying the on calculation time step, low calculation efficiency, and steady-state response analysis. To address these problems, a Laplace-domain algorithm based on the poles and corresponding residues of a decoupled vibrating system and exciting wave force is proposed to deal with the dynamic response analysis of offshore structures with asymmetric system matrices. A theoretical improvement is that the vibrating equation with asymmetric system matrices is decoupled by the lower parts of the left and right eigenvectors, providing the possibility of solving the vibrating equation based on the decoupled equations. Meanwhile, this method analyzes the dynamic response of offshore structures in the Laplace domain, indicating that the proposed method is insensitive to the calculation time step and has a higher calculation accuracy. Considering that this algorithm can calculate the transient response caused by the initial conditions, the wave force can be divided into a series of small segments, and the dynamic response is connected by the initial conditions of the small segments, thereby considerably improving the computing efficiency of the dynamic response analysis. Three test cases were applied to evaluate the performance of the proposed algorithm. The results show that (1) the proposed algorithm can estimate the dynamic response of offshore structures with asymmetric system matrices both in the process of transient and steady-state response analysis; (2) the computational accuracy of the proposed algorithm is insensitive to the calculation time step, which has a more stable calculation result compared with the Newmark-β method; and (3) the proposed algorithm has a higher calculational efficiency owning to the transient analysis capability.]]></description>
      <pubDate>Fri, 25 Feb 2022 08:58:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1908685</guid>
    </item>
    <item>
      <title>Aliasing in Modal Parameter Estimation</title>
      <link>https://trid.trb.org/View/1812271</link>
      <description><![CDATA[Experimentalists are familiar with the aliasing that happens in data acquisition when the sampling rate is less than twice the highest frequency of energy in the signal to be sampled. Much effort has been made over the years using a combination of analog and digital filters to make sure that the higher frequencies are filtered out to avoid or minimize the effect of this aliasing. Much less talked about is the aliasing that occurs in modal parameter estimation, or curvefitting, when the residual effects of out of band modes violate the assumptions of the finite dimensional parametric model that the experimentalist uses to curvefit the acquired digitized data. While the out of band energy has been filtered out of the now band limited data, the tails, sometimes called residual flexibility and inertial restraint of the out of band modes are still present in the data. This article will look at some classes of modal parameter estimation algorithms and show by theory and example that the algorithms based on continuous time or Laplace domain formulations are superior to the discrete time domain or z domain models in that they give results which are not contaminated by the aliasing effect of these residuals. In addition, it will introduce the Alias Free Polyreference Method, which uses orthogonal polynomials in the infinite frequency domain, corresponding to a family of orthogonal Green's functions in the continuous time domain.]]></description>
      <pubDate>Wed, 23 Feb 2022 16:16:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1812271</guid>
    </item>
    <item>
      <title>Exploration of Various Spatio-temporal Interactions in Crash Frequency Models</title>
      <link>https://trid.trb.org/View/1759030</link>
      <description><![CDATA[Extensive research efforts have been put forth to improve the prediction of crash frequencies by employing the spatio-temporal models. Despite the large number of studies exploring various spatial and temporal effects, there is still a lack of conclusive findings related with the performance of spatio-temporal interactions. The current study bridges the gap by performing a comprehensive comparison of different spatio-temporal interactions with distinct temporal treatments in crash frequency models. Fifteen spatio-temporal models were developed which can be clustered from different perspectives: (1) three groups of models based on temporal treatments containing linear time trend, autoregressive-1 (AR1), and random walk-1 (RW1); (2) models with and without spatio-temporal interaction terms; (3) four different types of interactions including both structured and unstructured spatial or temporal random effects. To estimate the model parameters, the present study employed a fast Bayesian inference approach, or, Integrated Nested Laplace Approximation (INLA). The predictive accuracy of alternative models was assessed by employing various evaluation criteria which include deviance information criterion (DIC), log pseudo marginal likelihoods (LPML), and Probability Integral Transform (PIT). The results illustrated that the models with spatiotemporal interaction perform better than the models without spatiotemporal interactions. The dynamic temporal effects, RW1 and AR1, were found to perform almost the same, with both being superior to the non-dynamic parametric linear trend. With respect to the average performance among all interactions, the interaction of both unstructured spatial and temporal effects was found to outperform others.]]></description>
      <pubDate>Thu, 04 Feb 2021 10:54:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1759030</guid>
    </item>
    <item>
      <title>A Laplace-domain method for motion response estimation of floating structures based on a combination of generalised transfer function and partial fraction</title>
      <link>https://trid.trb.org/View/1741300</link>
      <description><![CDATA[A Laplace-domain method is proposed to predict time-domain motion responses of floating structures. As a theoretical contribution, two techniques of generalising transfer functions of floating structures (GTFF) are developed, which are symbolic-based and Fourier transform-based techniques. Three cases are employed in this study: The first case involves a single degree-of-freedom system to demonstrate the correctness of the derived GTFF, which is assumed to have a purely analytical retardation function. The second case involves a truncated cylinder subjected to random waves that are defined by a Jonswap spectrum. Numerical results show that the symbolic approach simultaneously offers a perfect estimation of the transfer functions of a system, while the inverse Fourier-transform-based approach has some discrepancies at the first short parts of the phases. To further investigate potential applications, a floating platform is employed, and comparisons are drawn by using the commercial software SESAM, which found consistently estimated motion responses.]]></description>
      <pubDate>Fri, 30 Oct 2020 18:43:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1741300</guid>
    </item>
    <item>
      <title>A new residue-based dynamic analysis method for offshore structures with non-zero initial conditions</title>
      <link>https://trid.trb.org/View/1632855</link>
      <description><![CDATA[Different from the traditional time-domain methods, which usually employ a step-by-step procedure for response estimation of structures with non-zero initial conditions, a new time-domain response estimation method is proposed by using separated residues corresponding to original external loadings and non-zero initial conditions, to provide a more efficient algorithm for offshore structures with non-zero initial conditions. The key of the proposed method is that responses of the system are divided into three contributions in the Laplace domain: the first comes from the original external loadings, the second from the initial displacements, and the last from a simultaneous combination of initial displacements and velocities. One theoretical development of the proposed method is that these three parts are all represented by separated residues that can be estimated by using the state-space model, which is also the actual reason why each part of the Laplace-domain responses of the system can be easily transformed back to the time domain in terms of the inverse Laplace transform. Compared with the traditional time-domain methods, responses from the proposed method are directly estimated by utilizing the inverse Laplace transform, which implies that estimated time-domain responses will be continuous in the time domain, so more accurate results can be expected. In addition, the proposed method avoids the procedure of a step-by-step estimation; therefore, better computational efficiency can also be predicted. Three numerical examples and one experiment are used to investigate the performance of the proposed method: the first is a single-degree-of-freedom (SDOF) system to illustrate the procedure, the second is a six-DOF system aiming at extending the proposed method to multiple-DOF (MDOF) systems, and the last is a typically studied engineering structure, i.e., a beam model, to show the potential engineering applications of the proposed method. Numerical results show that the proposed method not only can provide much more accurate time-domain responses compared with those from the traditional time-domain methods, even when the time step used is not so accurate, but also has better computational efficiency, e.g., in the third example, the traditional time-domain method takes 172.39 s during the estimation of responses with 10 s, while the proposed method takes only 13.01 s. Finally, an experimental fixed offshore platform conducted at the lab of Ocean University of China is used to demonstrate the proposed method.]]></description>
      <pubDate>Fri, 30 Aug 2019 13:01:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1632855</guid>
    </item>
    <item>
      <title>Damage Identification for Beam Structures Using the Laplace Transform-Based Spectral Element Method and Strain Statistical Moment</title>
      <link>https://trid.trb.org/View/1501918</link>
      <description><![CDATA[The Laplace transform-based spectral element method (LTSEM) can avoid some limitations of the conventional Fourier transform-based spectral element method (FTSEM) in handling finite-length structures, such as the wrap effect. In this paper, a damage identification technique based on the LTSEM and strain statistical moment (SSM) is proposed, which is combined with a general genetic algorithm. The dynamic responses of beam structures were first analyzed using the LTSEM and were validated by finite-element analysis results. Then, the strain statistical moment was used as the damage indicator; the damage location and severity for beam structures were numerically identified on the basis of the proposed technique. Finally, an experimental investigation for damage detection on a simply supported steel beam was also implemented. The experimental results verified that the proposed damage identification technique is feasible and has robust antinoise performance.]]></description>
      <pubDate>Mon, 30 Apr 2018 17:21:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1501918</guid>
    </item>
    <item>
      <title>Exploring spatio-temporal effects in traffic crash trend analysis</title>
      <link>https://trid.trb.org/View/1488525</link>
      <description><![CDATA[Unobserved heterogeneity produced by spatial and temporal correlations of crashes often needs to be captured in crash frequency modeling. Although many studies have included either spatial or temporal effects in crash frequency modeling, only a limited number of studies have considered both. This study addresses the limitations of existing studies by exploring multiple models that best fit the spatial and temporal correlations. In this study, the authors used Bayesian spatio-temporal models to investigate regional crash frequency trends, and explored the effects of omitting spatial or temporal trends in spatio-temporal correlated data. The fast Bayesian inference approach, integrated nested Laplace approximation, was used to estimate parameters. It was found that fatal crashes showed decreasing trends in all Iowa counties from 2006 to 2015, but the decreasing rates varied by counties. Among all the covariates investigated, only vehicle miles traveled (VMT) was significant. None of the socio-economic or weather indicators were found to be significant in the presence of VMT. Both spatial and temporal effects were found to be important, and they were responsible for both over dispersion and zero inflation in the crash data. In addition, spatial effects played a more important role than did temporal effects in the studied dataset, but temporal component selection was still important in spatio-temporal modeling.]]></description>
      <pubDate>Mon, 20 Nov 2017 17:09:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1488525</guid>
    </item>
    <item>
      <title>An alternative method for computing thermal stress in asphalt mixture: the Laplace transformation</title>
      <link>https://trid.trb.org/View/1468380</link>
      <description><![CDATA[Low-temperature cracking is one of the most severe distresses for asphalt pavement experiencing severely cold weather conditions. Many road authorities recognise thermal stress as a crucial parameter for evaluating the low-temperature performance of asphalt pavement. Thermal stress is conventionally computed with a two-step approach where the relaxation modulus is derived from the experimental creep compliance after which the convolution integral is numerically solved. In this paper, a one-step computation solution based on Laplace transformation is proposed. Thermal stress and corresponding critical cracking temperature of a set of six mixtures are easily computed and graphically and statistically compared to the values obtained with the traditional approach. It is observed that the use of the Laplace-based method provides reliable and reasonably close results to those obtained with the conventional solution.]]></description>
      <pubDate>Tue, 27 Jun 2017 16:09:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468380</guid>
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