Actual Shape Research Articles

Improving the roller screen efficiency to classify green iron pellets using DEM simulation, novel roll design and implementing banana configuration

Roller screens play a decisive character in the efficiency of pelletizing circuits and induration furnaces. Unlike vibrating screens, there have been no studies on roller screens to determine their capacity and dimensions. Most studies have utilized the discrete element method (DEM) simulation to assess roller screen performance by employing a spherical shape and the Hertz-Mindlin elastic model. However, this approach is unsuitable due to green pellets’ non-spherical shape and elastic–plastic properties. This study introduces the incorporation of the actual shape of green pellets and a hysteretic spring elastoplastic contact model. In this research work, a novel design of rolls with a grooved surface was recommended for the first time, resulting in a Total Screening Efficiency (TSE) of 96.4% compared to 87.1% for rolls with a smooth surface. Additionally, while exploring the impact of the decks number on the roller screen, a new design, known as the banana roller screen, was introduced. Under similar conditions, the TSE increased by 1.22% compared to the general roller screen type. It was also found that the roller screen’s capacity is directly related to the diameter, speed of rotation, and the number of rolls, while it has a reverse relationship with TSE and deck angle.

Assessing the Efficacy of Cognitive-Behavioral Therapy on Body Image in Adolescent Scoliosis Patients Using Virtual Reality

Background/Objectives: Adolescents with idiopathic scoliosis require emotional support to change their experience of their desired body shape and to feel optimistic about the cosmetic results of surgical treatment. Recently, the use of virtual reality in psychological assessment and treatment has given specialists a technology that appears particularly well-suited for addressing body image disorders. The study objectives were two-fold. Firstly, we aimed to evaluate changes within the body image of scoliosis patients pre- and postoperatively. Secondly, we aimed to investigate if differences in body image exist in scoliosis females after implementing cognitive-behavioral therapy. Methods: Thirty-six total scoliosis patients participated in the 1st and 2nd study phases. The psychotherapy took place before and after surgery and during the patient’s stay in the hospital. Body image was assessed using a virtual reality-based application, “Avatar Scoliosis 3D”. Results: Regarding body image dissatisfaction evaluated via virtual tasks, the difference between the desired by patients and actual (based on the radiographic parameters) body shape is significant preoperatively in both scoliosis samples: with and without therapy (p < 0.000001 and p < 0.000001, respectively). Conclusions: The results of the present study may have important implications for developing standards for body image disorder treatments in scoliosis patients. We revealed that irrespective of received therapeutic support, scoliosis patients accurately estimate their body shape pre- and postoperatively, and they feel dissatisfied with their body preoperatively but not postoperatively.

Research on Non-Destructive Testing of Log Knot Resistance Based on Improved Inverse-Distance-Weighted Interpolation Algorithm

The objective of this paper is to propose a non-destructive resistance detection imaging algorithm for log knots based on improved inverse-distance-weighted interpolation algorithm, i.e., the eccentric circle-based inverse-distance-weighted (ECIDW) method, to predict the size, shape, and position of internal knots of logs; evaluate its precision and accuracy; and both lay a theoretical foundation and provide a scientific basis for predicting and assessing knots in standing trees. Six sample logs with natural knots were selected for this study. Resistance measurements were performed on the log cross-sections using a digital bridge, and resistance tomography was conducted using the improved ECIDW algorithm, which combines the azimuth search method with the eccentric circle search method. The results indicated that both the conventional inverse-distance-weighted (IDW) algorithm and the ECIDW algorithm accurately predicted the positions of the knots. However, neither algorithm was able to predict the shape of the knots with high precision, leading to some discrepancies between the predicted and actual knot shapes. The relative error (Dt1) between the knot areas measured by the IDW algorithm and the actual knot areas ranged from 18.97% to 88.34%. The relative error (Dt2) for the knot areas predicted by the ECIDW algorithm ranged from 1.82% to 74.16%. The average prediction accuracy for the knot areas using the IDW algorithm was 51.58%, compared to 72.90% using the ECIDW algorithm. This indicates that the ECIDW algorithm has higher accuracy in predicting knot areas compared to the conventional IDW algorithm. The ECIDW algorithm proposed in this paper provides a more reasonable and accurate prediction and evaluation of knots inside logs. Compared to the conventional IDW algorithm, the ECIDW algorithm demonstrates greater precision and accuracy in predicting the shape and size of knots. While the resistance method shows significant potential for predicting internal knots in logs and standing trees, further improvements to the algorithm were needed to enhance the imaging effects and the precision and accuracy of knot area and shape predictions.

Process-based reconstruction of digital rock based on discrete element method considering thermal-mechanical coupling effect and actual particle shape

The digital rock is a crucial platform for numerical simulations of pore-scale flow in various fields such as geo-energy, carbon (CO2) sequestration, and hydrogen (H2) storage. Under these conditions, rocks deform, and pore structures change due to temperature and stress effects. However, existing methods for reconstructing digital rocks, such as physical experimental, stochastic simulation, and machine learning, can not consider the influence of high temperature and stress. Therefore, a process-based reconstruction method based on the discrete element method (DEM) considering the thermal-mechanical coupling effect is proposed in this paper. Initially, the computed tomography (CT) images are segmented based on the watershed algorithm, and a contour database is established using the spherical harmonic analysis method. A clump template library is then constructed in PFC3D (Particle Flow Code in 3 Dimensions). Subsequently, the DEM model is established using clumps from the template library according to porosity and particle radius distribution, and the model's accuracy is evaluated based on two-point and linear path correlation functions. Micro-mechanical and thermal parameters between particles are calibrated, and different temperature and stress boundary conditions are applied to obtain digital rocks under varying conditions. Finally, digital rocks' geometric and topological structures under different conditions are analyzed, and permeability and relative permeability are calculated. Using Bentheim sandstone as an example, digital rocks are constructed under various temperature and stress conditions. The research findings indicate that high temperatures and stress result in decreased pore and throat radii, elongated throats, deteriorated connectivity, reduced porosity, and permeability, making the digital rocks more water-wet. This study provides theoretical guidance for the accurate pore-scale flow simulation of geo-energy fluids, CO2, and H2.

Digital twin technology facilitates precision improvement in complex product assembly: A progressive deduction method of data-driven tolerance allocation

Advancements in aerospace technology have significantly increased the demands on assembly precision, particularly for large aircraft models. These developments require sub-millimeter precision to be achieved in assembly, posing new challenges for conventional tolerance allocation methods, which rely heavily on theoretical models and static simulations. To address these limitations, this paper proposes a digital twin system for online deduction of assembly tolerances (DTS-ODTA) using point cloud registration and free-form deformation (FFD). The proposed method includes three key innovations. First, a digital twin (DT)-based assembly process control framework supports the simulation of assembly deviations by integrating virtual and actual data. Second, a data-driven method models the actual surface shapes, ensuring synchronization between physical and digital states. Third, a progressive deduction strategy for tolerance allocation combines virtual and actual information, providing effective inputs for real-time assembly process control. This approach was validated through an industrial case study, achieving a prediction accuracy of 91.64 % for assembly precision and effectively preventing out-of-tolerance issues during product assembly. By promptly identifying and addressing potential assembly discrepancies, this method enhances the overall assembly quality and provides critical support for design decisions. In summary, this paper introduces a novel DT-based tolerance allocation method that shifts from traditional open-loop design to closed-loop control, thereby meeting the high precision demands of modern aerospace manufacturing.

Energy dissipation damage constitutive relation of CFRP passively confined coal sample

In view of the stability problem of coal pillars left over during coal resource mining, (Carbon Fiber Reinforced Polymer) CFRP sheet is applied in coal pillar reinforcement. Uniaxial compression tests of CFRP passively confined coal samples are carried out to explore the mechanical response mechanism of passively confined coal samples under different layers, and the energy dissipation damage constitutive relationship of CFRP passively confined coal samples is established based on the energy dissipation principle. The conclusions are: As CFRP layers increased, the local damage of coal samples before the peak evolved from a 'cliff-like jagged' to a 'capillary jagged', with post-peak instability marked by a shift to more 'cliff-like' characteristics. The tests revealed improvements in peak strength and elastic modulus, with a defined functional relationship between these properties and CFRP layers. The energy storage capacity of passively confined coal samples improved with CFRP layers, requiring less axial deformation to achieve equivalent energy levels. The energy dissipation rate showed an initial decrease followed by an increase, with a minimum inflection point, the elastic energy consumption ratio tends to decrease slowly and then rapidly during post-peak instability. A damage constitutive relationship and evolution equation were developed, highlighting that the CFRP sheet significantly inhibits damage, with diminishing effectiveness beyond two layers. The study concludes that three-layer CFRP sheets provide optimal confinement, offering a novel strategy for the reinforcement of coal pillars and the prevention and control of rock burst, without considering the actual coal pillar dimensions and shape. To sum up, the use of CFRP sheet to strengthen coal pillar has considerable potential research value in strengthening coal pillar and improving the recovery rate of coal resources.

Numerical Study on the Unsteady Behavior of the Solid-Fuel Scramjet

The unsteady evolution of the flowfield in a solid-fuel scramjet is investigated. The researchers approximate the continuous working of the solid-fuel scramjet via stand-alone geometries. These directly correspond to the actual shapes of the combustor recorded during experimental tests of the engine. The flow is modeled using the compressible Navier–Stokes and species transport equations and the shear stress transport k−ω turbulence model. A two-dimensional axisymmetric formulation is employed. The fuel is the polymer polymethyl methacrylate. The integral parameters of the combustor are computed in the simulations using nonvarying geometries at discrete instants. These values are then compared with measurements taken at the same instant during the continuous working of the engine in experimental tests. The good agreement during the whole process demonstrates the permanent quasi-steadiness nature of the fluid flow in relation to the varying combustor shape. The discussion analyzes the evolution of critical combustor parameters, including thrust, fuel regression rate, and various efficiencies, and correlates them with the underlying flow variables. The findings provide valuable insights into the unsteady development of the flow physics within the combustor of a solid-fuel scramjet, contributing to a better understanding of this complex system.

Experimental and numerical investigations of bending mechanical properties and fracture characteristics of cemented tailings-waste rock backfill under three-point bending

The bending mechanical properties and fracture characteristics of cemented tailings-waste rock backfill (CT-WRB) have a significant impact on efficient mine production. In this study, the effects of waste rock content (WRC) and waste rock size (WRS) on the bending mechanical properties and macroscopic failure characteristics of CT-WRB were investigated through experiments. Concurrently, PFC3D numerical simulation software was used to establish a three-point bending numerical model of CT-WRB with actual waste rock shapes to explore the crack evolution law and microscopic damage characteristics. Results showed that adding appropriate waste rock improved the initial stiffness, flexural strength, and modulus of the backfill, with optimal WRC and WRS at 40 % and 4–6 mm, respectively. Simulations indicated that under load, the displacement field of CT-WRB formed a vortex, with tensile stress in the middle and lower parts and compressive stress in an upper arch. Cracks started at the bottom and extended upward, leading to failure. Compared to OCTB (without waste rock incorporation), CT-WRB had more total cracks and tension-shear composite failure of internal particles. Waste rock altered stress distribution and crack paths, resulting in curved, bifurcated, and discontinuous main cracks. These findings provide a reference for efficiently recycling tailings, waste rock and ensuring safe mine production.

Pathogen shape: Implication on pathogenicity via respiratory deposition

The shape of environmental aerosols contributes to the discrepancy in their dynamic behavior compared to spherical particles, which have received inadequate consideration. We reported deposition patterns of aerosols and aerosol-transmissible pathogens in real human respiratory systems, taking into account their actual shape, using a validated computational-based model. We found that the shape of the aerosols significantly influenced its deposits and accessibility within the respiratory system, significantly in the tracheobronchial region. As an example, we estimated that over 180 % of differences in deposits in the trachea and bronchi were attributable to pathogens shape, inferring the underlying pathogenicity difference of these regions. These findings, capturing the spatial heterogeneity of pathogens and aerosols deposition in human respiratory system, have major implication for understanding the evolution of aerosol-related disease.

Predicting and optimizing the dimensions of rod in lattice structures fabricated by laser powder bed fusion

Laser powder bed fusion (LPBF) is a highly effective method for manufacturing complex parts and is widely used in industry for creating lattice structures. However, during the manufacturing process, the actual dimensions and shapes of the lattice structure rod often deviate significantly from the design model due to limited understanding of the structure-process-property relationship in LPBF. This makes it difficult to carry out targeted structural design and process planning based on the technical characteristics of LPBF. This paper investigates the relationship between melt pool dimensions and lattice structure rod dimensions through theoretical analyses. Based on melt pool dimensions obtained with the help of numerical simulation, a prediction model for the actual dimensions of lattice structure rod is established. We design experiments to validate the accuracy of the predictive model, using LPBF to fabricate rods with varying inclinations, dimensions, and cross-sectional shapes. The actual dimensions are measured under a microscope and compared with the predicted dimensions. The results indicate a difference of no more than 0.1 mm. Furthermore, the experiments reveal a correlation between scan path curvature and actual dimensions. Based on this correlation, the dimensional prediction model is corrected, resulting in an improved generalization performance of the model for parts with varying scan paths. Based on the dimension prediction model, we propose an optimization method to modify the CAD dimensions of the rod to ensure the consistency between the actual and designed dimensions of the rod.

Mast Design Performance - Influence of the Non-Linear Elastic Behaviour of Carbon Fibres on the Accuracy of Fluid/Structure Interaction Models for Estimating Mast Bending

_ The masts of racing yachts are generally made of carbon fibre reinforced plastics (CFRP) and are subject to two main loads: dock tuning and the forces exerted by the sails. Both result in compression and bending of the mast. The mast design must ensure that for any given sailing configuration, the mast deflection is matched to the sail design to maximise the boat’s performance. Fluid/structure interaction models are generally employed by sail designers who use a stick model for the structural definition of the mast. The elastic properties of the CFRP plies involved in mast lamination are assumed to be constant in this latter model. However, stiffness increases under tension and decreases under compression (up to 30% at failure depending on the fibre type, standard modulus, intermediate modulus, etc) due to some reversible changes in the microstructure of the carbon fibres. As a result, the actual curvature of the mast can be very different from that calculated with the stick model, leading to a significant error in the actual shape of the sail during sailing. In this work, we use a series of three critical loading cases corresponding to those of an IMOCA mast. The influence of the elastic non-linearity of the CFRP plies on the performance of the racing yacht mast is quantified. It is concluded clearly that this elastic non-linear behaviour of carbon fibres is to be accounted for by sails designers to optimise performance. Such an influence is expected to be even more pronounced on spreader masts such as those used for America’s Cup. Keywords Yacht design; IMOCA mast; Carbon fibre composites; Non-linear elasticity

Real-Time Multimodal 3D Object Detection with Transformers

The accuracy and real-time performance of 3D object detection are key factors limiting its widespread application. While cameras capture detailed color and texture features, they lack depth information compared to LiDAR. Multimodal detection combining both can improve results but incurs significant computational overhead, affecting real-time performance. To address these challenges, this paper presents a real-time multimodal fusion model called Fast Transfusion that combines the benefits of LiDAR and camera sensors and reduces the computational burden of their fusion. Specifically, our Fast Transfusion method uses QConv (Quick Convolution) to replace the convolutional backbones compared to other models. QConv concentrates the convolution operations at the feature map center, where the most information resides, to expedite inference. It also utilizes deformable convolution to better match the actual shapes of detected objects, enhancing accuracy. And the model incorporates EH Decoder (Efficient and Hybrid Decoder) which decouples multiscale fusion into intra-scale interaction and cross-scale fusion, efficiently decoding and integrating features extracted from multimodal data. Furthermore, our proposed semi-dynamic query selection refines the initialization of object queries. On the KITTI 3D object detection dataset, our proposed approach reduced the inference time by 36 ms and improved 3D AP by 1.81% compared to state-of-the-art methods.

General Method for Fitting Kinetics from the SECM Images of Reactive Sites on Flat Surfaces.

Scanning electrochemical microscopy (SECM) is a technique for imaging electrochemical reactions at a surface. The interaction between electrochemical reactions occurring at the sample and scanning electrode tip is quite complicated and requires computer modeling to obtain quantitative information from SECM images. Often, existing computer models must be modified, or a new model must be created from scratch to fit kinetic parameters for different reactive features. This work presents a method that can simulate the SECM image of a reactive feature of any shape on a flat surface which is coupled to a computer program which effectuates the automated fitting of kinetic information from these images. This fitting program is evaluated along with several methods for estimating the shapes of reactive features from their SECM images. Estimates of the reactive feature shape from SECM images were not sufficiently accurate and produced median relative errors for the surface rate constant that were >50%. Fortunately, more precise techniques for imaging the reactive features such as optical microscopy can supply sufficiently accurate shapes for the fitting procedure to produce accurate results. Fits of simulated SECM images using the actual shape from the simulation produced median relative errors for the surface rate constant that were <10% for the smallest reactive features tested. This method was applied to the SECM images of aluminum alloy AA7075 which revealed diffusion-limited kinetics for ferrocene methanol reduction over inclusions in the surface of the alloy.

Development of new numerical approach to the flow and segregation behaviors of fresh concrete considering rebar restraint and its application in reinforced lightweight aggregate concrete

Although there are many studies on flow simulation methods for fresh concrete, there are very few studies on casting simulation of reinforced concrete, and in these studies the reinforcing bars are treated only as static boundaries without their restraining effect on the concrete flowing between them. In this study, we first developed a new numerical method based on the MPS method for simulating the flow and segregation behaviors of fresh concrete during casting reinforced member, considering the restraint of reinforcing bars by applying a normal stress to the concrete. Fresh concrete was treated as the double-phase granular fluid that follows a non-linear rheological model, and was represented by matrix mortar, and coarse aggregate particles with actual sizes and random shapes. Then, as an application of this numerical method, the flow and segregation behaviors of lightweight aggregate concrete (LWAC) in an L-shaped box with rebars were numerically investigated in addition to measurement. The comparison of the numerical and experimental results shows that this numerical method allows the LCA volume fraction to be calculated within 3 % error in predicting the segregation behavior of LCA in reinforced LWAC, and improves the accuracy of the flow simulation of LWAC by about 1.5 times. Furthermore, this numerical method can double the accuracy of concrete flow prediction, compared to treating the reinforcement as a static boundary.

Automated eyeball volume measurement based on CT images using neural network-based segmentation and simple estimation

With the increase in the dependency on digital devices, the incidence of myopia, a precursor of various ocular diseases, has risen significantly. Because myopia and eyeball volume are related, myopia progression can be monitored through eyeball volume estimation. However, existing methods are limited because the eyeball shape is disregarded during estimation. We propose an automated eyeball volume estimation method from computed tomography images that incorporates prior knowledge of the actual eyeball shape. This study involves data preprocessing, image segmentation, and volume estimation steps, which include the truncated cone formula and integral equation. We obtained eyeball image masks using U-Net, HFCN, DeepLab v3 +, SegNet, and HardNet-MSEG. Data from 200 subjects were used for volume estimation, and manually extracted eyeball volumes were used for validation. U-Net outperformed among the segmentation models, and the proposed volume estimation method outperformed comparative methods on all evaluation metrics, with a correlation coefficient of 0.819, mean absolute error of 0.640, and mean squared error of 0.554. The proposed method surpasses existing methods, provides an accurate eyeball volume estimation for monitoring the progression of myopia, and could potentially aid in the diagnosis of ocular diseases. It could be extended to volume estimation of other ocular structures.

Influence of framing coil orientation and its shape on the hemodynamics of a basilar aneurysm model.

Aneurysms are bulges of an artery, which require clinical management solutions. Due to the inherent advantages, endovascular coil filling is emerging as the treatment of choice for intracranial aneurysms (IAs). However, after successful treatment of coil embolization, there is a serious risk of recurrence. It is well known that optimal packing density will enhance treatment outcomes. The main objective of endovascular coil embolization is to achieve flow stasis by enabling significant reduction in intra-aneurysmal flow and facilitate thrombus formation. The present study numerically investigates the effect of framing coil orientation on intra-aneurysmal hemodynamics. For the purpose of analysis, actual shape of the embolic coil is used, instead of simplified ideal coil shape. Typically used details of the framing coil are resolved for the analysis. However, region above the framing coil is assumed to be filled with a porous medium. Present simulations have shown that orientation of the framing coil loop (FCL) greatly influences the intra-aneurysmal hemodynamics. The FCLs which were placed parallel to the outlets of basilar tip aneurysm (Coil A) were found to reduce intra-aneurysmal flow velocity that facilitates thrombus formation. Involving the coil for the region is modeled using a porous medium model with a packing density of 20 . The simulations indicate that the framing coil loop (FCL) has a significant influence on the overall outcome.

Impact of beam far side-lobe knowledge in the presence of foregrounds for LiteBIRD

We present a study of the impact of a beam far side-lobe lack of knowledge on the measurement of the Cosmic Microwave Background B-mode signal at large scale. Beam far side-lobes induce a mismatch in the transfer function of Galactic foregrounds between the dipole and higher multipoles which degrads the performances of component separation methods. This leads to foreground residuals in the CMB map. It is expected to be one of the main source of systematic effects in future CMB polarization observations. Thus, it becomes crucial for all-sky survey missions to take into account the interplays between beam systematic effects and all the data analysis steps. LiteBIRD is the ISAS/JAXA second strategic large-class satellite mission and is dedicated to target the measurement of CMB primordial B modes by reaching a sensitivity on the tensor-to-scalar ratio r of σ(r) ≤ 10-3 assuming r = 0. The primary goal of this paper is to provide the methodology and develop the framework to carry out the end-to-end study of beam far side-lobe effects for a space-borne CMB experiment. We introduce uncertainties in the beam model, and propagate the beam effects through all the steps of the analysis pipeline, most importantly including component separation, up to the cosmological results in the form of a bias δr. As a demonstration of our framework, we derive requirements on the calibration and modeling for the LiteBIRD's beams under given assumptions on design, simulation, component separation method and allocated error budget. In particular, we assume a parametric method of component separation with no mitigation of the far side-lobes effect at any stage of the analysis pipeline. We show that δr is mostly due to the integrated fractional power difference between the estimated beams and the true beams in the far side-lobes region, with little dependence on the actual shape of the beams, for low enough δr. Under our set of assumptions, in particular considering the specific foreground cleaning method we used, we find that the integrated fractional power in the far side-lobes should be known at the level of ∼ 10-4, to achieve the required limit on the bias δr < 1.9 × 10-5. The framework and tools developed for this study can be easily adapted to provide requirements under different design, data analysis frameworks and for other future space-borne experiments, such as PICO or CMB-Bharat. We further discuss the limitations of this framework and potential extensions to circumvent them.

In silico modelling of mechanical response of breast cancer cell to interstitial fluid flow

A cell’s mechanical environment regulates biological activities. Several studies have investigated the response of healthy epithelial mammary (MCF10A) and breast cancer (MCF7) cells to vascular and interstitial fluid motion-induced hydrodynamic forces. The mechanical stiffness of healthy and breast cancer cells differ significantly, which can influence the transduction of forces regulating the cell’s invasive behaviour. This aspect has not been well explored in the literature. The present work investigates the mechanical response of MCF10A and MCF7 cells to tissue-level interstitial fluid flow. A two-dimensional fluid flow–cell interaction model is developed based on the actual shapes of the cells, acquired from experimental fluorescent images. The material properties of the cell compartments (cytoplasm and nucleus) were assigned in the model based on the literature. The outcomes indicate that healthy MCF10A cells experience higher von Mises and shear stresses than the MCF7 cells. In addition, the MCF7 cell experiences higher strain and displacements than its healthy counterpart. Thus, the different mechano-responsiveness of MCF10A and MCF7 cells could be responsible for regulating the invasive potential of the cells. This work enhances our understanding of mechanotransduction activities involved in cancer malignancy which can further help in cancer diagnosis based on cell mechanotype.

Optimization of Welded Joints under Fatigue Loadings

In this paper, the notch effect in weldments has been investigated, and the optimal configuration of different types of welded joints has been analysed using the implicit gradient approach. By considering this implicit gradient method, it is possible to calculate the effective stress related to fatigue damage, with the effective stress being a continuous scalar function of the real stress tensor components, even in the presence of sharp edges. Hence, the search for the optimal configuration that maximises fatigue life can be tackled as the condition of minimum effective stress obtained by changing the weld shape and geometrical parameters. Both load-carrying cruciform joints and spot welds made of steel have been considered. The structural details have been studied by modelling actual shapes without any geometric simplification. Moreover, the same numerical procedure has been considered independently of the size, shape or load condition without imposing restrictive rules on the FE mesh.

A new car-following model with incorporation of Markkula's framework of sensorimotor control in sustained motion tasks

This study develops a car-following model called the “Markkula Intelligent Driver Model (MIDM)” based on Markkula's Framework of Sensorimotor Control. The MIDM predicts the start time of driver's reaction based on the evidence accumulation within Markkula's framework unlike the existing car-following models that use a constant reaction time parameter. The MIDM also accurately represents the actual shape and duration of acceleration maneuvers. Fifty drivers’ car-following behavior was observed in 2 different scenarios using a driving simulator – reaction to a decelerating lead vehicle and reaction to a stopped lead vehicle. Trajectory data from the NGSIM project were also used for the evaluation. Compared to the Gipps Model, the Wiedemann Model and the IDM, the MIDM realistically reproduced trajectories of speed, acceleration, jerk and spacing for both simulator and NGSIM data. The MIDM can also incorporate the effects of lead vehicle brake lights for more accurate estimation of the driver reaction time.