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Effect of the Particle Size Distribution of the Ballast on the Lateral Resistance of Continuously Welded Rail Tracks

Szabolcs Fischer Morteza Esmaeili R. M. Movahedi Jafar Chalabii Daniel Gosztola

Publication Name: Infrastructures

Publication Date: 2024-08-01

Volume: 9

Issue: 8

Page Range: Unknown

Description:

While the effect of ballast degradation on lateral resistance is noteworthy, limited research has delved into the specific aspect of ballast breakage in this context. This study is dedicated to assessing the influence of breakage on sleeper lateral resistance. For simplicity, it is assumed that ballast breakage has already occurred. Accordingly, nine granularity variations finer than No. 24 were chosen for simulation, with No. 24 as the assumed initial particle size distribution. Initially, a DEM model was validated for this purpose using experimental outcomes. Subsequently, employing this model, the lateral resistance of different particle size distributions was examined for a 3.5 mm displacement. The track was replaced by a reinforced concrete sleeper in the models, and no rails or rail fasteners were considered. The sleeper had a simplified model with clumps, the type of which was the so-called B70 and was applied in Western Europe. The sleeper was taken into consideration as a rigid body. The crushed stone ballast was considered as spherical grains with the addition that they were divided into fractions (sieves) in weight proportions (based on the particle distribution curve) and randomly generated in the 3D model. The complete 3D model was a 4.84 × 0.6 × 0.57 m trapezoidal prism with the sleeper at the longitudinal axis centered and at the top of the model. Compaction was performed with gravity and slope walls, with the latter being deleted before running the simulation. During the simulation, the sleeper was moved horizontally parallel to its longitudinal axis and laterally up to 3.5 mm in static load in the compacted ballast. The study successfully established a relationship between lateral resistance and ballast breakage. The current study’s findings indicate that lateral resistance decreases as ballast breakage increases. Moreover, it was observed that the rate of lateral resistance decrease becomes zero when the ballast breakage index reaches 0.6.

Open Access: Yes

DOI: 10.3390/infrastructures9080129

On the topology of two dimensional generalized cell systems

I. Zsoldos J. Janik Tamás Réti

Publication Name: Recent Advances in Multidisciplinary Applied Physics

Publication Date: 2005-12-01

Volume: Unknown

Issue: Unknown

Page Range: 559-564

Description:

No description provided

Open Access: Yes

DOI: 10.1016/B978-008044648-6.50085-9

Challenges and Implications of Pedestrian Yielding Compliance in Thailand and Laos: A Field Study Analysis

Emese Makó Souvathone Phetoudom

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 120-131

Description:

In Thailand and Laos, drivers frequently disregard international road traffic regulations, particularly the mandate to yield to pedestrians. This behavior compels pedestrians to rely on their judgment to assess safety gaps and cross independently, as drivers often do not prioritize them. Interestingly, many pedestrians choose to cross the road outside of designated crossings, which may reflect an adaptive behavior rooted in local cognitive and cultural contexts. In contrast, European countries have well-defined and strictly enforced regulations that require drivers to yield to pedestrians, resulting in safer pedestrian experiences. However, in Thailand and Laos, the lack of effective enforcement and compliance leads to hazardous pedestrian crossings. The disparity in pedestrian safety between these regions can be partly attributed to cognitive and behavioral factors, such as risk perception, learned behaviors, and cultural norms, which influence both pedestrian and driver actions. This study employed the field study method to analyze driver yielding rates at 12 locations in Udon Thani, Thailand, and Vientiane, Laos. Data collection encompassed traffic flow in both directions and was conducted under typical weather conditions on a standard working day, focusing on the rate and type of yielding by drivers. The findings reveal a minimal proportion of drivers who yield to pedestrians, with some locations exhibiting particularly low compliance rates. While a zero yielding rate theoretically increases road capacity by allowing continuous vehicle flow, it also endangers pedestrians, leading to potential accidents that can disrupt traffic flow. This situation underscores the need to consider cognitive and behavioral dimensions, such as how drivers perceive pedestrians and the habitual actions of both groups, in road design and traffic management policies. An understanding of these cognitive and behavioral aspects, alongside local cultural practices, is crucial for developing effective safety campaigns and infrastructural improvements that can enhance pedestrian safety in these regions.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_12

Discriminating Malignant from Benign Testicular Masses Using Multiparametric Magnetic Resonance Imaging—A Prospective Single-Center Study

Peter Törzsök Matthias Meissnitzer Herwig Brandtner David Oswald Lukas Lusuardi Michael Abenhardt Stefan Hecht Susanne Deininger Christian Deininger Rosemarie Forstner

Publication Name: Journal of Clinical Medicine

Publication Date: 2024-08-01

Volume: 13

Issue: 15

Page Range: Unknown

Description:

Objective: The objective of this study was to prospectively assess the extent to which magnetic resonance imaging (MRI) can differentiate malignant from benign lesions of the testis. Materials and Methods: All included patients underwent multiparametric testicular MRI, including diffusion-weighted imaging (DWI) and subtraction dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). Subsequently, all patients underwent a histopathological examination via orchiectomy or testicular biopsy/partial resection. The Kolmogorov–Smirnov test, t-test, Mann–Whitney U test, Fisher’s exact test, and logistic regression were applied for statistical analysis. Results: We included 48 male patients (median age 37.5 years [range 18–69]) with testicular tumors. The median tumor size on MRI was 2.0 cm for malignant tumors and 1.1 cm for benign tumors (p < 0.05). A statistically significant difference was observed for the type (type 0-III curve, p < 0.05) and pattern of enhancement (homogeneous, heterogeneous, or rim-like, p < 0.01) between malignant and benign tumors. The minimum apparent diffusion coefficient (ADC) value was 0.9 for benign tumors and 0.7 for malignant tumors (each ×103 mm2/s, p < 0.05), while the mean ADC was 0.05. The mean ADC value was significantly lower for malignant tumors; the mean ADC value was 1.1 for benign tumors and 0.9 for malignant tumors (each ×103 mm2/s, p < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value of multiparametric MRI for differentiating malignant from benign testicular lesions were 94.3%, 76.9%, 91.7%, and 83.3%, respectively. The surgical procedures performed included orchiectomy (n = 33; 71.7%) and partial testicular resection (n = 11; 23.9%). Histopathology (HP) revealed malignancy in 35 patients (72.9%), including 26 with seminomas and 9 with non-seminomatous germ cell tumors (NSGCTs). The HP was benign in 13 (27.1%) patients, including 5 with Leydig cell tumors. Conclusions: Malignant and benign tumors differ in MRI characteristics in terms of the type and pattern of enhancement and the extent of diffusion restriction, indicating that MRI can be an important imaging modality for the accurate diagnosis of testicular lesions.

Open Access: Yes

DOI: 10.3390/jcm13154390

Adaptive Adjustments in Lower Limb Muscle Coordination during Single-Leg Landing Tasks in Latin Dancers

János Gál Yaodong Gu Gusztáv Fekete Minjun Liang Datao Xu Xiangli Gao Tianle Jie

Publication Name: Biomimetics

Publication Date: 2024-08-01

Volume: 9

Issue: 8

Page Range: Unknown

Description:

Previous research has primarily focused on evaluating the activity of individual muscles in dancers, often neglecting their synergistic interactions. Investigating the differences in lower limb muscle synergy during landing between dancers and healthy controls will contribute to a comprehensive understanding of their neuromuscular control patterns. This study enrolled 22 Latin dancers and 22 healthy participants, who performed a task involving landing from a 30 cm high platform. The data were collected using Vicon systems, force plates, and electromyography (EMG). The processed EMG data were subjected to non-negative matrix factorization (NNMF) for decomposition, followed by classification using K-means clustering algorithm and Pearson correlation coefficients. Three synergies were extracted for both Latin dancers and healthy participants. Synergy 1 showed increased contributions from the tibialis anterior (p < 0.001) and medial gastrocnemius (p = 0.024) in Latin dancers compared to healthy participants. Synergy 3 highlighted significantly greater contributions from the vastus lateralis in healthy participants compared to Latin dancers (p = 0.039). This study demonstrates that Latin dancers exhibit muscle synergies similar to those observed in healthy controls, revealing specific adjustments in the tibialis anterior and medial gastrocnemius muscles among dancers. This research illustrates how dancers optimize control strategies during landing tasks, offering a novel perspective for comprehensively understanding dancers’ neuromuscular control patterns.

Open Access: Yes

DOI: 10.3390/biomimetics9080489

Determination of Optimal Process Parameters for L-PBF Produced 1.2709 Alloy †

I. Fekete I. Hatos A. L. Nagy Balázs Lőrincz

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

For L-PBF (Laser Powder Bed Fusion) metal additive manufacturing (AM) the choice of available materials is still limited. 1.2709 maraging steel powders are widely used for injection molds and high-quality engineering parts. The quality of the parts produced by L-PBF are significantly affected by the process parameters. The aim of this research was to find optimal process parameters for producing 1.2709 tool steel at a layer thickness of 20 µm and to reveal the possible parameter settings yielding comparable build quality as the “EOS surface” parameter set at a layer thickness of 20 µm. Findings showed that too low or too high input energies produce improper parts. A large range of parameters produce good quality parts, of which the optimum parameters can be chosen.

Open Access: Yes

DOI: 10.3390/engproc2025113017

Comprehensive assessment of oil degradation patterns in petrol and diesel engines observed in a field test with passenger cars – Conventional oil analysis and fuel dilution

Charlotte Besser A. L. Nagy Adam Agocs J. Rohde-Brandenburger József Perger Michael Schandl Zsolt Tabakov Nicole Dörr

Publication Name: Tribology International

Publication Date: 2021-09-01

Volume: 161

Issue: Unknown

Page Range: Unknown

Description:

Requirements for modern internal combustion engines are lower emissions, higher power density and longer maintenance intervals. These trends increase the demands on engine components, including lubricants. In a field study of petrol and diesel vehicles, oil condition of 47 engine oils from 12 vehicles are correlated with fresh oil properties and operating conditions, i.e., trip length and speed. Long-range petrol vehicles displayed accelerated chemical oil degradation compared to diesel vehicles. An explanation for this behaviour is assumed to be the difference air-to-fuel ratio. Short-range petrol vehicles showed an even faster oil degradation and significant changes in oil viscosity due to fuel dilution. Diesel vehicles exhibited higher soot loading and more pronounced engine wear indicated by iron content in the oils.

Open Access: Yes

DOI: 10.1016/j.triboint.2021.107079

Steering System Modification for Autonomous Test Vehicles and the Measurement of Steering Geometry †

Zoltan Pusztai László Illés Orova Máté Kapocsi

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

This study presents the development and implementation of an electronically actuated steering system in a Formula Student Driverless race car, aiming to support autonomous driving capability. A DC motor with a belt-drive mechanism was integrated into the original steering rack assembly without altering its core mechanical characteristics. The research also includes a validation of the steering geometry using both physical measurements and CAD simulations. The objective of this measurement is to determine the steering angle as a function of the steering wheel input angle, ensuring that the resulting data accurately informs vehicle dynamics models such as the kinematic bicycle model. These steps form the basis for closed-loop control integration in the autonomous driving platform.

Open Access: Yes

DOI: 10.3390/engproc2025113067

Hierarchical-interpolative fuzzy system construction by Genetic and Bacterial Programming Algorithms

Krisztián Balázs László T. Kóczy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2011-09-27

Volume: Unknown

Issue: Unknown

Page Range: 2116-2122

Description:

In this paper a method is proposed for constructing hierarchical- interpolative fuzzy rule bases in order to model black box systems defined by input-output pairs, i.e. to solve supervised machine learning problems. The resulting hierarchical rule base is the knowledge base, which is constructed by using evolutionary techniques, namely, Genetic and Bacterial Programming Algorithms. Applying hierarchical-interpolative fuzzy rule bases is an advanced way of reducing the complexity of the knowledge base, whereas evolutionary methods ensure a relatively efficient learning process. This is the reason of the investigation of this combination. © 2011 IEEE.

Open Access: Yes

DOI: 10.1109/FUZZY.2011.6007594