Hasil untuk "Bridge engineering"

J. Jeyashanthi, J. Barsana Banu, T. Deepika vinothini

Many power electronic applications utilize Cascaded H-Bridge (CHB) Multi-Level Inverters (MLIs) due to their bidirectional control capabilities. Multi-Level Inverters (MLIs) are utilized in Electric Vehicles (EVs) to minimize overall drive losses by reducing Total Harmonic Distortion. Also, MLI is preferred for solar energy generation to attain maximum power point tracking. This research work focuses on reducing drive losses and improving the transient response of induction motor drives for EV applications. For that, three different intelligent control algorithms are proposed. There are PI-PSO, PI-PSO-ANN, and PI-PSO-ANFIS controllers. This work uses the three-phase 15-level cascaded H-bridge multilevel inverter supplied by a solar energy source. Intelligent control algorithms generate pulses via pulse-width modulation, thereby reducing harmonic distortion. The drive's performance is analysed to investigate the operations of PI-PSO, PI-PSO-ANN, and PI-PSO-ANFIS controllers. The performance of this CHB-MLI-driven 4kW Induction Motor (IM) drive is verified by simulation using MATLAB/Simulink. This approach showed the successful implementation of the suggested design. The PI-PSO-ANFIS controller demonstrated better performance, with lower THD and faster dynamic response, when applied to control the IM drive with a 15-level CHB-MLI. The findings of this comparative analysis focus on features such as drive speed, load torque, and power-quality problems associated with total harmonic distortion (THD).

Rashina Hoda

Agentic AI is poised to usher in a seismic paradigm shift in Software Engineering (SE). As technologists rush head-along to make agentic AI a reality, SE researchers are driven to establish agentic SE as a research area. While early visions of agentic SE are primarily focused on code-related activities, early empirical evidence calls for a consideration of a wider range of socio-technical activities and concerns to make it work in practice. This paper contributes to the emerging visions by: (a) recommending an expansion of its scope beyond code, toward a 'whole of process' vision, grounding it in SE foundations and evolution and emerging agentic SE frameworks, (b) proposing a preliminary set of values and principles to guide community efforts, and (c) sharing guidance on designing and using well-defined vocabulary for agentic SE. It is hoped that these ideas will encourage collaborations and steer the SE community toward laying strong foundations of agentic SE so it is not limited to enabling coding acceleration but becomes the next process-level paradigm shift.

Shiruo Hu, Wenbo Shan, Yingjia Li et al.

Hydro-Science and Engineering (Hydro-SE) is a critical and irreplaceable domain that secures human water supply, generates clean hydropower energy, and mitigates flood and drought disasters. Featuring multiple engineering objectives, Hydro-SE is an inherently interdisciplinary domain that integrates scientific knowledge with engineering expertise. This integration necessitates extensive expert collaboration in decision-making, which poses difficulties for intelligence. With the rapid advancement of large language models (LLMs), their potential application in the Hydro-SE domain is being increasingly explored. However, the knowledge and application abilities of LLMs in Hydro-SE have not been sufficiently evaluated. To address this issue, we propose the Hydro-SE LLM evaluation benchmark (Hydro-SE Bench), which contains 4,000 multiple-choice questions. Hydro-SE Bench covers nine subfields and enables evaluation of LLMs in aspects of basic conceptual knowledge, engineering application ability, and reasoning and calculation ability. The evaluation results on Hydro-SE Bench show that the accuracy values vary among 0.74 to 0.80 for commercial LLMs, and among 0.41 to 0.68 for small-parameter LLMs. While LLMs perform well in subfields closely related to natural and physical sciences, they struggle with domain-specific knowledge such as industry standards and hydraulic structures. Model scaling mainly improves reasoning and calculation abilities, but there is still great potential for LLMs to better handle problems in practical engineering application. This study highlights the strengths and weaknesses of LLMs for Hydro-SE tasks, providing model developers with clear training targets and Hydro-SE researchers with practical guidance for applying LLMs.

Kumar Yelamarthi, Elizabeth Powell, Mazen Hussein

The Clay N. Hixson Student Success Center within the College of Engineering at Tennessee Tech University has undergone a transformative upgrade by integrating the Define, Measure, Analyze, Improve, and Control (DMAIC) framework with select Kaizen principles for continuous improvement to enhance student support services. Key performance indicators (KPIs) have been employed to assess the achievement of core goals, significantly advancing recruitment, retention, and overall student success. Implementing the DMAIC framework has streamlined processes such as a unified degree map and a math bridge program, resulting in a 53% increase in incoming first-year students and broadening the College of Engineering’s outreach. These efforts have also contributed to a 10% increase in first-to-second-year retention rates. Through the utilization of DMAIC, the regular redistribution of advisor caseloads and cross-training has been facilitated, ensuring timely student support without overburdening advisors. Additionally, targeted academic support initiatives have reduced the at-risk student population from 19% to 11%. These management techniques extend to multiple initiatives, including enhancements to high school summer camps, advisor listening sessions, and student surveys designed to meet evolving student needs. Creating specialized areas for academic advisors has also supported their professional growth, contributing to better student outcomes. This paper comprehensively analyzes these strategies and provides valuable insights for institutions seeking to apply DMAIC and continuous improvement models to strengthen student support systems.

Yuexin Su, Jianxiang Huang, Zaixing Yang et al.

Nanoparticle superlattices—periodic assemblies of uniformly spaced nanocrystals—bridge the nanoscale precision of individual particles with emergent collective properties akin to those of bulk materials. Recent advances demonstrate that multivalent ions and charged polymers can guide the co-assembly of nanoparticles, imparting electrostatic gating and enabling semiconductor-like behavior. However, the specific roles of anion geometry, valency, and charge density in mediating ion transport remain unclear. Here, we employ coarse-grained molecular dynamics simulations to investigate how applied electric fields (0–0.40 V/nm) modulate ionic conductivity and spatial distribution in trimethylammonium-functionalized gold nanoparticle superlattices assembled with four phosphate anions of distinct geometries and charges. Our results reveal that linear anions outperform ring-shaped analogues in conductivity due to higher charge densities and weaker interfacial binding. Notably, charge density exerts a greater influence on ion mobility than size alone. Under strong fields, anions accumulate at nanoparticle interfaces, where interfacial adsorption and steric constraints suppress transport. In contrast, local migration is governed by geometrical confinement and field strength. Analyses of transition probability and residence time further indicate that the rigidity and delocalized charge of cyclic anions act as mobility barriers. These findings provide mechanistic insights into the structure–function relationship governing ion transport in superlattices, offering guidance for designing next-generation ion conductors, electrochemical sensors, and energy storage materials through anion engineering.

James S. Wheaton, Daniel R. Herber

Traditional requirements engineering tools do not readily access the SysML-defined system architecture model, often resulting in ad-hoc duplication of model elements that lacks the connectivity and expressive detail possible in a SysML-defined model. Further integration of requirements engineering activities with MBSE contributes to the Authoritative Source of Truth while facilitating deep access to system architecture model elements for V&V activities. We explore the application of MBSE to requirements engineering by extending the Model-Based Structured Requirement SysML Profile to comply with the INCOSE Guide to Writing Requirements while conforming to the ISO/IEC/IEEE 29148 standard requirement statement patterns. Rules, Characteristics, and Attributes were defined in SysML according to the Guide to facilitate requirements definition, verification & validation. The resulting SysML Profile was applied in two system architecture models at NASA Jet Propulsion Laboratory, allowing us to assess its applicability and value in real-world project environments. Initial results indicate that INCOSE-derived Model-Based Structured Requirements may rapidly improve requirement expression quality while complementing the NASA Systems Engineering Handbook checklist and guidance, but typical requirement management activities still have challenges related to automation and support in the system architecture modeling software.

Ahmed Alhady, Mohamed Alanany, Yasser Khodair et al.

Abstract Although building information modelling (BIM) has been widely used in the building industry, its usage in infrastructure projects such as bridges has been very challenging. Extended Reality (XR) that simulates a construction project is still considered a new technology in the Architecture, Engineering, and Construction (AEC) industry. This paper investigates the viability of integrating both BIM and XR technologies into transportation infrastructure projects. A fully integrated workflow for introducing different XR, Augmented Reality (AR), and Virtual Reality (VR), and BIM technologies using different software for a case study of El-Merghani bridge, a reinforced concrete girder type bridge, was developed. The models for the bridge included GIS integration and geometric road design according to AASHTO, documentation, shop drawings and quantification were developed for the bridge. A hypothetical time schedule was generated in Oracle Primavera P6 elevating the BIM model to 4-D and developing VR and AR virtual experiences with the capability to investigate, visualize, and present the model in a virtual environment, at a high level of immersion. Additionally, the associated risk reduction for the considered XR technology was assessed using Monte Carlo simulation. The workflow and the detailed 3D models developed for the bridge along with the highly immersive VR and AR experiences have provided an interactive platform for engineers and different stakeholders to monitor the project during the design and construction phases. The risk analysis showed that significant cost savings can be achieved with the utilization of VR and AR technology in bridges construction.

Xia Zhang, Enli Chen, Wei Jiang et al.

Asphalt mixture is a viscoelastic material composed of aggregates, asphalt mastics, and voids. Meanwhile, the dynamic interaction between vehicle and bridge makes asphalt deck pavement in a more complex stress state, leading to premature damage such as cracks and ruts during its operation service period. Therefore, the effects of the viscoelastic characteristics of asphalt mixtures and vehicle-bridge interactions on the dynamic behaviors of deck pavement cannot be ignored. However, it is difficult to directly couple the viscoelastic properties of mixtures and vehicle-bridge interactions using the finite element method. Thus, this paper presents a decoupled method named the separation reconstruction algorithm. To theoretically verify whether the separate construction (SR) algorithm is consistent with the direct coupling (DC) algorithm, two dynamic system models of a Bernoulli–Euler composite beam under a moving vehicle are established, which correspond to the two algorithms. The kinematic equations of the system are derived and dispersed by the classical Galerkin method. The nonlinear integral term is simplified by the parity of the function, periodicity of the trigonometric function, and derivation. Then, the coupled equation can be rewritten in an ordinary differential form and solved with the Runge–Kutta method. Finally, it is proven that the proposed SR algorithm is basically consistent with the DC algorithm, and the SR algorithm is extended to practical engineering to study the coupling dynamic responses of viscoelastic deck pavement more accurately. Some new insight is gained by exploring the stress status of viscoelastic deck pavement under coupled conditions, which is conducive to more accurate evaluations of surface tensile effects induced by vehicle-bridge interactions.

Chen Songqiang, Zhou Jian, Wu Xi et al.

Semi-flexible concrete has been utilized in highway engineering due to its exceptional pavement performance. This study investigates the proportions of semi-flexible grout, the porosity of asphalt mixture, and the performance of semi-flexible concrete. Initially, 18 sets of semi-flexible grouting materials were proposed through an orthogonal test, resulting in the following material ratio: (cement: mineral powder): water cement ratio: sand cement ratio: Swelling agent: water reducer: flocculant = (0.85:0.15):0.45:0.2:0.04:0.001:0.005. Subsequently, the impact of the 2.36 mm sieve passing rate on the air void of SFAC-13 and SFAC-16 mixtures was analyzed, and a relationship between them was established. Observation of the semi-flexible concrete section and analysis of the grouting rate indicated that the developed grouting material effectively fills the gaps in the asphalt mixture. Lastly, the pavement performance of semi-flexible concrete was compared with SMA-13 asphalt mixture. The results demonstrate that semi-flexible composite concrete exhibits outstanding dynamic modulus, crack resistance, deformation resistance, water stability, and low-temperature performance. Moreover, the material properties of SFAC-13 are akin to those of SFAC-16.

Tatsumi Aoyama, Issaku Kanamori, Kazuyuki Kanaya et al.

Bridge++ is a general-purpose code set for lattice QCD simulations aiming at a readable, extensible, and portable code while keeping practical high performance. The new version 2.0 employs machine-dependent optimization, enabling flexible data layout in float/double precision, while it was fixed layout and only with the double precision in previous versions. We report the performance on supercomputer Fugaku with Arm A64FX-SVE architecture by Fujitsu.

Ertugrul Basar

Noise: an enemy to be dealt with and a major factor limiting communication system performance. However, what if there is gold in that garbage? In conventional engineering, our focus is primarily on eliminating, suppressing, combating, or even ignoring noise and its detrimental impacts. Conversely, could we exploit it similarly to biology, which utilizes noise-alike carrier signals to convey information? In this context, the utilization of noise, or noise-alike signals in general, has been put forward as a means to realize unconditionally secure communication systems in the future. In this tutorial article, we begin by tracing the origins of thermal noise-based communication and highlighting one of its significant applications for ensuring unconditionally secure networks: the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange scheme. We then delve into the inherent challenges tied to secure communication and discuss the imperative need for physics-based key distribution schemes in pursuit of unconditional security. Concurrently, we provide a concise overview of quantum key distribution (QKD) schemes and draw comparisons with their KLJN-based counterparts. Finally, extending beyond wired communication loops, we explore the transmission of noise signals over-the-air and evaluate their potential for stealth and secure wireless communication systems.

Jiuzhou Han, Wray Buntine, Ehsan Shareghi

Semi-structured explanation depicts the implicit process of a reasoner with an explicit representation. This explanation highlights how available information in a specific query is utilised and supplemented with information a reasoner produces from its internal weights towards generating an answer. Despite the recent improvements in generative capabilities of language models, producing structured explanations to verify a model's true reasoning capabilities remains a challenge. This issue is particularly pronounced for not-so-large LMs (e.g., FLAN-T5-XXL). In this work, we first underscore the limitations of supervised fine-tuning (SFT) in tackling this challenge, and then introduce a carefully crafted reward engineering method in reinforcement learning (RL) to better address this problem. We investigate multiple reward aggregation methods and provide a detailed discussion which sheds light on the promising potential of RL for future research. Our proposed method on two semi-structured explanation generation benchmarks (ExplaGraph and COPA-SSE) achieves new state-of-the-art results.

Matthew Tyler, Hengyun Zhou, Leigh S. Martin et al.

We introduce a framework for designing Hamiltonian engineering pulse sequences that systematically accounts for the effects of higher-order contributions to the Floquet-Magnus expansion. Our techniques result in simple, intuitive decoupling rules, despite the higher-order contributions naively involving complicated, non-local-in-time commutators. We illustrate how these rules can be used to efficiently design improved Hamiltonian engineering pulse sequences for a wide variety of tasks, such as dynamical decoupling, quantum sensing, and quantum simulation.

Alexandra Denisa Danciu, Ștefan I. Guțiu, Cătălin Moga et al.

The network arch bridge (NAB) is a new structural form of arch bridge that was devised 60 years ago by the Norwegian engineer Per Tveit, who is now prof. dr. docent emeritus at the University of Agder, Norway. The network arch is a tied-arch (also known as a bowstring-arch) bridge that combines the benefits of tied-arch bridges and trusses in a single system. While in a classical tied arch, the hangers are vertical, in a network arch, the suspension of the deck to the arch is ensured through a network of inclined hangers that intersect each other at least twice. Thus, the core of the NAB is the hanger arrangement that minimizes the bending moment in the arch to very small values, leading to compression in the arch. Compression with only small bending leads to very slender cross-sections for the elements of the bridge, and deep reductions in terms of materials used and economic and environmental costs. This paper reviews the research into the structural form proposed by Per Tveit and extended by researchers and engineers worldwide. The research methodology included bibliometric literature research, obtained by interrogating the ISI Web of Science (WoS) database and the cited references from the articles on WoS. While the first structural form of a network arch is still in use today and it has proven to be a good idea for spans around 100–120 m, engineers worldwide devised new bridge cross-sections. A brief view of the types of bridge cross-section in use today is given, with details about the bridges chosen as representative. Using analysis of Prof. Tveit’s map, Structurae database and literature review, a database of the network arches around the world was created, emphasizing the development of network arches from the perspectives of continental distribution, opening year, number of structures in different structural forms, and bridge purposes. The structural form was assessed from the perspective of materials used for the arch and the tie, span, purpose and number of lanes, the presence/absence of upper wind-bracings and arch disposition in the vertical plane. In the last part of this review, the newest research into the development of the network arch is discussed. In the past 15 years we have seen an acceleration in network arch development from multiple perspectives: new materials used, such as glulam for the arch or carbon fiber-reinforced plastic for the hangers; span lengths of 250 m and 380 m for large bridge widths; architectural constraints that lead to the outward inclination of the arch, that is pleasing to the eye, but difficult to address from an engineering perspective; the most slender arch bridge in the world, with very slender cross-sections for the arch and the tie.

Zeinab Abou Khalil, Stefano Zacchiroli

Background: Software development results in the production of various types of artifacts: source code, version control system metadata, bug reports, mailing list conversations, test data, etc. Empirical software engineering (ESE) has thrived mining those artifacts to uncover the inner workings of software development and improve its practices. But which artifacts are studied in the field is a moving target, which we study empirically in this paper.Aims: We quantitatively characterize the most frequently mined and co-mined software artifacts in ESE research and the research purposes they support.Method: We conduct a meta-analysis of artifact mining studies published in 11 top conferences in ESE, for a total of 9621 papers. We use natural language processing (NLP) techniques to characterize the types of software artifacts that are most often mined and their evolution over a 16-year period (2004-2020). We analyze the combinations of artifact types that are most often mined together, as well as the relationship between study purposes and mined artifacts.Results: We find that: (1) mining happens in the vast majority of analyzed papers, (2) source code and test data are the most mined artifacts, (3) there is an increasing interest in mining novel artifacts, together with source code, (4) researchers are most interested in the evaluation of software systems and use all possible empirical signals to support that goal.

Aljosha Köcher, Alexander Hayward, Alexander Fay

Today's production systems are complex networks of cyber-physical systems which combine mechanical and electronic parts with software and networking capabilities. To the inherent complexity of such systems additional complexity arises from the context in which these systems operate. Manufacturing companies need to be able to adapt their production to ever changing customer demands as well as decreasing lot sizes. Engineering such systems, which need to be combined and reconfigured into different networks under changing conditions, requires engineering methods to carefully design them for possible future uses. Such engineering methods need to preserve the flexibility of functions into runtime, so that reconfiguring machines can be done with as little effort as possible. In this paper we present a model-based approach that is focused on machine functions and allows to methodically develop system functionalities for changing system networks. These functions are implemented as so-called skills using automated code-generation.

Gang Zhou, Yi Tian, Liang Gong et al.

To address the inadequate performance of rejuvenated asphalt when waste engine oil bottom (WEOB) is used as an asphalt rejuvenator, liquid styrene-butadiene rubber (liquid SBR) was used to enhance the performance of WEOB-rejuvenated asphalt. By testing the basic physical properties of asphalt and using the high- and low-temperature rheology, differential scanning calorimetry, Fourier infrared spectroscopy, and atomic force microscopy (AFM) tests, the index and microstructure changes of asphalt before and after aging and regeneration, from macrolevels and microlevels, were studied, along with the high- and low-temperature performance and water stability of the rejuvenated asphalt mixture. The WEOB decreased the glass transition temperature and low-temperature performance grade of aged asphalt and resulted in a significant effect on the recovery of penetration and softening point of aged asphalt; however, the recovery of low-temperature ductility was inadequate. Compared with WEOB, a rejuvenator comprising WEOB and liquid SBR (WEOB-S) further decreased the glass transition and continuous grading temperatures of aged asphalt, improved its low-temperature performance, and significantly influenced its ductility recovery. The AFM test showed that WEOB-S effectively dispersed the agglomerated bee-like wax crystals or macromolecular asphaltene structures in the aged asphalt, decreased the number and crests of the bee-like structures, and improved the microscopic uniformity, thus obtaining better macroscopic physical properties. Both WEOB and WEOB-S improved the low-temperature performance and water stability of rejuvenated asphalt mixtures; however, WEOB-S was more effective.

Al-Bayati Maan A., Abdulrahman Mazin B., Alzeebaree Radhwan et al.

The aim of the present work was to investigate and achieve the optimum compressive strength of self-compacting geopolymer concrete (SCGC). Fly ash (FA) and ground granulated blast furnace slag (GGBFS) are used at different ratios as binder materials to produce the SCGC mixes. Alkaline solution was a mix of sodium silicate and sodium hydroxide. Three different ratios of binder materials were used to produce SCGC (0FA-100GGBFS; 50FA-50GGBFS; and 100FA-0GGBFS). The total binder weight was 500 kg/m3 within a constant alkali–binder proportion (0.5). Two curing conditions were used, at ambient environment and heat curing at 110°C for 24 h. The compressive strength and fresh properties of SCGC are evaluated. The compressive strength is utilized to demonstrate the mechanical properties of SCGC. The compressive strength is investigated at two ages (7 and 28 days). The results showed that the use of GGBFS had a negative effect on the fresh properties of SCGC. However, it has a significant impact on the mechanical behavior of the SCGC. SCGC’s early strength is heavily involved in heat curing. The compressive strength of 100% GGBFS in the ambient environment after 28 days was more than that of GGBFS cured at 110°C. The optimum eco-friendly mix is 50FA-50GGBFS.

Qiangsheng Lu, Jacob Cook, Xiaoqian Zhang et al.

In graphene and on the surfaces of many topological insulators, the Dirac cones are pinned to high symmetry points in reciprocal space. Here, the authors report that the Dirac cones in atomically-thin Sb layers occur at generic reciprocal-space points which can be tuned by lattice strain.

Peng Liu, Yixuan Chen, Hongping Lu et al.

The orthotropic steel deck is sensitive to fatigue, and a number of cracks have been found in existing bridges. Based on the long-span Guangzhou Mingzhu Bay steel arched bridge, this paper focus on the cracking process, fatigue mechanism, and fatigue performance evaluation of an orthotropic steel bridge deck under traffic load. A finite element model of a three-U-rib and three-span bridge deck was first established to investigate the stress state and the most unfavorable wheel loading position under the longitudinal wheel load. Then, four full-scale single-U-rib specimens were fabricated with high-strength lower alloy structural steel Q370qD in compliance with construction standards. High-cycle loading was subsequently implemented according to the Specification for Design of Highway steel bridge (JTG D64-2015), and the crack initiation, propagation process, and fatigue failure modes were studied. The results showed the stress at structural concern points is larger than in other locations, which was located around 35 mm from the welding seam of the U-rib and the lower end of the diaphragm plate. The Mingzhu Bay steel bridge deck meets the fatigue design requirements. However, the bottom of the welding seam between the U-rib and diaphragm plate is a dangerous fatigue position, and attention should be paid to the welding quality at this position during construction.