Hasil untuk "Engineering (General). Civil engineering (General)"

Mateus Cavalcante Sá, Marco Aurélio Holanda de Castro

Building Information Modeling (BIM) é uma tecnologia promissora na indústria da construção civil. Percebe-se sua consolidação, e as aplicações dessa tecnologia tornam-se indispensáveis para o dia a dia de empresas e projetistas. No segmento de projetos de infraestrutura, especificamente no setor de saneamento, a metodologia BIM vem sendo implementada e disseminada. Uma implementação apropriada facilita os processos de projeto e construção, podendo resultar em obras de melhor qualidade e prazos reduzidos. Nesse sentido, este trabalho apresenta uma proposta de automatização da geração de redes de abastecimento de água em BIM, utilizando uma interface entre o sistema UFC e o Civil 3D. Essa interface foi desenvolvida por meio de rotinas em Dynamo e linguagem Python. Entre as funcionalidades, a interface permite realizar conversões de arquivos do formato .inp para .xlsx. Para validar sua funcionalidade, realizaram-se testes de geração automática em BIM de redes de abastecimento de diversos formatos, incluindo tubos e conexões dimensionados com o sistema UFC, o que permitiu uma avaliação mais ampla. Os resultados demonstraram a aplicabilidade da ferramenta, que constitui uma alternativa viável para integração em fluxos de trabalho.

Florentin D. Hildebrandt

On-demand restaurant meal delivery platforms, such as DoorDash and Meituan, have recently introduced a multi-order delivery service: Customers may combine delivery requests from different restaurants in a single multi-order with the service promise of a synchronized delivery. However, the platform must not only ensure the synchronization of multi-orders but also improve punctuality and freshness for all customers. This is challenging because, as we show, synchronization, delay, and freshness are conflicting objectives. Uncertainty in the delivery process and unknown future orders further complicate the decision making. This raises several research questions: How does the introduction of a multi-order service affect the overall delivery operations with regard to service quality and operational expenses? How should a multi-order service be strategically rolled out? How can we balance the competing objectives of synchronizing deliveries while minimizing delay and maximizing freshness? To answer the research questions, we propose an effective policy that allows for a careful and controlled balance between the competing objectives and employ it in an extensive computational study. We evaluate the effect of different trade-offs between delay, freshness, and synchronization on delivery operations over varying demand for multi-orders. We observe that enforcing strict synchronization of multi-orders by assigning each multi-order to a single delivery driver is hardly operational feasible. Occasionally using split-deliveries provides the flexibility to better balance all objectives. Our detailed experiments further generate insights on how platforms may roll-out multi-orders as a new service offering without negatively affecting their existing delivery operation while benefiting from reduced operational expenses.

Jürgen Soom, Isabel Boavida, Renan Leite et al.

The need for efficient approaches to track and assess fish behavior in rivers impacted by hydropeaking is increasing. Nonetheless, employing an automated camera system for underwater monitoring requires that the algorithms function under highly variable environmental conditions, which affect the ability to detect and assess fish size. Additionally, there is a lack of openly accessible freshwater fish classification and size estimation datasets. To address these limitations, we propose a binocular underwater fish monitoring system capable of real-time fish detection and size estimation. The system was deployed and tested over one week in two Portuguese rivers affected by hydropeaking. The week-long analysis also provided new insights regarding wild fish behavior in rivers affected by hydropeaking. Results indicate that hydropeaking strongly influences how fish may use instream flow refuges during hydropeaking. Fish were less frequently detected in the flow refuge during peak flow events, suggesting that the flow conditions created habitat instability and difficulty accessing the flow refuge. In contrast, fish in the non-hydropeaking river consistently used refuge areas, reinforcing their importance as shelter during natural flow variations. This study demonstrates the potential of a computer vision-based pipeline for real-time, fully automated fish monitoring of hydropeaking’s impacts on riverine fish. Additionally, we provide PTFish, an open dataset with 18,523 manually annotated frames featuring infrared and color video frames. These findings emphasize that automated, camera-based solutions for hydropeaking monitoring can be used to develop evidence-based mitigation strategies to sustain fish populations in rivers impacted by hydropeaking.

Malaisree P, Youwai S, Kitkobsin T et al.

Object detection in civil engineering applications is constrained by limited annotated data in specialized domains. We introduce DINO-YOLO, a hybrid architecture combining YOLOv12 with DINOv3 self-supervised vision transformers for data-efficient detection. DINOv3 features are strategically integrated at two locations: input preprocessing (P0) and mid-backbone enhancement (P3). Experimental validation demonstrates substantial improvements: Tunnel Segment Crack detection (648 images) achieves 12.4% improvement, Construction PPE (1K images) gains 13.7%, and KITTI (7K images) shows 88.6% improvement, while maintaining real-time inference (30-47 FPS). Systematic ablation across five YOLO scales and nine DINOv3 variants reveals that Medium-scale architectures achieve optimal performance with DualP0P3 integration (55.77% mAP@0.5), while Small-scale requires Triple Integration (53.63%). The 2-4x inference overhead (21-33ms versus 8-16ms baseline) remains acceptable for field deployment on NVIDIA RTX 5090. DINO-YOLO establishes state-of-the-art performance for civil engineering datasets (<10K images) while preserving computational efficiency, providing practical solutions for construction safety monitoring and infrastructure inspection in data-constrained environments.

Timothé Boulet, Xavier Hinaut, Clément Moulin-Frier

Software Engineering Agents (SWE-Agents) have proven effective for traditional software engineering tasks with accessible codebases, but their performance for embodied tasks requiring well-designed information discovery remains unexplored. We present the first extended evaluation of SWE-Agents on controller generation for embodied tasks, adapting Mini-SWE-Agent (MSWEA) to solve 20 diverse embodied tasks from the Minigrid environment. Our experiments compare agent performance across different information access conditions: with and without environment source code access, and with varying capabilities for interactive exploration. We quantify how different information access levels affect SWE-Agent performance for embodied tasks and analyze the relative importance of static code analysis versus dynamic exploration for task solving. This work establishes controller generation for embodied tasks as a crucial evaluation domain for SWE-Agents and provides baseline results for future research in efficient reasoning systems.

Mansur Aliyu, Medhat A. Nemitallah, Mohamed A. Habib

This study investigates the impact of excess air factor (λ) on performance and NOx emissions of a 207-MW boiler furnace, used for steam generation in an industrial water tube boiler installed at Saudi Aramco, at fixed volumetric fuel composition of hydrogen/methane of 10%/90%. The numerical approach employed for this investigation utilized ANSYS-Fluent software. The findings of the study revealed robust correlations between λ, temperature, and NO emissions. An increase in λ led to a decrease in both the average furnace temperature and average NO emissions at the boiler exit. Specifically, increasing the value of λ from 1.05–1.45 consistently reduces the average NO emissions from 1541 ppm to 653 ppm. In other words, a 27% increase in λ resulted in approximately a 55% reduction in NOx emissions. As λ increases, the volumetric absorbed of radiation decreases owing to the reduced concentrations of CO2 and H2O. Notably, the maximum combustion efficiency, reaching 37.88%, is achieved at a λ value of 1.35, corresponding to the lowest average flue gas temperature. The results show that to achieve the best performance with high efficiency and low NO emissions, the boiler needs to be operated at an excess air factor of about 1.35.

Joanna Siwek, Konrad Pierzyński, Przemysław Siwek et al.

This paper introduces a novel artificial intelligence model that integrates artificial empathy into the decision-making processes of collaborative agent systems. The existing models of collaborative behaviors, especially in swarm applications, lack the aspect of empathy, known to improve cooperation in human teams. Emphasizing both cognitive and emotional aspects of empathy, the introduced model navigates communication uncertainties and ambiguities, transforming these challenges into opportunities for learning and adaptation in dynamic environments. A significant feature of this model is its handling of imprecision through fuzzy logic, using fuzzy similarity measures in the decision process. The main objective of the presented research is to introduce a new model for improving cooperativeness in multi-agent systems with the use of cognitive empathy. Future research focus on implementing the model on physical platform and optimize the artificial empathy algorithms in the decision-making module.

Karima Ezziane, Mayouf Sellami, Mostefa Kameche et al.

Abstract New limited pyrochlore solid solutions of formula Bi1.5-xMxSb1.5-xM'xZnO7 (M= Fe; M'=Fe, Cr) (x=0; 0.10; 0.15) are prepared from simple oxides at 1080°C by using the ceramic method. All the crystal phases are indexed in the cubic system (space group; No.227). Rietveld refinement method of the Bi1.5Sb1.5ZnO7 (x=0) compounds using powder XRD analysis confirms an overall A2B2O7 cubic pyrochlore structure according to B i 1 . 5 3 + Z n 0 . 5 2 + S b 1 . 5 5 + Z n 0 . 5 2 + O 7 formula with 10.44425(3) Å and F d 3 ¯ m space group. The substitution of Bi(III) and Sb(V) by Fe(III) and Cr(III) in the Bi1.5Sb1.5ZnO7 phase shows the appearance of solid solutions limited to x=0.15. The variation of the cell’s parameter is recorded to the element’s ionic radii. The paramagnetic character is observed in all substituted compounds. The measurements of the electrical conductivity as a function of the temperature, make evidence of the semi-conductive property. Whilst, the magnetic susceptibility satisfies the modified Curie Weiss (CW) and shows the magnetic behavior due to the magnetic moments of the iron and chromium ions being involved in the synthesis of the compounds. Besides, the UV-Visible reflectance displays light absorption in the visible domain.

Nelly Bencomo, Jordi Cabot, Marsha Chechik et al.

Modern software-based systems operate under rapidly changing conditions and face ever-increasing uncertainty. In response, systems are increasingly adaptive and reliant on artificial-intelligence methods. In addition to the ubiquity of software with respect to users and application areas (e.g., transportation, smart grids, medicine, etc.), these high-impact software systems necessarily draw from many disciplines for foundational principles, domain expertise, and workflows. Recent progress with lowering the barrier to entry for coding has led to a broader community of developers, who are not necessarily software engineers. As such, the field of software engineering needs to adapt accordingly and offer new methods to systematically develop high-quality software systems by a broad range of experts and non-experts. This paper looks at these new challenges and proposes to address them through the lens of Abstraction. Abstraction is already used across many disciplines involved in software development -- from the time-honored classical deductive reasoning and formal modeling to the inductive reasoning employed by modern data science. The software engineering of the future requires Abstraction Engineering -- a systematic approach to abstraction across the inductive and deductive spaces. We discuss the foundations of Abstraction Engineering, identify key challenges, highlight the research questions that help address these challenges, and create a roadmap for future research.

Chung-Yu Wang, Alireza DaghighFarsoodeh, Hung Viet Pham

Large Language Models (LLMs) have demonstrated impressive performance in software engineering tasks. However, improving their accuracy in generating correct and reliable code remains challenging. Numerous prompt engineering techniques (PETs) have been developed to address this, but no single approach is universally optimal. Selecting the right PET for each query is difficult for two primary reasons: (1) interactive prompting techniques may not consistently deliver the expected benefits, especially for simpler queries, and (2) current automated prompt engineering methods lack adaptability and fail to fully utilize multi-stage responses. To overcome these challenges, we propose PET-Select, a PET-agnostic selection model that uses code complexity as a proxy to classify queries and select the most appropriate PET. By incorporating contrastive learning, PET-Select effectively distinguishes between simple and complex problems, allowing it to choose PETs that are best suited for each query's complexity level. Our evaluations on the MBPP and HumanEval benchmarks using GPT-3.5 Turbo and GPT-4o show up to a 1.9% improvement in pass@1 accuracy, along with a 74.8% reduction in token usage. Additionally, we provide both quantitative and qualitative results to demonstrate how PET-Select effectively selects the most appropriate techniques for each code generation query, further showcasing its efficiency in optimizing PET selection.

Yali Xu, Xin Li, Yanjuan Zhang et al.

This article is a review of models for predicting ultra-low cycle fatigue life. In the article, the life prediction models are divided into three types: (1) microscopic ductile fracture models based on cavity growth and cavity merger; (2) fracture models based on porous plasticity; and (3) ductile fracture models based on continuum damage mechanics. Furthermore, the article provides a critical assessment of the current state of research on ultra-low cycle fatigue life prediction models, highlighting the limitations and challenges faced by each model type. Ultimately, this review aims to provide a comprehensive overview of the different models available for predicting ultra-low cycle fatigue life and to guide future research in this important area of materials science and engineering.

Chaohui Yin, Qingsong He, Peng Xie et al.

The assessment of ecological assets is of great significance for protecting and using ecological resources. Traditional methods of ecological assets assessment, which adopt the planar area as the standard, often ignore the impact of the surface area, resulting in a large difference between the evaluation and the actual result. To fill this gap, this paper conducted research on ecological assets assessment based on surface area. Taking mainland China into consideration, this paper constructed a triangulation network based on 30 m resolution DEM data to simulate the real land surface form and calculate its surface area. Then, land use/cover data from 1995, 2000, 2005, 2010, and 2015 were used to estimate the ecosystem service value (ESV) and analyze its spatial variation. This paper found that: (1) The surface area of mainland China is 1.04 × 107 km2, which is 8.2 × 105 km2 larger than the planar area; (2) A huge difference was found between the total ESV based on the surface and planar area, with an absolute difference of ∼$141.66-$144.14 billion and a relative difference of ∼ 10%. For different ecosystem types, the largest difference was found in the forest ecosystem, followed by the grassland ecosystem, while the wetland ecosystem showed the smallest difference; (3) The high value of absolute difference between the ESV based on the surface and planar area was concentrated in Tibet and Northeast China. The high value of relative difference was mainly distributed in Central and Southern China. On the provincial level, the absolute difference in Tibet ranked in the first place. There was a total of 14 provinces showing a relative difference above 10%; (4) The total ESV based on surface area was basically unchanged, while various ecosystems underwent significant changes. The ESV of wetland increased by nearly 50%, while the ESV of grassland decreased by more than 10%; and (5) Change in the ESV based on surface area showed obvious spatial heterogeneity. High-High cluster was located in Tibet and the Northeast China while the Low-Low cluster was distributed in the North China Plain and Xinjiang. This paper emphasized the importance of the surface area in resource survey and asset estimation and gave more effective suggestions for ecological protection.

Arslan Ashraf, Muhammad Saadi

Electric vehicles (EVs) are a promising solution to reduce carbon dioxide (CO₂) emissions, but this reduction depends on the fraction of renewable sources used to generate electricity. Wind energy is thus a vital candidate and has experienced a remarkable surge recently, establishing itself as a leading renewable power source worldwide. The research on Direct-Driven Permanent Magnet Synchronous Generator (PMSG)-based type 4 wind farms has indicated that the Phase-locked Loop (PLL) bandwidth significantly impacts Sub-Synchronous Resonance (SSR). However, the influence of PLL architecture on SSR remains unexplored and warrants investigation. Therefore, this paper investigates PLL architectural variations in PLL Loop Filter (LF) to understand their impact on SSR in type 4 wind farms. Specifically, an in-depth analysis of the Notch Filter (NF)-based enhanced PLL is conducted using eigenvalue analysis of the admittance model of a PMSG-based type 4 wind farm. The findings demonstrate that the NF-based enhanced PLL exhibits superior performance and improved passivity in the sub-synchronous frequency range, limiting the risk of SSR below 20 Hz. Additionally, Nyquist plots are employed to assess the impact on system stability resulting in increased stability margins. In the future, it is recommended to further investigate and optimize the PLL to mitigate SSR in wind farms.

Chaoyu WANG, Tingye QI, Guorui FENG et al.

As a renewable and clean source, biomass energy is one of the substitutes for traditional fossil energy. However, when biomass is burned as an industrial fuel, it produces a large amount of biomass ash with considerable pozzolanic activity. Currently, the activity of biomass ash is ignored in the utilization of biomass energy. Therefore, research on the regulation mechanism of calcination temperature on the pozzolanic activity of biomass ash will facilitate its efficient utilization. Therefore, we reviewed previous research and selected 500, 700, and 850 ℃ temperatures to calcinate willow leaves. The contents of SiO2, CaO, and other oxides in the willow leaf ash were determined through X-ray fluorescence spectrometer(XRF). The specific surface area of willow leaf ash was determined using a laser particle size analyzer. The mineral composition of willow leaf ash was characterized by X-ray diffraction (XRD), and the characterization of the chemical bonds of the minerals was supplemented by Fourier-transform infrared (FTIR) spectroscopy. The zeta potential of the willow leaf ash–Ca(OH)2 solution was determined through microelectrophoresis to evaluate the system’s stability. After determining the basic physical and chemical properties of willow leaf ash, the mechanical properties of willow leaf ash–cement-based materials were investigated by replacing 20% (mass fraction) cement with the ash, and the factors affecting performance were analyzed. The pozzolanic activity of willow leaf ash at 500, 700, and 850 ℃ was evaluated through the activity index. Rapid evaluation of pozzolanic activity was conducted by active ion extraction capability and inductively coupled plasma-optical emission spectrometer (ICP-OES) analyses. Scanning electron microscopy and XRD characterization methods were combined to analyze the effect of calcination temperature on the structure and composition of the ash and to elucidate the mechanism of the effect of calcination temperature on its pozzolanic activity. The results show that the SiO2 content in the ash was 20% to 30%, and the specific surface area increased with increasing temperature. However, the presence of xonotlite in willow leaf ash was detected through XRD at 850 ℃ Furthermore, the observed FTIR absorption peak at 1120.74 cm−1 corresponded to the stretching vibration of the Si–O–Si structure, which indicated that some amorphous SiO2 was crystallized. The absolute value of the zeta potential of the solution containing willow leaf ash at 500 ℃ and 700℃ was considerably higher than that at 850℃. After replacing a part of the cement with willow leaf ash, the willow leaf ash–cement-based material exhibited the highest compressive strength at 500 ℃ with an activity index of 0.79. The rate of conductivity variation of the willow leaf ash–Ca(OH)2 solution at 500 ℃ and 700 ℃ was higher than that at 850 ℃. The concentration of Si4+ precipitation decreased with the increase in calcination temperature, indicating that willow leaf ash had the highest pozzolanic activity at 500 ℃ followed by 700 ℃. Excessively high calcination temperatures lead to the crystallization of amorphous SiO2 and slagging in willow leaf ash, along with a decrease in the pozzolanic activity. This study provides theoretical support for the regulation of the pozzolanic activity of biomass ash and its applications.

Michael Dorner, Maximilian Capraro, Oliver Treidler et al.

The engineering of complex software systems is often the result of a highly collaborative effort. However, collaboration within a multinational enterprise has an overlooked legal implication when developers collaborate across national borders: It is taxable. In this article, we discuss the unsolved problem of taxing collaborative software engineering across borders. We (1) introduce the reader to the basic principle of international taxation, (2) identify three main challenges for taxing collaborative software engineering making it a software engineering problem, and (3) estimate the industrial significance of cross-border collaboration in modern software engineering by measuring cross-border code reviews at a multinational software company.

Huiying Gao, Xiaoqiang Zhang, Peng Huang et al.

Fatigue reliability assessment of welded joints can consider the uncertainties from various sources and can establish the design criteria and inspection plans. The present paper aims to address the uncertainties explicitly. The notch strain approach that accounts for the effects of the misalignment, local notch, and crack-like imperfection, which is referred to as secondary notch, is employed. Sensitivity analyses indicate that uncertainties in misalignment, flank angle, weld toe radius together with secondary notch are all important sources of the total uncertainty. The practical difficulty in the determination of the uncertainty models of the geometric parameters is discussed, and the acceptance limits for fabrication are used to derive the uncertainty models. And finally, the impacts of acceptance limits on the fatigue reliability of welded joints are assessed. The results indicate that the weld toe radius and secondary notch depth significantly affect the reliability index and the fatigue reliability increases with the weld quality of the welded joint becomes higher.

Yuji YAHAGI

Vortex structures behind two highly heated cylinders of equal diameter in tandem arrangements have been investigated experimentally. The experiments were performed under the following conditions: cylinders diameter, D = 4 mm; mean flow velocity of air, U∞ = 1.0 m/s; Reynolds number, Re = 250; cylinders spacing ratio, S/D = 1.0~10.0; and cylinder heat flux, q = 0~72.6 kW/m2. Two distinct flow structures are formed in the region of the cylinder clearance which depends on the S/D and the cylinder surface temperature, Tw. One is a quasi-stationary twin vortex at the small S/D condition (S/D&lt;3.0~5.0) and the other is a shedding Karman vortex for large S/D condition (S/D&gt;3.0~5.0). Behind the downstream cylinder, the Karman vortex street is formed in all conditions. The critical S/D changing to the Karman vortex increases with increasing the temperature of the upstream cylinder. The Strouhal number St under the twin vortex forming is in the range of 0.150 to 0.155 regardless of the S/D and heating conditions, while the St of the Karman vortex formed behind the downstream cylinder is decreased significantly as the S/D increases. For the large S/D, the Karman vortex is formed behind both of the cylinders then the upstream St agreed with the downstream St. St of the Karman vortex coincides with St in the single-cylinder condition taken into account of the cylinder heating conditions. For the small S/D and the upstream cylinder in a highly heated condition, the twin vortex structure behind the upstream cylinder plays a key role in the downstream shedding Karman vortex structure.

Robert Karsthof, Ymir Kalmann Frodason, Augustinas Galeckas et al.

Nickel oxide is a versatile p‐type semiconducting oxide with many applications in optoelectronic devices, but high doping concentrations are often required to achieve necessary electrical conductivity. In contrast to many other transparent oxide semiconductors, even moderate doping levels in NiO can lead to significant optical absorption in the visible spectral range, limiting the application range of the material. This correlation has been reported extensively in the literature, but its origin has been unknown until now. This work combines experimental data on optical properties from a variety of NiO samples with results from hybrid density functional theory calculations. It shows that strong electron–phonon interaction leads to a significant blueshift (0.6–1 eV) of electronic transitions from the valence band maximum to defect states by light absorption with respect to the thermodynamic charge transition levels. This essentially renders NiO a narrow‐gap semiconductor by defect band formation already at moderate doping levels, with strong light absorption for photon energies of approximately 1 eV. The calculations are also shown to be fully consistent with experimental data on defect‐related light emission in NiO.

Miroslav Vořechovský

The paper presents a new efficient and robust method for rare event probability estimation for computational models of an engineering product or a process returning categorical information only, for example, either success or failure. For such models, most of the methods designed for the estimation of failure probability, which use the numerical value of the outcome to compute gradients or to estimate the proximity to the failure surface, cannot be applied. Even if the performance function provides more than just binary output, the state of the system may be a non-smooth or even a discontinuous function defined in the domain of continuous input variables. In these cases, the classical gradient-based methods usually fail. We propose a simple yet efficient algorithm, which performs a sequential adaptive selection of points from the input domain of random variables to extend and refine a simple distance-based surrogate model. Two different tasks can be accomplished at any stage of sequential sampling: (i) estimation of the failure probability, and (ii) selection of the best possible candidate for the subsequent model evaluation if further improvement is necessary. The proposed criterion for selecting the next point for model evaluation maximizes the expected probability classified by using the candidate. Therefore, the perfect balance between global exploration and local exploitation is maintained automatically. The method can estimate the probabilities of multiple failure types. Moreover, when the numerical value of model evaluation can be used to build a smooth surrogate, the algorithm can accommodate this information to increase the accuracy of the estimated probabilities. Lastly, we define a new simple yet general geometrical measure of the global sensitivity of the rare-event probability to individual variables, which is obtained as a by-product of the proposed algorithm.

N. V. Krishnendu, Frank Ohme

The detections of gravitational-wave (GW) signals from compact binary coalescence by ground-based detectors have opened up the era of GW astronomy. These observations provide opportunities to test Einstein's general theory of relativity at the strong-field regime. Here we give a brief overview of the various GW-based tests of General Relativity (GR) performed by the LIGO-Virgo collaboration on the detected GW events to date. After providing details for the tests performed in four categories, we discuss the prospects for each test in the context of future GW detectors. The four categories of tests include the consistency tests, parametrized tests for GW generation and propagation, tests for the merger remnant properties, and GW polarization tests.