Hasil untuk "Structural engineering (General)"

Jia Zhang, Ping Xiao, Yong Huang et al.

To address the high energy consumption and low efficiency in shredding film–stalk mixtures during the resource utilization of cotton-field residues in Xinjiang—issues arising from the large mechanical-property differences among the mixture components—a custom single-support shearing fixture was developed to investigate the effects of residual-film wrapping layers, blade rake angle, sliding-cutting angle, and shearing speed on the <i>F</i>_j^max. Based on a Box–Behnken response surface design combined with analysis of variance and microscopic observations of the shearing process, the results showed that all main-effect factors had extremely significant influences on the <i>F</i>_j^max (<i>p</i> < 0.0001). Their relative contributions followed the following order: number of film wrapping layers > blade rake angle > shearing speed > sliding-cutting angle. Residual-film wrapping markedly increased shear resistance; increasing the sliding-cutting angle effectively reduced the shearing force; and reducing the rake angle facilitated more energy-efficient shredding. Interaction analysis further revealed significant coupling between sliding-cutting angle and shearing speed, rake angle and sliding-cutting angle, and rake angle and shearing speed (<i>p</i> < 0.05). Comparative shearing tests indicated that pure cotton stalks exhibited continuous brittle fracture with relatively stable force–displacement profiles, whereas film–stalk composites showed a sequentially coupled failure mode characterized by “residual-film pre-shearing–primary stalk fracture–secondary film stretching,” leading to multi-peak fluctuations in the force–displacement curves. Based on response surface optimization and mechanistic analysis, a parameter combination of a 35° rake angle, a 4–8° sliding-cutting angle, and medium-to-low shearing speed is recommended for shredding operations. This study elucidates the shearing and fragmentation mechanisms of film–stalk mixtures, provides theoretical guidance for optimizing key structural and operational parameters of post-recovery equipment, and offers important engineering value for promoting farmland residual-film pollution control and agricultural waste resource utilization.

Haimo Joehri

This paper gives an overview about aspects of mechanical engineering of undulators. It is based mainly on two types that are used in the SwissFEL facility. The U15 Undulator is an example of an in-vacuum type and the UE38 is an APPLE-X type. It describes the frame, the adjustment of the magnets with flexible keepers and the adjustment of the whole device with eccentric movers.

Al Muttakin, Saikat Mondal, Chanchal K. Roy

Replication packages are crucial for enabling transparency, validation, and reuse in software engineering (SE) research. While artifact sharing is now a standard practice and even expected at premier SE venues such as ICSE, the practical usability of these replication packages remain underexplored. In particular, there is a marked lack of studies that comprehensively examine the executability and reproducibility of replication packages in SE research. In this paper, we aim to fill this gap by evaluating 100 replication packages published in ICSE proceedings over the past decade (2015 - 2024). We assess the (1) executability of the replication packages, (2) efforts and modifications required to execute them, (3) challenges that prevent executability, and (4) reproducibility of the original findings for those that are executable. We spent approximately 650 person-hours in total to execute the artifacts and reproduce the study findings. Our analysis shows that only 40 of the 100 evaluated artifacts were fully executable. Among these, 32.5% ran without any modification. However, even executable artifacts required varying levels of effort: 17.5% required low effort, while 82.5% required moderate to high effort to execute successfully. We identified five common types of modifications and 13 challenges that lead to execution failure, encompassing environmental, documentation, and structural issues. Among the executable artifacts, only 35% (14 out of 40) reproduced the original results. These findings highlight a notable gap between artifact availability, executability, and reproducibility. Our study proposes three actionable guidelines to improve the preparation, documentation, and review of research artifacts, thereby strengthening the rigor and sustainability of open science practices in SE research.

Hüseyin Pehlivan

Traditional route optimization frameworks often suffer from “spatial blindness,” addressing the problem through abstract matrices devoid of geographical context. To address this fundamental methodological gap, this study proposes the Iterative Score Propagation Algorithm (ISPA), a transparent, GNN-inspired framework that reframes optimization as a holistic corridor problem. ISPA’s robustness and superiority were tested against established Multi-Criteria Decision-Making (MCDM) methods (WLC, TOPSIS, VIKOR) across three diverse engineering scenarios (Rural Highway, Pipeline, Trekking Trail) and two distinct weighting philosophies (Entropy and AHP). The holistic analysis reveals that ISPA achieves the highest final score (0.815) across all six test conditions, demonstrating both the highest overall mean performance (0.629) and the greatest stability (1.000). Furthermore, its flexible cost function successfully modeled unconventional objectives, such as a “climbing reward,” enabling a paradigm shift from cost minimization to experience maximization. ISPA’s superior performance stems from its structural advantage in contextualizing spatial data. This work introduces a new, spatially-aware approach that transforms route planning from a static calculation into a dynamic design and scenario analysis tool for planners and engineers.

YANG Lei 1, MI Xiangyun 2, LI Zhaofeng 1, TU Wenfeng 2, XIE Yunpeng 2, HU Hao 1, WANG Kang 3

Aiming at the problems of strong disasters caused by water-rich dense weak surrounding rock and weak applicability of the conventional grouting materials, a new type of high-strength acrylic acid grouting material is developed, its polymerization reaction mechanism and working performance are analyzed, and the permeability and reinforcement characteristics of the new material on dense pulverized silty rock are studied. Based on the organic-inorganic interpenetrating network method, the high-strength acrylic acid grouting material is developed, which is composed of the main agent, inorganic modifier, initiator, accelerator, crosslinking agent and other raw materials, and it has remarkable characteristics of high strength and high permeability. The polymerization reaction of the two components of the high strength acrylate material is sufficient after mixing, and the inorganic network structure is evenly interspersed in the acrylate organogels network. According to the orthogonal tests, the characteristics of the new materials with different compositions, such as the gelling time, compressive strength and water absorption expansion rate as well as the influence rules of the components, are obtained. The gelling time range of the slurry is 45~201 s, the uniaxial compressive strength of the gel is 1.2~2.1 MPa, and the water absorption expansion rate is 16%~51%. The sensitivity ranking of factors affecting the main working properties of the new materials is further clarified. In accordance with the laboratory tests and microanalytical analysis technology, the permeability and reinforcement characteristics of grout in dense crushed rock are studied. The results show that the permeability and diffusion capacity of the high-strength acrylate grout is close to that of the pure one, which is much higher than that of the cement grout. Moreover, the high-strength acrylate material has an obvious coating and strengthening effect on crushed rock particles, and the solid strength reache 2.31 MPa. It is 5.4 ~ 11.0 times the reinforcement strength of the pure acrylic salt material, which can provide a strong safety guarantee for disaster grouting control and safe excavation of tunnels.

Amr S. Mohamed, Emily Nguyen, Deepa Kundur

Amidst the growing demand for implementing advanced control and decision-making algorithms|to enhance the reliability, resilience, and stability of power systems|arises a crucial concern regarding the safety of employing machine learning techniques. While these methods can be applied to derive more optimal control decisions, they often lack safety assurances. This paper proposes a framework based on control barrier functions to facilitate safe learning and deployment of reinforcement learning agents for power system control applications, specifically in the context of automatic generation control. We develop the safety barriers and reinforcement learning framework necessary to establish trust in reinforcement learning as a safe option for automatic generation control - as foundation for future detailed verification and application studies.

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.

Vadim NANTOI, Daria NANTOI

This article explores the teaching methodologies and theoretical frameworks pertinent to instructing novice car drivers in the applied geometry necessary for maintaining dynamic safe following distances. The study integrates principles from physics, geometry, and psychomotor abilities to provide a comprehensive understanding of the factors influencing safe driving practices. It explores the laws of motion, reaction times, and vehicle dynamics, alongside geometric relationships governing perceived distance and car size. The article also elucidates instructional strategies for novice drivers to develop critical thinking, psychomotor skills, and adaptive behaviours essential for safe distance maintenance.

Chao KONG, Hailing XU, Dong LIN et al.

The integrated building-bridge structure system represents integrated railway stations in China and has emerged as a new structural approach in recent years. This paper presents a case study on large shaking table tests that explore various seismic responses of a pile group system based on the Kunming South Railway Station. The study focused on the dynamic characteristics of both the soil and the pile-superstructure interaction. Findings indicate that pile damage is concentrated on the side facing the direction of vibration, with the middle pile experiencing greater damage than the corner pile. Hysteresis is observed in the growth of the pore pressure ratio during soil liquefaction in saturated conditions. Both the bending moment and the ground pressure acting on the pile increase with the degree of liquefaction. The maximum pile bending moment occurs at the interface between liquefied and non-liquefied soil layers. During seismic events, the side piles facing the vibration direction experience increased seismic surcharge, while the central piles are subjected to lower loads due to the isolation effect of the side piles.

Sun Qi, Zhang Kaiyin

Resonance of multi-degree-of-freedom system or structure is a basic and important concept in structural vibration theory, but it lacks a complete and rigorous definition. In order to establish an accurate concept of structural resonance, based on the concept of single-degree-of-freedom system resonance and modal orthogonality, this paper discusses the necessary conditions of system resonance by analyzing the displacement response of multi-degree-of-freedom vibration system, that is, while ensuring that the vibration frequency of the system (a certain natural frequency) is equal to the excitation frequency, its displacement response should also present the corresponding modal shape. An example of simply supported beam is used to illustrate its rationality. At the same time, the theoretical method of pure modal resonance of multi-degree-of-freedom system is given by rational allocation of excitation force. The pure modal resonance of multi-degree-of-freedom system or structure can be realized, which can be used to accurately identify the modal parameters of the structure. It is of great theoretical significance and engineering application value to discriminate the concept of multi-degree-of-freedom system or structure resonance.

LI Jun, CUI Dehao, YOU Ri et al.

In view of the structural damage of an aqueduct pile-pillar supporting structure caused by ship collisions,relevant engineering data were collected,and on-site detection and monitoring analysis were carried out.In addition,the finite element method was used to establish a three-dimensional entity analytical model of the aqueduct pile-pillar structure.Under the joint action of the coupled foundation and pile foundation and superstructure,numerical simulation and calculation analysis were carried out on the pile-pillar collision process.The distribution and characteristics of the damage of the supporting structure caused by collisions were studied and verified.The finite element numerical simulation results show that the high-stress area of the aqueduct pile-pillar structure during the ship collision process can be divided into two categories according to the cause.One is the high-stress area caused by the direct contact load,which occurs in the collision contact surface and the adjacent area between the ship in a collision and the bearing platform,and the other is caused by the overall bending deformation of the pile-pillar structure,which occurs in the dangerous section of the pile-pillar structure and the bearing platform connection.In addition,the simulation analysis and on-site detection results are consistent.By assessing the influence of ship collisions and checking the potential safety hazards of the aqueduct,the research results lay a foundation for the maintenance,reinforcement,and design of the aqueduct.

陶思宇, 曲哲

在2022年9月5日四川泸定6.8级地震中，位于震中附近的一栋地上4层的隔震建筑的隔震层正常发挥作用，上部结构和非结构构件均基本完好，但是隔震层中的铅芯橡胶支座、排水管线和隔震缝附属非结构构件等均发生了不同程度的破坏。在介绍该建筑主要震害的基础上，通过基于简化分析模型和邻近烈度仪实际强震记录的非线性地震反应分析，推测该建筑的地震反应，并重点考察铅芯橡胶支座的竖向应力在地震中可能发生的变化。结果表明，尽管该场地附近的强震记录表现出明显的近断层脉冲特性，但在其作用下，该建筑上部结构的最大层间位移角小于设防地震下混凝土框架结构1/400的限值，隔震层也有效地减小了上部结构的楼面水平加速度反应。受比较显著的竖向地震作用影响，绝大多数隔震支座均可能短暂地处于拉剪耦合受力状态，但其最大拉应力水平远低于根据既有试验得到的相应水平剪应变下的极限拉应力。该建筑隔震层中橡胶隔震支座的大量破坏不能简单地归因于竖向地震作用。

L. Siddharth, Jianxi Luo

Aiming to support Retrieval Augmented Generation (RAG) in the design process, we present a method to identify explicit, engineering design facts - {head entity :: relationship :: tail entity} from patented artefact descriptions. Given a sentence with a pair of entities (based on noun phrases) marked in a unique manner, our method extracts the relationship that is explicitly communicated in the sentence. For this task, we create a dataset of 375,084 examples and fine-tune language models for relation identification (token classification) and elicitation (sequence-to-sequence). The token classification approach achieves up to 99.7 % accuracy. Upon applying the method to a domain of 4,870 fan system patents, we populate a knowledge base of over 2.93 million facts. Using this knowledge base, we demonstrate how Large Language Models (LLMs) are guided by explicit facts to synthesise knowledge and generate technical and cohesive responses when sought out for knowledge retrieval tasks in the design process.

Jie JW Wu

Software companies have widely used online A/B testing to evaluate the impact of a new technology by offering it to groups of users and comparing it against the unmodified product. However, running online A/B testing needs not only efforts in design, implementation, and stakeholders' approval to be served in production but also several weeks to collect the data in iterations. To address these issues, a recently emerging topic, called "Offline A/B Testing", is getting increasing attention, intending to conduct the offline evaluation of new technologies by estimating historical logged data. Although this approach is promising due to lower implementation effort, faster turnaround time, and no potential user harm, for it to be effectively prioritized as requirements in practice, several limitations need to be addressed, including its discrepancy with online A/B test results, and lack of systematic updates on varying data and parameters. In response, in this vision paper, I introduce AutoOffAB, an idea to automatically run variants of offline A/B testing against recent logging and update the offline evaluation results, which are used to make decisions on requirements more reliably and systematically.

Hannes M. Beyer, Hannes M. Beyer, Hideo Iwaï

Inteins catalyze their removal from a host protein through protein splicing. Inteins that contain an additional site-specific endonuclease domain display genetic mobility via a process termed “homing” and thereby act as selfish DNA elements. We elucidated the crystal structures of two archaeal inteins associated with an active or inactive homing endonuclease domain. This analysis illustrated structural diversity in the accessory domains (ACDs) associated with the homing endonuclease domain. To augment homing endonucleases with highly specific DNA cleaving activity using the intein scaffold, we engineered the ACDs and characterized their homing site recognition. Protein engineering of the ACDs in the inteins illuminated a possible strategy for how inteins could avoid their extinction but spread via the acquisition of a diverse accessory domain.

Olugbenga AMU, Oluwaseun ADETAYO, Feyidamilola FALUYI et al.

This research considered the viability of groundnut shell ash (GSA) on lime-stabilized lateritic soil for highway structural works. Three samples of lateritic soil, named samples A, B, and C, were gathered from Idita-Mokuro, NTA-Mokuro, and ETF burrow pits, respectively, in Ile-Ife, Osun State, Nigeria. Preliminary tests were completed on the samples in their natural states and when stabilized with optimum lime. Engineering properties were performed while 2, 4, and 6 % GSA contents were added to the soil samples at optimum lime. The Atterberg limit tests showed a significant reduction in the plasticity index for samples A and C when stabilized with lime. Compaction test showed a decrease in the maximum dry density from 1,685 to 1,590 kg/m3 for sample A, 1,599 to 1,512 kg/m3 for sample B, and 1,396 to 1,270 kg/m3 for sample C on stabilizing with lime; the introduction of GSA to stabilized lime soil diminished the maximum dry density for all the soil samples, with sample A reduced to 1,435 and 1,385 kg/m3 at 2 and 4 GSA contents, respectively. The addition of GSA improved the engineering properties of lime-stabilized soils as the unsoaked CBR esteems expanded for all soil samples. At an optimum lime dosage, the addition of 2 % GSA expanded the triaxial shear strength from 60.43 to 188.36 kN/m2 for sample A and, at 4 % GSA content, both soil samples B and C increased from 19.19 to 201.48 kN/m2 and 30.62 to 111.65 kN/m2, respectively. Conclusively, GSA improved the toughness and strength of lime-stabilized lateritic soil for highway structural works.

Benaissa Soufiane, Habibi Samir, Semsoum Djameleddine et al.

Elaborating an instrumented nanoindentation is to exercise non-destructive tests to be applied to volumes of polymethylmetacrylate (PMMA) materials in miniature. This work focuses on factors that explain the trends variation of mechanical properties like Young's modulus (E), contact hardness (H) and indentation force (P). The evolution of E and H with depth (h) and P shows a 2.77 nm inflection point at low penetrations, separating two zones: the first increasing and the second decreasing. This is respectively explained by the surface hardening induced by preparing the material surface, and the existence of a surface hardness gradient denoted by an indentation size effect (ISE) observed at very low depths. Moreover, In addition, a critical penetration depth of 9.71 nm below which the surface effect dominates the variation of the penetrating load is detected. E and H results differences between dynamic and static modes are 8.46% and 6.44% inducing an overestimation of 35 MPa in E value, and an underestimation of 1.23 MPa in H value. This tends to affect the expected nanoscale precision of the indentation to determine the nanomechanical properties of PMMA.

Liang Wei, Luiz Fernando Capretz

The design of recommendation systems is based on complex information processing and big data interaction. This personalized view has evolved into a hot area in the past decade, where applications might have been proved to help for solving problem in the software development field. Therefore, with the evolvement of Recommendation System in Software Engineering (RSSE), the coordination of software projects with their stakeholders is improving. This experiment examines four open source recommender systems and implemented a customized recommender engine with two industrial-oriented packages: Lenskit and Mahout. Each of the main functions was examined and issues were identified during the experiment.

Halima Mouhib, Bas Stringer, Hugo van Ingen et al.

While many good textbooks are available on Protein Structure, Molecular Simulations, Thermodynamics and Bioinformatics methods in general, there is no good introductory level book for the field of Structural Bioinformatics. This book aims to give an introduction into Structural Bioinformatics, which is where the previous topics meet to explore three dimensional protein structures through computational analysis. We provide an overview of existing computational techniques, to validate, simulate, predict and analyse protein structures. More importantly, it will aim to provide practical knowledge about how and when to use such techniques. We will consider proteins from three major vantage points: Protein structure quantification, Protein structure prediction, and Protein simulation & dynamics. The main emphasis of this work is to provide a background on experimental techniques for protein structure determination. The focus is set on X-ray crystallography and Nuclear Magnetic Resonance spectroscopy (NMR), which are by far the main methods used to determine the structure of soluble proteins. We will also introduce cryogenic Electron Microscopy (cryo-EM) and electron diffraction which are more suited to analyze membrane proteins and larger protein complexes. At the end, more qualitative techniques are summarized that are used to obtain insight on the overall structure and dynamics of proteins. Note that this introduction to protein structure determination aims at familiarizing the reader to different experimental techniques, their benefits and bottlenecks, but that a thorough mathematical and technical description of the concept is beyond the scope of this work.