Yasmany García-Ramírez, Fernando Arrobo-Herrera, Alejandra Cruz-Cortez
et al.
Pedestrian safety in developing countries faces critical challenges from rapid urbanization and infrastructure deficiencies. This study investigates how visual context influences pedestrian crossing preferences through a controlled stated preference experiment in multiple Ecuadorian cities. A sample of 875 participants was randomly assigned to view either non-compliant (mid-block crossing) or compliant (signalized crosswalk) imagery before evaluating six hypothetical scenarios involving three crossing alternatives. Multinomial logit models reveal that waiting time, traveling with a minor, and walking distance are primary determinants of choice. Visual context showed systematic associations with choice patterns: compliant imagery was associated with increased preference for safer alternatives (50.5% versus 43.8% prediction accuracy) and larger safety-related parameter magnitudes. Principal Component Analysis identified two latent perception constructs, safety/security and bridge-specific convenience, providing behavioral interpretation of choice patterns. Substantial spatial heterogeneity emerged across cities (χ<sup>2</sup> = 124.10 and 84.74, <i>p</i> < 0.001), with larger urban centers showing stronger responsiveness to formal infrastructure cues. The findings demonstrate that visual stimuli systematically alter choice distributions and attribute sensitivities through normative activation and perceptual recalibration. This research contributes methodologically by establishing visual framing effects in stated preference frameworks and provides actionable insights for pedestrian infrastructure design, emphasizing alignment of objective safety improvements with perceived risk and contextual behavioral cues.
Hydrogen as fuel in civil aviation gas turbines is promising due to its no-carbon content and higher net specific energy. For an entry-level market and cost-saving strategy, it is advisable to consider reusing existing engine components whenever possible and retrofitting existing engines with hydrogen. Feasible strategies of retrofitting state-of-the-art Jet A-1 fuelled turbofan engines with hydrogen while applying minimum changes to hardware are considered in the present study. The findings demonstrate that hydrogen retrofitted engines can deliver advantages in terms of core temperature levels and efficiency. However, the engine operability assessment showed that retrofitting with minimum changes leads to a ~5% increase in the HP spool rotational speed for the same thrust at take-off, which poses an issue in terms of certification for the HP spool rotational speed overspeed margin.
[Objective] Mobile 3D laser scanning technology is widely applied in single-tube tunnel monitoring due to its excellent measurement efficiency and high accuracy. However, the application of this technology for deformation monitoring in twin-tube shield tunnels is rare, necessitating analysis of the mobile 3D laser scanning accuracy for twin-tube shield tunnel deformation convergence monitoring. [Method] The feasibility of using this technology for convergence deformation monitoring in twin-tube shield tunnels is verified through accuracy validation. Point cloud data collected via mobile 3D laser scanning are processed using software parameter settings and segment ring correction to obtain convergence values, which are then compared with the convergence values measured by manual total station, thereby validating the accuracy of the mobile 3D laser scanning system. In addition, tunnel defects are analyzed by generating an unwrapped elevation view of the twin-tube shield tunnel. [Result & Conclusion] Based on a comparative analysis of 1 178 rings of measured data from a twin-tube shield tunnel on a rail transit line interval in Shanghai, it is found that: in both the first half and the second half of 2022, 90.66% of convergence changes in the twin-tube shield tunnel fell within the range of -1.0 to 1.0 mm, and 99.24% fell within -2.0 to 2.0 mm. The accuracy of the FARO S350 laser scanner in the twin-tube shield tunnel interval is 92.86% within -2.0 to 2.0 mm, and 99.58% within -3.0 to 3,0 mm. The field-measured data verifies the reliability of the mobile 3D laser scanning technology.
Abstract Coal mining induces changes in the nature of rock and soil bodies, as well as hydrogeological conditions, which can easily trigger the occurrence of geological disasters such as water inrush, movement of the coal seam roof and floor, and rock burst. Transparency in coal mine geological conditions provides technical support for intelligent coal mining and geological disaster prevention. In this sense, it is of great significance to address the requirements for informatizing coal mine geological conditions, dynamically adjust sensing parameters, and accurately identify disaster characteristics so as to prevent and control coal mine geological disasters. This paper examines the various action fields associated with geological disasters in mining faces and scrutinizes the types and sensing parameters of geological disasters resulting from coal seam mining. On this basis, it summarizes a distributed fiber‐optic sensing technology framework for transparent geology in coal mines. Combined with the multi‐field monitoring characteristics of the strain field, the temperature field, and the vibration field of distributed optical fiber sensing technology, parameters such as the strain increment ratio, the aquifer temperature gradient, and the acoustic wave amplitude are extracted as eigenvalues for identifying rock breaking, aquifer water level, and water cut range, and a multi‐field sensing method is established for identifying the characteristics of mining‐induced rock mass disasters. The development direction of transparent geology based on optical fiber sensing technology is proposed in terms of the aspects of sensing optical fiber structure for large deformation monitoring, identification accuracy of optical fiber acoustic signals, multi‐parameter monitoring, and early warning methods.
Engineering geology. Rock mechanics. Soil mechanics. Underground construction
Machine Learning has become prevalent nowadays for predicting data on the mechanical properties of various materials and is widely used in various polymeric applications. In the present study, Artificial Neural Network (ANN), a computational tool is used to predict the elastic modulus of a composite of longitudinally placed fiber-reinforced polymeric composite. The novelty in carried work is that the property prediction is carried out considering interphase and its properties. For this, tensile properties data of Longitudinally Placed Bamboo Fiber Reinforced Polyester Composite (LUDBPC), Longitudinally Placed Flax Fiber Reinforced Polyester Composite (LUDFPC) and Longitudinally Placed Jute Fiber Reinforced Polyester Composite (LUDJPC) has been procured to generate ANN models. The Levenberg-Marquardt training algorithm is used to generate the ANN models as it gives more accurate results compared to other ANN algorithms based on interphase properties data. The validation of ANN models was also carried out based on fresh experimental results of BPC/FPC by doing the fabrication with hand layup technique and testing of composites with a Universal Testing Machine (UTM). The present work signifies that the developed ANN models give accurate results with experimental results for the prediction of elastic modulus of composite (Ecl) and it can be used for the prediction of longitudinally placed fiber-reinforced composite and Ecl of BPC at volume fraction of fiber (vf):22% is 2248.75 MPa and Ecl of FPC at vf:10% is 3210.50 MPa.
ABSTRACT This paper proposes a controlled signal technique for visible light non‐orthogonal multiple access (VL‐NOMA) communication in an interference‐controlled environment with intelligent reflecting surfaces (IRS) for beyond 5G (B5G) and 6G communication networks. The light‐emitting diode (LED) is used for carrier signal generation to transmit signals to the two users (photodiodes, PDs) due to its advantages, such as its programmable nature and flexibility. The potential challenge is how the signals could be controlled with an IRS approach, which prompted this research. We have used IRS, which is a cutting‐edge enabling technology that modifies the signal's reflection by utilizing numerous inexpensive passive reflecting elements to improve the signal's performance. Furthermore, deep reinforcement learning (DRL) is deployed to control the reflected signals, simulate, make decisions, and link LED‐IRS‐PDs, redirecting the signals. The entire system is successfully synchronized, and then the bit error rate (BER), line of sight (LOS), and non‐line of sight (NLOS) performances are investigated. Furthermore, we place a blocker at the center of the model as a NLOS to check how the transmitted signals will perform. We observed that the propagated signal improved the BER as per LOS, hence, the NLOS blocker reduced the signal's performance. Furthermore, we optimized the signals to investigate BER, LOS, and NLOS signal performance. We observed that LOS signals performed better than NLOS signals.
Agriculture is one of the largest sectors that contribute to the economic growth of countries, including Malaysia. However, plant diseases affect the quality of the harvest and impede farmers’ maximum yield output. Therefore, early detection of diseases in plants is vital to curb infection, reduce food waste, and reduce their carbon footprint. However, many detection methods are complex, require high computational power and time to perform the required analysis and focus only on a particular species or strain of the disease. These requirements would likely deter most users in remote areas or poorer economic states. This paper proposes a convolutional neural network to determine multi-class plant diseases that is memory efficient, has a small trainable parameter number, and is compact enough to work even on mobile devices. The plant images were pre-processed to ensure that they were validated accurately and to minimise overfitting. Then, the proposed convolutional neural network was trained using a publicly available dataset consisting of 54306 images, followed by validation and testing. Finally, the completed model is saved, and the data obtained is transferred to a cloud network using wireless sensor networks. The proposed method obtained 96.87% accuracy with 100 epoch training iterations, rivalling famous architectures such as VGG16 and MobileNetV2. The experimental results demonstrate the feasibility and robustness of the method for disease detection in multi-crop plants.
Mechanics of engineering. Applied mechanics, Technology
Mohamed E. Issa, Nasser F. El-Shafey, Ahmed T. Baraghith
et al.
Abstract This study aims to explore the flexural behavior of crushed clay brick (CCB) lightweight concrete (LWC) beams strengthened with rubberized strain-hardening cementitious composite reinforced with glass fiber textile mesh layers (GFTM-RSHCC) at the tension side. For this purpose, an experimental investigation consisting of seven simply supported beams, including one un-strengthened specimen, was produced and tested using a monotonic 4-point loading scheme. All specimens had a 120 × 250 mm cross-section, a total length of 2400 mm, and a loaded span of 2200 mm. The studied parameters were the number of GFTM inside the RSHCC (1, 2, or 3) and the thickness of GFTM-RSHCC layer (30 or 40 mm). All the following aspects were tracked: crack pattern, ultimate load, mid-span defection, and ductility. The results show that increasing the number of layers of GFTM and the thickness of RSHCC generally leads to an increase in the ultimate loads and ductility, up to 68% and 83%, respectively, compared to the control beam. Finally, a proposed equation considering the contribution of the GFTM-RSHCC layer was developed to predict the flexural capacity of the strengthened beams. The proposed equation showed good agreement with the experimental results.
The target simulation of airplanes is an important research topic. It is particularly important to find the right balance between high performance and low cost. In order to balance the contradictions between realistic target simulations and controllable costs, the scientific formulation of the performance parameters of target simulation is the key to achieving high performance. This paper proposes an intelligent simulation technology based on RCS imaging simulation through the combination of 60° variation corner reflector and a Luneberg lens reflector. It is designed to simulate several important RCS characteristics of the aircraft. At the same time, the different RCS images are automatically shifted to the corresponding gear position to achieve the purpose of simulation, and the price is low and the performance is good. It can be used for the training of radar target searching.
This study measured the time it took to select a target moving along a circular trajectory with a computer mouse. The time was changed according to the speed of the target, the width of target and the distance from the starting point to the target. However, the effect of these independent variables on the dependent variable was different from what was expected. In the previous studies, it was assumed that the faster the moving target speed, the longer the target selection time, because increased target speed had the effect of narrowing the effective target width. However, as a result of the experiment, the target selection time was rather shortened when the moving speed of the target was increased. This may be because the subjects intend to speed up target selection while decreasing the accuracy of target selection in order to adapt to a fast-moving target. The modified Fitts’ model for the moving target selection time proposed in a previous study did not take these user responses into account. A more modified model is required to more accurately describe the selection time of moving target.
Ірина Берник, Іван Назаренко, Олександр Луговський
В роботі проведено дослідження та визначення акустичних параметрів руху кавітаційної бульбашки в рідинному середовищі за дискретною та континуальною моделями. В основу виконання досліджень покладена гіпотеза, що визначення ефективних параметрів робочого процесу акустичної обробки реалізується шляхом застосування перехідної фізичної моделі від дискретного до континуального виду обробки технологічного середовища. Отримані аналітичні залежності дозволяють розрахувати амплітуду коливань та частоту власних коливань. За допомогою вказаних формул представляється можливим визначити зони посилення або ослаблення амплітуди коливань для різних частот коливань. Запропонована формула для визначення частоти власних коливань, яка враховує зміни властивостей середовища від однорідного на початковій стадії до появи кавітаційних бульбашок при визначені частоти власних коливань. Наведені числові значення інтенсивності, тиску, амплітуд коливань, швидкості, прискорення, в’язкості та максимального радіусу бульбашки. Отримані числові значення можуть бути використанні в практичних розрахунках параметрів акустичної обробки різних за своєю природою та властивостям технологічних середовищ.
Oleksii M. Shushura, Liudmyla A. Asieieva, Oleksiy L. Nedashkivskiy
et al.
The widespread use of computer technology, its rapid development and use in almost all areas of human activity requires constant updating of information security issues. The activities of many enterprises in the field of IT, construction, and other areas are of a project nature and therefore further research on information security management of projects is relevant. Appearance of changes and the current state of the project results at certain points of time describe the documents that accompany it. In this paper, the information structure of the project is considered as a set of specific documents. During the life cycle of each project document, which includes the creation, transfer, preservation and transformation, there are generally threats to its confidentiality, integrity, accessibility and authenticity. This paper develops a method for assessing the risks of violation of the availability of project documents in solving information security problems. A formal description of many project documents in the form of a generalized hierarchical structure is presented, the connection of documents with the operations performed on them and information systems used during these operations is formalized. Given the incompleteness and dimension of the data, the based on fuzzy logic model was developed to assess the risk of document accessibility. Approaches to the assessment of the damage from the violation of the availability of the project document and the method of calculating the overall assessment of the risk of violation of the documents availability are proposed. The results presented in this paper can be used in decision-making processes regarding information security of projects in organizations that have project activities. The approaches proposed in this paper can serve as a basis for the creation of specialized information technologies to automate the calculation of project risk assessments.
The aims of this study were to propose a minimally invasive lateral approach technique for maxillary sinus floor elevation (MSFE) with simultaneous implant placement and to evaluate the surgical outcome and complications of this technique. This study reviewed 49 surgeries of MSFE with simultaneous implant placement (<i>n</i> = 83) using a minimally invasive lateral approach. A circular shape window with a diameter of 5 to 6 mm and an area of 20–30 mm<sup>2</sup> was made on the lateral wall of the maxillary sinus. After elevation of the Schneiderian membrane, the xenograft was used for bone grafting. The MSFE was possible with a minimum-sized window in 47 of 49 cases. For the remaining 2 cases, MSFE with a minimum-sized window was failed. In one case, it was expanded to be more than 30 mm<sup>2</sup> to repair the membrane perforation. In another case, MSFE was performed by forming two minimum-sized windows. Post-operative bleeding after MSFE occurred in one anticoagulant-treated patient. There was no failed implant during the follow-up period (mean 22 months). A minimally invasive lateral approach through a small circular window with a diameter of 5 to 6 mm is a feasible and safe technique for MSFE with simultaneous implant placement.
Stefano Cademartori, Carlo Cravero, Martino Marini
et al.
A CFD model to simulate the cooling technique trough slot jet impingement has been developed. Such a technique has been tested on an existing vertical galvanizing industrial line, which initially envisaged a round jet configuration, the subject of a previous work. Two different slot jet configurations have been simulated and compared to the pre-existing one, in order to provide design information for a possible new jet cooler after exploring different solutions. The numerical model has been appropriately calibrated and validated by comparing it with experimental measurements from a literature case. At first, a single slot jet configuration was simulated through a 2D model, then multi slot configurations were calculated using 3D models. Different turbulence models were compared to select the best candidate for the CFD approach. Finally, several configurations with different slots numbers and jet-wall distances were considered. It was possible to understand the physical mechanisms underlying this cooling technique and to be able to select the most promising configuration for the reference industrial cooling process.
The failure in 1984 of Carsington Dam near the end of its construction led to major advances in several areas of geotechnical engineering. It also led to major advances in understanding the nature and extent of geochemical and mineralogical reactions that can occur in earthworks and how these can be allowed for in design and construction. These aspects had not been considered in the original investigations and design. This resulted in much greater degradation of the fill materials than expected during construction, pollution of surface waters and the tragic deaths of four site personnel. The lessons learned in understanding the impact of geochemistry at Carsington were fundamental in further work by the authors in developing improved test methods for sulphur compounds and protocols for assessing their impact. The relevance of these lessons for civil engineering works remains as great as ever. Seven general principles for dealing with geochemical issues are presented.
Prior to planting, the soil must be prepared usually by machines called cultivators. Older field cultivators are suitable for modification for row cropping. The crops and the tractor power available will determine specific needs. Factors to consider include row spacing and row spacing flexibility, whether you need a towed or tractor mounted unit, frame size and layout, ease of levelling, ease of moving, removing, and replacing shanks, overall machine condition, and the robustness of the shanks. The paper describes the struggle concerning the 3D modelling of such a field cultivator with special features.
Architectural engineering. Structural engineering of buildings, Engineering design
In this paper, effects of the defect in an adhesively bonded joint have been investigated using cohesive zone modeling. Consequently, a 3D finite element model of a single lap-joint is constructed and validated with experiments. Strength prediction of current model is found desirable. Accordingly, different sizes of square shape defects are imported to model in the form of changing (raised or degraded) material properties (heterogeneity) and locally delaminated areas (as inclusion/void), respectively. Joint strength is investigated and a stress analysis is carried out for adhesive layer and adherends. Obtained Results show that, defect has significant impact on the results. It is found that at constant size of defect, local delamination has more impact on bonded joint strength than the heterogeneity. Furthermore, stress analyses demonstrate that the stress field does not change in adherends by taking defects into account. However, stress values decrease with degraded material properties and joint’s strength. Through evaluation of peel and transverse shear stresses in adhesive layer it is found that there is a change of stress distribution for both types of defects. Whereas, there is a considerable stress concentration in the delaminated adhesive layer.
In the last few years, multi-cameras and LIDAR systems draw the attention of the mapping community. They have been deployed on different mobile mapping platforms. The different uses of these platforms, especially the UAVs, offered new applications and developments which require fast and accurate results. The successful calibration of such systems is a key factor to achieve accurate results and for the successful processing of the system measurements especially with the different types of measurements provided by the LIDAR and the cameras. The system calibration aims to estimate the geometric relationships between the different system components. A number of applications require the systems be ready for operation in a short time especially for disasters monitoring applications. Also, many of the present system calibration techniques are constrained with the need of special arrangements in labs for the calibration procedures. In this paper, a new technique for calibration of integrated LIDAR and multi-cameras systems is presented. The new proposed technique offers a calibration solution that overcomes the need for special labs for standard calibration procedures. In the proposed technique, 3D reconstruction of automatically detected and matched image points is used to generate a sparse images-driven point cloud then, a registration between the LIDAR generated 3D point cloud and the images-driven 3D point takes place to estimate the geometric relationships between the cameras and the LIDAR.. In the presented technique a simple 3D artificial target is used to simplify the lab requirements for the calibration procedure. The used target is composed of three intersected plates. The choice of such target geometry was to ensure enough conditions for the convergence of registration between the constructed 3D point clouds from the two systems. The achieved results of the proposed approach prove its ability to provide an adequate and fully automated calibration without sophisticated calibration arrangement requirements. The proposed technique introduces high potential for system calibration for many applications especially those with critical logistic and time constraints such as in disaster monitoring applications.