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Suction bucket jackets are increasingly being used to support bottom-fixed offshore wind turbines. It is generally assumed that contact between the underside of the bucket lid and the seabed is mandatory to safeguard against additional settlement. Lid contact is usually ensured by underwater grout injection, albeit this has a significant impact on the duration and costs of installation. Although grouting is routine, there are limited available data regarding the benefits of ensuring contact between the lid and the soil. This paper presents data from centrifuge tests of completely and partially installed buckets in dense sand subjected to vertical cyclic loading to investigate the role of lid contact. Lid contact was shown to have a discernible effect on displacement accumulation when buckets were loaded beyond the drained skirt capacity in compression. Under these conditions, settlement of a completely installed bucket was limited by lid contact with the soil plug, while partially installed buckets experienced continuous settlement, as expected. The physical evidence indicates complex load transfer mechanisms that are influenced significantly by the drainage conditions. Hence, an understanding of the soil drainage characteristics at a particular site would provide value when evaluating the requirement for under-lid grouting. [ABSTRACT FROM AUTHOR]

Network flow measurement is an integral part of modern high-speed applications for network security and data-stream processing. However, processing at line rate while maintaining the required data structure within the on-chip memory of the hardware platform is a challenging task for measurement algorithms, especially when accuracy is of primary importance, such as in network security applications. Most of the existing measurement algorithms are no exception to such issues when deployed in high-speed networking environments and are also not tailored for efficient hardware implementation. Sketch-based measurement algorithms minimize the memory requirement and are suitable for high-speed networks but possess a low memory-accuracy trade-off and lack the versatility of individual flow mapping. To address these challenges, we present a hardware-friendly data structure named Sketch-based Pseudo-associative array Architecture (SPArch). SPArch is highly accurate and extremely memory-efficient, making it suitable for network flow measurement and security applications. The parallelism in SPArch ensures minimal and constant memory access cycles. Unlike other sketch architectures, SPArch provides the functionality of individual flow mapping similar to associative arrays, and the optimized version of SPArch allows the organization of counters in multiple buckets based on the flow sizes. An in-depth analysis of SPArch is carried out in this article and implemented SPArch on the Alveo data center accelerator card, demonstrating its suitability for high-speed networks. [ABSTRACT FROM AUTHOR]

Pelton turbines functioning in sandy river environments often encounter difficulties due to the swift movement of sediment particles, leading to erosion and damage to overflow components. These challenges can result in operational instability, particularly noticeable in large turbines. Pressure pulsation is crucial for turbine stability, and alterations in overflow component profiles caused by sediment erosion can worsen pressure pulsations. This study utilizes numerical simulations to analyze turbine pressure pulsations based on surface profile changes of runner buckets after 2 and 4 years of sediment erosion in a single 500 MW large‐scale Pelton turbine. Our findings reveal that erosion leads to a gradual decrease in pressure pulsation along the bucket's splitting edge from the notch to the root. After 4 years of erosion and wear, the relative pressure pulsation amplitude in the root region increased by more than 530%. Additionally, changes occur in the thickness of the water film in the erosion area on the working surface, disrupting the flow pattern and generating more vortices. This occurrence intensifies the relative pressure pulsation amplitude and reduces bucket stability. The study findings highlight the significant impact of sediment erosion on Pelton turbine pressure pulsation, posing a considerable risk to the unit's operational stability and safety. [ABSTRACT FROM AUTHOR]

The performance of sorting algorithms has a great impact on many computationally intensive applications. Researchers worked on parallelizing many sorting algorithms on various interconnection networks to improve their sequential counterpart performance. One of these interconnection networks is the optical chained-cubic tree (OCCT). In this paper, a parallel bucket sort (PBS) algorithm is presented and applied to the OCCT interconnection network. This PBS algorithm is evaluated analytically and by simulation in terms of various performance metrics including parallel runtime, computation time, communication time, concatenation time, speedup and efficiency, for a different number of processors, dataset sizes and data distributions including random and descending distributions. Simulation results show that the highest obtained speedup is approximately 912x on OCCT using 1020 processors, which means that the parallel runtime of the PBS on 1020 processors is 912 times faster than the sequential runtime of BS on a single processor. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In large mobile equipment in seismically active regions, seismic stability is often a decisive design criterion, and the behaviour of this large equipment, which is characterised by uplift, tilting and rocking, can only be calculated by means of nonlinear time history analyses. Here, the model damping approach has a significant influence on the results of these analyses but there are no scientific approaches for large mobile equipment with nonlinear behaviour such as uplift. In this paper, possible theoretical damping approaches for nonlinear time history analysis of structures with uplift such as large mobile equipment are discussed and numerical studies are conducted to investigate the influence of damping in the model on the concise results of the typical behaviour of large mobile equipment under seismic excitation. A suitable new approach is to be developed and a way of practical implementation is being prepared. Experimental studies on real typical bucket wheel machines will identify and validate important natural frequencies and associated damping for the numerical approach. These can be applied in numerical models using the damping approach engineered in the theoretical part. Thus, realistic results of the numerical models under nonlinear seismic time history analyses can be expected and more precise conclusions on the distinctive behaviour of large mobile equipment with uplift can be drawn. [ABSTRACT FROM AUTHOR]

Motivation Many tasks in sequence analysis ask to identify biologically related sequences in a large set. The edit distance, being a sensible model for both evolution and sequencing error, is widely used in these tasks as a measure. The resulting computational problem—to recognize all pairs of sequences within a small edit distance—turns out to be exceedingly difficult, since the edit distance is known to be notoriously expensive to compute and that all-versus-all comparison is simply not acceptable with millions or billions of sequences. Among many attempts, we recently proposed the locality-sensitive bucketing (LSB) functions to meet this challenge. Formally, a (d 1 , d 2) -LSB function sends sequences into multiple buckets with the guarantee that pairs of sequences of edit distance at most d 1 can be found within a same bucket while those of edit distance at least d 2 do not share any. LSB functions generalize the locality-sensitive hashing (LSH) functions and admit favorable properties, with a notable highlight being that optimal LSB functions for certain (d 1 , d 2) exist. LSB functions hold the potential of solving above problems optimally, but the existence of LSB functions for more general (d 1 , d 2) remains unclear, let alone constructing them for practical use. Results In this work, we aim to utilize machine learning techniques to train LSB functions. With the development of a novel loss function and insights in the neural network structures that can potentially extend beyond this specific task, we obtained LSB functions that exhibit nearly perfect accuracy for certain (d 1 , d 2) ⁠ , matching our theoretical results, and high accuracy for many others. Comparing to the state-of-the-art LSH method Order Min Hash, the trained LSB functions achieve a 2- to 5-fold improvement on the sensitivity of recognizing similar sequences. An experiment on analyzing erroneous cell barcode data is also included to demonstrate the application of the trained LSB functions. Availability and implementation The code for the training process and the structure of trained models are freely available at https://github.com/Shao-Group/lsb-learn. [ABSTRACT FROM AUTHOR]

To address the issue of seepage and soil plugging during the sinking of mono-column composite bucket foundations (MCCBFs), experiments were conducted on the installation of foundations under a variety of complex geological conditions. The effect of negative pressure sinking mode on the foundation's seepage field was analyzed, the formation mechanism of soil plugging in sand was explained, and an efficient method for calculating the height of soil plugging was proposed in conjunction with these investigations. The findings demonstrate that the finite element method simulation of the soil's seepage field is the most accurate, that the pumping volume of the foundation during sinking through is high, that the formation of the soil plug height is high, and that clear depressions can be seen on the foundation manifold's exterior. The equation presented in this study makes it easier to forecast the height of a foundation plug and can offer direction for engineering design. [ABSTRACT FROM AUTHOR]

In driverless formula car racing, cone detection faces two significant challenges: one is recognizing cones at long distances accurately, and the other is being prone to leakage under bright light conditions. These challenges directly affect the detection accuracy and response speed. In order to cope with these problems, the thesis is based on YOLOv8s to improve the cone bucket detection algorithm. Firstly, a P2 detection layer for detecting tiny objects is added on top of YOLOv8s to detect small targets with 160 × 160 pixels, which improves the detection of small conical buckets in the distant view. At the same time, to reduce the network's complexity to achieve lightweightness, the original 20 × 20 pixel detection header is deleted. Second, the head of the original YOLOv8 is replaced with a multi-scale fusion Dynamic Head, designed to improve the head's ability in scale, space, and task perception to enhance the detection performance of the model in complex scenes. Again, a novel loss function, MPDIoU, is introduced, which has advantages in simplifying the bounding box similarity comparison, and it can adapt to the overlapping or non-overlapping situation of the bounding box more effectively. It reduces the phenomenon of missed detection caused by overlapping conical buckets. Finally, the LAMP pruning method is used to trim the model to make the model lightweight. By adding and modifying the above modules, the improved algorithm improves the detection accuracy from 92.2% to 95.2%, the recall rate from 84.2% to 91.8%, and the average accuracy from 91.3% to 96%, while the number of parameters is reduced from 28.7 M to 26.6 M. The detection speed still meets the real-time requirement in real-vehicle testing compared to the original algorithm. In the real car test, compared with the original algorithm, the improved algorithm shows apparent advantages in reducing the missed detection of cones and barrels, which meets the demand for high accuracy of cones and barrel detection in the complex race environment and also meets the conditions for deployment on small devices with limited resources. [ABSTRACT FROM AUTHOR]

It is controversial which idioms can occur with which syntactic structures. For example, can Mary kicked the bucket (figurative meaning: 'Mary died') be passivized to The bucket was kicked by Mary ? We present a series of experiments in which we test which structures are compatible with which idioms in German (for which there are few experimental data so far) and English, using acceptability judgments. For some of the tested structures – including German left dislocation, scrambling, and prefield fronting – it is particularly contested to what extent they are restricted by semantic factors and, as a consequence, to what extent they are compatible with idioms. In our data, these structures consistently showed similar limitations: they were fully compatible with one subset of our test idioms (those categorized as semantically compositional) and degraded with another (those categorized as non-compositional). Our findings only partly align with previously proposed hierarchies of structures with respect to their compatibility with idioms. [ABSTRACT FROM AUTHOR]

This study presents the structure and principles of operation of the control system for a bucket conveyor operating in a jig preparation plant. The idea of controlling the conveyor speed is to maintain constant, nominal filling of the buckets, and thus achieve a constant mass of material on the conveyor. As part of the completed task, a new control algorithm was developed and implemented to increase transport efficiency. Simulation and industrial test results were analyzed, in which the traditional PID controller was replaced with a fuzzy controller, which enabled control error reduction, thus achieving better control quality. [ABSTRACT FROM AUTHOR]

To enhance the safety of the in-water sinking operation for an integrated system, including a bucket foundation (BF), tower, and rotor nacelle assembly (RNA), in complex marine environmental conditions, a model test of in-water sinking for an offshore wind turbine and bucket foundation (OWT–BF) is conducted. The motion behavior of the OWT–BF and the sling tensions during the in-water sinking process are investigated, and the numerical method is validated through test results. The results demonstrate a positive correlation between the wave height and motion response of the OWT–BF. The most critical stage of the in-water sinking operation occurs when the top cover of the bucket is fully submerged, resulting from the substantial cross-sectional difference between the bucket base and the transition section. Furthermore, the closer the OWT–BF is to the seabed, the less it is affected by waves in terms of motion response. It is advisable to conduct the in-water sinking operation of the OWT–BF in sea states with wave heights below 1.5 m. Simultaneously, slings can efficiently control the motion response of the OWT–BF, thereby enhancing the safety of the sinking operation. [ABSTRACT FROM AUTHOR]

The suction bucket jacket foundation is widely regarded as a crucial solution for constructing offshore wind farms in water depths ranging from 30 m to 50 m. When subjected to complex loads, the bucket primarily relies on vertical movement to withstand the corresponding loads. This paper investigates the undrained pullout characteristics of the bucket foundation through numerical simulation while keeping its weight constant. This study examined how the pullout capacity of the suction bucket jacket foundation is affected by the aspect ratio and soil conditions. It revealed the changing patterns of bucket–soil frictional resistance and suction during the undrained pullout process, along with their contributions to the pullout capacity of the foundation. The results indicate that the peak pullout load of the bucket increases with decreasing L/D, and the response is more pronounced in soft clay. The frictional resistance changes from upward to downward with increasing displacement, with the maximum frictional resistance occurring at the base of the foundation. The lower part of the footing has a faster response. The suction force increases with displacement, and the proportion of suction force to peak pullout tends to increase as L/D decreases. The soil failure displacement corresponding to the occurrence of the peak pullout load of the foundation lags behind the displacement at which the frictional resistance of the bucket wall stabilizes. [ABSTRACT FROM AUTHOR]

This work studies a two-stage hybrid flowshop problem with secondary resources (workers). The goal is to minimise the average tardiness. The workers are assigned to the workstations by time buckets (work shifts), and the assignment changes during the planning horizon. Two versions of the problem are studied: (i) the case where the average efficiency of the workers determines the time to process jobs; (ii) the case where the efficiency of the slowest worker assigned to a workstation determines the time to process jobs. The problem is NP hard and a set of heuristics are proposed to generate job sequences and worker assignments. Computational experiments are performed on randomly generated test problems. The experiments revealed that the proposed heuristics are able to find a large percentage of the optimal solutions for small sized instances, while on large sized instances the heuristic performance depended on experimental factors. [ABSTRACT FROM AUTHOR]

In this study, the raw material for the empty bucket wall consists of Dalun bricks unique to South Zhejiang. The investigation focuses on the changes in compressive properties of the empty bucket wall with masonry mortar strength grades of M 2.5, M 5.0, M 7.5, and M 10.0 after a designated period of maintenance in both dry and wet environments. Following this, the empty bucket wall undergoes reinforcement, and the compressive properties are studied. The ensuing comparisons yield pertinent conclusions. Unreinforced walls maintained with varying mortar strengths in a wet environment exhibit reduced cracking loads by 5.8 to 30% and damage loads by 5.6 to 10.8% compared to their counterparts in a dry environment. Reinforced walls, maintained with different mortar strengths in wet environments, show reduced cracking loads by 6.2% to 36% and damage loads by 2.5% to 5.7% compared to those in dry environments. The stress–strain curves of unreinforced and reinforced barrel walls of various strength classes are obtained by fitting the test stress–strain data to the stress–strain data derived from corresponding model equations. These stress–strain curves for unreinforced and reinforced walls align well with the model curves, affirming the precision of the tests. [ABSTRACT FROM AUTHOR]

Airport terminal buildings are large public transportation buildings with complex functions and dense crowds, and the wind environment has significant effects on passenger comfort and the energy consumption of air conditioning systems. In this study, we investigated Xianyang T3 Terminal as an example and used the Phoenics software to conduct comprehensive simulations based on different door bucket forms and parameters, as well as comprehensively considering the impacts of different outdoor wind environments. A terminal door bucket windproof design strategy was proposed based on our results. The results showed that door buckets could effectively reduce the entry of outdoor wind, and built-in door buckets performed the best. The width of the door bucket should be set to 9.3–11.3 m and the depth of the door bucket to 6.7–7.7 m. The height of the door bucket had little impact. A side door should be added to the door bucket, so it can be opened when the outdoor wind speed is high, and a mechanical ventilation system should be introduced to improve the indoor ventilation. [ABSTRACT FROM AUTHOR]

The suction bucket foundation is a non-penetrating shallow foundation with a large diameter and small height, usually sinking by suction, which is more suitable for deep sea areas than traditional mono-piles. The construction of suction bucket foundation has a strict requirement for structural stability and levelness, which make the sinking process complex. So it is necessary to study its control method and leveling strategy further. Relying on the installation and construction project of three-bucket suction bucket foundation in Changle offshore area, this paper analyzes and studies the attitude control process and its control technology and algorithm during suction penetration using the PID control of frequency converter. Based on automatic and manual leveling control processes, combined with the requirements of the bucket penetration depth and the pressure difference limits, an overall control system and on -site construction methods were designed in order to ensure the safety and accuracy of the construction. [ABSTRACT FROM AUTHOR]

A single radio frequency bucket of the 88-Inch Cyclotron is filled using a fast chopper located in the axial line. The bucket then accelerates until it reaches the deflector, at which point, it is extracted as a train of bunches. This phenomenon can be attributed to the characteristic multi-turn extraction of the cyclotron and, by simplifying the complex dynamics of a cyclotron, corresponds to the conceptual transfer function of the cyclotron. The confirmation of the single radio frequency bucket injection was achieved by operating the cyclotron in the third harmonic mode and observing the absence of intermediate bunches during the multiple-bunch extraction. [ABSTRACT FROM AUTHOR]

Bucket foundations are circular surface foundations with thin skirts around the circumference. They have been successfully installed using economical suction or vibratory methods. Large-diameter buckets, up to 22 m, have been successfully deployed. In offshore wind power applications, bucket foundations are commonly configured in a tripod arrangement for fixed foundation wind turbines. While bucket foundations may be subjected to complex conditions of combined loading, this study presents an in-depth focus on a single loading mode: vertical compression. This study presents a finite element investigation of the performance and vertical load capacity of skirt foundations installed in the sand and subjected to vertical load passing through the bucket center. To take advantage of symmetry for problem geometry and applied load, an extensive parametric study was performed in this research utilizing an axisymmetric (two-dimensional) finite-element analysis employing the non-associated flow rule of the Mohr-Coulomb soil model. Comparisons to previously published 3D FE and experimental studies showed good agreement. The results showed that the pure vertical capacity of the bucket foundation significantly depends on skirt diameter D, aspect depth ratio (L/D), and relative density Dr. This research introduced simple design charts relating the vertical bearing capacity of skirted foundations to aspect ratio, diameter, and relative density. [ABSTRACT FROM AUTHOR]

Suction bucket installation in pure clay or pure sand is well established. However, in layered soils, particularly in sand over clay soils, the soil plug uplift is considered a major installation risk and feasibility of installation is often questioned. In this paper, the experience from installation of two suction bucket jackets at two offshore wind farms in layered soils is reported. The installation at both sites was successful and no excess plug uplift was observed. The transfer of suction to the clay-sand interface is believed to have contributed to the success of the installations. The two cases presented in this paper provides confidence in suction bucket foundation installation in similar soil conditions. [ABSTRACT FROM AUTHOR]

In recent years, multi-bucket foundations have been studied and gradually adopted in engineering practices as a novel foundation for offshore wind turbines within a range of water depth of 30 to 50 m. This study investigated the motion characteristics of air-floating tripod bucket foundation (AFTBF) through a series of experiments during free air-floating. The experimental results show that the surge force appears to be the most important factor influencing pitch moment and motion, whether it is a change in water depth or a draft for AFTBF. The maximum amplitudes of surge acceleration and pitch angle show a trend of increasing with narrower spacing and decreasing with wider spacing, while the heave acceleration shows an opposite trend. The added mass and damping of heave motion for AFTBF increase with shallower water due to the increasing pressure difference between the inside and bottom of bucket foundation. The shallower the water depth and the larger the draft, the longer the resonance period of heave. [ABSTRACT FROM AUTHOR]

Bucket elevators generally operate on a 24/7 basis, and for this reason, one of the main requirements is their high reliability. This reliability can be ensured, among other things, by assessing the technical condition of drive assemblies and working assemblies and taking appropriate measures. Carrying out diagnostic measurements enables periodical monitoring of those mechanisms. Vibroacoustic methods are usually employed in operating conditions to measure vibration velocity and acceleration at specific points, and are used as diagnostic signals. This paper presents the results of tests of the intensity of vibrations generated in the drive unit of a large industrial bucket elevator. The analysis of the results in the time domain and frequency domain served as the basis for evaluating the suitability of the drive, and thus the elevator, for long-term operation. [ABSTRACT FROM AUTHOR]

Efficient energy conversion can improve Pelton turbine unit efficiency and bring higher economic benefits. However, the reasons that influence the energy conversion characteristics of the Pelton turbine have not been effectively revealed. The main reason is the lack of systematic research on the change process of flow patterns in the bucket and its relationship with the energy conversion characteristics. Experimental and numerical simulation studies of a Pelton turbine were conducted. The change process of the flow patterns from when the jet enters the bucket to when it is completely discharged is analyzed and three main flow patterns in the buckets are summarized. Through energy characteristic analysis, it was found that during the power change process of the bucket, the flow rate entering the bucket and the velocity moment at the inlet of the bucket shows a trend of first increasing and then decreasing, while the velocity moment at the outlet of the bucket and flow loss show an opposite trend, resulting in the most sufficient energy conversion when the jet is perpendicular to the bucket. The basic topology of the bucket energy conversion process is constructed to effectively understand the Pelton turbine's energy conversion characteristics. [ABSTRACT FROM AUTHOR]

Bucket foundations, as an innovative type of offshore wind turbine foundation, have been widely adopted for their cost competitiveness and time effectiveness in construction and installation. For a successful installation, the penetration process prediction is crucial. This paper investigates the penetration process of both thin-walled and thick-walled bucket foundations in silty clay through small-scale experiments. Based on the experimental results, empirical formulas of penetration resistance are modified. Next, a Coupled Eulerian-Lagrangian (CEL) numerical method is validated and used to simulate the sinking process of engineering prototypes. The penetration resistance obtained by the calculated and numerical methods is in good agreement. Additionally, through the 3D CEL analysis, the disturbance of bulkheads and skirts on soil plugs is gained. The Eulerian volume fraction shows that the soil surface within the outer compartments is prone to rise to form a soil plug, which will bring out a sudden sharp increase in the penetration resistance due to the contact of lid and soil, and consequently affect the ultimate installation depth. [ABSTRACT FROM AUTHOR]

Bucket foundations, especially multi-bucket foundations, have become an alternative for large offshore wind turbines. Vertical responses of a single bucket are critical for the serviceability design of tripod or tetrapod bucket foundations. Centrifuge tests are conducted to investigate the responses of a single bucket under monotonic and symmetric cyclic loading in over-consolidated clay. The strength of clay is obtained by cone penetration tests. The monotonic vertical capacity measured in the centrifuge tests are compared with the finite element results, with errors less than 6%. The effects of the ratio of cyclic loading amplitude to vertical capacity (ranging between 0.37 and 0.64) and the number of cycles on the accumulation of vertical displacement and evolution of stiffness are explored. Simplified functions are proposed to predict the evolutions of dimensional and dimensionless stiffness. [ABSTRACT FROM AUTHOR]

Published studies on agile effort estimation predominantly focus on comparisons of the accuracy of different estimation methods, while efficiency comparisons, i.e. how much time the estimation methods consume was not in the forefront. However, for practical use in software development, the time required can be a very important cost factor for enterprises, especially when the accuracy of different agile effort estimations is similar. In this study, we thus try to advance the current standard accuracy comparison between methods by introducing efficiency, i.e. time it takes to use a method as an additional dimension of comparison. We conduct this comparison between three agile effort estimation methods that were not yet compared in the literature, namely, Planning Poker, Bucket System and Affinity Estimation. For the comparison, we used eight student teams with 29 students who had to use all the effort estimation methods during the course where they had to finish a programming project in 3 weeks. The results indicate that after the students get used to using the different methods the accuracy between them is not statistically significantly different, however, the efficiency is. On average, Bucket System and Affinity Estimation methods take half as much time as Planning Poker. [ABSTRACT FROM AUTHOR]

In this study, a dynamic–discrete element-finite element coupling method is proposed to investigate the influence of structural parameters on the excavation performance and stress deformation of the bucket. The main research work is as follows: through ADAMS-EDEM co-simulation of the digging process of the bucket, the digging resistance and the loose force of each part of the bucket are obtained. The influence law of the change of the structural parameters of the excavator bucket on the digging resistance, filling rate and energy consumption is revealed. Through the coupling simulation of EDEM-ANSYS, the loose force is introduced into the finite element model of the bucket to enable the coupling of ADAMS-EDEM-ANSYS. The influence of the change of the bucket structure parameters on the stress and deformation of the bucket components is explored. The results show that the cutting angle and angle of throat of the bucket has a major influence on the digging performance of the bucket. While the angle of the throat and the thickness of the ear plate have a minor influence on the digging performance of the bucket. In the process of excavation, the teeth of the bucket are subjected to the largest digging resistance, resulting in relatively large deformation. All of the components of the bucket are subjected to different degrees of excavation resistance, but the stress concentration at the ear plate is the most obvious. The deformation and stress of the whole bucket can be reduced, to some extent, by reducing the thickness of the ear plate along with increasing the thickness of the stiffening plate. The results can be used to improve the digging performance of the bucket and reduce the stress and deformation of the bucket. [ABSTRACT FROM AUTHOR]

As a component directly in contact with materials in the excavation process of the excavator, the structure and performance of the bucket directly affect the efficiency of the excavator. With the increasingly prominent environmental and energy problems, it has become a research difficulty to optimize the bucket structure of excavators so as to reduce the digging resistance and energy consumption of excavators. Therefore, an orthogonal optimization method of bucket structure that couples Adams with EDEM was proposed to explore the excavation performance of buckets with different structures under different geological conditions. The particle size distribution and mass proportion of various ores under different geological conditions were obtained through geological investigation, and particle models with different shapes and sizes were constructed. The friction coefficient and collision recovery coefficient between bucket and ore and between ore and ore were measured using a self-made testing device. The results show that the excavation resistance of the bucket teeth during the excavation process is much greater than that of other components, and optimizing the bucket structure can effectively reduce the excavation resistance of the bucket teeth. Under different geological conditions, the optimization parameter combinations of bucket structure obtained through orthogonal experiments are different. In addition, after structural optimization, the excavation resistance and energy consumption of the bucket were reduced, and the filling rate was also improved. [ABSTRACT FROM AUTHOR]

Bucket wheel reclaimer is the core equipment of dry bulk port. It is of great significance to realize the unmanned intelligent operation of bucket wheel reclaimer for the construction of intelligent port. In this paper, an unmanned intelligent reclaiming system for bucket wheel reclaimer was proposed. By adding various sensors to perceive the surrounding working environment of bucket wheel reclaimer, and designing intelligent reclaiming production process flow, the unmanned intelligent operation of bucket wheel reclaimer was realized, and it is successfully applied in coal port project, and the material reclaiming flow is more stable compared to manual operations. The system solves the problems of poor manual operation environment and unstable manual operation of bucket wheel reclaimer. It has strong feasibility and operability, and provides reference for unmanned control of bucket wheel reclaimer in dry bulk port. [ABSTRACT FROM AUTHOR]

A composite bucket foundation (CBF) is a new foundation type of offshore wind turbine. The investigation of the bearing characteristic of CBF is a crucial part of the structural design and safety assessment of offshore wind turbines. This study investigates the bearing characteristic of CBF in sand and clay foundations using centrifuge model test and numerical simulation. Analysis revealed that as load increases, the rotation center of the CBF moves toward the central line and shallow area. The buried depth of the CBF rotation center in a clay foundation is shallower than in a sand foundation when the CBF is under ultimate loading. Due to the rotation and translation of CBF, the soil pressure–depth curves on the skirt wall in different directions will resemble parabolic, line, and triangle shapes, respectively. Under ultimate loading, the relationship between the depth and horizontal coordinate of the rotation center and embedment ratio is linear. The CBF's bearing capacity trend presents quadratic function characteristics as the embedment ratio increases. However, the bearing capacity ratio of the CBF in the clay foundation is faster than that in the sand foundation. The findings provide guidelines for offshore wind turbines. [ABSTRACT FROM AUTHOR]

The energy performance and efficiency of Pelton turbine units is the focus of attention in engineering. The countertorque of the bucket during the operation of the Pelton turbine will affect the above indicators of the unit. However, there is still a lack of systematic research on the generation mechanism of countertorque and control strategies. Numerical simulation and experimental research were conducted on a Pelton turbine. It was found that the countertorque of the bucket is generated during the initial contact stage between the jet and the suction surface of the bucket. At this time, the jet acts on the tip of the suction surface of the bucket, generating a force in the opposite direction of the bucket's rotation, resulting in the generation of countertorque. A geometric optimization method is proposed, which suppresses the countertorque by controlling the inclination angle of the bucket. As the inclination angle decreases, the countertorque, pressure, circumferential force, and entropy production rate of the bucket are effectively controlled. Compared to the original scheme, the optimal scheme reduces the maximum countertorque by 49.33% and improves the unit efficiency by 0.57%. [ABSTRACT FROM AUTHOR]

A monopod bucket foundation supporting an offshore wind turbine structure is subjected to lateral loading on account of combined wind and wave action, in addition to vertical loading from the self-weight of the turbine structure. In this numerical study, the bearing behavior of the bucket foundation in medium dense and very dense sands is investigated for varying bucket geometries, superstructure loads, and lateral loading cases. The nonlinear stress–strain response of the sandy soil is incorporated. The results of the modeling are described and evaluated in terms of the variations of displacement and rotation responses, ultimate and allowable lateral load capacities, depths of rotation center, surrounding soil deformation, and failure mechanisms. Interaction diagrams between lateral load capacity and resisting moment capacity for various limit states are presented, and their differences are brought out. As the design is dominated by requirements resulting from serviceability limit state, predictive expressions are proposed for the depth of rotation center, initial stiffness, and allowable lateral load capacity to serve as preliminary design guidelines for a monopod bucket foundation in sandy soils. The expressions are suitable for interpolation within the range of realistic parameters considered in the study. [ABSTRACT FROM AUTHOR]

In order to address the problems associated with low detection accuracy, weak detection ability of small targets, insufficiently obvious differentiation of colors, and inability to accurately locate the actual position of the target object in the Formula Student Autonomous China, the YOLOv5s algorithm is improved by adding coordinate attention, modifying the color space transformation module, and adding a normalized Gaussian Wasserstein distance module and a monocular camera distance measurement module. Finally, it is experimentally verified that by adding and modifying the above modules, the YOLOv5s algorithm's precision is improved by 6.9%, recall by 4.4%, and mean average precision by 4.9%; although the detection frame rate decreases, it still meets the requirement. Monocular camera distance measurement has a maximum error of 5.64% within 20 m in the Z-direction and 5.33% in the X-direction. [ABSTRACT FROM AUTHOR]

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Determining how to apply hydrogen as a therapeutic/preventive antioxidant for oxidative-stress-related diseases practically in daily life has not been studied. The effects of bathtubs and buckets filled with hydrogen water (41 °C, >10 min bathing) were investigated on six subjects, without a medical prescription, suffering from skin roughness on the foot, hand, finger, or elbow. They were also treated with an electrolyzer composed of a lattice-shaped, microscopically flat, platinum-plated three-layer electrode, except for one subject who was treated with a micro-porous emittance terminal hydrogen-jetting apparatus, resulting in improvements in both cases. For another subject with similar skin roughness on both hands, immersing the right hand in an electrolytically generated hydrogen water bucket showed more marked improvement than immersing the left hand in a bucket with normal water. The nano-bubbles (average, mode, and median sizes of 157 nm, 136 nm, and 94 nm, respectively) increased 3.79 fold to 2.20 × 108/mL after 30 min electrolysis with 2 L of tap water and were boiling (98 °C, 2 min)-resistant, with heat stability in nano-bubbles as small as 69–101 nm, as evaluated by laser-beam-based Brownian movement trailing Nano-Sight analysis. The marked increase in nano-bubbles caused by electrolysis correlated with an increase in dissolved hydrogen (<15 μg/L to 527 μg/L) but not a decrease in dissolved oxygen (9.45 mg/L to 6.94 mg/L). Thus, the present study proposed the novelty of hydrogen regarding its contribution to health from the perspective that hydrogen-nano-bubble-rich water in a foot bucket, which was additively used together with a conventional bathtub and can be frequently used in daily life, improved diverse types of skin roughness. [ABSTRACT FROM AUTHOR]

The development of autonomous detection technology is imperative in the field of construction. The bucket fill factor is one of the main indicators for evaluating the productivity of construction vehicles. Bucket detection is a prerequisite for bucket trajectory planning. However, previous studies have been conducted under ideal environments, a specific single environment, and several normal environments without considering the actual harsh environments at construction sites. Therefore, seven extreme environments are set in this paper to fill this gap, and an effective method is proposed. First, a novel framework for image restoration under extreme environments is proposed. It applies to all tasks conducted by vision on construction sites. Second, a combination of segmentation and classification networks is used for the first time in this area. Multitask learning is used to discover a positive correlation between fill factor estimation and bucket detection. Furthermore, probabilistic methods and transfer learning were introduced, and excellent results were achieved (97.40% accuracy in fill factor estimation and 99.76% accuracy in bucket detection for seven extreme environments). [ABSTRACT FROM AUTHOR]

Real-time and accurate bucket pose estimation plays a vital role in improving the intelligence level of mining excavators, as the bucket is a crucial component of the excavator. Existing methods for bucket pose estimation are realized by installing multiple non-visual sensors. However, these sensors suffer from cumulative errors caused by loose connections and short service lives caused by strong vibrations. In this paper, we propose a method for bucket pose estimation based on deep neural network and registration to solve the large registration error problem caused by occlusion. Specifically, we optimize the Point Transformer network for bucket point cloud semantic segmentation, significantly improving the segmentation accuracy. We employ point cloud preprocessing and continuous frame registration to reduce the registration distance and accelerate the Fast Iterative Closest Point algorithm, enabling real-time pose estimation. By achieving precise semantic segmentation and faster registration, we effectively address the problem of intermittent pose estimation caused by occlusion. We collected our own dataset for training and testing, and the experimental results are compared with other relevant studies, validating the accuracy and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, a new type of combined wind-wave system is proposed, that is, composite bucket foundation-oscillating buoy (CBF-OB) combined device. A three-dimensional numerical wave flume is established by using the renormalization group k–ε model. The hydrodynamic characteristics around the wave and the combined power generation device are studied. The relationship between wave parameters and wave run-up and wave pressure is analyzed. The absorption efficiency performance of the combined power generation device is evaluated. The results show that in the combined power generation system, the wave run-up and wave pressure at 0°–135° around the CBF are smaller than those in the presence of only CBF, but near 180° the ones are larger than those in the presence of only CBF. In the rear side of the combined power generation system, the smaller the scattering parameters, the more obvious the phenomenon of the second wave peak, and the stronger the nonlinearity of the wave and CBF-OB combined power generation system. The proposed CBF-OB combined power generation device can significantly improve the absorption efficiency of the buoy, which can be increased by about 1.5–4.0 times compared with the absorption efficiency under the action of only the buoy alone. There is an optimal power takeoff parameter, that is, when the damping parameter is 500 N·s/m, to maximize the absorption efficiency of the combined power generation device. [ABSTRACT FROM AUTHOR]

Based on a series of physical model tests and numerical simulations, the bearing characteristics of a tripod-bucket foundation are investigated. It is found that with the decrease in aspect ratio (L/D), the rotation center of the foundation will decrease, and the displacement model change from rotation to uplift. Characteristics of earth pressure on the buckets from both finite element analysis and model tests are studied, which is used to explain the failure mechanism for tripod-bucket foundations with different L/D. A revised method is proposed to estimate the moment bearing capacity of the tripod bucket foundation under horizontal and moment load. This method is thought to be more convenient and applicable in the practice. [ABSTRACT FROM AUTHOR]

Background: Many bioinformatics applications involve bucketing a set of sequences where each sequence is allowed to be assigned into multiple buckets. To achieve both high sensitivity and precision, bucketing methods are desired to assign similar sequences into the same bucket while assigning dissimilar sequences into distinct buckets. Existing k-mer-based bucketing methods have been efficient in processing sequencing data with low error rates, but encounter much reduced sensitivity on data with high error rates. Locality-sensitive hashing (LSH) schemes are able to mitigate this issue through tolerating the edits in similar sequences, but state-of-the-art methods still have large gaps. Results: In this paper, we generalize the LSH function by allowing it to hash one sequence into multiple buckets. Formally, a bucketing function, which maps a sequence (of fixed length) into a subset of buckets, is defined to be (d 1 , d 2) -sensitive if any two sequences within an edit distance of d 1 are mapped into at least one shared bucket, and any two sequences with distance at least d 2 are mapped into disjoint subsets of buckets. We construct locality-sensitive bucketing (LSB) functions with a variety of values of (d 1 , d 2) and analyze their efficiency with respect to the total number of buckets needed as well as the number of buckets that a specific sequence is mapped to. We also prove lower bounds of these two parameters in different settings and show that some of our constructed LSB functions are optimal. Conclusion: These results lay the theoretical foundations for their practical use in analyzing sequences with high error rates while also providing insights for the hardness of designing ungapped LSH functions. [ABSTRACT FROM AUTHOR]

The mono-column composite bucket foundation has gained practical application in offshore wind power due to its advantages of simple fabrication, fast construction, and low cost. To ensure the safe and stable transportation of this structure to its designated sinking position, this study focuses on producing a scaled model of the mono-column composite bucket foundation. Through model testing, the floating characteristics of the structure during towing in regular waves are examined. The conclusion of the study is as follows: a significant towing force is required to provide the initial velocity of the structure. As the wave period and height increase, the structure necessitates a larger towing force, experiences greater pitch and heave responses, and exhibits more noticeable fluctuations in internal air pressure. The paper aims at providing practical engineering insights. [ABSTRACT FROM AUTHOR]

Torsional load arising from horizontal load eccentricity has a significant effect on the ultimate horizontal load carrying capacity of tripod bucket foundations in clay. In this paper, the effect of torsional load on the failure mechanism and ultimate horizontal capacity of tripod bucket foundations in undrained clay was studied using 3D finite-element analyses. Three single buckets were connected to form a rigid tripod bucket foundation system. Two different shear strength profiles, that is, uniform and linearly increasing with depth were considered. A detailed parametric study was conducted by varying the bucket spacing and embedment depth to explore the effects of different governing parameters. All the analyses were carried out for smooth and rough interface conditions. The influence of torsion on horizontal capacity is presented in the form of combined horizontal-torsional (H-T) failure envelopes. Reductions in ultimate horizontal capacity with increasing load eccentricity were quantified for the ease of practice. Finally, an expression for estimating combined H-T capacity is provided as a function of normalized spacing and embedment. Additional analyses were also performed to evaluate the effect of moment arising from vertical eccentricity on the combined H-T capacity. [ABSTRACT FROM AUTHOR]

As the suction bucket foundation is gradually applied, studying the bearing capacity of the suction bucket is particularly important for the safe operation of offshore wind power. This paper proposes a suction bucket foundation with added supports; the supports automatically extend outward through the middle pipe pile of the suction bucket to enhance its stability. The bearing characteristics of the proposed and traditional suction bucket foundations are compared. The deformation and instability characteristics of the enhanced bucket foundation under ultimate load are investigated by varying the support dimensions. The results show that the added supports can enhance the ultimate bearing capacity and the stability of the bucket foundation. When the support's diameter remained constant while the length of the supports increased linearly from 20 to 80 mm, the vertical and horizontal ultimate bearing capacities increased by 20–29%, and 25–34%, respectively. In the case of the bucket with increased support, when other parameters remained unchanged and the displacement at the top center of the bucket had increased, the rotation point will move to the center of the bottom plane of the bucket. Under the same central displacement of the bucket top, the foundation rotation point moved vertically downward relative to the bucket as the length of supports became longer. Under the sinusoidal horizontal cyclic load with an amplitude of 150 N, the traditional bucket foundation had a plastic failure, while the bucket with supports showed no plastic failure and little displacement. [ABSTRACT FROM AUTHOR]

Purpose: The research in this paper helps to understand the difference between the Eulerian method and the Lagrangian method in describing the performance of Pelton turbine buckets, so as to improve the design level and design efficiency of the runner. Design/methodology/approach: This paper used DualSPHysics to calculate the unsteady flow of the Pelton turbine runner bucket and compared it with the mesh-based method to explore the difference between mesh-based and particle-based methods in torque curves, jet flow patterns and pressure characteristics. Findings: It is noted that the particle-based method is challenging to compare with the mesh-based method concerning accuracy. In addition to better describing the free water film, the particle method also captures many droplets near the water film, but it cannot well describe the negative pressure region on the bucket back and the resulting jet interference after cutting off the jet. Compared with the mesh-based method, the pressure measurement points obtained by the particle-based method generally have shorter periods and violent fluctuations, and the pressure value of some points is underestimated. Originality/value: This paper helped to calculate the unsteady characteristics of the Pelton turbine by Fluent, CFX and DualSPHysics; exploration jet flow pattern differences between the mesh and meshfree methods; prediction of the flow interference between the bucket back and the jet and the pressure curve of SPH usually has a shorter period and violent fluctuations. [ABSTRACT FROM AUTHOR]