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Abstract In the existing domain adaptation-based bearing fault diagnosis methods, the data difference between the source domain and the target domain is not obvious. Besides, parameters of target domain feature extractor gradually approach that of source domain feature extractor to cheat discriminator which results in similar feature distribution of source domain and target domain. These issues make it difficult for the domain adaptation-based bearing fault diagnosis methods to achieve satisfactory performance. An unsupervised domain adaptive bearing fault diagnosis method based on maximum domain discrepancy (UDA-BFD-MDD) is proposed in this paper. In UDA-BFD-MDD, maximum domain discrepancy is exploited to maximize the feature difference between the source domain and target domain, while the output feature of target domain feature extractor can cheat the discriminator. The performance of UDA-BFD-MDD is verified through comprehensive experiments using the bearing dataset of Case Western Reserve University. The experimental results demonstrate that UDA-BFD-MDD is more stable during training process and can achieve higher accuracy rate.

This study focuses on monitoring the deformation of the shallow unsymmetrical section of a super-large-span tunnel portal relying on the newly built Shimentangshan Tunnel, and through numerical simulations, the construction sequence and drift ratios were optimized to address challenges related to the stability of surrounding rock and structure. The findings indicate that employing the double-side drift method results in a maximum settlement value of 107.0 mm and a maximum convergence value of 108.8 mm, leading to larger deformations. Excavating the shallow buried side first followed by the deep buried side proves beneficial for deformation control of the support structure and effectively limits damage to the surrounding rock. A drift ratio of 0.3 ensures optimal support structure security and stability. Considering both structural deformation and surrounding rock damage, a ratio between 0.25 and 0.35 for the drifts is recommended. Taking into account construction efficiency and economic benefits, a construction plan for the shallow buried unsymmetrical section at the portal of super-large-span tunnels is proposed.

Abstract The performance of zeolite membrane supports directly determines the synthesis performance and industrial application of zeolite membranes. In this study, a novel and high permeation SiC supports for NaA zeolite membrane were prepared by carrying out in situ reaction bonding at high temperature in the air atmosphere to coat the SiC particles with aluminum sol. The effects of process parameters on the formation of porous structure of SiC supports were systematically investigated, and the underlying mechanism was explored. During the sintering process, high-temperature Al2O3 from aluminum sol reacted with SiO2 generated by oxidation of the surface of SiC particles to form mullite, which exhibited excellent chemical stability and improved the mechanical properties and chemical stability of the supports. The porous SiC supports for zeolite membrane displayed obvious three-dimensional connected pore structure, with smooth inner surface of the pores and obvious connection neck between the particles. The porous SiC supports for zeolite membrane showed good in situ mullite bonding between the particles, and high permeability. It has a porosity of 36.3%, an average pore size of 1.42 µm and a bending strength of 32.4 MPa. All these figures indicate good comprehensive properties that are consistent with the rigorous requirements of zeolite membrane synthesis and industrial application.

The IEEE 802.1 time sensitive networking working group has recently standardized the time aware shaper (TAS). The TAS provides deterministic latency guarantees but requires tight time synchronization in all network switches. This paper thoroughly evaluates the mean and maximum packet delays and packet losses of the TAS for a typical industrial control ring network for random (sporadic) and for periodic traffic. We propose and evaluate adaptive bandwidth sharing and adaptive slotted window mechanisms to make TAS adaptive to traffic fluctuations. This paper further evaluates the asynchronous traffic shaper (ATS), which has been proposed to provide low latency network service without the need for time synchronization in network nodes. Our evaluations indicate that TAS with proper configurations, e.g., accurate and precise gating schedules, generally achieves the specified latency bounds for both sporadic and periodic traffic. In contrast, ATS performs relatively well for sporadic traffic; but struggles for moderate to high loads of periodic traffic.

Abstract Wireless sensor nodes in wireless sensor networks are generally battery powered and it is usually hard to change their batteries. Therefore, energy saving has always been the basic critical problem of wireless sensor networks. In recent years, network coding has become a promising technology to improve network throughput, reduce transmission number, and save energy, which has great potential to solve the energy efficiency problem of wireless sensor networks. In addition, some network coding aware routings have been proposed. However, the network coding condition of existing network coding aware routings may experience the problem of false-coding effect in some scenarios, and usually neglect node energy, which greatly influences the energy efficiency performance. Therefore, existing network coding aware routings are not suitable for wireless sensor networks. This paper proposes network coding aware energy efficient routing (NAER) for wireless sensor networks. In NAER, universal network coding condition is presented and proved to avoid false-coding problem. Besides, combined with the coverage control and topology control mechanism at lower layer, cross layer coding opportunity discover mechanism is presented to increase coding opportunities. In addition, a network coding aware energy efficient routing metric (NERM) is presented, which takes coding opportunity, node energy, and link quality into account jointly. Simulation results demonstrate that NAER improves the accuracy of coding discovery mechanism, increases the number of coding opportunities, saves node’s energy consumption, and prolongs network lifetime.

Energy efficiency is a critical problem for wireless sensor networks. In past decades, network coding has been proved as a promising technology to reduce the number of transmissions, save energy, and improve network throughput, especially suitable for the wireless network that motivates the emergence of network coding aware routings. However, existing network coding aware routings have the failure decoding problem, because of defective network coding conditions. On the other hand, existing network coding aware routings usually consider the ideal traffic scheduling and neglect nodes' energy and load which are important to wireless sensor networks. Therefore, it is not appropriate to directly apply existing network coding aware routings in wireless sensor networks. Regarding the problems above problems, this paper proposes traffic-shaped network coding aware routing (TSCAR) for wireless sensor networks. In the TSCAR, a universal network coding condition is presented to solve the false decoding problem. And traffic shaping mechanism is proposed to shape the traffic of different flows to create more coding actions when coding opportunities exist. In addition, network calculus is used to analyze the delay of the TSCAR. Besides, a coding, load, and energy aware routing metrics are proposed to evaluate the discovered paths. Extensive simulation results demonstrate that the TSCAR increases the number of coding opportunities and the proportion of coded packets, improves network throughput, and extends the network lifetime of wireless sensor networks.

Network coding–based routing has been widely considered as a promising technology to improve the network throughput of wireless multihop network. However, existing network coding aware routings have the problem of failure decoding and usually neglect the transmission scheduling, which degrades the gain of network coding. In this article, a common network coding condition and traffic matching supported network coding aware routing is proposed for wireless multihop network. In this, common network coding condition is proposed to avoid the problem of failed decoding. In addition, traffic matching mechanism is presented to promote the occurrence of network coding. Besides, a coding and load aware routing metric, which jointly considers the network coding opportunity and node load, is designed to evaluate the discovered paths. Extensive simulations on NS2 demonstrate that CTNR increases the number of coding opportunities and network coding occurrence, and improves network throughput.

To strengthen the prevention of cracks in hydration heat engineering. On the basis of summarizing and analyzing the models for hydration heat of concrete, numerical methods are used to calculate the temperature change curve of the core concrete in cement hydration stage. The thermal performance parameters of steel tubes and concrete are the essential basic data, which serves as a basis for research. Sectional dimension largely influences the shrinkage distortion of the core concrete in the concrete-filled steel tubes, which increases as the dimensions of the cross-section expand.

Copyright of Journal of Central South University is the property of Springer Nature 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.)

Triphenyltin (TPT) is an organotin pollutant widely found in the aquatic environment. It has endocrine-disrupting and osmotic pressure toxicity. In this study, the physiological and biochemical effects of TPT and various salinities were investigated in different tissues (gut, gill, and brain) of marine medaka. The exposure experiments were conducted for 42 days in different salinities (0, 15, and 30 ppt) without TPT exposure and in different salinity groups with TPT exposure concentrations of 100 ng/L, respectively. The results showed that the Na+-K+-ATPase (NKA) and Ca2+ATPase activity had significant tissue-specific differences, with the highest activity observed in the gills, indicating their major contribution to osmoregulation. Changes in salinity also resulted in significant alterations in the ion concentrations of the gut and gill tissues in the 0-C and 15-C groups. While the changes in Na+ and Cl− were relatively stable, the presence of TPT disrupted the regulation of Ca2+ and K+. In conclusion, substantial variations were observed in the osmoregulatory capacity of marine medaka tissues. Environmental concentrations of TPT had little effect on osmotic enzyme activity but interfered with the regulation of Ca2+ and K+ concentrations in the tissues. This study provides valuable insights into the osmotic toxicity of TPT in aquatic environments with different salinities. [ABSTRACT FROM AUTHOR]

Aiming to address the problem that faults in rolling bearings make effective fault diagnosis difficult under small-sample and varying working conditions, this paper proposes a new fault diagnosis method for rolling bearings that monitors their vibration signals and is based on an improved deep residual Siamese neural network, called a WDRCNN. Firstly, the Siamese neural network is applied to extract features with shared weights to achieve an expansion in the number of fault samples. Then, multiple residual blocks are used to extract deeper feature information and effectively alleviate the problem of overfitting. In addition, the attention mechanism is employed to assign weights to the feature information to reduce the interference of redundant features. Finally, the Euclidean distance between the sample pairs is calculated to determine the similarity of the sample pairs and to classify bearing faults for end-to-end bearing fault diagnosis. The experimental results demonstrate that the WDRCNN achieves an average accuracy of 96.31% under different operating conditions. Even when only 90 training samples are available, the WDRCNN achieves an accuracy of over 93%. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell 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.)