Fiber Bragg grating (FBG) sensor has been considered as a reliable sensor for health monitoring of structural and geotechnical projects. Various types of FBG based sensors have been proposed in past ...few decades and employed for health monitoring of many geotechnical structures. This paper presents an overview of the recent development and application of FBG based sensors for health monitoring of several key geotechnical structures, including soil nail systems, slopes, and piles. Different sensor design, implementation and packaging methods, advantages and limitations of using FBG based sensors in different projects are reviewed. Comparative analysis of using two mathematical methods for the prediction of ground movement using FBG sensor data are also carried out. The two typical mathematical methods include Finite Difference Method (FDM) and Numerical Integration method (NIM). Possible technical challenges of applying FBG sensors for geotechnical monitoring are discussed.
A robust network intrusion detection system (NIDS) plays an important role in cyberspace security for protecting confidential systems from potential threats. In real world network, there exists ...complex correlations among the various types of network traffic information, which may be respectively attributed to different abnormal behaviors and should be make full utilized in NIDS. Regarding complex network traffic information, traditional learning based abnormal behavior detection methods can hardly meet the requirements of the real world network environment. Existing methods have not taken into account the impact of various modalities of data, and the mutual support among different data features. To address the concerns, this paper proposes a multi-dimensional feature fusion and stacking ensemble mechanism (MFFSEM), which can detect abnormal behaviors effectively. In order to accurately explore the connotation of traffic information, multiple basic feature datasets are established considering different aspects of traffic information such as time, space, and load. Then, considering the association and correlation among the basic feature datasets, multiple comprehensive feature datasets are set up to meet the requirements of real world abnormal behavior detection. In specific, stacking ensemble learning is conducted on multiple comprehensive feature datasets, and thus an effective multi-dimensional global anomaly detection model is accomplished. The experimental results on the dataset KDD Cup 99, NSL-KDD, UNSW-NB15, and CIC-IDS2017 have shown that MFFSEM significantly outperforms the basic and meta classifiers adopted in our method. Furthermore, its detection performance is superior to other well-known ensemble approaches.
•The proposed approach based on multi-dimensional feature fusion and stacking ensemble learning.•We propose a multi-dimensional data partition and feature construction strategy.•A permutation and combination strategy is proposed to provide mutual support among different data features.•The proposed approach could lead to a more robust NIDS.
The realization of luminescent materials with narrowband and circularly polarized luminescence (CPL) is of great significance for the development of future optical and photonic devices. Herein, ...through a steric‐hindrance‐assisted dual‐core strategy, two pairs of chiral dual‐core multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials (R/S‐DOBN and R/S‐DOBNT) are directly constructed by the bonding of two organoboron MR‐TADF monocores (SOBN and SOBNT) with carbazole/3,6‐di‐tert‐butyl‐9H‐carbazole and phenol derivative as donors, realizing obvious CPL and narrowband emissions. Furthermore, the dual‐core effect in the prepared R/S‐DOBN and R/S‐DOBNT increases the transition oscillator strength two times more than that of a monocore structure, while maintaining the ultrapure blue emissions peaking at 453 and 459 nm with a narrower full‐width at half‐maximum of 21 nm through reorganization energy reduction. The circularly polarized organic light‐emitting diodes based on the enantiomers exhibit ultrapure blue emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.14, 0.10) and (0.13, 0.12), high maximum external quantum efficiencies of 23.9% and 25.6%, and obvious circularly polarized electroluminescence with dissymmetry factors (|gEL|) ≈ 10−3.
Through a steric‐hindrance‐assisted dual‐core strategy, chiral organoboron structures are prepared by direct bonding of two multiple‐resonance thermally activated delayed fluorescence (MR‐TADF) monocores, realizing superior chiroptical property and dual‐channel enhanced ultrapure blue emission. Furthermore, highly efficient circularly polarized organic light‐emitting diodes (CP‐OLEDs) with maximum external quantum efficiencies of 23.9% and 25.6% are achieved.
The global climate and environment are deteriorating. Countries have accelerated the development of the carbon market. The interaction and integration research between electricity market and carbon ...market helps to better reduce carbon emissions. To understand the knowledge domains and evolution of carbon–electricity markets, we downloaded 54,739 related articles from the Web of Science Core Collection between 1991 and 2022 based on the themes of the “electricity market” and “carbon market”. CiteSpace visual software was used to perform cooperative analysis, keyword co-occurrence analysis and cocited analysis. Based on the visual analysis results, we further conducted qualitative analysis of hot research directions and analyzed the development direction of the coupling relationship. We found that there exists mechanism correlations, price interactions, transaction information interactions and transaction behavior interactions, which have an impact on low-carbon investment decisions, power structure optimization and carbon emission reduction. In the future, the development of a low-carbon economy and the integration of renewable energy into the grid will lead to more frequent electricity–carbon markets interactions.
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•Visual analysis of the interactive and integration development of electricity-carbon market.•Conduct qualitative analysis of hot research directions.•Conclude the development direction of the coupling relationship.
Distributed optical fiber sensors (DOFS) have been attracted significant attention from geotechnical engineering communities for a few decades. Innovative development of structural design, ...encapsulation and implementation methods of optical fiber sensors leads to many new applications in geotechnical monitoring field. This paper presents a comprehensive review of Brillouin based DOFS for health monitoring of various geotechnical structures include geotextiles, soil nails, anchors, pipelines, piles, retaining walls, tunnels, and landslides. Recent application status of using two successful commercialized technologies including Brillouin Optical Time Domain Reflectometry (BOTDR) and Brillouin Optical Time Domain Analysis (BOTDA) for geotechnical health monitoring was reviewed and discussed in details. Particular emphasis was given to sensor design, encapsulation, and installation methods of DOFS in various successful geotechnical applications. Comparison analysis regarding typical advantages and limitations of different technologies (DOFS, fiber Bragg grating sensors, and conventional sensors) for geotechnical health monitoring was also presented and discussed in this paper.
In this paper, the anti‐plane stress analysis of a V‐notch with complex boundary conditions in a piezomagnetic half space is studied. Firstly, SH wave is considered as an external load acting on ...piezomagnetic half space, on the basis of repeated image superposition, the analytical expression of scattering wave is conducted, which satisfies the boundary conditions on the boundary of the half space. Then, the analytical expression of standing wave is established, which satisfies the stress free and magnetic insulation conditions on the boundaries of V‐notch by the fractional Bessel function expansion method and Graf addition theorem. Finally, Green's function method is applied, the half space is divided into two parts along the vertical interface, a pair of in‐plane magnetic field and out‐plane forces are applied on the vertical interface, and the first kind of Fredholm integral equations are set up and solved by applying orthogonal function expansion technique and effective truncation. Results clarified the influence on the dynamic stress concentration factor and magnetic field intensity concentration factor under proper conditions. Besides, the analytical solutions are compared with the finite element solutions to verify the accuracy of the conclusions in this article.
In this study, we report the first circularly polarized white organic light‐emitting diodes (CP‐WOLEDs) based on all thermally activated delayed fluorescence (TADF) materials. Two pairs of spiro‐type ...TADF enantiomers, (R/S)‐SPOCN (5,5′‐((2,2′,3,3′‐tetrahydro‐1,1′‐spirobiindene‐7,7′‐diyl)bis(oxy))bis(4‐(10H‐phenoxazin‐10‐yl)phthalonitrile)) and (R/S)‐OSFSO (2′‐(trifluoromethyl)‐spiroquinolino3,2,1‐klphenoxazine‐9,9′‐thioxanthene‐10′,10′‐dioxide), serve as emitters with complementary emission. The CP‐OLEDs exhibit warm white emission with a CIE coordinate of (0.35, 0.46). Besides, decent device performances are observed with an external quantum efficiency of up to 21.6 % at maximum and 11.8 % at 1000 cd m−2. Obvious circularly polarized electroluminescence signals are detected with a dissymmetry factor |gEL| of around 3.0×10−3. This is the first report of CP‐WOLEDs that can harvest both singlet and triplet excitons, which provides a feasible strategy for the development of CP‐WOLEDs with remarkable device performances.
Circularly polarized white organic light‐emitting diodes that can harvest both singlet and triplet excitons have been developed by combining two pairs of spiro‐type circularly polarized delayed fluorescence enantiomers with complementary emissions as chiral emissive layers. Remarkable device performances are observed, with an external quantum efficiency of up to 21.6 % and intense circularly polarized luminescence having a |gEL| factor of 3.0×10−3.
The real-time availability of key water quality parameters is of great importance for an advanced and optimized process control in wastewater treatment plants (WWTPs). However, due to the complex ...environment conditions and costly measuring instruments, it is generally difficult and time-consuming to measure certain key water quality parameters online, such as the effluent biochemical oxygen demand (BOD) and the effluent total nitrogen (TN). Recently, artificial neural networks have powered the online prediction tasks in several WWTPs. Hence, in this paper, an adaptive task-oriented radial basis function (ATO-RBF) network is developed to design prediction models for accurate timely acquirements of the effluent BOD and the effluent TN. The advantage of ATO-RBF network is that the architecture is not designed by human engineers; it is adaptively generated from the data to be processed. First, to enhance the learning ability and generalization performance of prediction models, an error correction-based growing strategy and a second-order learning algorithm are combined to design the ATO-RBF network. Then, RFB nodes with low significance would be pruned without sacrificing the learning accuracy, making the prediction model more compact. Additionally, the convergence of the ATO-RBF network is analyzed based on the Lyapunov criterion, which can guarantee its feasibility in practical applications. Finally, the proposed methodology is verified by benchmark simulations and real industrial data, showing superior prediction accuracy in compared with conventional methods.
In this paper, the problem of a V-notch with complex boundary conditions in a piezoelectric/piezomagnetic bi-material strip is studied. Firstly, SH guided wave is considered as an external load ...acting on piezoelectric/piezomagnetic bi-material strip, on the basis of repeated image superposition, the analytical expression of scattering wave is conducted, which satisfies the boundary conditions on the upper and lower horizontal boundaries of the strip. Then, the analytical expression of standing wave is established, which satisfies the stress-free, electric insulation and magnetic insulation conditions on the boundaries of V-notch by the fractional Bessel function expansion method and Graf addition theorem. Finally, Green’s function method is applied, the bi-material strip is divided into two parts along the vertical interface, a pair of in-plane electric field, in-plane magnetic field and out-of-plane forces are applied on the vertical interface, and the first kind of Fredholm integral equations are set up and solved by applying orthogonal function expansion technique and effective truncation. Results clarified the influence on the dynamic stress concentration factor, electric field intensity concentration factor and magnetic field intensity concentration factor under proper conditions. Besides, the analytical solutions are compared with the finite element solutions to verify the accuracy of the conclusions in this article.
Conflict is inevitable and an essential part of organizational life, as the goals of employers and employees are often incompatible. In this study, by employing both qualitative and quantitative ...methods, we inductively identified the categories of labor relations conflicts (interest-based, rights-based, and affect-based conflicts) and developed a three-dimensional scale that reflects employees' perceptions of labor relations conflicts in the Chinese context. By using matched data from 1223 employees and 136 human resource (HR) managers and employing hierarchical linear modeling (HLM) analysis, we tested the hypotheses and examined the effectiveness of partnership practices on reducing labor relations conflicts, the negative effects of labor relations conflicts on employees' attitudes and behaviors, and the mediating role of labor relations conflicts on the relationship between partnership practices and employees' attitudes and behaviors. The theoretical contributions and practical implications of the findings are discussed.
