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The purpose of this paper is to exploit the multiple-Toeplitz matrices reconstruction method combined with quadratic spatial smoothing processing to improve the direction-of-arrival (DOA) estimation performance of coherent signals at low signal-to-noise ratio (SNRs).

An improved multiple-Toeplitz matrices reconstruction method is proposed via quadratic spatial smoothing processing. Our proposed method takes advantage of the available information contained in the auto-covariance matrices of individual Toeplitz matrices and the cross-covariance matrices of different Toeplitz matrices, which results in a higher noise suppression ability.

Theoretical analysis and simulation results show that, compared with the existing Toeplitz matrix processing methods, the proposed method improves the DOA estimation performance in cases with a low SNR. Especially for the cases with a low SNR and small snapshot number as well as with closely spaced sources, the proposed method can achieve much better performance on estimation accuracy and resolution probability.

The study investigates the possibility of reusing pre-existing designs for the DOA estimation of the coherent signals. The proposed technique enables achieve good estimation performance at low SNRs.

The paper includes implications for the DOA problem at low SNRs in communication systems.

The proposed method proved to be useful for the DOA estimation at low SNR.

The current studies on the clothing silhouette are very limited. The purpose of this paper is to propose an innovative framework to intelligently identify the womenswear silhouette with the latest computer technologies. To clearly define the womenswear silhouette, an accurate numerical definition is proposed.

The study first processes and segments the useful parts on the static catwalk image data files following existing graphic extraction approaches. Six basic alphabetical womenswear silhouette types are selected and numerically defined. Then, the proposed framework automatically classifies the six basic womenswear silhouettes considering the different slopes between three main clothing parts. Six clothing situations are discovered according to different designs and the detailed cases are systematically categorized. In addition, aspects influencing the judgment of the clothing silhouettes such as the skin, the background, the drastic change points are also considered. The proposed silhouette definition and identification framework is novel and proved accurate.

The proposed definition and identification framework of womenswear silhouettes have been proved a viable approach that is fully compatible with the current computer technologies. The validation study shows that the presented identification procedure has a desirable accuracy over 90 percent.

The proposed methodology develops brand new standards to numerically define and identify the womenswear silhouette, which was not available in the past. Besides, the measurement, the identification and the classification procedures are fully validated by the image data collected from 14 world famous brands over 11 consecutive seasons. It is shown that the proposed numerical framework of the womenswear silhouettes is a robust one, considering all of the observed design variabilities.

To examine the relationships among website design features, consumer experience responses and patronage intention toward online mass customization (OMC) apparel websites.

A total of 312 useable online surveys were obtained from Mainland China consumers. Multi-item scales were adopted to measure eight constructs: visual design; information quality; entertainment, aesthetic, educational, escapist experiences; flow; and patronage intention. Structural equation modeling (SEM) was conducted to determine factor structures and to test the hypothesized relationships among website design features, 4Es (entertainment, aesthetic, educational and escapist experiences), flow and consequent purchase intention toward OMC apparel websites.

All hypotheses, but one, were supported. OMC website visual design; information quality; and entertainment, aesthetic and educational experiences had a positive effect on consumer patronage intention.

Limitations include using a sample of consumers from major cities in China; results cannot be generalized to all Chinese consumers. Websites were not actively navigated. Additionally, the present study examined only two dimensions of OMC website quality, visual design and information quality; more tangible and specific features could be considered in future research.

The findings provide website designers and marketers with insights into experiences that may lead to an increase in patronage intention toward OMC websites.

The study provides evidence that flow helps explain the impact of experiential value (i.e. 4Es) from website design features on patronage intention.

The purpose of this paper is to evaluate the influence of microvia design on solder joint reliability and to present a printed circuit board (PCB) microvia design approach capable of reducing or eliminating voiding in solder joints.

Five different types of via‐in‐pad designs were incorporated into a test vehicle and their performance evaluated using a variety of standard reliability tests.

Solid vias, composed of 99.5 percent pure copper can be used to eliminate voiding in solder joints. Such vias are also much more robust than those employing metallic paste or other filled materials. Solid vias with flat surfaces have been shown to be able to meet the requirements of common reliability test standards and to offer a process compatible with traditional PCB manufacturing.

The occurrence of voiding in solder joints has been shown to be significantly influenced by microvia design. Although a design is reported for reducing/eliminating voiding, other factors that can cause voiding should be investigated. Also, further extended accelerated reliability testing could be undertaken to determine comparative long‐term reliability.

Serious voiding in solder joints is a major threat to the quality and reliability of electronics assemblies, mainly due to its role as a stress concentrator and particularly with the move to lead‐free assembly. Methods for reducing and eliminating the occurrence of voiding are needed by electronics assemblers and this work proposes one such method that can be implemented at the circuit board design stage.

To authenticate the existence and principles of the adhesion recovery phenomenon under water pollution conditions, an innovative circumferential rail–wheel adhesion test rig was used. The study conducted extensive tests on the adhesion characteristics under large sliding conditions.

Experiments were conducted to investigate the influence of speed, axle load and slip on adhesion recovery. Based on the experimental results, the adhesion recovery transition function was re-fitted.

The study reveals that the adhesion recovery phenomenon truly exists under water conditions. The adhesion coefficient shows an increasing trend with the growth of the slip ratio. Moreover, at the current speed and axle load levels, the adhesion recovery is directly proportional to the square of the slip ratio and inversely proportional to the axle load.

The phenomenon of adhesion recovery and the formulated equations in this study can serve as an experimental and theoretical foundation for the design of braking and anti-skid control algorithms for trains.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2023-0379/

This paper aims to analyze a failure case of a P110 tube in a CO₂ flooding well.

The chemical composition, microstructure and mechanical properties of the failed P110 tubing steel were tested, and met the API Spec 5CT standard. The fractures were investigated by scanning electron microscopy and energy dispersive spectroscopy.

Fracture was induced by stress corrosion cracking (SCC) and that the stress concentration caused by the mechanical damage played an important role in the failure. The failure case is a SCC failure affected by mechanical damage and galvanic corrosion.

The effect of the infiltration of groundwater was studied in the failure case. The stress concentration caused by the mechanical damage played an important role in the failure.

The purpose of this paper is to determine the failure reasons and failure mechanism of the commercially pure titanium air conditioning condenser.

In this paper, chemical analysis, metallographic observation, visual examination and scanning electron microscope examination, corrosion products analysis and working conditions analysis were adopted for determining the reasons for the failure of the condenser.

The results indicated that TA2 titanium pipe perforation failure is caused by the synergistic effect of crevice corrosion and deposit corrosion. The corrosion processes can be divided into three steps.

This research is an originality study on the failure case of a commercially pure titanium air conditioning condenser. This study makes up for the shortage of titanium alloy failure cases and also gives the result of the failure reason and failure mechanism for titanium, which has an engineering significance.

The purpose of this paper was to study the relationship between safe storage life and storage mode of hot-rolled sheet (Q235, X70) in humid environment, and a prediction model of safe storage life under different storage modes was established.

The corrosion behavior of hot-rolled sheets under different storage conditions was studied with immersion experiment and morphology observation.

The results show that pitting occurs on the hot-rolled sheets in humid environment, and the corrosion behavior is strongly related with the storage mode. When they are stored separately, the number and depth of pits first increase and then decrease as the Cl⁻ concentration rises, while for the stack storage, pit depth increases with increasing Cl⁻ concentration. The safe storage time of separate storage is longer than that of stack storage. Based on this, a model of chloride ion concentration and storage life was established.

A storage safe life model of hot-rolled sheet in humid environment is proposed.

The purpose of this paper is to develop new types of anchor bolt materials by adding corrosion-resistant elements for alloying and microstructure regulation.

Three new anchor bolt materials were designed around the 1Ni system. The stress corrosion cracking resistance of the new materials was characterized by microstructure observation, electrochemical testing and slow strain rate tensile testing.

The strength of the new anchor bolt materials has been improved, and the stress corrosion sensitivity has been reduced. The addition of Nb makes the material exhibit excellent stress corrosion resistance under –1,200 mV conditions, but the expected results were not achieved when Nb and Sb were coupled.

The new anchor bolt materials designed around 1Ni have excellent stress corrosion resistance, which is the development direction of future materials. Nb allows the material to retain its ability to extend in hydrogen-evolution environments.

The behavior of joints has a significant effect on the stability of water conveyance tunnel. The purpose of this paper is to study the contact and friction at the joint of the tunneling segment lining and establish its contact friction model. At the same time, the stress and deformation characteristics at the joint of the segment under hydrostatic load are analyzed.

In this study, the contact and friction in a bolted joint are examined using shear testing. The feasibility of the proposed model is verified by a numerical simulation of tests and a theoretical analysis. Accordingly, the effect of joints on the lining is explored under internal hydrostatic loading.

The results show that the openings of tunnel segments in joints gradually expand from the positions of the inner and outer edges to the location of the bolt. Moreover, the stress concentration zone is formed at the bolt. Under hydraulic loading, the opening displacement at the joint increases as the water pressure increases; nevertheless, it does not exceed engineering requirements. When the water pressure of the tunnel lining joint reaches 0.5 MPa, the opening of the joint slowly increases. When the water pressure exceeds 0.7 MPa, the opening of the joint rapidly and significantly increases.

Contact and friction in a bolted joint were examined using shear testing. A cohesive zone model of bolted joints was proposed based on test results. The influence of joint behavior on the stability of water conveyance tunnel was studied.