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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.

This paper examines the changes suggested by maritime stakeholders to achieve gender equality in seafaring, a male-dominated profession.

Adopting a four-stage career cycle framework, this paper analyzes changes proposed by 423 industry stakeholders to promote gender equality in seafaring. These proposed changes were posted on the Day of Seafarers 2019 virtual wall set up by the International Maritime Organization, which served as a forum for industry stakeholders from all over the world to voice their opinions and suggestions.

The data analysis shows that the suggested changes reflect many challenges and barriers women seafarers face. While stakeholders from Organisation for Economic Co-operation and Development (OECD) countries are more likely to call for changes to remove barriers in the retention and development stage, gender equality in seafaring in non-OECD countries is still seriously hindered by barriers in the recruitment stage. The paper also reveals that comparatively male stakeholders are less likely to appreciate the problems women seafarers face.

This paper takes a comparative approach, comparing the changes proposed by seafarers and other industry stakeholders from different parts of the world. This approach provides a nuanced understanding of issues related to gender equality in seafaring by showing that stakeholders from different backgrounds have different priorities.

Using the industrial data between 2000 and 2016, this study analysed the process of coupling and coordinated development of technological innovation and standardisation. Accordingly, the study considered the high-tech industry (five sub-sectors) in China as the research object.

Based on the summary of innovation and standardisation literature review, this study constructed a theoretical model of the influence of technological innovation and standardisation on industrial development from the perspective of the coupling system. Furthermore, the study employed multivariate linear regression analysis to explore coupling coordination relationships.

The study results revealed that high coupling coordination between technological innovation and standardisation is highly conducive to industrial development. Moreover, requirements for standardisation levels differ owing to different stages and characteristics in each segmented industry.

This study primarily contributes to the literature by using a bibliometrics tool to summarise related literature on innovation and standardisation and provides a new perspective of reviewing, and it also offers new evidence on the coupling coordination relationship between innovation and standardisation in the high-tech industry.

Studies of the antecedents of daily abusive supervision have mainly focused on work stressors and family stressors, ignoring the potential importance of commuting stressors that are encountered enroute to work. Based in affective events theory, the authors propose a daily, within-person model to examine how the commuting stressors faced by supervisors affect their propensity to engage in abusive supervision behavior and the mechanisms underlying this effect.

Using experience-sampling methodology, the authors collected data from 49 supervisors in China who responded to two daily surveys for 10 working days.

The authors found that daily morning commuting anger mediates the link between daily morning commuting stressors and subsequent abusive supervision. The authors also found that trait-displaced aggression moderates this relationship, such that the mediating effect occurs only when supervisors' trait-displaced aggression is high rather than low.

This study enriches the antecedents of daily abusive supervision and extends the commuting literature to the leadership context.

There are three double bonds in the chemical structure of diallyl maleate. The purpose of this study is that the acrylate is modified with diallyl maleic anhydride to make the propionate resin present a spatial network structure, thereby improving the performance of the acrylate resin.

Methyl methacrylate (MMA) and butyl acrylate(BA) were used as were used as main monomers. Diallyl maleate (DAM) was used as crosslinking monomer and dodecafluoroheptyl methacrylate (DFMA) was used as fluoromonomer. Potassium persulfate (KPS) was used as thermal decomposition initiator, sodium lauryl sulfate (AS) and sodium dodecyl sulfonate (SDS) were used as anionic emulsifiers, and EFS-470 (Alkyl alcohol polyether type nonionic emulsifier) was a non-ionic emulsifier.

Through optimizing the reaction conditions, the uniform and stable latex is obtained. The polymer of structure was characterized by Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA) and contact angle (CA) were tested on latex films. The particle size and distribution range of emulsion were tested with nano particle size analyzer.

The experimental results showed that the thermal decomposition temperature of the acrylic coating film increased by 20.56°C after modification. In addition, the effect of cross-linking density on the water contact angle of the fluorocarbon groups in DFMA when they migrate to the surface of the latex film during drying has been explored. The experimental results show that a higher degree of cross-linking will hinder the migration of fluorocarbon groups to the surface of the resin film.

Unlike other types of corporate disclosure, corporate political disclosure (CPD), which is the disclosure of corporate political contributions and the related governing policies and oversight mechanisms, does not provide completely new information to stakeholders. Some of the information disclosed in CPD is available from other public records (e.g. the Federal Election Committee website or OpenSecrets website). Given this unique feature of CPD, it is interesting to investigate the cost and benefit tradeoff for firms of altering their CPD practice in response to policy and political uncertainty.

This study employs recently developed indexes of aggregate economic policy uncertainty (EPU) and a novel dataset of CPD transparency to examine the impact of EPU on CPD transparency and how the proprietary cost of corporate political activities moderates this association. The sample consists of S&P 500 companies from the 2012 to 2019 period.

The authors document that firms mitigate the heightened information asymmetry associated with higher aggregate EPU by increasing CPD transparency. The positive association between EPU and CPD is less pronounced for firms that are more sensitive to EPU, for firms that more actively manage EPU through corporate political contributions or lobbying activities and for firms that are followed by more analysts. The authors also find that more transparent CPD helps to mitigate the information asymmetry caused by heightened EPU. This study’s results hold when the authors control for other types of voluntary corporate disclosure.

This study contributes to the emerging literature on the determinants of CPD transparency by identifying EPU's positive impact on CPD transparency. This study also provides empirical evidence that the proprietary costs arising from the controversial nature of corporate political activities dampen firms' incentives to provide transparent CPD in response to heightened EPU, and that information on corporate political activities gathered and processed by financial analysts seems to lower the marginal benefit to companies of publicizing CPD on their own website.

Human skin temperature data can provide reference advice for diagnosing many diseases, but current wearable skin temperature monitoring systems have few points and may miss temperature information in critical areas. This paper aims to develop a wearable system that can be used for local temperature monitoring and restore better the actual state of local human temperature by exploring ways to extend more temperature measurement points. This will provide better assistance in developing medical targeting and intelligent clothing.

The temperature measurement system contains modules for temperature monitoring, digital-to-analog conversion and regulated power supply, enabling fast reading of 12 channels of monitoring data. The microprocessor unit is the STM32F407. The instructions and control modes are written in C. The waist area was chosen as the monitoring area because it is susceptible to temperature, and many diseases are associated with skin temperature. Twelve points, including temperature-related acupuncture points and heat-sensitive points, were selected for testing and the data results agreed well with the infrared imaging results.

The waist is selected as the monitoring object, and an easy-to-wear waist temperature monitoring belt is designed to verify the application value of the system. The development of the system provides reference suggestions for the exploration of multi-point temperature monitoring systems and the integration capabilities of temperature measurement modules in wearable multifunctional systems.

In addition to waist temperature monitoring, the wearable temperature measurement system developed in this study can also be applied to other body parts. In addition, the system can be efficiently and effectively combined with various garments, making it a useful tool for researching human skin temperature.

The wearable temperature monitoring system designed in this paper extends the number of temperature test points to 12. The number of test points covers as many localized body areas as possible to indeed reproduce the temperature distribution of the human body. In addition, the selection of test points combines medically relevant body points with physiologically relevant heat-sensitive areas, which makes the temperature measurement data more valuable.

The production planning problem with fine-grained information has hardly been considered in practice. The purpose of this study is to investigate the data-driven production planning problem when a manufacturer can observe historical demand data with high-dimensional mixed-frequency features, which provides fine-grained information.

In this study, a two-step data-driven optimization model is proposed to examine production planning with the exploitation of mixed-frequency demand data is proposed. First, an Unrestricted MIxed DAta Sampling approach is proposed, which imposes Group LASSO Penalty (GP-U-MIDAS). The use of high frequency of massive demand information is analytically justified to significantly improve the predictive ability without sacrificing goodness-of-fit. Then, integrated with the GP-U-MIDAS approach, the authors develop a multiperiod production planning model with a rolling cycle. The performance is evaluated by forecasting outcomes, production planning decisions, service levels and total cost.

Numerical results show that the key variables influencing market demand can be completely recognized through the GP-U-MIDAS approach; in particular, the selected accuracy of crucial features exceeds 92%. Furthermore, the proposed approach performs well regarding both in-sample fitting and out-of-sample forecasting throughout most of the horizons. Taking the total cost and service level obtained under the actual demand as the benchmark, the mean values of both the service level and total cost differences are reduced. The mean deviations of the service level and total cost are reduced to less than 2.4%. This indicates that when faced with fluctuating demand, the manufacturer can adopt the proposed model to effectively manage total costs and experience an enhanced service level.

Compared with previous studies, the authors develop a two-step data-driven optimization model by directly incorporating a potentially large number of features; the model can help manufacturers effectively identify the key features of market demand, improve the accuracy of demand estimations and make informed production decisions. Moreover, demand forecasting and optimal production decisions behave robustly with shifting demand and different cost structures, which can provide manufacturers an excellent method for solving production planning problems under demand uncertainty.

Self-crosslinked long fluorocarbon acrylate polymer latex has good hydrophobic and oleophobicity, weather resistance, aging resistance, stability and other excellent properties, which make the polymer be widely used in coatings, dyes, adhesives and other products. The purpose of this study is to prepare self-crosslinked long fluorocarbon acrylate polymer latex via semi-continuous seeded emulsion technology and carry out comparative study on two different cross-linked monomers.

Methyl methacrylate (MMA) and butyl acrylate (BA) were used as the main monomers, dodecafluoroheptyl methacrylate (DFMA) as the fluoromonomer, hydroxypropyl methacrylate (HPMA) and N-methylol acrylamide (NMA) as cross-linked monomers, and 1-allyloxy-3–(4-nonylphenol)-2-propanol polyoxyethylene (10) ether (ANPEO10) and 1-allyloxy-3–(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (DNS-86) as compound emulsifiers via the semicontinuous-seeded emulsion polymerization.

The properties of the polymer emulsions, which are prepared with two different cross-linked monomers, are compared and discussed, and it is concluded that HPMA is more suitable for the preparation of self-crosslinked polymer emulsions. The formula of the polymer latex is ANPEO10: DNS-86 = 1:1, and the mass ratio of the monomers used in the polymer is MMA: BA: DFMA: HPMA = 14.40:14.40:0.60:0.60.

Self-crosslinked long fluorocarbon acrylate polymer latex can be used in many fields such as coatings, dyes, adhesives and other products.

The self-crosslinked long fluorocarbon acrylate polymer latex is prepared by mixing the nonionic emulsifier ANPEO10 and the anionic emulsifier DNS-86 when potassium persulfate is used as the thermal decomposition initiator and the semicontinuous-seeded emulsion technology is adopted and the comparative study on two different cross-linked monomer is carried out, which is not reported in the open literatures.

The structural adaptive ability of the soft robot is fully demonstrated in the grasping task of the soft hand. A soft hand can easily realize the envelope operation of the object without planning. With the continuous development of robot applications, researchers are no longer satisfied with the ability of the soft hand to grasp. The purpose of this paper is to perceive the object’s shape while grasping to provide a decision-making basis for more intelligent robot applications.

This paper proposes a dual-signal comparison method to obtain the fingertip position. The dual signal includes the displacement calculated by the static model without considering the external load change and the displacement calculated by the bending sensor. The dual-signal comparison method can use the obvious change trend difference between the above two signals in the hover and contact states to identify the touch position. The authors make the soft hand scan around the object through touch operation to detect the object’s shape, and the tracks of every touch fingertip position can envelop the object’s shape.

The experimental results show that the dual-signal comparison method can accurately identify the contact moment of soft fingers. This detection method makes the soft hand develop the shape detection ability. The soft hand in the experiment can perceive squares, circles and a few other complex shapes.

The dual-signal comparison method proposed in this paper can detect a touch action by using the signal change trend when the working condition suddenly changes with the rough robotic model and sensing, thus improving the utilization value of the measured signal. The problems of large model errors and inaccurate sensors also negatively impact the use of other soft robots. It is generally difficult to achieve good results by directly using these models and sensors with the thinking of rigid robot analysis. The dual-signal comparison method in this paper can provide some reference for this aspect.