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Acoustic signals of the underwater targets are susceptible to noise, reverberation, submarine topography and biology, therefore it is difficult to precisely locate underwater targets. This paper proposes a new underwater Hanbury Brown-Twiss (HBT) interference passive localization method. This study aims to achieve precise location of the underwater acoustic targets.

The principle of HBT interference with ultrasensitive detection characteristics in optical measurements was introduced in the field of hydroacoustics. The coherence of the underwater target signal was analyzed using the HBT interference measurement principle, and the corresponding relationship between the signal coherence and target position was obtained. Consequently, an HBT interference localization model was established, and its validity was verified through simulations and experiments.

The effects of different array structures on the localization performance were obtained by simulation analysis, and the simulations confirmed that the HBT method exhibited a higher positioning accuracy than conventional beamforming. In addition, the experimental analysis demonstrated the excellent positioning performance of the HBT method, which verified the feasibility of the proposed method.

This study provides a new method for the passive localization of underwater targets, which may be widely used in the field of oceanic explorations.

In the light of the acceleration in the international and local information and knowledge revolution, the University of Stellenbosch (US) has introduced an e‐learning strategy to gain maximum benefit from the developments in information technology. In support of this strategy, the US has implemented WebCT as an electronic course management system. Subsequent consultations have revealed doubt among accounting lecturers and students about the effectiveness of WebCT assessment of tests in Financial Accounting. The purpose of the study was therefore to investigate this perception on the basis of the available literature, our own experience, categories of student learning and feedback from students. The WebCT assessment function was also contrasted with traditional assessment methods. It was concluded that although WebCT is not a quick fix, it could be implemented successfully in bigger classes, provided that innovative lecturers are responsible for these classes.

This paper seeks to investigate the electronics industry's reaction to environmental regulations specifically in terms of lead‐free solders and halogen‐free flame‐retardants (FRs).

This work achieves its objective by discussing the various international environmental regulations pertaining to electronics manufacturing and relating the industry reactions to those regulations. It also provides the market trends related to lead‐ and halogen‐free products. The electronics industry is pursuing lead‐free solders and halogen‐free FRs, in part due to regulations. However, the paper includes examples of how the industry is successful in implementing environmentally friendly changes.

The authors compared regulations from Japan, the European Union, the USA, and China. While the regulations themselves vary in scope, industry actions to find alternatives do have common purposes. Electronics manufacturers recognize that environmentally motivated changes are beneficial in terms of waste minimization.

Electronics manufacturers that are interested in green design will benefit from understanding present regulations. They will also benefit from the included examples of product and process improvement for the purpose of environmental compatibility.

This paper derives its perspective from a similar review of literature and company findings that the authors completed in 2006. As refinement of the regulations has continued, the electronics industry has developed improvements in basic materials and processes.

This paper seeks to present a prognostics approach using the Mahalanobis distance (MD) method to predict the reliability of multilayer ceramic capacitors (MLCCs) in temperature‐humidity‐bias (THB) conditions.

Data collected during THB testing of 96 MLCCs were analyzed using the MD method. In the THB tests, three parameters (capacitance (C), dissipation factor (DF), and insulation resistance (IR)) were monitored in situ. A Mahalanobis space (MS) was formed from the MD values of a set of non‐failed MLCCs. MD values for the remaining MLCCs were compared with an MD threshold. Data for MLCCs which exceeded the threshold were examined using the failure criteria for the individual electrical parameters to identify failures and precursors to failure.

It was found that the MD method provided an ability to detect failures of the capacitors and identify precursors to failure, although the detection rate was not perfect.

It was observed that the quality and construction of the MS, together with the choice of the MD threshold, were the critical factors determining the sensitivity of the MD method. Recommendations are offered for improved sensitivity to enable assessment of intermittent failures.

MD analysis of the multivariate MLCC data set illustrates how detection of failures can be simplified in a system for which several parameters were monitored simultaneously. This makes the MD method of great potential value in a health‐monitoring system.

The purpose of this paper is to propose a novel serial structure repetitive control scheme for shunt active power filter (SAPF) to improve the steady-state accuracy and dynamic performance of SAPF. The novelty of this scheme lies in the reconfiguration of the pole of repetitive control internal model, so that the dynamic response of the repetitive control is improved greatly.

By analyzing the mathematical model of repetitive control, the repetitive control delay can reduce by giving up the needless poles of the internal model, and the general mk + i repetitive control can be designed through the pole configuration method. The controller can track a set of specific order harmonics.

The experimental results are coincident with the theoretical analyses, which prove the effectiveness of the proposed method on harmonic suppression and great performance in dynamic response.

An APF prototype has been designed with the serial structure repetitive control proposed in this paper, and it can successfully eliminate the harmonics current of nonlinear load with faster dynamic response. Moreover, the proposed controller can be applied to any three-phase system for fast dynamic response and high tracking accuracy.

In this paper, the mathematical model of the repetitive control for specific set of harmonica is developed. A novel serial structure repetitive control is designed, so that the SAPF can eliminate the fundamental reactive current and specific order harmonics and speed up the dynamic response of the repetitive control.

As the number of social media users continues to rise globally, a heated debate emerges on whether social media use improves or harms mental health, as well as the bidirectional relation between social media use and mental health. Motivated by this, the authors’ study adopts the stressor–strain–outcome model and social compensation hypothesis to disentangle the effect mechanism between social media use and psychological well-being. The purpose of this paper is to address this issue.

To empirically validate the proposed research model, a large-scale two-year longitudinal questionnaire survey on social media use was administered to a valid sample of 6,093 respondents recruited from a university in China. Structural equation modeling was employed for data analysis.

A longitudinal analysis reveals that social media use positively (negatively) impacts psychological well-being through the mediator of nomophobia (perceived social support) in a short period. However, social media use triggers more psychological unease, as well as more life satisfaction from a longitudinal perspective.

This study addresses the bidirectional relation between social media use and psychological unease. The current study also draws both theoretical and practical implications by unmasking the bright–dark duality of social media use on psychological well-being.

Research examining the “fear of missing out” (FoMO) is increasingly prominent, with a growing number of studies exploring this phenomenon. Despite the increased academic interest, no attempts have been made to synthesize extant knowledge on FoMO. There is limited holistic understanding of its conceptualization and operationalization. To address this gap, an exhaustive systematic literature review (SLR) on FoMO is presented.

Systematic review protocols and content analysis was used to analyze and synthesize insights from 58 empirical studies obtained from four academic databases: Scopus, Web of Science, PubMed and PsycINFO.

Significant diversity in prior research on FoMO was encapsulated in four themes. There are significant limitations in conceptualization of FoMO, along with narrow focus on geographic, methodological and contextual foci of prior studies. The authors propose a comprehensive framework and extensive gap-specific research directions to aid future research.

The SLR is limited in its consideration of empirical studies published in academic journal articles obtained from four databases.

The authors imply the critical need to ascertain motives for individuals' excessive engagement with social media and the subsequent impact on well-being indicators (e.g. sleep quality) and functional impairments (e.g. addiction).

This study magnifies and expands the intellectual boundaries of FoMO and suggests the adoption of a multidisciplinary perspective for further investigation. The use of novel theoretical lenses can further ascertain FoMO's effect on different cultures and social media users.

Explores the changing relationship between work and leisure with particular reference to women’s equality in economic and other activities through a review of the history of leisure opportunities since the industrial revolution; indicates the ways in which social and economic changes have had a major impact on women’s leisure needs and activities. Focuses in particular on the provision of workplace fitness facilities, undertaking a survey of more than 200 companies across a number of industry sectors (the rationale for selection is outlined here) to discover the reasons behind such provision and the actual facilities provided; identifies the reasons behind provision as primarily commercial (e.g. being seen as an additional benefit to help recruit high quality employees) and notes that assessment of user group needs was not carried out, with the result that women’s particular needs tended not to be taken into account, for example gyms (favoured by men) being more widely provided than space for aerobic exercise (favoured by women). Concludes that the findings strongly suggest that women remain unequal in their leisure as well as working lives.

The primary objectives of the article are to systematically investigate the effects of differentiated functions of WeChat use (social use and recreational use) on university students' online self-presentation, social support and sense of belonging.

The data were collected from a web-based survey on a sample of 485 university students in mainland China. Correlation analyses and structural equation modeling (SEM) were implemented to address the corresponding hypotheses.

The results demonstrate that the social use of WeChat is positively related to online self-presentation, whereas recreational use is unrelated to such behavior. Additionally, the findings verify that online self-presentation is a significant predictor of both social support and sense of belonging. Furthermore, online self-presentation could mediate the influence of social use of WeChat on social support and sense of belonging.

Theoretically, the study represents an initial effort to elucidate the joint impact of differentiated functions of WeChat use and online self-presentation on social support and sense of belonging. Practically, these findings identify the crucial mediation role of online self-presentation in assisting individuals to acquire social support and promote sense of belonging.

Although mobile social media has brought dramatic revolutions in interaction and interpersonal behaviors, the empirically studies regarding the potential influences of its utilization are equivocal. These outcomes may shed meaningful light on the comprehending of unique characteristics of WeChat communication and how it could impact people's psychosocial development in the digital era.

Over the past few years, electronic commerce has gradually grown into what has arguably become the most daunting challenge to date for taxsystems. Income tax principles have traditionally been based on the existence of some form of physical presence (either residency, source of income or a permanent establishment) in an area of jurisdiction before tax may be levied. The fact that the Internet can provide substantial economic activity in an area of jurisdiction without having a physical presence, requires an interpretation of and/or amendment to international tax principles. South Africa has adopted the residence principle of taxation with effect from 1 January 2001. The residence principle is more suited to dealing with Internet transactions than is the source principle. The residence principle does, however, require interpretation and/or amendment in the Internet environment. It is in particular the term “place of effective management” that requires interpretation. Internet transactions are borderless and therefore subject to doubletaxation agreements. The Fiscal Committee of the OECD plays a leading and co‐ordinating role in the examination of the effect of electronic commerce on taxation. Therefore the challenge with which South Africa is faced, is to develop a taxation policy that is not isolated from its ecommerce partners.