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The purpose of this paper is to demonstrate the theoretical relationship between the layout of four‐sensor dynamic acoustic array tracking system and systematic observation accuracy, and provide an algorithm to determine the optimal arrangement of four‐sensor acoustic array and an indicator to evaluate acoustic array system measurement accuracy.

In the present paper, the measurement principle of the four‐sensor dynamic acoustic array tracking system is analyzed, and the system observation model and the conversion relationship between models are established. Subsequently, the optimization algorithm for the four‐sensor dynamic acoustic array is deduced, the theoretical optimal arrangement of the four‐sensor dynamic acoustic array tracking measurement system is obtained based on the optimal position dilution of precision function (PDOPF) of 2D target, and the static experimental study on sound‐source bearing estimation is designed. The theoretical results are compared with the experimental results of the present study.

The measurement accuracy of the four‐sensor dynamic acoustic array tracking system is largely dependent on the layout of the acoustic sensor. Theoretical studies and experimental results demonstrated that an optimal PDPOF can be used to analyze the rationality of the layout. It can also serve as an indicator for the layout of the four‐sensor dynamic acoustic array tracking system.

The PDOPF value is presented as an indicator for the evaluation of the four‐sensor dynamic acoustic array systematic observation accuracy based on theoretical analysis. The feasibility of the indicator and the rationality of the sensor layout in practical engineering application are verified through experimental studies on sound‐source bearing estimation. The higher the PDOPF value is, the lower the accuracy of the system will be.

There are structural elements on the aircraft that may be exposed to high-intensity sound levels. One of them is an air inlet duct of the jet engine. To prepare data for the air duct damage tolerance analysis, flat panels were tested under acoustic loading. The paper aims to discuss this issue.

The acoustic fatigue test equipment for grazing wave’s incidence was designed based on the FE analyses. Flat composite panels were designed and manufactured using the Hexply 8552/AGP193-PW prepreg with the simulation of production imperfections or operational damage. The dynamic behaviour of panels has been tested using three regimes of acoustic loading: white noise spectrum, engine noise spectrum and discrete harmonic frequencies. The panel deflection was monitored along its longitudinal axis, and the ultrasonic NDT instruments were used for the monitoring of relevant delamination increments. The FE model of the panel was created in Abaqus to study panel dynamic characteristics.

No delamination progress was observed by NDT testing even if dynamic characteristics, especially modal frequency, of the panel changed during the fatigue test. Rayleigh damping coefficients were evaluated for their use in FE models. Significant differences were found between the measured and computed panel deflection curves near the edge of the panel.

The research results underscored the signification of the FE model boundary conditions and the element type selections when the panel works like a membrane rather than a plate because of their low bending stiffness.

To introduce a new, low‐cost and easy‐to‐use leak detection system to help water utilities improve their effectiveness in locating leaks. The paper also presents an overview of leakage management strategies including acoustic and other leak detection techniques.

The design approach was based on the use personal computers as a platform and enhanced signal processing algorithms. This eliminated the need for a major component of the usual hardware of leak pinpointing correlators which reduced the system's cost; made it easy to use, and improved the effectiveness of locating leaks in all types of pipes.

Effectiveness of the new leak detection system for pinpointing leaks was demonstrated using real world examples. The system has promising potential for all water utilities, including small and medium‐sized ones and utilities in developing countries.

The leak detection system presented in the paper will help all water utilities, including small and medium‐sized ones and utilities in developing countries, to save water by dramatically improving their effectiveness in locating leaks in all types of pipes.

The paper presents information about a new effective system for locating leaks in water distribution pipes. Effective leak detection tools are needed by water utilities worldwide.

The main purpose of this study was to evaluate the mechanical behaviour of layered fibrous carbon-fibre reinforced plastic (CFRP) under complex low-speed bending and impact loads and subsequent cyclic tensile loads.

A comprehensive approach was adopted to study the damage accumulation processes using state-of-the-art testing and diagnostic equipment. In the course of the study, a microstructure analysis of damages caused by a transverse impact and cyclic tension was performed.

A dependence of residual fatigue life of the studied composite material on the intensity of the preliminary impact bending was established. Temperature field distribution fields on the surface of the sample during tests were shown. Data on damage accumulation processes were presented, which were obtained during the registration of acoustic emission signals.

A connection was established between changes of registered acoustic response signals and thermal imaging camera data, which was supported by the results of an experimental study. The results of the comprehensive approach showed a qualitative correlation.

Examines the use of acoustic emission techniques for monitoring part mating during the assembly process. The frequency recorded during a peg insertion is compared with known frequencies of successful peg insertion by a microcomputer. This allows unsuccessful alignment to be readjusted which being monitored by a digital sound analyzer. Outlines the concept of part mating which is based on the peg‐in‐hole theory developed by Simunovic and describes an acoustic emission monitoring system. Concludes that acoustic monitoring provides a relatively low cost, low complexity system for part mating monitoring but may have limitation in manufacturing environments where there is excessive background noise or machine part vibration.

This report describes the progress that has been made to date on burn detection by acoustic emission with two‐inch camshafts produced for V6 and V8 engines on a Norton ‘camomatic’ grinding machine used for finish grinding valve cams.

The purpose of this paper is to present an acoustics-based method for measuring turbofan nozzle exhaust thrust, while assessing the potential of scaling the methods for in-flight measurements.

Although many methods proposed for achieving in-flight thrust measurements involve complicated, sensitive and expense instruments, an acoustics-based approach is discussed that greatly simplifies the technology development pathway to in-flight applications.

Results are provided for a minimum set of sensors applied in the exhaust of a research turbofan engine at Virginia Tech, showing the difference in acoustics-measured thrust and nozzle thrust found by integrating thermocouple and Kiel probe measurements to be less than 6 per cent at the maximum fan speed examined.

Measuring accurate thrust values in flight will prove immediately valuable for installed thrust validation and engine health monitoring. Acoustics-based methodologies are attractive because of the robustness and low cost of sensors and sources. The value of in-flight thrust measurements, along with the benefits of acoustic approaches, makes the current topic of great interest for further development.

This paper presents unique applications of a time-of-flight acoustic thrust sensor, while providing an original assessment of technological challenges involved with the progression of the technique for in-flight measurements.

Sheen salt spray corrosion test cabinets. Sheen Instruments has further expanded its range of coatings test equipment with the introduction of two salt spray corrosion test cabinets. Model SF/4 has a 450 litre capacity and SF/1000 has 1,000 litre capacity.

Senior citizen falls are one of the highest-cost factors of healthcare within this population group. Various approaches for automatic fall detection exist. However, little is known about the seniors’ acceptance of these systems. The purpose of this paper is to investigate the acceptance of automatic fall detection devices as well as the technological commitment and the health status in community-dwelling adults with a predefined risk of falling.

Seniors with a risk of falling were equipped with either an accelerometer or an accelerometer with an additional visual and optical fall detection system in a sub-group of the study population for a period of eight weeks. Pre- and post-study questionnaires were used to assess attitudes and acceptance toward technology.

In total, 14 subjects with a mean age of 75.1 years completed the study. Acceptance toward all sensors was high and subjects were confident in their ability to handle technology. Medical assessments showed only very mild physical and no mental impairments. Measures that assured subjects privacy protection were welcomed. Sensor technology should be as unobtrusive as possible.

Privacy protection and uncomplicated use of the fall detection equipment led to high acceptance in seniors with high-technical commitment and good health status. Issues to further improve acceptance could be identified. Future research on different populations is necessary.

The purpose of this paper is to explore and investigate the process of green management adoption in small and medium‐sized enterprises.

The study used the qualitative methods of case study, in‐depth interviews and document analysis to collect data from two companies, one in the acoustic equipment, the other in the electronics industry.

The paper finds that the extant literature in the field of business and management has largely ignored green management practices within small and medium‐sized enterprises (SMEs). The study finds that SMEs can make themselves greener by making strategic and organizational changes. For greener management, the factors of organizational structure, innovation capability, human resources, cost savings and competitive advantage can influence organizational change. The outcomes of the case studies confirmed this. The paper argues that further research is needed in order to identify how management practice might reduce negative sustainability impacts. The paper argues that such research can benefit from the methodological and theoretical insights of other disciplines.

The paper is of benefit to academics and managers by providing a new way to consider green management and strategies of SMEs. Since green sustainability is obviously challenging to all companies, to increase understanding of how to cope with green management is necessary, but has been rarely researched in SMEs.