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Climate change poses substantial risks to natural and human systems and effective response is essential. Underwater sculptures have been installed at multiple global locations to restore damaged reefs, increase tourism and educate visitors. There has been limited research that evaluates the environmental, social, cultural and economic costs of impacts such as cyclones and interventions such as underwater sculptures. Thisresearch investigated the social acceptance of underwater sculptures in Australia's Great Barrier Reef Marine Park. Following three months of planning and consultation, four sculptures were temporarily deployed at several habitats to facilitate action research on underwater sculptures and tourism. Respondents were supportive of installing sculptures in subtidal zones. The consultation and 'proof of concept' action research informed environmental assessment processes for installing permanent subtidal underwater sculptures. We report that tourist satisfaction of coral reefs damaged by a cyclone was low and following an intervention and installation of underwater sculptures satisfaction was high. [ABSTRACT FROM AUTHOR]

Summary: The health and diversity of coral reefs are critically important to the stability and value of the marine tourism industry. Declines in coral reef health through climate change impacts and cyclones, and associated media coverage, have impacted tourism visitation. In January 2018, a major change in Australian Government policy included a Reef Restoration and Adaptation Program to investigate the best science and technology options for helping the Great Barrier Reef recover and adapt to the changing environment. We report on a trial of two intervention methods, mineral accretion and coral gardening, to improve hard coral recovery at a popular site on the Great Barrier Reef. We installed six artificial reef substrates onto which an equal number of coral fragments of seven species were transplanted over the course of two years. During this time, three of the six treatments were connected to a low‐voltage power source to encourage mineral accretion and enhance coral growth. Electrolysis resulted in substantial mineral accretion on the steel substrate, however, the technology had no positive effect on the survival or growth of transplanted coral colonies. After 13 months, a second round of transplanted coral fragments was undertaken, and the electrolysis was discontinued. Over a four‐year period, mean live coral cover increased significantly in both treatment locations, from 1.7% and 0% to 80.8% and 75.8%, respectively. Control locations increased insignificantly from a mean of 5% to 14.2%. The mineral accretion technology proved technically challenging and did not support the growth or health of transplanted corals, providing no evidence to support the use of mineral accretion technology for this purpose. The technology may, however, have applications in the creation of new, solid substrates and for initial rubble stabilisation efforts. These results demonstrate the effective use of artificial substrates in conjunction with coral gardening techniques for the recovery of hard coral at degraded tourism sites. [ABSTRACT FROM AUTHOR]

An active noise control device called active noise absorber or ANA, which is based upon damped, resonant filters is developed and demonstrated. It is similar to structural positive position feedback (PPF) control, with two exceptions: (1) Acoustic transducers (microphone and speaker) cannot be truly collocated, and (2) the acoustic actuator (loudspeaker) has significant dynamics. The speaker dynamics can affect performance and stability and must be compensated. While acoustic modal control approaches are typically not sought, there are a number of applications where controlling a few room modes is adequate. A model of a duct with speakers at each end is developed and used to demonstrate the control method, including the impact of the speaker dynamics. An all-pass filter is used to provide phase compensation and improve controller performance and permits the control of nonminimum phase plants. A companion experimental study validated the simulation results and demonstrated nearly 8 dB of control in the first duct mode. A multi-modal control example was also demonstrated producing an average of 3 dB of control in the first four duct modes.

According to Mine Safety and Health Administration (MSHA) data, during 2008-2012 in the U.S., there were, on average, 65 lost-time accidents per year during routine mining and maintenance activities involving remote-controlled continuous mining machines (CMMs). To address this problem, the National Institute for Occupational Safety and Health (NIOSH) is currently investigating the implementation and integration of existing and emerging technologies in underground mines to provide automated, intelligent proximity detection (iPD) devices on CMMs. One research goal of NIOSH is to enhance the proximity detection system by improving its capability to track and determine identity, position, and posture of multiple workers, and to selectively disable machine functions to keep workers and machine operators safe. Posture of the miner can determine the safe working distance from a CMM by way of the variation in the proximity detection magnetic field. NIOSH collected and analyzed motion capture data and calculated joint angles of the back, hips, and knees from various postures on 12 human subjects. The results of the analysis suggests that lower body postures can be identified by observing the changes in joint angles of the right hip, left hip, right knee, and left knee.