No description available.

No description available.

No description available.

No description available.

No description available.

The aim of this study was to investigate noise levels in the New Zealand health industry. The goal was to investigate the room acoustics and the characteristics of the noise sources along with noise exposure of health care workers, in New Zealand, in dental clinics and orthopaedic cast clinics and assess whether they are at risk of noise-induced hearing loss (NIHL). A literature review was conducted to determine the definition, cause, and ways to prevent NIHL in relation to the dental clinics and orthopaedic cast clinics. Also determined from a review of the literature were ways to assess and monitor the acoustics of these spaces. Initially room acoustic measurements of background noise levels as well as reverberation times were made and frequency information on the major noise sources was obtained. This was followed by measurement of the daily noise dose exposure of staff working in the participating dental clinics and orthopaedic cast clinics. It was found that noise dose levels did not exceed the damage risk criterion set by The New Zealand Occupational Safety and Health Service of Leq8h of 85 dBA and therefore staff were considered to not be at risk of NIHL. However, the background noise levels measured may be putting healthcare workers at risk of non-auditory related effects of noise exposure, affecting work performance, cognitive abilities and vital communication between staff and patients. Healthcare workers may also be at risk of non-auditory health effects due to increased noise annoyance leading to raised stress levels, which may ultimately lead to pathophysiological changes in the myocardium. Future research in the area of noise levels in the New Zealand health industry should be performed to obtain noise data on a larger sample and look further at the non-auditory health effects of exposure to noise in the health industry.

One critical component of the communication receiver of front-end system is the low-noise amplifier (LNA). For good sensitivity and dynamic range, the LNA should provide a low noise figure and maximum attainable power gain. Another concern is the linearity of the LNA. Strong signals produce intermodulation products in a frequency band close to the operating frequency that might affect the performance of the receiver. In many cases, the intermodulation products can be reduced by increasing the current through the active device. Hence, a trade-off between power consumption and linearity must be considered when designing the LNA. The thesis includes the bias network design, stability analysis, matching network design and layout design of the LNA RF module with layout simulation. The simulation has been performed using Advanced Design System (ADS) simulation software. After implementation of LNA on a PCB, the LNA is measured with the help of the power supply unit and vector network analyzer. The proposed design aim is to provide a low noise figure (NF) and high gain while maintaining the low power consumption.

No description available.

The finest resolution that can be achieved in any real chaotic system is limited by the presence of noise. This noise can be used to define neighborhoods of the deterministic periodic orbits using the local eigenfunctions of the Fokker-Planck operator and its adjoint. We extend the work of D. Lippolis to include hyperbolic periodic orbits. The dynamics along the stable and unstable directions are separated. The neighborhoods on the stable and unstable manifolds can be defined in the same way as the neighborhoods for entirely stable or entirely unstable orbits. The neighborhoods are then returned to the original coordinates. The Fokker-Planck evolution can be described as a finite Markov transition graph between these neighborhoods. Its spectral determinant is used to calculate the time averages of observables. We apply this technique to calculate long time observables of the Lozi map.

This thesis compared the loudness discomfort levels (LDL) for a group of normal hearing children to those for a group of children with sensori-neural hearing losses. The children with a loss were students at a school for the deaf. The LDL’s for the frequencies 250, 500, 1000, 2000, and 4000 Hz and for speech were obtained.It was found that the sensori-neural loss group had higher LDL’s for both pure tones and speech than the normal hearers. It was further found that for the normal hearers, the LDL’s were higher for speech than for the average of the pure tone speech frequencies. The results of this study were also higher than previous researchers had found. The possible reasons for the differences between the groups and between the results of this study and previous ones were discussed.