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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

DESIGN OF THE TRANSCONDUCTANCE AMPLIFIER FOR FREQUENCY DOMAIN SAMPLING RECEIVER

Chen, XI 16 January 2010 (has links)
In this work, the circuit implementation of the front-end for Frequency Domain (FD) Sampling Receiver is presented. Shooting for two different applications, two transconductance amplifiers are designed. A high linear transconductance amplifier with 25 dBm IIP3 is proposed to form the high resolution and high sampling rate FD receiver. The whole system achieves an overall sampling rate of 2 Gs/s and resolution of 10 bits. Another low noise transconductance amplifier exploiting noise cancelling is designed to build up the FD wireless communication receiver, which is an excellent candidate for Software Define Radio (SDR) and Cognitve Radio (CR). The proposed noise cancelling scheme can suppress both thermal noise and flicker noise at the frontend. The system Noise Figure (NF) is improved by 3.28 dB. The two transconductance amplifiers are simulated and fabricated with TI 45nm CMOS technology.
2

Selective noise cancelling application for misophonia treatment

Wunrow, Timothy 10 May 2024 (has links) (PDF)
Misophonia is a sensory disorder where specific stimuli, usually auditory, trigger the fight-flight-freeze response, causing extreme reactions, typically anger, panic, or anxiety. Research into treatment for misophonia is limited, primarily consisting of case studies applying common methods of therapy. However, research into similar disorders like tinnitus shows that there are many avenues of treatment that should be investigated, including audiological treatment. To apply audiological treatment to misophonia, selective noise cancelling must be used to control specific trigger sounds. In this research, a basic selective noise cancelling algorithm was developed using a convolutional neural network and was evaluated using a survey. Participants rated their reaction to trigger sounds, non-trigger sounds, and trigger sounds that had been selectively cancelled. The misophonic reactions to selectively cancelled sounds were significantly less than to trigger sounds. This shows that selective noise cancelling could be used to apply audiological treatments to misophonia.
3

<strong>Enhancing Construction Workers Safety: The Design and Implementation of Interactive-Motivational Noise-Cancelling Headphones</strong>

Shima Jahani (16648824) 31 July 2023 (has links)
<p>  </p> <p>Noise-induced hearing loss (NIHL) is a significant occupational health concern in the construction industry, necessitating effective hearing protection for workers. This project explores the detrimental consequences of environmental pollutants, specifically noise pollution common in construction settings. The research incorporates user interviews with construction workers and managers to identify challenges and motivations surrounding the use of hearing protection devices.</p> <p>My findings underscore the necessity of addressing pollution in the construction industry to safeguard the well-being of workers. Noise pollution emerges as a primary concern, leading to hearing loss, stress, decreased productivity, and safety hazards. The research revealed that workers grapple with obstacles, including discomfort, lack of awareness, and cost barriers, while also recognizing driving forces, including fear of hearing loss and the encouragement of supervisors. The design process involved thorough research, including a literature review, competitive analysis, and semi-structured user interviews, resulting in an advanced hearing protection device that prioritizes effective communication, cleanliness, and user comfort. The final product incorporates innovative features such as lighting indicators, a compact charging case, strategically positioned buttons, secure fit with magnets, and a range of color options. Furthermore, the accompanying application features customizable ambient sounds, performance feedback, and gamification elements.</p>
4

On Enhancement and Quality Assessment of Audio and Video in Communication Systems

Rossholm, Andreas January 2014 (has links)
The use of audio and video communication has increased exponentially over the last decade and has gone from speech over GSM to HD resolution video conference between continents on mobile devices. As the use becomes more widespread the interest in delivering high quality media increases even on devices with limited resources. This includes both development and enhancement of the communication chain but also the topic of objective measurements of the perceived quality. The focus of this thesis work has been to perform enhancement within speech encoding and video decoding, to measure influence factors of audio and video performance, and to build methods to predict the perceived video quality. The audio enhancement part of this thesis addresses the well known problem in the GSM system with an interfering signal generated by the switching nature of TDMA cellular telephony. Two different solutions are given to suppress such interference internally in the mobile handset. The first method involves the use of subtractive noise cancellation employing correlators, the second uses a structure of IIR notch filters. Both solutions use control algorithms based on the state of the communication between the mobile handset and the base station. The video enhancement part presents two post-filters. These two filters are designed to improve visual quality of highly compressed video streams from standard, block-based video codecs by combating both blocking and ringing artifacts. The second post-filter also performs sharpening. The third part addresses the problem of measuring audio and video delay as well as skewness between these, also known as synchronization. This method is a black box technique which enables it to be applied on any audiovisual application, proprietary as well as open standards, and can be run on any platform and over any network connectivity. The last part addresses no-reference (NR) bitstream video quality prediction using features extracted from the coded video stream. Several methods have been used and evaluated: Multiple Linear Regression (MLR), Artificial Neural Network (ANN), and Least Square Support Vector Machines (LS-SVM), showing high correlation with both MOS and objective video assessment methods as PSNR and PEVQ. The impact from temporal, spatial and quantization variations on perceptual video quality has also been addressed, together with the trade off between these, and for this purpose a set of locally conducted subjective experiments were performed.

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