title: Computing the fast Fourier transform on SIMD microprocessors

authors: Blake, Anthony Martin

subjects: Fourier transform

abstract: This thesis describes how to compute the fast Fourier transform (FFT) of a power-of-two length signal on single-instruction, multiple-data (SIMD) microprocessors faster than or very close to the speed of state of the art libraries such as FFTW (“Fastest Fourier Transform in the West”), SPIRAL and Intel Integrated Performance Primitives (IPP).

The conjugate-pair algorithm has advantages in terms of memory bandwidth, and three implementations of this algorithm, which incorporate latency and spatial locality optimizations, are automatically vectorized at the algorithm level of abstraction. Performance results on 2- way, 4-way and 8-way SIMD machines show that the performance scales much better than FFTW or SPIRAL.

The implementations presented in this thesis are compiled into a high-performance FFT library called SFFT (“Streaming Fast Fourier Trans- form”), and benchmarked against FFTW, SPIRAL, Intel IPP and Apple Accelerate on sixteen x86 machines and two ARM NEON machines, and shown to be, in many cases, faster than these state of the art libraries, but without having to perform extensive machine specific calibration, thus demonstrating that there are good heuristics for predicting the performance of the FFT on SIMD microprocessors (i.e., the need for empirical optimization may be overstated).

text: Computing the fast Fourier transform on SIMD microprocessors This thesis describes how to compute the fast Fourier transform (FFT) of a power-of-two length signal on single-instruction, multiple-data (SIMD) microprocessors faster than or very close to the speed of state of the art libraries such as FFTW (“Fastest Fourier Transform in the West”), SPIRAL and Intel Integrated Performance Primitives (IPP).

The conjugate-pair algorithm has advantages in terms of memory bandwidth, and three implementations of this algorithm, which incorporate latency and spatial locality optimizations, are automatically vectorized at the algorithm level of abstraction. Performance results on 2- way, 4-way and 8-way SIMD machines show that the performance scales much better than FFTW or SPIRAL.

The implementations presented in this thesis are compiled into a high-performance FFT library called SFFT (“Streaming Fast Fourier Trans- form”), and benchmarked against FFTW, SPIRAL, Intel IPP and Apple Accelerate on sixteen x86 machines and two ARM NEON machines, and shown to be, in many cases, faster than these state of the art libraries, but without having to perform extensive machine specific calibration, thus demonstrating that there are good heuristics for predicting the performance of the FFT on SIMD microprocessors (i.e., the need for empirical optimization may be overstated).

year: 2012

title: Consumer-centric protection for online social networks

authors: Akram, Raja Naeem

abstract: Online Social Networks (OSNs) are a unique construct that is shaped by the advancement and availability of Internet technologies. A large portion of internet users make use of OSN services to share and celebrate their personal lives with friends and family. A substantial proportion of these shared experiences revolve around privacy-sensitive information. The OSN services handling privacy-sensitive information deploy state-of-the-art security and privacy preserving mechanisms. However, these protections are, to a great extent, not consumer-centric: this is the main focus of this study. In this paper, we define the notion of Consumer-Centric Protection (CCP) for OSNs. In this proposal, the individual user controls how her data can be accessed by her contacts (e.g. friends and family members) and others, thus giving control of user data back to the rightful owner — the user. This work is still in progress and in this paper we present our preliminary results

text: Consumer-centric protection for online social networks Online Social Networks (OSNs) are a unique construct that is shaped by the advancement and availability of Internet technologies. A large portion of internet users make use of OSN services to share and celebrate their personal lives with friends and family. A substantial proportion of these shared experiences revolve around privacy-sensitive information. The OSN services handling privacy-sensitive information deploy state-of-the-art security and privacy preserving mechanisms. However, these protections are, to a great extent, not consumer-centric: this is the main focus of this study. In this paper, we define the notion of Consumer-Centric Protection (CCP) for OSNs. In this proposal, the individual user controls how her data can be accessed by her contacts (e.g. friends and family members) and others, thus giving control of user data back to the rightful owner — the user. This work is still in progress and in this paper we present our preliminary results

year: 2014

title: The Te Aroha hot springs (mainly in the nineteenth century)

authors: Hart, Philip

abstract: Unique amongst New Zealand mining districts, the hot springs sited at the base of the mountain were popular with miners, residents, and an increasing number of visitors. Highly valued by Maori for their medicinal qualities, Pakeha visited them well before gold was discovered. Acquired by the Crown as part of the purchase of the Aroha Block, contention arose over whether the springs had been gifted to the Crown and whether Maori should be charged for using them. The provision of a small but free bath to Ngati Rahiri did not satisfy them.
 After Pakeha settled, the springs were developed and the surrounding domain was landscaped. Analysis of the water by experts produced claims about its curative qualities and many miracle cures were claimed, and the water was bottled until more recent analyses traced the existence of arsenic. Men reputedly skilled in hydropathy and similar ‘sciences’ were appointed to assist those suffering from rheumatism and the like. A local board beautified the area until the domain was taken over by the Tourist Department. Many tourists from throughout New Zealand and abroad were attracted by the facilities, which included a library, but some noticed a lack of cleanliness and were annoyed by larrikins. Despite such problems, as mining faded Te Aroha profited from becoming a tourist destination and sanatorium.

text: The Te Aroha hot springs (mainly in the nineteenth century) Unique amongst New Zealand mining districts, the hot springs sited at the base of the mountain were popular with miners, residents, and an increasing number of visitors. Highly valued by Maori for their medicinal qualities, Pakeha visited them well before gold was discovered. Acquired by the Crown as part of the purchase of the Aroha Block, contention arose over whether the springs had been gifted to the Crown and whether Maori should be charged for using them. The provision of a small but free bath to Ngati Rahiri did not satisfy them.
 After Pakeha settled, the springs were developed and the surrounding domain was landscaped. Analysis of the water by experts produced claims about its curative qualities and many miracle cures were claimed, and the water was bottled until more recent analyses traced the existence of arsenic. Men reputedly skilled in hydropathy and similar ‘sciences’ were appointed to assist those suffering from rheumatism and the like. A local board beautified the area until the domain was taken over by the Tourist Department. Many tourists from throughout New Zealand and abroad were attracted by the facilities, which included a library, but some noticed a lack of cleanliness and were annoyed by larrikins. Despite such problems, as mining faded Te Aroha profited from becoming a tourist destination and sanatorium.

year: 2016