Quantization effects in the polyphase N-path IIR structure

Polyphase IIR structures have recently proven themselves very attractive for very high performance filters that can be designed using very few coefficients. This, combined with their low sensitivity to coefficient quantization in comparison to standard FIR and IIR structures, makes them very applicable for very fast filtering when implemented in fixed-point arithmetic. However, although the mathematical description is very simple, there exist a number of ways to implement such filters. In this paper, we take four of these different implementation structures, analyze the rounding noise originating from the limited arithmetic wordlength of the mathematical operators, and check the internal data growth within the structure. These analyses need to be done to ensure that the performance of the implementation matches the performance of the theoretical design. The theoretical approach that we present has been proven by the results of the fixed-point simulation done in Simulink and verified by an equivalent bit-true implementation in VHDL.

A computationally efficient DAB bit-stream processor

This paper describes an MPEG (moving pictures expert group) audio layer II - LFE (lower frequency extension) bit-stream processor targeting DAB (digital audio broadcasting) receivers that will handle the decoding of the frames in a computationally efficient manner to provide a synthesis sub-band filter with the reconstructed sub-band samples. Focus is given to the frequency sample reconstruction part, which handles the re-quantization and re-scaling of the samples once the necessary information is extracted from the frame. The comparison to a direct implementation of the frequency sample reconstruction block is carried out to prove increased computational efficiency.

Something to show for it: the place of mementoes in women’s oral histories of work

Workplace memorabilia, regarded here as artifacts and mementoes kept from workplaces and stored in homes, is varied, including; tools of a trade, ephemeral leaflets and pamphlets, union mementoes, uniforms and badges, long service awards, gifts from colleagues, and photographs both formal and informal. These objects can symbolize many years of work-life history and the corollary of this, their absence, perhaps the need to forget the drudgery of ‘the daily grind’. The materiality of an object saved or taken from the workplace often prompts reminiscence (Bornat, 2001) but can also, in itself and its method of display, represent and express key identities, work processes and traditions. Using examples from a three year ESRC funded project on work and identity this paper focuses on the women who participated in the study and investigates what is kept or not, whether the ways in which work memorabilia is displayed or stored is gendered, and how this might illuminate gendered social relations in the workplace and gendered work identities.

Automated P.falciparum detection system for post-treatment malaria diagnosis using modified annular ring ratio method

The gametocytes of the malaria parasite Plasmodium falciparum are highly resistant to antimalarial drugs. Its presence in the blood can be detected even after a successful malaria treatment. This paper explains a modified Annular Ring Ratio method which successfully locates and differentiates gametocytes of P. falciparum species in thin blood film images. The method can be used as an efficient tool for gametocyte detection for post-treatment malaria diagnosis. It also identifies the presence of any White Blood Cells (WBCs) in the image, and discards other artifacts and non infected cells. It utilizes the information based on structure, color and geometry of the cells and does not require any segmentation or non-illumination correction techniques that are commonly used for cell detection.