ISSC 2013 24th IET Irish Signals and Systems Conferences
https://research.thea.ie/handle/20.500.12065/193
2024-03-29T06:47:55ZTowards shifted NMF for improved monaural separation
https://research.thea.ie/handle/20.500.12065/1056
Towards shifted NMF for improved monaural separation
Jaiswal, R.; Fitzgerald, D.; Coyle, E.; Rickard, S.
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The ability of Non-negative Matrix Factorisation (NMF) to decompose magnitude spectrogram into meaningful entities has found use in many audio applications. NMF can be used to factorise audio spectrogram of a music signal into parts based frequency basis functions which typically corresponds to notes and chords in music. However, these pitched basis functions needed to be clustered to their respective sources. Many clustering algorithms have been proposed to group these basis functions. Recently, Shifted Non-negative Matrix Factorisation (SNMF) based methods have been used to reconstruct individual sound sources. Clustering of basis functions using SNMF uses a Constant Q Transform (CQT) of the frequency basis functions. Here, we argue that incorporating the CQT into the SNMF model can be used to better the separation quality of individual sources. An algorithm is presented to estimate sound sources and is an improvement to the existing techniques. Results are compared to show the improvement.
2013-06-01T00:00:00ZImproved stereo instrumental track recovery using median nearest-neighbour inpainting
https://research.thea.ie/handle/20.500.12065/1055
Improved stereo instrumental track recovery using median nearest-neighbour inpainting
Jaiswal, R.; Fitzgerald, D.
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Several algorithms have been proposed for vocal removal which operate by finding the position of the vocals in the stereo field and removing the time-frequency bins associated with that position. However, in many cases, there will be other instruments such as drums and bass guitar present in the same position. These instruments will be removed along with the vocals and so adversely affect the sound quality of the recovered instrumental track. We present a method for estimating the missing information in the removed time-frequency bins, while still suppressing vocals, allowing recovery of an improved stereo instrumental track.
2013-06-01T00:00:00ZFormal verification of ‘full chip’ containing ‘shell’ partitions with and without feed-thrus
https://research.thea.ie/handle/20.500.12065/1054
Formal verification of ‘full chip’ containing ‘shell’ partitions with and without feed-thrus
Iqbal, R.
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The `Full Chip' module of an ASIC is made up of various partitions and similar to individual partitions, it also goes through various stages of the physical design. The initial design-planning works on the existing pins of a partition, adds feed-thru pins and performs custom placement and routing on signal and clock nets. Near tape-in, ECO (Engineering Change Order) forces manual changes to design as opposed to taking it through full implementation cycle. At the final stages, when layout database of each partition meets the requirements, a bottom up integration is carried out to create full chip layout. All these stages can create logical differences between layout and RTL of the top level interface. In order to verify that no unintentional logical change has happened to full chip, a robust formal verification strategy with numerous practical considerations is necessary. Designers also make use of 100% or partial shell models at the floor-planning phase which does bring advantages but also creates challenges for the formal verification flow. This article documents these challenges by explaining the formal verification approach taken on Intel's next generation network processing chip.
2013-06-01T00:00:00ZModeling user behaviour in response to cyberthreats
https://research.thea.ie/handle/20.500.12065/1053
Modeling user behaviour in response to cyberthreats
Caldwell, A.; McGarvey, J.
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Considerable challenges exist for the average computer user, organizations and indeed governmental agencies with the advent and evolution of threats directed against the computer user today. Combating cyberthreats has not only become a highly politicized issue but also a lucrative one as is evidenced from the growth in information security workforce. In conjunction with the nebulous existence of threats there is also an implied sense of calculability, even predictability, as often proclaimed by many security industry experts and academics. The end user must still make an independent decision on whether to react to these threats or not. To attempt to understand end user motivations when faced with threats, attitude-behaviour models are sometimes used. The theory of planned behaviour has been adapted to understand the impact of factors which may trigger behaviours in end users to deal with a cyberthreat. The model suggests that end users' intentions are not significantly mediated by their attitudes, perceived abilities to prevent threats or perceptions of their peer group. (7 pages)
2013-06-01T00:00:00Z