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Final conclusion drawn from our results.


Final thoughts

Our work has shown how important it is to have the right model for the right situation. The fact that the use of convolutive rather than a multiplicative mixing matrix led to success attests to the importance of proper modeling. This was clearly demonstrated by the results of our testing. The Fast ICA model is appropriate for the ideal case of mixing signals in Matlab because all the necessary fast ICA assumptions are met. In particular, the mixing matrix is multiplicative. However, for the case or acoustically mixing signals by recording two sources simutaneously, we saw that fast ICA failed competely to isolate individual sources because a convolutive mixing matrix is involved instead of a multiplicative one. It should be noted that there are a least two stages in which convolution occurs: both in the room and in the air on the way to the microphone, and as the microphone transduces the signal to an electric signal. These processes may be grouped into a single mixing matrix without loss of information because of the transitive property of convolution and because we are not exclusively interested in what the signal of the microphone was, but rather in what the original source sounded like. Using the STFICA algorithm, we were able to at least successfully separate the sources for the tone and noise case, therefore proving that the STFICA model is suited for this secnario. However, we were not successful in more complicated cases such as voice and tone due to the fact that our group did not have enough time to fully undertand and implement the concept of variable stages of prewhtening. So there is potential for the STFICA model to be fully applicable to all acoustically mixed sources, but further modifcations as well as a better understand of the model is needed. Another testament to the importance of choosing the correct model for a particular application, is that while it is true that fast ICA failed with acoustically mixed signals, fast ICA works exceptionally well with image applications such as visual noise removal.

Steps toward improvement

Since our team did not yet achieve exceptional separation of more complicated acoustic signals, such as the voice and tone case, there are some steps to take to improve our results. For example, there must be a refinement of the prewhitening process, which requires additional study on the part of our group members. With this better understanding of the prewhitening concept and process, we expect to gain a better comprehension of the number of required prewhitening stages to make the given mixed signals become more independent of one another in time and space. This should in effect significantly help in the demixing of any complicated mixed signals to its individual sources with as much success as with the tone and noise case. Another method for improvement includes the use of expected behavior in order to better isolate the signal sources. For exmaple, if we know that a man and a woman are speaking, we should be able to tell our algorithm some additional information about the expected spectra of our speakers.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Elec 301 projects fall 2008. OpenStax CNX. Jan 22, 2009 Download for free at http://cnx.org/content/col10633/1.1
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