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Feature separation

The neural network must be fed meaningful information. If there are not clusters within the data and distinguishing relationships between features, than there is nothing for the neural network to learn. Here we show that the features extracted from the LPC are in fact providing useful information to the neural network. A subset of four emotions has been selected for visual clarity. They have been normalized by mean and variance to generate a roughly Gaussian distribution of the frequency location of the fourth formant. Notice that the mean, variance, and skewness of each of the four probability density functions is are distinct.

Computation complexity

This algorithmic pipeline involves a significant number of computationally heavy tasks. In its original iteration, each sample required 50 seconds of processing time before the neural network was trained. We minimized the order of the filter to introduce an acceptable level of passband ripple, vectorized the LPC windowing implementation, and replaced the find operation used by in formant detection with logical indexing. These measures reduced the average computational time to only about half a second per sample.

Neural network learning curves

To evaluate the performance of the neural network, we split the database into two distinct sections. The training set (70% of the database) was used to train the neural network. A logarithmic distribution of regularization was tested. When each trained set of internodal weights was applied to the test set (30% of the database), we were able to determine the true accuracy of the neural network. We found that the test set accuracy actually peaked at a low value of regularization and then decreased. This is a characteristic signature of having far too small of a database. Given that the size of the database was fixed, we attempted to compensate by minimizing the number of input features to the neural network. It is important to have the ratio between training examples and inputs be large. If we had instead seen a gap between the training and test set performance even at high levels of regularization, we would have known that our choice of input features was inherently faulty.

Algorithm performance

We established a human performance baseline by playing a randomized list of 100 samples to three individuals. None were able to significantly outperform chance. Clearly humans struggle to classify a precise emotion from such a large list, especially without any context. If the test is altered to be a binary matching test where the subject is asked to evaluate whether a given emotion is intoned in a given sample, human performance markedly improves. This suggests that in normal everyday interaction, we rely on semantic content and situational context to derive an emotional expectation; then, we simply evaluate the speaker's tone to see if it matches that expectation.

The algorithm correctly identifies the tone of the speakers voice with 26 percent accuracy. The algorithm was particularly adept at detecting contempt (41%), anxiety (37%), sadness (33%), and boredom (31%). It struggled to identify cold anger (4%).

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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Robust classification of highly-specific emotion in human speech. OpenStax CNX. Dec 14, 2012 Download for free at http://cnx.org/content/col11465/1.1
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