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We're a little crazy, about science!

Posts tagged “education

Day #30 : Confidence Interval – 365 DoA

Confidence intervals

Yep, we’re talking confidence!

Day 30 already! Where does the time go? It feels like we just started this whole project and it probably wouldn’t be a good idea to look at the remaining time to completion, so let’s not and just enjoy the nice round 30. We will get back to our p.d.f another day, but today is going to be short. That’s what I usually say before typing out 10 pages worth of information so to avoid that, let’s touch on something important, but something I can do briefly. Today we’re talking about confidence intervals*

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Day #29 : Probability density functions, Part 3 – 365 DoA

gaussian CDF vs pdf

Don’t be scared, we’re going to tackle this guy today!

Well, apparently you guys really appreciated my probability density function posts. It’s good to see people interested in something a little less well-known (at least to me). So for those of you just joining us, you’ll want to start at part 1 here. For those of you who are keeping up with the posts, let’s review and then look at specific functions. Namely let’s start by going back to our gaussian distribution function and talk about what’s going on with that whole mess. It will be fun, so let’s do it!*

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Day #28 : Cumulative Distribution Functions – 365 DoA

Exponential_distribution_cdf

An example C.D.F. of an exponential distribution

Today we were going to do another deep dive into the p.d.f and C.D.F. relationship. Specifically today we were going to talk about specific p.d.f. functions and why we use them, however… I am not doing so hot today, so instead we are going to back track just a bit and talk about what how a C.D.F. differs from our p.d.f. even though we kind of covered it, it would be nice to be clear and I can do this in a (fairly) short post for the day. So that said, let’s get started and we will pick up our p.d.f. discussion next time (maybe).*

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Day #27 : Probability density functions, Part 2 – 365 DoA

PDF_CDF

Today we are looking at our p.d.f. (yes this image has p.d.f. written as PDF, please don’t be confused!) and our C.D.F.’s let’s do this!

Oh hi didn’t see you there. Today is part 2 of the probability density functions notes (posts?), whatever we are calling these. You can read part 1 here as you should probably be familiar with the (super confusing) notation we use to describe our p.d.f. and our C.D.F. now that we’ve given that lovely disclaimer, let’s look once again at probability density functions!*

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Day #26 : Probability density functions, Part 1 – 365 DoA

statisics jokes

Dashing dreams one comic at a time, via Saturday Morning Breakfast Cereal 

We are well on our way to wrapping up week 4, what a ride it’s been! It’s been a long day for me, so today might be short. However, I really, really, really want to break into probability density functions. This topic is going to be a bit more advanced than some of the things we’ve covered (IE more writing) so it will most definitely be broken up. Let’s look at why and discover the wonderful weirdness of probability density functions!*

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Day #13 : Significance, Part 1 – 365 DoA

Normally distributed data shown using a histogram plot
Normally distributed data shown using a histogram plot

Histogram of normally distributed data. It looks very… nomal. No it really is normally distributed, read on to find out what that means and how we can use it.

If you’ve read my last post I hinted that today we would discuss filtering. Instead I think I want to take this a different direction. That isn’t to say we won’t go over filtering, we most definitely will. Today I want to cover something else though, significance. So you’ve recorded your signal, took an ensemble average, and now how do we tell if it actually means something, or if you are looking at an artificial or arbitrary separation in your data (IE two separate conditions lead to no difference in your data). Let’s look at significance.*

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Day #12 : Signal, cutting through the noise – 365 DoA

example data

45 separate trials of very noisy data with the average of those trials (black). Believe it or not, this is actually very useful and very real data from something I am currently working on.

Noise, it can be troublesome. Whether you are studying and someone is being loud or you are trying to record something, noise is everywhere <stern look at people who talk during movies>. Interestingly enough the concept of noise in a signal recording sense isn’t all too different from dealing with talkative movie goers, so let’s talk noise!*

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Day #11 : Why even use the spectrogram? – 365 DoA

rotated spectrogram showing all three dimensions
rotated spectrogram showing all three dimensions

A spectrogram plot rotated so we can see all three dimensions.

So you wanna use a spectrogram… but why? What does a spectrogram do that we can’t do using some other methods for signal processing? As it turns out, there is a lot of reasons you may want to use the spectrogram and today we are going to cover some of those reasons and number four may shock you! (okay not really, what do you think this is a clickbait website?)*

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Day #10 : Spectrogram vs. the banana of uncertainty – 365 DoA

banana

The banana of uncertainty (okay, it’s not a real banana)

Well ten days in and we’ve just introduced the idea of the spectrogram. While a lot of this information is just the broad strokes, I like to think that we’ve covered enough to give you a good idea about how to use these tools and what they are used for. However, we do need to discuss a limitation to the spectrogram, something called the banana of uncertainty, okay not quite the name, but you’ll see why I keep calling it that.*

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Day #9 : Reading a Spectrogram – 365 DoA

rotated spectrogram showing all three dimensions
other example

Definitely not the same spectrogram as yesterday, no really look. Now for the part where I tell you how to read this thing…

Last post we introduced a new tool in our arsenal of signal processing analysis, the spectrogram. Without knowing how to read it, it just looks sort of like a colored mess. Don’t get me wrong, it is an interesting looking colored mess, but a mess nonetheless. Well today we are going to talk about how to interpret the plot and why exactly we would ever use this seeming monstrosity.*

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Day #8 : The Spectrogram Function – 365 DoA

Spectrogram

Example spectrogram from some data I had recently processed

To (somewhat) continue with our signal processing theme that we have going on at the moment, over the next few days, let’s look at something called the spectrogram. It’s three dimensions of fun!*

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Day #7 : Small waves, or wavelets! – 365 DoA

Meyer Mother wavelet

This is the Meyer wave, a representation of a so-called mother wavelet function to use for the wavelet transform. Notice that it is finite!

Waves! We’re officially one week through 365 Days of Academia! Woo! 1 week down, 51(.142…) weeks left! Let’s wrap up this weeks theme (there wasn’t originally a theme, but it kind of ended up that way) by talking about other ways we can get to the frequency domain. Specifically, let’s stop the wave puns and let’s talk wavelets!*

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Day #6 : The fast and the Fourier – 365 DoA

Fourier_transform_time_and_frequency_domains_(small)

A good example of how the Fourier transform can approximate signals. The red signal is our input signal and the blue shows how the output of the Fourier transform.

Okay, if you’ve been keeping up with these posts, we know about Welch’s method, Thomson’s method, the things that make them different, and the things that make them similar. The thing that both of these transforms rely on is the Fourier transform. What is the Fourier transform? Well, something I probably should have covered first, but whatever this is my blog we do it in whatever order we feel like, so let’s dive in!*

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Day #5 : Whose window function is it anyway? – 365 DoA

Window function - funny

This is not how we use a window function on the computer…

One day someone looked at the windowed fourier transform and said, “Don’t be such a square!” and thus window functions were invented. If you believe that, then I have an island for sale, real cheap. But seriously, let’s do a dive into what a window function is and why the heck there are so many of them, because there ARE a LOT! So let’s get started!*

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Day #4 : Spectral leakage… embarrassing – 365 DoA

Day 4 - Leakage - arrows

Look at that leakage!

Leakage, it’s never a good thing. For today’s post we’re going to cover a very important topic. Spectral leakage, it’s a big reason why spectral density estimation is well, an estimation. The other reason it is an estimation is because the fourier transform is an approximation of the original signal, but the Fourier transform is a whole other post on its own. So let’s talk leakage!*

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Day #3 : Power Spectral Density Overview – 365 DoA

In our last post we introduced the two main characters in this story of spectrogram. On one end we have Welch’s method (pwelch) on the other end we have the Thomson multitaper method (pmtm). As promised here is a awful basic breakdown of why is more than one way to compute power spectral density (in fact there are several, far more than the two I’m talking about). So, let’s just dig right in!*

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Day #2 : Power Spectral Density (pmtm) – 365 Days of Academia

Day 2 - EKG

A example EKG signal

This is a (somewhat) continuation on what we were discussing in the previous post. We covered the pwelch MATLAB function, this time we will cover the PMTM function, this function uses the Thomson multitaper method to calculate power spectral density. We can do a deep dive into the differences between the two next time, but for now let’s talk about the command itself.*

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Day #1 : Power Spectral Density (pwelch) – 365 Days of Academia

EEG

Some EEG data that I’ve aligned, processed, and made look nice and pretty.

Signal processing, it’s complex, there are a million ways to go about processing a signal, and like life, there is no best way to go about doing it. Trust me, it is as frustrating as it sounds. Today’s scratch pad note is on power spectral density or PSD for short. So let’s dive in.*

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Parents’ math skills ‘rub off’ on their children

children in math

children in math

Parents who excel at math produce children who excel at math. This is according to a recently released study, which shows a distinct transfer of math skills from parent to child. The study specifically explored intergenerational transmission–the concept of parental influence on an offspring’s behavior or psychology–in mathematical capabilities.

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Babies chew on subtle social, cultural cues at mealtime

baby eating food

baby eating food

At the dinner table, babies do a lot more than play with their sippy cups, new research suggests. Babies pay close attention to what food is being eaten around them – and especially who is eating it. The study adds evidence to a growing body of research suggesting even very young children think in sophisticated ways about subtle social cues.

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Neuroscientists discover new learning rule for pattern completion

brain remembers

brain remembers

Recently, scientists discovered a new learning rule for a specific type of excitatory synaptic connection in the hippocampus. These synapses are located in the so-called CA3 region of the hippocampus, which plays a critical role for storage and recall of spatial information in the brain. One of its hallmark properties is that memory recall can even be triggered by incomplete cues. This enables the network to complete neuronal activity patterns, a phenomenon termed pattern completion.

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The scientific brain: How the brain repurposes itself to learn scientific concepts

learning brain

learning brain

The human brain was initially used for basic survival tasks, such as staying safe and hunting and gathering. Yet, 200,000 years later, the same human brain is able to learn abstract concepts, like momentum, energy, and gravity, which have only been formally defined in the last few centuries. New research has now uncovered how the brain is able to acquire brand new types of ideas.

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Strongest evidence yet of a link between breakfast and educational outcomes

Study provides strongest evidence yet of a link between breakfast quality and educational outcomes

A direct and positive link between pupils’ breakfast quality and consumption, and their educational attainment, has for the first time been demonstrated in a ground-breaking new study carried out by public health experts at Cardiff University. The study of 5000 9-11 year-olds from more than 100 primary schools sought to examine the link between breakfast consumption and quality and subsequent attainment in Key Stage 2 Teacher Assessments* 6-18 months later.

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How reward and daytime sleep boost learning

How reward and daytime sleep boost learning

A new study suggests that receiving rewards as you learn can help cement new facts and skills in your memory, particularly when combined with a daytime nap. The findings from the University of Geneva reveal that memories associated with a reward are preferentially reinforced by sleep. Even a short nap after a period of learning is beneficial.

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‘Delayed remembering’: Kids can remember tomorrow what they forgot today

'Delayed remembering': Kids can remember tomorrow what they forgot today

For adults, memories tend to fade with time. But a new study has shown that there are circumstances under which the opposite is true for small children: they can remember a piece of information better days later than they can on the day they first learned it. While playing a video game that asked them to remember associations between objects, 4- and 5-year-olds who re-played the game after a two-day delay scored more than 20 percent higher than kids who re-played it later the same day.

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On Wikipedia, politically controversial science topics vulnerable to information sabotage

On Wikipedia, politically controversial science topics vulnerable to information sabotage

Wikipedia reigns. It’s the world’s most popular online encyclopedia, the sixth most visited website in America, and a research source most U.S. students rely on. But Wikipedia entries on politically controversial scientific topics can be unreliable due to information sabotage.

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How ‘science popularizers’ influence public opinion on religion

darwin fighting jesus

Two prominent scientists with drastically different views on the relationship of science and religion – Richard Dawkins and Francis Collins – have an equally different influence on these views among people who are unfamiliar with their work, according to new research from Rice University and West Virginia University.

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What musical taste tells us about social class

music conductor

Photo credit goes to: Hiroyuki Ito/Getty Images

Love the opera? Hungry for hip hop? It turns out that your musical likes and dislikes may say more about you than you think, according to UBC research. Even in 2015, social class continues to inform our cultural attitudes and the way we listen to music, according to the study.

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Girls suck at science, and other depressing stereotypes

The stereotype is still alive, girls suck at math and science

Image credit goes to: xkcd.com

The Netherlands had the strongest stereotypes associating science with men more than women, according to a new Northwestern University study that included data from nearly 350,000 people in 66 nations. These stereotypes are prevalent across the world — even in nations such as Argentina and Bulgaria where women are roughly half of science majors in colleges and universities and employed researchers, according to the study, the largest ever of its kind.

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Kids with ADHD must squirm to learn

Cats with adhd

For decades, frustrated parents and teachers have barked at fidgety children with ADHD to “Sit still and concentrate!” But new research shows that if you want ADHD kids to learn, you have to let them squirm. The foot-tapping, leg-swinging and chair-scooting movements of children with attention-deficit/hyperactivity disorder are actually vital to how they remember information and work out complex cognitive tasks.

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Study links brain anatomy, academic achievement, and family income

Family income can have lasting changes in the brain

Image credit goes to: Jose-Luis Olivares/MIT

Many years of research have shown that for students from lower-income families, standardized test scores and other measures of academic success tend to lag behind those of wealthier students. Well now a new study offers another dimension to this so-called “achievement gap”After imaging the brains of high- and low-income students, they found that the higher-income students had thicker brain cortex in areas associated with visual perception and knowledge accumulation.

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Study shows children and birds learn alike

Image credit goes to: John Petsel

Image credit goes to: John Petsel

Your child is your pride and joy — and why not, every parent should be a proud one, even if your child might be bird brained. Or maybe birds are baby brained? In any case, a new study has found that pigeons can categorize and name both natural and manmade objects–and not just a few objects. These birds categorized 128 photographs into 16 categories, and they did so simultaneously.

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When it comes to sleep recommendations, what about the children?

sleepy

Sleep is a hot topic lately, are we getting too much, too little, how much is enough? However, most of these questions are for adults, so what about children? Well as it turns out a new study used activity monitors to track how sleep habits changed in younger and older teens as they grew during a two-year period. Key findings from this study has also lent t0 new support to recent recommendations by the American Academy of Pediatrics that middle and high schools avoid starting earlier than 8:30 a.m.

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Quantum Conundrum, Puzzling People, and Survey Statistics

Order matters, we all know this when it comes to math, but did you know the order of questions asked can affect how you answer them? It’s true and it isn’t new news, the question-order effect is why survey organizations normally change the order of questions between different respondents, hoping to cancel out this bias. But that isn’t the interesting part, not by a long shot.

It turns out that quantum theory is a much better predictor of the survey results than conventional methods of predictions.

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Solar Freakin’ Roadways- 5 Concerns Analyzed

solarroad

Solar Roadways, I know most people have been in support of the new blossoming technology and I’m happy to be a part of that [at least in support]. However, no matter where I turn there are a handful of common concerns that are brought up against the technology. Well today I wanted to go over five of the main concerns. I also wanted to take a peek into what the future could look like, with solar roads.

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Land of the Free, Home of the Afraid?

smartphone science

Let’s take a Loony quiz! Do you believe any of these statements are true? Global warming isn’t real. GMO food is the devil. Organic and all natural are better. Science is just a belief like religion. Evolution is just a theory, so other theories should be taught along side. Vaccines do — or can– cause serious health concerns. If you answered yes to any of these questions, then you might be suffering from a lack of scientific understanding, but don’t worry you’re not alone.

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Genetically Modified Food: Myth and Legend

genetically-modified-food

Vermont, not quite the armpit of the United States, but not a place I would live [personally speaking of course]. Still, looking at history Vermont was the first to ban slavery [good], but now they are the first to do something else too, they are looking to ban all food that is genetically modified if it is not properly labeled [bad].

This bill is set to start a wildfire across the US with food scares, like any science scare, is easy to start and hard to stop [if at all]. Genetically modified food has helped cushion the ever growing population and the need to feed that population. People will [undoubtedly] argue otherwise, but all food is genetically modified one way or another.

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Is that Good Science? A Guide to Cutting through BS

WeirdScience

Part of getting an education isn’t about learning what to think, it is about learning how to find good information. When it comes to scientific literature [especially on-line], it’s hard to separate the good from the bad if you don’t know what to look for. With the emergence of pseudoscience in the mainstream I think it’s important to go over a few red flags when it comes to claims being made.

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5 Reasons Why Science is Losing the War

Science is losing an unseen war and like any war it isn’t without its casualties. The true body count won’t be evident, not at first. This isn’t a war over land, or freedoms, it is a war on ignorance, a fight for the future. Science has brought us a level of comfort and connectivity we have never really seen. Unfortunately that connectivity is being used against us, allowing people with dubious motives to shout from the rooftops bold faced lies and a call for people to follow.

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Is being a human conservationist selfish?

Earth-Day-2014

Earth day, it’s a lot like new years. You make resolutions that you will never follow, promise yourself you will attempt to do things you really don’t want to, and try to do without that thing you know you can live without, but can’t seem to do it.

Yesterday was Earth day, so happy belated earth day, I guess… So how about the state of the planet then? It’s the only one we have, it is the place we call home, and unless you want to deal with chest bursting aliens [hey, I’ve seen the movies] then we are stuck here.

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