Month: October 2013

Blame Bias & Project Unbreakable

Project Unbreakable is a project run by Grace Brown, Kaelyn Siversky, Christina Dunlop, and Kerri Pang. It was created to raise awareness of the common nature of sexual assault and serves to alter the general sociocultural perception of rape. Disproving the regular assumption that rape is an uncommon, unfortunate occurrence that happens only to those who deserve it. The project is a composed of a collection of art submitted by survivors. These submissions are photographs of a survivors holding posters decorated with quotes from their attackers. Submissions also include quotes from others in reaction to survivors seeking help (e.g., “You deserved it,” “I don’t believe you”). This project features male rape survivors and showcases the reality that men can get raped. There is no discrimination as to who can participate in Project Unbreakable (“anyone who has experienced any form of sexual abuse, whether physical or emotional”). However, they do not accept admissions from children.

In my psychology class, we discussed an unfortunate phenomenon colloquially known as blame bias. People tend to think that good things happen to them because they’ve earned it; they think that bad things happen to them for an environmental reason. Paradoxically, people tend to think that good things happen to others because they are lucky, and bad things happen to others because they have done something wrong deserve it. This blame bias is flipped in many persons afflicted with disorders/tendencies such as depression and anxiety.

In essence, blame bias is:
______ things happen to ______ because ______.

Normal Perception
Good; me; I deserved it
Good; others; of environmental factors
Bad; me; of environmental factors
Bad; others; they deserved it

Afflicted Perception
Bad; me; I deserved it
Bad; others; of environmental factors
Good; me; of environmental factors
Good; others; they deserved it

This flipped paradigm is prevalent in survivors of sexual assault. One of the scars left by assault tends to be a deep feeling of shame: a belief that the incident is somehow the victim’s fault. Project Unbreakable serves as a place to assure survivors that this is not the case. My professor, a clinical psychologist, explained that the correct treatment of rape survivors is incredibly difficult and extensive, for the hole they have been pushed and fallen into is so deep. This hole is dug in the victim’s perception by cultural messages and the reactions of others.

Project Unbreakable serves as a stepping-stone to begin to rise from the hole, it allows for rape survivors to face their memories and deal with them at a distance. It is far easier for rape survivors to look at the stories of others and see that these people are innocent. This triggering experience helps many internalize the objective truth that the incident was not their fault. Additionally, the Project helps lesson the ignorance of others with “blame bias,” showing that rape is a widespread problem, and not the fault of the victim. This education implicitly helps victims of sexual assault. The Project has received thousands of submissions and continues to bring self-awareness to those suffering from the negative effects of blame bias.

Do You Even Search, Bro?

I recently came across a software engineer I respect greatly who is unfamiliar with the basics of grep (I know, right? Blew my mind). This is for him, hopefully it will help others. If you’re already familiar with this black magic || want to see a cool implementation, check out Grep is a Magical Beast.

Grep’s syntax is fairly simple:

grep [options] search_string file|dir

Grep supports regex as the search string — whip it out if you’re versed in its beauty. If you’re using a multiword search string, you must wrap the string in single quotes. Search all directories by listing *. as dir. Search subdirectories by restricting the path and adding an -r flag:

grep -r 'Carl' ~/Dropbox/LlamasHats/*

The [extremely] basic flags are:

Searching for ___? The flag for you
Text in subfolders -r
Whole words only -w
Case-insensitive text -i
File names only -l
Number of occurrences only -c

Is your mind blown yet? No? Check out ack. The abundance of CL switches will blow your mind. The syntax of ack is the same as that of grep. Their documentation is great.

The main difference I’ve found between grep and ack is speed. Here is a great post by Perl Monks on reasons to switch.

Using find is great for filename searches. find‘s syntax is a bit different than grep’s

find file|dir [options] search_string

A generic search:

find . -iname '*.sty'

What Does This Wobbly “d” Do?

What is the difference between \(\frac{d}{dx}\) and \(\frac{\partial}{\partial x}\)?

…is a question I get surprisingly often when tutoring friends.

Short version: The difference is all about dependency!

The “regular d” in \(\frac{d}{d x}\) denotes ordinary differentiation: assumes all variables are dependent on \(x\) (\(\rightarrow\) envoke chain/product rule to treat the other variables as functions of \(x\)).

The “wobbly d” in \(\frac{\partial}{\partial x}\) denotes partial differentiation and assumes that all variables are independent of \(x\).

You can make a straight d from a wobbly d by using a beautiful thing:

\(\frac{df}{dx} = \frac{\partial f}{\partial x} + \frac{\partial f}{\partial y}\frac{dy}{dx} + \frac{\partial f}{\partial z}\frac{dz}{dx}\)

You can remember it this way: the partial derivative is partially a “d”, or the the “wobbly d” is partial to nemself and bends nir neck down to look at nirs reflection \(\partial\).

Sidenote: Ne/nem/nir/nirs/nemself is a pretty swell gender neutral pronoun set!

Longer version: Before we start – what is a derivative, anyway?

The derivative of a function at a chosen point describes the linear approximation of the function near that input value. Recall the trusty formula: \(\Delta y = m\Delta x\), where m is the slope and \(\Delta\) represents the change in the variable? For a (real-valued) function of a (real) single variable, the derivative at that point is = tangent line to the graph at that point.

The beauty of math is: \(m = \frac{\Delta y}{\Delta x} \equiv\) “How much one quantity (the function) is changing in response to changes in another quantity (\(x\)) at that point (it’s input, assuming \(y(x)\)).”

So, it makes sense that derivative of any constant is 0, since a constant (by definition) is constant \(\rightarrow\) unchanging!

\(\frac{d(c)}{dx}=0\), where \(c\) is any constant.

What about everything that isn’t a constant?

That means, \(\frac{d(x^2)}{dx} = 2x\), since \(x^2\) is dependent on \(x\). \(\frac{d}{dx}\) denotes ordinary differentiation, i.e. all variables are dependent on the given variable (in this case, \(x\)).

But what about \(\frac{d(y)}{dx}\)? Looking at this equation, we immediately assume \(y\) is a function of \(x\). Otherwise, it makes no sense. \(\frac{d(y)}{dx} \equiv \frac{d(y(x))}{dx}\)

On the other hand, \(\frac{\partial (y)}{\partial x}\) denotes partial differentiation. In this case, all variables are assumed to be independent.

\(\frac{\partial (y)}{\partial x} = 0\)

Let’s compare them with an example. \(f(x,y) = ln(x)sec(y) + y\)

\(\frac{\partial f}{\partial x} = \frac{sec(y)}{x}\)

\(\frac{df}{dx}\) implies that \(y\) is dependent(a function of) \(x\), i.e. \(f = (ln(x)sec(y(x)) + y(x))\)

\(\frac{df}{dx} = \frac{dy}{dx}(ln(x)tan(y(x))sec(y(x)) + 1) + \frac{sec(y(x))}{x}\)

As you can see, \(\frac{\partial f}{\partial x} \neq \frac{df}{dx}\).

By the way, to use LaTex in Blogger include the following before </head> in your Template (source):

<script type="text/x-mathjax-config"> MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\(','\)']]}}); </script> 
<script src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML" type="text/javascript"> </script>

A Simple Look at Nanowire Assemblies in Optics

Below is a quick attempt to summarize and extrapolate from an article on Optical Routing And Sensing With Nanowire Assemblies in a simple manner, without assuming the reader is deeply familiar with the esoteric lexicon of photonics and optoelectronics. I can’t freely distribute the article which inspired this post; check with your local university to find a copy. More information on the relevant article is post script.

Disclaimer: I am a relative n00b in the material science-y side of photonics; I’ve previously played in physics at a higher level of abstraction. I attempted to keep the oversimplification to a minimum in my “simple” discussion below.

Sidenote: I decided to include the definitions in-line rather than using footnotes. I found the use of footnotes to organize definitions very similar to spaghetti code – which I prefer to avoid.

Enough dabbling, onto the physics!

What are nanowires and nanoribbons?

A nanowire is any wire with a diameter on the nanoscale [order of 10^-9 meters], and nanoribbons are structures which filter for different wavelengths of light [colors] depending on their chemical composition and structure. These ribbons act as short-pass filters; that is, they will only allow the smaller wavelengths of any beam that is not monochromatic.

I recently came across an article exploring of the combined use of nanowires and nanoribbons. Nanowire assemblies could potentially replace/supplement lithographically [created by transferring a pattern by selective exposure to light] defined structures currently used in most integrated photonic circuits: circuits which transmit laser beams compared to electronic integrated circuits which transmit electrons.

The main advantage of using nanowire assemblies is that they stand without assistance from their substrate’s structure and they are flexible. This allows them to be manipulated on surfaces and to be used as mobile probes in fluids. This versatility contrasts with the permanent location of lithographically defined structures with respect to their substrates.

The team of physicists who published this paper experimented with the assemblies in both dry and liquid mediums. In the dry medium, they synthesized Tin-dioxide nanoribbons and manipulated the ribbons and wires with a probe under a dark-field microscope. They used both a HeCd laser [a laser which emits blue light] for continuous unfiltered light [constant stream of most colors of light] and a YAG laser [a laser which emits ultraviolet light] for pumped pulsing; laser pumping is a technique used here to create or amplify laser beams. They ran the laser beams through various nanowire assemblies [photonic circuit configurations] and measured the transmission efficiency by comparing the output intensity of the lasers to the input intensity.

Nanowire assemblies have unpredictable geometries; this introduces uncertainty into the functionality of their assemblies. Additionally, the precise geometry definable in lithography allows for less interwire coupling losses.

Photonic & Electronic Integrated Circuits

Let’s look at an alternative to lithographically (i.e., created by transferring a pattern by selective exposure to light) defined structures: optical integrated circuits.

Specifically, we’ll examine the usage of single-crystalline nanoribbons, useful because of their lack of edge effects. These edge effects, usually due to grain boundaries (defects in the crystal structures) cause significant loss of efficiency in the transmission of optical signals. Using far field microscopy and spectroscopy, the waveguiding behavior of individual nanoribbons can be observed in detail. The size of any given nanoribbon can be inferred from the color of it’s guided photoluminescence; large ribbons are white (less filtering), while smaller ribbons are blue (short-pass filtering). Waveguides are used in optics to transmit light and signals for long distances and with a high signal rate. The team [0] experimented with light injection into a ribbon cavity. Optical cavities are arrangements of mirrors that provide a type of filter for injected light. Light confined in an optical cavity will reflect multiple times and interfere with itself to filter for desired frequencies by eliminating undesirable frequencies by means of destructive interference. Various coupling geometries are usually tested using near-field optical microscopy (NSOM). For example, the quantification of the transmission loss of long straight ribbons using NSOM results in the finding that these single-crystalline ribbons had substrate-induced radiation loss and in some cases, imperfect single-crystalline leading to minor scattering crystal steps. However, this percentage of loss in the light’s amplitude is acceptable for use in sub-micrometer light-transmission (used in integrated planar photonic applications).

Nanowire light sources can be successfully coupled to ribbon waveguides to create input and output for future photonic devices. Most research into developing nanowire photonic circuitry explores various nanoribbon bondings, various ribbon geometries and especially focuses on the efficacy and efficiency of this alternative to electrical integrated circuits in the hope of proving that photonic integrated circuits have the potential to supplement and possibly overtake today’s electronically based circuitry.

Practical devices will require a combination of electrically driven nanowire light sources and nanoribbons: the next generation of integrated circuits will likely be a combination of parallel electrical and optical circuit elements. The main problem to overcome is developing better ways to integrate optical and electrical circuit elements for the parallel processing of electron and photon based signal transmission.

Sources Cited

0] Sirbuly, D. J. (2005). Optical Routing And Sensing With Nanowire Assemblies. Proceedings of the National Academy of Sciences, 102(22), 7800-7805.
1] Law, M. (2004). Nanoribbon Waveguides For Subwavelength Photonics Integration. Science, 305(5688), 1269-1273.

English to Morse Translator

Today, I wanted to code an efficient letter to Morse code translator in Python and whipped this up. I’ve found that a familiarity with many of Python’s lesser-known built-in functions is quite useful in situations such as this!

Just for fun, I encourage the reader to use this script to leave their comments in Morse.

#!usr/bin/python
#Catherine Ray
"""
morse.py {string} [{string} ... ]:
 Translates string of english letters and spaces to morse code.
"""
import string
import sys
if len(sys.argv)>=2:
 if sys.argv[1].isalpha():
  text = ''.join(sys.argv[1:]).lower()
  morse = ["01","1000","1010","100","0", "0010", "110", "0000", "00", "0111", "101", "0100", "11", "10", "111", "0110", "1101", "010", "000", "1", "001", "0001", "011", "1001", "1011", "1100"]  letter = map(chr, range(97, 123))
  LETTER_TO_MORSE = dict(zip(letter, morse))
  morse_out = [LETTER_TO_MORSE[x] for x in text]  print ' '.join(morse_out).replace("1","-").replace("0",".")
 else:
  "Restrict yourself to the english alphabet."
else: 
 print "Enter a string to translate, friend!"

Visual Grade 2 Braille Dictionary Introduction

I learned braille for 3 reasons. The first is my hobby of picking something random and learning it. The second is because I wanted to learn touch typing. The third is because I often fell asleep while reading and left the light on. This way, I can read myself to sleep without a light on!

If you are new to Braille here is an explanation of the basics. Many fluent sighted Grade 1 Braille readers have trouble with the contractions, so I thought I’d share my memory aids.

This is a small subset of all Grade 2 contractions: this subset will be appended to sporadically as time goes on.

Grade 2 is a large set of contractions; I’ve broken them up into the following parts. Peruse and enjoy!

1] Braille Alphabet
2] Prefix Indicator
3] Contraction for Part of Word
4] Final Letter Contraction for Middle or End of Word
5] Initial Letter Contraction for Whole or Part of Word
6] Abbreviation for Whole Word

The Purpose of Communicaton & Assigning Credit

It is tempting for some to take all of the glory.

It is a common misconception that research is purely original. However, scientific discovery is not magically creating original work. Innovation is almost entirely based off of combining old ideas in new ways. It’s about using an existing toolbox to piece together something that is more than the sum of its parts.

Innovation is based on making new connections. By embracing this realization, you become an ultimate collaborator: when you learn someone else has already found a similar set of connections, instead of brooding, you can congratulate them and add your own connections to help the idea come to fruition.

I think it worth your time to be careful that everyone who contributes to your project is properly credited, including relevant prior art.

While having a wonderful discussion with Chris Olah a few months ago, we dabbled on the topic of the purpose of communication.

We came to the conclusion that the main purpose of communication is to form connections. These connections are not just between people, they are between ideas.

The collaboration of ideas is relevant (if not crucial) to innovation and is halted if people feel that their ideas will be stolen. If you give proper credit to those you collaborate and build off of, they will not feel like you have cheated them, and will continue to be open and help you in your quest to better the world around you.

By giving credit to those who help you, you will become a better innovator in the process.

My Weekly Planner Template

Sometimes, when juggling a particularly busy lifestyle, a stand-alone Todo list isn’t enough. I find it useful to supplement my Todo system with a weekly schedule in order to quickly allocate Todos to each day.

At the beginning of the week, I created a weekly planner for myself (click the image to enlarge).

The goals section outlines what you’d like done by the end of the week, and the immediate section is for quick brainstorming and immediate dispensable todo lists. (The immediate section is used to eliminate excessive usage of post-it notes.)

Each day of the week is represented in abbreviated Grade 1 Braille, with a space to put the corresponding day number (as illustrated above).
1st column: S M T W
2nd column: R F Y

The remaining 3 sections are versatile (e.g. used for: quick notes, reminders, quotes, additional brainstorming space, random ideas).

I use black to write prevalent todos, blue to write “extra” todos, and highlighted text to indicate due dates and extremely time sensitive todos.

I’ve found to be useful and motivating. I hope you find use from it or are motivated to create your own personalized weekly template.