Analogy: Gear Backlash and Hysteresis

Gear backlash is a discretized version of hysteresis in materials.

This can be seen by comparing the hysteresis plot (displacement field vs. electric field) to the backlash plot (output vs. input).

It makes sense because depending on the direction of the input (field applied to a material), the output of the system exhibits a different set of responses.

Note Taking: Including Pictures

Pictures can greatly improve note taking, since readers are naturally attracted to visuals and it's easy to highlight the important aspects. However, be careful with color - you will need multiple, and often times a single pen will not suffice and instead end up as a mess.

Learning: Improving on Repetitive Tasks

Ask for someone experienced to watch you perform the task (such as coding, or solving problems), and suggesting any improvements, tricks they know, or things you could do to improve efficiency.

Alternatively, if it's time sensitive, you could also record yourself doing the tasks and ask someone to look at it later on.

Self-Imposed Deadlines via Accountability

I'm finding that the best way to get optional/long term things done is to be accountable to someone. But, it takes practice to get the time estimates right, and doesn't bode well when something else gets delayed and everything subsequently has to get postponed.

So, the trick is to also leave unscheduled time - you can't account for random things coming up, like events with friends or various meetings, and delays of things that must get done.

How I see robotics

Robotics can be split into:
Physics (kinematics, dynamics, control)
Mechanical design (making the physical robot)
Computer science ("coaching" the robots - making the machines do meaningful things. managing their interactions with the world and each other)
Math/signal processing (vision)

Suggestions/modifications?

Reorganized Blog System

I need to work on my writing and communication skills. To work on this, I reorganized my blogs to the following:

• Research log - document my research progress. guilt trip self into spending more time on research
• Organized writing - goal is to write a longer post once a week. currently i plan to focus on things i've learned that week or cool observations I've made. a good example is the gimbal analogy in planes and insects.
• Hobbies - cooking, bike trips, travel destinations, etc
• Project Updates - get myself writing more about what I work on, so that I have a better idea myself when explaining to other people. tech/computer discoveries will also go here. 
• Observations/Thoughts/Comments - life realizations, rants, short thoughts that I want to save, motivational stuff. lot of extra posts from the past, won't bother pruning those.

I will NOT save articles. That's a bad habit. I need to read and absorb the lessons from the articles instead, rather than hoarding browser tabs and links. 

Frustration with motivating myself

I don't think it's occurred to me that, especially now, no one will be monitoring me all the time to make sure that I'm doing something and that I need to take charge of my actions.

The options I have considered are to:

• work with other people - but then I'll get distracted unnecessarily sometimes (not that it's not FUN to work alongside others!)
• Xinhong suggests studying alone at the library or somewhere where people can see me so that I'll feel self-conscious if I slack off. This has worked pretty well in the past for me, but the problem is that it conditions you to be super lazy at home, and I would argue that in fact it makes it harder to work at home. 

I would be really happy to hear any suggestions you have or what you do to overcome this problem. Please leave a comment or email me!

Goal: Write my blog posts without revision

A lot of times I find myself putting too much thought into how I will phrase something on this blog. I don't think that's a good use of time in this scenario, whereas for something like project pages on my website I would put more careful revision and attention to design and content. But for something like a blog, which I shall treat as a mind dump from now on, I shouldn't spend the extraneous amount of time worrying about specific content or word choice or whatever.

My hope is that over time, I will get better at saying the intended things on the first try. Of course, it might not always be the right or best response, but for this scenario I am okay with that.

I will correct typos though!

The lesson for me here is to pick the appropriate response for the scenario/environment.

Troubles with sleeping at night

Ren brought this up. A potential cause for my sleep issues is overexposure to blue/ultraviolet light. Specifically, electronic device screens are probably messing up my circadian rhythm. Things I could do to improve this condition:

• more exposure to sunlight during the day
• stop using technology closer to bed time. Would need to come up with a way to do something at nights. Handwritten todolists + reading books?

Interesting side note: Most of the sun's energy is infrared, but it still contains some ultraviolet and of course visible light. (Integrate the solar radiation spectrum below for each region)

Source:

http://www.health.harvard.edu/newsletters/Harvard_Health_Letter/2012/May/blue-light-has-a-dark-side

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgywXlr-lOVrRyn6ztk-eDxlJMX7JG1kI1F5YAP4p4yaxuLQkzowjjpifes-hQtfmkh-l1fvug41tsMRCV_d_joetefH1659rP8XvbDxqKOIlqM_ARAshv4-A6GN0Hw1qAxNfI8yc8IAGYo/s1600/Solar_Spectrum.png

Hiding Desktop Icons on OSX

In terminal:

defaults write com.apple.finder CreateDesktop -bool false

killall Finder

Playing music with shower head

The stream of water coming out of my shower head exits at a certain frequency. By touching the shower head, I can control the frequency of the sound coming out and was able to play hot cross buns!

Mac: jump to beginning/end of line

Beginning: ctrl a
End: ctrl e

Git: Pull a remote branch to your local repository

In order to pull a remote branch to your local repository:

git pull
git checkout -b <new_branch> origin/<new_branch>

Do not:
git checkout -b < new_branch >
git pull origin < new_branch >


Source: http://www.wetware.co.nz/2009/07/pull-a-git-branch-from-remote/

Deleting your most recent git commit or push

If you have committed junk but not pushed,

git reset --soft HEAD~1

HEAD~1 is a shorthand for the commit before head. Alternatively you can refer to the SHA-1 of the hash you want to reset to. --soft option will delete the commit but it will leave all your changed files "Changes to be committed", as git status would put it.

If you want to get rid of any changes to tracked files in the working tree since the commit before head use --hard instead.

Now if you already pushed and someone pulled which is usually my case, you can't use git reset. You can however do a git revert,

git revert HEAD

This will create a new commit that reverses everything introduced by the accidental commit.

Source: http://nakkaya.com/2009/09/24/git-delete-last-commit/

Simulink: Multiple Scope Ports

In order to obtain a scope block with multiple inputs, open the graph, open settings, and change the number of axes.

This allows you to avoid the hassle of using muxes to parse and plot multiple input signals.

Source: http://www.mathworks.com/matlabcentral/answers/5687

Ubuntu - mouse wheel scrolls too much per scroll click

In order to fix the problem, where the mouse scrolls too much down a page each time you move the scroll wheel, unplug and plug the receiver dongle back in. It should reset the settings that cause the scroll wheel to jump too much.

This problem occurs probably because of dual booting ubuntu and windows 7.

Ashton Kutcher's speech

Neat indentation in vim

In order to neatly indent your code in vim, type:

gg=G

, while no command is active.

Another piece by James Altucher

TWO LIFEHACKS THAT WILL GET PEOPLE TO LIKE YOU

I'm taking a day off from writing about crying on the floor. I feel like I've written 600 posts about either failure or naked people. 

Instead, I'm going to share two things I've done that have changed my life for the better and I don't know anyone else who does them. 

A) Get yourself 1000 $2 bills. You can get $2 bills by going to your local bank and asking them to order it from the Federal Reserve. 

The Federal Reserve threw out all of their antique copy machines that were set aside for $2 bills. That said, they still have a million vintage 2003 (signed by John Snow) $2 bills lying around. If you go to your local bank branch and ask for $2 bills it will take about 2-3 weeks to get one thousand of them. 

Why? 

1) When you go to a place where you plan on being a regular, always tip 30% and do it all with $2 bills. Nobody is ever going to forget you and you will always be treated well. Plus people will fight with each other to be the one serving you. That's a nice feeling. You don't have to be rich. You just have to have $2 bills.

Note: DON'T waste $2 bills on tips for cab drivers. They are never going to see you again. 

2) When you are breaking into a new scene, always use $2 bills. For instance, when I started playing chess for money at Washington Square Park I would always pay off with $2 bills but when I won I'd get $1s or $5s. Pretty soon, everyone was hoarding their $2 bills. My currency was flowing through the local economy. Everyone knew who I was. It was a shortcut to popularity because that's how desperate I was for friends among a bunch of drug addict homeless chessplayers. 

3) When I was dating, I would carry a thick wad of cash. A $100 bill on top, $2 bills filling out the whole wad. Time to pay for dinner, I'd bring out the wad (impressive), peel off a $100 bill (pathetic) and then amaze by tipping with non-stop $2 bills. "Where did you get those?" people always ask. Give a cryptic answer. "I do some projects with the government." 

Extra tip: it helps to go to the same restaurant the night before the date so everyone who works there is excited, anticipating what you will do. 

4) Conversation piece. If you pull out a $2 bill people say three things: "what is that?", "where did you get that?", "they are so beautiful"

5) Because as far as money goes, they are beautiful. I love the back of the 2 dollar bill. So much detail. 

 Buy 100 waiters pads. I've written about it before but I can't stress it enough. 

1) It's easy to write ideas. And the width is too short for you to put a lot of details or write a novel or whatever. It's just for writing down ideas. I write at least ten ideas a day on waiter's pads. Over the course of a year that's almost 4000 ideas. I do it seven days a week. 

2) If you are writing down ideas in a restaurant then the waiter thinks you are in the business and serves you faster. 

Trust me, this always works. In fact, if I am getting poor service I just pull out my waiter's pad, put it on the table, and suddenly everyone is very attentive. 

3) At the beginning of a business meeting I pull out the waiters pad and someone always says, "I'll take two cheeseburgers and a coke" and everyone laughs. It's a good conversation starter. 

4) It's a good way of showing you're frugal. When everyone pulls out their moleskin notebooks that cost $40 a pad you can say you paid 10 cents for your waiter's pad. Frugality is great when you are trying to raise money. 

5) I'm bad at remembering names. At the top of every page in the waiter's pad are small shapes representing the different different types of tables. The shapes have numbers representing every sitting position. You can write down the names of who is at the meeting and where they sat. 

6) they fit in your shirt pocket. As opposed to almost every other pad. 

I tried to think of a third lifehack but I couldn't. For 10 years I've carried around waiter's pads and $2 bills every day and have had enormous success with both of them. 

The key is you are inviting people into your universe. To keep them guessing about what might happen next. It's a mystery! $2 bills and waiter's pads are a good start. 

Oh! And my special handshake. But I'll save that for another post.

[Note on rewriting: first draft of this was 1041 words. Final draft: 773 words]

Trouble Connecting to IRC via Pidgin on Windows7

http://wiki.freeculture.org/IRC_with_Pidgin

I was getting a "Could not connect" error, but was able to successfully access irc.freenode.net by using a different port rather than 6660-6669.

Sorting lists in Wunderlist

Hover your mouse over the bottom center of the screen and a task bar will appear. On the far right, there is a sort alphabetically or sort by due date option.

Modifying your origin branch in git

Say you accidentally made a typo while creating your origin branch via 'git remote add'. In order to fix that, you can remote remove the origin branch with:

git remote rm origin




Be careful about doing this for branches where you've made any commits because you will lose those modifications.

Help others when possible

Interview and engineering tips

http://www.ibm.com/developerworks/power/library/pa-enghints1/
http://www.engineerjobs.com/content/2013/9-questions-to-ask-on-an-interview.htm

Aaron Hernandez's Letter

Dear Mr. Caserio,

I am writing in regards to some of the feedback I am receiving from my agents, Florida coaches, and other personnel. These sources have indicated that NFL teams have questions about my alleged use of marijuana. I personally answered these questions during the pre-draft process, but understand that NFL teams want to conduct thorough due diligence before making the significant financial investment inherent in a high draft pick. I have no issue with these questions being asked, but thought that it made the most sense to communicate with you directly regarding this issue so you would not have to rely upon second-hand information.

Any information I volunteer to you about my past will be looked at with great skepticism as I am trying to get drafted as high as possible by an NFL team. As such, I thought that the best way to answer your questions and your concerns was to make a very simple proposition. If you draft me as a member of the New England Patriots, I will willfully submit to a bi-weekly drug test throughout my rookie season (8 drug tests during the 2010 regular season). In addition, I will tie any guaranteed portion of my 2010 compensation to these drug tests and reimburse the team a pro-rata amount for any failed drug test. My agents have explained that a direct forfeiture provision in my contract along these lines would violate the CBA rules. However, I have instructed them to be creative in finding a contract structure that would work on in the worst case scenario, I would donate the pro-rata portion of any guaranteed money to the team's choice of charities. My point is simple -- if I fail a drug test, I do not deserve that portion of the money.

I realize that this offer is somewhat unorthodox, but it is also the only way I could think of to let you know how serious I am about reaching my potential in the NFL. My coaches have told you that nobody on our Florida team worked harder than me in terms of workouts, practices or games. You have your own evaluation as to the type of impact I can have on your offense. The only X-factor, according to the reports I have heard, is concerns about my use of recreational drugs. To address that concern, I am literally putting my money where my mouth is and taking the financial risk away from the team and putting it directly on my back where it belongs.

In closing, I ask you to trust me when I say you have absolutely nothing to worry about when it comes to me and the use of recreational drugs. I have set very high goals for myself in the NFL and am focused 100% on achieving those goals. So, test me all you want during my rookie year ... all of the results will be negative while I am having an overwhelmingly positive impact on the field.

Good luck with your preparations for the NFL Draft and feel free to contact me or my agency (Athletes First/David Dunn) with any questions.

Sincerely,

Aaron Hernandez
University of Florida