Notes on Steve Jobs

Jobs has been a symbol in our era. His products have revolutionized human's life styles. I plan to read his biography.

“That’s been one of my mantras — focus and simplicity. Simple can be harder than complex; you have to work hard to get your thinking clean to make it simple.”

Tip: Create focus blocks of time. This way, you can focus on the work that matters most and block out all other distractions.

“Your time is limited, don’t waste it living someone else’s life. Don’t be trapped by dogma, which is living the result of other people’s thinking. Don’t let the noise of other opinions drown your inner voice. And most important, have the courage to follow your heart and intuition, they somehow already know what you truly want to become. Everything else is secondary.”

Cal Newport, professor of Computer Science at Georgetown University, explains that to build a career that you are satisfied with, you must first answer the question “What way of working and living will nurture my passion?”

Tip: Answering Newport’s question is an important step, but what’s more important is to not fixate on regrets.

“I’m as proud of many of the things we haven’t done as the things we have done. Innovation is saying no to a thousand things.”

Tip: Say “no” and say it often. If what is being asked of you does not align itself with your goals, then it will become a distraction from the work that needs to get done.

My favorite things in life don’t cost any money. It’s really clear that the most precious resource we all have is time.”

“We don’t get a chance to do that many things, and everyone should be really excellent. Because this is our life. Life is brief, and then you die, you know? So this is what we’ve chosen to do with our life.”

Tip: Ask yourself, “When it comes time for me to die, what will I regret not doing?” That is what matters most — so go and do it.

http://www.lifehack.org/270922/10-inspirational-quotes-from-steve-jobs-that-will-change-your-thoughts-your-career?

Notes on Yihui.name

I am trying to compare Markdown and Latex in my last post, and happened to find this guy, Yihui. He is an early pioneer in R and a founder of  online community on statistics http://cos.name.

Here are some interesting excerpts:

要说经验嘛，

• 一是要知道自己爱干啥，不然干啥都累；

• 二是从兴趣中做出一点成果，否则跟人说话苍白无力；

• 三呢，有自己独立的想法，不要为了出国而出国，人到哪里都是这山望着那山高，外国不一定有想象的那么好，先想清楚要做什么，再想什么地方适合自己（比如我觉得数学伤脑子我就不想去数学气氛太浓的学校

build website by https://jekyllrb.com

混开源社区就有这问题，人总是有种印象，啊你开源免费那你就该无偿帮我忙。哎凭啥呢？有些人混着混着就把自己混进去了，激情万丈，家破人亡。蟒蛇神教千秋万载一统江湖还是一桶浆糊？窃以为还是破帽遮颜靠谱一点。

Best Markdown Editor and Solution

Update on 2017-1-18

After 6 months, I stick to the little software Typora. The best features are immediate feedback, autosave and elegant. To render markdown in blogspot, just copy the source mode and convert it by an Chrome Extension “Markdown here“, which supports MathJax. Everything is nicely done.

By the way, the windows version of typora seems very unstable. Once it died half way and everything I wrote was lost.

In case you are in a public computer, then https://stackedit.io is the best choice.

Equations in Markdown

try $3n+\sum_2^n{\pi}$ to see whether it supports MathJax.

convert equation to LaTex code

http://www.hostmath.com/

or https://www.latex4technics.com

However, remember LaTeX Math Symbols will help you type equation faster.

Write equation in Github Markdown

Sadly, Github flavored Markdown doesn’t support MathJax. The solution is to use some websites to convert it into image, and insert it using ![]() syntax. Such websites include:

http://www.sciweavers.org/free-online-latex-equation-editor

how to use: convert-> download -> copy and paste

Write equations in gmail

A chrome extention “Tex for Gmail“ do the job. write equation by the above link and paste.

Note: simple equation is good, complex equation is terrible

MarkDown vs LaTex

MarkDown->html -> scrolling in one page

LaTex->PDF -> printing multiple pages

Let’s rock:

All roads lead to Rome, some people die at the starting line instead of on the roads.

​

broken window theory, technology timeline, qcloud

Broken window theory:
Not fixing problem is an indication that it's OK to have poor quality. So don't bother to look for the culprit, just fix it.  Be an example of the standards you want to reach, and praise those who follow the example.

Adoption Chart

qcloud conference:  http://www.qcloud.com/event/tcc2016/live 

Learning notes on DFT

I learn this to prepare for an interview. A very abstract theory. I will learn it anyway.DFT is an acronym for density functional theory, which is widely used in computational physics and computational chemistry to study the fundamental property of material. Density is for the density of electrons. Functional is a mathematical term, meaning "function of a function", e.g. F[f(x)]. There is a particular maths course called "functional analysis".
DFT was initially developed in Thomas and Fermi in 1920s, but hadn't achieve a good theoretical foundation until 1960s. Hohenberg-Kohn theorem demonstrated that the ground state properties of a many-electron system are uniquely determined by an electron density with only 3 spatial coordinates, and the correct ground state electron density minimizes the energy functional of the system. Later, Kohn-Sham equation provides a method to specifically describe the potential term. The effective potential is divided into external potential, and Coulomb interaction effect (exchange and correlation interaction). The interaction terms are difficult to model, and are treated by local-density approximation (LDA).

A real calculation by classical DFT on liquid Neon [^1] is a best way to dive in. This is done by a few lines of Mathematica codes revealed in its supplemental material.
A review paper on DFT by Burke's group [^2] provides in-depth overview, including its development, two most popular choices of functionals (empirical and nonempirical approaches) and the research trend.
[^1]: Jeanmairet, G., et al. (2014). "Introduction to Classical Density Functional Theory by a Computational Experiment." Journal of Chemical Education 91(12): 2112-2115.
[^2]: Pribram-Jones, A., et al. (2015). "DFT: A Theory Full of Holes?" Annual Review of Physical Chemistry 66(1): 283-304.

Gratitude Journal

After many hours of talk with Pastor Bill, I suddenly realized that the bast part of Christian is not the biblical teaching, but the grateful prayer that they keep practicing all the time.  In the past several months,  I have been indulging in a defensive mode or "victim mentalness"

Surprisingly, there's a professor in UC Davis, named Robert Emmons, doing many years of research on this particular subject.

Other approach: Gratitude visit.

Tips:

1. First make the conscious decision to become more happier and more grateful. Don't go through motions.
2. Elaborate in details about a particular person/thing instead of listing many superficial things.
3. reflect on what your life would be like without certain blessing, rather than just tallying up all those good things. No hurry, go deeper.
4. Try to record events unexpected or surprising, which provokes stronger level of gratitude
5. Weekly journaling is better than daily journaling.Gratitude journal forces us to pay attention to the good things in life we'd otherwise take for grated.  Over doing it will make the brain adapt to positive events quickly. 
6. Make the conscious effort to associate it with the word gift.
7. Translating thoughts into concrete language,whether oral or written, has advantages over just thinking the thoughts: It makes us more aware of them, deepening their emotional impact.
8. Writing help to organize thoughts, accept your own experience and put them in context. In essence, It allows you see the meaning of events around you and create meaning in your own life.

Ask question the smart way

Excerpt from E. S. Raymond's website http://www.catb.org/esr/faqs/smart-questions.html

1. Hackers like challenging, thought-provoking questions
2. People unwilling to think or do their homework are time sinks. They take without giving back.
3. Different people have different important things to do. We focus on what interests us most, otherwise we would become less effective  at the things we do best.
4. We filter the time-sinker ruthlessly, in particularly who appear to be losers. If you can't live with this discrimination, you 'd better pay for a paid support instead of asking hacker to donate help.
5. Before asking a technical question, do your homework by searching the web, reading the manual or FAQ, asking a skilled friend or find a answer by reading source code. Display the fact that you have done these things first.

• How to become a hacker

1. Hackers build things, crackers break them.
2. The fun of being a hacker takes lots of effort and motivation. Otherwise, your hacking energy is sapped by distractions like sex, money, and social approval.
3. There are so many fascinating new problems waiting out there, we shouldn't waste time re-invent the wheel.
4. Attitude is a must, but is no substitute for competence. Competence at demanding skills that involve mental acuteness, craft, and concentration is best.
5. First learn Python, then C, Perl and Lisp. Java is not recommended as first language. Because a good tool for production can be a bad one for learning. However, C is low-level language that is complex and bug-prone. We had better use machine time less efficiently but use our time more efficiently. 
6. Most of the best hackers are self-taught and learn by practice. (a) reading code; (b) writing code.
7. The best way to do it is to read some stuff written by masters of the form, write some things yourself, read a lot more, write a little more, read a lot more, write some more ...