Note: this note is about University of Michigan computing resources.
People working on numerical analysis often need to develop efficient code by doing multi-language programming, e.g. MATLAB/C++ or MATLAB/Fortran. Linux operating system is needed to have the best programming experience. (Mac OS has all sorts of compatibility issues.) For UM people who are using a Mac, I have explore the following four options for remotely accessing Linux-based computing resources.
今天无聊去搜了一下这个世界上有多少美元在流通，网上的信息来源一般说有超过一兆美金（1 后面 12 个零）。于是又不禁想到，既然最大是这个数，那最小的美元单位是多少呢？
色情和艺术是不是一线之隔的近义词？热情和沮丧是不是两种相反的情绪？我最近对这一类问题有一些思考，想把它们整理出来。
I have been having fun with the Julia language lately. It is a new programming language for scientific computing. You may wonder, why do we need a new language at all? Don’t we already have MATLAB, Mathematica, Python with NumPy and SciPy, etc., are’t those enough?
Well, it is true that those are awesome softwares for scientific computing, they have all the necessary functionalities and powerful libraries, and they are easy to learn. But there is a common (fatal) issue that prevents them from creating industrial quality codes – speed. We want faster speed! The Julia language is developed specifically for this.
This isn’t about theology, but I will talk about the number three.
We love the number three. Many of our rules/doctrines consist of three parts. For example, in Christianity, there is the theory of the Holy Trinity, stating that God manifests Himself in three forms: the Father, the Son, and the Holy Spirit. I’d love to cast them into a shamrock diagram:
The key idea here is that, although there are three forms, there is really only one God.
There are many readily available softwares (e.g. DjVu2PDF) for converting a book from .djvu to .pdf format, but none of those will preserve the table of contents in the output PDF.
As a researcher, I often need to make presentation slides, and want to embed movies in my slides for better illustrations. After doing a little research, I converged to the solution described in this article.
我对最开始的两编博客内容进行了更新。因为经过这段时间的学习，我的电脑水平有所增长，回头看当时写的东西不禁发现了各种不严谨和各种 bug，忍不修补了一下。
好了，本篇的主要内容完毕，以下完全是跑题的内容，是我对这个学期所学的一门课的吐嘈，可以随意忽略。。
This is something I learned today from the Fluid Mechanics class in the Chemical Engineering department, class number CHE 527.
We have had the intuitive ideas about what a fluid is versus what a solid is. A solid is something that can resist shear stress, and will maintain its shape, while a fluid is something that will deform continuously when a shear is applied to it, without changing back to the original shape.
But there are many substances in the world that cannot be classified into solid or fluid with the above simple and intuitive definitions. Here are some examples:
Do you know that our brain works logarithmically?