Xianfeng Songs blog

I’ve been having an iphone for two weeks. It works great, except the following two problems:

(1) All my contacts was once fully deleted during a sync process, though it gave me a warning message beforehand. It freaked me out. I consider this as a severe problem.

(2) The smart playlist sometimes does not sync with itunes. I have a smart playlist contains all unplayed podcasts. After I watcched several podcasts on my iphone, I connected it with my mac. Unfortunately after the sync, the played podcasts are still in my unplayed podcasts smart playlist on iphone, though they are removed from the same smart playlist on itunes.

Any of you guys have encountered these two problems?

This is the talk I gave for journal club in physics dept in November, 2005. An interesting topic: “How E.coli find its middle”. The quick answer is that E.coli uses Min-proteins oscillations to position its middle. For more detail, I hope How E.coli find its middle helps.

Great post!
What it takes to be great
Research now shows that the lack of natural talent is irrelevant to great success. The secret? Painful and demanding practice and hard work
In this article, the main points contain:

• There is no substitute for hard work!
• “Deliberate practice” is the activity that’s explicitly intended to improve performance, that reaches for objectives just beyond one’s levels of competence, provides feedback on results and involves high levels of repetition. You have to actively seek feedback.
• Consistency is crucial. Practice regularly, not sporadicaly.

This is the slide for my talk during APS Marching Meeting, 2005. The meeting was held in downtown LA. The name of my talk is “Transport Through the Myocardium of Pharmocokinetic Agents Placed in the Pericardial Sac:Insights From Physical Modeling”. The slides can be downloaded: Transport Through the Myocardium of Pharmocokinetic Agents Placed in the Pericardial Sac:Insights From Physical Modeling.

The course was taken in Fall, 2004. My final project is “Computer Simulation of Film Growth in 2 Dimensional Space”.

Since I was in Peking University, I was interested in the simulation on thin film growth and had been reading this for about one semester. So I know some important papers in this field. It helped me. The simulation method is basically a simple KMC (Kinetic Monto Carlo). The code was written in Java so you can run it even in a browser.

You can view the simulation in a java-enabled browser. If you want to know more, you can download the paper: Computer Simulation of Film Growth in 2 Dimensional Space, the code: The source code.

The course was taken in Fall, 2004, taught by Rob de Ruyter van Steveninck. The final project is to read the textbook for one chapter and write a paper for it. I chose “Chapter 12: Nerve Impulses”.

In the paper, I worte both on experimental result and theoretical result for Nerve impulses. You can download the paper: My final paper on Ch12: Nerve Impulses.

The course was taken in Spring, 2005. My final project is “Using Artificial Neural Networks to compute the switch time between two different Poissons”. The paper I worte contains two parts:

• Brief Introduction to Artificial Neural networks, including a small tutorial in using ANN in matlab.
• The model to solve the switch time between two different Poissons.

The supplement paper includes the analytical result on the prediction limit for the switch time.

• The paper: “Using Artificial Neural Networks to compute the switch time between two different Poissons”
• supplement paper
• Archives (contains both codes and papers)
  

This post So Many Free TV Episodes and Movies, So Little Time from a blogger who uses the same scheme and blog engine as I am using is great! You can see there are still some free movies outthere in the internet, though I am pretty sure they are not that legal! But anyway, they are there! It’s up to you whether you want see or not. And you may wonder why the hell they are still there?

IBIS

Resources
* Home page
* Manual
* Local directory: IBIS

Version
* No version info.
* The last modify date for manual is 06/19/1998, so it seems that this package is an old one.
* The webpage states that it is in the alpha development stage.

Distribution method
* Disclaimer: This software is made available “as is” without any assurance that it will work for your purposes. The software may in fact have defects, so use the software at your own risk.
* Open source, free.

About
* Written in Fortran
* Developed by David J. Eyre and Aaron L. Fogelson (Department of Mathematics,University of Utah)
* Designed to run on SGI workstations that have OPenGL
* A software system for immersed boundary and interface simulations
* Depends on C-shell, TCl/Tk, gnuplot, Net PBM library, MPeg library

How to use
* A user is required to write a short IBIS program that defines the initial conditions, properties of the fluid and properties of the immersed boundary
* The user is also required to write a short FORTRAN subroutine to specify the motion of the immersed boundaries
* Post-processing the data by using ibisiew

Program Architecture: (3 parts)
* IBIS Programming language: is a tool that was designed to allow users to easily set the parameters that are needed for an immersed boundary simulation.
* IBIS Numerical Software: it takes the parameters set by the user and calculates the evolution of the system. An interface to a user defined FORTRAN subroutine has been provided. In this interface, the immersed boundary and fluid data is passed to the user in a managable format, and can then be manipulated as needed.
* IBISVIEW Visualization Interface: The interface provides the user with point and click access to the data computed by IBIS. The data has two basic modes, color plots and line plots.

Aquasim: Computer program for the identification and Simulation of Aquatic Systems

Resources
* Homepage
* manual

Purpose
To support environmental scientists in finding an «adequate» model of the system they are investigating. It allows its users to perform simulations using different models, to assess the identifiability and to estimate the values of model parameters (using measured data), and to estimate prediction uncertainty.

Versions
The latest version is 2.1a released in March 2001.

Distribution
* AQUASIM was developed mainly for internal use, but it is also available to commercial companies at a price of CHF 2000 (ca. US$ 1200) and to university institutes at a price of CHF 1000 (ca. US$ 600). This price includes binary versions of the program for one platform, a user manual and additional documentation. Technical support for program usage is not provided.
* Demo version for MS Windows is available.

Documentation
* Complete manual is available for download
* Mailing list
* AQUASIM Training Courses

About
* Developed by the computer and systems sciences department of Swiss Federal Institute for Envronmental Science and Technology (EAWAG).
* Written in C++.

Program Intro
* Allow users to define the spatial configuration of the system to be investigated as a set of compartments which can be connected to each other by links. The available compartment types include mixed reactors, biofilm reactors (consisting of a biofilm and a bulk fluid phase), advective-diffusive reactors (plug flow reactors with or without dispersion), saturated soil columns (with sorption and pore volume exchange), river sections (describing water flow and substance transport and transformation in open channels) and lakes (describing stratification and substance transport and transformation in the water column of the lake and in adjacent sediment layers).
* Different links: (1) Advective links represent water flow and advective substance transport between compartments, including bifurcations and junctions. (2) Diffusive links represent boundary layers or membranes, which can be penetrated selectively by certain substances.
* User can specify any set of state variables and transformation processes to be active within the compartments.
* For the model as defined by the user, the program is able to perform simulations, sensitivity analyses and parameter estimations using measured data.
* Calculated results can be plotted to the screen (window interface version only), written to a Post-Script file for transfer to a printer, or written to a text file for external post-processing