Some kind people pointed to me that my journals seriously lack necessary backgrounds and explanation of mysterious terms, which leads to the terrible fact that no one can understand them even a bit. I feel very sorry and regretful.
Above all, I suppose it's important to introduce myself a little. I'm a Chinese student majored in Computer Science in Jiangsu University, who loves perl and gets very interested in Autrijus' journals on this site. I have the honor to be able to upload my own journals too, because there are a lot of great people here.
In my previous journals, I was mainly talking about two projects I am developing in this term. One is named CirSys, which is a problem solver aimed at dc and ac electric circuits appeared on the textbooks using basic theoretical consequences like the Kirchhoff-Current Law (KCL) and the Kirchhoff-Voltage Law (KVL). The other one is a toy hacker application named Thief, which can download some info from our university's web sites by means of the LWP module. Developing Thief is totally a proof-test, no other impure intentions at all.
CirSys is a model-builder written in perl 5, using Maple or MATLAB as the model-solver at the back-end. But what do we mean by "model" here? The term "model" in context of the CirSys project refers to a mathematical model composed of a list of equations, inequalities, and unknown variables. CirSys accepts a description of the user's circuit problem in the form of CIR scripts. CIR is a tiny language designed to describe the structure of electric circuits, much simpler than the netlist syntax used by SPICE. CirSys outputs the Maple commands corresponding to the math model and other solving actions with respect to the CIR input. This output is then fed into the mouth of Maple or MATLAB's solving engine by the user, getting the final solutions.
I've also added a lot of hyperlinks to my older journals, which may provide a comprehensible context.