Friday, March 28, 2025

Engle's ARCH motion prediction model with the simulation data with Python

 This is introduced in my cartoon video of Yukkuri Kaisetsu (Touhou Project fan-art):




Auto-Regressive Conditional Heteroscedasticity (ARCH)

ARCH was developed by an economist Robert F. Engle III having won the 2003 Nobel Memorial Prize in Economic Sciences for its achievement.

Dependent variable: the variance error terms of the first regression:
The explanatory variable X can be the lagged dependent variables and/or the other variables: 
Then, it find the coefficient γ of the lagged squared error terms with reference to the log-likelihood: 
 

Generalised Auto-Regressive Conditional Heteroscedasticity (GARCH)

GARCH assumes the variance of the error term symmetrically varies depending the average size of the error terms in pervious time steps. It adds the lagged variance on the explanatory variable of the second regression with reference to the log-likelihood for finding the coefficients γ and δ:

 

 Simulation Data with Python

The following exhibits display the simulation data evaluated using ARCH to illustrate how ARCH functions.

To facilitate the visual representation of this simulation, the most basic form of Engle's ARCH, as introduced in the Wikipedia entry below, has been implemented.

Ref: https://en.wikipedia.org/wiki/Autoregressive_conditional_heteroskedasticity

This simplified simulation demonstrates motion prediction for intercepting incoming flying projectiles with erratic movements, resembling the fluctuations of a stock price.

Following is my Python codes: 

Wednesday, March 19, 2025

Myonchan (Youmu) of Touhou 13 version for my own Yukkuri kaisetsu!

 


Posted on my pixiv page: https://www.pixiv.net/en/artworks/128369666
自家用ゆっくり解説用の自作みょんちゃん(東方神霊廟 Ver.)の立ち絵(振袖着物姿)を作りました!
I have created the standing picture of Myonchan (Youmu) of Touhou 13 version for my own Yukkuri kaisetsu!
YouTube: https://www.youtube.com/shorts/Z0LKM9nw5XU
NicoNico: https://www.nicovideo.jp/watch/sm44779416

 


 

































Thursday, March 06, 2025

Two Shinto shrine-maidens in Touhou Project

 Posted on my pixiv page: https://www.pixiv.net/en/artworks/127943067

5th March (3 5 can be pronounced Mi-Ko meaning a shrine-maiden) is the Shrine-Maiden day and 7th March (3 7 can be pronounced Sa-Na) is the Sanae's day. So, I have illustrated Sanae and Reimu with a Torii gate back.