Correct ways of deploying NFSv4

NFS is old. Its root can trace back to the remote file system in System V R3 while the first release of NFS (version 2) is in 1985 on SunOS 2.0. It must not be considered as a counterpart of Samba or CIFS, since NFS does not do user authentication... [more]

Threshold linear regression

Threshold regression means to do regression separately in different segments, as separated by some threshold. Take linear models as example, we have a response variable \(y\) and predictors \(X\), and additionally, we have a discriminator \(q\), which may be derived from \(X\), and set of transition functions \(g_i\). The model... [more]

Converting a DD-WRT router to OpenWRT

I have an old WiFi router (not my gateway, but that doesn’t matter) that used to be running DD-WRT and I am experimenting with the WiFi mesh or 802.11r roaming at home. Unfortunately the DD-WRT version is too old to do either of these – it was a Linux 2.4... [more]

Heat equation and Black-Scholes formula

It is well known for a long time that the quant finance borrowed a lot of results from physics. The notable Feynman-Kac formula is one example. In the case of vanilla European option pricing, the Black-Scholes formula gives the following result: [more]