Gunnar Uldall's Tax Tariff

, 2 min read

Gunnar Uldall wrote a a book with title "Die Steuerwende" in 1996. 1. Proposal. In this book he proposed the following tariff, $x$ is in DEM. $$ t_u(x) = \begin{cases} 0 & \mbox{if } x\le12000 \\ 0.08\left(x-12000\right) & \mbox{if } 12001\le x\le20000 \\ …

Splitting and anti-merging vCard files

, 2 min read

Sometimes vCard files need to be split into smaller files, or the file needs to be protected against merging in another application. 1. Splitting. Below Perl script splits the input file into as many files as required. Output files are named adr1.vcf, adr2.vcf, etc. You can pass a command line…

Automated Rebooting of Auerswald Communication System

, 2 min read

The wired telephones in my house are connected to a telephone-system from Auerswald. It's Auerswald COMpact 5020 VoIP. This PBX handles VoIP and ISDN. My children make fun of me that I still use landlines, they just use cell phones. Unfortunately since a couple of months the system no longer is…

Hosting Static Content with netlify.app

, 1 min read

Many people associate netlify.com with its integration to GitHub, GitLab or Bitbucket. But you can just deploy your local files to Netlify as well. Install netlify command via npm install netlify-cli. cd to the directory where you locate your static content. Login to Netlify site via netlify…

Hosting Static Content with now.sh

, 3 min read

now.sh, previously known under zeit.co, which has now rebranded as vercel.com, allows to host static content. There is no PHP, MySQL/MariaDB, Perl, CGI, etc. While surge.sh is super simple to use, in contrast now.sh uses the notion of 'environment', which can be either development, preview, or…

Hosting Static Content with surge.sh

, 1 min read

When you want totally hassle free hosting of static HTML then surge.sh is very attractive. It is easy to set-up and free of charge for most private users. It offers https out of the box from sectigo.com. It does not offer PHP, MySQL/MariaDB, CGI, Perl, etc. Just static HTML with CSS, JavaScript,…

Performance Comparison Pallene vs. Lua 5.1, 5.2, 5.3, 5.4 vs. C

, 6 min read

Installing Pallene is described in the previous post: Installing Pallene Compiler. In this post we test the performance of Pallene versus C, Lua 5.4, and LuaJIT. Furthermore we benchmark different Lua versions starting with Lua 5.1 up to 5.4. 1. Array Access. I checked a similar program as in…

Installing Pallene Compiler

, 4 min read

Pallene is a Lua based language. In contrast to Lua, which is untyped, Pallene is typed. A good paper on Pallene is "Pallene: A companion language for Lua", by Hugo Musso Gualandi, and Roberto Ierusalimschy. From above paper: The compiler itself is quite conventional. After a standard…

Performance Comparison in Computing Exponential Function

, 2 min read

If your computation is dominated by exponential function evaluations, then it makes a significant difference whether you evaluate the exponential function exp() in single precision or in double precision. You can reduce your computing time by roughly 25% when moving from double precision (double)…

youtube-dl HTTP 403 error

, 1 min read

youtube-dl is a set of Python scripts for downloading videos from YouTube, Twitter, Vimeo, and many other sites, see for example the list of supported sites. This is a handy tool if you want to watch videos or listen to music on your smartphone: Download them with youtube-dl and store them on your…

J-Pilot Plugin For SQLite Export

, 2 min read

In SQL Datamodel For J-Pilot I described the SQLite datamodel. I wrote a J-Pilot plugin which can export the below entities and write them to an SQLite database file. The direction is one-way: from J-Pilot to SQLite. Address Datebook Memo To-Do Expense Various categories for above entities Adding…

SQL Datamodel For J-Pilot

, 12 min read

Currently J-Pilot stores its data in binary form which is compatible with the original Palm data format. See Palm File Format Specification. Reading these binary formats is not simple, see for example pdbrd.c. Portion of the internal structure looks something like this: typedef struct { //…

Sharing Terminal Screen Using Tmux

, 3 min read

Sharing your terminal input and output can be done in different ways. kibitz, see Linux commands: expect and kibitz VNC Skype / Teams / Zoom, etc. tmux 1. tmux essentials. tmux (tmux wiki) uses the following vocabulary and hierarchy. server session-group session client window pane The…

J-Pilot Data on Android Phone: Contacts

, 2 min read

Keeping J-Pilot data in sync with Android smartphone is quite a challenge. See my post about Google calendar. Copying contact data from J-Pilot to Android in the past went like this: Export data from J-Pilot in vCard (vcf) format If required, fiddle with this vcf file with some Perl…

ssh and rsync for Android, Termux

, 1 min read

I used SSHelper for some time to rsync my files from my Linux machine to Android phones, see here. I most notably used this for transfering photos. I now use Termux. I prefer Termux over SSHelper as it allows to install new programs within Termux using pkg or apt-get. Starting Termux looks like…

Surfing the internet with 1 GBit/s

, 2 min read

Adding 30 Cents to my monthly bills bought me Gigabit internet access. I now pay 39.99 EUR per month. Previously I had 100 MBit/s. From user's experience I do not feel any significant difference. Of course, for all my mobile devices, like smartphones, laptop, there is and will be no difference as…

Aggressive Vodafone Router

, 1 min read

Vodafone router does not allow to turn off firewall permanently. It will insist on switching it on after 24 hours. Version of this router in question: Firmware version: 01.02.037.03.12.EURO.SIP Productname: Vodafone Docsis 3.1 This "Made in China" router using…

Statistics of this Blog: Crossed 100.000 Views

, 1 min read

This blog was viewed more than 100.000 times since its inception and had more than 76.750 visitors. The averages per month are: As numbers: The most popular posts over one year are: The most popular posts over all years are: Distribution of countries accessing this blog over last 365 days, USA…

Contribution to scientific publications in GPUGrid

, 1 min read

Looking at my account page in GPUGrid I notice that my computations have lead to some publications. Nice. Task Papers Topic 3063rd/3113 Giorgino et al, J. Chem. Theory Comput, 2012 cancer 3389th/5798 Sadiq et al, PNAS 2012 hiv 1801st/1995 Venken et al, JCTC 2013 hiv 1886th/3349 Buch et…

Chinese Hackers

, 3 min read

I am running fail2ban since November 2017 and all unsuccessful attempts to log-in to sshd are monitored. Breaking down these attempts according country shows that Chinese IP addresses are coming first here. The numbers are: 27639 China 13589 United States 8641 France 3985 India 3418 …