, 44 min read
window.MathJax = { tex: { tags: 'ams' } }; Introduction 1. Preliminaries 2. State of the art 3. Algorithms 3.1 Algorithm: ABORT 3.1.1 ABORT for open online Dial-a-Ride 3.1.2 ABORT for closed online Dial-a-Ride 3.2 Algorithm: ABORT-AND-WAIT (AAW) 3.2.1 AAW for closed online…
, 1 min read
This blog was viewed more than 110.000 times since its inception and had more than 84.500 visitors. The averages per month are: The most popular posts this year are: The most popular posts over all years are: Distribution of countries accessing this blog over last 365 days, USA is number one,…
, 2 min read
Main source for trouble-shooting is Arch-Wiki UEFI. It describes the commands: bcfg within UEFI shell Linux command efibootmgr 1. It is ighly recommended to install the UEFI-shell, which is in package edk2-shell. On Asrock copy cp -p /usr/share/edk2-shell/x64/Shell_Full.efi /boot/shellx64.efi So…
, 1 min read
In continuation of blog-post SSD Speed on Dell XPS 13 9350, here are performance measurements for a Samsung EVO 970 Plus in Dell XPS 13. Caveat from Dell xps 13 9350 and Samsung 970 evo M.2 nvme Compatability?: However, be aware that although the XPS 13 9350 uses a PCIe x4 configuration for its…
, 2 min read
In Chinese Hackers I mentioned that I block ssh attackers with the help of fail2ban. Unfortunately, fail2ban uses iptables to create firewall rules in "Chain f2b-SSH" for each individual IP address. For a modern processor this is no problem, even if you have thousands of these rules.…
, 4 min read
Below are some photographs during assembly of the Asrock A300M with an AMD Ryzen 5 Pro 3400G processor. The Asrock website detailing the specs of the A300M: DeskMini A300 Series. The specs are as in below table. Type Value CPU - Supports AMD AM4 Socket CPUs (Picasso, Raven Ridge, Bristol…
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This article is worth reading: Neural Network Back-Propagation Revisited with Ordinary Differential Equations I replied: Thank you very much for this very informative article providing many links, the Python code, and the results. According the mentioned paper from Owens + Filkin the speedup…
, 1 min read
Two ways to compute the error function or Bessel function in Julia. 1. Calling C. On UNIX libm provides erf() and j0(). So calling them goes like this: ccall(("erf","libm.so.6"),Float64,(Float64,),0.1) ccall(("j0"),Float64,(Float64,),3) In this case one can omit the…
, 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 \\ …
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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…
, 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…
, 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…
, 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…
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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,…
, 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…
, 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…
, 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)…
, 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…
, 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…
, 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 { //…