IT Sky Consulting GmbH
Deutsch 2013 2012 In 2014 I have visited the Devoxx conference in Antwerp in Belgium. Here are some notes about it: What is Devoxx? Devoxx ist a conference organized by the Belgian Java User Group. Belgium is trilingual (French, Flemish and German), but the conference is 100% in English. The location is a huge cinema …
„Devoxx 2014 in Belgium“ weiterlesen
Deutsch This blog post is based on a talk that I have given in the Ruby on Rails User Group. Who knows Transactions? Who knows really well what transactions are? What is a Transaction? Just common sense what transactions mean: We open an transaction (implicitely or explicitely) We perform a certain number of operations (for …
„Transaction Isolation Levels“ weiterlesen
By Karl Brodowsky IT Sky Consulting GmbH… Deutsch E-Banking examples „Calculator“ RSA-Number-Generator SMS Sheet with 100 Codes Android-App USB-Device SmartCard Not so common for banks: plain old username+password Login with google, twitter, facebook Calculator Enter PIN Code Enter Code from login page Read Result from calculator Enter Result in Login Page Security Questions: Depends on …
„Login Mechanisms“ weiterlesen
Deutsch Around mid of June 2014 I have been visiting the Scala Days in Berlin. Like usual these events contain a lot of speeches, which were distributed in four tracks, apart from the key notes. The event location was a cinama, like the Devoxx in Antwerp, but this time one that has been transformed to …
„Scala Days in Berlin 2014“ weiterlesen
Deutsch Are closures at all possible in C, without falling back to writing some interpreter in C and using that interpreted langauge? Function pointers alone are far less than what is needed for closures. But they are one of the building blocks. It is quite hard to get the signature right, but a typedef proves …
„Closures in C and Scala“ weiterlesen
Deutsch In a comment to Carry Bit: How does it work the question about shift and rotation functions has been asked. Which exist and how they work exactly depends off course on the CPU architecture, but I will try to give a high level overview anyway. The following aspects have to be considered: 8, 16, …
„Shift- and Rotation Functions“ weiterlesen
Deutsch This blog uses the Plugin WP QuickLaTeX which gets its -rendering done by QuickLaTeX. If only a page starts with , formulas can be embedded with or . They have to be written in LaTeX-notation. So this blog can use formulas like for example: …
„Mathematical Formulas in WordPress“ weiterlesen
Auf Unix- und Linux-artigen Systemen laufen immer einige sogenannte Daemon-Prozesse. Diese laufen im Hintergrund, haben also keine Verbindung mit einem Terminal. Beim Start kann man eine sogenannte Daemonisierung verwenden. Man startet von dem interaktiv gestarteten Prozess einen Child-Prozess. Dieser hat noch Verbindung zum ersten und damit zum Terminal. Nun startet man von diesem den eigentlichen …
„Dämonisierung von Prozessen“ weiterlesen
So etwas muss man ja heute selten machen, Applikationsentwicklung ist eher die Tätigkeit, mit der man sich herumschlägt, wenn man kundenspezifische „Business-Software“ entwickelt oder anpasst. Bei der Systemprogrammierung schreibt man Software, die direkt auf Betriebssystemfunktionen und Hardware zugreift oder Teile von Betriebssystemen im weiteren Sinn, also nicht unbedingt nur Teile des Linux-Kernels oder Kernelmodule, sondern …
„Systemprogrammierung“ weiterlesen
Deutsch Many numerical calculations deal with amounts of money. It is always nice if these calculations are somewhat correct or if we can at least rest assured that we do not loose money due to such inaccuracies. Off course there are calculations that may legitimately deal with approximations, for example when calculating profits as percentages …
„Rounding of Money Amounts“ weiterlesen