About me

My name is Lukas Fleischer. I was born on March 6th, 1990 near Stuttgart and I am currently living in Waterloo, ON.

From August 2015 to April 2019, I was a research assistant in the Institute for Formal Methods in Computer Science at the University of Stuttgart. From May 2019 to December 2019, I was a postdoctoral researcher in the Cheriton School of Computer Science at the University of Waterloo, working with Jeffrey Shallit. My primary research areas are automata theory, formal languages, semigroup theory, algorithms, computational complexity and formal verification. A list of my publications can be found here and on DBLP.

I actively contribute to several open source projects. Please scroll down for a (not necessarily complete) list.

Short CV

05/2019-12/2019 Postdoctoral Fellow, School of Computer Science, University of Waterloo
02/2019-04/2019 Research Assistant, FMI, University of Stuttgart
08/2015-02/2019 Ph.D. Computer Science, FMI, University of Stuttgart
04/2015-07/2015 Teaching Assistant, University of Stuttgart
10/2013-05/2015 M.Sc. Computer Science, University of Stuttgart
10/2010-11/2013 B.Sc. Computer Science, University of Stuttgart
2000-2009 High School, Gymnasien im Ellental, Bietigheim-Bissingen
1996-2000 Elementary School, Grundschule im Sand, Bietigheim-Bissingen

Publications

Conference Articles

  1. Lukas Fleischer and Manfred Kufleitner. Testing Simon's congruence. MFCS 2018.   
  2. Lukas Fleischer. The Intersection Problem for Finite Semigroups. DLT 2018.   
  3. Lukas Fleischer. On the Complexity of the Cayley Semigroup Membership Problem. CCC 2018.   
  4. Lukas Fleischer and Manfred Kufleitner. The Intersection Problem for Finite Monoids. STACS 2018.   
  5. Volker Diekert and Lukas Fleischer. Church-Rosser Systems, Codes with Bounded Synchronization Delay and Local Rees Extensions. WORDS 2017.   
  6. Lukas Fleischer and Manfred Kufleitner. Green's Relations in Finite Transformation Semigroups. CSR 2017.   
  7. Lukas Fleischer and Manfred Kufleitner. Operations on Weakly Recognizing Morphisms. DCFS 2016.   
  8. Lukas Fleischer and Manfred Kufleitner. Efficient Algorithms for Morphisms over Omega-Regular Languages. FSTTCS 2015.   
  9. Lukas Fleischer, Manfred Kufleitner and Alexander Lauser. Block Products and Nesting Negations in FO2. CSR 2014.   

Journal Articles

  1. Lukas Fleischer and Manfred Kufleitner. The Complexity of Operations on Weakly Recognizing Morphisms. RAIRO-Theor. Inf. Appl., volume 53, number 1-2, pp 1–17. EDP Sciences, 2018.  
  2. Lukas Fleischer and Manfred Kufleitner. Green's Relations in Deterministic Finite Automata. Theory of Computing Systems, volume 63, issue 4, pp 666–687. Springer, 2018.  
  3. Lukas Fleischer, Manfred Kufleitner and Alexander Lauser. The Half-Levels of the FO2 Alternation Hierarchy. Theory of Computing Systems, volume 61, issue 2, pp 352–370. Springer, 2017.  

Unpublished Papers

  1. Lukas Fleischer and Jeffrey Shallit. Words With Few Palindromes, Revisited. Technical report.  
  2. Lukas Fleischer and Jeffrey Shallit. Words Avoiding Reversed Factors, Revisited. Technical report.  
  3. Lukas Fleischer. Algorithms and Complexity Results for Finite Semigroups. PhD thesis.  
  4. Lukas Fleischer. Efficient Membership Testing for Pseudovarieties of Finite Semigroups. Technical report.  

Open Source Projects

Arch Linux

As an Arch Linux Trusted User and Developer, I am leading the development of the Arch User Repository web interface and maintaining the Arch Linux projects page as well as roughly 200 packages.

calcurse

I am the current maintainer of calcurse, a powerful command-line based calendar program.

cgit

I am a regular contributor to cgit, a hyperfast web frontend for Git repositories written in C.

jpeg-archive

In late 2017, I started co-maintaining jpeg-archive, a utility to compress JPEG images for long-term storage without sacrificing perceived visual quality.

Other Projects

aurdupes is a Python script that can be used to find duplicate packages in pacman databases and the Arch User Repository.

Deprecated Projects

cdlib-eject is a lightweight C program to control Dacal CD Library II devices.

Open Source Contributions

I occasionally contribute to other projects, such as

  • alot, a terminal-based mail user agent,
  • the version control system Git,
  • libfaketime, which can be used to modify the system time for a single application,
  • the package manager pacman,
  • the password manager pass,
  • pygit2, and
  • xwax, an open-source Digital Vinyl System (DVS) for Linux.

Contact

Email

Please do not send emails to Lukas Fleischer <spmtrp@lfos.de>.

  Lukas Fleischer <lfleischer@lfos.de>

GitHub

  lfos

GPG Key

  2E36 D862 0221 482F C45C B7F2 A917 6475 9326 B440