Christen, Patrik

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Christen
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Patrik
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Patrik Christen

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2018 - 201942020 - 202318

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Gerade angezeigt 1 - 10 von 22
  • Vorschaubild
    Publikation
    System Metamodelling of Open-Ended Evolution Implemented with Self-Modifying Code
    (Complex Systems Publications, inc., 2023) Christen, Patrik
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Kein Vorschaubild vorhanden
    Publikation
    04B - Beitrag Konferenzschrift
  • Kein Vorschaubild vorhanden
    Publikation
    Curb your self-modifying code
    (IEEE, 2022) Christen, Patrik
    Self-modifying code has many intriguing applications in a broad range of fields including software security, artificial general intelligence, and open-ended evolution. Having control over self-modifying code, however, is still an open challenge since it is a balancing act between providing as much freedom as possible so as not to limit possible solutions, while at the same time imposing restriction to avoid security issues and invalid code or solutions. In the present study, I provide a prototype implementation of how one might curb self-modifying code by introducing control mechanisms for code modifications within specific regions and for specific transitions between code and data. I show that this is possible to achieve with the so-called allagmatic method - a framework to formalise, model, implement, and interpret complex systems inspired by Gilbert Simondon’s philosophy of individuation and Alfred North Whitehead’s philosophy of organism. Thereby, the allagmatic method serves as guidance for self-modification based on concepts defined in a metaphysical framework. I conclude that the allagmatic method seems to be a suitable framework for control mechanisms in self-modifying code and that there are intriguing analogies between the presented control mechanisms and gene regulation.
    04B - Beitrag Konferenzschrift
  • Kein Vorschaubild vorhanden
    Publikation
    04B - Beitrag Konferenzschrift
  • Kein Vorschaubild vorhanden
    Publikation
    Philosophy-guided mathematical formalism for complex systems modelling
    (IEEE, 2022) Christen, Patrik; Del Fabbro, Olivier
    We recently presented the so-called allagmatic method, which includes a system metamodel providing a framework for describing, modelling, simulating, and interpreting complex systems. Its development and programming was guided by philosophy, especially by Gilbert Simondon’s philosophy of individuation, Alfred North Whitehead’s philosophy of organism, and concepts from cybernetics. Here, a mathematical formalism is presented to better describe and define the system metamodel of the allagmatic method, thereby further generalising it and extending its reach to a more formal treatment and allowing more theoretical studies. By using the formalism, an example for such a further study is provided with mathematical definitions and proofs for model creation and equivalence of cellular automata and artificial neural networks.
    04B - Beitrag Konferenzschrift
  • Kein Vorschaubild vorhanden
    Publikation
    04B - Beitrag Konferenzschrift
  • Vorschaubild
    Publikation
    Automatic programming as an open-ended evolutionary system
    (Machine Intelligence Research Labs, 2022) Fix, Sebastian; Probst, Thomas; Ruggli, Oliver; Hanne, Thomas; Christen, Patrik
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    Open-ended automatic programming through combinatorial evolution
    (Springer, 2021) Fix, Sebastian; Probst, Thomas; Ruggli, Oliver; Hanne, Thomas; Christen, Patrik; Abraham, Ajith; Gandhi, Niketa; Hanne, Thomas; Hong, Tzung-Pei; Rios, Tatiane Nogueira; Ding, Weiping
    04B - Beitrag Konferenzschrift
  • Kein Vorschaubild vorhanden
    Publikation
    Association of higher bone turnover with risk of curve progression in adolescent idiopathic scoliosis
    (Elsevier, 2021) Zhang, Jiajun; Wang, Yujia; Cheng, Ka-lo; Cheuk, Kayee; Lam, Tsz-ping; Hung, Alec L.H.; Cheng,  Jack Chun-Yiu; Qiu, Yong; Müller, Ralph; Christen, Patrik; Lee,  Yuk-Wai Wayne
    01A - Beitrag in wissenschaftlicher Zeitschrift
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    Publikation
    Simulating metaphyseal fracture healing in the distal radius
    (MDPI, 2021) Engelhardt, Lucas; Niemeyer, Frank; Christen, Patrik; Müller, Ralph; Stock, Kerstin; Blauth, Michael; Urban, Karsten; Ignatius, Anita; Simon, Ulrich
    Simulating diaphyseal fracture healing via numerical models has been investigated for a long time. It is apparent from in vivo studies that metaphyseal fracture healing should follow similar biomechanical rules although the speed and healing pattern might differ. To investigate this hypothesis, a pre-existing, well-established diaphyseal fracture healing model was extended to study metaphyseal bone healing. Clinical data of distal radius fractures were compared to corresponding geometrically patient-specific fracture healing simulations. The numerical model, was able to predict a realistic fracture healing process in a wide variety of radius geometries. Endochondral and mainly intramembranous ossification was predicted in the fractured area without callus formation. The model, therefore, appears appropriate to study metaphyseal bone healing under differing mechanical conditions and metaphyseal fractures in different bones and fracture types. Nevertheless, the outlined model was conducted in a simplified rotational symmetric case. Further studies may extend the model to a three-dimensional representation to investigate complex fracture shapes. This will help to optimize clinical treatments of radial fractures, medical implant design and foster biomechanical research in metaphyseal fracture healing.
    01A - Beitrag in wissenschaftlicher Zeitschrift