A mathematical model and computational implementation of a digital twin for a bioresorbable polylactide (PLA) bone scaffold with a functionally graded triply periodic minimal surface (TPMS) architecture are developed. The model comprises four state variables (polymer mass, osteoblast population, growth factor concentration, and newly formed bone mass) and a system of reaction–diffusion equations adapted to the 3D geometry. For the first time, it is shown that under certain physiological conditions, a simplified local (spatially homogeneous) version of the system exhibits chaotic dynamics resembling the Rössler, Aizawa and Rucklidge attractors. This finding allows interpreting unpredictable fluctuations in resorption and osteogenesis rates as a manifestation of deterministic chaos, which should be taken into account in clinical prognosis. A sigmoidal spatial porosity gradient is proposed to mimic the cortical–trabecular transition, and stable dynamics are demonstrated for the corresponding full 3D spatial model.
The results are packaged in the Greenfield Startup Model (GSM), which explains the priority of startups to release the product as quickly as possible, and the need to shorten time-to-market, by speeding up the development through low-precision engineering activities.
Carmine Giardino, Nicolò Paternoster, M. Unterkalmsteiner et al.· IEEE Transactions on Softwar...· 178 citations· ⚡14
Software startup companies develop innovative, software-intensive products within limited timeframes and with few resources, searching for sustainable and scalable business models.
M. Unterkalmsteiner, P. Abrahamsson, Xiaofeng Wang et al.· e-Informatica Software Engin...· 157 citations· ⚡17
This study conducts a case survey study based on the secondary data of the major pivots happened in 49 software startups, and demonstrates that customer need pivot is the most common among all pivot types.
Sohaib Shahid Bajwa, Xiaofeng Wang, Anh Nguyen-Duc et al.· Empirical Software Engineeri...· 127 citations· ⚡15
The comparison of adopter and non-adopter sample reveals three potential adoption inhibitor, security, data privacy, and portability, which underlines the importance of the technical and security perspectives for research investigating the adoption of technology.
Nattakarn Phaphoom, Xiaofeng Wang, S. Samuel et al.· Journal of Systems and Softw...· 111 citations· ⚡8
This study investigates how Lean internal startup facilitates software product innovation in large companies and identifies its enablers and inhibitors, and shows the potential of the method-in-action framework to investigate the Lean startup approach in non-startup context.
Henry Edison, Nina M. Smørsgård, Xiaofeng Wang et al.· Journal of Systems and Softw...· 78 citations· ⚡6
The application of agile software methods and more recently the integration of Lean practices contribute to the trend of continuous improvement in the software industry. One such area warranting proper empirical evidence is a project’s operational efficiency when using the Kanban method. This short paper takes a new an...
Marko Ikonen, Petri Kettunen, Nilay V. Oza et al.· EUROMICRO Conference on Soft...· 67 citations· ⚡9
