We introduce Fluidity, a framework enabling the flexible and adaptive deployment of serverless and modular applications in systems comprising cloud, edge, and mobile nodes. Based on a declarative description of application requirements, a custom placement policy, and a formal system infrastructure description, Fluidity plans and executes an initial deployment of application components in the cloud–edge–mobile continuum. Furthermore, at runtime, Fluidity monitors resource availability and the position of mobile nodes, and adapts the deployment of the application accordingly, without any manual intervention from the application owner or system administrator. These characteristics render Fluidity an enabler for serverless applications, allowing the application developers to focus on the application code itself while abstracting out the infrastructure management. Notably, Fluidity permits developers to provide their own deployment and adaptation policies as well as to switch between different policies while the application is running. We discuss the design and implementation of Fluidity in detail and provide a realistic evaluation using a lab testbed in which the mobile node is represented as a simulated drone. In addition, we evaluate the scalability of the proposed mechanisms. Our results show that the core mechanisms of Fluidity can support flexible application execution at a reasonable overhead and experimentation with different deployment policies with minimal effort.

Foivos Pournaropoulos; Alexandros Patras; Christos D. Antonopoulos; Nikos Bellas; Spyros Lalis. Fluidity: Providing flexible deployment and adaptation policy experimentation for serverless and distributed applications spanning cloud–edge–mobile environments. Future Generation Computer Systems 2024, 157, 210 -225.

Foivos Pournaropoulos, Alexandros Patras, Christos D. Antonopoulos, Nikos Bellas, Spyros Lalis. Fluidity: Providing flexible deployment and adaptation policy experimentation for serverless and distributed applications spanning cloud–edge–mobile environments. Future Generation Computer Systems. 2024; 157 ():210-225.

Foivos Pournaropoulos; Alexandros Patras; Christos D. Antonopoulos; Nikos Bellas; Spyros Lalis. 2024. "Fluidity: Providing flexible deployment and adaptation policy experimentation for serverless and distributed applications spanning cloud–edge–mobile environments." Future Generation Computer Systems 157, no. : 210-225.

The aim of this paper is to conduct a comparative analysis of three environmental approaches in the context of a bank production framework, considering the presence of nonperforming loans (NPLs). Specifically, we examine banks' inefficiency levels using the "by-production technology," "joint-weak disposable technology," and "material balanced technology." To ensure comparability within a directional slack inefficiency framework, we propose a two-step procedure. The study is based on a sample of 379 prominent banks operating in the United States from 2003 to 2017. Our findings reveal that the material balance and by-production technologies result in estimated inefficiency measures with higher sensitivity compared to the estimator utilizing the joint-weak disposable technology. Additionally, we identify distinct properties among the estimators, emphasizing their unique characteristics for modeling nonperforming loans. Finally, our paper sheds light on the differences between the three estimators in relation to banks' inefficiency levels, considering the incorporation of nonperforming loans in the production process.

Hirofumi Fukuyama; Roman Matousek; Nickolaos G. Tzeremes. A unified framework for nonperforming loan modeling in bank production: An application of data envelopment analysis. Omega 2024, 126 .

Hirofumi Fukuyama, Roman Matousek, Nickolaos G. Tzeremes. A unified framework for nonperforming loan modeling in bank production: An application of data envelopment analysis. Omega. 2024; 126 ():.

Hirofumi Fukuyama; Roman Matousek; Nickolaos G. Tzeremes. 2024. "A unified framework for nonperforming loan modeling in bank production: An application of data envelopment analysis." Omega 126, no. : .

Alexis T. Kermanidis; Christina-Margarita Charalampidou; Ioannis Goulas; Panagiotis Skarvelis; Nikolaos D. Alexopoulos. Fatigue and fracture behaviour of (Al-Cu-Li) AA2198 under different ageing conditions. International Journal of Fatigue 2024, 184 .

Alexis T. Kermanidis, Christina-Margarita Charalampidou, Ioannis Goulas, Panagiotis Skarvelis, Nikolaos D. Alexopoulos. Fatigue and fracture behaviour of (Al-Cu-Li) AA2198 under different ageing conditions. International Journal of Fatigue. 2024; 184 ():.

Alexis T. Kermanidis; Christina-Margarita Charalampidou; Ioannis Goulas; Panagiotis Skarvelis; Nikolaos D. Alexopoulos. 2024. "Fatigue and fracture behaviour of (Al-Cu-Li) AA2198 under different ageing conditions." International Journal of Fatigue 184, no. : .