Evaluation of SCION for User-driven Path Control:a Usability Study

The UPIN (User-driven Path verification and control in Inter-domain Networks) project aims to implement a way for users of a network to control how their data is traversing it. In this paper we investigate the possibilities and limitations of SCION for user-driven path control. Exploring several aspects of the performance of a SCION network allows us to define the most efficient path to assign to a user, following specific requests. We extensively analyze multiple paths, specifically focusing on latency, bandwidth and data loss, in SCIONLab, an experimental testbed and implementation of a SCION network. We gather data on these paths and store it in a database, that we then query to select the best path to give to a user to reach a destination, following their request on performance or devices to exclude for geographical or sovereignty reasons. Results indicate our software is a viable option to offer users many paths to choose from, following a series of requests, and therefore perform user-driven path control in a SCION network.</p

Investigation of FlexAlgo for User-driven Path Control

This paper examines the Flexible Algorithm (FlexAlgo) for its potential to enable user-driven path control in intra-domain Segment Routing (SR) enabled networks. FlexAlgo is a relatively new approach to intra-domain routing that allows multiple custom algorithms to coexist within a single domain. This capability has the potential to provide users with greater control over the paths their data takes through a network. The research includes a thorough investigation of the FlexAlgo approach, including an examination of its underlying techniques, as well as a practical implementation of a FlexAlgo-based solution. We depict performed experiments where we implemented FlexAlgo in three different scenarios. We also present how we developed an automated tool for users to control traffic steering using preferred metrics and constraints. The results of this investigation demonstrate the capabilities of FlexAlgo as a means of enabling user-driven path control and therefore increase security and trust of users towards the network.</p

Increasing the Transparency, Accountability and Controllability of multi-domain networks with the UPIN framework

Demands for a more trustworthy Internet are constantly increasing, in particular to support emerging critical services such as intelligent urban transport systems and smart energy grids. Such cyber-physical systems require more insight into the properties of network operators (e.g., in terms of the security posture of their equipment) and more control over which network operators transport their data, thus going well beyond the traditional security paradigm which the Internet security community currently focuses on (confidentiality, availability, and integrity). In this work-in-progress paper we propose the UPIN framework, which aims to fulfill these new trust requirements. The framework advances the state-of-the-art by defining components needed to incorporate transparency, accountability, and controllability into the Internet or other types of inter-domain networks. The framework is based on our analysis of a smart grid use case to understand the specific needs of critical service providers and a literature study on existing technologies. We also discuss our ongoing work, and the demands and challenges of implementing and deploying the UPIN framework

sheets impact simulation for safety guards design experiments and correlation for fe explicit models of non alloy steel

Abstract In the last few years, some international standards for the safety of machine tools have been developed improving the ballistic protection of safety guards. The uncontrolled projection of parts of work piece or tools can often cause very dangerous perforations of the safety guards. In such a way specific experimental tests like the ones conducted in EU, have assured the possibility to write appendices of ISO standards for safety guards design of machine tools. These tests are based on impact between a particular standardized projectile, which exemplifies an impacting fragment of variable size and energy, and a flat plate placed in the trajectory of the projectile. The penetration or buckling of the target determines the non-suitability of a particular material of a given thickness, for the design and production of safety guards. However, these tests have following limitations: they are valid only for: a limited type of thickness and materials, a perpendicular impact with flat plates of about 500 mm x 500 mm and when the standardized penetrator is a cylinder with a prismatic head. Another limitation is based on design of real safety guards: difficulties in taking into account curved design of guards such as the ones typically used in the spindles of machine tools. Moreover, it is very difficult to take into account innovative materials different from the ones provided by the standards. It is also impossible to consider projected objects whose geometry is not regular, for example fragmented parts of tools, broken as a result of a wrong manoeuvre of the machine user. The focus of this paper is to give an overview of possible material models usable for FEM explicit virtual testing of safety guards. Correlation between experimental penetration of international standards and numerical tests will be presented as a proof of the possibility to implement reliable testing virtual procedures. It is possible to think of exploring the uncertainty of the standardized tests procedure due to, as an example, non-perpendicular impact of the projectile on the safety guard, using simulations

Comparison of semi and fully-implicit time integration schemes applied to a damage and fatigue phase field model

In this work, we apply semi and fully-implicit time integration schemes to the damage and fatigue phase field presented in Boldrini et al. (2016). The damage phase field is considered a continuous dynamic variable whose evolution equation is obtained by the principle of virtual power. The fatigue phase field is a continuous internal variable whose evolution equation is considered as a constitutive relation to be determined in a thermodynamically consistent way. In the semi-implicit scheme, each equation is solved separately by suited implicit method. The Newton’s method is used to linearize the equations in the fully-implicit scheme. The time integration methods are compared and the results of damage and fracture evolution under the influence of fatigue effects are presented. The computational cost associated to the semi-implicit scheme showed be lower than the fully counterpart155116CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP306182/2014-9330030172013/50238-3; 2015/10310-2; 2015/20188-