324,559 research outputs found
La filogenesi del nuovo capitale sociale
No full textLa disciplina delle società di capitali è ormai consolidata negli anni, ma è anche oggetto di plurimi interventi legislativi volti a dare una diversa fisionomia e funzione al capitale sociale: la recente fissazione del capitale minimo delle s.p.a. a cinquantamila euro e la previsione di società semplificate a responsabilità limitata, con capitale sociale pari ad almeno 1 euro ed inferiore all’importo di diecimila euro, sono esempi di un innegabile interesse del legislatore al tema del capitale sociale, interesse che concretamente si esprime, in questi ultimi anni, per il tramite di norme ad hoc, destinate a soddisfare contingenti esigenze di crescita economica; le possibili ricadute sistematiche di tali interventi devono ancora essere approfonditamente vagliate e, certo, suggeriscono una rinnovata attenzione per uno dei temi centrali del diritto societario
Il nuovo capitale sociale
No full textCon questa pubblicazione si vuole fare il punto sul tema del capitale sociale ad oltre dieci anni dalla Riforma. La disciplina delle società di capitali è ormai consolidata negli anni, ma è anche oggetto di plurimi interventi legislativi volti a dare una diversa fisionomia e funzione al capitale sociale: la recente fissazione del capitale minimo delle s.p.a. a cinquantamila euro e la previsione di società semplificate a responsabilità limitata, con capitale sociale pari ad almeno 1 euro ed inferiore all’importo di diecimila euro, sono esempi di un innegabile interesse del legislatore al tema del capitale sociale, interesse che concretamente si esprime, in questi ultimi anni, per il tramite di norme ad hoc, destinate a soddisfare contingenti esigenze di crescita economica; le possibili ricadute sistematiche di tali interventi devono ancora essere approfonditamente vagliate e, certo, suggeriscono una rinnovata attenzione per uno dei temi centrali del diritto societario
Proton Therapy at the Institut Curie – CPO: operation of an IBA C235 cyclotron looking forward scanning techniques
No full textSince 1991, more than 6100 patients (mainly eye and
head&neck tumours) were treated at the Institut Curie –
Centre de Protonthèrapie d’Orsay (IC – CPO) using
Single Scattering and Double Scattering (DS) proton
beam delivery technique. After 19 years of activity, a 200
MeV synchrocyclotron has been shut down and replaced
by a 230 MeV C235 IBA proton cyclotron. This delivers
beam to two passive fixed treatment rooms and to one
universal nozzle equipped gantry (DS, Uniform Scanning
– US, Pencil Beam Scanning – PBS). In the past two
years of operation more than 95.5% of the scheduled
patients (near 500/year) were treated without being
postponed. According to IBA recommendations, we have
realized preventive maintenance and we have improved
some diagnostic tools allowing us to reduce the number of
downtime events from 499 in 2011 to 351 in 2012 [1]. In
order to enhance cancer treatment capabilities we are now
involved in the transition towards scanning particle
therapy, requiring even more accurate quality assurance
protocols. We describe here the main cyclotron issues
looking forward the scanning technique, the main goal
being the progress of our reliability performances
A graph with a thousand edges: rummaging in complex work varieties
No full textContext
The increasingly digitalization and technological advances ask for novel perspectives to ensure effective risk and safety management strategies. Socio-technical system (STS) have been advocated as constructs able to achieve a certain goal [1], acknowledging both the symbiotic interactions between technical and human elements. Nowadays, these latter have a dominant informative part, demanding for explicit focus on connectivity and communication aspects. This is where the notion of cyber-socio-technical system (CSTS) can be used to broaden the perspective of systemic analyses. CSTSs are systems where peculiar emphasis is reserved to data-accessing and data-processing activities for and from other socio-technical connected entities [2]. Studying - and even more engineering - resilience in such systems becomes a pressing challenge for these modern systems. On this basis, Patriarca et al. discussed the role of Resilience Engineering in combination with knowledge management, to explore different work varieties, as discussed in the WAx framework (Work-As-X) [3]. The framework is made up of three main elements: (i) the knowledge structure, (ii) the knowledge entities, and (iii) the knowledge dynamics, which are meant to capture diverse knowledge entities [4].
Challenge
The WAx framework embraces the idea of knowledge dynamics to map the creation and/or conversion of knowledge between agents in both tacit and explicit knowledge dimensions. Consequently, a knowledge model can be built with the intention to abandon any trivialized representation of a work setting and to empower analysts in gaining larger understanding of STSs and CSTSs inherent complexity. Nonetheless, in practical terms, these knowledge models become puzzling to manage and to maintain, requiring an additional systematic approach to make them actionable. This aspect in particular represents one of the modelling and computational frontiers of resilience engineering, in line with the 10th REA symposium “Resilience at frontiers, frontiers of resilience”.
Contribution
The WAx framework transfers the study of system properties towards the study of the knowledge linked to them, which becomes a big-data management problem. We believe this latter can be tackled as a knowledge graph modelling challenge: a knowledge graph is a model to organize available data based upon the semantic rules of an ontology. Accordingly, a graph G=(V,E) can be defined as a data structure containing a set of vertices V, and a set of edges E connecting them. Each element within the graph is characterized by a label, that classifies each data with an aspect from the common knowledge basis. It is possible to assign properties to each element of the graph with the intention of specifying data values related to certain graph elements. On this basis, a generic vertex in the graph can be defined as:
V_n=(L_n^V,p_(i n)^V ) ,0≤i≤I (1)
where V_n represents the n-th vertex in the graph (out of the N vertices), L_n^V is the label to be assigned to the n-th vertex, and p_1n^V,p_2n^V,...,p_In^V are the properties that describes n-th vertex. Edges and properties can be defined in a similar way to generate a systematic representation of the phenomenon under investigation.
After the selection of a proper ontology, and the subsequent extraction/classification of data through, e.g., natural language processing algorithm [5], the data from the process under analysis can be converted into a knowledge graph.
Implications
A set of vertices of the graph will represent the system elements to be marked through the agencies mapped via the WAx framework. These latter are all the elements which can generate, transform, or exchange knowledge. On the other hand, any subgraphs of G may represent specific knowledge entities to allow comparing elements (e.g. Work-As-Imagined, Work-As-Done, Work-As-Observed, etc.) across different agents. The interaction between the knowledge entities (i.e., knowledge dynamics) can be explored moving throughout the relationships (edges) connecting nodes (vertices). Such subgraphs can be retrieved by querying the graph and highlighting paths an agent can access offering an unprecedented systematicity to a RE investigation. They permit pinpointing at differences between different work varieties, strengths, ambiguities and weaknesses in the CSTS operations.
This research promotes RE as the discipline the frontier of safety and performance management, and pair it with computational advances to ultimately shorten the distance between its theoretical structure and an actionable proactive safety management.
References
[1] Walker, G., Come back sociotechnical systems theory, all is forgiven ... (2015) Civil Engineering and Environmental Systems, 32, pp. 170-179. DOI: 10.1080/10286608.2015.1024112
[2] Monostori, L., Kádár, B., Bauernhansl, T., Kondoh, S., Kumara, S., Reinhart, G., Sauer, O., Schuh, G., Sihn, W., Ueda, K., Cyber-physical systems in manufacturing (2016) CIRP Annals, 65 (2), pp. 621-641. DOI: 10.1016/j.cirp.2016.06.005
[3] Patriarca, R., Falegnami, A., Costantino, F., Di Gravio, G., De Nicola, A., Villani, M.L., WAx: An integrated conceptual framework for the analysis of cyber-socio-technical systems, (2021) Safety Science, 136, art. no. 105142, DOI: 10.1016/j.ssci.2020.105142
[4] Moppett, I.K., Shorrock, S.T., Working out wrong-side blocks, (2018) Anaesthesia, 73 (4), pp. 407-420. DOI: 10.1111/anae.14165
[5] Ansaldi, S., Agnello, P., Pirone, A., Vallerotonda, M. (2021). Near Miss Archive: A Challenge to Share Knowledge Among Inspectors and Improve Seveso Inspections. Sustainability. 13. 8456. 10.3390/su13158456
System-Theoretic Process Analysis for Security with Simulations (STPA-Sec/S): Combining STPA-Sec with simulation-based resilience assessment
No full textOver recent years, the call for digitalization and automation resulted in an increasing attention towards human-machine interactions and cooperation. Automation technologies opens new challenge towards this new environment in which human agents stand with wise and interconnected devices, stressing the need to acknowledge a cyber-socio-technical - rather than disjoint social, pure physical – dimension (Patriarca et al., 2021). If on one hand the systems that are more prone to human slips and lapses might benefit from this transformation, on the other, the same systems might suffer from unexpected new threats and disruptions. These latter emerge as a result of the tight interactions between the physical world and the Information Technology (IT) sphere. A cyber security issue does not necessarily refer to data or information leakage anymore, but it can have tangible consequences, too. In this context, the System-Theoretic Process Analysis for Security (STPA-Sec) represents a increasingly recognized valuable tool for security risk assessment (Patriarca et al., 2022a; Young and Leveson, 2013) . STPA-Sec extends the Systems-Theoretic Accident Modelling and Processes (STAMP) model considering cyber threats, identifying unsafe and unsecure controls throughout a cyber socio-technical system, and assisting in the definition of the requirements for technological failures and cyber attacks. Despite its large usage as a descriptive tool, there is still limited use of STPA-Sec in (semi-)quantitative terms. To contribute to this research path, we present System-Theoretic Process Analysis for Security with Simulations (STPA-Sec/S), a methodological support extending STPA-Sec with quantitative resilience assessment based on simulation models. The methodology is instantiated in a demonstrative case study of a water treatment plant, and its critical CPSs which may impact both community health, and environment. The obtained results show how STPA-Sec/S foster systems understanding, allow a systematic identification of its major criticalities, and the respective quantification
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