G-biliaison of ladder Pfaffian varieties

The ideals generated by pfaffians of mixed size contained in a subladder of a skew-symmetric matrix of indeterminates define arithmetically Cohen-Macaulay, projectively normal, reduced and irreducible projective varieties. We show that these varieties belong to the G-biliaison class of a complete intersection. In particular, they are glicci.Comment: 15 page

Local Digital Twin-based control of a cobot-assisted assembly cell based on Dispatching Rules

In the context of an increasing digitalization of production processes, Digital Twins (DT) are emerging as new simulation paradigm for manufacturing, which leads to potential advances in the production planning and control of production systems. In particular, DT can support production control activities thanks to the bidirectional connection in near real-time with the modeled system. Research on DT for production planning and control of automated systems is already ongoing, but manual and semi-manual systems did not receive the same attention. In this paper, a novel framework focused on a local DT is proposed to control a cobot-assisted assembly cell. The DT replicates the behavior of the cell, providing accurate predictions of its performances in alternative scenarios. Then, building on these predicted estimates, the controller selects, among different dispatching rules, the most appropriate one to pursue different performance objectives. This has been proven beneficial through a simulation assessment of the whole assembly line considered as testbed

Open Interfaces for Connecting Automated Guided Vehicles to a Fleet Management System

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Asset Administration Shell in Manufacturing: Applications and Relationship with Digital Twin

Within Industry 4.0 the communication between the physical and the cyber part of manufacturing system faces an ever-growing rise in complexity. The Asset Administration Shell (AAS) is an information framework, within Industry 4.0, that describes the technological features of an asset. It was created to present data and information in a structured and semantically defined format, allowing for interoperability. The work addresses the industrial implementation of AAS, where a systematic literature review has been carried out to investigate the features of the implemented AAS metamodel, and the tools used for the realization of the models. A study of the convergence present in literature between the AAS and Digital Twin (DT) has also been carried out. This paper presents a reference of AAS tools and information for industry practitioners, as well as suggestions for research gaps in the standardization of AAS information modelling. Copyright (C) 2022 The Authors

Universal Gröbner Bases for Maximal Minors

Bernstein, Sturmfels, and Zelevinsky proved in 1993 that the maximal minors of a matrix of variables form a universal Gröbner basis. We present a very short proof of this result, along with broad generalization to matrices with multihomogeneous structures. Our main tool is a rigidity statement for radical Borel fixed ideals in multigraded polynomial ring