Polytechnic University of Milan

About: Polytechnic University of Milan is a education organization based out in Milan, Italy. It is known for research contribution in the topics: Finite element method & Population. The organization has 18231 authors who have published 58416 publications receiving 1229711 citations. The organization is also known as: PoliMi & L-NESS.

Mechanical properties and debonding strength of Fabric Reinforced Cementitious Matrix (FRCM) systems for masonry strengthening

Abstract: Fabric Reinforced Cementitious Matrix (FRCM) composites are advanced cement-based materials often used for strengthening masonry or concrete structures. The system is usually composed of a dry grid of fibers embedded in a cementitious matrix enriched with short fibers. An important parameter for designing the structural reinforcement is the tensile load-bearing capacity of FRCM composites. For their heterogeneity, FRCM composites show an interesting mechanical behavior in tension, that depends on the properties of the components and of the bonding strength. These values could be estimated with mechanical models but must be validated experimentally by means of proper testing campaigns. In this work several FRCM materials made with different fiber grids were investigated. Four different types of fibers were considered: polyparaphenylene benzobisoxazole (PBO), carbon (C), glass (G) and PBO and glass (PBO-G) fibers and three different types of cementitious mortars. The behavior of FRCM under tension and the influence of the bond properties between the dry textile and the inorganic matrix are studied developing an extensive experimental program that included the characterization both of the materials components and of the composites. A series of push–pull double lap tests and pull-off tests were performed to determine the bonding properties of FRCM composites applied to masonry structures. The paper presents results and considerations that can provide background data for future recommendations for the use of FRCM systems in the rehabilitation of elements.

Multivariate multiparameter extreme value models and return periods: A copula approach

Abstract: [1] Multivariate extreme value models are a fundamental tool in order to assess potentially dangerous events. The target of this paper is two-fold. On the one hand we outline how, exploiting recent theoretical developments in the theory of copulas, new multivariate extreme value distributions can be easily constructed; in particular, we show how a suitable number of parameters can be introduced, a feature not shared by traditional extreme value models. On the other hand, we introduce a proper new definition of multivariate return period and show the differences with (and the advantages over) the definition presently used in literature. An illustration involving flood data is presented and discussed, and a generalization of the well-known multivariate logistic Gumbel model is also given.

An overview on video forensics

Abstract: Validating a given multimedia content is nowadays quite a hard task because of the huge amount of possible alterations that could have been operated on it. In order to face this problem, image and video experts have proposed a wide set of solutions to reconstruct the processing history of a given multimedia signal. These strategies rely on the fact that non-reversible operations applied to a signal leave some traces ("footprints") that can be identified and classified in order to reconstruct the possible alterations that have been operated on the original source. These solutions permit also to identify which source generated a specific image or video content given some device-related peculiarities. The paper aims at providing an overview of the existing video processing techniques, considering all the possible alterations that can be operated on a single signal and also the possibility of identifying the traces that could reveal important information about its origin and use.

SPECIES—Co-evolution of products, processes and production systems

Abstract: Manufacturing enterprises are changing the way they behave in the market to face the increasing complexity of the economic, socio-political and technological dynamics. Manufacturing products, processes and production systems result in being challenged by evolving external drivers, including the introduction of new regulations, new materials, technologies, services and communications, the pressure on costs and sustainability. The co-evolution paradigm synthesises the recent scientific and technical approaches proposed by academic and industrial communities dealing with methodologies and tools to support the coordinated evolution (co-evolution) of products, processes and production systems. This paper aims at reviewing and systemising the research carried out in the field of manufacturing co-evolution with a particular focus on production systems. An introductory investigation of various industrial perspectives on the problem of co-evolution is presented, followed by the description of the co-evolution model and the methodology adopted for framing the existing scientific contributions in the proposed model. Then, the core part of the work is presented, consisting in a systemised analysis of the current methodologies dealing with co-evolving product, process and system and a description of problems that remain unsolved, thus motivating future research strategies and roadmaps.