Gradient Boosting in Motor Insurance Claim Frequency Modelling

Modelling claim frequency and claim severity are topics of great interest in property-casualty insurance for supporting underwriting, ratemaking, and reserving actuarial decisions. This paper investigates the predictive performance of Gradient Boosting with Decision Trees as base learners to model the claim frequency in motor insurance using a private cross-country large insurance dataset. The Gradient Boosting algorithm combines many weak base learners to tackle conceptual uncertainty in empirical research. The findings show that the Gradient Boosting model is superior to the standard Generalised Linear Model in the sense that it provides closer predictions in the claim frequency model. The finding also shows that Gradient Boosting can capture the nonlinear relation between the claim counts and feature variables and their complex interactions being, thus, a valuable tool for feature engineering and the development of a data-driven approach to risk management

Modelling Motor Insurance Claim Frequency and Severity Using Gradient Boosting

Clemente, C., Guerreiro, G. R., & Bravo, J. M. (2023). Modelling Motor Insurance Claim Frequency and Severity Using Gradient Boosting. Risks, 11(9), 1-20. [163]. https://doi.org/10.3390/risks11090163 ---This research was funded by national funds through the FCT—Fundação para a Ciência e a Tecnologia, I.P., under the scope of the projects UIDB/00297/2020 and UIDP/00297/2020—Center for Mathematics and Applications—(G.R. Guerreiro) and grants UIDB/04152/2020—Centro de Investigação em Gestão de Informação (MagIC) and UIDB/00315/2020—BRU-ISCTE-IUL—(J.M. Bravo).Modelling claim frequency and claim severity are topics of great interest in property-casualty insurance for supporting underwriting, ratemaking, and reserving actuarial decisions. Standard Generalized Linear Models (GLM) frequency–severity models assume a linear relationship between a function of the response variable and the predictors, independence between the claim frequency and severity, and assign full credibility to the data. To overcome some of these restrictions, this paper investigates the predictive performance of Gradient Boosting with decision trees as base learners to model the claim frequency and the claim severity distributions of an auto insurance big dataset and compare it with that obtained using a standard GLM model. The out-of-sample performance measure results show that the predictive performance of the Gradient Boosting Model (GBM) is superior to the standard GLM model in the Poisson claim frequency model. Differently, in the claim severity model, the classical GLM outperformed the Gradient Boosting Model. The findings suggest that gradient boost models can capture the non-linear relation between the response variable and feature variables and their complex interactions and thus are a valuable tool for the insurer in feature engineering and the development of a data-driven approach to risk management and insurance.publishersversionpublishe

Timed Multiparty Session Types

We propose a typing theory, based on multiparty session types, for modular verification of real-time choreographic interactions. To model real-time implementations, we introduce a simple calculus with delays and a decidable static proof system. The proof system ensures type safety and time-error freedom, namely processes respect the prescribed timing and causalities between interactions. A decidable condition on timed global types guarantees time-progress for validated processes with delays, and gives a sound and complete characterisation of a new class of CTAs with general topologies that enjoys progress and liveness

Some applications of quasi-velocities in optimal control

In this paper we study optimal control problems for nonholonomic systems defined on Lie algebroids by using quasi-velocities. We consider both kinematic, i.e. systems whose cost functional depends only on position and velocities, and dynamic optimal control problems, i.e. systems whose cost functional depends also on accelerations. The formulation of the problem directly at the level of Lie algebroids turns out to be the correct framework to explain in detail similar results appeared recently (Maruskin and Bloch, 2007). We also provide several examples to illustrate our construction.Comment: Revtex 4.1, 20 pages. To appear in Int. J. Geom. Meth. Modern Physic

Chelator free gallium-68 radiolabelling of silica coated iron oxide nanorods via surface interactions

The commercial availability of combined magnetic resonance imaging (MRI)/positron emission tomography (PET) scanners for clinical use has increased demand for easily prepared agents which offer signal or contrast in both modalities. Herein we describe a new class of silica coated iron–oxide nanorods (NRs) coated with polyethylene glycol (PEG) and/or a tetraazamacrocyclic chelator (DO3A). Studies of the coated NRs validate their composition and confirm their properties as in vivo T₂ MRI contrast agents. Radiolabelling studies with the positron emitting radioisotope gallium-68 (t1/2 = 68 min) demonstrate that, in the presence of the silica coating, the macrocyclic chelator was not required for preparation of highly stable radiometal-NR constructs. In vivo PET-CT and MR imaging studies show the expected high liver uptake of gallium-68 radiolabelled nanorods with no significant release of gallium-68 metal ions, validating our innovation to provide a novel simple method for labelling of iron oxide NRs with a radiometal in the absence of a chelating unit that can be used for high sensitivity liver imaging

Micropiles for Support of Heavy Crane Ring Foundation

The replacement of a steam generator at a nuclear power plant was accomplished with the use of a massive crane, believed to be one of the largest available cranes in the world market. Four steam generators were replaced, with each generator weighing 3.2 MN. The crane used for the job had a circular support that required a ring foundation. The crane support imposed huge loads on the ring foundation. Because of the presence of soft to medium stiff clayey fill on one side of the ring foundation, the load-sensitive nature of existing underground safetyrelated duct banks, and the nature of the loads applied to the foundation, it was necessary to support the ring foundation on piles. In order to minimize vibrations next to the containment building (the plant was operational while the piles were being installed), micropiles were selected. A total of 80 micropiles were installed, most of them at a batter of 10o from vertical, to provide the required vertical and lateral load resistance. Despite significant challenges imposed by space constraints, subsurface conditions, buried utilities, and design changes, the micropiles were installed within schedule, and performed as designed

Hybrid Quantum-Classical Monte-Carlo Study of a Molecule-Based Magnet

Using a Monte Carlo (MC) method, we study an effective model for the Fe(II)Fe(III) bimetallic oxalates. Within a hybrid quantum-classical MC algorithm, the Heisenberg S=2 and $S'=5/2$ spins on the Fe(II) and Fe(III) sites are updated using a quantum MC loop while the Ising-like orbital angular momenta on the Fe(II) sites are updated using a single-spin classical MC flip. The effective field acting on the orbital angular momenta depends on the quantum state of the system. We find that the mean-field phase diagram for the model is surprisingly robust with respect to fluctuations. In particular, the region displaying two compensation points shifts and shrinks but remains finite.Comment: 8 pages, 7 figure

An Application of IoT in a Drone Inspection Service for Environmental Control

This paper presents an exploratory activity with a drone inspection service for environmental control. The aim of the service is to provide technical support to decision-makers in environmental risk management. The proposed service uses IoT for the interaction between a mobile application, a Smart City platform, and an Unmanned Aircraft System (UAS). The mobile application allows the users to report risky situations, such as fire ignition, spills of pollutants in water, or illegal dumping; the user has only to specify the class of the event, while the geographical coordinates are automatically taken from device-integrated GPS. The message sent from the mobile application arrives to a Smart City platform, which shows all the received alerts on a 3D satellite map, to support decision-makers in choosing where a drone inspection is required. From the Smart City platform, the message is sent to the drone service operator; a CSV file defining the itinerary of the drone is automatically built and shown through the platform; the drone starts the mission providing a video, which is used by the decision-makers to understand whether the situation calls for immediate action. An experimental activity in an open field was carried out to validate the whole chain, from the alert to the drone mission, enriched by a Smart City platform to enable a decision-maker to better manage the situation

Effects of changing the head coach on soccer team’s performance: a systematic review

Review question / Objective: The aim of this systematic review is to analyze the effects of changing the soccer head coach on the overall team’s performance, locomotor demands of players, technical/tactical responses of players, and psychological responses of players. Eligibility criteria: P: Among professional soccer players what is the effect of head-coach replacement; E: Exposure to the change of the head-coach; C: Last weeks of the fired head coach compared with the first weeks of the new head-coach; O: locomotor performance, sports results, mental health metrics. Inclusion criteria will be: (1) articles written in English; (2) carried out in professional football teams. Studies will be excluded if: (1) written in another language other than the one selected; (2) in the case of theses, books and non scientific articles.info:eu-repo/semantics/publishedVersio

Hepatocellular adenoma: An unsolved diagnostic enigma

Hepatocellular adenoma (HCA) is a rare benign liver tumour associated with the use of oral contraceptives or other steroid medications which occurs predominantly in young and middle-aged women. Unlike other benign liver tumours, an HCA may be complicated by bleeding and malignant transformation. HCAs have been divided into four subtypes based on molecular and pathological features: hepatocyte nuclear factor 1\u3b1-mutated HCA, inflammatory HCA, \u3b2-catenin-mutated HCA, and unclassified HCA. \u3b2-catenin-mutated HCA has the highest risk of haemorrhage or malignant transformation. In the latest upgrade of the guidelines regarding the management of benign liver tumours published in 2016 by the European Association for the Study of the Liver, magnetic resonance imaging (MRI) was recognized to be superior to all other imaging modalities in detecting HCAs and in being able to subtype HCAs up to 80%, with positive identification of 1\u3b1-mutated HCA or inflammatory HCA achievable with > 90% specificity. This review analyzed the imaging features of HCA using MRI with hepato-specific contrast agents, focusing on the limitations in the HCA characterization