A two-level local search heuristic for pickup and delivery problems in express freight trucking

We consider a multiattribute vehicle routing problem inspired by a freight transportation company operating a fleet of heterogeneous trucks. The company offers an express service for requests including multiple pickup and multiple delivery positions spread in a regional area, with associated soft or hard time windows often falling in the same working day. Routes are planned on a daily basis and reoptimized on-the-fly to fit new requests, taking into account constraints and preferences on capacities, hours of service, route termination points. The objective is to maximize the difference between the revenue from satisfied orders and the operational costs. The problem mixes attributes from both intercity less-than-truckload and express couriers operations, and we propose a two-level local search heuristic. The first level assigns orders to vehicles through a variable neighborhood stochastic tabu search; the second level optimizes the route service sequences. The algorithm, enhanced by neighborhood filtering and parallel exploration, is embedded in a decision support tool currently in use in a small trucking company. Results have been compared to bounds obtained from a mathematical programming model solved by column generation. Experience on the field and test on literature instances attest to the quality of results and the efficiency of the proposed approach

Transforming ML Predictive Pipelines into SQL with MASQ

Inference of Machine Learning (ML) models, i.e. the process of obtaining predictions from trained models, is often an overlooked problem. Model inference is however one of the main contributors of both technical debt in ML applications and infrastructure complexity. MASQ is a framework able to run inference of ML models directly on DBMSs. MASQ not only averts expensive data movements for those predictive scenarios where data resides on a database, but it also naturally exploits all the "Enterprise-grade"features such as governance, security and auditability which make DBMSs the cornerstone of many businesses. MASQ compiles trained models and ML pipelines implemented in scikit-learn directly into standard SQL: no UDFs nor vendor-specific syntax are used, and therefore queries can be readily executed on any DBMS. In this demo, we will showcase MASQ's capabilities through a GUI allowing attendees to: (1) train ML pipelines composed of data featurizers and ML models; (2) compile the trained pipelines into SQL, and deploy them on different DBMSs (MySQL and SQLServer in the demo); and (3) compare the related performance under different configurations (e.g., the original pipeline on the ML framework against the SQL implementations)

A parametric study of electrodes geometries for atmospheric electrohydrodynamic propulsion

This work presents a parametric analysis of corona thrusters performance as function of electrodes geometry, focusing on collector electrodes. A set of airfoil-shaped collectors with fixed chord and different profiles is tested on a propulsion system at bench. The setup consists in a parallel array of thruster units with adjustable spacing. The downstream velocity field is measured and used to determine thrust by momentum balance. Thrust-to-power ratio and thrust density are calculated as performance parameters to compare the different geometries. Optimal configurations are found within the examined parameter space, evidencing the importance of further systematic studies about the electrodes geometries

Using descriptions for explaining entity matches

Finding entity matches in large datasets is currently one of the most attractive research challenges. The recent interest of the research community towards Machine and Deep Learning techniques has led to the development of many and reliable approaches. Nevertheless, these are conceived as black-box tools that identify the matches between the entities provided as input. The lack of explainability of the process hampers its application to real-world scenarios where domain experts need to know and understand the reasons why entities can be considered as match, i.e., they represent the same real-world entity. In this paper, we show how data descriptions—a set of compact, readable and insightful formulas of boolean predicates—can be used to guide domain experts in understanding and evaluating the results of entity matching processes

Altitudinal and habitat selection of capercaillie Tetrao urogallus: an assessment of change after ten years in the Scanuppia reserve (Central Alps, Northern Italy)

Capercaillie (Tetrao urogallus L.), a territorial galliform, favours intermediate canopy cover forest, formed by old and open stands and with a high presence of ericaceous species (in particular Vaccinium myrtillus L.). Although Capercaillie is not thought to be at risk, it has undergone a decline over much of its range. This study was undertaken in the Scanuppia reserve (546 ha) in the Trento Province in spruce (Picea abies (L.) Karsten) dominated forest with some areas of silver-fir (Abies alba Miller), larch (Larix decidua Miller), beech (Fagus sylvatica L.), and mixed stands, as well as open areas of pasture. The aim of this study was to determine change in summer Capercaillie habitat between 2001 and 2011. A systematic sampling design was used in which 10-m radius circular plots were sampled along contour lines between ca. 1500 and 1800 m asl in which stand structural and vegetation characteristics were quantified and the presence/absence of Capercaillie was determined by droppings. Whilst the overall population count appeared to remain unchanged, the 2011 results showed that there had been an upward altitudinal shift in distribution whereas the 2001 results emphasised the effects of habitat variables at a lower altitude. The selection of habitat towards the upper limit of forests may be linked to increased summer temperatures, to anthropogenic disturbance or to a combination of both. This study underlines the need for further research to disentangle potential factors explaining the observed changes in Capercaillie habitat selection in relation to management