DAFSA: a Python library for Deterministic Acyclic Finite State Automata [Software]

This work describes dafsa, a Python library for computing graphs from lists of strings for identifying, visualizing, and inspecting patterns of substrings. The library is designed for usage by linguists in studies on morphology and formal grammars, and is intended for faster, easier, and simpler generation of visualizations. It collects frequency weights by default, it can condense structures, and it provides several export options. Figure 1 depicts a basic DAFSA, based upon five English words and generated with default settings

Basilica di Siponto

https://openscholarship.wustl.edu/bcs/1450/thumbnail.jp

The E-ELT adptive mirror: prototype and optical test

Ground-based optical-infrared 10m-class telescopes, such as Keck, Gemini, and Very Large Telescopes (VLT), are currently leading many of the astronomical research fields due to their unprecedented collecting areas. However, many new astrophysical quests arose from recent observations, justifying the need for even larger telescopes, with diameters > 30 m. The European scientific community, led by the European Southern Observatory (ESO), takes part in this challenging competition whit the "European-Extremely Large Telescope" (E-ELT), a revolutionary project for a 40m-class telescope that will allow us addressing many of the most pressing unsolved questions about our Universe. Building Extremely Large Telescopes asked for innovative technologies, from larger and repeatable optical manufacturing techniques to produce hundredths of aspherical off-axis hexagonal segments and large monolithic mirrors, or large thin optical shell mirrors, to better and faster controls (active and adaptive optics), together with more specialized focal plane instrumentations devoted to address specific astrophysical questions, more likely to large particle physics experiments. Moreover the challenge of building extremely large telescope pushes forward the parallel ability to measure and test optical components of large sizes. Adaptive Optics (AO) techniques allow to obtain enhanced ground-based astronomical observations, partially restoring diffraction-limited spatial resolutions, by compensating the degrading effects of the atmospheric turbulence. The delivered image quality of an AO-assisted telescope depends on the level of the correction of the wavefront error due to the atmosphere. This work focuses on the adaptive deformable mirror unit (M4AU) of the E-ELT. During my Ph.D. study, I took part in the competitive "EELT-M4 project" study, led by an Italian-French consortium (Microgate, ADS, SAGEM, INAF-O.A.Brera). Optical measurements were conceived, designed and performed on a similar, scaled-down, fully-representative prototype of the final system, to fully validate the proposed concept. Due to very stringent requirements in term of wavefront correction (10-100 nm rms), only interferometric optical setups were able to provide enough accuracy and sensitivity to carry out the work. A set of three devices has been designed for the tests: - a Ritchey-Common test setup (RCT), able to cover the full area of the M4AU DP optical surface with a single measurement, taken with a phase-shifting Fizeau interferometer; - a Stitching Interferometric Setup (SIS), where a scanning smaller optical beam is able to reconstruct the same optical surface with increased capture range and spatial resolution, useful in the first steps of the calibration procedures; - a piston sensing unit (PSU), which exploits the optical path difference between adjacent optical shells, after careful analysis of diffraction patterns. Those devices, together with purposely designed control softwares and data reduction softwares, were used during a 6-months measurement campaign, demonstrating the full compliance of the prototype system with the requirements to be obtained in the final system (flattening of each optical shell, co-phasing of the optical shells, optical stroke calibration, stability of calibration under time and changing environmental conditions). Results have been positively reviewed by the EELT project office, and were used as feedback on the design of final optical test system, to be operated on the 2.5m M4AU unit

A Global Lexical Dataset (GLED) with cognate annotation and phonological alignments

This repository comprises a dataset developed from a subset of ASJP, in which all lemmas are presented in a broad phonological transcription, automatically annotated for cognacy, and phonologically aligned. Per-family NEXUS files with binary annotation of presence/absence of cognate sets are also available. The dataset is intended to facilitate prototyping studies and methods in quantitative historical linguistics

Delay and disruption management in local public transportation via real-time vehicle and crew re-scheduling: a case study

Local public transport companies, especially in large cities, are facing every day the problem of managing delays and small disruptions. Disruption management is a well-established practice in airlines and railways. However, in local public transport the approaches to these problems have followed a different path, mainly focusing on holding and short-turning strategies not directly associated with the driver scheduling. In this paper we consider the case of the management of urban surface lines of Azienda Trasporti Milanese (ATM) of Milan. The main issues are the service regularity as a measure of the quality of service, and the minimization of the operational costs due to changes in the planned driver scheduling. We propose a simulation-based optimization system to cope with delays and small disruptions that can be effectively used in a real-time environment and takes into account both vehicle and driver scheduling. The proposed approach is tested on real data to prove its actual applicability

A cross-linguistic database of phonetic transcription systems

Contrary to what non-practitioners might expect, the systems of phonetic notation used by linguists are highly idiosyncratic. Not only do various linguistic subfields disagree on the specific symbols they use to denote the speech sounds of languages, but also in large databases of sound inventories considerable variation can be found. Inspired by recent efforts to link cross-linguistic data with help of reference catalogues (Glottolog, Concepticon) across different resources, we present initial efforts to link different phonetic notation systems to a catalogue of speech sounds. This is achieved with the help of a database accompanied by a software framework that uses a limited but easily extendable set of non-binary feature values to allow for quick and convenient registration of different transcription systems, while at the same time linking to additional datasets with restricted inventories. Linking different transcription systems enables us to conveniently translate between different phonetic transcription systems, while linking sounds to databases allows users quick access to various kinds of metadata, including feature values, statistics on phoneme inventories, and information on prosody and sound classes. In order to prove the feasibility of this enterprise, we supplement an initial version of our cross-linguistic database of phonetic transcription systems (CLTS), which currently registers five transcription systems and links to fifteen datasets, as well as a web application, which permits users to conveniently test the power of the automatic translation across transcription systems

Keep Rollin' - Whole-Body Motion Control and Planning for Wheeled Quadrupedal Robots

We show dynamic locomotion strategies for wheeled quadrupedal robots, which combine the advantages of both walking and driving. The developed optimization framework tightly integrates the additional degrees of freedom introduced by the wheels. Our approach relies on a zero-moment point based motion optimization which continuously updates reference trajectories. The reference motions are tracked by a hierarchical whole-body controller which computes optimal generalized accelerations and contact forces by solving a sequence of prioritized tasks including the nonholonomic rolling constraints. Our approach has been tested on ANYmal, a quadrupedal robot that is fully torque-controlled including the non-steerable wheels attached to its legs. We conducted experiments on flat and inclined terrains as well as over steps, whereby we show that integrating the wheels into the motion control and planning framework results in intuitive motion trajectories, which enable more robust and dynamic locomotion compared to other wheeled-legged robots. Moreover, with a speed of 4 m/s and a reduction of the cost of transport by 83 % we prove the superiority of wheeled-legged robots compared to their legged counterparts.Comment: IEEE Robotics and Automation Letter