2,398 research outputs found

    The Effect of Randomness on the Mott State

    Full text link
    We reinvestigate the competition between the Mott and the Anderson insulator state in a one-dimensional disordered fermionic system by a combination of instanton and renormalization group methods. Tracing back both the compressibility and the ac-conductivity to a vanishing kink energy of the electronic displacement field we do not find any indication for the existence of an intermediate (Mott glass) phase.Comment: 4 page

    An Embarrassingly Simple Method to Mitigate Undesirable Properties of Pretrained Language Model Tokenizers

    Get PDF
    We introduce FLOTA (Few Longest Token Approximation), a simple yet effective method to improve the tokenization of pretrained language models (PLMs). FLOTA uses the vocabulary of a standard tokenizer but tries to preserve the morphological structure of words during tokenization. We evaluate FLOTA on morphological gold segmentations as well as a text classification task, using BERT, GPT-2, and XLNet as example PLMs. FLOTA leads to performance gains, makes inference more efficient, and enhances the robustness of PLMs with respect to whitespace noise

    Novel microthermal sensor principle for determining the mixture ratio of binary fluid mixtures using Föppl vortices

    Get PDF
    A novel sensor principle for determining binary fluid mixtures of known components is presented, making use of different thermal and rheological properties of the mixture's components. Using a microheater, a heat pulse is introduced in the mixture. The resulting temperature increase depends on the thermal properties of the mixture, allowing determination of the mixture ratio. Placing a bluff body in the fluid channel causes the formation of a stationary pair of vortices behind the body. The length of the vortex pair depends on the mixture's viscosity and thus its composition. By placing the microheater in the vortex area and making use of forced convection which changes with the size of the vortex, the sensitivity for determination of the mixture ratio can be increased by a factor of 2.5 compared to the direct thermal measurement. The flow velocity is measured independently of the mixture ratio using time-of-flight thermal anemometry

    Agromyces italicus sp. nov., Agromyces humatus sp. nov. and Agromyces lapidis sp. nov., isolated from Roman catacombs

    Get PDF
    A polyphasic study was carried out to clarify the taxonomic positions of three Gram-positive isolates from the Catacombs of Domitilla, Rome (Italy). 16S rRNA gene sequence comparisons placed these strains within the genus Agromyces. The morphological and chemotaxonomic characteristics of these isolates were consistent wiih the description of the genus Agromyces. The three isolates could be readily distinguished from one another and from representatives of all Agromyces species with validly published names by a broad range of phenotypic characteristics and DNA-DNA relatedness studies. Therefore, these isolates are proposed to represent three novel species of the genus Agromyces, Agromyces italicus sp. nov. (type strain CD1T=HKI 0325T=DSM 16388T=NCIMB 14011T), Agromyces humatus sp. nov. (type strain CD5T=HKI 0327T=DSM 16389T=NCIMB 14012T) and Agromyces lapidis sp. nov. (type strain CD55T =HKI 0324T=DSM 16390T=NCIMB 14013T). © 2005 IUMS.V. J. and L. L. are grateful to fellowships from the Spanish Ministry of Education and Science (MEC) I3P programme and J. M. G. to an MEC contract from the ‘Ramo´n y Cajal’ programme. This study was supported by project CATS (EVK4-CT2000-00028) and MEC project BTE2002-04492-C02-01.Peer Reviewe

    Dynamic Contextualized Word Embeddings

    Get PDF
    Static word embeddings that represent words by a single vector cannot capture the variability of word meaning in different linguistic and extralinguistic contexts. Building on prior work on contextualized and dynamic word embeddings, we introduce dynamic contextualized word embeddings that represent words as a function of both linguistic and extralinguistic context. Based on a pretrained language model (PLM), dynamic contextualized word embeddings model time and social space jointly, which makes them attractive for a range of NLP tasks involving semantic variability. We highlight potential application scenarios by means of qualitative and quantitative analyses on four English datasets

    Superbizarre Is Not Superb: Derivational Morphology Improves BERT’s Interpretation of Complex Words

    Get PDF
    How does the input segmentation of pretrained language models (PLMs) affect their interpretations of complex words? We present the first study investigating this question, taking BERT as the example PLM and focusing on its semantic representations of English derivatives. We show that PLMs can be interpreted as serial dual-route models, i.e., the meanings of complex words are either stored or else need to be computed from the subwords, which implies that maximally meaningful input tokens should allow for the best generalization on new words. This hypothesis is confirmed by a series of semantic probing tasks on which DelBERT (Derivation leveraging BERT), a model with derivational input segmentation, substantially outperforms BERT with WordPiece segmentation. Our results suggest that the generalization capabilities of PLMs could be further improved if a morphologically-informed vocabulary of input tokens were used

    Laser beam steering for GRACE Follow-On intersatellite interferometry

    No full text
    The GRACE Follow-On satellites will use, for the first time, a Laser Ranging Interferometer to measure intersatellite distance changes from which fluctuations in Earth’s geoid can be inferred. We have investigated the beam steering method that is required to maintain the laser link between the satellites. Although developed for the specific needs of the GRACE Follow-On mission, the beam steering method could also be applied to other intersatellite laser ranging applications where major difficulties are common: large spacecraft separation and large spacecraft attitude jitter. The beam steering method simultaneously coaligns local oscillator beam and transmitted beam with the laser beam received from the distant spacecraft using Differential Wavefront Sensing. We demonstrate the operation of the beam steering method on breadboard level using GRACE satellite attitude jitter data to command a hexapod, a six-degree-of-freedom rotation and translation stage. We verify coalignment of local oscillator beam/ transmitted beam and received beam of better than 10 μrad with a stability of 10 μrad/ Hz−−−√ in the GRACE Follow-On measurement band of 0.002...0.1 Hz. Additionally, important characteristics of the beam steering setup such as Differential Wavefront Sensing signals, heterodyne efficiency, and suppression of rotation-to-pathlength coupling are investigated and compared with analysis results
    • …
    corecore