98 research outputs found

    Towards a Deep Understanding of Multilingual End-to-End Speech Translation

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    In this paper, we employ Singular Value Canonical Correlation Analysis (SVCCA) to analyze representations learnt in a multilingual end-to-end speech translation model trained over 22 languages. SVCCA enables us to estimate representational similarity across languages and layers, enhancing our understanding of the functionality of multilingual speech translation and its potential connection to multilingual neural machine translation. The multilingual speech translation model is trained on the CoVoST 2 dataset in all possible directions, and we utilize LASER to extract parallel bitext data for SVCCA analysis. We derive three major findings from our analysis: (I) Linguistic similarity loses its efficacy in multilingual speech translation when the training data for a specific language is limited. (II) Enhanced encoder representations and well-aligned audio-text data significantly improve translation quality, surpassing the bilingual counterparts when the training data is not compromised. (III) The encoder representations of multilingual speech translation demonstrate superior performance in predicting phonetic features in linguistic typology prediction. With these findings, we propose that releasing the constraint of limited data for low-resource languages and subsequently combining them with linguistically related high-resource languages could offer a more effective approach for multilingual end-to-end speech translation.Comment: Accepted to Findings of EMNLP 202

    GaitGS: Temporal Feature Learning in Granularity and Span Dimension for Gait Recognition

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    Gait recognition is an emerging biological recognition technology that identifies and verifies individuals based on their walking patterns. However, many current methods are limited in their use of temporal information. In order to fully harness the potential of gait recognition, it is crucial to consider temporal features at various granularities and spans. Hence, in this paper, we propose a novel framework named GaitGS, which aggregates temporal features in the granularity dimension and span dimension simultaneously. Specifically, Multi-Granularity Feature Extractor (MGFE) is proposed to focus on capturing the micro-motion and macro-motion information at the frame level and unit level respectively. Moreover, we present Multi-Span Feature Learning (MSFL) module to generate global and local temporal representations. On three popular gait datasets, extensive experiments demonstrate the state-of-the-art performance of our method. Our method achieves the Rank-1 accuracies of 92.9% (+0.5%), 52.0% (+1.4%), and 97.5% (+0.8%) on CASIA-B, GREW, and OU-MVLP respectively. The source code will be released soon.Comment: 14 pages, 6 figure

    Simulations of summertime fossil fuel CO2 in the Guanzhong basin, China

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    Recent studies on fossil fuel CO2 simulation associated with Delta(CO2)-C-14 measurements is quite limited, particularly in China. In this study, the fossil fuel CO2 recently added to the atmosphere (delta CO(2)ff) over the Guanzhong basin, central China, during summer 2012 is simulated using a modified WRF-CHEM model constrained by measured CO2 mixing ratio and Delta(CO2)-C-14. The model well captures the temporal variation of observed CO2 mixing ratio and Delta(CO2)-C-14, and reasonably reproduces the distribution of observed Delta(CO2)-C-14. The simulation shows a significant variation of delta CO(2)ff during summertime, ranging from <5 ppmv to similar to 100 ppmv and no remarkable trend of delta CO(2)ff is found for June, July, and August. The delta CO(2)ff level is closely associated with atmospheric diffusion conditions. The diurnal cycle of delta CO(2)ff presents a double-peak pattern, a nocturnal one and a rush-hour one, related to the development of planetary boundary layer and CO2 emission from vehicles. The spatial distributions of summertime delta CO(2)ff within the basin is clearly higher than the outside, reaching up to 40 ppmv in urban Xi'an and 15 ppmv in its surrounding areas, indicative of large local fossil fuel emissions. Furthermore, we find that neglecting the influence of summer heterotrophic respiration in terrestrial biosphere would slightly underestimate the calculated delta CO(2)ff by about 0.38 ppmv in the basin. (C) 2017 Elsevier B.V. All rights reserved

    Reliable Distributed Computing for Metaverse: A Hierarchical Game-Theoretic Approach

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    The metaverse is regarded as a new wave of technological transformation that provides a virtual space for people to interact through digital avatars. To achieve immersive user experiences in the metaverse, real-time rendering is the key technology. However, computing-intensive tasks of real-time rendering from metaverse service providers cannot be processed efficiently on a single resource-limited mobile device. Alternatively, such mobile devices can offload the metaverse rendering tasks to other mobile devices by adopting the collaborative computing paradigm based on Coded Distributed Computing (CDC). Therefore, this paper introduces a hierarchical game-theoretic CDC framework for the metaverse services, especially for the vehicular metaverse. In the framework, idle resources from vehicles, acting as CDC workers, are aggregated to handle intensive computation tasks in the vehicular metaverse. Specifically, in the upper layer, a miner coalition formation game is formulated based on a reputation metric to select reliable workers. To guarantee the reliable management of reputation values, the reputation values calculated based on the subjective logical model are maintained in a blockchain database. In the lower layer, a Stackelberg game-based incentive mechanism is considered to attract reliable workers selected in the upper layer to participate in rendering tasks. The simulation results illustrate that the proposed framework is resistant to malicious workers. Compared with the best-effort worker selection scheme, the proposed scheme can improve the utility of metaverse service provider and the average profit of CDC workers

    ELUCID. VII. Using constrained hydro simulations to explore the gas component of the cosmic web

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    Using reconstructed initial conditions in the Sloan Digital Sky Survey (SDSS) survey volume, we carry out constrained hydrodynamic simulations in three regions representing different types of the cosmic web: the Coma cluster of galaxies; the SDSS Great Wall; and a large low-density region at z ∼ 0.05. These simulations, which include star formation and stellar feedback but no active galactic nucleus formation and feedback, are used to investigate the properties and evolution of intergalactic and intracluster media. About half of the warm-hot intergalactic gas is associated with filaments in the local cosmic web. Gas in the outskirts of massive filaments and halos can be heated significantly by accretion shocks generated by mergers of filaments and halos, respectively, and there is a tight correlation between the gas temperature and the strength of the local tidal field. The simulations also predict some discontinuities associated with shock fronts and contact edges, which can be tested using observations of the thermal Sunyaev-Zel’dovich effect and X-rays. A large fraction of the sky is covered by Lyα and O vi absorption systems, and most of the O vi systems and low-column-density H i systems are associated with filaments in the cosmic web. The constrained simulations, which follow the formation and heating history of the observed cosmic web, provide an important avenue to interpret observational data. With full information about the origin and location of the cosmic gas to be observed, such simulations can also be used to develop observational strategie

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Aerodynamic damping analysis of horizontal axis wind turbine blade in steady stall

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    By analyzing on steady aerodynamic forces on an airfoil section of the wind turbine blade, combining with the blade modal analysis of the structural dynamics, a model for analyzing steady aerodynamic damping of wind turbine blade was established. Then, based on the accurate calculation on the aerodynamic damping of an airfoil section and a single blade, an effective analysis method of aerodynamic damping was established, and the key parameters which influence aerodynamic damping change were researched. Taking the negative aerodynamic damping which can easily initiate stall vibration of blade as the key point of the research, using a typical blade model as a sample, calculating on it, this paper modifies the parameters of blade model according to the established analysis method of aerodynamic damping. So that the negative aerodynamic damping in stall situation is improved, these can offer a more accurate realistic basis for aerodynamic optimization and vibration restraining design of wind turbine blade

    Comparison of the physiological responses and time-motion characteristics during football small-sided games: effect of pressure on the ball

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    Introduction: This study aimed to compare the effects of pressure on the ball on physiological responses and time-motion characteristics during football small-sided games between elite youth male players.Methods: 56 elite male youth football players (age: 15.43 ± 0.52 years) performed a 2+GK vs. 2+GK game on a 30 m × 15 m pitch area with two playing conditions: 1) free play (FP), the player has no limitation to play; 2) pressure on the ball (PB), the player has directly and aggressively closed down space (located within 1.5 m) between themselves and the opposition player with the ball and can compete for possession. The percentage of time spent in different maximum heart rate (HRmax) zones, mean heart rate, blood lactate acid concentration, total distance covered, distance covered in three speed zones (sprint, high speed, and moderate speed), number of high speed runs, number of sprint runs, top speed, number of direction changes, and ball recovery time were monitored.Results: We found very significantly higher number of high speed runs (p < 0.001; ES = 1.154), number of direction changes (p < 0.001; ES = 2.347), ball recovery time (p < 0.001; ES = 3.529), percentage of time spent in 90%–100% HRmax (p < 0.001; ES = 3.033), mean heart rate (p < 0.001; ES = 1.940), blood lactate acid concentration (p < 0.001; ES = 2.245) and significantly higher high speed running distance covered (p = 0.004; ES = 0.520) in the PB condition. Conversely, the FP condition showed very significantly higher moderate speed running distance covered (p < 0.001; ES = 1.814) and significantly higher percentage of time spent in 80%–90% HRmax (p = 0.012; ES = 0.440). No significant differences were revealed on sprint running distance covered (p = 0.407; ES = 0.140), number of sprint runs (p = 0.103; ES = 0.279), top speed (p = 0.130; ES = 0.258) and percentage of time spent in 60%–70% HRmax (p = 0.106; ES = 0.276), 70%–80% HRmax (p = 0.358; ES = 0.155).Discussion: We found that pressure on the ball had a substantial impact on the intensity of training, as evidenced by a significantly increased high speed running performance, number of directional changes, percentage of time spent at 90%–100% of maximum heart rate, mean heart rate, and blood lactate acid concentration. Additionally, ball recovery time decreased significantly

    LOW-FLOW PRESSURE GRADIENT PUMPING FOR ACTIVE ABSORPTION OF CO2 ON A MOLECULAR SIEVE

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    The authors have developed an active absorption system combining a molecular sieve with a pressure gradient as a way to overcome the shortcomings of the phosphoric acid solution displacement method. Taking advantage of the pressure gradient produced between the inside and outside of a bottle, as water moves through it, CO2 in the atmosphere can actively be absorbed onto a molecular sieve in its pathway. A comparative study showed that the technique was in agreement with the phosphoric acid displacement method, within error. We applied the new method to collect not only atmospheric CO2 samples, but also CO2 samples from soil respiration to verify its utility. Simple yet practical, our method is well suited to extended collection times in a variety of environments, and capable of providing relatively large amounts of carbon for high-precision accelerator mass spectrometry (AMS) C-14 analyses of atmospheric samples

    Numerical Simulation on Heat Transfer Characteristics of Water Flowing through the Fracture of High-Temperature Rock

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    Deep geothermal resources are becoming an increasingly important energy source worldwide. To achieve the optimal efficiency of this resource, the heat transfer characteristics between flowing water and rock need to be further studied. Using the stereotopometric scanning system 3D CaMega, the fracture geometry data of five cuboid granite rocks were obtained to determine the effects of fracture roughness on the heat transferability of rock. A 3-D model was built based upon the scanned geometry data to assess the effects of rock temperature, water velocity, and roughness, and aperture size of fracture surface on the heat transfer coefficient. The simulation tests show that water velocity has the most noticeable effect, followed by aperture size and rock roughness. On the other hand, the initial rock temperature has the least influence. A new heat transfer coefficient was proposed considering aperture size, water flow velocity, and rock fracture roughness. The calculated values of Reynolds, Prandtl, and Nusselt numbers obtained using this coefficient are in good agreement with the numerical simulation results. This study provides a reference for enhancing the heat transfer coefficient to benefit the exploitation of heat energy of hot dry rock
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