Hand in hand: automatic sign Language to English translation

In this paper, we describe the first data-driven automatic sign-language-to- speech translation system. While both sign language (SL) recognition and translation techniques exist, both use an intermediate notation system not directly intelligible for untrained users. We combine a SL recognizing framework with a state-of-the-art phrase-based machine translation (MT) system, using corpora of both American Sign Language and Irish Sign Language data. In a set of experiments we show the overall results and also illustrate the importance of including a vision-based knowledge source in the development of a complete SL translation system

Tropical precipitation influencing boreal winter midlatitude blocking

Recent studies using reanalysis data and complex models suggest that the Tropics influence midlatitude blocking. Here, the influence of tropical precipitation anomalies is investigated further using a dry dynamical model driven by specified diabatic heating anomalies. The model uses a quasi‐realistic setup based on idealized orography and an idealized representation of the land‐ocean thermal contrast. Results concerning the El Niño Southern Oscillation and the Madden‐Julian Oscillation are mostly consistent with previous studies and emphasize the importance of tropical dynamics for driving the variability of blocking at midlatitudes. It is also shown that a common bias in models of the Coupled Model Intercomparison Project Phase 5 (CMIP5), namely, excessive tropical precipitation, leads to an underestimation of midlatitude blocking in our model, also a common bias in the CMIP5 models. The strongest blocking anomalies associated with the tropical precipitation bias are found over Europe, where the underestimation of blocking in CMIP5 models is also particularly strong

Origin of Variability in Northern Hemisphere Winter Blocking on Interannual to Decadal Time Scales

Variability of mid-latitude blocking in the boreal winter northern hemisphere is investigated for the period 1960/61 to 2001/02 by means of relaxation experiments with the model of the European Center for Medium-Range Weather Forecasts. It is shown that there is pronounced interannual and decadal variability in blocking, especially over the Eurasian continent, consistent with previous studies. The relaxation experiments show that realistic variability in the tropics can account for a significant part of observed interannual blocking variability, but also that about half of the observed variability can only be explained by extratropical tropospheric variability. On the quasi-decadal time scale, extratropical sea surface temperature and sea-ice, in addition to tropical variability, play a more important role. The stratosphere, which has been shown to influence interannual variability of the North Atlantic Oscillation in previous studies, has no significant influence on blocking according to our analysis

Improvement in the decadal prediction skill of the North Atlantic extratropical winter circulation through increased model resolution

In this study the latest version of the MiKlip decadal hindcast system is analyzed, and the effect of an increased horizontal and vertical resolution on the prediction skill of the extratropical winter circulation is assessed. Four different metrics – the storm track, blocking, cyclone and windstorm frequencies – are analyzed in the North Atlantic and European region. The model bias and the deterministic decadal hindcast skill are evaluated in ensembles of five members in a lower-resolution version (LR, atm: T63L47, ocean: 1.5∘ L40) and a higher-resolution version (HR, atm: T127L95, ocean: 0.4∘ L40) of the MiKlip system based on the Max Planck Institute Earth System model (MPI-ESM). The skill is assessed for the lead winters 2–5 in terms of the anomaly correlation of the quantities' winter averages using initializations between 1978 and 2012. The deterministic predictions are considered skillful if the anomaly correlation is positive and statistically significant. While the LR version shows common shortcomings of lower-resolution climate models, e.g., a storm track that is too zonal and southward displaced as well as a negative bias of blocking frequencies over the eastern North Atlantic and Europe, the HR version counteracts these biases. Cyclones, i.e., their frequencies and characteristics like strength and lifetime, are particularly better represented in HR. As a result, a chain of significantly improved decadal prediction skill between all four metrics is found with the increase in the spatial resolution. While the skill of the storm track is significantly improved primarily over the main source region of synoptic activity – the North Atlantic Current – the other extratropical quantities experience a significant improvement primarily downstream thereof, i.e., in regions where the synoptic systems typically intensify. Thus, the skill of the cyclone frequencies is significantly improved over the central North Atlantic and northern Europe, the skill of the blocking frequencies is significantly improved over the Mediterranean, Scandinavia and eastern Europe, and the skill of the windstorms is significantly improved over Newfoundland and central Europe. Not only is the skill improved with the increase in resolution, but the HR system itself also exhibits significant skill over large areas of the North Atlantic and European sector for all four circulation metrics. These results are particularly promising regarding the high socioeconomic impact of European winter windstorms and blocking situations

Blocking and its response to climate change

Purpose of review: Atmospheric blocking events represent some of the most high-impact weather patterns in the mid-latitudes, yet they have often been a cause for concern in future climate projections. There has been low confidence in predicted future changes in blocking, despite relatively good agreement between climate models on a decline in blocking. This is due to the lack of a comprehensive theory of blocking and a pervasive underestimation of blocking occurrence by models. This paper reviews the state of knowledge regarding blocking under climate change, with the aim of providing an overview for those working in related fields. Recent Findings: Several avenues have been identified by which blocking can be improved in numerical models, though a fully reliable simulation remains elusive (at least, beyond a few days lead time). Models are therefore starting to provide some useful information on how blocking and its impacts may change in the future, although deeper understanding of the processes at play will be needed to increase confidence in model projections. There are still major uncertainties regarding the processes most important to the onset, maintenance and decay of blocking and advances in our understanding of atmospheric dynamics, for example in the role of diabatic processes, continue to inform the modelling and prediction efforts. Summary: The term ‘blocking’ covers a diverse array of synoptic patterns, and hence a bewildering range of indices has been developed to identify events. Results are hence not considered fully trustworthy until they have been found using several different methods. Examples of such robust results are the underestimation of blocking by models, and an overall decline in future occurrence, albeit with a complex regional and seasonal variation. In contrast, hemispheric trends in blocking over the recent historical period are not supported by different methods, and natural variability will likely dominate regional variations over the next few decades

Initialization and Ensemble Generation for Decadal Climate Predictions: A Comparison of Different Methods

Five initialization and ensemble generation methods are investigated with respect to their impact on the prediction skill of the German decadal prediction system “Mittelfristige Klimaprognose” (MiKlip). Among the tested methods, three tackle aspects of model‐consistent initialization using the ensemble Kalman filter, the filtered anomaly initialization, and the initialization method by partially coupled spin‐up (MODINI). The remaining two methods alter the ensemble generation: the ensemble dispersion filter corrects each ensemble member with the ensemble mean during model integration. And the bred vectors perturb the climate state using the fastest growing modes. The new methods are compared against the latest MiKlip system in the low‐resolution configuration (Preop‐LR), which uses lagging the climate state by a few days for ensemble generation and nudging toward ocean and atmosphere reanalyses for initialization. Results show that the tested methods provide an added value for the prediction skill as compared to Preop‐LR in that they improve prediction skill over the eastern and central Pacific and different regions in the North Atlantic Ocean. In this respect, the ensemble Kalman filter and filtered anomaly initialization show the most distinct improvements over Preop‐LR for surface temperatures and upper ocean heat content, followed by the bred vectors, the ensemble dispersion filter, and MODINI. However, no single method exists that is superior to the others with respect to all metrics considered. In particular, all methods affect the Atlantic Meridional Overturning Circulation in different ways, both with respect to the basin‐wide long‐term mean and variability and with respect to the temporal evolution at the 26° N latitude

Integrating a State-of-the-Art ASR System into the Opencast Matterhorn Platform

[EN] In this paper we present the integration of a state-of-the-art ASR system into the Opencast Matterhorn platform, a free, open-source platform to support the management of educational audio and video content. The ASR system was trained on a novel large speech corpus, known as poliMedia, that was manually transcribed for the European project transLectures. This novel corpus contains more than 115 hours of transcribed speech that will be available for the research community. Initial results on the poliMedia corpus are also reported to compare the performance of different ASR systems based on the linear interpolation of language models. To this purpose, the in-domain poliMedia corpus was linearly interpolated with an external large-vocabulary dataset, the well-known Google N-Gram corpus. WER figures reported denote the notable improvement over the baseline performance as a result of incorporating the vast amount of data represented by the Google N-Gram corpus.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 287755. Also supported by the Spanish Government (MIPRCV ”Consolider Ingenio 2010” and iTrans2 TIN2009-14511) and the Generalitat Valenciana (Prometeo/2009/014).Valor Miró, JD.; Pérez González De Martos, AM.; Civera Saiz, J.; Juan Císcar, A. (2012). Integrating a State-of-the-Art ASR System into the Opencast Matterhorn Platform. Communications in Computer and Information Science. 328:237-246. https://doi.org/10.1007/978-3-642-35292-8_25S237246328UPVLC, XEROX, JSI-K4A, RWTH, EML, DDS: transLectures: Transcription and Translation of Video Lectures. In: Proc. of EAMT, p. 204 (2012)Zhan, P., Ries, K., Gavalda, M., Gates, D., Lavie, A., Waibel, A.: JANUS-II: towards spontaneous Spanish speech recognition 4, 2285–2288 (1996)Nogueiras, A., Fonollosa, J.A.R., Bonafonte, A., Mariño, J.B.: RAMSES: El sistema de reconocimiento del habla continua y gran vocabulario desarrollado por la UPC. In: VIII Jornadas de I+D en Telecomunicaciones, pp. 399–408 (1998)Huang, X., Alleva, F., Hon, H.W., Hwang, M.Y., Rosenfeld, R.: The SPHINX-II Speech Recognition System: An Overview. Computer, Speech and Language 7, 137–148 (1992)Speech and Language Technology Group. Sumat: An online service for subtitling by machine translation (May 2012), http://www.sumat-project.euBroman, S., Kurimo, M.: Methods for combining language models in speech recognition. In: Proc. of Interspeech, pp. 1317–1320 (2005)Liu, X., Gales, M., Hieronymous, J., Woodland, P.: Use of contexts in language model interpolation and adaptation. In: Proc. of Interspeech (2009)Liu, X., Gales, M., Hieronymous, J., Woodland, P.: Language model combination and adaptation using weighted finite state transducers (2010)Goodman, J.T.: Putting it all together: Language model combination. In: Proc. of ICASSP, pp. 1647–1650 (2000)Lööf, J., Gollan, C., Hahn, S., Heigold, G., Hoffmeister, B., Plahl, C., Rybach, D., Schlüter, R., Ney, H.: The rwth 2007 tc-star evaluation system for european english and spanish. In: Proc. of Interspeech, pp. 2145–2148 (2007)Rybach, D., Gollan, C., Heigold, G., Hoffmeister, B., Lööf, J., Schlüter, R., Ney, H.: The rwth aachen university open source speech recognition system. In: Proc. of Interspeech, pp. 2111–2114 (2009)Stolcke, A.: SRILM - An Extensible Language Modeling Toolkit. In: Proc. of ICSLP (2002)Michel, J.B., et al.: Quantitative analysis of culture using millions of digitized books. Science 331(6014), 176–182Turro, C., Cañero, A., Busquets, J.: Video learning objects creation with polimedia. In: 2010 IEEE International Symposium on Multimedia (ISM), December 13-15, pp. 371–376 (2010)Barras, C., Geoffrois, E., Wu, Z., Liberman, M.: Transcriber: development and use of a tool for assisting speech corpora production. Speech Communication Special Issue on Speech Annotation and Corpus Tools 33(1-2) (2000)Apache. Apache felix (May 2012), http://felix.apache.org/site/index.htmlOsgi alliance. osgi r4 service platform (May 2012), http://www.osgi.org/Main/HomePageSahidullah, M., Saha, G.: Design, analysis and experimental evaluation of block based transformation in MFCC computation for speaker recognition 54(4), 543–565 (2012)Gascó, G., Rocha, M.-A., Sanchis-Trilles, G., Andrés-Ferrer, J., Casacuberta, F.: Does more data always yield better translations? In: Proc. of EACL, pp. 152–161 (2012)Sánchez-Cortina, I., Serrano, N., Sanchis, A., Juan, A.: A prototype for interactive speech transcription balancing error and supervision effort. In: Proc. of IUI, pp. 325–326 (2012

Partially coupled spin-up of the MPI-ESM: implementation and first results

Large-scale fully coupled Earth system models (ESMs) are usually applied in climate projections like the IPCC (Intergovernmental Panel on Climate Change) reports. In these models internal variability is often within the correct order of magnitude compared with the observed climate, but due to internal variability and arbitrary initial conditions they are not able to reproduce the observed timing of climate events or shifts as for instance observed in the El Niño–Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), or the Atlantic Meridional Overturning Circulation (AMOC). Additional information about the real climate history is necessary to constrain ESMs; not only to emulate the past climate, but also to introduce a potential forecast skill into these models through a proper initialisation. We attempt to do this by extending the fully coupled climate model Max Planck Institute Earth System Model (MPI-ESM) using a partial coupling technique (Modini-MPI-ESM). This method is implemented by adding reanalysis wind-field anomalies to the MPI-ESM's inherent climatological wind field when computing the surface wind stress that is used to drive the ocean and sea ice model. Using anomalies instead of the full wind field reduces potential model drifts, because of different mean climate states of the unconstrained MPI-ESM and the partially coupled Modini-MPI-ESM, that could arise if total observed wind stress was used. We apply two different reanalysis wind products (National Centers for Environmental Prediction, Climate Forecast System Reanalysis (NCEPcsfr) and ERA-Interim reanalysis (ERAI)) and analyse the skill of Modini-MPI-ESM with respect to several observed oceanic, atmospheric, and sea ice indices. We demonstrate that Modini-MPI-ESM has a significant skill over the time period 1980–2013 in reproducing historical climate fluctuations, indicating the potential of the method for initialising seasonal to decadal forecasts. Additionally, our comparison of the results achieved with the two reanalysis wind products NCEPcsfr and ERAI indicates that in general applying NCEPcsfr results in a better reconstruction of climate variability since 1980

Intraseasonal variation of the East Asian summer monsoon associated with the MJO

We investigate the daily variability of the East Asian summer monsoon (EASM) by projecting daily wind anomaly data onto the two major modes of an interannual multivariate Empirical Orthogonal Functions analysis. Mode 1, closely resembling the Pacific-Japan (PJ) pattern and referred to as PJ-mode, transits from positive to negative phase around mid-summer consistent with the Meiyu rains predominantly being an early summer phenomenon. Mode 2, which is influenced by the Indian summer monsoon (ISM) and referred to as ISM-mode, peaks in late July and early August and is associated with rainfall farther north over China. We then analyze the relation between the intraseasonal variation of the EASM and the Madden-Julian Oscillation (MJO) by analyzing circulation anomalies following MJO events. In the lower troposphere, the circulation anomalies associated with the MJO most strongly project on the PJ-mode. MJO phases 1-4 (5-8) favor the positive (negative) phase of the PJ-mode by favoring the anticyclonic (cyclonic) anomalies over the subtropical western North Pacific. In the upper troposphere, the circulation anomalies associated with the MJO project mainly on the ISM-mode