Semi-parametric analysis of multi-rater data

Datasets that are subjectively labeled by a number of experts are becoming more common in tasks such as biological text annotation where class definitions are necessarily somewhat subjective. Standard classification and regression models are not suited to multiple labels and typically a pre-processing step (normally assigning the majority class) is performed. We propose Bayesian models for classification and ordinal regression that naturally incorporate multiple expert opinions in defining predictive distributions. The models make use of Gaussian process priors, resulting in great flexibility and particular suitability to text based problems where the number of covariates can be far greater than the number of data instances. We show that using all labels rather than just the majority improves performance on a recent biological dataset

Čujni zvuk kao signal za izravnu kontrolu elektrolučnog procesa zavarivanja

In this paper sound generated during the gas-metal arc welding process was studded. Experimental analyses of the acoustic signals have shown that there are two main noise-generating mechanisms, first having impulse form is arc extinction and arc ignition; the second is the arc itself acting as an ionization sound source. The sound signal is used for assessing and monitoring of the welding process, and for prediction of welding process stability and quality. A new algorithm based on the measured welding current was established for the calculation of emitted sound during the welding process. The comparisons have shown that the calculated values are in good agreement with the measured values.U radu je istraživan čujni zvuk, koja se generira kod procesa elektrolučnog zavarivanja po MAG postupku. Eksperimentalna analiza zvučnog signala je pokazala, da se javljaju dva glavna mehanizma generiranja zvuka, prvi, koji ima karakter impulza, je posljedica paljenja i gašenja električnog luka (plazme); drugi je sam električni luk, koji djeluje kao ionizirajući izvor zvuka. Zvučni signal je upotrijebljen za ocjenjivanje i nadzor procesa zavarivanja, te za ocjenjivanje kvalitete i stabilnosti procesa zavarivanja. Razvijen je novi matematički model za izračun emitiranog zvuka kod procesa zavarivanja a koji bazira na izmjerenoj struji zavarivanja. Usporedba izračunanih i izmjerenih vrijednosti zvučnog signala je pokazala veliku suglasnost

Caracterización simbiótica y filogenética de rizobios que nodulan la nueva especie Lupinus mariae-josephi

Una nueva especie de altramuz, Lupinus mariae-josephi, ha sido identificado recientemente en Valencia (Pascual, H.). Esta especie, a diferencia de las descritas en la Península ibérica y en el viejo mundo, no crece en suelos ácidos sino en suelos alcalinos y con alto contenido en calcio. El objetivo general de este proyecto es investigar si existen diferencias fenotípicas y genéticas entre los rizobios que nodulan Lupinus mariae-josephi y lupinos de suelos ácidos nativos de la Península Ibérica (Lupinus angustifolius, L.luteus y otras cuatro especies). En este proyecto se han aislado bacterias (rizobios) de nódulos de L. maria-josephi a partir de suelos básicos de Valencia (localidad de LLombai) y se está realizando su caracterización a nivel morfológico, nutricional, simbiótico y molecular. A nivel molecular se han comparado los genes “housekeeping” 16S rRNA, recA, atpD, gln2 y el simbiótico, nodC de diversas cepas que nodulan L. mariae-josephi y con cepas de otras especies de rizobios. Por otra parte, también se está evaluando la capacidad de L. mariae-josephi de ser nodulada por diferentes rizobios bajo condiciones bacteriológicamente controladas

Substrate-borne vibrations disrupt the mating behaviors of the neotropical brown stink bug, Euschistus heros: implications for pest management.

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Evolving Gaussian Process Kernels for Translation Editing Effort Estimation

In many Natural Language Processing problems the combination of machine learning and optimization techniques is essential. One of these problems is estimating the effort required to improve, under direct human supervision, a text that has been translated using a machine translation method. Recent developments in this area have shown that Gaussian Processes can be accurate for post-editing effort prediction. However, the Gaussian Process kernel has to be chosen in advance, and this choice in- fluences the quality of the prediction. In this paper, we propose a Genetic Programming algorithm to evolve kernels for Gaussian Processes. We show that the combination of evolutionary optimization and Gaussian Processes removes the need for a-priori specification of the kernel choice, and achieves predictions that, in many cases, outperform those obtained with fixed kernels.TIN2016-78365-

Protein interaction detection in sentences via gaussian processes: a preliminary evaluation

Classification methods are vital for efficient access of knowledge hidden in biomedical publications. Support vector machines (SVMs) are modern non-parametric deterministic classifiers that produce state of the art performances in text mining, and across other disciplines, while reducing the need for feature engineering. In this paper we offer a much needed evaluation of the Gaussian Process (GP) classifier, as a non-parametric probabilistic analogue to SVMs, which has been rarely applied to text classification. To this end, we provide an extensive experimental comparison of the performance and properties of these competing classifiers on the challenging problem of protein interaction detection in biomedical publications. Our results show that GPs can match the performance of SVMs without the need for costly margin parameter tuning, whilst offering the advantage of an extendable probabilistic framework for text classification

Secondary spectral components of substrate-borne vibrational signals affect male preference

Animal sexual signals contain information about both compatibility and quality of the signaller, but combined with influence of the signalling medium, the complexity of mate selection makes it difficult to separate different components of this process. We approached the problem of teasing apart different functions of sexual signals by using the planthopper Hyalesthes obsoletus, which uses unimodal vibrational communication, as a model. Vibrational signals are known to encode information about identity in their temporal pattern, while a useful cue for quality may reside in their spectral properties. In this study, we demonstrate a connection between spectral properties and attractiveness of female signals based on male behavioural response to signal playback. Artificially increasing the amplitude of high-frequency components increases signal attractiveness and vice versa, which indicates that spectral properties could function as an index of quality. Presence of high-frequency spectral components might indicate a larger or healthier individual, but direct connection with female fitness is not yet clear. In addition, we found that H. obsoletus males are able to exploit female pulses as directional cues and can discriminate between female signals of different attractiveness coming from spatially separated sources

Advances in understanding and exploiting insect vibrational communication

Vibrational communication is an ubiquitous mode of communication in insects, often mediated by bending waves in herbaceous plant tissues they inhabit. Several new theoretical advances in the past years have been facilitated by the use of sensitive recording equipment (particularly laser vibrometers), computerized data acquisition and analysis, and callibrated transducers for playback. These tools have brought insight into a hitherto largely hidden world of information exchange by vibrational signals which are characterized by low amplitude, rapid amplitude modulation and frequency tuning with the substrate. Here, playback is commonly used to provide additional insight by manipulating insect behaviour, and knowledge has progressed enough to open possibilities of artificial behavioural manipulation in order to improve pest control. This idea is illustrated by two conceptually different examples of bioacoustic approach to behavioural manipulation of insect pests, currently in development: mating disruption of the American grapevine leafhopper Scaphoideus titanus Ball) using noise, and attraction of brown marmorated stink bugs (Halyomorpha halys Stål) using conspecific signals for mass trapping. They are among new developments that hold promise to substitute chemical methods of pest control with a more environment-friendly approach, at least in certain settings