28,708 research outputs found
Machine learning based adaptive soft sensor for flash point inference in a refinery realtime process
In industrial control processes, certain characteristics are sometimes difficult to measure by a physical sensor due to technical and/or economic limitations. This fact is especially true in the petrochemical industry. Some of those quantities are especially crucial for operators and process safety. This is the case for the automotive diesel Flash Point Temperature (FT). Traditional methods for FT estimation are based on the study of the empirical inference between flammability properties and the denoted target magnitude. The necessary measures are taken indirectly by samples from the process and analyzing them in the laboratory, this process implies time (can take hours from collection to flash temperature measurement) and thus make it very difficult for real-time monitorization, which in fact results in security and economical losses. This study defines a procedure based on Machine Learning modules that demonstrate the power of real-time monitorization over real data from an important international refinery. As input, easily measured values provided in real-time, such as temperature, pressure, and hydraulic flow are used and a benchmark of different regressive algorithms for FT estimation is presented. The study highlights the importance of sequencing preprocessing techniques for the correct inference of values. The implementation of adaptive learning strategies achieves considerable economic benefits in the productization of this soft sensor. The validity of the method is tested in the reality of a refinery. In addition, real-world industrial data sets tend to be unstable and volatile, and the data is often affected by noise, outliers, irrelevant or unnecessary features, and missing data. This contribution demonstrates with the inclusion of a new concept, called an adaptive soft sensor, the importance of the dynamic adaptation of the conformed schemes based on Machine Learning through their combination with feature selection, dimensional reduction, and signal processing techniques. The economic benefits of applying this soft sensor in the refinery's production plant and presented as potential semi-annual savings.This work has received funding support from the SPRI-Basque Gov-
ernment through the ELKARTEK program (OILTWIN project, ref. KK-
2020/00052)
Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole
Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates
The applied psychology of addictive orientations : studies in a 12-step treatment context.
The clinical data for the studies was collected at The PROMIS Recovery Centre, a Minnesota Model treatmentc entre for addictions,w hich encouragesth e membership and use of the 12 step Anonymous Fellowships, and is abstinence based. The area of addiction is contextualised in a review chapter which focuses on research relating to the phenomenon of cross addiction. A study examining the concept of "addictive orientations" in male and female addicts is described, which develops a study conductedb y StephensonM, aggi, Lefever, & Morojele (1995). This presents study found a four factor solution which appeared to be subdivisions of the previously found Hedonism and Nurturance factors. Self orientated nurturance (both food dimensions, shopping and caffeine), Other orientated nurturance (both compulsive helping dimensions and work), Sensation seeking hedonism (Drugs, prescription drugs, nicotine and marginally alcohol), and Power related hedonism (Both relationship dimensions, sex and gambling. This concept of "addictive orientations" is further explored in a non-clinical population, where again a four factor solution was found, very similar to that in the clinical population. This was thought to indicate that in terms of addictive orientation a pattern already exists in this non-clinical population and that consideration should be given to why this is the case. These orientations are examined in terms of gender differences. It is suggested that the differences between genders reflect power-related role relationships between the sexes. In order to further elaborate the significance and meaning behind these orientations, the next two chapters look at the contribution of personality variables and how addictive orientations relate to psychiatric symptomatology. Personality variables were differentially, and to a considerable extent predictably involved with the four factors for both males and females.Conscientiousness as positively associated with "Other orientated Nurturance" and negatively associated with "Sensation seeking hedonism" (particularly for men). Neuroticism had a particularly strong association with the "Self orientated Nurturance" factor in the female population. More than twice the symptomatology variance was explained by the factor scores for females than it was for males. The most important factorial predictors for psychiatric symptomatology were the "Power related hedonism" factor for males, and "Self oriented nurturance" for females. The results are discussed from theoretical and treatment perspectives
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NOAH-H, a deep-learning, terrain classification system for Mars: Results for the ExoMars Rover candidate landing sites
In this investigation a deep learning terrain classification system, the “Novelty or Anomaly Hunter – HiRISE” (NOAH-H), was used to classify High Resolution Imaging Science Experiment (HiRISE) images of Oxia Planum and Mawrth Vallis. A set of ontological classes was developed that covered the variety of surface textures and aeolian bedforms present at both sites. Labelled type-examples of these classes were used to train a Deep Neural Network (DNN) to perform semantic segmentation in order to identify these classes in further HiRISE images.
This contribution discusses the methods and results of the study from a geomorphologists perspective, providing a case study applying machine learning to a landscape classification task. Our aim is to highlight considerations about how to compile training datasets, select ontological classes, and understand what such systems can and cannot do. We highlight issues that arise when adapting a traditional planetary mapping workflow to the production of training data. We discuss both the pixel scale accuracy of the model, and how qualitative factors can influence the reliability and usability of the output.
We conclude that “landscape level” reliability is critical for the use of the output raster by humans. The output can often be more useful than pixel scale accuracy statistics would suggest, however the product must be treated with caution, and not considered a final arbiter of geological origin. A good understanding of how and why the model classifies different landscape features is vital to interpreting it reliably. When used appropriately the classified raster provides a good indication of the prevalence and distribution of different terrain types, and informs our understanding of the study areas. We thus conclude that it is fit for purpose, and suitable for use in further work
Interacción planta-abeja después de 100 años de cambios ecológicos globales. Análisis de redes de interacción según datos históricos y contemporáneos en la región de Mendoza
: 57 h. + Anexos. tabls.; figuras. Contiene Referencia BibliográficaEn este estudio se utilizaron dos grupos de registros de interacciones planta-ápidos recolectados alrededor de la Ciudad de Mendoza. Los registros, que fueron realizados en la misma categoría fisonómico-florística de estepa arbustiva semidesértica (Monte Típico), se encuentran temporalmente separados aproximadamente por 100 años. El muestreo histórico ocurrió entre 1904 y 1908, en cuatro comunidades y el contemporáneo en una, entre 2006 y 2011. Datos históricos de similar antigüedad son conocidos solamente para una comunidad de EEUU de herbáceas de sotobosque. Las cinco comunidades del presente estudio, se analizaron en su composición taxonómica, y a partir de matrices bipartitas de presencia y ausencia de interacciones, se
estimaron parámetros a los niveles de red, grupo, interacción y especie. Entre las cuatro comunidades históricas, una, que coincidió en tipo de hábitat y tipo de uso, resultó ser más similar a la contemporánea en composición de especies y número de participantes. Los análisis muestran cambios sustanciales en la composición y estructura de las redes de interacción entre sitios. Se destaca el aumento de anidamiento y las pérdidas de interacciones especializadas, en la comparación entre la comunidad históricas más semejante y la contemporánea. Las diferencias son atribuibles a la menor cantidad de interacciones entre abejas y plantas especialistas en la comunidad contemporánea. Las restantes poblaciones históricas, muestran parámetros también indicativos de pérdida de interacciones entre especialistas. Los resultados permiten concluir que hubo cambios sustanciales en la composición y estructura de las redes de interacción planta-polinizador. Los cambios en la composición incluyen pérdidas y ganancias de especies de plantas y abejas. Una parte muy minoritaria de las interacciones registradas en el pasado persisten en la actualidad. Los cambios en las interacciones se explican por la pérdida de especies de ambos grupos interactuantes, y las
reconexiones de especies persistentes con especies nuevas o con especies con las que antes no interactuaban. El patrón de cambio de estructura y de otros parámetros de las redes, indican que en las zonas no rurales de mayor altura hubo un pérdida sesgada de interacciones entre especies especialistas y reconexiones con especies generalistas. Las comunidades históricas en sitios rurales presentaban aspectos de su estructura reveladoras de disturbio temprano, incluso mayores al de la comunidad contemporánea no rural. Se postula que los cambios en la comunidad contemporánea de altura y no rural, serían atribuibles a un proceso de rotación de especies provenientes de menor altitud, presumiblemente a causa del calentamiento global. Finalmente, al comparar el presente estudio con el anteriormente realizado, es evidente que en ambos casos las redes de interacción, se tornan más anidadas debido a la pérdida de interacciones entre especialistas y a la reconexión con generalistas.Fil: Quipildor, Diana Cigali. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Quipildor, Diana Cigali. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina
Solar wind - magnetosphere coupling functions: pitfalls, limitations and applications
Solar wind-magnetosphere coupling functions have now been in use for almost 50 years. In that time, a very large number of formulations have been proposed. As they become increasingly subsumed into systems analysis and machine-learning studies of the magnetosphere, it is timely to establish best practice in their derivation and study their limitations. This paper reports on a number of studies carried out to establish some key points. Particular attention is paid to the best metric used to evaluate their performance and how it depends on the application for which the coupling function is intended
Patterns of subspecies diversity in the giraffe, Giraffa camelopardalis (L. 1758): comparison of systematic methods and their implications for conservation policy
This thesis examines the subspecific taxonomic status of the giraffe and considers the role of formal taxonomy in the formulation of conservation policy. Where species show consistent. geographically structured phenotypic variation such geographic patterns may indicate selective forces (or other population-level effects) acting. upon local populations. These consistent geographic patterns may be recognised formally as subspecies and may be of interest in single or multi-species biodiversity or biogeography studies for delimiting areas of conservation priority. Subspecies may also be used in the formulation of management policies and legislation. Subspecies are, by definition, allopatric. This thesis explicitly uses methodology of systematic biology and phylogenetic reconstruction to investigate patterns of variation between geographic groups. The taxonomic status of the giraffe is apposite for review. The species provides three independent data sets that may be analysed quantitatively for geographic structure; pelage patterns, morphology and genetics. Museum specimens. grouped according to geographic origin, were favoured for study as more than one type of data was often available for an individual. Population aggregation analysis of forty pelage pattern characters maintained six separate subspecies, while agglomerating some neighbouring populations into a subspecies. A 'traditional' morphometric approach, using multivariate statistical analysis of adult skull measurements, was complemented by a geometric morphometric approach; landmarkrestricted eigenshape analysis. Four morphologically distinct groups were recognised by both morphological analyses. Phylogenetic analysis of mitochondrial DNA control region sequences indicates five major cIades. Nested cIade analysis identifies population fragmentation, range expansion and genetic isolation by distance as contributing to the genetic structure of the giraffe. The results of the analyses show remarkable congruence. These results are discussed in terms of the formulation of conservation policy and the differing requirements of'blological and legal classification systems. The value of a formal taxonomic framework to the recognition, and subsequent conservation, of biodiversity is emphasised
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Lost in translation: collecting and coding data on social relations from audio-visual recordings
Some of the constitutive features of social relations are lost when information naturally produced by sequential social interaction is translated into network ties. Building on core concepts and ideas developed within conversation analysis, in this paper we argue that this happens because the sequential, multimodal and embodied character of social relations can be fully understood only with reference to the sequential constrains that are generated by – and at the same time shape the micro-dynamics of social interaction. We suggest that the translation of social interaction into social networks precludes analysis of the multiple interfaces that sustain social relations (multimodality), and the material resources around which social relations are organized (embodiment). We highlight audio-visual recording as a data collection technology that facilitates storage, retrieval, and analysis of complex information on social relations that is typically absent from social network data. An illustrative video supported case study based on the observation of social and task-related interaction among members of surgical teams provides the empirical context that supports and motivates our general reflection on network data collection strategies and technologies to study social interaction. The analysis highlights the need for social networks research to return to the study of social relations
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Galaxy-Scale Jets with New Extragalactic Radio Surveys
The effects of feedback from high luminosity radio-loud AGN have been extensively researched, but feedback from physically small, low-luminosity radio-loud AGN is less well understood. The advent of high sensitivity, high angular resolution, large field of view telescopes such as LOFAR is now allowing wide-area studies of such faint sources for the first time. Within this thesis I use data from the first release of the LOFAR Two Metre Sky Survey (LoTSS) to report on my discovery of a population of 195 low luminosity radio galaxies where the total extent of the radio emission is no larger than 80 kpc. These objects, which I term galaxy-scale jets (GSJ), are small enough to be directly influencing the evolution of the host on galaxy scales. Combining the LoTSS data with new observations taken with the Karl G. Jansky Very Large Array and the XMM-Newton telescope I report upon the host and radio properties of the sample, finding that GSJ exhibit a mix of FRI and FRII morphologies with host properties that are typical of those found in larger radio galaxies showing that they are ordinary AGN observed at a stage in their life shortly after the radio emission has expanded beyond the central regions of the host. I find that GSJ generally inhabit sparse environments and are primarily young sources that are expanding fast enough to drive shocks. Even ignoring shocks, which I do not detect for any of my sample, I find that approximately half of my GSJ have internal radio lobe energy within an order of magnitude of the ISM energy. For one source studied at X-ray wavelengths I find the radio lobes have a significant proton content suggesting high levels of entrainment. I conclude that GSJ are energetically capable of affecting the evolution of the host
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Choosers: A Visual Programming Language for Nondeterministic Music Composition by Non-Programmers
This thesis focuses on the design of Choosers, a prototype algorithmic programming system centred around a new abstraction (of the same name) designed to allow non-programmers access to nondeterministic music composition methods.
Algorithmic composition typically involves structural elements such as indeterminism, parallelism, choice, multi-choice, nesting, weighting, and looping. There are powerful existing tools for manipulating these and other elements of music. However, while these systems give substantial compositional power to musicians who are also skilled programmers, many musicians who lack programming skills find these tools inaccessible and difficult to understand and use. This thesis presents the design and evaluation of a prototype visual programming language designed to allow structural elements of the kind involved in nondeterministic music composition to be readily visualised and manipulated, while making little or no demand on programming ability.
Initially, a Cognitive Dimensions of Notations review of a representative selection of user interfaces for algorithmic composition software was conducted. The review led to a set of findings used to identify candidate design principles which were then tested via a series of design exercises. The findings from these design exercises led to the development of a new abstraction, the Chooser, via a series of iterative design cycles. Once a candidate design had been finalised it was evaluated with participants via two sets of programming walkthroughs, with the findings from each step used to refine the formalism. The final study used Choosers as a design probe through a series of interviews with domain experts in which manipulable compositions were introduced to prompt discussions on potential future implications for music computing education, music production, and music composition
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