57 research outputs found

    Conformance checking using activity and trace embeddings

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    Conformance checking describes process mining techniques used to compare an event log and a corresponding process model. In this paper, we propose an entirely new approach to conformance checking based on neural network-based embeddings. These embeddings are vector representations of every activity/task present in the model and log, obtained via act2vec, a Word2vec based model. Our novel conformance checking approach applies the Word Mover’s Distance to the activity embeddings of traces in order to measure fitness and precision. In addition, we investigate a more efficiently calculated lower bound of the former metric, i.e. the Iterative Constrained Transfers measure. An alternative method using trace2vec, a Doc2vec based model, to train and compare vector representations of the process instances themselves is also introduced. These methods are tested in different settings and compared to other conformance checking techniques, showing promising results

    Rijkswaterstaat:Guardian of the Dutch Delta

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    Founded in 1798, Rijkswaterstaat, the Dutch government’s agency for infrastructural works, brought flood security, navigable waterways and highways to the Netherlands. It is an iconic institution within Dutch society, best known for its ‘battle against the water’. The Zuiderzee Works (1920–1968) and the Delta Works (1954–1997) brought worldwide acclaim. This chapter tells the story of a humble semi-military organization that developed into a formidable institution of civil engineers with a strong technocratic mission mystique. It also recounts the institutional crisis the agency experienced in the 1970s–1990s when it was too slow to adapt to major sociocultural and political changes. To ride the waves of change, it eventually developed several proactive adaptation strategies and reinvented its mission mystique in managerial terms. Adaptation to climate change now presents another key challenge, for which Rijkswaterstaat will have to develop a new ‘social license to operate’

    Joint Practice Guidelines for Radionuclide Lymphoscintigraphy for Sentinel Node Localization in Oral/Oropharyngeal Squamous Cell Carcinoma

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    Involvement of the cervical lymph nodes is the most important prognostic factor for patients with oral/oropharyngeal squamous cell carcinoma (OSCC), and the decision of whether to electively treat patients with clinically negative necks remains a controversial topic. Sentinel node biopsy (SNB) provides a minimally invasive method for determining the disease status of the cervical node basin, without the need for a formal neck dissection. This technique potentially improves the accuracy of histologic nodal staging and avoids overtreating three-quarters of this patient population, minimizing associated morbidity. The technique has been validated for patients with OSCC, and larger-scale studies are in progress to determine its exact role in the management of this patient population. This document is designed to outline the current best practice guidelines for the provision of SNB in patients with early-stage OSCC, and to provide a framework for the currently evolving recommendations for its use. Preparation of this guideline was carried out by a multidisciplinary surgical/nuclear medicine/pathology expert panel under the joint auspices of the European Association of Nuclear Medicine (EANM) Oncology Committee and the Sentinel European Node Trial (SENT) Committee

    Joint practice guidelines for radionuclide lymphoscintigraphy for sentinel node localization in oral/oropharyngeal squamous cell carcinoma

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    Involvement of the cervical lymph nodes is the most important prognostic factor for patients with oral/oropharyngeal squamous cell carcinoma (OSCC), and the decision whether to electively treat patients with clinically negative necks remains a controversial topic. Sentinel node biopsy (SNB) provides a minimally invasive method of determining the disease status of the cervical node basin, without the need for a formal neck dissection. This technique potentially improves the accuracy of histological nodal staging and avoids over-treating three-quarters of this patient population, minimizing associated morbidity. The technique has been validated for patients with OSCC, and larger-scale studies are in progress to determine its exact role in the management of this patient population. This article was designed to outline the current best practice guidelines for the provision of SNB in patients with early-stage OSCC, and to provide a framework for the currently evolving recommendations for its use. These guidelines were prepared by a multidisciplinary surgical/nuclear medicine/pathology expert panel under the joint auspices of the European Association of Nuclear Medicine (EANM) Oncology Committee and the Sentinel European Node Trial Committee

    Africa and the global carbon cycle

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    The African continent has a large and growing role in the global carbon cycle, with potentially important climate change implications. However, the sparse observation network in and around the African continent means that Africa is one of the weakest links in our understanding of the global carbon cycle. Here, we combine data from regional and global inventories as well as forward and inverse model analyses to appraise what is known about Africa's continental-scale carbon dynamics. With low fossil emissions and productivity that largely compensates respiration, land conversion is Africa's primary net carbon release, much of it through burning of forests. Savanna fire emissions, though large, represent a short-term source that is offset by ensuing regrowth. While current data suggest a near zero decadal-scale carbon balance, interannual climate fluctuations (especially drought) induce sizeable variability in net ecosystem productivity and savanna fire emissions such that Africa is a major source of interannual variability in global atmospheric CO(2). Considering the continent's sizeable carbon stocks, their seemingly high vulnerability to anticipated climate and land use change, as well as growing populations and industrialization, Africa's carbon emissions and their interannual variability are likely to undergo substantial increases through the 21st century

    EuPRAXIA - A Compact, Cost-Efficient Particle and Radiation Source

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    Plasma accelerators present one of the most suitable candidates for the development of more compact particle acceleration technologies, yet they still lag behind radiofrequency (RF)-based devices when it comes to beam quality, control, stability and power efficiency. The Horizon 2020-funded project EuPRAXIA (“European Plasma Research Accelerator with eXcellence In Applications”) aims to overcome the first three of these hurdles by developing a conceptual design for a first international user facility based on plasma acceleration. In this paper we report on the main features, simulation studies and potential applications of this future research infrastructure

    Modelleren van land degradatie in IMAGE

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    Food security may be threatened by loss of soil productivity as a result of human-induced land degradation. Water erosion is the most important cause of land degradation, and its effects are irreversible. This report describes the IMAGE land degradation model developed for describing current and future global problems of water erosion at a 0.5 by 0.5 degree longitude and latitude resolution. The sensitivity to water erosion is computed from the terrain erodibility (based on soil and terrain characteristics), rainfall erosivity and land cover. Sensitivity is expressed in relative terms. The results can be used to identify regions where problems of water erosion may present under scenarios of population and economic growth, technological change and climate change.Achteruitgang van de kwaliteit van land voor landbouwproductie als gevolg van land degradatie kan een bedreiging vormen voor de voedselproductie. Erosie veroorzaakt door oppervlakkige afstroming van neerslag is wereldwijd de belangrijkste vorm van land degradatie, met irreversibele effecten. Dit rapport beschrijft het IMAGE land degradatie model waarmee huidige en toekomstige problemen van erosie door regenval kunnen worden beschreven met een ruimtelijke resolutie van 0.5 breedtegraad bij 0.5 lengtegraad. De gevoeligheid voor water erosie wordt berekend uit een aantal bodemhoedanigheden en relief, de intensiteit van regenval en de landbedekking. De relatieve gevoeligheid voor water erosie wordt uitgedrukt in een kwalitatieve index, omdat kwantificering van bodemverlies op de gewasproductiviteit van land op mondiale schaal niet mogelijk is. De resultaten kunnen worden gebruikt om gebieden te identificeren waar problemen van erosie op kunnen treden, op basis van scenario's van groeiende bevolking en economie, technologische vooruitgang en klimaatverandering

    Modelleren van land degradatie in IMAGE

    No full text
    Achteruitgang van de kwaliteit van land voor landbouwproductie als gevolg van land degradatie kan een bedreiging vormen voor de voedselproductie. Erosie veroorzaakt door oppervlakkige afstroming van neerslag is wereldwijd de belangrijkste vorm van land degradatie, met irreversibele effecten. Dit rapport beschrijft het IMAGE land degradatie model waarmee huidige en toekomstige problemen van erosie door regenval kunnen worden beschreven met een ruimtelijke resolutie van 0.5 breedtegraad bij 0.5 lengtegraad. De gevoeligheid voor water erosie wordt berekend uit een aantal bodemhoedanigheden en relief, de intensiteit van regenval en de landbedekking. De relatieve gevoeligheid voor water erosie wordt uitgedrukt in een kwalitatieve index, omdat kwantificering van bodemverlies op de gewasproductiviteit van land op mondiale schaal niet mogelijk is. De resultaten kunnen worden gebruikt om gebieden te identificeren waar problemen van erosie op kunnen treden, op basis van scenario's van groeiende bevolking en economie, technologische vooruitgang en klimaatverandering.Food security may be threatened by loss of soil productivity as a result of human-induced land degradation. Water erosion is the most important cause of land degradation, and its effects are irreversible. This report describes the IMAGE land degradation model developed for describing current and future global problems of water erosion at a 0.5 by 0.5 degree longitude and latitude resolution. The sensitivity to water erosion is computed from the terrain erodibility (based on soil and terrain characteristics), rainfall erosivity and land cover. Sensitivity is expressed in relative terms. The results can be used to identify regions where problems of water erosion may present under scenarios of population and economic growth, technological change and climate change.UNEP VROM NO

    A Spectrum of Entropy-Based Precision and Recall Measurements Between Partially Matching Designed and Observed Processes

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    Modern software systems are often built using service-oriented principles. Atomic components, be that web-or micro services, allow constructing ïŹ‚exible and loosely coupled systems. In such systems, services are building blocks orchestrated by business processes the system supports. Due to the complexity and heterogeneity of industrial software systems, implemented processes may deviate from those initially designed. In this paper, we propose a spectrum of conformance measurements. The spectrum results from a generalization of the recently introduced entropy-based approaches for measuring precision and recall between observed process executions and designed process models. The new generalized measures of precision and recall inherit the desired for this class of measures properties and provide analysts with ïŹ‚exible control over the sensitivity for identifying commonalities and discrepancies in the compared processes and performance of the techniques. The reported evaluation based on our implementation of the measures over real-world event logs and automatically discovered models conïŹrms the feasibility of using the approach in industrial settings
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