2,888 research outputs found

    ADEPT - Next Generation Process Management Technology

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    In the ADEPT project we have been working on the design and implementation of a next generation process management technology for several years. Based on a conceptual framework for dynamic process changes, on innovative process support functions, and on advanced implementation concepts, the developed system enables the realization of adaptive, process-aware information systems (PAIS). Basically, process changes can take place at the process type as well as the process instance level: Changes of single process instances may have to be carried out in an ad-hoc manner (e.g., to deal with an exceptional situation) and must not affect system robustness and consistency. Process type changes, in turn, must be quickly accomplished in order to adapt the PAIS to business process changes. This may also include the migration of (thousands of) instances to the new process schema (if desired). Important requirements are to perform respective migrations on-the-fly, to preserve correctness, and to avoid performance penalties

    ADEPT2 - Next Generation Process Management Technology

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    If current process management systems shall be applied to a broad spectrum of applications, they will have to be significantly improved with respect to their technological capabilities. In particular, in dynamic environments it must be possible to quickly implement and deploy new processes, to enable ad-hoc modifications of single process instances at runtime (e.g., to add, delete or shift process steps), and to support process schema evolution with instance migration, i.e., to propagate process schema changes to already running instances. These requirements must be met without affecting process consistency and by preserving the robustness of the process management system. In this paper we describe how these challenges have been addressed and solved in the ADEPT2 Process Management System. Our overall vision is to provide a next generation process management technology which can be used in a variety of application domains

    The dynamics of planetary nebulae in the Galaxy: evidence for a third integral

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    We present a dynamical analysis of 673 galactic Planetary Nebulae, using a two-integral axisymmetric model with a Kuzmin-Kutuzov St\"{a}ckel potential. The method fits the kinematics to the projected moments of a distribution function, by means of Quadratic Programming. The 2.2 μ\mum COBE brightness map has been used after correction for the interstellar extinction as a projected star counts map in the modeling, because it constitutes a galactic distribution view of evolved red populations which are considered to be the progenitors of PNe. The model we have obtained provides a 2-integral distribution function for the COBE 2.2 μ\mum map, and thus {\it a fortiori} a deprojection of it, which allows moreover the identification of all the major Galactic components. We derive the density laws for them. The projected velocity dispersions are not well fitted though, especially in the disk, which points at the likely presence of a third integral. If this result can be confirmed by additional data, this would mean that for the first time the presence and importance of a third integral on a global scale is demonstrated.Comment: 9 pages, uuencoded gzipped postscript file, 9 figures include

    Power systems research at MSFC

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    Power systems research reviews at Marshall Space Flight Cente

    Chemokines: structure, receptors and functions. A new target for inflammation and asthma therapy?

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    Five to 10% of the human population have a disorder of the respiratory tract called ‘asthma’. It has been known as a potentially dangerous disease for over 2000 years, as it was already described by Hippocrates and recognized as a disease entity by Egyptian and Hebrew physicians. At the beginning of this decade, there has been a fundamental change in asthma management. The emphasis has shifted from symptom relief with bronchodilator therapies (e.g. β2-agonists) to a much earlier introduction of anti-inflammatory treatment (e.g. corticosteroids). Asthma is now recognized to be a chronic inflammatory disease of the airways, involving various inflammatory cells and their mediators. Although asthma has been the subject of many investigations, the exact role of the different inflammatory cells has not been elucidated completely. Many suggestions have been made and several cells have been implicated in the pathogenesis of asthma, such as the eosinophils, the mast cells, the basophils and the lymphocytes. To date, however, the relative importance of these cells is not completely understood. The cell type predominantly found in the asthmatic lung is the eosinophil and the recruitment of these eosinophils can be seen as a characteristic of asthma. In recent years much attention is given to the role of the newly identified chemokines in asthma pathology. Chemokines are structurally and functionally related 8–10 kDa peptides that are the products of distinct genes clustered on human chromosomes 4 and 17 and can be found at sites of inflammation. They form a superfamily of proinflammatory mediators that promote the recruitment of various kinds of leukocytes and lymphocytes. The chemokine superfamily can be divided into three subgroups based on overall sequence homology. Although the chemokines have highly conserved amino acid sequences, each of the chemokines binds to and induces the chemotaxis of particular classes of white blood cells. Certain chemokines stimulate the recruitment of multiple cell types including monocytes, lymphocytes, basophils, and eosinophils, which are important cells in asthma. Intervention in this process, by the development of chemokine antagonists, might be the key to new therapy. In this review we present an overview of recent developments in the field of chemokines and their role in inflammations as reported in literature

    Evolutions in undirected travel (satisfaction) during the COVID-19 pandemic

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    The COVID-19 pandemic illustrated that undirected travel (UT), or trips taken for their own sake, can partly compensate for a reduction in destination-based trips due to governmental regulations. Consequently, UT (in general, but particularly during the pandemic) may be especially satisfying and therefore important to subjective well-being. However, through the course of the pandemic, changes in UT were anticipated as individuals adapted to a ‘new normal’. This research – conducted in Flanders, Belgium – first investigates whether the characteristics of and satisfaction with UT persisted after one year into the pandemic (April 2020 to May 2021) using longitudinal panel data from two waves (n = 332). Results of paired sample t-tests indicate that UT satisfaction increased though duration of trips decreased, and results of the Sign test indicate that the frequency of UT generally decreased. Second, this research investigates characteristics of individuals with different UT behavior. Six profiles of UT behavior were identified based on starting or stopping UT, increasing or decreasing UT, maintaining UT frequency, or not participating in UT. Chi2 tests identified differences among profiles based on wave 1 UT frequency, most recent trip mode, socio-demographic, and household characteristics. Results indicate that participation in UT might motivate future UT, one to three UT trips per week is a maintainable frequency, UT might be important to those with smaller living spaces and those living with children or other adults, and suggest that attention should be paid to mobility equity, including how and for whom systems are planned. These findings are important to understanding the effects of long-term governmental regulations in response to the COVID-19 pandemic on travel behavior, and how investigating UT might help to challenge and reimagine traditional mobility systems post-pandemic

    Searching for Faint Planetary Nebulae Using the Digital Sky Survey

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    Recent Halpha surveys such as SHS and IPHAS have improved the completeness of the Galactic planetary nebula (PN) census. We now know of ~3,000 PNe in the Galaxy, but this is far short of most estimates, typically ~25,000 or more for the total population. The size of the Galactic PN population is required to derive an accurate estimate of the chemical enrichment rates of nitrogen, carbon, and helium. In addition, a high PN count (~20,000) is strong evidence that most 1-8 Msun main sequence stars will go through a PN phase, while a low count (<10,000) argues that special conditions (e.g., a close binary interaction) are required to form a PN. We describe a technique for finding hundreds more PNe using the existing data collections of the digital sky surveys, thereby improving the census of Galactic PNe.Comment: 11 pages, 7 figures, accepted for publication in the Publications of the Astronomical Society of Australia (PASA), full resolution paper available at http://www.wiyn.org/jacoby_pasa.pd

    On undirected trips, satisfaction, and well-being: Evidence from Flanders (Belgium)

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    Despite having the potential to improve subjective well-being, satisfaction with undirected travel, or travel for its own sake (e.g. taking a walk, bike ride, or joy ride), has not yet been empirically investigated. Using mean-comparison and generalized linear regression models, this study analyzes 1579 undirected trips made by 852 respondents to a survey in Flanders, Belgium during the COVID-19 pandemic lockdown (18 March – 4 May 2020). Undirected travel was found to be longer in duration and more satisfying than results from directed trips in previous literature, with an indication that higher levels of physical activity are important to satisfaction. Undirected travel satisfaction was found to have a clear positive relationship to well-being. As these trips are often active and were found to imply a positive utility of travel, understanding them can be important to policy goals regarding health, sustainability, and improving individual well-being
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