542 research outputs found

    Ansätze zur Entwicklung von Workflow-basierten Anwendungssystemen:eine vergleichende Darstellung

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    Workflow-Management-Systeme werden entscheidende Impulse für die Gestaltung von Informationssystemen der nächsten Generation geben. Ähnlich wie Datenbank-Systeme heute werden Workflow-Systeme zukünftig als Basistechnologie in komplexen Informationssystemen verwendet werden. Sie ermöglichen eine geschäftsprozeßnahe Darstellung der betrieblichen Ablauflogik und die explizite und zentrale Abbildung dieser Geschäftsprozeßlogik mittels spezialisierter Softwarekomponenten im Gegensatz zu der heute üblichen impliziten Codierung der Prozeßlogik in Applikationen. Ansätze zur Entwicklung von Workflow-basierten Anwendungen sind somit von großem Interesse. Anhand eines Vorgehens-Meta-Modells stellt der Beitrag zunächst wichtige in der Literatur vorgeschlagene Vorgehensmodelle zur Entwicklung von Workflow-Anwendungen einheitlich und klassifizierend dar. Darauf aufbauend erfolgt eine vergleichende Einordnung der verschiedenen Ansätze anhand von Kriterien, die basierend auf dem Meta-Modell hergeleitet werden.<br/

    The Essence of Software Engineering

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    This open access book includes contributions by leading researchers and industry thought leaders on various topics related to the essence of software engineering and their application in industrial projects. It offers a broad overview of research findings dealing with current practical software engineering issues and also pointers to potential future developments. Celebrating the 20th anniversary of adesso AG, adesso gathered some of the pioneers of software engineering including Manfred Broy, Ivar Jacobson and Carlo Ghezzi at a special symposium, where they presented their thoughts about latest software engineering research and which are part of this book. This way it offers readers a concise overview of the essence of software engineering, providing valuable insights into the latest methodological research findings and adesso’s experience applying these results in real-world projects

    Automatic correction of hand pointing in stereoscopic depth

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    In order to examine whether stereoscopic depth information could drive fast automatic correction of hand pointing, an experiment was designed in a 3D visual environment in which participants were asked to point to a target at different stereoscopic depths as quickly and accurately as possible within a limited time window (≤300 ms). The experiment consisted of two tasks: "depthGO" in which participants were asked to point to the new target position if the target jumped, and "depthSTOP" in which participants were instructed to abort their ongoing movements after the target jumped. The depth jump was designed to occur in 20% of the trials in both tasks. Results showed that fast automatic correction of hand movements could be driven by stereoscopic depth to occur in as early as 190 ms.This work was supported by the Grants from the National Natural Science Foundation of China (60970062 and 61173116) and the Doctoral Fund of Ministry of Education of China (20110072110014)

    ATTENTION AND THE PARIETAL CORTEX: INVESTIGATIONS OF SPATIAL NEGLECT, OPTIC ATAXIA, AND THE INFLUENCE OF PRISM ADAPTATION ON ATTENTION

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    Some authors have argued that the primary function of the posterior parietal cortex is to control visual attention and awareness, whereas others have argued that the posterior parietal cortex is specialized for controlling actions. The purpose of the present thesis was to examine the influence of prism adaptation – a visuomotor adaptation technique – on visual attention deficits in patients with lesions of parietal cortex. Lesions to dorsal regions of the posterior parietal cortex lead to optic ataxia – a disorder in which visually guided reaching is disrupted. In contrast lesions to ventral (i.e. inferior) regions of the posterior parietal cortex of the right hemisphere lead to spatial neglect – a disorder in which patients are unaware of people or objects in contralesional (left) space. Chapter 1 presents an overview of the organization of the posterior parietal cortex, as well as an introduction to the disorders of spatial neglect and optic ataxia and the use of prism adaptation as a treatment for spatial neglect. Chapter 2 examined the influence of prism adaptation on attentional deficits in patients with right brain damage. Results demonstrated that prism adaptation reduced both the disengage deficit and the rightward attentional bias, two of the classic attentional deficits in neglect. Chapter 3 investigated the role of the dorsal posterior parietal cortex in controlling both reflexive and voluntary attention in two patients with optic ataxia. Lesions to the dorsal posterior parietal cortex led to both a disengage deficit and a rightward attentional bias, similar to patients with neglect, even though neither of the patients had any clinical symptoms of neglect. Contrary to previous work these results indicated that dorsal portions of the posterior parietal cortex – a region not commonly damaged in neglect – are important for controlling the orienting and reorienting of both reflexive and voluntary attention. Furthermore, these results indicated that optic ataxia is not purely a visuomotor disorder that is independent of any perceptual or attentional deficits as was previously assumed. Based on the results of Chapters 2 and 3 it was hypothesized that the beneficial effects of prism adaptation on attention may operate via the superior parietal lobe, a region which is typically undamaged in neglect, and is known to be important for controlling attention and action. Chapter 4 provided support for this hypothesis by demonstrating that a patient with lesions to the superior parietal lobe, who had the same attentional deficits as the right brain damaged patients tested in Chapter 2, failed to demonstrate any beneficial effects of prism adaptation on his attentional performance. Specifically, prism adaptation had no influence on his disengage deficit or his rightward attentional bias. Therefore, these data provide direct evidence that the beneficial effects of prisms on attention rely, at least in part, on the superior parietal lobe. Finally, Chapter 5 concludes with a summary of the research findings from the present thesis, and puts forward a new theory to conceptualize the mechanisms underlying the beneficial effects of prisms in patients with neglect

    Neighbourhood-based social integration. The importance of the local context for different forms of resource transfer

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    Due to their lack of financial resources, poor residents of deprived neighbourhoods are very much reliant on support and assistance from their personal networks. Studies refer to the key importance of neighbourhood contacts transcending social boundaries to promote upward social mobility. Based on a mix of quantitative and qualitative findings, this paper looks at the importance of social mix within a person’s neighbourhood and immediate surroundings for transferring different kinds of resources. The results show that even residents of deprived neighbourhoods can call on a well-developed support network to deal with everyday problems. The contribution also shows that network contacts to people endowed with more resources are no guarantee for the upward social mobility of the less well endowed. Indeed, it would seem that ‘getting-ahead’ resources are also accessible via their homogeneous networks. Much more to the point, the immediate surroundings turn out to be an important spatial context for contacts and resource transfers, especially for families with children.Peer reviewe

    Impaired peripheral reaching and on-line corrections in patient DF: optic ataxia with visual form agnosia

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    An influential model of vision suggests the presence of two visual streams within the brain: a dorsal occipito-parietal stream which mediates action and a ventral occipito-temporal stream which mediates perception. One of the cornerstones of this model is DF, a patient with visual form agnosia following bilateral ventral stream lesions. Despite her inability to identify and distinguish visual stimuli, DF can still use visual information to control her hand actions towards these stimuli. These observations have been widely interpreted as demonstrating a double dissociation from optic ataxia, a condition observed after bilateral dorsal stream damage in which patients are unable to act towards objects that they can recognize. In Experiment 1, we investigated how patient DF performed on the classical diagnostic task for optic ataxia, reaching in central and peripheral vision. We replicated recent findings that DF is remarkably inaccurate when reaching to peripheral targets, but not when reaching in free vision. In addition we present new evidence that her peripheral reaching errors follow the optic ataxia pattern increasing with target eccentricity and being biased towards fixation. In Experiments 2 and 3, for the first time we examined DF’s on-line control of reaching using a double-step paradigm in fixation-controlled and free-vision versions of the task. DF was impaired when performing fast on-line corrections on all conditions tested, similarly to optic ataxia patients. Our findings question the long-standing assumption that DF’s dorsal visual stream is functionally intact and that her on-line visuomotor control is spared. In contrast, in addition to visual form agnosia, DF also has visuomotor symptoms of optic ataxia which are most likely explained by bilateral damage to the superior parietal occipital cortex. We thus conclude that patient DF can no longer be considered as an appropriate single-case model for testing the neural basis of perception and action dissociations

    Stabilization of Ion Concentration Polarization Using a Heterogeneous Nanoporous Junction

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    We demonstrate a recycled ion-flux through heterogeneous nanoporous junctions, which induce stable ion concentration polarization with an electric field. The nanoporous junctions are based on integration of ionic hydrogels whose surfaces are negatively or positively charged for cationic or anionic selectivity, respectively. Such heterogeneous junctions can be matched up in a way to achieve continuous ion-flux operation for stable concentration gradient or ionic conductance. Furthermore, the combined junctions can be used to accumulate ions on a specific region of the device.Korea Research Foundation (Grant MOEHRD: KRF-2007-331-D00040)Korean Science and Engineering Foundation (Grant MOST: R01-2007-000-20675-0)Korea Research Foundation (Grant MOEHRD: KRF-J03000)National Research Foundation of Korea (Grant NRF-2009- 352-D00034)National Institutes of Health (U.S.) (EB005743)National Science Foundation (U.S.). (CBET-0347348

    Cerebellar tDCS alters the perception of optic flow

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