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  • 1
    Publication Date: 2020-08-05
    Description: The Graduate-Level Research in Industrial Projects (G-RIPS) Program provides an opportunity for high-achieving graduate-level students to work in teams on a real-world research project proposed by a sponsor from industry or the public sector. Each G-RIPS team consists of four international students (two from the US and two from European universities), an academic mentor, and an industrial sponsor. This is the report of the Rail-Lab project on the definition and integration of robustness aspects into optimizing rolling stock schedules. In general, there is a trade-off for complex systems between robustness and efficiency. The ambitious goal was to explore this trade-off by implementing numerical simulations and developing analytic models. In rolling stock planning a very large set of industrial railway requirements, such as vehicle composition, maintenance constraints, infrastructure capacity, and regularity aspects, have to be considered in an integrated model. General hypergraphs provide the modeling power to tackle those requirements. Furthermore, integer programming approaches are able to produce high quality solutions for the deterministic problem. When stochastic time delays are considered, the mathematical programming problem is much more complex and presents additional challenges. Thus, we started with a basic variant of the deterministic case, i.e., we are only considering hypergraphs representing vehicle composition and regularity. We transfered solution approaches for robust optimization from the airline industry to the setting of railways and attained a reasonable measure of robustness. Finally, we present and discuss different methods to optimize this robustness measure.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
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  • 2
    ISSN: 1432-0428
    Keywords: Tolbutamide stimulation ; glucose stimulation ; β-cell ultrastructure ; insulin secretion ; perfused rat pancreas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Des modifications ultrastructurales dans les cellules β du pancréas de rat isolé et perfusé ont été observées au cours de la réponse dynamique au glucose et au tolbutamide. On a noté une sécrétion granulaire évidente dans l'espace extracellulaire par émiocytose au cours des 60 premières secondes de stimulation par le glucose, mais non aprś et à aucun moment pendant la stimulation par le tolbutamide. Des amas de granules à l'intérieur de l'appareil de Golgi étaient apparents après 60 minutes d'injection de glucose, mais non dans le cas d'injection de tolbutamide. — Ces résultats renforcent l'idée que le glucose stimule initialement la libération d'un petit pool instable d'insuline préformée, tandis que l'administration continue stimule l'activité de stockage de l'appareil de Golgi et la provision d'insuline supplémentaire pour le processus de sécrétion. Par contre, le tolbutamide seul à forte concentration, augmente le complexe de Golgi, les vésicules à membrane hérissée (coated vesicles), les corps multivésiculaires et les cytosegresomes. Il peut ainsi stimuler le stockage sans provision d'insuline, ou alternativement, augmenter le processus lysosomal de dégradation.
    Abstract: Zusammenfassung Ultrastructurelle Veränderungen in den B-Zellen von isoliertem perfundierten Rattenpancreas wurden während der dynamischen Reaktion auf Glucose und Tolbutamid beobachtet. Augenscheinlich erfolgt eine Granula-Sekretion in den extracellulären Raum durch Emiocytose während der ersten 60 sec der Glucose-Stimulation, aber nicht danach, und auch nicht zu irgendeiner Zeit während der Tolbutamid-Stimulation. Dichtes Zusammenlagern von Granula innerhalb des Golgi-Apparates trat offensichtlich nach 60 min nach der Glucoseinjektion ein, aber nicht im Fall des Tolbutamid. — Diese Befunde unterstützen die Annahme, daß die Glucose im Anfang die Abgabe eines kleinen labilen pools von präformierten Insulin anregt, während fortgesetzte Verabreichung die Aktivität der dichten Anlagerung am Golgi-Apparat und die Bereitstellung von zusätzlichem Insulin für den Sekretionsprozeß stimuliert. Hohe Dosen von Tolbutamid allein vermehren andererseits den Golgi-Komplex, die bedeckten Bläschen, die multivesikulären Körper und die Cytosegresomen. Insofern könnte Tolbutamid die Anreicherung ohne Bereitstellung von Insulin stimulieren oder aber lysosomale Degradationsprozesse vermehren.
    Notes: Summary Ultrastructural changes in β cells of the isolated perfused rat pancreas were observed during the dynamic response to glucose and tolbutamide. Evidence of granule secretion into the extracellular space by emiocytosis was noted during the first 60 sec of glucose stimulation, but not thereafter nor at any time during tolbutamide stimulation. Packaging of granules within the Golgi apparatus was apparent after 60 min of glucose injection, but not in the case of tolbutamide. These findings support the concept that glucose initially stimulates the release of a small labile pool of preformed insulin, while continued administration stimulates Golgi packaging activity and the provision of additional insulin for the secretory process. High tolbutamide alone, in contrast increases the Golgi complex, coated vesicles, multivesicular bodies and cytosegresomes. Thus it may stimulate packaging without insulin provision, or alternatively, increase lysosomal degradative processes.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing
    Psychophysiology 42 (2005), S. 0 
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Does objective probability affect P300 size independently and in addition to subjective probability? The latter was manipulated by the number of stimuli presented and classification task. Five groups saw target and frequent stimuli. Two saw these with p=.2 or .067, with two different button presses. Three groups saw two additional nontarget stimuli each with p=.067. One group pressed a different button for each stimulus. A second group pressed one button for the three oddballs, another for the frequent. A third critical group pressed one button for the target and another for other stimuli. In this group, P300 was larger for targets versus nontargets, and larger for nontargets versus frequents. Although nontargets were classified with frequents, their actual low probability distinguished them from frequents, and their subjective probability distinguished them from targets. Therefore, actual and subjective probability effects were independently found.
    Type of Medium: Electronic Resource
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  • 4
    Worcester, Mass. : Periodicals Archive Online (PAO)
    Journal of Social Psychology. 133:1 (1993:Feb.) 43 
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