Propulsion Mechanisms for Leidenfrost Solids on Ratchets

We propose a model for the propulsion of Leidenfrost solids on ratchets based on viscous drag due to the flow of evaporating vapor. The model assumes pressure-driven flow described by the Navier-Stokes equations and is mainly studied in lubrication approximation. A scaling expression is derived for the dependence of the propulsive force on geometric parameters of the ratchet surface and properties of the sublimating solid. We show that the model results as well as the scaling law compare favorably with experiments and are able to reproduce the experimentally observed scaling with the size of the solid

CHALLENGES IN THE DEPLOYMENT AND OPERATION OF MACHINE LEARNING IN PRACTICE

Machine learning has recently emerged as a powerful technique to increase operational efficiency or to develop new value propositions. However, the translation of a prediction algorithm into an operationally usable machine learning model is a time-consuming and in various ways challenging task. In this work, we target to systematically elicit the challenges in deployment and operation to enable broader practical dissemination of machine learning applications. To this end, we first identify relevant challenges with a structured literature analysis. Subsequently, we conduct an interview study with machine learning practitioners across various industries, perform a qualitative content analysis, and identify challenges organized along three distinct categories as well as six overarching clusters. Eventually, results from both literature and interviews are evaluated with a comparative analysis. Key issues identified include automated strategies for data drift detection and handling, standardization of machine learning infrastructure, and appropriate communication and expectation management

Identitätskonstruktionen von "Störern und Gestörten"

Im Fokus der triangulativen Querschnittsuntersuchung (Vernetzung qualitativer und quantitativer Methodik) stehen Jugendliche der Schule zur Erziehungshilfe (SzE) (Vergleichsgruppe: Hauptschüler, Gymnasiasten) in Bayern, die aufgrund des sonderpädagogischen Förderbedarfs im Förderschwerpunkt soziale und emotionale Entwicklung in der allgemeinen Schule aktuell nicht ausreichend gefördert werden können (vgl. § 41 Abs. 1 BayEUG; § 9 VSO-F). Die 15- bis 16-jährigen Jugendlichen der 8. Klassen der SzE weisen (a) retrospektiv eine schulisch-institutionelle „Bruchbiographie“ (vgl. Beck & Beck-Gernsheim 1994) auf, die sich (b) aktuell in der Situation schulischer Aussonderung von der allgemeinen Schule manifestiert sowie (c) prospektiv eine Auseinandersetzung mit Anforderungen der postmodernen „Risikogesellschaft“ unter erschwerten Bedingungen bedeutet. Diese „erschwerten Bedingungen“ der Förderschüler in der „modernen Leistungsgesellschaft“ (vgl. Bundschuh 2002) unter Wegfall von haltgebenden „Normalbiographien“ führen nicht selten zu eingeschränkten Partizipationsmöglichkeiten an sozial-gesellschaftlichen Prozessen, konkret an Ausbildung, Arbeit, Wohlstand, Kultur, Weiterbildung und sonstigen Möglichkeiten der Teilhabe an sozialen Prozessen (vgl. u.a. Zusammenhänge von schulischer Bildung, beruflicher Bildung und Erwerbschancen des Konsortiums Bildungsberichterstattung 2006). Dieser externen Analyse bzgl. der Zukunftsperspektiven der Jugendlichen steht eine interne Reflexion des Subjekts gegenüber, die eine „Passung von Selbstansprüchen und sozialen Anforderungen“ (vgl. Keupp et al. 2006) zu erreichen sucht. Die konkrete Fragestellung der Untersuchung lautet dementsprechend: »Wie integrieren die Jugendlichen der Schule zur Erziehungshilfe ihre eigene „Bruchbiographie“, das subjektive Erleben von schulischer Aussonderung sowie die vermeintlich eingeschränkten Zukunftsperspektiven (die eigene, reflektierte „Risikobiographie“; Beck 1986) auf dem Hintergrund spezifischer Identitätskonstruktionen«. Auf der Basis einer sozialpsychologisch orientierten Theorie der Identitätskonstruktionen wird diese Frage der Verarbeitung der eigenen (schulisch-sozialen) Biographie, der aktuellen (Aussonderungs-)Situation sowie der Zukunftsvorstellungen (Identitätsentwürfe), der Zukunftspläne (Identitätsprojekte) und Zukunfts-/Identitätsstrategien untersucht. Durchgängig wird der Forschungsprozess anhand elementarer Fragestellungen der Sonderpädagogik diskutiert, wobei die Themenkomplexe (Re-)Integration versus Exklusion von besonderem Interesse sind

Responsibility and verification: Importance value in temporal logics

We aim at measuring the influence of the nondeterministic choices of a part of a system on its ability to satisfy a specification. For this purpose, we apply the concept of Shapley values to verification as a means to evaluate how important a part of a system is. The importance of a component is measured by giving its control to an adversary, alone or along with other components, and testing whether the system can still fulfill the specification. We study this idea in the framework of model-checking with various classical types of linear-time specification, and propose several ways to transpose it to branching ones. We also provide tight complexity bounds in almost every case.Comment: 22 pages, 12 figure

The role of saliva in oral processing: Reconsidering the breakdown path paradigm

We discuss food oral processing research over the last two decades and consider strategies for quantifying the food breakdown model, originally conceptualised by Hutchings and Lillford . The key innovation in their seminal 1988 paper was shifting the focus from intact food properties, measured in the lab, towards strategies to capture the dynamic nature of eating. This has stimulated great progress in the field, but a key aspect missing in oral processing research is the conversion of the Hutchings and Lillford breakdown path conceptual model into quantifiable parameters considered in the context of physiological factors such as saliva and oral movements. To address these short comings, we propose the following analysis: Hutchings’s and Lillford’s definitions of “Structure” and “Lubrication” are incomplete and they comprise many and varied physicochemical properties. We offer, here, a deeper analysis of each parameter, and propose strategies for researchers to consider in their quantification as an update of the Hutchings and Lillford Breakdown path

Enabling the Rational Design of Low-Fat Snack Foods: Insights from In Vitro Oral Processing

Texture perception can be conceptualized as an emergent cognitive response to several of the physical and chemical properties of a food. Contemporary oral processing research is focused on revealing the relationships between the sensory perceptions and the food properties, with the goal of enabling rational product design. One major challenge is the complexity of molecular and biocolloid interactions, underpinning even simple texture properties. Here, we will introduce the in vitro oral processing approach, which divides oral processing into discrete units of operation (first bite, comminution, granulation, bolus formation, and tribology) and then systematically investigates the material properties that govern each specific oral processing unit operation without the added complexity inherent to biological systems. We will describe how we used the approach to rationally design a low-fat potato chip by investigating the impact from adding back, to a low fat potato chip, a small amount of oil mixed with the surface active agent polyglycerol polyricinoleate (PGPR). The relevance of instrumental measures was validated by sensory assessment wherein panelists ranked the perceived oiliness of three different types of potato chips. The sensory results indicated that perceived oiliness was higher when the low- fat potato chip was supplemented with a 0.5% by weight topical coating (0.5% by weight 15% by weight PGPR in oil mixture) compared to the unaltered low-fat potato chip. The perceived difference in oiliness was found to correspond to in vitro transient friction of saliva in the presence and absence of PGPR. These results illustrate how dividing oral processing into distinct phases allows one to more readily align sensory and in vitro measures, allowing for integration of the two disciplines and more rational design when modifying macronutrients

Diagnosis of malaria in a traveler 9 months after returning from West Africa by illumigene® LAMP assay: A case report

Loop-mediated isothermal amplification (LAMP) is a rapid molecular technique that has been introduced into malaria diagnosis. The test is easy to perform and offers high sensitivity. We report a 53-year-old male patient who was hospitalized with fever attacks, chills, and headache caused 9 months after returning from Africa. During his stay in Africa, he used malaria chemoprophylaxis. Microscopy of thin and thick blood films and rapid diagnostic antigen testing remained negative for three times. The EDTA blood samples were tested using the Meridian illumigene® malaria LAMP assay that gave a positive result for Plasmodium spp. Diagnosis of malaria was subsequently specified as P. ovale infection by real-time PCR. Ovale malaria often manifests with delay and low parasitemia. The patient was treated with atovaquone-proguanil, followed by primaquine for prophylaxis of relapse. This case illustrates the usefulness of the illumigene® malaria LAMP assay for initial screening of malaria parasites