Topic-independent modeling of user knowledge in informational search sessions

Web search is among the most frequent online activities. In this context, widespread informational queries entail user intentions to obtain knowledge with respect to a particular topic or domain. To serve learning needs better, recent research in the field of interactive information retrieval has advocated the importance of moving beyond relevance ranking of search results and considering a user’s knowledge state within learning oriented search sessions. Prior work has investigated the use of supervised models to predict a user’s knowledge gain and knowledge state from user interactions during a search session. However, the characteristics of the resources that a user interacts with have neither been sufficiently explored, nor exploited in this task. In this work, we introduce a novel set of resource-centric features and demonstrate their capacity to significantly improve supervised models for the task of predicting knowledge gain and knowledge state of users in Web search sessions. We make important contributions, given that reliable training data for such tasks is sparse and costly to obtain. We introduce various feature selection strategies geared towards selecting a limited subset of effective and generalizable features. © 2021, The Author(s)

High‐resolution structural‐mechanical characterization and simulation of novel barrier coatings

Ceramic matrix composites and non-oxide ceramics are potential near-future materials for high temperature applications in gas turbines for energy production and aviation. Mechanical strength and the capability to withstand temperatures up to 1500 °C under load make these ceramic materials perfect candidates to increase efficiency and to lower emissions. However, corrosive attack by water vapor is still a reliability- and lifetime-limiting factor. Also, thermal insulation is important for oxide ceramic matrix composites because of their low temperature limit in comparison to non-oxide ceramics, e.g. silicon nitride. Therefore, protective coatings are a substantial component in such advanced applications. A new type of coating is investigated which shall act as an environmental and thermal barrier. As a novel approach, a single phase material with high corrosion resistance and low thermal conductivity will be deposited. Solid-state reactions between the substrate material and the coating should provide strong adhesion. In addition, a defined pore distribution should provide good thermal insulation and high tolerance against defects. As a result, a novel, superior coating system is supposed to be achieved for the industrial applications mentioned above. The development of new material systems and coatings requires extensive studies of structure-property relationships and knowledge about the material behavior in dependence on its structure. As a new approach, 3D reconstruction methods will be used to describe the material, using non-destructive micro-X-ray computed tomography and scanning electron microscopy combined with cross-sectioning using a focused ion beam. Especially the non-destructive X-ray technique has the distinct advantage of performing corrosion testing and studying several stages of the evaluation of weak spots in the material-coating system. On the other hand, electron microscopy allows to create 3D images of pores or cracks down to 1 nm resolution in order to improve the understanding of their formation and evolution. Both techniques are well-suited to quantify important structural parameters such as the pore size distribution and pore topology, which can hardly be measured with other methods. The structural information is supplemented by extensive multi-scale mechanical property studies using nano- and microindentation covering the scales from the nano- to the micro-range. To link the multi-scale structural to the multi-scale mechanical material information, both are combined in finite element simulations. With these simulations, the relations between the macroscopic barrier coating properties and the microscopic coating structure will be studied

Estimating glycemic impact of cooking recipes via online crowdsourcing and machine learning

National Research Foundation (NRF) Singapore under its International Research Centres in Singapore Funding Initiativ

Characterizing and predicting repeat food consumption behavior for just-in-time interventions

National Research Foundation (NRF) Singapore under its International Research Centres in Singapore Funding Initiativ

The Search as Learning Spaceship: Toward a Comprehensive Model of Psychological and Technological Facets of Search as Learning

Using a Web search engine is one of today’s most frequent activities. Exploratory search activities which are carried out in order to gain knowledge are conceptualized and denoted as Search as Learning (SAL). In this paper, we introduce a novel framework model which incorporates the perspective of both psychology and computer science to describe the search as learning process by reviewing recent literature. The main entities of the model are the learner who is surrounded by a specific learning context, the interface that mediates between the learner and the information environment, the information retrieval (IR) backend which manages the processes between the interface and the set of Web resources, that is, the collective Web knowledge represented in resources of different modalities. At first, we provide an overview of the current state of the art with regard to the five main entities of our model, before we outline areas of future research to improve our understanding of search as learning processes. Copyright © 2022 von Hoyer, Hoppe, Kammerer, Otto, Pardi, Rokicki, Yu, Dietze, Ewerth and Holtz

The Search as Learning Spaceship: Toward a Comprehensive Model of Psychological and Technological Facets of Search as Learning

Using a Web search engine is one of today’s most frequent activities. Exploratory search activities which are carried out in order to gain knowledge are conceptualized and denoted as Search as Learning (SAL). In this paper, we introduce a novel framework model which incorporates the perspective of both psychology and computer science to describe the search as learning process by reviewing recent literature. The main entities of the model are the learner who is surrounded by a specific learning context, the interface that mediates between the learner and the information environment, the information retrieval (IR) backend which manages the processes between the interface and the set of Web resources, that is, the collective Web knowledge represented in resources of different modalities. At first, we provide an overview of the current state of the art with regard to the five main entities of our model, before we outline areas of future research to improve our understanding of search as learning processes

Clinical, biochemical and genetic spectrum of 70 patients with ACAD9 deficiency: is riboflavin supplementation effective?

BACKGROUND: Mitochondrial acyl-CoA dehydrogenase family member 9 (ACAD9) is essential for the assembly of mitochondrial respiratory chain complex I. Disease causing biallelic variants in ACAD9 have been reported in individuals presenting with lactic acidosis and cardiomyopathy. RESULTS: We describe the genetic, clinical and biochemical findings in a cohort of 70 patients, of whom 29 previously unpublished. We found 34 known and 18 previously unreported variants in ACAD9. No patients harbored biallelic loss of function mutations, indicating that this combination is unlikely to be compatible with life. Causal pathogenic variants were distributed throughout the entire gene, and there was no obvious genotype-phenotype correlation. Most of the patients presented in the first year of life. For this subgroup the survival was poor (50% not surviving the first 2 years) comparing to patients with a later presentation (more than 90% surviving 10 years). The most common clinical findings were cardiomyopathy (85%), muscular weakness (75%) and exercise intolerance (72%). Interestingly, severe intellectual deficits were only reported in one patient and severe developmental delays in four patients. More than 70% of the patients were able to perform the same activities of daily living when compared to peers. CONCLUSIONS: Our data show that riboflavin treatment improves complex I activity in the majority of patient-derived fibroblasts tested. This effect was also reported for most of the treated patients and is mirrored in the survival data. In the patient group with disease-onset below 1 year of age, we observed a statistically-significant better survival for patients treated with riboflavin