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Learning with Limited Labelled Data
No full text7794Modern machine and deep learning require large amounts of training data. Yet, even if the data itself is abundantly available, the fraction of annotated data may still be proportionally small or missing. Hence, learning with limited labeled data is an important research field. Two streams of research attack this problem from opposite directions [64]. On the one hand, semi-supervised learning aims to leverage all information by directly incorporating unlabeled data. On the other hand, active learning finds unlabeled data for that annotations would be most beneficial for learning, and queries humans-in-the-loop of model training. This chapter discusses both concepts and their essential principles, methodological overlaps, and strengths and weaknesses. Furthermore, we elaborate on possible combinations and their advantages ands disadvantages. Finally, the conclusion refers to recent state-of-the-art and provides an outlook into the future of learning with few labeled data
Was fehlt zur flächendeckenden Automatisierung im ÖPNV?
No full text3243Automatisierte Shuttlebusse im ÖPNV gelten als wesentlicher Baustein für die urbane Mobilität der Zukunft. Doch trotz umfangreicher Pilotprojekte steht die flächendeckende Einführung vor wesentlichen Hürden. Im Rahmen der Vorbereitung eines Forschungsprojekts wurde differenziert unter Expertinnen und Experten erhoben, wo die Umsetzung derzeit noch auf Herausforderungen stößt.1
Accuracy Evaluation of a Low-Cost Differential Global Positioning System for Mobile Robotics
No full textDifferential GPS, commonly referred as DGPS, is a well-known and very accurate localization system for many outdoor applications in particular for mobile outdoor robotics. The most common drawback of DGPS systems are the high costs for both base station and receivers. In this paper, we present a setup that uses third-party open-source software and a Ublox ZED-F9P chip to build a ROS-enabled low-cost DGPS setup that is ready to use in a few hours. The main goal of this paper is to analyze and evaluate the repetitive and absolute accuracy of the system. The first measurement also examines the differences between a SAPOS [1] base station and a locally installed one consisting of low-cost components. During the evaluation process of the absolute accuracy, a moving mobile robot is used on the receiver side. It is tracked through a highly accurate VICON motion capture system [2]
Surface optimization of PMMA via oxygen plasma and APTES for antibody immobilization
No full textPolymethyl methacrylate (PMMA) chip-based biosensors have been widely used in bioanalysis due to their excellent optical transparency, biocompatibility, and ease of fabrication. However, the low surface reactivity and high non-specific adsorption of PMMA hinder efficient biomolecule immobilisation, which limits the analytical reproducibility and performance. In this study, we propose an optimised surface modification strategy to improve antibody immobilisation on PMMA substrates by systematically controlling oxygen plasma treatment and silanisation using 3-aminopropyltriethoxysilane (APTES). The surface morphology and hydrophilicity under various plasma conditions were characterised, and the effect of APTES concentration on antibody binding efficiency was quantitatively evaluated. The antibody immobilisation performance was evaluated based on the signal-to-noise ratio using a digital enzyme-linked immunosorbent assay device (Small Machines, Republic of Korea). Our results indicate that an APTES silanisation with 5% concentration, following 30 s oxygen plasma treatment at 50 W, yields the most functionally active surface for antibody immobilisation. This study presents a reliable surface engineering strategy for immobilising biomolecules on PMMA and provides a foundation for more reproducible and high-performance biosensor platforms.Online Firs
Pharmaceutical logistics within the meaning of the KHZG – a logistic perspective comprising orocesses, concepts and areas Arzneimittellogistik im Sinne des Krankenhauszukunftsgesetzes
No full text305314The introduction and further development of digital medication management in accordance with the Krankenhauszukunftsgesetz (KHZG) presents hospital pharmacies with the challenge of conceptualizing future processes, technical systems and areas in the pharmacy and on the nursing wards. This has a significant impact on the entire internal logistics of pharmaceuticals. With the help of the “Logistisches Betriebskonzept”, the authors of this paper present a method for developing a holistic logistical concept for drug supply. For this purpose, the findings and results of the application of the method are presented on the basis of two reference hospitals. In both hospitals, the changeover to patient-specific blistering was designed. During the implementation of the method, it becomes clear that the planning of the processes, the selection of the technical systems and the calculation of the required areas lead to individual results for each pharmacy despite general framework parameters.45
Design and Simulation of a High Cycle Fatigue Vibration Tester for Accelerated Stress Testing of Thin Films and Bimaterial interfaces
No full textWe introduce a high cycle fatigue test (HCF), which can be used for the accelerated stress testing of metallization layers and bi-material interfaces from microelectronic packages under controlled periodic displacement amplitudes and isothermal conditions. The main focus is the delamination of bi-material interfaces. For the test, samples are fabricated on a magnetic steel substrate using the same processes that are used to manufacture the microelectronic packages under consideration. Various schemes were developed for setting up the samples. To excite the sample, we use magnetic actuation. The sample is subjected to a cyclic strain by the oscillation and several million oscillation cycles can be carried out in a short time. The crack length is determined by a stiffness method recorded changes in the vibration spectrum of the beam. This stress method makes it possible to test the integrity of microelectronic components very fast under harsh conditions
A health equity monitoring framework based on process mining
No full textIn the United States, there is a proposal to link hospital Medicare payments with health equity measures, signaling a need to precisely measure equity in healthcare delivery. Despite significant research demonstrating disparities in health care outcomes and access, there is a noticeable gap in tools available to assess health equity across various health conditions and treatments. The available tools often focus on a single area of patient care, such as medication delivery, but fail to examine the entire health care process. The objective of this study is to propose a process mining framework to provide a comprehensive view of health equity. Using event logs which track all actions during patient care, this method allows us to look at disparities in single and multiple treatment steps, but also in the broader strategy of treatment delivery. We have applied this framework to the management of patients with sepsis in the Intensive Care Unit (ICU), focusing on sex and English language proficiency. We found no significant differences between treatments of male and female patients. However, for patients who don’t speak English, there was a notable delay in starting their treatment, even though their illness was just as severe and subsequent treatments were similar. This framework subsumes existing individual approaches to measure health inequities and offers a comprehensive approach to pinpoint and delve into healthcare disparities, providing a valuable tool for research and policy-making aiming at more equitable healthcare.3
English tweets on allergy: Content analysis and association with surveillance data
No full text500508Background: Analysis of X (formerly Twitter) posts can inform on the interest/perceptions that social media users have on health subjects. In this study, we aimed to analyse tweets on allergic conditions, comparing them with surveillance data. Methods: We retrieved tweets from England on “allergy,” “asthma,” and “allergic rhinitis,” published between 2016 and 2021. We estimated the correlation between the frequency of tweets on “asthma” and “allergic rhinitis” and English surveillance data on the incidence of asthma and allergic rhinitis medical visits. We performed sentiment analysis, computing a score informing on the emotional tone of assessed tweets. We applied a topic modelling approach to identify topics (clusters of words frequently occurring together) for tweets on each assessed condition. Results: We analysed a total of 13,605 tweets on “allergy,” 7767 tweets on “asthma,” and 11,974 tweets on “allergic rhinitis.” Food-related words were preponderant on tweets on “allergy,” while “eyes” was the most frequent meaningful word on “allergy rhinitis” tweets. We observed seasonal patterns for tweets on “allergic rhinitis,” both in their frequency and sentiment – the incidence of allergic rhinitis medical visits was moderately to strongly correlated with the frequency (ρ = 0.866) and sentiment (ρ = −0.474) of tweets on “allergic rhinitis.” For tweets on “asthma,” no such patterns/correlations were observed. The average sentiment score was negative for all assessed conditions, ranging from −0.004 (“asthma”) to −0.083 (“allergic rhinitis”). Conclusions: Tweets on “allergic rhinitis” displayed a seasonal pattern regarding their frequency and sentiment, which correlated with surveillance data. No such patterns were observed for “asthma.”.54
A direct and analytical method for inverse problems under uncertainty in energy system design: combining inverse simulation and Polynomial Chaos theory
No full textThis article introduces and formalizes a novel stochastic method that combines inverse simulation with the theory of generalized Polynomial Chaos (gPC) to solve and study inverse problems under uncertainty in energy system design applications. The method is particularly relevant to design tasks where only a deterministic forward model of a physical system is available, in which a target design quantity is an input to the model that cannot be obtained directly, but can be quantified reversely via the outputs of the model. In this scenario, the proposed method offers an analytical and direct approach to invert such system models. The method puts emphasis on user-friendliness, as it enables its users to conduct the inverse simulation under uncertainty directly in the gPC domain by redefining basic algebra operations for computations. Moreover, the method incorporates an optimization-based approach to integrate supplementary constraints on stochastic quantities. This feature enables the solution of inverse problems bounding the statistical moments of stochastic system variables. The authors exemplify the application of the proposed method with proof-of-concept tests in energy system design, specifically performing uncertainty quantification and sensitivity analysis for a Multi-Energy System (MES). The findings demonstrate the high accuracy of the method as well as clear advantages over conventional sampling-based methods when dealing with a small number of stochastic variables in a system or model. However, the case studies also highlight the current limitations of the proposed method such as slow execution speed due to the optimization-based approach and the challenges associated with, for example, the curse of dimensionality in gPC.7
Decoupling Nucleation and Growth in Fast Crystallization of Phase Change Materials
No full textDisentangling nucleation and growth in materials that crystallize on the nanosecond time scale is experimentally quite challenging since the relevant processes also take place on very small, i.e., sub-micrometer length scales. Phase change materials are bad glass formers, which often crystallize rapidly. Here systematic changes in crystallization kinetics are shown in pseudo-binary compounds of GeTe and Sb2Te3 and related solids subjected to short laser pulses. Upon systematic changes in stoichiometry, the speed of crystallization changes by three orders of magnitude concomitantly with pronounced changes in stochasticity. Resolving individual grains with electron backscatter diffraction (EBSD) permits to disentangle of the process of nucleation and growth. From these experiments, supported by multiphysics simulations of crystallization, it can be concluded that high crystallization speeds with small stochasticity characterize phase change materials with fast nucleation, while compounds that nucleate slowly crystallize much more stochastically.343