Integrated examination of 3D imaging systems for the systematic definition in production technology

In der industriellen Produktion sind Bildverarbeitungssysteme bereits in vielen Bereichen etabliert. Auch 3D-Bildverarbeitungssysteme werden in der Produktionstechnik für die unterschiedlichsten Problemlösungen eingesetzt. Der Einsatzbereich reicht von einfacher Qualitätskontrolle über Handlingsaufgaben bis hin zu komplexen Sicherheitsfunkionen in einer Produktionsanlage. Aufgrund der stetigen Entwicklung und der Vielfältigkeit der anwendbaren Verfahren in der industriellen Bildverarbeitung stellt die Projektierung von 3D-Bildverarbeitungs- systemen oft eine Herausforderung dar. Die Problematik bei der Integration von 3D-Bildverarbeitungssystemen in der Produktionstechnik besteht oft in der Vielzahl möglicher Ansätze, den Aufgabenstellungen der Produktionsautomation mittels Bildverarbeitung gerecht zu werden. Diese Arbeit beschreibt die Entwicklung einer Methodik zur effizienten Projektierung und Entwicklung von 3D-Bildverarbeitungssystemen im praxisnahen Umfeld des Sondermaschinenbaus. Es werden zunächst die auf das System wirkenden Einflussgrößen bestimmt, die sich aus der Aufgabenstellung, dem Produktionsprozess und dessen Peripherie ergeben. Hiervon ausgehend wird ein methodisches Vorgehen definiert, das es einem Entwickler von Produktionsanlagen ermöglicht, die notwendigen Maßnahmen zur Realisierung eines effizienten und effektiven 3D-Bildverarbeitungssystems im Verbund mit dem Produktionssystem zu definieren. In den entworfenen Ansätzen im Rahmen dieser Arbeit wird zunächst analytisch betrachtet, welche Formalien zur Auswahl bzw. Eingrenzung von bildgebenden Verfahren genutzt werden und wie damit die weitere Evaluierung der Projektierung des Bildverarbeitungssystems abläuft. Im Zuge von Beispielapplikationen wird die Anwendung des vorgestellten Verfahrens explizit verdeutlicht. Des Weiteren werden in dieser Arbeit objektorientierte Methoden zur Erfassung aller relevanter Merkmale eines 3D-Bildverarbeitungssystems im Bereich der Anlagenautomation und des Sondermaschinenbaus untersucht und angewendet. Dabei werden sowohl produktionstechnische Aspekte als auch spezielle Problematiken der Bildverarbeitung möglichst allgemeingültig dargestellt. Abschließend wird das Potential dieser Methodik diskutiert und eine Einschätzung zu Anwendungsmöglichkeiten und zukünftigen Entwicklungen gegeben.Machine vison systems are suitable in many areas of production in the industrial manufacturing. As well 3D-machine-vision-systems are used as solution for diverse problems in manufacturing engineering. The area of possible application ranges from simple tasks for quality control or manipulation and handling to complex security relevant issues. On account of its continued development and the diversity of applicable methods in the field of machine vision, the project planning of 3D machine-vision-application is a challenging task. The problem with the integration of 3D-vision-systems is the big variety of possibilities to solve problems in plant automation by means of machine-vision methods. This thesis describes the development of a method for the efficient project planning and design of 3D-machine-vision-systems in the field of special machine construction. First the influence variables effecting the vision-system are determined, which are arising from the task, the production process and the periphery of the process. Based on these characteristics a methodical approach is defined. This approach enables developers of production facilities to define the specific measures for implementing an effective and efficient machine-vision-setup, which is well integrated in the production process. The approach of this thesis is an analytical observation to describe the formalities of the selection of imaging sensors and how this decision is influencing the further project planning and evaluation procedure. In the context of example application, the application of the approach is presented explicit. Furthermore, object-oriented methods are investigated regarding their ability to gather all relevant features of a 3D-machine-vision system in the field of plant automation and special machine construction. Both aspects concerning the production and problems of machine vision are described universally. In conclusion, the potential of this approach is discussed and an evaluation of possibilities and further development is given

Towards Analyzing the Bias of News Recommender Systems Using Sentiment and Stance Detection

News recommender systems are used by online news providers to alleviate information overload and to provide personalized content to users. However, algorithmic news curation has been hypothesized to create filter bubbles and to intensify users' selective exposure, potentially increasing their vulnerability to polarized opinions and fake news. In this paper, we show how information on news items' stance and sentiment can be utilized to analyze and quantify the extent to which recommender systems suffer from biases. To that end, we have annotated a German news corpus on the topic of migration using stance detection and sentiment analysis. In an experimental evaluation with four different recommender systems, our results show a slight tendency of all four models for recommending articles with negative sentiments and stances against the topic of refugees and migration. Moreover, we observed a positive correlation between the sentiment and stance bias of the text-based recommenders and the preexisting user bias, which indicates that these systems amplify users' opinions and decrease the diversity of recommended news. The knowledge-aware model appears to be the least prone to such biases, at the cost of predictive accuracy

A high-flux BEC source for mobile atom interferometers

Quantum sensors based on coherent matter-waves are precise measurement devices whose ultimate accuracy is achieved with Bose-Einstein condensates (BEC) in extended free fall. This is ideally realized in microgravity environments such as drop towers, ballistic rockets and space platforms. However, the transition from lab-based BEC machines to robust and mobile sources with comparable performance is a challenging endeavor. Here we report on the realization of a miniaturized setup, generating a flux of $4 \times 10^5$ quantum degenerate $^{87}$Rb atoms every 1.6$\,$s. Ensembles of $1 \times 10^5$ atoms can be produced at a 1$\,$Hz rate. This is achieved by loading a cold atomic beam directly into a multi-layer atom chip that is designed for efficient transfer from laser-cooled to magnetically trapped clouds. The attained flux of degenerate atoms is on par with current lab-based BEC experiments while offering significantly higher repetition rates. Additionally, the flux is approaching those of current interferometers employing Raman-type velocity selection of laser-cooled atoms. The compact and robust design allows for mobile operation in a variety of demanding environments and paves the way for transportable high-precision quantum sensors.Comment: 22 pages, 6 figure

NeMig -- A Bilingual News Collection and Knowledge Graph about Migration

News recommendation plays a critical role in shaping the public's worldviews through the way in which it filters and disseminates information about different topics. Given the crucial impact that media plays in opinion formation, especially for sensitive topics, understanding the effects of personalized recommendation beyond accuracy has become essential in today's digital society. In this work, we present NeMig, a bilingual news collection on the topic of migration, and corresponding rich user data. In comparison to existing news recommendation datasets, which comprise a large variety of monolingual news, NeMig covers articles on a single controversial topic, published in both Germany and the US. We annotate the sentiment polarization of the articles and the political leanings of the media outlets, in addition to extracting subtopics and named entities disambiguated through Wikidata. These features can be used to analyze the effects of algorithmic news curation beyond accuracy-based performance, such as recommender biases and the creation of filter bubbles. We construct domain-specific knowledge graphs from the news text and metadata, thus encoding knowledge-level connections between articles. Importantly, while existing datasets include only click behavior, we collect user socio-demographic and political information in addition to explicit click feedback. We demonstrate the utility of NeMig through experiments on the tasks of news recommenders benchmarking, analysis of biases in recommenders, and news trends analysis. NeMig aims to provide a useful resource for the news recommendation community and to foster interdisciplinary research into the multidimensional effects of algorithmic news curation.Comment: Accepted at the 11th International Workshop on News Recommendation and Analytics (INRA 2023) in conjunction with ACM RecSys 202

Status of the GEO 600 squeezed-light laser

In the course of the high-frequency upgrade of GEO 600, its optical configuration was extended by a squeezed-light laser [1]. Recently, a non-classically enhanced measurement sensitivity of GEO 600 was reported [2]. In this paper, a characterization of the squeezed-light laser is presented. Thereupon, the status of the integration into GEO 600 is reviewed, focussing on the sources of optical loss limiting the shot noise reduction by squeezing at the moment. Finally, the possibilities for a future loss reduction are discussed.Comment: Proceeding of the 9th Edoardo Amaldi Conference on Gravitational Wave

Michelson interferometer with diffractively-coupled arm resonators in second-order Littrow configuration

Michelson-type laser-interferometric gravitational-wave (GW) observatories employ very high light powers as well as transmissively- coupled Fabry-Perot arm resonators in order to realize high measurement sensitivities. Due to the absorption in the transmissive optics, high powers lead to thermal lensing and hence to thermal distortions of the laser beam profile, which sets a limit on the maximal light power employable in GW observatories. Here, we propose and realize a Michelson-type laser interferometer with arm resonators whose coupling components are all-reflective second-order Littrow gratings. In principle such gratings allow high finesse values of the resonators but avoid bulk transmission of the laser light and thus the corresponding thermal beam distortion. The gratings used have three diffraction orders, which leads to the creation of a second signal port. We theoretically analyze the signal response of the proposed topology and show that it is equivalent to a conventional Michelson-type interferometer. In our proof-of-principle experiment we generated phase-modulation signals inside the arm resonators and detected them simultaneously at the two signal ports. The sum signal was shown to be equivalent to a single-output-port Michelson interferometer with transmissively-coupled arm cavities, taking into account optical loss. The proposed and demonstrated topology is a possible approach for future all-reflective GW observatory designs

Long-term stable squeezed vacuum state of light for gravitational wave detectors

Currently, the German/British gravitational wave detector GEO600 is being upgraded in course of the GEO-HF program. One part of this upgrade consists of the integration of a squeezed light laser to nonclassically improve the detection sensitivity at frequencies where the instrument is limited by shot noise. This has been achieved recently [1]. The permanent employment of squeezed light in gravitational wave observatories requires a long-term stability of the generated squeezed state. In this paper, we discuss an unwanted mechanism that can lead to a varying squeezing factor along with a changing phase of the squeezed field. We present an extension of the implemented coherent control scheme [2] that allowed an increase in the long-term stability of the GEO600 squeezed light laser. With it, a quantum noise reduction by more than 9 dB in the frequency band of 10 Hz - 10 kHz was observed over up to 20 hours with a duty cycle of more than 99%

Specific Varicella-Related Complications and Their Decrease in Hospitalized Children after the Introduction of General Varicella Vaccination: Results from a Multicenter Pediatric Hospital Surveillance Study in Bavaria (Germany)

Hagemann C, Krämer A, Grote V, Liese JG, Streng A. Specific Varicella-Related Complications and Their Decrease in Hospitalized Children after the Introduction of General Varicella Vaccination: Results from a Multicenter Pediatric Hospital Surveillance Study in Bavaria (Germany). Infectious Diseases and Therapy. 2019;8(4):1-15.Background Universal varicella vaccination (UVV) for children introduced in Germany in 2004 resulted in a significant overall decline of varicella-related hospitalizations (VRHs). We investigated the incidence of specific types of varicella-related complications (VRCs) in hospitalized children and the impact of UVV on VRCs during the first 7 years of UVV. Methods Children < 17 years of age hospitalized with an ICD-10-based (International Classification of Diseases, 10th Revision) discharge diagnosis of varicella were identified as VRH in pediatric hospitals in Bavaria by annual standardized data queries of the hospital databases (2005–2011). For each VRH, the hospitals reported basic demographic data, duration of hospital stay, all diagnostic and procedural codes, and outcome. VRCs were reported overall, per year, and by immune status. Complication rates were calculated as mean number per complication category per hospital and per year; VRC trends over time were assessed by linear regression. Results Between 78% (2005) and 61% (2011) of Bavarian hospitals participated and reported a total of 1263 VRHs. Specific VRCs were reported in 954 (76%) children. Complication rates per hospital and year decreased from 6.7 [95% confidence interval (CI): 5.1–8.3] in 2005 to 1.5 (95% CI: 0.8–2.3) in 2011, with the strongest reduction of 90% in children < 5 years of age from 5.3 (95% CI: 4.0–6.6) in 2005 to 0.5 (95% CI: 0.1–0.9) in 2011. Significant decreases were observed for children with upper respiratory tract (URT, by 97%), lower respiratory tract (LRT, by 90%), skin (by 81%), gastrointestinal (by 78%), and neurologic (by 65%) VRCs. Forty-eight children with VRCs were immunocompromised; their annual rate decreased by 87%. Discussion Corresponding to increasing varicella vaccination coverage in the population, the incidence of VRC decreased by 77% from 2005 to 2011, with the most substantial decrease in the target group for UVV. Conclusion Within 7 years, UVV in Germany led to a decrease of about 77% of all types of VRCs, with the highest reductions observed for VRCs of the respiratory tract

Towards analyzing the bias of news recommender systems using sentiment and stance detection

News recommender systems are used by online news providers to alleviate information overload and to provide personalized content to users. However, algorithmic news curation has been hypothesized to create filter bubbles and to intensify users' selective exposure, potentially increasing their vulnerability to polarized opinions and fake news. In this paper, we show how information on news items' stance and sentiment can be utilized to analyze and quantify the extent to which recommender systems suffer from biases. To that end, we have annotated a German news corpus on the topic of migration using stance detection and sentiment analysis. In an experimental evaluation with four different recommender systems, our results show a slight tendency of all four models for recommending articles with negative sentiments and stances against the topic of refugees and migration. Moreover, we observed a positive correlation between the sentiment and stance bias of the text-based recommenders and the preexisting user bias, which indicates that these systems amplify users' opinions and decrease the diversity of recommended news. The knowledge-aware model appears to be the least prone to such biases, at the cost of predictive accuracy.Comment: Accepted at the 2nd International Workshop on Knowledge Graphs for Online Discourse Analysis (KnOD 2022) collocated with The Web Conference 2022 (WWW'22), 25-29 April 2022, Lyon, Franc