Cross-calibration of the Transition Radiation Detector of AMS-02 for an Energy Measurement of Cosmic-Ray Ions

Since May 2011 the AMS-02 experiment is installed on the International Space Station and is observing cosmic radiation. It consists of several state-of-the-art sub-detectors, which redundantly measure charge and energy of traversing particles. Due to the long exposure time of AMS-02 of many years the measurement of momentum for protons and ions is limited systematically by the spatial resolution and magnetic field strength of the silicon tracker. The maximum detectable rigidity for protons is about 1.8~TV, for helium about 3.6~TV. We investigate the possibility to extend the range of the energy measurement for heavy nuclei ($Z\geq2$) with the transition radiation detector (TRD). The response function of the TRD shows a steep increase in signal from the level of ionization at a Lorentz factor $\gamma$ of about 500 to $\gamma\approx20000$, where the transition radiation signal saturates. For heavy ions the signal fluctuations in the TRD are sufficiently small to allow an energy measurement with the TRD beyond the limitations of the tracker. The energy resolution of the TRD is determined and reaches a level of about 20\% for boron ($Z=5$). After adjusting the operational parameters of the TRD a measurement of boron and carbon could be possible up to 5~TeV/nucleon.Comment: Accepted for publication in Advances in Space Researc

Factors Influencing Usage Intentions Towards a Self-service Kiosk with Biometric Authentication.

Self-service technologies have developed as helpful tools in our everyday lives while constantly being adapted to meet new challenges and requirements in today’s world. This study explores the factors influencing usage intentions towards a self-service kiosk with biometric authentication in a retail context. A quantitative study with 28 participants was conducted in a laboratory environment. Participants were asked to purchase a SIM card at a self-service kiosk. The findings revealed that convenience and relative advantage had a strong impact on usage intention. In contrast, functionality and security concerns towards biometric authentication showed no significant effects. In addition, the results indicate that usage intention affected positive word of mouth. Further analysis revealed that usage intention mediated the relationship between the significant influence factors (i.e., convenience, relative advantage) and word of mouth

Tell Me Why (I Want It That Way) – Effects of Explanations and Online Customer Reviews on Trust in Recommender Systems

Review-based recommender systems (RS) have shown great potential in helping users manage information overload and find suitable items. However, a lack of trust still impedes the widespread acceptance of RS. To increase users’ trust, research proposes various methods to generate justifications or explanations. Furthermore, online customer reviews (OCRs) are found to be a trustworthy and reliable source of information. However, it is still unclear how justifications compare to explanations in their influence on users’ trust and whether basing them on OCRs additionally adds trust. Hence, we conduct an online experiment with 531 participants and find that explanations exceed justifications in increasing users’ trust, while basing them on OCRs directly increases users’ intentions to use the system and adopt recommendations without increasing trust in the RS themselves. Unifying different research streams from review-based RS and Explainable Artificial Intelligence, we provide an overarching, holistic view on the conception of justifications and explanations

Event-Driven Duplicate Detection: A Probability-based Approach

The importance of probability-based approaches for duplicate detection has been recognized in both research and practice. However, existing approaches do not aim to consider the underlying real-world events resulting in duplicates (e.g., that a relocation may lead to the storage of two records for the same customer, once before and after the relocation). Duplicates resulting from real-world events exhibit specific characteristics. For instance, duplicates resulting from relocations tend to have significantly different attribute values for all address-related attributes. Hence, existing approaches focusing on high similarity with respect to attribute values are hardly able to identify possible duplicates resulting from such real-world events. To address this issue, we propose an approach for event-driven duplicate detection based on probability theory. Our approach assigns the probability of being a duplicate resulting from real-world events to each analysed pair of records while avoiding limiting assumptions (of existing approaches). We demonstrate the practical applicability and effectiveness of our approach in a real-world setting by analysing customer master data of a German insurer. The evaluation shows that the results provided by the approach are reliable and useful for decision support and can outperform well-known state-of-the-art approaches for duplicate detection

Ermittlung von Emissionen flüchtiger organischer Verbindungen und deren Zusammensetzung in Baden-Württemberg

Für eine Beurteilung der Umweltrelevanz von VOC-Emissionen ist somit nicht nur die Ermittlung der insgesamt emittierten Mengen erforderlich, sondern auch eine differenzierte Betrachtung einzelner Substanzen bzw. Substanzgruppen notwendig. In diesem Vortrag soll eine grobe Übersicht über die Emissionen in Baden-Württemberg gegeben werden. Für die wesentlichen Quellen werden die Emissionen für das Jahr 1985 abgeschätzt und die je nach Quelltyp unterschiedlichen Zusammensetzungen diskutiert

Efficient strategies for air pollution control in Baden-Württemberg

Neuzeitliche Waldschäden in Europa, erhöhte Ozonkonzentrationen in der Troposphäre, Ozonabbau in der Stratosphäre, Atemwegserkrankungen, Versauerung der Seen sowie andere Umweltbeeinträchtigungen haben das öffentliche Interesse auf die Luftschadstoffproblematik, als mögliche Ursache dieser Effekte, gelenkt. Wenngleich die Ursache-Wirkungs-Beziehungen zwischen Luftschadstoffemissionen und den genannten Umweltbeeinträchtigungen weder vollständig bewiesen noch in allen Einzelheiten bekannt sind, besteht vielfach Einigkeit darüber, daß Luftschadstoffe zumindest mitverantwortlich für diese Effekte sind. Die Reduzierung der Schadgasemissionen zum Schutz der Umwelt erfordert zusätzliche Ausgaben, die sich jedes Jahr zu Milliardenbeträgen summieren. Aus diesem Grund ist eine maximale Reduzierung der Emissionen mit den geringst möglichen Zusatzkosten eine wichtige umweltpolitische Zielsetzung. Dieser Beitrag stellt beispielhaft einige bisherige Forschungsarbeiten zusammen, deren Ergebnisse eine problemorientierte Unterstützung der politischen Entscheidungsträger im Hinblick auf die Verwirklichung effizienter Luftreinhaltestrategien in Baden-Württemberg bieten. Darüberhinaus werden notwendige Weiterentwicklungen der methodischen Ansätze und Systemanalysen sowie künftige Aufgabengebiete diskutiert.Damage to forests in Europe, increasing ozone-Ievels in the troposphere, ozone depletion in the stratosphere, respiratory deseases, acidification of lakes and other environmental damages have attracted public attention to the problem of air pollution as a possible cause of all these effects. Though, the cause-effect relationship between emission of air pollutants and some of those effects has neither been proven nor is the complex mechanism of environmental impact of pollutants fully understood. However, the general consent is, that the air pollutants are at least partly responsible for the above mentioned effects. Reduction of emissions of pollutants as a means of environmental protection results in additional expenditure, which adds up to annual costs of several billions of DM/year. Maximum reduction of emissions with least additional costs is therefore an important policy objective. In this contribution some research activities are summarized. their results giving an important support of political decision-makers with regard to the realization of efficient air pollution control strategies in Baden-Württemberg. Further developments of methods and systems analysis required. as well as future tasks will be discussed additionally

Nodal Disease and Survival in Oral Cancer: Is Occult Metastasis a Burden Factor Compared to Preoperatively Nodal Positive Neck?

Simple Summary Occult metastasis in oral squamous cell carcinoma patients is a feared complication. However, there are barely any existing data on survival of patients suffering from occult metastasis. This study aims to compare patients with oral squamous cell carcinoma, considering survival in occult metastases and different treatment approaches. The impact of neck involvement and occult metastasis (OM) in patients with oral squamous cell carcinoma (OSCC) favors an elective neck dissection. However, there are barely any existing data on survival for patients with OM compared with patients with positive lymph nodes detected preoperatively. This study aims to compare survival curves of patients suffering from lymph nodal metastases in a preoperatively N+ neck with those suffering from OM. In addition, clinical characteristics of the primary tumor were analyzed to predict occult nodal disease. This retrospective cohort study includes patients with an OSCC treated surgically with R0 resection with or without adjuvant chemoradiotherapy between 2010 and 2016. Minimum follow-up was 60 months. Kaplan-Meier analysis was used to compare the survival between patients with and without occult metastases and patients with N+ neck to those with occult metastases. Logistic regression was used to detect potential risk factors for occult metastases. The patient cohort consisted of 226 patients. Occult metastases occurred in 16 of 226 patients. In 53 of 226 patients, neck lymph nodes were described as suspect on CT imaging but had a pN0 neck. Higher tumor grading increased the chance of occurrence of occult metastasis 2.7-fold (OR = 2.68, 95% CI: 1.07-6.7). After 12, 24, 48 and 60 months, 82.3%, 73.8%, 69% and 67% of the N0 patients, respectively, were progression free. In the group with OM occurrence, for the same periods 66.6%, 50%, 33.3% and 33.3% of the patients, respectively, were free of disease. For the same periods, respectively, 81%, 63%, 47% and 43% of the patients in the N+ group but without OM remained disease free. The predictors for progression-free survival were a positive N status (HR = 1.44, 95% CI: 1.08-1.93) and the occurrence of OM (HR = 2.33, 95% CI: 1.17-4.64). The presence of occult metastasis could lead to decreased survival and could be a burdening factor requiring treatment escalation and a more aggressive follow-up than nodal disease detected in the preoperative diagnostic imaging

Emission data for VOC and CO with a high temporal and spatial resolution for the state of Baden-Württemberg

Im Rahmen des inzwischen abgeschlossenen Forschungsvorhabens "Zeitlicher Verlauf und räumliche Verteilung der Emissionen von flüchtigen organischen Verbindungen und Kohlenmonoxid in BadenWürttemberg" wurden Methoden entwickelt bzw. modifiziert, anhand derer für das Bezugsjahr 1985 stündliche VOC- und CO-Emissionen ausgewählter Emittentengruppen in Baden-Württemberg auf Gemeindeebene bzw. für Rasterflächen unterschiedlicher Größe abgeschätzt werden können. Die VOC-Emissionen wurden dabei in 17 Substanzgruppen untergliedert. In diesem Bericht werden neben den VOC- und CO-Gesamtemissionen im Jahr 1985 schwerpunktmäßig räumlich und zeitlich hochaufgelöste Emissionsdaten für eine Januar- und Septemberwoche dargestellt und erläutert.In the frame of a research project entitled "Temporal Variations and Spatial Distribution of Emissions of Volatile Organic Compounds and Carbon Monoxide in the State of Baden-Württemberg", which has been finished already, methods have been developed resp. rnodified that can be used to assess hourly emissions of VOC and CO for the reference year 1985 from selected source categories for each community resp. for grid elements of different size in the State of Baden-Württemberg. VOC-emissions have been subdivided into 17 classes. Yearly emissions of VOC and CO in 1985 as weIl as emission data with a high spatial and temporal resolution for one week in January and one in September are illustrated and discussed in this paper