Are We Ready Yet? Safety Assessment of Advanced Driver Assistance Systems (ADAS) and Highly Automated Driving (HAD) through Monte Carlo Simulations Using Cognitive Driver Behavior Models

In recent years, the automotive sector has seen a steady increase in the introduction of new Advanced Driving Assistance Systems (ADAS). This trend toward more complex systems will become even more pronounced with regard to Highly Automated Driving (HAD). In addition to the expected benefits of ADAS and HAD (increased comfort, efficiency, and safety), it is important to eliminate risks as much as possible to ensure that the system does not introduce new critical situations or road traffic accidents. Due to the increasing interaction of systems with the driver and their environment, it is no longer sufficient to investigate the system in isolation. There is also a need to investigate how the driver and the environment interact with the new system. Furthermore, the functional scope of the systems is expanding to cover entire application domains, such as highways and in the future rural and urban areas. This results in a significant increase in the number of parameters and scenarios that require testing for approval of these new technologies. This means that the scenario space to be analyzed is constantly expanding, which poses increasing problems for safety assessments. The expected number of test kilometers required to validate HAD is too large to be cost- and time-effective through real-world testing. This is why virtual safety assessments are necessary. In this context, the present thesis investigates whether virtual safety assessments can be efficiently performed today through Monte Carlo simulations using cognitive driver behavior models. The body of the thesis consists of four articles that consider different aspects of the safety assessment. Article 1 derives the cognitive core functions that driver behavior models must implement to display the causes and mechanisms of human error. This way, driver behavior models are able to map all hazard levels of realistic traffic, including normal traffic, critical situations, and road traffic accidents. By mapping the interactions of road users, cognitive models thus form the basis for the virtual safety assessment of ADAS and HAD systems. Due to the lack of existing cognitive driver behavior models that implement these cognitive core functions, the Driver Reaction Model (DReaM), a new driver behavior model, was developed and continuously improved as part of this work. Article 2 outlines a calibration and validation strategy, using DReaM as an example, to investigate whether driver behavior models are suitable for safety assessments, mapping all levels of realistic traffic. Subsequently, Article 3 estimates the time required to perform Monte Carlo studies for safety assessments, again using DReaM as an example. Therefore, an optimistic and pessimistic estimation is generated based on the minimum number of runs (MNR) required to simulate an exemplary traffic scenario. In summary, Articles 1–3 examine the quality of driver behavior models and the time required to perform safety-related studies. This lays the foundation for determining whether efficient safety assessments are feasible. Finally, Article 4 exemplarily assesses an urban Automatic Emergency Braking (AEB) system using DReaM to outline the overall virtual assessment methodology. Based on Article 4 and the findings of Article 1–3, minimal requirements are defined for improving and standardizing the virtual safety assessment process. These requirements aim to improve the reliability of safety assessments and enhance the comparability of results across various studies and model

Use of digestive gland explant cultures from blue mussels (Mytilus edulis) to assess biomarker effects of single and co-exposure of environmental contaminants

Urbanisering og økt sjøtrafikk rundt Tromsø øker presset på lokale marine økosystemer. Det er avgjørende å finne egnede metoder for å overvåke virkningene av menneskelige aktiviteter på havbestandene. Virvelløse dyr, som muslinger, har vist seg å være nyttige som bioindikatorer for miljøendringer, og passende modeller for marin økotoksikologi. Bruken av ex vivo-metoder gjør det mulig å studere spesifikke cellulære responser, og har et eksperimentelt design med høy økologisk relevans. I denne studien ble fordøyelseskjertlene i blåskjell (Mytilus edulis) utsatt for et utvalg av miljøforbindelser som forventes å bli funnet utenfor Tromsø, for å evaluere deres potensielle giftige påvirkninger. To eksperimenter ble utført, hvor eksplanter ble eksponert for m-xylen og BDE-99 i det første eksperimentet, og CdCl2 og østradiol-17-b i det andre eksperimentet. Dopaminnivåer ble påvist og kvantifisert i alle 48 prøver (kvantifiseringsgrense (LOQ)=52 pg/mg). Nivåene av serotonin var bare kvantifiserbare i 9 av de 48 prøvene (LOQ=150 pg/mg). Ekstraksjonen ga varierende ekstraksjonsutbytte, 1.0-45.2% for dopamin og 12.4-79.7% for serotonin. Resultatene indikerer en synergistisk effekt fra sameksponering av m-xylen og BDE-99, med 1.6 ganger høyere dopaminnivå sammenlignet med ren m-xylen-eksponering, og 2.2 ganger høyere dopaminnivå sammenlignet med ren BDE-99-eksponering. I tillegg reduserte sameksponering av CdCl2 og østradiol-17-b nivået av dopamin henholdsvis 2.2 ganger og 1.8 ganger, noe som antyder en mulig interaksjon av kadmium på østrogenreseptoren. De endrede nivåene av dopamin og serotonin i muslinger som er eksponert for disse kjemikaliene, viser mulige effekter av sameksponering for kjemiske blandinger i det marine miljøet rundt Tromsø.Strong urbanization and increased marine traffic around Tromsø are increasing the pressure on local marine ecosystems. Finding suitable methods for monitoring the impacts of human activities on marine populations is crucial. Invertebrates, such as bivalves, have been shown to be useful as bioindicators of environmental change, and appropriate models for marine ecotoxicology. The use of ex vivo methods allows for studying specific cellular responses, and have an experimental design with high ecological relevance. In this study, digestive glands of blue mussels (Mytilus edulis) were exposed to a selection of environmental compounds expected to be found outside Tromsø, to evaluate their toxic impacts. Two experiments were carried out, exposing explants to m-xylene and BDE-99 in the first experiment, and CdCl2 and estradiol-17-b in the second experiment. Dopamine levels were detected and quantified in all 48 samples (limit of quantification (LOQ) = 52 pg/mg). The levels of serotonin were quantifiable only in 9 of the 48 samples (LOQ = 150 pg/mg). The extraction yielded variable recoveries, 1.0-45.2% for dopamine and 12.4-79.7% for serotonin. The results indicate a synergistic effect from co-exposure of m-xylene and BDE-99, with 1.6-fold higher dopamine levels compared to single m-xylene exposure, and 2.2-fold higher dopamine levels compared to single BDE-99 exposure. In addition, co-exposure of CdCl2 and estradiol-17-b reduced the level of dopamine 2.2-fold and 1.8-fold respectively, suggesting a possible interaction of cadmium on the estrogen receptor. The altered levels of dopamine and serotonin in bivalves co-exposed to these chemicals demonstrates possible impacts of co-exposure to chemical mixtures within the marine environment surrounding Tromsø

A μ-biomimetic uncooled infrared psensor based on the infrared receptors of <em>Melanophila acuminata</em>

The pyrophilous beetle Melanophila acuminata possesses an organ sensitive to IR radiation. It employs a photomechanic detection principle: A liquid filled pressure chamber is heated by absorbing the radiation. The liquid expands and leads to the deflection of a mechanosensitive dendrite. In addition, a sophisticated compensation mechanism prevents the build-up of large pressures. In this work, a biomimetic IR sensor based on the IR receptors of Melanophila acuminata is developed by means of micro systems technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system. Absorption of IR radiation by one of the chambers leads to the heating and expansion of a liquid. The increasing pressure deflects a membrane which is part of a plate capacitor with a diameter of 500 μm and an electrode distance of 500 nm. The micro-fluidic system and the second chamber represent a fluidic low-pass filter, preventing slow, but large pressure changes. A theoretical model is developed which is able to predict the modulation frequency dependent response. It allows to calculate the filter properties of the compensation mechanism which is verified by an experimental test. A simplified sensor without the compensation mechanism is manufactured to analyse the influence of several parameters on the sensor’s sensitivity. Finally, a solution for the fabrication of the μ-capacitor is presented. The large aspect ratio between electrode diameter and distance prevents to use a standard sacrificial layer process. The obtained capacitors pave the way to fabricate the complete full-featured sensor

Studien zur Totalsynthese von Myxovalargin und Darstellung einer Myxovalargin-Bibliothek

Myxovalargin, ein lineares Peptid bestehend aus 14 Aminosäuren (AS), welches am C-Terminus mit 3-Methylbutansäure beginnt und am N-Terminus mit dem Amin Agmitin endet, wurde im Jahr 1981 aus dem Bakterium Myxococcus fulvus Mx f65 isoliert und entstammte ursprünglich einer Bodenprobe der Kaiserstuhl-Gebirge. Neben der nicht-kanonischen AS β-Tyrosin beinhaltet die Struktur des Myxovalargins Dehydrovalin und (E)-Dehydroisoleucin, Aminosäuren, deren Synthesen einen zentralen Aspekt dieser Arbeit darstellen. Seine bakterizide Wirkung gegenüber GRAM-positiven Bakterien beruht auf der Inhibierung der Proteinbiosynthese und macht das Myxovalargin zu einem Vertreter der Peptid-Antibiotika. Während ein Großteil der Aminosäuresequenz durch einen hohen Valin-Anteil sehr unpolar ist, besitzt das Peptid durch die Agmatin- und Arginin-Seitenketten einen kationischen Charakter in wässriger Lösung. Hieraus ergeben sich Sekundärinteraktionen mit der Zellmenbran und voraussichtlich auch die gemessene, nicht unerhebliche cyctotoxische Wirkung. Der erste Teil dieser Promotionsschrift befasst sich mit den Studien zur Totalsynthese des Myxovalargins und damit, wie ein Dipeptid und ein Tetrapeptid synthetisiert werden können, welche jeweils einmal Dehydrovalin beinhalten. Es wird gezeigt, wie der Baustein 3-Nitrovalin verwendet werden kann, um Doppelbindungen in Peptiden durch die Eliminierung der NO2-Funktion aufzubauen, was durch Verseifungsbedingungen oder den Einsatz starker Aminbasen gelingt. Außerdem befasst sich der erste Teil damit wie die Synthese eines Tripeptides, welches Dehydroisoleucin beinhaltet mithilfe einer Kupfer-katalysierten Kreuzkupplung gelingt, welche ein Vinyliodid und ein primäres Amid als Substrate verwendet. Das Vinyliodid konnte in der erforderlichen (E)-Konfiguration durch eine Cuprat-Addition an einen 2-Butinester gewonnen werden. Der zweite Teil dieser Arbeit handelt von der Synthese von vereinfachten Myxovalargin-Derivaten, welche für einen Festphasen-Ansatz optimiert werden und zwar mit dem Ziel, Informationen zu den Struktur-Wirk-Beziehungen der Dehydro-ASs zu erhalten und auf diese Weise zu überprüfen, ob diese eine Rolle für die biologische Aktivität spielen. Folglich werden Bestrebungen unternommen, zunächst alle Dehydroaminosäuren durch Kanonische Aminosäuren zu ersetzen. Im Laufe dieser Synthesestudien wurden entsprechend erste Erkenntnisse gewonnen, um Myxovalargin und seine Derivate unter den Bedingungen der Festphasenpeptidsynthese zugänglich zu machen.Myxovalargin, a linear peptide containing 14 amino acids (AA) and starting with 3-methylbutanic acid at its N-terminus and terminated with the amine agmatine at its C-terminus, was isolated from Myxococcus fulvus Mx f65 in 1981 after extraction from a soil sample of the Kaiserstuhl mountains. Beside the non-canonical AA β-tyrosine the structure of Myxovalargin contains dehydrovaline and dehydro-isoleucine, amino acids, whose syntheses represent the core of this work. Its bactercidal activity against GRAM-positve bacteria stems from the inhibition of protein synthesis and makes Myxovalargin a member of the peptide antibiotics. The structure of Myxovalargin is dominated by valine making its sequence unpolar to a great extend. But the peptide also contains agmatine and arginine sidechains making the molecule cationic in aqueous solution, which is supposed to cause cytotoxicity by secondary interactions with cell membranes. The first part of this work covers efforts towards the total synthesis of Myxovalargin, especially strategies on how to synthesize a dipeptide and a tetrapeptide containing a single dehydro-valine, respectively. It will be demonstrated, how the building block 3-NO2-valine can be used to build up α,β-alkenes in peptides by elimination of the NO2-group, which is achieved by saponification or by the use of strong amine bases. Furthermore, the first part will cover the synthesis of an (E)-dehydroisoleucine containing tripeptide, that can be achieved via copper-mediated cross-coupling starting from a primary amide and a vinyl iodide, whose (E)-selective synthesis was possible via a syn-selective cuprate-addition to a 2-pentyne ester. The second part of this work will be about the syntheses of simplified Myxovalargin derivatives. which are optimized for a solid phase approach with the main goal of getting insights into the structure-activity relationship of dehydo AAs and thus verifying their importance to the biologic activity. Therefore progress towards derivatives free of dehydro AAs has been pursued, replacing those AAs through canonical ones. In the course of these studies first insights into synthesizing Myxovalargin and its derivatives under solid-phase conditions were gained

Tigers vs Lions: Towards Characterizing Solitary and Group User Behavior in MMORPG

The development of Internet technologies enables software developers to build virtual worlds such as Massively Multi-Player Online Role-Playing Games (MMORPGs). The population of such games shows super-linear growing tendency. It is estimated that the number of Internet users subscribed in MMORPGs is more than 22 million worldwide [1]. However, only little is known about the characteristics of traffic generated by such games as well as the behavior of their subscribers. In this paper, we characterize the traffic behavior of World of Warcraft, the most subscribed MMORPG in the world, by analyzing Internet traffic data sets collected from a European tier-1 ISP in two different time periods. We find that World of Warcraft is an influential application regarding the time spent by users (1.76 and 4.17 Hours/day on average in our measurement), while its traffic share is comparatively low (< 1%). In this respect, we look at the World of Warcraft subscriber’s gaming behavior by categorizing them into two different types of users (solitary users and group users) and compare these two groups in relation to the playing behavior (duration as the metric) and the in-game behavior (distance as the metric)