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Bewertungsportale, in denen man seine Meinung zu Gütern oder Dienstleistungen äußern kann, sind seit einiger Zeit bekannt und verbreitet. Kann durch sie die Nachfrageseite eine neue, informationsgestützte Machtposition erlangen? Ein Projektteam des Instituts für Versicherungswesen an der TH Köln (ivwKöln) hat sich dieser Frage gewidmet und zunächst kontrastierende Hypothesen aus der Gegenüberstellung des informationsökonomischen und des diffusionstheoretischen Ansatzes entwickelt. Eine Hypothesengruppe bezog sich auf die Frage, von welchen Faktoren die Nachfrage und Wertschätzung von Bewertungsportalen abhängig ist, eine andere unterstellte, dass globale Produkteigenschaften auf der Dimension Such-, Erfahrungs-, Vertrauenseigenschaften sich auf die Nutzung von Portalen auswirkten. Untersucht wurden deshalb sehr unterschiedliche Portale, für Kleidung, Restaurants, Ärzte und Versicherungen. Empirische Grundlage war eine online-gestützte Befragung mit einem Convenience-Sample von 114 Befragten. Neben Studierenden des ivwKöln wurden Angestellte und Personen im Rentenalter zur Teilnahme motiviert, um eine breite Altersstreuung zu erreichen. Die Ergebnisse zur ersten Hypothesengruppe sprechen eindeutig für den diffusionstheoretischen Ansatz. Bei den beiden analysierbaren Portalen (Restaurants und Ärzte) ergibt sich: Entscheidende Faktoren für den Besuch von Restaurantportalen sind Internetaffinität, Alter, Produktinvolvement und Meinungsführerschaft; für den Besuch von Ärzteportalen sind es Internetaffinität und Produktinvolvement. Damit ist auch klar, dass sich die Machtposition der Nachfrager durch die Nutzung von Portalen allenfalls selektiv verstärkt. Die zweite Hypothese, dass Portalnutzung auch von globalen Produkteigenschaften abhängig sei, ließ sich nicht bestätigen.
Surrogate-assisted optimization has proven to be very successful if applied to industrial problems. The use of a data-driven surrogate model of an objective function during an optimization cycle has many bene ts, such as being cheap to evaluate and further providing both information about the objective landscape and the parameter space. In preliminary work, it was researched how surrogate-assisted optimization can help to optimize the structure of a neural network (NN) controller. In this work, we will focus on how surrogates can help to improve the direct learning process of a transparent feed-forward neural network controller. As an initial case study we will consider a manageable real-world control task: the elevator supervisory group problem (ESGC) using a simplified simulation model. We use this model as a benchmark which should indicate the applicability and performance of surrogate-assisted optimization to this kind of tasks. While the optimization process itself is in this case not onsidered expensive, the results show that surrogate-assisted optimization is capable of outperforming metaheuristic optimization methods for a low number of evaluations. Further the surrogate can be used for signi cance analysis of the inputs and weighted connections to further exploit problem information.
The performance of optimization algorithms relies crucially on their parameterizations. Finding good parameter settings is called algorithm tuning. Using
a simple simulated annealing algorithm, we will demonstrate how optimization algorithms can be tuned using the Sequential Parameter Optimization Toolbox (SPOT). SPOT provides several tools for automated and interactive tuning. The underlying concepts of the SPOT approach are explained. This includes key techniques such as exploratory fitness landscape analysis and response surface methodology. Many examples illustrate
how SPOT can be used for understanding the performance of algorithms and gaining insight into algorithm behavior. Furthermore, we demonstrate how SPOT can be used as an optimizer and how a sophisticated ensemble approach is able to combine several meta models via stacking.
To maximize the throughput of a hot rolling mill,
the number of passes has to be reduced. This can be achieved by maximizing the thickness reduction in each pass. For this purpose, exact predictions of roll force and torque are required. Hence, the predictive models that describe the physical behavior of the product have to be accurate and cover a wide range of different materials.
Due to market requirements a lot of new materials are tested and rolled. If these materials are chosen to be rolled more often, a suitable flow curve has to be established. It is not reasonable to determine those flow curves in laboratory, because of costs and time. A strong demand for quick parameter determination and the optimization of flow curve parameter with minimum costs is the logical consequence. Therefore parameter estimation and the optimization with real data, which were collected during previous runs, is a promising idea. Producers benefit from this data-driven approach and receive a huge gain in flexibility when rolling new
materials, optimizing current production, and increasing quality. This concept would also allow to optimize flow curve parameters, which have already been treated by standard methods. In this article, a new data-driven approach for predicting the physical behavior of the product and setting important parameters is presented.
We demonstrate how the prediction quality of the roll force and roll torque can be optimized sustainably. This offers the opportunity to continuously increase the workload in each pass to the theoretical maximum while product quality and process stability can also be improved.
Resilienz bezeichnet die Fähigkeit eines Systems nach einem exogenen Schock wieder in den Normalzustand zurück zu kehren. Wenn beispielsweise durch eine Katastrophe die Wasserversorgung der Bevölkerung nicht mehr gewährleistet ist, so geht es nicht um die Frage, was die Wiederherstellung der Versorgung kostet, sondern mit welchen Maßnahmen die Wiederherstellung überhaupt möglich ist. Eine Versorgungsstruktur ist also so zu gestalten, dass im Vorfeld schon klar ist, wie sie im Katastrophenfall wieder hergestellt werden kann. Bezogen auf ein Wirtschaftsunternehmen ist die Frage nach der Resilienz eine Erweiterung des klassischen Risikomanagements. Das 11. FaRis & DAV-Symposium bot einen Einblick in die Resilienzanalyse beim Katastrophenschutz, zeigte wie ein Resilienz-Management für ein Wirtschaftsunternehmen aussehen kann und schließlich wurde das Resilienz-Konzept auf Fragen der Versicherungsaufsicht übertragen.
Recovery after extreme events - Lessons learned and remaining challenges in Disaster Risk Reduction
(2017)
Disasters such as the Indian Ocean Tsunami 2004, but also other extreme events such as cyclones, earthquakes and tsunami substantially affect the lives of many thousands of people - they are events radically and abruptly changing local circumstances and needs. At the same time they can significantly reshape global paradigms of Disaster Risk Reduction (DRR). Such events also bring to light the challenges in coordinating assistance from the “global community” with all the intended and un-intended effects. Two of the most pressing questions therefore are whether the different actors have learned from the disaster and whether processes of DRR and livelihood improvements have been implemented successfully.
This volume gathers selected papers addressing the following key questions:
- Lessons learned: Which lessons have been learned in a way that a difference can be seen today for the livelihoods and resilience of local people in the regions affected?
- Lessons to be Learned: Despite the body of knowledge created and reflected in a good number of lessons learned studies – what is still unsolved or needs to be emphasized?
- Monitoring and evaluation: Which DRR measures have been perpetuated and how can they be monitored and evaluated scientifically?
- Resilience effects and (unintended) side-effects: Which coping, recovery and adaptation measures are
supported by the resilience paradigm and which other areas are side-lined, neglected or even contrary to the intended effects?
- Dynamics in risk: In which cases has resilience building taken place? In which cases have ulnerabilities
been shifted internally or new vulnerabilities been created?
- Relocation/resettlement: How did the relocation/resettlement process of displaced people take place and what are its long-term effects?
- Urban-rural divide: How have DRR measures in urban vs. rural areas differed and which linkages but also rifts in rehabilitation and reconstruction initiatives can be observed between the two?
- Early warning: What is the future of Early Warning and how can important top-down information chains benefit from or be balanced with bottom-up feedback of users and affected people?
It appears that extreme disaster events spark a plethora of actions in academia, civil society, media, policy, private sector and other organisations. Tragic, as such disasters are, they offer incentives for learning, locally and globally. Lately, disaster impacts have in many cases been detracted through the application of knowledge and experience gained from previous events. However, there are still a number of challenges with regards to learning from past disasters
In der vorliegenden Arbeit wird ausgehend von einer jährlichen inhomogenen Markov-Kette eine unterjährliche bewertete inhomogene Markov-Kette konstruiert. Die Konstruktion der unterjährlichen Übergangsmatrizen basiert auf der Taylorreihe der Potenzfunktion bzw. deren Partialsummen. Dieser Ansatz ist eine Verallgemeinerung des Falls, dass die unterjährlichen Übergangsmatrizen durch Interpolation der jährlichen Übergangsmatrizen und der Einheitsmatrix definiert werden. Anschließend liegt der Fokus der Arbeit auf der Verteilung der Zufallsvariablen „Barwert des Zahlungsstroms“ bzw. auf der zugehörigen charakteristischen Funktion, einem EDV-technischen Verfahren zur Berechnung der Momente der Zufallsvariablen und dessen Anwendung in zwei Fallbeispielen.
Social learning enables multiple robots to share learned experiences while completing a task. The literature offers examples where robots trained with social learning reach a higher performance compared to their individual learning counterparts. No explanation has been advanced for that observation. In this research, we present experimental results suggesting that a lack of tuning of the parameters in social learning experiments could be the cause. In other words: the better the parameter settings are tuned, the less social learning can improve the system performance.
Verunreinigungen im Wassernetz können weite Teile der Bevölkerung unmittelbar gefährden. Gefahrenpotenziale bestehen dabei nicht nur durch mögliche kriminelle Handlungen und terroristische Anschläge. Auch Betriebsstörungen, Systemfehler und Naturkatastrophen können zu Verunreinigungen führen.
When designing or developing optimization algorithms, test functions are crucial to evaluate
performance. Often, test functions are not sufficiently difficult, diverse, flexible or relevant to real-world
applications. Previously,
test functions with real-world relevance were generated by training a machine learning model based on
real-world data. The model estimation is used as a test function.
We propose a more principled approach using simulation instead of estimation.
Thus, relevant and varied test functions
are created which represent the behavior of real-world fitness landscapes.
Importantly, estimation can lead to excessively smooth test functions
while simulation may avoid this pitfall. Moreover, the simulation
can be conditioned by the data, so that the simulation reproduces the training data
but features diverse behavior in unobserved regions of the search space.
The proposed test function generator is illustrated with an intuitive, one-dimensional
example. To demonstrate the utility of this approach it
is applied to a protein sequence optimization problem.
This application demonstrates the advantages as well as practical limits of simulation-based
test functions.