Kolloq. Prof. Dr. Vitali Gretschko, topic: Sequential Procurement
Thursday, December 6, 2018, at 4:00 pm, FMI 01.10.033 (MI-Building, Campus Garching)
We analyze the problem of a buyer who chooses a supplier for a long-term relationship via auction. The buyer cannot commit that she will not renegotiate the terms of the contract with the chosen supplier in the long run. As the profits in the renegotiation depend on the buyer's information about the suppliers costs, suppliers will be cautious about the information they reveal during the procurement auction. We show that, on one hand, first-price auctions may perform poorly in terms of efficiency and buyer surplus as suppliers may pool on a high bid to conceal information. On the other hand, second-price auctions retain their efficient equilibrium and generate substantial buyer surplus. We demonstrate that, in general, neither first- nor second-price auction are optimal. We derive the optimal mechanism and show that it manages information by concealing the winning bid from the buyer with a positive probability.
Vitali Gretschko is head of the ZEW Research Group "Market Design" and Professor of Market Design at the University of Mannheim. He studied mathematics at the University of Münster before working as a business consultant at Accenture. Between 2009 and 2012 Gretschko completed a doctoral degree in economics at the University of Cologne. During this time he spent nine months as a guest researcher at Yale University in Connecticut. Having completed his doctorate, Vitali Gretschko became a postdoctoral researcher at the University of Cologne and worked as a project leader at TWS Partners. Vitali Gretschko's research interests extend across the field of market design, although he is particularly interested in mechanism design, applied auction theory and contract theory.
Martin Bichler Phone: +49.89.289.17500
Kolloq. Prof. Blaise Genest, topic: Distribution-based objectives for Markov Decision Processes
Monday, 26th of November 2018, 2:00 pm, FMI 00.12.019 (MI-Building, Campus Garching)
In this talk, we consider a population represented in a fluid/continuous way. A configuration of the population is represented by a distribution over states, and the actions of the controller is represented by a MDP. In this setting, we are interested in considering distribution-based objectives, that is objective talking about the distribution over states (=the configuration of the population). This class of objectives gives rise to an interesting trade-off between full and partial information. As in full observation, the strategy in the MDP can depend on the state of the system, but similar to partial information, the strategy needs to account for all the states at the same time. In this talk, we focus on two safety problems that arise naturally in this context, namely, existential and universal safety. Given an MDP A and a closed and convex polytope H of probability distributions over the states of A, the existential safety problem asks whether there exists some distribution ? i n H and a strategy of A, such that starting from ? and repeatedly applying this strategy keeps the distribution forever in H. The universal safety problem asks whether for all distributions in H, there exists such a strategy of A which keeps the distribution forever in H. Further, we compare these results with existential and universal safety problems for Rabin's probabilistic finite-state automata (PFA), the subclass of Partially Observable MDPs which have zero observation. Compared to MDPs, strategies of PFAs are not state dependent.
Joint work with S. Akshay and Nikhil Vyas.
Kolloq. Prof. Dr. Rainer Goebel, topic: High-Resolution Human Functional Brain Imaging: New insights for biological models of cognitive functions
Tuesday, 26th of June 2018, 2:30 pm, MW 1801 (ME-Building, Campus Garching)
Wednesday, 20th of June 2018, 16:45 pm, FMI BC2 0.01.17 (MI-Building, Campus Garching)
Kolloq. Prof. Nicolas Christin, topic: Demystifying the Dark Web: Measuring and analyzing online anonymous,marketplaces
Friday, 15th of June 2018, 13:00 pm, FMI ground-floor, Interims HS1 (MI-Building, Campus Garching)
Wednesday, 13th of June 2018, 02:00 pm, FMI 01.13.007 (MI-Building, Campus Garching)
Kolloq. Prof. Thomas C. Henderson, topic: BRECCIA: Unified Probabilistic Dynamic Geospatial Intelligence
Tuesday, 6th of March 2018, 9:30 am, FMI HS 2 (MI-Building, Campus Garching)
Friday, 24th of November 2017, 10:00 am FMI 03.13.010 (MI-Building, Campus Garching)
Kolloq. Prof. Dr. Rudolf Eigenmann, topic: On the Ever-Increasing Importance of Advanced Compilers and Programming Tools For High-Performance Computing
Thursday, 23rd of November 2017, 2 pm FMI 01.06.020 (MI-Building, Campus Garching)
Kolloq. Prof. Tobias Höllerer, Ph.D, topic: Simulating the Future of Augmented Reality
Tuesday, 17th of July 2018, 04:00 pm, FMI 00.013.009a (MI-Building, Campus Garching)
AR holds enormous promise as a potentially paradigm-shifting ubiquitous mobile computing technology, enabling the physical world to become the user interface. Clearly, we are still a sizable distance away from this promise, but, just as evidently, many major players in personal computing have already become aware of this potential. In this talk, I will take a look at the features that distinguish AR’s promise from that of other technologies that may also help define the future of personal computing, such as VR, pervasive and ubiquitous computing, agent-based computing, and physical computing. Many of the technologies that are needed for a smooth and seamless AR user experience are still under development. So, how can we help AR along its trajectory and make informed choices about future applications and user interfaces? One track of research in my lab in recent years has been concerned with the simulation of possible future capabilities in AR. With the goal to conduct controlled user studies evaluating technologies that are just not possible yet (such as a truly wide-field-of-view augmented reality display), we turn to high-end VR to simulate, predict, and assess these possible futures. In the very long term, when technological hurdles, such as real-time reconstruction of photorealistic environment models, are removed, VR and AR naturally converge. Until then, we have a very interesting playing field full of technological constraints to have fun with.
Tobias Höllerer is Professor of Computer Science at the University of California, Santa Barbara, where he leads the Four Eyes Laboratory, conducting research in the four I's of Imaging, Interaction, and Innovative Interfaces. Dr. Höllerer holds a Diplom in informatics from the Technical University of Berlin as well as an MS and PhD in computer science from Columbia University. He is a recipient of the US National Science Foundation's CAREER award, for his work on "Anywhere Augmentation", enabling mobile computer users to place annotations in 3D space wherever they go. He has been named an ACM Distinguished Scientist in 2013. Dr. Höllerer is author of over 200 peer-reviewed journal, conference, and workshop publications in the areas of augmented and virtual reality, information visualization, 3D displays and interaction, mobile and wearable computing, and social computing. Several of these publications have been selected for Best Paper or Honorable Mention awards at such venues as the IEEE International Symposium on Mixed and Augmented Reality (ISMAR), IEEE Virtual Reality, ACM Virtual Reality Software and Technology, ACM User Interface Software and Technology, ACM MobileHCI, IEEE SocialCom, and IEEE CogSIMA.
Prof. Gudrun Klinker, Ph.D.