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BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20230717T160000
DTEND;TZID=Europe/Berlin:20230717T170000
DTSTAMP:20230704T090825Z
CREATED:20230704T090825Z
LAST-MODIFIED:20230704T090825Z
UID:7238-1689609600-1689613200@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Gabriele Dragotto
DESCRIPTION:On Monday\, July 17\, 2023 at 16:00 c.t. Dr. Gabriele Dragotto\, Princeton University\, will speak at the ALOP Colloquium about his recent work: \n  \nLearn-and-Play: Data\, Agents\, and Interactions \nAbstract: \nHow should an energy company determine its optimal production schedule? How should transport authorities design transportation networks? How should graduate students from medical schools be matched with residency training? In all these contexts\, decision-making is rarely an individual task; on the contrary\, it often involves the mutual interaction of several self-interested decision-makers deciding by solving optimization problems. However\, the agents’ self-driven behavior often conflicts with the greater societal goals; in such cases\, external regulators (e.g.\, governments) can intervene in the agents’ interaction via incentives\, laws\, and regulations. This talk provides a method for learning the agents’ preferences from data to design prescriptive interventions that possibly improve social welfare.  \n  \nPlease join us at 16:00 c.t. in HS 10.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-gabriele-dragotto/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
CATEGORIES:Colloquium
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20230724T080000
DTEND;TZID=Europe/Berlin:20230726T140000
DTSTAMP:20230721T082025Z
CREATED:20230303T115741Z
LAST-MODIFIED:20230721T082025Z
UID:7019-1690185600-1690380000@alop.uni-trier.de
SUMMARY:German SIAM Student Chapters Meet Algorithmic Optimization
DESCRIPTION:The SIAM Student Chapter Trier proudly announces hosting the 6th Symposium of the German SIAM Student Chapters together with the Research Training Group on Algorithmic Optimization (ALOP) in 2023. The meeting is organized as a workshop titled “German SIAM Chapters Meet Algorithmic Optimization.“ This three-day event is scheduled to take place in person at Trier University. \nScope \nThe workshop targets the members of the German SIAM Student Chapters but other interested individuals are also welcome to participate. The goal is to bring together researchers from various fields of mathematical optimization and applied mathematics to exchange ideas from different research groups. In particular\, the aim of the workshop is to strengthen the connection of early career researchers from across Germany as well as to network with experienced invited plenary speakers. \nThe topics shall include but are not limited to \n\nSystem Models (PDE Constrained Optimization\, Model Order Reduction\,…)\nOptimization (Discrete Optimization\, Non-Smooth Optimization\, Shape Optimization\,…)\nStatistics\, Data Analysis\, and Machine Learning\n\nThere will be four plenary talks\, contributed talks by early career researchers\, and a poster session. \nConfirmed speakers: \nRoland Herzog (Heidelberg University) \nDaniel Walter (HU Berlin) \nChristina Brandt (Universität Hamburg) \nLaura Scarabosio (Radboud University Nijmegen) \nOrganizers: \nVolker Schulz (Trier University) \nYasmine Beck (Trier University) \nMaximilian Würschmidt (Trier University) \nProgramm Committee: \nYasmine Beck (Trier University) \nJosie König (University of Potsdam) \nHenrik Wyschka (Universität Hamburg) \nTimo Kreimeier (HU Berlin) \nSchedule\, Location\, and Travel Information:\n \nWorkshop Program - German SIAM Student Chapters meet Algorithmic Optimization\nSchedule can be downloaded here. \nThe workshop will take place in Building E located on Campus I at Trier University. \nFor travel tips on how to get to Trier\, please check  here;\nInstructions on how to find Campus I are located here.  \nYou would like to give a short presentation yourself? Send an e-mail to: sokolowski@uni-trier.de \nHotel Room Reservations: \nWe have reserved a hotel room contingent at the Best Western Hotel Trier City\, Kaiserstraße 29\, 54290 Trier. Please contact them directly to make your reservations under the keyword “ALOP”. \nThe contingent will be available for reservation until June 23\, 2023\, or until all available rooms have been booked. \nRegistration is closed.
URL:https://alop.uni-trier.de/event/german-siam-student-chapters-meet-algorithmic-optimization/
LOCATION:Trier University – E-Building – HS 9\, Universität Trier Gebäude E\, Trier\, Rhineland-Palatinate\, 54296\, Germany
CATEGORIES:Workshop
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231116T160000
DTEND;TZID=Europe/Berlin:20231116T170000
DTSTAMP:20231113T141958Z
CREATED:20231024T091139Z
LAST-MODIFIED:20231113T141958Z
UID:7310-1700150400-1700154000@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Daniel Walter
DESCRIPTION:On Thursday\, November 16\, 2023 at 16:00 c.t. Prof. Dr. Daniel Walter\, HU Berlin\, will speak at the ALOP Colloquium about his recent work. \nIf you would like to participate via Zoom\, please click here. \n  \nEfficient minimization in spaces of measures: Numerical methods and applications \nAbstract: \nMinimization problems in spaces of (vector) measures naturally emerge in a variety of challenging settings including e.g. inverse problems in acoustics and seismology\, micoscropy\, optimal sensor placement as well as the training of shallow neural networks. \nIn this talk\, we discuss several of these applications\, both from a theoretical and numerical perspective\, highlighting the difficulties posed by the (typical) nonsmoothness of the arising optimization problems as well as the lack of “nice” topological properties in the space of (vector) measures. Different practical solution ansatzes are discussed with a particular focus on generalized conditional gradient methods. \nFinally\, we further underline the practical relevance of “sparse” minimization problems by showing that a huge class of nonsmooth problems can be equivalently rewritten as an optimization problem over  measures on a compact metric space using arguments from convex representation theory. From a practical perspective\, this unification allows the derivation and analysis of an efficient general purpose solution algorithm by “lifting” arguments from the vector measure setting. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-daniel-walter/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231204T160000
DTEND;TZID=Europe/Berlin:20231204T170000
DTSTAMP:20231024T083813Z
CREATED:20230814T123308Z
LAST-MODIFIED:20231024T083813Z
UID:7275-1701705600-1701709200@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Marc Pfetsch
DESCRIPTION:On Monday\, December 4\, 2023 at 16:00 c.t. Prof. Dr. Marc Pfetsch\, TU Darmstadt\, will speak at the ALOP Colloquium about his recent work: \n  \nCombinatorial Aspects of Physical Networks \nAbstract:\n \nThis talk considers combinatorial properties of physical networks like water\, gas\, heat\, and electrical networks. One common model are potential-based flows\, for which\, in general\, the corresponding flows depend in a nonlinear way on potentials (e.g.\, pressures) and are unique. The talk will discuss two different topics. The first is how the fact that flows in physical networks are acyclic can be used to strengthen mixed-integer optimization formulations and to derive combinatorial models. The second concerns the recovery of the structure of the network\, given only information at the entries and exits. The talk will demonstrate positive and negative results in this direction. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-marc-pfetsch/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
CATEGORIES:Colloquium
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231207T160000
DTEND;TZID=Europe/Berlin:20231207T170000
DTSTAMP:20231123T093046Z
CREATED:20231123T093046Z
LAST-MODIFIED:20231123T093046Z
UID:7328-1701964800-1701968400@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Falk Hante
DESCRIPTION:On Thursday\, December 7\, 2023 at 16:00 c.t. Prof. Dr. Falk Hante\, will speak at the ALOP Colloquium about his recent work: \n  \nTime-Domain Decomposition for Mixed-Integer Optimal Control Problems \nAbstract:\n \nWe consider mixed-integer optimal control problems\, whose optimality conditions involve global combinatorial optimization aspects for the corresponding Hamiltonian pointwise in time. We propose a time-domain decomposition\, which makes this problem class accessible for mixed-integer programming using parallel-in-time direct discretizations. The approach is based on a decomposition of the optimality system and the interpretation of the resulting subproblems as suitably chosen mixed-integer optimal control problems on subintervals in time. An iterative procedure then ensures continuity of the states at the boundaries of the subintervals via co-state information encoded in virtual controls. We prove convergence of this iterative scheme for discrete-continuous linear-quadratic problems and present numerical results both for linear-quadratic as well as nonlinear problems. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-falk-hante/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231211T160000
DTEND;TZID=Europe/Berlin:20231211T170000
DTSTAMP:20230906T085744Z
CREATED:20230814T123248Z
LAST-MODIFIED:20230906T085744Z
UID:7277-1702310400-1702314000@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Mathias Staudigl
DESCRIPTION:On Monday\, December 11\, 2023 at 16:00 c.t. Prof. Dr. Mathias Staudigl\, University of Mannheim\, will speak at the ALOP Colloquium about his recent work: \n  \nA regularized variance-reduced modified extragradient method for stochastic hierarchical games \nAbstract:\n \nThe theory of learning in games has so far focused mainly on games with simultaneous moves. Recently\, researchers in machine learning have started investigating learning dynamics in games involving hierarchical decision-making. We consider an N-player hierarchical game in which the ith player’s objective comprises of an expectation-valued term\, parametrized by rival decisions\, and a hierarchical term. Such a framework allows for capturing a broad range of stochastic hierarchical optimization problems\, Stackelberg equilibrium problems\, and leader-follower games. We develop an iteratively regularized and smoothed variance-reduced modified extragradient framework for learning hierarchical equilibria in a stochastic setting. We equip our analysis with rate statements\, complexity guarantees\, and almost-sure convergence claims. We then extend these statements to settings where the lower-level problem is solved inexactly and provide the corresponding rate and complexity statements. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-mathias-staudigl/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
CATEGORIES:Colloquium
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240212T160000
DTEND;TZID=Europe/Berlin:20240212T170000
DTSTAMP:20231221T143522Z
CREATED:20231221T094533Z
LAST-MODIFIED:20231221T143522Z
UID:7334-1707753600-1707757200@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Dorothee Henke
DESCRIPTION:On Monday\, February 12\, 2024 at 16:00 c.t. Dorothee Henke\, University of Passau\, will speak at the ALOP Colloquium about her recent work: \n  \nOn the Complexity of the Bilevel Shortest Path Problem \nAbstract: \nWe introduce a new bilevel version of the classical shortest path problem and completely characterize its computational complexity with respect to several problem variants. In our problem\, the leader and the follower each control a subset of the edges of a graph and together aim at building a path between two given vertices\, while each of the two players minimizes the length of the resulting path according to their own edge lengths. We investigate both directed and undirected graphs\, as well as the special case of acyclic directed graphs. Moreover\, we distinguish two versions of the follower’s problem: Either he has to complete the edge set selected by the leader such that the joint solution is exactly a path\, without any additional edges\, or he is allowed to include only a subset of the leader’s selection into the final path. In general\, the bilevel problem turns out to be much harder in the former case: We show that the follower’s problem is already NP-hard here and the leader’s problem is even hard for the second level of the polynomial hierarchy\, while both problems are one level easier in the latter case. Interestingly\, for acyclic directed graphs\, this difference turns around\, as we give a polynomial-time algorithm for the first version of the bilevel problem\, but it stays NP-hard in the second case. \nThis is joint work with Lasse Wulf. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-dorothee-henke/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
CATEGORIES:Colloquium
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240226T160000
DTEND;TZID=Europe/Berlin:20240226T170000
DTSTAMP:20240118T072334Z
CREATED:20231019T094016Z
LAST-MODIFIED:20240118T072334Z
UID:7307-1708963200-1708966800@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Boris Detienne
DESCRIPTION:On Monday\, February 26\, 2024 at 16:00 c.t. Prof. Boris Detienne\, University of Bordeaux\, will speak at the ALOP Colloquium about his recent work. \n  \nThe Benders-by-batch algorithm to solve two-stage stochastic linear programs \nAbstract: \nIn this talk\, we will introduce a new exact algorithm to solve two-stage stochastic linear programs. Based on the multicut Benders reformulation of such problems\, with one subproblem for each scenario\, this method relies on a partition of the subproblems into batches. The key idea is to solve at most iterations only a small proportion of the subproblems by detecting as soon as possible that a first-stage candidate solution cannot be proven optimal. We also propose a general framework to stabilize our algorithm\, and show its finite convergence and exact behavior. We report an extensive computational study on large-scale instances of stochastic optimization literature that shows the efficiency of the proposed algorithm compared to nine alternative algorithms from the literature. We also obtain significant additional computational time savings using the primal stabilization schemes \n  \nPlease join us at 16:00 c.t. in HS 9. \n 
URL:https://alop.uni-trier.de/event/alop-colloquium-with-boris-detienne/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240506T160000
DTEND;TZID=Europe/Berlin:20240506T170000
DTSTAMP:20240418T125616Z
CREATED:20240418T123625Z
LAST-MODIFIED:20240418T125616Z
UID:7414-1715011200-1715014800@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Laura Vargas Koch
DESCRIPTION:On Monday\, May 6\, 2024 at 16:00 c.t. Prof. Dr. Laura Vargas Koch\, University of Bonn\, will speak at the ALOP Colloquium about her recent work. \n  \nMathematics in Traffic Modeling: Nash Flows over Time \nAbstract: \nIn traffic planning\, traffic simulations are widely used. However\, effective practical traffic simulations require good mathematical models as a foundation\, and one such model is Nash flows over time. Traffic is not a centrally controlled system. Instead\, each participant in traffic decides individually which route is best for them. When all participants do this\, so-called equilibrium states emerge. In our research\, we focus on these equilibria and their properties. Unlike static\, classical models\, the unique aspect of Nash flows over time is that temporal changes can be depicted. This means that a flow\, which models traffic\, moves through the network over time\, and the situation in the network can dynamically change. In this presentation\, we will learn about the model of Nash flows over time\, understand its close connection to the traffic simulation software MATSim and see what properties of the equilibria have already been understood\, and what questions are still open. \n  \nPlease join us at 16:00 c.t. in HS 9. \n 
URL:https://alop.uni-trier.de/event/alop-colloquium-with-laura-vargas-koch/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240513T080000
DTEND;TZID=Europe/Berlin:20240514T160000
DTSTAMP:20240528T133025Z
CREATED:20230627T130802Z
LAST-MODIFIED:20240528T133025Z
UID:7186-1715587200-1715702400@alop.uni-trier.de
SUMMARY:Variational Analysis and Applications for Modeling of Energy Exchange - VAME 2024
DESCRIPTION:We proudly announce hosting the third International Workshop on “Variational Analysis and Applications for Modeling of Energy Exchange” from May 13 to 14\, 2024 in Trier. \nThe aim of the workshop is to bring together specialists in the modeling of energy exchanges\, both from the point of view of Mathematics and Economics. In addition\, the workshop strives to stimulate the exchange of ideas among researchers and practitioners that develop or apply energy market models and approaches for policy identification and assessment. In an “informal context”\, the intent is to generate fruitful scientific exchanges on the following topics:  \n\nNonlinear optimization\,\nStochastic programming and robust optimization\,\nBilevel programming\, MPEC\, EPEC\,\nGeneralized Nash equilibrium problems (GNEPs)\,\nCapacity expansion models in renewable dominated power system\,\nDecarbonization and integration of renewable energy sources in power systems\,\nImpact of the development of electric vehicles\,\nElectricity market design\,\nRisk management in electricity markets.\n\nInvited Speakers: \n\nLuce Brotcorne\nJohn Cotrina (slides)\nMel Devine (slides)\nSteve Gabriel (slides)\nRené Henrion\nJalal Kazempour (slides)\nFrauke Liers (slides)\nGiorgia Oggioni\nSalvador Pineda (slides)\nRossana Riccardi\nClaudia Sagastizábal\nSimone Sagratella (slides)\nAfzal Siddiqui (slides)\nRamteen Sioshansi (slides)\nOliver Stein (slides)\nAnton Svensson\nJohannes Thürauf (slides)\nWim Van Ackooij\n\nScientific Committee: \n\nMiguel Anjos\nDidier Aussel\nMartine Labbé\nLorenzo Lampariello\nGiorgia Oggioni\nRossana Riccardi\nDavid Salas\nMartin Schmidt\nAlexandra Schwartz\nGregor Zöttl\n\nOrganizing Committee: \n\nLaura Sokolowski\nMartin Schmidt\n\nSchedule and location \nSchedule can be downloaded here. \nThe workshop will take place at the Bischöflisches Priesterseminar Trier. \nRegistration information (registration is closed)
URL:https://alop.uni-trier.de/event/variational-analysis-and-applications-for-modelling-of-energy-exchange-vame-2024/
LOCATION:Bischöfliches Priesterseminar Trier\, Jesuitenstraße 13\, Trier\, 54290
CATEGORIES:Workshop
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240715T170000
DTEND;TZID=Europe/Berlin:20240715T180000
DTSTAMP:20240529T075328Z
CREATED:20240529T075328Z
LAST-MODIFIED:20240529T075328Z
UID:7517-1721062800-1721066400@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Fabio Furini
DESCRIPTION:On Monday\, July 15\, 2024 at 16:00 c.t. Prof. Dr. Fabio Furini\, Sapienza University of Rome\, will speak at the ALOP Colloquium about his recent work. \n  \nSubmodular maximization of concave utility functions composed with a set-union operator with applications to maximal covering location problems \nAbstract: \nWe study a family of discrete optimization problems asking for the maximization of the expected value of a concave\, strictly increasing\, and differentiable function composed with a set-union operator. The expected value is computed with respect to a set of coefficients taking values from a discrete set of scenarios. The function models the utility function of the decision maker\, while the set-union operator models a covering relationship between two ground sets\, a set of items and a set of metaitems. This problem generalizes the problem introduced by Ahmed S\, Atamtürk A (Mathematical programming 128(1-2):149–169\, 2011)\, and it can be modeled as a mixed integer nonlinear program involving binary decision variables associated with the items and metaitems. Its goal is to find a subset of metaitems that maximizes the total utility corresponding to the items it covers. It has applications to\, among others\, maximal covering location\, and influence maximization problems. In the paper\, we propose a double-hypograph decomposition that allows for projecting out the variables associated with the items by separately exploiting the structural properties of the utility function and of the set-union operator. Thanks to it\, the utility function is linearized via an exact outer-approximation technique\, whereas the set-union operator is linearized in two ways: either (i) via a reformulation based on submodular cuts\, or (ii) via a Benders decomposition. We analyze from a theoretical perspective the strength of the inequalities of the resulting reformulations\, and embed them into two branch-and-cut algorithms. We also show how to extend our reformulations to the case where the utility function is not necessarily increasing. We then experimentally compare our algorithms inter se\, to a standard reformulation based on submodular cuts\, to a state-of-the-art global-optimization solver\, and to the greedy algorithm for the maximization of a submodular function. The results reveal that\, on our testbed\, the method based on combining an outer approximation with Benders cuts significantly outperforms the other ones. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-fabio-furini/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20241009T080000
DTEND;TZID=Europe/Berlin:20241011T160000
DTSTAMP:20240920T114250Z
CREATED:20240404T072758Z
LAST-MODIFIED:20240920T114250Z
UID:7393-1728460800-1728662400@alop.uni-trier.de
SUMMARY:Autumn School on Constrained Optimization and Machine Learning
DESCRIPTION:The Research Training Group on Algorithmic Optimization proudly announces its eighth Autumn School from October 9 – 11\, 2024. \nThis year’s focus will be on Constrained Optimization and Machine Learning \nIn today’s rapidly evolving technological landscape\, the intersection of constrained optimization and machine learning is gaining immense significance. As we tackle intricate real-world challenges\, the synergy between these two domains gets more and more important. While unconstrained optimization methods have predominantly been employed in machine learning so far\, constraints are becoming prevalent in a wide array of applications. This school offers a unique opportunity to deepen comprehension and delve into the latest advancements at the interface of the two fields. Thus\, participants will acquire invaluable skills to confront the challenges of tomorrow. \n  \nConfirmed Speakers: \nEmilio Carrizosa (University of Sevilla) – Mathematical Modeling for Counterfactual Explanations and Inverse Optimization \nTim Hoheisel (McGill University) – Regularized Least-Squares: Stability Properties and the Maximum Entropy of the Mean Method \nAndrea Lodi (Cornell University) – Machine-Learning-Augmented Mixed-Integer Programming \n  \nOrganizers: \nJan Pablo Burgard (Trier University) \nMartin Schmidt (Trier University) \nVolker Schulz (Trier University) \n  \nSchedule\, Location and Travel Information:  \n \nSchedule can be downloaded here. \nThe workshop will take place in Building E located on Campus I at Trier University. \nFor travel tips on how to get to Trier\, please check  here;\nInstructions on how to find Campus I are located here.  \n  \nRegistration information (registration is closed) \nThe registration fee of 60 € includes a welcome reception\, the conference dinner\, refreshments\, and extra-curricular activities. Detailed payment information will be communicated upon registration.  \n  \nTravel Stipend (application is closed)
URL:https://alop.uni-trier.de/event/autumn-school-on-constrained-optimization-and-machine-learning/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20241216T160000
DTEND;TZID=Europe/Berlin:20241216T170000
DTSTAMP:20241112T115510Z
CREATED:20241112T115510Z
LAST-MODIFIED:20241112T115510Z
UID:7632-1734364800-1734368400@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Christina Schenk
DESCRIPTION:On Monday\, December 16\, 2024 at 16:00 c.t. Dr. Christina Schenk\, IMDEA Materials Insitute\, Getafe (Madrid)\, will speak at the ALOP Colloquium about her recent work. \n  \nMixed-dimensional Linked Models and Reinforcement Learning-Based Control of Reaction-Diffusion Problems \nAbstract: \nIn Mathematical modeling is a powerful tool for tackling complex challenges across various fields. For instance\, during the SARS-CoV-2 pandemic\, modeling spatial dynamics and high-diffusion pathways\, such as airways and highways\, proved essential for effective decision-making in managing the crisis. \nIn this talk\, we present two approaches to enhance modeling and decision-making. We start with linking models of different dimensionalities to represent a single physical phenomenon\, specifically coupling two diffusive models—one over a continuum and another over a curve—resulting in a mixed-dimensional problem. We establish the unconditional stability and convergence of both continuous and discrete linked models using mixed finite elements. Supported by numerical examples\, we demonstrate the benefits of combining these models and show how our methods can infer solutions from incomplete data. \nBuilding on these results\, we explore the application of reinforcement learning (RL) to automatic control problems in thermal and disease transport. We adapt a stochastic policy gradient algorithm and propose novel reward functions to guide the RL agent in interacting with a reaction-diffusion model. Our approach successfully implements control strategies despite necessary model simplifications\, showcasing the potential of RL to solve complex control problems. \nBy combining theoretical and numerical insights from mixed-dimensional modeling and machine learning\, this talk highlights new results for advancing diffusive modeling and data-driven control strategies\, opening new avenues for research in data science and control applications. \n  \nThis is joint work with Aditya Vasudevan\, David Portillo (UPM)\, Ignacio Romero\, and Maciej Haranczyk. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-christina-schenk/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
CATEGORIES:Colloquium
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
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BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20250120T160000
DTEND;TZID=Europe/Berlin:20250120T170000
DTSTAMP:20250106T121301Z
CREATED:20250106T121301Z
LAST-MODIFIED:20250106T121301Z
UID:7671-1737388800-1737392400@alop.uni-trier.de
SUMMARY:ALOP Colloquium with Sonja Steffensen
DESCRIPTION:On Monday\, January 20\, 2025 at 16:00 c.t. Dr. Sonja Steffensen\, RWTH Aachen\, will speak at the ALOP Colloquium about her recent work. \n  \nRelaxation Approaches for Nonlinear Sparse Optimization Problems \nAbstract: \nIn many applications\, sparse solutions are favoured over non-sparse solutions with comparable objective value\, as for example in statistical and deep learning applications. One approach to induce sparsity relies on the l_0 norm as an additional term in the objective. Often this semicontinuous function is approximated using the continuous and convex l_1-norm as a surrogate function instead. However\, this can lead to suboptimal results with respect to the sparsity properties of the solution. \nIn this talk\, we will present an alternative exact reformulation (with respect to the l_0 norm)  using non-smooth nonlinear functions to formulate the minimization of the number of non-zero entries. The resulting problem is similar (but not equivalent) to the class of mathematical programs with complementarity constraints (MPCC). As for MPCCs relaxing the problem to a standard nonlinear program we can then apply a general nonlinear solver. In our talk we will discuss and relate the relations between the different reformulations in particular with respect to the original problem. Furthermore\, we accompany the theoretical results by some numerical tests using randomly generated data sets. \n  \nPlease join us at 16:00 c.t. in HS 9.
URL:https://alop.uni-trier.de/event/alop-colloquium-with-sonja-steffensen/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
CATEGORIES:Colloquium
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
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BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20250923T090000
DTEND;TZID=Europe/Berlin:20250926T170000
DTSTAMP:20250923T094025Z
CREATED:20250228T102157Z
LAST-MODIFIED:20250923T094025Z
UID:7677-1758618000-1758906000@alop.uni-trier.de
SUMMARY:International Workshop on Algorithmic Optimization
DESCRIPTION:As the research training group Algorithmic Optimization (ALOP) at Trier University enters its ninth and final year\, we are excited to host our last international workshop on algorithmic optimization. After seven successful international workshops and eight autumn schools\, this event marks a special opportunity to bring together researchers from across the field and to offer perspectives on its future evolution. \nThe workshop will feature a dynamic program\, including invited plenary talks\, contributed talks\, an engaging session with elevator pitches\, and a lively poster session. Covering the full spectrum of algorithmic optimization\, topics will range from mixed-integer programming to optimization with differential equations\, from applications in the energy sector to advancements in machine learning and data science\, as well as from foundational theory to cutting-edge algorithmic developments. \nConfirmed Invited Speakers: \nCarina Costa (State University of Maringá) \nMatthias Heinkenschloss (Rice University) \nMichael Hintermüller (WIAS Berlin) \nMartine Labbé (Université Libre de Bruxelles) \nMarina Leal (Univeritas Miguel Hernández) \nMarianna de Santis (Universitá degli Studi di Firenze) \nJohannes Thürauf (University of Technology Nuremberg) \nKathrin Welker (Helmut Schmidt University) \nOrganizers: \nMartin Schmidt (Trier University) \nVolker Schulz (Trier University) \nSchedule\, Location and Travel Information:  \n \nSchedule will be uploaded later. \nThe workshop will take place in Building E located on Campus I at Trier University. For travel tips on how to get to Trier\, please check here. Instructions on how to find Campus I are located here.  \nProgram: \nThe program and book of abstracts can be found here.
URL:https://alop.uni-trier.de/event/international-workshop-on-algorithmic-optimization/
LOCATION:Trier University\, E Building\, Universitätsring 15\, Trier\, Germany
ORGANIZER;CN="RTG ALOP at Trier University":MAILTO:ALOP@uni-trier.de
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