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TODAY UnRAVeL Survey Lecture: "Biggest Milestones"

von Kassing, Jan-Christoph

Dear all, this is a reminder for Britta Peis's talk with the title "Ascending Auctions and Matroids" taking place today at 12:30 in the B-IT room 5053.2. Please find the details below --- Abstract --- We consider matching markets, where an auctioneer is selling a set of indivisible items E to a set of bidders with private valuations v_j. In an ascending auction, the auctioneer decides on an assignment of items to bidders, together with prices p_i for all items i in E, based on the demand indicated by the bidders throughout the auction. In the first part of the talk, we consider computability and monotonicity of buyer-optimal Walrasian equilibria in ascending auctions. A price vector p is called "Walrasian", if there exists an assignment under which every bidder j receives a bundle S of maximum payoff v_j(S)-p(S), and, additionally, all items of positive price are sold. Walrasian prices are called "buyer-optimal" if they minimise the total payment of the bidders among all Walrasian prices. It is well-known that buyer-optimal Walrasian prices exist and can be computed efficiently if the valuations v_j are gross-substitute. Moreover, it is known that an ascending auction, which iteratively raises the prices uniformly on items in a so-called "inclusionswise minimal maximal overdemanded set" terminates with buyer-optimal Walrasian prices, and that these overdemanded sets can be computed efficiently with tools from Discrete Convexity. We will see how to compute the desired overdemanded set in each iteration in a simple combinatorial way with the matroid partition algorithm. Moreover, we will use the obtained structural insights to show that the buyer optimal Walrasian prices are monotone in supply and demand. In the second part of the talk, we consider ascending auctions where the auctioneer is restricted to sell a basis of a matroid to the bidders. It is known that a very natural and simple ascending auction is welfare-maximising and truthful in the sense that the prices coincide with the Vickrey payments. We will provide a simple proof of this result, combined with certain sensitivity results. (Joint work with Katharina Eickhoff, Niklas Rieken, and Laura Vargas Koch). ---------------- Part of the programme of the research training group UnRAVeL is a series of lectures on the topics of UnRAVeL’s research thrusts algorithms and complexity, verification, logic and languages, and their application scenarios. Each lecture is given by one of the researchers involved in UnRAVeL. This years topic is "Biggest Milestones - Research at Its Peak", UnRAVeL professors will present the most important milestone of their respective research. All interested doctoral researchers and master students are invited to attend the UnRAVeL lecture series 2023 and engage in discussions with researchers and doctoral students. Next week we have a talk from Gerhard Lakemeyer with the title "The Situation Calculus as Lingua Franca for Reasoning about Action" We are looking forward to seeing you at the lectures. Kind regards, Jan-Christoph for the organisation committee

1 Jahr, 1 Monat

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Women in AI event on 14 June

von Mann, Julia

Dear all, I’m happy to announce that the first Women in AI Aachen event will take place on 14 June. Could you please help to spread the word? [cid:image001.png@01D99D5B.5EF83590] Thanks a lot, Julia Dr Julia Mann Managing Director ______________________________________________ Center for Artificial Intelligence RWTH Aachen University Mies-van-der-Rohe-Strasse 15 office: 123 DE-52074 Aachen phone: +49-241-80 20757 Germany http://www.ai.rwth-aachen.de<http://www.ai.rwth-aachen.de/> [cid:image002.png@01D99D5B.5EF83590]

1 Jahr, 1 Monat

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Einladung Informatik-Oberseminar Vincent Drury

von Vincent Drury

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Freitag, 16. Juni 2023, 09.00 Uhr Ort: UMIC_025 (2165|025), Mies-van-der-Rohe-Str. 15, EG Referent: Vincent Drury M.Sc. Lehr- und Forschungsgebiet Informatik IT-Sicherheit Thema: Phishing Prevention: A Multi-Layered Approach Abstract: Phishing attacks have been a relevant and ongoing threat for several decades, resulting in monetary loss for private users and serving as a first step in attacks on larger organizations. Despite decades of research into automated detection, education, and design interventions to prevent phishing attacks, current solutions fall short of providing adequate and general protection to users and businesses against the evolving threat. In particular, we identify research gaps for anti-phishing learning games, which currently lack personalization and mainly offer rather simple game mechanics, the presentation of URLs in browsers, where attackers can easily insert malicious information to confuse untrained users, and automated phishing website classification, where the focus is on detection after the attack was executed, instead of aiming to disrupt attacks before they reach potential victims. This dissertation addresses these gaps and showcases the effectiveness of human-centered and technical phishing-prevention techniques based on a categorization of phishing URLs and a kill chain model, thus contributing to a multi-layered defense strategy where each layer addresses different attacks. Our main contributions in the research area of anti-phishing education are the evaluation of baseline detection capabilities for a new categorization of phishing URLs, as well as the comparative evaluation of four new learning games in two user studies. The result of these user studies motivate, which categories of URLs to focus on to optimize future educational interventions, and give insights into the effect of different game mechanics and personalization on the classification capabilities of users who played the learning games. We further demonstrate, that accurately reflecting the diversity of phishing attacks and measuring service familiarity in user studies is essential to ensure representative results. In the area of design interventions, we evaluate the effect of using Reverse Domain Name (RDN) notation for URLs on the classification performance of untrained users. The study reveals advantages of the proposed changes over the baseline and motivates further studies of the intervention’s effect on awareness outside of a lab setting. For automated phishing detection, we evaluate the detection of phishing websites on certificate transparency (CT) logs, which are publicly available stores of certificates. We show, how data cleaning and class imbalance during training, and the inclusion of additional certificate information in the classification task can have an effect on classification performance, resulting in classifiers that approach acceptable levels of false positives to be practical in the real world. In all, our results exemplify the advantages and disadvantages of several broader approaches to phishing prevention, and demonstrate how combining these approaches can provide a more comprehensive defense than each of its parts taken by itself. Es laden ein: die Dozentinnen und Dozenten der Informatik

1 Jahr, 1 Monat

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TODAY UnRAVeL Survey Lecture: "Biggest Milestones"

von Kassing, Jan-Christoph

Dear all, this is a reminder for Jürgen Giesl's talk with the title "Proving Termination with Dependency Pairs" taking place today at 12:30 in the B-IT room 5053.2. Please find the details below --- Abstract --- Until 2000, techniques for automated termination analysis were mainly studied in the areas of logic programming and term rewrite systems (TRSs). However, the power of the available methods and tools was quite limited. In particular, the techniques were not modular and thus, they often failed when applying them to larger programs. Therefore, from 1996 onwards, we started to develop the so-called dependency pair technique to overcome these drawbacks. This technique then evolved into a general framework for modular termination proofs of term rewrite systems and is nowadays used in essentially all termination provers for term rewriting. By applying the dependency pair framework for TRSs as a backend, we also developed techniques for the automated termination analysis of many different programming languages, such as Java, Haskell, or Prolog. While notions like positive almost-sure termination originated in the TRS community, until recently there was hardly any technique available to analyze the termination behavior of probabilistic TRSs (PTRSs). Therefore, in very recent work we started to adapt the dependency pair framework to the probabilistic setting in order to analyze almost-sure termination of PTRSs as well. All these techniques are implemented in our tool AProVE. ---------------- Part of the programme of the research training group UnRAVeL is a series of lectures on the topics of UnRAVeL’s research thrusts algorithms and complexity, verification, logic and languages, and their application scenarios. Each lecture is given by one of the researchers involved in UnRAVeL. This years topic is "Biggest Milestones - Research at Its Peak", UnRAVeL professors will present the most important milestone of their respective research. All interested doctoral researchers and master students are invited to attend the UnRAVeL lecture series 2023 and engage in discussions with researchers and doctoral students. The next talk after today will not take place until June 15th. Then, Britta Peis is going to give a talk with the title "Ascending Auctions and Matroids" We are looking forward to seeing you at the lectures. Kind regards, Jan-Christoph for the organisation committee

1 Jahr, 1 Monat

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!!ABSAGE!!: Informatik-Oberseminar Dr. Jakob Bossek 24.05.2023

von Andrea Gibbels

Sehr geehrte Damen und Herren, aufgrund einer akuten Erkrankung von Herrn Dr. Bossek kann das für morgen angesetzte Oberseminar leider nicht stattfinden. Wir bedauern diese kurzfristige Absage und werden versuchen, zeitnah einen neuen Termin zu finden. Mit freundlichen Grüßen Im Auftrag Andrea Gibbels -- Andrea Gibbels, M.A. Administrative Assistant Chair for AI Methodology / Lehrstuhl für Methodik der Künstlichen Intelligenz RWTH Aachen University E-mail: secret(a)aim.rwth-aachen.de Phone: +49 241 80 21452 Theaterstr. 35-39 52062 Aachen Germany +********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Mittwoch, 24. Mai 2023, 13.00 Uhr Ort: Raum 9222, Gebäude E3, Ahornstr. 55 Referent: Dr. Jakob Bossek Lehrstuhl Informatik 14 Thema: Tailored Evolutionary Operators for the Multi-Objective Spanning Tree Problem Abstract: With this talk I want to introduce myself to the RWTH computer science department. In the first part I will go into detail on paper recently accepted in the evolutionary computation journal (Bossek & Grimme, 2023) entitled “Tailored Evolutionary Operators for the Multi-Objective Spanning Tree Problem”. The second part will give a broader overview of my research foci and projects in the fields of Evolutionary Optimisation and Automated Artificial Intelligence. The Minimum Spanning Tree (MST) problem is the challenge of finding a tree in an edge-weighted graph that maintains connectivity of all nodes and has minimal costs among all such trees. The MST problem is a fundamental combinatorial optimisation problem with countless applications, e.g., in the construction of communication networks, medical imaging, or many other areas that range from logistic via graph drawing to power grid network design. The basic single-objective version of the MST problem can be solved efficiently, i.e., in polynomial time, e.g., by Prim’s algorithm. The multi-objective MST (moMST) version though (i.e., multiple weights per edge) is NP-hard and suffers from intractability. Thus, efficient heuristics are needed to approximate the set of optimal trade-off solutions. Evolutionary Algorithms are randomised search heuristics that are among the most successful when it comes to solving NP-hard multi-objective optimisation problems. I will present recent work on the design of several highly biased sub-graph-based mutation operators for the moMST problem. In a nutshell, these operators replace (un)connected sub-trees of candidate solutions with locally (Pareto-)optimal sub-trees. The latter (biased) step is realised by applying Kruskal’s single-objective MST algorithm to a weighted sum scalarisation of a sub-graph. I will detail some runtime complexity results for the introduced operators and demonstrate results that show that the sub-graph based operators beat baseline algorithms from the literature even with severely restricted computational budget in terms of function evaluations on four different classes of complete graphs. Es laden ein: die Dozentinnen und Dozenten der Informatik

1 Jahr, 2 Monate

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Invitation to AI Colloquium event on 25. May

von Mann, Julia

Dear all, We'd like to announce our next AI colloquium which will take place on 25 May 2023, 4-6pm. Jens Kober, TU Delft, will present on "Robots Learning Through Interaction" (in English) in SuperC/Generali-Saal from 4-5pm. The talk will be held in person but also live streamed via Zoom. The event is free, but a registration is required, and the link can be found on our web page<https://www.ai.rwth-aachen.de/go/id/baofsc>. After the talk, there will be a networking session in the foyer with drinks and nibbles and all are welcome to stay. [cid:image002.png@01D9874E.DB9193D0] We kindly ask you to distribute this among your groups and students. Please feel free to use the attached slide. Thank you in advance. Julia Mann (part of the organising team) Dr Julia Mann Managing Director ______________________________________________ Center for Artificial Intelligence RWTH Aachen University Mies-van-der-Rohe-Strasse 15 office: 123 DE-52074 Aachen phone: +49-241-80 20757 Germany http://www.ai.rwth-aachen.de<http://www.ai.rwth-aachen.de/> [cid:image001.png@01D9872C.13EB5180]

1 Jahr, 2 Monate

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Einladung Informatik-Oberseminar Dr. Jakob Bossek

von Andrea Gibbels

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Mittwoch, 24. Mai 2023, 13.00 Uhr Ort: Raum 9222, Gebäude E3, Ahornstr. 55 Referent: Dr. Jakob Bossek Lehrstuhl Informatik 14 Thema: Tailored Evolutionary Operators for the Multi-Objective Spanning Tree Problem Abstract: With this talk I want to introduce myself to the RWTH computer science department. In the first part I will go into detail on paper recently accepted in the evolutionary computation journal (Bossek & Grimme, 2023) entitled “Tailored Evolutionary Operators for the Multi-Objective Spanning Tree Problem”. The second part will give a broader overview of my research foci and projects in the fields of Evolutionary Optimisation and Automated Artificial Intelligence. The Minimum Spanning Tree (MST) problem is the challenge of finding a tree in an edge-weighted graph that maintains connectivity of all nodes and has minimal costs among all such trees. The MST problem is a fundamental combinatorial optimisation problem with countless applications, e.g., in the construction of communication networks, medical imaging, or many other areas that range from logistic via graph drawing to power grid network design. The basic single-objective version of the MST problem can be solved efficiently, i.e., in polynomial time, e.g., by Prim’s algorithm. The multi-objective MST (moMST) version though (i.e., multiple weights per edge) is NP-hard and suffers from intractability. Thus, efficient heuristics are needed to approximate the set of optimal trade-off solutions. Evolutionary Algorithms are randomised search heuristics that are among the most successful when it comes to solving NP-hard multi-objective optimisation problems. I will present recent work on the design of several highly biased sub-graph-based mutation operators for the moMST problem. In a nutshell, these operators replace (un)connected sub-trees of candidate solutions with locally (Pareto-)optimal sub-trees. The latter (biased) step is realised by applying Kruskal’s single-objective MST algorithm to a weighted sum scalarisation of a sub-graph. I will detail some runtime complexity results for the introduced operators and demonstrate results that show that the sub-graph based operators beat baseline algorithms from the literature even with severely restricted computational budget in terms of function evaluations on four different classes of complete graphs. Es laden ein: die Dozentinnen und Dozenten der Informatik -- Andrea Gibbels, M.A. Administrative Assistant Chair for AI Methodology / Lehrstuhl für Methodik der Künstlichen Intelligenz RWTH Aachen University E-mail: secret(a)aim.rwth-aachen.de Phone: +49 241 80 21452 Theaterstr. 35-39 52062 Aachen Germany

1 Jahr, 2 Monate

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TODAY UnRAVeL Survey Lecture: "Biggest Milestones"

von Kassing, Jan-Christoph

Dear all, this is a reminder for Nils Nießen's talk with the title "Can Trains Be on Time?" taking place today at 12:30 in the B-IT room 5053.2. Please find the details below --- Abstract --- Why are trains always delayed and how is a delay defined at all? In the talk "Can trains be on time", the influences and conditions in the occurrence of delays in the railway system will be discussed. The distribution of buffer times has an influence on the propagation of delays. Using a two-train model, the mechanisms of delay propagation are derived. Approaches to increase punctuality and capacity are shown. ---------------- Part of the programme of the research training group UnRAVeL is a series of lectures on the topics of UnRAVeL’s research thrusts algorithms and complexity, verification, logic and languages, and their application scenarios. Each lecture is given by one of the researchers involved in UnRAVeL. This years topic is "Biggest Milestones - Research at Its Peak", UnRAVeL professors will present the most important milestone of their respective research. All interested doctoral researchers and master students are invited to attend the UnRAVeL lecture series 2023 and engage in discussions with researchers and doctoral students. Next week is no talk so that the next one will be held on the 25th May. Here, Jürgen Giesl is going to talk about "Proving Termination with Dependency Pairs". We are looking forward to seeing you at the lectures. Kind regards, Jan-Christoph for the organisation committee

1 Jahr, 2 Monate

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Ankündigung: Informatik-Oberseminar Christopher Kugler

von Kugler, Christopher

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Freitag, 19. Mai 2023, 13.00 Uhr Ort: Seminarraum 2202, Hauptbau, Ahornstr. 55 Referent: Christopher Kugler, M.Sc. Ehem. Lehrstuhl Informatik 11 Thema: Systematic Derivation of Feature-driven and Risk-based Test Strategies for Automotive Applications Abstract: The automotive industry is currently characterized by a disruptive change in terms of electro-mobility and highly autonomous driving. Similarly, new mobility concepts pose particular challenges for quality assurance measures in automotive product development. Traditional, experience-based approaches for deriving quality assurance strategies do not address these challenges and lead to potentially high failure rates during product operation. Therefore, a risk-based approach for the derivation of feature-specific test strategies is proposed in this thesis, which enables the objective definition of test end criteria and, through appropriate prioritization, an increase in the efficiency and effectiveness of performed verification and validation activities. On the basis of a two-stage risk assessment, quality assurance measures can initially be defined in early project phases and then be refined for individual product features as soon as required information is available. A framework for the derivation of test strategies is presented, which considers the current state of the art with regard to functional safety and distinguishes the applied acceptance thresholds for test-end criteria based on previously defined risk classes. The presented approach is evaluated in context of series development projects, where the significance of the risk assessment is verified through data analysis. The test strategy applied in those projects is retrospectively evaluated and compared against the risk-based approach presented in this thesis in terms of achieved effectiveness and efficiency. Finally, two different concepts for measuring quality of automotive products are introduced and profound product release criteria are defined. Es laden ein: die Dozentinnen und Dozenten der Informatik

1 Jahr, 2 Monate

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TODAY UnRAVeL Survey Lecture: "Biggest Milestones"

von Kassing, Jan-Christoph

Dear all, this is a reminder for Sebastian Trimpe's talk with the title "Event-Triggered Learning" taking place today at 12:30 in the B-IT room 5053.2. Please find the details below --- Abstract --- The ability to learn is an essential aspect of autonomous systems facing uncertain and changing environments. However, the process of learning a new model or behavior often does not come for free, but involves a certain cost. For example, gathering informative data often means to deviate from normal operation, it may be challenging due to physical limitations, or updating models can require substantial computation. Hence, the question of "when to learn?" is essential for the efficient and persistent operation of autonomous systems. In this talk, I will be discussing recent research on the concept of event-triggered learning (ETL), which we have proposed for making principled decisions on when to learn a new dynamics model or controller. We will present some specific trigger designs that trigger learning when needed, and also highlight experimental application leading to significant resource savings. Moreover, I will give a personal "historical" perspective and trace back, how our recent research was itself triggered by my own PhD research and papers. I will also dare to look into the future and discuss what potential "milestone" papers there might still be to come. ---------------- Part of the programme of the research training group UnRAVeL is a series of lectures on the topics of UnRAVeL’s research thrusts algorithms and complexity, verification, logic and languages, and their application scenarios. Each lecture is given by one of the researchers involved in UnRAVeL. This years topic is "Biggest Milestones - Research at Its Peak", UnRAVeL professors will present the most important milestone of their respective research. All interested doctoral researchers and master students are invited to attend the UnRAVeL lecture series 2023 and engage in discussions with researchers and doctoral students. Next week, Nils Nießen is going to give a talk with the title "Can Trains Be on Time?" We are looking forward to seeing you at the lectures. Kind regards, Jan-Christoph for the organisation committee

1 Jahr, 2 Monate

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