- informatik-vortraege - lists.rwth-aachen.de

Einladung: Informatik-Oberseminar Bastian Küppers
by Küppers, Bastian 28 May '21

28 May '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Montag, 28. Juni 2021, 14.00 Uhr Ort: https://rwth.zoom.us/my/b.kueppers?pwd=dDFyZkJvUDRFbFlFbnh0R3hQZVVRdz09 Referent: Bastian Küppers, M.Sc. IT Center / Learning Technologies Research Group Thema: Development of a Framework for E-Assessment on Students’ Devices Abstract: In line with the general trend towards digitization, teaching at German universities is increasingly relying on digital elements, such as learning management systems or smartphone apps. This evolution is also taking place in exercises and practical courses associated with lectures. For example, it is quite common for students to use their own devices in programming exercises. However, examinations are not yet part of this development. The decision to continue writing exams on paper is often made based on reservations, most of which concern the fairness and reliability of e-assessment. In particular, students’ reservations, because they may feel responsible for a functioning device, are a major obstacle to the introduction of e-Assessment. It is therefore important to overcome these reservations, to be able to successfully implement e-assessment. In addition to reservations, financial reasons are often an obstacle. The acquisition and administration of a suitable IT infrastructure is expensive, both in terms of material costs and personnel costs. Since the majority of students already own devices that are potentially suitable for e-assessment, Bring Your Own Device (BYOD) is a possible solution to the financial aspect. However, a BYOD approach to e-assessment comes with new challenges that have to be tackled. On the way to a solution that works in the previously described scenario, requirements engineering has been a vital part of the process. Therefore, students and teachers as well as official policies have been consulted to derive the requirements to a feasible BYOD approach to e-assessment. In addition to the found requirements, a threat model has been developed to identify additional requirements to the security of such an approach. Afterwards, a software framework was developed and implemented which fulfilled the gathered requirements. Finally, the software prototype was evaluated regarding functionality, usability, performance, and security. Beyond the software prototype, an organizational framework has been developed which covers (hardware) requirements for the institute of higher education as well as important organizational details for the conduction of electronic assessment. In this talk, we discuss important key points of the research process and present the results of our work. Es laden ein: die Dozentinnen und Dozenten der Informatik

1 0

Einladung: Informatik-Oberseminar Marcel Hark
by Marcel Hark 25 May '21

25 May '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Freitag, 18. Juni 2021, 15.00 Uhr Ort: Zoom-Videokonferenz Link: https://rwth.zoom.us/j/94806153993?pwd=dUIwQWYxNUx1cG1jOEpLc25WdmJwUT09 Referent: Marcel Hark M.Sc. Lehr- und Forschungsgebiet Informatik 2 Thema: Towards Complete Methods for Automatic Complexity and Termination Analysis of (Probabilistic) Programs Abstract: The increasing importance of computer programs in our everyday life has led to more and more complex software systems. To prove correctness of such a system, formal verification is the standard methodology. Two of the most important properties of a program are its termination behavior and its efficiency. Moreover, in recent years randomization in programming has gained a lot of interest. For example, to model non-deterministic behavior in real-world applications, probabilistic concepts have proved very successful. In this talk, we investigate formal verification of programs which also feature assignments via discrete probability distributions. In particular, we are interested in proving (non-)termination and inferring bounds on the (expected) worst-case runtime of such programs. In general, formal verification of programs is undecidable. Still, whenever possible, complete approaches for verifying certain properties on (sub-)classes of programs are preferable to incomplete ones since they always yield definite results, i.e., either a proof or a counterexample. Hence, we also characterize sub-classes of programs for which we can present complete approaches for analyzing termination and runtime complexity. To analyze systems arising from real-world applications, formal verification has to proceed automatically. Thus, we discuss the automation of our results as well. Es laden ein: die Dozentinnen und Dozenten der Informatik -- Marcel Hark Research Group Computer Science 2 RWTH Aachen University Ahornstr. 55 52074 Aachen Germany E-Mail: marcel.hark(a)cs.rwth-aachen.de" Phone: +49-241/80-21218 Fax: +49-241/80-22217 Room: 4208

1 0

Einladung: Informatik-Oberseminar Philipp Wacker
by Philipp Wacker 14 May '21

14 May '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Mittwoch, 26. Mai 2021, 14:00 Uhr Zoom: https://rwth.zoom.us/j/92362727123?pwd=MjhBT2VaczI0RDE1c2VNQkxGckw3UT09 <https://rwth.zoom.us/j/92362727123?pwd=MjhBT2VaczI0RDE1c2VNQkxGckw3UT09> Referent: Philipp Wacker, M.Sc. Lehrstuhl Informatik 10 Thema: Interaction Techniques for Mid-Air Pen Input in Handheld Augmented Reality Abstract: Augmented Reality changes the way we interact with virtual information. Currently, virtual information is shown on 2D screens, separated from the real world. With Augmented Reality, virtual content can be shown directly embedded in the real world. This opens up the area of situated modeling in which virtual models are designed in context of the real world to, for example, print them out using a 3D printer. In an initial study, we show that sketching on physical objects improves stroke accuracy compared to strokes on virtual objects, and that features guiding a stroke, either through a concave or convex shape or through a visual guide, further improve the accuracy especially for physical objects. The most available form of Augmented Reality (AR) is Handheld Augmented Reality which shows the virtual information embedded in the camera view of everyday smartphones or tablets. However, continuously specifying a 3D position—needed, e.g., for drawing in mid-air—is not directly possible in today’s systems. We build the ARPen system to allow for situated modeling in Handheld AR, requiring only a 3D-printed pen and a consumer smartphone. But many essential interactions are not yet clear for such a bimanual system. We design and evaluate selection & manipulation techniques to adjust the pose of a mid-air object, as well as menu techniques to control properties of objects in the scene. We show that ray-casting techniques, especially through the tip of the pen, generally perform well. However, interacting on the touchscreen or even combinations of both touchscreen and mid-air input also achieve promising results. To overcome perception issues of determining the depth of virtual objects in Handheld AR, we design depth visualizations that show the position of the pen tip in relation to other objects in the scene. We identify that a heatmap visualization, coloring every object in the scene depending on their distance to the pen tip, achieves best results and was preferred by study participants. We release the ARPen system as an open-source toolbox, enabling researchers to implement and evaluate interaction techniques for Handheld AR with a mid-air pen. Our findings on essential interaction techniques provide a starting point for the development and evaluation of specialized application scenarios. Es laden ein: die Dozentinnen und Dozenten der Informatik

1 0

12.05.2021, 10:30: Guest Talk on Neural Termination Analysis by Mirco Giacobbe
by Bolke-Hermanns, Helene 30 Apr '21

30 Apr '21

Dear all, on Wednesday, May 12, at 10:30 am, Mirco Giacobbe from the University of Oxford will give a talk on his recent work of applying neural networks to perform termination analysis. Wednesday, 12.05.2021, 10:30 am https://rwth.zoom.us/j/99669198425?pwd=NTNzTGNnYjNrQUc0ZDFTTVdiWjY4UT09 Meeting-ID: 996 6919 8425, Passcode: 878733 Everybody is welcome! Best regards Helen Bolke-Hermanns ----------------------------------------------------------------------------------------- Mirco Giacobbe (University of Oxford, UK): Neural Termination Analysis Termination analysis answers the question of whether a program always responds or, dually, never gets stuck in an infinite loop. This is unsolvable in general, yet tools that work in practice have been developed in industry and academia. The major existing methods construct termination proofs via symbolic reasoning from the source code. I will talk about a novel method for learning termination proofs from execution traces. We let neural networks fit termination witnesses over execution traces and then use satisfiability modulo theories for checking whether they generalise to all possible executions. Thanks to the ability of neural networks to generalise well, neural termination analysis succeeds over a wide variety of programs. Moreover, it is extremely simple to implement. I will talk about how we apply neural termination analysis to the termination analysis of Java programs that use data structures, to the almost-sure termination analysis of probabilistic programs, and to the stability analysis of cyber-physical systems. More information: https://www.unravel.rwth-aachen.de/go/id/nyoee

1 0

Ankündigung: Informatik-Oberseminar
by Schweigler, Martin 21 Apr '21

21 Apr '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Mittwoch, 5. Mai 2021, 11.00 Uhr Ort: Videokonferenz (Zoom-Meeting, Information siehe unten) Referent: Martin Schweigler, M.Sc. RWTH Informatik 11 - Embedded Software Thema: Ground Surface Pattern Recognition for Enhanced Navigation Abstract: With the continuous increase in sales of electrical assisted bicycles over the last decade, the number of bicycle accidents across Europe has simultaneously grown significantly. At the same time the technology lacks on active safety systems, even though the electrification of the so-called Pedelecs would allow their development. This dissertation can be seen as the first step in the process of developing position and situation dependent active safety systems by improving the position determination accuracy of bicycle navigation systems. In the core of this work a position estimation system is developed, which uses road sections with significant surface conditions to improve the positioning accuracy of a conventional GNSS/INS. Based on the vertical accelerations acting on the moving Pedelec, the system recognizes individual spots in the road surface, e.g. manholes or potholes. To be more precise, the individual acceleration profiles that occur when passing different spots, are recorded with a smartphone and statistically modeled offline with the help of continuous hidden Markov models during the training phase. In online mode, the trained models are then used to recognize the spots by the acceleration profiles of the revisited road sections. The absolute positions of the Pedelec, relative to the global coordinates of the recognized spots, are subsequently determined by an inertial calculation of the distances traveled in the time between their detection and classification. The system thus uses statistical models to estimate the absolute position of the Pedelec and is consequently called Statistical Absolute Position Estimator, or SAPE. In the second part of this work, SAPE is used to develop a navigation system, which shows the potential of the ground surface pattern recognition. For this purpose the SAPE and GNSS position determinations are fused with an inertial navigation system using an extended Kalman filter. Since the inertial sensors provided by the chosen smartphone are not accurate enough to realize a stand-alone INS, an odometry is developed and implemented to support the navigation solution. The resulting GNSS, SAPE and odometry supported INS is finally evaluated using an RTK GNSS and its accuracy is compared to that of a conventional odometry supported GNSS/INS created with the same low-cost hardware. Es laden ein: die Dozentinnen und Dozenten der Informatik ******************************** Thema: Promotionsvortrag Martin Schweigler Uhrzeit: 05. Mai 2021 11:00 AM Amsterdam, Berlin, Stockholm, Wien Zoom-Meeting beitreten https://rwth.zoom.us/j/96325334175?pwd=R2o3TWNKYk9kS0hWN3k3UHVhblNYZz09 Meeting-ID: 963 2533 4175 Kenncode: 988764

1 0

[infprof-l] Einladung Informatik-Oberseminar Philipp Weidel, December 15, 2020
by Abigail Morrison 02 Mar '21

02 Mar '21

********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Dienstag, 15. Dezember 2020, 10:00 Uhr Zoom: https://rwth.zoom.us/j/99233095930?pwd=dHhTV253V1ZYUzRtSkk1L3A1REZVUT09 Meeting-ID: 992 3309 5930 Kenncode: 626162 Referent: Philipp Weidel, Dipl. Inform. Thema: Learning and decision making in closed loop simulations of plastic spiking neural networks Abstract: To understand how animals and humans learn, form memories and make decisions is a highly relevant goal both for neuroscience and for fields that take some inspiration from neuroscience, such as machine learning and artificial intelligence. Many models of learning and decision making were developed in the fields of machine learning, artificial intelligence, and computational neuroscience. Although these models aim to describe similar mechanisms, they do not all pursue the same goal. These models can be differentiated between models aiming to reach optimal performance on a specific task (or set of tasks) and models trying to explain how animals and humans learn. Some models of the first class use biologically inspired methods (such as deep learning) but are usually not biologically realistic and are therefore not well suited to explain the function of the brain. Models in the second class focus on being biologically plausible to explain how the brain works, but often demonstrate their capability on too simplistic tasks and yield low performance on well-known tasks from machine learning. This work aims to close the gap between these two types of models. In the first part of this talk, tools are described that allow the combination of biologically plausible neural network models together with powerful toolkits known from machine learning and robotics. To this end, MUSIC, the middleware for spiking neural network simulators such as NEST and NEURON is interfaced with ROS, a middleware for robotic hardware and simulators such as Gazebo. This toolchain is extended with interfaces to reinforcement learning toolkits such as the OpenAI Gym. The second part addresses the question of how the brain can represent its environment in the neural substrate of the cortex and how a realistic model of reinforcement learning can make use of these representations. To this end, a spiking neural network model of unsupervised learning is presented which is able to learn its input projections such that it can detect and represent repeating patterns. By using an actor-critic reinforcement learning architecture driven by a realistic dopamine modulated plasticity rule the model can make use of the representations and learn a range tasks. Es laden ein: die Dozentinnen und Dozenten der Informatik -- Prof. Dr. Abigail Morrison IAS-6 / INM-6 / SimLab Neuroscience Jülich Research Center & Computer Science 3 - Software Engineering RWTH Aachen http://www.fz-juelich.de/inm/inm-6 http://www.fz-juelich.de/ias/jsc/slns http://www.se-rwth.de Office: +49 2461 61-9805 Fax # : +49 2461 61-9460 ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Volker Rieke Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------

1 1

Einladung: Informatik-Kolloquium Christina Büsing
by Bolke-Hermanns, Helene-Maria 15 Feb '21

15 Feb '21

********************************************************************** * * * Einladung * * * * Informatik-Kolloquium * * * ********************************************************************** Zeit: Mittwoch, 24. Februar 2021, 16:15-17:00 Uhr Ort: https://rwth.zoom.us/j/98137553896?pwd=WmVnYmhKdXhrM0hjS3NvQy84SjcwUT09 Meeting ID: 981 3755 3896 Passcode: 395762 ********************************************************************** Vortragende: Christina Büsing (RWTH) Titel: Operational Planning for Mobile Medical Units Abstract: Mobile medical units allow for an efficient medical coverage of sparsely populated, spacious areas. Unfortunately, flexibility comes at the price of a highly complex operation planning process. We developed a multi-staged optimization approach for the operation of mobile medical units combining facility location, scheduling and routing problems. To determine our vehicle routes, we have to solve a budgeted matching problem on an edge colored graph, which we refer to as budgeted colored matching problem (BCM). We show the strong NP-hardness of the BCM on bipartite graphs with uniform edge weights, costs and budgets using a reduction from (3,B2)-SAT. On special graph classes, the BCM is solvable in pseudo-polynomial time. Finally, we evaluate the usage of mobile medical units in our model region situated in the northern Eifel. To assess the quality of solutions, we developed an agent-based simulation, which models the interaction between patients and general practitioners. Es laden ein: die Dozentinnen und Dozenten der Informatik **********************************************************************

1 0

Einladung: Informatik-Oberseminar Frau Sarah Suleri
by Leany Maaßen 09 Feb '21

09 Feb '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Donnerstag, 18. Februar 2021, 11:00-12:00 Uhr Zoom: https://rwth.zoom.us/j/92762889185?pwd=ZVdJV2o1bk13SlJCSDFRanB2TEYwUT09 Meeting-ID: 927 6288 9185 Kenncode: 725212 Referentin: Frau Sarah Suleri, M. Sc. Lehrstuhl Informatik 5 Thema: Impact of Technological Support on the Workload of Software Prototyping Abstract: Prototyping is a broadly utilized iterative technique for brainstorming, communicating, and evaluating user interface (UI) designs. This research aims to analyze this process from three aspects: traditional UI prototyping, rapid prototyping, and prototyping for accessibility. We propose three novel approaches and realize them by introducing three artifacts: 1) Eve, a sketch-based prototyping workbench that supports automation of transforming low fidelity prototypes to higher fidelities, 2) Kiwi, a UI design pattern and guidelines library to support UI design pattern-driven prototyping, 3) Personify, a persona-based UI design guidelines library for accessible UI prototyping. We evaluate the usability of these artifacts, and the results indicate good usability and learnability. Furthermore, we use NASA-TLX to study the impact of using these three novel approaches on the subjective workload experienced by the designers during the software prototyping process. This work aims to extend prior work on UI prototyping and is broadly applicable to understand the impact of using deep learning, UI design patterns, and personas on the workload of UI prototyping. Es laden ein: die Dozentinnen und Dozenten der Informatik _______________________________ Leany Maaßen RWTH Aachen University Lehrstuhl Informatik 5, LuFG Informatik 5 Prof. Dr. Stefan Decker, Prof. Dr. Matthias Jarke, Prof. Gerhard Lakemeyer Ph.D. Ahornstrasse 55 D-52074 Aachen Tel: 0241-80-21509 Fax: 0241-80-22321 E-Mail: maassen(a)dbis.rwth-aachen.de

1 0

Einladung: Informatik-Oberseminar Herr Gustavo Alejandro Aragón Cabrera
by Leany Maaßen 09 Feb '21

09 Feb '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Mittwoch, 24. Februar 2021, 15:00-16:00 Uhr Zoom: <https://rwth.zoom.us/j/95286199371?pwd=M3hCUWk3VER6WnE0RlZzQUFBVFMzdz09> https://rwth.zoom.us/j/95286199371?pwd=M3hCUWk3VER6WnE0RlZzQUFBVFMzdz09 Meeting-ID: 952 8619 9371 Kenncode: 424815 Referent: Herr Gustavo Alejandro Aragón Cabrera, M. Sc. Lehrstuhl Informatik 5 Thema: Extended Model Predictive Control Software Framework for Real-Time Local Management of Complex Energy Systems Abstract: Regarding the requirements of the future electrical grid due to high share of renewable distributed generation, smart energy management systems (EMS) are necessary to integrate the rapid development of ICT technologies and new sensor and actuator technologies. This thesis deals with the challenges of Model Predictive Control (MPC)-based EMS and introduces the concept of extended MPC framework that includes ICT aspects of the integration of new sensor and actuator technologies, forecasting methods, data management, flexible optimization model definition and solvers integration in consideration of user needs and deployment requirements in real systems. The extended MPC framework is validated through its deployment in three different use cases: as discrete and stochastic MPC in real test sites and linked to a power flow simulator. Es laden ein: die Dozentinnen und Dozenten der Informatik _______________________________ Leany Maaßen RWTH Aachen University Lehrstuhl Informatik 5, LuFG Informatik 5 Prof. Dr. Stefan Decker, Prof. Dr. Matthias Jarke, Prof. Gerhard Lakemeyer Ph.D. Ahornstrasse 55 D-52074 Aachen Tel: 0241-80-21509 Fax: 0241-80-22321 E-Mail: maassen(a)dbis.rwth-aachen.de

1 0

Einladung: Informatik-Oberseminar Anton Pirogov
by Anton Pirogov 02 Feb '21

02 Feb '21

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Donnerstag, 18. Februar 2021, 10:15 Uhr Ort: Zoom Videokonferenz Link: https://rwth.zoom.us/j/96519556069?pwd=MUVqbXpvZE5XVXBSdDNHZW5LMmJpQT09 Meeting-ID: 965 1955 6069 Kenncode: 482378 Referent: Anton Pirogov, M.Sc. Lehrstuhl Informatik 7 Thema: Determinization and Ambiguity of Classical and Probabilistic Büchi Automata Abstract: Büchi automata can be seen as a straight-forward generalization of ordinary NFA, adapted to handle infinite words. While they were originally introduced for applications in decidability of logics, they became a popular tool for practical applications, e.g. in automata-based approaches to model checking and synthesis problems. Being arguably both the simplest and most well-known variant in the zoo of so-called omega-automata that are considered in this setting, they serve as an intermediate representation of omega-regular specifications of verification or synthesis requirements that are usually expressed in a more declarative fashion, e.g. using linear temporal logic. Unfortunately, nondeterministic automata are not directly suitable for certain applications, whereas deterministic Büchi automata are less expressive. This problem is usually solved by either constructing deterministic automata of a different kind, or by restricting their ambiguity, i.e., the maximal number of accepting runs on some word. In both cases, the transformation is expensive, yielding an exponential blow-up of the state space in the worst case. Therefore, optimized constructions and heuristics for common special cases are useful and in demand for actual practical applications. In this talk we present a new general construction for determinization from nondeterministic Büchi to deterministic parity automata that unifies the dominant branches of previous approaches based on the Safra construction and the Muller-Schupp construction. Additionally, we sketch a number of new heuristics for determinization, some of which exploit properties of our unified construction. Apart from the classical nondeterministic and deterministic variants of automata, it is natural to consider probabilistic automata, i.e., automata that use a probability distribution on the states instead of nondeterminism to decide which state to go to next. It is known that in general, such automata are more expressive than classical automata and many decision problems are undecidable. We present subclasses of probabilistic automata that correspond to certain ambiguity classes and are not more expressive than classical automata. Es laden ein: die Dozentinnen und Dozenten der Informatik

1 0