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

Einladung Informatik-Kolloquium Prof. Salil Kanhere
by Roman Matzutt 16 Oct '19

16 Oct '19

+********************************************************************** * * * Einladung * * * * Informatik-Kolloquium * * * +********************************************************************** Zeit: Montag, 21. Oktober 2019, 10.30 Uhr Ort: Informatikzentrum, E3, Raum 9007 Referent: Prof. Salil Kanhere School of Computer Science and Engineering, UNSW Sydney Thema: TrustChain: Trust Management in Blockchain and IoT supported Supply Chains Abstract: Traceability and integrity are major challenges for the increasingly complex supply chains of today’s world. Although blockchain technology has the potential to address these challenges through providing a tamper-proof audit trail of supply chain events and data associated with a product lifecycle, it does not solve the trust problem associated with the data itself. Reputation systems are an effective approach to solve this trust problem. However, current reputation systems are not suited to the blockchain based supply chain applications as they are based on limited observations, they lack granularity and automation, and their overhead has not been explored. In this talk, we propose TrustChain, as a three-layered trust management framework which uses a consortium blockchain to track interactions among supply chain participants and to dynamically assign trust and reputation scores based on these interactions. The novelty of TrustChain stems from: (a) the reputation model that evaluates the quality of commodities, and the trustworthiness of entities based on multiple observations of supply chain events, (b) its support for reputation scores that separate between a supply chain participant and products, enabling the assignment of product-specific reputations for the same participant, (c) the use of smart contracts for transparent, efficient, secure, and automated calculation of reputation scores, and (d) its minimal overhead in terms of latency and throughput when compared to a simple blockchain based supply chain model. Speaker Biography: Salil Kanhere is a Professor in the School of Computer Science and Engineering at UNSW Sydney. He is also a conjoint researcher at CSIRO's Data61 and a participating researcher in the Cyber Security Cooperative Research Centre. He has held visiting appointments at Technical University Darmstadt, University of Zurich, Graz University of Technology and Institute of Infocom Research Singapore. His research interests include Internet of Things, blockchain, cyber physical systems, applied machine learning and cybersecurity. His research has been featured in various media outlets including ABC News Australia, Forbes, IEEE Spectrum, Wired, ZDNET, Computer World, Medium and MIT Technology Review. He serves as the Editor in Chief of the Ad Hoc Networks Journal and as Associate Editor of Pervasive and Mobile Computing and Computer Communications journals. He is an Humboldt Research Fellow and ACM Distinguished Speaker. He regularly serves on the organising committee of top-tier IEEE/ACM conferences in his discipline. Es laden ein: die Dozentinnen und Dozenten der Informatik

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Einladung: Informatik-Oberseminar Florian Göbe
by Göbe, Florian 15 Oct '19

15 Oct '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Donnerstag, 7. November 2019, 10.00 Uhr Ort: Raum 2359|222 (9222), Informatikzentrum Erweiterungsbau 3 Referent: Florian Göbe, M.Sc.RWTH Informatik 11 – Embedded Software Thema: Überwachung von SPS-Programmen zur Laufzeit mittels ereignisdiskreter Systeme Kurzfassung: Bei der von Ramadge und Wonham eingeführten Supervisory Control Theory (SCT) handelt es sich um einen der verbreitetsten Ansätze für die Synthese von Lösungen im Bereich diskreter Steuerungen. In diesem Vortrag wird ein Ansatz vorgestellt, der das SCT-Rahmenwerk zur Überwachung existierender SPS-Steuerungsprogramme einsetzt. Letztere werden als vom Benutzer manuell implementiert angenommen, weswegen ihre Fehlerfreiheit in Bezug auf gewisse Anforderungen, beispielsweise an die funktionale Sicherheit, nicht in allen prinzipiell möglichen Situationen formal sichergestellt werden kann. Im vorgestellten Ansatz können diese Anforderungen als ereignisdiskrete Systeme formalisiert werden. Mittels einer modifizierten Form des Ramadge-Wonham-Rahmenwerkes wird aus diesen Modellen schließlich eine Überwachungsschicht generiert. Diese verhindert frühzeitig solche Aktionen der Steuerung, die schlussendlich zu einer Verletzung der Anforderungen führen könnten. Um eine möglichst große Bandbreite realistischer Anwendungsfälle abzudecken, wurden mehrere Anpassungen am ursprünglichen Rahmenwerk vorgenommen und Erweiterungen eingeführt, beispielsweise bedingte Transitionen, Vorlagen sowie Ereigniserzwingung zur Verhinderung unerwünschter Vorkommnisse. Das vorgestellte Konzept bildet den gesamten Prozess von der Erstellung der Anforderungsmodelle bis hin zu einer auf der Zielhardware direkt einsetzbaren Sicherheitsschicht ab und wurde in Form eines Werkzeugs prototypisch realisiert und evaluiert. Es laden ein: die Dozentinnen und Dozenten der Informatik

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Einladung Oberseminar Stefan Schupp
by Stefan Schupp 16 Sep '19

16 Sep '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Mittwoch, 25. September 2019, 15.00 Uhr Ort: Informatikzentrum, E3, Raum 9222 Referent: Stefan Schupp M.Sc.(Theory of Hybrid Systems) Thema: State Set Representations and their Usage in the Reachability Analysis of Hybrid Systems Abstract: Hybrid systems in computer science are systems with combined discrete-continuous behavior. This work presents results obtained in the field of safety verification for linear hybrid systems whose continuous behavior can be described by linear differential equations. We focus on a special technique named flowpipe-construction-based reachability analysis, which over-approximates the reachable states of a given hybrid system as a finite union of state sets. In these computations we can use different geometric and symbolic representations for state sets as datatypes. In this talk we focus on the following aspects: - We present our C++ library HyPro, offering implementations for several state set representations that are commonly used in flowpipe-construction-based reachability analysis. - We show the applicability of HyPro by embedding a flowpipe-construction-based reachability analysis method in a CEGAR-based abstraction refinement framework. - We present our approach to decompose the search space and replace high-dimensional computations by computations in lower-dimensional subspaces. Es laden ein: die Dozentinnen und Dozenten der Informatik

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Einladung Informatik Oberseminar Simon Hacks
by Hacks, Simon 13 Aug '19

13 Aug '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Donnerstag, 12. September 2019, 10.00 Uhr Ort: AH VI (2356|051), Ahornstr. 55 Referent: Simon Hacks, M.Sc. Lehr- und Forschungsgebiet Informatik 3 Thema: Improving the Quality of Enterprise Architecture Models: Processes and Techniques Abstract: Information technology (IT) pervades organizations more and more and becomes increasingly important for their business models. It has evolved from a purely supportive role to an important strategic pillar in many organizations. Even more, it is important that IT is aligned to the needs of the organization. Approaches that realize this are often subsumed under the term "business-IT-alignment". One instrument for achieving business-IT-alignment is Enterprise Architecture (EA). EAs provide a holistic perspective on the structure of the organization and provide a set of techniques to guide and steer the evolution of the organization to a desired goal state. A key artifact of EA is the EA model. It abstracts the elements and their relationships to an understandable and manageable measure. Usually enterprise architects model business processes, applications, hardware components, data models and customer relationships. Based on the information stored in the EA model, the organization's management makes important decisions regarding future focus. Contrary, also on the operational level, the model can provide important information, for example which application is used in which business environment and exchanges data with other applications. In order to be able to derive meaningful decisions from the EA model, their quality is of crucial importance. Therefore, this work is elaborates on developing different processes and techniques that ensure the quality of the EA model. First, we present a process to ensure the quality of the EA model, where model maintenance is understood as a continuous evolution. For this purpose, we define different steps, which have to be considered in such a process. This process will serve as foundation for a continuous delivery pipeline that will help automate as many of these steps as possible. Next, we present an approach that allows storing contrary information in EA models. In addition to the aforementioned processes, we developed also several techniques to improve the quality of EA models. However, for improvement, we need a method to evaluate the quality, which we also introduce within this work. Subsequently, we facilitate machine-learning techniques to support the modeler reuse existing elements of the model. In addition, we compare the performance of different algorithms to determine the best on in a certain situation. Additionally, we present a method to identify unnecessary elements in the model. Es laden ein: die Dozentinnen und Dozenten der Informatik

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Einladung Informatik Oberseminar Sebastian Pick
by Sebastian Pick 15 Jul '19

15 Jul '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Montag, 15. Juli 2019, 16.00 Uhr Ort: Seminarraum 001, IT Center, Kopernikusstr. 6 Referent: Dipl.-Inform. Sebastian Pick Thema: Interactive Data Annotation for Virtual Reality Applications Abstract: Virtual Reality (VR) offers the unique possibility to explore data sets in a highly immersive and interactive fashion. A key aspect of this exploration process is the acquisition of insights and findings concerning the involved data. In this context, it becomes the task of so-called annotation systems to enable users to preserve said findings and review them at a later time. Even though the design of VR-based annotation systems has been a research topic for many years, crucial challenges remain unresolved. Many interaction solutions focus on isolated issues and are rather limited in scope. Additionally, they usually forgo holistic workflow designs that are vital for covering all relevant annotation operations in a consistent fashion. Similarly, available annotation presentation techniques are usually inappropriate for use within immersive virtual environments (IVEs) or they perform sub-optimally. Lastly, the design of annotation systems is usually further complicated if they are to be reused in context of other usage scenarios that impose a different and varying set of requirements on them. In this thesis, I set out to address the aforementioned issues. To this end, I present an annotation framework that was specifically designed to be configurable and extensible in accordance to the changing requirements of different application scenarios. It is grounded in a specialized data model that facilitates the integration not only of required data types, which are used to describe annotations, but also techniques to capture and present them. I employ this model to develop a flexible solution to the design of holistic interaction workflows. My design approach covers all essential operations, including the creation, modication, and review of arbitrary types of annotations from within IVEs. To provide a set of ready-to-use interaction techniques to acquire annotation contents, I identify the most relevant data types and devise appropriate interaction concepts. Similarly, I present a generalized two-tier presentation strategy that facilitates the access to and review of arbitrary annotation contents. While the tier one representation provides basic access to a selection of contents in a customizable form, the tier two representation allows for access to all contents in a generalized manner. I furthermore introduce a novel automated annotation layout approach that prevents occlusions of and by annotations to maintain visual access to them and the original data. In order to determine the viability of my approaches, I cover a series of technical analyses and user studies. They are rounded off by a presentation of concrete application examples that utilize varying subsets of techniques to demonstrate the usefulness and flexibility of my framework. Es laden ein: die Dozentinnen und Dozenten der Informatik

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Einladung Informatik-Kolloquium Prof. Richard Fujimoto
by Mirko Stoffers 05 Jul '19

05 Jul '19

+********************************************************************** * * * Einladung * * * * Informatik-Kolloquium * * * +********************************************************************** Zeit: Freitag, 5. Juli 2019, 11.30 Uhr Ort: Informatikzentrum, E3, Raum 9007 Referent: Prof. Richard Fujimoto Georgia Institute of Technology, Atlanta Thema: Power Consumption in Parallel and Distributed Simulations Abstract: Energy and power consumption are important concerns for many computing systems ranging from battery-powered embedded and mobile devices to supercomputers and data centers. Although this issue has been extensively studied at the hardware and operating system levels, thus far only a limited amount of work has considered power consumption in parallel and distributed simulations. This presentation addresses this topic and discusses a variety of options to reduce power consumption. Further, parallel and distributed discrete event simulations require a synchronization algorithm to ensure the concurrent execution of the program produces the same results as a sequential execution. The energy consumed by synchronization algorithms for distributed simulation programs is considered, and experimental data presented highlighting that a significant portion of the energy consumed by distributed simulations can be attributed to synchronization. The concept of zero energy synchronization is introduced and techniques to reduce the energy consumed by synchronization algorithms are presented and evaluated. The presentation highlights that many open areas of research concerning power and energy consumption of distributed simulations remain to be explored. Speaker Biography: Richard Fujimoto is a Regents’ Professor in the School of Computational Science and Engineering at the Georgia Institute of Technology. He received the Ph.D. degree from the University of California at Berkeley in 1983. He has been an active researcher in the parallel and distributed simulation field since that time. He led the definition of the time management services in the High Level Architecture for Modeling and Simulation, IEEE standard 1516. His publications include seven award winning papers and he has received the ACM Distinguished Contributions in Modeling and Simulation Award. He has played various leadership roles in a variety of modeling and simulation conferences, journals and other activities. He was the founding chair of the School of Computational Science and Engineering (CSE) at Georgia Tech and established it as an academic unit devoted to the study of computer-based models of natural and engineered systems. In that role he led the creation of the interdisciplinary PhD and MS degree programs in CSE as well as two undergraduate minors. Es laden ein: die Dozentinnen und Dozenten der Informatik

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Einladung Informatik-Oberseminar Mirko Stoffers
by Mirko Stoffers 26 Jun '19

26 Jun '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Freitag, 5. Juli 2019, 15.00 Uhr Ort: Informatikzentrum, E3, Raum 9007 Referent: Mirko Stoffers, M.Sc. Lehrstuhl Informatik 4 (COMSYS) Thema: Automated Optimization of Discrete Event Simulations without Knowing the Model Abstract: Modeling and simulation is an essential element in the research and development of new concepts and products in any domain. The demand for the development of more and more complex systems drives the complexity of the simulation models as well, which in turn urges the research of methodologies to reduce the execution times down to a feasible amount. We identified two major types of resources that can be exploited for acceleration: On the one hand, multiple computing instances (e. g., CPU cores) can be used to distribute the workload and perform independent computations simultaneously. On the other hand, workload stemming from redundant computations can be avoided altogether by exploiting the presence of unused main memory to store intermediate results. We observe that typically in the development cycle of products and simulation models neither time and resources nor required expertise is available to apply sophisticated runtime optimization manually. We conclude that it is of utmost importance to investigate approaches to speed up simulation automatically. The most prevalent challenge of automating optimization is that, at the time of researching and developing the acceleration concepts and tools, the model is not yet available, and we need to assume that the model will not be implemented for a specific optimization technique. Hence, our methodologies need to be devised without the model at hand, which can only be used by the finally implemented optimization tool at its runtime. In this talk, we discuss how computer simulations can be automatically accelerated using either of the two optimization potentials mentioned above (multiple computing instances or available memory) without the model being provided at the time of researching the concepts and developing the tools. Finally, we discuss how by combining the two optimization vectors the full power of both can be unleashed at the same time. Es laden ein: die Dozentinnen und Dozenten der Informatik

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[Vision-assistants] [Informatik-assistenten] Einladung: Informatik Oberseminar Aljosa Osep
by Aljosa Osep 24 Jun '19

24 Jun '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Donnerstag, 27. Juni 2019, 9:30 Uhr Ort: UMIC Research Centre, room 025, Mies-van-der-Rohe Strasse 15 Referent: Aljosa Osep, MSc., Lehrstuhl Informatik 8 (Computer Vision) Thema: Vision-based Category-Agnostic Object Tracking for Mobile Robots and Intelligent Vehicles Abstract: The majority of existing vision-based methods perform multi-object tracking in the image domain. Yet, in mobile robotics and autonomous driving scenarios, pixel-precise object localization and trajectory estimation in 3D space are of fundamental importance. Furthermore, the leading paradigms for vision-based multi-object tracking and trajectory prediction rely heavily on object detectors and effectively limit tracking and motion prediction to a set of predefined classes, while the set of object classes that appear in the real-world is unbounded. In this talk I will present novel methods for vision-based, category-agnostic multi-object tracking that overcome this limitation. The Category-Agnostic Multi-Object Tracker (CAMOT) leverages recent developments in the area of learning-based object proposal generation and lifts image-based proposal estimates to 3D space in order to estimate trajectories of arbitrary objects. We further extend CAMOT for the task of video-object proposal generation and demonstrate that by utilizing motion and parallax as consistency filters, can robustly track known and unknown objects and mine large video collections. I will conclude my talk by demonstrating how such a video-object mining approach can be used for video-object discovery and self-supervised object detector learning. Es laden ein: die Dozentinnen und Dozenten der Informatik _______________________________________________ Informatik-assistenten mailing list -- informatik-assistenten(a)lists.rwth-aachen.de To unsubscribe send an email to informatik-assistenten-leave(a)lists.rwth-aachen.de https://lists.rwth-aachen.de/postorius/lists/informatik-assistenten.lists.r… _______________________________________________ Vision-assistants mailing list -- vision-assistants(a)lists.rwth-aachen.de To unsubscribe send an email to vision-assistants-leave(a)lists.rwth-aachen.de https://lists.rwth-aachen.de/postorius/lists/vision-assistants.lists.rwth-a…

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[Vision-assistants] [Informatik-assistenten] Einladung: Informatik Oberseminar Prof. Dr. David Held, Carnegie Mellon University
by Aljosa Osep 24 Jun '19

24 Jun '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Donnerstag, 27. Juni 2019, 14.15 Uhr Ort: UMIC Research Centre, room 025, Mies-van-der-Rohe Strasse 15 Referent: Prof. Dr. David Held, The Robotics Institute, Carnegie Mellon University Thema: Uncertainty-Aware Perceptual Robot Learning Abstract: Robot learning systems need to deal with perceptual uncertainty, due to a variety of factors such as occlusions, sensor noise, small objects, limited capacity models, and novel objects. We believe that perceptual systems should be aware of their uncertainty and that decision-making algorithms should incorporate such uncertainty. We present three current directions for achieving this. First, we present an object instance detection system that combines machine learning with correspondence matching to verify the proposed detections and reject uncertain detections. Next, we show an approach for estimate a distribution over orientation uncertainty by augmenting any deep pose estimation system. Last, we present an approach for reinforcement learning with deformable objects that does not assume access to the ground-truth state. Together, these directions represent our current approach to dealing with perceptual uncertainty in robot learning systems. Es laden ein: die Dozentinnen und Dozenten der Informatik _______________________________________________ Informatik-assistenten mailing list -- informatik-assistenten(a)lists.rwth-aachen.de To unsubscribe send an email to informatik-assistenten-leave(a)lists.rwth-aachen.de https://lists.rwth-aachen.de/postorius/lists/informatik-assistenten.lists.r… _______________________________________________ Vision-assistants mailing list -- vision-assistants(a)lists.rwth-aachen.de To unsubscribe send an email to vision-assistants-leave(a)lists.rwth-aachen.de https://lists.rwth-aachen.de/postorius/lists/vision-assistants.lists.rwth-a…

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Einladung Informatik-Oberseminar Torsten Zimmermann
by Torsten Zimmermann 19 Jun '19

19 Jun '19

+********************************************************************** * * * Einladung * * * * Informatik-Oberseminar * * * +********************************************************************** Zeit: Dienstag, 2. Juli 2019, 11.30 Uhr Ort: Seminarraum 9007, Gebäude E3, Ahornstr. 55 Referent: Torsten Zimmermann, M.Sc. Lehrstuhl Informatik 4 Thema: Improving Content and Service Distribution beyond Infrastructure Upgrades Abstract: The Internet has evolved into an essential platform for communication and access to information. This manifests itself in the steadily growing traffic due to rising user demands for content and services. However, these demands put pressure on operators to constantly improve performance and availability, e.g., by upgrading infrastructures. Despite these efforts, there are limits to upgrades and their impact, ranging from technical to economic aspects. To still achieve improvements, research also focuses on other aspects of content and service distribution, including protocol optimization, better infrastructure utilization, and approaches to overcome limited infrastructure support. However, these optimizations can have unknown consequences in real-world deployments. Even if protocols underwent a rigorous standardization process, their adoption and impact are often unpredictable. The same holds for approaches that support infrastructures, which face practical challenges when deployed outside of testbeds, e.g., missing user acceptance due to the lack of control. Overcoming these challenges is relevant to achieve improvements beyond the current state-of-the-art solutions. In this talk, we approach the problem of how to provide improvements for content and service distribution beyond infrastructure upgrades from the aforesaid viewpoints: the deployment of a new protocol and the applicability of supporting approaches. We provide the first large-scale adoption study of HTTP/2, as the new standard protocol for the Web, and especially focus on its promising new feature Server Push. Despite being considered a key feature of HTTP/2, we observe that its use does not always lead to improvements, but also to human-perceivable detrimental effects, which we verified in a user study. Building on this, we further inspect which factors influence performance and provide a novel strategy for the use of this feature, which can lead to significant performance improvements. Focusing on how to support infrastructures, we present an approach that enables roaming mobile users to connect to private Access Points, using provider-assisted authentication and the creation of an on-demand single purpose network. By that, we provide connectivity in case other infrastructures, such as the cellular network, are temporarily not available. Finally, we provide a brief outlook on how to realize content distribution between devices with only limited infrastructure support. In summary, our contributions provide valuable insights and practical technical solutions that complement infrastructure-based improvements. Es laden ein: die Dozentinnen und Dozenten der Informatik

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